Decreased expression of miR-3135b reduces sensitivity to 5-fluorouracil in colorectal cancer by direct repression of PIM1

xlomafota13 shared this article with you from Inoreader Decreased expression of miR-3135b reduces sensitivity to 5-fluorouracil in colorectal cancer by direct repression of PIM1 Via Experimental and therapeutic medicine Exp Ther Med. 2021 Oct;22(4):1151. doi: 10.3892/etm.2021.10585. Epub 2021 Aug 10. ABSTRACT 5-Fluorouracil (5-FU)-based chemotherapy is the conventional treatment approach for patients with colorectal cancer (CRC). However, de novo and acquired resistance to 5-FU are frequently observed during treatment, which eventually lead to patients succumbing to the disease. Accumulating data have revealed an association of CRC resistance to 5-FU with aberrant expression of microRNAs (miRs). In the present study, Cell Counting Kit-8 was performed to measure cell viability, flow cytometry was performed to detect cell apoptosis, reverse transcription-quantitative PCR was conducted to measure proviral integration site for Moloney murine leukemia virus 1 (PIM1) and miR-3135b expression, western blotting was conducted to measure PIM1 expression. Microarray data analysis indicated that the level of miR-3135b expression was decreased in patients w ith recurrent CRC that were treated with 5-FU when compared with non-recurrent cases. Overexpression of miR-3135b increased the sensitivity of CRC cells to 5-FU treatment. Moreover, PIM1 was identified as a target gene of miR-3135b using bioinformatics analysis, reverse transcription-quantitative PCR and western blotting. The direct interaction between these two targets was confirmed by luciferase reporter assays. Notably, PIM1 overexpression compensated the effect of miR-3135b in CRC cells. Furthermore, an inverse correlation between PIM1 mRNA expression levels and miR-3135b expression was observed in clinical samples. Therefore, the present study identified miR-3135b as a novel regulator of 5-FU sensitivity in CRC. PMID:3450459 6 | PMC:PMC8392875 | DOI:10.3892/etm.2021.10585 View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.