Objective: Although human chemokinelike factor (CKLF)-like MAL and related proteins for vesicle trafficking transmembrane, domain-containing member 5 (CMTM5) has been proved to play an important role in carcinogenesis and apoptosis in several types of human tumors, the expression of CMTM5 in ovarian cancer remains unclear. We aimed to investigate the association between CMTM5 expression and the survival of patients with epithelial ovarian cancer.
Methods: Normal surface ovarian epithelium tissues, ovarian cystadenoma tissues, ovarian cancer tissues, and 5 ovarian cancer cell lines were collected. The CMTM5 expressions were determined by reverse transcription polymerase chain reaction, Western blotting, and immunohistochemical staining. The survival information was analyzed by the Kaplan-Meier method.
Results: The CMTM5 expression was down-regulated in ovarian cancers. The expression of CMTM5 was absent in 30% (24 of 80) of ovarian cancers compared with 4.55% (1 of 22) of normal surface ovarian epithelium tissues and ovarian cystadenomas by immunohistochemistry. The results from the reverse transcription polymerase chain reaction were consistent with those from Western blotting. Furthermore, we found that although CMTM5 expression has no significant correlation with the age of the patients (P = 0.342), clinical stages (P = 0.155), pathologic types (P = 0.0605), or status of metastasis (P = 0.554), it was associated with the 3 groups of different differentiation levels (P = 0.0026) and an increase of CMTM5 loss of expression ratio in patients with preoperative CA125 level more than 500 mIU/mL compared to those with less than 500 mIU/mL (48.57% vs 16.67%, P = 0.0130). Statistical analysis by the Kaplan-Meier method showed that CMTM5 expression had no significant impact on the prognosis of patients with ovarian cancer (P = 0.24).
Conclusions: The reduced expression of CMTM5 correlates significantly with poorly differentiated ovarian cancer and high preoperative CA125 level. CMTM5 may contribute to the pathogenesis of human epithelial ovarian cancer.