Figure 3 Troponin C1, slow skeletal and cardiac type (TNNC1) promoted gemcitabine (GEM)-induced autophagy and protected the nonsmall-cell lung cancer cells from apoptosis. (A, B) 3-Methyladenine (3-MA, 10 mM) and rapamycin (10 μM) were added to A549 and A549/GemR model cell cultures respectively for 4 h before GEM exposure. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to estimate the relative survival rate. The results are shown as mean±SD (*** P<0.001). (C) Western blot assay was used to evaluate the autophagy-related proteins LC3B and P62 in A549 and A549/GemR model cells after GEM treatment at 24 h and 3-MA (10 mM) or rapamycin(10 μM) was added at 4 h respectively. (D) Flow cytometry with annexin V–fluorescein isothiocyanate/propidium iodide double staining was used to detect cell apoptosis.