The Role Of CCX-CKR And CCL21 In Colorectal Cancer Development And Metastasis And Drug Regulatory Mechanism

Background:Colorectal cancer(CRC)is one of the most common malignant tumor in digestive system.So far,the pathogenesis of colorectal cancer has not been fully elucidated.Many studies have shown that the main reason of rapidly increased mortality in colorectal cancer is the tumor recurrence and metastasis,one of the most common is lymph node metastasis.Therefore,inhibition of invasion and metastasis of colorectal cancer is the important way to improve the patients’ life quality and prolong the patients’ life.In recent years,it have been proved that chemokines and chemokine receptors play an important role in malignant tumor proliferation,invasion,angiogenesis and metastasis.It is a process that the primary tumor growth,invasion and metastasis involved many factors and many steps.As an important migration guide medium of many kinds of cells including tumor cells in vivo,chemokines and their receptors may participate in the each step of above mentioned process.Atypical chemokine receptors also called chemokine decoy receptor,is a special kind of chemokine receptor.Unlike the typical chemokine receptor,although atypical chemokine receptors can also identify and combined with the corresponding ligands,it doesn’t cause any signal transduction.Chemokine decoy receptors play a role mainly through effective internalization of homologous chemokine ligand and making its degradation.CCX-CKR has been called CCRL1 or CCR11,is a member of this kind receptor.CCX-CKR has three high affinity ligands,CCL21(SLC,6 ckine),CCL19(ELC)and CCL25(TECK).It has been confirmed by a large amount of research that the biological axis consisted with those ligands CCR7/CCL21,CCR7/CCL19,CCL25/CCR9 play the crucial role in tumor proliferation,survival and metastasis.So the present paper is to discuss the role of CCX-CKR and CCL21 in colorectal cancer occurrence and metastasis by detecting the CCX-CKR and CCL21 expression in colorectal cancer tissues.Meanwhile,to explore the probably mechanism of drugs by observing the expression of CCX-CKR in colon cancer cell line HCT-8 after treated by different concentrations of paclitaxel and 5fluorouracil respectively.We try to find news to reduce the morbidity and mortality in colorectal cancer based on above research.Objective:1)To explore the role of CCX-CKR and CCL21 in colorectal cancer development and metastasis by detecting the expression of CCX-CKR、CCL21 in normal colorectal tissues and colorectal cancer tissues and the CCX-CKR expression differences in Lymph node metastasis and no lymph node metastasis tissues in colorectal cancer tissues2)To investigate the mechanism of paclitaxel and 5-fluorouracil in inhibition the growth and metastasis of cancer cells and its relationship with CCX-CKR,by observing the CCX-CKR alterations in colon cancer cell line HCT-8 were treated with different concentrations of paclitaxel and 5-fluorouracil.Experimental foundation and theoretical basis can be provided through this research for finding new therapeutic targets.Methods:Collect the colorectal cancer tissue samples from the first affiliated hospital of Dalian Medical University.To observe the expression of CCX-CKR,CCL21 in colorectal cancer tissue and in normal colorectal tissues,CCX-CKR expression in lymph node metastasis and lymph node metastasis group by immunohistochemistry,western blot and RT-PCR method.CCX-CKR expressions in colon cancer cells HCT-8 after treated with different concentrations of paclitaxel and 5-fluorouracil were detected by immunocytochemistry,Western blot and RT-PCR method.Results:1)Immunohistochemical results showed that expression of CCX-CKR in normal colorectal tissue was obviously higher than that of in colorectal cancer tissue,the difference was statistically significant(P<0.01);The expression of CCX-CKR in lymph node metastasis group was obviously lower than no lymph node metastasis group,difference was statistically significant(P<0.01);Western blot,RT-PCR test results are consistent with the immunohistochemical results.2)Immunohistochemical results showed that in normal colorectal tissues,the expression of CCL21 significantly lower than that of in colorectal cancer tissues,the difference was statistically significant(P<0.01);Western blot,RT-PCR test results are consistent with the immunohistochemical results.3)Immunocytochemistry results showed that the expression of CCX-CKR was significantly increased in HCT-8 after treated with different concentrations of paclitaxel and 5-fluorouracil for 48 hours,especially in high concentration group(P<0.05).Western blot,RT-PCR test results confirmed the immunocytochemistry results.Conclusion:1)The expression CCX-CKR were low in colorectal cancer tissues compared with normal colorectal tissues,and were lower in lymph node metastasis group than in no lymph node metastasis group.We guess that CCX-CKR play an important role in the occurrence and metastasis in colorectal cancer.As a result,the CCX-CKR has hopes to become a marker of the occurrence and metastasis of colorectal cancer,provide theoretical basis for clinical early diagnosis and prognosis judgement.2)CCL21 has high expression in colorectal cancer tissue compared with in normal colorectal tissues.The role of CCX-CKR in the occurrence and metastasis of colorectal cancer has a closely relationship with specific binding to CCL21.The mechanism may be involved with the binding of CCX-CKR to chemokine CCL21 weaken it binding to the typical functional receptor and blocking tumor growth and metastasis consequently.3)The expression of CCX-CKR were higher in colon cancer cell line HCT-8 after treated with different concentrations of paclitaxel and 5-fluorouracil.This results suggest that paclitaxel and 5-fluorouracil may inhibit tumor growth and metastasis by regulating the CCX-CKR expression.