Expression of interleukin 6 (IL-6) correlates with oestrogen receptor in human breast carcinoma

Establishing conditions for the generation and maintenance of estrogen receptor-positive organoid models of breast cancer

Patient-derived organoid models of estrogen receptor-positive (ER+) breast cancer would provide a much-needed tool to understand drug resistance and disease progression better. However, the establishment and long-term maintenance of ER expression, function, and response in vitro remains a significant challenge. Here, we report the development of an ER+ breast tumor organoid medium (BTOM-ER) that conserves ER expression, estrogen responsiveness, and dependence, as well as sensitivity to endocrine therapy of ER+ patient-derived xenograft organoids (PDXO). Our findings demonstrate the utility of subtype-specific culture conditions that better mimic the characteristics of the breast epithelial biology and microenvironment, providing a powerful platform for investigating therapy response and disease progression of ER+ breast cancer.

DNA methylation and gene expression changes in mouse mammary tissue during successive lactations: part I - the impact of inflammation

Mastitis is among the main reasons women cease breastfeeding, which leads to them supplementing breast milk with artificial formula. In farm animals, mastitis results in significant economic losses and the premature culling of some animals. Nevertheless, researchers do not know enough about the effect of inflammation on the mammary gland. This article discusses the changes to DNA methylation in mouse mammary tissue caused by lipopolysaccharide-induced inflammation (4 h post-injection of lipopolysaccharide). We analysed the expression of some genes related to mammary gland function, epigenetic regulation, and the immune response. The analysis focused on three comparisons: inflammation during the first lactation, inflammation during second lactation with no history of inflammation, and inflammation during second lactation with previous inflammation. We identified differentially methylated cytosines (DMCs), differentially methylated regions (DMRs), and some differentially expressed genes (DEGs) for each comparison. The three comparisons shared some DEGs; however, few DMCs and only one DMR were shared. These observations suggest that inflammation is one of several factors affecting epigenetic regulation during successive lactations. Furthermore, the comparison between animals in second lactation with and without inflammation, with no inflammation history during first lactation showed a different pattern compared to the other conditions in this experiment. This indicates that inflammation history plays an important role in determining epigenetic changes. The data presented in this study suggest that lactation rank and previous inflammation history are equally important when explaining mammary tissue gene expression and DNA methylation changes.Abbreviations: RRBS, reduced representation bisulfite sequencing; RT-qPCR, real-time quantitative polymerase chain reaction; MEC, mammary epithelial cells; TSS, transcription start site; TTS, transcription termination site; UTR, untranslated region; SINE, short interspersed nuclear element; LINE, long interspersed nuclear element; CGI, CpG island; DEG, differentially expressed gene; DMC, differentially methylated cytosine; DMR, differentially methylated region; GO term, gene ontology term; MF, molecular function; BP, biological process.

Establishing conditions for the generation and maintenance of estrogen receptor-positive organoid models of breast cancer

Patient-derived organoid models of estrogen receptor-positive (ER+) breast cancer would provide a much-needed tool to understand drug resistance and disease progression better. However, the establishment and long-term maintenance of ER expression, function, and response in vitro remains a significant challenge. Here, we report the development of an ER+ breast tumor organoid medium (BTOM-ER) that conserves ER expression, estrogen responsiveness, and dependence, as well as sensitivity to endocrine therapy of ER+ patient-derived xenograft organoids (PDXO). Our findings demonstrate the utility of subtype-specific culture conditions that better mimic the characteristics of the breast epithelial biology and microenvironment, providing a powerful platform for investigating therapy response and disease progression of ER+ breast cancer.

Fusobacterium nucleatum: a novel immune modulator in breast cancer?

Breast cancer was the most commonly diagnosed cancer worldwide in 2020. Greater understanding of the factors which promote tumour progression, metastatic development and therapeutic resistance is needed. In recent years, a distinct microbiome has been detected in the breast, a site previously thought to be sterile. Here, we review the clinical and molecular relevance of the oral anaerobic bacterium Fusobacterium nucleatum in breast cancer. F. nucleatum is enriched in breast tumour tissue compared with matched healthy tissue and has been shown to promote mammary tumour growth and metastatic progression in mouse models. Current literature suggests that F. nucleatum modulates immune escape and inflammation within the tissue microenvironment, two well-defined hallmarks of cancer. Furthermore, the microbiome, and F. nucleatum specifically, has been shown to affect patient response to therapy including immune checkpoint inhibitors. These findings highlight areas of future research needed to better understand the influence of F. nucleatum in the development and treatment of breast cancer.

Variation in IL6ST cytokine family function and the potential of IL6 trans-signalling in ERα positive breast cancer cells

High expression of the transmembrane receptor IL6ST (gp130) has been identified as a predictive biomarker of endocrine treatment response in ERα-positive breast cancers. To investigate its function further in this disease, this study evaluated the expression, function and signalling of IL6ST in ERα-positive breast cancer cell lines and investigated crosstalk between ERα and IL6ST. IL6ST was differentially expressed in ERα-positive breast cancer cell lines (low in MCF-7, high in ZR751 and T47D), while multiple soluble isoforms of IL6ST were identified. IL6ST is the common signal transducing receptor component for the IL6ST family of cytokines and the effects of seven IL6ST cytokines on these cell lines were studied. These cytokines caused differential growth and migration effects in these cell lines e.g. MCF-7 cells were growth-stimulated, while ZR751 cells were inhibited by IL6 and OSM.. Activation of the STAT and ERK pathways is associated with these responses. Evidence to support trans-signalling involved in cell growth and migration was obtained in both MCF-7 and ZR751 models. Interaction between cytokines and estrogen on ERα-positive cell lines growth were analysed. High expression of IL6ST (in ZR751) may lead to growth inhibition by interacting cytokines while lower expression (in MCF-7) appears associated with proliferation. High IL6ST expression is consistent with a more beneficial clinical outcome if cytokine action contributes to anti-estrogen action.

The IL6-like Cytokine Family: Role and Biomarker Potential in Breast Cancer

IL6-like cytokines are a family of regulators with a complex, pleiotropic role in both the healthy organism, where they regulate immunity and homeostasis, and in different diseases, including cancer. Here we summarise how these cytokines exert their effect through the shared signal transducer IL6ST (gp130) and we review the extensive evidence on the role that different members of this family play in breast cancer. Additionally, we discuss how the different cytokines, their related receptors and downstream effectors, as well as specific polymorphisms in these molecules, can serve as predictive or prognostic biomarkers with the potential for clinical application in breast cancer. Lastly, we also discuss how our increasing understanding of this complex signalling axis presents promising opportunities for the development or repurposing of therapeutic strategies against cancer and, specifically, breast neoplasms.

A roadmap to target interleukin-6 in osteoarthritis

Joint inflammation is present in the majority of OA patients and pro-inflammatory mediators, such as IL-6, are actively involved in disease progression. Increased levels of IL-6 in serum or synovial fluid from OA patients correlate with disease incidence and severity, with IL-6 playing a pivotal role in the development of cartilage pathology, e.g. via induction of matrix-degrading enzymes. However, IL-6 also increases expression of anti-catabolic factors, suggesting a protective role. Until now, this dual role of IL-6 is incompletely understood and may be caused by differential effects of IL-6 classic vs trans-signalling. Here, we review current evidence regarding the role of IL-6 classic- and trans-signalling in local joint pathology of cartilage, synovium and bone. Furthermore, we discuss targeting of IL-6 in experimental OA models and provide future perspective for OA treatment by evaluating currently available IL-6 targeting strategies.

Prognostic impact of interleukin-6 and C-reactive protein on patients with breast cancer

The prognostic impacts of preoperative C-reactive protein (CRP) and interleukin (IL)-6 expression levels in patients with breast cancer remain controversial. A total of 55 female patients with invasive breast cancer were enrolled, and preoperative prognostic parameters including IL-6 and CRP were analyzed. Overall survival (OS) and recurrence-free survival (RFS) were estimated using the Kaplan-Meier method, and candidates' prognostic factors were examined using a Cox proportional hazard model. Using receiver operating characteristic curve analysis, IL-6 at 10.0 pg/ml and CRP at 0.12 mg/dl were determined as threshold values to predict OS and RFS, respectively. Patients with IL-6 ≥10.0 pg/ml had poorer OS compared with those with IL-6 <10.0 pg/ml (P=0.003), and patients with CRP ≥0.12 mg/dl had poorer RFS compared with those with CRP <0.12 mg/dl (P<0.001). Serum IL-6 level (hazard ratio, 13.230; 95% confidence interval, 1.285-136.214; P=0.030) and triple-negative subtype (hazard ratio, 11.739; 95% confidence interval, 1.415-97.362; P=0.023) were independent prognostic factors for OS, and CRP expression level was an independent prognostic factor for RFS in patients with breast cancer (hazard ratio, 18.571; 95% confidence interval, 2.240-153.949; P=0.007). In patients with invasive breast cancer, preoperative serum IL-6 and triple-negative subtype may be independent prognostic factors for OS, while for RFS, preoperative CRP may be a more accurate prognostic factor compared with those currently established.

Simulation Study of cDNA Dataset to Investigate Possible Association of Differentially Expressed Genes of Human THP1-Monocytic Cells in Cancer Progression Affected by Bacterial Shiga Toxins

Shiga toxin (Stxs) is a family of structurally and functionally related bacterial cytotoxins produced by Shigella dysenteriae serotype 1 and shigatoxigenic group of Escherichia coli that cause shigellosis and hemorrhagic colitis, respectively. Until recently, it has been thought that Stxs only inhibits the protein synthesis and induces expression to a limited number of genes in host cells, but recent data showed that Stxs can trigger several signaling pathways in mammalian cells and activate cell cycle and apoptosis. To explore the changes in gene expression induced by Stxs that have been shown in other systems to correlate with cancer progression, we performed the simulated analysis of cDNA dataset and found differentially expressed genes (DEGs) of human THP1-monocytic cells treated with Stxs. In this study, the entire data (treated and untreated replicates) was analyzed by statistical algorithms implemented in Bioconductor packages. The output data was validated by the k-fold cross technique using generalized linear Gaussian models. A total of 50 DEGs were identified. 7 genes including TSLP, IL6, GBP1, CD274, TNFSF13B, OASL, and PNPLA3 were considerably (<0.00005) related to cancer proliferation. The functional enrichment analysis showed 6 down-regulated and 1 up-regulated genes. Among these DEGs, IL6 was associated with several cancers, especially with leukemia, lymphoma, lungs, liver and breast cancers. The predicted regulatory motifs of these genes include conserved RELA, STATI, IRFI, NF-kappaB, PEND, HLF, REL, CEBPA, DI_2, and NFKB1 transcription factor binding sites (TFBS) involved in the complex biological functions. Thus, our findings suggest that Stxs has the potential as a valuable tool for better understanding of treatment strategies for several cancers.

IL-6 and IL-10 are associated with good prognosis in early stage invasive breast cancer patients

Macrophage-associated cytokines play an important role in cancer metastasis; however, the functions of interleukins (IL) 6 and 10 in breast cancer (BC) progression and metastasis are not clear. In this study the roles of IL-6/IL-10 in regulating vascular invasion and their prognostic significance in BC are investigated. MDA-MB-231 and MCF-7 migration (± IL-6 or IL-10) was assessed by scratch wound assay. Cancer cell adhesion to IL-6/IL-10 stimulated blood and lymphatic endothelial cells (EC) was investigated. Expression of IL-6 /IL-10 was assessed using immunohistochemistry in an annotated cohort of early stage BC (n = 1380) and associations with clinicopathological variables and clinical outcome evaluated. IL-6 did not alter BC cell migration however a dose-dependent inhibition in MDA-MB-231 migration with IL-10 treatment was observed (P = 0.03). BC cells were more adhesive to blood vs lymphatic EC, however, IL-6/IL-10 had no effect on adhesion patterns. High expression of IL-6/IL-10 was associated with clinicopathological criteria (e.g. hormone receptor status, all P < 0.05), improved disease-free survival (DFS; P < 0.05) and improved BC-specific survival (BCSS; only IL-6, P = 0.017). However, neither IL-6 nor IL-10 expression were independent prognostic factors from multivariate analysis. In BC subgroups, IL-6 and IL-10 were good prognosticators in terms of DFS in non-basal, non-triple-negative (non-TN), ER-positive, PgR-positive (only IL-10), and Her-2-negative (only IL-6) BC (all P < 0.05). IL-6 was associated with improved BCSS in non-basal, ER-positive and non-TN BC (all P < 0.05).

The Impact of Adenomyosis on Women's Fertility

Until recently, adenomyosis has been associated with multiparity, not impaired fertility. Currently, adenomyosis is diagnosed with increasing frequency in infertile patients since women delay their first pregnancy until their late 30s or early 40s. Although an association between adenomyosis and infertility has not been fully established, based on the available information, recent studies suggested that adenomyosis has a negative impact on female fertility. Several uncontrolled studies with limited data also suggested that treatment of adenomyosis may improve fertility. This article discusses (i) the hypothesis and epidemiology of adenomyosis, (ii) diagnostic techniques, (iii) clinical evidence of correlation between adenomyosis and infertility, (iv) proposed mechanism of infertility in women with adenomyosis, (v) different treatment strategies and reproductive outcomes, and (vi) assisted reproductive technology outcome in women with adenomyosis.

What Is Breast in the Bone?

The normal developmental program that prolactin generates in the mammary gland is usurped in the cancerous process and can be used out of its normal cellular context at a site of secondary metastasis. Prolactin is a pleiotropic peptide hormone and cytokine that is secreted from the pituitary gland, as well as from normal and cancerous breast cells. Experimental and epidemiologic data suggest that prolactin is associated with mammary gland development, and also the increased risk of breast tumors and metastatic disease in postmenopausal women. Breast cancer spreads to the bone in approximately 70% of cases with advanced breast cancer. Despite treatment, new bone metastases will still occur in 30%–50% of patients. Only 20% of patients with bone metastases survive five years after the diagnosis of bone metastasis. The breast cancer cells in the bone microenvironment release soluble factors that engage osteoclasts and/or osteoblasts and result in bone breakdown. The breakdown of the bone matrix, in turn, enhances the proliferation of the cancer cells, creating a vicious cycle. Recently, it was shown that prolactin accelerated the breast cancer cell-mediated osteoclast differentiation and bone breakdown by the regulation of breast cancer-secreted proteins. Interestingly, prolactin has the potential to affect multiple proteins that are involved in both breast development and likely bone metastasis, as well. Prolactin has normal bone homeostatic roles and, combined with the natural “recycling” of proteins in different tissues that can be used for breast development and function, or in bone function, increases the impact of prolactin signaling in breast cancer bone metastases. Thus, this review will focus on the role of prolactin in breast development, bone homeostasis and in breast cancer to bone metastases, covering the molecular aspects of the vicious cycle.

Interleukin-6 as a Prognostic Marker for Breast Cancer: A Meta-analysis

Aims and background

Interleukin-6 (IL-6) has been shown to promote tumor survival, metastasis, and angiogenesis, in addition to possessing antitumor activities. In light of the conflicting data, we sought to determine whether IL-6 could be used as a prognostic factor for patients with breast cancer.

Methods

Eligible studies describing the use of IL-6 as a prognostic factor for breast cancer were identified. Data describing overall survival (OS), disease-free survival (DFS), and clinicopathologic features were collected and analyzed.

Results

Thirteen articles containing 3,224 breast cancer patients were identified. The results showed that IL-6 expression was not associated with lymph node metastasis, tumor size, or histologic grade. Moreover, there was no correlation between IL-6 expression and DFS. However, the combined hazard ratio (95% confidence interval) for OS was 2.15 (1.46, 3.17). Sensitivity analysis further demonstrated that, for OS, the results of this meta-analysis were stable. A subgroup analysis showed that the source used to detect IL-6 levels may have altered the pooled results for OS.

Conclusions

Taken together, these results indicate that IL-6 expression is associated with poor prognosis for breast cancer and the prognostic role is affected by the source used to detect IL-6 levels.

Estrogen receptor, progesterone receptor, interleukin-6 and interleukin-8 are variable in breast cancer and benign stem/progenitor cell populations

Background

Estrogen receptor positive breast cancers have high recurrence rates despite tamoxifen therapy. Breast cancer stem/progenitor cells (BCSCs) initiate tumors, but expression of estrogen (ER) or progesterone receptors (PR) and response to tamoxifen is unknown. Interleukin-6 (IL-6) and interleukin-8 (IL-8) may influence tumor response to therapy but expression in BCSCs is also unknown.

Methods

BCSCs were isolated from breast cancer and benign surgical specimens based on CD49f/CD24 markers. CD44 was measured. Gene and protein expression of ER alpha, ER beta, PR, IL-6 and IL-8 were measured by proximity ligation assay and qRT-PCR.

Results

Gene expression was highly variable between patients. On average, BCSCs expressed 10-10⁶ fold less ERα mRNA and 10-10³ fold more ERβ than tumors or benign stem/progenitor cells (SC). BCSC lin-CD49f⁻CD24⁻cells were the exception and expressed higher ERα mRNA. PR mRNA in BCSCs averaged 10-10⁴ fold less than in tumors or benign tissue, but was similar to benign SCs. ERα and PR protein detection in BCSCs was lower than ER positive and similar to ER negative tumors. IL-8 mRNA was 10-10⁴ higher than tumor and 10² fold higher than benign tissue. IL-6 mRNA levels were equivalent to benign and only higher than tumor in lin-CD49f⁻CD24⁻cells. IL-6 and IL-8 proteins showed overlapping levels of expressions among various tissues and cell populations.

Conclusions

BCSCs and SCs demonstrate patient-specific variability of gene/protein expression. BCSC gene/protein expression may vary from that of other tumor cells, suggesting a mechanism by which hormone refractory disease may occur.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-733) contains supplementary material, which is available to authorized users.

The role of intratumoral and systemic IL-6 in breast cancer

Chronic low-grade inflammation plays an important role in the pathogenesis of several cancer forms including breast cancer. The pleiotropic cytokine IL-6 is a key player in systemic inflammation, regulating both the inflammatory response and tissue metabolism during acute stimulations. Here, we review the associations between IL-6 and breast cancer ranging from in vitro cell culture studies to clinical studies, covering the role of IL-6 in controlling breast cancer cell growth, regulation of cancer stem cell renewal, as well as breast cancer cell migration. Moreover, associations between circulating IL-6 and risk of breast cancer, prognosis for patients with prevalent disease, adverse effects and interventions to control systemic IL-6 levels in patients are discussed. In summary, direct application of IL-6 on breast cancer cells inhibits proliferation in estrogen receptor positive cells, while high circulating IL-6 levels are correlated with a poor prognosis in breast cancer patients. This discrepancy reflects distinct roles of IL-6, with elevated systemic levels being a biomarker for tumor burden, physical inactivity, and impaired metabolism, while local intratumoral IL-6 signaling is important for controlling breast cancer cell growth, metastasis, and self renewal of cancer stem cells.

Adenomyosis and infertility

Today an accurate diagnosis of adenomyosis can be made thanks to progress in imaging techniques: sonography and magnetic resonance imaging (MRI). This has made it possible to clinically correlate the presence of adenomyosis to infertility. At the same time, a series of pathogenetic hypotheses have been presented to explain this correlation. First, the identification of the myometrial junctional zone (JZ) and of its disruption and thickening has been linked to poor reproductive performance mainly through perturbed uterine peristalsis, a phenomenon that originates exclusively from the JZ in the nonpregnant uterus. In addition, a number of biochemical and functional alterations in both eutopic and heterotopic endometrium in women with adenomyosis have now been found to lead to lower receptivity, indicated by the presence of 'implantation marker' defects. In these patients there is also an altered decidualization and abnormal concentrations of intrauterine free radicals. All these abnormalities in the endometrial environment seem to contribute to subfertility. Several attempts have been made to restore fertility in adenomyosis patients, the oldest being gonadotrophin-releasing hormone agonists coupled to conservative surgery. Also, uterine artery embolization and MRI-assisted high-intensity focused ultrasound ablation have been tried with some degree of success.

Predictors of inflammation in response to anthracycline-based chemotherapy for breast cancer

Although chemotherapy for breast cancer can increase inflammation, few studies have examined predictors of this phenomenon. This study examined potential contributions of demographics, disease characteristics, and treatment regimens to markers of inflammation in response to chemotherapy for breast cancer. Thirty-five women with stage I-III-A breast cancer (mean age 50 years) were studied prior to cycle 1 and prior to cycle 4 of anthracycline-based chemotherapy. Circulating levels of inflammatory markers with high relevance to breast cancer were examined, including C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-alpha), Interleukin-1 receptor antagonist (IL1-RA), vascular endothelial growth factor (VEGF), soluble intercellular adhesion molecule-1 (sICAM-1), Interleukin- (IL-6), soluble P-selectin (sP-selectin), and von Willebrand factor (vWf). Chemotherapy was associated with elevations in VEGF (p < or = 0.01), sICAM-1 (p < or = 0.01), sP-selectin (p < or = 0.02) and vWf (p < or = 0.05). Multiple regression analysis controlling for age and body mass index (BMI) showed that higher post-chemotherapy levels of inflammation were consistently related to higher pre-chemotherapy levels of inflammation (ps < or =0.05) as well as to certain disease characteristics. Post-chemotherapy IL-6 levels were higher in patients who had larger tumors (p < or = 0.05) while post-chemotherapy VEGF levels were higher in patients who had smaller tumors (p < or = 0.05). Post-chemotherapy sP-selectin levels were highest in women who had received epirubicin, cytoxan, 5-fluorouracil chemotherapy (p < or = 0.01). These findings indicate that chemotherapy treatment can be associated with elevations in certain markers of inflammation, particularly markers of endothelial and platelet activation. Inflammation in response to chemotherapy is most significantly related to inflammation that existed prior to chemotherapy but also potentially to treatment regimen and to certain disease characteristics.

Significance of interleukin-6 (IL-6) in breast cancer (review)

Cytokines are factors that are known to have both tumor-promoting and inhibitory effects on breast cancer growth depending presumably on their relative concentrations and the presence of other modulating factors. Different cytokines play an important role in controlling the immune system. Interleukin-6 (IL-6) is a pleiotropic cytokine with obviously tumor-promoting and tumor-inhibitory effects. Here, we review the role of IL-6 in in vitro experiments of breast tumor cells, in breast tumor tissues (BTs) and assess its potential as a prognostic indicator in breast cancer patients. A literature search was conducted using PubMed, restricted to articles published in English language. In summary, results regarding the effect of IL-6 on breast tumor cells and on BTs are not unique indicating both tumor-promoting and inhibitory effects of IL-6. Concerning patients' serum IL-6 levels, data are surprisingly unique showing IL-6 to be a negative prognosticator in breast tumor patients.

Interleukin 6 G−174 C polymorphism and breast cancer risk

Interleukin-6 (IL-6) is a growth factor involved in many processes including carcinogenesis. The C allele of the G-174 C promoter single nucleotide polymorphism (SNP) in the IL-6 gene decreases levels of IL-6 expression and it has been studied in the context of breast cancer progression yielding contradicting results. Furthermore a recent study found that carriers of the C allele were at an increased risk for this disease. We aim to evaluate the association between this variant and breast cancer risk in Caucasian postmenopausal women. Women participating in the Rotterdam Study (N=3822), including 171 patients with breast cancer were genotyped for this polymorphism. In order to assess the relationship between this SNP and breast cancer we carried out a logistic regression in relation to the incidence of breast cancer. The C allele frequency was 41.3% and the genotypes followed Hardy-Weinberg distribution (p=0.3). The logistic regression analysis showed a slight increase of risk for C allele carriers (odds ratio=1.24, 95% CI: 0.8-1.9), compared to non-carriers of this allele. This increased risk was not statistically significant. Our data suggest that the IL-6 G-174 C polymorphism does not seem to play a role in breast cancer risk, although its role as a prognostic factor remains to be studied.

Estrogen receptor-alpha (ER-alpha) and defects in uterine receptivity in women

Endometriosis is a disorder that affects 5% of the normal population but is present in up to 40% of women with pelvic pain and/or infertility. Recent evidence suggests that the endometrium of women with endometriosis exhibits progesterone insensitivity. One endometrial protein that fluctuates in response to progesterone is the estrogen receptor-alpha (ER alpha), being down-regulated at the time of peak progesterone secretion during the window of implantation. Here we demonstrate that the biomarker of uterine receptivity, beta 3 integrin subunit, is reduced or absent in some women with endometriosis and that such defects are accompanied by inappropriate over-expression of ER alpha during the mid-secretory phase. Using a well-differentiated endometrial cell line we showed that the beta 3 integrin protein is negatively regulated by estrogen and positively regulated by epidermal growth factor (EGF). By competing against estrogen with various selective estrogen receptor modulators (SERMs) and estrogen receptor agonists and antagonists, inhibition of expression of the beta 3 integrin by estrogen can be mitigated. In conclusion, we hypothesize that certain types of uterine receptivity defects may be caused by the loss of appropriate ER alpha down-regulation in the mid-secretory phase, leading to defects in uterine receptivity. Such changes might be effectively treated by timely administration of the appropriate anti-estrogens to artificially block ER alpha and restore normal patterns of gene expression. Such treatments will require further clinical studies.

Pathological approach to evolving prognostic and predictive factors of breast cancer

Among the evolving concepts of prognostic and predictive factors in breast carcinoma pathology are those relating to lymph node status, tumor size, histological type, histological grade, bone marrow micrometastasis, and lymphatic and blood vessel involvement. Correct identification based on a uniform and complete pathological evaluation of tumor specimens is vital to correctly decide treatment. In addition we describe inflammatory cell infiltrates in breast carcinoma as not only prognostic and predictive factors but also pleiotropic regulators and/or effectors.

Genetic aberrance of sporadic MEN 2A component tumours: analysis of RET

AIM

The molecular pathogenesis of familial multiple endocrine neoplasia (MEN) type 2 (parathyroid adenoma with medullary thyroid carcinoma and adrenal pheochromocytoma) is associated with a germ-line mutation in the RET proto-oncogene. We undertook this study to clarify the relationship between the tumorigenesis of apparently sporadic MEN type 2 component endocrine tumours and RET mutations.

METHODS

Direct sequencing for RET exon 10, 11, 12, 13, 14, 15 and 16 and immunohistochemistry for RET monoclonal antibody were performed on the archival tissues of 84 cases of sporadic endocrine tumours, including 22 medullary thyroid carcinomas (MTCs), 35 adrenal pheochromocytomas (APCs), 18 paragangliomas (PGs), and nine parathyroid adenomas (PTAs).

RESULTS

PCR-based direct sequencing revealed somatic point missense mutation within 22.7% of exon 13 of the RET proto-oncogene (four cases of E768D, one case of S7781) in MTCs. No RET genotype and morphological association was observed in MTCs or APCs. APCs revealed significantly lower levels of immunoexpression of RET, even versus PGs.

CONCLUSIONS

The genetic mutation in RET is relatively low in incidence, and likely to play an insignificant role in the molecular pathogenesis of sporadic MTC. The molecular bases of PG and APC seem to be different despite their embryological and histological similarities.

From mice to humans: identification of commonly deregulated genes in mammary cancer via comparative SAGE studies

Genetically engineered mouse mammary cancer models have been used over the years as systems to study human breast cancer. However, much controversy exists on the utility of such models as valid equivalents to the human cancer condition. To perform an interspecies gene expression comparative study in breast cancer we used a mouse model that most closely resembles human breast carcinogenesis. This system relies on the transplant of p53 null mouse mammary epithelial cells into the cleared mammary fat pads of syngeneic hosts. Serial analysis of gene expression (SAGE) was used to obtain gene expression profiles of normal and tumor samples from this mouse mammary cancer model (>300,000 mouse mammary-specific tags). The resulting mouse data were compared with 25 of our human breast cancer SAGE libraries (>2.5 million human breast-specific tags). We observed significant similarities in the deregulation of specific genes and gene families when comparing mouse with human breast cancer SAGE data. A total of 72 transcripts were identified as commonly deregulated in both species. We observed a systematic and significant down-regulation in all of the tumors from both species of various cytokines, including CXCL1 (GRO1), LIF, interleukin 6, and CCL2. All of the mouse and most human mammary tumors also displayed decreased expression of genes known to inhibit cell proliferation, including NFKBIA (IKBalpha), GADD45B, and CDKN1A (p21); transcription-related genes such as CEBP, JUN, JUNB, and ELF1; and apoptosis-related transcripts such as IER3 and GADD34/PPP1R15A. Examples of overexpressed transcripts in tumors from both species include proliferation-related genes such as CCND1, CKS1B, and STMN1 (oncoprotein 18); and genes related to other functions such as SEPW1, SDFR1, DNCI2, and SP110. Importantly, abnormal expression of several of these genes has not been associated previously with breast cancer. The consistency of these observations was validated in independent mouse and human mammary cancer sets. This is the first interspecies comparison of mammary cancer gene expression profiles. The comparative analysis of mouse and human SAGE mammary cancer data validates this p53 null mouse tumor model as a useful system closely resembling human breast cancer development and progression. More importantly, these studies are allowing us to identify relevant biomarkers of potential use in human studies while leading to a better understanding of specific mechanisms of human breast carcinogenesis.

The -174 G/C gene polymorphism in interleukin-6 is associated with an aggressive breast cancer phenotype

Serum and tissue levels of interleukin-6 (IL-6) have been implicated in the biological phenotype of breast carcinoma. A common G/C polymorphism at position −174 of the IL-6 promoter can influence the expression level of this gene. We therefore investigated for associations between this polymorphism and various phenotypic features in a series of 256 breast cancers. Individuals who were homozygous for the C allele (n=55) were more likely to have higher-grade tumours (P=0.039) with ductal histology (P=0.030) compared to those harbouring at least one wild-type G allele (n=201). Homozygosity for the C allele was also associated with significantly worse overall survival (P=0.031). We conclude that the −174 C allele of IL-6 is associated with a more aggressive breast cancer phenotype.

Prognostic value of serum levels of interleukin 6 and of serum and plasma levels of vascular endothelial growth factor in hormone-refractory metastatic breast cancer patients

Prediction of survival for patients with metastatic breast cancer is often inaccurate and may be helped by new biological parameters. Tumour growth being angiogenesis-dependent, it has been hypothesised that the assessment of angiogenic factor production might reflect the clinical behaviour of cancer progression. This study was designed to investigate the clinical significance of vascular endothelial growth factor (VEGF) and interleukin 6 (IL-6) in hormone-refractory metastatic breast cancer. Serum and plasma concentrations of VEGF and serum concentration of IL-6 were measured in 87 patients with a fully documented history of metastatic breast cancer using an enzyme-linked immunoassay. All patients had detectable levels of VEGF, whereas 39% patients had detectable serum levels of IL-6. There was a positive correlation between IL-6 levels and the theoretical VEGF load of platelets (P<0.001). The presence of high levels of serum IL-6, but not VEGF, was significantly correlated to a shorter survival. In a multivariate analysis along with clinical prognostic parameters, serum IL-6 was identified as an independent adverse prognostic variable for overall survival (P&<0.001). These results indicate that serum IL-6 levels correlate to poor survival in patients with hormone-refractory metastatic breast cancer. Vascular endothelial growth factor serum and plasma levels are not useful indicators of prognosis for these patients.

IL-8 expression and its possible relationship with estrogen-receptor-negative status of breast cancer cells

Estrogen-receptor (ER) status is an important parameter in breast cancer management as ER-positive breast cancers have a better prognosis than ER-negative tumors. This difference comes essentially from the lower aggressiveness and invasiveness of ER-positive tumors. Here, we demonstrate, that interleukin-8 (IL-8) was clearly overexpressed in most ER-negative breast, ovary cell lines and breast tumor samples tested, whereas no significant IL-8 level could be detected in ER-positive breast or ovarian cell lines. We have also cloned human IL-8 from ER-negative MDA-MB-231 cells, and we show that IL-8 produced by breast cancer cells is identical to monocyte-derived IL-8. Interestingly, the invasion potential of ER-negative breast cancer cells is associated at least in part with expression of IL-8, but not with IL-8 receptor levels. Moreover, IL-8 increases the invasiveness of ER-positive breast cancer cells by two fold, thus confirming the invasion-promoting role of IL-8. On the other hand, exogenous expression of estrogen receptors in ER-negative cells led to a decrease of IL-8 levels. In summary, our data show that IL-8 expression is negatively linked to ER status of breast and ovarian cancer cells. We also support the idea that IL-8 expression is associated with a higher invasiveness potential of cancer cells in vitro, which suggests that IL-8 could be a novel marker of tumor aggressiveness.

Association between nitrotyrosine levels and microvascular density in human breast cancer

Nitrotyrosine (NO2Y) is a global marker of protein modification by reactive nitrogen species such as peroxynitrite derived from nitric oxide (NO). Because NO and its derivatives are postulated to enhance carcinogenesis, we used stable isotope dilution mass spectrometry to measure the levels of NO2Y in 30 samples of human breast cancer of varying pathologic types. In the samples tested, the NO2Y levels were generally low (average of 14.1 +/- 9.2 micromol NO2Y per mole of tyrosine). Breast cancers with a high microvascular density, however, had a significantly higher average level of NO2Y than tumors with a low microvascular density (20 v.s. 10 micromol NO2Y per mole of tyrosine, p = 0.007 by two-tailed t-test, assuming unequal variances of two samples). There was no apparent association between NO2Y levels and the differentiation of the tumors, tumor aneuploidy, estrogen receptor status, HER-2 expression, lymph node status, or infiltration of the tumors by neutrophils or eosinophils. When the tissues were stained by immunohistochemistry for NO2Y, the NO2Y was localized predominantly within inflammatory cells located immediately adjacent to blood vessels at the edges of the tumors. NO2Y was generally not evident within the tumor cells or inflammatory cells in the stroma. We conclude that low levels of reactive nitrogen species are located predominantly within inflammatory cells near blood vessels of breast cancer and that higher NO2Y levels are associated with an increased density of blood vessels. Our findings, therefore, support a possible association between inflammatory cells and reactive nitrogen species in modulating microvascular density at the edges of breast cancer.

Immunolocalization of matrix metalloproteinases and their inhibitors in clinical specimens of bone metastasis from breast carcinoma

Matrix metalloproteinases (MMPs) are essential in several stages of the metastatic process, and in normal bone development and remodeling. We explored whether the interaction between tumor cells and bone leads to changes in MMP and tissue inhibitor of MMP (TIMP) expression thus affecting osteolysis in metastatic bone disease. Using immunohistochemistry we have investigated the MMP/TIMP expression in tumor cells, fibroblasts, osteoblasts and osteoclasts. Thirty one specimens of bone metastasis from breast carcinoma were stained for MMP-1, -2, -9, MT1-MMP and TIMP-1, and -2 and compared with staining in normal breast tissue, primary breast carcinoma and normal bone. Specimens came from patients in three clinical scenarios: from open biopsies without or with pathological fracture, or bone marrow biopsies containing tumor from patients with pancytopenia but without clinical evidence of osteolysis. By bone histomorphometry the latter group showed a heavy tumor load not different from the open biopsy groups but displayed little active bone resorption and low numbers of osteoclasts. Cell type-specific MMP/TIMP expression was observed and the staining patterns were comparable between the three groups of patients. Though no major differences in the MMP/TIMP staining of tumor cells and fibroblasts were observed between bone metastasis and primary tumor, we showed that tumor cells do express MMPs capable of degrading bone matrix collagen. The number and activity of osteoclasts and osteoblasts was increased dramatically in bone metastases, their MMP/TIMP profiles, however, were not different from normal bone, suggesting that the mechanism of bone degradation by osteoclasts is not different from normal bone remodelling.

Interleukins-6 and -11 expression in primary breast cancer and subsequent development of bone metastases

Breast cancers frequently metastasize to bone where they often cause extensive tumor-induced osteoclast-mediated osteolysis. Interleukin-6 (IL-6) and IL-11 are two cytokines exhibiting osteolytic properties through their potent stimulation of osteoclast formation. We investigated the expression of IL-6 and IL-11 in 99 invasive primary breast tumors by immunohistochemistry and in situ hybridization, respectively. We examined their potential as predictive factors for further development of bone metastases. 52/90 (57%) of tumor samples showed IL-6 cytoplasmic immunostaining. There was no significant association between IL-6 status and any of the classical prognostic factors. 15/89 (17%) of the tumor samples expressed IL-11 mRNA. A positive IL-11 mRNA status was associated with a low tumor grade (P=0.05). Tumors expressing IL-11 mRNA had a statistically significant (P=0.002) higher rate of bone metastases occurrence (12/15, 80%) than IL-11 negative tumors (27/74, 37%). Such association was not found for IL-6. Our findings demonstrate for the first time IL-11 gene expression in some primary invasive breast tumors and suggest the potential of this cytokine as possible biological predictive factor for the development of bone metastases.

Regulation of interleukin-6 secretion from breast cancer cells and its clinical implications

Interleukin (IL)-6 may play possible roles in the proliferation and metastasis of cancer cells, in the development of osteolysis and humoral hypercalcemia, and in the regulation of estrogen production in breast cancer tissues. IL-6 is also suggested to be a cachectic factor in cancer patients. A decrease in serum IL-6 levels induced by medroxyprogesterone acetate (MPA) has been reported to correlate with a reversion of body weight loss in patients with advanced breast cancer. To elucidate the mechanisms of action of the anti-cachectic effect of MPA its effects on IL-6 secretion from the KPL-4 cell line, the first human breast cancer cell line to secrete IL-6 and to induce cachexia, were explored. It has been suggested that an inhibitory effect of MPA on IL-6 secretion from breast cancer cells causes the anti-cachectic effect of MPA. Our other studies have revealed that 5'-fluorouridine (5'-DFUR) inhibits the growth of KPL-4 tumors and decreases IL-6 levels in both serum and tumor tissues. Decreasing serum IL-6 levels resulted in alleviation of body weight loss. Docetaxel increased IL-6 levels in both serum and KPL-4 tumors, but combined treatment with docetaxel and 5'-DFUR resulted not only in a potent antitumor effect but also in a drastic decrease of serum IL-6 levels. In the present paper the possible roles of IL-6 in the development and progression of breast cancer are reviewed, and the regulatory mechanisms of IL-6 secretion from breast cancer cells and the possible clinical implications of decreasing IL-6 secretion by therapeutic agents are discussed.

Cytokines facilitate chemotactic motility of breast carcinoma cells

BACKGROUND

Both growth and motility of various tumor cells have been shown to be influenced by surrounding cells such as lymphocytes, histiocytes and fibroblasts through various cytokines, growth factors and extracellular matrices. The role of cytokines and extracellular matrices produced by lymphocytes, histiocytes and fibroblasts on migration and invasion of breast carcinoma cells has not been fully investigated

METHODS

We investigated the effect of hepatocyte growth factor (HGF), interleukin (IL)-6, IL-8, IL-11, soluble type IV collagen and soluble laminin on the migration of 3 human breast carcinoma cell lines, MDA-MB-231, MCF-7 and T-47D, using a cell culture insert and a biocoat matrigel invasion chamber to assess migration across a matrigel-coated polyethylene telephtalate membrane.

RESULTS

HGF, IL-6, IL-11 and IL-8 induced significant migration of MDA-MB-231 cells depending on the dose of each cytokine. However, type IV collagen and laminin inhibited migration of MDA-MB-231 cells. In contrast, IL-8 inhibited migration of MCF-7 cells and IL-6 induced significant migration of T-47D cells, while no other cytokine or extracellular matrix induced significant migration of MCF-7 and T-47D cells. Only HGF induced significant invasion of MDA-MB-231 cells depending on the dose. MCF-7 and T-47D cells did not invade in response to any of the cytokines and extracellular matrices tested.

CONCLUSIONS

These results suggest the possibility that the potency of chemotaxis or chemoinvasion differs according to the breast carcinoma cell line and that various cytokines and extracellular matrices secreted by lymphocytes, histiocytes and fibroblasts in the stroma of breast carcinoma can affect the invasion of breast carcinoma cells.

An analysis of serum interleukin-6 levels to predict benefits of medroxyprogesterone acetate in advanced or recurrent breast cancer

Treatment of advanced or recurrent breast cancer with medroxyprogesterone acetate (MPA) shows high response rates and the accessory effects of appetite stimulation, improvement in performance status (PS) and bone marrow protection. In recent years, interleukin-6 (IL-6) has been reported to cause cachexia. In this study, to clarify the significance of IL-6 in advanced or recurrent breast cancer, the relationship between the IL-6 level and clinical findings or effect of MPA was investigated. Sixty-five patients with recurrent or advanced breast cancer participated in a prospective study. The age of patients ranged from 28 to 79 years with an average age of 51.3 years. IL-6 level was investigated in these patients dosed with 800 mg/day of MPA and in 17 postoperative nonrecurrent patients. Serum MPA level was measured by high-performance liquid chromatography and IL-6 level was measured prior to MPA administration, 4 weeks (in 59 cases) and 12 weeks (in 32 patients) after MPA administration by ELISA. Serum IL-6 level was significantly higher in recurrent cases, especially in those with visceral metastasis. Further, in patients for whom MPA therapy was effective, the IL-6 level prior to the treatment was clearly low. The IL-6 level was significantly increased after 4 weeks. However, response to MPA was significantly higher and PS was improved in those cases demonstrating less increased IL-6 levels after 4 weeks. In addition, the effect of MPA was significantly related to a higher serum concentration of MPA-positive ER, and longer disease-free interval, although there was no significant predictive factor for the clinical effect of MPA therapy in multivariate analysis. In conclusion, MPA therapy was effective in cases demonstrating a low IL-6 level and less increased IL-6 levels after 4 weeks. PS was improved in those cases in which the degree of IL-6 increase was suppressed by MPA, and many such cases showed low IL-6 levels prior to MPA therapy. Furthermore, PS was improved even in nonresponders to MPA. Therefore, it is suggested that MPA therapy might be useful in treating recurrent breast cancer, and its benefits might be mediated by IL-6.

Direct activation of oestrogen receptor-alpha by interleukin-6 in primary cultures of breast cancer epithelial cells

Interleukin 6 (IL-6) is secreted by breast tumours and shows synergistic activity with 17beta-oestradiol (E2), leading to increases in reductive 17beta-hydroxysteroid dehydrogenase activity in breast cancer epithelial cells. However, the mechanisms involved are poorly understood. Using short-term epithelial cultures established from primary breast tumours, we have examined whether IL-6 could directly affect transcriptional activity of oestrogen reception alpha (ERalpha). Tumour epithelial cultures were established from 15 breast tumours, grown to 70% confluence and transiently transfected with a plasmid reporter containing the vitellogenin oestrogen response element and the luciferase coding sequence (ERE-TK-LUC). Following transfection, cells were incubated with E2, IL-6, the pure anti-oestrogen ZM 182780 or combinations of these substances for 48 h. Luciferase activity was then measured in cell lysates. E2 caused a dose-dependent increase in luciferase expression, causing a maximum threefold stimulation at 100 pM. In the presence of IL-6, transcriptional activity was increased by up to 2.5-fold in ERalpha+ cultures (11/15). In combination with E2, synergistic effects were observed with increases in luciferase activity of up to sixfold over controls. This effect could be blocked by treatment with ZM 182780. Pre-incubation of cells with an antibody directed against the signalling component of IL-6, gp130, was ineffective in blocking the E2 response. This antibody reduced, but did not completely block the effect of IL-6 either alone or in combination with E2, suggesting cross-talk between the two signalling pathways. In conclusion, these results provide evidence for direct transcriptional activation of ERalpha by IL-6.