MicroRNA 196B Regulates HOXA5, HOXB6 and GLTP Expression Levels in Colorectal Cancer Cells

MiRNAs are non-coding RNAs that play important roles in the pathogenesis of human diseases by regulating target gene expression in specific cells or tissues. Previously we identified colorectal cancer (CRC) associated MIR196B , which was specifically up-regulated in CRC cells and tissue. We also identified 18 putative MIR196B target genes by comparing the mRNAs down-regulated in MIR196B -overexpressed cells with MIR196B target genes predicted by public bioinformatics tools. In this study, we verified the association between MIR196B and three genes, HOXA5 , HOXB6 and GLTP . HOXA5 , HOXB6 and GLTP transcripts were directly down-regulated by MIR196B . The mRNA and proteins levels of HOXA5, HOXB6 and GLTP were also down-regulated in CRC cells by the up-regulated MIR196B . GLTP protein expression was decreased in CRC tissues compared to adjacent non-tumor tissues. These results suggest that HOXA5 , HOXB6 , and GLTP were direct target genes of MIR196B in CRC cells, and that the up-regulated MIR196B in CRC tissue regulates the expression levels of HOXA5, HOXB6, and GLTP during colorectal carcinogenesis.