5241

PGR

progesterone receptor;PGR;progesterone receptor

nuclear receptor subfamily 3 group C member 3

11q22-q23

protein-coding

BACKGROUND: In breast cancer cyclooxygenase-2 overexpression is related with poor outcomes, but the clinical relevance of cyclooxygenase-2 is still unclear. Progesterone receptor is a regulator of cyclooxygenase-2 expression. We postulate that progesterone receptor was associated to cyclooxygenase-2 expression and clinicopathologic factors in breast cancer. METHODS: Cyclooxygenase-2 and progesterone receptor expression was analyzed, by immunohistochemistry, in 31 cases of invasive ductal carcinoma. RESULTS: The expression of cyclooxygenase-2 and progesterone receptor was observed in 64.5% and 45.2% of the tumors, respectively. We found 11 tumors with both cyclooxygenase-2 and progesterone receptor overexpression and they are related with tumor lower size and lower axillary node metastasis. CONCLUSION: These results suggest that progesterone receptor has a protective role in breast cancer by inhibiting chronic inflammatory pathway.

Wnt/beta-catenin signalling has been suggested to be active in basal-like breast cancer. However, in highly aggressive metastatic triple-negative breast cancers (TNBC) the role of beta-catenin and the underlying mechanism(s) for the aggressiveness of TNBC remain unknown. We illustrate that WNT10B induces transcriptionally active beta-catenin in human TNBC and predicts survival-outcome of patients with both TNBC and basal-like tumours. We provide evidence that transgenic murine Wnt10b-driven tumours are devoid of ERalpha, PR and HER2 expression and can model human TNBC. Importantly, HMGA2 is specifically expressed during early stages of embryonic mammogenesis and absent when WNT10B expression is lost, suggesting a developmentally conserved mode of action. Mechanistically, ChIP analysis uncovered that WNT10B activates canonical beta-catenin signalling leading to up-regulation of HMGA2. Treatment of mouse and human triple-negative tumour cells with two Wnt/beta-catenin pathway modulators or siRNA to HMGA2 decreases HMGA2 levels and proliferation. We demonstrate that WNT10B has epistatic activity on HMGA2, which is necessary and sufficient for proliferation of TNBC cells. Furthermore, HMGA2 expression predicts relapse-free-survival and metastasis in TNBC patients.

BACKGROUND: The primary aim of this retrospective study was to investigate intraindividual correlation of estrogen receptor (ER) status, progesterone receptor (PR) status, and HER2 status between primary breast cancer and metastatic breast cancer (mBC). Secondary aims included patients' characteristics, overall survival, feasibility of histopathological evaluation in the metastatic setting, and predictive factors associated with receptors status discordance. METHODS: Patients with either biopsy of metastatic relapse or surgery of metastasis were identified. Demographics, tumor characteristics, treatment characteristics, and ER, PR, and HER2 statuses were retrospectively obtained in patients' reports. Receptors statuses were assessed by immunohistochemistry with a positivity cutoff of more than 10% for ER and PR. HER2 was considered as positive if overexpression was scored at 3+ in immunohistochemistry or if amplification ratio was >2 in fluorescent in situ hybridization. RESULTS: From a cohort of 489 patients with mBC, 269 patients had histopathological samples of metastatic relapse. Histopathological analysis of the specimen confirmed the diagnosis of mBC in 235 patients. Discordance in one or more receptors between primary breast cancer and mBC was found in 99 patients (42%). A switch in receptor status was identified for ER in 17% of tumors (p = 4 x 10(-3)), PR in 29% of cancers (p < 4 x 10(-4)), and HER2 in 4% of lesions (p = .16). Exposure to chemotherapy and to anthracycline-based chemotherapy was statistically associated with switches in ER status. Seven (2%) second malignancies and three benign diseases (1%) were diagnosed. CONCLUSIONS: This study confirms that discordance in ER and PR receptor expression between the primary breast tumor and the corresponding metastatic lesions is high, whereas HER2 status remains relatively constant. Chemotherapy, and specifically anthracycline-based chemotherapy, was associated with switch in ER status. These results were obtained in a selected population of patients; further studies are warranted to confirm these data and to determine the interest of systematic rebiopsy in the metastatic setting.

Breast cancer is the most common cancer in women worldwide. Studies have shown that the high temperature requirement factor A3 (HtrA3) is involved in important physiological processes including maintenance of mitochondrial homeostasis, cell death, and cell signaling. HtrA3 is reported to be downregulated in several cancers and has been correlated with advancing cancer stage. We performed a retrospective study using our breast cancer tissue bank to investigate whether the expression of HtrA3 correlated with lymphatic metastasis in breast cancer and whether the expression of HtrA3 was correlated with estrogen receptor (ER) and progesterone receptor (PR) expression in breast cancer. Breast cancer tissues from 156 invasive ductal breast cancer patients with or without lymphatic metastasis were collected and the levels of HtrA3 were measured by immunohistochemistry and western blotting. The expression of HtrA3 was lower in breast cancer. In particular, HtrA3 expression in breast cancer with lymphatic metastasis was lower than that in breast cancer without lymphatic metastasis. In breast cancers with no lymphatic metastasis, the expression of HtrA3 was lower in patients with ER- and PR-positive tumors, but when breast cancers with lymphatic metastasis were analyzed, there was no difference in HtrA3 expression between ER- and PR-positive or ER- and PR-negative tumors. These data suggest that the expression of HtrA3 was negatively correlated with lymphatic metastasis in breast cancer but not correlated with ER and PR positivity or negativity. A better understanding of the mechanism of HtrA3 may provide the basis for future development of a novel therapeutic target in breast cancer.

PURPOSE: Epidermal growth factor (EGF) is a ligand for the epidermal growth factor receptor (EGFR). Human epidermal growth factor receptor 2 (HER2) shares common signal pathways and forms a heterodimer with EGFR. In this study, we investigated the clinical and pathologic implications of serum EGF levels in patients with HER2-positive metastatic breast cancer (MBC). METHODS: We analyzed serum EGF levels from baseline serum samples of consecutive patients with HER2-positive MBC who received first-line trastuzumab plus taxane chemotherapy and correlated them with treatment outcomes and pathologic features. RESULTS: A total of 50 women were analyzed. The median age was 47 years (range 27-72 years). Patients with high serum EGF levels (>/=10.0 pg/mL) had significantly longer overall survival (47.0 months (95 % confidence interval (CI) 28.3-65.7 months) vs. 23.3 months (95 %

OBJECTIVE: Loss of expression of progesterone receptors (PR) in endometrial cancer is related to a more invasive and metastatic phenotype. In this study we aim to investigate whether selective loss of PRA or PRB affects the invasive capacity of endometrial cancer cells. METHODS: cDNA microarrays were performed to compare gene expression profiles of a set of endometrial cancer sub-cell lines expressing PRA and/or PRB. In vitro invasion assays were performed to assess whether differences in gene expression between the lines were reflected by their invasive behavior. RESULTS: It was observed that cell lines that express only PRA express higher levels of cadherins, and show a lower level of invasion compared to cell lines that express PRB. When cadherin function was inhibited in exclusively PRA-expressing cell lines, an increase of in vitro invasion was observed. In support of these findings, it was observed that in higher grade and more invasive endometrial cancer, expression of E-cadherin decreased. CONCLUSIONS: These results indicate that relative loss of PRA during progression of endometrial cancer can have a negative impact on cadherin expression, which may lead to development of a more metastatic phenotype.

OBJECTIVE: In endometrial cancer loss of progesterone receptor (PR, gene name PGR) is associated with aggressive disease and altered response to hormonal treatment. The aim of this study was to investigate changes in PR expression level with disease progression, and explore whether differences in gene expression according to PR status can be linked to processes involved in cancer development elucidating new therapeutic opportunities. METHODS: 686 primary endometrial cancers and 171 metastatic lesions were investigated for PR expression in relation to clinical and histopathological data. Protein levels were investigated by immunohistochemistry and reverse phase protein array, and mRNA levels by DNA oligonucleotide microarray. RESULTS: PR protein level was significantly associated with PGR mRNA expression (P<0.001) and patient survival (P<0.001). Loss of PR increased with disease progression, with 23% of the primary tumours and 76% of metastases demonstrating PR loss. Using a cell cycle progression signature score, PR loss was associated with increased proliferation for both oestrogen receptor (ER) positive and negative tumours. Through a Connectivity Map search, CDK inhibitors and other drugs with anti-proliferative effects were suggested in particular for treatment of patients with loss of PR. CONCLUSION: Loss of PR in endometrial cancer is associated with increased proliferation, poor survival, and increases from primary to metastatic lesions. Based on expression profiles, CDK inhibitors may have activity in PR negative tumours, supporting further testing in clinical trials for patients with systemic endometrial cancer dependent on PR status.