MiR-26a inhibits proliferation and migration of HaCaT keratinocytes through regulating PTEN expression

• Here, we revealed that ectopic expression of miR-26a mimic or inhibitor increased or decreased miR-26a expression respectively in HaCaT cells. Proliferation and migration of HaCaT keratinocyte was suppressed or promoted by overexpression or down-expression of miR-26a in vitro cell model. In mechanism analysis, miR-26a was showed to regulate PTEN expression in HaCaT cells. In rescue experiment, knockdown of PTEN in the miR-26a mimic transduced cells recovered the migration ability. Together these results suggested that miR-26a modulates proliferation and migration of keratinocytes via PTEN/AKT signaling.

MicroRNAs (miRNAs) have been shown to be associated with differentiation, migration and apoptosis in keratinocyte. Although it has been reported that microRNA-26a (miR-26a) plays important roles in tumor cells, its biological functions in keratinocytes are still not well elucidated. In this study, we confirmed expression of miR-26a in human keratinocytes using RT-PCR and further studied the role of miR-26a in cell proliferation and cell migration. Ectopic expression of MiR-26a mimic or inhibitor increased or decreased miR-26a expression respectively in HaCaT cells. Proliferation of HaCaT keratinocyte can be suppressed or promoted by overexpression or down-expression of miR-26a. In scratch wound-healing assay and Boyden chamber cell migration assay, upregulating miR-26a expression blocked cell migration, while downregulating miR-26a expression enhanced the migration. Using quantitative RT-PCR (qRT-PCR) and western blot, we further discovered that both mRNA and protein level of phosphatase and tensin homolog deleted from chromosome 10(PTEN) were regulated by miR-26a in HaCaT cells. Meanwhile the level of active form of AKT was also regulated by the miR-26a. In rescue experiment, knockdown of PTEN in the miR-26a mimic transduced cells recovered the migration ability of HaCaT cells. Together these results suggest that miR-26a modulates the proliferation and migration of keratinocytes via regulating PTEN/AKT signaling pathway.