| Hepatocellular carcinoma(HCC)is a worldwide health problem,with 850,000 new cases globally every year.This human malignancy is currently the second leading cause of cancer-associated death worldwide.The 5-year survival rates of HCC remain grim,primarily owing to tumor relapse and distant metastasis.Understanding the molecular profiling of HCC will certainly facilitate biological insights,detection of novel therapeutic targets,and the characterization of accurate subsets with prognostic implications influencing HCC clinical surveillance.Spindle and Kinetochore Associated complex subunit 3(SKA3)is a novel discovered component involved in the formation of the Spindle and Kinetochore-Associated complex(SKA).The SKA3 protein might be indispensable for normal chromosome separation and cell division.SKA3 has been identified as original prostate cancer metastasis susceptibility gene.Up-regulation of SKA3 facilitated the conversion of colorectal adenoma to carcinoma.However,the molecular expression signatures,prognostic role of SKA3 in HCC have not been reported.In this study,we systematically analyzed the TCGA database and screened for a novel gene SKA3 which was distinctly up-regulated in HCC tissues at the mRNA level compared adjacent tissues(P＜0.0001).In our 45 pairs of fresh HCC and para-cancerous tissues,we further confirmed the overexpression of SKA3 at mRNA level in HCC tissues(P＜0.0001)by conducting q-PCR.The results of immunohistochemical analysis of tissue microarray in 36 normal liver tissues,31 para-tumor tissues and 166 HCC samples showed that SKA3 was also dramatically overexpressed at protein levels.Further clinical and survival analysis for TCGA cohort revealed that higher expression of SKA3 was remarkably associated with worse histological grade(P<0.0001),shorter overall survival(P=0.0039)and disease-free survival(P=0.0412).Univariate and multivariate analysis of COX regression models performed in TCGA and PUMCH cohort suggested that overexpression of SKA3 was an independent risk factor for poor prognosis in HCC patients with HR=1.894 P=0.008 and HR=1.655,P=0.01,respectively.The functional investigation of SKA3 in HCC cells and normal hepatocyte displayed that knockdown of SKA3 can prominently inhibit the proliferation,cloning,migration and invasion of HCC cells and have no significant effect on the proliferation and cloning formation of normal hepatocyte.At the same time,we preliminarily explored the mechanism of SKA3 over-expression in HCC and discovered that E2F1 could be the upstream transcription factor which regulates SKA3 expression.Our results showed for the first time that the expression of SKA3 in HCC is significantly increased and could be the prognostic biomarker of HCC patients.Silencing of SKA3 can distinctly inhibit the malignant phenotype of HCC cells and has no significant effect on normal hepatocyte,suggesting that it can be used as a potential prognostic biomarker and therapeutic target.Bioinformatic analysis and related experiments verify that E2F1 may be an important upstream transcription factor to regulate the expression of SKA3.Cytoskeleton-Associated Protein 2-Like(CKAL2L),exerts crucial function in cell-cycle progression of neural stem/progenitor cells and the formation of mitotic spindle.CKAP2L has been shown high expression patterns in breast cancer tissues,and preliminary bioinformatics predicted the interaction between the gene and BRCA1 to participate in the occurrence and development of breast cancer.In HCC,however,the expression and biological function of CKAP2L in the evolvement of HCC remain largely unknown.In this study,we systematically analyzed the TCGA database and screened for a novel with high expression in HCC,CKAP2L,which was dramatically up-regulated in HCC tissues at the mRNA level compared adjacent tissues(P＜0.0001).In our 48 pairs of fresh HCC and para-cancerous tissues,we further confirmed the overexpression of CKAP2L at mRNA level in HCC tissues(P<0.0001)by conducting q-PCR.The results of immunohistochemical analysis of tissue microarray in 36 normal liver tissues,31 para-tumor tissues and 158 HCC samples showed that CKAP2L was also dramatically overexpressed at protein levels.Further clinical and survival analysis for TCGA cohort revealed that higher expression of CKAP2L was remarkedly associated with worse histological grade(P<0.0001),TNM stage(P＜0.000 1),shorter overall survival(P=0.0024)and no disease progression(P=0.0171).Univariate and multivariate analysis of COX regression models from TCGA and PUMCH cohort suggested that overexpression of CKAP2L was an independent risk factor for poor prognosis in HCC patients with HR=1.733 P=0.007 and HR=1.604,P=0.046,respectively.Preliminary bioinformatics GO(Gene Ontology)and KEGG(Kyoto Encyclopedia of Genes and Genomes)analysis displayed that CKAP2L may be a vital protein in cell cycle regulation and P53 signaling pathway.In summary,this study confirms for the first time that high expression of CKAP2L in HCC tissue is significantly associated with poor prognosis of HCC patients,and this gene may play a momentous function in the regulation of cell cycle and P53 signaling pathway,thus providing us with new prognostic biomarkers and potential therapeutic targets. |
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