Aquaporin 1 (AQP1) expression is a novel characteristic feature of a particularly aggressive subgroup of basal-like breast carcinomas.

Aquaporin1 (AQP1) is a water channel protein that facilitates water flux across cell membranes. It is widely expressed in epithelial and endothelial cells in several tissues. AQP1 is also associated with angiogenesis, cell migration and metastasis in some human malignancies. In this study the immunohistochemical expression of AQP1 in 203 invasive breast carcinomas with long-term follow up was investigated. AQP1 expression was demonstrated in 11 tumours (5.4%) and showed highly significant correlation with high tumour grade, medullary-like histology, "triple-negativity", cytokeratin 14 and smooth muscle actin expression. In univariate analysis, AQP1 was significantly associated with poor prognosis. In multivariate analysis, AQP1 expression proved to be an independent prognostic marker if stratified by age, tumour size, lymph node status, histological grade, ER status and CMF therapy. Our results strongly suggest that AQP1 expression is a new characteristic feature of a particularly aggressive subgroup of basal-like breast carcinomas.

Altered angiogenesis in preeclampsia: evaluation of a new test system for measuring placental growth factor.

BACKGROUND: Decreased concentrations of the circulating angiogenic factors, free placental growth factor (PLGF) and free vascular endothelial growth factor (VEGF), and increased concentrations of the anti-angiogenic factor, soluble fms-like tyrosine kinase 1 (sFLT-1) have been observed during clinical preeclampsia. We established a new PLGF-ELISA kit for the measurement of PLGF in sera. In the present study, we demonstrated the assay characteristics by measurement of PLGF expression in normal and preeclamptic pregnancies as compared to an established research kit. METHODS: Blood samples were taken from 64 women with singleton uncomplicated pregnancies for longitudinal measurement of PLGF in the course of pregnancy. In 30 preeclamptic patients, serum levels of PLGF and sFLT-1 were measured by Human PLGF-ELISA and Human sVEGF R1 ELISA according to the described test principles. The assay characteristics of the new PLGF-ELISA were determined and the results were compared to those performed with an available research kit. RESULTS: The PLGF concentration in normal pregnancies showed a steady increase starting at the beginning of the second trimester with a peak at 28-32 weeks and a consistent decline thereafter. The preeclamptic pregnancies had significant lower serum concentrations of PLGF and significant higher serum concentrations of sFLT-1 as compared to the non-preeclamptic pregnancies. All the measured assay characteristics fulfilled the required specifications. Comparison of the values of the new PLGF-ELISA and the established research kit resulted in a correlation coefficient of 0.921. CONCLUSIONS: Our results support the hypothesis that an imbalance between factors promoting angiogenesis, such as PLGF, and factors antagonizing angiogenesis, such as sFLT-1, has a fundamental role in the pathogenesis of preeclampsia. The new established ELISA test can be considered reliable and it offers many advantages. As it is authorized for routine diagnostic testing, it may offer new possibilities in the prediction of preeclampsia in clinical routine.

The AA genotype of the regulatory BCL2 promoter polymorphism ( 938C>A) is associated with a favorable outcome in lymph node negative invasive breast cancer patients.

PURPOSE: Expression of the antiapoptotic and antiproliferative protein Bcl-2 has been repeatedly shown to be associated with better clinical outcome in breast cancer. We recently showed a novel regulatory (-938C>A) single-nucleotide polymorphism (SNP) in the inhibitory P2 BCL2 gene promoter generating significantly different BCL2 promoter activities. EXPERIMENTAL DESIGN: Paraffin-embedded neoplastic and nonneoplastic tissues from 274 patients (161 still alive after a follow-up period of at least 80 months) with primary unilateral invasive breast carcinoma were investigated. Bcl-2 expression of tumor cells was shown by immunohistochemistry; nonneoplastic tissues were used for genotyping. Both the Bcl-2 expression and the (-938C>A) genotypes were correlated with the patients' survival. RESULTS: Kaplan-Meier curves revealed a significant association of the AA genotype with increased survival (P = 0.030) in lymph node-negative breast cancer patients, whereas no genotype effect could be observed in lymph node-positive cases. Ten-year survival rates were 88.6% for the AA genotype, 78.4% for the AC genotype, and 65.8% for the CC genotype. Multivariable Cox regression identified the BCL2 (-938CC) genotype as an independent prognostic factor for cancer-related death in lymph node-negative breast carcinoma patients (hazard ratio, 3.59; P = 0.032). Immunohistochemical Bcl-2 expression was significantly associated with the clinical outcome of lymph node-positive but not of lymph node-negative breast cancer patients. In lymph node-negative cases, the (-938C>A) SNP was both significantly related with the immunohistochemically determined level of Bcl-2 expression (P = 0.044) and the survival of patients with Bcl-2-expressing carcinomas (P = 0.006). CONCLUSIONS: These results suggest the (-938C>A) polymorphism as a survival prognosticator as well as indicator of a high-risk group within patients with lymph node-negative breast cancer.

The T393C polymorphism in the gene GNAS1 of G protein is associated with survival of patients with invasive breast carcinoma.

The GNAS1 locus encodes the G(alpha)s protein which stimulates the formation of cyclic AMP (cAMP). Subsequently the cAMP pathway mediates various pleiotropic effects including regulation of apoptosis and proliferation. We have recently shown that genotypes of the single nucleotide polymorphism (SNP) T393C in the gene GNAS1 are associated with survival of patients suffering from bladder, renal cell and colorectal carcinoma. In the present study, the genotypes of the T393C SNP were determined in 279 patients with invasive breast carcinoma. Comparing the genotypes with the overall survival as well as important clinico-pathological parameters showed that carriers of the T allele had a significantly less favourable course of the disease when compared to carriers of the homozygous CC genotype. In multivariate analysis the homozygous TT genotype was independently associated with a decreased overall survival. Our results suggest that the GNAS1 T393C SNP is a novel genetic host factor for disease progression in patients with invasive breast carcinoma.

High expression of focal adhesion kinase (p125FAK) in node-negative breast cancer is related to overexpression of HER-2/neu and activated Akt kinase but does not predict outcome.

INTRODUCTION: Focal adhesion kinase (FAK) regulates multiple cellular processes including growth, differentiation, adhesion, motility and apoptosis. In breast carcinoma, FAK overexpression has been linked to cancer progression but the prognostic relevance remains unknown. In particular, with regard to lymph node-negative breast cancer it is important to identify high-risk patients who would benefit from further adjuvant therapy. METHODS: We analyzed 162 node-negative breast cancer cases to determine the prognostic relevance of FAK expression, and we investigated the relationship of FAK with major associated signaling pathways (HER2, Src, Akt and extracellular regulated kinases) by immunohistochemistry and western blot analysis. RESULTS: Elevated FAK expression did not predict patient outcome, in contrast to tumor grading (P = 0.005), Akt activation (P = 0.0383) and estrogen receptor status (P = 0.0033). Significant positive correlations were observed between elevated FAK expression and HER2 overexpression (P = 0.001), as well as phospho-Src Tyr-215 (P = 0.021) and phospho-Akt (P < 0.001), but not with phospho-ERK1/2 (P = 0.108). Western blot analysis showed a significant correlation of FAK Tyr-861 activation and HER2 overexpression (P = 0.01). CONCLUSIONS: Immunohistochemical detection of FAK expression is of no prognostic significance in node-negative breast cancer but provides evidence that HER2 is involved in tumor malignancy and metastatic ability of breast cancer through a novel signaling pathway participating FAK and Src.

Prognostic relevance of activated Akt kinase in node-negative breast cancer: a clinicopathological study of 99 cases.

Patients with lymphnode-negative breast cancer show a 10-year tumor recurrence rate of approximately 30%. Therefore, it is important to identify high-risk patients who would benefit from further adjuvant therapy. For this purpose, we examined the activation state of two kinases important in the regulation of cell proliferation and apoptosis in a series of 99 node-negative breast cancer cases with a mean follow-up of 10 years: Akt and extracellular regulated kinase (ERK1/2). The activation of Akt and ERK1/2 was investigated by immunohistochemistry using phospho-specific antibodies. The results were correlated with HER-2/neu expression, histological grading, receptor status, overall survival (OS) as well as with cell proliferation (Ki67 immunoreactivity, mitotic count) and tumor apoptosis assessed by TUNEL staining. Activation of Akt (pAkt) but not activation of ERK1/2 (pERK1/2) correlated with HER-2/neu overexpression (P<0.05) and was related to reduced tumor apoptosis (P<0.05). No association was found between pAkt or pERK1/2 with cell proliferation assessed by Ki67 and mitotic count (MC). Survival analysis of receptor status, HER2/neu expression, histological grading, MC and pAkt immunoexpression showed a significant correlation with decreased OS, but only pAkt reached statistical significance in the multivariate Cox regression analysis (P=0.015). Activation of Akt in node-negative breast cancer may indicate aggressive tumor behavior and may constitute an independent prognostic factor of OS. The determination of pAkt status may be of value in identifying high-risk patients, who would benefit from adjuvant therapy, and gives a rationale to investigate new therapy strategies by specific inhibition of the Akt signaling pathway in breast cancer.