Associação da expressão de anexina A1 e proteínas de reparo do DNA e sobrevivência de pacientes com câncer colorretal

Abstract

Nowadays, the colorectal cancer (CRC) is considered a global disease. In the past years, there were a predominance in developed countries, but this year, in Brazil, about 34.000 new cases are expected. Among the mechanisms of the colorectal cancer carcinogenesis, the microsatellite instability (MI) pathway has highlighted, by screening of the DNA mismatch repair (MMR) proteins. Annexin A1 (ANXA1) is a relatively recently studied protein in CRC tumorigenesis, there are few studies involving this. The aim of this study is to associate the expression of ANXA1 and the DNA MMR proteins, to the tumor stage and survival of the CRC patients. They were assessed 81 patients from two hospitals (one public and one private), being researched the ANXA1 expression by immunofluorescence and the DNA MMR proteins by immunohistochemistry and the association between themselves and the independent variables (gender, tumor location, histological grade, histological type, tumor stage and survival). It was demonstrated in this study that the ANXA1 is over expressed in CRC than in normal tissue margin, regardless of tumor location.There was an association of tumors expressing ANXA1 with those who showed inactivation of MutS dimer, both when assessed exclusively in the colon, as regardless of its location. It showed higher incidence of death in patients with tumors showing positivity for ANXA1 and located in colon. It found no association between positivity for ANXA1 and the presence of microsatellite instability in the assessed CRC. According to the literature, CRC localized in rectum, represent stable tumors, associated with isolated expression of MLH1 and MSH2 proteins. It found no statistically significant between tumor stage and ANXA1 expressionor presence of microsatellite instability. In conclusion, it observed that the high incidence of positive tumors for ANXA1 and their association with the inactivation of the DNA MMR protein (MSH2), even in isolation, demonstrates the importance of these proteins in CRC biology.