Research IndicatorsGraph generated 01 September 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 (5)
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
Cancer Genome Anatomy Project, NCI
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: IGF2R (cancer-related)
Lautem A, Simon F, Hoppe-Lotichius M, et al.Expression and prognostic significance of insulin‑like growth factor-2 receptor in human hepatocellular carcinoma and the influence of transarterial chemoembolization.
Oncol Rep. 2019; 41(4):2299-2310 [PubMed
] Related Publications
Hepatocellular carcinoma (HCC) is one of the most common human malignancies, the incidence of which is growing worldwide. The prognosis of HCC is very poor and it is often accompanied by a high rate of recurrence. Conventional chemotherapeutic approaches are largely inefficient. In order to develop novel effective methods for the early detection and prognosis of HCC, novel markers and therapeutic targets are urgently required. The present study focused on the effects of the expression of the tumor suppressor gene insulin‑like growth factor‑2 receptor (IGF2R) on patient survival and tumor recurrence in patients with HCC; this study paid specific attention to the influence of transarterial chemoembolization (TACE) prior to surgery. The mRNA expression levels of IGF2R were measured in primary human HCC and corresponding non‑neoplastic tumor‑surrounding tissue (TST) by reverse transcription‑polymerase chain reaction (RT‑PCR) (n=92). Subsequently, the associations between IGF2R expression and clinicopathological parameters, outcomes of HCC and TACE pretreatment prior to surgery were determined. Furthermore, the effects of the IGF2R gene polymorphisms rs629849 and rs642588 on susceptibility and on clinicopathological features of HCC were investigated. RT‑PCR demonstrated that the mRNA expression levels of IGF2R were downregulated in HCC compared with in TST samples (P=0.004), which was associated with a worse recurrence‑free survival of patients with HCC (P=0.002) and a lower occurrence of cirrhosis (P=0.05). TACE‑pretreated patients with HCC (n=26) exhibited significantly higher IGF2R mRNA expression in tumor tissues (P=0.019). In addition, significantly more patients with HCC in the TACE‑pretreated group exhibited upregulated IGF2R mRNA expression compared with in the non‑treated patients (P=0.032). The IGF2R SNPs rs629849 and rs642588 were not significantly associated with HCC risk, whereas a homozygous IGF2R rs629849 GG genotype was associated with a significantly elevated risk of non‑viral liver cirrhosis (P=0.05). In conclusion, these data suggested an important role for IGF2R expression in HCC, particularly with regards to TACE treatment prior to surgery.
BACKGROUND: Primary mucosal melanoma (MM) is a rare subtype of melanoma that arises from melanocytes in the mucosa. MM has not been well profiled for mutations and its etiology is not well understood, rendering current treatment strategies unsuccessful. Hence, we investigated mutational landscape for MM to understand its etiology and to clarify mutations that are potentially relevant for MM treatment.
METHODS: Forty one MM and 48 cutaneous melanoma (CM) tissues were profiled for mutations using targeted deep next-generation sequencing (NGS) for 89 cancer-related genes. A total of 997 mutations within exons were analyzed for their mutational spectrum and prevalence of mutation, and 685 non-synonymous variants were investigated to identify mutations in individual genes and pathways. PD-L1 expression from 21 MM and 18 CM were assessed by immunohistochemistry.
RESULTS: Mutational spectrum analysis revealed a lower frequency of UV-induced DNA damage in MM than in CM (p = 0.001), while tobacco exposure was indicated as a potential etiologic factor for MM. In accordance with low UV damage signatures, MM demonstrated an overall lower number of mutations compared to CM (6.5 mutations/Mb vs 14.8 mutations/Mb, p = 0.001), and less PD-L1 expression (p = 0.003). Compared to CM, which showed frequent mutations in known driver genes (BRAF 50.0%, NRAS 29.2%), MM displayed lower mutation frequencies (BRAF; 12.2%, p < 0.001, NRAS; 17.1%), and was significantly more enriched for triple wild-type (no mutations in BRAF, RAS, or NF1, 70.7% vs 25.0%, p < 0.001), IGF2R mutation (31.7% vs 6.3%, p = 0.002), and KIT mutation (9.8% vs 0%, p = 0.042). Of clinical relevance, presence of DCC mutations was significantly associated with poorer overall survival in MM (log-rank test, p = 0.02). Furthermore, mutational spectrum analysis distinguished primary anorectal MM from CM metastasized to the bowel (spectrum analysis p < 0.001, number of mutations p = 0.002).
CONCLUSIONS: These findings demonstrated a potential etiologic factor and driver mutation for MM and strongly suggested that MM initiation or progression involves distinct molecular-mechanisms from CM. This study also identified mutational signatures that are clinically relevant for MM treatment.
Chen H, Wang J, Zhuang Y, Wu HIdentification of the potential molecular mechanism and driving mutations in the pathogenesis of familial intestinal gastric cancer by whole exome sequencing.
Oncol Rep. 2018; 40(4):2316-2324 [PubMed
] Related Publications
The genetic alterations in familial intestinal gastric cancer (FIGC) have not been clearly understood. Aiming to explore the molecular basis and the driving mutations underlying the pathogenesis of FIGC, we performed exome sequencing of the blood samples of the members of an extended family with FIGC. The differences in mutation patterns between family members with gastric cancer and controls were analysed and the overlapped variants were screened by comparing previously published data for blood and tumours from gastric cancer patients. The overlapped genes harbouring insertions‑deletions (INDELs) and single‑nucleotide variants (SNVs) were subjected to function, pathway and network analysis. The INDELs were enriched in DNA packaging and in the neurological system process related to the biological process (BP), while SNVs were closely related to cell‑function‑related BPs. ESR was the significant node with marked centrality in the SNV network. ERK 1/2 was the hub node in the INDEL network, interacting with EZK and IGF2R. Sequencing analysis revealed ESR1 homozygous mutations in exon 1 (216G > C) and exon 10 (2234C > T) and EZR1 heterozygous deletion of 68‑69 GT nucleotides in exon 13 of the family members. The IGF2R gene only demonstrated a mutation in exon 48 of the propositus. All hub proteins had direct or indirect interactions in the protein‑protein interaction network.
Liu L, Yu D, Shi H, et al.Reduced lncRNA Aim enhances the malignant invasion of triple-negative breast cancer cells mainly by activating Wnt/β-catenin/mTOR/PI3K signaling.
Pharmazie. 2017; 72(10):599-603 [PubMed
] Related Publications
Increasing evidence has suggested the important role of lncRNAs in the progression of triple-negative breast cancer (TNBC). In the current study, we first demonstrated that the expression of Airn was reduced in TNBC tissues and cells. Our data showed that the level of Airn was reduced in TNBC tissues and cell lines compared with that of normal control. Furthermore, silencing of Airn markedly enhanced MDA-MB-231 cell migration. Meanwhile, knockdown of Airn significantly increased MDA-MB-231 cell invasion. Western blot analysis showed that knockdown of Airn markedly enhanced the activation of Wnt/β-catenin/mTOR/PI3K in both MDA-MB-231 cells. Moreover, real time PCR analysis showed that the mRNA level of IGF2R was significantly enhanced when Airn was silenced in MDA-MB-231 cells. In addition, overexpression of IGF2R significantly increased MDA-MB-231 cell migration and invasion. To further explore whether Airn activated Wnt/β-catenin/mTOR/PI3K signaling independent of IGF-2R, a specific siRNA targeting IGF2R was selected. Western blot analysis showed that Wnt/β-catenin/mTOR/PI3K signaling could be largely activated in MDA-MB-231 cells transfected with siRNA targeting Airn, even when the protein level of IGF2R was silenced. In summary, decreased expression of lncRNA Aim enhanced the malignant invasion of triple-negative breast cancer cells mainly by activating Wnt/β-catenin/mTOR/PI3K signaling independent of Igf2R.
Vacher S, Castagnet P, Chemlali W, et al.High AHR expression in breast tumors correlates with expression of genes from several signaling pathways namely inflammation and endogenous tryptophan metabolism.
PLoS One. 2018; 13(1):e0190619 [PubMed
] Free Access to Full Article Related Publications
Increasing epidemiological and animal experimental data provide substantial support for the role of aryl hydrocarbon receptor (AhR) in mammary tumorigenesis. The effects of AhR have been clearly demonstrated in rodent models of breast carcinogenesis and in several established human breast cancer cell lines following exposure to AhR ligands or AhR overexpression. However, relatively little is known about the role of AhR in human breast cancers. AhR has always been considered to be a regulator of toxic and carcinogenic responses to environmental contaminants such as TCDD (dioxin) and benzo[a]pyrene (BaP). The aim of this study was to identify the type of breast tumors (ERα-positive or ERα-negative) that express AHR and how AhR affects human tumorigenesis. The levels of AHR, AHR nuclear translocator (ARNT) and AHR repressor (AHRR) mRNA expression were analyzed in a cohort of 439 breast tumors, demonstrating a weak association between high AHR expression and age greater than fifty years and ERα-negative status, and HR-/ERBB2 breast cancer subtypes. AHRR mRNA expression was associated with metastasis-free survival, while AHR mRNA expression was not. Immunohistochemistry revealed the presence of AhR protein in both tumor cells (nucleus and/or cytoplasm) and the tumor microenvironment (including endothelial cells and lymphocytes). High AHR expression was correlated with high expression of several genes involved in signaling pathways related to inflammation (IL1B, IL6, TNF, IL8 and CXCR4), metabolism (IDO1 and TDO2 from the kynurenine pathway), invasion (MMP1, MMP2 and PLAU), and IGF signaling (IGF2R, IGF1R and TGFB1). Two well-known ligands for AHR (TCDD and BaP) induced mRNA expression of IL1B and IL6 in an ERα-negative breast tumor cell line. The breast cancer ER status likely influences AhR activity involved in these signaling pathways. The mechanisms involved in AhR activation and target gene expression in breast cancers are also discussed.
Developing a system of molecular subtyping for endometrial tumors might improve insight into disease etiology and clinical prediction of patient outcomes. High body mass index (BMI) has been implicated in development of endometrial cancer through hormonal pathways and might influence tumor expression of biomarkers involved in BMI-sensitive pathways. We evaluated whether endometrial tumor expression of 7 markers from BMI-sensitive pathways of insulin resistance could effectively characterize molecular subtypes: adiponectin receptor 1, adiponectin receptor 2, leptin receptor, insulin receptor (beta subunit), insulin receptor substrate 1, insulin-like growth factor 1 receptor, and insulin-like growth factor 2 receptor. Using endometrial carcinoma tissue specimens from a case-only prospective sample of 360 women from the Nurses' Health Study, we scored categorical immunohistochemical measurements of protein expression for each marker. Logistic regression was used to estimate associations between endometrial cancer risk factors, especially BMI, and tumor marker expression. Proportional hazard modeling was performed to estimate associations between marker expression and time to all-cause mortality as well as time to endometrial cancer-specific mortality. No association was observed between BMI and tumor expression of any marker. No marker was associated with time to either all-cause mortality or endometrial cancer-specific mortality in models with or without standard clinical predictors of patient mortality (tumor stage, grade, and histologic type). It did not appear that any of the markers evaluated here could be used effectively to define molecular subtypes of endometrial cancer.
Neuzillet Y, Chapeaublanc E, Krucker C, et al.IGF1R activation and the in vitro antiproliferative efficacy of IGF1R inhibitor are inversely correlated with IGFBP5 expression in bladder cancer.
BMC Cancer. 2017; 17(1):636 [PubMed
] Free Access to Full Article Related Publications
BACKGROUND: The insulin growth factor (IGF) pathway has been proposed as a potential therapeutic target in bladder cancer. We characterized the expression of components of the IGF pathway - insulin growth factor receptors (INSR, IGF1R, IGF2R), ligands (INS, IGF1, IGF2), and binding proteins (IGFBP1-7, IGF2BP1-3) - in bladder cancer and its correlation with IGF1R activation, and the anti-proliferative efficacy of an IGF1R kinase inhibitor in this setting.
METHODS: We analyzed transcriptomic data from two independent bladder cancer datasets, corresponding to 200 tumoral and five normal urothelium samples. We evaluated the activation status of the IGF pathway in bladder tumors, by assessing IGF1R phosphorylation and evaluating its correlation with mRNA levels for IGF pathway components. We finally evaluated the correlation between inhibition of proliferation by a selective inhibitor of the IGF1R kinase (AEW541), reported in 13 bladder cancer derived cell lines by the Cancer Cell Line Encyclopedia Consortium and mRNA levels for IGF pathway components.
RESULTS: IGF1R expression and activation were stronger in non-muscle-invasive than in muscle-invasive bladder tumors. There was a significant inverse correlation between IGF1R phosphorylation and IGFBP5 expression in tumors. Consistent with this finding, the inhibition of bladder cell line viability by IGF1R inhibitor was also inversely correlated with IGFBP5 expression.
CONCLUSION: The IGF pathway is activated and therefore a potential therapeutic target for non muscle-invasive bladder tumors and IGFBP5 could be used as a surrogate marker for predicting tumor sensitivity to anti-IGF therapy.
Pickard A, Durzynska J, McCance DJ, Barton ERThe IGF axis in HPV associated cancers.
Mutat Res Rev Mutat Res. 2017 Apr - Jun; 772:67-77 [PubMed
] Related Publications
Human papillomaviruses (HPV) infect and replicate in stratified epithelium at cutaneous and mucosal surfaces. The proliferation and maintenance of keratinocytes, the cells which make up this epithelium, are controlled by a number of growth factor receptors such as the keratinocyte growth factor receptor (KGFR, also called fibroblast growth factor receptor 2b (FGFR2b)), the epithelial growth factor receptor (EGFR) and the insulin-like growth factor receptors 1 and 2 (IGF1R and IGF2R). In this review, we will delineate the mutation, gene transcription, translation and processing of the IGF axis within HPV associated cancers. The IGFs are key for developmental and postnatal growth of almost all tissues; we explore whether this crucial axis has been hijacked by HPV.
Malignant rhabdoid tumors (MRTs) are rare, lethal, pediatric tumors predominantly found in the kidney, brain and soft tissues. MRTs are driven by loss of tumor suppressor SNF5/INI1/SMARCB1/BAF47. The prognosis of MRT is poor using currently available treatments, so new treatment targets need to be identified to expand treatment options for patients experiencing chemotherapy resistance. The growth hormone insulin-like growth factor 2 (IGF2) signaling pathway is a promising target to overcome drug resistance in many cancers. Here, we evaluated the role of IGF2 axis in MRT cell proliferation. We showed that microenvironment stress, including starvation treatment and chemotherapy exposure, lead to elevated expression of IGF2 in the SNF5-deficient MRT cell line. The autocrine IGF2, in turn, activated insulin-like growth factor 1 receptor (IGF1R), insulin receptor (INSR), followed by PI3K/AKT pathway and RAS/ERK pathway to promote cancer cell proliferation and survival. We further demonstrated that impairment of IGF2 signaling by IGF2 neutralizing antibody, IGF1R inhibitor NVP-AEW541 or AKT inhibitor MK-2206 2HCl treatment prevented MRT cell growth in vitro. Taken together, our characterization of this axis defines a novel mechanism for MRT cell growth in the microenvironment of stress. Our results also demonstrated the necessity to test the treatment effect targeting this axis in future research.
Verbeek RE, Siersema PD, Vleggaar FP, et al.Toll-like Receptor 2 Signalling and the Lysosomal Machinery in Barrett's Esophagus.
J Gastrointestin Liver Dis. 2016; 25(3):273-82 [PubMed
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BACKGROUND AND AIMS: Inflammation plays an important role in the development of esophageal adenocarcinoma and its metaplastic precursor lesion, Barrett's esophagus. Toll-like receptor (TLR) 2 signalling and lysosomal function have been linked to inflammation-associated carcinogenesis. We examined the expression of TLR2 in the esophagus and the effect of long-term TLR2 activation on morphological changes and expression of factors involved in lysosomal function in a Barrett's esophagus epithelium cell line.
METHODS: TLR2 expression in normal squamous esophagus, reflux esophagitis, Barrett's esophagus and esophageal adenocarcinoma biopsies was assessed with Q-RT-PCR, in situ hybridization and immunohistochemistry. Barrett's esophagus epithelium cells (BAR-T) were incubated with acid and bile salts in the presence or absence of the TLR2 agonist Pam3CSK4 for a period up to 4 weeks. Morphological changes were assessed with electron microscopy, while Q-RT-PCR was used to determine the expression of lysosomal enzymes (Cathepsin B and C) and factors involved in endocytosis (LAMP-1 and M6PR) and autophagy (LC3 and Rab7).
RESULTS: TLR2 was expressed in normal squamous esophagus, reflux esophagitis, Barrett's esophagus but was most prominent in esophageal adenocarcinoma. Long-term TLR2 activation in acid and bile salts exposed BAR-T cells resulted in more and larger lysosomes, more mitochondria and increased expression of LAMP-1, M6PR, Cathepsin B and C when compared to BAR-T cells incubated with acid and bile salts but no TLR2 agonist. Factors associated with autophagy (LC3 and Rab7) expression remained largely unchanged.
CONCLUSION: Activation of TLR2 in acid and bile salts exposed Barrett epithelium cells resulted in an increased number of mitochondria and lysosomes and increased expression of lysosomal enzymes and factors involved in endocytosis.
Dror S, Sander L, Schwartz H, et al.Melanoma miRNA trafficking controls tumour primary niche formation.
Nat Cell Biol. 2016; 18(9):1006-17 [PubMed
] Related Publications
Melanoma originates in the epidermis and becomes metastatic after invasion into the dermis. Prior interactions between melanoma cells and dermis are poorly studied. Here, we show that melanoma cells directly affect the formation of the dermal tumour niche by microRNA trafficking before invasion. Melanocytes, cells of melanoma origin, are specialized in releasing pigment vesicles, termed melanosomes. In melanoma in situ, we found melanosome markers in distal fibroblasts before melanoma invasion. The melanosomes carry microRNAs into primary fibroblasts triggering changes, including increased proliferation, migration and pro-inflammatory gene expression, all known features of cancer-associated fibroblasts (CAFs). Specifically, melanosomal microRNA-211 directly targets IGF2R and leads to MAPK signalling activation, which reciprocally encourages melanoma growth. Melanosome release inhibitor prevented CAF formation. Since the first interaction of melanoma cells with blood vessels occurs in the dermis, our data suggest an opportunity to block melanoma invasion by preventing the formation of the dermal tumour niche.
Yermachenko A, Dvornyk VUGT2B4 previously implicated in the risk of breast cancer is associated with menarche timing in Ukrainian females.
Gene. 2016; 590(1):85-9 [PubMed
] Related Publications
Age at menarche (AAM) is a multifactorial trait that is regulated by dozens environmental and genetic factors. Recent meta-analysis of GWAS showed significant association of 106 loci with AAM. These polymorphisms need replicating in different ethnic populations in order to confirm their association with menarche timing. This study was aimed to replicate 53 polymorphisms that were previously associated with AAM. DNA samples were collected from 416 Ukrainian young females for further genotyping. After data quality control 47 polymorphisms remained for the association analysis using the linear regression model. SNP rs13111134 located in UGT2B4 showed the most significant association with AAM (0.431years per allele A, padj=0.044 after the Bonferroni correction). Polymorphisms rs7589318 in POMC, rs11724758 in FABP2, rs7753051 in IGF2R, rs2288696 in FGFR1 and rs12444979 in GPRC5B may also contribute to menarche timing. However, none of these associations remained significant after the Bonferroni correction for multiple testing. The obtained results provide evidence that UGT2B4, which was previously associated with predisposition to breast cancer, may play a role in the onset of menarche.
Cancer biomarkers with a strong predictive power for diagnosis/prognosis and a potential to be therapeutic targets have not yet been fully established. Here we employed a loss-of-function screen in glioblastoma (GBM), an infiltrative brain tumor with a dismal prognosis, and identified 20 survival kinase genes (SKGs). Survival analyses using The Cancer Genome Atlas (TCGA) datasets revealed that the expression of CDCP1, CDKL5, CSNK1E, IRAK3, LATS2, PRKAA1, STK3, TBRG4, and ULK4 stratified GBM prognosis with or without temozolomide (TMZ) treatment as a covariate. For the first time, we found that GBM patients with a high level of NEK9 and PIK3CB had a greater chance of having recurrent tumors. The expression of CDCP1, IGF2R, IRAK3, LATS2, PIK3CB, ULK4, or VRK1 in primary GBM tumors was associated with recurrence-related prognosis. Notably, the level of PIK3CB in recurrent tumors was much higher than that in newly diagnosed ones. Congruent with these results, genes in the PI3K/AKT pathway showed a significantly strong correlation with recurrence rate, further highlighting the pivotal role of PIK3CB in the disease progression. Importantly, 17 SKGs together presented a novel GBM prognostic signature. SKGs identified herein are associated with recurrence rate and present prognostic significance in GBM, thereby becoming attractive therapeutic targets.
Jahn SW, Kashofer K, Thüringer A, et al.Mutation Profiling of Usual Ductal Hyperplasia of the Breast Reveals Activating Mutations Predominantly at Different Levels of the PI3K/AKT/mTOR Pathway.
Am J Pathol. 2016; 186(1):15-23 [PubMed
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Usual ductal hyperplasia (UDH) of the breast is generally regarded as a nonneoplastic proliferation, albeit loss of heterozygosity has long been reported in a part of these lesions. To gain deeper insights into the molecular drivers of these lesions, an extended mutation profiling was performed. The coding regions of 409 cancer-related genes were investigated by next-generation sequencing in 16 cases of UDH, nine unassociated with neoplasia (classic) and seven arising within papillomas. Phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin (mTOR) activation was investigated by phosphorylated AKT, mTOR, and S6 immunohistochemistry. Of 16 lesions, 10 (63%) were mutated; 56% of classic lesions were unassociated with neoplasia, and 71% of lesions arose in papillomas. Fourteen missense mutations were detected: PIK3CA [6 (43%) of 14], AKT1 [2 (14%) of 14], as well as GNAS, MTOR, PIK3R1, LPHN3, LRP1B, and IGF2R [each 1 (7%) of 14]. Phosphorylated mTOR was seen in 83% and phosphorylated S6 in 86% of evaluable lesions (phospho-AKT staining was technically uninterpretable). In conclusion, UDH displays mutations of the phosphatidylinositol 3-kinase/AKT/mTOR axis at different levels, with PIK3R1, MTOR, and GNAS mutations not previously described. Specifically, oncogenic G-protein activation represents a yet unrecognized route to proliferation in UDH. On the basis of evidence of activating mutations, loss of heterozygosity, and a mass forming proliferation, we propose that UDH is most appropriately viewed as an early neoplastic intraductal proliferation.
We sought to investigate genetic variation in hormone pathways in relation to risk of overall and subtype-specific breast cancer in women of African ancestry (AA). Genotyping and imputation yielded data on 143,934 SNPs in 308 hormone-related genes for 3663 breast cancer cases (1098 ER-, 1983 ER+, 582 ER unknown) and 4687 controls from the African American Breast Cancer Epidemiology and Risk (AMBER) Consortium. AMBER includes data from four large studies of AA women: the Carolina Breast Cancer Study, the Women's Circle of Health Study, the Black Women's Health Study, and the Multiethnic Cohort Study. Pathway- and gene-based analyses were conducted, and single-SNP tests were run for the top genes. There were no strong associations at the pathway level. The most significantly associated genes were GHRH, CALM2, CETP, and AKR1C1 for overall breast cancer (gene-based nominal p ≤ 0.01); NR0B1, IGF2R, CALM2, CYP1B1, and GRB2 for ER+ breast cancer (p ≤ 0.02); and PGR, MAPK3, MAP3K1, and LHCGR for ER- disease (p ≤ 0.02). Single-SNP tests for SNPs with pairwise linkage disequilibrium r (2) < 0.8 in the top genes identified 12 common SNPs (in CALM2, CETP, NR0B1, IGF2R, CYP1B1, PGR, MAPK3, and MAP3K1) associated with overall or subtype-specific breast cancer after gene-level correction for multiple testing. Rs11571215 in PGR (progesterone receptor) was the SNP most strongly associated with ER- disease. We identified eight genes in hormone pathways that contain common variants associated with breast cancer in AA women after gene-level correction for multiple testing.
Mohlin S, Hamidian A, von Stedingk K, et al.PI3K-mTORC2 but not PI3K-mTORC1 regulates transcription of HIF2A/EPAS1 and vascularization in neuroblastoma.
Cancer Res. 2015; 75(21):4617-28 [PubMed
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Hypoxia-inducible factor (HIF) is a master regulator of cellular responses to oxygen deprival with a critical role in mediating the angiogenic switch in solid tumors. Differential expression of the HIF subunits HIF1α and HIF2α occurs in many human tumor types, suggesting selective implications to biologic context. For example, high expression of HIF2α that occurs in neuroblastoma is associated with stem cell-like features, disseminated disease, and poor clinical outcomes, suggesting pivotal significance for HIF2 control in neuroblastoma biology. In this study, we provide novel insights into how HIF2α expression is transcriptionally controlled by hypoxia and how this control is abrogated by inhibition of insulin-like growth factor-1R/INSR-driven phosphoinositide 3-kinase (PI3K) signaling. Reducing PI3K activity was sufficient to decrease HIF2α mRNA and protein expression in a manner with smaller and less vascularized tumors in vivo. PI3K-regulated HIF2A mRNA expression was independent of Akt or mTORC1 signaling but relied upon mTORC2 signaling. HIF2A mRNA was induced by hypoxia in neuroblastoma cells isolated from metastatic patient-derived tumor xenografts, where HIF2A levels could be reduced by treatment with PI3K and mTORC2 inhibitors. Our results suggest that targeting PI3K and mTORC2 in aggressive neuroblastomas with an immature phenotype may improve therapeutic efficacy.
Kashyap MKRole of insulin-like growth factor-binding proteins in the pathophysiology and tumorigenesis of gastroesophageal cancers.
Tumour Biol. 2015; 36(11):8247-57 [PubMed
] Related Publications
The insulin family of proteins include insulin-like growth factor binding proteins (IGFBPs) that are classified into two groups based on their differential affinities to IGFs: IGF high-affinity binding proteins (IGFBP1-6) and IGF low-affinity IGFBP-related proteins (IGFBP-rP1-10). IGFBPs interact with many proteins, including their canonical ligands insulin-like growth factor 1 (IGF-I) and IGF-II. Together with insulin-like growth factor 1 (IGF1) receptor (IGF1R), IGF2R, and ligands (IGF1 and IGF2), IGFBPs participate in a complex signaling axis called IGF-IGFR-IGFBP. Numerous studies have demonstrated that the IGF-IGFR-IGFBP axis is relevant in gastrointestinal (GI) and other cancers. The presence of different IGFBPs have been reported in gastrointestinal cancers, including esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAD or EAC), and gastric adenocarcinoma (GAD or GAC). A literature-based survey clearly indicates that an urgent need exists for a focused review of the role of IGFBPs in gastrointestinal cancers. The aim of this review is to present the biochemical and molecular characteristics of IGFBPs with an emphasis specifically on the role of these proteins in the pathophysiology and tumorigenesis of gastroesophageal cancers.
Amyloid β (Aβ) peptides originating from amyloid precursor protein (APP) in the endosomal-lysosomal compartments play a critical role in the development of Alzheimer's disease (AD), the most common type of senile dementia affecting the elderly. Since insulin-like growth factor II (IGF-II) receptors facilitate the delivery of nascent lysosomal enzymes from the trans-Golgi network to endosomes, we evaluated their role in APP metabolism and cell viability using mouse fibroblast MS cells deficient in the murine IGF-II receptor and corresponding MS9II cells overexpressing the human IGF-II receptors. Our results show that IGF-II receptor overexpression increases the protein levels of APP. This is accompanied by an increase of β-site APP-cleaving enzyme 1 levels and an increase of β- and γ-secretase enzyme activities, leading to enhanced Aβ production. At the cellular level, IGF-II receptor overexpression causes localization of APP in perinuclear tubular structures, an increase of lipid raft components, and increased lipid raft partitioning of APP. Finally, MS9II cells are more susceptible to staurosporine-induced cytotoxicity, which can be attenuated by β-secretase inhibitor. Together, these results highlight the potential contribution of IGF-II receptor to AD pathology not only by regulating expression/processing of APP but also by its role in cellular vulnerability.
Vaillant O, El Cheikh K, Warther D, et al.Mannose-6-phosphate receptor: a target for theranostics of prostate cancer.
Angew Chem Int Ed Engl. 2015; 54(20):5952-6 [PubMed
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The development of personalized and non-invasive cancer therapies based on new targets combined with nanodevices is a major challenge in nanomedicine. In this work, the over-expression of a membrane lectin, the cation-independent mannose 6-phosphate receptor (M6PR), was specifically demonstrated in prostate cancer cell lines and tissues. To efficiently target this lectin a mannose-6-phosphate analogue was synthesized in six steps and grafted onto the surface of functionalized mesoporous silica nanoparticles (MSNs). These MSNs were used for in vitro and ex vivo photodynamic therapy to treat prostate cancer cell lines and primary cell cultures prepared from patient biopsies. The results demonstrated the efficiency of M6PR targeting for prostate cancer theranostic.
Tian Z, Yao G, Song H, et al.IGF2R expression is associated with the chemotherapy response and prognosis of patients with advanced NSCLC.
Cell Physiol Biochem. 2014; 34(5):1578-88 [PubMed
] Related Publications
BACKGROUND: Insulin-like growth factor (IGF) pathway has been suggested as a new molecular target for the treatment of cancer including Non-small cell lung cancer (NSCLC). We postulated that IGF-2 receptor (IGF2R) may be associated with treatment response and prognosis of NSCLC patients receiving chemotherapy.
METHODS: A total of 464 patients with inoperable advanced stage of NSCLC were enrolled. All patients received platinum-based chemotherapy. Meanwhile, the IGF2R expression in tumor samples was detected by Immunohistochemical analysis. The IGF2R expression was inhibited in several human NSCLC cell lines (H292, A549, NCI-H460, Calu-3 and NCI-H23) after small interfering RNA (siRNA) transfection and the cellular biology behavior were evaluated.
RESULTS: Of all NSCLC patients, 204 had high IGF2R expression and 260 had low IGF2R expression. The low IGF2R expression was significantly associated with the smoking status, higher tumor stage, and poorer differentiation status of these patients. Notably, we found that the low IGF2R expression was closely associated with the chemotherapy response in NSCLC patients. Patients with low IGF2R expressions had a poorer prognosis than those with high IGF2R expressions. IGF2R inhibition by si-RNA technique in NSCLC cell lines increased the proliferation, migration and invasion abilities, but reduced the apoptosis rate. IGF2R silencing significantly enhanced the chemo-resistance of NSCLC cell lines to cisplatin treatment.
CONCLUSION: The IGF2R expression in tumor is associated with the chemotherapy response and prognosis of Patients with advanced NSCLC.
Xie HY, Xing CY, Wei BJ, et al.Association of IGF1R polymorphisms with the development of HBV-related hepatocellular carcinoma.
Tissue Antigens. 2014; 84(3):264-70 [PubMed
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Although the involvement of insulin-like signaling in cancer has been well documented in various types of cancers, the association between the genetic variants in the insulin-like signaling and the development of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) remains unclear. In this study, a total of 498 individuals including 173 HBV related cirrhosis patients, 171 HBV-related HCC patients, and 154 healthy controls were enrolled. Sixteen single nucleotide polymorphisms (SNPs) in IGF1, IGF2, IGF1R and IGF2R have been genotyped by employing SNaPshot assays. We found A/A genotype at rs3743251 of IGF1R was negatively associated with HBV related HCC [odds ratio (OR) = 0.38, 95% confidence interval (CI) = 0.20-0.72, P = 0.037]; A/G genotype decreased the risk of portal vein thrombosis (OR = 0.38, 95%CI = 0.18-0.82, P = 0.01). These results indicate that rs3743251 polymorphism in IGF1R is associated with the susceptibility of HBV-related HCC.
Rashad NM, El-Shal AS, Abd Elbary EH, et al.Impact of insulin-like growth factor 2, insulin-like growth factor receptor 2, insulin receptor substrate 2 genes polymorphisms on susceptibility and clinicopathological features of hepatocellular carcinoma.
Cytokine. 2014; 68(1):50-8 [PubMed
] Related Publications
BACKGROUND: Hepatocellular carcinoma (HCC) is one of the major causes of cancer-related death worldwide. Insulin-like growth factor-2 (IGF-2) is an important autocrine and paracrine growth factor which may induce cell proliferation and inhibit cell apoptosis leading to the transformation of normal cells into malignant cells. This study aimed to evaluate the possible roles of IGF-2, insulin-like growth factor-2 receptor (IGF-2R), and insulin receptor substrate (IRS)-2 genes polymorphisms in susceptibility and clinicopathological features of HCC in Egyptian population.
MATERIALS AND METHODS: Four hundred and twenty-six HCC patients and 334 controls were enrolled in the study. Polymorphisms of IGF-2+3580, IGF-2+3123, IGF-2R 1619, and IRS-2 1057 gene were detected using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Serum IGF-2 were determined using ELISA.
RESULTS: Serum IGF-2 levels were significantly lower in HCC patients than in healthy controls. IGF-2+3580 AA genotype, IGF-2+3123 GG genotype or G allele, IRS-2 1057 DD genotype and D allele were significantly associated with HCC risk. The combination of IGF-2+3580 AA homozygosity and IGF-2R 1619 GG homozygosity presented a significant protective effect against HCC (OR=0.16,95% CI=0. 08-0.34, P=0. 005). Serum IGF-2 concentrations were significantly increased in HCC patients with the IGF-2+3580 AA genotype. We also observed that increased alpha-fetoprotein (AFP), Child-Pugh grade, tumor size, and number of malignant lesions were accompanied by a significant increase of serum IGF-2 mean values of in HCC patients.
CONCLUSION: IGF-2, IGF-2R, and IRS-2 genes polymorphisms and their combinations are associated with risk of HCC.
PURPOSE: Insulin resistance is believed to play an important role in the link between energy imbalance and colon carcinogenesis. Emerging evidence suggests that there are substantial racial differences in genetic and anthropometric influences on insulin-like growth factors (IGFs); however, few studies have examined racial differences in the associations of IGFs and colorectal adenoma, precursor lesions of colon cancer.
METHODS: We examined the association of circulating levels of IGF-1, IGFBP-3 and IGFBP-1, and SNPs in the IGF-1 receptor (IGF1R), IGF-2 receptor (IGF2R), and insulin receptor genes with risk of adenomas in a sample of 410 incident adenoma cases and 1,070 controls from the Case Transdisciplinary Research on Energetics and Cancer (TREC) Colon Adenomas Study.
RESULTS: Caucasians have higher IGF-1 levels compared to African Americans; mean IGF-1 levels are 119.0 ng/ml (SD = 40.7) and 109.8 ng/ml (SD = 40.8), respectively, among cases (p = 0.02). Mean IGF-1 levels are also higher in Caucasian controls (122.9 ng/ml, SD = 41.2) versus African American controls (106.9, SD = 41.2), p = 0.001. We observed similar differences in IGFBP3 levels by race. Logistic regression models revealed a statistically significant association of IGF-1 with colorectal adenoma in African Americans only, with adjusted odds ratios (ORs) of 1.68 (95 % CI 1.06-2.68) and 1.68 (95 % CI 1.05-2.71), respectively, for the second and third tertiles as compared to the first tertile. One SNP (rs496601) in IGF1R was associated with adenomas in Caucasians only; the per allele adjusted OR is 0.73 (95 % CI 0.57-0.93). Similarly, one IGF2R SNP (rs3777404) was statistically significant in Caucasians; adjusted per allele OR is 1.53 (95 % CI 1.10-2.14).
CONCLUSION: Our results suggest racial differences in the associations of IGF pathway biomarkers and inherited genetic variance in the IGF pathway with risk of adenomas that warrant further study.
Kubisch R, Fröhlich T, Arnold GJ, et al.V-ATPase inhibition by archazolid leads to lysosomal dysfunction resulting in impaired cathepsin B activation in vivo.
Int J Cancer. 2014; 134(10):2478-88 [PubMed
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The myxobacterial agent archazolid inhibits the vacuolar proton pump V-ATPase. V-ATPases are ubiquitously expressed ATP-dependent proton pumps, which are known to regulate the pH in endomembrane systems and thus play a crucial role in endo- and exocytotic processes of the cell. As cancer cells depend on a highly active secretion of proteolytic proteins in order to invade tissue and form metastases, inhibition of V-ATPase is proposed to affect the secretion profile of cancer cells and thus potentially abrogate their metastatic properties. Archazolid is a novel V-ATPase inhibitor. Here, we show that the secretion pattern of archazolid treated cancer cells includes various prometastatic lysosomal proteins like cathepsin A, B, C, D and Z. In particular, archazolid induced the secretion of the proforms of cathepsin B and D. Archazolid treatment abrogates the cathepsin B maturation process leading to reduced intracellular mature cathepsin B protein abundance and finally decreased cathepsin B activity, by inhibiting mannose-6-phoshate receptor-dependent trafficking. Importantly, in vivo reduced cathepsin B protein as well as a decreased proteolytic cathepsin B activity was detected in tumor tissue of archazolid-treated mice. Our results show that inhibition of V-ATPase by archazolid reduces the activity of prometastatic proteases like cathepsin B in vitro and in vivo.
Caixeiro NJ, Martin JL, Scott CDSilencing the mannose 6-phosphate/IGF-II receptor differentially affects tumorigenic properties of normal breast epithelial cells.
Int J Cancer. 2013; 133(11):2542-50 [PubMed
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Although loss of the mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/IGF-IIR) in breast cancer is believed to play a role in tumorigenesis, it has not been demonstrated that M6P/IGF-IIR loss is sufficient to confer a malignant phenotype in an untransformed cell. We investigated the impact of M6P/IGF-IIR silencing using phenotypically normal (MCF-10A) and oncogenically transformed (MCF-10T, the c-Ha-ras transformed derivative of MCF-10A) human breast epithelial cell lines as model systems. In both cell lines, silencing of M6P/IGF-IIR increased cell proliferation and motility, with the effects being more pronounced in MCF-10A cells. Although anchorage-independent growth was increased by M6P/IGF-IIR silencing in MCF-10T cells, MCF-10A cells did not acquire the ability to grow in soft agar. Conversely, reduced M6P/IGF-IIR expression increased the invasive potential of MCF-10A cells, but did not enhance the already high rate of invasion of MCF-10T cells. M6P/IGF-IIR silencing had no effect on basal or IGF-II-stimulated IGF-I receptor (IGF-IR) or AKT phosphorylation in either cell line, but both were abrogated by IGF-IR kinase inhibition, which also reduced the stimulatory effect of M6P/IGF-IIR silencing on proliferation under basal and IGF-II-stimulated conditions in both cell lines. However, cell motility was neither stimulated by IGF-II nor reduced by IGF-IR inhibition, suggesting that potentiation of specific tumorigenic features in response to M6P/IGF-IIR silencing involves IGF-II- dependent and -independent mechanisms. Collectively, these data suggest that M6P/IGF-IIR silencing alone is insufficient to confer a tumorigenic phenotype, but can enhance tumorigenicity in an already transformed cell.
Hepatocellular carcinoma is the third most frequent cause of cancer-related death worldwide; and its incidence rate is increasing. Clinical and molecular medical analyses have revealed substantial information on hepatocarcinogenesis. Hepatocarcinogenesis is a stepwise process during which multiple genes are altered. Genetic changes and their biological consequences in human HCC can be divided into at least 4 groups: i) tumor suppressor genes (p53, retinoblastoma, phosphatase tensin homolog and runt-related transcription factor 3), ii) oncogenes (myc, K-ras, BRAF), iii) reactivation of developmental pathways (Wnt, hedgehog), and iv) growth factors and their receptors (transforming growth factor-α, insulin-like growth factor-2 receptor). An experimental model of human hepatocarcinogenesis such as in vitro neoplastic transformation of human hepatocytes has not been successfully achieved yet, but several immortalized human hepatocyte cell lines have been established. These immortalized human hepatocytes will become useful tools for the elucidation of hepatocarcinogenesis, especially for the initial step of multistep hepatocarcinogenesis.
INTRODUCTION: Prognosis of patients with operable laryngeal cancer is highly variable and therefore potent prognostic biomarkers are warranted. The insulin-like growth factor receptor (IGFR) signaling pathway plays a critical role in laryngeal carcinogenesis and progression.
PATIENTS AND METHODS: We identified all patients with localized TNM stage I-III laryngeal cancer managed with potentially curative surgery between 1985 and 2008. Immunohistochemical (IHC) expression of IGF1R-alpha, IGF1R-beta and IGF2R was evaluated using the immunoreactive score (IRS) and mRNA levels of important effectors of the IGFR pathway were assessed, including IGF1R, IGF-binding protein 3 (IGFBP3), suppressor of cytokine signaling 2 (SOCS2) and members of the MAP-kinase (MAP2K1, MAPK9) and phosphatidyl-inositol-3 kinase (PIK3CA, PIK3R1) families. Cox-regression models were applied to assess the predictive value of biomarkers on disease-free survival (DFS) and overall survival (OS).
RESULTS: Among 289 eligible patients, 95.2% were current or ex smokers, 75.4% were alcohol abusers, 15.6% had node-positive disease and 32.2% had received post-operative irradiation. After a median follow-up of 74.5 months, median DFS was 94.5 months and median OS was 106.3 months. Using the median IRS as the pre-defined cut-off, patients whose tumors had increased IGF1R-alpha cytoplasm or membrane expression experienced marginally shorter DFS and significantly shorter OS compared to those whose tumors had low IGF1R-alpha expression (91.1 vs 106.2 months, p = 0.0538 and 100.3 vs 118.6 months, p = 0.0157, respectively). Increased mRNA levels of MAPK9 were associated with prolonged DFS (p = 0.0655) and OS (p = 0.0344). In multivariate analysis, IGF1R-alpha overexpression was associated with a 46.6% increase in the probability for relapse (p = 0.0374). Independent predictors for poor OS included node-positive disease (HR = 2.569, p<0.0001), subglottic/transglottic localization (HR = 1.756, p = 0.0438) and IGF1R-alpha protein overexpression (HR = 1.475, p = 0.0504).
CONCLUSION: IGF1R-alpha protein overexpression may serve as an independent predictor of relapse and survival in operable laryngeal cancer. Prospective evaluation of the IGF1R-alpha prognostic utility is warranted.
van Dorp W, van den Heuvel-Eibrink MM, Stolk L, et al.Genetic variation may modify ovarian reserve in female childhood cancer survivors.
Hum Reprod. 2013; 28(4):1069-76 [PubMed
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STUDY QUESTION: Are genetic polymorphisms, previously identified as being associated with age at menopause in the healthy population, associated with ovarian reserve and predicted age at menopause in adult long-term survivors of childhood cancer?
SUMMARY ANSWER: The CT genotype of rs1172822 in the BRSK1 gene is associated with lower serum anti-Müllerian hormone (AMH) levels and a younger predicted age at menopause in adult survivors of childhood cancer.
WHAT IS KNOWN ALREADY: Gonadotoxicity is a well-known late side effect of chemotherapy and radiotherapy in adult survivors of childhood cancer. In the healthy population, several genetic polymorphisms are associated with age at natural menopause. Currently, data on the impact of previously identified variants in gene loci associated with ovarian reserve in adult long-term survivors of childhood cancer are lacking.
STUDY DESIGN, SIZE, DURATION: We performed a pilot study in a single-centre cohort of adult female Caucasian childhood cancer survivors (n = 176).
PARTICIPANTS/MATERIALS, SETTING, METHODS: We determined serum AMH levels (a marker of ovarian reserve) in adult survivors of childhood cancer (n = 176) and studied single nucleotide polymorphisms (SNPs) previously reported to be associated with age at natural menopause: BRSK1 (rs1172822), ARHGEF7 (rs7333181), MCM8 (rs236114), PCSK1 (rs271924), IGF2R (rs9457827) and TNF (rs909253). Association analysis was performed using the additive genetic model. Linear regression was conducted to assess the effect of significant polymorphisms in two previously published menopause prediction models.
MAIN RESULTS AND THE ROLE OF CHANCE: The CT genotype of rs1172822 in the BRSK1 (BR serine/threonine kinase 1) gene was negatively associated with serum AMH levels in our cohort (odds ratio: 3.15, 95% confidence interval: 1.35-7.32, P = 0.008) and significantly associated with the predicted age at menopause (P = 0.04). The other five SNPs were not associated with serum AMH levels.
LIMITATIONS, REASONS FOR CAUTION: This is a pilot study showing preliminary data which must be confirmed. To confirm our findings and enlarge the project, a nationwide genome-wide association (GWA) project on the ovarian reserve in female survivors of childhood cancer should be performed, including a replication cohort.
WIDER IMPLICATIONS OF THE FINDINGS: Our findings support the hypothesis that previously identified genetic polymorphisms associated with age at menopause in healthy women may have an effect on the onset of menopause in female survivors of childhood cancer. Our study highlights a new aspect of the influences on the ovarian reserve after childhood cancer, which should be investigated further in a nationwide GWA study. Eventually, this information can help us to improve counselling on fertility preservation prior to cancer treatment based on genetic factors in individual patients.
STUDY FUNDING AND CONFLICT OF INTEREST: W.D. is supported by the Paediatric Oncology Centre Society for Research (KOCR), Rotterdam, The Netherlands. J.S.E.L. has received fees and grant support from the following companies (in alphabetic order): Ferring, Genovum, Merck-Serono, Organon, Schering Plough and Serono. All other authors have nothing to disclose.
The M6P (mannose 6-phosphate)/IGF2R (insulin-like growth factor II receptor) interacts with a variety of factors that impinge on tumour invasion and metastasis. It has been shown that expression of wild-type M6P/IGF2R reduces the tumorigenic and invasive properties of receptor-deficient SCC-VII squamous cell carcinoma cells. We have now used mutant forms of M6P/IGF2R to assess the relevance of the different ligand-binding sites of the receptor for its biological activities in this cellular system. The results of the present study demonstrate that M6P/IGF2R does not require a functional binding site for insulin-like growth factor II for inhibition of anchorage-independent growth and matrix invasion by SCC-VII cells. In contrast, the simultaneous mutation of both M6P-binding sites is sufficient to impair all cellular functions of the receptor tested. These findings highlight that the interaction between M6P/IGF2R and M6P-modified ligands is not only important for intracellular accumulation of lysosomal enzymes and formation of dense lysosomes, but is also crucial for the ability of the receptor to suppress SCC-VII growth and invasion. The present study also shows that some of the biological activities of M6P/IGF2R in SCC-VII cells strongly depend on a functional M6P-binding site within domain 3, thus providing further evidence for the non-redundant cellular functions of the individual carbohydrate-binding domains of the receptor.
Haouzi D, Assou S, Monzo C, et al.Altered gene expression profile in cumulus cells of mature MII oocytes from patients with polycystic ovary syndrome.
Hum Reprod. 2012; 27(12):3523-30 [PubMed
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STUDY QUESTION: Oocyte developmental competence is altered in patients with polycystic ovary syndrome (PCOS); is gene expression in cumulus cells (CCs) from mature metaphase II oocytes of patients with PCOS altered as well?
SUMMARY ANSWER: Compared with CCs from non-PCOS patients, the gene expression profile of CCs isolated from mature oocytes of patients with PCOS present alterations that could explain the abnormal folliculogenesis and reduced oocyte competence in such patients.
WHAT IS KNOWN ALREADY: Abnormal mRNA expression of several members of the insulin-like growth factor (IGF) family in CCs from PCOS patients was previously reported. Moreover, the whole transcriptome has been investigated in cultured CCs from PCOS patients.
STUDY DESIGN, SIZE AND DURATION: This retrospective study included six PCOS patients diagnosed following the Rotterdam Criteria and six non-PCOS patients who all underwent ICSI for male infertility in the assisted reproduction technique (ART) Department of Montpellier University Hospital, between 2009 and 2011.
PARTICIPANTS/MATERIALS, SETTING AND METHODS: CCs from PCOS and non-PCOS patients who underwent controlled ovarian stimulation (COS) were isolated mechanically before ICSI. Gene expression profiles were analysed using the microarray technology and the Significance Analysis of Microarray was applied to compare the expression profiles of CCs from PCOS and non-PCOS patients.
MAIN RESULTS: The gene expression profile of CCs from patients with PCOS was significantly different from that of CCs from non-PCOS patients. Specifically, CCs from women with PCOS were characterized by abnormal expression of many growth factors, including members of the epidermal growth factor-like (EGFR, EREG and AREG) and IGF-like families (IGF1R, IGF2R, IGF2BP2 and IGFBP2), that are known to play a role in oocyte competence. In addition, mRNA transcripts of factors involved in steroid metabolism, such as CYP11A1, CYP1B1, CYP19A1 and CYP2B7P1, were deregulated in PCOS CCs, and this could explain the abnormal steroidogenesis observed in these women. Functional annotation of the differentially expressed genes suggests that defects in the transforming growth factor β and estrogen receptors signalling cascades may contribute to the reduced oocyte developmental competence in patients with PCOS.
LIMITATIONS AND REASONS FOR CAUTION: Owing to the strict selection criteria (similar age, weight and reasons for ART), this study included a small sample size (six cases and six controls), and thus, further investigations using a large cohort of patients are needed to confirm these results.
WIDER IMPLICATIONS OF THE FINDINGS: This study opens a new perspective for understanding the pathogenesis of PCOS.
STUDY FUNDING/COMPETING INTERESTS: This work was partially supported by a grant from the Ferring Pharmaceutical. The authors of the study have no competing interests to report.
TRIAL REGISTRATION NUMBER: Not applicable.