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BackgroundClear cell carcinomas (CCCs) are a distinct histopathological subtype defined by a clear cytoplasm comprised of glycogen and lipids and characterised by poor prognosis and widespread chemoresistance. In the present work we investigate glycogen metabolism as a targetable modality for these cancers.Methods and ResultsAdopting the indole carboxamide site pan-glycogen phosphorylase inhibitor CP91149 against clear cell ovarian and renal cancer cell line models, we note antiproliferative and antimigratory effects, as well as energetic stress reflected by reduced ATP pools and increased superoxide-derived reactive oxygen species. Following this, using the agent alongside standard of care chemotherapies for clear cell ovarian (ccOC) and renal cell carcinoma (ccRCC), we note specific synergy with microtubule disrupting chemotherapy paclitaxel, a phenomenon retained in ccOC lines made stably resistant to paclitaxel. Rescue experiments, as well as phenotypic assays suggest that combination-treated cells undergo ferroptotic cell death. We postulate this synergistic efficacy to arise from subjecting the already hypersensitive clear cell cancers to the mitochondrial stress elicited by taxol chemotherapy alongside the oxidative stress augured by glycogen phosphorylase inhibition.ConclusionsGiven that CCCs are widely chemoresistant, the present work potentially presents a novel therapeutic avenue for this shared histotype.

Antibodies targeting “immune checkpoints” have revolutionized cancer therapy by reactivating tumor-resident cytotoxic lymphocytes, primarily CD8+ T cells. Interest in targeting analogous pathways in other cytotoxic lymphocytes is growing. Natural killer (NK) cells are key to cancer immunosurveillance by eradicating metastases and driving solid tumor inflammation. NK-cell antitumor function is dependent on the cytokine IL15. Ablation of the IL15 signaling inhibitor CIS (Cish) enhances NK-cell antitumor immunity by increasing NK-cell metabolism and persistence within the tumor microenvironment (TME). The TME has also been shown to impair NK-cell fitness via the production of immunosuppressive transforming growth factor β (TGFβ), a suppression which occurs even in the presence of high IL15 signaling. Here, we identified an unexpected interaction between CIS and the TGFβ signaling pathway in NK cells. Independently, Cish- and Tgfbr2-deficient NK cells are both hyperresponsive to IL15 and hyporesponsive to TGFβ, with dramatically enhanced antitumor immunity. Remarkably, when both these immunosuppressive genes are simultaneously deleted in NK cells, mice are largely resistant to tumor development, suggesting that combining suppression of these two pathways might represent a novel therapeutic strategy to enhance innate anticancer immunity.

Supplementary Figure from TGFβ and CIS Inhibition Overcomes NK-cell Suppression to Restore Antitumor Immunity

Androgen-dependent pathways regulate maintenance and growth of normal and malignant prostate tissues. Androgen deprivation therapy (ADT) exploits this dependence and is used to treat metastatic prostate cancer; however, regression initially seen with ADT gives way to development of incurable castration-resistant prostate cancer (CRPC). Although ADT generates a therapeutic response, it is also associated with a pattern of metabolic alterations consistent with metabolic syndrome including elevated circulating insulin. Because CRPC cells are capable of synthesizing androgens de novo, we hypothesized that insulin may also influence steroidogenesis in CRPC. In this study, we examined this hypothesis by evaluating the effect of insulin on steroid synthesis in prostate cancer cell lines. Treatment with 10 nmol/L insulin increased mRNA and protein expression of steroidogenesis enzymes and upregulated the insulin receptor substrate insulin receptor substrate 2 (IRS-2). Similarly, insulin treatment upregulated intracellular testosterone levels and secreted androgens, with the concentrations of steroids observed similar to the levels reported in prostate cancer patients. With similar potency to dihydrotestosterone, insulin treatment resulted in increased mRNA expression of prostate-specific antigen. CRPC progression also correlated with increased expression of IRS-2 and insulin receptor in vivo. Taken together, our findings support the hypothesis that the elevated insulin levels associated with therapeutic castration may exacerbate progression of prostate cancer to incurable CRPC in part by enhancing steroidogenesis. Cancer Res; 71(17); 5754–64. ©2011 AACR.

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Metformin, the first line pharmacotherapy for type 2 diabetes has demonstrated favourable effects in prostate cancer (PCa) across a range of studies evaluating PCa patient outcomes amongst metformin users. However, a lack of rigorously conducted prospective studies has stalled clinical use in this setting. Despite multiple studies evaluating the mechanisms underpinning antitumour effects of metformin in PCa, to date, no reviews have compared these findings. This systematic review and meta-analysis consolidates the mechanisms accounting for the antitumour effect of metformin in PCa and evaluates the antitumour efficacy of metformin in preclinical PCa studies. Data were obtained through Medline and EMBASE, extracted by two independent assessors. Risk of bias was assessed using the TOXR tool. Meta-analysis compared in vivo reductions of PCa tumour volume with metformin. In total, 447 articles were identified with 80 duplicates, and 261 articles excluded based on eligibility criteria. The remaining 106 articles were assessed and 71 excluded, with 35 articles included for systematic review, and eight included for meta-analysis. The mechanisms of action of metformin regarding tumour growth, viability, migration, invasion, cell metabolism, and activation of signalling cascades are individually discussed. The mechanisms by which metformin inhibits PCa cell growth are multimodal. Metformin regulates expression of multiple proteins/genes to inhibit cellular proliferation, cell cycle progression, and cellular invasion and migration. Published in vivo studies also conclusively demonstrate that metformin inhibits PCa growth. This highlights the potential of metformin to be repurposed as an anticancer agent, warranting further investigation of metformin in the setting of PCa.

Antibodies targeting “immune checkpoints” have revolutionized cancer therapy by reactivating tumor-resident cytotoxic lymphocytes, primarily CD8+ T cells. Interest in targeting analogous pathways in other cytotoxic lymphocytes is growing. Natural killer (NK) cells are key to cancer immunosurveillance by eradicating metastases and driving solid tumor inflammation. NK-cell antitumor function is dependent on the cytokine IL15. Ablation of the IL15 signaling inhibitor CIS (Cish) enhances NK-cell antitumor immunity by increasing NK-cell metabolism and persistence within the tumor microenvironment (TME). The TME has also been shown to impair NK-cell fitness via the production of immunosuppressive transforming growth factor β (TGFβ), a suppression which occurs even in the presence of high IL15 signaling. Here, we identified an unexpected interaction between CIS and the TGFβ signaling pathway in NK cells. Independently, Cish- and Tgfbr2-deficient NK cells are both hyperresponsive to IL15 and hyporesponsive to TGFβ, with dramatically enhanced antitumor immunity. Remarkably, when both these immunosuppressive genes are simultaneously deleted in NK cells, mice are largely resistant to tumor development, suggesting that combining suppression of these two pathways might represent a novel therapeutic strategy to enhance innate anticancer immunity.

1.0SummaryCellular energy and biomass demands of cancer drive a complex dynamic between uptake of extracellular fatty acids (FA) and de novo synthesis. Given that oxidation of de novo synthesised FAs for energy would result in net-energy loss, there is an implication that FAs from these two sources must have distinct metabolic fates - however hitherto FAs were considered part of a common pool. To probe FA metabolic partitioning, cancer cells were supplemented with stable-isotope labelled FAs. Structural analysis of the resulting glycerophospholipids revealed that labelled FAs from uptake were largely incorporated to canonical (sn-)positions on the glycerol backbone. Surprisingly, labelled FA uptake disrupted canonical isomer patterns of the unlabelled lipidome and induced repartitioning of n-3 and n-6 polyunsaturated-FAs into glycerophospholipid classes. These structural changes evidence differences in the metabolic fate of FAs derived from uptake or de novo sources and demonstrate unique signalling and remodelling behaviours usually hidden to conventional lipidomics.HighlightsLipid isomers reveal discrete metabolic compartmentalisation in cancerFAs derived from uptake and de novo synthesis have different metabolic fatesStearate uptake signals for PUFA (n-3 and n-6) repartitioning between lipid classessn-positional isomers are a marker for aberrant lipid metabolism

Background: Emerging evidence has revealed that genetic variations in microRNA (miRNA) binding sites called miRSNPs can alter miRNA binding in an allele-specific manner and impart prostate cancer (PCa) risk. Two miRSNPs, rs1530865 (G &gt, C) and rs2357637 (C &gt, A), in the 3′ untranslated region of pyruvate dehydrogenase kinase 1 (PDK1) have been previously reported to be associated with PCa risk. However, these results have not been functionally validated. Methods: In silico analysis was used to predict miRNA–PDK1 interactions and was tested using PDK1 knockdown, miRNA overexpression and reporter gene assay. Results: PDK1 expression was found to be upregulated in PCa metastasis. Further, our results show that PDK1 suppression reduced the migration, invasion, and glycolysis of PCa cells. Computational predictions showed that miR-3916, miR-3125 and miR-3928 had a higher binding affinity for the C allele than the G allele for the rs1530865 miRSNP which was validated by reporter gene assays. Similarly, miR-2116 and miR-889 had a higher affinity for the A than C allele of the rs2357637 miRSNP. Overexpression of miR-3916 and miR-3125 decreased PDK1 protein levels in cells expressing the rs1530865 SNP C allele, and miR-2116 reduced in cells with the rs2357637 SNP A allele. Conclusions: The present study is the first to report the regulation of the PDK1 gene by miRNAs in an allele-dependent manner and highlights the role of PDK1 in metabolic adaption associated with PCa progression.

BACKGROUNDMetabolic reprogramming is a hallmark of cancer. MicroRNAs (miRNAs) have been found to regulate cancer metabolism by regulating genes involved in metabolic pathways. Understanding this layer of complexity could lead to the development of novel therapeutic approaches.CONTENTmiRNAs are noncoding RNAs that have been implicated as master regulators of gene expression. Studies have revealed the role of miRNAs in the metabolic reprogramming of tumor cells, with several miRNAs both positively and negatively regulating multiple metabolic genes. The tricarboxylic acid (TCA) cycle, aerobic glycolysis, de novo fatty acid synthesis, and altered autophagy allow tumor cells to survive under adverse conditions. In addition, major signaling molecules, hypoxia-inducible factor, phosphatidylinositol-3 kinase/protein kinase B/mammalian target of rapamycin/phosphatase and tensin homolog, and insulin signaling pathways facilitate metabolic adaptation in tumor cells and are all regulated by miRNAs. Accumulating evidence suggests that miRNA mimics or inhibitors could be used to modulate the activity of miRNAs that drive tumor progression via altering their metabolism. Currently, several clinical trials investigating the role of miRNA-based therapy for cancer have been launched that may lead to novel therapeutic interventions in the future.SUMMARYIn this review, we summarize cancer-related metabolic pathways, including glycolysis, TCA cycle, pentose phosphate pathway, fatty acid metabolism, amino acid metabolism, and other metabolism-related oncogenic signaling pathways, and their regulation by miRNAs that are known to lead to tumorigenesis. Further, we discuss the current state of miRNA therapeutics in the clinic and their future potential.

Endometrial cancer is the most commonly diagnosed gynaecological malignancy. Unfortunately, 15-20% of women demonstrate persistent or recurrent tumours that are refractory to current chemotherapies. We previously identified activating mutations in fibroblast growth factor receptor 2 (FGFR2) in 12% (stage I/II) to 17% (stage III/IV) endometrioid ECs and found that these mutations are associated with shorter progression-free and cancer-specific survival. Although FGFR inhibitors are undergoing clinical trials for treatment of several cancer types, little is known about the mechanism by which they induce cell death. We show that treatment with BGJ398, AZD4547 and PD173074 causes mitochondrial depolarization, cytochrome c release and impaired mitochondrial respiration in two FGFR2-mutant EC cell lines (AN3CA and JHUEM2). Despite this mitochondrial dysfunction, we were unable to detect caspase activation following FGFR inhibition; in addition, the pan-caspase inhibitor Z-VAD-FMK was unable to prevent cell death, suggesting that the cell death is caspase-independent. Furthermore, while FGFR inhibition led to an increase in LC3 puncta, treatment with bafilomycin did not further increase lipidated LC3, suggesting that FGFR inhibition led to a block in autophagosome degradation. We confirmed that cell death is mitochondrial-dependent as it can be blocked by overexpression of Bcl-2 and/or Bcl-XL. Importantly, we show that combining FGFR inhibitors with the BH3 mimetics ABT737/ABT263 markedly increased cell death in vitro and is more effective than BGJ398 alone in vivo, where it leads to marked tumour regression. This work may have implications for the design of clinical trials to treat a wide range of patients with FGFR-dependent malignancies.

Hyperleptinaemia is a well-established therapeutic side effect of drugs inhibiting the androgen axis in prostate cancer (PCa), including main stay androgen deprivation therapy (ADT) and androgen targeted therapies (ATT). Given significant crossover between the adipokine hormone signalling of leptin and multiple cancer-promoting hallmark pathways, including growth, proliferation, migration, angiogenesis, metabolism and inflammation, targeting the leptin axis is therapeutically appealing, especially in advanced PCa where current therapies fail to be curative. In this study, we uncover leptin as a novel universal target in PCa and are the first to highlight increased intratumoural leptin and leptin receptor (LEPR) expression in PCa cells and patients' tumours exposed to androgen deprivation, as is observed in patients' tumours of metastatic and castrate resistant (CRPC) PCa. We also reveal the world-first preclinical evidence that demonstrates marked efficacy of targeted leptin-signalling blockade, using Allo-aca, a potent, specific, and safe LEPR peptide antagonist. Allo-aca-suppressed tumour growth and delayed progression to CRPC in mice bearing LNCaP xenografts, with reduced tumour vascularity and altered pathways of apoptosis, transcription/translation, and energetics in tumours determined as potential mechanisms underpinning anti-tumour efficacy. We highlight LEPR blockade in combination with androgen axis inhibition represents a promising new therapeutic strategy vital in advanced PCa treatment.

It is now appreciated that long non-coding RNAs (lncRNAs) are important players in the orchestration of cancer progression. In this study we characterizedGHSROS, a human lncRNA gene on the opposite DNA strand (antisense) to the ghrelin receptor gene, in prostate cancer. The lncRNA was upregulated by prostate tumors from different clinical datasets. Consistently, transcriptome data revealed thatGHSROSalters the expression of cancer-associated genes. Functional analysesin vitroshowed thatGHSROSmediates tumor growth, migration, and survival and resistance to the cytotoxic drug docetaxel. Increased cellular proliferation ofGHSROS-overexpressing PC3, DU145, and LNCaP prostate cancer cell linesin vitrowas recapitulated in a subcutaneous xenograft model. Conversely,in vitroantisense oligonucleotide inhibition of the lncRNA reciprocally regulated cell growth and migration, and gene expression. Notably,GHSROSmodulates the expression of PPP2R2C, the loss of which may drive androgen receptor pathway-independent prostate tumor progression in a subset of prostate cancers. Collectively, our findings suggest thatGHSROScan reprogram prostate cancer cells toward a more aggressive phenotype and that this lncRNA may represent a potential therapeutic target.

Once thought to be exclusively a storage hub for glucose, glycogen is now known to be essential in a range of physiological processes and pathological conditions. Glycogen lies at the nexus of diverse processes that promote malignancy, including proliferation, migration, invasion, and chemoresistance of cancer cells. It is also implicated in processes associated with the tumor microenvironment such as immune cell effector function and crosstalk with cancer-associated fibroblasts to promote metastasis. The enzymes of glycogen metabolism are dysregulated in a wide variety of malignancies, including cancers of the kidney, ovary, lung, bladder, liver, blood, and breast. Understanding and targeting glycogen metabolism in cancer presents a promising but under-explored therapeutic avenue. In this review, we summarize the current literature on the role of glycogen in cancer progression and discuss its potential as a therapeutic target for cancer treatment.

The critical role of metabolism in facilitating cancer cell growth and survival has been demonstrated by a combination of methods including, but not limited to, genomic sequencing, transcriptomic and proteomic analyses, measurements of radio-labelled substrate flux and the high throughput measurement of oxidative metabolism in unlabelled live cells using the Seahorse Extracellular Flux (XF) technology. These studies have revealed that tumour cells exhibit a dynamic metabolic plasticity, using numerous pathways including both glycolysis and mitochondrial oxidative phosphorylation (OXPHOS) to support cell proliferation, energy production and the synthesis of biomass. These advanced technologies have also demonstrated metabolic differences between cancer cell types, between molecular subtypes within cancers and between cell states. This has been exemplified by examining the transitions of cancer cells between epithelial and mesenchymal phenotypes, referred to as epithelial-mesenchymal plasticity (EMP). A growing number of studies are demonstrating significant metabolic alterations associated with these transitions, such as increased use of glycolysis by triple negative breast cancers (TNBC) or glutamine addiction in lung cancer. Models of EMP, including invasive cell lines and xenografts, isolated circulating tumour cells and metastatic tissue have been used to examine EMP metabolism. Understanding the metabolism supporting molecular and cellular plasticity and increased metastatic capacity may reveal metabolic vulnerabilities that can be therapeutically exploited. This chapter describes protocols for using the Seahorse Extracellular Flux Analyzer (XFe96), which simultaneously performs real-time monitoring of oxidative phosphorylation and glycolysis in living cells. As an example, we compare the metabolic profiles generated from two breast cancer sublines that reflect epithelial and mesenchymal phenotypes, respectively. We use this example to show how the methodology described can generate bioenergetic results that in turn can be correlated to EMP phenotypes. Normalisation of bioenergetic studies should be considered with respect to cell number, and to potential differences in mitochondrial mass, itself being an important bioenergetics endpoint.

The spirooxepinisoxazoline alkaloid psammaplysin F (1) was selected as a scaffold for the generation of a unique screening library for both drug discovery and chemical biology research. Large-scale extraction and isolation chemistry was performed on a marine sponge (Hyattella sp.) collected from the Great Barrier Reef in order to acquire >200 mg of the desired bromotyrosine-derived alkaloidal scaffold. Parallel solution-phase semisynthesis was employed to generate a series of psammaplysin-based urea (2–9) and amide analogues (10–11) in low to moderate yields. The chemical structures of all analogues were characterized using NMR and MS data. The absolute configuration of psammaplysin F and all semisynthetic analogues was determined as 6R, 7R by comparison of ECD data with literature values. All compounds (1–11) were evaluated for their effect on cell cycle distribution and changes to cancer metabolism in LNCaP prostate cancer cells using a multiparametric quantitative single-cell imaging approach. These investigations identified that in LNCaP cells psammaplysin F and some urea analogues caused loss of mitochondrial membrane potential, fragmentation of the mitochondrial tubular network, chromosome misalignment, and cell cycle arrest in mitosis.

High stage and recurrent ovarian clear cell carcinoma (OCC) are associated with poor prognosis and resistance to chemotherapy. A distinguishing histological feature of OCC is abundant cytoplasmic stores of glucose, in the form of glycogen, that can be mobilized for cellular metabolism. Here, we report the effect on preclinical models of OCC of disrupting glycogen utilization using the glucose analogue 2-deoxy-D-glucose (2DG). At concentrations significantly lower than previously reported for other cancers, 2DG markedly improves the efficacy in vitro of carboplatin chemotherapy against chemo-sensitive TOV21G and chemo-resistant OVTOKO OCC cell lines, and this is accompanied by the depletion of glycogen. Of note, 2DG doses&mdash, of more than 10-fold lower than previously reported for other cancers&mdash, significantly improve the efficacy of carboplatin against cell line and patient-derived xenograft models in mice that mimic the chemo-responsiveness of OCC. These findings are encouraging, in that 2DG doses, which are substantially lower than previously reported to cause adverse events in cancer patients, can safely and significantly improve the efficacy of carboplatin against OCC. Our results thus justify clinical trials to evaluate whether low dose 2DG improves the efficacy of carboplatin in OCC patients.

The propensity of cancer cells to transition between epithelial and mesenchymal phenotypic states via the epithelial–mesenchymal transition (EMT) program can regulate metastatic processes, cancer progression, and treatment resistance. Transcriptional investigations using reversible models of EMT, revealed the mesenchymal-to-epithelial reverting transition (MErT) to be enriched in clinical samples of metastatic castrate resistant prostate cancer (mCRPC). From this enrichment, a metastasis-derived gene signature was identified that predicted more rapid cancer relapse and reduced survival across multiple human carcinoma types. Additionally, the transcriptional profile of MErT is not a simple mirror image of EMT as tumour cells retain a transcriptional “memory” following a reversible EMT. This memory was also enriched in mCRPC samples. Cumulatively, our studies reveal the transcriptional profile of epithelial–mesenchymal plasticity and highlight the unique transcriptional properties of MErT. Furthermore, our findings provide evidence to support the association of epithelial plasticity with poor clinical outcomes in multiple human carcinoma types.

Background: Cancer cells notoriously escape radiation therapy, chemotherapy, hormonal therapy, and other anti-cancer therapies. Among various breast cancer subtypes, triple negative breast cancers (TNBCs) are known for their poor clinical outcome and dearth of effective targeted therapies due to the absence of druggable receptors. Cold atmospheric plasma (CAP) holds promise as a cancer-specific treatment agent that selectively kills basal-like/TN breast cancer cells. Method: In this study, we used plasma-activated media (PAM) to capture and store the multi-modal chemical species of CAP, which significantly expands the treatment scope and flexibility of plasma medicine as a clinical therapeutic approach. The PAM was diluted into different doses and cells were treated for 12 or 24 hours. The effects of PAM on cell viability and ROS levels in 9 different cell lines; normal cells (MCF-10A and HEK-293T), luminal breast cancer cell lines (MCF-7, T47D, HCC70), and TNBC cell lines (MDA-MB-468, SUM-159PT, SUM-149PT, MDA-MB-231), were assessed. Results: The results showed that TNBC cells were more highly sensitive, in a dose-dependent manner, to PAM treatment. PAM selectively caused apoptosis of TNBC cell lines compared to luminal lines and had little effect on the normal cell lines. It has been hypothesised that the cancer-selective CAP and PAM cytotoxicity is due in part to reactive oxygen (ROS) and nitrogen species (RNS). Constitutive RONS levels, combined with those present in and/or induced by PAM, can combine to push the cells over a cytotoxic threshold. In support of this, we found a tight correlation (R2=0.7502) between the constitutive ROS level of different cell lines used and their response (cell viability) to 100% PAM treatment, and found that ROS levels selectively increased further in the TNBC>luminal>normal cells in response to PAM. We have also identified a strong synergistic molecular partner that further promotes sensitivity and selectivity of PAM for TNBC cells. Conclusion: We demonstrated that treatment with PAM promotes apoptosis n cell lines representing the most aggressive TNBC subtype. This discovery opens new TNBC-selective opportunities for simultaneous inhibition of diverse (parallel) cancer development factors through synergistic interactions enabled through plasma activated biochemical media. Citation Format: Peiyu Wang, Renwu Zhou, Rusen Zhou, Jennifer Gunter, Fiona Simpson, Kostya (Ken) Ostrikov, Derek Richard, Xiaofeng Dai, Erik (Rik) Walter Thompson. Cold atmospheric plasma therapy selectively targets triple negative breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 996.

Recent evidence has implicated the transmembrane co-receptor neuropilin-1 (NRP1) in cancer progression. Primarily known as a regulator of neuronal guidance and angiogenesis, NRP1 is also expressed in multiple human malignancies, where it promotes tumor angiogenesis. However, non-angiogenic roles of NRP1 in tumor progression remain poorly characterized. In this study, we define NRP1 as an androgen-repressed gene whose expression is elevated during the adaptation of prostate tumors to androgen-targeted therapies (ATTs), and subsequent progression to metastatic castration-resistant prostate cancer (mCRPC). Using short hairpin RNA (shRNA)-mediated suppression of NRP1, we demonstrate that NRP1 regulates the mesenchymal phenotype of mCRPC cell models and the invasive and metastatic dissemination of tumor cells in vivo. In patients, immunohistochemical staining of tissue microarrays and mRNA expression analyses revealed a positive association between NRP1 expression and increasing Gleason grade, pathological T score, positive lymph node status and primary therapy failure. Furthermore, multivariate analysis of several large clinical prostate cancer (PCa) cohorts identified NRP1 expression at radical prostatectomy as an independent prognostic biomarker of biochemical recurrence after radiation therapy, metastasis and cancer-specific mortality. This study identifies NRP1 for the first time as a novel androgen-suppressed gene upregulated during the adaptive response of prostate tumors to ATTs and a prognostic biomarker of clinical metastasis and lethal PCa. Refereed/Peer-reviewed

Androgen deprivation therapy (ADT) is the standard treatment for advanced prostate cancer (PCa), yet many patients relapse with lethal metastatic disease. With this loss of androgens, increased cell plasticity has been observed as an adaptive response to ADT. This includes gain of invasive and migratory capabilities, which may contribute to PCa metastasis. Hyperinsulinemia, which develops as a side-effect of ADT, has been associated with increased tumor aggressiveness and faster treatment failure. We investigated the direct effects of insulin in PCa cells that may contribute to this progression. We measured cell migration and invasion induced by insulin using wound healing and transwell assays in a range of PCa cell lines of variable androgen dependency (LNCaP, 22RV1, DuCaP, and DU145 cell lines). To determine the molecular events driving insulin-induced invasion we used transcriptomics, quantitative real time-PCR, and immunoblotting in three PCa cell lines. Insulin increased invasiveness of PCa cells, upregulating Forkhead Box Protein C2 (FOXC2), and activating key PCa cell plasticity mechanisms including gene changes consistent with epithelial-to-mesenchymal transition (EMT) and a neuroendocrine phenotype. Additionally, analysis of publicly available clinical PCa tumor data showed metastatic prostate tumors demonstrate a positive correlation between insulin receptor expression and the EMT transcription factor FOXC2. The insulin receptor is not suitable to target clinically however, our data shows that actions of insulin in PCa cells may be suppressed by inhibiting downstream signaling molecules, PI3K and ERK1/2. This study identifies for the first time, a mechanism for insulin-driven cancer cell motility and supports the concept that targeting insulin signaling at the level of the PCa tumor may extend the therapeutic efficacy of ADT.

Summary: Histone deacetylases (HDACs) drive innate immune cell-mediated inflammation. Here we identify class IIa HDACs as key molecular links between Toll-like receptor (TLR)-inducible aerobic glycolysis and macrophage inflammatory responses. A proteomic screen identified the glycolytic enzyme pyruvate kinase M isoform 2 (Pkm2) as a partner of proinflammatory Hdac7 in murine macrophages. Myeloid-specific Hdac7 overexpression in transgenic mice amplifies lipopolysaccharide (LPS)-inducible lactate and promotes a glycolysis-associated inflammatory signature. Conversely, pharmacological or genetic targeting of Hdac7 and other class IIa HDACs attenuates LPS-inducible glycolysis and accompanying inflammatory responses in macrophages. We show that an Hdac7-Pkm2 complex acts as an immunometabolism signaling hub, whereby Pkm2 deacetylation at lysine 433 licenses its proinflammatory functions. Disrupting this complex suppresses inflammatory responses in vitro and in vivo. Class IIa HDACs are thus pivotal intermediates connecting TLR-inducible glycolysis to inflammation via Pkm2. : Das Gupta et al. show that HDAC7 and other class IIa HDAC enzymes control macrophage metabolism. They initiate TLR-inducible glycolysis in these cells and interact with the glycolytic enzyme PKM2 to drive inflammatory responses in vitro and in vivo. Class IIa HDAC inhibitors may have potential for attenuating immunometabolism-linked inflammation. Keywords: glycolysis, histone deacetylases, immunometabolism, inflammation, lysine acetylation, macrophage, post-translational modification, pyruvate kinase, toll-like receptor

The majority of prostate cancer (PCa) deaths occur due to the metastatic spread of tumor cells to distant organs. Currently, there is a lack of effective therapies once tumor cells have spread outside the prostate. It is therefore imperative to rapidly develop therapeutics to inhibit the metastatic spread of tumor cells. Gain of cell motility and invasive properties is the first step of metastasis and by inhibiting motility one can potentially inhibit metastasis. Using the drug repositioning strategy, we developed a cell-based multi-parameter primary screening assay to identify drugs that inhibit the migratory and invasive properties of metastatic PC-3 PCa cells. Following the completion of the primary screening assay, 33 drugs were identified from an FDA approved drug library that either inhibited migration or were cytotoxic to the PC-3 cells. Based on the data obtained from the subsequent validation studies, mitoxantrone hydrochloride, simvastatin, fluvastatin and vandetanib were identified as strong candidates that can inhibit both the migration and invasion of PC-3 cells without significantly affecting cell viability. By employing the drug repositioning strategy instead of a de novo drug discovery and development strategy, the identified drug candidates have the potential to be rapidly translated into the clinic for the management of men with aggressive forms of PCa.

INTRODUCTION AND OBJECTIVES: Precision medicine aims to provide the right treatment for the right patient at the right time with treatment directed on the basis of the targetable tumoral aberrations rather than just a traditional histologic subtype. However to facilitate this approach, clinicians require patient derived samples. Prostate cancer is challenging to culture in vitro. Recent development of novel organoid in vitro culture technology has led to the development of multiple new in vitro prostate cancer cell line models. We aim to apply organoid culture technology to develop novel in vitro prostate cancer cell line models and propagate patient derived samples to allow drug testing and next generation sequencing as part of a precision medicine approach to early recurrent prostate cancer. METHODS: Patient derived metastatic tissue samples were collected as part of a larger clinical trial. These were digested in Type II Collagenase (Gibco) for 2 hours and seeded directly onto Collagen Type I coated plates in novel media. Samples were cultured in vitro for a minimum of 2 weeks prior to validation. PSA ELISA (GenWay Biotech) of conditioned media along with RT-qPCR comparison of various gene products of interest between cultured patient samples and established prostate cancer cell lines was performed. In vitro samples were subsequently utilised for therapeutic screening. RESULTS: A total of 5 patient samples were available for culture with histologically proven metastatic prostate cancer. Tissue from a 67 year old male with biochemical recurrence of prostate cancer following retro-pubic radical prostatectomy was obtained fresh at time of salvage lymph node dissection (PSA was 1.5 ng/ml). Tissue was successfully cultured for a minimum of 4 weeks prior to validation. PSA ELISA of conditioned media was positive. RT-qPCR confirmed expression of Prostate specific genes PSA, AR, FKBP5 and TMPRSS. Drug screen revealed a marked response to Docetaxel, Cabazitaxel and Enzalutamide and minimal effect to Bicalutamide. CONCLUSIONS: We have successfully cultured patient derived samples for precision medicine. Further therapeutic screening and next generation sequencing of derived cultures is ongoing in order to potentially inform therapeutic strategies. Organoid in vitro culture technology could provide a vital stepping stone towards precision medicine in the future, involving the rapid generation of patient specific in vitro models for therapeutic screening to guide individualized treatment.

The propensity of cancer cells to transition between epithelial and mesenchymal phenotypic states via the epithelial–mesenchymal transition (EMT) program can regulate metastatic processes, cancer progression, and treatment resistance. Transcriptional investigations using reversible models of EMT, revealed the mesenchymal-to-epithelial reverting transition (MErT) to be enriched in clinical samples of metastatic castrate resistant prostate cancer (mCRPC). From this enrichment, a metastasis-derived gene signature was identified that predicted more rapid cancer relapse and reduced survival across multiple human carcinoma types. Additionally, the transcriptional profile of MErT is not a simple mirror image of EMT as tumour cells retain a transcriptional “memory” following a reversible EMT. This memory was also enriched in mCRPC samples. Cumulatively, our studies reveal the transcriptional profile of epithelial–mesenchymal plasticity and highlight the unique transcriptional properties of MErT. Furthermore, our findings provide evidence to support the association of epithelial plasticity with poor clinical outcomes in multiple human carcinoma types.

INTRODUCTION AND OBJECTIVES: Androgen deprivation therapy (ADT) plays a pivotal role in managing men with metastatic prostate cancer. Whilst it provides cancer specific survival advantage in those with metastatic disease and those undergoing radiotherapy for intermediate to high risk localized prostate cancer, it is associated with significant metabolic adverse effects. ADMET (ADT and metformin) trial was set up to determine whether adjuvant metformin would reverse metabolic syndrome induced by ADT, and whether molecular changes in CTCs could be detected during the treatment. METHODS: We established a multi-centre randomized, placebo controlled clinical trial. In total, 80 patients with metastatic prostate cancer who are commenced on ADT are expected to be recruited and reviewed 6 weekly for 42 weeks. Forty seven patients have so far been screened as a part of the trial. 5ml of whole blood was collected from patients for CTC enrichment, enumeration and propagation. Enrichment was performed using CD45 negative selection kit (RosetteSep). CTCs were identified using immunofluorescence imaging with antibodies against prostate specific antigen, cytokeratin, CD45 and nucleus. Cells were propagated in customized stem cell solution with hypoxic conditions (8%). RESULTS: At screening, 39 of 47 patients demonstrated circulating tumour cells with the mean number of 847 (range 1-4750, SD+/-1731). In 32 of 39 samples, the enriched samples could be propagated temporarily with the peak population being reached at 7-20 days. Cells were cultured in both 2D and 3D conditions and temporary organoids could be developed from 12 patients. Cultured cells were then prepared for RNA extraction, with the ultimate aim of being able to propagate enough samples for RNA sequencing. With the ability to further culture the harvested CTCs, we were able to observe the cells under the influence of numerous prostate cancer treatment medications using Incucyte, demonstrating the potential for personalized medicine. In 26 patients, who were available for longitudinal follow up, all patients demonstrated persistence of CTCs. CONCLUSIONS: Circulating tumour cell technology remains a viable option as a means of providing biomarker information and tumour activity indicator in delivering precision medicine. Firstly, enumeration can be used to help determine the response to a treatment. Secondly, temporary culture and progression into development of organoids may be used to allow for downstream analysis and therapeutic decision.

Androgen-dependent pathways regulate maintenance and growth of normal and malignant prostate tissues. Androgen deprivation therapy (ADT) exploits this dependence and is used to treat metastatic prostate cancer; however, regression initially seen with ADT gives way to development of incurable castration-resistant prostate cancer (CRPC). Although ADT generates a therapeutic response, it is also associated with a pattern of metabolic alterations consistent with metabolic syndrome including elevated circulating insulin. Because CRPC cells are capable of synthesizing androgens de novo, we hypothesized that insulin may also influence steroidogenesis in CRPC. In this study, we examined this hypothesis by evaluating the effect of insulin on steroid synthesis in prostate cancer cell lines. Treatment with 10 nmol/L insulin increased mRNA and protein expression of steroidogenesis enzymes and upregulated the insulin receptor substrate insulin receptor substrate 2 (IRS-2). Similarly, insulin treatment upregulated intracellular testosterone levels and secreted androgens, with the concentrations of steroids observed similar to the levels reported in prostate cancer patients. With similar potency to dihydrotestosterone, insulin treatment resulted in increased mRNA expression of prostate-specific antigen. CRPC progression also correlated with increased expression of IRS-2 and insulin receptor in vivo. Taken together, our findings support the hypothesis that the elevated insulin levels associated with therapeutic castration may exacerbate progression of prostate cancer to incurable CRPC in part by enhancing steroidogenesis. Cancer Res; 71(17); 5754–64. ©2011 AACR.

Long noncoding RNAs (lncRNAs) play key regulatory roles in cancer progression and are novel therapeutic targets. We recently discovered the lncRNA gene, GHSROS (GHSR opposite strand), on the antisense DNA strand of the ghrelin receptor gene (GHSR). Here, we studied the expression and function of GHSROS in prostate cancer. Interrogation of microarray and RNA-seq data sets revealed that (similar to other lncRNA oncogenes) GHSROS is actively transcribed, although expressed at very low levels in cancer cell lines and tissues. By quantitative RT-PCR we demonstrate that GHSROS is highly expressed in a subset of high-grade prostate cancers (~11.4%). Moreover, the lncRNA is upregulated in high Gleason-score prostate tumors in two clinical data sets. Forced GHSROS overexpression significantly increased in vitro cell proliferation and migration of PC3, DU145, and LNCaP prostate cancer cell lines (P ≤ 0.05, Student's t-test). Increased cell proliferation observed in GHSROS-overexpressing prostate cancer cell lines was recapitulated in PC3, DU145, and LNCaP prostate cancer xenografts in NOD/SCID mice. Cell survival was significantly increased in GHSROS-overexpressing LNCaP cells treated with the cytotoxic drug docetaxel (P ≤ 0.05, Student's t-test). Docetaxel treatment also increased GHSROS expression in native LNCaP and PC3 cells in a dose-dependent manner (P ≤ 0.05, Student's t-test). These data suggest that GHSROS mediates tumor survival and resistance to docetaxel. To identify fundamental drivers of the observed tumorigenic phenotype of GHSROS-overexpressing cell lines, high-throughput RNA-seq data from in vitro cultured PC3 cells and LNCaP xenografts were examined. A quarter of the genes differentially expressed by GHSROS-overexpressing PC3 cells were also differentially expressed by GHSROS-overexpressing LNCaP xenografts. These 101 genes include several transcription factors with established roles in prostate cancer (including the androgen receptor) and genes associated with metastasis and poor prognosis. Finally, we developed two distinct antisense oligonucleotides (ASOs) targeting GHSROS, achieving >60% knockdown, and their function was assessed in vitro. ASO inhibition of GHSROS expression reciprocally regulated cell growth and migration and the expression of a range of genes. These ASOs are currently being assessed in preclinical animal models. Our findings suggest that the long noncoding RNA GHSROS reprograms prostate cancer cells toward a more aggressive phenotype and that the lncRNA represents a promising therapeutic target. Citation Format: Patrick B. Thomas, Penny L. Jeffery, Gahete D. Manuel, Eliza J. Whiteside, Michelle Maugham, Carina Walpole, Jennifer H. Gunter, Elizabeth D. Williams, Colleen C. Nelson, Adrian C. Herington, Raul M. Luque, Rakesh N. Veedu, Lisa K. Chopin, Inge Seim. Dysregulated expression of the human long noncoding RNA GHSROS may influence prostate cancer progression and resistance to docetaxel [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2452.

Endometrial cancer (EC) is the most commonly diagnosed malignancy of the female reproductive tract. Unfortunately, 15-20% of women demonstrate persistent or recurrent tumors that are refractory to current chemotherapies with an associated poor prognosis. Our laboratory identified activating mutations in Fibroblast Growth Factor Receptor 2 (FGFR2) in 12% (stage I/II) to 17% (stage III/IV) endometrioid endometrial tumors and have since shown in a large (n=970) multi-institutional cohort they are associated with shorter progression free and cancer specific survival. Although FGFR inhibitors are in clinical trials in several cancer types, no detailed study of the mechanism of cell death has been published. We now show that treatment with BGJ398, AZD4547 and PD173074 leads to the induction of mitochondrial depolarization and changes in metabolic flux in two endometrial cancer cell lines (JHUEM2 and AN3CA) carrying activating mutations (C383R and N550K respectively). Despite this mitochondrial dysfunction, we have convincingly shown that the cell death following FGFR inhibition was caspase-independent, as evidenced by the lack of caspase-3, -7, and -9 activation, absence of PARP cleavage, and the inability of the broad-spectrum caspase inhibitor, Z-VAD-FMK, to prevent cell death. Knockdown of EndoG and AIF, common mediators of caspase-independent death, had no effect. Detailed quantification of LC3 positive puncta shows an increase in autophagy in JHUEM2 and AN3CA cells treated with all FGFR inhibitors. Knockdown of ATG3, ATG7 and ATG12 resulted in a slight increase in Annexin positive cell death indicating that the autophagy was cytoprotective in this context. We have now confirmed this novel caspase-independent cell death is mitochondrial dependent as it can be blocked by overexpression of Bcl-2 and/or Bcl-XL. Importantly we have shown that the combination of FGFR inhibitors with the BH3 mimetic ABT737 can markedly augment this caspase-independent cell death which may have implications for the design of more effective clinical trials. Citation Format: Leisl Packer, Sara Byron, Samantha Stehbens, Vanessa Bonazzi, David Loch, Andreas Wortmann, Mike Gartside, Nigel Waterhouse, Jennifer Gunter, Pamela M. Pollock. FGFR inhibition in endometrial cancer induces caspase-independent cell death that can be augmented with ABT-737 [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr LB-B31.

We previously described a putative role for inosine monophosphate dehydrogenase (IMPDH), a rate-limiting enzyme in de novo guanine nucleotide biosynthesis, in lipid accumulation. Here we present data which demonstrate that IMPDH activity is required for differentiation of preadipocytes into mature, lipid-laden adipocytes and maintenance of adipose tissue mass. In 3T3-L1 preadipocytes inhibition of IMPDH with mycophenolic acid (MPA) reduced intracellular GTP levels by 60% (p

In mammals there are two ubiquitous, catalytically indistinguishable isoforms of inosine monophosphate dehydrogenase and mutations in the type I isoform, but not type II, cause retina-specific disorders. We have characterised the spatio-temporal expression of these proteins during development of the rat retina and performed functional investigations of the recently described retinal type I variants. Inosine monophosphate dehydrogenase was present in all immature cells throughout the retina during embryonic and neonatal development. Following eye opening and cell differentiation its distribution was restricted to the photoreceptors and bipolar cells, becoming prominent in Müller cells with aging. Type II was present in early, developing retinae whilst type I was undetectable. An isoform switch occurred around P10, after which the type I variants, type Ialpha and type Igamma, were the major forms. Functional investigations indicate type Igamma has greater catalytic activity compared with other variants and isoforms. Finally, all forms of type I show an increased propensity to form intracellular macrostructures compared to type II and these structures appear to be regulated in response to changing intracellular GTP levels. Collectively these data demonstrate that (i) type I does not play a role in early retinal development, (ii) type Igamma has greater activity and (iii) there are differences between type I and type II isoforms. These observations are consistent with the aetiology of retinitis pigmentosa and raise the possibility that programmed expression of specific inosine monophosphate dehydrogenase proteins may have arisen to meet the requirements of the cellular environment.

Transplantation of islets is a viable option for the treatment of diabetes. A significant proportion of islets is lost during isolation, storage and after transplantation as a result of apoptosis. cAMP response element binding protein (CREB) is an important cell survival factor. The aim of the present study was to determine whether preservation of CREB function is needed for survival of human islets. To determine the effects of downregulation of CREB activity on beta cell apoptosis in a transplantation setting, adenoviral vectors were used to express two dominant negative mutant forms of CREB in human islets isolated from cadaveric donors. Markers of apoptosis were determined in these transduced islets under basal conditions and following treatment with growth factor. Expression of CREB mutants in human islets resulted in significant (p

Reactivation of the embryonic developmental pathway, epithelial-to-mesenchymal transition (EMT) is associated with prostate cancer (PCa) metastasis and therapy resistance. Recent evidence has demonstrated EMT is stimulated following androgen targeted therapy (ATT). In the present study we investigated the role of EMT transcription factor ZEB1 in ATT-driven EMT, PCa metastasis and drug resistance. Immunohistochemistry (IHC) staining of ZEB1 on tissue microarrays of primary tumors from clinical samples demonstrated ZEB1 expression correlated with increased tumor aggressiveness and Gleason score. Upon stratification of patient data (n=198), high ZEB1 protein expression correlated with a shorter time to biochemical recurrence (BCR). Furthermore, IHC staining of primary tumours from 148 treatment-naïve patients with and without metastasis demonstrated high ZEB1 levels and correlated to a reduced time to metastasis. To delineate the role of ZEB1 as a molecular driver of late-stage PCa, microarray analysis of an in vivo LNCaP progression model demonstrated ZEB1 levels increased following castration. Significantly, high ZEB1 levels were associated with patients who had undergone neoadjuvant hormone therapy with or without docetaxel and high ZEB1 levels were associated with a shorter time to BCR and metastasis. Inhibition of the androgen/androgen receptor (AR) axis in LNCaP cells using antiandrogen treatment or shRNA targeting AR resulted in upregulation of ZEB1 in LNCaP cells suggesting enhanced levels of ZEB1 may drive the early adaptive response of PCa after hormone therapy. Interestingly, in models where ZEB1 expression was elevated this was accompanied with repression of classical androgen-regulated genes suggesting ZEB1 is able to regulate the AR transcriptional pathway. We also investigated the role of ZEB1 in cancer invasion and chemoresistance. An inducible model of ZEB1 overexpression in LNCaP cells produced a robust EMT upon ZEB1 expression and was accompanied by an invasive phenotype in 3D cultures. ZEB1 overexpression also conferred resistance to docetaxel (IC50 of 8.17±2.45nM in ZEB1-expressing cells vs. 3.35±0.23nM in control cells) potentially as a result of a reduced apoptotic cell death response mediated by ZEB1. At suboptimal doses of docetaxel, the percentage of apoptotic cells (annexin-V+/propidium iodide-) decreased 4-fold when ZEB1 was expressed compared with control cells and was accompanied by a reduction in PARP cleavage and cleaved caspase-7 expression. In summary, we provide evidence that ZEB1 expression is increased in response to ATTs and correlates with disease progression, metastasis and therapy resistance. We also show ZEB1 is a transcriptional regulator of AR signalling in PCa, Together this provides the rationale to target ZEB1 for the development of novel therapies for the treatment of CRPC. Note: This abstract was not presented at the meeting. Citation Format: Katrina G. Sweeney, Nataly Stylianou, Gregor Tevz, Atefeh Taherianfard, Katrina Pirlo, Akanksha Upadhyaya, Ellca Ratther, Melanie Lehman, Martin Gleave, Jennifer Gunter, Elizabeth D. Williams, Colleen C. Nelson, Brett Hollier. Androgen targeted therapy induces ZEB1 expression and is associated with suppression of androgen signalling and therapy resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4909. doi:10.1158/1538-7445.AM2017-4909

Long non-coding RNAs (lncRNAs) play key regulatory roles in cancer progression and are emerging therapeutic targets. The objective of this study was to investigate the expression and function of the lncRNA GHSROS in prostate cancer. Quantitative RT-PCR revealed that GHSROS is highly expressed in a subset of prostate cancers (Gleason score 8-10; z-score >1; Mann-Whitney-Wilcoxon test P=0.0021). Forced overexpression of the lncRNA stimulated cell migration in vitro in the PC3 (1.82 ± 0.35, P=0.006; Student’s t-test), DU145 (1.94 ± 0.34, P=0.017), and LNCaP (1.27 ± 0.02, P=0.0002) prostate cancer cell lines. Cell proliferation was increased in GHSROS overexpressing PC3 (3.36 ± 1.91, P=0.029), DU145 (1.749 ± 0.59, P=0.026), and LNCaP (1.39 ± 0.26, P=0.040) prostate cancer cell lines. These results were recapitulated in NOD/SCID mice, with increased tumor growth and Ki67 immunohistochemical staining in PC3 (P=0.0040) and DU145 (P = 0.036) xenografts overexpressing the lncRNA.High-throughput transcriptome sequencing (RNA-seq) identified 400 differentially expressed genes in GHSROS overexpressing PC3 cells, with enrichment of genes associated with motility, migration and regulation of cell growth. Further interrogation of the 400 gene set using Oncomine concept mapping, and interrogation of publicly-available clinical prostate cancer data sets, revealed a 34-gene signature associated with poorer disease outcome and metastatic progression. Preliminary analysis of The Cancer Genome Atlas (TCGA) data, suggest that the signature has potential as a prognostic indicator for disease free- or overall survival in numerous cancers. Finally, locked antisense oligonucleotide (LNA-ASO) inhibition of endogenous GHSROS reciprocally regulated cell growth (Student’s t-test; RNV124: -1.14 ± 0.06, P=0.049 and RNV104L: -1.18 ± 0.05, P=0.030, migration (RNV124: -1.96 ± 0.11, P=0.004) and gene expression changes, supporting the observations from forced GHSROS overexpression experiments.In summary, we provide evidence that GHSROS is a prostate cancer associated lncRNA that promotes a gene expression signature which enhances the propensity for metastasis and adverse disease outcomes. We also demonstrate that GHSROS can be targeted using antisense oligonucleotides. Further studies on this lncRNA may provide new prognostic and therapeutic opportunities. Citation Format: Patrick B. Thomas, Penny L. Jeffery, Eliza Whiteside, Carina Walpole, Michelle Maugham, Lidija Jovanovic, Jennifer H. Gunter, Colleen C. Nelson, Adrian C. Herington, Rakesh Veedu, Lisa K. Chopin, Inge Seim. The long non-coding RNA GHSROS mediates expression of genes associated with tumor growth, metastasis and adverse disease outcome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3442. doi:10.1158/1538-7445.AM2017-3442

To provide an up-to-date summary of current literature on the management of adverse effects of androgen-deprivation therapy (ADT).All relevant medical literature on men with prostate cancer treated with ADT from 2005 to 2014, and older relevant papers, were reviewed. Recent health advisory statements from the Australian government, societies and advocacy groups have been incorporated to the document.There are numerous adverse effects of ADT that require pro-active prevention and treatment. Ranging from cardiovascular disease, diabetes and osteoporosis, to depression, cognitive decline and sexual dysfunction, the range of adverse effects is wide. Baseline assessment, monitoring, prevention and consultation from a multidisciplinary team are important in minimising the harm from ADT.This review provides a series of practical recommendations to assist with managing the adverse effects of ADT.

Free to read Androgen-dependent pathways regulate maintenance and growth of normal and malignant prostate tissues. Androgen deprivation therapy (ADT) exploits this dependence and is used to treat metastatic prostate cancer; however, regression initially seen with ADT gives way to development of incurable castration-resistant prostate cancer (CRPC). Although ADT generates a therapeutic response, it is also associated with a pattern of metabolic alterations consistent with metabolic syndrome including elevated circulating insulin. Because CRPC cells are capable of synthesizing androgens de novo, we hypothesized that insulin may also influence steroidogenesis in CRPC. In this study, we examined this hypothesis by evaluating the effect of insulin on steroid synthesis in prostate cancer cell lines. Treatment with 10 nmol/L insulin increased mRNA and protein expression of steroidogenesis enzymes and upregulated the insulin receptor substrate insulin receptor substrate 2 (IRS-2). Similarly, insulin treatment upregulated intracellular testosterone levels and secreted androgens, with the concentrations of steroids observed similar to the levels reported in prostate cancer patients. With similar potency to dihydrotestosterone, insulin treatment resulted in increased mRNA expression of prostate-specific antigen. CRPC progression also correlated with increased expression of IRS-2 and insulin receptor in vivo. Taken together, our findings support the hypothesis that the elevated insulin levels associated with therapeutic castration may exacerbate progression of prostate cancer to incurable CRPC in part by enhancing steroidogenesis.

Obesity and type 2 diabetes are recognised risk factors for the development of some cancers and, increasingly, predict more aggressive disease, treatment failure, and cancer-specific mortality. Many factors may contribute to this clinical observation. Hyperinsulinaemia, dyslipidaemia, hypoxia, ER stress, and inflammation associated with expanded adipose tissue are thought to be among the main culprits driving malignant growth and cancer advancement. This observation has led to the proposal of the potential utility of “old players” for the treatment of type 2 diabetes and metabolic syndrome as new cancer adjuvant therapeutics. Androgen-regulated pathways drive proliferation, differentiation, and survival of benign and malignant prostate tissue. Androgen deprivation therapy (ADT) exploits this dependence to systemically treat advanced prostate cancer resulting in anticancer response and improvement of cancer symptoms. However, the initial therapeutic response from ADT eventually progresses to castrate resistant prostate cancer (CRPC) which is currently incurable. ADT rapidly induces hyperinsulinaemia which is associated with more rapid treatment failure. We discuss current observations of cancer in the context of obesity, diabetes, and insulin-lowering medication. We provide an update on current treatments for advanced prostate cancer and discuss whether metabolic dysfunction, developed during ADT, provides a unique therapeutic window for rapid translation of insulin-sensitising medication as combination therapy with antiandrogen targeting agents for the management of advanced prostate cancer.