Comparative Study Of CD151 In Rectal Cancer Tissues And Urine Exosome Expressed

Objective: Exosome, which are vesicles secreted by a variety of cells, and that carry the cytogenetic materials and proteins, play a role in material transportation and signal transduction between cells. In recent years, it is becoming a hotspot of research. The exosome globule may carry some information that could regulate and control the immune function, and that could influence the development of tumor by regulating the immunologic function, as well as promoting the tumor vessel’s rebirth and tumor metastasis, and acting on the tumor cells directly. In the paper, the expressions of CD151 m RNA and CD151 proteins in the rectal cancer tissues were tested using the methods of RT ﹣ PCR and Western blot, compared with the expressions in the normal rectal mucosa tissues as control. And at the same time, the expressions of CD151 protein in the exosome of urine from rectal cancer patients and healthy volunteers were also tested and compared using the method of Western blot. Combined with the clinical data, the expressions of CD151 gene in exosome of rectal cancer tissues and urine were investigated as well as the relationship between the expressions and the clinic pathological features, through the two methods. Meanwhile, it could help find a way to non-invasively measure the expression of this gene clinically.Methods:1 The expressions of CD151 m RNA and CD151 proteins were tested in the rectal cancer tissues of 40 patients and normal tissues near the cancer tissues(the distance away from the cancer tissues≥10cm), using the methods of RT﹣PCR and Western blot respectively.2 The exosome in the urine of 40 rectal cancer patients and 40 healthy volunteers were separated and extracted respectively by ultracentrifugation, and then the expressions of CD151 protein in the exosome were tested by the method of Western blot.3 Finally, by comparing the expressions of CD151 proteins in the exsome of urine from rectal cancer patients and in the rectal cancer tissues, and combined with the clinical data, the relationship between the expressions and the patient pathological features were investigated. We could compare the advantages and disadvantages as well as the reliability of the two methods.Results:1 The relative expression quantity of CD151 m RNA and CD151 protein in the cancer tissues of rectal cancer patients exceeded the comparison group significantly. With the application of RT-PCR method, the tested result showed that the relative expression quantity of CD151 RNA in the comparison group is 0.099±0.012, and in the rectal cancer group is 0.541±0.056. Through the analysis of independent sample t test, the relative expression quantity of CD151 m RNA in the rectal cancer tissues was significantly higher than the normal control group(P<0.05). By using the method of Western blot, the tested results showed that in the normal control group, the relative expression quantity of CD151 protein is 0.117±0.007, and in the rectal cancer group is 0.537±0.025. Through the analysis of independent sample t test, the relative expression quantity of CD151 protein in the rectal cancer tissues was significantly higher than the normal control group(P<0.05). To analyze the correlation between the patients pathological features and the relative expression quantity of CD151 protein and CD151 m RNA in the rectal cancer tissues, and apply independent sample t test analysis to process data, we found the results showed that patients rectal cancer clinical stages 、 depth of invasion、differentiated degree、lymph node metastasis, all contributed to the relative expression quantity of CD151 m RNA and CD151 protein, and the differences have its statistical significance(P<0.05), but nothing to do with the age and gender of the patients, and the differences don’t have its statistical significance(P>0.05).2 The relative expression quantity of CD151 protein in the exosome of urine from rectal cancer patients exceeded the comparison group significantly. By using the method of Western blot, the tested results showed that in the normal control group, the relative expression quantity of CD151 protein is 0.153±0.015, and in the rectal cancer group is 0.366±0.016. Through the analysis of independent sample t test, the relative expression quantity of CD151 protein in the urine of patients was significantly higher than the normal control group(P<0.05). To analyze the correlation between the patients pathological features and the relative expression quantity of CD151 protein in the urine of rectal cancer patients, and apply independent sample t test analysis to process data, we found the results showed that patients rectal cancer clinical stages、depth of invasion、differentiated degree、lymph node metastasis, all contributed to the relative expression quantity of CD151 protein, and the difference has its statistical significance(P<0.05), but nothing to do with the age and gender of the patients, and the differences don’t have its statistical significance(P>0.05).3 To test the expression rate of CD151 protein from the cancer tissues and the exosomes in the urine of rectal cancer patients using chi-square test, the results show that the positive rate of the CD151 protein expression in the cancer tissues of 40 cases of rectal cancer patients is 87.5%, and in the exosome is 82.5%. Comparing the two groups, we found c2=0.392,P=0.531, and the differences didn’t have statistical significances(P>0.05),which means that there exists no differences in the positive rate that the CD151 protein express in the cancer tissues and in the exosome globules. Therefore, there could have the same significance of clinical instructions by using the Western blot method to test the expression that CD151 protein in the exosome globules and the cancer tissues.Conclusions:1 CD151 may be involved in the occurrence and progression of the rectal cancer, and its expression level has a close relationship with the progression of the rectal cancer. The relative expression quantity of CD151 m RNA and CD151 protein in the rectal cancer tissues is related to rectal cancer clinical stages、depth of invasion、differentiated degree、lymph node metastasis. In addition, with the development of the clinical stages and the increase of the depth of invasion and the lymph node metastasis, the relative expression quantity increases markedly.2 To test the expression of CD151 protein in the urine exosome globules by using Western blot method, and compare with the results that test in the fresh tumor tissues, we found the results were similar, which could reflect that the expression differences of CD151 protein is related to rectal cancer clinical stages、depth of invasion、differentiated degree、lymph node metastasis.3 The method that tests the expression of target gene in the urine exosome globule could be tested repeatedly, which is reliable and convenient. As this method being improved and popularized, it could provide strong instructed basis for the therapy of tumor and the monitoring of pathogenetic condition.