CircTADA2A Up-regulates MAPK8 by targeting MiR-214-3p and recruiting EIF4A3 to promote the invasion and migration of non-small cell lung cancer cells

Background. Non-small cell lung cancer (NSCLC) occupies 87% of all lung cancer cases. Due to delayed diagnosis, the prognosis of NSCLC is unfavorable. To improve the survival of patients with NSCLC, more effective therapeutic targets urgently need to be identified. Recently, circular RNAs (circRNAs) have been revealed to play a crucial role in NSCLC progression. Purpose. This research focused on the influence of circTADA2A on the malignant phenotype of NSCLC cells and its in-depth regulatory mechanisms. Methods. RT-qPCR and western blot assays were done to examine the level of gene/protein of interest. Wound healing and transwell assays were conducted to monitor the migration and invasion of NSCLC cells. Bioinformatics tools and mechanistic assays were utilized to delve into the underlying mechanism of circTADA2A in NSCLC cells. Results. The results demonstrated that circTADA2A presented a high expression in NSCLC. CircTADA2A knockdown was revealed to hamper migration and invasion of NSCLC cells. Mechanistically, circTADA2A elevated MAPK8 expression through sequestering miR214-3p and recruiting EIF4A3. Conclusion. CircTADA2A enhances MAPK8 expression by serving as a miR-214-3p sponge and EIF4A3 decoy, consequently promoting invasion and migration of NSCLC cells

CMTM5 is downregulated and suppresses tumour growth in hepatocellular carcinoma through regulating PI3K-AKT signalling

Abstract Background Human chemokine like factor (CKLF)-like MAL and related proteins for vesicle trafficking transmembrane, domain-containing member 5 (CMTM5) has been shown to involved and may function as a tumour suppressor in tumorigenesis. The current study aimed to investigate the expression and function of CMTM5 in human hepatocellular carcinoma (HCC). Methods CMTM5 expression was examined by immunohistochemistry, and its clinical significance was analysed in 76 HCC specimens. The role and molecular mechanisms of CMTM5 in cell proliferation, apoptosis and invasion were examined in vitro and in vivo. Results CMTM5 expression was significantly downregulated in HCC tissues as well as cell lines. The expression of CMTM5 was absent in 77.6% of HCC tissues compared with 3.9% in normal liver tissues. Low CMTM5 expression was significantly correlated with poor overall survival in patients with HCC (P = 0.009). Restoring CMTM5 expression in Huh7 cells significantly inhibited cell growth, promoted cell apoptosis, and reduced cell metastatic and invasion ability compared with mock transfected cells in vitro. Overexpression of CMTM5 also suppressed xenograft tumour growth in vivo in a HCC xenograft model. Reduced cell growth and metastasis ability mediated by CMTM5 overexpression was associated with downregulation of PI3K/AKT and its downstream Bcl2, cyclinD1, cyclinE, MMP2 and MMP9 expressions, and an upregulation of p21, Bax, Bad, cleaved caspase3 expressions. Conclusions Our data suggest that CMTM5 might function as a tumour suppressor in human HCC, and represent a valuable potential therapeutic target for HCC