Jing-Wen Yang1, Qing-Huai Zhang1, Tong Liu2. 1. Department of Anorectal Surgery, Tianjin Union Medicine Centre, Tianjin, P.R. China. 2. Department of General Surgery, Institute of General Surgery, General Hospital, Tianjin Medical University, Tianjin, P.R. China.
Abstract
AIM OF STUDY: The roles of autophagy performed in chemotherapy-induced cell death or proliferation inhibition were still in debate. In this study, we aimed to disclose the function of autophagy in chemotherapy of HCT-116 colon cells. MATERIALS AND METHODS: Pharmacological and genetic methods were applied to induce and inhibit autophagy and elucidate the roles of autophagy performed in chemotherapy-induced proliferation inhibition and apoptosis. Autophagy was assessed by microtubule-associated protein light chain 3 (LC3) expression and monodansylcadaverine (MDC) staining. RESULTS: After treatment with 5-fluorouracil (5-FU), HCT-116 cells showed typical autophagy as stained by MDC. Autophagy inhibitor (3-methyladenine [3-MA]) or inducer (rapamycin) was applied in combination with 5-FU, respectively. As evidenced by our data, 3-MA inhibited while rapamycin facilitated 5-FU-induced apoptosis and proliferation inhibition of HCT-116 cells. Consistently, 3-MA inhibited, while rapamycin facilitated 5-FU-induced expressions of Beclin1 and LC3B. Moreover, 3-MA inhibited while rapamycin facilitated 5-FU-induced p53 protein expression. Using genetic method, Beclin1 overexpression increased while Beclin1 knockdown decreased 5-FU-induced cell proliferation inhibition and apoptosis. Especially, Beclin1 overexpression increased while Beclin1 knockdown decreased 5-FU-induced p53 expression. CONCLUSION: Our study provides both of pharmacological and genetic evidence to support that autophagy facilitates anticancer effect of the chemotherapeutic agent. The associated application of autophagy inducer with 5-FU would be beneficial for the chemotherapy in HCT-116 cancer cells.
AIM OF STUDY: The roles of autophagy performed in chemotherapy-induced cell death or proliferation inhibition were still in debate. In this study, we aimed to disclose the function of autophagy in chemotherapy of HCT-116 colon cells. MATERIALS AND METHODS: Pharmacological and genetic methods were applied to induce and inhibit autophagy and elucidate the roles of autophagy performed in chemotherapy-induced proliferation inhibition and apoptosis. Autophagy was assessed by microtubule-associated protein light chain 3 (LC3) expression and monodansylcadaverine (MDC) staining. RESULTS: After treatment with 5-fluorouracil (5-FU), HCT-116 cells showed typical autophagy as stained by MDC. Autophagy inhibitor (3-methyladenine [3-MA]) or inducer (rapamycin) was applied in combination with 5-FU, respectively. As evidenced by our data, 3-MA inhibited while rapamycin facilitated 5-FU-induced apoptosis and proliferation inhibition of HCT-116 cells. Consistently, 3-MA inhibited, while rapamycin facilitated 5-FU-induced expressions of Beclin1 and LC3B. Moreover, 3-MA inhibited while rapamycin facilitated 5-FU-induced p53 protein expression. Using genetic method, Beclin1 overexpression increased while Beclin1 knockdown decreased 5-FU-induced cell proliferation inhibition and apoptosis. Especially, Beclin1 overexpression increased while Beclin1 knockdown decreased 5-FU-induced p53 expression. CONCLUSION: Our study provides both of pharmacological and genetic evidence to support that autophagy facilitates anticancer effect of the chemotherapeutic agent. The associated application of autophagy inducer with 5-FU would be beneficial for the chemotherapy in HCT-116 cancer cells.