Efficacy of Combination of Immunotherapies in a Murine in a Murine Squamous Cell Carcinoma Model

Introduction: Head and neck squamous cell carcinomas (HNSCCs) are a type of neoplasm found in the epithelium of the oral cavity, oropharynx, nasopharynx, larynx, or hypopharynx. Recent evidence has demonstrated that 70-90% of HNSCC are associated with Human Papillomavirus (HPV), particularly strain 16 producing oncogenic proteins E6/E7. Currently, HNSCCs are treated with surgery, chemotherapy, and radiation, however immunotherapy with immune checkpoint (PD-1) blocking agents promises to improve outcomes in HNSCC. Objective: This study examined the therapeutic effects of dual and triple combination immunotherapies in a mouse model of HPV-associated HNSCC. Methods: Treatment modalities included a tumor vaccine (attenuated Listeria monocytogenes based vaccine encoding HPV16 E6/E7 (AXAL)), an immune checkpoint inhibitor targeting PD1 (RMP1-14) and topical subtherapeutic radiation. Mice were injected subcutaneously with tumor cells expressing HPV16 E6/E7 (TC-1). When tumors were established, mice were vaccinated with AXAL (3 injections) either alone and/or with anti-PDi and/or with a single dose of radiation. Results: Partial responses were observed in some mice receiving dual combination therapies. Most mice treated with triple immunotherapy revealed complete tumor regression. Discussion: Combination immunotherapy is effective in the TC-1 HNSCC model system. The results obtained set the stage for investing immune mechanism underpinning treatment-associated tumor regression

Metabolic reprogramming of murine cardiomyocytes during autophagy requires the extracellular nutrient sensor decorin.

The extracellular matrix is a master regulator of tissue homeostasis in health and disease. Here we examined how the small, leucine-rich, extracellular matrix proteoglycan decorin regulates cardiomyocyte metabolism during fasting in vivo. First, we validated in Dcn-/- mice that decorin plays an essential role in autophagy induced by fasting. High-Throughput metabolomics analyses of cardiac tissue in Dcn-/- mice subjected to fasting revealed striking differences in the hexosamine biosynthetic pathway resulting in aberrant cardiac O-β-N-Acetylglycosylation as compared with WT mice. Functionally, Dcn-/- mice maintained cardiac function at a level comparable with nonfasted animals whereas fasted WT mice showed reduced ejection fraction. Collectively, our results suggest that reduced sensing of nutrient deprivation in the absence of decorin preempts functional adjustments of cardiac output associated with metabolic reprogramming. © 2018 Gubbiotti et al

Nuclear Factor κB Inhibitors Alleviate and the Proteasome Inhibitor PS-341 Exacerbates Radiation Toxicity in Zebrafish Embryos

Inflammatory changes are a major component of the normal tissue response to ionizing radiation, and increased nuclear factor κB (NF-κB) activity is an important mediator of inflammatory responses. Here, we used zebrafish embryos to assess the capacity of two different classes of pharmacologic agents known to target NF-κB to modify radiation toxicity in the vertebrate organism. These were proteasome inhibitors, including lactacystin, MG132, and PS-341 (Bortezomib/VELCADE), and direct inhibitors of NF-κB activity, including ethyl pyruvate (EP) and the synthetic triterpenoid CDDO-TFEA (RTA401), among others. The proteasome inhibitors either did not significantly affect radiation sensitivity of zebrafish embryos (MG132, lactacystin) or rendered zebrafish embryos more sensitive to the lethal effects of ionizing radiation (PS-341). Radiosensitization by PS-341 was reduced in fish with impaired p53 expression or function but not associated with enhanced expression of select p53 target genes. In contrast, the direct NF-κB inhibitors EP and CDDO-TFEA significantly improved overall survival of lethally irradiated zebrafish embryos. In addition, direct NF-κB inhibition reduced radiation-induced apoptosis in the central nervous system, abrogated aberrations in body axis development, restored metabolization and secretion of a reporter lipid through the gastrointestinal system, and improved renal clearance compromised by radiation. In contrast to amifostine, EP and CDDO-TFEA not only protected against but also mitigated radiation toxicity when given 1 to 2 hours postexposure. Finally, four additional IκB kinase inhibitors with distinct mechanisms of action similarly improved overall survival of lethally irradiated zebrafish embryos. In conclusion, inhibitors of canonical pathways to NF-κB activation may be useful in alleviating radiation toxicity in patients. [Mol Cancer Ther 2009;8(9):2625-34] Reprinted with permission from the American Association of Cancer Research, “Nuclear factor κB inhibitors alleviate and the proteasome inhibitor PS-341 exacerbates radiation toxicity in zebrafish embryos”, Molecular Cancer Therapy, 2009;8(9), pages 2625-2634

Inhibition of p73 Function by Pifithrin-α as Revealed by Studies in Zebrafish Embryos

The p53 family of proteins contains two members that have been implicated in sensitization of cells and organisms to genotoxic stress, i.e., p53 itself and p73. In vitro, lack of either p53 or p73 can protect certain cell types in the adult organism against death upon exposure to DNA damaging agents. The present study was designed to assess the relative contribution of p53 to radiation resistance of an emerging vertebrate model organism, i.e., zebrafish embryos. Consistent with previous reports, suppressing p53 protein expression using antisense morpholino oligonucleotides (MOs) increased survival and reduced gross morphological alterations in zebrafish embryos exposed to ionizing radiation. By contrast, a pharmacological inhibitor of p53 function [Pifithrin-α (PFTα)] caused developmental abnormalities affecting the head, brain, eyes and kidney function and did not protect against lethal effects of ionizing radiation when administered at 3 hours post fertilization (hpf). The phenotypic abnormalities associated with PFTα treatment were similar to those caused by antisense MO knock down (kd) used to reduce p73 expression. PFTα also inhibited p73-dependent transcription of a reporter gene construct containing canonical p53-responsive promoter sequences. Notably, when administered at later stages of development (23 hpf), PFTα did not cause overt developmental defects but exerted radioprotective effects in zebrafish embryos. In summary, this study highlights off-target effects of the pharmacological p53 inhibitor PFTα related to inhibition of p73 function and essential roles of p73 at early but not later stages of zebrafish development. Abreviations: MO, antisense morpholino oligonucleotide; PFTα, pifithrin-α; Hpf, hours post fertilization; Kd, knock down; IR, ionizing radiation Cell Cycle, Volume 7, Issue 9, pp. 1224-1230

Inhibition of HIF-1 alpha by PX-478 enhances the anti-tumor effect of gemcitabine by inducing immunogenic cell death in pancreatic ductal adenocarcinoma

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Dying with ‘Infinity Mushrooms’ – Mortuary Rituals, Mycoremediation and Multispecies Legacies

In a world conceptualised as Anthropocene, in which human activities are transforming every part of the biosphere, funerals have become political and ethical activities in new and unforeseen ways. The use of formaldehyde in embalming practices and the release of air pollutants during cremation are only two of many points of criticism which have led to the rise of alternative ‘greener’ burial methods. The ‘infinity burial project’ is one such alternative, but it exceeds discourses on sustainable funerals by highlighting the toxicity of human bodies and challenging cultural taboos surrounding corporeal decomposition. Infinity burial employs ‘mycoremediation’, the usage of fungi for decomposing and cleaning up contaminated bodies and landscapes. Departing from Donna Haraway’s call for embracing situated technical projects in order to make ‘oddkin’, this article explores how the infinity burial project engenders queer communities which dismiss taxonomical lines between species as well as ontological claims about life and death. Drawing on new materialisms’ work on the radical openness of bodies, I explore how the infinity burial project sheds light on the material reality of decaying and the implications of dying in a polluted world

Radiation protection of the gastrointestinal tract and growth inhibition of prostate cancer xenografts by a single compound.

Normal tissue toxicity markedly reduces the therapeutic index of genotoxic anticancer agents, including ionizing radiation. Countermeasures against tissue damage caused by radiation are limited by their potential to also protect malignant cells and tissues. Here, we tested a panel of signal transduction modifiers for selective radioprotection of normal but not tumor tissues. These included three inhibitors of GSK3 (LiCl, SB216763, and SB415286) and two inhibitors of NF-κB (ethyl pyruvate and RTA 408). Among these, the thiol-reactive triterpenoid RTA 408 emerged as a robust and effective protector of multiple organ systems (gastrointestinal, skin, and hemopoietic) against lethal doses of radiation. RTA 408 preserved survival and proliferation of intestinal crypt cells in lethally irradiated mice while reducing apoptosis incidence in crypts and villi. In contrast, RTA 408 uniformly inhibited growth of established CWR22Rv1, LNCaP/C4-2B, PC3, and DU145 xenografts either alone or combined with radiation. Antitumor effects in vivo were associated with reduced proliferation and intratumoral apoptosis and with inhibition of NF-κB-dependent transcription in PC3 cells. Selective protection of normal tissue compartments by RTA 408 critically depended on tissue context and could not be replicated in vitro. Collectively, these data highlight the potential of RTA 408 as a cytoprotective agent that may be safely used in chemoradiation approaches