Abstract: Expression of Ets-1 and Integrin α6β4 and Its Clinical Significance in Colorectal CarcinomaChengmei ZHAO1,2, Gang KIU1, Yujie QIU1, Liwei ZHU11Department of General Surgery, Tianjin Medical University General Hospital, Tianjin 300052, China2Tianjin Medical, Tianjin 300222, ChinaCorrespondence to: Liwei ZHU, E-mail: zhuliwei0804@126.comAbstract Objective: To detect the expression of Ets-1 and integrin α6β4 in colorectal carcinoma ( CRC ), and to explore therole and clinical significance of these transcription factors in the invasion and metastasis of CRC. Methods: Surgical specimens from40 CRC patients were used in this study. The mRNA and protein levels of Ets-1 and integrin α6β4 in CRC tissue and the surgical mar-ginal zone were assayed using real-time quantitative PCR and immunohistochemical methods. Statistical analysis for the results of theassay and clinicopathologic data was conducted. Results: Both mRNA and protein expression of Ets-1 and integrin α6β4 were signifi-cantly higher in CRC tissue than in the marginal zones ( P < 0.05 ). There was no correlation among the Ets-1 mRNA expression, histo-logical type, location, size of the CRC, or the extent of differentiation ( P > 0.05 ). The level of Ets-1 mRNA expression was significant-ly higher in the cases with positive lymph nodes than in the cases with negative nodes. There were significant differences between thetwo groups ( P < 0.05 ). There was a positive correlation among the expression of Ets-1 mRNA, depth of CRC infiltration and Duke’ sstaging ( P < 0.05 ). The positive rate of Ets-1 protein detection was 91.3% ( 21/23 cases ) in the cases with nodal metastasis and 58.8%( 10/17 cases ) in the cases without nodal metastasis. There were significant differences between the two groups ( P < 0.05 ). There wasa significant increase in the positive rate of Ets-1 protein in CRC, with a corresponding increase in tumor invasion depth and Duke'sstaging ( P < 0.05 ). Integrin α6β4 protein expression was similar to that of ETS-1. No relationship was detected between integrin α6β4expression and pathologic type or extent of tumor differentiation ( P < 0.05 ). A positive correlation between Ets-1 and integrin α6β4 inCRC was confirmed ( P < 0.05 ). Conclusion: Ets-1 and integrin α6β4 expression in CRC may be an important factor in metastasis anddetection of these proteins may assist in determining prognosis. Ets-1 may become a new target for gene therapy of CRC.Keywords Ets-1; Integrin α6β4; Colorectal carcinoma