Fig. 5
From: NLK functions to maintain proliferation and stemness of NSCLC and is a target of metformin
Metformin treatment inhibits cell proliferation in NSCLC cell lines, consistent with down-regulation of NLK protein levels. a MTS assay showing reduced cell growth in A549 and SK-MES-1 cells by different dosage of metformin treatment. *p < 0.05, **p < 0.01. b Cell counting assay showing decreased cell numbers in A549 and SK-MES-1 cells by the indicated dosages of metformin treatment. **p < 0.01. c The growth of normal human bronchial epithelial cells (BEAS-2B) is not affected by metformin treatment shown by MTS and cell counting assay. d A549 (IC50 7.97 ± 0.17) and SK-MES-1 (IC50 13.36 ± 0.44) were found to be more sensitive to metformin than BEAS-2B (IC50 32.57 ± 0.64). **p < 0.01. e Western blots showing that NLK expression in BEAS-2B is lower than A549 and SK-MES-1 cells and the treatment of metformin did not decrease NLK protein expression level markedly. f Western blots showing decreased NLK protein level upon metformin treatment (5 mM) with indicated times in A549 and SK-MES-1 cells. α-tubulin was used as loading control