Expression profile of lncRNAs in CSCs and non-CSCs of bladder cancer cell line

Bladder cancer stem cells (CSCs) contribute to tumorigenesis, recurrence and chemoresistance of bladder cancer. However, the molecular mechanisms underlying their self-renewal are poorly unknown. Long noncoding RNAs (lncRNAs) act as crucial regulators in a lot of human cancers, yet their potential roles and molecular mechanisms in bladder CSCs are poorly understood. The goal of this study is to identify the differentially expressed lncRNAs in bladder CSCs (UM-UC-3 4th spheres), its two differentiation sublines and bladder non-CSCs (UM-UC-3). Our study reveals that deregulation of lncRNAs is involved in the bladder CSCs. We first constructed a gemcitabine resistant bladder cancer cell line termed UM-UC-3 4th by consecutively passaging bladder cancer cells in NOD/SCID mice treated with chemotherapy. Next, we found that UM-UC-3 4th cells had stronger chemoresistant and self-renewal ability than parental UM-UC-3 cells in vitro and in vivo. Furthermore, UM-UC-3 4th formative spheres had contained more ALDH+ cells and increased CSCs marker expression, such as OCT4, SOX2 and NANOG. Therefore we used UM-UC-3 4th spheres as bladder CSCs for further study. Previous study showed that when the spheres were digested into single cells and cultured in 10% FBS medium, the CSCs was gradually differentiation. So we detected differentially expressed lncRNAs in bladder CSCs (UM-UC-3 4th spheres), bladder CSCs differentiation 10 hours, 1 day and bladder non-CSCs (UM-UC-3) by microarray.