The Effets Of KIAA1199 On Tumorgenesis And Development Of Non-small Cell Cancer And Relative Mechanism

Objectives:The leading cause of death among cancer patients in China is lung cancer,among which non-small cell lung cancer(NSCLC)takes up the vast majority.Due to the limitation of treatment,patients still face a poor survival rate.Thus,it is important that we continue to explore the tumorigenesis of NSCLC and search for new options for targeted therapy.In recent years,more and more researches have shown that KIAA1199 is related to oncogenesis and development of multiple tumors,while its role in NSCLC remains unknown.In this study,we aimed to investigate the effects of KIAA1199 on NSCLC tumorigenesis and the mechanism underneath.Methods:48 NSCLC tissue samples and 48 adjacent non-cancerous tissue samples were collected.Quantitative real-time PCR(qRT-PCR)was used to detect the expression of KIAA1199 and miR-486-5p on mRNA level in tissue samples and cell lines.KIAA1199 knock-down and over-expressing stable cell lines were established for further study.CCK-8 and clonogenic assays were used to investigate cell proliferation ability.Wound healing assays and Transwell assays were used to investigate the motility of cells.A lung carcinoma xenograft mouse model was used to investigate the effects of KIAA1199 in vivo.Western blot was used to investigate the expression level of KIAA1199 and other related proteins.A dual-luciferase assay was used to illustrate the targeted relationship between KIAA1199 and miR-486-5p.Cell proliferation and motility abilities were detected again by CCK-8,cologenic,Transwell and wound healing assays in miR-486-5p mimics or inhibitor transfected cells.Results:(1)KIAA1199 mRNA levels were higher in NSCLC tissues than in adjacent normal tissues.(2)The mRNA and protein expression levels of KIAA1199 were significantly higher in NSCLC cell lines than in the normal cell line,among which A549 and SPC-A1 were chosen for the following experiments.(3)KIAA1199 knock-down and over-expressing stable cell lines were established in A549 and SPC-A1 cells.Inhibition of KIAA1199 suppressed cell growth,migration,and invasion in vitro whereas overexpression of KIAA1199 resulted in the opposite.(4)And inhibition of KIAA1199 can significantly suppress tumor growth in mouse NSCLC xenograft models.(5)MiR-486-5p overexpression can lead to decreased proliferation,migration and invasion of NSCLC cells by suppressing the expression of KIAA1199.(6)In dual-luciferase reporter system,the relative luciferase detected was much lower in the wild-type group,while no significant difference was found in the mutant-type group.(7)In KIAA1199-knockdown cell lines,p-EGFR,EGFR,p-Src,p-Akt,and p-Erk were down-regulated as well as EMT markers Snail,Slug,N-cadherin and Vimentin,which was in consistence with the results in miR-486-5p overexpression cell lines.Adverse results were observed in KIAA1199 overexpressing cell line and miR-486-5p inhibited cell lines.Conclusion:Our study defined KIAA1199 as an oncogenic protein overexpressed in NSCLC and targeted by miR-486-5p.Its downregulation can inhibit tumor proliferation,migration,and invasion by suppressing EGFR signaling and regulating downstream EGFR-induced signaling pathways.