Metformin Inhibits Proliferation of Human Thyroid Cancer TPC-1 Cells by Decreasing LRP2 to Suppress the JNK Pathway

He, Yang; Cao, Lingling; Wang, Li; Liu, Lingping; Huang, Ying; Gong, Xuan

A retrospective epidemiological study conducted by Evans et al 13 in 2005 pointed out that the application of metformin markedly reduces the incidences of malignant tumors in patients with diabetes. Later, the tumor-suppressor effect of metformin has been well concerned. A relevant study demonstrated that metformin treatment suppresses tumor growth, elevates the complete remission rate and prolongs the disease-free survival in patients with thyroid cancer. 14 Cho et al 15 suggested that the application of different doses of metformin reduces the tumor volume and suppresses tumor cell growth in tumor-bearing nude mice. In a recent study, metformin like drug AICAR that affects cancer cell proliferation which in turn effective to create cell death in cancer cells via activating AMPK pathway. 16 In this paper, metformin treatment markedly inhibited proliferative ability and induced apoptosis in TPC-1 cells. Furthermore, LRP2 level was downregulated and the JNK pathway was activated by metformin application.