Longitudinal mRNA expression analysis of the adaptive response to Enzalutimde in LNCaP cells
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ABSTRACT: The aim of this study is to investigate metabolic alterations involved in the adaptive response of prostate cancer cells to androgen-deprivation therapy (ADT) and AR-targeted therapies (ATTs) in hopes of identifying novel targets to help delay progression to castrate-resistant prostate cancer (CRPC). We developed an in vitro model of long-term ATT and used transcriptomics, proteomics and lipidomics to identify metabolic pathways contributing to cell survival.
Project description:Despite the clinical benefit of androgen-deprivation therapy (ADT), the majority of patients with advanced prostate cancer (PCa) ultimately develop lethal castration-resistant prostate cancer (CRPC). In this study, we identified thioesterase superfamily member 6 (THEM6) as a marker of ADT resistance in PCa. In patients, THEM6 expression correlates with progressive disease and is associated with poor survival. THEM6 deletion reduces in vivo tumour growth and restores castration sensitivity in orthograft models of CRPC. Mechanistically, THEM6 is located at the endoplasmic reticulum (ER) membrane and controls lipid homeostasis by regulating intracellular levels of ether lipids. As a consequence, THEM6 loss in CRPC cells significantly alters ER function, preventing lipid-mediated induction of ATF4 and reducing de novo sterol biosynthesis. Finally, we show that THEM6 is required for the establishment of the MYC-induced stress response. Thus, similar to PCa, THEM6 loss significantly impairs tumorigenesis in the MYC-dependent subtype of triple negative breast cancer. Altogether our results highlight THEM6 as a novel component of the treatment-induced stress response and a promising target for the treatment of CRPC and MYC-driven cancer.
Project description:Androgen-deprivation therapy (ADT) is the standard of care for the treatment of non-resectable prostate cancer (PCa). Despite high treatment efficiency, most patients ultimately develop lethal castration-resistant prostate cancer (CRPC). In this study, we perform a comparative proteomic analysis of three in vivo, androgen receptor (AR)–driven, orthograft models of CRPC. Differential proteomic analysis reveals that distinct molecular mechanisms, including amino acid (AA) and fatty acid (FA) metabolism, are involved in the response to ADT between the different models. Despite this heterogeneity, we identify SLFN5 as an AR-regulated biomarker in CRPC. SLFN5 expression is high in CRPC tumours and correlates with poor patient outcome. In vivo, SLFN5 depletion strongly impairs tumour growth in castrated condition. Mechanistically, SLFN5 interacts with ATF4 and regulates the expression of LAT1, an essential AA transporter. Consequently, SLFN5 depletion in CRPC cells decreases intracellular levels of essential AA and impairs mTORC1 signalling in a LAT1-dependent manner.
Project description:Androgen-deprivation therapy (ADT) is the standard of care for the treatment of non-resectable prostate cancer (PCa). Despite high treatment efficiency, most patients ultimately develop lethal castration-resistant prostate cancer (CRPC). In this study, we perform a comparative proteomic analysis of three in vivo, androgen receptor (AR)–driven, orthograft models of CRPC. Differential proteomic analysis reveals that distinct molecular mechanisms, including amino acid (AA) and fatty acid (FA) metabolism, are involved in the response to ADT between the different models. Despite this heterogeneity, we identify SLFN5 as an AR-regulated biomarker in CRPC. SLFN5 expression is high in CRPC tumours and correlates with poor patient outcome. In vivo, SLFN5 depletion strongly impairs tumour growth in castrated condition. Mechanistically, SLFN5 interacts with ATF4 and regulates the expression of LAT1, an essential AA transporter. Consequently, SLFN5 depletion in CRPC cells decreases intracellular levels of essential AA and impairs mTORC1 signalling in a LAT1-dependent manner.
Project description:The development and progression of castrate resistant prostate cancer (CRPC), a lethal disease, is thought to be driven by multiple events. A hallmark of CRPC is the ability to evade the cytotoxic effects of anti-androgen therapy. Importantly, persistent androgen receptor (AR) signalling is thought to play a principal role in maintaining CRPC. The precise molecular alterations driving this condition, however, are not clearly understood. Our previous studies identified specific metabolic alterations associated with localized prostate cancer (PCa) and CRPC, implicating metabolic re-programming in disease progression. Building on these findings, using a novel network-based integromics approach, here we show distinct alterations in the Hexosamine Biosynthetic Pathway (HBP) to be critical for sustaining the castrate resistant state. We found expression of the HBP enzyme glucosamine-phosphate N-acetyltransferase 1 (GNPNAT1) was regulated by androgens and elevated in androgen dependent (AD) PCa while relatively diminished in CRPC possessing either full length AR (AR-FL) or the spliced V7 variant (AR-V7). Genetic loss of function experiments for GNPNAT1 in CRPC-like cells led to increased proliferation and aggressiveness, both, in vitro and in vivo. This was mediated by specific cell cycle genes regulated by the PI3K-AKT pathway activating either AR in cells with AR-FL or SP1-ChREBP (carbohydrate response element binding protein) in cells containing AR-V7. Strikingly, addition of HBP metabolite UDP-N-acetylglucosamine (UDP) to CRPC-like cells reduced the expression of cell cycle genes and attenuated tumor cell proliferation, both in vitro and in vivo. Furthermore, addition of UDP sensitized CRPC-like cells, inclusive of those possessing AR-V7, to enzalutamide, demonstrating the therapeutic value of targeting altered metabolic pathways in lethal PCa. We anticipate that our findings will motivate the development of novel metabolic therapeutic strategies that complement existing treatments for men with lethal prostate cancer We used microarray analysis to determine key molecular alterations associated with inhibition of HBP pathway in CRPC by knocking down GNPNAT1 transcript level using lentiviral particle bearing shRNA in 22Rv1 and LNCaP-ABL cells GNPNAT1 expression was knockdown in two independent prostate cancer cells, 22Rv1 and LNCaP-ABL
Project description:Identifying biological change from hormone-naive prostate cancer to CRPC is a major clinical challenge for developing therapeutic agents. Although the pathways that lead to CRPC are not fully understood, recent evidence demonstrates that androgen signaling is often maintained through varied mechanisms. Here, we investigated PCa tissues at each stage of progression from benign prostatic hyperplasia (BPH) to CRPC based on quantitative proteomic technology, including tissues after ADT therapy. MS-based quantitative proteomics approach based on 6-plex TMT (126-131) was performed in patient tissues from T2G2 to CRPC, and benign prostatic hyperplasia (BPH) patient tissues were used as a control. We analyzed the peptide samples using two types of high resolution and accuracy mass spectrometers as LTQ orbitrap velos and Q-exactive mass spectrometer. In total, 4,768 proteins were identified in this study, among which 4,069 proteins were quantified in the combined prostate cancer tissues. Among the quantified proteins, DEPs were 865 (21.2%), those with a quantitative ratio greater than 2 were considered as upregulated, whereas those with a quantitative ratio of less than 0.5 as downregulated. Based on quantitative protein results, we performed systematic bioinformatics analysis including GO, Interpro, KEGG pathway, functional enrichment-based cluster analysis on DEPs. Finally, we found that 15 proteins including FOXA1 and HMGN1-3 between T3G3, T3GX, and CRPC were increased despite ADT treatment. Among all target, we verified increased level of FOXA1 and HMGN1-3 in CRPC by immunoblotting and indirect ELISA. In summary, we provides intracellular mechanical changes on PCa tissues according to treatment before and after ADT by mean of regulating ADT treatment. In addition, this results were identified through bioinformatics analysis, and those were suggested as potential CRPC-related factors.
Project description:Despite the clinical benefit of androgen-deprivation therapy (ADT), the majority of patients with advanced prostate cancer (PCa) ultimately develop lethal castration-resistant prostate cancer (CRPC). In this study, we identified thioesterase superfamily member 6 (THEM6) as a marker of ADT resistance in PCa. In patients, THEM6 expression correlates with progressive disease and is associated with poor survival. THEM6 deletion reduces in vivo tumour growth and restores castration sensitivity in orthograft models of CRPC. Mechanistically, THEM6 is located at the endoplasmic reticulum (ER) membrane and controls lipid homeostasis by regulating intracellular levels of ether lipids. As a consequence, THEM6 loss in CRPC cells significantly alters ER function, preventing lipid-mediated induction of ATF4 and reducing de novo sterol biosynthesis. Finally, we show that THEM6 is required for the establishment of the MYC-induced stress response. Thus, similar to PCa, THEM6 loss significantly impairs tumorigenesis in the MYC-dependent subtype of triple negative breast cancer. Altogether our results highlight THEM6 as a novel component of the treatment-induced stress response and a promising target for the treatment of CRPC and MYC-driven cancer.
Project description:Despite the clinical benefit of androgen-deprivation therapy (ADT), the majority of patients with advanced prostate cancer (PCa) ultimately develop lethal castration-resistant prostate cancer (CRPC). In this study, we identified thioesterase superfamily member 6 (THEM6) as a marker of ADT resistance in PCa. In patients, THEM6 expression correlates with progressive disease and is associated with poor survival. THEM6 deletion reduces in vivo tumour growth and restores castration sensitivity in orthograft models of CRPC. Mechanistically, THEM6 is located at the endoplasmic reticulum (ER) membrane and controls lipid homeostasis by regulating intracellular levels of ether lipids. As a consequence, THEM6 loss in CRPC cells significantly alters ER function, preventing lipid-mediated induction of ATF4 and reducing de novo sterol biosynthesis. Finally, we show that THEM6 is required for the establishment of the MYC-induced stress response. Thus, similar to PCa, THEM6 loss significantly impairs tumorigenesis in the MYC-dependent subtype of triple negative breast cancer. Altogether our results highlight THEM6 as a novel component of the treatment-induced stress response and a promising target for the treatment of CRPC and MYC-driven cancer.
Project description:The TP53 tumor suppressor is frequently altered in lethal, castration-resistant prostate cancer (CRPC). However, to date there are no effective treatments that specifically target TP53 alterations. Using transcriptomic and metabolomic analyses, we show here that TP53-altered prostate cancer (PCa) exhibits an increased dependency on asparagine and overexpresses asparagine synthetase (ASNS, the enzyme catalyzing the synthesis of asparagine). Mechanistically, loss/mutation of TP53 transcriptionally activate ASNS expression, directly as well as via ATF4, driving de novo asparagine biosynthesis to support CRPC growth. TP53-altered CRPC cells are sensitive to asparagine restriction by knockdown of ASNS and L-asparaginase treatment to deplete the intracellular and extracellular sources of asparagine respectively. This effect was rescued by asparagine addition. Notably, pharmacological inhibition of intracellular asparagine biosynthesis using a glutaminase (GLS) inhibitor and depletion of extracellular asparagine with L-asparaginase significantly reduced asparagine production and effectively impaired CRPC growth. This study highlights the significance of ASNS-mediated metabolic adaptation as a synthetic vulnerability in CRPC with TP53 alterations, providing a rationale for co-targeting intracellular and extracellular asparagine production to treat these lethal prostate cancers.
Project description:The retinoblastoma protein (RB) is preferentially lost in the progression to castrate resistant prostate cancer (CRPC). However, the alterations associated with such loss have been scantly described. The current study aims to provide molecular mechanisms underlying Rb loss-driven CRPC phenotypes
Project description:The retinoblastoma protein (RB) is preferentially lost in the progression to castrate resistant prostate cancer (CRPC). However, the alterations associated with such loss have been scantly described. The current study aims to provide molecular mechanisms underlying Rb loss-driven CRPC phenotypes.