Abstract P4-09-18: Characterization of circulating myeloid derived suppressor cells and cytokines in patients undergoing neo-adjuvant chemotherapy for breast cancer

Myeloid derived suppressor cells (MDSC) are immature immune cells that expand in patients (pts) with cancer and suppress anti-tumor immunity. MDSC are also known to support angiogenesis. Higher circulating MDSC levels are seen in patients with greater tumor burden. Therefore, circulating MDSC levels could be affected by chemotherapy and could correlate with response. In this prospective pilot trial, peripheral blood (PB) levels of granulocytic (G-MDSC) and monocytic (M-MDSC) MDSC were measured in pts with operable breast cancer (BC) treated with neo-adjuvant chemotherapy (NAC) to study their association with pathologic complete response. It was hypothesized that MDSC % would show an association with complete pathologic response (pCR). The association of 10 different cytokine levels (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, IFN-γ, TNF-α) with pCR was also explored. Linear mixed models tested the associations between MDSC % or cytokines across time points with pCR. Levels of MDSC were measured by flow cytometry as a % of PB mononuclear cells prior to cycle (C) 1 and 2 of doxorubicin and cyclophosphamide (AC) and 1st and last administration of paclitaxel (T) or T and anti-HER2 therapy (in HER2+ pts). For other regimens, MDSC were measured prior to 1st, 2nd and last cycle. MDSC were defined as HLA-DR-, CD11b+, CD33+ cells with G-MDSC and M-MDSC cells expressing CD15 and CD14, respectively. Plasma cytokine levels were measured using a multiplex assay (Bio-Rad). Of 24 enrolled pts, 1, 20 and 3 had clinical stage I, II, IIIA, respectively. Median age was 48 (range 32-70). 11, 6 and 7 pts were triple negative (TN), HER2+ and hormone receptor (HR)+, respectively. PCR rate was 45.8% (46%, 50%, 43%, 20% for TN, HER2+, HR+ and >10% HR+ pts). Rate of residual cancer burden (RCB) class 0-1 was 58.3% (63.6%, 50%, 57.1%, 40% in TN, HER2+, HR+ and >10% HR+ pts). Mean M-MDSC % were <1 at all time points. Mean G-MDSC % and 95% confidence intervals (CI) were 0.88 (0.23-1.54), 5.07 (2.45-7.69), 9.32(4.02-14.61) and 1.97 (0.53-3.41) at times 1-4. The increase in MDSC by C1 of T was significant (p<0.0001) in all BC types. Baseline G-MDSC % did not differ in pts with or without pCR. G-MDSC levels at the last time point were also not statistically different but were numerically slightly lower in pts with pCR (1.15; 95%CI 0.14-2.16) versus pts with no pCR (2.71; 95%CI 0-5.47). Levels of all 10 cytokines were measurable in pts throughout NAC. The mean levels of IL-1β, IL-2, IL-4, IL-13 and IFN-γ peaked by C1 of T, while levels of IL-5, IL-6, IL-10, IL-12 and TNF-α were the highest at draw 1 and decreased during NAC. This pilot study confirmed feasibility of measuring circulating MDSC and cytokines in breast cancer pts receiving neo-adjuvant chemotherapy. The results showed that G-MDSC % increase during AC and then decrease during T and that a mixture of Th1 and Th2 cytokines peak during treatment. Levels of MDSC and cytokines did not significantly differ between pts with or without a pCR. However, a larger study with greater power to detect smaller differences and evaluate association between MDSC levels and pCR in different BC subtypes is needed.

Citation Format: Wesolowski R, Duggan M, Stiff A, Trikha P, Schoenfield L, Abdel-Rasoul M, Layman R, Ramaswamy B, Macrae E, Lustberg MB, Mrozek E, Carson WE. Characterization of circulating myeloid derived suppressor cells and cytokines in patients undergoing neo-adjuvant chemotherapy for breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-09-18.

NK Cell-Mediated Antitumor Effects of a Folate-Conjugated Immunoglobulin Are Enhanced by Cytokines

Optimally effective antitumor therapies would not only activate immune effector cells but also engage them at the tumor. Folate conjugated to immunoglobulin (F-IgG) could direct innate immune cells with Fc receptors to folate receptor-expressing cancer cells. F-IgG bound to human KB and HeLa cells, as well as murine L1210JF, a folate receptor (FR)-overexpressing cancer cell line, as determined by flow cytometry. Recognition of F-IgG by natural killer (NK) cell Fc receptors led to phosphorylation of the ERK transcription factor and increased NK cell expression of CD69. Lysis of KB tumor cells by NK cells increased by about 5-fold after treatment with F-IgG, an effect synergistically enhanced by treatment with IL2, IL12, IL15, or IL21 (P< 0.001). F-IgG also enhanced the lysis of chronic lymphocytic leukemia cells by autologous NK cells. NK cells significantly increased production of IFNγ, MIP-1α, and RANTES in response to F-IgG-coated KB target cells in the presence of the NK cell-activating cytokine IL12, and these coculture supernatants induced significant T-cell chemotaxis (P< 0.001). F-IgG-coated targets also stimulated FcR-mediated monocyte effector functions. Studies in a murine leukemia model confirmed the intratumoral localization and antitumor activity of F-IgG, as well as enhancement of its effects by IL12 (P =0.05). The antitumor effect of this combination was dependent on NK cells and led to decreased tumor cell proliferation in vivo Thus, F-IgG can induce an immune response against FR-positive tumor cells that is mediated by NK cells and can be augmented by cytokine therapy.

A Comprehensive Program for the Enhancement of Accrual to Clinical Trials

BACKGROUND

The Ohio State University Comprehensive Cancer Center (OSUCCC) embarked on a single institution campaign over 2 years to enhance the enrollment of cancer patients into therapeutic clinical trials. The goal of this campaign was to achieve a 40 % increase in accrual over a 2-year period.

METHODS

The entire process of accruing patients to clinical trials at the OSUCCC was carefully evaluated and broken down into several interlocking components. The four key areas of emphasis were as follows: (i) tasking of OSUCCC leadership with increased oversight of the entire process; (ii) education of all stakeholders [patients, their families, nurses and staff, physicians (both internal and external), Disease-Specific Committees (DSCs), and the OSUCCC leadership] as to the purpose, advantages, and availability of clinical trials, with an emphasis on accrual to cancer clinical trials (CCTs) being a critical function of all OSUCCC employees; (iii) increased oversight of the portfolio of clinical trials by DSCs; and (iv) optimization of accrual operations and infrastructure center-wide.

RESULTS

The accrual goal was achieved a full 4 months ahead of schedule. In total, 2327 patients were accrued to therapeutic clinical trials over the course of this 2-year campaign. Prior to implementation of the accrual program, the accrual rate was consistently below 15 %. From 2009 onwards, the therapeutic accrual rate was always greater than 25 %.

CONCLUSIONS

A campaign to educate key stakeholders in the clinical trials accrual process was successful in its goal of increasing accrual to therapeutic trials.

Analysis of the Effects of the Bruton's tyrosine kinase (Btk) Inhibitor Ibrutinib on Monocyte Fcγ Receptor (FcγR) Function

The irreversible Bruton's tyrosine kinase (Btk) inhibitor ibrutinib has shown efficacy against B-cell tumors such as chronic lymphocytic leukemia and B-cell non-Hodgkin lymphoma. Fcγ receptors (FcγR) on immune cells such as macrophages play an important role in tumor-specific antibody-mediated immune responses, but many such responses involve Btk. Here we tested the effects of ibrutinib on FcγR-mediated activities in monocytes. We found that ibrutinib did not affect monocyte FcγR-mediated phagocytosis, even at concentrations higher than those achieved physiologically, but suppressed FcγR-mediated cytokine production. We confirmed these findings in macrophages from Xid mice in which Btk signaling is defective. Because calcium flux is a major event downstream of Btk, we tested whether it was involved in phagocytosis. The results showed that blocking intracellular calcium flux decreased FcγR-mediated cytokine production but not phagocytosis. To verify this, we measured activation of the GTPase Rac, which is responsible for actin polymerization. Results showed that ibrutinib did not inhibit Rac activation, nor did the calcium chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis(acetoxymethyl ester). We next asked whether the effect of ibrutinib on monocyte FcγR-mediated cytokine production could be rescued by IFNγ priming because NK cells produce IFNγ in response to antibody therapy. Pretreatment of monocytes with IFNγ abrogated the effects of ibrutinib on FcγR-mediated cytokine production, suggesting that IFNγ priming could overcome this Btk inhibition. Furthermore, in monocyte-natural killer cell co-cultures, ibrutinib did not inhibit FcγR-mediated cytokine production despite doing so in single cultures. These results suggest that combining ibrutinib with monoclonal antibody therapy could enhance chronic lymphocytic leukemia cell killing without affecting macrophage effector function.

Systemic Delivery of Anti-miRNA for Suppression of Triple Negative Breast Cancer Utilizing RNA Nanotechnology

MicroRNAs play important roles in regulating the gene expression and life cycle of cancer cells. In particular, miR-21, an oncogenic miRNA is a major player involved in tumor initiation, progression, invasion and metastasis in several cancers, including triple negative breast cancer (TNBC). However, delivery of therapeutic miRNA or anti-miRNA specifically into cancer cells in vivo without collateral damage to healthy cells remains challenging. We report here the application of RNA nanotechnology for specific and efficient delivery of anti-miR-21 to block the growth of TNBC in orthotopic mouse models. The 15 nm therapeutic RNA nanoparticles contains the 58-nucleotide (nt) phi29 pRNA-3WJ as a core, a 8-nt sequence complementary to the seed region of miR-21, and a 39-nt epidermal growth factor receptor (EGFR) targeting aptamer for internalizing RNA nanoparticles into cancer cells via receptor mediated endocytosis. The RNase resistant and thermodynamically stable RNA nanoparticles remained intact after systemic injection into mice and strongly bound to tumors with little or no accumulation in healthy organs 8 h postinjection, and subsequently repressed tumor growth at low doses. The observed specific cancer targeting and tumor regression is a result of several key attributes of RNA nanoparticles: anionic charge which disallows nonspecific passage across negatively charged cell membrane; "active" targeting using RNA aptamers which increases the homing of RNA nanoparticles to cancer cells; nanoscale size and shape which avoids rapid renal clearance and engulfment by lung macrophages and liver Kupffer cells; favorable biodistribution profiles with little accumulation in healthy organs, which minimizes nonspecific side effects; and favorable pharmacokinetic profiles with extended in vivo half-life. The results demonstrate the clinical potentials of RNA nanotechnology based platform to deliver miRNA based therapeutics for cancer treatment.

Increased visceral to subcutaneous fat ratio is associated with decreased overall survival in patients with metastatic melanoma receiving anti-angiogenic therapy

BACKGROUND

Body fat distribution is an emerging prognostic indicator in patients treated with anti-angiogenic (AA) therapy. We sought to evaluate the association of visceral and subcutaneous fat with progression free survival (PFS) and overall survival (OS) in patients with metastatic melanoma treated with AA therapy.

METHODS

Stage IV melanoma patients received bevacizumab ± interferon-alpha. Total abdominal fat, visceral fat area (VFA) and subcutaneous fat area (SFA) were measured at L3-L4 on CT images (cm(2)). PFS and OS were estimated by the Kaplan-Meier method. Cox proportional hazards model was used to assess the association of fat and clinical variables with PFS and OS. Prediction accuracy was evaluated using receiver operating characteristic curve with area under the curve (AUC).

RESULTS

Forty-two patients were evaluated. Median VFA/SFA and body mass index (BMI) were used to group patients into high and low cohorts. PFS and OS were significantly decreased in patients with high VFA/SFA versus low (PFS, p=0.009; OS, p = 0.007), but not for BMI (PFS, p=0.774; OS, p=0.881). VFA/SFA, LDH and liver metastasis (LM) were predictors of PFS and OS on multivariate analysis. A prognostic score combining VFA/SFA, LDH, and presence or absence of LM had a higher accuracy for predicting PFS at 3 months (AUC 0.759) and OS at 24 months (AUC 0.846) than LDH and LM alone (PFS, AUC 0.705; OS, AUC 0.786).

CONCLUSION

Increased VFA/SFA is associated with decreased PFS and OS in patients with metastatic melanoma treated with AA therapy, indicating body fat distribution is an important prognostic factor.

Gene expression profiling of the human natural killer cell response to Fc receptor activation: unique enhancement in the presence of interleukin-12

Background

Traditionally, the CD56^dimCD16⁺ subset of Natural Killer (NK) cells has been thought to mediate cellular cytotoxicity with modest cytokine secretion capacity. However, studies have suggested that this subset may exert a more diverse array of immunological functions. There exists a lack of well-developed functional models to describe the behavior of activated NK cells, and the interactions between signaling pathways that facilitate effector functions are not well understood. In the present study, a combination of genome-wide microarray analyses and systems-level bioinformatics approaches were utilized to elucidate the transcriptional landscape of NK cells activated via interactions with antibody-coated targets in the presence of interleukin-12 (IL-12).

Methods

We conducted differential gene expression analysis of CD56^dimCD16⁺ NK cells following FcR stimulation in the presence or absence of IL-12. Next, we functionally characterized gene sets according to patterns of gene expression and validated representative genes using RT-PCR. IPA was utilized for biological pathway analysis, and an enriched network of interacting genes was generated using GeneMANIA. Furthermore, PAJEK and the HITS algorithm were employed to identify important genes in the network according to betweeness centrality, hub, and authority node metrics.

Results

Analyses revealed that CD56^dimCD16⁺ NK cells co-stimulated via the Fc receptor (FcR) and IL-12R led to the expression of a unique set of genes, including genes encoding cytotoxicity receptors, apoptotic proteins, intracellular signaling molecules, and cytokines that may mediate enhanced cytotoxicity and interactions with other immune cells within inflammatory tissues. Network analyses identified a novel set of connected key players, BATF, IRF4, TBX21, and IFNG, within an integrated network composed of differentially expressed genes in NK cells stimulated by various conditions (immobilized IgG, IL-12, or the combination of IgG and IL-12).

Conclusions

These results are the first to address the global mechanisms by which NK cells mediate their biological functions when encountering antibody-coated targets within inflammatory sites. Moreover, this study has identified a set of high-priority targets for subsequent investigation into strategies to combat cancer by enhancing the anti-tumor activity of CD56^dimCD16⁺ NK cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12920-015-0142-9) contains supplementary material, which is available to authorized users.

Surgical management of ovarian carcinoma metastatic to the breast and axilla: A role for metastasectomy?

As patients with ovarian cancer are living longer, surgeons will be faced with the management of metastatic lesions amenable to resection more frequently. We present two patients with ovarian cancer metastatic to the breast who underwent resection for their metastases, but their outcomes differed significantly. After reviewing the literature, we propose that there can be definite benefit to resection in the appropriately selected patients and discuss factors to consider prior to proceeding with surgery.

The Raf Kinase Inhibitor Sorafenib Inhibits JAK-STAT Signal Transduction in Human Immune Cells

Sorafenib is an oral multikinase inhibitor that was originally developed as a Raf kinase inhibitor. We hypothesized that sorafenib would also have inhibitory effects on cytokine signaling pathways in immune cells. PBMCs from normal donors were treated with varying concentrations of sorafenib and stimulated with IFN-α or IL-2. Phosphorylation of STAT1 and STAT5 was measured by flow cytometry and confirmed by immunoblot analysis. Changes in IFN-α- and IL-2-stimulated gene expression were measured by quantitative PCR, and changes in cytokine production were evaluated by ELISA. Cryopreserved PBMCs were obtained from cancer patients before and after receiving 400 mg sorafenib twice daily. Patient PBMCs were thawed, stimulated with IL-2 or IFN-α, and evaluated for phosphorylation of STAT1 and STAT5. Pretreatment of PBMCs with 10 μM sorafenib decreased STAT1 and STAT5 phosphorylation after treatment with IFN-α or IL-2. This inhibitory effect was observed in PBMCs from healthy donors over a range of concentrations of sorafenib (5-20 μM), IL-2 (2-24 nM), and IFN-α (10(1)-10(6) U/ml). This effect was observed in immune cell subsets, including T cells, B cells, NK cells, regulatory T cells, and myeloid-derived suppressor cells. Pretreatment with sorafenib also inhibited PBMC expression of IFN-α- and IL-2-regulated genes and inhibited NK cell production of IFN-γ, RANTES, MIP1-α, and MIG in response to IFN-α stimulation. PBMCs from patients receiving sorafenib therapy showed decreased responsiveness to IL-2 and IFN-α treatment. Sorafenib is a Raf kinase inhibitor that could have off-target effects on cytokine-induced signal transduction in immune effector cells.

Abstract 4278: Soy isoflavones and their metabolites modulate IL-12-induced NK cell IFN-γ production

Soybeans and foods derived from them are a rich source of phytochemcials that have gained attention due to their ability to affect obesity, metabolism, cancer, and inflammation. Soy isoflavones (genistein and daidzein) have also been shown to be differentially metabolized between individuals. This is presumably due to differences in gut microbiota, and can lead to production of terminal isoflavone metabolites such as O-desmethylangolensin (ODMA) and equol. In a prior phase-I clinical study conducted by our group, patients with prostate cancer received a novel soy-enriched bread product. Analysis of blood and urine following soy intervention revealed that men clustered into distinct groups based on their ability to metabolize daidizein into either ODMA or equol. Reduced pro-inflammatory cytokines and percentages of Tregs and MDSC were also observed in the blood of patients after 8 weeks of soy bread intervention as compared to baseline. Given these differences, we hypothesized that individual isoflavones and metabolites would have unique immunomodulatory effects upon human natural killer (NK) cell function. Although a limited number of prior studies have evaluated how soy isoflavones or their metabolites modulate inflammation and different immune subsets (monocytes, macrophages, DCs), their role in NK cell biology remains poorly defined. Understanding the role of soy isoflavones and their metabolites in regulating NK cell activity is critical due to NK cells’ importance in the anti-tumor response and immunosurveillance. We found that the soy isoflavones and their metabolites did not affect the viability of healthy donor PBMC (n = 3) at concentrations as high as 25μM. However, pre-treatment of healthy donor PBMC (n = 3) with genistein (mean 7.1 ng/ml ±1.3) or equol (mean 6.7 ng/ml ±1.8) for 4 hours and then stimulated with IL-12/18 for 72 hours decreased IFN-γ production compared to unstimulated controls (mean 26.7 ng/ml ±16.1). In contrast, daidzein and ODMA had no effect. We next utilized intracellular flow cytometry to determine the cellular subset(s) that were modulated by soy isoflavones or their metabolites. These data revealed that only genistein and equol decreased the percentage of IL-12/18 induced IFN-γ producing NK cells (CD56+CD3-) by 30% and 53%, respectively. There was no observed difference in other IFN-γ producing immune subsets (T and NKT cells) when cultured with the soy isoflavones or metabolites. Furthermore, we found soy isoflavones and metabolites altered in vitro cytotoxicity of human IL-12 stimulated NK cells. Ongoing studies in our laboratory are elucidating the precise signaling pathways downstream of IL-12 in human NK cells that are modulated in response to soy isoflavones and their bioactive metabolites. This study provides critical insight regarding the impact of dietary soy on NK cell mediated responses potentially informing the use of soy during chemopreventive or immune based therapies.

Citation Format: Thomas A. Mace, Samantha King, Matthew Farren, Elizabeth McMichael, Steven Scoville, William E. Carson, Gregory Young, Jennifer Thomas-Ahner, Kenneth M. Riedl, Steven Schwartz, Steven K. Clinton, Gregory Lesinski. Soy isoflavones and their metabolites modulate IL-12-induced NK cell IFN-γ production. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4278. doi:10.1158/1538-7445.AM2015-4278

Modulation of the tumor microenvironment and inhibition of EGF/EGFR pathway: novel anti-tumor mechanisms of Cannabidiol in breast cancer

The anti-tumor role and mechanisms of Cannabidiol (CBD), a non-psychotropic cannabinoid compound, are not well studied especially in triple-negative breast cancer (TNBC). In the present study, we analyzed CBD's anti-tumorigenic activity against highly aggressive breast cancer cell lines including TNBC subtype. We show here -for the first time-that CBD significantly inhibits epidermal growth factor (EGF)-induced proliferation and chemotaxis of breast cancer cells. Further studies revealed that CBD inhibits EGF-induced activation of EGFR, ERK, AKT and NF-kB signaling pathways as well as MMP2 and MMP9 secretion. In addition, we demonstrated that CBD inhibits tumor growth and metastasis in different mouse model systems. Analysis of molecular mechanisms revealed that CBD significantly inhibits the recruitment of tumor-associated macrophages in primary tumor stroma and secondary lung metastases. Similarly, our in vitro studies showed a significant reduction in the number of migrated RAW 264.7 cells towards the conditioned medium of CBD-treated cancer cells. The conditioned medium of CBD-treated cancer cells also showed lower levels of GM-CSF and CCL3 cytokines which are important for macrophage recruitment and activation. In summary, our study shows -for the first time-that CBD inhibits breast cancer growth and metastasis through novel mechanisms by inhibiting EGF/EGFR signaling and modulating the tumor microenvironment. These results also indicate that CBD can be used as a novel therapeutic option to inhibit growth and metastasis of highly aggressive breast cancer subtypes including TNBC, which currently have limited therapeutic options and are associated with poor prognosis and low survival rates.

PTEN is a negative regulator of NK cell cytolytic function

Human NK cells are characterized by their ability to initiate an immediate and direct cytolytic response to virally infected or malignantly transformed cells. Within human peripheral blood, the more mature CD56(dim) NK cell efficiently kills malignant targets at rest, whereas the less mature CD56(bright) NK cells cannot. In this study, we show that resting CD56(bright) NK cells express significantly more phosphatase and tensin homolog deleted on chromosome 10 (PTEN) protein when compared with CD56(dim) NK cells. Consistent with this, forced overexpression of PTEN in NK cells resulted in decreased cytolytic activity, and loss of PTEN in CD56(bright) NK cells resulted in elevated cytolytic activity. Comparable studies in mice showed PTEN overexpression did not alter NK cell development or NK cell-activating and inhibitory receptor expression yet, as in humans, did decrease expression of downstream NK activation targets MAPK and AKT during early cytolysis of tumor target cells. Confocal microscopy revealed that PTEN overexpression disrupts the NK cell's ability to organize immunological synapse components including decreases in actin accumulation, polarization of the microtubule organizing center, and the convergence of cytolytic granules. In summary, our data suggest that PTEN normally works to limit the NK cell's PI3K/AKT and MAPK pathway activation and the consequent mobilization of cytolytic mediators toward the target cell and suggest that PTEN is among the active regulatory components prior to human NK cells transitioning from the noncytolytic CD56(bright) NK cell to the cytolytic CD56(dim) NK cells.

RAGE mediates S100A7-induced breast cancer growth and metastasis by modulating the tumor microenvironment

RAGE is a multifunctional receptor implicated in diverse processes including inflammation and cancer. In this study, we report that RAGE expression is upregulated widely in aggressive triple-negative breast cancer (TNBC) cells, both in primary tumors and in lymph node metastases. In evaluating the functional contributions of RAGE in breast cancer, we found that RAGE-deficient mice displayed a reduced propensity for breast tumor growth. In an established model of lung metastasis, systemic blockade by injection of a RAGE neutralizing antibody inhibited metastasis development. Mechanistic investigations revealed that RAGE bound to the proinflammatory ligand S100A7 and mediated its ability to activate ERK, NF-κB, and cell migration. In an S100A7 transgenic mouse model of breast cancer (mS100a7a15 mice), administration of either RAGE neutralizing antibody or soluble RAGE was sufficient to inhibit tumor progression and metastasis. In this model, we found that RAGE/S100A7 conditioned the tumor microenvironment by driving the recruitment of MMP9-positive tumor-associated macrophages. Overall, our results highlight RAGE as a candidate biomarker for TNBCs, and they reveal a functional role for RAGE/S100A7 signaling in linking inflammation to aggressive breast cancer development.

Tumor Infiltrating Lymphocytes - The Next Step in Assessing Outcome and Response to Treatment in Patients with Breast Cancer

Tumor infiltrating lymphocytes are studied for their potential as new clinically useful prognostic and predictive biomarkers in patients with triple negative and HER-2/neu amplified breast cancer. This area of research could also help guide the development of novel therapeutic approaches for these diseases.

Cytokine signaling-1 suppressor is inducible by IL-1beta and inhibits the catabolic effects of IL-1beta in chondrocytes: its implication in the paradoxical joint-protective role of IL-1beta

INTRODUCTION

Although IL-1β is believed to be crucial in the pathogenesis of osteoarthritis (OA), the IL-1β blockade brings no therapeutic benefit in human OA and results in OA aggravation in several animal models. We explored the role of a cytokine signaling 1 (SOCS1) suppressor as a regulatory modulator of IL-1β signaling in chondrocytes.

METHODS

Cartilage samples were obtained from patients with knee OA and those without OA who underwent surgery for femur-neck fracture. SOCS1 expression in cartilage was assessed with immunohistochemistry. IL-1β-induced SOCS1 expression in chondrocytes was analyzed with quantitative polymerase chain reaction and immunoblot. The effect of SOCS1 on IL-1β signaling pathways and the synthesis of matrix metalloproteinases (MMPs) and aggrecanase-1 was investigated in SOCS1-overexpressing or -knockdown chondrocytes.

RESULTS

SOCS1 expression was significantly increased in OA cartilage, especially in areas of severe damage (P < 0.01). IL-1β stimulated SOCS1 mRNA expression in a dose-dependent pattern (P < 0.01). The IL-1β-induced production of MMP-1, MMP-3, MMP-13, and ADAMTS-4 (aggrecanase-1, a disintegrin and metalloproteinase with thrombospondin motifs 4) was affected by SOCS1 overexpression or knockdown in both SW1353 cells and primary human articular chondrocytes (all P values < 0.05). The inhibitory effects of SOCS1 were mediated by blocking p38, c-Jun N-terminal kinase (JNK), and nuclear factor κB (NF-κB) activation, and by downregulating transforming growth factor-β-activated kinase 1 (TAK1) expression.

CONCLUSIONS

Our results show that SOCS1 is induced by IL1-β in OA chondrocytes and suppresses the IL-1β-induced synthesis of matrix-degrading enzymes by inhibiting IL-1β signaling at multiple levels. It suggests that the IL-1β-inducible SOCS1 acts as a negative regulator of the IL-1β response in OA cartilage.

Combined vaccination with HER-2 peptide followed by therapy with VEGF peptide mimics exerts effective anti-tumor and anti-angiogenic effects in vitro and in vivo

Overexpression of HER-2 and VEGF plays a key role in the development and metastasis of several human cancers. Many FDA-approved therapies targeting both HER-2 (Trastuzumab, Herceptin) and VEGF (Bevacizumab, Avastin) are expensive, have unacceptable toxicities and are often associated with the development of resistance. Here, we evaluate the dual antitumor effects of combining designed particular HER-2 peptide vaccine with VEGF peptide mimics. In vitro, HER-2 phosphorylation and antibody-dependent cellular toxicity were used to validate whether combining HER-2- and VEGF-targeting therapies would be effective. Moreover, a two-pronged approach was tested in vivo: (1) active immunotherapy with conformational HER-2 B-cell epitope vaccines and (2) anti-angiogenic therapy with a peptide structured to mimic VEGF. A transplantable BALB/c mouse model challenged with TUBO cells was used to test the effects of the HER-2 peptide vaccine combined with VEGF peptide mimics. Tumor sections after treatment were stained for blood vessel density and actively dividing cells. Our results show that immunization with an HER-2 peptide epitope elicits high affinity HER-2 native antibodies that are effective in inhibiting tumor growth in vivo, an effect that is enhanced by VEGF peptide mimics. We demonstrate that the combination of HER-2 and VEGF peptides induces potent anti-tumor and anti-angiogenic responses.

Immunotherapy with HER-2 and VEGF peptide mimics plus metronomic paclitaxel causes superior antineoplastic effects in transplantable and transgenic mouse models of human breast cancer

HER-2 and the vascular endothelial factor receptor (VEGF) represent validated targets for the therapy of multiple tumor types and inhibitors of these receptors have gained increasing importance in the clinic. In this context, novel bioactive agents associated with better therapeutic outcomes and improved safety profile are urgently required. Specifically engineered HER-2- and VEGF-derived peptides in combination with low-dose chemotherapy might provide a substantial impact on tumor metastasis and cancer progression. We tested the antitumor effects of HER-2 and VEGF peptide mimics in combination with metronomic paclitaxel in both PyMT and Balb/c murine model challenged with TUBO cells. The combination of low-dose paclitaxel and HER-2 or VEGF peptide mimics had greater inhibitory effects than either agent alone. Peptide treatment caused virtually no cardiotoxic effects, while paclitaxel and the anti-HER-2 antibody trastuzumab (Herceptin), exerted consistent cardiotoxicity. The combination regimen also promoted significant reductions in tumor burden and prolonged survival rates in both transgenic and transplantable tumor models. Tumor weights were significantly reduced in mice treated with HER-2 peptides alone, and even more in animals that received HER-2 peptide with low-dose paclitaxel, which alone had no significant effects on tumor growth in the transgenic model. Specifically engineered native peptide sequences from HER-2 and VEGF used in combination with metronomic paclitaxel demonstrate enhanced anticancer efficacy and an encouraging safety profile. This novel approach to targeted therapy may offer new avenues for the treatment of breast cancer and other solid tumors that overexpress HER-2 and VEGF.

Patients with pancreatic adenocarcinoma exhibit elevated levels of myeloid-derived suppressor cells upon progression of disease

Elevated levels of myeloid-derived suppressor cells (MDSCs) induced by tumor-derived factors are associated with inhibition of immune responses in patients with gastrointestinal malignancies. We hypothesized that pro-MDSC cytokines and levels of MDSC in the peripheral blood would be elevated in pancreatic adenocarcinoma patients with progressive disease. Peripheral blood mononuclear cells (PBMCs) were isolated from 16 pancreatic cancer patients undergoing chemotherapy and phenotyped for MDSC using a five antigen panel (CD33, HLA-DR, CD11b, CD14, CD15). Patients with stable disease had significantly lower MDSC levels in the peripheral blood than those with progressive disease (1.41 ± 1.12 vs. 5.14 ± 4.58 %, p = 0.013, Wilcoxon test). A cutoff of 2.5 % MDSC identified patients with progressive disease. Patients with ECOG performance status ≥2 had a weaker association with increased levels of MDSC. Plasma was obtained from 15 chemonaive patients, 13 patients undergoing chemotherapy and 9 normal donors. Increases in the levels of pro-MDSC cytokines were observed for pancreatic cancer patients versus controls, and the pro-MDSC cytokine IL-6 was increased in those patients undergoing chemotherapy. This study suggests that MDSC in peripheral blood may be a predictive biomarker of chemotherapy failure in pancreatic cancer patients.

Attachment anxiety is related to Epstein-Barr virus latency

Attachment theory provides a framework for understanding individual differences in chronic interpersonal stress. Attachment anxiety, a type of relationship insecurity characterized by worry about rejection and abandonment, is a chronic interpersonal stressor. Stress impacts cellular immunity, including herpesvirus reactivation. We investigated whether attachment anxiety was related to the expression of a latent herpesvirus, Epstein-Barr virus (EBV), when individuals were being tested for breast or colon cancer and approximately 1 year later. Participants (N=183) completed a standard attachment questionnaire and provided blood to assess EBV viral capsid antigen (VCA) IgG antibody titers. Individuals with more attachment anxiety had higher EBV VCA IgG antibody titers than those with less attachment anxiety. The strength of the association between attachment anxiety and antibody titers was the same at both assessments. This study is the first to show an association between latent herpesvirus reactivation and attachment anxiety. Because elevated herpesvirus antibody titers reflect poorer cellular immune system control over the latent virus, these data suggest that high attachment anxiety is associated with cellular immune dysregulation.

Adjuvant vaccine immunotherapy of resected, clinically node-negative melanoma: long-term outcome and impact of HLA class I antigen expression on overall survival

Associations between HLA class I antigen expression and the efficacy of a melanoma vaccine (Melacine; Corixa Corp.) were initially described in stage IV melanoma. Similar associations were observed in S9035, a phase III adjuvant trial evaluating Melacine for 2 years compared with observation in patients with stage II melanoma. This report provides long-term results. The effects of treatment on relapse-free survival (RFS) and overall survival (OS) were evaluated, and prespecified analyses investigated associations between treatment and HLA expression. Multivariable analyses were adjusted for tumor thickness, ulceration and site, method of nodal staging, and sex. P = 0.01 was considered statistically significant in subset analyses to account for multiple comparisons. For the entire study population of 689 patients, there were no significant differences in RFS or OS by treatment arm. HLA serotyping was performed on 553 (80%) patients (vaccine, 294; observation, 259). Among the subpopulation with HLA-A2 and/or HLA-Cw3 serotype, vaccine arm patients (n = 178) had marginally improved RFS (adjusted P = 0.02) and significantly improved OS compared with observation arm patients (n = 145), with 10-year OS of 75% and 63%, respectively [hazard ratio (HR), 0.62; 99% confidence interval (CI), 0.37-1.02; P = 0.01]. There was no impact of HLA-A2 and/or HLA-Cw3 expression on observation arm patients. An analysis of mature data from S9035 indicates a significant OS benefit from adjuvant vaccine therapy for patients with HLA-A2- and/or HLA-Cw3-expressing melanoma. The possibility of interactions between HLA type and outcome should be considered in future immunotherapy trials. Further investigations of melanoma-associated antigens present in Melacine and presented by HLA-A2 and HLA-Cw3 may be warranted.