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Cancer progression requires cells surrounding tumors be reeducated and activated to support tumor growth. Oncogenic signals from malignant cells directly influence stromal composition and activation, but the factors mediating this communication are still not well understood. We have previously shown that the transcription factor POU class 1 homeobox 1 (POU1F1), also known as Pit-1, induces profound changes on neoplastic cell-autonomous processes favoring metastasis in human breast cancer. Here we describe for the first time Pit-1-mediated paracrine actions on macrophages in the tumor microenvironment by using cell lines in vitro, zebrafish and mouse models in vivo, and samples from human breast cancer patients. Through the release of CXCL12, Pit-1 in tumor cells was found to mediate the recruitment and polarization of macrophages into tumor-associated macrophages (TAMs). In turn, TAMs collaborated with tumor cells to increase tumor growth, angiogenesis, extravasation and metastasis to lung. Our data reveal a new mechanism of cooperation between tumor cells and macrophages favoring metastasis and poor clinical outcome in human breast cancer, which suggests that Pit-1 and CXCL12 should be further studied as potential prognostic and therapeutic indicators. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd., (© 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Development of human tumors is driven by accumulation of alterations in tumor suppressor genes and oncogenes in cells. The POU1F1 transcription factor (also known Pit-1) is expressed in the mammary gland and its overexpression induces profound phenotypic changes in proteins involved in breast cancer progression. Patients with breast cancer and elevated expression of Pit-1 show a positive correlation with the occurrence of distant metastasis and poor overall survival. However, some mediators of Pit-1 actions are still unknown. Here, we show that CXCR4 chemokine receptor and its ligand CXCL12 play a critical role in the pro-tumoral process induced by Pit-1. We found that Pit-1 increases mRNA and protein in both CXCR4 and CXCL12. Knock-down of CXCR4 reduces tumor growth and spread of Pit-1 overexpressing cells in a zebrafish xenograft model. Furthermore, we described for the first time pro-angiogenic effects of Pit-1 through the CXCL12-CXCR4 axis, and that extravasation of Pit-1 overexpressing breast cancer cells is strongly reduced in CXCL12-deprived target tissues. Finally, in breast cancer patients, expression of Pit-1 in primary tumors was found to be positively correlated with CXCR4 and CXCL12, with specific metastasis in liver and lung, and with clinical outcome. Our results suggest that Pit-1-CXCL12-CXCR4 axis could be involved in chemotaxis guidance during the metastatic process, and may represent prognostic and/or therapeutic targets in breast tumors.

The POU class 1 homeobox 1 (POU1F1, also known as Pit-1), pertaining to the Pit-Oct-Unc (POU) family of transcription factors, has been related to tumor growth and metastasis in breast. However, its role in response to breast cancer therapy is unknown. We found that Pit-1 down-regulated DNA-damage and repair genes, and specifically inhibited BRCA1 gene expression, sensitizing breast cancer cells to DNA-damage agents. Administration of 1α, 25-dihydroxy-3-epi-vitamin D3 (3-Epi, an endogenous low calcemic vitamin D metabolite) reduced Pit-1 expression, and synergized with cisplatin, thus, decreasing cell proliferation and apoptosis in vitro, and reducing tumor growth in vivo. In addition, fifteen primary cultures of human breast tumors showed significantly decreased proliferation when treated with 3-Epi+cisplatin, compared to cisplatin alone. This response positively correlated with Pit-1 levels. Our findings demonstrate that high levels of Pit-1 and reduced BRCA1 levels increase breast cancer cell susceptibility to 3-Epi+cisplatin therapy.

The Pit-1 transcription factor (also know as POU1F1) plays a critical role in cell differentiation during organogenesis of the anterior pituitary in mammals and is a transcriptional activator for pituitary gene transcription. Increased expression of Pit-1 has been reported in human tumorigenic breast cells. Here, we found that Pit-1 overexpression or knockdown in human breast cancer cell lines induced profound phenotypic changes in the expression of proteins involved in cell proliferation, apoptosis, and invasion. Some of these protumorigenic effects of Pit-1 were mediated by upregulation of Snai1, an inductor of the epithelial-mesenchymal transition. In immunodeficient mice, Pit-1 overexpression induced tumoral growth and promoted metastasis in lung. In patients with invasive ductal carcinoma of the breast and node-positive tumor, high expression of Pit-1 was significantly correlated with Snai1 positivity. Notably, in these patients elevated expression of Pit-1 was significantly and independently associated with the occurrence of distant metastasis. These findings suggest that Pit-1 could help to make a more accurate prognosis in patients with node-positive breast cancer and may represent a new therapeutic target.

Aims: Matrix metalloproteases (MMPs) and their inhibitors (TIMPs) play an essential role in the degradation of stromal connective tissue and basement membrane components. The aim of this study was to determine whether the dynamic analysis of these components can help to predict tumour aggressiveness., Methods and Results: An immunohistochemical study was performed using tissue arrays and specific antibodies against MMPs -1, -2, -7, -9, -11, -13 and -14 and TIMPs -1, -2 and -3. More than 5000 determinations on cancer specimens from 124 patients with invasive breast cancer were performed on the tumour centre core as well as on the invasive front. Immunostaining for MMPs/TIMPs on mononuclear inflammatory cells (MICs) was evaluated. To identify specific groups of tumours with distinct expression profiles, data obtained from both MICs populations were analysed by unsupervised hierarchical cluster analysis. When compared with MICs at the invasive front, intratumour MICs more frequently showed expression of MMP-7 and -1 and TIMP-3, but less frequently expression of MMP-9 and -11 and TIMP-2., Conclusions: Our data led us to consider the need of further studies in order to identify subsets of MICs and other protein elements of the microenvironment as attractive targets for new therapeutic strategies against cancer., (© 2010 Blackwell Publishing Limited.)

Aims: This study aimed to investigate the expression of matrix metalloproteases (MMPs) and their inhibitors (TIMPs) in ductal carcinoma in situ (DCIS)., Methods: We used inmunohistochemistry to compare the expression of MMPs and TIMPs in tumor or stromal cells for 50 pure DCIS and 12 DCIS with microinvasive foci., Results: Score values for collagenase-1 (MMP-1), membrane type 1 MMP (MMP-14), and TIMP-1, were significantly higher in pure DCIS than in DCIS with microinvasive foci, whereas stromalysin-3 (MMP-11) expression was significantly higher in DCIS with microinvasive foci. Both fibroblasts and mononuclear inflammatory cells (MICs) surrounding pure DCIS showed more frequently expression of MMP-1, MMP-14, and TIMP-3, whereas MMP-11 expression was more frequent in MICs of microinvasive tumors. MICs of microinvasive foci more frequently showed the expression of gelatinase A (MMP-2), MMP-11, collagenase-3 (MMP-13), and TIMP-1, than MICs surrounding pure DCIS; whereas peri-ductal MICs and fibroblasts from pure DCIS expressed TIMP-3 more commonly than these cells at microinvasive foci., Conclusions: There are significant differences in the expression of MMPs and TIMPs, so in tumor cells and stromal cells, between pure DCIS and DCIS with microinvasive foci. Therefore, these staining patterns might display potential applications as biological markers, such as in evaluating microinvasion in resection specimens of breast tumors.

Purpose: Metalloproteases (MMPs) and their tissue inhibitors of metalloproteases (TIMPs) are involved in several key aspects of tumoral growth, invasion and metastasis. The purpose of this study was to characterize on how the different histological types of breast cancer differ in the expression of several components of this enzymatic system., Methods: An immunohistochemical study was performed in 50 ductal, 23 lobular, 14 mucinous, 7 tubular, 4 papillary and 5 medullary invasive carcinomas, using tissue arrays and specific antibodies against 7 MMPs and 3 tisullar TIMPs. Staining results were categorized by means of a specific software program (score values)., Results: Carcinomas of the ductal type showed higher score values for MMPs and TIMPs than the other histological types; whereas mucinous carcinomas had lower scores values for expressions of the majority of these proteins. Stromal fibroblasts were more frequently positive for MMP-1, -7 and -13 and TIMP-1 and -3, when present in carcinomas of the ductal type than in other histological types of breast carcinomas. Stromal mononuclear inflammatory cells were more frequently positive for MMP-1 and TIMP-3, but more often negative for MMP-7, -9 and -11, when located in carcinomas of the ductal type than in other histological types of breast carcinomas., Conclusions: We found variations in MMP/TIMP expressions among the different histological subtypes of breast carcinomas suggesting differences in their tumor pathophysiology.

The transcription factor Pit-1/Pou1f1 regulates GH and prolactin (PRL) secretion in the pituitary gland. Pit-1 expression and GH regulation by Pit-1 have also been demonstrated in mammary gland. However, no data are available on the role of Pit-1 on breast PRL. To evaluate this role, several human breast cancer cell lines were transfected with either the Pit-1 expression vector or a Pit-1 small interference RNA construct, followed by PRL mRNA and protein evaluation. In addition, transient transfection of MCF-7 cells by a reporter construct containing the proximal PRL promoter, and ChIP assays were performed. Our data indicate that Pit-1 regulates mammary PRL at transcriptional level by binding to the proximal PRL promoter. We also found that Pit-1 raises cyclin D1 expression before increasing PRL levels, suggesting a PRL-independent effect of Pit-1 on cell proliferation. By using immunohistochemistry, we found a significant correlation between Pit-1 and PRL expression in 94 human breast invasive ductal carcinomas. Considering the possible role of PRL in breast cancer disorders, the function of Pit-1 in breast should be the focus of further research.

An immunohistochemical study was performed using tissue arrays and specific antibodies against MMPs -1, -2, -7, -9, -11, -13, -14, and TIMPs -1, -2 and -3. More than 5,000 determinations on cancer specimens from 124 patients with invasive breast cancer were performed at the center of the tumor and the invasive front. Immunostaining for MMPs/TIMPs by fibroblasts was evaluated. To identify specific groups of tumors with distinct expression profiles, the data obtained from both fibroblast populations were analyzed by unsupervised hierarchical cluster analysis. Intratumor stromal fibroblasts more frequently showed expression of MMP-2, -7, and -14, and TIMP-3, but less frequently of MMP-9 than fibroblasts at the invasive front. Multivariate analysis showed that a high profile of MMPs and TIMPs staining in both fibroblast populations was the most potent predictor factor of distant metastases, whereas a low staining profile in fibroblasts was associated with a low risk of metastases.

Objectives: Gene expression analysis has identified several breast cancer subtypes, including luminal, epidermal growth factor receptor-2 positive (HER2+), and basal-like. To determine if our proposed molecular taxonomy correlates with biological and clinical behavior. This is based on four biological markers: estrogen and progesterone receptors (ER and PR, respectively), HER2 and the epidermal growth factor receptor-1 (HER1), all of them being determined by quantitative assays., Study Design: The biological parameters were examined by enzyme immunoassay, radioligand-binding assay or ELISA, in tumors from 787 patients with invasive breast cancer. Patients were prospectively evaluated over a median follow-up period of 50 months. Subtype definitions were as follows: luminal (ER+), HER2+ (HER2+, ER-, PgR-) and basal-like (HER2-, ER-, PgR-). In addition, we divided basal tumors into two groups based on their HER1 status., Results: A 55.8% of tumors were of luminal type, 11.9% basal-like HER1+, 10.7 basal-like HER1-, and the remainder 21.6% HER2+. Both HER2+ and basal-like subtypes were more frequent in younger and premenopausal women, showing a higher percentage of cases of poorly differentiated tumors and higher S-phase fraction, when compared with those of luminal subtype. Multivariate analysis demonstrated that the subtype of tumor was related to both relapse and overall survival, being those of luminal subtype associated with the best prognosis., Conclusions: Through the classification of breast tumors in four groups, according to their ER, PgR, HER2 and HER1 status, it is possible to obtain a major division of breast tumors associated with significant differences in biological features and clinical behavior.

Aims: To analyse the expression of metalloproteinases (MMPs) and their inhibitors (TIMPs) in ductal carcinoma in situ of the breast (DCIS)., Methods and Results: An immunohistochemical study was performed in 56 patients with pure DCIS, in 39 with DCIS adjacent to invasive carcinoma (IDC) and 63 patients with T1 IDC, using tissue microarrays and specific antibodies against MMPs and TIMPs. Immunohistochemical results were categorized using a specific software program. The data were analysed by unsupervised hierarchical cluster analysis by each cellular type. IDC showed a higher expression rate of MMP-7 and TIMP-1 than pure DCIS, as well as a higher expression rate of MMP-9 and TIMP-3 than the DCIS component of mixed cases, whereas pure DCIS showed a higher rate of expression of MMP-9 and -11 and TIMP-3 than in the DCIS component of mixed cases. Pure DCIS with a periductal inflammatory infiltrate showed significantly higher MMP-2, -14 and TIMP-1. Dendograms identified two cluster groups with distinct MMP/TIMP expression profiles in neoplastic cells and fibroblastic or mononuclear inflammatory cells surrounding the neoplastic ducts of pure DCIS., Conclusions: The results indicate the distinct variability in MMP/TIMP expression by DCIS, which may be of potential biological and clinical interest in breast cancer.

An immunohistochemical study was performed using tissue microarrays and specific antibodies against matrix metalloproteinase (MMP)-1, -2, -7, -9, -11, -13 and -14, tissular inhibitors of metalloproteinase (TIMP)-1, -2 and -3. More than 2600 determinations on cancer specimens from 131 patients with primary ductal invasive tumours of the breast were performed. To identify specific groups of tumours with distinct expression profiles the data were analysed by unsupervised hierarchical cluster analysis by each cellular type. We did not find well-defined cluster of cases for tumour cells or fibroblastic cells. However, for mononuclear inflammatory cells the dendogram shows a first-order division of the tumours into two distinct MMP/TIMP molecular profiles, designated group 1 (n=89) and group 2 (n=42). Matrix metalloproteinase-7, -9, -11, -13 and -14, and TIMP-1 and -2, were identified as showing significant high expression in group 2 compared with group 1. Multivariate analysis demonstrated that clustering for mononuclear inflammatory cells was the most potent independent factor associated with distant relapse-free survival (group 2: 5.6 (3.5-9.6), P<0.001). We identify a phenotype of mononuclear inflammatory cells infiltrating tumours, which is associated with the development of distant metastasis. Therefore, this finding suggests that these host inflammatory cells could be a possible target for inhibition of metastasis.

Aims: To evaluate the expression of androgen receptors (AR) and two androgen-induced proteins [apolipoprotein D (ApoD) and pepsinogen C (PepC)] in ductal carcinoma in situ (DCIS) of the breast., Methods and Results: AR, ApoD and PepC expression was examined in 28 cases of pure DCIS and in 31 cases of DCIS adjacent to invasive carcinoma of the breast using immunohistochemical methods and then correlated with the architectural subtype, the degree of differentiation and the ostrogen receptor (ER)/progesterone receptor (PgR)/HER-2 status. We found no significant differences between pure DCIS and DCIS adjacent to invasive breast cancer regarding the percentage of positive cases for ApoD (64.3% versus 54.8%), PepC (42.9% versus 48.4%), ER (64.3% versus 58.1%), PgR (60.7% versus 58.1%) and HER-2 (39.3% versus 67.7%). However, there was a significantly higher percentage of AR+ DCIS among those adjacent to invasive carcinomas of the breast than among pure DCIS lesions (93.5% versus 60.9%) (P = 0.009). AR expression did not correlate with architectural subtype, degree of differentiation, or ER/PgR/HER-2/ApoD/PepC status, in cases of pure DCIS, nor in DCIS adjacent to invasive carcinoma of the breast., Conclusions: AR expression may represent an independent predictive factor in DCIS of the breast.

An immunohistochemical study was performed using tissue microarrays and specific antibodies against matrix metalloproteinases (MMPs) 1, 2, 7, 9, 11, 13, 14, and their tisullar inhibitors (TIMPs) 1, 2, and 3. More than 2600 determinations on cancer specimens from 131 patients with primary ductal invasive tumours of the breast (65 with and 66 without distant metastasis) and controls were performed. Staining results were categorised using a score based on the intensity of the staining and a specific software program calculated the percentage of immunostained cells automatically. We observed a broad variation of the total immunostaining scores and the cell type expressing each protein. There were multiple and significant associations between the expression of the different MMPs and TIMPs evaluated and some parameters indicative of tumour aggressiveness, such as large tumour size, advanced tumour grade, high Nottinham prognostic index, negative oestrogen receptor status, peritumoural inflammation, desmoplastic reaction, and infiltrating tumoural edge. Likewise, the detection of elevated immunohistochemical scores for MMP-9, 11, TIMP-1, and TIMP-2, was significantly associated with a higher rate of distant metastases. The expression of MMP-9 or TIMP-2 by tumour cells, MMP-1, 7, 9, 11, 13, or TIMP-3 by fibroblastic cells, and MMP-7, 9, 11, 13, 14, TIMP-1, or TIMP-2 by mononuclear inflammatory cells, was also significantly associated with a higher rate of distant metastases.

Background: CA15.3 (also known as MUCI) is the most widely used marker in breast cancer. The aim of the present work was the evaluation of the prognostic value of preoperative serum CA15.3 levels in patients with primary breast cancer., Patients and Methods: This study included 818 women with a histologically verified diagnosis of invasive breast cancer. The serum values of CA15.3 were investigated at the time of primary diagnosis by means of an immunoradiometric assay based on the "sandwich" principle. The median follow-up period of patients free of recurrence was 38 months., Results: Pre-operative CA15.3 serum levels ranged from 6 to 452 U/ml. Elevated CA15.3 levels (>30 U/ml) were found in 15.2% of patients. Statistical analysis showed that pre-operative CA15.3 serum levels were significantly higher in patients with large size tumors (T3 or T4) (p = 0.0001), as well as in those with node-positive tumors (p = 0.0001). In the univariate analysis, high CA15.3 levels were significantly associated with a lower probability of both relapse-free and overall survival in the overall group of patients (p = 0.0001 and p = 0.004, respectively) and in the subgroup with node-positive breast cancer (p = 0.001 and p = 0.03, respectively). In addition, multivariate analysis demonstrated that pre-operative levels of the antigen were significantly and independently associated with relapse-free survival in the overall group of patients, as well as in the subgroup of patients with node-positive breast cancer (p = 0.02 and p = 0.01, respectively)., Conclusion: These results show that high pre-operative CA15.3 levels correlate with large size tumors and the presence of lymph node metastases and suggest that this antigen could be used as an additional prognostic marker.

Background: The Trefoil Factor 1 (TFF1/pS2), a peptide consisting of 60 amino acids, is the most abundant estrogen-induced messenger RNA present in MCF-7 breast cancer cells. The objective of this work was to evaluate the cytosolic TFF1 content in breast carcinomas, its possible relationship with different clinical-pathological parameters, and its potential prognostic significance and predictive value., Methods: Cytosolic TFF1 levels were examined by immunoradiometric assay in 1031 patients with invasive breast cancer. The median follow-up period was of 50 months., Results: There was a wide variability of cytosolic TFF1 levels in tumors (0.9-743.2 ng/mg protein). Statistical analysis showed that TFF1 levels were significantly higher in premenopausal patients (p = 0.001), as well as in tumors showing any of the following characteristics: good differentiation (p = 0.0001), ER and PgR positivity (p = 0.0001 and p = 0.001, respectively), diploidy (p = 0.045) and a high S-phase fraction (p = 0.001). In addition, the presence of high intratumoral TFF1 levels (cut-off: 2 ng/mg protein) was independently associated with a shorter overall survival in the group of patients as a whole (p = 0.001) as well as in the subgroup with node-negative breast cancer (p = 0.0004). Likewise, high intratumoral TFF1 levels were associated with a more prolonged overall survival in patients who received adjuvant tamoxifen (p = 0.004)., Conclusions: In breast cancer patients, intratumoral TFF1 levels are associated with a better clinical outcome, especially in those with node-negative tumors. In addition, TFF1 levels have a low but significant predictive value in regards to response to adjuvant therapy with tamoxifen.

Epidermal growth factor receptor (EGFR) is a membrane receptor expressed in a variety of solid human cancers and directly related with poor prognosis. The objective of this work was to evaluate the EGFR content in breast carcinomas, its possible relationship with different clinical-pathological parameters, and its potential prognostic significance and predictive value. EGFR levels were examined by radioligand binding assays in 846 patients with invasive breast cancer. The median follow-up period was 50 months. There was a wide variability of EGFR levels among the studied tumors (0.01-403 fmol/mg protein). Statistical analysis showed that EGFR levels were significantly higher in younger patients (p=0.0001). EGFR were also notably higher in ER-negative or PgR-negative tumors than in ER-positive (p=0.0001) or PgR-positive tumors (p=0.001). In addition, the presence of high intratumoral EGFR levels (cut-off: 6 fmol/mg protein) was associated with both shorter relapse-free survival (p=0.04) and overall survival (p=0.01) in the group of patients as a whole, as well as with overall survival in the subgroup of patients without any type of systemic adjuvant treatment (p=0.02). However, EGFR levels did not achieve significance as independent prognostic factor in the multivariate analysis. There is a wide variability of intratumoral EGFR levels in breast carcinomas, and these protein levels correlated positively with a poor prognosis in the t univariate analysis. However, further studies are necessary in order to assess the possible clinical value of EGFR in combination with other essential components of the EGFR family network.

Background: Cathepsin D is the proteolytic enzyme most frequently implicated as a prognostic factor in primary breast cancer. In the present study we evaluated by means of an immunoradiometric assay the tumor content of this protease in primary breast cancer, its relationship with tumor-related clinical and pathological parameters, and its prognostic significance in a large series of breast cancer patients., Method: The study comprised 1033 women with histologically established invasive breast cancer. Cathepsin D was measured in cytosol samples by means of an immunoradiometric assay to determine the total amount of cathepsin D (52 kDa, 48 kDa and 34 kDa). Evaluation of relapse-free survival and cause-specific survival was performed in the group of 1003 patients without evidence of metastasis at the time of initial diagnosis. The median follow-up of the patients who were free of recurrence was 54 months., Results: Cathepsin D levels showed a wide range among the studied tumors (n = 1033; median (range) 41 (0.9-2504) pmol/mg protein). Statistical analysis showed that the median cathepsin D levels were considerably higher in large tumors (T2-4) than in smaller ones (T1) (p = 0.017), as well as in node-positive than in node-negative tumors (p = 0.004). Cathepsin D levels were also higher in ductal tumors than in the other histological types (p = 0.001), as well as in moderately or poorly differentiated tumors (p < 0.001). Likewise, the median value of the protease was significantly higher in ER or PgR-positive tumors than in hormone receptor-negative ones (p = 0.011 and p = 0.004, respectively), as well as in aneuploid tumors than in diploid tumors (p = 0.029). Multivariate analysis demonstrated that elevated cathepsin D levels (> 59 pmol/mg protein) were notably associated with a shorter cause-specific survival in the whole group of patients with breast cancer, as well as in the subgroup of node-positive patients (p < 0.05)., Conclusions: This study suggests that elevated intratumoral cathepsin D levels may identify a subset of node-positive breast cancer patients showing a high probability of earlier death.

Background: Tissue-type plasminogen activator (tPA) is a serine protease primarily involved in the intravascular dissolution of blood clots. High intratumoral tPA levels are associated with prognosis in several human tumors. In addition, tPA has been shown to be an estrogen-inducible protein in human breast cancer cell lines. The aim of the present study was to analyze the cytosolic tPA content in primary breast carcinomas and its potential clinical value., Materials and Methods: tPA was measured by a solid-phase enzyme immunoassay in tumor cytosol samples obtained from 800 patients with breast cancer. The median follow-up period was of 49.2 months., Results: Cytosolic tPA levels ranged widely in breast carcinomas (median: 3.9; range: 0.1- 315.3 ng/mg protein). tPA levels were significantly lower in large tumors, as well as in those showing poor differentiation, estrogen (ER) or PgR-negativity, aneuploidy, or a high S-phase fraction. In addition, low tPA intratumoral levels were associated with a high probability of both shortened relapse-free and overall survival in all patients and in the subgroup with node-negative tumors. However, our results did not show any significant relationship between intratumoral tPA levels and prognosis in the different subgroups of patients, stratified according to the type of systemic adjuvant therapy received (chemotherapy, tamoxifen or chemotherapy plus sequential tamoxifen)., Conclusion: The results of the present investigation indicate that low intratumoral tPA levels are associated with aggressiveness and poor prognosis in breast cancer patients. However, the study suggests that tPA levels do not predict response to systemic adjuvant therapy.

Objective: To determine the content of epidermal growth factor receptor (EGFR) using a radioligand method in breast cancer and to analyze the relationship between the EGFR levels and the characteristics of patients and tumors. Prognostic significance was also analyzed., Material and Methods: EGFR was measured by a single point radioligand assay in 265 invasive breast carcinomas tissues. In addition, estrogen and progesterone receptors (ER and PR) were measured by enzymatic immunoassays. We analyze the relationship of EGFR levels with the different clinico-pathologic parameters., Results: EGFR levels in breast carcinomas varied widely (0.1 to 403) with a median at 4 fmol/mg prot. The significantly higher concentrations of EGFR were detected in patients under 60 years old (p = 0.042), undifferentiated tumors (p = 0.04), and carcinomas with negative ER and PR (p < 0.019 y p < 0018, respectively). In addition, there was a negative correlation between EGFR and the ER and PR levels (p < 0.05). EGFR levels did not show any relationship with the patient's prognosis., Conclusions: In addition, intratumoral levels of EGFR in breast carcinomas vary widely and the highest concentrations are associated with the most aggresive characteristics of the tumor.

Objective: To analyze pS2 cytosolic levels in breast carcinomas and their correlation with different clinical characteristics of the patients and their tumours., Material and Methods: Cytosolic pS2 levels were measured by radioimmunometric assay in tumours from 168 breast cancer patients., Results: The pS2 values ranged from 0 to 251 ng/mg protein (mean SD: 21.8 38.1; median: 7.9 ng/mg protein). These protein levels were significantly (p < 0.05) higher in premenopausal patients (27.6 45.2) than in postmenopausal patients (19.5 33.8). Intratumour pS2 levels were also significantly (p < 0.05) correlated with histologic grade of the tumours, and were higher in well diferentiated tumours (grade I: 28.8 42.8) than in moderately differentiated tumours (grade II: 19.7 35.6) and than in poorly differentiated tumours (grade III: 18.9 37.3). Similarly, significant differences in pS2 content were found between positive estrogen receptor (ER) tumours and ER-negative tumours (29.1 46.5 vs 11.3 15.9, respectively; p<0.0001), as well as between positive progesterone receptor (PR) tumours and PR-negative tumours (29.1 49.8 vs 15.3 21.5, respectively; p < 0.05)., Conclusions: The results suggest that pS2 may be a useful prognostic marker in breast cancer, and may also be useful to identify patients who are likely to benefit from hormone therapy.

Collagenase-3 (matrix metalloproteinase 13; MMP-13), a protease originally identified in breast carcinoma, is characterized by a potent degrading activity against a wide spectrum of extracellular matrix proteins. The aims of this study were to localize and identify the MMP-13-expressing cells in invasive human breast carcinoma and to evaluate the role of MMP-13 in transition to invasive lesions by studying ductal carcinoma in situ (DCIS). We found expression of MMP-13 in stromal fibroblast-like cells in all 21 invasive ductal carcinomas studied and in 4 of 9 invasive lobular carcinomas. In most carcinomas, expression of MMP-13 was limited to small stromal foci in the tumor area. Combined in situ hybridization and immunohistochemistry showed coexpression of alpha-smooth muscle actin immunoreactivity and MMP-13 mRNA in myofibroblasts. In contrast, cytokeratin-positive cancer cells, alpha-smooth muscle actin-positive vascular smooth muscle cells, CD68-positive macrophages, and CD31-positive endothelial cells were all MMP-13 mRNA negative. In situ hybridization for MMP-13 in 17 DCIS lesions revealed expression in 10 cases. Immunohistochemical analysis of all DCIS cases identified microinvasion in 8 of the 17 lesions. Seven of the eight lesions with microinvasion were MMP-13 positive. Further analysis showed that MMP-13 expression was often associated with the microinvasive events. This particular expression pattern was unique for MMP-13 among other MMPs analyzed, including MMP-2, -11, and -14. We conclude that MMP-13 is primarily expressed by myofibroblasts in human breast carcinoma and that expression in DCIS lesions often is associated with microinvasive events. On the basis of these data, we propose that MMP-13 may play an essential role during transition of DCIS lesions to invasive ductal carcinomas.

Background: Here we evaluate the expression and prognostic value of lysozyme, a milk protein that is also synthesized by a significant percentage of breast carcinomas, in women with breast cancer., Methods: Lysozyme expression was examined by immunohistochemical methods in a series of 177 breast cancer tissue sections. Staining was quantified by using the HSCORE system, which considers both the intensity and the percentage of cells staining at each intensity. The prognostic value of lysozyme was retrospectively evaluated by multivariate analysis that took into account conventional prognostic factors., Results: A total of 126 of 177 carcinomas (69.4%) stained positive for this protein, but there were clear differences among them with regard to the intensity and percentage of stained cells. Lysozyme values were higher in well-differentiated and moderately differentiated tumors than in poorly differentiated tumors (P < .05). Similarly, lysozyme levels were higher in small and node-negative tumors than in large and node-positive tumors (P < .05). Moreover, results indicated that low lysozyme content predicted shorter relapse-free survival and overall survival (P < .005). Separate Cox multivariate analysis in subgroups of patients as defined by node status showed that lysozyme expression was an independent prognostic factor able to predict both relapse-free survival and overall survival in node-negative patients (P < .05)., Conclusions: Tumoral expression of lysozyme is associated with lesions of favorable evolution in breast cancer. This milk protein may be a new prognostic factor in patients with breast cancer.

Background: Male breast cancer (MBC) is a rare tumor in comparison to the same disease in the female population (FBC). Classical prognostic factors (tumor size, node status, estrogen receptor positivity, histological grade) have a similar prognostic value in both tumors, but MBC seems to have a worse outcome. Several markers under estrogen control have been shown with a similar incidence in breast tumors of both sexes, while androgen-induced markers have been detected in a higher percentage of breast tumors in males., Aims and Methods: Our purpose was to compare in 68 MBC and in 68 FBC the expression of Pepsinogen C (Pep C) and Apolipoprotein D (Apo D), two proteins under androgen control, by immunohistochemical methods., Results: Pep C was expressed by 52 of 68 (76.4%) MBC patients, whereas 34 of 68 (50%) FBC showed positive staining. Apo D was expressed by 57 of 68 (83.8%) MBC patients, while 40 of 68 (41.2%) FBC stained positively. Differences between percentages of positive expression were significant (p<0.005 for Pep C; p<0.0001 for Apo D). Moreover, differences between expression levels of Pep C and Apo D in both populations of patients were significant. The mean value of Pep C was significantly higher in male breast tumors (HSCORE = 141.3) than in the females (HSCORE = 80.3) (p<0.0001). Similarly, Apo D mean value was significantly higher in MBC (HSCORE = 161.5) than in FBC (HSCORE = 102.3) (p=0.006)., Conclusion: These differences can open the field of a more selective hormonal therapy that should not be based on estrogen receptor status only, but also on androgen receptor status.

Background: Apolipoprotein D is a glycoprotein of the human plasma whose functional role remains unclear. On the other hand, this protein is also produced by breast carcinomas and is positively associated with a favorable outcome of patients. However, none study has focused on metastasic lesions., Aim: To analyze apolipoprotein D expression in breast cancer patients and their synchronous metastasic axillary lymph nodes., Methods: We analyzed by immunohistochemical assay both, the tumoral expression of apolipoprotein D in primary tumors and in their synchronous metastasic axillary lymph nodes of 30 node-positive breast cancer patients., Results: Of the primary tumors, 28 (93.3%) showed a positive immunostaining for apolipoprotein D, although there was wide variability immunostaining values. On the other hand, 16 (53.3%) patients showed a positive immunostaining for the protein in their tumoral lymph nodes. In addition, there was a significant positive relationship between the tumoral expression of apolipoprotein D in primary tumors and metastasic lymph nodes (P < 0.05). However, only immunostaining values of the protein in primary tumors achieve statistical signification (P < 0.05) as prognostic factor of favorable evolution to predict overall survival from patients., Conclusions: Apolipoprotein D is also expressed in metastasic lymph nodes of breast carcinomas, but with a different pattern of immunostaining and less clinical significance than in primary tumors.

Human p21 (also known as WAF1, CIP1, or SDI1) is a dual inhibitor of cyclin dependent kinases (CDKs) and the replication factor PCNA, which plays a role as a downstream mediator of the cell-cycle arrest induced by the tumor suppressor p53. To determine whether inactivation of downstream targets of p53 might contribute to cellular transformation, we have examined the integrity of the p21 gene in 36 invasive ductal breast carcinomas. Direct sequence analysis of the polymerase chain reaction-amplified p21 gene revealed a C to T transition in codon 94 that caused the substitution of a tryptophan for an arginine in a tumor specimen. This mutation was not detected in normal DNA extracted from the same patient nor in a polymerase chain reaction-restriction fragment length polymorphism of 50 unrelated individuals, indicating that it corresponds to a tumor-specific alteration. Functional analysis of the p21(R94W) protein produced in different eukaryotic and prokaryotic expression systems revealed that this mutation impaired the ability of p21 to inhibit CDKs. By contrast, the R94W mutant was unaltered in its ability to promote cyclin-CDK association as well as in its ability to bind proliferating cell nuclear antigen, thus leaving its putative functions as kinase activator or as inhibitor of replicative DNA synthesis intact. On the basis of these functional analysis, we propose that the Arg residue at position 94 is important for the CDK inhibitory role of p21.

The human p27kip1 gene encodes a cyclin-dependent kinase inhibitor implicated in the negative regulation of the cell cycle. In order to elucidate the possible role of p27 mutations in the development or progression of human breast cancer, we have studied the occurrence of genetic abnormalities in this gene in a series of 30 primary breast carcinomas. Direct sequence analysis of the polymerase chain reaction amplified human p27 gene revealed the occurrence of two sequence variations with respect to the reported sequence; both variants were also present in the lymphocyte DNA from the same patients. First, a silent G to A change at codon 142 (Thr) was detected in a single case. Second, a T to G transversion at codon 109, resulting in a Val to Gly change, was observed in eight tumour DNA samples (26%) and in 31 out of 80 unrelated normal individuals (39%). This latter change creates a Bg/I restriction site that might be useful for genetic analysis of human tumours. Despite the occurrence of these polymorphisms, we did not however find any evidence of somatic mutations in the coding region of the p27 gene. On the basis of these results, we suggest that alterations in the integrity of the human p27 gene are not common events in human breast carcinomas.

Purpose: Here we evaluate in breast cancer patients the prognostic value of pepsinogen C, a proteolytic enzyme involved in the digestion of proteins in the stomach that is also synthesized by a significant percentage of breast carcinomas., Patients and Methods: Pepsinogen C expression was examined by immunoperoxidase staining in a series of 243 breast cancer tissue sections, and results obtained were quantified using the HSCORE system, which considers both the intensity and the percentage of cells staining at each intensity. Evaluation of the prognostic value of pepsinogen C was performed retrospectively in corresponding patients by multivariate analysis that took into account conventional prognostic factors. The mean follow-up period was 48.5 months., Results: A total of 113 carcinomas (46.5%) stained positively for this proteinase, but there were clear differences among them with regard to the intensity and percentage of stained cells. Pepsinogen C values were significantly higher in well differentiated (grade I, 89.1) and moderately differentiated (grade II, 88.5) tumors than in poorly differentiated (grade III, 27.7) tumors (P < .001). Similarly, significant differences in pepsinogen C content were found between estrogen receptor (ER)-positive tumors and ER-negative tumors (85.9 v 41.2, respectively; P < .05). Moreover, results indicated that low pepsinogen C content predicted shorter relapse-free survival duration and overall survival duration (P < .0001). Separate Cox multivariate analysis for relapse-free survival and overall survival in subgroups of patients as defined by node status showed that pepsinogen C expression was the strongest factor to predict both relapse-free survival and overall survival in node-positive patients (P < .0001 for both) and node-negative patients (P < .005 and P < .01, respectively)., Conclusion: Pepsinogen C is a new prognostic factor for early recurrence and death in both node-positive and node-negative breast cancer. In addition, and in contrast to most studies that concern the prognostic significance of proteolytic enzymes in cancer, pepsinogen C production by breast cancer cells is associated with lesions of favorable evolution.

Apolipoprotein D (apo D) is a glycoprotein involved in the human plasma lipid transport system and present at large amounts in cyst fluid from women with gross cystic disease of the breast. Apo D expression in breast carcinomas was examined by immunoperoxidase staining of a series of 163 tumors. A total of 60 (36.8%) tumors were negative for apo D immunostaining, 28 (17.2%) carcinomas were weakly positive, 33 (20.2%) were moderately stained, whereas the remaining 42 (25.8%) tumors were strongly stained with the specific antibodies. No significant correlation was found between apo D content and tumor size, lymph node involvement, or biochemical parameters such as estrogen receptors, cathepsin D, or pS2 protein. However, the finding of a significant association between apo D and menopausal status of patients or differentiation grade of tumors, with apo D values being lower in tumors from premenopausal women or in poorly differentiated carcinomas, suggested a potential value of this glycoprotein as a prognostic factor in breast cancer. Preliminary analysis of relapse-free survival and overall survival in a subgroup of 152 women with a mean follow-up of 42 months confirmed that low apo D values were significantly associated to a shorter relapse-free survival and poorer survival. According to these data, we propose that apo D in combination with other well-established prognostic factors may contribute to more accurately identify subgroups of breast cancer patients with low or high risk for relapse and death.

We have examined by immunohistochemistry the ability of breast carcinomas to produce pepsinogen C, an aspartyl proteinase usually involved in the digestion of proteins in the stomach. A total of 113 out of 245 breast tumours (46%) were positive for pepsinogen C immunostaining. There was a significant association between pepsinogen C and oestrogen receptors with proteinase levels higher (HSCORE) in oestrogen receptor positive tumours than in oestrogen receptor negative. There was also a significant association between pepsinogen C and histological grade, pepsinogen C levels being higher in well and moderately differentiated breast carcinomas than in poorly differentiated tumours. On the basis of these results, we suggest that pepsinogen C may be useful as a marker of good prognosis in breast cancer.

A proteinase accumulated in breast secretions from women with breast cancer has been characterised. Inhibition of the proteolytic activity of breast secretions by pepstatin A showed that the main enzyme involved was an aspartyl proteinase. Determination of its cleavage specificity by SDS-PAGE and amino acid sequence analysis revealed that it was identical to that of cathepsin D, an aspartyl proteinase suggested to be involved in breast cancer development. The identity between both proteins was further confirmed by immunological analysis with monoclonal antibodies against cathepsin D. Quantification of cathepsin D in nipple fluids from 41 women with benign or malignant breast diseases and from 19 control women without breast pathology revealed the presence of variable amounts of this proteinase. The average concentration of cathepsin D in breast secretions from cancer-bearing breasts was 7.2 +/- 2.2 fmol micrograms of protein, which was significantly higher than those of nipple fluids from control women (2.9 +/- 0.6 fmol micrograms-1) (P = 0.04) or from patients with benign breast diseases (2.1 +/- 0.3 fmol micrograms-1) (P = 0.004). Though the number of cancer patients studied was small (n = 21), no correlations were found with cytosolic concentrations of cathepsin D or oestrogen receptors, neither with other parameters such as tumour size, histological grade, axillary node involvement or menopausal status.

Zn-alpha 2-glycoprotein (Zn-alpha 2-gp), a protein present at high levels in breast cyst fluid, has been measured in 104 breast tumour cytosols by using an immunoenzymatic assay. Concentrations of Zn-alpha 2-gp ranged from 0 to 23.5 micrograms/mg of total soluble protein, with an average value of 2.4 micrograms/mg. There was no significant correlation between Zn-alpha 2-gp and menopausal status, tumour size or lymph node involvement, or between this protein and biochemical parameters such as oestrogen receptor, cathepsin D or pS2 levels. However, there was a significant association between Zn-alpha 2-gp and histological grade of tumours, with higher Zn-alpha 2-gp levels in well-differentiated tumours (mean 4.6 micrograms/mg) than in moderately (1.8 micrograms/mg) or poorly (0.9 micrograms/mg) differentiated tumours. On the basis of these results, we propose that Zn-alpha 2-gp may be considered as a biochemical marker of differentiation in breast cancer.

Breast secretions can be classified into two types according to their major protein components. Type I fluids contain Zn-alpha 2-glycoprotein, apolipoprotein D, and gross cystic disease fluid protein-15, while Type II fluids are characterized by the presence of lactoferrin, lysozyme, and alpha-lactalbumin. In this study, the polypeptide composition of breast secretions from 719 nonlactating women was evaluated by using polyacrylamide gel electrophoresis. The required amount for the analysis (1 microliter) was obtained from 50% of control women and from 75% of women with mammary disease. There were more secretors in premenopausal than in postmenopausal women, as well as in parous than in nulliparous women. Evaluation of factors affecting protein composition of breast secretions revealed that Type II fluids were found in the majority of women who had given birth in the last four years and in a high proportion of oral contraceptive users. After excluding both of these groups, Type II fluids were detected in 47% of patients with breast cancer, but only in 8% of control women and in 16% of women with benign breast diseases. Taken together, these results suggest that protein analysis of breast secretions could be an useful tool for the study of breast pathologies.