Expression And Clinical Significance Of MiR-195 And Tumor Infiltrating Lymphocytes CD3~+CD4~+CD8~+ In Gastric Carcinoma

BackgroundGastric carcinoma(GC) is one of the most common malignant tumors, and it is also the second fatal disease in malignant tumors. At present, the prognosis of GC patients was evaluated by TNM staging and histological type(malignant degree), and it has become the prognostic indicator for patients with malignant tumors. However,TNM staging is closely related to the time to progress, and although the pathological types of tumors can reflect the malignant degree of the tumor, there is no effective immunological and biological indicators to predict the progression of GC. In recent years, many research have reported that small RNA(micro RNAs, miRNAs) can promote the formation of tumor, and the expression of miRNA-195(miR-195) in normal gastric mucosa was found to be highly expressed by miRNA expression profile. However, the specific role of miR-195 in the occurrence and development of GC is still not clear, whether miR-195 can be used as a prognostic indicator of GC patients deserve further study.In addition, research shows that the distribution and expression level of immune cells in tumor micro environment such as T lymphocytes and NK cells could be a prognostic indicator in patients with cancer Therefore, it is of great significance to understand the expression level of immune T lymphocytes in malignant tumor micro environment, and it may be a valuable parameter for prognostic of GC and could guide treatment for chemotherapy and immunotherapy.The aim of this study was to detect the expression of miR-195 and tumor infiltrating lymphocytes(TILs) in GC and its relationship with prognosis, and explore the possibilities of miR-195 and TILs as biomarkers for prognosis of GC, and its correlation with pathological type, clinical stages and prognosis. Then compared withclinical data and sensitive rate of blood circulating tumor cells(CTCs), we discussed the correlation between the expression of miR-195 and TILs, and pathological features, as well as clinical staging and prognosis in GC, and to evaluate the predictive value.ObjectiveAnalysis of expression and clinical significance of miR-195 and tumor infiltrating lymphocytes CD3~+, CD4~+ and CD8~+ in GC.Methods(1) Real-time quantitative polymerase chain reaction(qRT-PCR)method to detect the expression of miR-195 in GC and adjacent normal tissues, and analyze its relationship with clinical pathological characteristics.(2) immunohistochemistry method to detect CD3~+, CD4~+ and CD8~+ T lymphocytes between the GC and adjacent normal tissue, as well as metastatic lymph node and negative lymph node.(3)Immune fluorescence in situ hybridization(imFISH) method to detect peripheral blood CTCs in 47 patients with GC.Results(1) Compared with the adjacent normal tissues, the cancerous tissues presented down-regulation of miR-195 expression, which was correlated with degree of tumor differentiation(P<0.05); Also the cancerous tissues presented down-regulation of miR-195 expression, which was correlated with lymph node metastasis(P<0.05), and the more lymph node metastasis, the lower expression of miR-195(P<0.05); Besides,the cancerous tissues expression of miR-195 is not correlated with gender, age, T stage and M stage.(2) Receiver operator characteristic curve(ROC curve) analysis revealed the following results: for GC patients with lymph node metastases, the best critical value is 0.584; sensibility of miR-195 is 70.21%; specificity is 19.61%; areaunder the curve(AUC)is 0.772±0.096; 95%confidence interval(CI) is 0.584-0.959.(3) Kaplan-Meier survival curve showed that the median RFS of low and high expression of miR-195 were 21.1 months(95%CI:19.0~23.2) and 23.8 months(95%CI:16.7~31.0), and there has no significant difference between the two groups(P>0.05).(4) Counts of CD3~+, CD4~+, and CD8~+ T lymphocytes in GC tissue are obviously higher than those in the adjacent normal tissue, and the difference is statistically significant(P<0.05). Counts of CD3~+, CD4~+, and CD8~+ T lymphocytes in positive lymph nodes are obviously lower than those in negative lymph nodes, and the difference is statistically significant(P<0.05). The lower the tumor differentiation degree, the higher the counts of CD3~+, CD4~+, and CD8~+ T lymphocytes in GC tissue were observed; the more the CD3~+ T lymphocytes in positive lymph nodes, the less the CD4~+, and CD8~+ T lymphocytes in the positive lymph nodes were observed; the differences are statistically significant(P<0.05). The more the lymph node metastases,the higher the counts of CD3~+, CD4~+, and CD8~+ T lymphocytes in GC tissue and the lower the counts of CD3~+, CD4~+, and CD8~+ T lymphocytes in positive lymph nodes were observed; the difference is statistically significant(P<0.05).(4) The positive number of CTCs is 16(34.04%), and the numbers in N0/1/2/3 stage were 1/1/9/5.Conclusions(1) The expression of miR-195 in GC was negatively correlated with the degree of malignancy.(2) The expression of miR-195 in GC may be negatively correlated with lymph node metastasis.(3) The expression level of CD3~+, CD4~+ and CD8~+T cells in tumor infiltrating lymphocytes of GC was positively correlated with tumor pathological stage, suggesting that it can be used as an independent immunological evaluation index to predict the prognosis of GC patients.(4) The combined detection of miR-195 and TILs in GC can take account of both tumor specificity and individual micro environment of immune status,which may better evaluate the prognosis ofpatients with tumor.