Cancer Management and Research (Feb 2020)

Long Non-Coding RNA Cancer Susceptibility 9 (CASC9) Up-Regulates the Expression of ERBB2 by Inhibiting miR-193a-5p in Colorectal Cancer

  • Ding Y,
  • Li X,
  • Zhang Y,
  • Zhang J

Journal volume & issue
Vol. Volume 12
pp. 1281 – 1292

Abstract

Read online

Yuansheng Ding, Xiaoyan Li, Yucui Zhang, Jie Zhang The First Department of General Surgery, Linyi Central Hospital, Linyi 276400, Shandong Province, People’s Republic of ChinaCorrespondence: Jie ZhangThe First Department of General Surgery, Linyi Central Hospital, Jiankang Road No. 17, Yishui, Linyi 276400, Shandong, People’s Republic of ChinaEmail [email protected]: Emerging studies have reported that long non-coding RNAs (lncRNAs) were crucial regulators in the progression of colorectal cancer (CRC). LncRNA susceptibility 9 (CASC9) was involved in several cancers; however, its role in CRC remains unknown.Methods: RT-PCR was done to probe the expression of CASC9 and miR-193a-5p in CRC samples. CRC cell lines (HCT116 and SW480) were used as cell models. The biological influence of CASC9 on cancer cells was studied using CCK-8 assay, Transwell assay and TUNEL assay in vitro, and subcutaneous xenotransplanted tumor model in vivo. Interaction between CASC9 and miR-193a-5p was investigated by bioinformatics analysis, RT-PCR, and luciferase reporter assay. The expression level of the downstream gene of miR-193a-5p, erb-b2 receptor tyrosine kinase 2 (ERBB2), was tested by Western blot.Results: CASC9 was significantly up-regulated in CRC samples, while miR-193a-5p was markedly down-regulated. Overexpression of CASC9 promoted viability, migration and invasion of CRC cells, while overexpression of miR-193a-5p had the opposite effect. CASC9 could down-regulate miR-193a-5p via sponging it, and there was a negative relevancy between CASC9 and miR-193a-5p in CRC samples. CASC9 also enhanced the expression levels of ERBB2, while this effect could be reversed by co-transfection with miR-193a-5p.Conclusion: CASC9, an oncogenic lncRNA, was abnormally up-regulated in CRC tissues, and it could indirectly modulate the expression of ERBB2 via reducing the expression level of miR-193a-5p.Keywords: colorectal cancer, long non coding RNA cancer susceptibility 9, CASC9, microRNA-193a-5p, erb-b2 receptor tyrosine kinase 2, ERBB2

Keywords