Research IndicatorsGraph generated 31 August 2019 using data from PubMed using criteria.
Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic. Tag cloud generated 31 August, 2019 using data from PubMed, MeSH and CancerIndex
Specific Cancers (1)
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).
OMIM, Johns Hopkin University
Referenced article focusing on the relationship between phenotype and genotype.
International Cancer Genome Consortium.
Summary of gene and mutations by cancer type from ICGC
COSMIC, Sanger Institute
Somatic mutation information and related details
GEO Profiles, NCBI
Search the gene expression profiles from curated DataSets in the Gene Expression Omnibus (GEO) repository.
Latest Publications: ZBTB16 (cancer-related)
Wang JB, Jin Y, Wu P, et al.Tumor suppressor PLZF regulated by lncRNA ANRIL suppresses proliferation and epithelial mesenchymal transformation of gastric cancer cells.
Oncol Rep. 2019; 41(2):1007-1018 [PubMed
] Related Publications
Promyelocytic leukemia zinc finger (PLZF) plays important roles in tumorigenic and developmental processes of various types of cancers. However, the expression of PLZF in gastric cancer (GC) has not been reported. The aim of the present study was to investigate the expression level and potential status of PLZF in GC as well as its possible mechanism. In the present study, we found that PLZF was downregulated in the majority of GC cell lines and tumor tissues and that alteration of PLZF expression was closely correlated with a malignant phenotype, epithelial‑mesenchymal transformation and overall survival. Evaluation of in vitro proliferation, colony information, migration and invasion indicated that PLZF gene transduction induced a less malignant phenotype, which was also confirmed through in vivo studies performed in athymic nude mice. Furthermore, we assessed the expression levels of the lncRNA ANRIL in GC and found that it was negatively associated with the level of PLZF and that ANRIL indirectly methylated PLZF to suppress its expression via binding with polycomb repressive complex 2. When GC cells were treated with the methylation inhibitor 5‑Aza‑2'‑deoxycytidine, the expression of PLZF increased, which further confirmed that PLZF was methylated. These results indicated that constitutive ANRIL activation was a possible cause of the lack of PLZF expression in GC cells. Coupled deregulation of PLZF and ANRIL may account for most of the alterations described in GC, and PLZF may become a potential target of GC therapy.
Gallbladder cancer (GBC) is a malignant cancer with very poor prognosis. Although promyelocytic leukemia zinc-finger protein (PLZF) was reported to be deregulated in numerous cancers and also relevant to clinical prognosis, its role in GBC progression has been little known. In this study, we found PLZF expression was decreased in GBC, correlating to advanced TNM stage, distant metastasis, and shorter overall survival. Moreover, ectopic PLZF expression in GBC cells (NOZ and GBC-SD) significantly reduced the cell proliferation, migration, and invasion. Consistently, overexpression of PLZF in xenograft mice model could suppress tumor growth and liver metastasis. Mechanical investigations verified PLZF could regulate the expression of cell cycle arrest-associated gene p21 and epithelial-mesenchymal transition (EMT)-related genes (E-cadherin and N-cadherin) in GBC cell lines. Importantly, PLZF remarkably increased the mRNA transcription of interferon-induced protein with tetratricopeptide repeat 2 (IFIT2) by increasing STAT1 protein level, a known factor involved in tumor progression. Furthermore, ablation of IFIT2 in PLZF overexpression cells abrogated the tumor-suppressive function of PLZF, at least partially, leading to impaired tumor growth and EMT program. These studies indicated PLZF inhibited the proliferation and metastasis via regulation of IFIT2. In conclusion, our study demonstrated PLZF could be a promising tumor biomarker for GBC, and also be a potential therapeutic target.
T-cell acute lymphoblastic leukemia (T-ALL) is a clonal malignancy of immature T cells. Recently, the next-generation sequencing approach has allowed systematic identification of molecular features in pediatric T-ALL. Here, by performing RNA-sequencing and other genomewide analysis, we investigated the genomic landscape in 61 adult and 69 pediatric T-ALL cases. Thirty-six distinct gene fusion transcripts were identified, with
The disruption of estrogen signaling is widely associated with the development of breast, endometrial and ovarian cancers. As a multifunctional mediator of carcinogenesis, metadherin (MTDH)/astrocyte elevated gene-1 (AEG-1) overexpression has been associated with numerous types of cancer, with reported roles in tumor initiation, proliferation, invasion, metastasis and chemoresistance. At the molecular level, MTDH has been shown to interact with proteins that drive tumorigenesis, including nuclear factor-κB (NF-κB), promyelocytic leukaemia zinc finger (PLZF), BRCA2- and CDKN1A (p21Cip1/Waf-1/mda-6)-interacting protein α (BCCIPα) and staphylococcal nuclease and tudor domain containing 1 (SND1). Through the analysis of the Cancer Genome Atlas (TCGA) datasets for estrogen receptor (ER)-positive endometrial and breast cancers, we found that over 25% of all gene expression correlated with MTDH. Using Affymetrix microarrays, we characterized the differences in gene expression between estrogen-treated parental and MTDH-deficient endometrial and breast cancer cells. We also explored a possible interaction between MTDH and ER by immunoprecipitation, and found that MTDH and ER associated in both breast and endometrial cancer cells in response to estrogen. Reciprocal co-immunoprecipitation analysis demonstrated that acute estrogen stimulation promoted the interaction of MTDH with ER in the nucleus. These data, to the best of our knowledge, provide the first evidence that MTDH and ERα interact in the nucleus with estrogen treatment to regulate gene expression.
Freedland SJ, Aronson WJCommentary on "Integrative clinical genomics of advanced prostate cancer". Robinson D, Van Allen EM, Wu YM, Schultz N, Lonigro RJ, Mosquera JM, Montgomery B, Taplin ME, Pritchard CC, Attard G, Beltran H, Abida W, Bradley RK, Vinson J, Cao X, Vats P, Kunju LP, Hussain M, Feng FY, Tomlins SA, Cooney KA, Smith DC, Brennan C, Siddiqui J, Mehra R, Chen Y, Rathkopf DE, Morris MJ, Solomon SB, Durack JC, Reuter VE, Gopalan A, Gao J, Loda M, Lis RT, Bowden M, Balk SP, Gaviola G, Sougnez C, Gupta M, Yu EY, Mostaghel EA, Cheng HH, Mulcahy H, True LD, Plymate SR, Dvinge H, Ferraldeschi R, Flohr P, Miranda S, Zafeiriou Z, Tunariu N, Mateo J, Perez-Lopez R, Demichelis F, Robinson BD, Schiffman M, Nanus DM, Tagawa ST, Sigaras A, Eng KW, Elemento O, Sboner A, Heath EI, Scher HI, Pienta KJ, Kantoff P, de Bono JS, Rubin MA, Nelson PS, Garraway LA, Sawyers CL, Chinnaiyan AM.Cell. 21 May 2015;161(5):1215-1228.
Urol Oncol. 2017; 35(8):535 [PubMed
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Toward development of a precision medicine framework for metastatic, castration-resistant prostate cancer (mCRPC), we established a multi-institutional clinical sequencing infrastructure to conduct prospective whole-exome and transcriptome sequencing of bone or soft tissue tumor biopsies from a cohort of 150 mCRPC affected individuals. Aberrations of AR, ETS genes, TP53, and PTEN were frequent (40%-60% of cases), with TP53 and AR alterations enriched in mCRPC compared to primary prostate cancer. We identified new genomic alterations in PIK3CA/B, R-spondin, BRAF/RAF1, APC, β-catenin, and ZBTB16/PLZF. Moreover, aberrations of BRCA2, BRCA1, and ATM were observed at substantially higher frequencies (19.3% overall) compared to those in primary prostate cancers. A total of 89% of affected individuals harbored a clinically actionable aberration, including 62.7% with aberrations in AR, 65% in other cancer-related genes, and 8% with actionable pathogenic germline alterations. This cohort study provides clinically actionable information that could affect treatment decisions for these affected individuals.
Increased glucocorticoid receptor (GR) expression and activity following androgen blockade can contribute to castration-resistant prostate cancer (CRPC) progression. Therefore, we hypothesized that GR antagonism will have therapeutic benefit in CRPC. However, the FDA-approved nonselective, steroidal GR antagonist, mifepristone, lacks GR specificity, reducing its therapeutic potential. Here, we report that two novel nonsteroidal and highly selective GR modulators (SGRM), CORT118335 and CORT108297, have the ability to block GR activity in prostate cancer and slow CRPC progression. In contrast to mifepristone, these novel SGRMs did not affect androgen receptor (AR) signaling, but potently inhibited GR transcriptional activity. Importantly, SGRMs decreased GR-mediated tumor cell viability following AR blockade.
PLZF is a transcription factor that confers aberrant self-renewal in leukemogenesis, and the
Due to the high frequency of loco-regional recurrences, which could be explained by changes in the field surrounding the tumor, patients with squamous cell carcinoma of head and neck show poor survival. Here we identified a total of 554 genes as dysregulated in clinically tumor free tongue tissue in patients with tongue tumors when compared to healthy control tongue tissue. Among the top dysregulated genes when comparing control and tumor free tissue were those involved in apoptosis (CIDEC, MUC1, ZBTB16, PRNP, ECT2), immune response (IFI27) and differentiation (KRT36). Data suggest that these are important findings which can aid in earlier diagnosis of tumor development, a relapse or a novel squamous cell carcinoma of the tongue, in the absence of histological signs of a tumor.
Cheng W, Ren X, Zhang C, et al.Bioinformatic profiling identifies an immune-related risk signature for glioblastoma.
Neurology. 2016; 86(24):2226-34 [PubMed
] Related Publications
OBJECTIVE: To investigate the local immune status and its prognostic value in glioma.
METHODS: A cohort of 297 glioma samples with whole genome microarray expression data from the Chinese Glioma Genome Atlas database were included for discovery. The Cancer Genome Atlas (TCGA) database was used for validation. Principal components analysis and gene set enrichment analysis were used to explore the bioinformatic implication.
RESULTS: Distinct local immune status was identified according to histologic grade. Glioblastoma (GBM) exhibited an enhanced immune phenotype compared to lower grade glioma. We profiled the immune-related gene set and identified 8 genes (FOXO3, IL6, IL10, ZBTB16, CCL18, AIMP1, FCGR2B, and MMP9) with the greatest prognostic value in GBM. A local immune-related risk signature was developed from the genes to distinguish cases as high or low risk of unfavorable prognosis, which could be validated in TCGA database. High-risk patients conferred an enhanced intensity of local immune response compared to low-risk ones. Additionally, the signature exhibited different distribution based on molecular features. The signature had prognostic significance in the stratified cohorts and was identified as an independent prognostic factor for GBM.
CONCLUSIONS: We profiled the immune status in glioma and established a local immune signature for GBM, which could independently identify patients with a high risk of reduced survival, indicating the relationship between prognosis and local immune response.
Feng Y, Tian J, Krylova I, et al.Chronic TCDD exposure results in the dysregulation of gene expression in splenic B-lymphocytes and in the impairments in T-cell and B-cell differentiation in mouse model.
J Environ Sci (China). 2016; 39:218-227 [PubMed
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2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) exposure in humans is associated with marked immune suppressions and increased incidence of lymphoblastic diseases. To elucidate mechanisms of impairments in humoral immune responses, we used a murine model. Following a 20-week administration of low doses of TCDD, we observed severely reduced antibody titers, dramatically decreased number of splenic Th1 and Th2 cells and an increase in CD19(+) B cells. Transcriptional profiling of CD19(+) B cells showed that markers of pre-B cells were significantly elevated, indicating delayed B cell maturation. These changes in B cells were accompanied by decreases of T helper cell numbers and reduced IgM and IgG titers. A transcriptome analysis of splenic B cells followed by Ingenuity Pathway Analysis (IPA) revealed a set of differentially expressed genes known to play roles in tumorigenesis, cell-proliferation and cell-migration. The most up-regulated transcript gene was Eph receptor A2 (EphA2), a known oncogene, and the most down-regulated transcript was ZBTB16 that codes for a negative transcriptional regulator important in epigenetic chromatin remodeling. IPA identified cAMP-responsive element modulator (CREM) and cAMP-responsive element binding protein 1 (CREB1) as top upstream regulators. Consistently, a MAPPER promoter database analysis showed that all top dysregulated genes had CREM and/or CREB1 binding sites in their promoter regions. In summary, our data showed that chronic TCDD exposure in mice caused suppressed humoral immunity accompanied with profound dysregulation of gene expression in splenic B-lymphocytes, likely through cAMP-dependent pathways. This dysregulation resulted in impairments in T-cell and B-cell differentiation and activation of the tumorigenic transcription program.
Mutations in the maternal effect gene NLRP7 cause biparental hydatidiform mole (HYDM1). HYDM1 is characterized by abnormal growth of placenta and lack of proper embryonic development. The molar tissues are characterized by abnormal methylation patterns at differentially methylated regions (DMRs) of imprinted genes. It is not known whether this occurs before or after fertilization, but the high specificity of this defect to the maternal allele indicates a possible maternal germ line-specific effect. To better understand the unknown molecular mechanism leading to HYDM1, we performed a yeast two-hybrid screen against an ovarian library using NLRP7 as bait. We identified the transcriptional repressor ZBTB16 as an interacting protein of NLRP7 and verified this interaction in mammalian cells by immunoprecipitation and confocal microscopy. Native protein analysis detected NLRP7 and ZBTB16 in a 480kD protein complex and both proteins co-localize in the cytoplasm in juxtanuclear aggregates. HYDM1-causing mutations in NLRP7 did not show altered patterns of interaction with ZBTB16. Hence, the biological significance of the NLRP7-ZBTB16 interaction remains to be revealed. However, a clear effect of harvesting ZBTB16 to the cytoplasm when the NLRP7 protein is overexpressed may be linked to the pathology of the molar pregnancy disease.
(Pro)renin receptor (PRR) has a single transmembrane domain that co-purifies with the vacuolar H(+)-ATPase (V-ATPase). In addition to its role in cellular acidification, V-ATPase has been implicated in membrane fusion and exocytosis via its Vo domain. Results from the present study show that PRR is expressed in pituitary adenoma cells and regulates growth hormone (GH) release via V-ATPase-induced cellular acidification. Positive PRR immunoreactivity was detected more often in surgically resected, growth hormone-producing adenomas (GHomas) than in nonfunctional pituitary adenomas. GHomas strongly expressing PRR showed excess GH secretion, as evidenced by distinctly high plasma GH and insulin-like growth factor-1 levels, as well as an elevated nadir GH in response to the oral glucose tolerance test. Suppression of PRR expression in rat GHoma-derived GH3 cells using PRR siRNA resulted in reduced GH secretion and significantly enhanced intracellular GH accumulation. GH3 treatment with bafilomycin A1, a V-ATPase inhibitor, also blocked GH release, indicating mediation via impaired cellular acidification of V-ATPase. PRR knockdown decreased Atp6l, a subunit of the Vo domain that destabilizes V-ATPase assembly, increased intracellular GH, and decreased GH release. To our knowledge, this is the first report demonstrating a pivotal role for PRR in a pituitary hormone release mechanism.
Toward development of a precision medicine framework for metastatic, castration-resistant prostate cancer (mCRPC), we established a multi-institutional clinical sequencing infrastructure to conduct prospective whole-exome and transcriptome sequencing of bone or soft tissue tumor biopsies from a cohort of 150 mCRPC affected individuals. Aberrations of AR, ETS genes, TP53, and PTEN were frequent (40%-60% of cases), with TP53 and AR alterations enriched in mCRPC compared to primary prostate cancer. We identified new genomic alterations in PIK3CA/B, R-spondin, BRAF/RAF1, APC, β-catenin, and ZBTB16/PLZF. Moreover, aberrations of BRCA2, BRCA1, and ATM were observed at substantially higher frequencies (19.3% overall) compared to those in primary prostate cancers. 89% of affected individuals harbored a clinically actionable aberration, including 62.7% with aberrations in AR, 65% in other cancer-related genes, and 8% with actionable pathogenic germline alterations. This cohort study provides clinically actionable information that could impact treatment decisions for these affected individuals.
Fujii S, Srivastava V, Hegde A, et al.Regulation of AURKC expression by CpG island methylation in human cancer cells.
Tumour Biol. 2015; 36(10):8147-58 [PubMed
] Related Publications
AURKC, a member of the Aurora kinase gene family, is highly expressed in testis but is either moderately expressed or repressed in most somatic cells. Varying expression of AURKC has been observed in human cancers, but the underlying mechanisms of differential expression have been investigated only to a limited extent. We investigated the role of promoter CpG methylation in the regulation of AURKC gene expression in human cancer cells, in relation to a recently reported AURKC transcription repressor PLZF/ZBTB16, implicated in transformation and tumorigenesis. AURKC and PLZF/ZBTB16 expression profiles were investigated in reference to CpG methylation status on the AURKC promoter experimentally, and also in The Cancer Genome Atlas (TCGA) dataset involving multiple cancer types. AURKC promoter showed dense to moderate hypermethylation correlating with low to moderate expression of the gene in normal somatic cells and cancer cell lines, while testis with high expression revealed marked hypo-methylation. Treatment with the demethylating agent, 5-aza-dC, but not the histone deacetylase (HDAC) inhibitor, TSA, led to elevated expression in cancer cell lines, indicating that promoter DNA methylation negatively regulates AURKC expression. High expression of PLZF in PLZF-transfected cells treated with 5-aza-dC only partially repressed expression of AURKC despite 5-aza-dC also inducing elevated PLZF expression. Analyses of the TCGA data showed differential expression of AURKC in multiple cancer types and stronger correlation of AURKC expression with CpG methylation compared to PLZF levels. These findings demonstrate that differential promoter CpG methylation is an important mechanism regulating AURKC expression in cancer cells.
Coltella N, Valsecchi R, Ponente M, et al.Synergistic Leukemia Eradication by Combined Treatment with Retinoic Acid and HIF Inhibition by EZN-2208 (PEG-SN38) in Preclinical Models of PML-RARα and PLZF-RARα-Driven Leukemia.
Clin Cancer Res. 2015; 21(16):3685-94 [PubMed
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PURPOSE: Retinoic acid-arsenic trioxide (ATRA-ATO) combination therapy is the current standard of care for patients with acute promyelocytic leukemia (APL) carrying the oncogenic fusion protein PML-RARα. Despite the high cure rates obtained with this drug combination, resistance to arsenic is recently emerging. Moreover, patients with APL carrying the PLZF-RARα fusion protein are partially resistant to ATRA treatment. Hypoxia-inducible factor-1α (HIF-1α) activation has been recently reported in APL, and EZN-2208 (PEG-SN38) is a compound with HIF-1α inhibitory function currently tested in clinical trials. This study investigates the effect of EZN-2208 in different preclinical APL models, either alone or in combination with ATRA.
EXPERIMENTAL DESIGN: Efficacy of EZN-2208 in APL was measured in vitro by assessing expression of HIF-1α target genes, cell migration, clonogenicity, and differentiation, vis a vis the cytotoxic and cytostatic effects of this compound. In vivo, EZN-2208 was used in mouse models of APL driven by PML-RARα or PLZF-RARα, either alone or in combination with ATRA.
RESULTS: Treatment of APL cell lines with noncytotoxic doses of EZN-2208 causes dose-dependent downregulation of HIF-1α bona fide target genes and affects cell migration and clonogenicity in methylcellulose. In vivo, EZN-2208 impairs leukemia progression and prolongs mice survival in APL mouse models. More importantly, when used in combination with ATRA, EZN-2208 synergizes in debulking leukemia and eradicating leukemia-initiating cells.
CONCLUSIONS: Our preclinical data suggest that the combination ATRA-EZN-2208 may be tested to treat patients with APL who develop resistance to ATO or patients carrying the PLZF-RARα fusion protein.
Song G, Wang L, Bi K, Jiang GRegulation of the C/EBPα signaling pathway in acute myeloid leukemia (Review).
Oncol Rep. 2015; 33(5):2099-106 [PubMed
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The transcription factor CCAAT/enhancer binding protein α (C/EBPα), as a critical regulator of myeloid development, directs granulocyte and monocyte differentiation. Various mechanisms have been identified to explain how C/EBPα functions in patients with acute myeloid leukemia (AML). C/EBPα expression is suppressed as a result of common leukemia-associated genetic and epigenetic alterations such as AML1-ETO, RARα-PLZF or gene promoter methylation. Recent data have shown that ubiquitination modification also contributes to its downregulation. In addition, 10-15% of patients with AML in an intermediate cytogenetic risk subgroup were characterized by mutations of the C/EBPα gene. As a transcription factor, C/EBPα can translocate into the nucleus and further regulate a variety of genes directly or indirectly, which are all key factors for cell differentiation. This review summarizes recent reports concerning the dysregulation of C/EBPα expression at various levels in human AML. The currently available data are persuasive evidence suggesting that impaired abnormal C/EBPα expression contributes to the development of AML, and restoration of C/EBPα expression as well as its function represents a promising target for novel therapeutic strategies in AML.
Ishiguro S, Yoshimura K, Tsunedomi R, et al.Involvement of angiotensin II type 2 receptor (AT2R) signaling in human pancreatic ductal adenocarcinoma (PDAC): a novel AT2R agonist effectively attenuates growth of PDAC grafts in mice.
Cancer Biol Ther. 2015; 16(2):307-16 [PubMed
] Free Access to Full Article Related Publications
We have recently discovered the potential involvement of angiotensin II type 2 receptor (AT2R) signaling in pancreatic cancer using AT2R deficient mice. To examine the involvement of AT2R expression in human PDAC, expressions of AT2R as well as the major angiotensin II receptor (type 1 receptor, AT1R) in human PDAC and adjacent normal tissue was evaluated by immunohistochemistry and real time PCR using surgically dissected human PDAC specimens. In immunohistochemical analysis, relatively strong AT1R expression was detected consistently in both normal pancreas and PDAC areas, whereas moderate AT2R expression was detected in 78.5% of PDAC specimens and 100% of normal area of the pancreas. AT1R, but not AT2R, mRNA levels were significantly higher in the PDAC area than in the normal pancreas. AT2R mRNA levels showed a negative correlation trend with overall survival. In cell cultures, treatment with a novel AT2R agonist significantly attenuated both murine and human PDAC cell growth with negligible cytotoxicity in normal epithelial cells. In a mouse study, administrations of the AT2R agonist in tumor surrounding connective tissue markedly attenuated growth of only AT2R expressing PAN02 murine PDAC grafts in syngeneic mice. The AT2R agonist treatment induced apoptosis primarily in tumor cells but not in stromal cells. Taken together, our findings offer clinical and preclinical evidence for the involvement of AT2R signaling in PDAC development and pinpoint that the novel AT2R agonist could serve as an effective therapeutic for PDAC treatment.
Hui AW, Lau HW, Cao CY, et al.Downregulation of PLZF in human hepatocellular carcinoma and its clinical significance.
Oncol Rep. 2015; 33(1):397-402 [PubMed
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Promyelocytic leukemia zinc finger (PLZF) acts as a tumor-suppressor gene in a series of cancers including prostate, melanoma, colon cancer and leukemia. However, its role in hepatocellular carcinoma (HCC) has not yet been illustrated. The present study aimed to investigate the expression and epigenetic regulation of PLZF as well as its clinical significance in HCC. We found that the expression of PLZF was significantly downregulated in HCC samples at both the RNA level (P<0.001) and protein level compared with these levels in adjacent normal tissues. The relative expression level of PLZF was also positively correlated with the ALP level (P=0.026) noted in the HCC patients. However, hypermethylation was only detected in one out of 5 paired HCC samples, indicating that methylation of the selected promoter region (from -1702 to -1388) may not be the major regulatory mechanism for the downregulation of PLZF in HCC. A receiver operating characteristic (ROC) curve was created to evaluate the diagnostic value for differentiating between HCC and benign diseases. The area under the ROC curve (AUC) for indicating the value of PLZF as an HCC biomarker was 0.794 (95% CI, 0.697-0.892; P<0.001). Taken together, our results suggest that PLZF may play an important role in HCC development and may be a potential biomarker for the diagnosis of HCC.
Choi WI, Kim MY, Jeon BN, et al.Role of promyelocytic leukemia zinc finger (PLZF) in cell proliferation and cyclin-dependent kinase inhibitor 1A (p21WAF/CDKN1A) gene repression.
J Biol Chem. 2014; 289(27):18625-40 [PubMed
] Free Access to Full Article Related Publications
Promyelocytic leukemia zinc finger (PLZF) is a transcription repressor that was initially isolated as a fusion protein with retinoic acid receptor α. PLZF is aberrantly overexpressed in various human solid tumors, such as clear cell renal carcinoma, glioblastoma, and seminoma. PLZF causes cellular transformation of NIH3T3 cells and increases cell proliferation in several cell types. PLZF also increases tumor growth in the mouse xenograft tumor model. PLZF may stimulate cell proliferation by controlling expression of the genes of the p53 pathway (ARF, TP53, and CDKN1A). We found that PLZF can directly repress transcription of CDKN1A encoding p21, a negative regulator of cell cycle progression. PLZF binds to the proximal Sp1-binding GC-box 5/6 and the distal p53-responsive elements of the CDKN1A promoter to repress transcription. Interestingly, PLZF interacts with Sp1 or p53 and competes with Sp1 or p53. PLZF interacts with corepressors, such as mSin3A, NCoR, and SMRT, thereby deacetylates Ac-H3 and Ac-H4 histones at the CDKN1A promoter, which indicated the involvement of the corepressor·HDACs complex in transcription repression by PLZF. Also, PLZF represses transcription of TP53 and also decreases p53 protein stability by ubiquitination. PLZF may act as a potential proto-oncoprotein in various cell types.
Dorantes-Acosta E, Medina-Sanson A, Jaimes-García Y, López-Martínez BClinical features and treatment outcomes of pediatric acute promyelocytic leukemia in a Mexican pediatric hospital.
Rev Invest Clin. 2013 Sep-Oct; 65(5):392-8 [PubMed
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INTRODUCTION: Acute promyelocytic leukemia (APL) is a distinct type of acute myeloid leukemia (AML) characterized by chromosomal translocations involving the retinoid acid receptor α (RARA) gene on chromosome 17. APL is a relatively rare blood disease that is highly curable with current treatment strategies; however, patient outcomes are heterogeneous in countries with limited resources. Promyelocytic leukemia accounts for 20-25% of all AML cases in Latin American countries.
MATERIAL AND METHODS: We conducted a study from July 2007 to July 2012 and applied the IC-APL2006 protocol. This case study reports the results from eleven patients with AML M3 (five males and six females). In all cases, the diagnoses were made by aspirating bone marrow and evaluating the t(15:17) or t(11:17) transcript. In eight cases, the molecular biology-based diagnostics for the PLM-RARa transcript were positive, and they were negative in two cases. One patient was positive for the PLZF-RARa transcript.
RESULTS: The mean WBC at the time of diagnosis was 10.1 x 10(9)/L, and the mean platelet count was 17.1 x 10(9)/L. The mean percentage of abnormal promyelocytes in the bone marrow aspirates was 68%. Of the eleven patients, four presented with disseminated intravascular coagulation. All of the patients began treatment with transretinoic acid (ATRA) (45 mg/m(2)/day), which led to 4 cases of ATRA syndrome. There were 2 relapses, and the patient died in one case. The remaining ten patients were alive after the median follow-up period of 33.6 months (range from 11 to 60 months).
CONCLUSION: The authors report on a series of cases involving pediatric patients with AML M3 seen at a single institution; the patients were stratified and treated with a standard protocol to obtain satisfactory results. Although the number of patients is limited, the health outcomes are relevant. To our knowledge, this is the first series of pediatric APL patients in Mexico who were treated with the IC-APL2006 protocol.
BACKGROUND: Increasing evidence suggests that forkhead box A1 (FOXA1) is frequently dysregulated in many types of human cancers. However, the exact function and mechanism of FOXA1 in human endometrial cancer (EC) remains unclear.
METHODS: FOXA1 expression, androgen receptor (AR) expression, and the relationships of these two markers with clinicopathological factors were determined by immunohistochemistry analysis. FOXA1 and AR were up-regulated by transient transfection with plasmids, and were down-regulated by transfection with siRNA or short hairpin RNA (shRNA). The effects of FOXA1 depletion and FOXA1 overexpression on AR-mediated transcription as well as Notch pathway and their impact on EC cell proliferation were examined by qRT-PCR, western blotting, co-immunoprecipitation, ChIP-PCR, MTT, colony-formation, and xenograft tumor-formation assays.
RESULTS: We found that the expression of FOXA1 and AR in ECs was significantly higher than that in a typical hyperplasia and normal tissues. FOXA1 expression was significantly correlated with AR expression in clinical tissues. High FOXA1 levels positively correlated with pathological grade and depth of myometrial invasion in EC. High AR levels also positively correlated with pathological grade in EC. Moreover, the expression of XBP1, MYC, ZBTB16, and UHRF1, which are downstream targets of AR, was promoted by FOXA1 up-regulation or inhibited by FOXA1 down-regulation. Co-immunoprecipitation showed that FOXA1 interacted with AR in EC cells. ChIP-PCR assays showed that FOXA1 and AR could directly bind to the promoter and enhancer regions upstream of MYC. Mechanistic investigation revealed that over-expression of Notch1 and Hes1 proteins by FOXA1 could be reversed by AR depletion. In addition, we showed that down-regulation of AR attenuated FOXA1-up-regulated cell proliferation. However, AR didn't influence the promotion effect of FOXA1 on cell migration and invasion. In vivo xenograft model, FOXA1 knockdown reduced the rate of tumor growth.
CONCLUSIONS: These results suggest that FOXA1 promotes cell proliferation by AR and activates Notch pathway. It indicated that FOXA1 and AR may serve as potential gene therapy in EC.
Mariani F, Sena P, Magnani G, et al.PLZF expression during colorectal cancer development and in normal colorectal mucosa according to body size, as marker of colorectal cancer risk.
ScientificWorldJournal. 2013; 2013:630869 [PubMed
] Free Access to Full Article Related Publications
Promyelocytic leukemia zinc finger protein (PLZF) is a protein involved in various signaling, growth regulatory, and differentiation pathways, including development/function of some T cells. Here, we aimed at the detection of PLZF during colorectal carcinogenesis, using immunofluorescence, and at the evaluation of the colocalization of PLZF with CD2 and CD56 positive cells (T, γ δ , NK, and NKT cells), using confocal-microscopy, along colorectal carcinogenesis, since its earliest stages, that is, dysplastic aberrant crypt foci (ACF). Furthermore, we analyzed PLZF in the normal colonic mucosa (NM) according to anthropometric parameters of the subject. NM exhibited strong CD56 fluorescent staining. This infiltration was lost in both ACF and colorectal carcinoma (CRC), while PLZF presence increased from NM to ACF and CRC. Strong association was found between CD56+ colonic mucosa cell infiltration and body mass index. Interestingly, an increased stromal PLZF-reactivity was present in NM of obese subjects. This study shows that overexpression of PLZF and exclusion of NK cells in dysplastic microenvironment are very early events in the stepwise sequence leading to CRC and that lower levels of CD56+ cells in NM, together with increased levels of PLZF+ cells, can be a reflection of colon cancer risk due to obesity.
Promyelocytic leukemia zinc finger (PLZF) protein expression is closely related to the progression of human cancers, including prostate cancer (PCa). However, the according context of a signaling pathway for PLZF to suppress prostate tumorigenesis remains greatly unknown. Here we report that PLZF is a downstream mediator of the PTEN signaling pathway in PCa. We found that PLZF expression is closely correlated with PTEN expression in a cohort of prostate cancer specimens. Interestingly, both PTEN rescue and phosphoinositide 3-kinase (PI3K) inhibitor LY294002 treatment increase the PLZF expression in prostate cancer cell lines. Further, luciferase reporter assay and chromatin immunoprecipitation assay demonstrate that FOXO3a, a transcriptional factor phosphorylated by PI3K/AKT, could directly bind to the promoter of PLZF gene. These results indicate that PTEN regulates PLZF expression by AKT/FOXO3a. Moreover, our animal experiments also demonstrate that PLZF is capable of inhibiting prostate tumorigenesis in vivo. Taken together, our study defines a PTEN/PLZF pathway and would shed new lights for developing therapeutic strategy of prostate cancer.
In acute promyelocytic leukemia, granulocytic differentiation is arrested at the promyelocyte stage. The variant t(11;17) translocation produces two fusion proteins, promyelocytic leukemia zinc finger-retinoic acid receptor α (PLZF-RARα) and RARα-PLZF, both of which participate in leukemia development. Here we provide evidence that the activity of CCAAT/enhancer binding protein α (C/EBPα), a master regulator of granulocytic differentiation, is severely impaired in leukemic promyelocytes with the t(11;17) translocation compared with those associated with the t(15;17) translocation. We show that RARα-PLZF inhibits myeloid cell differentiation through interactions with C/EBPα tethered to DNA, using ChIP and DNA capture assays. Furthermore, RARα-PLZF recruits HDAC1 and causes histone H3 deacetylation at C/EBPα target loci, thereby decreasing the expression of C/EBPα target genes. In line with these results, HDAC inhibitors restore in part C/EBPα target gene expression. These findings provide molecular evidence for a mechanism through which RARα-PLZF acts as a modifier oncogene that subverts differentiation in the granulocytic lineage by associating with C/EBPα and inhibiting its activity.
Ono R, Masuya M, Nakajima H, et al.Plzf drives MLL-fusion-mediated leukemogenesis specifically in long-term hematopoietic stem cells.
Blood. 2013; 122(7):1271-83 [PubMed
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Oncogenic transformation requires unlimited self-renewal. Currently, it remains unclear whether a normal capacity for self-renewal is required for acquiring an aberrant self-renewal capacity. Our results in a new conditional transgenic mouse showed that a mixed lineage leukemia (MLL) fusion oncogene, MLL-ENL, at an endogenous-like expression level led to leukemic transformation selectively in a restricted subpopulation of hematopoietic stem cells (HSCs) through upregulation of promyelocytic leukemia zinc finger (Plzf). Interestingly, forced expression of Plzf itself immortalized HSCs and myeloid progenitors in vitro without upregulation of Hoxa9/Meis1, which are well-known targets of MLL fusion proteins, whereas its mutant lacking the BTB/POZ domain did not. In contrast, depletion of Plzf suppressed the MLL-fusion-induced leukemic transformation of HSCs in vitro and in vivo. Gene expression analyses of human clinical samples showed that a subtype of PLZF-high MLL-rearranged myeloid leukemia cells was closely associated with the gene expression signature of HSCs. These findings suggested that MLL fusion protein enhances the self-renewal potential of normal HSCs to develop leukemia, in part through a Plzf-driven self-renewal program.
Wang X, Wang L, Guo S, et al.Hypermethylation reduces expression of tumor-suppressor PLZF and regulates proliferation and apoptosis in non-small-cell lung cancers.
FASEB J. 2013; 27(10):4194-203 [PubMed
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Deregulation of promyelocytic leukemia zinc finger protein (PLZF), a tumor suppressor gene, was reported in different types of solid tumors. This study for the first time explored the reduced expression of PLZF and its effects in non-small-cell lung cancer (NSCLC) carcinogenesis. PLZF was found to be down-regulated by 62.8% in 87.1% of 154 paired NSCLC samples by quantitative real-time PCR, and its expression was found to be associated with the sex of the patient (P=0.02). Further analysis showed that down-regulation of PLZF in 35.6% NSCLC samples (31 out of 87) was triggered by hypermethylation in the promoter region. This was validated by demethylation analysis using the A549 cell line. Dual-luciferase reporter assay indicated that CTCF binding to the promoter region could activate PLZF transcription. Overexpression of PLZF in both A549 and LTEP lung cancer cell lines was found to inhibit proliferation and increase apoptosis. Therefore, reduced expression of PLZF was found to be common in NSCLC. PLZF down-regulation was partially correlated with hypermethylation in the promoter region. Decreased levels of PLZF expression may contribute to the pathogenesis of NSCLC by promoting cell survival. Therefore, the restoration of PLZF expression may serve as a new strategy for NSCLC therapy.
The androgen receptor (AR) and the phosphoinositide 3-kinase (PI3K)/protein kinase B/mammalian target of rapamycin (mTOR) signaling are two of the major proliferative pathways in a number of tissues and are the main therapeutic targets in various disorders, including prostate cancer (PCa). Previous work has shown that there is reciprocal feedback regulation of PI3K and AR signaling in PCa, suggesting that cotargeting both pathways may enhance therapeutic efficacy. Here we show that proteins encoded by two androgen-regulated genes, kallikrein related peptidase 4 (KLK4) and promyelocytic leukemia zinc finger (PLZF), integrate optimal functioning of AR and mTOR signaling in PCa cells. KLK4 interacts with PLZF and decreases its stability. PLZF in turn interacts with AR and inhibits its function as a transcription factor. PLZF also activates expression of regulated in development and DNA damage responses 1, an inhibitor of mTORC1. Thus, a unique molecular switch is generated that regulates both AR and PI3K signaling. Consistently, KLK4 knockdown results in a significant decline in PCa cell proliferation in vitro and in vivo, decreases anchorage-independent growth, induces apoptosis, and dramatically sensitizes PCa cells to apoptosis-inducing agents. Furthermore, in vivo nanoliposomal KLK4 siRNA delivery in mice bearing PCa tumors results in profound remission. These results demonstrate that the activities of AR and mTOR pathways are maintained by KLK4, which may thus be a viable target for therapy.
Petruccelli LA, Pettersson F, Del Rincón SV, et al.Expression of leukemia-associated fusion proteins increases sensitivity to histone deacetylase inhibitor-induced DNA damage and apoptosis.
Mol Cancer Ther. 2013; 12(8):1591-604 [PubMed
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Histone deacetylase inhibitors (HDI) show activity in a broad range of hematologic and solid malignancies, yet the percentage of patients in any given malignancy who experience a meaningful clinical response remains small. In this study, we sought to investigate HDI efficacy in acute myeloid leukemia (AML) cells expressing leukemia-associated fusion proteins (LAFP). HDIs have been shown to induce apoptosis, in part, through accumulation of DNA damage and inhibition of DNA repair. LAFPs have been correlated with a DNA repair-deficient phenotype, which may make them more sensitive to HDI-induced DNA damage. We found that expression of the LAFPs PLZF-RARα, PML-RARα, and RUNX1-ETO (AML1-ETO) increased sensitivity to DNA damage and apoptosis induced by the HDI vorinostat. The increase in apoptosis correlated with an enhanced downregulation of the prosurvival protein BCL2. Vorinostat also induced expression of the cell-cycle regulators p19(INK4D) and p21(WAF1) and triggered a G2-M cell cycle arrest to a greater extent in LAFP-expressing cells. The combination of LAFP and vorinostat further led to a greater downregulation of several base excision repair (BER) enzymes. These BER genes represent biomarker candidates for response to HDI-induced DNA damage. Notably, repair of vorinostat-induced DNA double-strand breaks was found to be impaired in PLZF-RARα-expressing cells, suggesting a mechanism by which LAFP expression and HDI treatment cooperate to cause an accumulation of damaged DNA. These data support the continued study of HDI-based treatment regimens in LAFP-positive AMLs.
The (pro)renin receptor ((P)RR) signaling is involved in different pathophysiologies ranging from cardiorenal end-organ damage via diabetic retinopathy to tumorigenesis. We have previously shown that the transcription factor promyelocytic leukemia zinc finger (PLZF) is an adaptor protein of the (P)RR. Furthermore, recent publications suggest that major functions of the (P)RR are mediated ligand-independently by its transmembrane and intracellular part, which acts as an accessory protein of V-ATPases. The transcriptome and recruitmentome downstream of the V-ATPase function and PLZF in the context of the (P)RR are currently unknown. Therefore, we performed a set of microarray and chromatin-immunoprecipitation (ChIP)-chip experiments using siRNA against the (P)RR, stable overexpression of PLZF, the PLZF translocation inhibitor genistein and the specific V-ATPase inhibitor bafilomycin to dissect transcriptional pathways downstream of the (P)RR. We were able to identify distinct and overlapping genetic signatures as well as novel real-time PCR-validated target genes of the different molecular functions of the (P)RR. Moreover, bioinformatic analyses of our data confirm the role of (P)RŔs signal transduction pathways in cardiovascular disease and tumorigenesis.
Hechtman JF, Beasley MB, Kinoshita Y, et al.Promyelocytic leukemia zinc finger and histone H1.5 differentially stain low- and high-grade pulmonary neuroendocrine tumors: a pilot immunohistochemical study.
Hum Pathol. 2013; 44(7):1400-5 [PubMed
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Promyelocytic leukemia zinc finger is a zinc finger transcription factor that functions as a transcriptional repressor. Its expression has been shown to be down-regulated in hematopoietic, melanocytic, and mesothelial malignancies. Histone H1.5 is a variant of histone H1, a family of linker proteins that organizes chromosomes into higher order structures. Its function is of key importance in gene expression and has been linked to more aggressive forms of prostatic carcinoma. This study aimed to investigate the immunohistochemical detectability of promyelocytic leukemia zinc finger and histone H1.5 in pulmonary neuroendocrine tumors, comprising 11 carcinoid tumorlets, 24 typical carcinoids, 12 atypical carcinoids, 20 small cell carcinomas, 11 large cell neuroendocrine carcinomas, and 2 combined small cell carcinomas-large cell neuroendocrine carcinomas. Promyelocytic leukemia zinc finger immunohistochemistry revealed moderate or strong nuclear staining in all carcinoid tumorlets, 23 of 24 typical carcinoids, and 7 of 12 atypical carcinoids in contrast to 9 of 11 large cell neuroendocrine carcinomas, all small cell carcinoma, and both combined small cell carcinoma-large cell neuroendocrine carcinomas, which showed no nuclear immunoreactivity. Histone H1.5 immunohistochemistry revealed only focal or no immunoreactivity in all carcinoid tumorlets and 19 of 24 typical carcinoids, whereas 7 of 12 atypical carcinoids, 19 of 20 small cell carcinomas, 10 of 11 large cell neuroendocrine carcinomas, and both combined small cell carcinomas-large cell neuroendocrine carcinomas displayed positive (≥ 10%) nuclear immunoreactivity-ranging from a minority of weak staining to a majority of strong staining cases. Our data suggest that the relative expression ratios of promyelocytic leukemia zinc finger and histone H1.5 may correlate with grade of pulmonary neuroendocrine tumors. Immunohistochemical stains for these markers, especially on small biopsies with crush artifact, may prove to be diagnostically useful.