Lipophagy and prostate cancer: association with disease aggressiveness and proximity to periprostatic adipose tissue

Prostate cancers with distinct transcriptional programs in Black and White men

BACKGROUND

Black men are at a higher risk of prostate cancer (PC) diagnosis and present with more high-grade PC than White men in an equal access setting. This study aimed to identify differential transcriptional regulation between Black and White men with PC.

METHODS

We performed microarray of radical prostatectomy tissue blocks from 305 Black and 238 White men treated at the Durham Veterans Affairs Medical Center. Differential expression, gene set enrichment analysis, master regulator analysis, and network modeling were conducted to compare gene expression by race. Findings were validated using external datasets that are available in the Gene Expression Omnibus (GEO) database. The first was a multi-institutional cohort of 1152 prostate cancer patients (596 Black, 556 White) with microarray data (GEO ID: GSE169038). The second was an Emory cohort of 106 patients (22 Black, 48 White, 36 men of unknown race) with RNA-seq data (GEO ID: GSE54460). Additionally, we analyzed androgen receptor (AR) chromatin binding profiles using paired AR ChIP-Seq datasets from Black and White men (GEO IDs: GSE18440 and GSE18441).

RESULTS

We identified 871 differentially expressed genes between Black and White men. White men had higher activity of MYC-related pathways, while Black men showed increased activity of inflammation, steroid hormone responses, and cancer progression-related pathways. We further identified the top 10 transcription factors (TFs) in Black patients, which formed a transcriptional regulatory network centered on the AR. The activities of this network and the pathways were significantly different in Black vs. White men across multiple cohorts and PC molecular subtypes.

CONCLUSIONS

These findings suggest PC in Black and White men have distinct tumor transcriptional profiles. Furthermore, a highly interactive TF network centered on AR drives differential gene expression in Black men. Additional study is needed to understand the degree to which these differences in transcriptional regulatory elements contribute to PC health disparities.

[Research Progress of Cellular Lipid Droplets in Oral Diseases]

Lipid droplets are dynamic multifunctional organelles composed of a neutral lipid core and a phospholipid monolayer membrane modified by a specific set of proteins. PAT family proteins are the most characteristic lipid droplet proteins, playing an important role in regulating lipid droplet structure, function, and metabolism. The biogenesis of lipid droplets involves neutral lipid synthesis and the nucleation, budding, and growth of the lipid droplets. Lipid droplets not only serve as the energy metabolism reserve of cells but also participate in intracellular signal transduction and the development of inflammation and tumor. Lipid droplets are closely connected to and interact with various organelles, regulating the division, the transportation, and the genetics of organelles. The complexity of lipid droplets biogenesis and the diversity of their functions may have provided a physiological basis for the pathogenesis and development of diseases, but further research is needed in order to better understand the relevant processes. Published findings have helped elucidate the association between lipid droplets and diseases, such as obesity, non-alcoholic fatty liver disease, neurodegenerative disease, cancer, and cardiovascular disease, but the relationship between lipid droplets and oral diseases has not been fully studied. Topics that warrant further research include the role and mechanisms of lipid droplets in the pathogenesis and development of oral diseases, the relationship between oral diseases and systemic diseases, and translation of the effect of lipid droplets on oral diseases into valuable clinical diagnostic and treatment methods. Herein, we reviewed the biogenesis and functions of lipid droplets and the progress in research concerning lipid droplets in oral diseases, including mouth neoplasms, periodontitis, and dental caries.

Silencing of matrix metalloprotease-12 delays the progression of castration-resistant prostate cancer by regulating autophagy and lipolysis

The complex pathogenesis of castration-resistant prostate cancer (CRPC) makes it challenging to identify effective treatment methods. Matrix metalloproteinase (MMP)-12 can degrade elastin as well as various extracellular matrix (ECM) components, which is associated with cancer progression. However, the relationship between MMP-12 and CRPC progression is poorly understood. In this study, we observed the effect of MMP-12 on the progression of CRPC and further explored its potential mechanism of action. High levels of MMP-12 were observed in patients with CRPC. We therefore developed cell co-culture and mouse models to study the function of MMP-12. Silencing MMP-12 in CRPC cells disrupted lipid utilization and autophagy marker expression via the CD36/CPT1 and P62/LC3 pathways, respectively, leading to reduced CRPC cell migration and invasion. Moreover, animal experiments confirmed that MMP-12-knockdown CRPC xenograft tumors exhibited reduced tumor growth, and the mechanisms involved the promotion of cancer cell autophagy and the inhibition of lipid catabolism. According to our results, MMP-12 played important roles in the progression of CRPC by disrupting adipocyte maturation and regulating cancer migration and invasion via the modulation of autophagy and lipid catabolism pathways.

Variable effects of periprostatic adipose tissue on prostate cancer cells: Role of adipose tissue lipid composition and cancer cells related factors

BACKGROUND

Periprostatic adipose tissue (PPAT) is likely to modulate prostate cancer (PCa) progression. We analyzed the variations in the effect of PPAT on cancer cells, according to its fatty acid (FA) composition and tumor characteristics.

METHODS

The expression of markers of aggressiveness Ki67 and Zeb1, and epigenetic marks that could be modified during PCa progression, was analyzed by immunohistochemistry on a tissue-micro-array containing 59 pT3 PCa, including intra-prostatic areas and extra-prostatic foci in contact with PPAT belonging to the same tumor. In addition, we cocultivated PC3 and LNCaP cell lines with PPAT, which were then analyzed for FA composition.

RESULTS

Although the contact between PPAT and cancer cells led overall to an increase in Ki67 and Zeb1, and a decrease in the epigenetic marks 5MC, 5HMC, and H3K27ac, these effects were highly heterogeneous. Increased proliferation in extra-prostatic areas was associated with the international society of uropathology score. PC3 and LNCaP cocultures with PPAT led to increased Ki67, Zeb1 and H3K27me3, but only for PPAT associated with aggressive PCa. PC3 proliferation was correlated with high 20.2 n-6 and low 20.5n-3 in PPAT.

CONCLUSIONS

These results suggest that the effects of PPAT on cancer cells may depend on both PCa characteristics and PPAT composition, and could lead to propose nutritional supplementation.

Recent advances of ferroptosis in tumor: From biological function to clinical application

Ferroptosis is a recently recognized form of cell death with distinct features in terms of morphology, biochemistry, and molecular mechanisms. Unlike other types of cell death, ferroptosis is characterized by iron dependence, reactive oxygen species accumulation and lipid peroxidation. Recent studies have demonstrated that selective autophagy plays a vital role in the induction of ferroptosis, including ferritinophagy, lipophagy, clockophagy, and chaperone-mediated autophagy. Emerging evidence has indicated the involvement of ferroptosis in tumorigenesis through regulating various biological processes, including tumor growth, metastasis, stemness, drug resistance, and recurrence. Clinical and preclinical studies have found that novel therapies targeting ferroptosis exert great potential in the treatment of tumors. This review provides a comprehensive overview of the molecular mechanisms in ferroptosis, especially in autophagy-driven ferroptosis, discusses the recent advances in the biological roles of ferroptosis in tumorigenesis, and highlights the application of novel ferroptosis-targeted therapies in the clinical treatment of tumors.

Toward a Unifying Hypothesis for Redesigned Lipid Catabolism as a Clinical Target in Advanced, Treatment-Resistant Carcinomas

We review extensive progress from the cancer metabolism community in understanding the specific properties of lipid metabolism as it is redesigned in advanced carcinomas. This redesigned lipid metabolism allows affected carcinomas to make enhanced catabolic use of lipids in ways that are regulated by oxygen availability and is implicated as a primary source of resistance to diverse treatment approaches. This oxygen control permits lipid catabolism to be an effective energy/reducing potential source under the relatively hypoxic conditions of the carcinoma microenvironment and to do so without intolerable redox side effects. The resulting robust access to energy and reduced potential apparently allow carcinoma cells to better survive and recover from therapeutic trauma. We surveyed the essential features of this advanced carcinoma-specific lipid catabolism in the context of treatment resistance and explored a provisional unifying hypothesis. This hypothesis is robustly supported by substantial preclinical and clinical evidence. This approach identifies plausible routes to the clinical targeting of many or most sources of carcinoma treatment resistance, including the application of existing FDA-approved agents.

Ultrastructural analysis of prostate cancer tissue provides insights into androgen-dependent adaptations to membrane contact site establishment

Membrane trafficking and organelle contact sites are important for regulating cell metabolism and survival; processes often deregulated in cancer. Prostate cancer is the second leading cause of cancer-related death in men in the developed world. While early-stage disease is curable by surgery or radiotherapy there is an unmet need to identify prognostic biomarkers, markers to treatment response and new therapeutic targets in intermediate-late stage disease. This study explored the morphology of organelles and membrane contact sites in tumor tissue from normal, low and intermediate histological grade groups. The morphology of organelles in secretory prostate epithelial cells; including Golgi apparatus, ER, lysosomes; was similar in prostate tissue samples across a range of Gleason scores. Mitochondrial morphology was not dramatically altered, but the number of membrane contacts with the ER notably increased with disease progression. A three-fold increase of tight mitochondria-ER membrane contact sites was observed in the intermediate Gleason score group compared to normal tissue. To investigate whether these changes were concurrent with an increased androgen signaling in the tissue, we investigated whether an anti-androgen used in the clinic to treat advanced prostate cancer (enzalutamide) could reverse the phenotype. Patient-derived explant tissues with an intermediate Gleason score were cultured ex vivo in the presence or absence of enzalutamide and the number of ER-mitochondria contacts were quantified for each matched pair of tissues. Enzalutamide treated tissue showed a significant reduction in the number and length of mitochondria-ER contact sites, suggesting a novel androgen-dependent regulation of these membrane contact sites. This study provides evidence for the first time that prostate epithelial cells undergo adaptations in membrane contact sites between mitochondria and the ER during prostate cancer progression. These adaptations are androgen-dependent and provide evidence for a novel hormone-regulated mechanism that support establishment and extension of MAMs. Future studies will determine whether these changes are required to maintain pro-proliferative signaling and metabolic changes that support prostate cancer cell viability.

Adipose Tissue-Derived Extracellular Vesicles Contribute to Phenotypic Plasticity of Prostate Cancer Cells

Metastatic prostate cancer is one of the leading causes of male cancer deaths in the western world. Obesity significantly increases the risk of metastatic disease and is associated with a higher mortality rate. Systemic chronic inflammation can result from a variety of conditions, including obesity, where adipose tissue inflammation is a major contributor. Adipose tissue endothelial cells (EC) exposed to inflammation become dysfunctional and produce a secretome, including extracellular vesicles (EV), that can impact function of cells in distant tissues, including malignant cells. The aim of this study was to explore the potential role of EVs produced by obese adipose tissue and the ECs exposed to pro-inflammatory cytokines on prostate cancer phenotypic plasticity in vitro. We demonstrate that PC3ML metastatic prostate cancer cells exposed to EVs from adipose tissue ECs and to EVs from human adipose tissue total explants display reduced invasion and increased proliferation. The latter functional changes could be attributed to the EV miRNA cargo. We also show that the functional shift is TWIST1-dependent and is consistent with mesenchymal-to-epithelial transition, which is key to establishment of secondary tumor growth. Understanding the complex effects of EVs on prostate cancer cells of different phenotypes is key before their intended use as therapeutics.

Obesity-Related Cross-Talk between Prostate Cancer and Peripheral Fat: Potential Role of Exosomes

Simple Summary

Obesity is involved in many aspects of prostate cancer progression as a risk factor for prostate cancer, especially in the process of biochemical recurrence in the prostate. Approximately 27–53% of prostate cancer patients can develop biochemical recurrence after radical prostatectomy, which poses difficulties in the clinical management of prostate cancer, and this is closely related to the release of exosomes from adipose tissue in the obese state. In this review, we summarize the crosstalk between prostate cancer peripheral adiposity and prostate cancer and discuss the potential role of exosomes in this process and the prospects for the use of adipose exosomes. Exosomes play an important role in the crosstalk between the two this may be a new basis to explain obesity as a biochemical recurrence after prostate cancer surgery and a potential avenue for future prostate therapy.

Abstract

The molecular mechanisms of obesity-induced cancer progression have been extensively explored because of the significant increase in obesity and obesity-related diseases worldwide. Studies have shown that obesity is associated with certain features of prostate cancer. In particular, bioactive factors released from periprostatic adipose tissues mediate the bidirectional communication between periprostatic adipose tissue and prostate cancer. Moreover, recent studies have shown that extracellular vesicles have a role in the relationship between tumor peripheral adipose tissue and cancer progression. Therefore, it is necessary to investigate the feedback mechanisms between prostate cancer and periglandular adipose and the role of exosomes as mediators of signal exchange to understand obesity as a risk factor for prostate cancer. This review summarizes the two-way communication between prostate cancer and periglandular adipose and discusses the potential role of exosomes as a cross-talk and the prospect of using adipose tissue as a means to obtain exosomes in vitro. Therefore, this review may provide new directions for the treatment of obesity to suppress prostate cancer.

Curcumin in the treatment of urological cancers: Therapeutic targets, challenges and prospects

Urological cancers include bladder, prostate and renal cancers that can cause death in males and females. Patients with urological cancers are mainly diagnosed at an advanced disease stage when they also develop resistance to therapy or poor response. The use of natural products in the treatment of urological cancers has shown a significant increase. Curcumin has been widely used in cancer treatment due to its ability to trigger cell death and suppress metastasis. The beneficial effects of curcumin in the treatment of urological cancers is the focus of current review. Curcumin can induce apoptosis in the three types of urological cancers limiting their proliferative potential. Furthermore, curcumin can suppress invasion of urological cancers through EMT inhibition. Notably, curcumin decreases the expression of MMPs, therefore interfering with urological cancer metastasis. When used in combination with chemotherapy agents, curcumin displays synergistic effects in suppressing cancer progression. It can also be used as a chemosensitizer. Based on pre-clinical studies, curcumin administration is beneficial in the treatment of urological cancers and future clinical applications might be considered upon solving problems related to the poor bioavailability of the compound. To improve the bioavailability of curcumin and increase its therapeutic index in urological cancer suppression, nanostructures have been developed to favor targeted delivery.

Emerging Roles of Lipophagy in Cancer Metastasis

Simple Summary

Metastasis is the main cause of death in patients with malignant tumors worldwide. Mounting evidence suggests lipid droplet metabolism is involved in the process of metastasis. As a mechanism to selectively degrade lipid droplets, the current research on lipophagy and tumor metastasis is quite limited. This review summarizes the crosstalk among lipophagy, tumor lipid metabolism and cancer metastasis, which will provide a new reference for the development of effective targeted drugs.

Abstract

Obesity is a prominent risk factor for certain types of tumor progression. Adipocytes within tumor stroma contribute to reshaping tumor microenvironment (TME) and the metabolism and metastasis of tumors through the production of cytokines and adipokines. However, the crosstalk between adipocytes and tumor cells remains a major gap in this field. Known as a subtype of selective autophagy, lipophagy is thought to contribute to lipid metabolism by breaking down intracellular lipid droplets (LDs) and generating free fatty acids (FAs). The metastatic potential of cancer cells closely correlates with the lipid degradation mechanisms, which are required for energy generation, signal transduction, and biosynthesis of membranes. Here, we discuss the recent advance in the understanding of lipophagy with tumor lipid metabolism and review current studies on the roles of lipoghagy in the metastasis of certain human malignancies. Additionally, the novel candidate drugs targeting lipophagy are integrated for effective treatment strategies.

Interplay between Prostate Cancer and Adipose Microenvironment: A Complex and Flexible Scenario

Adipose tissue is part of the prostate cancer (PCa) microenvironment not only in the periprostatic area, but also in the most frequent metastatic sites, such as bone marrow and pelvic lymph nodes. The involvement of periprostatic adipose tissue (PPAT) in the aggressiveness of PCa is strongly suggested by numerous studies. Many molecules play a role in the reciprocal interaction between adipocytes and PCa cells, including adipokines, hormones, lipids, and also lipophilic pollutants stored in adipocytes. The crosstalk has consequences not only on cancer cell growth and metastatic potential, but also on adipocytes. Although most of the molecules released by PPAT are likely to promote tumor growth and the migration of cancer cells, others, such as the adipokine adiponectin and the n-6 or n-3 polyunsaturated fatty acids (PUFAs), have been shown to have anti-tumor properties. The effects of PPAT on PCa cells might therefore depend on the balance between the pro- and anti-tumor components of PPAT. In addition, genetic and environmental factors involved in the risk and/or aggressiveness of PCa, including obesity and diet, are able to modulate the interactions between PPAT and cancer cells and their consequences on the growth and the metastatic potential of PCa.

The lipidomic profile of the tumoral periprostatic adipose tissue reveals alterations in tumor cell's metabolic crosstalk

BACKGROUND

Periprostatic adipose tissue (PPAT) plays a role in prostate cancer (PCa) progression. PPAT lipidomic composition study may allow us to understand the tumor metabolic microenvironment and provide new stratification factors.

METHODS

We used ultra-high-performance liquid chromatography-mass spectrometry-based non-targeted lipidomics to profile lipids in the PPAT of 40 patients with PCa (n = 20 with low-risk and n = 20 high-risk). Partial least squares-discriminant analysis (PLS-DA) and variable importance in projection (VIP) analysis were used to identify the most relevant features of PPAT between low- and high-risk PCa, and metabolite set enrichment analysis was used to detect disrupted metabolic pathways. Metabolic crosstalk between PPAT and PCa cell lines (PC-3 and LNCaP) was studied using ex vivo experiments. Lipid uptake and lipid accumulation were measured. Lipid metabolic-related genes (SREBP1, FASN, ACACA, LIPE, PPARG, CD36, PNPLA2, FABP4, CPT1A, FATP5, ADIPOQ), inflammatory markers (IL-6, IL-1B, TNFα), and tumor-related markers (ESRRA, MMP-9, TWIST1) were measured by RT-qPCR.

RESULTS

Significant differences in the content of 67 lipid species were identified in PPAT samples between high- and low-risk PCa. PLS-DA and VIP analyses revealed a discriminating lipidomic panel between low- and high-risk PCa, suggesting the occurrence of disordered lipid metabolism in patients related to PCa aggressiveness. Functional analysis revealed that alterations in fatty acid biosynthesis, linoleic acid metabolism, and β-oxidation of very long-chain fatty acids had the greatest impact in the PPAT lipidome. Gene analyses of PPAT samples demonstrated that the expression of genes associated with de novo fatty acid synthesis such as FASN and ACACA were significantly lower in PPAT from high-risk PCa than in low-risk counterparts. This was accompanied by the overexpression of inflammatory markers (IL-6, IL-1B, and TNFα). Co-culture of PPAT explants with PCa cell lines revealed a reduced gene expression of lipid metabolic-related genes (CD36, FASN, PPARG, and CPT1A), contrary to that observed in co-cultured PCa cell lines. This was followed by an increase in lipid uptake and lipid accumulation in PCa cells. Tumor-related genes were increased in co-cultured PCa cell lines.

CONCLUSIONS

Disturbances in PPAT lipid metabolism of patients with high-risk PCa are associated with tumor cell metabolic changes.

Lipid droplets and perilipins in canine osteosarcoma. Investigations on tumor tissue, 2D and 3D cell culture models

Lipid droplets were identified as important players in biological processes of various tumor types. With emphasis on lipid droplet-coating proteins (perilipins, PLINs), this study intended to shed light on the presence and formation of lipid droplets in canine osteosarcoma. For this purpose, canine osteosarcoma tissue samples (n = 11) were analyzed via immunohistochemistry and electron microscopy for lipid droplets and lipid droplet-coating proteins (PLINs). Additionally, we used the canine osteosarcoma cell lines D-17 and COS4288 in 2D monolayer and 3D spheroid (cultivated for 7, 14, and 21 days) in vitro models, and further analyzed the samples by means of histochemistry, immunofluorescence, molecular biological techniques (RT-qPCR, Western Blot) and electron microscopical imaging. Lipid droplets, PLIN2, and PLIN3 were detected in osteosarcoma tissue samples as well as in 2D and 3D cultivated D-17 and COS4288 cells. In spheroids, specific distribution patterns of lipid droplets and perilipins were identified, taking into consideration cell line specific zonal apportionment. Upon external lipid supplementation (oleic acid), a rise of lipid droplet amount accompanied with an increase of PLIN2 expression was observed. Detailed electron microscopical analyzes revealed that lipid droplet sizes in tumor tissue were comparable to that of 3D spheroid models. Moreover, the biggest lipid droplets were found in the central zone of the spheroids at all sampling time-points, reaching their maximum size at 21 days. Thus, the 3D spheroids can be considered as a relevant in vitro model for further studies focusing on lipid droplets biology and function in osteosarcoma.

Thromboinflammatory Processes at the Nexus of Metabolic Dysfunction and Prostate Cancer: The Emerging Role of Periprostatic Adipose Tissue

Simple Summary

As overweight and obesity increase among the population worldwide, a parallel increase in the number of individuals diagnosed with prostate cancer was observed. There appears to be a relationship between both diseases where the increase in the mass of fat tissue can lead to inflammation. Such a state of inflammation could produce many factors that increase the aggressiveness of prostate cancer, especially if this inflammation occurred in the fat stores adjacent to the prostate. Another important observation that links obesity, fat tissue inflammation, and prostate cancer is the increased production of blood clotting factors. In this article, we attempt to explain the role of these latter factors in the effect of increased body weight on the progression of prostate cancer and propose new ways of treatment that act by affecting how these clotting factors work.

Abstract

The increased global prevalence of metabolic disorders including obesity, insulin resistance, metabolic syndrome and diabetes is mirrored by an increased incidence of prostate cancer (PCa). Ample evidence suggests that these metabolic disorders, being characterized by adipose tissue (AT) expansion and inflammation, not only present as risk factors for the development of PCa, but also drive its increased aggressiveness, enhanced progression, and metastasis. Despite the emerging molecular mechanisms linking AT dysfunction to the various hallmarks of PCa, thromboinflammatory processes implicated in the crosstalk between these diseases have not been thoroughly investigated. This is of particular importance as both diseases present states of hypercoagulability. Accumulating evidence implicates tissue factor, thrombin, and active factor X as well as other players of the coagulation cascade in the pathophysiological processes driving cancer development and progression. In this regard, it becomes pivotal to elucidate the thromboinflammatory processes occurring in the periprostatic adipose tissue (PPAT), a fundamental microenvironmental niche of the prostate. Here, we highlight key findings linking thromboinflammation and the pleiotropic effects of coagulation factors and their inhibitors in metabolic diseases, PCa, and their crosstalk. We also propose several novel therapeutic targets and therapeutic interventions possibly modulating the interaction between these pathological states.