Cholesterol homeostasis and cancer: a new perspective on the low-density lipoprotein receptor

Cystic Fluid Total Proteins, Low-Density Lipoprotein Cholesterol, Lipid Metabolites, and Lymphocytes: Worrisome Biomarkers for Intraductal Papillary Mucinous Neoplasms

Objectives: Pancreatic cystic neoplasms (PCNs), particularly intraductal papillary mucinous neoplasms (IPMNs), present a challenge for their potential malignancy. Despite promising biomarkers like CEA, amylase, and glucose, our study investigates whether metabolic indices in blood and cystic fluids (CFs), in addition to lymphocyte subsets and hematopoietic stem/progenitor cells (HSPCs), can effectively differentiate between high- and low-risk PCNs. Materials and Methods: A total of 26 patients (11 males, mean age 69.5 ± 9 years) undergoing Endoscopic Ultrasound-guided Fine Needle Aspiration were consecutively enrolled. Analyses included blood, serum, and CF, assessing glucose, CEA, cholesterol (total, HDL, and LDL), and total proteins. Flow cytometry examined immunophenotyping in peripheral blood and cystic fluids. Mass spectrometry was used for the metabolomic analysis of CF. Sensitivity, specificity, and ROC analyses evaluated discriminatory power. Results: A total of 25 out of 26 patients had IPMN. Patients were categorized as low or high risk based on multidisciplinary evaluation of clinical, radiological, and endoscopic data. High-risk patients showed lower CF total proteins and LDL cholesterol (p = 0.005 and p = 0.031), with a marked reduction in CF lymphocytes (p = 0.005). HSCPs were absent in CF. In blood, high-risk patients showed increased non-MHC-restricted cytotoxic T cells (p = 0.019). The metabolomic analysis revealed significantly reduced middle and long-chain acyl carnitines (AcCa) and tryptophan metabolites in high-risk patients. ROC curves indicated comparable discriminant abilities for CF lymphocytes (AUC 0.868), CF total proteins (AUC 0.859), and CF LDL cholesterol (AUC 0.795). The highest performance was achieved by the AcCa 14:2 and 16:0 (AUC: 0.9221 and 0.8857, respectively). Conclusions: CF levels of glucose, CEA, LDL cholesterol, and total proteins together with lymphocyte counts are easy translational biomarkers that may support risk stratification of PCNs in IPMN patients and might be endorsed by metabolomic analysis. Further studies are required for potential clinical integration.

Acyl-CoA thioesterase 8 induces gemcitabine resistance via regulation of lipid metabolism and antiferroptotic activity in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) comprises a group of highly malignant tumors of the pancreas. Metabolic reprogramming in tumors plays a pivotal role in promoting cancer progression. However, little is known about the metabolic alterations in tumors that drive cancer drug resistance in patients with PDAC. Here, we identified acyl-CoA thioesterase 8 (ACOT8) as a key player in driving PDAC gemcitabine (GEM) resistance. The expression of ACOT8 is significantly upregulated in GEM-resistant PDAC tissues and is closely associated with poor survival in patients with PDAC. Gain- and loss-of-function studies have shown that ACOT8 drives PDAC GEM resistance both in vitro and in vivo. Mechanistically, ACOT8 regulates cellular cholesterol ester (CE) levels, decreases the levels of phosphatidylethanolamines (PEs) that bind to polyunsaturated fatty acids and promote peroxisome activation. The knockdown of ACOT8 promotes ferroptosis and increases the chemosensitivity of tumors to GEM by inducing ferroptosis-associated pathway activation in PDAC cell lines. The combination of orlistat, an ACOT8 inhibitor, and GEM significantly inhibited tumor growth in PDAC organoid and mouse models. This study reveals the biological importance of ACOT8 and provides a potential combination therapy for treating patients with advanced GEM-resistant PDAC.

Low-Density Lipoprotein (LDL) is Associated with Earlier Progression in Synchronous Metastatic Colorectal Cancer Treated without Curative Intent

BACKGROUND

Low-density lipoprotein cholesterol (LDL) is associated with the occurrence of colorectal cancer (CRC). This study aims to investigate its prognostic role and associated clinicopathological factors in the metastatic setting.

METHODS

Patients with newly diagnosed synchronous metastatic CRC were included. Patients were grouped according to the serum LDL levels at the diagnosis (≤ 130 mg/dL: Normal-LDL, > 130 mg/dL: High-LDL). LDL-associated clinicopathological factors, progression-free survival (PFS), and overall survival (OS) were assessed.

RESULTS

A total of 90 patients were included. 44.4% (n = 40) was in the normal-LDL and 56.6% (n = 50) in the high-LDL group. Colonic localization of the primary tumor was more frequent in the high-LDL group (90% vs. 67.5%, p = 0.009). The high-LDL group more frequently had local treatments [metastasectomy (26% vs. 2.5%, p = 0.002) and embolization-ablation (38% vs. 17.5%, p = 0.033)]. Despite higher curative intent with local treatments in the high-LDL group, PFS [10.03 months (95% Confidence Interval (CI):6.97-14.77) vs 9.63 mo. (95% CI: 7.93-14.00), p = 0.872] and OS [20.87 mo. (95% CI: 14.87-36.47) vs. 17.63 mo. (95% CI: 14.30-43.03), p = 0.925] did not differ from the normal-LDL. Among patients treated without any curative intent, high LDL was associated with significantly worse PFS [4.97 mo. (95% CI: 3.00-7.73) vs. 8.43 mo. (95% CI: 6.10-9.90), p = 0.048].

CONCLUSION

This study suggests that serum LDL is associated with colonic primary localization in synchronous metastatic CRC. Levels > 130 mg/dL at diagnosis may be associated with worse survival and may be further investigated as a biomarker. Larger, multicenter and prospective studies are needed.

Theoretical framework and emerging challenges of lipid metabolism in cancer

Elevated lipid metabolism is one of hallmarks of malignant tumors. Lipids not only serve as essential structural components of biological membranes but also provide energy and substrates for the proliferation of cancer cells and tumor growth. Cancer cells meet their lipid needs by coordinating the processes of lipid absorption, synthesis, transport, storage, and catabolism. As research in this area continues to deepen, numerous new discoveries have emerged, making it crucial for scientists to stay informed about the developments of cancer lipid metabolism. In this review, we first discuss relevant concepts and theories or assumptions that help us understand the lipid metabolism and -based cancer therapies. We then systematically summarize the latest advancements in lipid metabolism including new mechanisms, novel targets, and up-to-date pre-clinical and clinical investigations of anti-cancer treatment with lipid metabolism targeted drugs. Finally, we emphasize emerging research directions and therapeutic strategies, and discuss future prospective and emerging challenges. This review aims to provide the latest insights and guidance for research in the field of cancer lipid metabolism.

Novel design of fractional cholesterol dynamics and drug concentrations model with analysis on machine predictive networks

Within the intricate fabric of human physiology, cholesterol, a lipid present in cell membranes exerts a discernible effect on the concentration of the drug in human body that influence the aspects of drug pharmacokinetics. The objective of this work is to design a case study based fractional order cholesterol drug interaction model that encapsulates the nuanced dynamics inherent in the multifaceted human physiology with identification of essential variables including drug concentration Ksb and cholesterol level γ. The strength of nonlinear autoregressive with exogenous inputs (NARX) neural networks are exploited to predict the temporal dynamics that reveal the hidden intricacies and subtle patterns within the fractional model. Grünwald-Letnikov (GL) based fractional solver is used to generate the synthetic data, serving as a robust foundation for training, testing and validation of the NARX neural networks for different use cases of cholesterol drug interaction control strategies. A thorough comparative analysis based on exhaustive simulation unveiled a marginal distinction between the results obtained from NARX and the outcomes of fractal technique showing remarkably low MSE in the range of 10-12. The strength of the designed methodology is further verified by using other performance metrics such as MSE, regression index, autocorrelation and cross correlation. The integration of genetic and genomic information tailor the model to address the unique characteristics of individual patient facilitating advancement in precision medicines.

Striate palmoplantar keratoderma: a novel DSG1 mutation, combined with an LDLR mutation

BACKGROUND

Palmoplantar keratoderma (PPK) is a heterogeneous group of disorders characterized by abnormal thickening of the skin on the palms and soles. Striate palmoplantar keratoderma (SPPK) is commonly caused by heterozygous mutations in the desmoglein-1 (DSG1) gene.

OBJECTIVE

This study aimed to report a case of a 36-year-old Chinese female patient with SPPK caused by a novel DSG1 gene mutation, along with her family history, and explore its potential relationship with other genetic variants.

METHODS

Whole-exome sequencing was performed on the patient and their family members to identify the pathogenic mutation, which was validated by Sanger sequencing. Histological and electron microscopy analyses were conducted to examine the pathological characteristics of skin tissue.of skin tissue.

RESULTS

A frameshift mutation, c.1285del, in exon 10 of the DSG1 gene was identified, leading to a loss of protein function and resulting in SPPK. This mutation was also detected in two other family members with similar phenotypes. Additionally, a classical splicing variant, c.313+2dup, in the low-density lipoprotein receptor (LDLR) gene associated with hypercholesterolemia was identified in the patient; however, no direct association with SPPK was observed.

CONCLUSION

This study was the first to report a novel mutation in the DSG1 gene associated with SPPK and suggested a potential role of the LDLR gene variant in SPPK patients, providing new insights for further research into the genetic mechanisms underlying SPPK.

Dyslipidemia progression and increased lung cancer risk: a prospective cohort study

OBJECTIVES

To investigate the associations of changes in lipidemic profile with the risk of lung cancer incidence, and to elucidate how modifiable risk factors contribute to the associations.

DESIGN AND PARTICIPANTS

The prospective study enrolled a cohort of 137,075 individuals with lipidemic profiles spanning from January 1, 1996 to December 31, 2006 in the Taiwan MJ Cohort. Follow-up was extended from the second clinical visit until December 31, 2007, with an average duration of 6.3 years. Participants was divided into four groups based on alterations in their lipidemic profile within a 1-3 year interval subsequent to initial enrollment. The associations of changes in lipidemic profiles with the incidence of lung cancer were assessed with Cox proportional hazard models. Associations between modifiable risk factors and lipidemic profile changes were evaluated using multivariable logistic regression models.

RESULTS

Of 137,075 participants with lipidemic profile, progression to dyslipidemia within a 3-year period was associated with elevated risks of lung cancer incidence (hazard ratio [HR] = 1.46; 95% CI: 1.01, 2.10) in comparison to persistent normolipidemic. However, reversion to normolipidemic did not contribute to a decreased lung cancer incidence risk (HR = 1.10; 95% CI: 0.74, 1.63), in comparison to persistent dyslipidemia. Body mass index and smoking as risk factors, along with physical activity as a protective factor, were associated with changes in lipidemic profile.

CONCLUSIONS

Within this large-scale cohort, progression to dyslipidemia emerged as a risk factor for lung cancer incidence, highlighting the significance of lipid control. The modifiable risk factors associated with dyslipidemia progression encompassed body mass index, physical activity, and smoking status, suggesting potential interventions targets.

Machine Learning Analysis of RNA-Seq Data Identifies Key Gene Signatures and Pathways in Mpox Virus-Induced Gastrointestinal Complications Using Colon Organoid Models

Mpox, caused by the Mpox virus (MPXV), emerged globally in 2022 with the Clade IIb strain, presenting a critical public health challenge. While MPXV is primarily characterized by fever and rash, gastrointestinal (GI) complications, such as diarrhea and proctitis, have also been observed. This study is a reanalysis of GSE219036 without own data and focuses on the impact of MPXV infection on the colon, using human-induced pluripotent stem cell-derived colon organoids as a model. We applied a tailored statistical framework for RNA-seq data, Generalized Linear Models with Quasi-Likelihood F-tests and Relaxed Magnitude-Altitude Scoring (GLMQL-RMAS), to identify differentially expressed genes (DEGs) across MPXV clades: MPXV I (Zr-599 Congo Basin), MPXV IIa (Liberia), and MPXV IIb (2022 MPXV). Through a novel methodology called Cross-RMAS, we ranked genes by integrating statistical significance and biological relevance across all clades. Machine learning analysis using the genes identified by Cross-RMAS, demonstrated 100% accuracy in differentiating between the different MPXV strains and mock samples. Furthermore, our findings reveal that MPXV Clade I induces the most extensive alterations in gene expression, with significant upregulation of stress response genes, such as HSPA6 and FOS, and downregulation of genes involved in cytoskeletal organization and vesicular trafficking, such as PSAP and CFL1. In contrast, Clade IIb shows the least impact on gene expression. Through Gene Ontology (GO) analysis, we identified pathways involved in protein folding, immune response, and epithelial integrity that are disrupted in infected cells, suggesting mechanisms by which MPXV may contribute to GI symptoms.

Berberine alters the gut microbiota metabolism and impairs spermatogenesis

Berberine (BBR) is used to treat diarrhea clinically. However, its reproductive toxicity is unclear. This study aims to investigate the impact of BBR on the male reproductive system. Intragastric BBR administration for 14 consecutive days results in a significant decrease in the serum testosterone concentration, epididymal sperm concentration, mating rate and fecundity of male mice. Testicular treatment with testosterone propionate (TP) partially reverses the damage caused by BBR to the male reproductive system. Mechanistically, the decrease in Muribaculaceae abundance in the gut microbiota of mice is the principal cause of the BBR-induced decrease in the sperm concentration. Both fecal microbiota transplantation (FMT) and polyethylene glycol (PEG) treatment demonstrate that Muribaculaceae is necessary for spermatogenesis. The intragastric administration of Muribaculaceae intestinale to BBR-treated mice restores the sperm concentration and testosterone levels. Metabolomic analysis reveals that BBR affects arginine and proline metabolism, of which ornithine level is downregulated. Combined analysis via 16S rRNA metagenomics sequencing and metabolomics shows that Muribaculaceae regulates ornithine level. The transcriptomic results of the testes indicate that the expressions of genes related to the low-density lipoprotein receptor (LDLR)-mediated testosterone synthesis pathway decrease after BBR administration. The transcriptional activity of the Ldlr gene in TM3 cells is increased with increased ornithine supplementation in the culture media, leading to increased testosterone synthesis. Overall, this study reveals an association between a BBR-induced decrease in Muribaculaceae abundance and defective spermatogenesis, providing a prospective therapeutic approach for addressing infertility-related decreases in serum testosterone triggered by changes in the gut microbiota composition.

Lipid metabolism reprogramming in endometrial cancer: biological functions and therapeutic implications

BACKGROUND

Endometrial cancer is one of the major gynecological cancers, with increasing incidence and mortality in the past decades. Emerging preclinical and clinical data have indicated its close association with obesity and dyslipidemia. Metabolism reprogramming has been considered as the hallmark of cancer, to satisfy the extensive need of nutrients and energy for survival and growth. Particularly, lipid metabolism reprogramming has aroused the researchers' interest in the field of cancer, including tumorigenesis, invasiveness, metastasis, therapeutic resistance and immunity modulation, etc. But the roles of lipid metabolism reprogramming in endometrial cancer have not been fully understood. This review has summarized how lipid metabolism reprogramming induces oncogenesis and progression of endometrial cancer, including the biological functions of aberrant lipid metabolism pathway and altered transcription regulation of lipid metabolism pathway. Besides, we proposed novel therapeutic strategies of targeting lipid metabolism pathway and concentrated on its potential of sensitizing immunotherapy and hormonal therapy, to further optimize the existing treatment modalities of patients with advanced/metastatic endometrial cancer. Moreover, we expect that targeting lipid metabolism plus hormone therapy may block the endometrial malignant transformation and enrich the preventative approaches of endometrial cancer.

CONCLUSION

Lipid metabolism reprogramming plays an important role in tumor initiation and cancer progression of endometrial cancer. Targeting the core enzymes and transcriptional factors of lipid metabolism pathway alone or in combination with immunotherapy/hormone treatment is expected to decrease the tumor burden and provide promising treatment opportunity for patients with advanced/metastatic endometrial cancer.

AGXT2 Suppresses the Proliferation and Dissemination of Hepatocellular Carcinoma Cells by Modulating Intracellular Lipid Metabolism

Purpose

Alanine glyoxylate aminotransferase (AGXT) family members are crucial in cancer processes, but their role in hepatocellular carcinoma (HCC) metabolism is unclear. This study investigates AGXT2's function in HCC.

Patients and Methods

AGTX2 expression was studied using bioinformatics, real-time reverse transcriptase-polymerase chain reaction (RT-qPCR), Western blot, and Enzyme-linked immunosorbent assay (ELISA). A lentivirus-induced AGTX2 overexpression cell model was analyzed with RNA sequencing (RNA-seq) and liquid chromatography-mass spectrometry (LC-MS). Cholesterol levels were confirmed by Oil Red O staining. AGTX2 effects were evaluated through cell cycle analysis, wound healing, and transwell migration assays.Tumorigenic effects were observed in NOD-SCID IL2Rγnull (NTG) mice in subcutaneous experiments. Protein interaction was examined through co-immunoprecipitation methods.

Results

We observed a significant reduction in AGXT2 mRNA and protein levels in both HCC tumor tissues and serum samples from patients with liver cancer, which was associated with a worse prognosis. The activation of AGXT2 has been shown to effectively decrease cholesterol levels in liver cancer cells, serving as an antagonist in the cholesterol metabolism pathway. An increase in low density lipoprotein receptor (LDLR) mRNA was noted in cells overexpressing AGXT2, accompanied by a decrease in LDLR protein and an elevation in proprotein convertase subtilisin/kexin type 9 (PCSK9) mRNA and protein levels. Molecular docking and co-immunoprecipitation experiments further elucidated the interaction between AGXT2 and LDLR proteins. AGXT2 was observed to suppress the migratory and invasive capabilities of HCC cells, inducing cell cycle arrest in the G2/M phase. AGXT2 activation inhibited subcutaneous liver cancer tumor growth in NTG mice.

Conclusion

AGXT2 was found to lower cholesterol levels in liver cancer cells, possibly through interactions with the LDLR protein and modulation of PCSK9-mediated LDLR degradation. This mechanism may impede cholesterol transport to liver cancer cells, thereby suppressing their growth and metastasis.

Estrogen Induces LCAT to Maintain Cholesterol Homeostasis and Suppress Hepatocellular Carcinoma Development

Hepatocellular carcinoma (HCC) is an aggressive disease that occurs predominantly in men. Estrogen elicits protective effects against HCC development. Elucidation of the estrogen-regulated biological processes that suppress HCC could lead to improved prevention and treatment strategies. Here, we performed transcriptomic analyses on mouse and human liver cancer and identified lecithin cholesterol acyltransferase (LCAT) as the most highly estrogen-upregulated gene and a biomarker of favorable prognosis. LCAT upregulation inhibited HCC in vitro and in vivo and mediated estrogen-induced suppression of HCC in an ESR1-dependent manner. LCAT facilitated high-density lipoprotein cholesterol production and uptake via the LDLR and SCARB1 pathways. Consistently, high HDL-C levels corresponded to a favorable prognosis in HCC patients. The enhanced HDL-C absorption induced by LCAT impaired SREBP2 maturation, which ultimately suppressed cholesterol biosynthesis and dampened HCC cell proliferation. HDL-C alone inhibited HCC growth comparably to the cholesterol-lowering drug lovastatin, and SREBF2 overexpression abolished the inhibitory activity of LCAT. Clinical observations and cross-analyses of multiple databases confirmed the correlation of elevated LCAT and HDL-C levels to reduced cholesterol synthesis and improved HCC patient prognosis. Furthermore, LCAT deficiency mimicked whereas LCAT overexpression abrogated the tumor growth-promoting effects of ovariectomy in HCC-bearing female mice. Most importantly, HDL-C and LCAT delayed the development of subcutaneous tumors in nude mice, and HDL-C synergized with lenvatinib to eradicate orthotopic liver tumors. Collectively, this study reveals that estrogen upregulates LCAT to maintain cholesterol homeostasis and to dampen hepatocarcinogenesis. LCAT and HDL-C represent potential prognostic and therapeutic biomarkers for targeting cholesterol homeostasis as a strategy for treating HCC. Significance: Estrogen mediates the sex differences in hepatocellular carcinoma development by reducing cholesterol biosynthesis through activation of an LCAT/HDL-C axis, providing strategies for improving liver cancer prevention, prognosis, and treatment.

Dyslipidemia, lipid-lowering agents and neuroendocrine neoplasms: new horizons

PURPOSE

Neuroendocrine neoplasms (NENs) are a heterogeneous group of malignancies originating from cells with a neuroendocrine phenotype. The complex relationship between lipid metabolism and cancer is gaining interest and a potential anti-cancer effect of lipid lowering agents is being considered. This review aims to discuss the current understanding and treatment of dyslipidaemia in NENs, focusing on the role of lipid lowering agents, including new therapeutic approaches, and future perspectives as possible tool in cancer prevention and tumor-growth control.

METHODS

We performed an electronic-based search using PubMed updated until December 2023, summarizing the available evidence both in basic and clinical research about lipid lowering agents in NENs.

RESULTS

Dyslipidemia is an important aspect to be considered in NENs management, although randomized studies specifically addressing this topic are lacking, unlike other cancer types. Available data mainly regard statins, and in vitro studies have demonstrated direct antitumor effects, including antiproliferative effects in some cancers, supporting possible pleiotropic effects also in NENs, but data remain conflicting. Ezetimibe, omega 3-fatty acids, fibrates and inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9) may enhance the regulation of lipid homeostasis, as demonstrated in other cancers.

CONCLUSIONS

Targeting dyslipidemia in NENs should be part of the multidisciplinary management and an integrated approach may be the best option for both metabolic and tumor control. Whether lipid lowering agents may directly contribute to tumor control remains to be confirmed with specific studies, focusing on association with other metabolic risk, disease stage and primary site.

Adaptations of membrane trafficking in cancer and tumorigenesis

Membrane trafficking, a fundamental cellular process encompassing the transport of molecules to specific organelles, endocytosis at the plasma membrane and protein secretion, is crucial for cellular homeostasis and signalling. Cancer cells adapt membrane trafficking to enhance their survival and metabolism, and understanding these adaptations is vital for improving patient responses to therapy and identifying therapeutic targets. In this Review, we provide a concise overview of major membrane trafficking pathways and detail adaptations in these pathways, including COPII-dependent endoplasmic reticulum (ER)-to-Golgi vesicle trafficking, COPI-dependent retrograde Golgi-to-ER trafficking and endocytosis, that have been found in cancer. We explore how these adaptations confer growth advantages or resistance to cell death and conclude by discussing the potential for utilising this knowledge in developing new treatment strategies and overcoming drug resistance for cancer patients.

Focusing on the Abnormal Events of NPC1, NPC2, and NPC1L1 in Pan-Cancer and Further Constructing LUAD and KICH Prediction Models

Cancer's high incidence and death rate jeopardize human health and life, and it has become a global public health issue. Some members of NPCs have been studied in a few cancers, but comprehensive and prognostic analysis is lacking in most cancers. In this study, we used the Cancer Genome Atlas (TCGA) data genomics and transcriptome technology to examine the differential expression and prognosis of NPCs in 33 cancer samples, as well as to investigate NPCs mutations and their effect on patient prognosis and to evaluate the methylation level of NPCs in cancer. The linked mechanisms and medication resistance were subsequently investigated in order to investigate prospective tumor therapy approaches. The relationships between NPCs and immune infiltration, immune cells, immunological regulatory substances, and immune pathways were also investigated. Finally, the LUAD and KICH prognostic prediction models were built using univariate and multivariate COX regression analysis. Additionally, the mRNA and protein levels of NPCs were also identified.

PCSK9 inhibition ameliorates experimental autoimmune myocarditis by reducing Th17 cell differentiation through LDLR/STAT-3/ROR-γt pathway

Proprotein convertase subtilisin kexin type 9 (PCSK9) was characterized as a protein regulating circulating cholesterol metabolism; however, recent studies demonstrated a role for PCSK9 in inflammatory and autoimmune diseases unrelated to cholesterol alterations. The implication of PCSK9 in myocarditis is unclear and we aim at investigating the roles and mechanisms of PCSK9 in myocarditis. Male BALB/c mice received subcutaneous immunization with MyHC-α peptide on days 0 and 7 to establish the experimental autoimmune myocarditis (EAM) model. PCSK9 inhibitor, evolocumab, was administered subcutaneously once a week starting on day 0 and all mice were euthanized on day 21. Our results showed that PCSK9 inhibition ameliorated the cardiac inflammation of EAM mice. PCSK9 inhibition reduced both the levels of cardiac and peripheral blood PCSK9. We found that CD4+ T cells, CD8+ T cells, macrophages, and cardiomyocytes in the heart of EAM mice could express PCSK9. PCSK9 inhibition decreased the differentiation of cardiac Th17 cells by lowering ROR-γt levels but had no effects on Th1, Th2, and Treg cell differentiation. In vitro experiments of CD4+ T cells, we found that PCSK9 directly promoted Th17 cell differentiation through LDLR/STAT3/ROR-γt pathway. Collectively, we demonstrated that PCSK9 inhibition ameliorated the severity of EAM mice by reducing Th17 cell differentiation. PCSK9 is a promising target for treating myocarditis.

Overcoming Cancer Resistance to Platinum Drugs by Inhibiting Cholesterol Metabolism

Drug resistance is a serious challenge for platinum anticancer drugs. Platinum complexes may get over the drug resistance via a distinct mechanism of action. Cholesterol is a key factor contributing to the drug resistance. Inhibiting cellular cholesterol synthesis and uptake provides an alternative strategy for cancer treatment. Platinum(IV) complexes FP and DFP with fenofibric acid as axial ligand(s) were designed to combat the drug resistance through regulating cholesterol metabolism besides damaging DNA. In addition to producing reactive oxygen species and active platinum(II) species to damage DNA, FP and DFP inhibited cellular cholesterol accumulation, promoted cholesterol efflux, upregulated peroxisome proliferator-activated receptor alpha (PPARα), induced caspase-1 activation and gasdermin D (GSDMD) cleavage, thus leading to both apoptosis and pyroptosis in cancer cells. The reduction of cholesterol significantly relieved the drug resistance of cancer cells. The double-acting mechanism gave the complexes strong anticancer activity in vitro and in vivo, particularly against cisplatin-resistant cancer cells.

Unraveling the Anticancer Potential of Statins: Mechanisms and Clinical Significance

Statins are an essential medication class in the treatment of lipid diseases because they inhibit 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. They reduce cholesterol levels and reduce the risk of cardiovascular disease in both primary and secondary prevention. In addition to their powerful pharmacologic suppression of cholesterol production, statins appear to have pleitropic effects in a wide variety of other diseases by modulating signaling pathways. In recent years, statins have seen a large increase in interest due to their putative anticancer effects. Statins appear to cause upregulation or inhibition in key pathways involved in cancer such as inhibition of proliferation, angiogenesis, and metastasis as well as reducing cancer stemness. Further, statins have been found to induce oxidative stress, cell cycle arrest, autophagy, and apoptosis of cancer cells. Interestingly, clinical studies have shown that statin use is associated with a decreased risk of cancer formation, lower cancer grade at diagnosis, reduction in the risk of local reoccurrence, and increasing survival in patients. Therefore, our objective in the present review is to summarize the findings of the publications on the underlying mechanisms of statins' anticancer effects and their clinical implications.

Association between blood lipid levels and risk of gastric cancer: A systematic review and meta-analysis

OBJECTIVE

The association between blood lipid levels and the risk of gastric cancer (GC) is well known. Therefore, to clarify this association, all relevant prospective cohort studies were included in this meta-analysis.

METHODS

Our study was registered in PROSPERO (CRD42022354899) prior to its commencement. A systematic review and meta-analysis were conducted in accordance with the PRISMA recommendations. Chinese databases (CNKI, CBM, Wanfang, and VIP) and English databases (PubMed, Embase, Web of Science, and the Cochrane Library) were systematically searched up to October 2022. This study included all relevant cohort studies that reported hazard ratios (HRs) or relative risks (RRs) and their corresponding 95% confidence intervals (95% CIs) to examine the association between various lipid profiles (e.g., total cholesterol, triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol) and the risk of developing gastric cancer (GC). Fixed effects or random effects models were used based on the level of heterogeneity among the studies, and these models were employed to obtain pooled hazard ratios. Additionally, sensitivity analysis and publication bias analysis were conducted to ensure the robustness and reliability of the findings.

RESULTS

After conducting a systematic search, a total of 10 studies were selected out of 10,525 papers involving a total of 5,564,520 individuals. Among these individuals, there were 41,408 GC cases. The analysis revealed that the highest versus lowest serum total cholesterol (TC) concentration was associated with a pooled hazard ratio of 0.89 (95% CI = 0.87-0.92, I2 = 15%). For triglycerides (TGs), the hazard ratio was 1.00 (95% CI = 0.96-1.04, I2 = 37%), while for high-density lipoprotein cholesterol (HDL-C), the hazard ratio was 0.90 (95% CI = 0.86-0.93, I2 = 0%). The hazard ratio for low-density lipoprotein cholesterol (LDL-C) was 0.96 (95% CI = 0.91-1.00, I2 = 0%).

CONCLUSIONS

Based on the results of this meta-analysis, it was found that serum TC and HDL-C levels were inversely correlated with the risk of GC. No association was observed between serum TG levels and the risk of GC. Similarly, no association was found between serum LDL-C levels and the risk of GC.

Contribution of serum lipids and cholesterol cellular metabolism in lung cancer development and progression

Neoplasms of the lungs are the leading cause of cancer incidence and mortality worldwide. Although immunotherapy has increased the overall survival of patients with lung cancer, there is the need to improve this treatment. At this regard, blood lipid levels are thought to be linked to cancer risk and thus a preventive intervention through regulation of the nutrition of patients with lung cancer is gaining much attention. In this study, we therefore asked about the contribution of serum lipids and cholesterol cellular metabolism in lung cancer development and progression. We measured different serum lipids and analyzed cholesterol synthesis enzymes 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR) and acetyl-coenzyme A cholesterol acetyltransferase 1 (ACAT1) as well as the cholesterol cellular export protein ATP-binding cassette (ABC) A-1 mRNA by quantitative PCR (qPCR) in the control and tumoral regions of post-surgery lung tissues to analyze the accumulation of cholesterol in cancer cells in a cohort of patients with lung adenocarcinoma (LUAD). We found that triglycerides in serum directly correlated with the body mass index (BMI) in patients with LUAD. By contrast, we found that high-density lipoprotein (HDL) cholesterol inversely correlated with the BMI, C-reactive protein (CRP) and overall survival and total cholesterol inversely correlated with the tumor diameter, serum CRP and overall survival in these LUAD patients. Functionally, the role of cholesterol is indispensable for the growth and development of normal animal cells where it is tightly regulated. Excess of cellular cholesterol regulated by HMGCR is converted to cholesteryl esters by the enzyme ACAT1 and exported extracellularly by the cholesterol transporter ABCA1. Here we found HMGCR and ACAT1 upregulated and ABCA1 downregulated in the lung's tumoral region of our LUAD cohort, indicating cholesterol dysregulated cellular export in lung tumor cells.

Preoperative serum low-density lipoprotein cholesterol is an independent prognostic factor in patients with renal cell carcinoma after nephrectomy

BACKGROUND

Little is known about the association between the preoperative low-density lipoprotein cholesterol (LDL-C) level and prognosis in patients with renal cell carcinoma (RCC) after nephrectomy, and its prognostic value needs to be elucidated.

METHODS

The clinical and follow-up data of 737 RCC patients who underwent nephrectomy were retrospectively analyzed. The optimal cut-off LDL-C level was determined using X-tile, and then patients were divided into low and high LDL-C groups. The association between LDL-C levels and survival of RCC patients was assessed using the Kaplan-Meier method and Cox regression analysis.

RESULTS

The optimal cut-off LDL-C level was 1.93 mmol/L, and patients were divided into the low (≤ 1.93 mmol/L) and high LDL-C (> 1.93 mmol/L) groups. The Kaplan-Meier analysis showed that patients in the low LDL-C group had significantly shorter overall survival (OS), cancer-specific survival (CSS) and recurrence-free survival (RFS) than those in the high LDL-C group (P = 0.001, P = 0.001, and P = 0.003, respectively). The COX univariate analysis showed that the preoperative LDL-C level was closely associated with OS, CSS, and RFS in RCC patients (P = 0.002, P = 0.003, and P = 0.005, respectively). The multivariate analysis showed that the preoperative LDL-C level was an independent factor for predicting survival (OS, CSS and RFS) in RCC patients after nephrectomy. The low preoperative LDL-C levels predicted worse OS (hazard ratio [HR]: 2.337; 95% confidence interval [CI]: 1.192-4.581; P = 0.013), CSS (HR: 3.347; 95% CI: 1.515-7.392; P = 0.003), and RFS (HR: 2.207; 95% CI: 1.178-4.132; P = 0.013).

CONCLUSIONS

The preoperative LDL-C level is an independent factor for the prognosis of RCC patients after nephrectomy, and low preoperative LDL-C levels predict worse survival (OS, CSS, and RFS).

Molecular features and predictive models identify the most lethal subtype and a therapeutic target for osteosarcoma

Background

Osteosarcoma is the most common primary malignant bone tumor. The existing treatment regimens remained essentially unchanged over the past 30 years; hence the prognosis has plateaued at a poor level. Precise and personalized therapy is yet to be exploited.

Methods

One discovery cohort (n=98) and two validation cohorts (n=53 & n=48) were collected from public data sources. We performed a non-negative matrix factorization (NMF) method on the discovery cohort to stratify osteosarcoma. Survival analysis and transcriptomic profiling characterized each subtype. Then, a drug target was screened based on subtypes' features and hazard ratios. We also used specific siRNAs and added a cholesterol pathway inhibitor to osteosarcoma cell lines (U2OS and Saos-2) to verify the target. Moreover, PermFIT and ProMS, two support vector machine (SVM) tools, and the least absolute shrinkage and selection operator (LASSO) method, were employed to establish predictive models.

Results

We herein divided osteosarcoma patients into four subtypes (S-I ~ S-IV). Patients of S- I were found probable to live longer. S-II was characterized by the highest immune infiltration. Cancer cells proliferated most in S-III. Notably, S-IV held the most unfavorable outcome and active cholesterol metabolism. SQLE, a rate-limiting enzyme for cholesterol biosynthesis, was identified as a potential drug target for S-IV patients. This finding was further validated in two external independent osteosarcoma cohorts. The function of SQLE to promote proliferation and migration was confirmed by cell phenotypic assays after the specific gene knockdown or addition of terbinafine, an inhibitor of SQLE. We further employed two machine learning tools based on SVM algorithms to develop a subtype diagnostic model and used the LASSO method to establish a 4-gene model for predicting prognosis. These two models were also verified in a validation cohort.

Conclusion

The molecular classification enhanced our understanding of osteosarcoma; the novel predicting models served as robust prognostic biomarkers; the therapeutic target SQLE opened a new way for treatment. Our results served as valuable hints for future biological studies and clinical trials of osteosarcoma.