Gene expression analysis

Background and Aim: Colorectal cancer (CRC) is a malignancy with a significant global disease burden. Trimethylamine N-oxide (TMAO) plays a role in tumorigenesis. The oncogenic long non-coding RNA highly upregulated in liver cancer (HULC) plays a pivotal role in CRC progression. However, the exact molecular mechanism of HULC and its correlation with TMAO in CRC pathogenesis has remained unclear. The present study investigated whether TMAO causes CRC development through HULC.

Material and Methods: HULC expression was measured at the exposure of TMAO (300μM) in caco-2 cells using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). HULC was knocked down using CRISPR/Cas13 system, followed by gene expression analysis of its downstream targets, including miR21-5p, miR-200a-3p, and miR34a-5p. A one-way ANOVA test was used to compare the mean ± SD of gene expression across various groups, followed by post-hoc tests.

Results: HULC was significantly upregulated in Caco-2 cell lines under TMAO treatment. Additionally, treatment with TMAO increased the expression of the oncogenic downstream target of HULC, comprising miR-21-5p and miR-200a-3p, while the knockdown of HULC led to a reduction of these miRNAs even under TMAO treatment.

Conclusion: This study showcases the potential of TMAO to elevate an oncogenic lncRNA, HULC, which is highly associated with CRC development, mediated by miR-21-5p and miR200a-3p.