Metformin, an inexpensive and well-tolerated oral agent commonly used in the first-line treatment of type 2 dia-betes, has become the focus of intense research as a candidate anticancer agent. Here, we discuss the potential of metformin in cancer therapeutics, particularly its functions in multiple signaling pathways, including AMP-activated protein kinase, mammalian target of rapamycin, insulin-like growth factor, c-Jun N-terminal kinase/mitogen-activated protein kinase (p38 MAPK), human epidermal growth factor receptor-2, and nuclear factor kappaB pathways. In addi-tion, cutting-edge targeting of cancer stem cells by metformin is summarized.
National Natural Science Foundation of China (NSFC) Key Project 81130046NSFC81171993NSFC81272415Guangxi Key Projects 2013GXNSFEA053004Guangxi Projects 1355004-52012GXNSFCB053004Guangxi Ministry of Education 201202ZD022201201ZD004 (to JZ). The authors thank Ms. Xin Huang and Ms. Xiaolin Zhou for editing