Expression Of CCDC34 In Gastric Cancer And Its Correlation With Patients’ Prognosis

BackgroundGastric cancer is one of the most common malignant gastrointestinal tumors in the world,and its morbidity and mortality are the second highest among all malignant tumors.Most patients have reached the stage of diagnosis and lost the opportunity for best treatment,while the overall prognosis is poor.In view of this,how to improve the early diagnosis rate,explore highly sensitive biological diagnostic markers and identify new molecular targets to develop better targeted drugs have become one of the hot topics in the field of gastric cancer research.This study will mainly detect the expression level of CCDC34 in gastric cancer and evaluate its clinical prognostic significance in order to provide some theoretical reference for the targeted therapy of gastric cancer.ObjectiveTo detect the expression level of CCDC34 in gastric cancer and explore its clinical significance.MethodsFirstly,we analyzed the gastric cancer and normal tissues data of cancer public databases(TCGA,GEO and GTX)by bioinformatics methods to predict the expression of CCDC34 mRNA.Then,80 cases of gastric cancer and matched adjacent normal tissues were retrospectively collected to detect the expression level of CCDC34 protein by immunohistochemical staining.Besides,bioinformatics method was used to determine the difference between CCDC34 expression and gastric cancer patients with various clinicopathological parameters,and survival analysis using Kaplan-Meier method was performed to determine whether it has a clinical prognostic significance.Finally,immunohistochemical real data were analyzed to explore the potential molecular mechanism,through investigation of relationship between CCDC34 and angiogenesis related indicators(VEGF,MVD value labeled by CD31).ResultsBased on the TCGA and Oncomine databases,we found that the mRNA expression of CCDC34 in gastric cancer was significantly higher than that in normal gastric tissue(All P <0.05).Then,immunohistochemical staining confirmed that CCDC34 expression was significantly higher in gastric cancer tissues(80%,64/80)than in adjacent normal tissues,with significant difference between the two groups(P <0.001).Subsequently,Kaplan-Meier Plotter tool survival analysis found that patients with high expression of CCDC34 mRNA had significantly lower overall survival(OS)and progression-free survival(PFS)than those with low expression of CCDC34 mRNA(P = 0.0014 and 0.034,respectively).The risk factors HR were 1.42 and 1.29,respectively.Meanwhile,the subgroup survival analysis based on the clinicopathological parameters of gastric cancer patients showed that there was a difference in OS and PFS between patients with low-and high-expression of CCDC34,of which the clinical parameters in both OS and PFS were statistically significant were listed as follows: stage 2,T2,T3,N3,M0,mixed Lauren classification,poorly histological differentiation,female patients.In addition,based on immunohistochemical data,correlation analysis showed that there was a significant positive relationship between the expression of CCDC34 and VEGF or CD31(r = 0.75 and 0.74,respectively,all P <0.05).Moreover,patients with high expression of CCDC34 had higher MVD counts than those with low expression of CCDC34(P <0.001).ConclusionsCCDC34 was significantly higher expressed in gastric cancer and patients with high expression of CCDC34 had poor prognosis,the mechanism of which may be associated with promoting tumor angiogenesis by CCDC34.These results suggest that CCDC34 may be a potential target for anti-angiogenic therapy of gastric cancer,which is worth further exploration in the future.