Colorectal cancer stem cell-derived exosomal long intergenic noncoding RNA 01315 (LINC01315) promotes proliferation, migration, and stemness of colorectal cancer cells

Abstract

The effect of long intergenic noncoding RNA 01315 (LINC01315) on colorectal cancer has widely been proved. Nevertheless, how LINC01315 functions in the stemness of colorectal cancer and whether LINC01315 exists in colorectal cancer stem-like cell-derived exosomes remain dim, which are thus investigated in this research. CD133+/CD44+ colorectal cancer stem cells were sorted and verified through flow cytometry. Exosomes derived from CD133+/CD44+ colorectal cancer stem cells were collected. The viability, proliferation, stemness and migration of CD133+/CD44+, CD133−/CD44−, and colorectal cancer cells after transfection or the co-culture with exosomes were detected by MTT, colony formation, spheroid, and wound healing assays, respectively. Expressions of LINC01315, BCL-2, Bax, cleaved caspase-3, MMP-9, E-cadherin, and vimentin in cells or exosomes were analyzed using western blot or qRT-PCR. Genes interacted with LINC01315 in colorectal cancer were predicted by bioinformatics analysis. The results showed that LINC01315 was high-expressed in CD133+/CD44+ colorectal cancer stem cells and exosomes. Compared with colorectal cancer cells, the viability, proliferation, stemness, and migration of CD133+/CD44+ cancer cells were stronger, while these of CD133−/CD44− cancer cells were weaker. Besides, LINC01315 silencing decreased the viability, proliferation, stemness, and migration of CD133+/CD44+ cancer cells, while sh-LINC01315 inhibited the promotive effects of CD133+/CD44+ cancer cell-derived exosomes on the viability, proliferation, stemness, and migration of colorectal cancer cells. LINC01315 was also found to be correlated with DPEP1, KRT23, ASCL2, AXIN2, and DUSP4 in colorectal cancer. In conclusion, colorectal cancer stem cell-derived exosomal LINC01315 promotes the proliferation, migration, and stemness of colorectal cancer cells.