Roles of H19/miR-29a-3p/COL1A1 axis in COE-induced lung cancer

Occupational lung cancer caused by coke oven emissions (COE) has attracted increasing attention, but the mechanism is not clear. Many evidences show ceRNA (competing endogenous RNA) networks play important regulatory roles in cancers. In this study, we aimed to construct and verify the ceRNA regulatory network in the occurrence of COE-induced lung squamous cell carcinoma (LUSC). We performed RNA sequencing with lung bronchial epithelial cell (16HBE) and COE induced malignant transformed cell (Rf). Furthermore, we analyzed RNA sequencing data of LUSC and adjacent tissues in the cancer genome atlas (TCGA) database. Combined our data and TCGA data to determine the differentially expressed lncRNAs, miRNAs, mRNAs. lncBASE, miRDB and miRTarBase were used to predict the binding relationship between lncRNA and miRNA, miRNA and mRNA. Based on these, we construct the ceRNA network. FREMSA, dual-luciferase reporter assay, quantitative real-time PCR (qRT-PCR), western-blot were used to verify the regulatory axis. CCK8 assay, phalloidin staining, p53 detection were used to explore the roles of this axis in the COE induced malignant transformation. Results showed 7 lncRNAs, 7 miRNAs and 146 mRNAs were identified. Among these, we constructed a ceRNA network including 1 lncRNA, 2 miRNAs and 9 mRNAs. Further verification confirmed the trend of lncRNA H19, miR-29a-3p and COL1A1 were consistent with sequencing results. H19 and COL1A1 were significantly higher in Rf than in 16HBE and miR-29a-3p was reverse. Regulatory investigation revealed H19 increased COL1A1 expression by sponging miR-29a-3p. Knockdown of H19, COL1A1 or overexpression of miR-29a-3p in Rf cells could inhibit cell proliferation, increased cell adhesion and p53 level. However, knockdown of H19 while suppressing the miR-29a-3p partially rescue the malignant phenotype of Rf caused by H19. In conclusion, all these indicated H19 functioned as a ceRNA to increase COL1A1 by sponging miR-29a-3p and promoted COE-induced cell malignant transformation.