| Background and purposeGastric cancer(GC)is one of the most common malignant tumors in China.More than 90% of the pathological types of gastric cancer are gastric adenocarcinoma,and the mortality rate is second in the death rate of malignant tumors in the world.In recent years,the incidence of gastric adenocarcinoma in China is younger.Due to the increase of population and the acceleration of aging,as well as the unhealthy lifestyle,the burden of gastric adenocarcinoma has gradually increased.At the same time,the incidence of type 2 diabetes mellitus(T2DM)is increasing year by year in China.Studies have shown that type 2 diabetes can promote the occurrence of gastric adenocarcinoma.But its specific mechanism is not yet very clear.JNK signal pathway exists in many life processes,and it is closely related to the development of type 2 diabetes and gastric adenocarcinoma.The HIP55-HPK1-JNK signal transduction pathway is one of the important JNK signaling pathways.In recent years,more and more studies have been made about this pathway.The study found that HIP-55 can recruit HPK-1 to the lipid rafts of the cell membrane,interact with the protein and mediate the downstream signal pathway,and Caveolin-1 is the most important protein in the lipid rafts.The changes in the expression of Caveolin-1 and HIP55 in the tissues of patients with simple gastric adenocarcinoma and type 2 diabetes with gastric adenocarcinoma were studied in this study.Objective to investigate the correlation between Caveolin-1 and HIP55-HPK1-JNK signal transduction pathway in T2 DM patients with gastric adenocarcinoma.Furthermore,the relationship between Caveolin-1 protein expression and HIP55-HPK1-JNK signaling pathway was further confirmed by in vitro gastric adenocarcinoma cell experiment.Material method1.general situationA total of 380 cases of radical gastrectomy from January 2016 to January 2018 in the center of Tai'an,Shandong Province,were selected.All of them were confirmed by pathology as primary gastric adenocarcinoma after operation.The clinical data including admission and test were collected.The cases were divided into simple gastric adenocarcinoma group(group GC)(group GC)and type 2 diabetic gastric adenocarcinoma group(T2DM-GC)(58 cases).There were no differences in age,sex,blood sugar,blood lipid,smoking and drinking history in the two groups.2.ImmunohistochemistryThe specimens of gastric cancer in the pathology department of Tai'an Central Hospital were collected.All specimens were confirmed by pathology as primary gastric adenocarcinoma tissue.The specimens were divided into group GC(30 cases)and group T2DM-GC(30 cases).The immunohistochemical SP method(Streptomyces anti biotin protein-peroxisome enzyme linking method)was used to detect each group.The expression level of protein in gastric adenocarcinoma tissue(GCT),para cancer tissue(GPT)and normal gastric mucosa(GT)(range of cancer tissue > 5cm).The positive rate distribution of HIP-55 and Caveolin-1 protein in gastric adenocarcinoma tissue,para cancer tissue and normal gastric mucosa tissue was analyzed by chi square test.There was no statistical difference(? = 0.05).3.Western blotThe fresh gastric adenocarcinoma tissue,para cancerous tissue and the corresponding normal tissue were collected in the patients with radical gastrectomy in Tai'an Central Hospital.All specimens were confirmed by pathology as primary gastric adenocarcinoma.There were 30 cases in group GC and 30 cases in group T2DM-GC,and all tissues were stored in liquid nitrogen or-80 C refrigerator in vitro 30 min.4.cell experimentHuman gastric adenocarcinoma cell line SGC-7901 was cultured,and the cells were passaged for 2~3 generations.Meanwhile,high glucose(20mmol/L)medium was used to culture gastric adenocarcinoma cells.After the culture,the cells were collected.The expression of HIP-55 and Caveolin-1 protein in each group was detected by immunoblotting(Western Blot),and the expression of Caveolin-1 protein was further observed,and the expression of HIP-55 protein was observed.Research results1.general clinical features and indicators(1)the overall age of group T2DM-GC was higher than that in group GC,and the difference between the two groups was statistically significant(P < 0.01).Among the patients aged 65 and above,the proportion of T2DM-GC group was significantly higher than that of the GC group,and the difference between the two groups was statistically significant(P < 0.01),but the proportion of the GC group was significantly higher than that of the T2DM-GC group in the patients under the age of 65 years,with a statistically significant difference(P < 0.01).(2)gender: men in group GC were higher than females,while the proportion of male patients in T2DM-GC group was also significantly higher than that in females(P < 0.01).(4)smoking: the proportion of smokers in group GC and group T2DM-GC was 69% and 62%,respectively,which were significantly higher than those of non smokers,and the difference was statistically significant(P < 0.01).(5)high density lipoprotein(HDL): the value of HDL in group T2DM-GC was significantly lower than that in group GC,and the difference was statistically significant(P < 0.01).(6)low density lipoprotein,very low density lipoprotein and cholesterol: there was no significant difference between group T2DM-GC and group GC(P > 0.05).(7)uric acid and creatinine: there was no significant difference between group T2DM-GC and group GC(P > 0.05).2.Immunohistochemistry(1)The positive rate of HIP-55 and Caveolin-1 protein expression in GCgroupThe positive expression rates of HIP-55 protein in gastric adenocarcinoma,adjacent tissues and normal gastric mucosa were 33.33%,86.67% and 90%,respectively.The expression level of HIP-55 protein in normal gastric mucosa tissues was higher than that in gastric adenocarcinoma tissues(P<0.05).The expression level of HIP-55 protein in para cancerous tissue was also higher than that of gastric adenocarcinoma(P <0.05),but the positive rate of HIP-55 protein expression between normal gastric mucosa and para cancerous tissue was not statistically significant(P>0.05).The positive expression rates of Caveolin-1 protein in gastric adenocarcinoma,adjacent tissues and normal gastric mucosa were 26.67%,83.33% and 90%,respectively.The expression level of Caveolin-1 protein in normal gastric mucosa and paracancerous tissues was also higher than that in gastric adenocarcinoma tissues(P<0.05).The expression level of Caveolin-1 protein in para cancerous tissue was also higher than that of gastric adenocarcinoma(P<0.05),but the positive rate of Caveolin-1 protein expression between normal gastric mucosa and para cancerous tissues was also not statistically significant(P>0.05).The expression of HIP-55 and Caveolin-1 protein in GC group was positively correlated with gastric adenocarcinoma(r=0.427,P<0.05).(2)The positive rate of HIP-55 and Caveolin-1 protein expression in T2DM-GC groupThe positive expression rates of HIP-55 protein in gastric adenocarcinoma,paracancerous tissue and normal gastric mucosa were respectively 20%,70%,73.33%.The expression level of HIP-55 protein in normal gastric mucosa tissues was higher than that in gastric adenocarcinoma tissues(P<0.05).The expression level of HIP-55 protein in para cancerous tissue was also higher than that of gastric adenocarcinoma(P <0.05),but the positive rate of HIP-55 protein expression between normal gastric mucosa and para cancerous tissue was not statistically significant(P>0.05).The positive expression rates of Caveolin-1 protein in gastric adenocarcinoma,paracancerous tissue and normal gastric mucosa were respectively.13.33%,63.33%,66.67%.The expression level of Caveolin-1 protein in normal gastric mucosa and paracancerous tissues was also higher than that in gastric adenocarcinoma tissues(P <0.05).The expression level of Caveolin-1 protein in para cancerous tissue was also higher than that of gastric adenocarcinoma(P<0.05),but the positive rate of Caveolin-1 protein expression between normal gastric mucosa and para cancerous tissues was also not statistically significant(P>0.05).The expression of HIP-55 and Caveolin-1 in group T2DM-GC was also positively correlated with gastric adenocarcinoma(r=0.682,P<0.05).3.Western BlotIn order to verify the results of immunohistochemistry,we further detected the expression of HIP-55 and Caveolin-1 protein in the gastric adenocarcinoma tissue,para cancer tissue and the corresponding normal tissues in group GC and T2DM-GC by Western blot.(1)Expression and correlation of HIP-55 and Caveolin-1 protein in GC groupThe expression of HIP-55 protein in gastric adenocarcinoma was significantly lower than that in normal gastric mucosa and adjacent tissues(P<0.01).There was no significant difference in the expression of Caveolin-1 protein between adjacent tissues and normal gastric mucosa(P > 0.05).The expression of Caveolin-1 protein in gastric adenocarcinoma tissues was also significantly lower than that in normal gastric mucosa and adjacent tissues(P<0.01).There was no significant difference in the expression of Caveolin-1 protein between adjacent tissues and normal gastric mucosa(P > 0.05).There was a positive correlation between the expression of HIP-55 and Caveolin-1 in group GC(r=0.7549,P < 0.01).(2)Expression of HIP-55 and Caveolin-1 protein in T2DM-GC groupThe expression of HIP-55 protein in gastric adenocarcinoma was significantly lower than that in normal gastric mucosa and adjacent tissues(P<0.01).There was no significant difference in the expression of Caveolin-1 protein between adjacent tissues and normal gastric mucosa(P > 0.05).The expression of Caveolin-1 protein in gastric adenocarcinoma tissues was also significantly lower than that in normal gastric mucosa and adjacent tissues(P<0.01).There was no significant difference in the expression of Caveolin-1 protein between adjacent tissues and normal gastric mucosa(P > 0.05).The expression of HIP-55 and Caveolin-1 protein in T2DM-GC group was also positively correlated(r=0.6197,P < 0.01).4.cell culture(1)The expression of HIP-55 and Caveolin-1 protein was detected after the glucose culture medium was cultured for gastric adenocarcinoma cells.Compared with the control group,the expression of HIP-55 protein in the high glucose group decreased by 8.7%(P < 0.01),and the expression of Caveolin-1 protein was reduced by 10.4%,with a significant difference(P < 0.01)and confirmed by the results(P < 0.01).The two protein in gastric adenocarcinoma cells decreased in high glucose,which was consistent with the results in vivo.(2)Through Caveolin-1 protein silence: compared with the control group,the expression of Caveolin-1 protein in the si-Cav-1+ high glucose group decreased by 36.8%,with significant statistical difference(P < 0.01).The expression of HIP-55 protein in the si-Caveolin-1+ high glucose group decreased by 19.8%,and the statistical difference was significant(P < 0.01).Results there was a correlation between the expression of Caveolin-1 and the expression of HIP55 protein.Conclusion1.In T2 DM group,HIP-55 and Caveolin-1 were significantly lower than those in GC group,suggesting that both may inhibit the occurrence of T2 DM gastric adenocarcinoma.2.This study confirmed that HIP-55 and Caveolin-1 were positively correlated in group GC and T2DM-GC.3.Down regulation of Caveolin-1 may be involved in T2 DM gastric adenocarcinoma by down-regulation of HIP-55 mediated HPK1-JNK signal transduction pathway. |
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