Long non-coding RNA HULC affects the proliferation, apoptosis, migration, and invasion of mesenchymal stem cells.

Further studies on the molecular mechanisms of mesenchymal stem cells in the maintenance of growth and function are essential for their clinical application. Growing evidence has shown that long non-coding RNAs (lncRNAs) play an important role in the regulation of mesenchymal stem cells. Recently, it is reported that highly upregulated in liver cancer (HULC), with another lncRNA MALAT-1, accelerated liver cancer stem cell growth. The regulating role of MALAT-1 in mesenchymal stem cells has been investigated. However, the effects of HULC on the mesenchymal stem cells are unknown. In this study, we overexpressed HULC in mesenchymal stem cells derived from umbilical cord and analyzed the cell phenotypes, proliferation, apoptosis, migration, invasion and differentiation of mesenchymal stem cells. We found that overexpression of HULC significantly promotes cell proliferation through promoting cell division and inhibits cell apoptosis. HULC-overexpressed mesenchymal stem cells migrate and invade faster than control mesenchymal stem cells. HULC has no effect on phenotypes and differentiation of mesenchymal stem cells. Furthermore, we found that the expression of HULC in mesenchymal stem cells could be reduced by several inflammatory factors, including TNF-α, TGF-β1, and R848. Taken together, our data demonstrated that HULC has a vital role in the growth and function maintenance of mesenchymal stem cells without affecting differentiation. Impact statement Exploring the molecular mechanisms of growth and function in MSCs is the key to improve their clinical therapeutic effects. Currently, more and more evidence show that the long non-coding RNA (lncRNA) plays an important role in the growth, stemness and function of MSCs.Both HULC and MALAT1 are the earliest discovered LNCRNAs, which are closely related to tumor growth. All of them can promote the growth of liver cancer stem cells. Previously, we have studied the effects of MALAT1 on the growth and function of MSCs. In this study, we focused on the effects of HULC on MSCs. We elucidated the effects of HULC on the growth and differentiation of MSCs, and explored the relationship between inflammatory stimuli and HULC expression in MSCs. Our findings provide a new molecular target for the growth and clinical application of MSCs.