The Expression And Significance Of Lgr5Gene In Human Colorectal Cancer Tissue

From the view of the world, malignant tumor has become a serious hazard to humanhealth " killer” after cardiovascular disease. Colorectal cancer is a common malignant tumorof digestive tract, according to the International Agency for Research on Cancer（IARC）WHO data display, rising in the whole world the incidence and mortality of colorectal canceris still the trend. Because our country western diet structure, life style change, mental tensionand other many factors, the incidence and mortality of colorectal cancer are increasing yearby year. The investigation of colorectal cancer after operation for recurrence and metastasisrate as high as80%, and metastasis of cancer cells and tumor recurrence in patients withrectal cancer is reason of death. At present, domestic and foreign researchers from differentangles expounds the mechanism of occurrence and development of colorectal cancer, inorder to completely cure the tumor. In recent years, the theory of Cancer stem cells providesa new direction for the study of tumor.With the continues development of cancer stem cells (Cancer Stem Cells, CSC) theoryand the experiment data,accumulated, it provides a new opportunity for tumor diagnosisand treatment. CSC is considered as the tumor tissue in the few, has the infinite proliferationand self-renewal ability and can produce the heterogeneity of tumor cells, the source fortumor growth, metastasis and recurrence, may become a new target to cure malignant tumor.At present, CSC specific molecular marker of colorectal cancer has not yet been determined.For the CD133, CD44, CD24, CD166and other possible CSC markers, which surfacemarkers are specific for molecular marker of human colorectal cancer, the correlativity ofspecific tumor markers and histological type, grade, metastasis and prognosis are shoud befuther explored.Leucine-rich repeat containing G protein-coupled receptor5,(LGR5) is the target geneof Wnt signal pathway, expression in the small intestine and colon crypt basal columnarepithelial cell specificly,It has been confirmed that Lgr5is the stem cell marker of smallintestine and colorectum,and its increased expression can promote self-renew capacity of intestinal mucosaincreased expression can promote intestinal mucosa self-renewal capacity.This study aimed to investigate the expression of Lgr5in human colorectal tumor gene, andthe relationship with the clinical pathological features, in order to provide theoretical basisand technical support for Lgr5as the diagnosis and therapy of colorectal cancer.METHODS:Detect the expression of Lgr5mRNA in27cases of colorectal tumor tissues and normaltissues5cm within tumor operation margin by using real-time PCR method of SYBR Green.Outcome comparisons were performed by Wilcoxon, Kruskal-Wallis rank sum test toanalysis of lgr5mRNA expression differences in colorectal cancer tissues and pairednormal tissue、 clinical pathological parameters.RESUITS:Lgr5mRNA was expressed both in normal tissues of colorectal cancer tissue and paired.But the colorectal tumor tissue Lgr5mRNA expression was1(0.012496.353) which wassignificantly higher than that in matched normal tissues,0.147(0.004,73.002), thedifference was statistically significant (Z=8.029, P <0.01). Lgr5mRNA colorectal tumortissues in different sex, age, primary tumor site, tumor size, histological type was nostatistically significant difference (P>0.05), but the Lgr5expression of mRNA in lymphnode metastasis than those without lymph node metastasis, the difference was statisticallysignificant (Z=2.066, P <0.05).CONCLUSION：the up-regulation of Lgr5expression may be involved in proliferation, differentiation ofcolorectal tumor cells, and play a key role of the process of development and tumorigenesis.The expression of Lgr5in colorectal tumor tissue increase is expected to become a newtherapeutic target in colorectal cancer stem cells.