Association of Hypoxiainducible factor α subunits with TSGA10 transcripts in HeLa, MCF7 and MDA-MB231- cell lines

Background: Hypoxia is a common phenomenon in cancer cells. Due angiogenesis and cell proliferation the hypoxia-inducible factor family (HIFs) is the primary transcriptional factor to hypoxic stress. Cancer-testis (CT) antigens are almost expressed in male germ cells, aberrantly expressed in some malignancies as well. The CT gene, TSGA10, prevents the nuclear accumulation of HIF-α and may be involved in organ-specific regulation of hypoxic gene expression during sperm maturation. TSGA10 is supposed to regulate the HIF expression in germ cells and cancer cells. The HIF-α subunit has three isoforms, involved in oxygen transport, angiogenesis and tumor metastasis, detection of which is the subject of the current study. Methods: Three cell lines, MCF7, MDA-MB-231 and HeLa were cultured, passaged and categorized into normal and synchronized groups. The cells were subjected to RNA extraction and reverse-transcribed into cDNAs. Realtime RT-PCR was performed to amplify TSGA10 and HIF-α isoforms and HPRT, as the normalizer gene, using appropriate primers. The REST and SPSS software were used for statistical analysis. Results: The expression of the three isoforms of HIF-α in HeLa cell line was higher than MCF7, and MCF7 was higher than MDA-MB-231. Moreover the expression relationship between HIF-α isoforms and TSGA10 was evaluated in each three cell lines. The results were significant in all cases with P =0.01. Before and after synchronization in each three cell lines, the isoform expressions of HIF-α and TASGA10 were evaluated, and the results were revealed their dependent expression. The relationship between HIF-α isoforms and TSGA10 expression was compared with each other. The cell lines with less TSGA10 expression had the higher expression of HIF-α isoforms and vice versa, according to the extent of TSGA10. Conclusion: The significant relationship between expressions of TSGA10 and HIF-α isoforms is confirmed.