Project description:Triple negative breast cancer (TNBC) constitutes the most aggressive molecular subtype among breast tumors. Despite progress on the underlying tumor biology, clinical outcomes for TNBC unfortunately remain poor. The median overall survival for patients with metastatic TNBC is approximately eighteen months. Chemotherapy is the mainstay of treatment while there is a growing body of evidence that targeted therapies may be on the horizon with poly-ADP-ribose polymerase (PARP) and immune check-point inhibitors already established in the treatment paradigm of TNBC. A large number of novel therapeutic agents are being evaluated for their efficacy in TNBC. As novel therapeutics are now incorporated into clinical practice, it is clear that tumor heterogeneity and clonal evolution can result to de novo or acquired treatment resistance. As precision medicine and next generation sequencing is part of cancer diagnostics, tailored treatment approaches based on the expression of molecular markers are currently being implemented in clinical practice and clinical trial design. The scope of this review is to highlight the most relevant current knowledge regarding underlying molecular profile of TNBC and its potential application in clinical practice.
Project description:Tumor-associated macrophages (TAM) promote triple-negative breast cancer (TNBC) progression. Here, we report BRCA1-IRIS-overexpressing (IRISOE) TNBC cells secrete high levels of GM-CSF in a hypoxia-inducible factor-1? (HIF1?)- and a NF-?B-dependent manner to recruit macrophages to IRISOE cells and polarize them to protumor M2 TAMs. GM-CSF triggered TGF?1 expression by M2 TAMs by activating STAT5, NF-?B, and/or ERK signaling. Despite expressing high levels of TGF?1 receptors on their surface, IRISOE TNBC cells channeled TGF?1/T?RI/II signaling toward AKT, not SMAD, which activated stemness/EMT phenotypes. In orthotopic and syngeneic mouse models, silencing or inactivating IRIS in TNBC cells lowered the levels of circulating GM-CSF, suppressed TAM recruitment, and decreased the levels of circulating TGF?1. Coinjecting macrophages with IRISOE TNBC cells induced earlier metastasis in athymic mice accompanied by high levels of circulating GM-CSF and TGF?1. IRISOE TNBC cells expressed low levels of calreticulin (the "eat me" signal for macrophages) and high levels of CD47 (the "do not eat me" signal for macrophages) and PD-L1 (a T-cell inactivator) on their surface. Accordingly, IRISOE TNBC tumors had significantly few CD8+/PD-1+ cytotoxic T cells and more CD25+/FOXP3+ regulatory T cells. These data show that the bidirectional interaction between IRISOE cells and macrophages triggers an immunosuppressive microenvironment within TNBC tumors that is favorable for the generation of immune-evading/stem-like/IRISOE TNBC metastatic precursors. Inhibiting this interaction may inhibit disease progression and enhance patients' overall survival. SIGNIFICANCE: The BRCA1-IRIS oncogene promotes breast cancer aggressiveness by recruiting macrophages and promoting their M2 polarization.
Project description:Oncolytic viral therapy is under evaluation for toxicity and efficacy in clinical trials relating to several different tumors. We report a significant increase in the angiogenic index of oncolytic virus (OV)-treated glioma-matrigel implants (2.83-fold, P < 0.02). In a rat intracranial glioma model, large tumors from OV-treated animals were significantly more angiogenic than the phosphate-buffered saline (PBS)-treated control tumors (OV: 101 +/- 21.6; PBS: 19.8 +/- 10; P = 0.0037). Transcript profiling of OV-treated tumors revealed dysregulation of several transcripts involved in glioma angiogenesis. OV-mediated induction of CYR61 gene expression (8.94-fold, P = 0.001) correlated significantly with the presence of OV in tumor tissue in vivo (R = 0.7, P < 0.001). Further, induction of CYR61 mRNA and protein were confirmed in multiple human cancer cell lines and primary human tumor-derived cells in vitro, and in tumor lysate and cerebrospinal fluid (CSF) in vivo. Finally, we show that treatment of glioma cells with Cilengitide, known to counter CYR61-induced integrin activation, significantly suppressed the proangiogenic effect of OV treatment of gliomas (P < 0.05).
Project description:<h4>Background</h4>The current strategy for the elimination of onchocerciasis is based on annual or bi-annual mass drug administration with ivermectin. However, due to several limiting factors there is a growing concern that elimination of onchocerciasis cannot be achieved solely through the current strategy. Additional tools are critically needed including a prophylactic vaccine. Presently Ov-103 and Ov-RAL-2 are the most promising vaccine candidates against an Onchocerca volvulus infection.<h4>Methodology/principal findings</h4>Protection induced by immunization of mice with the alum-adjuvanted Ov-103 or Ov-RAL-2 vaccines appeared to be antibody dependent since AID-/- mice that could not mount antigen-specific IgG antibody responses were not protected from an Onchocerca volvulus challenge. To determine a possible association between antigen-specific antibody responses and anti-larvae protective immunity in humans, we analyzed the presence of anti-Ov-103 and anti-Ov-RAL-2 cytophilic antibody responses (IgG1 and IgG3) in individuals classified as putatively immune, and in infected individuals who developed concomitant immunity with age. It was determined that 86% of putatively immune individuals and 95% individuals with concomitant immunity had elevated IgG1 and IgG3 responses to Ov-103 and Ov-RAL-2. Based on the elevated chemokine levels associated with protection in the Ov-103 or Ov-RAL-2 immunized mice, the profile of these chemokines was also analyzed in putatively immune and infected individuals; both groups contained significantly higher levels of KC, IP-10, MCP-1 and MIP-1? in comparison to normal human sera. Moreover, human monospecific anti-Ov-103 antibodies but not anti-Ov-RAL-2 significantly inhibited the molting of third-stage larvae (L3) in vitro by 46% in the presence of naïve human neutrophils, while both anti-Ov-103 and anti-Ov-RAL-2 antibodies significantly inhibited the molting by 70-80% when cultured in the presence of naive human monocytes. Interestingly, inhibition of molting by Ov-103 antibodies and monocytes was only in part dependent on contact with the cells, while inhibition of molting with Ov-RAL-2 antibodies was completely dependent on contact with the monocytes. In comparison, significant levels of parasite killing in Ov-103 and Ov-RAL-2 vaccinated mice only occurred when cells enter the parasite microenvironment. Taken together, antibodies to Ov-103 and Ov-RAL-2 and cells are required for protection in mice as well as for the development of immunity in humans.<h4>Conclusions/significance</h4>Alum-adjuvanted Ov-103 and Ov-RAL-2 vaccines have the potential of reducing infection and thus morbidity associated with onchocerciasis in humans. The development of cytophilic antibodies, that function in antibody-dependent cellular cytotoxicity, is essential for a successful prophylactic vaccine against this infection.
Project description:BACKGROUND:In some regions in Africa, elimination of onchocerciasis may be possible with mass drug administration, although there is concern based on several factors that onchocerciasis cannot be eliminated solely through this approach. A vaccine against Onchocerca volvulus would provide a critical tool for the ultimate elimination of this infection. Previous studies have demonstrated that immunization of mice with Ov-103 and Ov-RAL-2, when formulated with alum, induced protective immunity. It was hypothesized that the levels of protective immunity induced with the two recombinant antigens formulated with alum would be improved by formulation with other adjuvants known to enhance different types of antigen-specific immune responses. METHODOLOGY/ PRINCIPAL FINDINGS:Immunizing mice with Ov-103 and Ov-RAL-2 in conjunction with alum, Advax 2 and MF59 induced significant levels of larval killing and host protection. The immune response was biased towards Th2 with all three of the adjuvants, with IgG1 the dominant antibody. Improved larval killing and host protection was observed in mice immunized with co-administered Ov-103 and Ov-RAL-2 in conjunction with each of the three adjuvants as compared to single immunizations. Antigen-specific antibody titers were significantly increased in mice immunized concurrently with the two antigens. Based on chemokine levels, it appears that neutrophils and eosinophils participate in the protective immune response induced by Ov-103, and macrophages and neutrophils participate in immunity induced by Ov-RAL-2. CONCLUSIONS/SIGNIFICANCE:The mechanism of protective immunity induced by Ov-103 and Ov-RAL-2, with the adjuvants alum, Advax 2 and MF59, appears to be multifactorial with roles for cytokines, chemokines, antibody and specific effector cells. The vaccines developed in this study have the potential of reducing the morbidity associated with onchocerciasis in humans.
Project description:Triple-negative breast cancer (TNBC) is a highly metastatic and aggressive disease with limited treatment options. Recently, the combination of the immune checkpoint inhibitor (ICI) atezolizumab (anti-PD-L1) with nab-paclitaxel was approved following a clinical trial that showed response rates in at least 43% of patients. While this approval marks a major advance in the treatment of TNBC it may be possible to improve the efficacy of ICI therapies through further modulation of the suppressive tumor immune microenvironment (TIME). Several factors may limit immune response in TNBC including aberrant growth factor signaling, such as VEGFR2 and cMet signaling, inefficient vascularization, poor delivery of drugs and immune cells, and the skewing of immune cell populations toward immunosuppressive phenotypes. Here we investigate the immune-modulating properties of AXT201, a novel 20 amino-acid integrin-binding peptide in two syngeneic mouse TNBC models: 4T1-BALB/c and NT4-FVB. AXT201 treatment improved survival in the NT4 model by 20% and inhibited the growth of 4T1 tumors by 47% over 22 days post-inoculation. Subsequent immunohistochemical analyses of 4T1 tumors also showed a 53% reduction in vascular density and a 184% increase in pericyte coverage following peptide treatment. Flow cytometry analyses demonstrated evidence of a more favorable anti-tumor immune microenvironment following treatment with AXT201, including significant decreases in the populations of T regulatory cells, monocytic myeloid-derived suppressor cells, and PD-L1 expressing cells and increased expression of T cell functional markers. Together, these findings demonstrate immune-activating properties of AXT201 that could be developed in combination with other immunomodulatory agents in the treatment of TNBC.
Project description:Triple-negative breast cancer (TNBC) is an aggressive disease with poor prognosis and limited therapeutic options. Recent advances in the immunotherapy field have enabled the development of new treatment strategies, among which the use of bispecific antibodies (BsAbs), able to redirect T cells against tumors, has shown promising results. In particular, a BsAb that uses TNF-related apoptosis-inducing ligand receptor 2 (TRAIL-R2) as a target was constructed and demonstrated good results in redirecting CD3+ T cells to kill TRAIL-R2-expressing TNBC cells. In the present study, we investigated whether treatment with selinexor, a selective inhibitor of nuclear export (SINE) targeting exportin-1/chromosome maintenance protein 1 (XPO1/CRM1), could potentiate the antitumor activity of this BsAb. In combination experiments, we found that selinexor-exposed TNBC cells exhibited greater growth inhibition when treated with the TRAIL-R2xCD3 BsAb than that expected by simple additivity. Similarly, the apoptosis rate in selinexor/TRAIL-R2xCD3 BsAb-treated TNBC cells was significantly higher than that observed after exposure to either single agent. Together, our results suggest that the combination of selinexor and TRAIL-R2xCD3 BsAb can be a viable anticancer strategy and indicate this treatment as a promising therapeutic option for TNBC patients.
Project description:BACKGROUND:To evaluate the cross-talk between BRCA1-IRIS (IRIS)-overexpressing (IRISOE) TNBC cells and tumor-resident mesenchymal stem cells (MSCs) that triggers the aggressiveness or elimination of IRISOE TNBC tumors. METHODS:We analyzed the effect of silencing or inactivating IRIS on the bi-directional interaction between IRISOE TNBC cells and MSCs on tumor formation and progression. We analyzed the downstream signaling in MSCs induced by IL-6 secreted from IRISOE TNBC cells. We compared the effect of MSCs on the formation and progression of IRIS-proficient and deficient-TNBC cells/tumors using in vitro and in vivo models. Finally, we analyzed the association between IL-6, PTGER2, and PTGER4 overexpression and breast cancer subtype; hormone receptor status; and distant metastasis-free or overall survival. RESULTS:We show high-level IL-6 secreted from IRISOE TNBC cells that enhances expression of its receptor (IL-6R) in MSCs, their proliferation, and migration toward IRISOE, in vitro, and recruitment into IRISOE TNBC tumors, in vivo. In serum-free medium, recombinant IL-6 and the IL-6-rich IRISOE TNBC cell condition media (CM) decreased STAT3Y705 phosphorylation (p-STAT3Y705) in MSCs. Inhibiting IRIS expression or activity prolonged STAT3Y705 phosphorylation in MSCs. The interaction with IRISOE TNBC cells skewed MSC differentiation toward prostaglandin E2 (PGE2)-secreting pro-aggressiveness cancer-associated fibroblasts (CAFs). Accordingly, co-injecting human or mouse MSCs with IRISOE TNBC tumor cells promoted the formation of aggressive mammary tumors, high circulating IL-6 and PGE2 levels, and reduced overall survival. In contrast, IRIS-silenced or inactivated cells showed reduced tumor formation ability, limited MSC recruitment into tumors, reduced circulating IL-6 and PGE2 levels, and prolonged overall survival. A positive correlation between IL-6, PTGER2, and PTGER4 expression and basal phenotype; ER-negativity; distant metastasis-free and overall survival in basal; or BRCAmutant carriers was observed. Finally, the bi-directional interaction with MSCs triggered death rather than growth of IRIS-silenced TNBC cells, in vitro and in vivo. CONCLUSIONS:The IL-6/PGE2-positive feedback loop between IRISOE TNBC tumor cells and MSCs enhances tumor aggressiveness. Inhibiting IRIS expression limits TNBC tumor growth and progression through an MSC-induced death of IRIS-silenced/inactivated TNBC cells.
Project description:Treatment options are limited for patients with triple negative breast cancer (TNBC). Understanding genes that participate in cancer progression and DNA damage response (DDR) may improve therapeutic strategies for TNBC. DAXX, a death domain-associated protein, has been reported to be critically involved in cancer progression and drug sensitivity in multiple cancer types. However, its role in breast cancer, especially for TNBC, remains unclear. Here, we demonstrated a tumor suppressor function of DAXX in TNBC proliferation, colony formation, and migration. In Mouse Xenograft Models, DAXX remarkably inhibited tumorigenicity of TNBC cells. Mechanistically, DAXX could directly bind to the promoter region of RAD51 and impede DNA damage repair, which impacted the protection mechanism of tumor cells that much depended on remaining DDR pathways for cell growth. Furthermore, DAXX-mediated inefficient DNA damage repair could sensitize BRCA-proficient TNBC cells to PARP inhibitors. Additionally, we identified that dual RAD51 and PARP inhibition with RI-1 and ABT888 significantly reduced TNBC growth both in vitro and in vivo, which provided the first evidence of combining RAD51 and PARP inhibition in BRCA-proficient TNBC. In conclusion, our data support DAXX as a modulator of DNA damage repair and suppressor of TNBC progression to sensitize tumors to the PARP inhibitor by repressing RAD51 functions. These provide an effective strategy for a better application of PARP inhibition in the treatment of TNBC.
Project description:Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer that harbors enriched cancer stem cell (CSC) populations in tumors. Conventional chemotherapy is a standard treatment for TNBC, but it spares the CSC populations, which cause tumor recurrence and progression. Therefore, identification of the core molecular pathway that controls CSC activity and expansion is essential for developing effective therapeutics for TNBC. In this study, we identify that USP2 deubiquitinating enzyme is upregulated in CSCs and is a novel regulator of CSCs. Genetic and pharmacological targeting of USP2 substantially inhibits the self-renewal, expansion and chemoresistance of CSCs. We show that USP2 maintains the CSC population by activating self-renewing factor Bmi1 and epithelial-mesenchymal transition through Twist upregulation. Mechanistically, USP2 promotes Twist stabilization by removing ?-TrCP-mediated ubiquitination of Twist. Animal studies indicate that pharmacological inhibition of USP2 suppresses tumor progression and sensitizes tumor responses to chemotherapy in TNBC. Furthermore, the histological analyses reveal a positive correlation between USP2 upregulation and lymph node metastasis. Our findings together demonstrate a previously unrecognized role of USP2 in mediating Twist activation and CSC enrichment, suggesting that targeting USP2 is a novel therapeutic strategy to tackle TNBC.