Expression Of TLR4in Colorectal Cancer And Its Relationships With FasL And EGFR

Background and objective:There are many abnormal changes of several kinds of genes in the development of colorectal cancer. Previous studies have demonstrated that chronic intestinal inflammation increase the risks of progress of colorectal cancer, and toll like receptor4(TLR4) plays a key role in chronic intestinal inflammation. Recent researches showed that TLR4could promote the development of colorectal cancer, but the mechanism was not completely clear. In addition, in colorectal cancer, the expression of Fas ligand (FasL) was significantly higher than that in normal intestinal tissues, which could induce the apoptosis of lymphocytes and counterattack the body’s immune system. The increased expression of the epidermal growth factor receptor (EGFR) could promote growth and metastasis of colorectal cancer. So this paper is to analyze the relationship between the expression of TLR4and its clinical pathology characteristic which can elucidate its clinical significance and prognosis. It can also further explore the role of TLR4in the development of colorectal cancer through the observation of TLR4, FasL and EGFR expression in colorectal cancer and normal intestinal tissues.Methods:Immunohistochemical methods was performed to detect the expression of TLR4/FasL and EGFR in the tissue sections obtained from58colorectal samples which were confirmed by pathology after resection of colorectal cancer in between2007and2011and25normal colorectal tissues achieved by colonoscopy biopsy. None of the samples received preoperative chemotherapy, radiation therapy, or immune therapy. In the58cases,38cases were male, the rest were female. They were22-83years old, the median age was61,56cases were colon cancer, and2cases were rectal cancer;9cases well-differentiated,34cases middle differentiation,15cases poorly differentiated; as for Duke’s stage,14cases A period,14cases B period,14cases C period,16cases D period. The TLR4/EGFR monoclonal antibody and FasL polyclonal antibody were diluted at a concentration of1:3001:4001:400respectively, and the rest steps were performed strictly according to the instructions of the antibody kit, phosphate buffer (PBS) was selected to replace the primary antibody as a negative control. And this paper discussed the relationship between TLR4and FasL EGFR expression through the Spearman’s related analysis and the relationship between TLR4expression and its clinical pathological features of colorectal cancer tissue with the analysis of χ2test.Results:1. The expression of TLR4FasL and EGFR in colorectal cancer: The expression of TLR4was mainly located in the cytoplasm and membrane of colorectal cancer cells and normal bowel mucosa cells, and there was no expression in the nucleus. There was negative expression in most of the normal bowel mucosal cells. The positive rate of TLR4expression in colorectal cancer tissue was59%(34/58), significantly higher than that in the normal bowel mucosa tissues20%(5/25)(χ2=10.461, P<0.01).The positive expression of FasL EGFR was mainly located in cytoplasm and membrane of colorectal cancer cells, and there was no expression in the nucleus. Furthermore, we could find the EGFR positive staining in colorectal cancer stroma occasionally. The positive rate of FasL/EGFR expression in colorectal cancer were71%and83%respectively, which were significantly higher than that in normal colorectal organization (22%and31%, respectively)(χ2=5.018, P<0.05;χ2=3.708,P<0.05, respectively).2. Through the analysis of relationship between the TLR4expression in colorectal cancer tissue and its clinical pathology characteristic, such as the patient’s age, gender, colorectal cancer differentiation and local lymph node metastasis, we found there was no significant correlation between TLR4expression and local lymph node metastasis. But the expression of the TLR4was correlated with colorectal cancer distant metastases (χ2=4.063, P<0.05). 3. Through the analysis of relationship between TLR4expression and FasL EGFR expression, there was the strong positive correlation (r=0.249, P<0.01) between TLR4and FasL expression, and in a series of colorectal tissue sections, the positive staining area of TLR4expression was consistent with that of FasL expression. But there was no apparent correlation between TLR4EGFR.(r-0.345, P>0.05), the positive staining area of TLR4expression was not in accordance with that of EGFR expression.Conclusions:1. The high expression of the TLR4is correlated with distant metastasis of colorectal cancer, which suggests that TLR4may promote progress and metastasis of cancer, and could be identified as an indicator of distant metastasis in colorectal cancer.2. Our results show that there is strong positive correlation between TLR4and FasL expression, which indicates TLR4may participate in immune counterattack of colorectal cancer and promote the growth and metastasis of colorectal cancer through up-regulation of FasL expression.3. According to our results, TLR4expression is not associated with that of EGFR, so the relationship between TLR4EGFR expressions should be further researched.