Correlations among ERCC1, XPB, UBE2I, EGF, TAL2 and ILF3 revealed by gene signatures of histological subtypes of patients with epithelial ovarian cancer

The aim of this study was to better understand the mechanisms of tumor developmentand disease progression in human epithelial ovarian cancer. Fifty genes were screenedfor gene signature; 20 expressed genes were assessed in tumor and normal samplesof EOC patients by RT-PCR. Expression of UBE2I, EGF, TAL2 and ILF3 was validatedby qPCR on the ABI Prism 7000 Detection System. ERCC1 and XPB expression was previouslydetermined by RT-PCR in these specimens. Statistical analyses include two-sidedKruskal-Wallis test, pairwise comparison, Pearson correlation coefficient andpaired t-test. In comparison to normal samples, 6 genes demonstrated distinctexpression patterns in tumor tissues, with high expression observed for ERCC1,XPB and ILF3 (p=0.001, 0.0007 and 0.002, respectively) and low expression observedfor TAL2 and EGF (both p<0.0001). This differential expression pattern betweennormal and tumor tissues may reflect in part the development of ovarian cancer.Significant differences in expression patterns of these genes in clear cell, endometrioid,mucinous and serous ovarian cancer were observed. Comparison of expression ofany two EOC subtypes revealed multiple gene involvement in histopathological differentiationand cancer progression. A positive association was found between ERCC1 and XPBexpression (r=0.53, p<0.0001) and between TAL2 and EGF expression (r=0.817,p<0.0001) suggesting the existence of gene linkage in these tumors. The differencesin expression patterns of studied genes between tumors and normal specimens, betweenhistological subtypes and correlations among studied genes, may indicate theirinvolvement in tumor growth and disease progression in human epithelial ovariancancer. Further investigation of these genes may enable better understanding ofthe molecular mechanism of tumorigenesis and identification of potential biomarkers.