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Brooks, D. A.

Publications and source records attributed to Brooks, D. A..

3 recordsLinked to original sources

Nanoparticle mediated delivery of PD-L1 inhibitor enhances γδ T cell immunotherapy against metastatic ovarian cancer cells

IntroductionImmune checkpoint inhibitors (ICIs) have only shown limited efficacy for patients with ovarian cancer (OC), partly due to the immune suppressive tumour microenvironment (TME) and platelet cloaking of the cancer cells. We tested a nanomedicine strategy to enhance {gamma}{delta} T cell immunotherapy by conjugating the PD-L1 inhibitor (BMS202) to nanodiamonds (NDs). MethodsPatient-derived ascites cells were exposed to activated platelets to model platelet cloaking and the immunosuppressive phenotype in metastatic OC. ND/BMS202 nanocomplexes were then applied to platelet-conditioned OC cells and co-cultured with expanded {gamma}{delta} T cells. Cytotoxicity and immune activation were assessed by quantifying Granzyme B, CD107a, {gamma}-H2AX, cleaved caspase-3, and cleaved caspase-8. ResultsND-mediated delivery of BMS202 significantly enhanced {gamma}{delta} T cell-mediated killing of platelet cloaked OC cells in a dose-dependent manner, with greater efficacy than free BMS202 This enhanced cytotoxicity was supported by increased degranulation (CD107a), Granzyme B release, tumour cell apoptosis (caspase cleavage) and DNA damage ({gamma}-H2AX staining). ConclusionsND-based delivery of the PD-L1 inhibitor (BMS202) enhances {gamma}{delta} T cell-mediated killing of platelet-cloaked metastatic OC cells. While our data support enhanced {gamma}{delta} T cell cytotoxicity following BMS202 delivery, direct evidence of PD-L1 target engagement or PD-1/PD-L1 binding inhibition was not demonstrated in this study. These findings nonetheless justify further validation in patient-derived organoid models to optimize this {gamma}{delta} T cell-based combination immunotherapy and advance its development as a precision therapeutic strategy for metastatic OC.

immunology↗

Design, Synthesis, and Efficacy of Novel Trojan Horse Compounds Targeting Metabolic Vulnerabilities in Prostate Cancer

Background and purposeProstate cancer (PCa) remains a significant global health concern, warranting the development of new therapeutic strategies.1 Metabolic reprogramming, an emerging hallmark of PCa progression characterized by aberrant nutrient utilization, has become a focus area in developing new treatments. Among these metabolic alterations, the Warburg effect--a shift towards aerobic glycolysis-- has garnered significant attention as a potential therapeutic target. 2 To explore this, we synthesised a novel class of Trojan Horse compounds designed to exploit the unique metabolic profile of cancer cells and investigated their therapeutic potential using cell based models of PCa, as a proof of principle strategy. Experimental approachPreliminary cytotoxicity analysis revealed that native menadione had low efficacy against PCa cells. Consequently, we developed glucose and fatty acid conjugated TH compounds based on a menadione backbone. A library of six novel menadione-glucose and fatty acid-based TH compounds were synthesized through copper-catalysed click chemistry. These compounds were designed to mimic a desirable fuel source (sugar or fatty acid) acting as a "Trojan Horse" for PCa cells to modulate their metabolism. The cytotoxic and selective effects of the TH compounds were evaluated in PCa and non-malignant cell lines cultured under varying glucose conditions. To elucidate the mechanisms of action, mitochondrial bioenergetics, metabolic phenotyping, and metabolomic profiling were employed to assess the impact of each TH compound on cellular metabolism. Key resultsTH3 (glucose) and TH5 (fatty acid) compounds demonstrated promising cytotoxicity for PCa cell lines, with TH5 exhibiting superior selectivity compared to TH3 and particularly over native menadione. Despite these results, alterations in metabolic phenotypes were only modest. Mitochondrial bioenergetics were notably impacted by TH5, while ROS levels remained stable post-treatment, likely due to an increase in ROS scavenging amino acids as a compensatory antioxidant response. Conclusion and ImplicationsThis study demonstrates the potential of employing glucose and fatty acid-conjugated compounds to target the unique metabolic features of PCa. These findings offer promising new avenues for further investigation, aimed at optimizing efficacy and selectivity of these compounds for clinical translation. The intricate relationship between ROS production and antioxidant defence mechanisms emphasizes the complex nature of metabolic interventions in cancer. Elucidating the mode of action and exploring molecular modifications may pave the way for personalised and targeted PCa therapies, ultimately improving patient outcomes and mitigating the global burden of this disease. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/610353v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1af7915org.highwire.dtl.DTLVardef@1368f16org.highwire.dtl.DTLVardef@ebfe63org.highwire.dtl.DTLVardef@18a181b_HPS_FORMAT_FIGEXP M_FIG C_FIG Significance statementThis body of work gives critical insights into the metabolic vulnerabilities of prostate cancer (PCa), particularly of androgen-independent and metastatic disease, which currently present significant treatment challenges. By designing, synthesising and testing innovative menadione-based Trojan Horse compounds that target altered cancer cell metabolism, this research highlights a promising new therapeutic strategy against malignant cells. The findings underscore the potential for metabolic reprogramming to combat treatment resistance in advanced PCa, paving the way forward for the development of new drugs and personalised treatment approaches. This could lead to improved outcomes for patients with currently untreatable forms of the disease.

cancer biology↗

Cis-vaccenic acid is a key product of stearoyl-CoA desaturase 1 and a critical oncogenic factor in prostate cancer

Altered monounsaturated fatty acid (MUFA) metabolism is a hallmark of oncogenic transformation. Recently, the MUFA cis-vaccenic acid (cVA) was identified as a putative regulator of prostate cancer cell viability. cVA production requires the activity of stearoyl CoA desaturase 1 (SCD1), an enzyme frequently dysregulated in cancer, but the role of cVA in regulating cancer cell phenotypes has not been extensively explored, compared with the more commonly studied product and structural isomer of cVA, oleic acid. Here, we utilised SCD1 inhibition to study the effects of cVA in prostate cancer cells. We found that cVA consistently rescues reductions in cell viability due to SCD1 inhibition and promotes cell growth under normal conditions, thereby identifying cVA as an important and previously unrecognised product of SCD1 in prostate cancer. More broadly, we demonstrate that individual MUFA species exert a diverse range of influence on oncogenic phenotypes, highlighting a need to more precisely characterise the lipidome of cancer cells to understand the molecular pathology of the disease.

cell biology↗