Differential Expression Of Epithelial-mesenchymal Transition-related Markers Between Primary Colon Cancer And Corresponding Matched Liver Metastasis Tissue

Objective:This paper aims to investigate the expression of epithelial-mesenchymal transition(EMT)-related markers in colon cancer with no distant metastases,primary colon cancer and corresponding matchedliver metastasis tissues.Furthermore,we analyze the association between E-cadherin expression and clinicopathological characteristics in order to indicate the role of EMT in metastasis of colon cancer.Methods:The pathological slides including 15 colon cancer patients with no distant metastases and 20 colon cancerpatients with liver metastasis were collected in the First Hospital of Shanxi Medical University and Shanxi Cancer Center from January 2011 to December2014.The immunohistochemistry methods(SP) were used to detect expression levels of E-cadherin and Vimentin in human primary colon cancer and corresponding matched liver metastasis tissues.The results were determined as(-),(±),(+) according to the positive expression cells. Additionally, the average intensity was measured. All the data were showed as mean±s.d. and analyzed by SPSS. Mean values were compared using thet-test in20 pairs of tissues. The count data was analyzed by using χ2test. P-value of less than 0.05 was considered as statistically significant.Results:(1) E-cadherin was expressed positively in 86.7%(13/15) colon cancer with no distant organ metastases and 35.7%(5/14) colon cancer with liver metastases,and the difference between the two groups was statistically significant(P<0.05).(2) E-cadherin was mainly expressed on cell membrane. The positive expression rate of primary colon cancer was 25%(5/20),however, the rate is 40%(8/20) in corresponding matched liver metastasis tissue.Moreover,the average membrane intensity were173.075±29.770 and 175.540±26.5738.There was no significant difference between thetwo groups(t=-0.425,P>0.05).Vimentin was expressed in stroma tissues of tumor,and rarely in tumor cell cytoplasmic.The positive rate in colon cancer and its liver metastases were corresponding 80%(16/20) and 65%(13/20).The average intensity were 110.079±22.434 and 100.187±13.891, and the difference was not significant.(t=1.506, P>0.05).(3) The expression of E-cadherin has no significant difference in different clinicopathological characteristics such as sex, age, tumor size, differentiation level, depth of invasive(P>0.05).Conclusion:(1) The differential expression of E-cadherin in the colon cancer with no distant metastases and those which has distant metastases probably predicated the risk of metastasis.(2) There were no significant differences of E-cadherin or Vimentin in primary colon cancer tissues compared with corresponding matched liver metastasis tissue,suggesting that the colon cancer cells may undergo EMT which could promote tumor progression at early stage, and then may go through MET while moving to a new location(such as liver).(3) The heterogeneity of tumor tissue may be the reason for the imbalanced expression of tumor markers.