Expression Of Slp-2 And Cdc42 Proteins In Human Colorectal Carcinoma And Its Clinical Significance

Background and ObjectivesColorectal cancer (CRC) is one of the common malignant tumors. Its incidence is rising with global population aging and the development of living standard, and increased by 2% per year from 2000 to 2005 according to statistics. It already severely impacted people's health. Investigate the mechanism of the invasion and metastasis of colorectal cancer has been one of research hot spots because invasion and metastasis are main death reasons for colorectal cancer patients. Therefore, there is great significance to research colorectal cancer -related genes or proteins.The Chinese academy of medical sciences institute of tumor state key laboratory of molecular oncology first discovered gene with Stomatin-like protein 2 (SLP-2), it is closely related with the development of esophageal, lung, throat and endometrial cancers. Maybe it is a new oncogene. And there was report that it has an important role in the tumor invasion and metastasis. Cell division cycle 42 (CDC42) protein belongs to the small G proteins of the Rho families. Rho (Ras homologue) family play an important role in the organization of the actin cytoskeleton and regulate transcription. Not until recently have they been linked to the tumorigenesis and metastasis.So far, there is no domestic and foreign reports involving SLP-2 and CDC42 proteins and its relationship with colorectal cancer. The aim of this experiment is to observe the expression of SLP-2 and CDC42 protein in carcinoma, adenoma with dysplasia and normal mucosa in large intestine, to evaluate the relationship between the expression of SLP-2 and CDC42 protein in colorectal carcinoma and the clinicopathological parameters and to analyze the correlativity of the two proteins, to investigate the effect of SLP-2 and CDC42 protein in the occurrence and development of colorectal cancer in order to provide some theoretical basis for the clinical diagnosis and gene therapy of colorectal cancer.Materials and MethodsThe 2-step immunohistochemical (IHC) method was used to detect the expression of SLP-2 and CDC42 protein in 21 normal colorectal mucosa, 18 colorectal adenoma with dysplasia and 63 carcinoma. Results were analyzed by using SPSS version 13.0. The comparison of positive rates uses the Chi-square, the relation of two variable s was analyzed by the spearman level correlation analysis. Statistically significant level was considered as"alpha equals 0.05".Results(1) The rates of positive expression of SLP-2 protein in the tissue of normal colorectal mucosa, adenoma and carcinoma were 19.0%, 38.9% and 69.8%, respectively, the difference of the expression of SLP-2 protein between the tissue of normal colorectal mucosa and adenoma was not significant (P>0.05), the difference between anyother two groups was significant (P<0.05).(2) The rates of positive expression of CDC42 protein in the tissue of normal colorectal mucosa, adenoma and carcinoma were 38.1%, 44.4% and 73.0%, respectively, the difference of the expression of CDC42 protein between the tissue of normal colorectal mucosa and adenoma was not significant (P>0.05), the difference between anyother groups was significant (P<0.05).(3) The rates of positive expression of SLP-2 protein in CRC with lymph nodes metastasis and without lymph nodes metastasis were 84.0% and 60.5%, respectively, the difference between the two groups was significant (P<0.05). (4)The rates of positive expression of CDC42 protein in CRC with lymph nodes metastasis and without lymph nodes metastasis were 88.0% and 55.3%, respectively, the difference between the two groups was significant (P<0.05); The positive expression of CDC42 protein in CRC was related with Dukes stage, the rates of positive expression of CDC42 protein in stage C+D and A+B were 87.0% and 62.5%, respectively, the difference between the two groups was significant (P <0.05).(5)There was correlation between the expression of protein SLP-2 and CDC42 (r=0.458, p<0.01).Conclusions(1)The positive expression of SLP-2 and CDC42 protein is siginificantly higher in the colorectal carcinoma and adenoma than in the normal controls, and is closely correlated with Dukes stages and lymph nodes metastasis. It can be deduced that they may have an important role in the pathogenesis and development of CRC.(2)The positive expression of SLP-2 protein is closely correlated with the positive expression of CDC42 protein, it can be deduced that they cooperate with each other during the development of CRC.