| This study was to analyze the expression of key signal molecular proteins in PI3K/AKT/mTOR signaling pathway in gastric cancer tissues,adjacent tissues(From the edge of the tumor more than 5cm),normal gastric mucosa tissues,To analyze the roleof PI3K/AKT/mTOR signaling pathway in gastric cancer and its regulatory mechanism at the organizational level.And to analyze the variation of SNP in gastric cancer patients and normal people,and to explore the relationship between mTOR gene polymorphism and gastric cancer.To provide a scientific basis for targeted therapy of gastric cancer.Objective:1.To compare the expression levels of PTEN,p-AKT and p-mTOR in PI3K/AKT/mTOR signaling pathways in gastric cancer tissues,adjacent tissues(above 5cm from the edge of the tumor)and normal gastric mucosa tissues,To compare the expression levels of PTEN,p-AKT,p-mTOR proteins in different clinical features of gastric cancer cases.To investigate the relationship between the expression of PTEN,p-AKT and p-mTOR in gastric carcinoma,and to explore the relationship between PI3K/AKT/mTOR signaling pathway and gastric cancer.2.Based on the two SNP of mTOR gene(rs3806317,rs1034528),the genotype and allele distribution of rs1034528 and rs3806317 SNP loci in gastric cancer patients and normal subjects were compared with those of gastric cancer patients in Nanjing.Jiangsu province.And to analyze the relationship between genotype and allele distribution of SNP between patients with different clinical features,to explore the relationship between mTOR gene polymorphism and gastric cancer.Methods:1.Immunohistochemistry technology was used to detect the expression of PTEN,p-AKT and p-mTOR in 66 cases of gastric carcinoma,66 cases of adjacent tissues and 39 cases of normal gastric mucosa.The chi-square test was used to analyze whether the distribution of PTEN,p-AKT and p-mTOR proteins expression in gastric cancer tissue,adjacent tissue and normal gastric mucosa was statistically different(?=0.05).To compare the differences between PTEN,p-AKT and p-mTOR proteins in different clinical features of gastric cancer.The correlation analysis of PTEN,p-AKT and p-mTOR positive expression was performed by Spearman correlation analysis.2.The DNA of 128 cases of gastric cancer patients(case group)and 129 cases of normal(control group)DNA was extracted by the kit.Two the target gene mTOR SNP(rs3806317,rs 1034528)were amplified by PCR.The sanger method was used to sequencing the PCR samples.The genotype and allele distribution of rs1034528 and rs3806317 SNP were analyzed by chi-square test.To compare the differences in genotype and allele distribution between SNP between patients with different clinical characteristics.Logistic regression was used to analyze the genotype of each SNP relative to the risk of wild genotype and 95%confidence interval,to assess the risk of each genotype.Results:1.The positive expression rates of PTEN protein in gastric cancer tissues,adjacent tissues and normal gastric mucosa were 53.03%(35/66),84.85%(56/66)and 74.36%(29/39),respectively.The positive rate of PTEN protein expression in gastric cancer tissues,adjacent tissues and normal gastric mucosa was statistically significant(P<0.001).The expression level of PTEN protein in paracancerous tissue was higher than that in gastric cancer tissues(P<0.0125),There was no significant difference in the positive expression rate of PTEN protein between adjacent tissues and normal gastric mucosa(P>0.0125),There was no significant difference in the positive expression rate of PTEN protein between gastric carcinoma and normal gastric mucosa(P>0.0125).2.The positive expression rates of p-AKT protein in gastric cancer tissues,adjacent tissues and normal gastric mucosa were 56.06%(37/66),16.67%(11/66)and 2.56%(1/39).The positive rate of p-AKT protein expression in gastric cancer tissues,adjacent tissues and normal gastric mucosa was statistically significant(P<0.001).At the same time,the positive expression level of p-AKT protein in gastric cancer tissues was higher than that in adjacent tissues,normal gastric mucosa(P<0.0125).3.The positive expression rates of p-mTOR protein in gastric cancer tissues,adjacent tissues and normal gastric mucosa were 90.91%(60/66),71.21%(47/66)and 5.13%(2/39),respectively.The positive rate of p-mTOR protein expression in gastric cancer tissues,adjacent tissues and normal gastric mucosa was statistically significant(P<0.001).The positive expression level of p-mTOR protein in gastric cancer tissues,adjacent tissues and normal gastric mucosa showed a decreasing trend(P<0.05).4.There was no correlation between the expression level of PTEN protein and the age,sex,tumor diameter,tumor differentiation,depth of tumor invasion,lymph node metastasis and TNM staging of gastric cancer(P>0.05).5.Positive expression rate of p-AKT protein in the depth of invasion to reach the serous layer of gastric canceris higher than the cancer tissue is not infiltrated to the serous layer(P<0.05).The positive expression rate of p-AKT protein in poorly differentiated gastric cancer was higher than that in medium and well-differentiated gastric cancer(P<0.05).The positive expression rate of p-AKT protein in gastric carcinoma with lymph node metastasis was higher than that in gastric cancer without lymph node metastasis(P<0.05).The positive expression rate of p-AKT protein in stage ? and stage ? gastric cancer was lower than that in stage ? and stage ?gastric cancer(P<0.05).There was no correlation between p-AKT protein and other clinical features(age,sex,tumor diameter)of gastric cancer(P>0.05).6.Positive expression rate of p-mTOR protein in the depth of invasion to reach the serous layer of gastric canceris higher than the cancer tissue which is not infiltrated to the serous layer(P<0.05).There was no correlation between p-mTOR protein and other clinical features(age,sex,tumor diameter,degree of tumor differentiation,lymph node metastasis and TNM staging)of gastric cancer(P>0.05).7.There was a negative correlation between PTEN protein and p-AKT protein positive expression rate(P<0.05).There was no correlation between PTEN protein and p-mTOR protein positive expression rate(P>0.05).There was no correlation between p-AKT protein and p-mTOR protein positive expression rate(P>0.05).8.The frequencies of C and G alleles in the mTOR rs1034528 locus were 18.85%and 81.15%in the case group,16.67%and 83.33%in the control group,respectively.The proportion of CC,CG and GG were 4.92%,27.87%and 67.21%respectively in the case group,the proportion in the control group was 1.63%,30.08%and 68.29%respectively.Statistical analysis showed that there was no significant difference in the genotype and allele frequency of mTOR rs1034528 between gastric cancer patients and normal population(P>0.05).9.The frequencies of C and T alleles in the mTOR rs3806317 locus were 9.05%and 90.95%in the case group,14.92%and 85.08%in the control group,respectively.The proportions ofCC,CT and TT were 0%,18.10%and 81.90%in thecase group,respectively,and the proportionswere 0.81%,28.23%and 70.97%respectively in thecontrol group.There was a statistically significant difference(P<0.05)in the distribution of C genotype(CC/CT)compared with non-carrying C genotype(TT)in gastric cancer patients and normal population(P<0.05),And the risk of developing gastric cancer in people with C genotype(CC/CT)was 0.54 times higher than the people without the C genotype(TT)(OR=0.54,95%CI=0.293-0.996).The allele frequency of rs3806317 was statistically different between gastric cancer patients and normal population(P<0.05).The risk of gastric cancer in C allele was 0.568 times higher than that in T allele population(OR=0.568,95%CI =0.321-1.002).10.Rs3806317 genotype frequency distribution in different age,gender,tumor diameter,differentiation degree,depth of invasion,TNM staging,distant metastasis of gastric cancer patients were not found the statistical differences.The frequency distribution of rs3806317 genotype was statistically significant in gastric cancer patients with lymph node metastasis and gastric cancer without lymph node metastasis.Rs 1034528 genotype frequency distribution in different age,sex,tumor diameter,differentiation,depth of invasion,TNM staging,lymph node metastasis,distant metastasis of gastric cancer patients were not found the statistical differences.Conclusion1.The expression levels of PTEN,p-AKT and p-mTOR in gastric carcinoma,adjacent tissues and normal gastric mucosa were different in different degree,The high expression of p-AKT and p-mTOR and the low expression of PTEN in gastric carcinoma confirmed that PI3K/AKT/mTOR signaling pathway was inactive in gastric cancer.The expression level of p-AKT and p-mTOR in gastric cancer patients with different clinical characteristics was different,and the higher the degree of malignancy,the higher the expression level of p-AKT and p-mTOR.2.MTOR rs3806317 may have a certain correlation with the pathogenesis of gastric cancer,carrying C genotype(CC/CT)may be a protective factor to prevent the incidence of gastric cancer.At the same time,the frequency of rs3806317(T>C)mutation was found to be related to the lymph node metastasis of gastric cancer patients.No relationship was found between mTOR rs 1034528 and gastric cancer. |
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