Expression Of P120ctn And E-cadherin In Human Colorectal Cancer And Its Clinical Significance

Objective:colorectal cancer is one of the most lethal malignant tumors,and the primary causes of this lethality include tumor recurrence and metastasis.Dysfunction of adhesion molecule and destruction of cell adhesion are the initial steps of tumor Metasta sis.E-cadherin,a member of cadherin family,is a transmembrane glycoptein which connects adjacent cells through C_a²⁺dependent homophilic interaction.As the major epirhelial adhesion molecule,the loss of E-cadherin is reported to be associated with tumor dedifferentiation and metastasis.P120ctn is a catenin whose direct binding to the juxtamembrane domain of classical cadherins suggests a role in regulating cell-cell adhesion.Abnormal expression of cadherin\catenin complex may affects related cell proliferation,differetiation and biological behaviour,which induce tumor's invasion and metastasis.The expression of p120ctn and E-cadherin can be regarded as valuable indicators for evaluating biological behavior and the prognosis of colon carcinoma.Methods:immunohistochemical method was used to detect the P120ctn and E-cadherin expression in 71 cases with human colorectal cancer after surgical treatment,which to discusses relations with colorectal cancer. Meanwhile 41 samples of normalmucosa and cancer tissues from patients with colorectal cancer were detected for their expression levels of P120ctn and E-cadherin by RT-PCR,and makes the comparison with result of immunohistochemical method.Results:There is a significant correlation between abnormal expression of p120ctn and E-cadherin and tumor differentiation,tiation clinical stage,lymph node metastasis and poor prognosis(P＜0.05).Moreover,there is a positive correlation between the expression of P120 ctn and E-cadherin(P＜0.05). Immunohistochemical:normal colorectal cells showed membranous expression for p120ctn and E-cadherin.while P120ctn in human colorectal cancer was characterized by cytop lasmic or diminished membranous stainingl,the rate of abnormal p120ctn exp ression was 70.4%;The rate of abnormal E-cadherin expression was 63.4%by cytop lasmic.RT-PCR:A significant decrease in P120ctn and E-cadherin mRNA expression was found in colorectal cancer tissues(0.589±0.055 VS 1.710±0.026å’Œ0.809±0.102 VS 1.595±0.125,P＜0.05).Conclusion:P120ctn and E-cadherin may contribute significantly to colorectal cancer invasion and metastasis.The simultaneous detection of expression of both P120ctn and E-cadherin may serve as a marker of lymph node metastasis in colorectal cancer and for evaluating the prognosis of the patients with colorectal cancer.