Silence of URI in gastric cancer cells promotes cisplatin-induced DNA damage and apoptosis

Huiqin Bian; Yu Gu; Chen Chen; Jinnan Chen; Fei Zhang; Zhonghai Xu; Qian Wang; Rui Mi; Xuan Wu; Yaojuan Lu; Qiping Zheng; Junxia Gu

Silence of URI in gastric cancer cells promotes cisplatin-induced DNA damage and apoptosis

Am J Cancer Res. 2023 Mar 15;13(3):936-949. eCollection 2023.

Authors

Huiqin Bian¹, Yu Gu^{2

3}, Chen Chen¹, Jinnan Chen¹, Fei Zhang¹, Zhonghai Xu¹, Qian Wang¹, Rui Mi¹, Xuan Wu¹, Yaojuan Lu^{1

4}, Qiping Zheng^{1

4}, Junxia Gu¹

Affiliations

¹ Department of Hematology and Hematological Laboratory Science, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, School of Medicine, Jiangsu University Zhenjiang 212013, Jiangsu, China.
² Department of Hematology, Affiliated People's Hospital of Jiangsu University Zhenjiang 212001, Jiangsu, China.
³ Laboratory Center, Affiliated People's Hospital of Jiangsu University Zhenjiang 212001, Jiangsu, China.
⁴ Shenzhen Walgenron Bio-Pharm Co., Ltd. Shenzhen 518118, Guangdong, China.

PMID: 37034221
PMCID: PMC10077030

Abstract

URI, a prefoldin family member, has been implicated roles in cancer development. We have previously shown that URI can attenuate DNA damage in gastric cancer cells treated with potassium dichromate. The aim of this study was to investigate how URI involves cisplatin-induced DNA damage response (DDR) in gastric cancer cells and its possible mechanism relating to the ATM/CHK2 pathway. Here, MGC-803 and SGC-7901 gastric cancer cells were treated with different concentrations of cisplatin. Comet assay was used to detect DNA damage and the results confirmed the dose-effect of cisplatin-induced DNA damage in gastric cancer cells. URI knockdown cell lines were established with siRNA transfection. Cell viability and proliferation were detected by counting kit 8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assays respectively. Apoptosis and cell cycle were analyzed by flow cytometry. The results indicated that URI knockdown increased the sensitivity of cells to cisplatin by inhibiting proliferation and promoting apoptosis. The levels of P-ATM, P-CHK2 and γH2AX were detected by Western blot. Increased levels of P-ATM, P-CHK2, and γH2AX were observed in cisplatin treated cells, indicating that cisplatin induced a DNA damage response (DDR). URI knockdown in cisplatin-treated cells significantly decreased the levels of P-ATM and P-CHK2 at 12 hours, but not at 0 and 6 hours after drug withdrawal, while significantly increased γH2AX levels were detected at 6 hours, but not at 0 and 12 hours after drug withdrawal compared with the control cells. However, the levels of γH2AX were significantly increased in URI knockdown cells after cisplatin treatment for 12 hours. The cell cycle analysis showed that the number of cells entering S phase was significantly reduced and the cells were arrested in the G1 phase in URI-silenced cisplatin-exposed cells, indicating that cell cycle progression was inhibited. In conclusion, our results suggest that URI is involved in the cisplatin-induced DNA damage response via the ATM/CHK2 pathway, and silencing URI can increase cisplatin-induced DNA damage and enhance drug sensitivity in gastric cancer cells.

Keywords: ATM/CHK2 pathway; DNA damage response; URI; cisplatin; gastric cancer.