Long Noncoding RNA PCAT18 Upregulates SPRR3 to Promote Colorectal Cancer Progression by Binding to miR-759

Daqing Yang,1 Rizeng Li,1 Jianfu Xia,1 Wencai Li,1 Lili Ma,2 Lechi Ye,3 Haibo Xue4 1Department of Colorectal Surgery, Wenzhou Central Hospital, Wenzhou 325000, People’s Republic of China; 2Department of Rheumatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, People’s Republic of China; 3Department of Colorectal and Anal Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, People’s Republic of China; 4The First Department of Gastroenterology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, People’s Republic of ChinaCorrespondence: Haibo XueThe First Department of Gastroenterology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, People’s Republic of ChinaEmail xuehaibo0409@163.comBackground: Long noncoding RNAs (lncRNAs) play essential functions in the development of several cancers, including colorectal cancer (CRC). Nevertheless, how PCAT18 regulates CRC tumorigenesis remains unclear. In this research, we aimed to investigate the roles of PCAT18 in CRC.Materials and Methods: qRT-PCR and Western blot were used to analyze RNA and protein levels. CCK8, colony formation, transwell and wound healing assays were utilized to analyze proliferation, migration and invasion. Luciferase reporter assay was used to analyze RNA interactions.Results: PCAT18 was found to be highly expressed in CRC tissues and cells. PCAT18 level was positively correlated with lymph node metastasis and TNM stage. Functionally, PCAT18 silencing induced impairment of CRC proliferation, migration and invasion. Besides, PCAT18 was identified to inhibit miR-759. PCAT18 promotes SPRR3 expression through binding to miR-759. Furthermore, miR-759 inhibitors or SPRR3 ectopic expression partially rescued the abilities of proliferation, migration and invasion in CRC cells transfected with sh-PCAT18.Conclusion: Therefore, our study demonstrated that PCAT18 contributes to CRC progression through regulating miR-759/SPRR3 axis, which provides a new theoretical basis of explaining CRC tumorigenesis.Keywords: long noncoding RNA, PCAT18, miR-759, SPRR3, colorectal cancer