Dr. Weeks’ Comment: More support for the cancer STEM cell hypothesis.
MiR-155 targets TP53INP1 to regulate liver cancer stem cell acquisition and self-renewal
- •MiR-155 was up-regulated in enriched tumor-sphere cells.
- •MiR-155 overexpression and TP53INP1 down-regulation is associated with stem cell-like cells generation and self-renewal.
- •MiR-155 targets TP53INP1 to regulate the stem cell-like cells acquisition and self-renewal.
In liver cancer, miR-155 up-regulation can regulate cancer-cell invasion. However, whether miR-155 expression is associated with liver cancer stem cells (CSCs) remains unknown. Here, we show that miR-155 expression is up-regulated in tumor spheres. Knock-down of miR-155 resulted in suppression of tumor sphere formation, through a decrease in the proportion of CD90+ and CD133+ CSCs and in the expression of Oct4, whereas miR-155 overexpression had the opposite effect. TP53INP1 was determined to be involved in the CSCs-like properties that were regulated by miR-155. Thus, miR-155 may play an important role in promoting the generation of stem cell-like cells and their self-renewal by targeting the gene TP53INP1.