The Study On MARVELD1-mediated Intronic MiR-186and MiR-335Expression

MARVELD1(MARVEL domain containing1) is a novel tumor suppressor gene,downregulated in multiple Tumor tissue and tumor cells. Our lab has found that manymiRNAs changed with expression levels of MARVELD1by miRNA microarrayexpression profiling, and there are significant differences in the expression ofhsa-miR-186and hsa-miR-335. However, the study of the expression of hsa-miR-186and hsa-miR-335regulated by MARVELD1and regulatory mechanisms is not validatedin cell experiments.Therefore, the study preliminarily discussed the regulation ofMARVELD1on the expression of has-miR-186and has-miR-335.Using real-time quantitative RT-PCR (qRT-PCR), we found that the expression ofhas-miR-186and has-miR-335is significantly positive correlated with the expression ofMARVELD1in lung cancer cell lines. Furthermore, we found the expression ofhsa-miR-186and hsa-miR-335is up-regulated in A549cells and HepG2cells containhigh expression levels of exogenous MARVELD1. The positive correlation betweenMARVELD1and hsa-miR-186or hsa-miR-335was also confirmed in NCI-H520cellsand HeLa cells which are interfered by MARVELD1shRNA.It has been confirmed that hsa-miR-186and hsa-miR-335are intronic miRNA, andtheir host genes are ZRANB2and MEST respectively by bioinformatic analysis. Thenour study analyzed the relationship between MARVELD1and the host gene. we foundthat MARVELD1can upregulate the expression levels of host genes ZRANB2andMEST by Using qRT-PCR. In order to investigate the mechanism ofMARVELD1-mediated intronic mir-186and mir-335expression, we foundMARVELD1can interacted with histone H4K20mono-methylation which is located inpromoter of host gene, thereby affecting the expression of host genes, intronichas-miR-186and/or has-miR-335by using chromatin immuno-precipitation techniques.In addition，application of dual luciferase reporter system analysis shows thatCHD7may be a target gene of hsa-miR-186; CHD7and FBXL10may be target genes ofhas-miR-335.In summary, our study identified that when MARVELD1downregulate theexpression of histone H4K20mono-methylation, it can reduce the interaction betweenhistone H4K20mono-methylation and promoter DNA of host gene ZRANB2and/orMEST, thus upregulating the expression of host genes ZRANB2and MEST and alsohsa-miR-186and hsa-miR-335.