Cancer cell-derived interleukin 1alpha contributes to autocrine and paracrine induction of pro-metastatic genes in breast cancer

Host-derived Interleukin 1α induces an immunosuppressive tumor microenvironment via regulating monocyte-to-macrophage differentiation

Tumor-associated macrophages exhibit high heterogeneity and contribute to the establishment of an immunosuppressive tumor microenvironment (TME). Although numerous studies have demonstrated that extracellular factors promote macrophage proliferation and polarization, the regulatory mechanisms governing the differentiation process to generate phenotypically, and functionally diverse macrophage subpopulations remain largely unexplored. In this study, we examined the influence of interleukin 1α (IL-1α) on the development of an immunosuppressive TME using orthotopic transplantation murine models of breast cancer. Deletion of host Il1α led to the rejection of inoculated congenic tumors. Single-cell sequencing analysis revealed that CX3CR1+ macrophage cells were the primary sources of IL-1α in the TME. The absence of IL-1α reprogrammed the monocyte-to-macrophage differentiation process within the TME, characterized by a notable decrease in the subset of CX3CR+ ductal-like macrophages and an increase in iNOS-expressing inflammatory cells. Comparative analysis of gene signatures in both human and mouse macrophage subsets suggested that IL-1α deficiency shifted the macrophage polarization from M2 to M1 phenotypes, leading to enhanced cytotoxic T lymphocyte activity in the TME. Importantly, elevated levels of IL-1α in human cancers were associated with worse prognosis following immunotherapy. These findings underscore the pivotal role of IL-1α in shaping an immune-suppressive TME through the regulation of macrophage differentiation and activity, highlighting IL-1α as a potential target for breast cancer treatment.

Interindividual variation contributes to differential PCB 126 induced gene expression in primary breast epithelial cells and tissues

PCB 126 is a pervasive, dioxin-like chemical pollutant which can activate the aryl hydrocarbon receptor (AhR). Despite being banned from the market, PCB 126 can be detected in breast milk to this day. The extent to which interindividual variation impacts the adverse responses to this chemical in the breast tissue remains unclear. This study aimed to investigate the impact of 3 nM PCB 126 on gene expression in a panel of genetically diverse benign human breast epithelial cell (HBEC) cultures and patient derived breast tissues. Six patient derived HBEC cultures were treated with 3 nM PCB 126. RNAseq was used to interrogate the impact of exposure on differential gene expression. Gene expression changes from the top critical pathways were confirmed via qRT-PCR in a larger panel of benign patient derived HBEC cultures, as well as in patient-derived breast tissue explant cultures. RNAseq analysis of HBEC cultures revealed a signature of 144 genes significantly altered by 3 nM PCB 126 treatment. Confirmation of 8 targets using a panel of 12 HBEC cultures and commercially available breast cell lines demonstrated that while the induction of canonical downstream target gene, CYP1A1, was consistent across our primary HBECs, other genes including AREG, S100A8, IL1A, IL1B, MMP7, and CCL28 exhibited significant variability across individuals. The dependence on the activity of the aryl hydrocarbon receptor was confirmed using inhibitors. PCB 126 can induce significant and consistent changes in gene expression associated with xenobiotic metabolism in benign breast epithelial cells. Although the induction of most genes was reliant on the AhR, significant variability was noted between genes and individuals. These data suggest that there is a bifurcation of the pathway following AhR activation that contributes to the variation in interindividual responses.

Epigenetic Modifications in Tumor-Associated Macrophages: A New Perspective for an Old Foe

Tumorigenesis is frequently accompanied by chronic inflammation, and the tumor microenvironment (TME) can be considered an ecosystem that consists of tumor cells, endotheliocytes, fibroblasts, immune cells and acellular components such as extracellular matrix. For tumor cells, their survival advantages are dependent on both genetic and epigenetic alterations, while other cells mainly present epigenetic modifications. Macrophages are the most plastic type of immune cells and undergo diverse epigenetic alterations in the TME. Some of these epigenetic modifications mitigate against cancer progression, and others accelerate this process. Due to the complex roles of macrophages in the TME, it is urgent to understand their epigenetic modifications associated with the TME. Here, we mainly summarize recent findings on TME-associated epigenetic alterations of tumor-associated macrophages (TAMs), including DNA methylation, posttranslational modifications of histone proteins, chromatin remodeling, and noncoding RNA-mediated epigenetic regulation. At the end of this review, we also discuss the translational potential of these epigenetic modifications for developing novel cancer therapies targeting TAMs.

The Extracellular Matrix and Vesicles Modulate the Breast Tumor Microenvironment

Emerging evidence has shown multiple roles of the tumor microenvironment (TME) components, specifically the extracellular matrix (ECM), in breast cancer development, progression, and metastasis. Aside from the biophysical properties and biochemical composition of the breast ECM, the signaling molecules are extremely important in maintaining homeostasis, and in the breast TME, they serve as the key components that facilitate tumor progression and immune evasion. Extracellular vesicles (EVs), the mediators that convey messages between the cells and their microenvironment through signaling molecules, have just started to capture attention in breast cancer research. In this comprehensive review, we first provide an overview of the impact of ECM in breast cancer progression as well as the alterations occurring in the TME during this process. The critical importance of EVs and their biomolecular contents in breast cancer progression and metastasis are also discussed. Finally, we discuss the potential biomedical or clinical applications of these extracellular components, as well as how they impact treatment outcomes.

Novel mechanistic targets of forkhead box Q1 transcription factor in human breast cancer cells

The transcription factor forkhead box Q1 (FoxQ1) is overexpressed in different solid tumors including breast cancer, but the mechanism underlying its oncogenic function is still not fully understood. In this study, we compared RNA-seq data from FoxQ1 overexpressing SUM159 cells with that of empty vector-transfected control cells to identify novel mechanistic targets of this transcription factor. Analysis of The Cancer Genome Atlas (TCGA) data set revealed significantly higher expression of FoxQ1 in black breast cancer patients compared with white women with this disease. In contrast, expression of FoxQ1 was comparable in ductal and lobular carcinomas in the breast cancer TCGA data set. Complementing our published findings in basal-like subtype, immunohistochemistry revealed upregulation of FoxQ1 protein in luminal-type human breast cancer tissue microarrays when compared with normal mammary tissues. Many previously reported transcriptional targets of FoxQ1 (eg, E-cadherin, N-cadherin, fibronectin 1, etc) were verified from the RNA-seq analysis. FoxQ1 overexpression resulted in the downregulation of genes associated with cell cycle checkpoints, M phase, and cellular response to stress/external stimuli as evidenced from the Reactome pathway analysis. Consequently, FoxQ1 overexpression resulted in mitotic arrest in basal-like SUM159 and human mammary epithelial cell line, but not in luminal-type MCF-7 cells. Finally, we show for the first time that FoxQ1 is a direct transcriptional regulator of interleukin (IL)-1α, IL-8, and vascular endothelial growth factor in breast cancer cells as evidenced by chromatin immunoprecipitation assay. In conclusion, the present study reports novel mechanistic targets of FoxQ1 in human breast cancer cells.

Whole Transcriptomic Analysis of Apigenin on TNFα Immuno-activated MDA-MB-231 Breast Cancer Cells

BACKGROUND

Triple-negative breast cancer is categorized by a lack of hormone receptors, inefficacy of anti-estrogen or aromatase inhibitor chemotherapies and greater mortality rates in African American populations. Advanced-stage breast tumors have a high concentration of tumor necrosis factor-α (TNFα) throughout the tumor/stroma milieu, prompting sustained release of diverse chemokines (i.e. C-C motif chemokine ligand 2 (CCL2)/CCL5). These potent chemokines can subsequently direct mass infiltration of leukocyte sub-populations to lodge within the tumor, triggering a loss of tumor immune surveillance and subsequent rapid tumor growth. Previously, we demonstrated that in the MDA-MB-231 TNBC cell line, TNFα evoked a rise in immune signaling proteins: CCL2, granulocyte macrophage colony-stimulating factor, interleukin (IL)1α, IL6 and inhibitor of nuclear factor kappa-B kinase subunit epsilon (IKBKε) all of which were attenuated by apigenin, a dietary flavonoid found in chamomile and parsley.

MATERIALS AND METHODS

The present work elucidates changes evoked by TNFα in the presence or absence of apigenin by examining the entire transcriptome for mRNA and long intergenic non-coding RNA with Affymetrix Hugene-2.1_ST human microarrays. Differential gene-expression analysis was conducted on 48,226 genes.

RESULTS

TNFα caused up-regulation of 75 genes and down-regulation of 10. Of these, apigenin effectively down-regulated 35 of the 75 genes which were up-regulated by TNFα. These findings confirm our previous work, specifically for the TNFα-evoked spike in IL1A vs. untreated controls [+21-fold change (FC), p<0.0001] being attenuated by apigenin in the presence of TNFa (-15 FC vs. TNFα, p<0.0001). Similar trends were seen for apigenin-mediated down-regulation of TNFα-up-regulated transcripts: IKBKE (TNFα: 4.55 FC vs. control, p<0.001; and TNFα plus apigenin: -4.92 FC, p<0.001), CCL2 (2.19 FC, p<0.002; and -2.12 FC, p<0.003), IL6 (3.25 FC, p<0.020; and -2.85 FC, p<0.043) and CSF2 (TNFα +6.04 FC, p<0.001; and -2.36 FC, p<0.007). In addition, these data further establish more than a 65% reduction by apigenin for the following transcripts which were also up-regulated by TNFα: cathepsin S (CTSS), complement C3 (C3), laminin subunit gamma 2 (LAMC2), (TLR2), toll-like receptor 2 G protein-coupled receptor class C group 5 member B (GPRC5B), contactin-associated protein 1 (CNTNAP1), claudin 1 (CLDN1), nuclear factor of activated T-cells 2 (NFATC2), C-X-C motif chemokine ligand 10 (CXCL10), CXCL11, interleukin 1 receptor-associated kinase 3 (IRAK3), nuclear receptor subfamily 3 group C member 2 (NR3C2), interleukin 32 (IL32), IL24, slit guidance ligand 2 (SLIT2), transmembrane protein 132A (TMEM132A), TMEM171, signal transducing adaptor family member 2 (STAP2), mixed lineage kinase domain-like pseudokinase (MLKL), kinase insert domain receptor (KDR), BMP-binding endothelial regulator (BMPER), and kelch-like family member 36 (KLHL36).

CONCLUSION

There is a possible therapeutic role for apigenin in down-regulating diverse genes associated with tumorigenic leukocyte sub-population infiltration by triple-negative breast cancer. The data have been deposited into the Gene Expression Omnibus for public analysis at https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE120550.

IL-1 Signaling in Tumor Microenvironment

Interleukin 1 (IL-1) has long been known for its pleiotropic effects on inflammation that plays a complex, and sometimes contrasting, role in different stages of cancer development. As a major proinflammatory cytokine, IL-1β is mainly expressed by innate immune cells. IL-1α, however, is expressed by various cell types under physiological and pathological conditions. IL-1R1 is the main receptor for both ligands and is expressed by various cell types, including innate and adaptive immune cell types, epithelial cells, endothelial cells, adipocytes, chondrocytes, fibroblasts, etc. IL-1 and IL-1R1 receptor interaction leads to a set of common signaling pathways, mainly the NF-kB and MAP kinase pathways, as a result of complex positive and negative regulations. The variety of cell types with IL-1R1 expression dictates the role of IL-1 signaling at different stages of cancer, which under certain circumstances leads to contrasting roles in tumor development. Recent availability of IL-1R1 conditional knockout mouse model has made it possible to dissect the role of IL-1/IL-1R1 signaling transduction in different cell types within the tumor microenvironment. This chapter will focus on the role of IL-1/IL-1R1 in different cell types within the tumor microenvironment and discuss the potential of targeting this pathway in cancer therapy.

Breast Cancer Metastasis: Are Cytokines Important Players During Its Development and Progression?

In breast cancer, an uncontrolled cell proliferation leads to tumor formation and development of a multifactorial disease. Metastasis is a complex process that involves tumor spread to distant parts of the body from its original site. Metastatic dissemination represents the main physiopathology of cancer. Inter- and intracellular communication in all systems in vertebrates is mediated by cytokines, which are highly inducible, secretory proteins, produced not only by immune system cells, but also by endocrine and nervous system cells. It has become clear in recent years that cytokines, as well as their receptors are produced in the organisms under physiological and pathological conditions; recently, they have been closely related to breast cancer metastasis. The exact initiation process of breast cancer metastasis is unknown, although several hypotheses have emerged. In this study, we thoroughly reviewed the role of several cytokines in breast cancer metastasis. Data reviewed suggest that cytokines and growth factors are key players in the breast cancer metastasis induction. This knowledge must be considered with the aim to development of new therapeutic approaches to counter breast cancer metastasis.

Nitric oxide, the new architect of epigenetic landscapes

Nitric oxide (NO) is an endogenously produced signaling molecule with multiple regulatory functions in physiology and disease. The most studied molecular mechanisms underlying the biological functions of NO include its reaction with heme proteins and regulation of protein activity via modification of thiol residues. A significant number of transcriptional responses and phenotypes observed in NO microenvironments, however, still lack mechanistic understanding. Recent studies shed new light on NO signaling by revealing its influence on epigenetic changes within the cell. Epigenetic alterations are important determinants of transcriptional responses and cell phenotypes, which can relay heritable information during cell division. As transcription across the genome is highly sensitive to these upstream epigenetic changes, this mode of NO signaling provides an alternate explanation for NO-mediated gene expression changes and phenotypes. This review will provide an overview of the interplay between NO and epigenetics as well as emphasize the unprecedented importance of these pathways to explain phenotypic effects associated with biological NO synthesis.

Cytokine Regulation of Metastasis and Tumorigenicity

The human body combats infection and promotes wound healing through the remarkable process of inflammation. Inflammation is characterized by the recruitment of stromal cell activity including recruitment of immune cells and induction of angiogenesis. These cellular processes are regulated by a class of soluble molecules called cytokines. Based on function, cell target, and structure, cytokines are subdivided into several classes including: interleukins, chemokines, and lymphokines. While cytokines regulate normal physiological processes, chronic deregulation of cytokine expression and activity contributes to cancer in many ways. Gene polymorphisms of all types of cytokines are associated with risk of disease development. Deregulation RNA and protein expression of interleukins, chemokines, and lymphokines have been detected in many solid tumors and hematopoetic malignancies, correlating with poor patient prognosis. The current body of literature suggests that in some tumor types, interleukins and chemokines work against the human body by signaling to cancer cells and remodeling the local microenvironment to support the growth, survival, and invasion of primary tumors and enhance metastatic colonization. Some lymphokines are downregulated to suppress tumor progression by enhancing cytotoxic T cell activity and inhibiting tumor cell survival. In this review, we will describe the structure/function of several cytokine families and review our current understanding on the roles and mechanisms of cytokines in tumor progression. In addition, we will also discuss strategies for exploiting the expression and activity of cytokines in therapeutic intervention.

Transitions from mono- to co- to tri-culture uniquely affect gene expression in breast cancer, stromal, and immune compartments

Heterotypic interactions in cancer microenvironments play important roles in disease initiation, progression, and spread. Co-culture is the predominant approach used in dissecting paracrine interactions between tumor and stromal cells, but functional results from simple co-cultures frequently fail to correlate to in vivo conditions. Though complex heterotypic in vitro models have improved functional relevance, there is little systematic knowledge of how multi-culture parameters influence this recapitulation. We therefore have employed a more iterative approach to investigate the influence of increasing model complexity; increased heterotypic complexity specifically. Here we describe how the compartmentalized and microscale elements of our multi-culture device allowed us to obtain gene expression data from one cell type at a time in a heterotypic culture where cells communicated through paracrine interactions. With our device we generated a large dataset comprised of cell type specific gene-expression patterns for cultures of increasing complexity (three cell types in mono-, co-, or tri-culture) not readily accessible in other systems. Principal component analysis indicated that gene expression was changed in co-culture but was often more strongly altered in tri-culture as compared to mono-culture. Our analysis revealed that cell type identity and the complexity around it (mono-, co-, or tri-culture) influence gene regulation. We also observed evidence of complementary regulation between cell types in the same heterotypic culture. Here we demonstrate the utility of our platform in providing insight into how tumor and stromal cells respond to microenvironments of varying complexities highlighting the expanding importance of heterotypic cultures that go beyond conventional co-culture.

Neutrophils drive accelerated tumor progression in the collagen-dense mammary tumor microenvironment

Background

High mammographic density has been correlated with a 4-fold to 6-fold increased risk of developing breast cancer, and is associated with increased stromal deposition of extracellular matrix proteins, including collagen I. The molecular and cellular mechanisms responsible for high breast tissue density are not completely understood.

Methods

We previously described accelerated tumor formation and metastases in a transgenic mouse model of collagen-dense mammary tumors (type I collagen-α1 (Col1α1)^tm1Jae and mouse mammary tumor virus - polyoma virus middle T antigen (MMTV-PyVT)) compared to wild-type mice. Using ELISA cytokine arrays and multi-color flow cytometry analysis, we studied cytokine signals and the non-malignant, immune cells in the collagen-dense tumor microenvironment that may promote accelerated tumor progression and metastasis.

Results

Collagen-dense tumors did not show any alteration in immune cell populations at late stages. The cytokine signals in the mammary tumor microenvironment were clearly different between wild-type and collagen-dense tumors. Cytokines associated with neutrophil signaling, such as granulocyte monocyte-colony stimulated factor (GM-CSF), were increased in collagen-dense tumors. Depleting neutrophils with anti-Ly6G (1A8) significantly reduced the number of tumors, and blocked metastasis in over 80 % of mice with collagen-dense tumors, but did not impact tumor growth or metastasis in wild-type mice.

Conclusion

Our study suggests that tumor progression in a collagen-dense microenvironment is mechanistically different, with pro-tumor neutrophils, compared to a non-dense microenvironment.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-016-0703-7) contains supplementary material, which is available to authorized users.

Nitric Oxide Regulates Gene Expression in Cancers by Controlling Histone Posttranslational Modifications

Altered nitric oxide (•NO) metabolism underlies cancer pathology, but mechanisms explaining many •NO-associated phenotypes remain unclear. We have found that cellular exposure to •NO changes histone posttranslational modifications (PTM) by directly inhibiting the catalytic activity of JmjC-domain containing histone demethylases. Herein, we describe how •NO exposure links modulation of histone PTMs to gene expression changes that promote oncogenesis. Through high-resolution mass spectrometry, we generated an extensive map of •NO-mediated histone PTM changes at 15 critical lysine residues on the core histones H3 and H4. Concomitant microarray analysis demonstrated that exposure to physiologic •NO resulted in the differential expression of over 6,500 genes in breast cancer cells. Measurements of the association of H3K9me2 and H3K9ac across genomic loci revealed that differential distribution of these particular PTMs correlated with changes in the level of expression of numerous oncogenes, consistent with epigenetic code. Our results establish that •NO functions as an epigenetic regulator of gene expression mediated by changes in histone PTMs.

NOS Inhibition Modulates Immune Polarization and Improves Radiation-Induced Tumor Growth Delay

Nitric oxide synthases (NOS) are important mediators of progrowth signaling in tumor cells, as they regulate angiogenesis, immune response, and immune-mediated wound healing. Ionizing radiation (IR) is also an immune modulator and inducer of wound response. We hypothesized that radiation therapeutic efficacy could be improved by targeting NOS following tumor irradiation. Herein, we show enhanced radiation-induced (10 Gy) tumor growth delay in a syngeneic model (C3H) but not immunosuppressed (Nu/Nu) squamous cell carcinoma tumor-bearing mice treated post-IR with the constitutive NOS inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME). These results suggest a requirement of T cells for improved radiation tumor response. In support of this observation, tumor irradiation induced a rapid increase in the immunosuppressive Th2 cytokine IL10, which was abated by post-IR administration of L-NAME. In vivo suppression of IL10 using an antisense IL10 morpholino also extended the tumor growth delay induced by radiation in a manner similar to L-NAME. Further examination of this mechanism in cultured Jurkat T cells revealed L-NAME suppression of IR-induced IL10 expression, which reaccumulated in the presence of exogenous NO donor. In addition to L-NAME, the guanylyl cyclase inhibitors ODQ and thrombospondin-1 also abated IR-induced IL10 expression in Jurkat T cells and ANA-1 macrophages, which further suggests that the immunosuppressive effects involve eNOS. Moreover, cytotoxic Th1 cytokines, including IL2, IL12p40, and IFNγ, as well as activated CD8(+) T cells were elevated in tumors receiving post-IR L-NAME. Together, these results suggest that post-IR NOS inhibition improves radiation tumor response via Th1 immune polarization within the tumor microenvironment.

Alterations of gene expression and protein synthesis in co-cultured adipose tissue-derived stem cells and squamous cell-carcinoma cells: consequences for clinical applications

Introduction

This is the first study evaluating the interactions of human adipose tissue derived stem cells (ADSCs) and human squamous cell carcinoma cells (SCCs), with regard to a prospective cell-based skin regenerative therapy and a thereby unintended co-localization of ADSCs and SCCs.

Methods

ADSCs were co-cultured with A431-SCCs and primary SCCs (pSCCs) in a transwell system, and cell-cell interactions were analyzed by assessing doubling time, migration and invasion, angiogenesis, quantitative real time PCR of 229 tumor associated genes, and multiplex protein assays of 20 chemokines and growth factors and eight matrix metalloproteinases (MMPS). Results of co-culture were compared to those of the respective mono-culture.

Results

ADSCs’ proliferation on the plate was significantly increased when co-cultured with A431-SCCs (P = 0.038). PSCCs and ADSCs significantly decreased their proliferation in co-culture if cultured on the plate (P <0.001 and P = 0.03). The migration of pSCC was significantly increased in co-culture (P = 0.009), as well as that of ADSCs in A431-SCC-co-culture (P = 0.012). The invasive behavior of pSCCs and A431-SCCs was significantly increased in co-culture by a mean of 33% and 35%, respectively (P = 0.038 and P <0.001). Furthermore, conditioned media from co-cultured ADSC-A431-SCCs and co-cultured ADSCs-pSCCs induced tube formation in an angiogenesis assay in vitro.

In A431-SCC-co-culture 36 genes were up- and 6 were down-regulated in ADSCs, in A431-SCCs 14 genes were up- and 8 genes were down-regulated. In pSCCs-co-culture 36 genes were up-regulated in ADSCs, two were down-regulated, one gene was up-regulated in pSCC, and three genes were down-regulated. Protein expression analysis revealed that three proteins were exclusively produced in co-culture (CXCL9, IL-1b, and MMP-7). In A431-SCC-co-culture the concentration of 17 proteins was significantly increased compared to the ADSCs mono-culture (2.8- to 357-fold), and 15 proteins were expressed more highly (2.8- to 1,527-fold) compared to the A431-SCCs mono-culture. In pSCC-co-culture the concentration of 10 proteins was increased compared to ADSCs-mono-culture (2.5- to 77-fold) and that of 15 proteins was increased compared to pSCC mono-culture (2.6- to 480-fold).

Conclusions

This is the first study evaluating the possible interactions of primary human ADSCs with human SCCs, pointing towards a doubtlessly increased oncological risk, which should not be neglected when considering a clinical use of isolated human ADSCs in skin regenerative therapies.

Matrix metalloproteinases: the gene expression signatures of head and neck cancer progression

Extracellular matrix degradation by matrix metalloproteinases (MMPs) plays a pivotal role in cancer progression by promoting motility, invasion and angiogenesis. Studies have shown that MMP expression is increased in head and neck squamous cell carcinomas (HNSCCs), one of the most common cancers in the world, and contributes to poor outcome. In this review, we examine the expression pattern of MMPs in HNSCC by microarray datasets and summarize the current knowledge of MMPs, specifically MMP-1, -3, -7 -10, -12, -13, 14 and -19, that are highly expressed in HNSCCs and involved cancer invasion and angiogenesis.

Loss of p120-catenin induces metastatic progression of breast cancer by inducing anoikis resistance and augmenting growth factor receptor signaling

Metastatic breast cancer remains the chief cause of cancer-related death among women in the Western world. Although loss of cell-cell adhesion is key to breast cancer progression, little is known about the underlying mechanisms that drive tumor invasion and metastasis. Here, we show that somatic loss of p120-catenin (p120) in a conditional mouse model of noninvasive mammary carcinoma results in formation of stromal-dense tumors that resemble human metaplastic breast cancer and metastasize to lungs and lymph nodes. Loss of p120 in anchorage-dependent breast cancer cell lines strongly promoted anoikis resistance through hypersensitization of growth factor receptor (GFR) signaling. Interestingly, p120 deletion also induced secretion of inflammatory cytokines, a feature that likely underlies the formation of the prometastatic microenvironment in p120-negative mammary carcinomas. Our results establish a preclinical platform to develop tailored intervention regimens that target GFR signals to treat p120-negative metastatic breast cancers.

Protein expression changes during human triple negative breast cancer cell line progression to lymph node metastasis in a xenografted model in nude mice

Triple negative breast cancers (TNBC) lacking hormone receptors and HER-2 amplification are very aggressive tumors. Since relevant differences between primary tumors and metastases could arise during tumor progression as evidenced by phenotypic discordances reported for hormonal receptors or HER-2 expression, in this analysis we studied changes that occurred in our TNBC model IIB-BR-G throughout the development of IIB-BR-G-_MTS6 metastasis to the lymph nodes (LN) in nude mice, using an antibody-based protein array to characterize their expression profile. We also analyzed their growth kinetics, migration, invasiveness and cytoskeleton structure in vitro and in vivo.

In vitro IIB-BR-G-_MTS6 cells grew slower but showed higher anchorage independent growth. In vivo IIB-BR-G-_MTS6 tumors grew significantly faster and showed a 100% incidence of LN metastasis after s.c. inoculation, although no metastasis was observed for IIB-BR-G. CCL3, IL1β, CXCL1, CSF2, CSF3, IGFBP1, IL1α, IL6, IL8, CCL20, PLAUR, PlGF and VEGF were strongly upregulated in IIB-BR-G-_MTS6 while CCL4, ICAM3, CXCL12, TNFRSF18, FIGF were the most downregulated proteins in the metastatic cell line. IIB-BR-G-_MTS6 protein expression profile could reflect a higher NFκB activation in these cells. In vitro, IIB-BR-G displayed higher migration but IIB-BR-G-_MTS6 had more elevated matrigel invasion ability. In agreement with that observation, IIB-BR-G-_MTS6 had an upregulated expression of MMP1, MMP9, MMP13, PLAUR and HGF. IIB-BR-G-_MTS6 tumors presented also higher local lymphatic invasion than IIB-BR-G but similar lymphatic vessel densities. VEGFC and VEGFA/B expression were higher both in vitro and in vivo for IIB-BR-G-_MTS6. IIB-BR-G-_MTS6 expressed more vimentin than IB-BR-G cells, which was mainly localized in the cellular extremities and both cell lines are E-cadherin negative.

Our results suggest that IIB-BR-G-_MTS6 cells have acquired a pronounced epithelial-to-mesenchymal transition phenotype. Protein expression changes observed between primary tumor-derived IIB-BR-G and metastatic IIB-BR-G-_MTS6 TNBC cells suggest potential targets involved in the control of metastasis.

Diet-induced obesity alters dendritic cell function in the presence and absence of tumor growth

Obesity is a mounting health concern in the United States and is associated with an increased risk for developing several cancers, including renal cell carcinoma (RCC). Despite this, little is known regarding the impact of obesity on antitumor immunity. Because dendritic cells (DC) are critical regulators of antitumor immunity, we examined the combined effects of obesity and tumor outgrowth on DC function. Using a diet-induced obesity (DIO) model, DC function was evaluated in mice bearing orthotopic RCC and in tumor-free controls. Tumor-free DIO mice had profoundly altered serum cytokine and chemokine profiles, with upregulation of 15 proteins, including IL-1α, IL-17, and LIF. Tumor-free DIO mice had elevated percentages of conventional splenic DC that were impaired in their ability to stimulate naive T cell expansion, although they were phenotypically similar to normal weight (NW) controls. In DIO mice, intrarenal RCC tumor challenge in the absence of therapy led to increased local infiltration by T cell-suppressive DC and accelerated early tumor outgrowth. Following administration of a DC-dependent immunotherapy, established RCC tumors regressed in normal weight mice. The same immunotherapy was ineffective in DIO mice and was characterized by an accumulation of regulatory DC in tumor-bearing kidneys, decreased local infiltration by IFN-γ-producing CD8 T cells, and progressive tumor outgrowth. Our results suggest that the presence of obesity as a comorbidity can impair the efficacy of DC-dependent antitumor immunotherapies.

Interleukin 1α sustains the expression of inflammatory factors in human pancreatic cancer microenvironment by targeting cancer-associated fibroblasts

The tumor microenvironment in pancreatic ductal adenocarcinoma (PDAC) is dynamic, with an extensive interaction between the stroma and tumor cells. The aim of this study was to delineate the cross talk between PDAC and cancer-associated fibroblasts (CAFs), with a focus on the mechanism creating the chronic inflammatory tumor milieu. We assessed the effects of the cross talk between PDAC and CAF cell lines on the creation and sustenance of the inflammatory tumor microenvironment in pancreatic cancer. The coculture of PDAC and CAF cell lines enhanced the levels of inflammatory factors including IL-1α, IL-6, CXCL8, VEGF-A, CCL20, and COX-2. CAFs were superior to tumor cells regarding the production of most inflammatory factors, and tumor cell-associated IL-1α was established as the initiator of the enhanced production of inflammatory factors through the binding of IL-1α to IL-1 receptor 1 (IL-1R1) expressed predominantly by CAFs. Furthermore, we found a correlation between IL-1α and CXCL8 expression levels in PDAC tissues and correlation between IL-1α expression and the clinical outcome of the patients. This confirmed an important role for the IL-1 signaling cascade in the creation and sustenance of a tumor favorable microenvironment. Neutralization of the IL-1α signaling efficiently diminished the cross talk-induced production of inflammatory factors. These data suggest that the cross talk between PDAC cells and the main stroma cell type, i.e. CAFs, is one essential factor in the formation of the inflammatory tumor environment, and we propose that neutralization of the IL-1α signaling might be a potential therapy for this cancer.

Inflammatory mediators in breast cancer: coordinated expression of TNFα & IL-1β with CCL2 & CCL5 and effects on epithelial-to-mesenchymal transition

Background

The inflammatory chemokines CCL2 (MCP-1) & CCL5 (RANTES) and the inflammatory cytokines TNFα & IL-1β were shown to contribute to breast cancer development and metastasis. In this study, we wished to determine whether there are associations between these factors along stages of breast cancer progression, and to identify the possible implications of these factors to disease course.

Methods

The expression of CCL2, CCL5, TNFα and IL-1β was determined by immunohistochemistry in patients diagnosed with: (1) Benign breast disorders (=healthy individuals); (2) Ductal Carcinoma In Situ (DCIS); (3) Invasive Ducal Carcinoma without relapse (IDC-no-relapse); (4) IDC-with-relapse. Based on the results obtained, breast tumor cells were stimulated by the inflammatory cytokines, and epithelial-to-mesenchymal transition (EMT) was determined by flow cytometry, confocal analyses and adhesion, migration and invasion experiments.

Results

CCL2, CCL5, TNFα and IL-1β were expressed at very low incidence in normal breast epithelial cells, but their incidence was significantly elevated in tumor cells of the three groups of cancer patients. Significant associations were found between CCL2 & CCL5 and TNFα & IL-1β in the tumor cells in DCIS and IDC-no-relapse patients. In the IDC-with-relapse group, the expression of CCL2 & CCL5 was accompanied by further elevated incidence of TNFα & IL-1β expression. These results suggest progression-related roles for TNFα and IL-1β in breast cancer, as indeed indicated by the following: (1) Tumors of the IDC-with-relapse group had significantly higher persistence of TNFα and IL-1β compared to tumors of DCIS or IDC-no-relapse; (2) Continuous stimulation of the tumor cells by TNFα (and to some extent IL-1β) has led to EMT in the tumor cells; (3) Combined analyses with relevant clinical parameters suggested that IL-1β acts jointly with other pro-malignancy factors to promote disease relapse.

Conclusions

Our findings suggest that the coordinated expression of CCL2 & CCL5 and TNFα & IL-1β may be important for disease course, and that TNFα & IL-1β may promote disease relapse. Further in vitro and in vivo studies are needed for determination of the joint powers of the four factors in breast cancer, as well as analyses of their combined targeting in breast cancer.

Cell surface-bound IL-1alpha is an upstream regulator of the senescence-associated IL-6/IL-8 cytokine network

Inflammation underlies most age-related diseases, including cancer, but the etiology is poorly understood. One proposed factor is the presence of senescent cells, which increase with age. The senescence response arrests the proliferation of potentially oncogenic cells, and most senescent cells secrete high levels of proinflammatory cytokines and other proteins. The complex senescence-associated secretory phenotype is likely regulated at multiple levels, most of which are unknown. We show that cell surface-bound IL-1alpha is essential for signaling the senescence-associated secretion of IL-6 and IL-8, 2 proinflammatory cytokines that also reinforce the senescence growth arrest. Senescent human fibroblasts expressed high levels of IL-1alpha mRNA, intracellular protein, and cell surface-associated protein, but secreted very little protein. An IL-1 receptor (IL1R) antagonist, neutralizing IL-1alpha antibodies, and IL-1alpha depletion by RNA interference all markedly reduced senescence-associated IL-6/IL-8 secretion. Depletion of the key IL-1R signaling component IRAK1 also suppressed this secretion, and IL-1alpha neutralizing antibodies prevented IRAK1 degradation, indicating engagement of the IL-1R signaling pathway. Furthermore, IL-1alpha depletion reduced the DNA binding activity of NF-kappaB and C/EBPbeta, which stimulate IL-6/IL-8 transcription. IL-1alpha was a general regulator of senescence-associated IL-6/IL-8 secretion because IL-1alpha blockade reduced IL-6/IL-8 secretion whether cells senesced owing to DNA damage, replicative exhaustion, oncogenic RAS, or chromatin relaxation. Furthermore, conditioned medium from IL-1alpha-depleted senescent cells markedly reduced the IL-6/IL-8-dependent invasiveness of metastatic cancer cells, indicating that IL-1alpha regulates the biological effects of these cytokines. Thus, cell surface IL-1alpha is an essential cell-autonomous regulator of the senescence-associated IL-6/IL-8 cytokine network.

Ovarian cancer cells stimulate uPA gene expression in fibroblastic stromal cells via multiple paracrine and autocrine mechanisms

OBJECTIVES

Expression of uPA mRNA is massively up-regulated in the stroma of poorly differentiated ovarian tumors. We hypothesized that this expression was induced by paracrine signals from the epithelial tumor cells, and established an in vitro model of ovarian cancer microenvironment to study intercellular cross-talk.

METHODS

ES-2 clear cell carcinoma cells were grown in tissue culture inserts in a double-chamber system with fibroblastic stromal LEP cells embedded in Matrigel. Binding-site directed antibodies were used to neutralize soluble cytokines in ES-2 conditioned medium (CM) before incubation with LEP cells. Real time PCR measured uPA mRNA in LEP cells, as well as mRNA for cytokines in both cell types.

RESULTS

Co-culture with ES-2 cells as well as incubation with ES-2 CM induced uPA mRNA in LEP cells about two-fold. In short time (12 h) incubation of LEP cells with CM, antibodies to EGF and bFGF reduced induction of uPA mRNA, suggesting that these cytokines function as paracrine signals. EGF mRNA and bFGF mRNA were also found in ES-2 cells. At longer incubation (24 h) antibodies to bFGF, HB-EGF, HGF, IGF-1, and IL-1alpha reduced uPA mRNA induction, suggesting an autocrine function for these cytokines in LEP cells. In fact, expression of the same five cytokines was up-regulated in LEP cells exposed to CM.

CONCLUSION

We identified two cytokines as paracrine signals, and five cytokines as autocrine signals in ovarian cancer cell induced up-regulation of uPA mRNA in stromal fibroblastic cells. It is crucial to understand intra-tumoral cross-talk, since it can offer new therapeutic approaches.

Secreted interleukin-1alpha induces a metastatic phenotype in pancreatic cancer by sustaining a constitutive activation of nuclear factor-kappaB

Transcription factor nuclear factor-kappaB (NF-kappaB) is constitutively activated in most pancreatic cancer tissues and cell lines but not in normal pancreas nor in immortalized/nontumorigenic human pancreatic ductal epithelial cells. Inhibition of constitutive NF-kappaB activation in pancreatic cancer cell lines suppresses tumorigenesis and tumor metastasis. Recently, we identified autocrine secretion of proinflammatory cytokine interleukin (IL)-1alpha as the mechanism of constitutive NF-kappaB activation in metastatic pancreatic cancer cell lines. However, the role of IL-1alpha in determining the metastatic potential of pancreatic tumor remains to be further investigated. In the current study, we stably expressed IL-1alpha in the nonmetastatic, IL-1alpha-negative MiaPaCa-2 cell lines. Our results showed that the secretion of IL-1alpha in MiaPaCa-2 cells constitutively activated NF-kappaB and increased the expression of NF-kappaB downstream genes involved in the different steps of the metastatic cascade, such as urokinase-type plasminogen activator, vascular endothelial growth factor, and IL-8. MiaPaCa-2/IL-1alpha cells showed an enhanced cell invasion in vitro compared with parental MiaPaCa-2 cells and induced liver metastasis in an orthotopic mouse model. The metastatic phenotype induced by IL-1alpha was inhibited by the expression of phosphorylation-defective IkappaB (IkappaB S32, 36A), which blocked NF-kappaB activation. Consistently, silencing the expression of IL-1alpha by short hairpin RNA in the highly metastatic L3.6pl pancreatic cancer cells completely suppressed their metastatic spread. In summary, these findings showed that IL-1alpha plays key roles in pancreatic cancer metastatic behavior through the constitutive activation of NF-kappaB. Our findings further support the possible link between inflammation and cancer and suggest that IL-1alpha may be a potential therapeutic target for treating pancreatic adenocarcinoma.

The prognostic value of four interleukin-1 gene polymorphisms in Caucasian women with breast cancer: a multicenter study

Background

The proinflammatory cytokine interleukin-1 (IL-1) is known to play an important role in the carcinogenesis of breast cancer. Although IL-1 gene polymorphisms were reported to be associated with increased risk of breast cancer, their influence on survival of Caucasian breast cancer patients remains to be shown.

Methods

We studied the influence of four common gene polymorphisms (IL1A -889C/T, IL1B -511C/T, IL1B +3953E1/E2, and IL1RN long/2) of the IL-1 family on survival in 262 Caucasian patients with breast cancer by univariate and multivariate survival analysis. The combined effect of the four gene polymorphisms on overall survival was studied by haplotype analysis.

Results

In the present study 38 cases of cancer related death and a median time of follow-up (range) of 55.3 (0.4–175.8) months was observed. IL1RN 2/2 (homozygous mutant) gene polymorphism was associated with shortened disease free and overall survival in a univariate (p = 0.001 and p = 0.01, respectively) and multivariate analysis (p = 0.002, Odds Ratio [95% Confidence Interval] = 3.6 [1.6–8.0] and p = 0.05, Odds Ratio = 3.0 [1.1–9.3], respectively). Presence of the homozygous mutant genotype of the IL1A -889 and IL1B +3953 gene polymorphism was associated with overall survival in the univariate (p = 0.004 and p = 0.002, respectively), but not in the multivariate analysis. No association was observed between all possible haplotype combinations and overall survival.

Conclusion

Carriage of the mutant alleles of IL1RN was independently associated with shortened disease free and overall survival rates in Caucasian patients with breast cancer.

Characterization of Primary Breast Carcinomas Grown in Three-Dimensional Cultures

BACKGROUND

The process of progression and spread of cancer is not easily replicated in animal models and is difficult to examine in vitro. This is particularly true for human primary breast carcinoma cells, whose in vitro growth is shown to be limited to one or two passages in monolayer culture. Three-dimensional (3D) growth of breast cancer cells suggests that cell aggregates grown in this manner have many similarities to in vivo behavior.

MATERIALS AND METHODS

Primary tumors obtained from five breast cancer patients were grown in 3D cultures using the rotating-wall vessel bioreactor. Tumor aggregates were assessed for DNA ploidy, cell cycle kinetics, and expression of tumor markers and cytokines. Comparisons between fresh tumor cells and 3D aggregates were performed.

RESULTS

All five breast cancers were found to be aneuploid after 3D culture, with elevated S-phase fractions. Reverse transcription-polymerase chain reaction analyses revealed mRNA expression of HER2/neu, H-ras, K-ras, p53, transforming growth factor-alpha, transforming growth factor-beta, interleukin-1, and interleukin-6 in 3D-grown tumor cells; in most cases, expression appeared increased when compared with mRNA obtained from freshly isolated primary tumor cells.

CONCLUSIONS

After prolonged 3D growth in the rotating wall bioreactor, complex tissue-like constructs of primary breast tumor cells exhibited significantly increased proliferative activity in conjunction with oncogene activation and developed into aggressive aneuploid populations.

Activation of a nuclear factor kappaB/interleukin-1 positive feedback loop by amphiregulin in human breast cancer cells

We have recently shown that an amphiregulin-mediated autocrine loop is responsible for growth factor-independent proliferation, motility, and invasive capacity of some aggressive breast cancer cells, such as the SUM149 breast cancer cell line. In the present study, we investigated the mechanisms by which amphiregulin activation of the epidermal growth factor receptor (EGFR) regulates these altered phenotypes. Bioinformatic analysis of gene expression networks regulated by amphiregulin implicated interleukin-1alpha (IL-1alpha) and IL-1beta as key mediators of amphiregulin's biological effects. The bioinformatic data were validated in experiments which showed that amphiregulin, but not epidermal growth factor, results in transcriptional up-regulation of IL-1alpha and IL-1beta. Both IL-1alpha and IL-1beta are synthesized and secreted by SUM149 breast cancer cells, as well as MCF10A cells engineered to express amphiregulin or MCF10A cells cultured in the presence of amphiregulin. Furthermore, EGFR, activated by amphiregulin but not epidermal growth factor, results in the prompt activation of the transcription factor nuclear factor-kappaB (NF-kappaB), which is required for transcriptional activation of IL-1. Once synthesized and secreted from the cells, IL-1 further activates NF-kappaB, and inhibition of IL-1 with the IL-1 receptor antagonist results in loss of NF-kappaB DNA binding activity and inhibition of cell proliferation. However, SUM149 cells can proliferate in the presence of IL-1 when EGFR activity is inhibited. Thus, in aggressive breast cancer cells, such as the SUM149 cells, or in normal human mammary epithelial cells growing in the presence of amphiregulin, EGFR signaling is integrated with NF-kappaB activation and IL-1 synthesis, which cooperate to regulate the growth and invasive capacity of the cells.

Cancer cell-derived IL-1alpha induces IL-8 release in endothelial cells

PURPOSE

Cancer cells release a multitude of cytokines and growth factors that influence neighboring cells and help establish a favorable environment for tumor development. As part of our studies designed to elucidate the complex cellular interactions within the tumor microenvironment that facilitate tumor development, we investigated cancer cell-induced changes in gene expression in endothelial cells.

METHODS

After treatment of human umbilical vein endothelial cells (HUVEC) with conditioned medium (CM) of SNUC5 colon cancer cells, gene expression profile in HUVEC was analyzed using cDNA microarray. Neutralizing antibodies against pro-inflammatory cytokines were used to identify the major effecter in SNUC5 CM.

RESULTS

IL-8 was one of the four genes up-regulated over fourfold, and IL-1alpha in SNUC5 CM was revealed as a major effecter of IL-8 over-expression and release, which was nearly completely neutralized by anti-IL-1alpha antibody. Constitutive secretion of IL-1alpha was confirmed in many other human cancer cells.

CONCLUSIONS

IL-1alpha is constitutively expressed in many human cancer cells and directly induces IL-8 secretion in neighboring endothelial cells.

Interleukin-1alpha protein secretion in breast cancer is associated with poor differentiation and estrogen receptor alpha negativity

While interleukins (IL)-1alpha and beta are thought to play an important role in malignant disease, little is still known about their expression in breast cancer. We have used reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry (IHC) to analyze the expression of IL-1alpha and beta in breast cancer tissues, and compared their expression to estrogen receptor (ER) status and grading. In breast cancer cell lines, we found an inverse correlation between IL-1alpha and beta gene expression and differentiation, and only one highly invasive tumor cell line expressed IL-1alpha protein, while IL-beta was not detectable. Breast cancer tissue expressed variable amounts of IL-1alpha and beta messenger RNA, but consistently high levels of IL-1 type I receptor. IL-1alpha protein was detectable in malignant epithelium and adjacent stroma in 88% of cases. IL-1alpha expression was correlated with poor differentiation (P= 0.002; r= 0.469) and decreasing ERalpha expression (P= 0.004; r=-0.387). Stromal IL-1alpha was confined to areas with low or absent ERalpha protein expression in adjacent tumor epithelium (P= 0.001; r=-0.457). Taken together, we have demonstrated a functional IL-1 system in breast cancer and observed an inverse correlation between IL-1alpha and sex steroid receptor expression. We suggest that the expression of IL-1alpha in poorly differentiated, ERalpha-negative tumors contributes to their malignant phenotype.

The involvement of IL-1 in tumorigenesis, tumor invasiveness, metastasis and tumor-host interactions

Interleukin-1 (IL-1) includes a family of closely related genes; the two major agonistic proteins, IL-1alpha and IL-1beta, are pleiotropic and affect mainly inflammation, immunity and hemopoiesis. The IL-1Ra antagonist is a physiological inhibitor of pre-formed IL-1. Recombinant IL-1alpha and IL-1beta bind to the same receptors and induce the same biological functions. As such, the IL-1 molecules have been considered identical in normal homeostasis and in disease. However, the IL-1 molecules differ in their compartmentalization within the producing cell or the microenvironment. Thus, IL-1beta is solely active in its secreted form, whereas IL-1alpha is mainly active in cell-associated forms (intracellular precursor and membrane-bound IL-1alpha) and only rarely as a secreted cytokine, as it is secreted only in a limited manner. IL-1 is abundant at tumor sites, where it may affect the process of carcinogenesis, tumor growth and invasiveness and also the patterns of tumor-host interactions. Here, we review the effects of microenvironment- and tumor cell-derived IL-1 on malignant processes in experimental tumor models and in cancer patients. We propose that membrane-associated IL-1alpha expressed on malignant cells stimulates anti-tumor immunity, while secretable IL-1beta, derived from the microenvironment or the malignant cells, activates inflammation that promotes invasiveness and also induces tumor-mediated suppression. Inhibition of the function of IL-1 by the IL-1Ra, reduces tumor invasiveness and alleviates tumor-mediated suppression, pointing to its feasibility in cancer therapy. Differential manipulation of IL-1alpha and IL-1beta in malignant cells or in the tumor's microenvironment can open new avenues for using IL-1 in cancer therapy.

Interleukin-1 and cancer progression: the emerging role of interleukin-1 receptor antagonist as a novel therapeutic agent in cancer treatment

The tumor microenvironment consists of tumor, immune, stromal, and inflammatory cells which produce cytokines, growth factors, and adhesion molecules that promote tumor progression and metastasis. Of particular interest in this setting is interleukin-1 (IL-1), a pleiotropic cytokine with numerous roles in both physiological and pathological states. It is known to be up regulated in many tumor types and has been implicated as a factor in tumor progression via the expression of metastatic and angiogenic genes and growth factors. A number of studies have reported that high IL-1 concentrations within the tumor microenvironment are associated with a more virulent tumor phenotype. Solid tumors in which IL-1 has been shown to be up regulated include breast, colon, lung, head and neck cancers, and melanomas, and patients with IL-1 producing tumors have generally bad prognoses. The exact mechanisms by which IL-1 promotes tumor growth remain unclear, though the protein is believed to act via induction of pro-metastatic genes such as matrix metalloproteinases and through the stimulation of adjacent cells to produce angiogenic proteins and growth factors such as VEGF, IL-8, IL-6, TNFα, and TGFβ. The IL-1 receptor antagonist (IL-1ra) is a naturally occurring inhibitor to IL-1 and acts by binding to the IL-1 receptor without activating it. The protein has been shown to decrease tumor growth, angiogenesis, and metastases in murine xenograft models. Our focus in this review is to summarize the known data on the role of IL-1 in tumor progression and metastasis and the use of IL-1 inhibition as a novel therapeutic approach in the treatment of solid organ malignancies.

NF-kappaB represses E-cadherin expression and enhances epithelial to mesenchymal transition of mammary epithelial cells: potential involvement of ZEB-1 and ZEB-2

The transcription factor nuclear factor kappa B (NF-kappaB) is constitutively active in both cancer cells and stromal cells of breast cancer; however, the precise role of activated NF-kappaB in cancer progression is not known. Using parental MCF10A cells and a variant that expresses the myoepithelial marker p63 stably overexpressing the constitutively active p65 subunit of NF-kappaB (MCF10A/p65), we show that NF-kappaB suppresses the expression of epithelial specific genes E-cadherin and desmoplakin and induces the expression of the mesenchymal specific gene vimentin. P65 also suppressed the expression of p63 and the putative breast epithelial progenitor marker cytokeratin 5/6. MCF10A/p65 cells were phenotypically similar to cells undergoing epithelial to mesenchymal transition (EMT). MCF10A/p65 cells failed to form characteristic acini in three-dimensional Matrigel. Analysis of parental and MCF10A/p65 cells for genes previously shown to be involved in EMT revealed elevated expression of ZEB-1 and ZEB-2 in MCF10A/p65 cells compared to parental cells. In transient transfection assays, p65 increased ZEB-1 promoter activity. Furthermore, MCF10A cells overexpressing ZEB-1 showed reduced E-cadherin and p63 expression and displayed an EMT phenotype. The siRNA against ZEB-1 or ZEB-2 reduced the number of viable MCF10A/p65 but not parental cells, suggesting the dependence of MCF10A/p65 cells to ZEB-1 and ZEB-2 for cell cycle progression or survival. MCF10A cells chronically exposed to tumor necrosis factor alpha (TNFalpha), a potent NF-kappaB inducer, also exhibited the EMT-like phenotype and ZEB-1/ZEB-2 induction, both of which were reversed following TNFalpha withdrawal.

Interleukin gene polymorphisms and breast cancer: a case control study and systematic literature review

BACKGROUND

Interleukins and cytokines play an important role in the pathogenesis of many solid cancers. Several single nucleotide polymorphisms (SNPs) identified in cytokine genes are thought to influence the expression or function of these proteins and many have been evaluated for their role in inflammatory disease and cancer predisposition. The aim of this study was to evaluate any role of specific SNPs in the interleukin genes IL1A, IL1B, IL1RN, IL4R, IL6 and IL10 in predisposition to breast cancer susceptibility and severity.

METHODS

Candidate single nucleotide polymorphisms (SNPs) in key cytokine genes were genotyped in breast cancer patients and in appropriate healthy volunteers who were similar in age, race and sex. Genotyping was performed using a high throughput allelic discrimination method. Data on clinico-pathological details and survival were collected. A systematic review of Medline English literature was done to retrieve previous studies of these polymorphisms in breast cancer.

RESULTS

None of the polymorphisms studied showed any overall predisposition to breast cancer susceptibility, severity or to time to death or occurrence of distant metastases. The results of the systematic review are summarised.

CONCLUSION

Polymorphisms within key interleukin genes (IL1A, IL1B, IL1RN, IL4R, IL6 and IL10 do not appear to play a significant overall role in breast cancer susceptibility or severity.

Endometriosis as a model for inflammation–hormone interactions in ovarian and breast cancers

Chronic inflammation has been implicated in a variety of cancers. In this review, we consider associations between endometriosis and cancers both local (ovarian) and distant (breast). We review the epidemiological data linking endometriosis to ovarian and breast cancers. We then consider evidence for a role for sex steroid hormones and for inflammation in the aetiology of each of these cancers. Finally, we consider that endometriosis may promote alterations in sex steroid hormones and inflammatory mediators. A possible explanation for the association between endometriosis and these reproductive cancers may then be local and systemic enhancement of aberrant inflammatory and hormonal mediators. If this hypothesis is true, endometriosis may need to be considered as a risk factor for ovarian and breast cancers, triggering increasingly intensive surveillance. Moreover, treatments for endometriosis may require consideration of the impact on long-term cancer risk.

Gene Expression Profiling Reveals Cross-talk between Melanoma and Fibroblasts: Implications for Host-Tumor Interactions in Metastasis

Host-tumor interaction is considered critical in carcinogenesis, tumor invasion, and metastasis. To explore the reciprocal effects of host-tumor interaction, we developed a system to assess the gene expression patterns of A2058 human melanoma cells cocultured in fibrillar collagen with HS-68 primary human fibroblasts. The gene expression pattern of the cocultured A2058 cells was only modestly affected, whereas the HS-68 fibroblast gene expression pattern was significantly altered. Interleukin-11 and inhibitor of DNA-binding domain-1 gene expression in the cocultured A2058 cells was down-regulated, indicative of a proinflammatory response and resistance to apoptosis, respectively. The overall pattern of up-regulated genes indicated triggering of the proinflammatory process. In addition, the melanoma growth and migration stimulatory chemokines CXCL1 and CXCL2 were significantly up-regulated in the cocultured fibroblasts. These results were corroborated by additional coculture experiments with the melanoma cell lines WM-164, BLM, and SK-Mel-28 and immunohistochemistry on invasive human melanoma sections. Taken together, these results indicate that tumor cells cause a proinflammatory and melanoma growth-promoting response in stromal fibroblasts. The role of inflammation in carcinogenesis, tumor promotion, invasion, and metastasis is viewed as being increasingly important and the results of these studies underscore this as well as identify certain key proteins that are expressed as a result of the complex interactive processes in the host-tumor microenvironment.

IL-1beta induces stabilization of IL-8 mRNA in malignant breast cancer cells via the 3' untranslated region: Involvement of divergent RNA-binding factors HuR, KSRP and TIAR

IL-8 plays an integral role in promoting the malignant phenotype in breast cancer, and its production is directly influenced by inflammatory cytokines in the tumor microenvironment. Here, we show that activation of IL-1beta receptors on malignant HS578t and MDA-MB-231 breast cancer cells strongly induces IL-8 expression and that RNA stabilization is persistently activated at least 12-24 hr after stimulation. SB 203580 and rapamycin reversed the RNA stabilization effect of IL-1beta in a dose-dependent manner, suggesting involvement of the p38/MAP kinase and mTOR pathways. A luciferase reporter assay indicated that the stabilization effect was dependent on cis elements in the 3'-untranslated region (UTR) of the IL-8 transcript. By UV cross-linking, we identified multiple cellular factors that interact with the IL-8 3'UTR, ranging 34-76 kDa. Immunoprecipitation analysis indicated that HuR, KSRP and TIAR bound to one or more loci in the 3'UTR. While the cross-linking patterns were similar, quantitative immunoprecipitation of native IL-8 RNA from IL-1beta-stimulated cytoplasmic extract revealed a 20-fold greater association of transcript with the stabilizing factor HuR vs. the destabilizing factor KSRP. In conclusion, IL-1beta is a potent cytokine stimulus for IL-8 RNA stabilization in breast cancer cells, possibly by enhanced binding of cytoplasmic HuR to the 3'UTR.

Antitumor agent parthenolide reverses resistance of breast cancer cells to tumor necrosis factor-related apoptosis-inducing ligand through sustained activation of c-Jun N-terminal kinase

The antitumor activity of the sesquiterpene lactone parthenolide, an active ingredient of medicinal plants, is believed to be due to the inhibition of DNA binding of transcription factors NF-kappaB and STAT-3, reduction in MAP kinase activity and the generation of reactive oxygen. In this report, we show that parthenolide activates c-Jun N-terminal kinase (JNK), which is independent of inhibition of NF-kappaB DNA binding and generation of reactive oxygen species. Parthenolide reversed resistance of breast cancer cells to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. Cancer cells treated with a combination of TRAIL and parthenolide underwent massive typical apoptosis and atypical apoptosis involving the loss of plasma membrane integrity. JNK activity is necessary for the parthenolide-induced sensitization to TRAIL because a dominant-negative JNK or the JNK inhibitor SP600125 reduced TRAIL plus parthenolide-induced apoptosis. Parthenolide induced phosphorylation of Bid and increased TRAIL-dependent cleavage of Bid without affecting caspase 8 activities. Cytochrome c but not Smac/DIABLO was released from the mitochondria in cells treated with parthenolide alone. Parthenolide through JNK increased the TRAIL-mediated degradation of the antiapoptotic protein X-linked inhibitor of apoptosis (XIAP). Enhanced XIAP cleavage correlated with increased and prolonged caspase 3 activity and PARP cleavage, suggesting that the sensitization to TRAIL involves 'feed forward' activation of caspase 3. These results identify a new antitumor activity of parthenolide, which can be exploited to reverse resistance of cancer cells to TRAIL, particularly those with elevated XIAP levels.

Expression profiling of small cellular samples in cancer: less is more

Expression profiling of tumours from cancer patients has uncovered several genes that are critically important in the progression of a normal cell to an oncogenic phenotype. Leading the way in these discoveries is the use of microarrays, a technology that is currently in transition from basic science applications to use in the clinic. Microarrays can determine the global gene regulation of an individual cancer, which may be useful in formulating an individualised therapy for the patient. Currently, cells used in breast cancer microarray studies often come from either homogenous cultures or heterogeneous biopsy samples. Both cell sources are at a disadvantage in determining the most accurate gene profile of cancer, which often consists of multiple subspecies of cancerous cells within a background of normal cells. Therefore, acquisition of small, but highly specific biopsies for analysis may be required for an accurate expression analysis of the disease. Amplification methods, such as polymerase chain reaction (PCR) and amplified antisense RNA (aRNA) amplification, have been used to amplify the mRNA signal from very small samples, which can then be used for microarray analysis. In this study, we describe the acquisition, amplification, and analysis of very small samples (<10000 cells) for expression analysis and demonstrate that the ultimate resolution of cancer expression analysis, one cell, is both feasible and practical.

Inhibition of Breast Cancer Regrowth and Pulmonary Metastasis in Nude Mice by Anti-gastric Ulcer Agent, Irsogladine

Irsogladine is a commonly used anti-gastric ulcer agent in Japan, and recent in vivo studies have shown it to have anti-angiogenic properties. The exact role of irsogladine as an inhibitor of angiogenesis remains uncertain. In this study, we show that irsogladine inhibited breast cancer regrowth and pulmonary metastasis but had no anti-angiogenic function against HUVEC cells. Irsogladine failed to inhibit proliferation, tubular formation, and the uPA/MMP-1 mRNA expression of HUVEC cells. We also examined the effect of irsogladine in an orthotopic transplant model of human breast cancer metastasis in athymic mice. Human MDA-MB-435 cells were injected into the mammary fat pads. After 9 weeks, the tumors were resected under general anesthesia. Irsogladine or vehicle was given p.o. daily thereafter. Daily administration of irsogladine at 120 mg/kg per day over a 5-week period had no effect on the body weight of the mice. Tumor regrowth, average volume of pulmonary metastases, and the number of metastases were inhibited by 40, 48 and 64%, respectively. These results suggest that irsogladine may be useful in the breast cancer adjuvant setting.

Interleukin-1 alpha promotes tumor growth and cachexia in MCF-7 xenograft model of breast cancer

Progression of breast cancer involves cross-talk between epithelial and stromal cells. This cross-talk is mediated by growth factors and cytokines secreted by both cancer and stromal cells. We previously reported expression of interleukin (IL)-1 alpha in a subset of breast cancers and demonstrated that IL-1 alpha is an autocrine and paracrine inducer of prometastatic genes in in vitro systems. To understand the role of IL-1 alpha in breast cancer progression in vivo, we studied the growth of MCF-7 breast cancer cells overexpressing a secreted form of IL-1 alpha (MCF-7IL-1 alpha) in nude mice. MCF-7IL-1 alpha cells formed rapidly growing estrogen-dependent tumors compared to parental cells. Interestingly, IL-1 alpha expression alone was not sufficient for metastasis in vivo although in vitro studies showed induction of several prometastatic genes and matrix metalloproteinase activity in response to cross-talk between IL-1 alpha-expressing cancer cells and fibroblasts. Animals implanted with MCF-7IL-1 alpha cells were cachetic, which correlated with increased leptin serum levels but not other known cachexia-inducing cytokines such as IL-6, tumor necrosis factor, or interferon gamma. Serum triglycerides, but not blood glucose were lower in animals with MCF-7IL-1 alpha cell-derived tumors compared to animals with control cell-derived tumors. Cachexia was associated with atrophy of epidermal and adnexal structures of skin; a similar phenotype is reported in triglyceride-deficient mice and in ob/ob mice injected with leptin. Mouse leptin-specific transcripts could be detected only in MCF-7IL-1 alpha cell-derived tumors, which suggests that IL-1 alpha increases leptin expression in stromal cells recruited into the tumor microenvironment. Despite increased serum leptin levels, animals with MCF-7IL-1 alpha cell-derived tumors were not anorexic suggesting only peripheral action of tumor-derived leptin, which principally targets lipid metabolism. Taken together, these results suggest that cancer cell-derived cytokines, such as IL-1 alpha, induce cachexia by affecting leptin-dependent metabolic pathways.

The fibroblast: sentinel cell and local immune modulator in tumor tissue

Development and progression of epithelial malignancies are frequently accompanied by complex phenotypic alterations of resident tissue fibroblasts. Some of these changes, such as myofibroblastic differentiation and an oncofetal extracellular matrix (ECM) expression profile, are also implicated in inflammation and tissue repair. Studies over the past decade revealed the relevance of reciprocal interactions between tumor cells and tumor-associated host fibroblasts (TAF) in the malignant process. In many tumors, a considerable fraction of the inflammatory infiltrate is located within the fibroblast- and ECM-rich stromal compartment. However, while fibroblasts are known as "sentinel cells" in various nonneoplastic diseases, where they often regulate the composition and function of recruited leucocytes, they are hardly considered active participants in the inflammatory host response in tumors. This article focuses on the functional impact of TAF on immune cells. The complex network of immune-modulating effects transduced by TAF and TAF-derived factors is highlighted, and recent reports that support the hypothesis that TAF are involved in the inflammatory response and immune suppression in tumors are reviewed. The role of TAF-dependent ECM remodeling and TAF-derived peptide growth factors, cytokines, and chemokines in the immune modulation is stressed and the idea of TAF as an important therapeutic target is emphasized.

Nuclear factor-κB as a predictor of treatment response in breast cancer

PURPOSE OF REVIEW

To examine the links of nuclear factor-kappa B (NF-kappa B) to treatment-induced signaling in breast cancer and to propose further studies to elucidate the role of NF-kappa B in breast cancer response to chemotherapy and radiation.

RECENT FINDINGS

The authors' group and others have investigated the clinical relevance of ubiquitously expressed NF-kappa B in breast cancer. Possibly through its effects on apoptosis, NF-kappa B has been implicated in tumor resistance to chemotherapy and radiation in many types of tumors. Furthermore, both in vitro and in vivo studies have shown that targeted inhibition of NF-kappa B can sensitize tumor cells to chemotherapy and radiation.

SUMMARY

The molecular mechanisms involved in chemotherapy-induced and radiation-induced cell death in breast cancer are not fully known, nor are the mechanisms of treatment resistance. NF-kappa B is a transcription factor for a number of genes involved in tumor progression and resistance to systemic therapies and is a major regulator of the apoptotic pathway. Gaining further insights into molecular factors such as NF-kappa B as biomarkers for treatment response may help clinicians predict treatment outcome and lead to the development of targeted therapeutics.

Tumor necrosis factor-alpha induces interleukin-6 production via extracellular-regulated kinase 1 activation in breast cancer cells

Interleukin-6 (IL-6) and interleukin-11 (IL-11) are frequently produced by breast cancer cells. These interleukins promote osteoclast formation and may mediate osteolysis at the site of breast cancer bone metastases. Transforming growth factor-beta (TGF-beta), tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) up-regulate IL-6 and IL-11 production in a cytokine-dependent fashion in breast cancer cells, but very little is known about their intracellular signaling pathways in breast cancer cells. To study TGF-beta, TNF-alpha and IL-1beta regulation of IL-6 and IL-11 production in human MDA-MB-231 breast cancer cells, we established single cell clones stably expressing dominant negative (DN) forms of the mitogen-activated protein kinases p38 (p38/AF) or ERK1 (ERK1K71R). We show here, that while basal, TGF-beta and IL-1beta induced IL-6 production was similar in parental cells and in pcDNA3 control, ERK1K71R and p38/AF clones, TNF-alpha induced IL-6 production was blunted in the ERK1K71R clones. TGF-beta and IL-1beta, but not TNF-alpha, induced IL-11 production in parental MDA-MB-231 cells. Similar findings were detected in clones stably expressing p38/AF and ERK1K71R, which did not change basal IL-11 production either. In conclusion, TNF-alpha induced IL-6 production is mediated via ERK1 activation in MDA-MB-231 cells. These observations may be helpful in designing new anti-osteolytic therapies.

NF-kappaB promotes breast cancer cell migration and metastasis by inducing the expression of the chemokine receptor CXCR4

Metastasis of cancer cells is a complex process involving multiple steps including invasion, angiogenesis, and trafficking of cancer cells through blood vessels, extravasations, organ-specific homing, and growth. While matrix metalloproteinases, urokinase-type plasminogen activator, and cytokines play a major role in invasion and angiogenesis, chemokines such as stromal derived factor-1alpha (SDF-1alpha) and their receptors such as CXCR4 are thought to play a critical role in motility, homing, and proliferation of cancer cells at specific metastatic sites. We and others have previously reported that the extracellular signal-activated transcription factor NF-kappaB up-regulates the expression of matrix metalloproteinases, urokinase-type plasminogen activator, and cytokines in highly metastatic breast cancer cell lines. In this report, we demonstrate that NF-kappaB regulates the motility of breast cancer cells by directly up-regulating the expression of CXCR4. Overexpression of the inhibitor of kappaB (IkappaB) in breast cancer cells with constitutive NF-kappaB activity resulted in reduced expression of CXCR4 and a corresponding loss of SDF-1alpha-mediated migration in vitro. Introduction of CXCR4 cDNA into IkappaB-expressing cells restored SDF-1alpha-mediated migration. Electrophoretic mobility shift assays and transient transfection assays revealed that the NF-kappaB subunits p65 and p50 bind directly to sequences within the -66 to +7 region of the CXCR4 promoter and activate transcription. We also show that the cell surface expression of CXCR4 and the SDF-1alpha-mediated migration are enhanced in breast cancer cells isolated from mammary fat pad xenografts compared with parental cells grown in culture. A further increase in CXCR4 cell surface expression and SDF-1alpha-mediated migration was observed with cancer cells that metastasized to the lungs. Taken together, these results implicate NF-kappaB in the migration and the organ-specific homing of metastatic breast cancer cells.

IL-1 is required for tumor invasiveness and angiogenesis

Here, we describe that microenvironmental IL-1 beta and, to a lesser extent, IL-1 alpha are required for in vivo angiogenesis and invasiveness of different tumor cells. In IL-1 beta knockout (KO) mice, local tumor or lung metastases of B16 melanoma cells were not observed compared with WT mice. Angiogenesis was assessed by the recruitment of blood vessel networks into Matrigel plugs containing B16 melanoma cells; vascularization of the plugs was present in WT mice, but was absent in IL-1 beta KO mice. The addition of exogenous IL-1 into B16-containing Matrigel plugs in IL-1 beta KO mice partially restored the angiogenic response. Moreover, the incorporation of IL-1 receptor antagonist to B16-containing plugs in WT mice inhibited the ingrowth of blood vessel networks into Matrigel plugs. In IL-1 alpha KO mice, local tumor development and induction of an angiogenic response in Matrigel plugs was less pronounced than in WT mice, but significantly higher than in IL-1 beta KO mice. These effects of host-derived IL-1 alpha and IL-1 beta were not restricted to the melanoma model, but were also observed in DA/3 mammary and prostate cancer cell models. In addition to the in vivo findings, IL-1 contributed to the production of vascular endothelial cell growth factor and tumor necrosis factor in cocultures of peritoneal macrophages and tumor cells. Host-derived IL-1 seems to control tumor angiogenesis and invasiveness. Furthermore, the anti-angiogenic effects of IL-1 receptor antagonist, shown here, suggest a possible therapeutic role in cancer, in addition to its current use in rheumatoid arthritis.

Interleukin-1--a major pleiotropic cytokine in tumor-host interactions

Interleukin-1 (IL-1) represents a family of two agonistic proteins, IL-1alpha and IL-1beta, that are pleiotropic and affect hemopoiesis, inflammation, and immunity. In the context of the producing cell, IL-1beta is solely active in its secreted form, whereas IL-1alpha is active as an intracellular precursor, as a membrane-associated cytokine and to a lesser extent as a secreted molecule. IL-1 is abundant at tumor sites, where it may not only affect the growth and invasiveness of malignant cells, but where it may also induce antitumor immunity. Here we review the effects of microenvironmental and tumor cell-associated IL-1 on malignant processes, in experimental tumor models and in cancer patients.

Possible co-regulation of genes associated with enhanced progression of mammary adenocarcinomas

Tumor progression is a multistep process in which alterations in the expression of numerous gene products may give rise to highly malignant cellular variants. In the present study, we analyzed the differential expression of several genes in cellular variants of mammary adenocarcinomas with high or low malignancy potential, which originated in a common ancestor. To assess the generality of our findings, high and low malignancy variants were derived from two different mammary adenocarcinoma cell lines, namely DA3 and CSML cells. Of major importance is the fact that the differences between high- and low-malignancy variants observed in one system of mammary adenocarcinoma cells (DA3 cells) were identically reproduced in the other system of mammary adenocarcinoma cells (CSML cells). The high malignancy variants of tumors both DA3-high and CSML-high (previously called CSML-100), expressed higher levels of factors that induce monocyte migration than the low malignancy DA3-low and CSML-low (previously called CSML-0) variants. In addition, it was found that DA3-high and CSML-high cell variants expressed higher levels of monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6) and matrix metalloproteinases (MMPs) than the low malignancy variants (DA3-low and CSML-low). These results suggest that MCP-1, IL-6 and MMPs potentially contribute to mammary adenocarcinoma progression and that their expression is regulated by a common pathway. The expression of MCP-1, IL-6 and MMPs in both DA3-high and CSML-high cells was up-regulated by tumor necrosis factor alpha (TNFalpha). The fact that TNFalpha exerted similar effects on the expression of these three factors in both cell systems raises the possibility of a coordinated co-regulation of tumor-promoting factors.