TCF19 Contributes to Cell Proliferation of Non-Small Cell Lung Cancer by Inhibiting FOXO1.

Transcription factor 19 (TCF19) harbors a forkhead association (FHA) domain, a proline-rich region, a PHD or RING finger region, suggesting that TCF19 possesses a powerful function. However, its expression and function remains unknown in non-small-cell lung cancer (NSCLC). The function cluster analysis was carried out using Metascape website. 3-(4,5-Dimethyl-2-thiazolyl)2,5-diphenyl-2H-tetrazolium bromide (MTT), colony formation, and anchorage-independent growth ability assay were carried out to detect the effect of TCF19 on cell proliferation. Bromodeoxyuridine (Brdu) labeling and flow cytometry assay were used to evaluate the effect of TCF19 on cell-cycle progression. Quantitative polymerase chain reaction and chromatin immunoprecipitation assay were performed to investigate the mechanism by which TCF19 is involved in cell-cycle transition. By analyzing the publicly available dataset, The Cancer Genome Atlas (TCGA), we found that TCF19 is significantly increased in the lung adenocarcinoma (LAC) and squamous cell carcinoma (SCC), two primary histological subtype of NSCLC. Besides, further function cluster analysis exhibited that TCF19 may mainly participate in cell cycle. MTT, colony formation, and anchorage-independent growth ability assay confirmed that overexpression of TCF19 enhances the proliferation of both LAC and SCC cells. Besides, further experiments revealed that TCF19 contributes to cell cycle G1/S transition. Not only that, upregulation of TCF19 can inhibit the expression of p21, p27, and p57, while promote the expression of cyclin D1 by inhibiting FOXO1. Our research offers important evidence that TCF19 can promote cell-cycle progression of NSCLC cells, and TCF19 may served as novel therapeutic targets.