C1orf74 positively regulates the EGFR/AKT/mTORC1 signaling in lung adenocarcinoma cells

BACKGROUND: Lung adenocarcinoma (LUAD) is a major type of lung cancer with poor prognosis and low 5-year survival rate, which urgently needs further investigation in order to elucidate its mechanisms completely and discover novel therapeutic targets. C1orf74 is a novel protein with unknown function either in normal cells or cancer cells. The aim of this study is to investigate the expression and function of C1orf74 in LUAD cells. METHODS: The expression of C1orf74 in LUAD was analyzed using the LUAD datasets from public databases. The prognostic value of C1orf74 in LUAD was analyzed using Kaplan-Meier Plotter. C1orf74 expression in LUAD cell line A549, H1993 and HCC827 was silenced using small interfering RNA, and then the effects of C1orf74 knockdown on proliferation, migration and invasion of LUAD cells were detected by colony formation assay and Transwell assay, the role of C1orf74 in EGFR/AKT/mTORC1 signaling pathway was examined by Western blot, and the function of C1orf74 in cell cycle was detected by flow cytometry. RESULTS: The results of LUAD clinical data showed that C1orf74 was upregulated in LUAD tissues, and its high expression was associated with poor prognosis. The results from cultured LUAD cells demonstrated that C1orf74 knockdown inhibited cell proliferation, migration and invasion, but induced cell cycle arrest and autophagy. Moreover, C1orf74 knockdown suppressed EGFR/AKT/mTORC1 signaling in LUAD cells. In conclusion, the present study revealed that C1orf74 is upregulated in LUAD tissues and plays an oncogenic role in LUAD, and that C1orf74 positively regulates cell proliferation and mobility through the EGFR/AKT/mTORC1 signaling pathway in LUAD cells.