| Background:Cervical cancer is the second-most common malignancy in women worldwide and is often diagnosed at a local and advanced stage.Most cases of cervical cancer occur in developing countries,with a trend of younger patients being observed.Although the 5-year survival rate of early cervical cancer is 85%or higher,the prognosis of locally advanced disease remains unfavorable,with an overall 5-year survival rate of approximately 30-50%.Therefore,it is urgent to identify novel molecular markers of cervical cancer to facilitate a more accurate prediction of clinical outcomes and prescribe effective treatments.Analysis of The Cancer Genome Atlas(TCGA)database showed that the KIF18B gene is highly expressed in cervical cancer tissue but exhibits low expression in paracancerous tissue.KIF18B was identified as a potential oncogene in cervical cancer.The present study aimed to investigate the function and mechanism research of KIF18B promotes tumor progression of cervical cancer.Methods:1.By analyzing the TCGA_CESC_exp_HiSeqV22015-02-24 dataset,cervical cancer tissues showed 3.4-fold hyperexpression of KIF18B compared with normal cervical tissues,in close association with a large primary tumor size and an advanced FIGO stage.Subsequently,Human Protein Atlas immunohistochemistry(IHC)analyses showed that KIF18B was not expressed in normal cervical tissues but was expressed in cervical cancer tissue samples.We next detected expression of KIF18B in 30 paired cervical cancer tissue samples(tumor and adjacent normal cervical tissues)using qRT-PCR.IHC were used for detection of KIF18B expression in normal cervical tissues and in cervical cancer tissues.2.KIF18B expression was examined in cervical cancer cell lines by real-time PCR and western blot analyses.Specific siRNAs was designed to silence the expression of KIF18B in Hela and Siha cell lines,evaluated the effects of KIF18B on cervical cancer cell proliferation,migration,and invasion both in vitro and in vivo.Overexpression plasmids was construct to overexpression of KIF18B in C33A and Caski cell lines,also evaluated the effects of KIF18B on cervical cancer cell proliferation,migration,and invasion both in vitro.3.GO enrichment analysis were used to predict the potential pathway where KIF18B might exert its oncogenic role.The expression of cell cycle related proteins were examined in cervical cancer cell lines by real-time PCR and western blot analyses.4.Western blot was engaged for determining the protein levels of Wnt/?-catenin signaling pathway related proteins ?-catenin,C-myc,GSK3 ?,p-GSK3 ?.5.Silence the expression of KIF18B in Hela cell,use the TOP/FOP luciferase report gene detect the luciferase activity.6.The Wnt/?-catenin signaling pathway activation agent lithium chloride(LiCl)was used for processing Hela.The effects of LiCl on cell proliferation and migration were observed,the changes of Wnt/?-catenin signaling pathway related proteins was also investigated by Western blot analyses.Results1.By analyzing the TCGA_CESC_exp_HiSeqV22015-02-24 dataset,cervical cancer tissues showed 3.4-fold hyperexpression of KIF18B compared with normal cervical tissues,in close association with a large primary tumor size and an advanced FIGO stage.Subsequently,Human Protein Atlas immunohistochemistry(IHC)analyses showed that KIF18B was not expressed in normal cervical tissues but was expressed in cervical cancer tissue samples.We next detected expression of KIF18B in 30 paired cervical cancer tissue samples(tumor and adjacent normal cervical tissues)using qRT-PCR and found that KIF18B was overexpressed in 87%(26 of 30)these patients.Overexpression of KIF18B was positively correlated with a large primary tumor size,an advanced tumor grade and an advanced FIGO stage.2.KIF18B was hyperexpressed in cervical canacer cell lines compared with that in cultured human keratinocyte(Hacat)cells.Knockdown of KIF18B induces cell cycle G1-phase arrest and inhibits the proliferation,migration,and invasion of cervical cancer cells,whereas its overexpression promotes proliferation,migration and invasion in these cells.When compared with the control group,tumor volumes and tumor weight were smaller in the shKIF18B-treated groups for Hela and Siha cell lines.IHC staining revealed weaker Ki-67 expression in the sh-NC group than in the sh-KIF18B group,suggesting that silencing KIF18B inhibits tumor growth in vivo.3.si-KIF18B treatment decreased both the mRNA and protein levels of CyclinD1 compared with si-NC treatment,whereas expression of p21,p27,and CyclinE was not affected.4.We then assessed proteins related to the Wnt/?-catenin pathway found that compared to the si-NC group,the si-KIF18B group showed decreased levels of C-myc,?-catenin and the phosphorylation of GSK3 ?,but the total level of GSK3? has no obvious differences.5.After silence the expression of KIF18B in Hela cell,the luciferase activity of TOP/FOP luciferase was significantly decreased.6.The proliferation and migration capacity of Hela cells was increased after the addition of the Wnt/?-catenin signaling pathway activator(LiCl),and the levels of CyclinD1,?-catenin,C-myc and p-GSK3 ? were increased in the cells.Conclusions:1.KIF18B can serve as a novel oncogene that promotes the tumorigenicity of cervical cancer cells.2.KIF18B was overexpressed in cervical cancer,can promote the proliferation,migration and invasion of cervical cancer.Knockdown of KIF18B induces cell cycle G1-phase arrest and inhibits the proliferation,migration,and invasion of cervical cancer cells,whereas its overexpression promotes proliferation,migration and invasion in these cells.3.KIF18B is able to regulate cervical cancer invasion and metastasis by Wnt/?catenin signaling pathway. |
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