Fan Wu1, Shu-Chao Su2, Guo-Qian Tan2, Lun Yan2, Ting-Yue Li2, Hao-Lu Zhang2, Ji-Shang Yu2, Bai-Lin Wang2. 1. Guangzhou Red Cross Hospital, Medical College, Jinan University, General Surgery, Tongfu Roud 396, 510220 Guangzhou, China. Electronic address: wufan7911@163.com. 2. Guangzhou Red Cross Hospital, Medical College, Jinan University, General Surgery, Tongfu Roud 396, 510220 Guangzhou, China.
Abstract
PURPOSE: The inhibition of Mus81, a critical DNA repair gene, is recently related to the chemosensitivity of several human cancer cells such as hepatocellular carcinoma (HCC) cells. However, the role of Mus81 knockdown in chemotherapy response of colon cancer cells remains largely unknown. METHODS AND MATERIALS: The effects of Mus81 knockdown by lentivirus-mediated short hairpin RNA in sensitivity of HCT116 and LS180 colon cancer cell lines to four therapeutic drugs, including cisplatin (CDDP), were evaluated by MTT assay as well as a mouse model. Apoptosis and cell cycle distribution of HCT116 cell line was detected by flow cytometric analysis. Western blot was also employed to determine the expression of CHK1 pathway and apoptosis-related proteins in HCT116 cells and the xenograft mouse tumors. RESULTS: Mus81 knockdown could significantly improve the chemosensitivity of colon cancer cells in vitro and in vivo, especially to CDDP. Mus81 knockdown also induced S phase arrest and elevated apoptosis in CDDP treated HCT116 cells through activating CHK1/CDC25A/CDK2 and CHK1/p53/Bax pathways, while these effects could be counteracted by CHK1 inhibition. CONCLUSION: Mus81 knockdown improves the chemosensitivity of colon cancer cells by inducing S phase arrest and promoting apoptosis through activating CHK1 pathway.
PURPOSE: The inhibition of Mus81, a critical DNA repair gene, is recently related to the chemosensitivity of several humancancer cells such as hepatocellular carcinoma (HCC) cells. However, the role of Mus81 knockdown in chemotherapy response of colon cancer cells remains largely unknown. METHODS AND MATERIALS: The effects of Mus81 knockdown by lentivirus-mediated short hairpin RNA in sensitivity of HCT116 and LS180 colon cancer cell lines to four therapeutic drugs, including cisplatin (CDDP), were evaluated by MTT assay as well as a mouse model. Apoptosis and cell cycle distribution of HCT116 cell line was detected by flow cytometric analysis. Western blot was also employed to determine the expression of CHK1 pathway and apoptosis-related proteins in HCT116 cells and the xenograft mousetumors. RESULTS:Mus81 knockdown could significantly improve the chemosensitivity of colon cancer cells in vitro and in vivo, especially to CDDP. Mus81 knockdown also induced S phase arrest and elevated apoptosis in CDDP treated HCT116 cells through activating CHK1/CDC25A/CDK2 and CHK1/p53/Bax pathways, while these effects could be counteracted by CHK1 inhibition. CONCLUSION:Mus81 knockdown improves the chemosensitivity of colon cancer cells by inducing S phase arrest and promoting apoptosis through activating CHK1 pathway.