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Metabolic reprogramming is considered hallmarks of cancer. Aerobic glycolysis in tumors cells has been well-known for almost a century, but specific factors that regulate lactate generation and the effects of lactate in both cancer cells and stroma are not yet well understood. In the present study using breast cancer cell lines, human primary cultures of breast tumors, and immune deficient murine models, we demonstrate that the POU1F1 transcription factor is functionally and clinically related to both metabolic reprogramming in breast cancer cells and fibroblasts activation. Mechanistically, we demonstrate that POU1F1 transcriptionally regulates the lactate dehydrogenase A (LDHA) gene. LDHA catalyzes pyruvate into lactate instead of leading into the tricarboxylic acid cycle. Lactate increases breast cancer cell proliferation, migration, and invasion. In addition, it activates normal-associated fibroblasts (NAFs) into cancer-associated fibroblasts (CAFs). Conversely, LDHA knockdown in breast cancer cells that overexpress POU1F1 decreases tumor volume and [18F]FDG uptake in tumor xenografts of mice. Clinically, POU1F1 and LDHA expression correlate with relapse- and metastasis-free survival. Our data indicate that POU1F1 induces a metabolic reprogramming through LDHA regulation in human breast tumor cells, modifying the phenotype of both cancer cells and fibroblasts to promote cancer progression This study was supported by FEDER/Ministerio de Ciencia, Innovación y Universidades- Agencia Estatal de Investigación-PGC2018-100776-B-I00 and from Conselleria de Cultura, Educación e Ordenacion Universitaria (GPC2014/001), AM-O was supported by an FPU grant (Ministerio de Educación—FPU14/00548) SI

Aims It is known that matrix metalloproteinase (MMP)-11 has a role in tumour development and progression, and also that immune cells can influence cancer cells to increase their proliferative and invasive properties. The aim of the present study was to propose the evaluation of MMP11 expression by intratumoral mononuclear inflammatory cells (MICs) as a useful biological marker for breast cancer prognosis. Methods and results This study comprised 246 women with invasive breast carcinoma, and a long follow-up period. Patients were stratified with regard to nodal status and to the development of metastatic disease. The median follow-up period in patients without metastasis was 146 months and in patients with metastatic disease 31 months. MMP11 was determined by immunohistochemistry. For relapse-free survival (RFS) and overall survival (OS) analysis we used the Cox's univariate method. Cox's regression model was used to examine the interactions between different prognostic factors in a multivariate analysis. Conclusions Our results showed that MMP11 expression by stromal cells was significantly associated with prognosis. MMP11 expression by cancer-associated fibroblasts (CAFs) was associated with both shortened RFS and OS, but MMP11 expression by MICs showed a stronger association with both shortened RFS and OS, therefore being the most potent and independent factor to predict RFS and OS.

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.

Tumor-infiltrating immune cells phenotype is associated with tumor progression. However, little is known about the phenotype of the peripheral blood mononuclear cells (PBMC) from breast cancer patients. We investigated MMP1 and MMP11 expression in PBMC from breast cancer patients and we analyzed gene expression changes upon their interaction with cancer cells and cancer-associated fibroblasts (CAF). We measured the impact of PBMC on proinflammatory gene expression in breast cancer cells, normal fibroblast (NF), and CAF and the impact on proliferation and invasiveness capacity of breast cancer cells. Gene expression of MMP1 and MMP11 in PBMC from breast cancer patients (n = 54) and control (n = 28), expression of IL1A, IL6, IL17, IFN&beta, and NFĸB in breast cancer cell lines (MCF-7 and MDA-MB-231), and, additionally, IL10 and MMP11 in CAF and NF were analyzed by qRT-PCR before and after co-culture. Our results show the existence of a subpopulation of breast cancer patients (25.9%) with very high levels of MMP11 gene expression in PBMC. Also, gene expression of MMP1 and MMP11 increases in PBMC after co-culture with breast cancer cell lines, NF or CAF. PBMC from healthy or breast cancer patients induce an increased proliferation rate on MCF-7 and an increased invasiveness capacity of MDA-MB-231. Finally, we show a differential expression profile of inflammatory genes in NF and CAF when co-cultured with control or breast cancer PBMC. We have observed that MMPs&rsquo, expression in PBMC is regulated by the microenvironment, while the expression of inflammatory genes in NF or CAF is differentially regulated by PBMC. These findings confirm the importance of the crosstalk between stromal cells and suggest that PBMC would play a role in promoting aggressive tumor behavior.

Luminal tumors are the most frequent type of breast carcinomas showing less tumor aggressiveness, although heterogeneity exists in their clinical outcomes. Cancer-associated fibroblasts (CAFs) are a key component of the tumor stroma which contribute to tumor progression. We investigated by real-time PCR the gene expression of 19 factors implicated in tumor progression. Those factors included the calcium-binding protein S100A4, several growth factors (FGF2, FGF7, HGF, PDGFA, PDGFB, TGF&beta, VEGFA, and IGF2), and we also studied inflammatory cytokines (IL6 and IL8), chemokines (CCL2, CXCL12), important proteases (uPA, MMP2, MMP9 and MMP11), the nuclear factor NF&kappa, B, and the metalloprotease inhibitor TIMP1, from luminal A and luminal B breast carcinoma CAFs. We performed a similar analysis after co-culturing CAFs with MCF-7 and MDA-MB-231 breast cancer cell lines. MMP-9 and CCL2 gene expressions were higher in CAFs from luminal B tumors. We also found different patterns in the induction of pro-tumoral factors from different CAFs populations co-cultured with different cancer cell lines. Globally, CAFs from luminal B tumors showed a higher expression of pro-tumor factors compared to CAFs from luminal A tumors when co-cultured with breast cancer cell lines. Moreover, we found that CAFs from metastatic tumors had higher IGF-2 gene expression, and we detected the same after co-culture with cell lines. Our results show the variability in the capacities of CAFs from luminal breast carcinomas, which may contribute to a better biological and clinical characterization of these cancer subtypes.

Introduction The objective of the present work was to evaluate the impact of the phenotype of both intratumoral mononuclear inflammatory cells (MICs) and cancer-associated fibroblast (CAFs), assessed as to their expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) on prognosis in different breast cancer subtypes. Materials and Methods A total of 247 tumors of patients with primary ductal invasive breast cancer were categorized into 1 of 4 major subtypes, using the 3 standard immunohistochemical markers (estrogen receptor [ER], progesterone receptor [PR], and human epidermal growth factor receptor/Neu 2 [HER2] receptor status). An immunohistochemical study was performed using tissue arrays and specific antibodies against MMP-9, MMP-11, and MMP-14, and TIMP-1 and TIMP-2. Results MMP-11 expression by MICs was significantly and strongly associated with prognosis in all breast cancer subtypes. There were other significant associations with poor prognosis in luminal A tumors: expressions of MMP-9, MMP-11, and TIMP-2 by CAFs, in luminal B tumors: MMP-14 expression by MICs and TIMP-2 expression by MICs, in HER-2-positive tumors: expression of MMP-9 by MICs, and in triple negative breast cancers: expression of TIMP-1 by MICs. Conclusion Characterization of both tumor stromal CAFs and MICs, with regard to the expression of MMPs and TIMPs, improve the prognostic evaluation of all breast cancer subtypes.

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.

Although the mechanisms underlying the genesis and progression of breast cancer are better understood than ever, it is still the most frequent malignant tumor in women and one of the leading causes of cancer death. Therefore, we need to establish new approaches that lead us to better understand the prognosis of this heterogeneous systemic disease and to propose new therapeutic strategies. Cancer is not only a malignant transformation of the epithelial cells merely based on their autonomous or acquired proliferative capacity. Today, data support the concept of cancer as an ecosystem based on a cellular sociology, with diverse components and complex interactions between them. Among the different cell types that make up the stroma, which have a relevant role in the dynamics of tumor/stromal cell interactions, the main ones are cancer associated fibroblasts, endothelial cells, immune cells and mesenchymal stromal cells. Several factors expressed by the stroma of breast carcinomas are associated with the development of metastasis, such as matrix metalloproteases, their tissular inhibitors or some of their regulators like integrins, cytokines or toll-like receptors. Based on the expression of these factors, two types of breast cancer stroma can be proposed with significantly different influence on the prognosis of patients. In addition, there is evidence about the existence of bi-directional signals between cancer cells and tumor stroma cells with prognostic implications, suggesting new therapeutic strategies in breast cancer.

© The Royal Society of Chemistry 2017. In recent years, several studies have shown that concentrations of essential trace elements naturally present in breast tissues (e.g. Ca, Fe, Cu and Zn) may be significantly increased in breast cancer tissues. This is not surprising because essential elements are responsible for a great number of metabolic and biological processes. The essential trace elements may play some major functions in life: stabilizers, elements of structure, elements for hormonal function and cofactors in enzymes. In any case, the role of trace elements in breast cancer is complex, because it affects many types of molecules, cells and tissues. The combination of analytical and immunehistochemical assays is crucial for better understanding of the role of essential trace elements in promoting tumor growth and migration. Bioimaging analytical techniques with adequate spatial resolution are today of crucial interest to investigate the spatial distribution of trace elements and correlate them with histological aspects in breast tissues. In this vein, in this particular study the application of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been used for the first time to investigate the actual distribution of the essential trace bioelements (Ca, Fe, Cu and Zn) in breast cancer tissues, and its possible application for tumor diagnostic and prognostic purposes. As has been demonstrated in this study, the levels of Ca, Fe, Cu and Zn in the tumor area are significantly higher than the levels found in the non-tumor one, as well as, a heterogeneous distribution of the investigated metals.

Aim Matrix metalloproteases (MMPs) expression and their inhibitors (TIMPs) play an important role in tumor physiopathology, so we investigated the relationship between the magnetic resonance (MR) and MMPs/TIMPs expression by breast carcinomas. Materials and methods MRI parameters of 64 breast carcinomas were investigated. An immunohistochemical study was also performed in these cases using tissue microarrays and specific antibodies against MMP-1, MMP-2, MMP-7, MMP-9, MMP-11, MMP-13, MMP-14, TIMP-1, TIMP-2 and TIMP-3. Results Tumors with spiculated margins had a high global (score) values of MMP-1 or MMP-7, and high expression of TIMP-3 by tumor cells. Heterogeneous tumors had a higher score values of MMP-1, MMP-13, TIMP-2 or TIMP-3, and frequent expression of TIMP-3 by tumor cells. Tumors showing fast enhancement, had higher score values of MMP-1 or MMP-11. Associations between washout curve (type III) and MMP-1, MMP-11, MMP-13 and TIMP-1 expression by tumor cells, were found. Conclusions MRI features may predict in some grade the expressions of MMPs/TIMPs in breast tumors, which might to contribute to a better biological characterization of breast cancer.

MMP-11 is a member of the matrix metalloproteinase family (MMPs) which are overexpressed in cancer cells, stromal cells and the adjacent microenvironment. The MMP protein family encompasses zinc-dependent endopeptidases that degrade the extracellular matrix (ECM), facilitating the breakdown of the basal membrane and matrix connective tissues. This function is believed to be important in cancer development and metastasis. This paper investigated a gold nanoparticle-based immunohistochemical assay to visualise the distribution of MMP-11 in human breast cancer tissues from eight patients with and without metastases by employing laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The expression of MMP-11 was increased and more heterogeneous in metastatic specimens compared to non-metastatic tumour samples. These findings demonstrate that imaging breast tumours by LA-ICP-MS may be a useful tool to aid the prognosis and treatment of breast cancer. As an example, samples of two patients are presented who were diagnosed with matching characteristics and grades of breast cancer. Although both patients had a similar prognosis and treatment, only one developed metastases.

The biological heterogeneity of breast cancer leads to the need for finding new approaches to understand the mechanisms implicated in breast cancer progression. The tumor stroma appears as a key in the progression of solid tumors towards a malignant phenotype. Cancer associated fibroblasts (CAFs) may orchestrate a functional "corrupted" stroma which in turn helps metastatic spread. In this study, we investigated by real-time PCR, the expression of 19 factors by normal breast-associated fibroblasts (NAFs) and CAFs, which were implicated in several actions promoting tumor growth, such as extracellular matrix remodeling, inflammation and invasion. Also, we explored the influence of inflammatory cells phenotypes (MMP11 status) and breast cancer cell lines (MCF-7 and MDA-MB-231) on the molecular profile of CAFs. If we consider that one of the major sources of CAFs are resident NAFs, the transition of NAFs into CAFs is associated with molecular changes involving the overexpression of some molecular factors of biological importance in tumor progression. In addition, the characterization of the tumor stroma regarding to the MMP11 status by MICs reflects a type of fibroblasts which contribute even more to tumor progression. Moreover, different patterns in the induction of the expression of factors by CAFs were observed, depending on the tumor cell line which they were co-cultured with. Furthermore, CAFs influence TGFβ expression in both cancer cell lines. Therefore, this study can help to a better characterization of tumor stroma in order to improve the prognostic evaluation, as well as to define the different populations of CAFs as potential therapeutic targets in breast cancer. © 2015 Wiley Periodicals, Inc.

It has been reported that stromal cell features may affect the clinical outcome of breast cancer patients. Cancer associated fibroblasts (CAFs) represent one of the most abundant cell types within the breast cancer stroma. Here, we aimed to explore the influence of CAFs on breast cancer gene expression, as well as on invasion and angiogenesis. qRT-PCR was used to evaluate the expression of several cancer progression related genes (S100A4, TGFβ, FGF2, FGF7, PDGFA, PDGFB, VEGFA, IL-6, IL-8, uPA, MMP2, MMP9, MMP11 and TIMP1) in the human breast cancer-derived cell lines MCF-7 and MDA-MB-231, before and after co-culture with CAFs. Stromal mononuclear inflammatory cell (MIC) MMP11 expression was used to stratify primary tumors. In addition, we assessed the in vitro effects of CAFs on both MDA-MB-231 breast cancer cell invasion and endothelial cell (HUVEC) tube formation. We found that the expression levels of most of the genes tested were significantly increased in both breast cancer-derived cell lines after co-culture with CAFs from either MMP11+ or MMP11- MIC tumors. IL-6 and IL-8 showed an increased expression in both cancer-derived cell lines after co-culture with CAFs from MMP11+ MIC tumors. We also found that the invasive and angiogenic capacities of, respectively, MDA-MB-231 and HUVEC cells were increased after co-culture with CAFs, especially those from MMP11+ MIC tumors. Our data indicate that tumor-derived CAFs can induce up-regulation of genes involved in breast cancer progression. Our data additionally indicate that CAFs, especially those derived from MMP11+ MIC tumors, can promote breast cancer cell invasion and angiogenesis.

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases. The main functions of these metalloproteinases are the degradation of the stromal connective tissue and basement membrane components. Recent data from model systems suggest that MMPs are involved in breast cancer (BC) initiation, invasion, and metastasis. Particularly, MMP-11 (stromelysin-3) is expressed in stromal fibroblasts adjacent to epithelial tumor cells, and high levels of this metalloproteinase were associated with tumor progression and poor prognosis of BC. Consequently, MMP-11 involved in these processes can be a candidate as a new potential prognostic biomarker in BC. Bioimaging techniques based on laser ablation/desorption and mass spectrometry are rapidly growing in biology and medicine for studies of biological systems to provide information of biomolecules (such as proteins, metabolites, and lipids) and metals with lateral resolution at the micrometer scale. In this study, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) has been used for the first time to investigate the distribution of MMP-11 in human breast cancer tissues in order to show a possible correlation between cancerous and healthy samples, by differential proteomics and using such differences for possible cancer diagnosis and/or prognosis. Additionally, those human breast tissue samples were analyzed in parallel by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) in order to gather additional information about the elemental distribution of Zn and its possible associations with MMPs.

// Noemi Eiro 1,5,* , Juan Sendon-Lago 2,* , Samuel Seoane 2 , Maria A. Bermudez 2 , Maria Luz Lamelas 1 , Tomas Garcia-Caballero 3 , Jose Schneider 4,5 , Roman Perez-Fernandez 2,5 and Francisco J. Vizoso 1,5 1 Unidad de Investigacion, Fundacion Hospital de Jove, Gijon, Spain 2 Departamento de Fisiologia-CIMUS, Universidad de Santiago de Compostela, Spain 3 Departamento de Ciencias Morfologicas, Universidad de Santiago de Compostela, Spain 4 Universidad Rey Juan Carlos, Facultad de Ciencias de la Salud, Spain 5 Fundacion para la Investigacion con Celulas Madre Uterinas (FICEMU), Gijon, Spain * These authors contributed equally to this work Correspondence: Francisco J. Vizoso, email: // Keywords : Mesenchymal stem cell; uterine cervix; breast cancer; tumor stroma; cancer-associated fibroblasts; macrophages Received : July 16, 2014 Accepted : September 25, 2014 Published : September 26, 2014 Abstract Evidences indicate that tumor development and progression towards a malignant phenotype depend not only on cancer cells themselves, but are also deeply influenced by tumor stroma reactivity. The present study uses mesenchymal stem cells from normal human uterine cervix (hUCESCs), isolated by the minimally invasive method of routine Pap cervical smear, to study their effect on the three main cell types in a tumor: cancer cells, fibroblasts and macrophages. Administration of hUCESCs-conditioned medium (CM) to a highly invasive breast cancer MDA-MB-231 cell line and to human breast tumors with high cell proliferation rates had the effect of reducing cell proliferation, modifying the cell cycle, inducing apoptosis, and decreasing invasion. In a xenograft mouse tumor model, hUCESCs-CM reduced tumor growth and increased overall survival. In cancer-associated fibroblasts, administration of hUCESCs-CM resulted in reduced cell proliferation, greater apoptosis and decreased invasion. In addition, hUCESCs-CM inhibited and reverted macrophage differentiation. The analysis of hUCESCs-CM (fresh and lyophilized) suggests that a complex paracrine signaling network could be implicated in the anti-tumor potential of hUCESCs. In light of their anti-tumor potential, the easy cell isolation method, and the fact that lyophilization of their CM conserves original properties make hUCESCs good candidates for experimental or clinical applications in anticancer therapy.

Aims Fibronectin (FN) has attracted interest in cancer research, owing to its role in tumour progression. The aims of this study were to investigate the expression and clinical relevance of FN in breast cancer, and to explore its relationship with the expression of matrix metalloproteases (MMPs) and their inhibitors (TIMPs). Methods and results An immunohistochemical study was performed using tumours from 110 breast cancer patients, with tissue arrays and specific antibodies against FN, MMP-7, MMP-9, MMP-11, TIMP-1, and TIMP-2. The results indicated that FN expression was related to tumour size, histological grade, and MMP-9 expression. Tumours with high FN expression by tumour cells were significantly associated with a higher probability of metastasis, poorer overall survival, and expression of MMP-7, MMP-9, MMP-11, TIMP-1 and TIMP-2 by mononuclear inflammatory cells (MICs). In addition, the combination of FN expression by tumour cells and MMP-11 by MICs was strongly associated with distant metastasis development. Conclusions Breast carcinomas with distant metastasis frequently have tumour cells expressing intracellular FN. There is a strong association between FN expression by tumour cells and MMP or TIMP expression by stromal MICs, and this may represent crosstalk that is of prognostic relevance in breast cancer.

Background Given that tumor blood vessels are important in tumor progression and metastasis, tumor endothelial cells (ECs) are the main targets of antiangiogenic therapy. The aim of the present work was to evaluate the phenotype of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) from ECs at the tumor center and its relationship to MMP/TIMP global expression and its relationship to the occurrence of distant metastasis. Patients and Methods An immunohistochemical study was performed using tissue arrays and specific antibodies against MMPs (MMP-2, -7, -9, -11, -13, and -14) and TIMPs (TIMP-1, -2, and -3) at the tumor center in 104 patients with primary ductal invasive breast tumors. Results MMP-11 expression by ECs was related to shorter relapse-free survival, whereas TIMP-3 expression was related to low occurrence of distant metastasis. In addition, MMP-11 and TIMP-2 expression by ECs was associated with shorter overall survival, whereas TIMP-3 expression by ECs was associated with longer overall survival. Our findings indicate significant relationships between the expression of MMPs/TIMPs by ECs and the global expression of these factors at the tumor scene. Conclusion High MMP/TIMP expression by ECs from breast carcinomas, which may be consequence of the cross-talk between tumor cells and their surrounding microenvironment.

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 objective of the present work was to evaluate the impact of the phenotype of both mononuclear inflammatory cells (MICs) and cancer-associated fibroblast (CAFs) in early breast cancer patients, specifically assessed as to their expression of MMP/TIMP relative to their position within the tumor (i.e., localization at the tumor center or invasive front) and the occurrence of distant metastases.. An immunohistochemical study was performed using tissue arrays and specific antibodies against matrix metalloproteinase (MMP)-1, -2, -7, -9, -11, -13 and -14, tissue inhibitors of metalloproteinase (TIMP)-1, -2 and -3, both at tumor center and at invasive front, in 107 patients with primary ductal invasive breast tumors. Data were analyzed by unsupervised hierarchical clustering analysis. Our results indicated that MMP-11 expression by MICs, and TIMP-2 expression by CAFs at either the tumor center or the invasive front, were the most potent independent prognostic factors for predicting the clinical outcome of patients. Using the unsupervised hierarchical clustering analysis, we found well-defined clusters of cases identifying subgroups of tumors showing a high molecular profile of MMPs/TIMPs expression by stromal cells (CAFs and MICs), both at the tumor center and at the invasive front, which were strongly associated with a higher prevalence of distant metastasis. In addition, we found combinations of these clusters defining subpopulations of breast carcinomas differing widely in their clinical outcome. The results presented here identify biologic markers useful to categorize patients into different subgroups based on their tumor stroma, which may contribute to improved understanding of the prognosis of breast cancer patients.

Introduction The POU class 1 homeobox 1 transcription factor (POU1F1, also known as Pit-1) is expressed in the mammary gland and its overexpression induces profound phenotypic changes in proteins involved in cell proliferation, apoptosis, and invasion. Patients with breast cancer and elevated expression of Pit-1 show a positive correlation with the occurrence of distant metastasis. In this study we evaluate the relationship between Pit-1 and two collagenases: matrix metalloproteinase-1 (MMP-1) and matrix metalloproteinase-13 (MMP-13), which have been related to metastasis in breast cancer. Methods We began by transfecting the MCF-7 and MDA-MB-231 human breast adenocarcinoma cell lines with the Pit-1 overexpression vector (pRSV-hPit-1). Afterward, the mRNA, protein, and transcriptional regulation of both MMP-1 and MMP-13 were evaluated by real-time PCR, Western blot, chromatin immunoprecipitation (ChIP), and luciferase reporter assays. We also evaluated Pit-1 overexpression with MMP-1 and MMP-13 knockdown in a severe combined immunodeficiency (SCID) mouse tumor xenograft model. Finally, by immunohistochemistry we correlated Pit-1 with MMP-1 and MMP-13 protein expression in 110 human breast tumors samples. Results Our data show that Pit-1 increases mRNA and protein of both MMP-1 and MMP-13 through direct transcriptional regulation. In SCID mice, knockdown of MMP-13 completely blocked lung metastasis in Pit-1-overexpressing MCF-7 cells injected into the mammary fat pad. In breast cancer patients, expression of Pit-1 was found to be positively correlated with the presence of both MMP-1 and MMP-13. Conclusions Our data indicates that Pit-1 regulates MMP-1 and MMP-13, and that inhibition of MMP-13 blocked invasiveness to lung in Pit-1-overexpressed breast cancer cells. Electronic supplementary material The online version of this article (doi:10.1186/s13058-014-0505-8) contains supplementary material, which is available to authorized users.

Degradation of the stromal connective tissue and basement membrane components are key elements in tumor invasion and metastasis. Some components, particularly the interstitial collagens, are very resistant to proteolytic attacks and can be degraded by specific proteinases like Matrix Metalloproteinases (MMPs). MMPs can also impact on tumor cell behavior in vivo as a consequence of their ability to cleave growth factors, cell surface receptors, cell adhesion molecules, or chemokines/cytokines, and for stimulating angiogenesis. Different molecular expression profiles of MMPs and their inhibitors (TIMPs) have been associated with the main steps in breast cancer progression, such as creating a potential invasive phenotype in Ductal Carcinoma in situ (DCIS), favoring the hematogenous dissemination, and enabling the metastatic progression across the axillary lymphatic system. These associations have clinical interests, as they can contribute to a better characterization of early breast carcinomas (which differ in their both biological and clinical behavior), evaluate microinvasion in resection specimens of breast tumors, provide a more precise prognostic, and predict the tumoral status of non-sentinel lymph nodes in breast cancer. It is also especially remarkable the evidences indicating that MMPs and TIMPs expression in individual cell populations from tumor stroma, such as mononuclear inflammatory cells (MICs) and fibroblast, clearly impacts on the clinical outcome of breast cancer patients. There are several factors linking inflammation, MMP activity and breast cancer. This knowledge will be useful to develop novel therapies and prevention strategies targeting critical components.

Tumors are infiltrated by macrophages, T and B-lymphocytes, which may favor tumor development by promoting angiogenesis, growth and invasion. The aim of this study was to investigate the clinical relevance of the relative amount of macrophages (CD68+), T-cells (CD3+) and B-cells (CD20+) at the invasive front of breast carcinomas, and the expression of matrix metalloproteases (MMPs) and their inhibitors (TIMPs) either at the invasive front or at the tumor center. We performed an immunohistochemical study counting CD3, CD20 and CD68 positive cells at the invasive front, in 102 breast carcinomas. Also, tissue sections were stained with MMP-2, -9, -11, -14 and TIMP-2 antibodies, and immunoreactivity location, percentage of reactive area and intensity were determined at the invasive front and at the tumor center. The results showed that an increased CD68 count and CD68/(CD3+CD20) ratio were directly associated with both MMP-11 and TIMP-2 expression by mononuclear inflammatory cells at the tumor center (p = 0.041 and p = 0.025 for CD68 count and p = 0.001 and p = 0.045 for ratio, respectively for MMP-11 and TIMP-2). In addition, a high CD68/(CD3+CD20) ratio (>0.05) was directly associated with a higher probability of shortened relapse-free survival. Multivariate analysis revealed that CD68/(CD3+CD20) ratio was an independent factor associated with distant relapse-free survival (RR: 2.54, CI: (1.23–5.24), p

Inflammatory conditions may promote tumor progression and aggressiveness. In previous reports, we found a group of breast cancer tumors characterized by metalloprotease-11 (MMP-11) expression by intratumoral mononuclear inflammatory cells (MICs), which was associated with distant metastasis development. Thus, in the present study we evaluated the relationship between MMP-11 expression by MICs, distant metastasis development, and a wide panel of inflammatory factors in breast carcinoma. In an initial approach, we analyzed 65 factors associated with tumor progression and inflammation, in a tumor population classified in good or bad prognosis, based on MMP-11 expression by intratumoral MICs. The most differentially expressed factors were then analyzed in a wider tumor population classified according to MMP-11 expression by MICs and also according to metastasis development. These analyses were carried out by Real-time PCR. The results showed that of the 65 starting factors analyzed, those related with MMP-11 expression by MICs were: IL-1, −5, −6, −8, −17, −18, MMP-1, TIMP-1, ADAM-8, −10, −15, −23, ADAMTS-1, −2, −15, Annexin A2, IFNβ, Claudin-3, CCL-3, MyD88, IRAK-4 and NFκB. Of them, factors more differentially expressed between both groups of tumors were IL-1, IL-5, IL-6, IL-17, IFNβ and NFκB. Thereafter, we confirmed in the wider tumor population, that there is a higher expression of those factors in tumors infiltrated by MMP-11 positive MICs. Altogether these results indicate that tumors developing worse prognosis and identified by MMP-11 expression by intratumoral MICs, shows an up-regulation of inflammatory-related genes.