TMEM100 induces cell death in non-small cell lung cancer via the activation of autophagy and apoptosis

Lung cancer is one of the most malignant type of tumors worldwide. Non-small cell lung cancer (NSCLC), which is the most common type of lung cancer, is defined as a distinct disease that exhibits both genetic and cellular heterogeneity. Although in the past two decades significant advances in the treatment of NSCLC have besen performed, the 5-year survival rate of patients with NSCLC remains <20%. Thus, there is an urgent requirement to gain an in-depth understanding of the molecular mechanisms that promote NSCLC development and to identify novel therapeutic targets. In the present study, the gene expression profiles of patients with NSCLC from The Cancer Genome Atlas database were analyzed to determine potential therapeutic targets, and transmembrane protein 100 (TMEM100) was identified as a candidate tumor suppressor. TMEM100 expression level was discovered to be decreased in both NSCLC tissues and cell lines, and it was observed to be negatively associated with the TNM stage and positively associated with prognosis. Moreover, TMEM100 inhibited tumor growth and promoted cell apoptosis in A549 and H460 cells. Mechanistically, TMEM100 was demonstrated to induce autophagy in A549 cells via inhibiting the PI3K/AKT signaling pathway, whereas inhibiting autophagy using bafilomycin A1 significantly enhanced TMEM100-induced apoptosis to compensate for the cell death. In conclusion, these findings suggested that TMEM100 may serve as a tumor suppressor in NSCLC and promote autophagy via inhibiting the PI3K/AKT signaling pathway.