Low Dose Radiation Enhances Susceptibility To Cisplatin In Resistant Ovarian Cancer Cells Via Downregulation Of ERCC1 And Bcl-2

Objective: Ovarian cancer is one of the leading causes of mortality in malignant gynecological tumors. After surgical intervention for ovarian cancer, cisplatin based chemotherapy is the mainstay for treatment. However, the major challenge to fight ovarian cancer is the development of chemoresistance. So the first aim of this study was to determine the effect of low dose radiation that it can enhance the susceptibility of resistant ovarian cancer cells to cisplatin. And the second aim was to provide new strategies for treating cisplatin-resistant ovarian cancer through probing into its mechanism.Methods: CCK8 assay was performed to measure the cell proliferation. Flow cytometric(FCM) method was utilized to quantify apoptosis of cisplatin-resistant ovarian cancer cells(SKOV3/DDP) through Annexin V and propidium iodide(PI) staining. Real-time Quantitative PCR(q PCR) analyzed the m RNA expression level of ERCC1 and Bcl-2 in SKOV3/DDP.Results: The IC50 values of control group, conventional-dose group and low-dose group were 9.367±0.16,9.289±0.16 and 3.847±0.15 respectively(p < 0.05 versus control group and conventional-dose group).Compared with control group and conventional-dose group, low-dose radiation group produced significantly more remarkable apoptosis which was detected by flow Cytometry(p< 0.05).The relative m RNA expressions of ERCC1 and Bcl-2 in the low-dose group were significantly lower than in the control group and conventional-dose group(p<0.05).Conclusion: low dose radiation had the effect of enhancing the sensitivity of resistant ovarian cancer cells to cisplatin and low dose radiation may exert this effect through decreasing DNA repair capacity of tumor cells and promoting apoptosis.