Wu Di, Lu Pan, Mi Xue, Miao Jinwei
Department of Gynecologic Oncology, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China.
Arch Gynecol Obstet. 2018 Mar;297(3):699-707. doi: 10.1007/s00404-018-4649-0. Epub 2018 Jan 11.
Cisplatin is an important chemotherapeutic agent frequently used in the treatment of ovarian cancer. However, resistance to cisplatin is an obstacle to the treatment of ovarian cancer. Recently, many studies have demonstrated that microRNAs (miRNAs) are involved in the drug resistance of ovarian cancer cells. In this study, we explored the role of miR-503 in cisplatin-resistant ovarian cancer.
To investigate the relationship between miR-503 expression and the sensitivity of ovarian cancer cells to cisplatin, the cells were transfected with miR-503 mimics/inhibitors. The relative expression of miR-503 RNA and its targeted gene PI3K mRNA were detected by real-time PCR (RT-PCR). Western blot was used to measure relevant protein levels. Flow cytometry and CCK-8 assay were used to analyze cell proliferation and apoptosis.
MiR-503 expression was significantly downregulated in cisplatin-resistant ovarian cancer cell line SKOV3/DDP compared with parental SKOV3. Over-expression and knock-down of miR-503 partially regulated apoptotic activity and changed the cisplatin resistance of ovarian cancer cells. In exploring the underlying mechanisms of miR-503 in ovarian cancer cells' resistance to cisplatin, we found that miR-503 can directly target PI3K p85 and participates in the regulation of the PI3K/Akt signaling pathway. In vivo, miR-503 agomirs combined with cisplatin treatment significantly reduced the growth of tumors compared with cisplatin alone.
Our data suggest that miR-503 might be a sensitizer to cisplatin treatment in ovarian cancer by targeting PI3K p85, thus giving a new insight into developing therapeutic strategies to overcome cisplatin resistance in ovarian cancer.
顺铂是治疗卵巢癌常用的重要化疗药物。然而，对顺铂耐药是卵巢癌治疗的一个障碍。最近，许多研究表明，微小RNA（miRNA）参与了卵巢癌细胞的耐药性。在本研究中，我们探讨了miR-503在顺铂耐药卵巢癌中的作用。
为研究miR-503表达与卵巢癌细胞对顺铂敏感性之间的关系，用miR-503模拟物/抑制剂转染细胞。通过实时荧光定量PCR（RT-PCR）检测miR-503 RNA及其靶向基因PI3K mRNA的相对表达。采用蛋白质免疫印迹法检测相关蛋白水平。通过流式细胞术和CCK-8法分析细胞增殖和凋亡情况。
与亲本SKOV3相比，顺铂耐药卵巢癌细胞系SKOV3/DDP中miR-503表达显著下调。miR-503的过表达和敲低部分调节了凋亡活性，并改变了卵巢癌细胞的顺铂耐药性。在探索miR-503在卵巢癌细胞对顺铂耐药中的潜在机制时，我们发现miR-503可以直接靶向PI3K p85并参与PI3K/Akt信号通路的调控。在体内，与单独使用顺铂相比，miR-503激动剂联合顺铂治疗显著降低了肿瘤的生长。
我们的数据表明，miR-503可能通过靶向PI3K p85成为卵巢癌顺铂治疗的增敏剂，从而为开发克服卵巢癌顺铂耐药的治疗策略提供了新的见解。
