Expression and clinical significance of ELOVL6 gene in high-grade serous ovarian carcinoma

Abstract

To investigate the expression of elongation of very long-chain fatty acids family member 6 (ELOVL6) in high-grade serous ovarian carcinoma (HSOC), and explore the correlation between its expression and clinical prognosis in these patients. The expression of ELOVL6 at mRNA and protein levels were respectively detected by reverse transcription (RT)-PCR and immune histochemistry method in 12 cases with normal ovarian tissues and 172 cases with HSOC from primary tumor site, forty of which had paired peritoneal metastatic tissues. (1) The results tested by RT-PCR showed that ELOVL6 expression in normal ovarian tissue was 4.8±1.1, while 1.2±0.7 in primary tumors and 1.8±0.9 peritoneal metastatic sites in HSOC. Compared with normal ovarian tissue, the level of ELOVL6 mRNA was significantly lower in HSOC (P<0.05). There was no significant difference between primary and peritoneal metastatic sites in HSOC (P=0.610). It was shown that ELOVL6 protein localized in cytoplasm of ovarian cancer cell by immunostaining assay. (2) ELOVL6 expression was observed in all normal ovarian tissue, 70.2% of G1-G2 and 48.8% of G3 HSOC (P<0.05). ELOVL6 expression in drug-resistant group were significantly lower than that in non-resistant group (39.1% vs 65.0%, P<0.01). The median disease-free survival was 41 months in the ELOVL6-positive group and 39 months in ELOVL6-negative group (P>0.05). The total median survival was 52 months in ELOVL6-positive group and 44 months in ELOVL6-negative group (P>0.05). Low expression of ELOVL6 may correlate with the poor differentiation and drug resistance in HSOC.