Document Type : Original Article
Authors
1
Student Research Committee, Kurdistan University of Medical Sciences, Sanandaj, Iran.
2
Department of Immunology, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran.
3
Cellular and Molecular Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran.
4
Liver& Digestive Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran.
Abstract
Colorectal cancer (CRC) is a malignancy with a significant global disease
burden.Trimethylamine N-oxide (TMAO), a gut microbiota-derived metabolite, has been
implicated 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. This study tested whether TMAO regulates HULC and whether HULC
mediates changes in selected miRNAs relevant to CRC.
Caco-2 cells were treated with TMAO (300 µM, 24 h) and HULC expression was
quantified by RT-qPCR. HULC was transiently silenced using CRISPR/Cas13 (CasRx)
and the expression of candidate downstream miRNAs (miR-21-5p, miR-200a-3p and
miR-34a-5p) was measured by stem-loop RT-qPCR. Data are presented as mean ± SD of
at least three independent biological replicates. Group differences were analyzed by
ANOVA with appropriate post-hoc testing.
TMAO treatment significantly increased HULC expression in Caco-2 cells. TMAO also
elevated miR-21-5p and miR-200a-3p levels; these increases were attenuated when
HULC was silenced. miR-34a-5p expression was not significantly affected by TMAO or
by HULC knockdown.
This study demonstrates that TMAO upregulates the oncogenic lncRNA HULC, and this
upregulation is associated with increases the expression of miR-21-5p and miR-200a-3p.
These findings reveal a TMAO-HULC signaling axis that positively influences the levels
of oncogenic miRNAs. However, since a single cell line model was used in this study, it
needs for further investigation across diverse CRC cell lines to confirm its
generalizability.
Keywords: CRISPR/Cas13, CRC, HULC, TMAO, miRNA
Keywords