Induction of MiR-17-3p and MiR-106a [corrected] by TNFα and LPS.

MicroRNAs (miRNAs), small non-coding molecules, regulate gene expression in response to stimuli. Lipopolysaccharide (LPS) was reported to induce the expression of miR-146 and miR-155 in HL-60. The effects of LPS and the related stimulus, tumour necrosis factor alpha (TNFα), on miRNA expression required to be further studied. Using T7-oligo ligation assay (OLA)-based miRNA array, we profiled the expression of 132 miRNAs and identified a number of TNFα-regulated miRNAs in HeLa cells, including miR-17-3p and miR-106a. TNFα induction of miR-17-3p and miR-106a was verified by Northern blot analysis with RNU48 normalization. Northern blot analysis also showed that LPS was able to induce the expression of both miR-17-3p and miR-106a in HeLa cells. Furthermore, both array assay and Northern blot analysis showed that the expression levels of miR-146 and miR-155 were either low or undetectable in HeLa cells and TNFα- and LPS-mediated induction of these two miRNAs was not found. Luciferase reporter analysis confirmed the induction of miR-17-3p and miR-106a in response to TNFα and LPS treatment in HeLa cells. These results suggested that the expression of miR-17-3p and miR-106a is regulated by TNFα and LPS in HeLa cells.