Targeting lipid metabolism in metastatic prostate cancer

ERLNs augment simultaneous delivery of GFSV into PC-3 cells: Influence of drug combination on SDH, GPX-4, 5α-RD, and cytotoxicity

Objective

Prostate cancer (PCA) is the second most widespread cancer among men globally, with a rising mortality rate. Enzyme-responsive lipid nanoparticles (ERLNs) are promising vectors for the selective delivery of anticancer agents to tumor cells. The goal of this study is to fabricate ERLNs for dual delivery of gefitinib (GF) and simvastatin (SV) to PCA cells.

Methods

ERLNs loaded with GF and SV (ERLNGFSV) were assembled using bottom-up and top-down techniques. Subsequently, these ERLN cargoes were coated with triacylglycerol, and phospholipids and capped with chitosan (CS). The ERLNGFSV, and CS engineered ERLNGFSV (CERLNGFSV) formulations were characterized for particle size (PS), zeta potential (ZP), and polydispersity index (PDI). The biocompatibility, and cytotoxicity of the plain and GF plus SV-loaded ERLN cargoes were assessed using erythrocytes and PC-3 cell line. Additionally, molecular docking simulations (MDS) were conducted to examine the influence of GF and SV on succinate dehydrogenase (SDH), glutathione peroxidase-4 (GPX-4), and 5α-reductase (5α-RD).

Results

These results showed that plain, ERLNGFSV, and CERLNGFSV cargoes have a nanoscale size and homogeneous appearance. Moreover, ERLNGFSV and CERLNGFSV were biocompatible, with no detrimental effects on erythrocytes. Treatment with GF, SV, GF plus SV, ERLNGFSV, and CERLNGFSV significantly reduced the viability of PC-3 cells compared to control cells. Particularly, the blend of GF and SV, as well as ERLNGFSV and CERLNGFSV augmented PC-3 cell death. Also, treating PC-3 cells with free drugs, their combination, ERLNGFSV, and CERLNGFSV formulations elevated the percentage of apoptotic cells. MDS studies demonstrated that GF and SV interact with the active sites of SDH, GPX-4, and 5α-reductase.

Conclusions

This study concludes that SVGF combination and ERLNs loading induce particular delivery, and synergism on PC-3 death through action on multiple pathways involved in cell proliferation, and apoptosis, besides the interaction with SDH, GPX-4, and 5α-RD. Therefore, GFSV-loaded ERLN cargoes are a promising strategy for PCA treatment. In vivo studies are necessary to confirm these findings for clinical applications.

Unsupervised self-organising map classification of Raman spectra from prostate cell lines uncovers substratified prostate cancer disease states

Prostate cancer is a disease which poses an interesting clinical question: Should it be treated? Only a small subset of prostate cancers are aggressive and require removal and treatment to prevent metastatic spread. However, conventional diagnostics remain challenged to risk-stratify such patients; hence, new methods of approach to biomolecularly sub-classify the disease are needed. Here we use an unsupervised self-organising map approach to analyse live-cell Raman spectroscopy data obtained from prostate cell-lines; our aim is to exemplify this method to sub-stratify, at the single-cell-level, the cancer disease state using high-dimensional datasets with minimal preprocessing. The results demonstrate a new sub-clustering of the prostate cancer cell-line into two groups-protein-rich and lipid-rich sub-cellular components-which we believe to be mechanistically linked. This finding shows the potential for unsupervised machine learning to discover distinct disease-state features for more accurate characterisation of highly heterogeneous prostate cancer. Applications may lead to more targeted diagnoses, prognoses and clinical treatment decisions via molecularly-informed stratification that would benefit patients. A method that could discover distinct disease-state features that are mechanistically linked could also assist in the development of more effective broad-spectrum treatments that simultaneously target linked disease-state processes.

Prostate cancer risk biomarkers from large cohort and prospective metabolomics studies: A systematic review

Prostate cancer (PCa) is one of the leading causes of cancer-related deaths among men. The heterogeneous nature of this disease presents challenges in its diagnosis, prognosis, and treatment. Numerous potential predictive, diagnostic, prognostic, and risk assessment biomarkers have been proposed through various population studies. However, to date, no metabolite biomarker has been approved or validated for the diagnosis, prognosis, or risk assessment of PCa. Recognizing that systematic reviews of case reports or heterogenous studies cannot reliably establish causality, this review analyzed 29 large prospective metabolomics studies that utilized harmonized criteria for patient selection, consistent methodologies for blood sample collection and storage, data analysis, and that are available in public repositories. By focusing on these large prospective studies, we identified 42 metabolites that were consistently replicated by different authors and across cohort studies. These metabolites have the potential to serve as PCa risk-assessment or predictive biomarkers. A discussion on their associations with dietary sources or dietary patterns is also provided. Further detailed exploration of the relationship with diet, supplement intake, nutrition patterns, contaminants, lifestyle factors, and pre-existing comorbidities that may predispose individuals to PCa is warranted for future research and validation.

Evolocumab in metastatic castration-resistant prostate cancer: study protocol for a single-arm, phase II trial, and initial experience with use of a validated lipid biomarker to direct therapy

Background

Despite advances in the treatment of metastatic castration-resistant prostate cancer (mCRPC), primary and secondary resistance to current therapies remains. Elevated circulating sphingolipids are associated with poor outcomes in patients with mCRPC, including therapeutic resistance and shorter overall survival. PCPro is a clinically accessible, regulatory compliant plasma lipid biomarker of poor prognosis in mCRPC, which incorporates prognostic sphingolipids. We hypothesize that reversal of the PCPro signature in men with mCRPC by sphingolipid-lowering agents will improve their clinical outcomes. However, the first step is to determine whether this poor prognostic lipid signature can be modulated. A potential sphingolipid-lowering agent is the PCSK9-inhibitor evolocumab, which is used in the management of hypercholesterolemia.

Objectives

Our primary objective is to assess whether treatment with evolocumab during standard anticancer therapy can safely modify the PCPro signature in men with mCRPC.

Design

This is a multicenter, open label phase II trial.

Methods

Men with mCRPC commencing docetaxel, cabazitaxel, abiraterone, enzalutamide, olaparib, or lutetium-177 PSMA for disease progression will be screened for the presence of PCPro. Those who are PCPro positive will receive a 12-week course of evolocumab concurrent with their standard therapy. Dosage is as per cardiovascular guidelines (420 mg subcutaneously every 4 weeks). PCPro will be repeated after 12 weeks. The primary endpoint is reversal of PCPro. The secondary endpoint is the safety of combination therapy with exploratory endpoints characterizing changes in comprehensive lipid profiles pre- and post-treatment.

Discussion

This study will evaluate whether evolocumab can safely modify the PCPro signature in men with mCRPC, providing essential data to the development of precision metabolic therapy in the management of prostate cancer.

Trial registration

This study is approved by the Human Research Ethics Committee (X22-0072 and 2022/ETH00427). It is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12622001003763).

Nodularin-R Synergistically Enhances Abiraterone Against Castrate- Resistant Prostate Cancer via PPP1CA Inhibition

Clinically, most prostate cancer (PCa) patients inevitably progress to castration-resistant prostate cancer (CRPC) with poor prognosis after androgen deprivation therapy (ADT), including abiraterone, the drug of choice for ADT. Therefore, it is necessary to explore the resistance mechanism of abiraterone in depth. Genome-wide CRISPR/Cas9 knockout technology was used to screen CRPC cell line 22Rv1 for abiraterone-resistant genes. Combined with bioinformatics, a key gene with high expression and poor prognosis in CRPC patients was screened. Then, the effects of target gene on abiraterone-resistant 22Rv1 cell function were explored by silencing and overexpression. Further, a natural product with potential targeting effect was identified and validated by molecular docking and protein expression. Molecular dynamics simulations revealed potential mechanism for the natural product affecting target protein expression. Finally, the combined anti-CRPC effects of the natural product and abiraterone were validated by cellular and in vivo experiments. Five common resistance genes (KCNJ3, COL2A1, PPP1CA, MDH2 and EXOSC5) were identified successfully, among which high PPP1CA expression had the worst prognosis for disease-free survival. Moreover, PPP1CA was highly expressed in abiraterone-resistant 22Rv1 cells. Silencing PPP1CA increased cell sensitivity to abiraterone while promoting apoptosis and inhibiting clone formation. Overexpressing PPP1CA exerted the opposite effects. Molecular docking revealed the binding mode of the natural product nodularin-R to PPP1CA with a dose-dependent manner for inhibition. Mechanistically, nodularin-R attenuates the interaction between PPP1CA and USP11 (deubiquitinating enzyme), potentially promoting PPP1CA degradation. Additionally, combination of 2.72 μM nodularin-R and 54.5 μM abiraterone synergistically inhibited the resistant 22Rv1 cell function. In vivo experiments also revealed that combination therapy significantly inhibited tumour growth and reduced inducible expression of PPP1CA. PPP1CA is a key driver for abiraterone resistance, and nodularin-R enhances the anti-CRPC effects of abiraterone by inhibiting PPP1CA.

Alpha-1-B glycoprotein (A1BG) inhibits sterol-binding and export by CRISP2

Proteins belonging to the CAP superfamily are present in all kingdoms of life and have been implicated in various processes, including sperm maturation and cancer progression. They are mostly secreted glycoproteins and share a unique conserved CAP domain. The precise mode of action of these proteins, however, has remained elusive. Saccharomyces cerevisiae expresses three members of this protein family, which bind sterols in vitro and promote sterol secretion from cells. This sterol-binding and export function of yeast Pry proteins is conserved in the mammalian cysteine-rich secretory protein (CRISP) proteins and other CAP superfamily members. CRISP3 is an abundant protein of the human seminal plasma and interacts with alpha-1-B glycoprotein (A1BG), a human plasma glycoprotein that is upregulated in different types of cancers. Here, we examined whether the interaction between CRISP proteins and A1BG affects the sterol-binding function of CAP family members. Coexpression of A1BG with CAP proteins abolished their sterol export function in yeast and their interaction inhibits sterol-binding in vitro. We map the interaction between A1BG and CRISP2 to the third of five repeated immunoglobulin-like domains within A1BG. Interestingly, the interaction between A1BG and CRISP2 requires magnesium, suggesting that coordination of Mg2+ by the highly conserved tetrad residues within the CAP domain is essential for a stable interaction between the two proteins. The observation that A1BG modulates the sterol-binding function of CRISP2 has potential implications for the role of A1BG and related immunoglobulin-like domain containing proteins in cancer progression and the toxicity of reptile venoms containing CRISP proteins.

Unlocking ferroptosis in prostate cancer - the road to novel therapies and imaging markers

Ferroptosis is a distinct form of regulated cell death that is predominantly driven by the build-up of intracellular iron and lipid peroxides. Ferroptosis suppression is widely accepted to contribute to the pathogenesis of several tumours including prostate cancer. Results from some studies reported that prostate cancer cells can be highly susceptible to ferroptosis inducers, providing potential for an interesting new avenue of therapeutic intervention for advanced prostate cancer. In this Perspective, we describe novel molecular underpinnings and metabolic drivers of ferroptosis, analyse the functions and mechanisms of ferroptosis in tumours, and highlight prostate cancer-specific susceptibilities to ferroptosis by connecting ferroptosis pathways to the distinctive metabolic reprogramming of prostate cancer cells. Leveraging these novel mechanistic insights could provide innovative therapeutic opportunities in which ferroptosis induction augments the efficacy of currently available prostate cancer treatment regimens, pending the elimination of major bottlenecks for the clinical translation of these treatment combinations, such as the development of clinical-grade inhibitors of the anti-ferroptotic enzymes as well as non-invasive biomarkers of ferroptosis. These biomarkers could be exploited for diagnostic imaging and treatment decision-making.

Aurantio‑obtusin regulates lipogenesis and ferroptosis of liver cancer cells through inhibiting SCD1 and sensitizing RSL3

Ferroptosis, characterized by iron‑mediated non‑apoptotic cell death and alterations in lipid redox metabolism, has emerged as a critical process implicated in various cellular functions, including cancer. Aurantio‑obtusin (AO), a bioactive compound derived from Cassiae semen (the dried mature seeds of Cassie obtusifolia L. or Cassia toral L.), has anti‑hyperlipidemic and antioxidant properties; however, to the best of our knowledge, the effect of AO on liver cancer cells remains unclear. The Cell Counting Kit‑8, EdU staining and migration assays were employed to assess the anti‑liver cancer activity of AO. Intracellular levels of glutathione peroxidase 4 protein and lipid peroxidation were measured as indicators of ferroptotic status. Immunohistochemical analyses, bioinformatics analyses and western blotting were conducted to evaluate the potential of stearoyl‑CoA desaturase 1 (SCD1) in combination with ferroptosis inducers for the personalized treatment of liver cancer. The present study revealed that AO significantly inhibited the proliferation of liver cancer cells in vitro and in vivo. Mechanistically, AO inhibited AKT/mammalian target of rapamycin (mTOR) signaling, suppressed sterol regulatory element‑binding protein 1 (SREBP1) expression, and downregulated fatty acid synthase expression, thereby inhibiting de novo fatty acid synthesis. Further investigations demonstrated that AO suppressed glutathione peroxidase 4 protein expression through the nuclear factor erythroid 2‑related factor 2/heme oxygenase‑1 pathway, induced ferroptosis in liver cancer cells, and simultaneously inhibited lipogenesis by suppressing SCD1 expression through the AKT/mTOR/SREBP1 pathway. Consequently, this increased the sensitivity of liver cancer cells to the ferroptosis inducer RSL3. Additionally, the enhanced effects of AO and RSL3, which resulted in significant tumor suppression, were confirmed in a xenograft mouse model. In conclusion, the present study demonstrated that AO induced ferroptosis, downregulated the expression of SCD1 and enhanced the sensitivity of liver cancer cells to the ferroptosis inducer RSL3. The synergistic use of AO and a ferroptosis inducer may have promising therapeutic effects in liver cancer cells.

Docetaxel-Induced Cell Death Is Regulated by a Fatty Acid-Binding Protein 12-Slug-Survivin Pathway in Prostate Cancer Cells

Chemotherapy is an important treatment option for advanced prostate cancer, especially for metastatic prostate cancer (PCa). Resistance to first-line chemotherapeutic drugs such as docetaxel often accompanies prostate cancer progression. Attempts to overcome resistance to docetaxel by combining docetaxel with other biological agents have been mostly unsuccessful. A better understanding of the mechanisms underlying docetaxel resistance may provide new avenues for the treatment of advanced PCa. We have previously found that the fatty acid-binding protein 12 (FABP12)-PPARγ pathway modulates lipid-related bioenergetics and PCa metastatic transformation through induction of Slug, a master driver of epithelial-to-mesenchymal transition (EMT). Here, we report that the FABP12-Slug axis also underlies chemoresistance in PCa cells. Cell sensitivity to docetaxel is markedly suppressed in FABP12-expressing cells, along with induction of Survivin, a typical apoptosis inhibitor, and inhibition of cleaved PARP, a hallmark of programmed cell death. Importantly, Slug depletion down-regulates Survivin and restores cell sensitivity to docetaxel in FABP12-expressing cells. Finally, we also show that high levels of Survivin are associated with poor prognosis in PCa patients, with FABP12 status determining its prognostic significance. Our research identifies a FABP12-Slug-Survivin pathway driving docetaxel resistance in PCa cells, suggesting that targeting FABP12 may be a precision approach to improve chemodrug efficacy and curb metastatic progression in PCa.

APOA1 mRNA and serum APOA1 protein as diagnostic and prognostic biomarkers in gastric cancer

Background

Gastric cancer (GC) remains a formidable challenge in oncology, ranking as a leading cause of cancer mortality globally. This underscores an urgent need for innovative prognostic markers that can revolutionize patient management and outcomes. Recent insights into cancer biology have spotlighted the profound influence of lipid metabolism alterations on tumorigenesis, tumor progression, and the tumor microenvironment. These alterations not only fuel cancer cell growth and proliferation but also play a strategic role in evading immune surveillance and promoting metastasis. The intricate web of lipid metabolism in cancer cells, characterized by deregulated uptake, synthesis, and oxidation of fatty acids (FAs), opens new avenues for targeted therapeutic interventions and prognostic evaluations. Specifically, this study zeroes in on apolipoprotein A-I (APOA1), a key player in lipid metabolism, to unearth its prognostic value in GC. By delving into the role of lipid metabolism-related genes, particularly APOA1, we aim to unveil their potential as groundbreaking biomarkers for GC prognosis. This endeavor not only aims to enhance our understanding of the molecular underpinnings of GC but also to spearhead the development of lipid metabolism-based strategies for improved diagnostic, prognostic, and therapeutic outcomes.

Methods

Transcriptomic and clinical data from GC patients and healthy individuals were sourced from The Cancer Genome Atlas (TCGA) database, a comprehensive project that molecularly characterizes over 20,000 primary cancer and matched normal samples across 33 cancer types. Significantly differentially expressed lipid metabolism-related genes were identified using the "limma" package in R. Prognostic genes were selected via univariate Cox regression analysis. Differential gene enrichment analysis was performed using Metascape (http://www.metascape.org). The Human Protein Atlas (HPA, https://www.proteinatlas.org) provided information on APOA1 protein expression in GC and healthy tissues. Immune cell infiltration was analyzed using the CIBERSORT algorithm (http://cibersort.stanford.edu).

Results

Significant differences in lipid metabolism-related gene expression were observed between GC and normal tissues, closely linked to FA metabolism, oxidoreductase activity, and sphingolipid metabolism. APOA1 emerged as a potential prognostic biomarker by intersecting prognostic and differentially expressed lipid metabolism genes. Immunohistochemical analysis confirmed APOA1 downregulation in GC. The receiver operating characteristic (ROC) analysis demonstrated its predictive value, with the area under the curve (AUC) being 0.64 [95% confidence interval (CI): 0.52-0.76]. APOA1 expression correlated with immune cell infiltrations. Clinical serum APOA1 results revealed lower levels in GC patients (1.38 vs. 1.26; P<0.05), associated with poor prognosis (hazard ratio =1.50; P<0.001) and clinical characteristics. ROC analysis of serum APOA1 demonstrated good diagnostic ability (AUC: 0.63, 95% CI: 0.61-0.65). Serum APOA1 levels significantly increased after treatment.

Conclusions

This study highlights lipid metabolism reprogramming in GC and identifies APOA1 as a potential diagnostic and prognostic biomarker, suggesting its clinical utility in managing GC.

Periprostatic Adipose Tissue: A New Perspective for Diagnosing and Treating Prostate Cancer

Prostate cancer (PCa) is the most common tumor of the male genitourinary system. It will eventually progress to fatal metastatic castration-resistant prostate cancer, for which treatment options are limited. Adipose tissues are distributed in various parts of the body. They have different morphological structures and functional characteristics and are associated with the development of various tumors. Periprostatic adipose tissue (PPAT) is the closest white visceral adipose tissue to the prostate and is part of the PCa tumor microenvironment. Studies have shown that PPAT is involved in PCa development, progression, invasion, and metastasis through the secretion of multiple active molecules. Factors such as obesity, diet, exercise, and organochlorine pesticides can affect the development of PCa indirectly or directly through PPAT. Based on the mechanism of PPAT's involvement in regulating PCa, this review summarized various diagnostic and therapeutic approaches for PCa with potential applications to assess the progression of patients' disease and improve clinical outcomes.

Acetyl-CoA metabolism as a therapeutic target for cancer

Acetyl-coenzyme A (acetyl-CoA), an essential metabolite, not only takes part in numerous intracellular metabolic processes, powers the tricarboxylic acid cycle, serves as a key hub for the biosynthesis of fatty acids and isoprenoids, but also serves as a signaling substrate for acetylation reactions in post-translational modification of proteins, which is crucial for the epigenetic inheritance of cells. Acetyl-CoA links lipid metabolism with histone acetylation to create a more intricate regulatory system that affects the growth, aggressiveness, and drug resistance of malignancies such as glioblastoma, breast cancer, and hepatocellular carcinoma. These fascinating advances in the knowledge of acetyl-CoA metabolism during carcinogenesis and normal physiology have raised interest regarding its modulation in malignancies. In this review, we provide an overview of the regulation and cancer relevance of main metabolic pathways in which acetyl-CoA participates. We also summarize the role of acetyl-CoA in the metabolic reprogramming and stress regulation of cancer cells, as well as medical application of inhibitors targeting its dysregulation in therapeutic intervention of cancers.

Exploring the role of the inflammasomes on prostate cancer: Interplay with obesity

Obesity is a weight-related disorder characterized by excessive adipose tissue growth and dysfunction which leads to the onset of a systemic chronic low-grade inflammatory state. Likewise, inflammation is considered a classic cancer hallmark affecting several steps of carcinogenesis and tumor progression. In this regard, novel molecular complexes termed inflammasomes have been identified which are able to react to a wide spectrum of insults, impacting several metabolic-related disorders, but their contribution to cancer biology remains unclear. In this context, prostate cancer (PCa) has a markedly inflammatory component, and patients frequently are elderly individuals who exhibit weight-related disorders, being obesity the most prevalent condition. Therefore, inflammation, and specifically, inflammasome complexes, could be crucial players in the interplay between PCa and metabolic disorders. In this review, we will: 1) discuss the potential role of each inflammasome component (sensor, molecular adaptor, and targets) in PCa pathophysiology, placing special emphasis on IL-1β/NF-kB pathway and ROS and hypoxia influence; 2) explore the association between inflammasomes and obesity, and how these molecular complexes could act as the cornerstone between the obesity and PCa; and, 3) compile current clinical trials regarding inflammasome targeting, providing some insights about their potential use in the clinical practice.

Fatty acid binding protein 5 regulates docetaxel sensitivity in taxane-resistant prostate cancer cells

Prostate cancer is a leading cause of cancer-related deaths in men in the United States. Although treatable when detected early, prostate cancer commonly transitions to an aggressive castration-resistant metastatic state. While taxane chemotherapeutics such as docetaxel are mainstay treatment options for prostate cancer, taxane resistance often develops. Fatty acid binding protein 5 (FABP5) is an intracellular lipid chaperone that is upregulated in advanced prostate cancer and is implicated as a key driver of its progression. The recent demonstration that FABP5 inhibitors produce synergistic inhibition of tumor growth when combined with taxane chemotherapeutics highlights the possibility that FABP5 may regulate other features of taxane function, including resistance. Employing taxane-resistant DU145-TXR cells and a combination of cytotoxicity, apoptosis, and cell cycle assays, our findings demonstrate that FABP5 knockdown sensitizes the cells to docetaxel. In contrast, docetaxel potency was unaffected by FABP5 knockdown in taxane-sensitive DU145 cells. Taxane-resistance in DU145-TXR cells stems from upregulation of the P-glycoprotein ATP binding cassette subfamily B member 1 (ABCB1). Expression analyses and functional assays confirmed that FABP5 knockdown in DU145-TXR cells markedly reduced ABCB1 expression and activity, respectively. Our study demonstrates a potential new function for FABP5 in regulating taxane sensitivity and the expression of a major P-glycoprotein efflux pump in prostate cancer cells.

New insights into the therapeutic potentials of statins in cancer

The widespread clinical use of statins has contributed to significant reductions of cardiovascular morbidity and mortality. Increasing preclinical and epidemiological evidences have revealed that dyslipidemia is an important risk factor for carcinogenesis, invasion and metastasis, and that statins as powerful inhibitor of HMG-CoA reductase can exert prevention and intervention effects on cancers, and promote sensitivity to anti-cancer drugs. The anti-cancer mechanisms of statins include not only inhibition of cholesterol biosynthesis, but also their pleiotropic effects in modulating angiogenesis, apoptosis, autophagy, tumor metastasis, and tumor microenvironment. Moreover, recent clinical studies have provided growing insights into the therapeutic potentials of statins and the feasibility of combining statins with other anti-cancer agents. Here, we provide an updated review on the application potential of statins in cancer prevention and treatment and summarize the underneath mechanisms, with focuses on data from clinical studies.