Authors

Jianhua Jiang*, Haixing Fang**,#, Wenhui Sun**, Yonghang Feng*, Lina Zhou***

Departments

*Department of Gastroenterology, The First People's Hospital of Fuyang District, Hangzhou 311400, P.R. China - **Department of General Surgery, The First People's Hospital of Fuyang District, Hangzhou 311400, P.R. China - ***Endoscopy Center of the First People's Hospital of Fuyang District, Hangzhou 311400, P.R. China

Abstract

Gastric cancer is the fifth most common malignant tumor in the world, second only to lung cancer, breast cancer, colorectal cancer and prostate cancer. In 2012, there were an estimated 952,000 new cases of gastric cancer and 723,000 gastric cancer-related deaths worldwide. With the frequent use of chemotherapy, the therapeutic effect of chemotherapy on gastric cancer patients has gradually decreased, and drug resistance is the main obstacle to tumor treatment. This study aimed to investigate miR-503 reverse drug resistance of gastric cancer cells and its mechanism. MKN-45/DDP, HGC-27/DDP, SGC-7901/DDP gastric cancer cisplatin-resistant cell lines were constructed. The effects of over-expression of miR-503 on the cisplatin therapeutic effect of gastric cancer cells and on the expression of E2F transcription factor 3 (E2F3) were observed. The differences between the therapeutic effects of co-transfected miR-503 and E2F3 mimetics and cisplatin transfected miR-503 mimetics alone were analyzed to explore the mechanism of miR-503 action. miR-503 was low expressed in gastric cancer cells (P<0.05), and further decreased in gastric cancer drug-resistant cell lines (P<0.05). Up-regulation of miR-503 expression could increase the growth inhibition effect of cisplatin on gastric cancer drug-resistant cells (P<0.05), while up-regulation of E2F2 expression could weaken this effect (P<0.05). Double luciferase report showed that there was a targeting regulation relationship between microRNA-503 and E2F3. miR-503 can targeting inhibit E2F3 reverse cisplatin resistance in gastric cancer cells.

Keywords

miR-503, Gastric cancer, Drug resistance, E2F transcription factor 3.

DOI:

10.19193/0393-6384_2020_3_289