Resistance to Androgen Deprivation Leads to Altered Metabolism in Human and Murine Prostate Cancer Cell and Tumor Models

Xihuang pills targeting the Warburg effect through inhibition of the Wnt/β-catenin pathway in prostate cancer

Objective

Prostate cancer, marked by a high incidence and mortality rate, presents a significant challenge, especially in the context of castration-resistant prostate cancer (CRPC) with limited treatment options due to drug resistance. This study aims to explore the anti-tumor effects of Xihuang Pills (XHP) on CRPC, focusing on metabolic reprogramming and the Wnt/β-catenin pathway.

Methods

In vitro and in vivo biofunctional assays were employed to assess the efficacy and mechanisms of XHP. Subcutaneous xenografts of PC3 in mice served as an in vivo model to evaluate XHP's anti-tumor activity. Tumor volume, weight, proliferation, and apoptosis were monitored. Various assays, including CCK8, TUNEL assay, QRT-PCR, and Western Blotting, were conducted to measure metabolic reprogramming, proliferation, apoptosis, and cell cycle in prostate cancer cells. RNA-seq analysis predicted XHP's impact on prostate cancer, validating the expression of Wnt/β-catenin-related proteins and mRNA. Additionally, 58 compounds in XHP were identified via LC-MS/MS, and molecular docking analysis connected these compounds to key genes.

Results

In vitro and in vivo experiments demonstrated that XHP significantly inhibited CRPC cell viability, induced apoptosis, and suppressed invasion and migration. mRNA sequencing revealed differentially expressed genes, with functional enrichment analysis indicating modulation of key biological processes. XHP treatment downregulated Wnt signaling pathway-related genes, including CCND2, PRKCG, and CCN4. Moreover, XHP effectively inhibited glucose uptake and lactate production, leading to reduced HIF-1α and glycolytic enzymes (GLUT1, HK2, PKM2), suggesting its potential in attenuating the Warburg effect. Molecular docking analysis suggested a plausible interaction between XHP's active compounds and Wnt1 protein, indicating a mechanism through which XHP modulates the Wnt/β-catenin pathway.

Conclusion

XHP demonstrated remarkable efficacy in suppressing the growth, proliferation, apoptosis, migration, and invasiveness of prostate tumors. The interaction between XHP's active constituents and Wnt1 was evident, leading to the inhibition of Wnt1 and downstream anti-carcinogenic factors, thereby influencing the β-catenin/HIF-1α-mediated glycolysis.

Targeted metabolomics reveals PFKFB3 as a key target for elemene-mediated inhibition of glycolysis in prostate cancer cells

BACKGROUND

Elemene, an active anticancer extract derived from Curcuma wenyujin, has well-documented anticarcinogenic properties. Nevertheless, the role of elemene in prostate cancer (PCa) and its underlying molecular mechanism remain elusive.

PURPOSE

This study focuses on investigating the anti-PCa effects of elemene and its underlying mechanisms.

METHODS

Cell-based assays, including CCK-8, scratch, colony formation, cell cycle, and apoptosis experiments, to comprehensively assess the impact of elemene on PCa cells (LNCaP and PC3) in vitro. Additionally, we used a xenograft model with PC3 cells in nude mice to evaluate elemene in vivo efficacy. Targeted metabolomics analysis via HILIC-MS/MS was performed to investigate elemene potential target pathways, validated through molecular biology experiments, including western blotting and gene manipulation studies.

RESULTS

In this study, we discovered that elemene has remarkable anti-PCa activity in both in vitro and in vivo settings, comparable to clinical chemotherapeutic drugs but with fewer side effects. Using our established targeted metabolomics approach, we demonstrated that β-elemene, elemene's primary component, effectively inhibits glycolysis in PCa cells by downregulating 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) expression. Furthermore, we found that β-elemene accomplishes this downregulation by upregulating p53 and FZR1. Knockdown and overexpression experiments conclusively confirmed the pivotal role of PFKFB3 in mediating β-elemene's anti-PCa activity.

CONCLUSION

This finding presents compelling evidence that elemene exerts its anti-PCa effect by suppressing glycolysis through the downregulation of PFKFB3. This study not only improves our understanding of elemene in PCa treatment but also provides valuable insights for developing more effective and safer therapies for PCa.

YAP1 inhibits RSL3-induced castration-resistant prostate cancer cell ferroptosis by driving glutamine uptake and metabolism to GSH

High levels of YAP1 and ferroptosis activation in castration-resistant prostate cancer (CRPC) can inhibit CRPC progression and improve its sensitivity toward chemotherapeutics drugs. However, whether YAP1 regulates ferroptosis in CRPC cells and the underlying mechanisms are unknown. The protein levels of YAP1, SLC1A5, and GLS1 in benign prostatic hyperplasia (BPH), prostate cancer (PCa) that did not progress to CRPC, and CRPC tissue samples were evaluated using western blotting. In PC-3 and DU-145 cells, YAP1 overexpression vector, small-interfering RNA, specific inhibitor verteporfin, ferroptosis-inducer RSL3, SLC1A5-inhibitor V-9302, and GLS1-inhibitor CB-839 were used. Immunofluorescence, flow cytometry, dual-luciferase reporter gene, and related kits were used to investigate the effect of YAP1 on the ferroptosis activity in CRPC cells and its underlying mechanisms. YAP1 promoted extracellular glutamine uptake and subsequent production of glutamate and glutathione (GSH), and increases the GPX4 activity. For the activation of ferroptosis by RSL3, YAP1 decreased the levels of reactive oxygen species, malondialdehyde, and lipid peroxidation, and the proportion of dead cells. Mechanistically, YAP1 promoted the expression of SCL1A5 and GLS1 and further increased the GSH levels and GPX4 activity. Thus, inhibiting SLC1A5 or GLS1 activity could alleviate the antagonistic effect of YAP1 on the ferroptosis of RSL3-induced CRPC cells. In CRPC, the YAP1 level is high, which enters the nucleus and promotes the expressions of SLC1A5 and GLS1, thereby promoting cellular glutamine uptake and metabolism to generate glutamate and further synthesizing GSH, increasing GPX4 activity, improving cellular antioxidant capacity, and inhibiting cell death.

Lactate as Key Metabolite in Prostate Cancer Progression: What Are the Clinical Implications?

Advanced prostate cancer represents the fifth leading cause of cancer death in men worldwide. Although androgen-receptor signaling is the major driver of the disease, evidence is accumulating that disease progression is supported by substantial metabolic changes. Alterations in de novo lipogenesis and fatty acid catabolism are consistently reported during prostate cancer development and progression in association with androgen-receptor signaling. Therefore, the term "lipogenic phenotype" is frequently used to describe the complex metabolic rewiring that occurs in prostate cancer. However, a new scenario has emerged in which lactate may play a major role. Alterations in oncogenes/tumor suppressors, androgen signaling, hypoxic conditions, and cells in the tumor microenvironment can promote aerobic glycolysis in prostate cancer cells and the release of lactate in the tumor microenvironment, favoring immune evasion and metastasis. As prostate cancer is composed of metabolically heterogenous cells, glycolytic prostate cancer cells or cancer-associated fibroblasts can also secrete lactate and create "symbiotic" interactions with oxidative prostate cancer cells via lactate shuttling to sustain disease progression. Here, we discuss the multifaceted role of lactate in prostate cancer progression, taking into account the influence of the systemic metabolic and gut microbiota. We call special attention to the clinical opportunities of imaging lactate accumulation for patient stratification and targeting lactate metabolism.

Management of Advanced Prostate Cancer in the Precision Oncology Era

Prostate cancer (PC) is the second leading cause of cancer death in men in the United States. While diversified and improved treatment options for aggressive PC have improved patient outcomes, metastatic castration-resistant prostate cancer (mCRPC) remains incurable and an area of investigative therapeutic interest. This review will cover the seminal clinical data supporting the indication of new precision oncology-based therapeutics and explore their limitations, present utility, and potential in the treatment of PC. Systemic therapies for high-risk and advanced PC have experienced significant development over the past ten years. Biomarker-driven therapies have brought the field closer to the goal of being able to implement precision oncology therapy for every patient. The tumor agnostic approval of pembrolizumab (a PD-1 inhibitor) marked an important advancement in this direction. There are also several PARP inhibitors indicated for patients with DNA damage repair deficiencies. Additionally, theranostic agents for both imaging and treatment have further revolutionized the treatment landscape for PC and represent another advancement in precision medicine. Radiolabeled prostate-specific membrane antigen (PSMA) PET/CT is rapidly becoming a standard of care for diagnosis, and PSMA-targeted radioligand therapies have gained recent FDA approval for metastatic prostate cancer. These advances in precision-based oncology are detailed in this review.

Role of Metabolism and Metabolic Pathways in Prostate Cancer

Prostate cancer (PCa) is the common cause of death in men. The pathophysiological factors contributing to PCa are not well known. PCa cells gain a protective mechanism via abnormal lipid signaling and metabolism. PCa cells modify their metabolism in response to an excessive intake of nutrients to facilitate advancement. Metabolic syndrome (MetS) is inextricably linked to the carcinogenic progression of PCa, which heightens the severity of the disease. It is hypothesized that changes in the metabolism of the mitochondria contribute to the onset of PCa. The studies of particular alterations in the progress of PCa are best accomplished by examining the metabolome of prostate tissue. Due to the inconsistent findings written initially, additional epidemiological research is required to identify whether or not MetS is an aspect of PCa. There is a correlation between several risk factors and the progression of PCa, one of which is MetS. The metabolic symbiosis between PCa cells and the tumor milieu and how this type of crosstalk may aid in the development of PCa is portrayed in this work. This review focuses on in-depth analysis and evaluation of the metabolic changes that occur within PCa, and also aims to assess the effect of metabolic abnormalities on the aggressiveness status and metabolism of PCa.

Multiparametric Magnetic Resonance Imaging and Metabolic Characterization of Patient-Derived Xenograft Models of Clear Cell Renal Cell Carcinoma

Patient-derived xenografts (PDX) are high-fidelity cancer models typically credentialled by genomics, transcriptomics and proteomics. Characterization of metabolic reprogramming, a hallmark of cancer, is less frequent. Dysregulated metabolism is a key feature of clear cell renal cell carcinoma (ccRCC) and authentic preclinical models are needed to evaluate novel imaging and therapeutic approaches targeting metabolism. We characterized 5 PDX from high-grade or metastatic ccRCC by multiparametric magnetic resonance imaging (MRI) and steady state metabolic profiling and flux analysis. Similar to MRI of clinical ccRCC, T2-weighted images of orthotopic tumors of most PDX were homogeneous. The increased hyperintense (cystic) areas observed in one PDX mimicked the cystic phenotype typical of some RCC. The negligible hypointense (necrotic) areas of PDX grown under the highly vascularized renal capsule are beneficial for preclinical studies. Mean apparent diffusion coefficient (ADC) values were equivalent to those of ccRCC in human patients. Hyperpolarized (HP) [1-13C]pyruvate MRI of PDX showed high glycolytic activity typical of high-grade primary and metastatic ccRCC with considerable intra- and inter-tumoral variability, as has been observed in clinical HP MRI of ccRCC. Comparison of steady state metabolite concentrations and metabolic flux in [U-13C]glucose-labeled tumors highlighted the distinctive phenotypes of two PDX with elevated levels of numerous metabolites and increased fractional enrichment of lactate and/or glutamate, capturing the metabolic heterogeneity of glycolysis and the TCA cycle in clinical ccRCC. Culturing PDX cells and reimplanting to generate xenografts (XEN), or passaging PDX in vivo, altered some imaging and metabolic characteristics while transcription remained like that of the original PDX. These findings show that PDX are realistic models of ccRCC for imaging and metabolic studies but that the plasticity of metabolism must be considered when manipulating PDX for preclinical studies.

Metabolic changes during prostate cancer development and progression

Metabolic reprogramming has been recognised as a hallmark in solid tumours. Malignant modification of the tumour's bioenergetics provides energy for tumour growth and progression. Otto Warburg first reported these metabolic and biochemical changes in 1927. In prostate cancer (PCa) epithelial cells, the tumour metabolism also changes during development and progress. These alterations are partly driven by the androgen receptor, the key regulator in PCa development, progress, and survival. In contrast to other epithelial cells of different entities, glycolytic metabolism in prostate cells sustains physiological citrate secretion in the normal prostatic epithelium. In the early stages of PCa, citrate is utilised to power oxidative phosphorylation and fuel lipogenesis, enabling tumour growth and progression. In advanced and incurable castration-resistant PCa, a metabolic shift towards choline, amino acid, and glycolytic metabolism fueling tumour growth and progression has been described. Therefore, even if the metabolic changes are not fully understood, the altered metabolism during tumour progression may provide opportunities for novel therapeutic strategies, especially in advanced PCa stages. This review focuses on the main differences in PCa's metabolism during tumourigenesis and progression highlighting glutamine's role in PCa.

Pharmacometabolomics Applied to Personalized Medicine in Urological Cancers

Prostate cancer (PCa), bladder cancer (BCa), and renal cell carcinoma (RCC) are the most common urological cancers, and their incidence has been rising over time. Surgery is the standard treatment for these cancers, but this procedure is only effective when the disease is localized. For metastatic disease, PCa is typically treated with androgen deprivation therapy, while BCa is treated with chemotherapy, and RCC is managed primarily with targeted therapies. However, response rates to these therapeutic options remain unsatisfactory due to the development of resistance and treatment-related toxicity. Thus, the discovery of biomarkers with prognostic and predictive value is needed to stratify patients into different risk groups, minimizing overtreatment and the risk of drug resistance development. Pharmacometabolomics, a branch of metabolomics, is an attractive tool to predict drug response in an individual based on its own metabolic signature, which can be collected before, during, and after drug exposure. Hence, this review focuses on the application of pharmacometabolomic approaches to identify the metabolic responses to hormone therapy, targeted therapy, immunotherapy, and chemotherapy for the most prevalent urological cancers.

Electrochemical LAMP-based assay for detection of RNA biomarkers in prostate cancer

Current molecular diagnostics of prostate cancer relies on detection of elevated levels of PSA protein in serum, but its specificity has been questioned due to its higher levels also in non-malignant prostate diseases. A long non-coding RNA biomarker, PCA3, demonstrated excellent specificity for prostate cancer, and thus has become an interesting alternative to PSA monitoring. Its detection utilizes mostly reverse transcription PCR with optical detection, making the protocol longer and more expensive. To avoid PCR, we have developed an electrochemical assay coupled with LAMP, an isothermal amplification technique showing high sensitivities at constant temperatures and shorter reaction times. We amplified PCA3 RNA as well as PSA mRNA (serving as a control), hybridized LAMP products on magnetic beads and measured them with chronoamperometry at carbon electrode chips. We show good sensitivity and specificity for both biomarkers in prostate cancer cell lines, and successful detection of PCA3 in clinical samples, i.e., urine samples from 11 prostate cancer patients and 7 healthy controls, where we obtained excellent correlation with clinical data. This is to our knowledge a first such attempt to apply electrochemistry to determine two RNA biomarkers directly in urine samples of prostate cancer patients in a minimally invasive diagnostics format.

Personalized Medicine for Prostate Cancer: Is Targeting Metabolism a Reality?

Prostate cancer invokes major shifts in gene transcription and metabolic signaling to mediate alterations in nutrient acquisition and metabolic substrate selection when compared to normal tissues. Exploiting such metabolic reprogramming is proposed to enable the development of targeted therapies for prostate cancer, yet there are several challenges to overcome before this becomes a reality. Herein, we outline the role of several nutrients known to contribute to prostate tumorigenesis, including fatty acids, glucose, lactate and glutamine, and discuss the major factors contributing to variability in prostate cancer metabolism, including cellular heterogeneity, genetic drivers and mutations, as well as complexity in the tumor microenvironment. The review draws from original studies employing immortalized prostate cancer cells, as well as more complex experimental models, including animals and humans, that more accurately reflect the complexity of the in vivo tumor microenvironment. In synthesizing this information, we consider the feasibility and potential limitations of implementing metabolic therapies for prostate cancer management.

Glutamine and Cholesterol Plasma Levels and Clinical Outcomes of Patients with Metastatic Castration-Resistant Prostate Cancer Treated with Taxanes

Altered metabolism is a hallmark of cancer. Malignant cells metabolise glutamine to fulfil their metabolic needs. In prostate cancer, androgen receptor signalling promotes glutamine metabolism, which is also involved in cholesterol homeostasis. We aimed to determine whether the plasma glutamine levels correlate with the blood lipid profile, clinical characteristics and outcomes in patients with metastatic castration resistance prostate cancer (mCRPC) undergoing taxanes. We retrospectively assessed the glutamine and glutamate levels in plasma samples by a bioluminescent assay. Pre-treatment glutamine, glutamate, cholesterol and triglycerides levels were correlated with patients' clinical characteristics, taxanes response and clinical outcomes. Seventy-five patients with mCRPC treated with taxanes were included. The plasma glutamine levels were significantly higher in patients that received abiraterone or enzalutamide prior to taxanes (p = 0.003). Besides, patients with low glutamine levels were more likely to present a PSA response to taxanes (p = 0.048). Higher glutamine levels were significantly correlated with shorter biochemical/clinical progression-free survival (PSA/RX-PFS) (median 2.5 vs. 4.2 months; p = 0.048) and overall survival (OS) (median 12.6 vs. 20.3; p = 0.008). High cholesterol levels independently predicted early PSA/RX-PFS (p = 0.034). High glutamine and cholesterol in the plasma from patients with mCRPC were associated with adverse clinical outcomes, supporting the relevance of further research on metabolism in prostate cancer progression.