Low expression of lncRNA TUBA4B promotes proliferation and inhibits apoptosis of colorectal cancer cells via regulating P15 and P16 expressions.

Abstract

To explore the expression, function, and regulation mechanism of the long non-coding ribonucleic acid (lncRNA) tubulin alpha 4b (TUBA4B) in colorectal cancer (CRC) tissues and cells. Cancer and adjacent tissues were collected from 60 CRC patients. CRC cell lines SW480, SW620, HCT116, Caco-2, DLD-1 and HT29, and colonic epithelial cell line CCD841 were also enrolled. Then, the expression of TUBA4B in CRC tissues and cell lines was detected via quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). In vitro assays [cell counting kit-8 (CCK-8) assay, clone formation assay, and flow cytometry] were performed to study the biological function of TUBA4B in CRC. Additionally, the downstream regulatory targets of TUBA4B were investigated through Western blotting analysis and qRT-PCR assay. The results of qRT-PCR revealed that compared with adjacent tissues, the expression of TUBA4B was down-regulated in 47/60 CRC tissues (47/60, 78.3%). According to in vitro assays (CCK-8 assay, clone formation assay, and flow cytometry), over-expression of TUBA4B inhibited the proliferation and promoted the apoptosis of CRC cells. TUBA4B remarkably regulated mRNA and protein levels of p15 and p16. LncRNA TUBA4B is down-regulated expression in CRC tissues and cells, which facilitates CRC cell proliferation and suppresses apoptosis by regulating the expressions of p15 and p16.