Expression And Significance Of LGR5and Nanog In Colon Carcinoma

Background and ObjectiveColon cancer is one of the common malignant tumors in digestive tract in China. The incidence rate is the fourth in malignant tumors. The rate of the incidence and mortality is increasing tendency. The early symptoms of colorectal carcinoma are not very typical, the cases are often in advanced stage with poor prognosis when diagnosed. Therefore, It is very important for patients to early diagnosis and treatment. The development of colon cancer is a gradual accumulation and complicated process that involved in a multiple phase and multiple genetic. Many studies have confirmed the existence of cancer stem cells in colon cancer. Cancer stem cells (Cancer Stem Cell, CSC) is a kind of populations cells of self-renewal, multiple differentiation potential and proliferation, It play an important role in the occurrence and development of tumors. Currently considered the existence of cancer stem cells is a major cause of tumor drug resistance and lead to the failure of cancer chemotherapy. Leucine rich repeat containing G protein coupled receptor5(Leucine rich repeat containing G protein coupled receptor5, Lgr5) is one of the G protein coupled receptor family members, which is a large glycoprotein molecules composed of17leucine rich repeats and7a transmembrane region. It has been confirmed that there are expressed in human brain, breast, and gastrointestinal tract and hair follicle. Nanog is a newly discovered transcription factor of embryonic stem cells (embryonic stem cells, ESCs). It is essential to maintaining gene stem cell self-renewal, proliferation and sub totipotent. Current research shows that Lgr5and Nanog involved in tumor invasion and metastasis, but did not have the same time research reports expression and correlation of Lgr5and Nanog in colon cancer. This study was detected two expression by immunohistochemistry among in colon cancer, colon adenoma and normal tissue, and its relationship with clinicopathologic factors in colon cancer. Explore to both Lgr5and Nanog the growth, invasion, and metastasis of colon cancer. It is role in providing some clinical significance for the diagnosis and treatment of colon cancer.Methods1. In this experiment,134cases of colon cancer, colon adenoma and normal tissue archived paraffin were collected from the First Affiliated Hospital of Zhengzhou University, department of pathology from March2012to March2013. Immunohistochemistry was used detect the expression of Lgr5and Nanog in68cases of colon cancer,30cases of colorectal adenoma,36cases of normal tissues, and analyze the both expression levels of colon cancer patients,gender, age, Dukes stage, differentiation degree and lymph node metastasis as well as the correlation between Lgr5and Nanog.2. Statistical analysis Application SPSS17.0statistical software for statistical analysis. Qualitative data using χ2test, Correlation analysis using Spearman rank correlation analysis. P<0.05was considered statistically significant differences.Results1.Lgr5is mainly expressed in the cytoplasm, the positive expression rate of Lgr5in colorectal cancer tissues is (61.7%(42/68)), the positive rate of expression in colon adenomas is (26.6%(8/30)), the positive rate expression in normal colon tissue is (16.6%(6/36)).The difference among the three groups are statistically significant (P <0.05), there is no significant difference of the expression of the latter two (P>0.05). The expression of Lgr5and differentiation degree, Dukes stage, lymph node metastasis of colon cancer was statistically significant (P<0.05), but with clinical parameters gender, age, is not statistically significant (P>0.05).2. Nanog is mainly expressed in the nucleus, the positive expression rate of Nanog in colorectal cancer tissues is (69.1%(47/68)), the positive expression rate in adenomas is (43.3%(12/30)), the positive expression rate in normal colon tissue for (17.9%(7/36)), and the positive expression rate of Nanog in colorectal cancer is significantly higher than those in colon adenoma and normal tissues(P<0.05), there is no significant difference of the expression of the latter two (P>0.05). The expression of Nanog and differentiation degree, Dukes stage, lymph node metastasis of colon cancer is statistically significant (P<0.05), but with clinical parameters gender, age, is not statistically significant (P>0.05).3. There is positive correlation between the expressions Lgr5and Nanog in colorectal cancer tissues (r=0.373, P<0.05).Conclusions1. Expression of Lgr5in colorectal cancer tissues is higher than that of colon adenoma, normal tissues, and which is significantly correlated with^degree of differentiation, Dukes stage and lymph node metastasis. It is suggesting that Lgr5may play an important role in the process of carcinogenesis and infiltration and metastasis of colon cancer.2. Expression of Nanog in colorectal cancer tissues is higher than that of colon adenoma, normal tissues, and which is significantly correlated with degree of differentiation, Dukes stage and lymph node metastasis. Suggesting that Nanog may be involved in the occurrence and development of colon cancer, and invasive and metastatic ability of colorectal cancer.3. There is positive correlation between the expressions Lgr5and Nanog in colorectal cancer tissues. Suggesting that both expression in colon cancer may have a common regulatory mechanisms or regulation mechanism of collaboration.