ACSL3 promotes intratumoral steroidogenesis in prostate cancer cells

Dysregulation of genes involved in the long-chain fatty acid transport in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive lethal malignancy with limited options for treatment and a 5-year survival rate of 11% in the United States. As for other types of tumors, such as colorectal cancer, aberrant de novo lipid synthesis and reprogrammed lipid metabolism have been suggested to be associated with PDAC development and progression.

AIM

To identify the possible involvement of lipid metabolism in PDAC by analyzing in tumoral and non-tumoral tissues the expression level of the most relevant genes involved in the long-chain fatty acid (FA) import into cell.

METHODS

A gene expression analysis of FASN, CD36, SLC27A1, SLC27A2, SLC27A3, SLC27A4, SLC27A5, ACSL1, and ACSL3 was performed by qRT-PCR in 24 tumoral PDAC tissues and 11 samples from non-tumoral pancreatic tissues obtained via fine needle aspiration or via surgical resection. The genes were considered significantly dysregulated between the groups when the p value was < 0.05 and the fold change (FC) was ≤ 0.5 and ≥ 2.

RESULTS

We found that three FA transporters and two long-chain acyl-CoA synthetases genes were significantly upregulated in the PDAC tissue compared to the non-tumoral tissue: SLC27A2 (FC = 5.66; P = 0.033), SLC27A3 (FC = 2.68; P = 0.040), SLC27A4 (FC = 3.13; P = 0.033), ACSL1 (FC = 4.10; P < 0.001), and ACSL3 (FC = 2.67; P = 0.012). We further investigated any possible association between the levels of the analyzed mRNAs and the specific characteristics of the tumors, including the anatomic location, the lymph node involvement, and the presence of metastasis. A significant difference in the expression of SLC27A3 (FC = 3.28; P = 0.040) was found comparing patients with and without lymph nodes involvement with an overexpression of this transcript in 17 patients presenting tumoral cells in the lymph nodes.

CONCLUSION

Despite the low number of patients analyzed, these preliminary results seem to be promising. Addressing lipid metabolism through a broad strategy could be a beneficial way to treat this malignancy. Future in vitro and in vivo studies on these genes may offer important insights into the mechanisms linking PDAC with the long-chain FA import pathway.

The impact of epithelial-mesenchymal transition (EMT) induced by metabolic processes and intracellular signaling pathways on chemo-resistance, metastasis, and recurrence in solid tumors

The intricate cellular process, known as the epithelial-mesenchymal transition (EMT), significantly influences solid tumors development. Changes in cell shape, metabolism, and gene expression linked to EMT facilitate tumor cell invasion, metastasis, drug resistance, and recurrence. So, a better understanding of the intricate processes underlying EMT and its role in tumor growth may lead to the development of novel therapeutic approaches for the treatment of solid tumors. This review article focuses on the signals that promote EMT and metabolism, the intracellular signaling pathways leading to EMT, and the network of interactions between EMT and cancer cell metabolism. Furthermore, the functions of EMT in treatment resistance, recurrence, and metastasis of solid cancers are covered. Lastly, treatment approaches that focus on intracellular signaling networks and metabolic alterations brought on by EMT will be discussed.

Targeting ACSLs to modulate ferroptosis and cancer immunity

Five acyl-CoA synthetase long-chain family members (ACSLs) are responsible for catalyzing diverse long-chain fatty acids (LCFAs) into LCFA-acyl-coenzyme A (CoA) for their subsequent metabolism, including fatty acid oxidation (FAO), lipid synthesis, and protein acylation. In this review, we focus on ACSLs and their LCFA substrates and introduce their involvement in regulation of cancer proliferation, metastasis, and therapeutic resistance. Along with the recognition of the decisive role of ACSL4 in ferroptosis - an immunogenic cell death (ICD) initiated by lipid peroxidation - we review the functions of ACSLs on regulating ferroptosis sensitivity. Last, we discuss the current understanding of ACSL on the antitumor immune response. We emphasize the necessity to explore the functions of immune cells expressing ACSLs for developing novel strategies to augment immunotherapy by targeting ACSL.

Anillin actin-binding protein expression correlates with poor prognosis for prostate cancer patients

Objective

Octamer transcription factor 1 (OCT1), a transcription factor that interacts with androgen receptor, is involved in prostate cancer (PCa) progression. The OCT1 target gene, Anillin actin-binding protein (ANLN), is highly expressed in castration-resistant PCa tissue; however, it remains unclear whether ANLN expression in hormone-sensitive PCa tissue could be used as a predictive biomarker for poor prognosis of patients. We aimed to investigate ANLN expression in PCa tissue obtained via radical prostatectomy and its correlation with clinical parameters.

Methods

Immunohistochemical staining for ANLN was performed on 86 PCa specimens, followed by evaluation using immunoreactivity (IR) scores. Prognosis was analyzed by the log-rank test using the Kaplan-Meier method to generate a cancer-specific survival curve. The correlations between ANLN IR and clinical parameters as well as OCT1 IR were analyzed using the Chi-squared test.

Results

The median IR score was 0 for ANLN. Accordingly, given the low median IR score, an IR score of ≥3 was defined as positive. There were 17 (19.8%) ANLN-positive cases, and these cases had a significantly poorer prognosis. Multivariate analysis revealed that the Gleason score, pathological tumor and lymph node stages, and positive ANLN expression were significant predictors of poor prognosis. Notably, patients with both positive ANLN and high OCT1 expression had a significantly decreased overall survival (p=0.001).

Conclusion

ANLN, which is a OCT1 target gene especially in castration-resistant PCa, is expressed in a small number of hormone-sensitive PCa cases. Both positive ANLN expression and high OCT1 expression are significantly correlated with poor prognosis for PCa patients.

Liquidambaric acid inhibits the proliferation of hepatocellular carcinoma cells by targeting PPARα-RXRα to down-regulate fatty acid metabolism

Hepatocellular carcinoma (HCC) is a primary malignant tumor of the liver. As the global obesity rate rises, non-alcoholic fatty liver disease (NAFLD) has emerged as the most rapidly increasing cause of HCC. Consequently, the regulation of lipid metabolism has become a crucial target for the prevention and treatment of HCC. Liquidambaric acid (LDA), a pentacyclic triterpenoid compound derived from various plants, exhibits diverse biological activities. We found that LDA could inhibit HCC cell proliferation by arresting cell cycle and prompting apoptosis. Additionally, LDA can augment the therapeutic efficacy of Regorafenib in HCC in vitro and vivo. Our study utilized transcriptome analysis, luciferase reporter assays, and co-immunocoprecipitation experiments to elucidate the anti-HCC mechanism of LDA. We discovered that LDA disrupts the formation of the PPARα-RXRα heterodimer, leading to the down-regulation of the ACSL4 gene and subsequently impacting the fatty acid metabolism of HCC cells, ultimately inhibiting HCC proliferation. Our research contributes to the identification of novel therapeutic agents and targets for the treatment of HCC.

Molecular landscape for risk prediction and personalized therapeutics of castration-resistant prostate cancer: at a glance

Prostate cancer (PCa) is commonly occurred with high incidence in men worldwide, and many patients will be eventually suffered from the dilemma of castration-resistance with the time of disease progression. Castration-resistant PCa (CRPC) is an advanced subtype of PCa with heterogeneous carcinogenesis, resulting in poor prognosis and difficulties in therapy. Currently, disorders in androgen receptor (AR)-related signaling are widely acknowledged as the leading cause of CRPC development, and some non-AR-based strategies are also proposed for CRPC clinical analyses. The initiation of CRPC is a consequence of abnormal interaction and regulation among molecules and pathways at multi-biological levels. In this study, CRPC-associated genes, RNAs, proteins, and metabolites were manually collected and integrated by a comprehensive literature review, and they were functionally classified and compared based on the role during CRPC evolution, i.e., drivers, suppressors, and biomarkers, etc. Finally, translational perspectives for data-driven and artificial intelligence-powered CRPC systems biology analysis were discussed to highlight the significance of novel molecule-based approaches for CRPC precision medicine and holistic healthcare.

Exploring androgen receptor signaling pathway in prostate cancer: A path to new discoveries

Androgen deprivation therapy has achieved significant success in treating prostate cancer through strategies centered on the androgen receptor. However, the emergence of castration-resistant prostate cancer highlights this therapy limitation, underscoring the need to elucidate the mechanisms of treatment resistance. This review aimed to focus on multifaceted resistance mechanisms, including androgen receptor overexpression, splice variants, missense mutations, the involvement of the glucocorticoid receptor, and alterations in coregulators and transcription factors, revealing their roles in castration-resistant prostate cancer progression. These mechanisms promote cell survival and proliferation, depending on the androgen receptor signaling pathway, leading to resistance to conventional therapies. Amplification and mutations in the androgen receptor gene facilitate selective adaptation in treatment-resistant cells, consequently diminishing therapeutic efficacy. Furthermore, the activation of glucocorticoid receptors and aberrant regulation of specific coregulators and transcription factors contribute to the activation of androgen receptor-independent signaling pathways, promoting cell survival and proliferation. These findings hold promise for identifying new targets for treating castration-resistant prostate cancer and developing personalized treatment strategies. The development of future therapies will hinge on precisely targeting the androgen receptor signaling pathway, necessitating a deeper understanding of the molecular targets unique to castration-resistant prostate cancer.

A ferroptosis-related signature predicts the clinical diagnosis and prognosis, and associates with the immune microenvironment of lung cancer

Targeting ferroptosis-related pathway is a potential strategy for treatment of lung cancer (LC). Consequently, exploration of ferroptosis-related markers is important for treating LC. We collected LC clinical data and mRNA expression profiles from TCGA and GEO database. Ferroptosis-related genes (FRGs) were obtained through FerrDB database. Expression analysis was performed to obtain differentially expressed FRGs. Diagnostic and prognostic models were constructed based on FRGs by LASSO regression, univariate, and multivariate Cox regression analysis, respectively. External verification cohorts GSE72094 and GSE157011 were used for validation. The interrelationship between prognostic risk scores based on FRGs and the tumor immune microenvironment was analyzed. Immunocytochemistry, Western blotting, and RT-qPCR detected the FRGs level. Eighteen FRGs were used for diagnostic models, 8 FRGs were used for prognostic models. The diagnostic model distinguished well between LC and normal samples in training and validation cohorts of TCGA. The prognostic models for TCGA, GSE72094, and GSE157011 cohorts significantly confirmed lower overall survival (OS) in high-risk group, which demonstrated excellent predictive properties of the survival model. Multivariate Cox regression analysis further confirmed risk score was an independent risk factor related with OS. Immunoassays revealed that in high-risk group, a significantly higher proportion of Macrophages_M0, Neutrophils, resting Natural killer cells and activated Mast cells and the level of B7H3, CD112, CD155, B7H5, and ICOSL were increased. In conclusion, diagnostic and prognostic models provided superior diagnostic and predictive power for LC and revealed a potential link between ferroptosis and TIME.

Lipid droplets provide metabolic flexibility for cancer progression

A hallmark of cancer cells is their remarkable ability to efficiently adapt to favorable and hostile environments. Due to a unique metabolic flexibility, tumor cells can grow even in the absence of extracellular nutrients or in stressful scenarios. To achieve this, cancer cells need large amounts of lipids to build membranes, synthesize lipid-derived molecules, and generate metabolic energy in the absence of other nutrients. Tumor cells potentiate strategies to obtain lipids from other cells, metabolic pathways to synthesize new lipids, and mechanisms for efficient storage, mobilization, and utilization of these lipids. Lipid droplets (LDs) are the organelles that collect and supply lipids in eukaryotes and it is increasingly recognized that the accumulation of LDs is a new hallmark of cancer cells. Furthermore, an active role of LD proteins in processes underlying tumorigenesis has been proposed. Here, by focusing on three major classes of LD-resident proteins (perilipins, lipases, and acyl-CoA synthetases), we provide an overview of the contribution of LDs to cancer progression and discuss the role of LD proteins during the proliferation, invasion, metastasis, apoptosis, and stemness of cancer cells.

The interplay between autophagy and ferroptosis presents a novel conceptual therapeutic framework for neuroendocrine prostate cancer

In American men, the incidence of prostate cancer (PC) is the highest among all types of cancer, making it the second leading cause of mortality associated with cancer. For advanced or metastatic PC, antiandrogen therapies are standard treatment options. The administration of these treatments unfortunately carries the potential risk of inducing neuroendocrine prostate cancer (NEPC). Neuroendocrine differentiation (NED) serves as a crucial indicator of prostate cancer development, encompassing various factors such as phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR), Yes-associated protein 1 (YAP1), AMP-activated protein kinase (AMPK), miRNA. The processes of autophagy and ferroptosis (an iron-dependent form of programmed cell death) play pivotal roles in the regulation of various types of cancers. Clinical trials and preclinical investigations have been conducted on many signaling pathways during the development of NEPC, with the deepening of research, autophagy and ferroptosis appear to be the potential target for regulating NEPC. Due to the dual nature of autophagy and ferroptosis in cancer, gaining a deeper understanding of the developmental programs associated with achieving autophagy and ferroptosis may enhance risk stratification and treatment efficacy for patients with NEPC.

Crosstalk between lipid metabolism and EMT: emerging mechanisms and cancer therapy

Lipids are the key component of all membranes composed of a variety of molecules that transduce intracellular signaling and provide energy to the cells in the absence of nutrients. Alteration in lipid metabolism is a major factor for cancer heterogeneity and a newly identified cancer hallmark. Reprogramming of lipid metabolism affects the diverse cancer phenotypes, especially epithelial-mesenchymal transition (EMT). EMT activation is considered to be an essential step for tumor metastasis, which exhibits a crucial role in the biological processes including development, wound healing, and stem cell maintenance, and has been widely reported to contribute pathologically to cancer progression. Altered lipid metabolism triggers EMT and activates multiple EMT-associated oncogenic pathways. Although the role of lipid metabolism-induced EMT in tumorigenesis is an attractive field of research, there are still significant gaps in understanding the underlying mechanisms and the precise contributions of this interplay. Further study is needed to clarify the specific molecular mechanisms driving the crosstalk between lipid metabolism and EMT, as well as to determine the potential therapeutic implications. The increased dependency of tumor cells on lipid metabolism represents a novel therapeutic target, and targeting altered lipid metabolism holds promise as a strategy to suppress EMT and ultimately inhibit metastasis.

Dual targeting of the androgen receptor and PI3K/AKT/mTOR pathways in prostate cancer models improves antitumor efficacy and promotes cell apoptosis

Prostate cancer is a frequent malignancy in older men and has a very high 5-year survival rate if diagnosed early. The prognosis is much less promising if the tumor has already spread outside the prostate gland. Targeted treatments mainly aim at blocking androgen receptor (AR) signaling and initially show good efficacy. However, tumor progression due to AR-dependent and AR-independent mechanisms is often observed after some time, and novel treatment strategies are urgently needed. Dysregulation of the PI3K/AKT/mTOR pathway in advanced prostate cancer and its implication in treatment resistance has been reported. We compared the impact of PI3K/AKT/mTOR pathway inhibitors with different selectivity profiles on in vitro cell proliferation and on caspase 3/7 activation as a marker for apoptosis induction, and observed the strongest effects in the androgen-sensitive prostate cancer cell lines VCaP and LNCaP. Combination treatment with the AR inhibitor darolutamide led to enhanced apoptosis in these cell lines, the effects being most pronounced upon cotreatment with the pan-PI3K inhibitor copanlisib. A subsequent transcriptomic analysis performed in VCaP cells revealed that combining darolutamide with copanlisib impacted gene expression much more than individual treatment. A comprehensive reversal of the androgen response and the mTORC1 transcriptional programs as well as a marked induction of DNA damage was observed. Next, an in vivo efficacy study was performed using the androgen-sensitive patient-derived prostate cancer (PDX) model LuCaP 35 and a superior efficacy was observed after the combined treatment with copanlisib and darolutamide. Importantly, immunohistochemistry analysis of these treated tumors showed increased apoptosis, as revealed by elevated levels of cleaved caspase 3 and Bcl-2-binding component 3 (BBC3). In conclusion, these data demonstrate that concurrent blockade of the PI3K/AKT/mTOR and AR pathways has superior antitumor efficacy and induces apoptosis in androgen-sensitive prostate cancer cell lines and PDX models.

Development of targeted hydrophilic interaction liquid chromatography-tandem mass spectrometry method for acyl-Coenzyme A covering short- to long-chain species in a single analytical run

Acyl-CoAs play a significant role in numerous physiological and metabolic processes making it important to assess their concentration levels for evaluating metabolic health. Considering the important role of acyl-CoAs, it is crucial to develop an analytical method that can analyze these compounds. Due to the structural variations of acyl-CoAs, multiple analytical methods are often required for comprehensive analysis of these compounds, which increases complexity and the analysis time. In this study, we have developed a method using a zwitterionic HILIC column that enables the coverage of free CoA and short- to long-chain acyl-CoA species in one analytical run. Initially, we developed the method using an LC-QTOF instrument for the identification of acyl-CoA species and optimizing their chromatography. Later, a targeted HILIC-MS/MS method was created in scheduled multiple reaction monitoring mode using a QTRAP MS detector. The performance of the method was evaluated based on various parameters such as linearity, precision, recovery and matrix effect. This method was applied to identify the difference in acyl-CoA profiles in HepG2 cells cultured in different conditions. Our findings revealed an increase in levels of acetyl-CoA, medium- and long-chain acyl-CoA while a decrease in the profiles of free CoA in the starved state, indicating a clear alteration in the fatty acid oxidation process.

The BRD4-SRPK2-SRSF2 signal modulates the splicing efficiency of ACSL3 pre-mRNA and influences erastin-induced ferroptosis in osteosarcoma cells

Lipid metabolism is the key to ferroptosis susceptibility. However, little is known about the underlying mechanisms in osteosarcoma cells. Functional restriction of bromodomain-containing protein 4 (BRD4) reduced the susceptibility to erastin-induced ferroptosis of osteosarcoma cells both in vitro and in vivo. Mechanically, BRD4 controls the splicing efficiency of the RNA precursor (pre-mACSL3) of ACSL3 (ACSL3) by recruiting serinerich/threonine protein kinase 2 (SRPK2) to assemble the splicing catalytic platform. Moreover, the AMP-binding domain of ACSL3 significantly influences arachidonic acid synthesis and thus determines the susceptibility to erastin-induced ferroptosis. Overall, we found a BRD4-mediated pre-mACSL3 splicing influences erastin-induced ferroptosis by affecting arachidonic acid synthesis in osteosarcoma cells. Data in this study fills some of the gap in understanding the post-transcriptional regulatory mechanisms of ACSL3 and provides new insights into the mechanisms of lipid metabolism regulation and its effect on susceptibility to ferroptosis in osteosarcoma cells.

Targeting fatty acid uptake and metabolism in cancer cells: A promising strategy for cancer treatment

Despite scientific development, cancer is still a fatal disease. The development of cancer is thought to be significantly influenced by fatty acids. Several mechanisms that control fatty acid absorption and metabolism are reported to be altered in cancer cells to support their survival. Cancer cells can use de novo synthesis or uptake of extracellular fatty acid if one method is restricted. This factor makes it more difficult to target one pathway while failing to treat the disease properly. Side effects may also arise if several inhibitors simultaneously target many targets. If a viable inhibitor could work on several routes, the number of negative effects might be reduced. Comparative investigations against cell viability have found several potent natural and manmade substances. In this review, we discuss the complex roles that fatty acids play in the development of tumors and the progression of cancer, newly discovered and potentially effective natural and synthetic compounds that block the uptake and metabolism of fatty acids, the adverse side effects that can occur when multiple inhibitors are used to treat cancer, and emerging therapeutic approaches.

Recent developments in the analytical approaches of acyl-CoAs to assess their role in mitochondrial fatty acid oxidation disorders

Fatty acid oxidation disorders (FAOD) are inborn errors of metabolism that occur due to deficiency of specific enzyme activities and transporter proteins involved in the mitochondrial metabolism of fatty acids, causing a deficiency in ATP production. The identification of suitable biomarkers plays a crucial role in predicting the future risk of disease and monitoring responses to therapies. Acyl-CoAs are directly involved in the steps of fatty acid oxidation and are the primary biomarkers associated with FAOD. However, acyl-CoAs are not used as diagnostic biomarkers in hospitals and clinics as they are present intracellularly with low endogenous levels. Additionally, the analytical method development of acyl-CoAs is quite challenging due to diverse physicochemical properties and instability. Hence, secondary biomarkers such as acylcarnitines are used for the identification of FAOD. In this review, the focus is on the analytical techniques that have evolved over the years for the identification and quantitation of acyl-CoAs. Among these techniques, liquid chromatography-mass spectrometry clearly has an advantage in terms of sensitivity and selectivity. Stable isotope labeling by essential nutrients in cell culture (SILEC) enables the generation of labeled internal standards. Each acyl-CoA species has a distinct pattern of instability and degradation, and the use of appropriately matched internal standards can compensate for such issues. Although significant progress has been made in measuring acyl-CoAs, more efforts are needed for bringing these technical advancements to hospitals and clinics. This review also highlights the difficulties involved in the routine use of acyl-CoAs as a diagnostic biomarker and some of the measures that can be adopted by clinics and hospitals for overcoming these limitations.

Ferroptosis landscape in prostate cancer from molecular and metabolic perspective

Prostate cancer is a major disease that threatens men's health. Its rapid progression, easy metastasis, and late castration resistance have brought obstacles to treatment. It is necessary to find new effective anticancer methods. Ferroptosis is a novel iron-dependent programmed cell death that plays a role in various cancers. Understanding how ferroptosis is regulated in prostate cancer will help us to use it as a new way to kill cancer cells. In this review, we summarize the regulation and role of ferroptosis in prostate cancer and the relationship with AR from the perspective of metabolism and molecular pathways. We also discuss the feasibility of ferroptosis in prostate cancer treatment and describe current limitations and prospects, providing a reference for future research and clinical application of ferroptosis.

miR-202-5p Inhibits Lipid Metabolism and Steroidogenesis of Goose Hierarchical Granulosa Cells by Targeting ACSL3

miRNAs are critical for steroidogenesis in granulosa cells (GCs) during ovarian follicular development. We have previously shown that miR-202-5p displays a stage-dependent expression pattern in GCs from goose follicles of different sizes, suggesting that this miRNA could be involved in the regulation of the functions of goose GCs; therefore, in this study, the effects of miR-202-5p on lipid metabolism and steroidogenesis in goose hierarchical follicular GCs (hGCs), as well as its mechanisms of action, were evaluated. Oil Red O staining and analyses of intracellular cholesterol and triglyceride contents showed that the overexpression of miR-202-5p significantly inhibited lipid deposition in hGCs; additionally, miR-202-5p significantly inhibited progesterone secretion in hGCs. A bioinformatics analysis and luciferase reporter assay indicated that Acyl-CoA synthetase long-chain family member 3 (ACSL3), which activates long-chain fatty acids for the synthesis of cellular lipids, is a potential target of miR-202-5p. ACSL3 silencing inhibited lipid deposition and estrogen secretion in hGCs. These data suggest that miR-202-5p exerts inhibitory effects on lipid deposition and steroidogenesis in goose hGCs by targeting the ACSL3 gene.

Construction of a fatty acid metabolism-related gene signature for predicting prognosis and immune response in breast cancer

Background: Breast cancer has the highest incidence among malignant tumors in women, and its prevalence ranks first in global cancer morbidity. Aim: This study aimed to explore the feasibility of a prognostic model for patients with breast cancer based on the differential expression of genes related to fatty acid metabolism. Methods: The mRNA expression matrix of breast cancer and paracancer tissues was downloaded from The Cancer Genome Atlas database. The differentially expressed genes related to fatty acid metabolism were screened in R language. The TRRUST database was used to predict transcriptional regulators related to hub genes and construct an mRNA-transcription factor interaction network. A consensus clustering approach was used to identify different fatty acid regulatory patterns. In combination with patient survival data, Lasso and multivariate Cox proportional risk regression models were used to establish polygenic prognostic models based on fatty acid metabolism. The median risk score was used to categorize patients into high- and low-risk groups. Kaplan-Meier survival curves were used to analyze the survival differences between both groups. The Cox regression analysis included risk score and clinicopathological factors to determine whether risk score was an independent risk factor. Models based on genes associated with fatty acid metabolism were evaluated using receiver operating characteristic curves. A comparison was made between risk score levels and the fatty acid metabolism-associated genes in different subtypes of breast cancer. The differential gene sets of the Kyoto Encyclopedia of Genes and Genomes for screening high- and low-risk populations were compared using a gene set enrichment analysis. Furthermore, we utilized CIBERSORT to examine the abundance of immune cells in breast cancer in different clustering models. Results: High expression levels of ALDH1A1 and UBE2L6 prevented breast cancer, whereas high RDH16 expression levels increased its risk. Our comprehensive assessment of the association between prognostic risk scoring models and tumor microenvironment characteristics showed significant differences in the abundance of various immune cells between high- and low-risk breast cancer patients. Conclusions: By assessing fatty acid metabolism patterns, we gained a better understanding of the infiltration characteristics of the tumor microenvironment. Our findings are valuable for prognosis prediction and treatment of patients with breast cancer based on their clinicopathological characteristics.

ACSL3 and ACSL4, Distinct Roles in Ferroptosis and Cancers

The long-chain fatty acyl CoA synthetase (ACSLs) family of enzymes contributes significantly to lipid metabolism and produces acyl-coenzyme A by catalyzing fatty acid oxidation. The dysregulation of ACSL3 and ACSL4, which belong to the five isoforms of ACSLs, plays a key role in cancer initiation, development, metastasis, and tumor immunity and may provide several possible therapeutic strategies. Moreover, ACSL3 and ACSL4 are crucial for ferroptosis, a non-apoptotic cell death triggered by the accumulation of membrane lipid peroxides due to iron overload. Here, we present a summary of the current knowledge on ACSL3 and ACSL4 and their functions in various cancers. Research on the molecular mechanisms involved in the regulation of ferroptosis is critical to developing targeted therapies for cancer.

ACSL3 is a potential prognostic biomarker for immune infiltration in clear cell renal cell carcinoma

Objective

Long-chain acyl-coenzyme A synthases (ACSLs) catalyze the activation of fatty acid and are often dysregulated in malignancies. The purpose of this research was to figure out the ACSL3's prognostic value and mechanism in clear cell renal cell carcinoma (ccRCC).

Methods

The expression of ACSL3 in ccRCC was investigated in this work using data from the GEO, TCGA, Oncomine and HPA databases. The expression differences of ACSL3 in the cell lines were further detected by qPCR and Western blot. GEPIA, MethSurv, cBioPortal, and the TIMER were used to perform survival and correlation analysis on ACSL3. GO and KEGG analyses were carried out in R using clusterProfiler and GOplot. Protein-protein interactions (PPI) are constructed from Strings website, and the results were visualized in Cytoscape software.

Results

The expression level of ACSL3 was significantly reduced in ccRCC tissues, and its mRNA and protein expression were also significantly lower in both renal cancer cell lines. ACSL3 is significantly related to clinical stage, OS, DFS, DNA methylation, and immune-cell infiltration.

Conclusion

Our findings demonstrated that data mining was capable of eliciting information on ACSL3 levels and its role in genetic regulatory pathways in ccRCC.

Resistance to prostate cancer treatments

A review of the current treatment options for prostate cancer and the formation of resistance to these regimens has been compiled including primary, acquired, and cross-resistance. The diversification of the pathways involved and the escape routes the tumor is utilizing have been addressed. Whereas early stages of tumor can be cured, there is no treatment available after a point of no return has been reached, leaving palliative treatment as the only option. The major reasons for this outcome are the heterogeneity of tumors, both inter- and intra-individually and the nearly endless number of escape routes, which the tumor can select to overcome the effects of treatment. This means that more focus should be applied to the individualization of both diagnosis and therapy of prostate cancer. In addition to current treatment options, novel drugs and ongoing clinical trials have been addressed in this review.

Antitumor effects of pyrrole-imidazole polyamide modified with alkylating agent on prostate cancer cells

Androgens and androgen receptor (AR) have a central role in prostate cancer progression by regulating its downstream signaling. Although androgen depletion therapy (ADT) is the primary treatment for most prostate cancers, they acquires resistance to ADT and become castration resistant prostate cancers (CRPC). AR complex formation with multiple transcription factors is important for enhancer activity and transcriptional regulation, which can contribute to cancer progression and resistance to ADT. We previously demonstrated that OCT1 collaborates with AR in prostate cancer, and that a pyrrole-imidazole (PI) polyamide (PIP) targeting OCT1 inhibits cell and castration-resistant tumor growth (Obinata D et al. Oncogene 2016). PIP can bind to DNA non-covalently without a drug delivery system unlike most DNA targeted therapeutics. In the present study, we developed a PIP modified with a DNA alkylating agent, chlorambucil (ChB) (OCT1-PIP-ChB). Then its effect on the growth of prostate cancer LNCaP, 22Rv1, and PC3 cells, pancreatic cancer BxPC3 cells, and colon cancer HCT116 cells, as well as non-cancerous MCF-10A epithelial cells, were analyzed. It was shown that the IC50s of OCT1-PIP-ChB for 22Rv1 and LNCaP were markedly lower compared to other cells, including non-cancerous MCF-10A cells. Comprehensive gene expression analysis of CRPC model 22Rv1 cells treated with IC50 concentrations of OCT1-PIP-ChB revealed that the gene group involved in DNA double-strand break repair was the most enriched among gene sets repressed by OCT1-PIP-ChB treatment. Importantly, in vivo study using 22Rv1 xenografts, we showed that OCT1-PIP-ChB significantly reduced tumor growth compared to the control group without showing obvious adverse effects. Thus, the PIP combined with ChB can exert a significant inhibitory effect on prostate cancer cell proliferation and castration-resistant tumor growth, suggesting a potential role as a therapeutic agent.

Baicalin Alleviates Short-Term Lincomycin-Induced Intestinal and Liver Injury and Inflammation in Infant Mice

The adverse effects of short-term megadose of antibiotics exposure on the gastrointestinal and liver tissue reactions in young children have been reported. Antibiotic-induced intestinal and liver reactions are usually unpredictable and present a poorly understood pathogenesis. It is, therefore, necessary to develop strategies for reducing the adverse effects of antibiotics. Studies on the harm and rescue measures of antibiotics from the perspective of the gut–liver system are lacking. Here, we demonstrate that lincomycin exposure reduced body weight, disrupted the composition of gut microbiota and intestinal morphology, triggered immune-mediated injury and inflammation, caused liver dysfunction, and affected lipid metabolism. However, baicalin administration attenuated the lincomycin-induced changes. Transcriptome analysis showed that baicalin improved immunity in mice, as evidenced by the decreased levels of intestinal inflammatory cytokines and expression of genes that regulate Th1, Th2, and Th17 cell differentiation, and inhibited mucin type O-glycan biosynthesis pathways. In addition, baicalin improved liver function by upregulating the expression of genes involved in bile acid secretion and lipid degradation, and downregulating genes involved in lipid synthesis in lincomycin-treated mice. Bile acids can regulate intestinal immunity and strengthen hepatoenteric circulation. In addition, baicalin also improved anti-inflammatory bacteria abundance (Blautia and Coprobacillus) and reduced pathogenic bacteria abundance (Proteobacteria, Klebsiella, and Citrobacter) in lincomycin-treated mice. Thus, baicalin can ameliorate antibiotic-induced injury and its associated complications such as liver disease.

OCT1-target neural gene PFN2 promotes tumor growth in androgen receptor-negative prostate cancer

Androgen and androgen receptor (AR) targeted therapies are the main treatment for most prostate cancer (PC) patients. Although AR signaling inhibitors are effective, tumors can evade this treatment by transforming to an AR-negative PC via lineage plasticity. OCT1 is a transcription factor interacting with the AR to enhance signaling pathways involved in PC progression, but its role in the emergence of the AR-negative PC is unknown. We performed chromatin immunoprecipitation sequencing (ChIP-seq) in patient-derived castration-resistant AR-negative PC cells to identify genes that are regulated by OCT1. Interestingly, a group of genes associated with neural precursor cell proliferation was significantly enriched. Then, we focused on neural genes STNB1 and PFN2 as OCT1-targets among them. Immunohistochemistry revealed that both STNB1 and PFN2 are highly expressed in human AR-negative PC tissues. Knockdown of SNTB1 and PFN2 by siRNAs significantly inhibited migration of AR-negative PC cells. Notably, knockdown of PFN2 showed a marked inhibitory effect on tumor growth in vivo. Thus, we identified OCT1-target genes in AR-negative PC using a patient-derived model, clinicopathologial analysis and an animal model.

In Vitro Analysis of Deoxynivalenol Influence on Steroidogenesis in Prostate

Deoxynivalenol (DON) is a type-B trichothecene mycotoxin produced by Fusarium species, reported to be the most common mycotoxin present in food and feed products. DON is known to affect the production of testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH) in male rats, consequently affecting reproductive endpoints. Our previous study showed that DON induces oxidative stress in prostate cancer (PCa) cells, however the effect of DON on the intratumor steroidogenesis in PCa and normal prostate cells was not investigated. In this study human normal (PNT1A) and prostate cancer cell lines with different hormonal sensitivity (PC-3, DU-145, LNCaP) were exposed to DON treatment alone or in combination with dehydroepiandrosterone (DHEA) for 48 h. The results of the study demonstrated that exposure to DON alone or in combination with DHEA had a stimulatory effect on the release of estradiol and testosterone and also affected progesterone secretion. Moreover, significant changes were observed in the expression of genes related to steroidogenesis. Taken together, these results indicate that DON might affect the process of steroidogenesis in the prostate, demonstrating potential reproductive effects in humans.

ACSL family: The regulatory mechanisms and therapeutic implications in cancer

Accumulating evidence shows that deregulation of fatty acid (FA) metabolism is associated with the development of cancer. Long-chain acyl-coenzyme A synthases (ACSLs) are responsible for activating long-chain FAs and are frequently deregulated in cancers. Among the five mammalian ACSL family members, ACSL1 is involved in the TNFα-mediated pro-inflammatory phenotype and mainly facilitates cancer progression. ACSL3 is an androgen-responsive gene. High ACSL3 expression has been detected in a variety of cancers, including melanoma, triple-negative breast cancer (TNBC) and high-grade non-small cell lung carcinoma (NSCLC), and correlates with worse prognosis of patients with these diseases. ACSL4 can exert opposing roles acting as a tumor suppressor or as an oncogene depending on the specific cancer type and tissue environment. Moreover, ACSL4 behaves as a crucial regulator in ferroptosis that is defined as a cell death process caused by iron-dependent peroxidation of lipids. ACSL5 is nuclear-coded and expressed in the mitochondria and physiologically participates in the pro-apoptotic sensing of cells. ACSL5 mainly acts as a tumor suppressor in cancers. ACSL6 downregulation has been observed in many forms of cancers, except in colorectal cancer (CRC). Here, we address the differential regulatory mechanisms of the ACSL family members as well as their functions in carcinogenesis. Moreover, we enumerate the clinical therapeutic implications of ACSLs, which might serve as valuable biomarkers and therapeutic targets for precision cancer treatment.

Pieces of the Complex Puzzle of Cancer Cell Energy Metabolism: An Overview of Energy Metabolism and Alternatives for Targeted Cancer Therapy

Over the past decades, several advances in cancer cell biology have led to relevant details about a phenomenon called the 'Warburg effect'. Currently, it has been accepted that the Warburg effect is not compatible with all cancer cells, and thus the process of aerobic glycolysis is now challenged by the knowledge of a large number of cells presenting mitochondrial function. The energy metabolism of cancer cells is focused on the bioenergetic and biosynthetic pathways in order to meet the requirements of rapid proliferation. Changes in the metabolism of carbohydrates, amino acids and lipids have already been reported for cancer cells and this might play an important role in cancer progression. To the best of our knowledge, these changes are mainly attributed to genetic reprogramming which leads to the transformation of a healthy into a cancerous cell. Indeed, several enzymes that are highly relevant for cellular energy are targets of oncogenes (e.g. PI3K, HIF1, and Myc) and tumor suppressor proteins (e.g. p53). As a consequence of extensive studies on cancer cell metabolism, some new therapeutic strategies have appeared that aim to interrupt the aberrant metabolism, in addition to influencing genetic reprogramming in cancer cells. In this review, we present an overview of cancer cell metabolism (carbohydrate, amino acid, and lipid), and also describe oncogenes and tumor suppressors that directly affect the metabolism. We also discuss some of the potential therapeutic candidates which have been designed to target and disrupt the main driving forces associated with cancer cell metabolism and proliferation.

Ferroptosis-Related Gene Model to Predict Overall Survival of Ovarian Carcinoma

Background

Ovarian cancer (OC) is the eighth most common cause of cancer death and the second cause of gynecologic cancer death in women around the world. Ferroptosis, an iron-dependent regulated cell death, plays a vital role in the development of many cancers. Applying expression of ferroptosis-related gene to forecast the cancer progression is helpful for cancer treatment. However, the relationship between ferroptosis-related genes and OC patient prognosis is still vastly unknown, making it still a challenge for developing ferroptosis therapy for OC.

Methods

The Cancer Genome Atlas (TCGA) data of OC were obtained and the datasets were randomly divided into training and test datasets. A novel ferroptosis-related gene signature associated with overall survival (OS) was constructed according to the training cohort. The test dataset and ICGC dataset were used to validate this signature.

Results

We constructed a model containing nine ferroptosis-related genes, namely, LPCAT3, ACSL3, CRYAB, PTGS2, ALOX12, HSBP1, SLC1A5, SLC7A11, and ZEB1, and predicted the OS of OC in TCGA. At a suitable cutoff, patients were divided into low risk and high risk groups. The OS curves of the two groups of patients had significant differences, and the time-dependent receiver operating characteristics (ROCs) were as high as 0.664, respectively. Then, the test dataset and the ICGC dataset were used to evaluate our model, and the ROCs of test dataset were 0.667 and 0.777, respectively. In addition, functional analysis and correlation analysis showed that immune-related pathways were significantly enriched. Meanwhile, we also integrated with other clinical factors and we found the synthesized clinical factors and ferroptosis-related gene signature improved prognostic accuracy relative to the ferroptosis-related gene signature alone.

Conclusion

The ferroptosis-related gene signature could predict the OS of OC patients and improve therapeutic decision-making.

Identification of transcription factor co-regulators that drive prostate cancer progression

In prostate cancer (PCa), and many other hormone-dependent cancers, there is clear evidence for distorted transcriptional control as disease driver mechanisms. Defining which transcription factor (TF) and coregulators are altered and combine to become oncogenic drivers remains a challenge, in part because of the multitude of TFs and coregulators and the diverse genomic space on which they function. The current study was undertaken to identify which TFs and coregulators are commonly altered in PCa. We generated unique lists of TFs (n = 2662), coactivators (COA; n = 766); corepressors (COR; n = 599); mixed function coregulators (MIXED; n = 511), and to address the challenge of defining how these genes are altered we tested how expression, copy number alterations and mutation status varied across seven prostate cancer (PCa) cohorts (three of localized and four advanced disease). Testing of significant changes was undertaken by bootstrapping approaches and the most significant changes were identified. For one commonly and significantly altered gene were stably knocked-down expression and undertook cell biology experiments and RNA-Seq to identify differentially altered gene networks and their association with PCa progression risks. COAS, CORS, MIXED and TFs all displayed significant down-regulated expression (q.value < 0.1) and correlated with protein expression (r 0.4-0.55). In localized PCa, stringent expression filtering identified commonly altered TFs and coregulator genes, including well-established (e.g. ERG) and underexplored (e.g. PPARGC1A, encodes PGC1α). Reduced PPARGC1A expression significantly associated with worse disease-free survival in two cohorts of localized PCa. Stable PGC1α knockdown in LNCaP cells increased growth rates and invasiveness and RNA-Seq revealed a profound basal impact on gene expression (~ 2300 genes; FDR < 0.05, logFC > 1.5), but only modestly impacted PPARγ responses. GSEA analyses of the PGC1α transcriptome revealed that it significantly altered the AR-dependent transcriptome, and was enriched for epigenetic modifiers. PGC1α-dependent genes were overlapped with PGC1α-ChIP-Seq genes and significantly associated in TCGA with higher grade tumors and worse disease-free survival. These methods and data demonstrate an approach to identify cancer-driver coregulators in cancer, and that PGC1α expression is clinically significant yet underexplored coregulator in aggressive early stage PCa.

Metabolic enzyme ACSL3 is a prognostic biomarker and correlates with anticancer effectiveness of statins in non-small cell lung cancer

Lung cancer is one of the most common cancers, still characterized by high mortality rates. As lipid metabolism contributes to cancer metabolic reprogramming, several lipid metabolism genes are considered prognostic biomarkers of cancer. Statins are a class of lipid-lowering compounds used in treatment of cardiovascular disease that are currently studied for their antitumor effects. However, their exact mechanism of action and specific conditions in which they should be administered remains unclear. Here, we found that simvastatin treatment effectively promoted antiproliferative effects and modulated lipid metabolism-related pathways in non-small cell lung cancer (NSCLC) cells and that the antiproliferative effects of statins were potentiated by overexpression of acyl-CoA synthetase long-chain family member 3 (ACSL3). Moreover, ACSL3 overexpression was associated with worse clinical outcome in patients with high-grade NSCLC. Finally, we found that patients with high expression levels of ACSL3 displayed a clinical benefit of statins treatment. Therefore, our study highlights ACSL3 as a prognostic biomarker for NSCLC, useful to select patients who would obtain a clinical benefit from statin administration.

Long-Chain Acyl-CoA Synthetase 4-Mediated Fatty Acid Metabolism Sustains Androgen Receptor Pathway-Independent Prostate Cancer

Androgen deprivation therapy has led to elevated cases of androgen receptor (AR) pathway-independent prostate cancer with dysregulated fatty acid metabolism. However, it is unclear how prostate cancer cells sustain dysregulated fatty acid metabolism to drive AR-independent prostate cancer. Long-chain acyl-CoA synthetases (ACSL) catalyze the conversion of fatty acids into fatty acyl-CoAs that are required for fatty acid metabolism. In this study, we demonstrate that expression levels of ACSL3 and 4 were oppositely regulated by androgen-AR signaling in prostate cancer cells. AR served as a transcription suppressor to bind at the ACSL4 promoter region and inhibited its transcription. Inhibition of androgen-AR signaling significantly downregulated ACSL3 and PSA, but elevated ACSL4 levels. ACSL4 regulated a broad spectrum of fatty acyl-CoA levels, and its catalytic efficiency in fatty acyl-CoAs biosynthesis was about 1.9- to 4.3-fold higher than ACSL3. In addition, in contrast to ACSL3, ACSL4 significantly regulated global protein myristoylation or myristoylation of Src kinase in prostate cancer cells. Knockdown of ACSL4 inhibited the proliferation, migration, invasion, and xenograft growth of AR-independent prostate cancer cells. Our results suggest that the surge of ACSL4 levels by targeting AR signaling increases fatty acyl-CoAs biosynthesis and protein myristoylation, indicating the opposite, yet complementary or Yin-Yang regulation of ACSL3 and 4 levels in sustaining fatty acid metabolism when targeting androgen-AR signaling. This study reveals a mechanistic understanding of ACSL4 as a potential therapeutic target for treatment of AR-independent prostate cancer. IMPLICATIONS: AR coordinately regulates the expression of ACSL3 and ACSL4, such that AR pathway-independent prostate tumors become dependent on ACSL4-mediated fatty acid metabolism.

Recent Discoveries in the Androgen Receptor Pathway in Castration-Resistant Prostate Cancer

The androgen receptor (AR) is the main therapeutic target in advanced prostate cancer, because it regulates the growth and progression of prostate cancer cells. Patients may undergo multiple lines of AR-directed treatments, including androgen-deprivation therapy, AR signaling inhibitors (abiraterone acetate, enzalutamide, apalutamide, or darolutamide), or combinations of these therapies. Yet, tumors inevitably develop resistance to the successive lines of treatment. The diverse mechanisms of resistance include reactivation of the AR and dysregulation of AR cofactors and collaborative transcription factors (TFs). Further elucidating the nexus between the AR and collaborative TFs may reveal new strategies targeting the AR directly or indirectly, such as targeting BET proteins or OCT1. However, appropriate preclinical models will be required to test the efficacy of these approaches. Fortunately, an increasing variety of patient-derived models, such as xenografts and organoids, are being developed for discovery-based research and preclinical drug screening. Here we review the mechanisms of drug resistance in the AR signaling pathway, the intersection with collaborative TFs, and the use of patient-derived models for novel drug discovery.

Long Non-coding RNAs Involved in Metabolic Alterations in Breast and Prostate Cancers

Breast and prostate cancers are the most prevalent cancers in females and males, respectively. These cancers exhibit sex hormone dependence and thus, hormonal therapies are used to treat these cancers. However, acquired resistance to hormone therapies is a major clinical problem. In addition, certain portions of these cancers initially exhibit hormone-independence due to the absence of sex hormone receptors. Therefore, precise and profound understanding of the cancer pathophysiology is required to develop novel clinical strategies against breast and prostate cancers. Metabolic reprogramming is currently recognized as one of the hallmarks of cancer, as exemplified by the alteration of glucose metabolism, oxidative phosphorylation, and lipid metabolism. Dysregulation of metabolic enzymes and their regulators such as kinases, transcription factors, and other signaling molecules contributes to metabolic alteration in cancer. Moreover, accumulating lines of evidence reveal that long non-coding RNAs (lncRNAs) regulate cancer development and progression by modulating metabolism. Understanding the mechanism and function of lncRNAs associated with cancer-specific metabolic alteration will therefore provide new knowledge for cancer diagnosis and treatment. This review provides an overview of recent studies regarding the role of lncRNAs in metabolism in breast and prostate cancers, with a focus on both sex hormone-dependent and -independent pathways.

Expression of UDP Glucuronosyltransferases 2B15 and 2B17 is associated with methylation status in prostate cancer cells

Studies have suggested that abrogated expression of detoxification enzymes, UGT2B15 and UGT2B17, are associated with prostate tumour risk and progression. We investigated the role of EGF on the expression of these enzymes since it interacts with signalling pathways to also affect prostate tumour progression and is additionally associated with decreased DNA methylation. The expression of UGT2B15, UGT2B17, de novo methyltransferases, DNMT3A and DNMT3B was assessed in prostate cancer cells (LNCaP) treated with EGF, an EGFR inhibitor PD16893, and the methyltransferase inhibitor, 5-azacytidine, respectively. The results showed that EGF treatment decreased levels of expression of all four genes and that their expression was reversed by PD16893. Treatment with 5-azacytidine, markedly decreased expression of UGT2B15 and UGT2B17 over 85% as well as significantly decreased expression of DNMT3B, but not the expression of DNMT3A. DNMT3B siRNA treated LNCaP cells had decreased expression of UGT2B15 and UGT2B17, while DNMT3A siRNA treated cells had only moderately decreased UGT2B15 expression. Treatment with DNMT methyltransferase inhibitor, RG108, significantly decreased UGT2B17 expression. Additionally, methylation differences between prostate cancer samples and benign prostate samples from an Illumina 450K Methylation Array study were assessed. The results taken together suggest that hypomethylation of the UGT2B15 and UGT2B17 genes contributes to increased risk of prostate cancer and may provide a putative biomarker or epigenetic target for chemotherapeutics. Mechanistic studies are warranted to determine the role of the methylation marks in prostate cancer.

The Impact of Whole Genome Data on Therapeutic Decision-Making in Metastatic Prostate Cancer: A Retrospective Analysis

BACKGROUND

While critical insights have been gained from evaluating the genomic landscape of metastatic prostate cancer, utilizing this information to inform personalized treatment is in its infancy. We performed a retrospective pilot study to assess the current impact of precision medicine for locally advanced and metastatic prostate adenocarcinoma and evaluate how genomic data could be harnessed to individualize treatment.

METHODS

Deep whole genome-sequencing was performed on 16 tumour-blood pairs from 13 prostate cancer patients; whole genome optical mapping was performed in a subset of 9 patients to further identify large structural variants. Tumour samples were derived from prostate, lymph nodes, bone and brain.

RESULTS

Most samples had acquired genomic alterations in multiple therapeutically relevant pathways, including DNA damage response (11/13 cases), PI3K (7/13), MAPK (10/13) and Wnt (9/13). Five patients had somatic copy number losses in genes that may indicate sensitivity to immunotherapy (LRP1B, CDK12, MLH1) and one patient had germline and somatic BRCA2 alterations.

CONCLUSIONS

Most cases, whether primary or metastatic, harboured therapeutically relevant alterations, including those associated with PARP inhibitor sensitivity, immunotherapy sensitivity and resistance to androgen pathway targeting agents. The observed intra-patient heterogeneity and presence of genomic alterations in multiple growth pathways in individual cases suggests that a precision medicine model in prostate cancer needs to simultaneously incorporate multiple pathway-targeting agents. Our whole genome approach allowed for structural variant assessment in addition to the ability to rapidly reassess an individual's molecular landscape as knowledge of relevant biomarkers evolve. This retrospective oncological assessment highlights the genomic complexity of prostate cancer and the potential impact of assessing genomic data for an individual at any stage of the disease.

EMT Factors and Metabolic Pathways in Cancer

The epithelial-mesenchymal transition (EMT) represents a biological program during which epithelial cells lose their cell identity and acquire a mesenchymal phenotype. EMT is normally observed during organismal development, wound healing and tissue fibrosis. However, this process can be hijacked by cancer cells and is often associated with resistance to apoptosis, acquisition of tissue invasiveness, cancer stem cell characteristics, and cancer treatment resistance. It is becoming evident that EMT is a complex, multifactorial spectrum, often involving episodic, transient or partial events. Multiple factors have been causally implicated in EMT including transcription factors (e.g., SNAIL, TWIST, ZEB), epigenetic modifications, microRNAs (e.g., miR-200 family) and more recently, long non-coding RNAs. However, the relevance of metabolic pathways in EMT is only recently being recognized. Importantly, alterations in key metabolic pathways affect cancer development and progression. In this review, we report the roles of key EMT factors and describe their interactions and interconnectedness. We introduce metabolic pathways that are involved in EMT, including glycolysis, the TCA cycle, lipid and amino acid metabolism, and characterize the relationship between EMT factors and cancer metabolism. Finally, we present therapeutic opportunities involving EMT, with particular focus on cancer metabolic pathways.

The modification of ferroptosis and abnormal lipometabolism through overexpression and knockdown of potential prognostic biomarker perilipin2 in gastric carcinoma

BACKGROUND

To investigate the biological relationship, mechanism between perilipin2 and the occurrence, advancement of gastric carcinoma, and explore the mechanism of lipid metabolism disorder leading to gastric neoplasm, and propose that perilipin2 is presumably considered as a potential molecular biomarker of gastric carcinoma.

METHODS

RNA-seq was applied to analyze perilipin2 and differentially expressed genes modulated by perilipin2 in neoplastic tissues of both perilipin2 overexpression and knockdown groups in vivo. The mechanism was discovered and confirmed by Rt-qPCR, immunoblotting, immunohistochemistry, staining and microassay, respectively. Cellular function experiments were performed by flow cytometry, CCK8, clonogenic assay, etc. RESULTS: Overexpression and knockdown of perilipin2 augmented the proliferation and apoptosis of gastric carcinoma cell lines SGC7901 and MGC803, respectively. The neoplastic cells with perilipin2-overexpression obtained more conspicuously rapid growth than knockdown group in vivo, and perilipin2 affected the proliferation and apoptosis of gastric carcinoma cells by modulating the related genes:acyl-coa synthetase long-chain family member 3, arachidonate 15-lipoxygenase, microtubule associated protein 1 light chain 3 alpha, pr/set domain 11 and importin 7 that were participated in Ferroptosis pathway. Moreover, RNA-seq indicated perilipin2 was an indispensable gene and protein in the suppression of Ferroptosis caused by abnormal lipometabolism in gastric carcinoma.

CONCLUSION

Our study expounded the facilitation of perilipin2 in regulating the proliferation and apoptosis of gastric carcinoma cells by modification in Ferroptosis pathway, and we interpreted that the mechanism of gastric neoplasm caused by obesity, we also discovered that pr/set domain 11 and importin 7 are novel transcription factors relevant to gastric carcinoma. Furthermore, perilipin2 probably serves not only as a diagnostic biomarker, but also a new therapeutic target.

A Role of the Heme Degradation Pathway in Shaping Prostate Inflammatory Responses and Lipid Metabolism

The molecular mechanisms of prostate inflammation are unclear. We hypothesized that heme oxygenase 1 (HMOX1; HO-1), an enzyme responsible for degradation of heme to carbon monoxide, bilirubin, and iron, is an important regulator of inflammation and epithelial responses in the prostate. Injection of non-uropathogenic Escherichia coli (MG1655 strain) or phosphate-buffered saline into the urethra of mice led to increased numbers of CD45⁺ leukocytes and mitotic markers (phosphorylated histone H₃ and phosphorylated ERK1/2) in the prostate glands. Leukocyte infiltration was elevated in the prostates harvested from mice lacking HO-1 in myeloid compartment. Conversely, exogenous carbon monoxide (250 ppm) increased IL-1β levels and suppressed cell proliferation in the prostates. Carbon monoxide did not affect the number of infiltrating CD45⁺ cells in the prostates of E. coli- or phosphate-buffered saline-treated mice. Interestingly, immunomodulatory effects of HO-1 and/or carbon monoxide correlated with early induction of the long-chain acyl-CoA synthetase 1 (ACSL1). ACSL1 levels were elevated in response to E. coli treatment, and macrophage-expressed ACSL1 was in part required for controlling of IL-1β expression and prostate cancer cell colony growth in soft agar. These results suggest that HO-1 and/or carbon monoxide might play a distinctive role in modulating prostate inflammation, cell proliferation, and IL-1β levels in part via an ACSL1-mediated pathway.

Reprogramming of fatty acid metabolism in cancer

A common feature of cancer cells is their ability to rewire their metabolism to sustain the production of ATP and macromolecules needed for cell growth, division and survival. In particular, the importance of altered fatty acid metabolism in cancer has received renewed interest as, aside their principal role as structural components of the membrane matrix, they are important secondary messengers, and can also serve as fuel sources for energy production. In this review, we will examine the mechanisms through which cancer cells rewire their fatty acid metabolism with a focus on four main areas of research. (1) The role of de novo synthesis and exogenous uptake in the cellular pool of fatty acids. (2) The mechanisms through which molecular heterogeneity and oncogenic signal transduction pathways, such as PI3K-AKT-mTOR signalling, regulate fatty acid metabolism. (3) The role of fatty acids as essential mediators of cancer progression and metastasis, through remodelling of the tumour microenvironment. (4) Therapeutic strategies and considerations for successfully targeting fatty acid metabolism in cancer. Further research focusing on the complex interplay between oncogenic signalling and dysregulated fatty acid metabolism holds great promise to uncover novel metabolic vulnerabilities and improve the efficacy of targeted therapies.

Identification of new octamer transcription factor 1-target genes upregulated in castration-resistant prostate cancer

Octamer transcription factor 1 (OCT1) is an androgen receptor (AR)‐interacting partner and regulates the expression of target genes in prostate cancer cells. However, the function of OCT1 in castration‐resistant prostate cancer (CRPC) is not fully understood. In the present study, we used 22Rv1 cells as AR‐positive CRPC model cells to analyze the role of OCT1 in CRPC. We showed that OCT1 knockdown suppressed cell proliferation and migration of 22Rv1 cells. Using microarray analysis, we identified four AR and OCT1‐target genes, disks large‐associated protein 5 (DLGAP5), kinesin family member 15 (KIF15), non‐SMC condensin I complex subunit G (NCAPG), and NDC80 kinetochore complex component (NUF2) in 22Rv1 cells. We observed that knockdown of DLGAP5 and NUF2 suppresses growth and migration of 22Rv1 cells. Furthermore, immunohistochemical analysis showed that positive expression of DLGAP5 in prostate cancer specimens is related to poor cancer‐specific survival rates of patients. Notably, enhanced expression of DLGAP5 was observed in CRPC tissues of patients. Thus, our findings suggest that these four genes regulated by the AR/OCT1 complex could have an important role in CRPC progression.

Targeting Long Chain Acyl-CoA Synthetases for Cancer Therapy

The deregulation of cancer cell metabolic networks is now recognized as one of the hallmarks of cancer. Abnormal lipid synthesis and extracellular lipid uptake are advantageous modifications fueling the needs of uncontrolled cancer cell proliferation. Fatty acids are placed at the crossroads of anabolic and catabolic pathways, as they are implicated in the synthesis of phospholipids and triacylglycerols, or they can undergo β-oxidation. Key players to these decisions are the long-chain acyl-CoA synthetases, which are enzymes that catalyze the activation of long-chain fatty acids of 12-22 carbons. Importantly, the long-chain acyl-CoA synthetases are deregulated in many types of tumors, providing a rationale for anti-tumor therapeutic opportunities. The purpose of this review is to summarize the last up-to-date findings regarding their role in cancer, and to discuss the related emerging tumor targeting opportunities.

Long non-coding RNA FLJ22763 is involved in the progression and prognosis of gastric cancer

Long noncoding RNAs (lncRNAs) play important roles in carcinogenesis. It is necessary to uncover the detailed pattern of comprehensive lncRNA expression in the genome during the development of gastric cancer (GC). We implemented lncRNA microarray analysis in 5 paired GC tissues to detect the lncRNA expression profile. Moreover, we set out to explore the biological function, clinical application and molecular basis of the aberrant lncRNA in GC. In addition, we used the high-throughput microarray to identify the target gene of the aberrant lncRNA. We found that FLJ22763, a novel lncRNA, had significantly lower expression in GC tissues. Decreased expression of FLJ22763 was positively correlated with a lower-level histological grade and the depth of invasion. The ectopic expression of lncRNA FLJ22763 significantly suppressed the biological malignant behavior of GC cells and inhibited xenograft tumor growth (both P < 0.001). Notably, FLJ22763 displayed a considerable predictive effect in the prognosis of GC (log-rank, P = 0.003). Furthermore, we found that FLJ22763 was negatively associated with ACLY, regulating the mRNA and protein levels of ACLY. Our findings suggested that FLJ22763 may act as a suppressor gene to regulate the expression of ACLY, and its down-expression may be an independent prognostic factor in patients with GC.

Integrative Genomic Analysis of OCT1 Reveals Coordinated Regulation of Androgen Receptor in Advanced Prostate Cancer

The ligand-dependent transcription factor androgen receptor (AR) plays a critical role in prostate cancer progression. We previously reported that Octamer transcription factor 1 (OCT1), an AR collaborative factor, facilitated the AR genomic bindings to regulate diverse programs of gene expression in AR-dependent prostate cancer cells. Repression of OCT1 binding can serve as a potential treatment strategy for advanced prostate cancer. However, the precise mechanism underlying the functions of OCT1 in advanced prostate cancer, especially lethal castration-resistant prostate cancer (CRPC), is still unclear. To uncover specific OCT1 functions in disease progression, we explored global OCT1-binding regions by performing chromatin immunoprecipitation sequencing in CRPC model 22Rv1 cells. We found that the OCT1 expression level and the obtained OCT1-binding regions increased in 22Rv1 cells compared with AR-dependent prostate cancer LNCaP cells. Interestingly, microarray analysis revealed that OCT1 regulates CRPC-specific target genes in addition to representative AR-regulated genes such as ACSL3. Pathway analysis showed the importance of OCT1 in regulating cell cycle‒related genes. By performing the chromatin immunoprecipitation assay, we validated anillin actin-binding protein (ANLN), which is highly expressed in CRPC and robustly regulated with OCT1 recruitment to the intron and promoter regions in 22Rv1 cells in comparison with LNCaP cells. Furthermore, knockdown of ANLN exhibited impaired cell growth and cell cycle progression, suggesting an important function of ANLN in CRPC cells. In conclusion, these findings raise the possibility that OCT1 coordinates AR signaling in a specific manner that is dependent on disease stage and promotes progression to CRPC.

Canonical and Noncanonical Androgen Metabolism and Activity

Androgens are critical drivers of prostate cancer. In this chapter we first discuss the canonical pathways of androgen metabolism and their alterations in prostate cancer progression, including the classical, backdoor and 5α-dione pathways, the role of pre-receptor DHT metabolism, and recent findings on oncogenic splicing of steroidogenic enzymes. Next, we discuss the activity and metabolism of non-canonical 11-oxygenated androgens that can activate wild-type AR and are less susceptible to glucuronidation and inactivation than the canonical androgens, thereby serving as an under-recognized reservoir of active ligands. We then discuss an emerging literature on the potential non-canonical role of androgen metabolizing enzymes in driving prostate cancer. We conclude by discussing the potential implications of these findings for prostate cancer progression, particularly in context of new agents such as abiraterone and enzalutamide, which target the AR-axis for prostate cancer therapy, including mechanisms of response and resistance and implications of these findings for future therapy.

Fatty acid activation in carcinogenesis and cancer development: Essential roles of long-chain acyl-CoA synthetases

The significance of fatty acid metabolism in cancer initiation and development is increasingly accepted by scientists and the public due to the high prevalence of overweight and obese individuals. Fatty acids have different turnovers in the body: Either breakdown into acetyl-CoA to aid ATP generation through catabolic metabolism or incorporation into triacylglycerol and phospholipid through anabolic metabolism. However, these two distinct pathways require a common initial step known as fatty acid activation. Long-chain acyl-CoA synthetases (ACSLs), which are responsible for activation of the most abundant long-chain fatty acids, are commonly deregulated in cancer. This deregulation is also associated with poor survival in patients with cancer. Fatty acids physiologically regulate ACSL expression, but cancer cells could hijack certain involved regulatory mechanisms to deregulate ACSLs. Among the five family isoforms, ACSL1 and ACSL4 are able to promote ungoverned cell growth, facilitate tumor invasion and evade programmed cell death, while ACSL3 may have relatively complex functions in different types of cancer. Notably, ACSL4 is also essential for the induction of ferroptosis (another form of programmed cell death) by facilitating arachidonic acid oxidation, which makes the enzyme a desirable cancer target. The present review thus evaluates the functions of deregulated ACSLs in cancer, the possible molecular mechanisms involved and the chemotherapeutic potentials to target ACSLs. A better understanding of the pathological effects of ACSLs in cancer and the involved molecular mechanisms will aid in delineating the exact role of fatty acid metabolism in cancer and designing precise cancer prevention and treatment strategies.

Quantitative proteomics and systems analysis of cultured H9C2 cardiomyoblasts during differentiation over time supports a 'function follows form' model of differentiation

The rat cardiomyoblast cell line H9C2 has emerged as a valuable tool for studying cardiac development, mechanisms of disease and toxicology. We present here a rigorous proteomic analysis that monitored the changes in protein expression during differentiation of H9C2 cells into cardiomyocyte-like cells over time. Quantitative mass spectrometry followed by gene ontology (GO) enrichment analysis revealed that early changes in H9C2 differentiation are related to protein pathways of cardiac muscle morphogenesis and sphingolipid synthesis. These changes in the proteome were followed later in the differentiation time-course by alterations in the expression of proteins involved in cation transport and beta-oxidation. Studying the temporal profile of the H9C2 proteome during differentiation in further detail revealed eight clusters of co-regulated proteins that can be associated with early, late, continuous and transient up- and downregulation. Subsequent reactome pathway analysis based on these eight clusters further corroborated and detailed the results of the GO analysis. Specifically, this analysis confirmed that proteins related to pathways in muscle contraction are upregulated early and transiently, and proteins relevant to extracellular matrix organization are downregulated early. In contrast, upregulation of proteins related to cardiac metabolism occurs at later time points. Finally, independent validation of the proteomics results by immunoblotting confirmed hereto unknown regulators of cardiac structure and ionic metabolism. Our results are consistent with a 'function follows form' model of differentiation, whereby early and transient alterations of structural proteins enable subsequent changes that are relevant to the characteristic physiology of cardiomyocytes.

ACSL3 promotes intratumoral steroidogenesis in prostate cancer cells

Long‐chain acyl‐coenzyme A (CoA) synthetase 3 (ACSL3) is an androgen‐responsive gene involved in the generation of fatty acyl‐CoA esters. ACSL3 is expressed in both androgen‐sensitive and castration‐resistant prostate cancer (CRPC). However, its role in prostate cancer remains elusive. We overexpressed ACSL3 in androgen‐dependent LNCaP cells and examined the downstream effectors of ACSL3. Furthermore, we examined the role of ACSL3 in the androgen metabolism of prostate cancer. ACSL3 overexpression led to upregulation of several genes such as aldo‐keto reductase 1C3 (AKR1C3) involved in steroidogenesis, which utilizes adrenal androgen dehydroepiandrosterone sulfate (DHEAS) as substrate, and downregulated androgen‐inactivating enzyme UDP‐glucuronosyltransferase 2 (UGT2B). Exposure to DHEAS significantly increased testosterone levels and cell proliferative response in ACSL3‐overexpressing cells when compared to that in control cells. A public database showed that ACSL3 level was higher in CRPC than in hormone‐sensitive prostate cancer. CRPC cells showed an increased expression of ACSL3 and an expression pattern of AKR1C3 and UGT2B similar to ACSL3‐overexpressing cells. DHEAS stimulation significantly promoted the proliferation of CRPC cells when compared to that of LNCaP cells. These findings suggest that ACSL3 contributes to the growth of CRPC through intratumoral steroidogenesis (i.e. promoting androgen synthesis from DHEAS and preventing the catabolism of active androgens).