Abscopal responses in patients with metastatic melanoma involving skin and subcutaneous tissues treated with intralesional IL2 plus BCG

Cutaneous melanoma is relatively common with increasing incidence and significant mortality. While the mainstay of therapy is surgical, patients with stage III and IV disease fare poorer than those with early-stage disease and often benefit from adjuvant therapies. While systemic immunotherapy has changed the landscape of melanoma treatment, for some patients systemic toxicities related to these treatments prohibit successful administration or completion of therapy. Moreover, it is becoming increasingly evident that nodal, regional, and in-transit disease appears to be resistant to systemic immunotherapy relative to responses observed in distant metastatic disease sites. In this scenario, intralesional immunotherapies may offer benefit. In this case series, we describe the use of intralesional IL-2 and BCG at our institution in ten patients with in-transit plus or minus distant cutaneous metastatic melanoma over the last twelve years. All patients received intralesional IL2 and BCG. Both treatments were very well tolerated with only grade 1/2 adverse events. In our cohort, complete clinical response was 60% (6/10), progressive disease in 20% (2/10), and no response in 20% (2/10) of patients. The overall response rate (ORR) was 70%. The median overall survival was 35.5 months and mean overall survival 43 months in this cohort. Herein we further highlight the clinical, histopathological, and radiological course of two complete responders, showing evidence of an abscopal effect with resolution of distant untreated metastasis. Together, this limited data supports the safe and effective use of intralesional IL2 and BCG for the treatment of metastatic or in-transit melanoma in this challenging patient cohort. To our knowledge, this is the first formal study to report on this combination therapy for the treatment of melanoma

Annexin A2 is a novel Cellular Redox Regulatory Protein involved in Tumorigenesis

Annexins are a structurally related family of calcium and phospholipid-binding proteins that are involved in the regulation of a wide range of molecular and cellular processes. Annexin A2 is unique among the annexins in that it possesses redox sensitive cysteine(s). The ubiquitous and abundant expression of ANXA2 in cells and its reactivity with hydrogen peroxide led us to hypothesize that this protein could play a role in cellular redox regulation. Here we show that ANXA2 protein levels are induced by hydrogen peroxide. Furthermore, depletion of ANXA2 resulted in the elevation of cellular reactive oxygen species (ROS) upon oxidative stress, increased activation of the ROS-induced pro-apoptotic kinases, JNK, p38 and Akt and elevated sensitivity to ROS-mediated cellular damage/death. ANXA2-null mice showed significantly elevated protein oxidation in the liver and lung tissues compared to WT mice. ANXA2 depleted cancer cells showed enhanced cellular protein oxidationconcomitant with decreased tumor growth compared to control cancer cells andboth the oxidation of cellular proteins and tumor growth deficit werereversed by the antioxidant N-acetyl cysteine, indicating that ANXA2 plays akey role in the regulation of cellular redox during tumorigenesis. Ex-vivo human cancer studies showed that up-regulation of the reduced form of ANXA2 is associated with protection of the tumor proteins from oxidation. In summary, our results indicate that ANXA2 plays an important role incellular redox regulation by protecting cells from oxidative stress, aneffect that is particularly important during tumorigenesis

Annexin A2 regulates AKT upon H₂O₂-dependent signaling activation in cancer cells

Hydrogen peroxide (H2O2) is a main second messenger in oncogenic signaling networks including the Ras and the growth factor receptor pathways. This is achieved predominantly through the oxidation of redox-sensitive cysteine (Cys) residues in proteins resulting in changes to their structure and function. We previously identified annexin A2 (ANXA2) as a redox regulatory protein that plays an important cellular role during oxidative stress and also promoting tumorigenesis. Here we investigated the role of ANXA2 in the regulation of H2O2-dependent signaling that drives tumor progression. We show that depletion of ANXA2 leads to the enhanced activation of AKT following either EGF/EGFR stimulation or oncogenic Ras transformation. The phosphatase and tensin homologue (PTEN) protein negatively regulates the PI3K/AKT pathway. We demonstrate that ANXA2 via its reactive Cys-8 residue, binds to PTEN and that the co-expression of PTEN and ANXA2, but not ANXA2 Cys-8-Ala mutant, inhibits AKT phosphorylation on Ser 473. These results indicate that ANXA2 is important for PTEN regulation within the PI3K/AKT signaling cascade. Furthermore, we also reveal that ANXA2 inversely regulates the expression of the peroxidase, peroxiredoxin 2, in a reactive oxygen species dependent manner

The effect of silica inhibition of macrophage on renal allograft rejection

Kidney failure, one of the most serious complications of diabetes is routinely managed by kidney allograft transplantation. Research into the etiology of diabetes has revealed that macrophages are primarily responsible for the β-islet cell destruction in diabetes and that depletion of macrophages using intraperitoneal (i.p.) silica, which is selectively toxic to macrophages, prevents this. Macrophages accounts for approximately 50% of the graft infiltrating cells (GIC) observed in an acutely rejecting kidney, a process phenotypically very similar to a delayed type hypersensitivity (DTH) reaction. Macrophages are known to be essential for DTH reactions. Their exact role has never been elucidated in acute rejection. Silica has been shown to prolong islet allograft survival. Using a rat model, we wondered if depletion of macrophages using i.p. silica prior to renal allograft transplantation would delay or prevent acute rejection. To evaluated acute kidney rejection in our model we transplanted Brown Norway (BN) kidneys into nephrectomized Lewis (Lew) recipients. Using groups of four animals, kidneys were harvested at days 0, 2, 3, 4 and 5. Tissue was evaluated histologically, morphometrically and cytoflurometricall

Insights into the Molecular Mechanisms Behind Intralesional Immunotherapies for Advanced Melanoma

The incidence of cutaneous melanoma, a highly malignant skin cancer, is increasing yearly. While surgical removal of the tumor is the mainstay of treatment for patients with locally confined disease, those with metastases face uncertainty when it comes to their treatment. As melanoma is a relatively immunogenic cancer, current guidelines suggest using immunotherapies that can rewire the host immune response to target melanoma tumor cells. Intralesional therapy, where immunomodulatory agents are injected directly into the tumor, are an emerging aspect of treatment for in-transit melanoma because of their ability to mitigate severe off-target immune-related adverse events. However, their immunomodulatory mechanisms are poorly understood. In this review, we will summarize and discuss the different intralesional therapies for metastatic melanoma with respect to their clinical outcomes and immune molecular mechanisms

Mast Cells and Skin and Breast Cancers: A Complicated and Microenvironment-Dependent Role

Mast cells are important sentinel cells in host defense against infection and major effector cells in allergic disease. The role of these cells in cancer settings has been widely debated. The diverse range of mast cell functions in both immunity and tissue remodeling events, such as angiogenesis, provides multiple opportunities for mast cells to modify the tumor microenvironment. In this review, we consider both skin and breast cancer settings to address the controversy surrounding the importance of mast cells in the host response to tumors. We specifically address the key mediators produced by mast cells which impact tumor development. The role of environmental challenges in modifying mast cell responses and opportunities to modify mast cell responses to enhance anti-tumor immunity are also considered. While the mast cell’s role in many cancer contexts is complicated and poorly understood, the activities of these tissue resident and radioresistant cells can provide important opportunities to enhance anti-cancer responses and limit cancer development

Resolution of Metastatic Subungal Eccrine Porocarcinoma Treated with Intralesional Interleukin-2

Eccrine porocarcinoma is a rare aggressive cutaneous malignancy. Complete surgical excision is the standard of care, although there are high rates of local and distant recurrence. We present a unique case of locally recurrent and metastatic subungal porocarcinoma successfully treated with intralesional interleukin-2

DNA Methylation Predicts the Response of Triple-Negative Breast Cancers to All-Trans Retinoic Acid

All-trans retinoic acid (atRA) regulates gene expression and is used to treat acute promyelocytic leukemia. Attempts to use atRA in breast cancer without a stratification strategy have resulted in limited overall effectiveness. To identify biomarkers for the treatment of triple-negative breast cancer (TNBC) with atRA, we characterized the effects of atRA on the tumor growth of 13 TNBC cell lines. This resulted in a range of effects that was not predictable based on previously hypothesized predictors of response, such as the levels of atRA nuclear shuttling proteins fatty acid binding protein 5 (FABP5) and cellular retinoic acid binding protein 2 (CRABP2). Transcriptional profiling revealed that atRA induced distinct gene expression changes in the sensitive versus resistant cell lines that were mostly independent of the presence of retinoic acid response elements (RAREs) or peroxisome proliferator response elements (PPREs). Given the importance of DNA methylation in regulating gene expression, we hypothesized that differential DNA methylation could predict the response of TNBCs to atRA. We identified over 1400 sites that were differentially methylated between atRA resistant and sensitive cell lines. These CpG sites predicted the response of four TNBC patient-derived xenografts to atRA, and we utilized these xenografts to refine the profile and identified that as many as 17% of TNBC patients could benefit from atRA treatment. These data illustrate that differential methylation of specific CpGs may be useful biomarkers for predicting the response of patient tumors to atRA treatment