Fig. 2.

Furin promotes PTC cell growth in vitro. (A) Basal expression of furin in PTC cell lines. Proteins were isolated from three PTC cell lines and immunoblotted with antibodies against Furin, pMEK1/2, MEK1/2, pERK1/2, ERK1/2 and β‐Actin (n = 3). (B) Forced expression of furin in low‐expressing cells. TPC‐1 cells were transfected with either an empty vector or FURIN cDNA and overexpression was confirmed by immunoblotting (n = 3). (C, D) Forced expression of furin increases clonogenicity. TPC‐1 cells were transfected with either an empty vector or FURIN cDNA for 48 h. Selected clones were seeded at a density of 500 cells per well in a 6‐well plate, and grew for an additional 10 days, then stained with crystal violet, and colonies were counted. Data were presented as mean ± SD (n = 3). (E) Furin promotes TPC‐1 cell proliferation. TPC‐1 cells carrying empty vector and FURIN cDNA were grown for 48 h and cell proliferation was measured by MTT assay. Data were presented as mean ± SD (n = 6). (F) TPC‐1 cells were transfected with either an empty vector or FURIN cDNA for 48 h. Cells were stained with propidium iodide (PI) followed by flow cytometry analysis. Data were presented as mean ± SD (n = 3). Statistical analyses were performed using two‐tailed Student's t‐tests. *P < 0.05.