LncRNA SLCO4A1-AS1 modulates colon cancer stem cell properties by binding to miR-150-3p and positively regulating SLCO4A1

Long non-coding RNAs (lncRNAs) play important roles in a range of different human cancers. However, the role of lncRNA solute carrier organic anion transporter family member 4A1-AS1 (SLCO4A1-AS1) in colon cancer remains enigmatic. Hence, we aimed to explore the specific role of SLCO4A1-AS1 in colon cancer stem cells. Colon cancer-related differentially expressed lncRNA and mRNA were screened using microarray-based analysis, and the expression of SLCO4A1-AS1 and SLCO4A1 in colon cancer tissues was determined using reverse transcription quantitative polymerase chain reaction and western blot analysis. The interaction among SLCO4A1-AS1, microRNA-150-3p (miR-150-3p) and SLCO4A1 was verified using dual-luciferase reporter assay, RNA immunoprecipitation and RNA pull-down. Moreover, SLCO4A1-AS1, miR-150-3p and/or SLCO4A1 were overexpressed or depleted in colon cancer cells to detect their effects on migration, invasion, sphere formation, apoptosis and tumorigenesis abilities of colon cancer stem CD133(+)CD44(+) cells using both in vitro and in vivo assays. SLCO4A1-AS1 and SLCO4A1 were screened as the differentially expressed lncRNA and mRNA in colon cancer tissues. SLCO4A1-AS1 was confirmed to competitively bind to miR-150-3p to elevate SLCO4A1 expression. Moreover, knockdown of SLCO4A1-AS1 decreased SLCO4A1 expression, thus inhibiting cell migration, invasion, sphere formation, and tumorigenesis abilities and enhancing the apoptosis of CD133(+)CD44(+) cells. Collectively, these findings provide evidence demonstrating that depleting SLCO4A1-AS1 competitively binds to miR-150-3p, which downregulates SLCO4A1 expression, thus hindering colon cancer progression.