Study On Centromere Protein O Expression Enhances Angiogenesis Via PI3K/AKT/VEGF Signaling Pathway In Gastric Cancer

Background:Gastric cancer is one of the most common malignant tumors of the digestive tract and is the third leading cause of cancer death worldwide.Early stage gastric cancer is usually asymptomatic.50% of patients are diagnosed with advanced gastric cancer.Surgical resection and chemotherapy are common modalities of treatment in gastric cancer.However,with the development of precision medicine,antiangiogenic therapy and immunotherapy has started to play a more important role.Angiogenesis is correlated with the occurrence and development of advanced gastric cancer.Centromere protein O(CENPO)is a member of centromere proteins and a transient kinetochore protein.Recently,several reports have indicated that centromere proteins are associated with angiogenesis.Through public databases analysis and experiments,we examined that CENPO was higher in gastric cancer tissues,compared with that in adjacent noncancerous tissues.Association of CENPO expression and angiogenesis was verified in vitro and in vivo.The results of the present study suggest a potential novel therapeutic target for the treatment of gastric cancer.Methods:1.Through Timer databases,GEPIA analysis,q RT-PCR and Western Blot analysis,we examined the differential expression of CENPO in gastric cancer tissues and in adjacent noncancerous tissues.2.The CENPO-RNA interference(RNAi)lentiviral vector was constructed and stable expression cell lines were established by virus infection.Following transfection,the cancer cells were co-cultured with human umbilical vein endothelial cells(HUVECs).Flow Cytometer,CCK-8 assay,wound healing and tube formation assay was performed to evaluate the effects of downregulated CENPO on cell cycle and angiogenesis.3.Transcriptome analysis was performed on the gastric cancer cell lines and control cell lines with low expression of CENPO.Differential Gene Expression were screened.Pathway analysis was performed using the KEGG and Western Blot to identify significant enrichment of signal pathways.4.Using gastric cancer cell line stably expressing CENPO,a nude mouse model of peritoneal transplantation was established,and the effect of silencing CENPO expression on tumor growth was observed by tumor number and imaging analysis.HE staining and immunohistochemical examination were performed to evaluate the effects of downregulated CENPO on angiogenesis.Results:1.We examined that CENPO was higher expressed in gastric cancer tissues than in adjacent noncancerous tissues through Timer databases,GEPIA analysis,q RT-PCR and Western Blot analysis.2.Downregulation of CENPO expression cause cell cycle arrest at the G2 phase in gastric cells.Downregulation of CENPO expression suppresses cell proliferation migration and tube formation in HUVEC.3.Transcriptome sequencing results showed that there were 605 up-regulated genes,and 593 downregulated specific genes in HGC27 cell lines;there were 342up-regulated genes,and 409 downregulated specific genes in MGC803 cell lines;The KEGG pathway analysis found that CENPO may exert angiogenesis effect mainly through PI3K/AKT/VEGF signaling pathway.The expression levels of p-PI3 K,p-AKT and VEGF in gastric cancer cells by western blot analysis.4.The number of xenograft tumors in the abdominal cavity of nude mice and the mean fluorescence intensity of GFP in the group of downregulation of CENPO expression were significantly decreased.HE staining and immunohistochemical staining showed that in microvascular density were significantly decreased.Conclusions:CENPO is upregulated in gastric cancer.CENPO could regulate the angiogenesis of gastric cancer via the PI3K/AKT/VEGF signaling pathway,and provide new therapeutic targets for the treatment of gastric cancer.