Docetaxel radiosensitizes castration-resistant prostate cancer by downregulating CAV-1.

PURPOSE: Docetaxel (DXL), a noted radiosensitizer, is one of the few chemotherapy drugs approved for castration-resistant prostate cancer (CRPC), though only a fraction of CRPCs respond to it. CAV-1, a critical regulator of radioresistance, has been known to modulate DXL and radiation effects. Combining DXL with radiotherapy may create a synergistic anticancer effect through CAV-1 and improve CRPC patients' response to therapy. Here, we investigate the effectiveness and molecular characteristics of DXL and radiation combination therapy in vitro. MATERIALS AND METHODS: We used live/dead assays to determine the IC50 of DXL for PC3, DU-145, and TRAMP-C1 cells. Colony formation assay was used to determine the radioresponse of the same cells treated with radiation with/without IC50 DXL (4, 8, and 12 Gy). We performed gene expression analysis on public transcriptomic data collected from human-derived prostate cancer cell lines (C4-2, PC3, DU-145, and LNCaP) treated with DXL for 8, 16, and 72 hours. Cell cycle arrest and protein expression were assessed using flow cytometry and western blot, respectively. RESULTS: Compared to radiation alone, combination therapy with DXL significantly increased CRPC death in PC3 (1.48-fold, p < .0001), DU-145 (1.64-fold, p < .05), and TRAMP-C1 (1.13-fold, p < .05) at 4 Gy of radiation. Gene expression of CRPC treated with DXL revealed downregulated genes related to cell cycle regulation and upregulated genes related to immune activation and oxidative stress. Confirming the results, G2/M cell cycle arrest was significantly increased after treatment with DXL and radiation. CAV-1 protein expression was decreased after DXL treatment in a dose-dependent manner; furthermore, CAV-1 copy number was strongly associated with poor response to therapy in CRPC patients. CONCLUSIONS: Our results suggest that DXL sensitizes CRPC cells to radiation by downregulating CAV-1. DXL + radiation combination therapy may be effective at treating CRPC, especially subtypes associated with high CAV-1 expression, and should be studied further.

Mining cancer genomes for change-of-metabolic-function mutations.

Enzymes with novel functions are needed to enable new organic synthesis techniques. Drawing inspiration from gain-of-function cancer mutations that functionally alter proteins and affect cellular metabolism, we developed METIS (Mutated Enzymes from Tumors In silico Screen). METIS identifies metabolism-altering cancer mutations using mutation recurrence rates and protein structure. We used METIS to screen 298,517 cancer mutations and identify 48 candidate mutations, including those previously identified to alter enzymatic function. Unbiased metabolomic profiling of cells exogenously expressing a candidate mutant (OGDHLp.A400T) supports an altered phenotype that boosts in vitro production of xanthosine, a pharmacologically useful chemical that is currently produced using unsustainable, water-intensive methods. We then applied METIS to 49 million cancer mutations, yielding a refined set of candidates that may impart novel enzymatic functions or contribute to tumor progression. Thus, METIS can be used to identify and catalog potentially-useful cancer mutations for green chemistry and therapeutic applications.

Single-fraction Radiation Treatment Dose Response in a Genetically Engineered Mouse Model of Medulloblastoma.

Medulloblastoma is the most common malignant brain tumor of children. Although standard of care radiotherapy for pediatric medulloblastoma (PM) can lead to long-term remission or cure in many patients, it can also cause life-long cognitive impairment and other adverse effects. The pathophysiological mechanisms involved in radiation-induced cerebral damage are incompletely understood, and their elucidation may lead to interventions that mitigate radiation toxicity. To explore the mechanisms of radiation-induced cerebral damage, transgenic mouse models of PM and non-tumor-bearing controls were exposed to radiation doses that ranged from 0 to 30 Gy. Between 0-20 Gy, a significant dose-dependent reduction in tumor-associated hydrocephalus and increase in overall survival were observed. However, at 30 Gy, hydrocephalus incidence increased and median overall survival fell to near-untreated levels. Immunohistochemistry revealed that both tumor-bearing and non-tumor-bearing mice treated with 30 Gy of radiation had significantly more reactive astrocytes and microvascular damage compared to untreated controls. This effect was persistent across mice that were given 1 and 2 weeks of recovery time after irradiation. Our data suggest that radiation therapy promotes neural death by inducing long-term neuroinflammation in PM, suggesting radiation delivery methods that limit inflammation may be effective at widening the therapeutic window of radiation therapy in PM patients.

Pooled genetic screens to identify vulnerabilities in TERT-promoter-mutant glioblastoma.

Pooled genetic screens represent a powerful approach to identify vulnerabilities in cancer. Here we used pooled CRISPR/Cas9-based approaches to identify vulnerabilities associated with telomerase reverse transcriptase (TERT) promoter mutations (TPMs) found in >80% of glioblastomas. We first developed a platform to detect perturbations that cause long-term growth defects in a TPM-mutated glioblastoma cell line. However, we could not detect dependencies on either TERT itself or on an E-twenty six transcription (ETS) factor known to activate TPMs. To explore this finding, we cataloged TPM status for 441 cell lines and correlated this with genome-wide screening data. We found that TPM status was not associated with differential dependency on TERT, but that E-twenty six (ETS) transcription factors represent key dependencies in both TPM+ and TPM- lines. Further, we found that TPMs are associated with expression of gene programs regulated by a wide array of ETS-factors in both cell lines and primary glioblastoma tissues. This work contributes a unique TPM cell line reagent, establishes TPM status for many deeply-profiled cell lines, and catalogs TPM-associated vulnerabilities. The results highlight challenges in executing genetic screens to detect TPM-specific vulnerabilities, and suggest redundancy in the genetic network that regulates TPM function with therapeutic implications.

The impact of telehealth in sepsis care: A systematic review.

OBJECTIVES: Sepsis is associated with significant mortality. Telehealth may improve the quality of early sepsis care, but the use and impact of telehealth applications for sepsis remain unclear. We aim to describe the telehealth interventions that have been used to facilitate sepsis care, and to summarize the reported effect of telehealth on sepsis outcomes. DATA SOURCES: We identified articles reporting telehealth use for sepsis using an English-language search of PubMed, CINAHL Plus (EBSCO), Academic Search Ultimate (EBSCO), APA PsycINFO (EBSCO), Public Health (ProQuest), and Web of Science databases with no restrictions on publication date. STUDY SELECTION: Included studies described the use of telehealth as an intervention for treating sepsis. Only comparative effectiveness analyses were included. DATA EXTRACTION AND SYNTHESIS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) guidelines, two investigators independently selected articles for inclusion and abstracted data. A random-effects subgroup analysis was conducted on patient survival treated with and without telehealth. RESULTS: A total of 15 studies were included, involving 188,418 patients with sepsis. Thirteen studies used observational study designs, and the most common telehealth applications were provider-to-provider telehealth consultation and intensive care unit telehealth. Clinical and methodological heterogeneity was significantly high. Telehealth use was associated with higher survival, especially in settings with low control group survival. The effect of telehealth on other care processes and outcomes were more varied and likely dependent on hospital-level factors. CONCLUSIONS: Telehealth has been used in diverse applications for sepsis care, and it may improve patient outcomes in certain contexts. Additional interventional trials and cost-based analyses would clarify the causal role of telehealth in improving sepsis outcomes.

3-Bromopyruvate inhibits pancreatic tumor growth by stalling glycolysis, and dismantling mitochondria in a syngeneic mouse model.

Pancreatic cancer (PC) is the fourth-most-deadly cancer in the United States with a 5-year survival rate of only 8%. The majority of patients with locally advanced pancreatic cancer undergo chemotherapy and/or radiation therapy (RT). However, current treatments are inadequate and novel strategies are desperately required. 3-Bromopyruvate (3-BP) is a promising anticancer drug against pancreatic cancer. It exerts potent anticancer effects by inhibiting hexokinase II enzyme (HK2) of the glycolytic pathway in cancer cells while not affecting the normal cells. 3-BP killed 95% of Panc-2 cells at 15 µM concentration and severely inhibited ATP production by disrupting the interaction between HK2 and mitochondrial Voltage Dependent Anion Channel-1 (VDAC1) protein. Electron microscopy data revealed that 3-BP severely damaged mitochondrial membrane in cancer cells. We further examined therapeutic effect of 3-BP in syngeneic mouse pancreatic cancer model by treating animals with 10, 15 and 20 mg/kg dose. 3-BP at 15 & 20 mg/kg dose level significantly reduced tumor growth by approximately 75-80% in C57BL/6 female mice. Immunohistochemistry data showed complete inhibition of hexokinase II (HK2) and TGFß, in animals treated with 3-BP drug. We also observed enhanced expression of active caspase-3 in tumor tissues exhibited apoptotic death. Flow Cytometry analysis showed significant inhibition in MDSC (CD11b) population in treated tumor which may have allowed infiltration of CD8+ T cells and inhibited tumor growth. Notably, metabolomic data also revealed severe inhibition in glycolysis, NADP, ATP and lactic acid production in cancer cells treated with 40 µM 3-BP. Importantly, we also observed inhibition in lactic acid production responsible for tumor aggression. These results provide new evidence that 3-BP severely inhibit glucose metabolism in cancer cells by blocking hexokinase II, and disrupting mitochondria by suppressing BCL2L1 in pancreatic cancer.

Amyloid-beta and tau pathologies act synergistically to induce novel disease stage-specific microglia subtypes.

BACKGROUND: Amongst risk alleles associated with late-onset Alzheimer's disease (AD), those that converged on the regulation of microglia activity have emerged as central to disease progression. Yet, how canonical amyloid-ß (Aß) and tau pathologies regulate microglia subtypes during the progression of AD remains poorly understood. METHODS: We use single-cell RNA-sequencing to profile microglia subtypes from mice exhibiting both Aß and tau pathologies across disease progression. We identify novel microglia subtypes that are induced in response to both Aß and tau pathologies in a disease-stage-specific manner. To validate the observation in AD mouse models, we also generated a snRNA-Seq dataset from the human superior frontal gyrus (SFG) and entorhinal cortex (ERC) at different Braak stages. RESULTS: We show that during early-stage disease, interferon signaling induces a subtype of microglia termed Early-stage AD-Associated Microglia (EADAM) in response to both Aß and tau pathologies. During late-stage disease, a second microglia subtype termed Late-stage AD-Associated Microglia (LADAM) is detected. While similar microglia subtypes are observed in other models of neurodegenerative disease, the magnitude and composition of gene signatures found in EADAM and LADAM are distinct, suggesting the necessity of both Aß and tau pathologies to elicit their emergence. Importantly, the pattern of EADAM- and LADAM-associated gene expression is observed in microglia from AD brains, during the early (Braak II)- or late (Braak VI/V)- stage of the disease, respectively. Furthermore, we show that several Siglec genes are selectively expressed in either EADAM or LADAM. Siglecg is expressed in white-matter-associated LADAM, and expression of Siglec-10, the human orthologue of Siglecg, is progressively elevated in an AD-stage-dependent manner but not shown in non-AD tauopathy. CONCLUSIONS: Using scRNA-Seq in mouse models bearing amyloid-ß and/or tau pathologies, we identify novel microglia subtypes induced by the combination of Aß and tau pathologies in a disease stage-specific manner. Our findings suggest that both Aß and tau pathologies are required for the disease stage-specific induction of EADAM and LADAM. In addition, we revealed Siglecs as biomarkers of AD progression and potential therapeutic targets.

Therapeutic Efficacy of Variable Biological Effectiveness of Proton Therapy in U-CH2 and MUG-Chor1 Human Chordoma Cell Death.

BACKGROUND: Chordoma is a cancer of spinal cord, skull base, and sacral area. Currently, the standard of care to treat chordoma is resection followed by radiation therapy. Since, chordoma is present in the spinal cord and these are very sensitive structures and often complete removal by surgery is not possible. As a result, chordoma has a high chance of recurrence and developing resistance to radiation therapy. In addition, treatment of chordoma by conventional radiation therapy can also damage normal tissues surrounding chordoma. Thus, current therapeutic options to treat chordoma are insufficient and novel therapies are desperately needed to treat locally advanced and metastatic chordoma. (2) Methods: In the present investigation, human chordoma cell lines of sacral origin MUG-Chor1 and U-CH2 were cultured and irradiated with Proton Beam Radiation using the clinical superconducting cyclotron and pencil-beam (active) scanning at Middle and End of the Spread-Out Bragg Peak (SOBP). Proton radiation was given at the following doses: Mug-Chor1 at 0, 1, 2, 4, and 8 Gy and U-CH2 at 0, 4, 8, 12, and 16 Gy. These doses were selected based on a pilot study in our lab and attempted to produce approximate survival fractions in the range of 1, 0.9, 0.5, 0.1, and 0.01, respectively, chosen for linear quadratic model fitting of the dose response. (3) Results: In this study, we investigated relative biological effectiveness (RBE) of proton radiation at the end of Spread Out Bragg Peak assuming that the reference radiation is a proton radiation in the middle of the SOBP. We observed differences in the survival of both Human chordoma cell lines, U-CH2 and MUG-Chor1. The data showed that there was a significantly higher cell death at the end of the Bragg peak as compared to middle of the Bragg peak. Based on the linear quadratic (LQ) fit for cell survival we calculated the RBE between M-SOBP and E-SOBP at 95% CI level and it was observed that RBE was higher than 1 at E-SOBP and caused significantly higher cell killing. Proton field at E-SOBP caused complex DNA damage in comparison to M-EOBP and the genes such as DNA topoisomerase 1, GTSE1, RAD51B were downregulated in E-SOBP treated cells. Thus, we conclude that there seems to be substantial variation in RBE (1.3-1.7) at the E-SOBP compared with the M-SOBP.