The autophagy induced by curcumin via MEK/ERK pathway plays an early anti-leukemia role in human Philadelphia chromosome-positive acute lymphoblastic leukemia SUP-B15 cells

• Published in: Journal of cancer research and therapeutics 2018-01, Vol.14 (8), p.125-131
• Main Authors: Guo, Yong, Shan, Qing, Gong, Ping, Wang, Sen
• Format: Article
• Language: English
• Subjects: Antineoplastic Agents, Phytogenic - pharmacology; Apoptosis; Autophagy; Autophagy - drug effects; Cell Line, Tumor; Cell Proliferation - drug effects; Cell Survival - drug effects; Colorectal cancer; Curcumin - pharmacology; Cytotoxicity; Fusion Proteins, bcr-abl - genetics; Hematology; Humans; Kinases; Laboratories; Leukemia; MAP Kinase Signaling System - drug effects; Medical prognosis; Penicillin; Precursor Cell Lymphoblastic Leukemia-Lymphoma - genetics; Precursor Cell Lymphoblastic Leukemia-Lymphoma - metabolism; Protein Kinase Inhibitors - pharmacology; Proteins; raf Kinases - metabolism
• ISSN: 0973-1482; 1998-4138
• DOI: 10.4103/0973-1482.172111

Background: Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL) is triggered by BCR/ABL tyrosine kinase which activates the downstream signaling pathways, such as Akt/mTOR, RAF/MEK/ERK, and STAT5 pathways. Curcumin has been shown to have inhibitory effects on cancers by inducing apoptosis and autophagy. We demonstrated that curcumin inhibited activation of Akt-mTOR, ABL/STAT5 pathways, inhibited cell proliferation, and induced apoptosis in Ph + ALL cells. Experiments here, were conducted to determine whether autophagy via MEK/ERK pathway involved in anti-leukemia effect of curcumin in Ph + ALL. Materials and Methods: Ph + ALL cell line SUP-B15 was treated with curcumin. Cytotoxic activity of curcumin was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay. Signaling protein and specific maker of autophagy and conversion of LC3-I to LC3-II were determined by Western blot analysis. Cell apoptosis was determined by flow cytometry. Results: Curcumin treatment up-regulated the activation of RAF/MEK/ERK at 4 h and 8 h after curcumin exposure in SUP-B15 cells, curcumin treatment induced autophagy at exactly 4 h and 8 h after curcumin exposure. Curcumin exerted cytotoxic activity against SUP-B15 cells at 4 h and 8 h, which was independent of apoptosis. MEK specific inhibitor U0126 inhibited the occurrence of autophagy, and then blocked curcumin-induced cytotoxicity at 4 h and 8 h. Conclusions: Curcumin induce autophagic cell death in SUP-B15 cells via activating RAF/MEK/ERK pathway. These findings suggest that autophagic mechanism contribute to the curcumin-induced early SUP-B15 cell death, and autophagy is another anti-leukemia mechanism of curcumin.