A trio of genes might potentially distinguish doxorubicin-responsive from nonresponsive tumors, but further validation by a larger number of samples is still needed.

No abstract

In a previous study, using differential display reverse transcriptase-PCR (DDRT-PCR) we showed that down-regulation of the PHLDA1 (pleckstrin homology-like domain, family A, member 1; also named TDAG51) mRNA was down-regulated in breast tumors compared with normal breast tissue. The present study was conducted to determine the expression pattern and predictive prognostic value of PHLDA1 in breast cancer. A series of 720 primary invasive breast tumors were examined for PHLDA1 expression. PHLDA1 mRNA expression was determined in 74 breast tumors using quantitative Real Time PCR analysis (qPCR). PHLDA1 protein expression was evaluated by immunohistochemistry (IHC) using Tissue Microarrays (TMA) containing 699 primary invasive breast tumors. Reduced PHLDA1 mRNA expression was identified in 72% (53/74) of the primary breast tumors analyzed. Seventy-three percent (512/699) of cases analyzed showed negative PHLDA1 protein expression. Down-regulation of PHLDA1 protein was a strong predictor of poor prognosis for breast cancer patients. Breast cancer patients with tumors that were negative for PHLDA1 protein expression had shorter disease free survival (P < 0.001) and overall survival (P < 0.001) than patients with tumors that were positive for PHLDA1 protein expression. In addition patients with tumors exhibiting reduced PHLDA1 expression and paucity for ER had the worse outcome (P < 0.001). Multivariate analysis indicated that PHLDA1 protein expression is an independent prognostic factor of patient survival. To our knowledge, the expression pattern of PHLDA1 in breast cancer has not previously been investigated. Our results provide strong evidence that reduced PHLDA1 expression is important in breast cancer progression and could serve as useful prognostic marker of disease outcome.

Germline mutations in BRCA1, BRCA2 and TP53 genes have been identified as one of the most important disease-causing issues in young breast cancer patients worldwide. The specific defective biological processes that trigger germline mutation-associated and -negative tumors remain unclear. To delineate an initial portrait of Brazilian early-onset breast cancer, we performed an investigation combining both germline and tumor analysis. Germline screening of the BRCA1, BRCA2, CHEK2 (c.1100delC) and TP53 genes was performed in 54 unrelated patients <35 y; their tumors were investigated with respect to transcriptional and genomic profiles as well as hormonal receptors and HER2 expression/amplification. Germline mutations were detected in 12 out of 54 patients (22%) [7 in BRCA1 (13%), 4 in BRCA2 (7%) and one in TP53 (2%) gene]. A cancer familial history was present in 31.4% of the unrelated patients, from them 43.7% were carriers for germline mutation (37.5% in BRCA1 and in 6.2% in the BRCA2 genes). Fifty percent of the unrelated patients with hormone receptor-negative tumors carried BRCA1 mutations, percentage increasing to 83% in cases with familial history of cancer. Over-representation of DNA damage-, cellular and cell cycle-related processes was detected in the up-regulated genes of BRCA1/2-associated tumors, whereas cell and embryo development-related processes were over-represented in the up-regulated genes of BRCA1/2-negative tumors, suggesting distinct mechanisms driving the tumorigenesis. An initial portrait of the early-onset breast cancer patients in Brazil was generated pointing out that hormone receptor-negative tumors and positive familial history are two major risk factors for detection of a BRCA1 germline mutation. Additionally, the data revealed molecular factors that potentially trigger the tumor development in young patients.

The purpose of this study was to investigate the association among matrix metalloproteinases (gelatinases A and B, stromelysin-3 (ST3) and matrilysin) mRNAs expressed in primary breast carcinomas and standard prognostic parameters and clinical outcome. mRNA levels were determined by Northern analysis in samples of 81 breast cancer patients (median follow-up, 40 months) and 27 samples of uninvolved adjacent breast tissue. Proteases were expressed by the majority of the tumors and normal breast tissues examined. ST3, gelatinase A and matrilysin mRNAs were more often expressed at high levels in carcinomatous than in normal breast tissues. Differences in the distribution of gelatinase B mRNA were not found. However, paired normal tissues generally produced weaker signals when compared to matched tumor samples. Univariate analysis showed no significant association of gelatinase A and matrilysin mRNAs with the classical prognostic markers (age, menopausal status, stage, size, nodal status, vascular infiltrate, necrosis, steroid receptors, metastasis and survival). Overexpression of ST3 was more frequently found in tumors of post-menopausal women (P < 0.022). Elevated expression of gel B mRNA was associated with the presence of vascular infiltrate (P < 0.026), necrosis (P < 0.039), PR negative tumors (P < 0.014) and inversely correlated to the number of survivors (P < 0.021). Multivariate analysis including 68 patients for whom all information was available indicated that neither stromelysin correlated significantly with pathological, clinical or biochemical features. High levels of gelatinase A and B mRNAs were inversely associated with the number of survivors. Our findings suggest that measurements of gelatinase A and B mRNAs expression in breast carcinoma may help to identify patients with an aggressive form of the disease.