Publications by authors named "Zeyad D Nassar"

Solid tumors are highly reliant on lipids for energy, growth, and survival. In prostate cancer, the activity of the androgen receptor (AR) is associated with reprogramming of lipid metabolic processes. Here, we identified acyl-CoA synthetase medium chain family members 1 and 3 (ACSM1 and ACSM3) as AR-regulated mediators of prostate cancer metabolism and growth.

View Article and Find Full Text PDF

Background: Peroxisomes are central metabolic organelles that have key roles in fatty acid homoeostasis. As prostate cancer (PCa) is particularly reliant on fatty acid metabolism, we explored the contribution of peroxisomal β-oxidation (perFAO) to PCa viability and therapy response.

Methods: Bioinformatic analysis was performed on clinical transcriptomic datasets to identify the perFAO enzyme, 2,4-dienoyl CoA reductase 2 (DECR2) as a target gene of interest.

View Article and Find Full Text PDF

Recently, the fatty acid elongation enzyme ELOVL5 was identified as a critical pro-metastatic factor in prostate cancer, required for cell growth and mitochondrial homeostasis. The fatty acid elongation reaction catalyzed by ELOVL5 utilizes malonyl-CoA as the carbon donor. Here, we demonstrate that ELOVL5 knockdown causes malonyl-CoA accumulation.

View Article and Find Full Text PDF

Background: Resistance to androgen receptor signalling inhibitors (ARSIs) represents a major clinical challenge in prostate cancer. We previously demonstrated that the ARSI enzalutamide inhibits only a subset of all AR-regulated genes, and hypothesise that the unaffected gene networks represent potential targets for therapeutic intervention. This study identified the hyaluronan-mediated motility receptor (HMMR) as a survival factor in prostate cancer and investigated its potential as a co-target for overcoming resistance to ARSIs.

View Article and Find Full Text PDF

Cancer cells feature increased macromolecular biosynthesis to support the formation of new organelles and membranes for cell division. In particular, lipids are key macromolecules that comprise cellular membrane components, substrates for energy generation and mediators of inter- and intracellular signaling. The emergence of more sensitive and accurate technology for profiling the "lipidome" of cancer cells has led to unprecedented leaps in understanding the complexity of cancer metabolism, but also highlighted promising therapeutic vulnerabilities.

View Article and Find Full Text PDF

Background: Prostate cancer growth is driven by androgen receptor signaling, and advanced disease is initially treatable by depleting circulating androgens. However, prostate cancer cells inevitably adapt, resulting in disease relapse with incurable castrate-resistant prostate cancer. Androgen deprivation therapy has many side effects, including hypercholesterolemia, and more aggressive and castrate-resistant prostate cancers typically feature cellular accumulation of cholesterol stored in the form of cholesteryl esters.

View Article and Find Full Text PDF

Dysregulated lipid metabolism is a prominent feature of prostate cancer that is driven by androgen receptor (AR) signaling. Here we used quantitative mass spectrometry to define the "lipidome" in prostate tumors with matched benign tissues ( = 21), independent unmatched tissues ( = 47), and primary prostate explants cultured with the clinical AR antagonist enzalutamide ( = 43). Significant differences in lipid composition were detected and spatially visualized in tumors compared with matched benign samples.

View Article and Find Full Text PDF
Article Synopsis
  • The androgen receptor (AR) is a major driver of prostate cancer, and despite new therapies, patients with metastatic disease often have poor outcomes, highlighting the need for deeper understanding of AR-related processes in cancer cells.
  • This study uses mass spectrometry to show that increased fatty acyl chain length in phospholipids is a key change in lipid metabolism influenced by AR, particularly focusing on the enzyme ELOVL5 that elongates fatty acids.
  • Results indicate that ELOVL5 is crucial for prostate cancer cell proliferation and metastasis, with its depletion causing harmful mitochondrial effects, while supplementation with a fatty acid product of ELOVL5 counteracts these effects, suggesting targeted therapies could focus on lipid elongation pathways.
View Article and Find Full Text PDF

Objective: Achillea fragrantissima L. (Asteraceae) is a traditionally used medicinal herb in the rural communities of Jordan.

Methods: The present study evaluated the efficacy of the ethanol extract of this species on angiogenesis in both, ex vivo using a rat aortic ring assay and in vivo using a rat excision wound model.

View Article and Find Full Text PDF

Emerging advances in cancer therapy have transformed the landscape towards cancer immunotherapy regimens. Recent discoveries have resulted in the development of clinical immune checkpoint inhibitors that are 'game-changers' for cancer immunotherapy. Here we show that eEF2K, an atypical protein kinase that negatively modulates the elongation stage of protein synthesis, promotes the synthesis of PD-L1, an immune checkpoint protein which helps cancer cells to escape from immunosurveillance.

View Article and Find Full Text PDF

Prostate cancer is an androgen-dependent cancer with unique metabolic features compared to many other solid tumors, and typically does not exhibit the "Warburg effect". During malignant transformation, an early metabolic switch diverts the dependence of normal prostate cells on aerobic glycolysis for the synthesis of and secretion of citrate towards a more energetically favorable metabolic phenotype, whereby citrate is actively oxidised for energy and biosynthetic processes ( lipogenesis). It is now clear that lipid metabolism is one of the key androgen-regulated processes in prostate cells and alterations in lipid metabolism are a hallmark of prostate cancer, whereby increased lipogenesis accompanied by overexpression of lipid metabolic genes are characteristic of primary and advanced disease.

View Article and Find Full Text PDF

Fatty acid β-oxidation (FAO) is the main bioenergetic pathway in human prostate cancer (PCa) and a promising novel therapeutic vulnerability. Here we demonstrate therapeutic efficacy of targeting FAO in clinical prostate tumors cultured ex vivo, and identify encoding the rate-limiting enzyme for oxidation of polyunsaturated fatty acids (PUFAs), as robustly overexpressed in PCa tissues and associated with shorter relapse-free survival. is a negatively-regulated androgen receptor (AR) target gene and, therefore, may promote PCa cell survival and resistance to AR targeting therapeutics.

View Article and Find Full Text PDF

HSP90 is a molecular chaperone required for stabilization and activation of hundreds of client proteins, including many known oncoproteins. AUY922 (luminespib), a new-generation HSP90 inhibitor, exhibits potent preclinical efficacy against several cancer types including prostate cancer. However, clinical use of HSP90 inhibitors for prostate cancer has been limited by toxicity and treatment resistance.

View Article and Find Full Text PDF

Caveolae are specialised and dynamic plasma membrane subdomains, involved in many cellular functions including endocytosis, signal transduction, mechanosensing and lipid storage, trafficking, and metabolism. Two protein families are indispensable for caveola formation and function, namely caveolins and cavins. Mutations of genes encoding these caveolar proteins cause serious pathological conditions such as cardiomyopathies, skeletal muscle diseases, and lipodystrophies.

View Article and Find Full Text PDF

In solid tumours, elevated interstitial fluid pressure (osmotic and hydrostatic pressure) is a barrier to drug delivery and correlates with poor prognosis. Glioblastoma (GBM) further experience compressive force when growing within a space limited by the skull. Caveolae are proposed to play mechanosensing roles, and caveola-forming proteins are overexpressed in GBM.

View Article and Find Full Text PDF

Introduction: Glioblastoma (GBM) is the most common primary brain cancer. The average survival time for the majority of patients is approximately 15 months after diagnosis. A major feature of GBM that contributes to its poor prognosis is its high invasiveness.

View Article and Find Full Text PDF

Prostate cancer cells exhibit altered cellular metabolism but, notably, not the hallmarks of Warburg metabolism. Prostate cancer cells exhibit increased synthesis of fatty acids (FA); however, little is known about how extracellular FAs, such as those in the circulation, may support prostate cancer progression. Here, we show that increasing FA availability increased intracellular triacylglycerol content in cultured patient-derived tumor explants, LNCaP and C4-2B spheroids, a range of prostate cancer cells (LNCaP, C4-2B, 22Rv1, PC-3), and prostate epithelial cells (PNT1).

View Article and Find Full Text PDF

The purpose of this study is to investigate the potential interplay between opioid analgesia and tumor metastasis through modulation of μ-opioid receptor (MOR), Toll-like receptor 4 (TLR4) activation, and matrix degradation potential. Plasma samples were collected from 60 patients undergoing elective lower limb joint replacement preoperatively and at 3, 6, and 24 hours after surgery; pain scores were documented at the same time points. Opioid administration was recorded and converted into morphine IV equivalents.

View Article and Find Full Text PDF

Emerging data have linked certain features of clinical prostate cancer (PCa) to obesity and, more specifically, increased adiposity. Whereas the large number of clinical studies and meta-analyses that have explored the associations between PCa and obesity have shown considerable variability, particularly in relation to prostate cancer risk, there is an accumulating weight of evidence consistently linking obesity to greater aggressiveness of disease. In probing this association mechanistically, it has been posited that peri-prostatic adipose tissue (PPAT), a significant component of the prostate microenvironment, may be a critical source of fatty acids and other mitogens and thereby influences PCa pathogenesis and progression.

View Article and Find Full Text PDF

After the publication [1] it came to the attention of the authors that one of the co-authors was incorrectly included as Hamza Somrain. The correct spelling is as follows: Hamzeh Sumrein.

View Article and Find Full Text PDF

The molecular chaperone Hsp90 is overexpressed in prostate cancer (PCa) and is responsible for the folding, stabilization and maturation of multiple oncoproteins, which are implicated in PCa progression. Compared to first-in-class Hsp90 inhibitors such as 17-allylamino-demethoxygeldanamycin (17-AAG) that were clinically ineffective, second generation inhibitor AUY922 has greater solubility and efficacy. Here, transcriptomic and proteomic analyses of patient-derived PCa explants identified cytoskeletal organization as highly enriched with AUY922 treatment.

View Article and Find Full Text PDF

Platelet derived growth factor beta receptor (PDGFR- β) plays an important role in angiogenesis. PDGFR-β expression is correlated with increased vascularity and maturation of blood vessels in cancer. Pharmacophore modeling and quantitative structure-activity relationship (QSAR) analysis were combined to explore the structural requirements for ligand-PDGFR-β recognition using 107 known PDGFR-β inhibitors.

View Article and Find Full Text PDF

Opioids modulate the tumor microenvironment with potential functional consequences for tumor growth and metastasis. We evaluated the effects of morphine administration on the circulating proteolytic profile of tumor-free mice. Serum from morphine-treated (1 or 10 mg/kg, i.

View Article and Find Full Text PDF

In this study, we quantified the ability of opioids present in biological samples to activate the μ-opioid receptor and TLR4 using cell-based assays. Each assay was standardised, in the presence of plasma, using morphine, its μ receptor-active metabolite morphine-6 glucuronide (M6G) and its μ receptor-inactive, but TLR4-active metabolite morphine-3 glucuronide (M3G). Specificity was verified using antagonists.

View Article and Find Full Text PDF

Background: While there is compelling rationale to use heat shock protein 90 (Hsp90) inhibitors for treatment of advanced prostate cancer, agents that target the N-terminal ATP-binding site of Hsp90 have shown little clinical benefit. These N-terminal binding agents induce a heat shock response that activates compensatory heat shock proteins, which is believed to contribute in part to the agents' lack of efficacy. Here, we describe the functional characterization of two novel agents, SM253 and SM258, that bind the N-middle linker region of Hsp90, resulting in reduced client protein activation and preventing C-terminal co-chaperones and client proteins from binding to Hsp90.

View Article and Find Full Text PDF