Expression Of GPR120 And VEGF In Non-small Cell Lung Cancer And Clinical Significance

Research background and purpose:Lung cancer is the malignant tumor with the highest morbidity and mortality in China,and about 85% of them are non-small cell lung cancer(NSCLC).Most patients have reached the advanced stage with symptom,which result in a low five-year survival rate.One of the important reasons is the lack of effective assessment methods and individualized comprehensive treatment measures for lung cancer invasion and metastasis.Therefore,finding molecular targets to identify the ability to evaluate the invasion and metastasis of lung cancer is great significant for lung cancer assessment and individualized treatment.G-protein coupled receptor 120(GPR120)is a newly discovered cell membrane surface protein that can promote or inhibit the development of some tumors.Vascular endothelial growth factor(VEGF)is the most important cytokine that regulates and promotes vascular regeneration during tumorigenesis and development,and it plays an important role in tumor cell proliferation,migration,anti-apoptosis,and angiogenesis.Many studies have shown that VEGF plays an important role in promoting the invasion and metastasis of lung cancer.Meantime,some studies have shown that GPR120 has the effect of upregulating VEGF in colorectal cancer and esophageal cancer to promote tumor invasion and metastasis.However,the role of GPR120 in NSCLC and its relationship with VEGF has not been reported.Therefore,exploring GPR120 and elucidating its relationship with VEGF is not only of great significance in assessing the invasion and metastasis of NSCLC,but also has important practical significance in guiding the clinical establishment of an effective NSCLC treatment system.Clinical pathological specimens were used as the research object in this experiment,the expression of GPR120 and VEGF in tumor tissues of NSCLC patients was detected,and the correlation between GPR120 and VEGF was analyzed.To clarify the expression of GPR120 and VEGF,analyzing the relationship between GPR120,VEGF and the clinicopathological characteristics of NSCLC and the survival of patients,and preliminary explore the role of GPR120 and VEGF in the development and progression of NSCLC.Materials and Methods:42 NSCLC tumor tissues and 42 corresponding adjacent lung tissues were collected from 42 patients who diagnosed with NSCLC in the Department of Thoracic and Cardiovascular Surgery of the First Affiliated Hospital of Chengdu Medical College.The qPR and Western blot were used to detect the mRNA and protein expression of GPR120 and VEGF in the tissues.Immunohistochemistry was used to detect the expression of GPR120 and VEGF protein in 85 NSCLC tumor paraffin specimens and62 matched paraffin specimens from the pathology department of the First Affiliated Hospital of Chengdu Medical College.Exploring the correlation between GPR120 and VEGF,and analyze the relationship between clinicopathological characteristics of NSCLC patients and GPR120,VEGF;Kaplan-Meier survival curve analyzed the relationship between the expression of GPR120,VEGF and the survival of NSCLC patients;Cox regression analysis determined the prognostic factors affecting 85 NSCLC patients.Result:1.The relative expression levels of GPR120 mRNA in cancer tissue and corresponding adjacent tissues in NSCLC were 1.82±0.58and1.32±0.58,the difference was statistically significant(t=5.219,P=0.000);The relative expression levels of VEGF mRNA in cancer tissue and the corresponding adjacent tissues were1.73±0.43 and 0.95± 0.35,the differences were statistically significant(t=8.900,P=0.000).The relative expression of GPR120 protein in NSCLC tumor tissue was higher than that of adjacent normal tissue(1.41±0.55vs1.00±0.28),and the difference was statistically significant(t = 4.492,P=0.000).Similarly,the relative expression levels of VEGF protein in NSCLC tumor tissue were significantly higher than those of matched adjacent tissues(1.58±0.76vs1.01 ± 0.23,t=4.990,P=0.000).the expression levels of VEGF and GPR120 increased with the later TNM staging of tumors,and the differences were statistically significant(P<0.05).50 cases of GPR120 and 52 cases of VEGF high expression was observed in 85 NSCLC tumor pathological wax sample,while only 14 cases of GPR120 and 10 cases of VEGF high expression observed in 62 corresponding normal lung tissues pathological wax sample.The difference between the groups was statistically significant(P<0.05).The above results indicate that the expression levels of mRNA andprotein of GPR120 and VEGF in tumor tissues of patients with NSCLC are significantly higher than those in normal lung tissues adjacent to the cancer.2.The analysis of IHC results combined with the clinicopathological data of patients showed that the high expression rate of GPR120 protein in NSCLC was closely related to lymph node metastasis,distant metastasis,and TNM staging,and the difference was statistically significant(P<0.05),but has no significant correlation with gender,age,tumor size,tumor tissue type,and degree of tumor differentiation(P>0.05).The high expression rate of VEGF protein in NSCLC is closely related to lymph node metastasis and TNM stage of NSCLC(P<0.05),but has no significant correlation with gender,age,tumor size,tumor tissue type,tumor differentiation degree,and distant metastasis(P>0.05)3.39 cases common high expression and 22 common low expression of GPR120 and VEGF proteins in the 85 NSCLC tumor tissues,which indicated that the expression of GPR120 was significantly correlated to VEGF(r = 0.413,P= 0.000).4.Kaplan-Meier survival analysis showed that patients with high expression of GPR120 and VEGF protein had a worse prognosis levels than patients with low expression,and the cumulative survival time was lower than those with low GPR120 and VEGF expression,the difference was statistically significant(P<0.05).Cox proportional hazard regression showed that lymph node metastasis(P=0.017),distant metastasis(P=0.007),high expression of GPR120 protein(P=0.027)were all risk factors for the prognosis of NSCLC patients.