The Novel lncRNA RP9P Promotes Colorectal Cancer Progression by Modulating miR-133a-3p/FOXQ1 Axis

Zhichao Jin; Baoxinzi Liu; Bofan Lin; Ran Yang; Cunen Wu; Weiwei Xue; Xi Zou; Jun Qian

doi:10.3389/fonc.2022.843064

The Novel lncRNA RP9P Promotes Colorectal Cancer Progression by Modulating miR-133a-3p/FOXQ1 Axis

Front Oncol. 2022 May 5:12:843064. doi: 10.3389/fonc.2022.843064. eCollection 2022.

Authors

Zhichao Jin^{1

2}, Baoxinzi Liu^{1

2}, Bofan Lin^{1

2}, Ran Yang^{1

2}, Cunen Wu^{1

2}, Weiwei Xue^{1

2}, Xi Zou^{1

2}, Jun Qian^{1

2}

Affiliations

¹ Department of Oncology, Jiangsu Province Hospital of Chinese Medicine, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China.
² Jiangsu Collaborative Innovation Center of TCM Cancer Prevention and Treatment, Nanjing, China.

Abstract

Background: The long non-coding RNA (lncRNA) RP9 pseudogene (RP9P) is a pseudogene-derived lncRNA that has never been reported in cancer, and its function underlying tumorigenesis in colorectal cancer (CRC) remains unknown.

Methods: RP9P and miR-133a-3p were filtered through bioinformatics analysis. The level of RP9P, miR-133a-3p, and FOXQ1 in CRC cell lines was detected by real-time PCR. Cell Counting Kit-8 and flow cytometric analyses were used to detect cell proliferation and apoptosis, respectively. Interactions between RP9P, miR-133a-3p, and FOXQ1 were confirmed by a dual-luciferase reporter assay.

Results: RP9P was overexpressed in CRC compared to normal control tissues and cells. Knockdown of RP9P inhibited CRC cell viability. RP9P directly interacted with miR-133a-3p, and miR-133a-3p downregulation abrogated the tumor-suppressing effect of RP9P knockdown. miR-133a-3p directly targeted FOXQ, which was positively regulated by RP9P. RP9P knockdown decreased FOXQ1 expression levels in CRC cells by directly targeting miR-133a-3p via a sponge mechanism. In addition, in vivo experiments in a xenograft model revealed that downregulated RP9P expression inhibited CRC cell tumorigenesis.

Conclusion: RP9P promotes colorectal cancer progression by regulating the miR-133a-3p/FOXQ1 axis.

Keywords: RP9P; ceRNA; colorectal cancer; lncRNA; miR-133a-3p.