LAUSR

ABSTRACT Colorectal cancer (CRC) is the third most common cancer worldwide. Previous research revealed that microRNA 130b-3p (miR-130b-3p) significantly upregulated in CRC patients can be detected in feces from patients with such a neoplasm. In this study, the biological role and molecular mechanism of miR-130b-3p in CRC were explored. The miR-130b-3p level in CRC tissues, feces and cell lines was measured using RT-qPCR analysis. CCK-8, EdU, TUNEL, flow cytometry, Western blotting, and in vivo experiments were performed to explore the biological function of miR-130b-3p in CRC progression. For this purpose, 16 BALB/c nude mice were assigned to two groups. The experiment lasted for four months. Bioinformatics analysis and luciferase reporter assay were used to investigate the regulatory mechanism related to miR-130b-3p. In our research, miR-130b-3p was upregulated in CRC tissues and cells and it was detected in feces from CRC patients. Moreover, miR-130b-3p inhibition suppressed CRC cell proliferation and promoted cell apoptosis in vitro as well as repressed CRC tumor growth in vivo. Mechanistically, miR-130b-3p directly targeted the 3′untranslated region (UTR) of chromodomain helicase DNA binding protein 9 (CHD9) and negatively regulated CHD9 expression. Furthermore, CHD9 played an anti-oncogenic role in CRC. Inhibition of CHD9 expression was likely to be a key mechanism by which miR-130b-3p increased CRC cell growth, with a target protector experiment revealing miR-130b-3p influenced proliferation via direct inhibition of CHD9. MiR-130b-3p promotes the progression and tumorigenesis of CRC at least partially by targeting CHD9. Abbreviations: CRC: Colorectal cancer; miR-130b-3p: microRNA 130b-3p; CHD9: chromodomain helicase DNA binding protein 9; UTR: untranslated region; FIT: fecal immunochemical test; AAs: advanced adenomas