Reduction in serum IL-6 after vacination of breast cancer patients with tumour-associated antigens is related to estrogen receptor status

The Role of IL-6 in Cancer Cell Invasiveness and Metastasis-Overview and Therapeutic Opportunities

Interleukin 6 (IL-6) belongs to a broad class of cytokines involved in the regulation of various homeostatic and pathological processes. These activities range from regulating embryonic development, wound healing and ageing, inflammation, and immunity, including COVID-19. In this review, we summarise the role of IL-6 signalling pathways in cancer biology, with particular emphasis on cancer cell invasiveness and metastasis formation. Targeting principal components of IL-6 signalling (e.g., IL-6Rs, gp130, STAT3, NF-κB) is an intensively studied approach in preclinical cancer research. It is of significant translational potential; numerous studies strongly imply the remarkable potential of IL-6 signalling inhibitors, especially in metastasis suppression.

IL-6/JAK/STAT3 Signaling in Breast Cancer Metastasis: Biology and Treatment

Breast cancer is the most commonly diagnosed cancer in women. Metastasis is the primary cause of mortality for breast cancer patients. Multiple mechanisms underlie breast cancer metastatic dissemination, including the interleukin-6 (IL-6)-mediated signaling pathway. IL-6 is a pleiotropic cytokine that plays an important role in multiple physiological processes including cell proliferation, immune surveillance, acute inflammation, metabolism, and bone remodeling. IL-6 binds to the IL-6 receptor (IL-6Rα) which subsequently binds to the glycoprotein 130 (gp130) receptor creating a signal transducing hexameric receptor complex. Janus kinases (JAKs) are recruited and activated; activated JAKs, in turn, phosphorylate signal transducer and activator of transcription 3 (STAT3) for activation, leading to gene regulation. Constitutively active IL-6/JAK/STAT3 signaling drives cancer cell proliferation and invasiveness while suppressing apoptosis, and STAT3 enhances IL-6 signaling to promote a vicious inflammatory loop. Aberrant expression of IL-6 occurs in multiple cancer types and is associated with poor clinical prognosis and metastasis. In breast cancer, the IL-6 pathway is frequently activated, which can promote breast cancer metastasis while simultaneously suppressing the anti-tumor immune response. Given these important roles in human cancers, multiple components of the IL-6 pathway are promising targets for cancer therapeutics and are currently being evaluated preclinically and clinically for breast cancer. This review covers the current biological understanding of the IL-6 signaling pathway and its impact on breast cancer metastasis, as well as, therapeutic interventions that target components of the IL-6 pathway including: IL-6, IL-6Rα, gp130 receptor, JAKs, and STAT3.

Estrogen/ER in anti-tumor immunity regulation to tumor cell and tumor microenvironment

As the essential sexual hormone, estrogen and its receptor has been proved to participate in the regulation of autoimmunity diseases and anti-tumor immunity. The adjustment of tumor immunity is related to the interaction between cancer cells, immune cells and tumor microenvironment, all of which is considered as the potential target in estrogen-induced immune system regulation. However, the specific mechanism of estrogen-induced immunity is poorly understood. Typically, estrogen causes the nuclear localization of estrogen/estrogen receptor complex and alternates the transcription pattern of target genes, leading to the reprogramming of tumor cells and differentiation of immune cells. However, the estrogen-induced non-canonical signal pathway activation is also crucial to the rapid function of estrogen, such as NF-κB, MAPK-ERK, and β-catenin pathway activation, which has not been totally illuminated. So, the investigation of estrogen modulatory mechanisms in these two manners is vital for the tumor immunity and can provide the potential for endocrine hormone targeted cancer immunotherapy. Here, this review summarized the estrogen-induced canonical and non-canonical signal transduction pathway and aimed to focus on the relationship among estrogen and cancer immunity as well as immune-related tumor microenvironment regulation. Results from these preclinical researches elucidated that the estrogen-target therapy has the application prospect of cancer immunotherapy, which requires the further translational research of these treatment strategies.

Effect of Tai Chi Chuan in Breast Cancer Patients: A Systematic Review and Meta-Analysis

Background: Tai Chi Chuan(TCC), as a mind-body exercise, may have a positive impact on physical function and psychological well-being in breast cancer patients. The latest systematic review and meta-analysis of TCC for breast cancer was made 4 years ago and some new clinical trials about it were published. We remade a systematic review and meta-analysis to evaluate the effect of TCC in breast cancer patients.

Methods: In this systematic review and meta-analysis, we searched MEDLINE (via PubMed), EMBASE (via embase.com), CENTRAL, CNKI, COVIP, Wanfang, Chaoxing, CiNii, J-SSTAGE, DBpia, and ThaiJO with no language restrictions from inception to December 31, 2018 (updated on February 16, 2020), for randomized clinical trials comparing TCC with non-exercised therapy in breast cancer patients. The primary outcome was quality of life in patients with breast cancer and data pooled by a random-effects model. Subgroup analyses were conducted to estimate the effect of different durations of TCC for breast cancer patients. This study was registered in PROSPERO, number CRD 4201810326.

Results: Fifteen articles involving a total of 885 breast cancer participants were included in this review. Compared with non-exercised therapy, TCC had a significant effect on quality of life in breast cancer patients (SMD = 0.37, 95% CI 0.15–0.59, p = 0.001), and subgroup analysis found that TCC showed beneficial effect in 12 weeks and 25 weeks (12 weeks: SMD = 0.40, 95% CI 0.19–0.62, p = 0.0003; 25 weeks: SMD = 0.38, 95% CI 0.15–0.62, p = 0.002). Meta-analyses of secondary outcomes showed that 3 weeks TCC increased shoulder function (SMD = 1.08, 95% CI 0.28–1.87, p = 0.008), 12 weeks TCC improved pain (SMD = 0.30, 95% CI 0.08–0.51, p = 0.007), shoulder function (SMD = 1.34, 95% CI 0.43–2.25, p = 0.004), strength of arm (SMD = 0.44, 95% CI 0.20–0.68, p = 0.0004), and anxiety (MD = −4.90, 95% CI −7.83 to −1.98, p = 0.001) in breast cancer patients compared with the control group.

Conclusions: TCC appears to be effective on some physical and psychological symptoms and improves the quality of life in patients with breast cancer. Additional randomized controlled trials with a rigorous methodology and low risk of bias are needed to provide more reliable evidence.

Balancing STAT Activity as a Therapeutic Strategy

Driven by dysregulated IL-6 family member cytokine signaling in the tumor microenvironment (TME), aberrant signal transducer and activator of transcription (STAT3) and (STAT5) activation have been identified as key contributors to tumorigenesis. Following transformation, persistent STAT3 activation drives the emergence of mesenchymal/cancer-stem cell (CSC) properties, important determinants of metastatic potential and therapy failure. Moreover, STAT3 signaling within tumor-associated macrophages and neutrophils drives secretion of factors that facilitate metastasis and suppress immune cell function. Persistent STAT5 activation is responsible for cancer cell maintenance through suppression of apoptosis and tumor suppressor signaling. Furthermore, STAT5-mediated CD4+/CD25+ regulatory T cells (T_regs) have been implicated in suppression of immunosurveillance. We discuss these roles for STAT3 and STAT5, and weigh the attractiveness of different modes of targeting each cancer therapy. Moreover, we discuss how anti-tumorigenic STATs, including STAT1 and STAT2, may be leveraged to suppress the pro-tumorigenic functions of STAT3/STAT5 signaling.

Antitumor and Anti-Invasive Effect of Apigenin on Human Breast Carcinoma through Suppression of IL-6 Expression

Interleukin (IL)-6 plays a crucial role in the progression, invasion, and metastasis of breast cancer. Triple-negative breast cancer (TNBC) cell line MDA-MB-231 is known for its aggressive metastasis. Epithelial to mesenchymal transition (EMT) is a critical process in cancer metastasis. The positive correlation between IL-6 and EMT in tumor microenvironment is reported. We found significantly upregulated IL-6 expression in MDA-MB-231 cells. A blockade of IL-6 expression decreased levels of phosphorylated signal transducer and activator of transcription 3 (pSTAT3), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), phosphorylated protein kinase B (pAkt), and cell cycle-related molecules, including cyclin-dependent kinases (CDKs) and cyclins in MDA-MB-231 cells. A short-hairpin RNA (shRNA)-mediated blockade of IL-6 expression inhibited migration and N-cadherin expression and induced E-cadherin expression in MDA-MB-231 cells. Growth rate was slower for the tumors derived from IL-6 shRNA-treated MDA-MB-231 cells than for those derived from control shRNA-treated MDA-MB-231 cells. The expression of pSTAT3, phosphorylated extracellular signal-regulated kinase (pERK), PI3K, pAkt, snail, vimentin, and N-cadherin was significantly lower in tumors from IL-6 shRNA-treated MDA-MB cells. In addition, apigenin treatment significantly inhibited the growth of MDA-MB-231-derived xenograft tumors along with the protein expressions of pSTAT3, pERK, IL-6, PI3K, pAkt, and N-cadherin. Our results demonstrate that the anti-invasive effect of apigenin in MDA-MB-231-derived xenograft tumors is mediated by the inhibition of IL-6-linked downstream signaling pathway.

Interleukin-6 as a biomarker in patients with hepatobiliary cancers

Background

The role of inflammation has been well established in many cancers, including hepatobiliary cancers. Elevated levels of interleukin-6 (IL-6), a pro-inflammatory marker, are associated with poor overall survival (OS) in hepatocellular carcinoma (HCC) patients.

Methods

We performed a study to establish the role of IL-6 as a prognostic biomarker in both HCC and biliary cancer patients and further assessed the impact of IL-6 on pain score and performance status, two parameters that affect the quality of life. We evaluated 91 patients with newly diagnosed unresectable hepatobiliary cancer and compared them with age, gender and BMI matched healthy controls.

Results

We found that IL-6 levels were elevated in hepatobiliary cancer patients compared to healthy controls. Higher levels of IL-6 were associated with poor prognosis, elevated pain scores and poor performance status in patients. Interestingly, we found an association between elevated IL-6 levels and the presence of portal vein thrombosis (PVT) at the time of cancer diagnosis.

Conclusions

This study suggests that IL-6 is an important prognostic biomarker in hepatobiliary cancers, where elevated levels are not only associated with a worse survival but also linked to an inferior quality of life.

Pretreatment Cancer-Related Cognitive Impairment-Mechanisms and Outlook

Cognitive changes are common in patients with active cancer and during its remission. This has largely been blamed on therapy-related toxicities and diagnosis-related stress, with little attention paid to the biological impact of cancer itself. A plethora of clinical studies demonstrates that cancer patients experience cognitive impairment during and after treatment. However, recent studies show that a significant portion of patients with non-central nervous system (CNS) tumors experience cognitive decline prior to treatment, suggesting a role for tumor-derived factors in modulating cognition and behavior. Cancer-related cognitive impairment (CRCI) negatively impacts a patient’s quality of life, reduces occupational and social functioning, and increases morbidity and mortality. Furthermore, patients with cancer cachexia frequently experience a stark neurocognitive decline, suggesting peripheral tumors exert an enduring toll on the brain during this chronic paraneoplastic syndrome. However, the scarcity of research on cognitive impairment in non-CNS cancers makes it difficult to isolate psychosocial, genetic, behavioral, and pathophysiological factors in CRCI. Furthermore, clinical models of CRCI are frequently confounded by complicated drug regimens that inherently affect neurocognitive processes. The severity of CRCI varies considerably amongst patients and highlights its multifactorial nature. Untangling the biological aspects of CRCI from genetic, psychosocial, and behavioral factors is non-trivial, yet vital in understanding the pathogenesis of CRCI and discovering means for therapeutic intervention. Recent evidence demonstrating the ability of peripheral tumors to alter CNS pathways in murine models is compelling, and it allows researchers to isolate the underlying biological mechanisms from the confounding psychosocial stressors found in the clinic. This review summarizes the state of the science of CRCI independent of treatment and focuses on biological mechanisms in which peripheral cancers modulate the CNS.

Senescence-associated IL-6 and IL-8 cytokines induce a self- and cross-reinforced senescence/inflammatory milieu strengthening tumorigenic capabilities in the MCF-7 breast cancer cell line

Background

There is compelling evidence associating senescent cells with the malignant progression of tumours. Of all senescence-related mechanisms, the so-called senescence-associated secretory phenotype (SASP) has attracted much attention. Since the pro-inflammatory cytokines IL-6 and IL-8 are consistently present in the SASP, and secreted by highly aggressive breast cancer cell lines, we aimed at elucidating their role on the less aggressive breast cancer cell line MCF-7, which does not secret these cytokines.

Methods

The MCF-7 cell line was treated with either senescence-conditioned medium (SCM), IL-6 or IL-8 and then evaluated for phenotypic (CD44 and CD24 by FACS) and functional changes associated with an EMT program (migration/invasion) and for the acquisition of stem cell properties: mammosphere-forming capacity, expression of reprogramming factors (by qRT-PCR) and multilineage differentiation potential. We also evaluated the role of IL6 and IL8 in the cytokine-secreting, highly tumorigenic cell line MDA-MB-231.

Results

Our results show that treatment of MCF-7 cells with IL6 and IL8, alone or together, induced the appearance of cells with fibroblastoid morphology, increased CD44 expression and migration, self-renewal and multilineage differentiation capacity, all characteristics compatible with an EMT program and stemness. These changes closely resembled those induced by a SCM. Interestingly, SCM treatments further increased IL6 and IL8 secretion by MCF-7 cells, thus suggesting the participation of an autocrine loop. Indeed, neutralizing antibodies against IL6 and IL8 reversed the effects of SCM on MCF-7, pinpointing these cytokines as major mediators of EMT and stemness-related effects associated with the senescent microenvironment. Additionally, prolonged exposure of MCF cells to IL6 or IL8 induced the appearance of senescent cells, suggesting a mechanism by which senescence and inflammation are reinforced favouring the acquisition of EMT and stem-like features at the population level, thus increasing tumour aggressiveness. Strikingly, our results also show that both IL6 and IL8 are important to maintain aggressive traits in MDA-MB-231 cells, a highly tumorigenic cell line, which appears to be devoid of stemness-related features.

Conclusions

This study demonstrates that, similar to what is observed with a senescent microenvironment, purified IL6 and IL8 induce a self- and cross-reinforced senescence/inflammatory milieu responsible for the emergence of epithelial plasticity and stemness features, thus conferring more aggressive phenotypes to a luminal breast cancer cell line. On the other hand, the basal-like MDA-MB-231 cells, whose aggressiveness-related features depend on IL6 and IL8 secretion, almost completely lack mammosphere formation and differentiation capacities, suggesting that tumour aggressiveness is not always related to stemness.

Electronic supplementary material

The online version of this article (doi:10.1186/s12964-017-0172-3) contains supplementary material, which is available to authorized users.

Interleukin-6 is a potential therapeutic target in interleukin-6 dependent, estrogen receptor-α-positive breast cancer

Introduction

Interleukin-6 (IL-6) is an important growth factor for estrogen receptor-α (ERα)-positive breast cancer, and elevated serum IL-6 is associated with poor prognosis.

Methods

The role of the phosphorylated signal transducer and activator of transcription 3 pathway was investigated in ERα-positive breast cancer. A panel of cell lines was treated with exogenous IL-6. An IL-6 specific gene signature was generated by profiling ten ERα-positive breast cancer cell lines alone or following treatment with 10 ng/mL recombinant IL-6 or human marrow stromal cell-conditioned media, with or without siltuximab (a neutralizing anti-IL-6 antibody) and grown in three-dimensional tumor microenvironment-aligned cultures for 4 days, 5 days, or 6 days. The established IL-6 signature was validated against 36 human ERα-positive breast tumor samples with matched serum. A comparative MCF-7 xenograft murine model was utilized to determine the role of IL-6 in estrogen-supplemented ERα-positive breast cancer to assess the efficacy of anti-IL-6 therapy in vivo.

Results

In eight of nine ERα-positive breast cancer cell lines, recombinant IL-6 increased phosphorylation of tyrosine 705 of STAT3. Differential gene expression analysis identified 17 genes that could be used to determine IL-6 pathway activation by combining their expression intensity into a pathway activation score. The gene signature included a variety of genes involved in immune cell function and migration, cell growth and apoptosis, and the tumor microenvironment. Validation of the IL-6 gene signature in 36 matched human serum and ERα-positive breast tumor samples showed that patients with a high IL-6 pathway activation score were also enriched for elevated serum IL-6 (≥10 pg/mL). When human IL-6 was provided in vivo, MCF-7 cells engrafted without the need for estrogen supplementation, and addition of estrogen to IL-6 did not further enhance engraftment. Subsequently, we prophylactically treated mice at MCF-7 engraftment with siltuximab, fulvestrant, or combination therapy. Siltuximab alone was able to blunt MCF-7 engraftment. Similarly, siltuximab alone induced regressions in 90% (9/10) of tumors, which were established in the presence which were established in the presence of hMSC expressing human IL-6 and estrogen.

Conclusion

Given the established role for IL-6 in ERα-positive breast cancer, these data demonstrate the potential for anti-IL-6 therapeutics in breast cancer.

A phase II double-blinded study to evaluate the efficacy of EW02 in reducing chemotherapy-induced neutropenia in breast cancer

EW02, a polysaccharide-enriched crude extract from black soybean, has been shown to assist hematopoiesis in chemotherapy-treated animals. The present study aimed to clarify the safety, quality of life (QOL) and efficacy for myelopoiesis of EW02 administration in early breast cancer (EBC) patients receiving adjuvant chemotherapy. A total of 60 eligible EBC patients were enrolled in a randomized, double-blinded trial, 40 of whom were prescribed 700 mg oral EW02 three times daily for 15 days in chemotherapy cycle (C)2. The remainder were prescribed a placebo. All subjects took EW02 in C3 for 15 days. Blood samples were collected at different time-points for determining the blood cell count, and the serum level of granulocyte colony-stimulating factor (G-CSF) and interleukin (IL)-6. All patients tolerated EW02 well without severe side-effects. QOL evaluation showed that only the score of one questionnaire section (QLQ-C30) was significantly increased at C1 day (D)8 to C2D8 when the EW02 and placebo groups were compared (P=0.045). No significant myelopoiesis recovery, and no incremental change in IL-6 and G-CSF levels were found in C2. Subgroup analysis showed a slightly lower decrease in absolute neutrophil count (ANC) in the EW02 patients who underwent Adriamycin + cyclophosphamide treatment compared with the placebo group. Although EW02 failed to show efficacy for myelopoiesis in the present study, EW02 was still well tolerated in EBC patients who underwent adjuvant chemotherapy.

The Stat3 paradox: a killer and an oncogene

Stat proteins regulate many aspects of mammary gland development, including the profound changes that occur during pregnancy, lactation and involution. Stat3 induces transcriptional activation of genes involved in the inflammatory response, and in seemingly contradictory cellular events such as apoptosis, differentiation and stem cell maintenance. While Stat3 signalling during mammary gland involution induces epithelial cell death, aberrant Stat3 activation is widely implicated in breast tumourigenesis. Specific cytokines may initiate either a Stat3-driven proliferative or death response depending on the cell-type and cell-context specific availability of particular combinations of signals and receptors. The paradoxical functions of Stat3 may also be due to the degree and extent of activation in different circumstances, in addition to paracrine signalling between mammary epithelial cells and the surrounding microenvironment. Deciphering the enigmatic nature of Stat3 in the mammary gland may benefit future therapeutic strategies for inducing cell death in breast tumours.

The role of inflammation in inflammatory breast cancer

Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer. Despite extensive study, whether inflammation contributes to the tumorigenicity or aggressiveness of IBC remains largely unknown. In this chapter, we will review the potential role played by inflammation in IBC based on the results of in vitro, in vivo, and patient studies. Current evidence suggests that several major inflammatory signaling pathways are constitutively active in IBC and breast cancer. Among them, the NF-κB, COX-2, and JAK/STAT signaling systems seem to play a major role in the tumorigenesis of IBC. Inflammatory molecules such as interleukin-6, tumor necrosis factor alpha (TNF-α), and gamma interferon have been shown to contribute to malignant transformation in preclinical studies of IBC, while transforming growth factor-β, interleukins 8 and 1β, as well as TNF-α appear to play a role in proliferation, survival, epithelial-mesenchymal transition, invasion, and metastasis. In this chapter, we also describe work thus far involving inhibitors of inflammation in the development of prevention and treatment strategies for IBC.

Adjuvant breast cancer vaccine improves disease specific survival of breast cancer patients with depressed lymphocyte immunity

PURPOSE

Beginning in 1995 breast cancer patients were vaccinated in the adjuvant setting with an autologous, allogeneic whole cell vaccine to evaluate the effect on host lymphocyte immunity and disease specific survival.

METHODS

The breast cancer patients had host lymphocyte immunity against tumor associated antigens evaluated by a Lymphocyte Blastogenesis Assay (LBA) before vaccination. Thirty-seven patients with depressed immunity were vaccinated in the adjuvant setting. Patients were given six intradermal injections (three weekly followed by three monthly). Ten weeks after the last injection the LBA was repeated.

RESULTS

Some patients experienced slight pain and swelling at the injection site with slight chills and fever, but there were no severe toxicities. The vaccinated patients had a mean follow-up of 12.7 years with mean follow-up of 8.9 and 9.2 years for the patients with normal and depressed immunity, respectively, in the historic control. The 10 year survival was 95% (20 of 21 patients) in the normal immunity historic control, 59% (33 of 56 patients) in the depressed immunity historic control and 89% (33 of 37 patients) in the patients with depressed immunity that were vaccinated in the present clinical trial. The disease specific survival of the vaccinated patients with depressed immunity in this trial is significantly greater than that of the historic controls of unvaccinated patients with depressed immunity to their tumor associated antigens.

CONCLUSION

This study confirms the importance of maintaining good host lymphocyte immunity after completion of standard therapy and validates the value of cancer immunotherapy in the adjuvant setting.

The role of chronic inflammation in obesity-associated cancers

There is a strong relationship between metabolism and immunity, which can become deleterious under conditions of metabolic stress. Obesity, considered a chronic inflammatory disease, is one example of this link. Chronic inflammation is increasingly being recognized as an etiology in several cancers, particularly those of epithelial origin, and therefore a potential link between obesity and cancer. In this review, the connection between the different factors that can lead to the chronic inflammatory state in the obese individual, as well as their effect in tumorigenesis, is addressed. Furthermore, the association between obesity, inflammation, and esophageal, liver, colon, postmenopausal breast, and endometrial cancers is discussed.

Correlation of levels of IL-6 with tumor burden and receptor status in patients of locally advanced carcinoma breast

Inflammatory pathways have garnered considerable interest in the recent past as an important mediator of the molecular mechanisms leading to carcinogenesis. The present study was conducted to evaluate the correlation of levels of IL-6 with tumor burden and receptor status in patients of locally advanced carcinoma breast. This prospective study was conducted by the collaborative efforts of the departments of Surgery and Biochemistry, Maulana Azad Medical College and associated Lok Nayak Hospital and GB Pant Hospitals, New Delhi. The study population comprised of 30 cases of locally advanced breast carcinoma recruited from the surgical outpatient department. The various parameters that were evaluated include detailed clinico-pathological profile and IL-6 levels. Tissue specimens received after surgeries were examined for the various characteristics indicative of tumor prognosis. Majority of the patients was in the age group of 41-50 years and was postmenopausal. The serum level of IL-6 increased as the disease progressed from T3N1M0 to T4dN2M0 (41.4 ± 31.9 vs. 164.0 ± 31.1 pg/ml respectively). There was significant correlation of IL-6 levels with lymph node involvement, tumor grade, mitotic index and adipose tissue invasion. Emerging molecular markers are being investigated for breast cancer prognosis assessment and prediction of response to chemotherapy including selection of best possible treatment modality. Our study showed that there is progressive increase in IL-6 levels as the stage of disease progresses.

Effects of Tai Chi Chuan on insulin and cytokine levels in a randomized controlled pilot study on breast cancer survivors

BACKGROUND

Tai Chi Chuan (TCC) is an integrative medicine mind-body practice with a physical activity component that has positive effects on aerobic capacity, muscular strength, and quality of life among cancer survivors, similar to the effects elicited by other modes of moderate-intensity exercise. Inflammatory cytokines and insulin and insulin-related signaling molecules may contribute to weight gain and affect cancer recurrence rates and survival; exercise can curb cancer- and treatment-related weight gain, increase survival, and reduce levels of insulin and inflammatory cytokines. Despite knowing the beneficial effects of conventional exercise interventions on these mediators, little is known about the physiologic effects of TCC on these pathways in breast cancer survivors.

METHODS

We assessed the effects of a 12-week, moderately intense, TCC intervention (n = 9) compared with a non-physical activity control (n = 10) consisting of psychosocial support therapy (PST), on levels of insulin, insulin-like growth factor (IGF)-1, insulin growth factor-like binding protein (IGFBP)-1, IGFBP-3, and cytokines interleukin (IL)-6, IL-2, and interferon (IFN)-γ in breast cancer survivors.

RESULTS

Levels of insulin are significantly different in TCC and PST groups; levels remained stable in the TCC group but increased in the PST control group (P = .099). Bivariate analysis revealed novel and significant correlations (all r > 0.45, all P ≤ .05) of both decreased fat mass and increased fat-free mass with increased IL-6 and decreased IL-2 levels.

CONCLUSIONS

This pilot study shows that TCC may be associated with maintenance of insulin levels and changes in cytokine levels that may be important for maintenance of lean body mass in breast cancer survivors.

Circadian effects in cancer-relevant psychoneuroendocrine and immune pathways

Human biology is deeply integrated with the rotation of the Earth: healthy physiology is synchronized with circadian cycles, while unhealthy states are often marked by poor circadian coordination. In certain cancers including breast cancer, striking circadian rhythm dysregulation extends to endocrine, immune, metabolic, and cellular function. Disruption resulting from biological and behavioral influences has been linked with higher incidence and faster tumor progression in humans and animals. The hypothalamic SCN coordinates circadian events at the tissue and cellular level, partly via glucocorticoids that regulate genes involved in tumor growth, cell proliferation, apoptosis, immune cell trafficking, and cytotoxicity. We present a revision of our previously published model of circadian effects in cancer (Sephton and Spiegel, 2003) based on evaluation of new data from divergent lines of investigation. Human clinical studies show circadian endocrine disruption may be accompanied by suppressed functional cellular immunity and overactive inflammatory responses that could promote tumor growth, angiogenesis, and metastasis. Animal data provide strong evidence of clock gene regulation of tumor cell growth. Tissue culture research demonstrates that biologically or behaviorally mediated down-regulation of clock gene expression can accelerate tumor growth. An integrated view suggests mechanisms by which circadian effects on tumor growth may be mediated. These include psychoneuroendocrine and psychoneuroimmune pathways, the relevance of which we highlight in the context of breast cancer. Taken together, data from clinical, systemic, cellular, and molecular research suggest the circadian clock is a tumor suppressor under both biological and behavioral control.

Expression of HSP27, HSP72 and MRP proteins in in vitro co-culture of colon tumour cell spheroids with normal cells after incubation with rhTGF- beta1 and/or CPT-11

We studied the expression of inducible heat shock protein (HSP27, HSP72) and multidrug-resistance protein (MRP) in co-cultures of human colon carcinoma cell spheroids obtained from different grades of tumour with normal human colon epithelium, myofibroblast and endothelial cell monolayers. We also measured the influence of recombinant human transforming growth factor beta1 (rhTGF-beta1) and camptothecin (CPT-11), added as single agents or in combination, on the levels of the HSPs, MRP, interleukin (IL)-6 and nitric oxide (NO). An immunoblotting analysis with densitometry showed that rhTGF-beta1 and/or CPT-11 increased HSP27, HSP72 and MRP expression in tumour cells and myofibroblasts, as well as in co-cultures compared with appropriate controls. By contrast, in colonic epithelium, inhibition of HSPs and MRP was comparable with that of the control. In endothelial cells, HSP72 was undetectable. Direct interaction of colon tumour spheroids with normal myofibroblasts caused a significant, tumour-grade dependent increase in IL-6 production. Production of IL-6 was significantly lowered by rhTGF-beta1 and/or CPT-11. Tumour cell spheroids cultivated alone produced larger amounts of NO than normal cells. In co-culture, the level of the radical decreased compared with the sum of NO produced by the monocultures of the two types of cells. rhTGF-beta1 and/or CPT-11 decreased NO production both in tumour and normal cell monocultures and their co-cultures. In conclusion, direct interactions between tumour and normal cells influence the expression of HSP27, HSP72 and MRP, and alter IL-6 and NO production. rhTGF-beta1 and/or CPT-11 may potentate resistance to chemotherapy by increasing HSP and MRP expression but, on the other hand, they may limit tumour cell spread by decreasing the level of some soluble mediators of inflammation (IL-6 and NO).

Convergence of hormones, inflammation, and energy-related factors: a novel pathway of cancer etiology

Colorectal cancer (CRC) is a multifactorial disease with several hypothesized etiologic factors including inflammatory processes; hormones such as estrogen, androgen, and insulin; and energy-related factors. We present evidence that integrates these elements in a pathway we call the convergence of hormones, inflammation, and energy-related factors (CHIEF). First, given the physiology of the gut, substantial epidemiologic and molecular data support the hypothesis that activation of innate immunity in the normal gut mucosa by various environmental agents (commensal bacteria, dietary antigens, mucosal irritants, pathogens) and endogenous factors such as estrogen, androgens, and insulin levels provokes basal inflammation as an underlying factor of the association of insulin, estrogen, and energy-related factors with CRC. Second, critical genes involved in this pathway, e.g., phosphatase tensin homologue on chromosome 10 (PTEN) and serine threonine kinase 11 (STK11)/LKB1, are tumor suppressor genes often mutated in intestinal cancer or CRC. Third, laboratory experiments show that cellular PTEN and STK11/LKB1 tumor suppressor enzymes are vulnerable to inactivation by redox-active species, especially chemically reactive lipid mediators of inflammation and redox stress. Epidemiologic data further support the underlying proposal that CHIEF comprises important elements of CRC risk. Although this discussion of the CHIEF pathway focuses on CRC, we believe that this pathway may play an important role in the etiology of other cancers as well.

Cancer protection of soy resembles cancer protection during pregnancy

It has been established that carrying a pregnancy to full-term at an early age can protect against contracting cancer by up to 50% in later life. The trophoblast theory of cancer states that trophoblast and cancer tissue are very similar. New findings suggest that the loss of fetal cells during pregnancy resemble those cells responsible for causing metastasis in cancer. Fetal cells and spreading cancer cells are highly proliferative. They are similar to stem cells, exhibiting no or low hormone receptor expression, and require a hormone receptor independent mechanism for control. Control of membrane stability during pregnancy is of vital importance for a successful pregnancy and is mediated by androstenediol and 2-methoxyestradiol. 2-Methoxyestradiol has no hormone receptor affinity and elicits strong anticancer effects particularly against cancer stem cells and fetal cells, for which currently no treatment has yet been established. There is a discussion whether pregnancy reduces cancer stem cells in the breast. Soy isoflavones are structurally similar to both hormones, and elicit strong anticancer effects and antiangiogenesis via inhibition of NF-κB, even in hormone receptor independent breast cancers seen in epidemiologic studies. The trophoblast theory of cancer could help to explain why soy baby nutrition formulas have no effect on baby physiology, other than the nutritional aspect, although soy elicits many effects on the adult immune system. To survive the immune system of the mother, the immune system of the fetus has to be separated; otherwise, the reduction of the immune system in the mother, a necessary feature for the blastocyst to grow, would immediately reduce the immunity for the fetus and endanger its survival. Similar to a fetus, newly born babies show immune insensitive to Th1 and Th2 cytokines, which are necessary and crucial for regulating the immune system of the mother, thus raising the risk of the baby of developing allergies and neurodermatitis. Gene expression studies in vitro as well as in circulating tumor cells from patients consuming a fermented soy product support the antiangiogenic as well as antiproliferative effects of soy.

Interleukin-6 induces an epithelial-mesenchymal transition phenotype in human breast cancer cells

Breast tumor interleukin-6 (IL-6) levels increase with tumor grade, and elevated serum IL-6 correlates with poor breast cancer patient survival. Epithelial-mesenchymal transition (EMT) phenotypes such as impaired E-cadherin expression or aberrant Vimentin induction are associated with enhanced metastasis and unfavorable clinical outcome in breast cancer. Despite this fact, few tumor microenvironment-derived extracellular signaling factors capable of provoking such a phenotypic transition have been identified. In this study, we showed that IL-6 promoted E-cadherin repression among a panel of estrogen receptor-alpha-positive human breast cancer cells. Furthermore, ectopic stable IL-6 expressing MCF-7 breast adenocarcinoma cells (MCF-7(IL-6)) exhibited an EMT phenotype characterized by impaired E-cadherin expression and induction of Vimentin, N-cadherin, Snail and Twist. MCF-7(IL-6) cells formed xenograft tumors that displayed loss of E-cadherin, robust Vimentin induction, increased proliferative indices, advanced tumor grade and undifferentiated histology. Finally, we showed aberrant IL-6 production and STAT3 activation in MCF-7 cells that constitutively express Twist, a metastatic regulator and direct transcriptional repressor of E-cadherin. To our knowledge, this is the first study that shows IL-6 as an inducer of an EMT phenotype in breast cancer cells and implicates its potential to promote breast cancer metastasis.

Physical activity and postmenopausal breast cancer: proposed biologic mechanisms and areas for future research

Convincing evidence now supports a probable preventive role for physical activity in postmenopausal breast cancer. The mechanisms by which long-term physical activity affect risk, however, remain unclear. The aims of this review were to propose a biological model whereby long-term physical activity lowers postmenopausal breast cancer risk and to highlight gaps in the epidemiologic literature. To address the second aim, we summarized epidemiologic literature on 10 proposed biomarkers, namely, body mass index (BMI), estrogens, androgens, sex hormone binding globulin, leptin, adiponectin, markers of insulin resistance, tumor necrosis factor-alpha, interleukin-6, and C-reactive protein, in relation to postmenopausal breast cancer risk and physical activity, respectively. Associations were deemed "convincing," "probable," "possible," or "hypothesized" using set criteria. Our proposed biological model illustrated the co-occurrence of overweight/obesity, insulin resistance, and chronic inflammation influencing cancer risk through interrelated mechanisms. The most convincing epidemiologic evidence supported associations between postmenopausal breast cancer risk and BMI, estrogens, and androgens, respectively. In relation to physical activity, associations were most convincing for BMI, estrone, insulin resistance, and C-reactive protein. Only BMI and estrone were convincingly (or probably) associated with both postmenopausal breast cancer risk and physical activity. There is a need for prospective cohort studies relating the proposed biomarkers to cancer risk and for long-term exercise randomized controlled trials comparing biomarker changes over time, specifically in postmenopausal women. Future etiologic studies should consider interactions among biomarkers, whereas exercise trials should explore exercise effects independently of weight loss, different exercise prescriptions, and effects on central adiposity.

Cytokines and their relationship to the symptoms and outcome of cancer

Tumours contain immune cells and a network of pro- and anti-inflammatory cytokines, which collaborate in the development and progression of cancer. Cytokine profiles might prove to be prognostic. The systemic effects of pro-inflammatory cytokines are associated with fatigue, depression and cognitive impairment, and can affect quality of life before, during and after treatment. In people with advanced cancer, pro-inflammatory cytokines are additionally associated with anorexia and cachexia, pain, toxicity of treatment and resistance to treatment. However, physical activity might modify cytokine levels and decrease fatigue in patients with cancer, and might also improve their prognosis.

Systematic review of the association between circulating interleukin-6 (IL-6) and cancer

Our aim was to systematically review the epidemiologic evidence for an association of circulating interleukin-6 (IL-6), an inflammatory cytokine and cancer. We systematically searched electronic databases Embase, Medline and Web of Science for the studies of circulating IL-6 and any form of cancer. We identified and reviewed 189 discrete studies, consisting of 177 prevalent studies and three prospective studies. Cancer patients' IL-6 concentrations were higher than healthy controls' in most studies, but the results of investigations comparing IL-6 in cancer patients and individuals with benign diseases were less consistent. Due to the small number of prospective studies it is impossible to determine whether IL-6 is causally related to cancer. Large prospective studies of circulating IL-6 or studies using the functional variants of the IL-6 gene as instruments for circulating IL-6 concentrations would provide information on possible aetiological links between IL-6 and malignancy.

IL6, aspirin, nonsteroidal anti-inflammatory drugs, and breast cancer risk in women living in the southwestern United States

Interleukin-6 is a cytokine thought to be involved in inflammation, insulin, and estrogen-related pathways. We evaluate genetic variation in the IL6 gene with risk of breast cancer. We also evaluate breast cancer associations with aspirin and nonsteroidal anti-inflammatory drugs. A breast cancer case-control study (n = 1,527 non-Hispanic white cases, 1,601 non-Hispanic white controls, 798 Hispanic/Native American cases, and 924 Hispanic/Native American controls) was conducted among women living in the southwestern United States (4-Corner's Breast Cancer Study). Five IL6 single nucleotide polymorphisms (SNP) and IL6 haplotypes based on these SNPs were evaluated. Allele frequencies were significantly different between non-Hispanic white and Hispanic/Native American women. Among postmenopausal women not recently exposed to hormones, the AG/GG genotypes of rs1800797 (-596A>G) and the GC/CC genotypes of rs1800795 (-174G>C) significantly reduced risk of breast cancer among non-Hispanic white women [odds ratio (OR), 0.69; 95% confidence interval (95% CI), 0.48-1.00 and OR, 0.68; 95% CI, 0.47-0.99, respectively] and Hispanic/Native American women (OR, 0.48; 95% CI, 0.28-0.83 and OR, 0.44; 95% CI, 0.26-0.99, respectively). Haplotypes of the five IL6 SNPs further defined these associations. Recent aspirin use significantly decreased risk of breast cancer among postmenopausal Hispanic/Native American women not recently exposed to hormones (OR, 0.56; 95% CI, 0.33-0.96). Among non-Hispanic white, the inverse association with aspirin was not statistically significant. IL6 genotype and haplotype significantly modified the association between aspirin and breast cancer, with the greatest effect modification being among women not recently exposed to hormones [P interaction = 0.06 (for non-Hispanic white) and 0.04 (for Hispanic/Native American) and SNP rs1800796 or -572G>C]. These data suggest that IL6 is associated with breast cancer risk and modifies the association between estrogen and aspirin and breast cancer risk.

Vitamin D, tamoxifen and beta-estradiol modulate breast cancer cell growth and interleukin-6 and metalloproteinase-2 production in three-dimensional co-cultures of tumor cell spheroids with endothelium

Reciprocal interactions between tumor cells and endothelial cells constitute the most important stage of tumor metastasis. There is growing evidence suggesting that beta-estradiol and vitamin D modulate the progression of steroid-sensitive breast cancers. In keeping with those results, the purpose of the study reported here was to determine the cytotoxic and antiproliferative activity of tamoxifen (TAM) in the T47D human breast cancer cell line depending on the cell culture model (three-dimensional (3D, spheroid) or two-dimensional (2D, monolayer)) and to estimate the antiproliferative activity of vitamin D in balanced TAM/beta-estradiol conditions. The study was also designed to investigate whether vitamin D might influence interleukin-6 (IL-6) and metalloproteinase-2 (MMP-2) production in a co-culture of T47D cell spheroids with an endothelial cell monolayer in the presence of beta-estradiol and TAM. Spectrophotometric analysis with MTT revealed that the cytotoxic and antiproliferative activity of TAM was dependent on the culture model, the density of cell culture, and culture medium supplements. In balanced TAM/beta-estradiol medium, vitamin D only slightly inhibited T47D cell proliferation in both 2D and 3D cultures. Direct contact of tumor cell spheroids with the endothelium induced production of MMP-2 and IL-6, which was significantly inhibited in TAM/beta-estradiol balanced medium. Addition of vitamin D further inhibited MMP-2 production, but enhanced the production of IL-6 as was shown by ELISA assay. Our co-culture model in TAM/beta-estradiol balanced medium proved to be useful for examining direct and paracrine interactions of tumor cells with the endothelium in conditions that were closer to in vivo conditions than in the standard 2D model.

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.

Exercise and lymphocyte activation following chemotherapy for breast cancer

PURPOSE

To determine whether exercise training would increase lymphocyte activation in patients with breast cancer following chemotherapy. Activation was determined by the presence of CD4(+)CD69(+) T-helper lymphocytes, mitogen-induced proliferation, and levels of cytokines produced by mitogen-stimulated lymphocytes and in the patients' plasma.

METHODS

Patients with breast cancer (N = 28) who participated in a 6-month exercise program were compared with patients (N = 21) who did not exercise. Following chemotherapy, and 3 and 6 months later, patients underwent fitness evaluations and had blood drawn. The exercise program consisted of resistance training and aerobic activity at 60-75% functional capacity three times a week with a personal trainer. Immunochemistry and flow cytometry were used to measure the number of CD4(+)CD69(+) blood lymphocytes. Whole blood was stimulated with concanavalin A (ConA), phytohemagglutin (PHA), or pokeweed mitogen (PWM) to determine proliferation potential. Enzyme-linked immunosorbent assays (ELISA) were used to determine the concentration of interferon-gamma (IFN-gamma) and interleukin-6 (IL-6) in the culture medium of mitogen-stimulated lymphocytes as well as the plasma concentrations of IL-6, soluble IL-6 receptor, soluble gp130, and IFN-gamma. Analysis of groups across time was done using the Wilcoxon signed rank test, and comparisons of groups were done using the Mann-Whitney U test.

RESULTS

The exercising patients showed increases in maximal oxygen uptake and upper body strength. This group also showed a greater percentage of CD4(+)CD69(+) cells and a greater level of tritiated thymidine incorporation (DNA synthesis) when stimulated with ConA, PHA, and PWM at the end of the intervention. Plasma and mitogen-stimulated IL-6 and IFN-gamma production were similar in both groups.

CONCLUSION

Exercise may improve immune function by increasing lymphocyte activation in patients with breast cancer following treatment.

Vaccination with a mixed vaccine of autogenous and allogeneic breast cancer cells and tumor associated antigens CA15-3, CEA and CA125--results in immune and clinical responses in breast cancer patients

In breast cancer there is often overexpression of the breast cancer antigen CA15-3, the carcinoembryonic antigen (CEA) and the ovarian cancer antigen CA125, which makes them potential target antigens for immunotherapy. In this study, we used a multi-antigen vaccine, which included the following antigens: autologous breast cancer cells (AUTOC), allogeneic breast cancer MCF-7 cells (ALLOC), and the tumor associated antigens CA15-3, CEA and CA125, plus low doses of granulocyte/macrophage-colony-stimulating factor (GM-CSF) and interleukin 2 (IL-2). Forty-two breast cancer patients received weekly subcutaneous vaccination at the 1st, 2nd, 3rd, 7th, 11th and 15th weeks. Their lymphocyte proliferative responses to AUTOC, ALLOC, CA15-3, CEA and CA125 were tested in lymphocyte blastogenesis assays (LBA) before and after vaccination. The disease stage and serum CA15-3, CEA and CA125 concentrations were also determined pre- and post-vaccination. We found that the vaccine was safe, and the only major side effects were swelling at the site of injection, muscle pain, and weakness or fatigue. The vaccine induced a significant increase in post-vaccination lymphocyte proliferative responses to AUTOC, CA15-3, CEA and CA125 but not ALLOC, compared to pre-vaccination (p < 0.05, p < 0.01, p < 0.05, p < 0.01 and p > 0.05, respectively, a paired t Test). Computed tomography (CT), ultrasound or bone scan showed evidence of disease improvement in 2 (12%) patients after vaccination. Hepatic metastases were reduced in size and number and some actually disappeared one patient. Metastatic disease in the L5 vertebra and the skull decreased in size and some osteolytic sites completely healed in a second patient. In addition, 7 patients (44%) had stable disease and 7 patients (44%) had disease progression. We did not find vaccination significantly reduced serum tumor markers CA15-3, CEA and CA125 of these breast cancer patients. These results suggest that the vaccine mixture of autologous and allogeneic breast cancer cells and tumor associated antigens plus GM-CSF and IL-2 can be administered safely to breast cancer patients and there is evidence for improved immunity and clinical efficacy.