Gene Summary

Gene:IGFBP7; insulin like growth factor binding protein 7
Summary:This gene encodes a member of the insulin-like growth factor (IGF)-binding protein (IGFBP) family. IGFBPs bind IGFs with high affinity, and regulate IGF availability in body fluids and tissues and modulate IGF binding to its receptors. This protein binds IGF-I and IGF-II with relatively low affinity, and belongs to a subfamily of low-affinity IGFBPs. It also stimulates prostacyclin production and cell adhesion. Alternatively spliced transcript variants encoding different isoforms have been described for this gene, and one variant has been associated with retinal arterial macroaneurysm (PMID:21835307). [provided by RefSeq, Dec 2011]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:insulin-like growth factor-binding protein 7
Source:NCBIAccessed: 16 March, 2017


What does this gene/protein do?
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Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 16 March 2017 using data from PubMed using criteria.

Literature Analysis

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Tag cloud generated 16 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (8)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: IGFBP7 (cancer-related)

Sambuudash O, Kim HM, Jo H, et al.
Molecular characteristics of colorectal serrated polyps and hyperplastic polyps: A STROBE compliant article.
Medicine (Baltimore). 2016; 95(49):e5592 [PubMed] Free Access to Full Article Related Publications
The serrated neoplasia pathway of colorectal carcinogenesis is characterized by BRAF mutation and aberrant DNA methylation, which have not been reported on Korean patients. The aim of this study was to investigate BRAF mutation and DNA methylation in colorectal serrated polyps and the right colon.Between 2005 and 2013, 146 colon polyps (47 tubular adenomas [TAs], 53 traditional serrated adenomas [TSAs], 17 sessile serrated adenomas/polyps [SSAs], and 29 hyperplastic polyps in the proximal colon [PHPs]) were collected from patients. Paraffin-embedded colon polyp tissue was used for DNA extraction. BRAF V600E mutation was identified through polymerase chain reaction (PCR) and pyrosequencing assay. The methylation status of the long interspersed nucleotide element-1, insulin-like growth factor binding protein 7 (IGFBP7), mutL homolog 1 (hMLH1), and CD133 genes were evaluated through disulfite conversion, PCR, and pyrosequencing assay.BRAF V600E mutation was found in 2.1% of TAs, 47.2% of TSAs, 41.2% of SSAs, and 20.7% of PHPs. TSA and SSA had higher BRAF mutation rates than did TA (P < 0.0001). TSA had higher BRAF mutation rates than did PHP (P = 0.018). IGFBP7 hypermethylation was found in 17% of TAs, 37.7% of TSAs, 88.2% of SSAs, and 37.5% of PHPs. TSA and SSA had higher hypermethylation of IGFBP7 than did TA (P = 0.021 and P < 0.0001, respectively). SSA had higher hypermethylation of IGFBP7 than did PHP (P = 0.002). hMLH1 hypermethylation was found in 2.1% of TAs, 5.7% of TSAs, 0% of SSAs, and 0% of PHPs. CD133 hypermethylation was found in 21.3% of TAs, 9.4% of TSAs, 35.3% of SSAs, and 17.4% of PHPs.BRAF mutation and methylation in TSA and SSA are different from those in PHP in Koreans. These findings suggested that PHP may have different molecular characteristics compared with other serrated polyps.

Pharoah PD, Song H, Dicks E, et al.
PPM1D Mosaic Truncating Variants in Ovarian Cancer Cases May Be Treatment-Related Somatic Mutations.
J Natl Cancer Inst. 2016; 108(3) [PubMed] Free Access to Full Article Related Publications
Mosaic truncating mutations in the protein phosphatase, Mg(2+)/Mn(2+)-dependent, 1D (PPM1D) gene have recently been reported with a statistically significantly greater frequency in lymphocyte DNA from ovarian cancer case patients compared with unaffected control patients. Using massively parallel sequencing (MPS) we identified truncating PPM1D mutations in 12 of 3236 epithelial ovarian cancer (EOC) case patients (0.37%) but in only one of 3431 unaffected control patients (0.03%) (P = .001). All statistical tests were two-sided. A combination of Sanger sequencing, pyrosequencing, and MPS data suggested that 12 of the 13 mutations were mosaic. All mutations were identified in post-chemotherapy treatment blood samples from case patients (n = 1827) (average 1234 days post-treatment in carriers) rather than from cases collected pretreatment (less than 14 days after diagnosis, n = 1384) (P = .002). These data suggest that PPM1D variants in EOC cases are primarily somatic mosaic mutations caused by treatment and are not associated with germline predisposition to EOC.

Zhao W, Wang J, Zhu B, et al.
IGFBP7 functions as a potential lymphangiogenesis inducer in non-small cell lung carcinoma.
Oncol Rep. 2016; 35(3):1483-92 [PubMed] Related Publications
Lymphangiogenesis is not only involved in the processes of embryonic development, tissue repair and chronic inflammation, but also in tumor lymphatic metastasis. Metastatic tumor cells spreading through lymphatic vessels occur in non-small cell lung carcinoma (NSCLC), with regional lymph node metastasis often being the most important prognostic factor for carcinoma patients. Recent research has identified a range of lymphangiogenic growth factors that could conceivably play a great role in promoting tumor lymphangiogenesis and lymphatic metastasis. The most extensively accepted signaling pathways promoting lymphangiogenesis in tumors include the secreted lymphangiogenic proteins: vascular endothelial growth factor-C (VEGF-C) and VEGF-D, and their cognate receptor on lymphatic endothelium VEGF receptor-3 (VEGFR-3). Targeting VEGF pathway strategy sometimes failed to decrease tumor metastasis in vivo experiments and clinical trials. It is unclear whether the tumor cells induced the lymphangiogenesis process, while VEGF pathway could not completely illustrate the mechanism of tumor cell lymphatic metastasis. To explore the novel tumor lymphangiogenesis targets, we screened 181 candidate genes between high lymphatic vascular density (LVD) and low LVD in lung adenocarcinomas using Human Genome U133 Plus 2.0 Microarray. Insulin-like growth factor binding protein 7 (IGFBP7) was proven to be associated with metastatic clinicopathological features and high LVD. Furthermore, by assessing the capability of lymphatic endothelial cell forming lymphatic vessel-like structures in vitro, it appears to enhance lymphangiogenesis.

Jones TA, Jeyapalan JN, Forshew T, et al.
Molecular analysis of pediatric brain tumors identifies microRNAs in pilocytic astrocytomas that target the MAPK and NF-κB pathways.
Acta Neuropathol Commun. 2015; 3:86 [PubMed] Free Access to Full Article Related Publications
INTRODUCTION: Pilocytic astrocytomas are slow-growing tumors that usually occur in the cerebellum or in the midline along the hypothalamic/optic pathways. The most common genetic alterations in pilocytic astrocytomas activate the ERK/MAPK signal transduction pathway, which is a major driver of proliferation but is also believed to induce senescence in these tumors. Here, we have conducted a detailed investigation of microRNA and gene expression, together with pathway analysis, to improve our understanding of the regulatory mechanisms in pilocytic astrocytomas.
RESULTS: Pilocytic astrocytomas were found to have distinctive microRNA and gene expression profiles compared to normal brain tissue and a selection of other pediatric brain tumors. Several microRNAs found to be up-regulated in pilocytic astrocytomas are predicted to target the ERK/MAPK and NF-κB signaling pathways as well as genes involved in senescence-associated inflammation and cell cycle control. Furthermore, IGFBP7 and CEBPB, which are transcriptional inducers of the senescence-associated secretory phenotype (SASP), were also up-regulated together with the markers of senescence and inflammation, CDKN1A (p21), CDKN2A (p16) and IL1B.
CONCLUSION: These findings provide further evidence of a senescent phenotype in pilocytic astrocytomas. In addition, they suggest that the ERK/MAPK pathway, which is considered the major driver of these tumors, is regulated not only by genetic aberrations but also by microRNAs.

Warnecke-Eberz U, Metzger R, Hölscher AH, et al.
Diagnostic marker signature for esophageal cancer from transcriptome analysis.
Tumour Biol. 2016; 37(5):6349-58 [PubMed] Related Publications
Esophageal cancer is often diagnosed at an advanced stage. Diagnostic markers are needed for achieving a cure in esophageal cancer detecting and treating tumor cells earlier. In patients with locally advanced squamous cell carcinoma of the esophagus (ESCC), we profiled the gene expression of ESCC compared to corresponding normal biopsies for diagnostic markers by genome microarrays. Profiling of gene expression identified 4844 genes differentially expressed, 2122 upregulated and 2722 downregulated in ESCC. Twenty-three overexpressed candidates with best scores from significance analysis have been selected for further analysis by TaqMan low-density array-technique using a validation cohort of 40 patients. The verification rate was 100 % for ESCC. Twenty-two markers were additionally overexpressed in adenocarcinoma of the esophagus (EAC). The markers significantly overexpressed already in earlier tumor stages (pT1-2) of both histological subtypes (n = 19) have been clustered in a "diagnostic signature": PLA2G7, PRAME, MMP1, MMP3, MMP12, LIlRB2, TREM2, CHST2, IGFBP2, IGFBP7, KCNJ8, EMILIN2, CTHRC1, EMR2, WDR72, LPCAT1, COL4A2, CCL4, and SNX10. The marker signature will be translated to clinical practice to prove its diagnostic impact. This diagnostic signature may contribute to the earlier detection of tumor cells, with the aim to complement clinical techniques resulting in the development of better detection of concepts of esophageal cancer for earlier therapy and more favorite prognosis.

Collet G, Szade K, Nowak W, et al.
Endothelial precursor cell-based therapy to target the pathologic angiogenesis and compensate tumor hypoxia.
Cancer Lett. 2016; 370(2):345-57 [PubMed] Related Publications
Hypoxia-inducing pathologies as cancer develop pathologic and inefficient angiogenesis which rules tumor facilitating microenvironment, a key target for therapy. As such, the putative ability of endothelial precursor cells (EPCs) to specifically home to hypoxic sites of neovascularization prompted to design optimized, site-specific, cell-mediated, drug-/gene-targeting approach. Thus, EPC lines were established from aorta-gonad-mesonephros (AGM) of murine 10.5 dpc and 11.5 dpc embryo when endothelial repertoire is completed. Lines representing early endothelial differentiation steps were selected: MAgEC10.5 and MagEC11.5. Distinct in maturation, they differently express VEGF receptors, VE-cadherin and chemokine/receptors. MAgEC11.5, more differentiated than MAgEC 10.5, displayed faster angiogenesis in vitro, different response to hypoxia and chemokines. Both MAgEC lines cooperated to tube-like formation with mature endothelial cells and invaded tumor spheroids through a vasculogenesis-like process. In vivo, both MAgEC-formed vessels established blood flow. Intravenously injected, both MAgECs invaded Matrigel(TM)-plugs and targeted tumors. Here we show that EPCs (MAgEC11.5) target tumor angiogenesis and allow local overexpression of hypoxia-driven soluble VEGF-receptor2 enabling drastic tumor growth reduction. We propose that such EPCs, able to target tumor angiogenesis, could act as therapeutic gene vehicles to inhibit tumor growth by vessel normalization resulting from tumor hypoxia alleviation.

Minchenko DO, Kharkova AP, Tsymbal DO, et al.
IRE1 inhibition affects the expression of insulin-like growth factor binding protein genes and modifies its sensitivity to glucose deprivation in U87 glioma cells.
Endocr Regul. 2015; 49(4):185-97 [PubMed] Related Publications
OBJECTIVE: The aim of the present study was to investigate the effect of inhibition of endoplasmic reticulum stress signaling mediated by IRE1/ERN1 (inositol-requiring enzyme 1/endoplasmic reticulum to nucleus signaling 1) on the expression of genes encoding different groups of insulin-like growth binding proteins (IGFBP6 and IGFBP7) and CCN family (IGFBP8/CTGF/CCN2, IGFBP9/NOV/CCN3, IGFBP10/CYR61/CCN1, WISP1/CCN4, and WISP2/CCN5) and its sensitivity to glucose deprivation in U87 glioma cells.
METHODS: The expression of IGFBP6, IGFBP7, IGFBP8, IGFBP9, IGFBP10, WISP1, and WISP2 genes was studied by qPCR in control U87 glioma cells (wild-type) and its subline with IRE1 signaling enzyme loss of function upon glucose deprivation.
RESULTS: The expression of IGFBP8, IGFBP9, and WISP2 genes was up-regulated in control glioma cells upon glucose deprivation with most significant changes for IGFBP9 gene. At the same time, the expression of IGFBP6, IGFBP10, and WISP1 genes was resistant to glucose deprivation in these glioma cells, but the IGFBP7 gene expression was down-regulated. The inhibition of both enzymatic activities (kinase and endoribonuclease) of IRE1 in glioma cells modified the sensitivity of most studied gene expressions to glucose deprivation condition: introduced sensitivity of IGFBP10 and WISP1 genes to glucose deprivation, enhanced the effect of this deprivation on IGFBP7 and IGFBP9 gene expressions, and reduced this effect on WISP2 gene and induced suppressive effect of glucose deprivation on the expression of IGFBP8 gene. Furthermore, the inhibition of IRE1 strongly affected the expression of all studied genes in glioma cells upon regular growing condition in gene specific manner: up-regulated the expression levels of IGFBP7, IGFBP8, IGFBP10, WISP1, and WISP2 genes and down-regulated the IGFBP6 and IGFBP9 genes.
CONCLUSIONS: The data of this investigation demonstrate that the expression of IGFBP7, IGFBP8, IGFBP9, and WISP2 genes are sensitive to glucose deprivation in U87 glioma cells and that inhibition of IRE1 signaling enzyme function may significantly affect the expression of all studied genes in the presence of glucose as well as modify the effect of glucose deprivation on the expression of most studied genes. These data also show that proteins encoded by these genes may participate in the regulation of metabolic and proliferative processes via IGF/INS receptors and possibly other signaling pathways as well, via IRE1 signaling, which is a central mediator of the unfolded protein response and an important component of the tumor growth and metabolic diseases.

Bartram I, Erben U, Ortiz-Tanchez J, et al.
Inhibition of IGF1-R overcomes IGFBP7-induced chemotherapy resistance in T-ALL.
BMC Cancer. 2015; 15:663 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: T-cell acute lymphoblastic leukemia (T-ALL) is a genetically heterogeneous disease with the need for treatment optimization. Previously, high expression of Insulin-like growth factor binding protein 7 (IGFBP7), a member of the IGF system, was identified as negative prognostic factor in adult T-ALL patients. Since aberrant IGFBP7 expression was observed in a variety of neoplasia and was relevant for prognosis in T-ALL, we investigated the functional role of IGFBP7 in Jurkat and Molt-4 cells as in vitro models for T-ALL.
METHODS: Jurkat and Molt-4 cells were stably transfected with an IGFBP7 over-expression vector or the empty vector as control. Proliferation of the cells was assessed by WST-1 assays and cell cycle status was measured by flow-cytometry after BrDU/7-AAD staining. The effect of IGFBP7 over-expression on sensitivity to cytostatic drugs was determined in AnnexinV/7-AAD assays. IGF1-R protein expression was measured by Western Blot and flow-cytometric analysis. IGF1-R associated gene expression profiles were generated from microarray gene expression data of 86 T-ALL patients from the Microarrays Innovations in Leukemia (MILE) multicenter study.
RESULTS: IGFBP7-transfected Jurkat cells proliferated less, leading to a longer survival in a nutrient-limited environment. Both IGFBP7-transfected Jurkat and Molt-4 cells showed an arrest in the G0/G1 cell cycle phase. Furthermore, Jurkat IGFBP7-transfected cells were resistant to vincristine and asparaginase treatment. Surface expression and whole protein measurement of IGF1-R protein expression showed a reduced abundance of the receptor after IGFBP7 transfection in Jurkat cells. Interestingly, combination of the IGF1-R inhibitor NPV-AEW541 restored sensitivity to vincristine in IGFBP7-transfected cells. Additionally, IGF1-R associated GEP revealed an up-regulation of important drivers of T-ALL pathogenesis and regulators of chemo-resistance and apoptosis such as NOTCH1, BCL-2, PRKCI, and TP53.
CONCLUSION: This study revealed a proliferation inhibiting effect of IGFBP7 by G0/G1 arrest and a drug resistance-inducing effect of IGFBP7 against vincristine and asparaginase in T-ALL. These results provide a model for the previously observed association between high IGFBP7 expression and chemotherapy failure in T-ALL patients. Since the resistance against vincristine was abolished by IGF1-R inhibition, IGFBP7 could serve as biomarker for patients who may benefit from therapies including IGF1-R inhibitors in combination with chemotherapy.

Ramus SJ, Song H, Dicks E, et al.
Germline Mutations in the BRIP1, BARD1, PALB2, and NBN Genes in Women With Ovarian Cancer.
J Natl Cancer Inst. 2015; 107(11) [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy, responsible for 13 000 deaths per year in the United States. Risk prediction based on identifying germline mutations in ovarian cancer susceptibility genes could have a clinically significant impact on reducing disease mortality.
METHODS: Next generation sequencing was used to identify germline mutations in the coding regions of four candidate susceptibility genes-BRIP1, BARD1, PALB2 and NBN-in 3236 invasive EOC case patients and 3431 control patients of European origin, and in 2000 unaffected high-risk women from a clinical screening trial of ovarian cancer (UKFOCSS). For each gene, we estimated the prevalence and EOC risks and evaluated associations between germline variant status and clinical and epidemiological risk factor information. All statistical tests were two-sided.
RESULTS: We found an increased frequency of deleterious mutations in BRIP1 in case patients (0.9%) and in the UKFOCSS participants (0.6%) compared with control patients (0.09%) (P = 1 x 10(-4) and 8 x 10(-4), respectively), but no differences for BARD1 (P = .39), NBN1 ( P = .61), or PALB2 (P = .08). There was also a difference in the frequency of rare missense variants in BRIP1 between case patients and control patients (P = 5.5 x 10(-4)). The relative risks associated with BRIP1 mutations were 11.22 for invasive EOC (95% confidence interval [CI] = 3.22 to 34.10, P = 1 x 10(-4)) and 14.09 for high-grade serous disease (95% CI = 4.04 to 45.02, P = 2 x 10(-5)). Segregation analysis in families estimated the average relative risks in BRIP1 mutation carriers compared with the general population to be 3.41 (95% CI = 2.12 to 5.54, P = 7×10(-7)).
CONCLUSIONS: Deleterious germline mutations in BRIP1 are associated with a moderate increase in EOC risk. These data have clinical implications for risk prediction and prevention approaches for ovarian cancer and emphasize the critical need for risk estimates based on very large sample sizes before genes of moderate penetrance have clinical utility in cancer prevention.

Short E, Thomas LE, Hurley J, et al.
Inherited predisposition to colorectal cancer: towards a more complete picture.
J Med Genet. 2015; 52(12):791-6 [PubMed] Related Publications
Colorectal carcinoma (CRC) is the third most common cancer worldwide. Hereditary factors are important in 15%-35% of affected patients. This review provides an update on the genetic basis of inherited predisposition to CRC. Currently known genetic factors include a group of highly penetrant mutant genes associated with rare mendelian cancer syndromes and a group of common low-penetrance alleles that have been identified through genetic association studies. Additional mechanisms, which may underlie a predisposition to CRC, will be outlined, for example, variants in intermediate penetrance alleles. Recent findings, including mutations in POLE, POLD1 and NTHL1, will be highlighted, and we identify gaps in present knowledge and consider how these may be addressed through current and emerging genomic approaches. It is expected that identification of the missing heritable component of CRC will be resolved through evermore comprehensive cataloguing and phenotypic annotation of CRC-associated variants identified through sequencing approaches. This will have important clinical implications, particularly in areas such as risk stratification, public health and CRC prevention.

Rao Q, Shen Q, Xia QY, et al.
PSF/SFPQ is a very common gene fusion partner in TFE3 rearrangement-associated perivascular epithelioid cell tumors (PEComas) and melanotic Xp11 translocation renal cancers: clinicopathologic, immunohistochemical, and molecular characteristics suggesting classification as a distinct entity.
Am J Surg Pathol. 2015; 39(9):1181-96 [PubMed] Related Publications
An increasing number of TFE3 rearrangement-associated tumors, such as TFE3 rearrangement-associated perivascular epithelioid cell tumors (PEComas), melanotic Xp11 translocation renal cancers, and melanotic Xp11 neoplasms, have recently been reported. We examined 12 such cases, including 5 TFE3 rearrangement-associated PEComas located in the pancreas, cervix, or pelvis and 7 melanotic Xp11 translocation renal cancers, using clinicopathologic, immunohistochemical, and molecular analyses. All the tumors shared a similar morphology, including a purely nested or sheet-like architecture separated by a delicate vascular network, purely epithelioid cells displaying a clear or granular eosinophilic cytoplasm, a lack of papillary structures and spindle cell or fat components, uniform round or oval nuclei containing small visible nucleoli, and, in most cases (11/12), melanin pigmentation. The levels of mitotic activity and necrosis varied. All 12 cases displayed moderately (2+) or strongly (3+) positive immunoreactivity for TFE3 and cathepsin K. One case labeled focally for HMB45 and Melan-A, whereas the others typically labeled moderately (2+) or strongly (3+) for 1 of these markers. None of the cases were immunoreactive for smooth muscle actin, desmin, CKpan, S100, or PAX8. PSF-TFE3 fusion genes were confirmed by reverse transcription polymerase chain reaction in cases (7/7) in which a novel PSF-TFE3 fusion point was identified. All of the cases displayed TFE3 rearrangement associated with Xp11 translocation. Furthermore, we developed a PSF-TFE3 fusion fluorescence in situ hybridization assay for the detection of the PSF-TFE3 fusion gene and detected it in all 12 cases. Clinical follow-up data were available for 7 patients. Three patients died, and 2 patients (cases 1 and 3) remained alive with no evidence of disease after initial resection. Case 2 experienced recurrence and remained alive with disease. Case 5, a recent case, remained alive with extensive abdominal cavity metastases. Our data suggest that these tumors belong to a single clinicopathologic spectrum and expand the known characteristics of TFE3 rearrangement-associated tumors.

Bolomsky A, Hose D, Schreder M, et al.
Insulin like growth factor binding protein 7 (IGFBP7) expression is linked to poor prognosis but may protect from bone disease in multiple myeloma.
J Hematol Oncol. 2015; 8:10 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Insulin like growth factor binding protein 7 (IGFBP7) is a secreted protein binding insulin like growth factor 1 (IGF-1), insulin, vascular endothelial growth factor A (VEGFA), and activin A. It antagonizes bone morphogenetic proteins and is involved in the tumour propagation of solid as well as haematological malignancies. Its role in multiple myeloma (MM) is not defined so far. We therefore aim here to investigate its prognostic and pathophysiological role in MM.
METHODS: The clinical significance of IGFBP7 gene expression was investigated by gene expression profiling in two independent cohorts (n = 948) of newly-diagnosed MM patients. Methylation of the IGFBP7 promoter was analysed by pyrosequencing and treatment of MM cell lines with 5-aza-2-deoxycytidine. The impact of IGFBP7 on MM cells was studied by CCK-8 assay, BrdU assay and flow cytometry, respectively. IGFBP7 expression in bone marrow stromal cells (BMSCs) was studied by quantitative RT-PCR. For osteoblast development, immortalized and primary human BMSCs were cultured in osteogenic differentiation medium for 7-14 days in the presence of recombinant human IGFBP7 and/or activin A.
RESULTS: Median IGFBP7 expression is significantly lower in CD138-purified plasma cells from individuals with MGUS and MM, compared to normal bone marrow plasma cells. IGFBP7 gene expression in MM cells is regulated by methylation, shown by pyrosequencing and exposure to demethylating agents (5-aza-2-deoxycytidine). High expression of IGFBP7 in MM cells is associated with adverse survival in two independent cohorts of 247 and 701 newly-diagnosed MM patients treated with high-dose therapy and autologous stem cell transplantation. IGFBP7 is associated with prognostically adverse chromosomal aberrations (t(4;14) and gain of 1q21), MMSET expression, and higher myeloma cell proliferation. In vitro, IGFBP7 overcomes activin A induced osteoblast suppression and promotes osteogenesis. MM cells downregulate IGFBP7 in stromal cells, possibly contributing to the osteoblast suppression found in MM. Conversely, higher IGFBP7 expression is associated with a lower probability of myeloma bone disease.
CONCLUSIONS: Our data indicate that IGFBP7 expression is a marker for a specific methylation pattern in myeloma, linked to translocation t(4;14) associated MMSET expression, showing clinical features of adverse prognosis with absence of myeloma bone disease.

Gambaro K, Quinn MC, Cáceres-Gorriti KY, et al.
Low levels of IGFBP7 expression in high-grade serous ovarian carcinoma is associated with patient outcome.
BMC Cancer. 2015; 15:135 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Insulin-like growth factor binding protein 7 (IGFBP7) has been suggested to act as a tumour suppressor gene in various human cancers, yet its role in epithelial ovarian cancer (EOC) has not yet been investigated. We previously observed that IGFBP7 was one of several genes found significantly upregulated in an EOC cell line model rendered non-tumourigenic as consequence of genetic manipulation. The aim of the present study was to investigate the role of IGFBP7 in high-grade serous ovarian carcinomas (HGSC), the most common type of EOC.
METHODS: We analysed IGFBP7 gene expression in 11 normal ovarian surface epithelial cells (NOSE), 79 high-grade serous ovarian carcinomas (HGSC), and seven EOC cell lines using a custom gene expression array platform. IGFBP7 mRNA expression profiles were also extracted from publicly available databases. Protein expression was assessed by immunohistochemistry of 175 HGSC and 10 normal fallopian tube samples using tissue microarray and related to disease outcome. We used EOC cells to investigate possible mechanisms of gene inactivation and describe various in vitro growth effects of exposing EOC cell lines to human recombinant IGFBP7 protein and conditioned media.
RESULTS: All HGSCs exhibited IGFBP7 expression levels that were significantly (p = 0.001) lower than the mean of the expression value of NOSE samples and that of a whole ovary sample. IGFBP7 gene and protein expression were lower in tumourigenic EOC cell lines relative to a non-tumourigenic EOC cell line. None of the EOC cell lines harboured a somatic mutation in IGFBP7, although loss of heterozygosity (LOH) of the IGFBP7 locus and epigenetic methylation silencing of the IGFBP7 promoter was observed in two of the cell lines exhibiting loss of gene/protein expression. In vitro functional assays revealed an alteration of the EOC cell migration capacity. Protein expression analysis of HGSC samples revealed that the large majority of tumour cores (72.6%) showed low or absence of IGFBP7 staining and revealed a significant correlation between IGFBP7 protein expression and a prolonged overall survival (p = 0.044).
CONCLUSION: The low levels of IGFPB7 in HGSC relative to normal tissues, and association with survival are consistent with a purported role in tumour suppressor pathways.

Chen LH, Liu DW, Chang JL, et al.
Methylation status of insulin-like growth factor-binding protein 7 concurs with the malignance of oral tongue cancer.
J Exp Clin Cancer Res. 2015; 34:20 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Aberrant insulin-like growth factor-binding protein 7 (IGFBP-7) expression has been found in various cancers such as prostate, breast, and colon. IGFBP-7 induced the apoptosis of tumor and potentially predicted the clinical outcome in some cancers is further demonstrated. This study investigates the causes and underlying mechanisms of aberrant IGFBP-7 expression in unravelling head and neck squamous cell carcinoma (HNSCC).
METHODS: A total of 47 oral tongue cancer patient samples were primarily analyzed for the methylation status in 5' region of IGFBP-7 by methylation-specific PCR (MS-PCR). Subsequently the invasion, overexpression, and knockdown of IGFBP-7 in the HNSCC A253 invasive subpopulation were employed to examine the effect of IGFBP-7. The epithelial-mesenchymal transition (EMT) marker genes and AKT/GSK3β/β-catenin signaling were further evaluated by Western blot for the understanding the role of aberrant IGFBP-7 expression and thereof putative mechanism.
RESULTS: EMT expressed in the invasive subpopulation of HNSCC cell lines (A253 and RPMI 2650) was contemporary with the down-regulation of IGFBP-7. After treatment with 5-AZA-2' deoxycytidine, the de-methylated CpG sites in the 5' region of IGFBP-7 were observed and IGFBP-7 mRNA expression was also restored. Accordingly, re-expression IGFBP-7 in invasive subpopulation of A253 could induce the mesenchymal-epithelial transition (MET) and concurrently inhibited the cell invasion. Moreover, IGFBP-7 methylation status of 47 oral tongue tumors showed a positive correlation to invasive depth of the tumor, loco-regional recurrence, and cancer sequence.
CONCLUSIONS: IGFBP-7 can alter EMT relative marker genes and suppress cell invasion in A253 cell through AKT/GSK3β/β-catenin signaling. The epigenetic control of IGFBP-7 in the invasion and metastasis of HNSCC was reported, suggesting that IGFBP-7 could be a prognostic factor for the probability of invasion and a therapeutic remedy.

Agaram NP, Sung YS, Zhang L, et al.
Dichotomy of Genetic Abnormalities in PEComas With Therapeutic Implications.
Am J Surg Pathol. 2015; 39(6):813-25 [PubMed] Free Access to Full Article Related Publications
Perivascular epithelioid cell neoplasms (PEComa) are a family of rare mesenchymal tumors with hybrid myo-melanocytic differentiation. Although most PEComas harbor loss-of-function TSC1/TSC2 mutations, a small subset were reported to carry TFE3 gene rearrangements. As no comprehensive genomic study has addressed the molecular classification of PEComa, we sought to investigate by multiple methodologies the incidence and spectrum of genetic abnormalities and their potential genotype-phenotype correlations in a large group of 38 PEComas. The tumors were located in soft tissue (11 cases) and visceral sites (27) including uterus, kidney, liver, lung, and urinary bladder. Combined RNA sequencing and fluorescence in situ hybridization analysis identified 9 (23%) TFE3 gene-rearranged tumors, with 3 cases showing an SFPQ/PSF-TFE3 fusion and 1 case showing a novel DVL2-TFE3 gene fusion. The TFE3-positive lesions showed a distinctive nested/alveolar morphology and were equally distributed between soft tissue and visceral sites. In addition, novel RAD51B gene rearrangements were identified in 3 (8%) uterine PEComas, which showed a complex fusion pattern and were fused to RRAGB/OPHN1 genes in 2 cases. Other nonrecurrent gene fusions, HTR4-ST3GAL1 and RASSF1-PDZRN3, were identified in 2 cases. Targeted exome sequencing using the IMPACT assay was used to address whether the presence of gene fusions is mutually exclusive from TSC gene abnormalities. TSC2 mutations were identified in 80% of the TFE3 fusion-negative cases tested. Coexistent TP53 mutations were identified in 63% of the TSC2-mutated PEComas. Our results showed that TFE3-rearranged PEComas lacked coexisting TSC2 mutations, indicating alternative pathways of tumorigenesis. In summary, this comprehensive genetic analysis significantly expands our understanding of molecular alterations in PEComas and brings forth the genetic heterogeneity of these tumors.

Nosho K, Igarashi H, Ito M, et al.
Clinicopathological and molecular characteristics of serrated lesions in Japanese elderly patients.
Digestion. 2015; 91(1):57-63 [PubMed] Related Publications
BACKGROUND: The population in Japan is aging more rapidly than in any other country. However, no studies have determined the characteristics of the large population of elderly patients with colorectal tumors. Therefore, we examined the clinicopathological and molecular features of these tumors in elderly patients.
METHODS: In total, 1,627 colorectal tumors (393 serrated lesions, 277 non-serrated adenomas and 957 colorectal cancers) were acquired from patients. Tumor specimens were analyzed for BRAF and KRAS mutations, CpG island methylator phenotype-specific promoters (CACNA1G, CDKN2A, IGF2 and RUNX3), IGFBP7, MGMT, MLH1 and RASSF2 methylation, microsatellite instability (MSI) and microRNA- 31 (miR-31).
RESULTS: The frequency of elderly patients (aged ≥75 years) with sessile serrated adenomas (SSAs) with cytological dysplasia was higher than that of those with other serrated lesions and non-serrated adenomas (p < 0.0001). In elderly patients, all SSAs were located in the proximal colon (particularly the cecum to ascending colon). High miR-31 expression, MLH1 methylation and MSI-high status were more frequently detected in SSAs from elderly patients than in those from non-elderly patients. In contrast, no significant differences were found between older age of onset and high-grade dysplasia for traditional serrated adenomas or non-serrated adenomas in any of these molecular alterations.
CONCLUSION: In elderly patients, all SSAs were located in the proximal colon. Furthermore, cytological dysplasia and molecular alterations were more frequently detected in elderly patients with SSAs than in non-elderly patients. Thus, careful colonoscopic examinations of the proximal colon are necessary for elderly patients because SSAs in those patients may exhibit malignant potential.

Lu B, Wang C, Zhang J, et al.
Perivascular epithelioid cell tumor of gastrointestinal tract: case report and review of the literature.
Medicine (Baltimore). 2015; 94(3):e393 [PubMed] Free Access to Full Article Related Publications
Perivascular epithelioid cell tumors of gastrointestinal tract (GI PEComas) are exceedingly rare, with only a limited number of published reports worldwide. Given the scarcity of GI PEComas and their relatively short follow-up periods, our current knowledge of their biologic behavior, molecular genetic alterations, diagnostic criteria, and prognostic factors continues to be very limited.We present 2 cases of GI PEComas, one of which showed an aggressive histologic behavior that underwent multiple combined chemotherapies. We also review the available English-language medical literature on GI PEComas-not otherwise specified (PEComas-NOS) and discuss their clinicopathological and molecular genetic features.Pathologic analyses including histomorphologic, immunohistochemical, and ultrastructural studies were performed to evaluate the clinicopathological features of GI PEComas, their diagnosis, and differential diagnosis. Immunohistochemistry, semiquantitative reverse transcriptase polymerase chain reaction, and DNA sequencing assays were carried out to detect the potential molecular genetic alterations in our cases. Microscopically, the tumors showed distinctive histologic features of PEComas-NOS, including fascicular or nested architecture, epithelioid or spindled cell type, and clear to eosinophilic cytoplasm. The tumor cells were immunohistochemically positive for melanocytic markers. Molecular pathological assays confirmed a PSF-TFE3 gene fusion in one of our cases. Furthermore, in this case microphthalmia-associated transcription factor and its downstream genes were found to exhibit elevated transcript levels.Knowledge about the molecular genetic alterations in GI PEComas is still limited and warrants further study.

Sarkar D, Leung EY, Baguley BC, et al.
Epigenetic regulation in human melanoma: past and future.
Epigenetics. 2015; 10(2):103-21 [PubMed] Free Access to Full Article Related Publications
The development and progression of melanoma have been attributed to independent or combined genetic and epigenetic events. There has been remarkable progress in understanding melanoma pathogenesis in terms of genetic alterations. However, recent studies have revealed a complex involvement of epigenetic mechanisms in the regulation of gene expression, including methylation, chromatin modification and remodeling, and the diverse activities of non-coding RNAs. The roles of gene methylation and miRNAs have been relatively well studied in melanoma, but other studies have shown that changes in chromatin status and in the differential expression of long non-coding RNAs can lead to altered regulation of key genes. Taken together, they affect the functioning of signaling pathways that influence each other, intersect, and form networks in which local perturbations disturb the activity of the whole system. Here, we focus on how epigenetic events intertwine with these pathways and contribute to the molecular pathogenesis of melanoma.

Zhan HQ, Chen H, Wang CF, Zhu XZ
A case of PSF-TFE3 gene fusion in Xp11.2 renal cell carcinoma with melanotic features.
Hum Pathol. 2015; 46(3):476-81 [PubMed] Related Publications
Xp11.2 translocation renal cell carcinoma (Xp11.2 RCC) with PSF-TFE3 gene fusion is a rare neoplasm. Only 22 cases of Xp11.2 RCCs with PSF-TFE3 have been reported to date. We describe an additional case of Xp11.2 RCC with PSF-TFE3 showing melanotic features. Microscopically, the histologic features mimic clear cell renal cell carcinoma. However, the dark-brown pigments were identified and could be demonstrated as melanins. Immunohistochemically, the tumor cells were widely positive for CD10, human melanoma black 45, and TFE3 but negative for cytokeratins, vimentin, Melan-A, microphthalmia-associated transcription factor, smooth muscle actin, and S-100 protein. Genetically, we demonstrated PSF-TFE3 fusion between exon 9 of PSF and exon 5 of TFE3. The patient was free of disease with 50 months of follow-up. The prognosis of this type of tumor requires more cases because of limited number of cases and follow-up period. Xp11.2 RCC with PSF-TFE3 inevitably requires differentiation from other kidney neoplasms. Immunohistochemical and molecular genetic analyses are essential for accurate diagnosis.

Szalontay L, Schally AV, Popovics P, et al.
Novel GHRH antagonists suppress the growth of human malignant melanoma by restoring nuclear p27 function.
Cell Cycle. 2014; 13(17):2790-7 [PubMed] Free Access to Full Article Related Publications
Malignant melanoma is the deadliest form of skin cancer; the treatment of advanced and recurrent forms remains a challenge. It has recently been reported that growth hormone-releasing hormone (GHRH) receptor is involved in the pathogenesis of melanoma. Therefore, we investigated the effects of our new GHRH antagonists on a human melanoma cancer cell line. Antiproliferative effects of GHRH antagonists, MIA-602, MIA-606 and MIA-690, on the human melanoma cell line, A-375, were studied in vitro using the MTS assay. The effect of MIA-690 (5 μg/day 28 d) was further evaluated in vivo in nude mice bearing xenografts of A-375. Subcellular localization of p27 was detected with Western blot and immunofluorescent staining. MIA-690 inhibited the proliferation of A-375 cells in a dose-dependent manner (33% at 10 μM, and 19.2% at 5 μM, P < 0 .05 vs. control), and suppressed the growth of xenografted tumors by 70.45% (P < 0.05). Flow cytometric analysis of cell cycle effects following the administration of MIA-690 revealed a decrease in the number of cells in G2/M phase (from 19.7% to 12.9%, P < 0.001). Additionally, Western blot and immunofluorescent studies showed that exposure of A-375 cells to MIA-690 triggered the nuclear accumulation of p27. MIA-690 inhibited tumor growth in vitro and in vivo, and increased the translocation of p27 into the nucleus thus inhibiting progression of the cell cycle. Our findings indicate that patients with malignant melanoma could benefit from treatment regimens, which combine existing chemotherapy agents and novel GHRH-antagonists.

Takeshima H, Wakabayashi M, Hattori N, et al.
Identification of coexistence of DNA methylation and H3K27me3 specifically in cancer cells as a promising target for epigenetic therapy.
Carcinogenesis. 2015; 36(2):192-201 [PubMed] Related Publications
Alterations of epigenetic modifications are promising targets for cancer therapy, and several epigenetic drugs are now being clinically utilized. At the same time, individual epigenetic modifications have physiological functions in normal cells, and cancer cell specificity is considered difficult to achieve using a drug against a single epigenetic modification. To overcome this limitation, a combination of epigenetic modifications specifically or preferentially present in cancer cells is a candidate target. In this study, we aimed to demonstrate (i) the presence of a cancer cell-specific combination of epigenetic modifications by focusing on DNA methylation and trimethylation of histone H3 lysine 27 (H3K27me3) and (ii) the therapeutic efficacy of a combination of DNA demethylation and EZH2 inhibition. Analyses of DNA methylation and H3K27me3 in human colon, breast and prostate cancer cell lines revealed that 24.7±4.1% of DNA methylated genes had both DNA methylation and H3K27me3 (dual modification) in cancer cells, while it was 11.8±7.1% in normal cells. Combined treatment with a DNA demethylating agent, 5-aza-2'-deoxycytidine (5-aza-dC) and an EZH2 inhibitor, GSK126, induced marked re-expression of genes with the dual modification, including known tumor-suppressor genes such as IGFBP7 and SFRP1, and showed an additive inhibitory effect on growth of cancer cells in vitro. Finally, an in vivo combined treatment with 5-aza-dC and GSK126 inhibited growth of xenograft tumors more efficiently than a single treatment with 5-aza-dC. These results showed that the dual modification exists specifically in cancer cells and is a promising target for cancer cell-specific epigenetic therapy.

Puig M, Lugo R, Gabasa M, et al.
Matrix stiffening and β1 integrin drive subtype-specific fibroblast accumulation in lung cancer.
Mol Cancer Res. 2015; 13(1):161-73 [PubMed] Related Publications
UNLABELLED: The crucial role of tumor-associated fibroblasts (TAF) in cancer progression is now clear in non-small cell lung cancer (NSCLC). However, therapies against TAFs are limited due to a lack of understanding in the subtype-specific mechanisms underlying their accumulation. Here, the mechanical (i.e., matrix rigidity) and soluble mitogenic cues that drive the accumulation of TAFs from major NSCLC subtypes: adenocarcinoma (ADC) and squamous cell carcinoma (SCC) were dissected. Fibroblasts were cultured on substrata engineered to exhibit normal- or tumor-like stiffnesses at different serum concentrations, and critical regulatory processes were elucidated. In control fibroblasts from nonmalignant tissue, matrix stiffening alone increased fibroblast accumulation, and this mechanical effect was dominant or comparable with that of soluble growth factors up to 0.5% serum. The stimulatory cues of matrix rigidity were driven by β1 integrin mechano-sensing through FAK (pY397), and were associated with a posttranscriptionally driven rise in β1 integrin expression. The latter mechano-regulatory circuit was also observed in TAFs but in a subtype-specific fashion, because SCC-TAFs exhibited higher FAK (pY397), β1 expression, and ERK1/2 (pT202/Y204) than ADC-TAFs. Moreover, matrix stiffening induced a larger TAF accumulation in SCC-TAFs (>50%) compared with ADC-TAFs (10%-20%). In contrast, SCC-TAFs were largely serum desensitized, whereas ADC-TAFs responded to high serum concentration only. These findings provide the first evidence of subtype-specific regulation of NSCLC-TAF accumulation. Furthermore, these data support that therapies aiming to restore normal lung elasticity and/or β1 integrin-dependent mechano regulation may be effective against SCC-TAFs, whereas inhibiting stromal growth factor signaling may be effective against ADC-TAFs.
IMPLICATIONS: This study reveals distinct mechanisms underlying the abnormal accumulation of tumor-supporting fibroblasts in two major subtypes of lung cancer, which will assist the development of personalized therapies against these cells.

Sakashita K, Kato I, Daifu T, et al.
In vitro expansion of CD34(+)CD38(-) cells under stimulation with hematopoietic growth factors on AGM-S3 cells in juvenile myelomonocytic leukemia.
Leukemia. 2015; 29(3):606-14 [PubMed] Related Publications
Using serum-containing culture, we examined whether AGM-S3 stromal cells, alone or in combination with hematopoietic growth factor(s), stimulated the proliferation of CD34(+) cells from patients with juvenile myelomonocytic leukemia (JMML). AGM-S3 cells in concert with stem cell factor plus thrombopoietin increased the numbers of peripheral blood CD34(+) cells to approximately 20-fold of the input value after 2 weeks in nine JMML patients with either PTPN11 mutations or RAS mutations, who received allogeneic hematopoietic transplantation. Granulocyte-macrophage colony-stimulating factor (GM-CSF) also augmented the proliferation of JMML CD34(+) cells on AGM-S3 cells. The expansion potential of CD34(+) cells was markedly low in four patients who achieved spontaneous hematological improvement. A large proportion of day-14-cultured CD34(+) cells were negative for CD38 and cryopreservable. Cultured JMML CD34(+)CD38(-) cells expressed CD117, CD116, c-mpl, CD123, CD90, but not CXCR4, and formed GM and erythroid colonies. Day-7-cultured CD34(+) cells from two of three JMML patients injected intrafemorally into immunodeficient mice stimulated with human GM-CSF after transplantation displayed significant hematopoietic reconstitution. The abilities of OP9 cells and MS-5 cells were one-third and one-tenth, respectively, of the value obtained with AGM-S3 cells. Our culture system may provide a useful tool for elucidating leukemogenesis and for therapeutic approaches in JMML.

Ji Q, Zhang L, Liu X, et al.
Long non-coding RNA MALAT1 promotes tumour growth and metastasis in colorectal cancer through binding to SFPQ and releasing oncogene PTBP2 from SFPQ/PTBP2 complex.
Br J Cancer. 2014; 111(4):736-48 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Metastasis associated with lung adenocarcinoma transcript-1 (MALAT1) is a functional long non-coding RNA (lncRNA), which is highly expressed in several tumours, including colorectal cancer (CRC). Its biological function and mechanism in the prognosis of human CRC is still largely under investigation.
METHODS: This study aimed to investigate the new effect mechanism of MALAT1 on the proliferation and migration of CRC cells in vitro and in vivo, and detect the expression of MALAT1, SFPQ (also known as PSF (PTB-associated splicing factor)), and PTBP2 (also known as PTB (polypyrimidine-tract-binding protein)) in CRC tumour tissues, followed by correlated analysis with clinicopathological parameters.
RESULTS: We found that overexpression of MALAT1 could promote cell proliferation and migration in vitro, and promote tumour growth and metastasis in nude mice. The underlying mechanism was associated with tumour suppressor gene SFPQ and proto-oncogene PTBP2. In CRC, MALAT1 could bind to SFPQ, thus releasing PTBP2 from the SFPQ/PTBP2 complex. In turn, the increased SFPQ-detached PTBP2 promoted cell proliferation and migration. SFPQ critically mediated the regulatory effects of MALAT1. Moreover, in CRC tissues, MALAT1 and PTBP2 were overexpressed, both of which were associated closely with the invasion and metastasis of CRC. However, the SFPQ showed unchanged expression either in CRC tissues or adjacent normal tissues.
CONCLUSIONS: Our findings implied that MALAT1 might be a potential predictor for tumour metastasis and prognosis. Furthermore, the interaction between MALAT1 and SFPQ could be a novel therapeutic target for CRC.

Simons CC, van den Brandt PA, Stehouwer CD, et al.
Body size, physical activity, early-life energy restriction, and associations with methylated insulin-like growth factor-binding protein genes in colorectal cancer.
Cancer Epidemiol Biomarkers Prev. 2014; 23(9):1852-62 [PubMed] Related Publications
BACKGROUND: We investigated body size, physical activity, and early-life energy restriction in relation to colorectal tumors with and without methylated insulin-like growth factor-binding protein (IGFBP) genes, which are putative tumor-suppressor genes.
METHODS: We determined IGFBP2, IGFBP3, and IGFBP7 promoter CpG island hypermethylation in tumors of 733 colorectal cancer cases from the Netherlands Cohort Study (N = 120,852). Participants self-reported lifestyle and dietary factors at baseline in 1986. Using a case-cohort approach (N subcohort = 5,000), we estimated hazard ratios (HR) for colorectal cancer by extent of IGFBP methylation.
RESULTS: Comparison of the highest versus lowest sex-specific tertiles of adult body mass index (BMI) gave multivariable-adjusted HRs [95% confidence intervals (CI)] for colorectal cancers with 0 (18.7%), 1 (29.5%), 2 (32.4%), and 3 (19.5%) methylated genes of 1.39 (0.88-2.19), 1.11 (0.77-1.62), 1.67 (1.17-2.38), and 2.07 (1.29-3.33), respectively. Other anthropometric measures and physical activity were not associated with colorectal cancer risk by extent of IGFBP methylation, except height in sex-specific analyses for women. Exposure to energy restriction during the Dutch Hunger Winter versus nonexposure gave HRs (95% CIs) for colorectal cancers with 0, 1, 2, and 3 methylated genes of 1.01 (0.67-1.53), 1.03 (0.74-1.44), 0.72 (0.52-0.99), and 0.50 (0.32-0.78), respectively.
CONCLUSIONS: Adult BMI, height (in women only), and early-life energy restriction were associated with the risk of having a colorectal tumor characterized by IGFBP methylation.
IMPACT: Body size may particularly increase the risk of IGFBP gene-methylated colorectal tumors; this finding might facilitate more targeted approaches to prevent obesity-related colorectal cancers.

Verhagen HJ, de Leeuw DC, Roemer MG, et al.
IGFBP7 induces apoptosis of acute myeloid leukemia cells and synergizes with chemotherapy in suppression of leukemia cell survival.
Cell Death Dis. 2014; 5:e1300 [PubMed] Free Access to Full Article Related Publications
Despite high remission rates after chemotherapy, only 30-40% of acute myeloid leukemia (AML) patients survive 5 years after diagnosis. This extremely poor prognosis of AML is mainly caused by treatment failure due to chemotherapy resistance. Chemotherapy resistance can be caused by various features including activation of alternative signaling pathways, evasion of cell death or activation of receptor tyrosine kinases such as the insulin growth factor-1 receptor (IGF-1R). Here we have studied the role of the insulin-like growth factor-binding protein-7 (IGFBP7), a tumor suppressor and part of the IGF-1R axis, in AML. We report that IGFBP7 sensitizes AML cells to chemotherapy-induced cell death. Moreover, overexpression of IGFBP7 as well as addition of recombinant human IGFBP7 is able to reduce the survival of AML cells by the induction of a G2 cell cycle arrest and apoptosis. This effect is mainly independent from IGF-1R activation, activated Akt and activated Erk. Importantly, AML patients with high IGFBP7 expression have a better outcome than patients with low IGFBP7 expression, indicating a positive role for IGFBP7 in treatment and outcome of AML. Together, this suggests that the combination of IGFBP7 and chemotherapy might potentially overcome conventional AML drug resistance and thus might improve AML patient survival.

Liu L, Yang Z, Zhang W, et al.
Decreased expression of IGFBP7 was a poor prognosis predictor for gastric cancer patients.
Tumour Biol. 2014; 35(9):8875-81 [PubMed] Related Publications
Increasing evidence indicated that insulin-like growth factor binding protein 7 (IGFBP7) was regarded as a potential tumor suppressor in various human cancers, but its role in gastric cancer is still largely unknown. In the present study, we performed a retrospective study which includes 247 gastric cancer patients. Among them, the IGFBP7 expression was detected by qRT-PCR in 138 cases of gastric cancer and adjacent non-tumor tissues and was further correlated with the expression of p53, Ki-67, and the clinicopathologic features. The results indicated that both IGFBP7 mRNA and protein in gastric cancer tissues were significantly lower than those in the adjacent non-tumor tissues. Additionally, the expression of IGFBP7 was correlated with the depth of invasion, lymph node metastasis, and TNM stage. Interestingly, the expression of IGFBP7 was negatively associated with Ki-67 (r = -0.227, P < 0.001) but positively associated with p53 (r = 0.140, P = 0.028). Univariate analysis showed that low expression of IGFBP7 was associated with poor prognosis (P < 0.001), and multivariate analysis showed that IGFBP7 (HR = 1.87; 95 % CI 1.65-2.17), distant metastasis (HR = 2.68; 95 % CI 1.58-4.56), and tumor size (HR = 1.45; 95 % CI 0.90-2.32) were independent prognostic factors for gastric cancer patients. These results demonstrated that IGFBP7 was downregulated in gastric cancer, and its low expression was potentially correlated with increased cancer cell proliferation and could be used to predicate poor prognosis in these patients.

Yang W, Wang X, Li X, et al.
The specific methylation characteristics of cancer related genes in Chinese colorectal cancer patients.
Tumour Biol. 2014; 35(8):8267-79 [PubMed] Related Publications
Aberrant DNA methylation at CpG islands has been implicated as a critical player in colorectal cancer (CRC). However, its biological role and clinical significance in carcinogenesis have not been clearly clarified in Chinese CRC patients. In order to examine the methylation status of cancer-related genes in CRC progression, 184 tumor tissues were collected from Chinese patients diagnosed with CRC during 2008-2011. Promoter methylation was assessed by combined bisulphite-restriction analysis, methylation-specific PCR, and bisulphite sequencing PCR . The relationship between the gene promoter methylation status and clinicopathological factors/CRC mortality was examined by using the chi-square test/Cox-proportional hazards models. Promoter hypermethylation of MLH1, p16, SFRP2, PHD3, KLOTHO, and IGFBP7 was observed in 1.6, 10.9, 97.3, 44.0, 59.8, and 88.6 % of CRC samples, respectively. KLOTHO promoter methylation reduced with age (P = 0.018) whereas p16 promoter methylation increased with age (P = 0.044) and was more frequent among males (P = 0.017). Tumor tissues (73.9 %) had concurrent methylation of two or more genes, with the most frequent combination as KLOTHO and IGFBP7 (53.8 %). Concurrent methylation of KLOTHO and IGFBP7 occurred more frequently among patients less than 70 years old (P = 0.035) and those with poor differentiation (P = 0.024). CRC-specific mortality was not associated with promoter methylation and clinicopathological features except for age (P = 0.038; risk ratio (RR), 1.96; 95 % confidence interval (CI), 1.04-3.70) and TNM stage (P = 0.034; RR, 3.47; 95 % CI, 1.10-10.92). Methylation frequencies of MLH1, p16, PHD3, KLOTHO, and IGFBP7 in CRC tissues were significantly higher than that in the paired normal tissues, while promoter hypermethylation of SFRP2 was widespread in normal tissues. In conclusion, we suggest that methylation of some genes (MLH1, PHD3, KLOTHO, p16, and IGFBP7) is important in CRC progression whereas SFRP2 methylation is unlikely to contribute to CRC development in Chinese patients. Besides, by identifying the characteristics of concordant methylation, we confirm the multifactorial nature of tumor progression.

Tian X, Zhang L, Sun L, et al.
Low expression of insulin-like growth factor binding protein 7 associated with poor prognosis in human glioma.
J Int Med Res. 2014; 42(3):651-8 [PubMed] Related Publications
OBJECTIVES: To investigate insulin-like growth factor binding protein 7 (IGFBP7) mRNA levels in human glioma and normal brain tissue, and to determine their clinical significance.
METHODS: In this retrospective study, IGFBP7 mRNA was quantified by real-time reverse transcription-polymerase chain reaction in brain tissue samples from patients with glioma and normal control subjects. Kaplan-Meier and Cox proportional hazards analyses were performed to determine any clinical and prognostic associations.
RESULTS: IGFBP7 mRNA levels were significantly lower in glioma tissue (n = 120) than in normal brain tissue (n = 20). Low (i.e. below the median, 5.9) IGFBP7 mRNA levels were significantly associated with larger tumour size (≥ 5 cm, compared with <5 cm, diameter). Patients with high (above median) IGFBP7 had longer overall survival than those with low IGFBP7. Tumour grade and IGFBP7 mRNA level were independent predictors of overall survival.
CONCLUSIONS: IGFBP7 downregulation is associated with poor prognosis in glioma, and this molecule may represent both a prognostic marker and a potential therapeutic target.

Komiya E, Sato H, Watanabe N, et al.
Angiomodulin, a marker of cancer vasculature, is upregulated by vascular endothelial growth factor and increases vascular permeability as a ligand of integrin αvβ3.
Cancer Med. 2014; 3(3):537-49 [PubMed] Free Access to Full Article Related Publications
Angiomodulin (AGM) is a member of insulin-like growth factor binding protein (IGFBP) superfamily and often called IGFBP-rP1 or IGFBP-7. AGM was originally identified as a tumor-derived cell adhesion factor, which was highly accumulated in blood vessels of human cancer tissues. AGM is also overexpressed in cancer-associated fibroblasts (CAFs) and activates fibroblasts. However, some studies have shown tumor-suppressing activity of AGM. To understand the roles of AGM in cancer progression, we here investigated the expression of AGM in benign and invasive breast cancers and its functions in cancer vasculature. Immunohistochemical analysis showed that AGM was highly expressed in cancer vasculature even in ductal carcinoma in situ (DCIS) as compared to normal vasculature, while its expression in CAFs was more prominent in invasive carcinomas than DCIS. In vitro analyses showed that AGM was strongly induced by vascular endothelial cell growth factor (VEGF) in vascular endothelial cells. Although AGM stimulated neither the growth nor migration of endothelial cells, it supported efficient adhesion of endothelial cells. Integrin αvβ3 was identified as a novel major receptor for AGM in vascular endothelial cells. AGM retracted endothelial cells by inducing actin stress fibers and loosened their VE-cadherin-mediated intercellular junction. Consequently, AGM increased vascular permeability both in vitro and in vivo. Furthermore, AGM and integrin αvβ3 were highly expressed and colocalized in cancer vasculature. These results suggest that AGM cooperates with VEGF to induce the aberrant functions of cancer vasculature as a ligand of integrin αvβ3.

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