Estrogen disrupts chemokine-mediated chemokine release from mammary cells: implications for the interplay between estrogen and IP-10 in the regulation of mammary tumor formation

Fuch's Endothelial Corneal Dystrophy in Cataract Patients Is Associated with Elevated Levels of Inflammatory Chemokines, but Not Growth Factors, in the Aqueous Humor

The study investigated a profile of chemokines and growth factors in the aqueous humor (AH) of eyes with Fuch's endothelial corneal dystrophy (FECD) and cataracts in comparison with cataract patients as a control group. A total of 52 AH samples (26 FECD + cataract and 26 cataract/control) were collected before cataract surgery. None of the patients had any clinically apparent inflammation at the time of AH collection. The AH levels of MCP-1 (CCL2), MIP-1α (CCL3), MIP-1β(CCL4), RANTES (CCL5), eotaxin (CCL11), IP-10 (CXCL10), FGF basic, G-CSF, GM-CSF, PDGF-bb, and VEGF were compared between the groups. The analyses were performed using the Bio-Plex 200 System from Bio-Rad. Among the studied parameters, the AH levels of RANTES, eotaxin, and IP-10 significantly increased in the FECD + cataract eyes, compared with the cataract controls (p < 0.05). Elevated levels of the RANTES, Eotaxin, and IP-10 indicate more intense inflammation in the eyes of patients in the FECD + cataract group. Moreover, these factors exhibit potential as predictive biomarkers for early detection of FECD in cataract patients. The discovery of elevated concentrations of biochemical markers in a patient, who has not yet received a clinical diagnosis, may suggest the need for heightened observation of the other eye to monitor the potential development of FECD.

CXCL10 mediates breast cancer tamoxifen resistance and promotes estrogen-dependent and independent proliferation

Although 70% of estrogen receptor (ER)-positive breast cancer patients can benefit from tamoxifen therapy, the rapid development of tamoxifen resistance hampers the treatment advantage. In this investigation, we found that the serum level of CXCL10 in breast cancer patients was positively correlated with tumor size and ER status. Furthermore, GSE22220 dataset analysis demonstrated that CXCL10 expression in the tumor was correlated with tumor grade and lymphatic metastasis status, and Kaplan-Meier analysis indicated that patients with high CXCL10 expression had a poor prognosis. Estrogen-deprived MCF7 cells were transfected with CXCL10 luciferase reporter plasmid and treated with 10 nM estrogen. Luciferase reporter assay confirmed that CXCL10 was regulated by estrogen. CXCL10 promoted the proliferation of both parental MCF7 cells and tamoxifen-resistant (TamR) MCF7 cells through the AKT pathway, while CXCL10 inhibition restored the sensitivity of TamR cells to tamoxifen. All of these data indicate that CXCL10 could be utilized as a biomarker to predict the prognosis of breast cancer and as a therapeutic target to treat tamoxifen resistant cases.

Interactions between Adipocytes and Breast Cancer Cells Stimulate Cytokine Production and Drive Src/Sox2/miR-302b-Mediated Malignant Progression

Consequences of the obesity epidemic on cancer morbidity and mortality are not fully appreciated. Obesity is a risk factor for many cancers, but the mechanisms by which it contributes to cancer development and patient outcome have yet to be fully elucidated. Here, we examined the effects of coculturing human-derived adipocytes with established and primary breast cancer cells on tumorigenic potential. We found that the interaction between adipocytes and cancer cells increased the secretion of proinflammatory cytokines. Prolonged culture of cancer cells with adipocytes or cytokines increased the proportion of mammosphere-forming cells and of cells expressing stem-like markers in vitro. Furthermore, contact with immature adipocytes increased the abundance of cancer cells with tumor-forming and metastatic potential in vivo. Mechanistic investigations demonstrated that cancer cells cultured with immature adipocytes or cytokines activated Src, thus promoting Sox2, c-Myc, and Nanog upregulation. Moreover, Sox2-dependent induction of miR-302b further stimulated cMYC and SOX2 expression and potentiated the cytokine-induced cancer stem cell-like properties. Finally, we found that Src inhibitors decreased cytokine production after coculture, indicating that Src is not only activated by adipocyte or cytokine exposures, but is also required to sustain cytokine induction. These data support a model in which cancer cell invasion into local fat would establish feed-forward loops to activate Src, maintain proinflammatory cytokine production, and increase tumor-initiating cell abundance and metastatic progression. Collectively, our findings reveal new insights underlying increased breast cancer mortality in obese individuals and provide a novel preclinical rationale to test the efficacy of Src inhibitors for breast cancer treatment.

C-X-C ligand 10 and C-X-C receptor 3 status can predict tamoxifen treatment response in breast cancer patients

To investigate the expression levels of CXCL10 and CXCR3 in tumors from breast cancer patients randomized to adjuvant tamoxifen treatment or no endocrine treatment, in order to further study the connection to prognosis and prediction of tamoxifen treatment outcome. Immunohistochemistry on tissue microarrays from 912 breast cancer patients randomized to tamoxifen or no endocrine treatment. CXCR3 status was found to be a prognostic tool in predicting distant recurrence, as well as reduced breast cancer-specific survival. In patients with estrogen receptor (ER)-positive tumors, tumors with strong CXCL10 levels had improved effect of tamoxifen treatment in terms of local recurrence-free survival [risk ratio (RR) 0.46 (95 % CI 0.25–0.85, P = 0.01)] compared with patients with tumors expressing weak CXCL10 expression. Further, patients with ER-positive tumors with strong CXCR3 expression had an improved effect of tamoxifen in terms of breast cancer-specific survival [RR 0.34 (95 % CI 0.19–0.62, P < 0.001)] compared with the group with weak CXCR3 levels [RR 1.33 (95 % CI 0.38–4.79, P = 0.65)]. We show here for the first time that CXCL10 and CXCR3 expression are both predictors of favorable outcome in patients treated with tamoxifen.

CXCL10/IP-10 in infectious diseases pathogenesis and potential therapeutic implications

C-X-C motif chemokine 10 (CXCL10) also known as interferon γ-induced protein 10 kDa (IP-10) or small-inducible cytokine B10 is a cytokine belonging to the CXC chemokine family. CXCL10 binds CXCR3 receptor to induce chemotaxis, apoptosis, cell growth and angiostasis. Alterations in CXCL10 expression levels have been associated with inflammatory diseases including infectious diseases, immune dysfunction and tumor development. CXCL10 is also recognized as a biomarker that predicts severity of various diseases. A review of the emerging role of CXCL10 in pathogenesis of infectious diseases revealed diverse roles of CXCL10 in disease initiation and progression. The potential utilization of CXCL10 as a therapeutic target for infectious diseases is discussed.

The emerging role of CXCL10 in cancer (Review)

The chemokine interferon-γ inducible protein 10 kDa (CXCL10) is a member of the CXC chemokine family which binds to the CXCR3 receptor to exert its biological effects. CXCL10 is involved in chemotaxis, induction of apoptosis, regulation of cell growth and mediation of angiostatic effects. CXCL10 is associated with a variety of human diseases including infectious diseases, chronic inflammation, immune dysfuntion, tumor development, metastasis and dissemination. More importantly, CXCL10 has been identified as a major biological marker mediating disease severity and may be utilized as a prognostic indicator for various diseases. In this review, we focus on current research elucidating the emerging role of CXCL10 in the pathogenesis of cancer. Understanding the role of CXCL10 in disease initiation and progression may provide the basis for developing CXCL10 as a potential biomarker and therapeutic target for related human malignancies.

Primary human mammary epithelial cells endocytose HIV-1 and facilitate viral infection of CD4+ T lymphocytes

The contribution of mammary epithelial cells (MEC) to human immunodeficiency virus type 1 (HIV-1) in breast milk remains largely unknown. While breast milk contains CD4(+) cells throughout the breast-feeding period, it is not known whether MEC directly support HIV-1 infection or facilitate infection of CD4(+) cells in the breast compartment. This study evaluated primary human MEC for direct infection with HIV-1 and for indirect transfer of infection to CD4(+) target cells. Primary human MEC were isolated and assessed for expression of HIV-1 receptors. MEC were exposed to CCR5-, CXCR4- and dual-tropic strains of HIV-1 and evaluated for viral reverse transcription and integration and productive viral infection. MEC were also tested for the ability to transfer HIV to CD4(+) target cells and to activate resting CD4(+) T cells. Our results demonstrate that MEC express HIV-1 receptor proteins CD4, CCR5, CXCR4, and galactosyl ceramide (GalCer). While no evidence for direct infection of MEC was found, HIV-1 virions were observed in MEC endosomal compartments. Coculture of HIV-exposed MEC resulted in productive infection of activated CD4(+) T cells. In addition, MEC secretions increased HIV-1 replication and proliferation of infected target cells. Overall, our results indicate that MEC are capable of endosomal uptake of HIV-1 and can facilitate virus infection and replication in CD4(+) target cells. These findings suggest that MEC may serve as a viral reservoir for HIV-1 and may enhance infection of CD4(+) T lymphocytes in vivo.

Postinjury estrogen treatment of chronic spinal cord injury improves locomotor function in rats

Spinal cord injury (SCI) causes loss of neurological function and, depending on serverity, may cause paralysis. The only recommended pharmacotherapy for the treatment of SCI is high-dose methylprednisolone, and its use is controversial. We have previously shown that estrogen treatment attenuated cell death, axonal and myelin damage, calpain and caspase activities, and inflammation in acute SCI. The aim of this study was to examine whether posttreatment of SCI with estrogen would improve locomotor function by protecting cells and axons and reducing inflammation during the chronic phase following injury. Moderately severe injury (40 g . cm force) was induced in male Sprague-Dawley rats following laminectomy at T10. Three groups of animals were used: sham (laminectomy only), vehicle (dimethyl sulfoxide; DMSO)-treated injury group, and estrogen-treated injury group. Animals were treated with 4 mg/kg estrogen at 15 min and 24 hr postnjury, followed by 2 mg/kg estrogen daily for the next 5 days. After treatment, animals were sacrificed at the end of 6 weeks following injury, and 1-cm segments of spinal cord (lesion, rostral to lesion, and caudal to lesion) were removed for biochemical analyses. Estrogen treatment reduced COX-2 activity, blocked nuclear factor-kappaB translocation, prevented glial reactivity, attenuated neuron death, inhibited activation and activity of calpain and caspase-3, decreased axonal damage, reduced myelin loss in the lesion and penumbra, and improved locomotor function compared with vehicle-treated animals. These findings suggest that estrogen may be useful as a promising therapeutic agent for prevention of damage and improvement of locomotor function in chronic SCI. (c) 2010 Wiley-Liss, Inc.

Antitumor/antiestrogenic effect of the chemokine interferon inducible protein 10 (IP-10) involves suppression of VEGF expression in mammary tissue

Vascular endothelial growth factor (VEGF) promotes angiogenesis in a number of tumor model systems. We reported previously that estrogen supports the growth of CCL-51 cell-based mammary tumors in mice, which could be blocked with specific chemokines. We investigated whether promotion of tumor growth by estrogen, and suppression of tumor growth by chemokines, was associated with VEGF protein expression. Female C3H mice were treated with vehicle, estradiol, or with one of several chemokines for 72 h. The presence of VEGF in mammary tissue samples was detected and quantified by sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting using antimurine VEGF antibodies. Estrogen significantly increased mammary VEGF expression. Cotreatment with tamoxifen or the chemokine interferon-inducible protein-10 (IP-10) suppressed the action estrogen on VEGF expression. CCL-51 tumor cells were placed into mammary tissue of C3H mice. Mice were treated every 72-h with either vehicle or estradiol, in the presence or absence of IP-10 for 21 days. Estrogen supported CCL-51 tumor growth, with an average of 2.3 tumors present/animal. Cotreatment of mice with estrogen and IP-10 resulted in significantly lower numbers of tumors in mammary tissue in comparison to animals treated with estrogen alone. VEGF levels in mammary tissue and tumors of IP-10 and estrogen cotreated mice were 40-50% less than those detected in mammary tissue of estrogen-treated mice. Our results suggest that estrogenic support of CCL-51 mammary tumor growth is related to increased VEGF expression, and that the inhibitory action of IP-10 may be related to suppressing VEGF levels in mammary tissue.

Physiology of membrane oestrogen receptor signalling in reproduction

The best characterised oestrogen receptors (ERs) that are responsible for membrane-initiated oestradiol signalling are the classic ERs, ERalpha and ERbeta. When in the nucleus, these proteins are oestradiol activated transcription factors but, when trafficked to the cell membrane, ERalpha and ERbeta rapidly activate protein kinase pathways, alter membrane electrical properties, modulate ion flux and can mediate long-term effects through gene expression. To initiate cell signalling, membrane ERs transactivate metabotropic glutamate receptors (mGluRs) to stimulate Gq signalling through pathways using PKC and calcium. In this review, we discuss the interaction of membrane ERalpha with metabotropic glutamate receptor 1a (mGluR1a) to initiate rapid oestradiol cell signalling and its critical roles in female reproduction: sexual behaviour and oestrogen positive feedback of the luteinising hormone (LH) surge. Although long considered to be regulated by the long-term actions of oestradiol on gene transcription, recent results indicate that membrane oestradiol cell signalling is vital for a full display of sexual receptivity. Similarly, the source of pre-ovulatory progesterone necessary for initiating the LH surge is hypothalamic astrocytes. Oestradiol rapidly amplifies progesterone synthesis through the release of intracellular calcium stores. The ERalpha-mGluR1a interaction is necessary for critical calcium flux. These two examples provide support for the hypothesis that membrane ERs are not themselves G-protein receptors; rather, they use mGluRs to signal.

Concomitant expression of the chemokines RANTES and MCP-1 in human breast cancer: a basis for tumor-promoting interactions

The chemokines RANTES (CCL5) and MCP-1 (CCL2) were suggested to contribute, independently, to breast malignancy. In the present study, we asked if the two chemokines are jointly expressed in clinical samples of breast cancer patients, and do they interact in breast tumor cells. We found that RANTES and MCP-1 were expressed by breast tumor cells in primary tumors of Ductal Carcinoma In Situ and of Invasive Ductal Carcinoma, but minimally in normal breast epithelial duct cells. The chemokines were also detected in metastases and pleural effusions. Novel findings showed that co-expression of RANTES and MCP-1 in the same tumor was associated with more advanced stages of disease, suggesting that breast tumors "benefit" from interactions between the two chemokines. Accordingly, MCP-1 significantly promoted the release of RANTES from endogenous pre-made vesicles, in an active process that depended on calcium from intracellular and extracellular sources, and on intracellular transport of RANTES towards exocytosis. Our findings show a chemokine-triggered release of stored pro-malignancy chemokine from breast tumor cells. These observations support a major tumor-promoting role for co-expression of the chemokines in breast malignancy, and agree with the significant association of joint RANTES and MCP-1 expression with advanced stages of breast cancer.

The inflammatory chemokines CCL2 and CCL5 in breast cancer

A causal role was recently attributed to inflammation in many malignant diseases, including breast cancer. The different inflammatory mediators that are involved in this disease include cells, cytokines and chemokines. Of these, many studies have addressed the involvement and roles of the inflammatory chemokines CCL2 (MCP-1) and CCL5 (RANTES) in breast malignancy. While minimally expressed by normal breast epithelial duct cells, both chemokines are highly expressed by breast tumor cells at primary tumor sites, indicating that CCL2 and CCL5 expression is acquired in the course of malignant transformation, and suggesting that the two chemokines play a role in breast cancer development and/or progression. Supporting this possibility are findings showing significant associations between CCL2 and CCL5 and more advanced disease course and progression. Furthermore, studies in animal model systems have shown active and causative roles for the two chemokines in this disease. In line with the tumor-promoting roles of CCL2 and CCL5 in breast cancer, the two chemokines were shown to mediate many types of tumor-promoting cross-talks between the tumor cells and cells of the tumor microenvironment: (1) they shift the balance at the tumor site between different leukocyte cell types by increasing the presence of deleterious tumor-associated macrophages (TAM) and inhibiting potential anti-tumor T cell activities; (2) of the two chemokines, mainly CCL2 promotes angiogenesis; (3) CCL2 and CCL5 which are expressed by cells of the tumor microenvironment osteoblasts and mesenchymal stem cells play a role in breast metastatic processes. In addition, both chemokines act directly on the tumor cells to promote their pro-malignancy phenotype, by increasing their migratory and invasion-related properties. Together, the overall current information suggests that CCL2 and CCL5 are inflammatory mediators with pro-malignancy activities in breast cancer, and that they should be considered as potential therapeutic targets for the limitation of this disease.

17Beta-estradiol suppresses TLR3-induced cytokine and chemokine production in endometrial epithelial cells

BACKGROUND

The human endometrium is an important site for contact between the host and pathogens ascending the reproductive tract, and thus plays an important role in female reproductive tract immunity. Previous work in our laboratory has suggested that Toll-like receptors (TLRs) are involved in endometrial epithelial recognition of pathogens and that ligation of endometrial TLRs results in the production of cytokines and chemokines important for both immune and reproductive functions of the endometrium. We have also demonstrated cyclic regulation of TLR3 mRNA and protein expression in human endometrium, suggesting that steroid hormones might play a role in the expression and function of TLR3. In this study, the effects of 17beta-estradiol (E2) and progesterone (P) on TLR3 expression and function in endometrial cell lines were investigated.

METHODS

Endometrial epithelial cell lines were cultured and examined for the presence of TLR3 and hormone receptors by endpoint RT-PCR. For hormonal studies, cells were pre-treated with ethanol vehicle, 10(-8) M E2, and/or 10(-7) M P. For antagonist assays, cells were treated with the ER antagonist, ICI 182, 780, or the PR antagonist, RU486, for two hours prior to treatment with hormones. Following hormone or hormone/antagonist pre-treatment, cells were stimulated with vehicle, the synthetic TLR3 ligand, polyinosinic-polycytidylic acid (Poly I:C), a negative dsDNA control, or a positive control. Cytokine and chemokine production post-stimulation was measured by ELISA. The effects of E2 and P on TLR3 mRNA and protein expression were measured using Real Time RT-PCR and FACS analysis, respectively.

RESULTS

Stimulation of TLR3-expressing cells with the synthetic TLR3 ligand, Poly I:C, resulted in the production of cytokines and chemokines important for endometrial function and regulation. Suppression of Poly I:C-induced cytokine and chemokine production by cells treated with 10(-8) M E2, but not cells treated with 10(-7) M P, was observed in endometrial epithelial cell lines expressing TLR3 and estrogen receptor alpha (ERalpha). The effects of E2 were not observed on cells which did not express ERalpha or in cells pre-treated with the ER antagonist, ICI 182, 780. Treatment with E2 did not affect TLR3 mRNA or protein expression. However, treatment with E2 did suppress cytokine and chemokine production resulting from TLR3 stimulation with Poly I:C, suggesting that E2 modulates TLR3 function.

CONCLUSION

The data presented in this study are the first indication that E2 can markedly alter the innate immune response to dsRNA, providing a previously unreported process by which E2 can alter immune responses.

Sex steroid regulation of angiogenesis in breast tissue

Angiogenesis is essential for normal function in the female reproductive tract and a prerequisite for growth and metastasis of solid tumors. Several factors, both inducers and inhibitors, play essential roles in the regulation of the angiogenic process. Exposure to sex steroids increases the risk of breast cancer but the mechanisms are poorly understood and the importance of angiogenesis in breast carcinogenesis is undefined. In the female reproductive tract ovarian hormones tightly regulate angiogenesis. The breast is also a target organ for sex steroids but very little is known about sex steroid effects on angiogenesis in normal breast tissue and breast cancer. In this review several regulators of angiogenesis, and their relation to sex steroids, in breast tissue are discussed. Increased knowledge in this area is of utmost importance for future therapeutic treatment options and for breast cancer prevention.

Estrogen attenuated markers of inflammation and decreased lesion volume in acute spinal cord injury in rats

Spinal cord injury (SCI) is a devastating neurologic injury with functional deficits for which the only currently recommended pharmacotherapy is high-dose methylprednisolone, which has limited efficacy. Estrogen is a multi-active steroid that has shown antiinflammatory and antioxidant effects, and estrogen may modulate intracellular Ca(2+) and attenuate apoptosis. For this study, male rats were divided into three groups. Sham group animals received a laminectomy at T12. Injured rats received both laminectomy and 40 g x cm force SCI. Estrogen-group rats received 4 mg/kg 17beta-estradiol (estrogen) at 15 min and 24 hr post-injury, and vehicle-group rats received equal volumes of dimethyl sulfoxide (vehicle). Animals were sacrificed at 48 hr post-injury, and 1-cm-long segments of the lesion, rostral penumbra, and caudal penumbra were excised. Inflammation was assessed by examining tissue edema, infiltration of macrophages/microglia, and levels of cytosolic and nuclear NFkappaB and inhibitor of kappa B (IkappaBalpha). Myelin integrity was examined using Luxol fast blue staining. When compared to sham, vehicle-treated animals revealed increased tissue edema, increased infiltration of inflammatory cells, decreased cytosolic levels of NFkappaB and IkappaBalpha, increased levels of nuclear NFkappaB, and increased myelin loss. Treatment of SCI rats with estrogen reduced edema and decreased inflammation and myelin loss in the lesion and penumbral areas, suggesting its potential as a therapeutic agent. Further work needs to be done, however, to elucidate the neuroprotective mechanism of estrogen.