High expression of cyclin A is associated with poor prognosis in endometrial endometrioid adenocarcinoma.

Cyclins are a group of proteins that act as activators to cyclin-dependent kinases and are required for normal cell cycle transitions. Cyclin A is involved in the transitions between G1 to S and G2 to M. Its deregulation has been linked to a number of neoplasms, including endometrial cancer. The prognostic significance of cyclin A expression seems to be cancer-specific, and current knowledge on its impact on survival of endometrial cancer is limited. This study aimed to investigate the effect of cyclin A expression on cancer-specific survival and its correlation with conventional prognostic factors in endometrioid adenocarcinoma. Biopsies obtained from 211 patients were immunohistochemically stained for cyclin A and differences in expression analyzed at the Oulu University Hospital. Patients were divided into two groups utilizing the ROC curve. Further survival analyses were carried out between these two groups. In this study, we show that cyclin A expression correlates with tumor grade and FIGO stage. We also show that cyclin A is an independent prognostic factor in endometrioid adenocarcinoma. Whether cyclin A plays a role in tumorigenesis or merely is a marker of increased proliferation requires further studies.

Immunoreactivity for TIMP-2 is associated with a favorable prognosis in endometrial carcinoma.

Tissue inhibitors of metalloproteinases are important regulators of metalloproteinase activity, and the balance of active enzyme and inhibitor is a critical determinant of tumor cell invasiveness. This study aimed to evaluate the prognostic and clinical implications of the two main inhibitors of matrix metalloproteinases, TIMP-1 and TIMP-2, in endometrial carcinoma. The material consisted of 241 patients with primary endometrial carcinoma. The median follow-up time was 77 months. Expressions of TIMP-1 and TIMP-2 proteins were examined in paraffin-embedded tumor sections by immunohistochemical methods. Positive staining for TIMP-1 and -2 was observed in 88% and 86% of the primary tumors, respectively. The Kaplan-Meier analysis showed that the 5-year cancer-specific survival rate of the patients with TIMP-2 positive immunostaining was 89% and that of the TIMP-2 negative patients 78%. Positive immunoreaction for TIMP-2 correlated with favorable cancer-specific and overall survival. When including only endometrioid adenocarcinomas, a similar trend towards favorable survival was seen. Excluding stage IA carcinomas, the difference became again statistically significant. For TIMP-1, there was no statistically significant association with overall or cancer-specific survival. The Cox regression analysis showed stage, grade and TIMP-2 to be significant predictors of survival. We suggest that TIMP-2 may have a more important role in endometrial carcinoma progression than TIMP-1 and might serve as a potential marker for favorable prognosis in this type of cancer.

Modulating the binding properties of an anti-17beta-estradiol antibody by systematic mutation combinations.

The anti-17beta-estradiol antibody 57-2 has been a subject for several protein engineering studies that have produced a number of mutants with improved binding properties. Here, we generated a set of 16 antibody 57-2 variants by systematically combining mutations previously identified from phage display-derived improved antibody mutants. These mutations included three point mutations in the variable domain of the light-chain and a heavy-chain variant containing a four-residue random insertion in complementarity determining region CDR-H2. The antibody variants were expressed as Fab fragments, and they were characterized for affinity toward estradiol, for cross-reactivity toward three related steroids, and for dissociation rate of the Fab/estradiol complex by using time-resolved fluorescence based immunoassays. The double-mutant cycle method was used to address the cooperativity effects between the mutations. The experimental data were correlated with structural information by using molecular modeling and visual analysis of the previously solved antibody 57-2 crystal structures. These analyses provided information about the steroid-binding mode of the antibody, the potential mechanisms of individual mutations, and their mutual interactions. Furthermore, several combinatorial mutants with improved affinity and specificity were obtained. The capacity of one of these mutants to detect estradiol concentrations at a clinically relevant range was proved by establishing a time-resolved fluorescence based immunoassay.

Combination of strong MMP-2 and weak TIMP-2 immunostainings is a significant prognostic factor in endometrial carcinoma.

OBJECTIVE: The aim of this study was to evaluate the combined effects of MMP-2 and TIMP-2 protein immunoreactivities on the prognosis in endometrial carcinoma. METHODS: Paraffin-embedded tissue samples from 225 primary endometrioid adenocarcinomas and 13 histologies other than endometrioid adenocarcinoma were immunohistochemically stained for MMP-2 and TIMP-2. RESULTS: In Kaplan-Meier analysis, the 5-year cancer-specific survival rate of the endometrioid adenocarcinoma patients with negative MMP-2 and positive TIMP-2 staining was 100%, whereas only 78% of patients presenting with positive MMP-2 and negative TIMP-2 staining results were alive at that time. In Cox regression analysis, patients with positive MMP-2 and negative TIMP-2 immunostaining had a 4.7-fold relative risk of death from endometrial carcinoma compared to the group of patients with negative MMP-2 and positive or negative TIMP-2 immunoreaction. CONCLUSIONS: MMP-2 seems to be the main metalloproteinase determining the prognosis in endometrial carcinoma. Combination of strong MMP-2 and weak TIMP-2 immunostainings was the most potent prognostic marker for poor survival.