PDCD1 strengthens the sensitivity of ovarian cancer to cisplatin chemotherapy by promoting apoptosis.

PURPOSE The primary purpose of this study was to make clear the role of PDCD1 in the occurrence and progression of ovarian cancer, and explain its mechanism. METHODS RT-PCR, westem blot, MTT and immunohistochemistry were used to detect the expression levels of PDCD1 mRNA and protein in human ovarian cancer cell lines (SKOV3, 3AO, CAOV3 and OVCAR3), human normal ovary, serous cystadenoma, and serous cystadenocarcinoma tissue. SKOV3, SKOV3-MOCK, and SKOV3-PDCD1 cells were subcutaneously injected into the armpit of nude mice to observe the effect of PDCD1 expression on tumorigenic ability. Cisplatin, carboplatin, cyclophosphamide, etoposide and paclitaxel were used in the experiments. RESULTS PDCD1 was lowly expressed in SKOV3 and 3AO, moderately expressed in CAOV3, and highly expressed in OVCAR3. PDCD1 significantly inhibited the proliferation and clone formation ability of the ovarian carcinoma cell line SKOV3. In the SKOV3-PDCD1 group, the tumor formation rate decreased significantly and the tumor formation time prolonged significantly. The CAOV3 and OVCAR3 cells with high expression of PDCD1 were more sensitive to cisplatin. The SKOV3 and 3AO cells with low expression of PDCD1 were less sensitive to cisplatin. Compared with the SKOV3- MOCK control group, the apoptosis rate and the expression levels of the caspase-3/8 proteins activity increased significantly in the PDCD1 overexpression group. The expression levels of caspase-9 and Bax increased slightly. No significant changes were observed in the expression of Bcl-2. CONCLUSION The expression of PDCD1 decreased significantly in human ovarian cancer. Overexpression of PDCD1 can inhibit the proliferation capacity of ovarian cancer. PDCD1 strengthens the sensitivity of ovarian cancer to cisplatin by promoting cisplatin-induced apoptosis.