Correlation of cholesteryl ester metabolism to pathogenesis, progression and disparities in colorectal Cancer

Biomarker Profile of Colorectal Cancer: Current Findings and Future Perspective

OBJECTIVE

Breakthroughs in omics technology have led to a deeper understanding of the fundamental molecular changes that play a critical role in the development and progression of cancer. This review delves into the hidden molecular drivers of colorectal cancer (CRC), offering potential for clinical translation through novel biomarkers and personalized therapies.

METHODS

We summarizes recent studies utilizing various omics approaches, including genomics, transcriptomics, proteomics, epigenomics, metabolomics and data integration with computational algorithms, to investigate CRC.

RESULTS

Integrating multi-omics data in colorectal cancer research unlocks hidden biological insights, revealing new pathways and mechanisms. This powerful approach not only identifies potential biomarkers for personalized prognosis, diagnosis, and treatment, but also predicts patient response to specific therapies, while computational tools illuminate the landscape by deciphering complex datasets.

CONCLUSIONS

Future research should prioritize validating promising biomarkers and seamlessly translating them into clinical practice, ultimately propelling personalized CRC management to new heights.

Deficiency of neutral cholesterol ester hydrolase 1 (NCEH1) impairs endothelial function in diet-induced diabetic mice

BACKGROUND

Neutral cholesterol ester hydrolase 1 (NCEH1) plays a critical role in the regulation of cholesterol ester metabolism. Deficiency of NCHE1 accelerated atherosclerotic lesion formation in mice. Nonetheless, the role of NCEH1 in endothelial dysfunction associated with diabetes has not been explored. The present study sought to investigate whether NCEH1 improved endothelial function in diabetes, and the underlying mechanisms were explored.

METHODS

The expression and activity of NCEH1 were determined in obese mice with high-fat diet (HFD) feeding, high glucose (HG)-induced mouse aortae or primary endothelial cells (ECs). Endothelium-dependent relaxation (EDR) in aortae response to acetylcholine (Ach) was measured.

RESULTS

Results showed that the expression and activity of NCEH1 were lower in HFD-induced mouse aortae, HG-exposed mouse aortae ex vivo, and HG-incubated primary ECs. HG exposure reduced EDR in mouse aortae, which was exaggerated by endothelial-specific deficiency of NCEH1, whereas NCEH1 overexpression restored the impaired EDR. Similar results were observed in HFD mice. Mechanically, NCEH1 ameliorated the disrupted EDR by dissociating endothelial nitric oxide synthase (eNOS) from caveolin-1 (Cav-1), leading to eNOS activation and nitric oxide (NO) release. Moreover, interaction of NCEH1 with the E3 ubiquitin-protein ligase ZNRF1 led to the degradation of Cav-1 through the ubiquitination pathway. Silencing Cav-1 and upregulating ZNRF1 were sufficient to improve EDR of diabetic aortas, while overexpression of Cav-1 and downregulation of ZNRF1 abolished the effects of NCEH1 on endothelial function in diabetes. Thus, NCEH1 preserves endothelial function through increasing NO bioavailability secondary to the disruption of the Cav-1/eNOS complex in the endothelium of diabetic mice, depending on ZNRF1-induced ubiquitination of Cav-1.

CONCLUSIONS

NCEH1 may be a promising candidate for the prevention and treatment of vascular complications of diabetes.

Targeting ACAT1 in cancer: from threat to treatment

Altered cholesterol metabolism has been identified as a critical feature of cancers. Cholesterol functions as the main component of cell membrane, cholesterol and is required for sustaining membrane integrity and mediating signaling transduction for cell survival. The intracellular level of cholesterol is dynamically regulated. Excessive cholesterol could be converted to less toxic cholesteryl esters by acyl-coenzyme A:cholesterol acyltransferases (ACATs). While ACAT2 has limited value in cancers, ACAT1 has been found to be widely participated in tumor initiation and progression. Moreover, due to the important role of cholesterol metabolism in immune function, ACAT1 is also essential for regulating anti-tumor immunity. ACAT1 inhibition may be exploited as a potential strategy to enhance the anti-tumor immunity and eliminate tumors. Herein, a comprehensive understanding of the role of ACAT1 in tumor development and anti-tumor immunity may provide new insights for anti-tumor strategies.

Identification of Plasma Lipid Alterations Associated with Melanoma Metastasis

The aim of this study was to apply a state-of-the-art quantitative lipidomic profiling platform to uncover lipid alterations predictive of melanoma progression. Our study included 151 melanoma patients; of these, 83 were without metastasis and 68 with metastases. Plasma samples were analyzed using a targeted Lipidyzer™ platform, covering 13 lipid classes and over 1100 lipid species. Following quality control filters, 802 lipid species were included in the subsequent analyses. Total plasma lipid contents were significantly reduced in patients with metastasis. Specifically, levels of two out of the thirteen lipid classes (free fatty acids (FFAs) and lactosylceramides (LCERs)) were significantly decreased in patients with metastasis. Three lipids (CE(12:0), FFA(24:1), and TAG47:2-FA16:1) were identified as more effective predictors of melanoma metastasis than the well-known markers LDH and S100B. Furthermore, the predictive value substantially improved upon combining the lipid markers. We observed an increase in the cumulative levels of five lysophosphatidylcholines (LPC(16:0); LPC(18:0); LPC(18:1); LPC(18:2); LPC(20:4)), each individually associated with an elevated risk of lymph node metastasis but not cutaneous or distant metastasis. Additionally, seventeen lipid molecules were linked to patient survival, four of which (CE(12:0), CE(14:0), CE(15:0), SM(14:0)) overlapped with the lipid panel predicting metastasis. This study represents the first comprehensive investigation of the plasma lipidome of melanoma patients to date. Our findings suggest that plasma lipid profiles may serve as important biomarkers for predicting clinical outcomes of melanoma patients, including the presence of metastasis, and may also serve as indicators of patient survival.

Helicobacter cinaedi bacterium association with atherosclerosis and other diseases

Helicobacter is a genus of spiral-shaped Gram-negative enterohepatic bacteria whose members are capable of causing bacteremia in humans. One of the poorly studied members of this genus is the bacterium Helicobacter cinaedi. This microorganism was first isolated from human fecal samples in 1984. Although it was long considered to be associated with only immunocompromised patients, more evidence in recent years has implicated H. cinaedi in causing serious pathologies in immunocompetent populations. In addition, H. cinaedi is also reported to be associated with a few chronic or severe illnesses, such as atherosclerosis, which in turn can lead to the development of other cardiovascular pathologies: one of the leading causes of mortality worldwide. Helicobacter cinaedi often goes unnoticed in standard diagnostic methods due to its slow growth under microaerobic conditions. This often leads to significant underdetection and hence undermines the role of this bacterium in the pathogenesis of various diseases and the extent of its spread in humans. In this review, we have compiled information on pathologies associated with H. cinaedi, the occurrence of the bacterium in humans and animals, and the latest developments in diagnosing the bacterium and treating associated diseases.

Soat2 inhibitor avasimibe alleviates acute pancreatitis by suppressing acinar cell ferroptosis

Ferroptosis, characterized by lipid peroxidation, plays a significant role in the pathogenesis of acute pancreatitis (AP). While sterol O-acyltransferase 2 (Soat2) is known for its crucial regulatory role in cholesterol homeostasis, its involvement in the development of AP remains unreported. We conducted this study to identify the pivotal role of Soat2 in AP using transcriptomic databases. Subsequently, we confirmed its alterations through both in vitro and in vivo experimental models. Furthermore, we performed intervention with the Soat2 inhibitor avasimibe to evaluate pancreatic tissue pathology and serum enzymatic levels and observe inflammatory cell infiltration through immunohistochemistry. Additionally, changes in indicators related to ferroptosis were also observed. The results showed that in the AP mouse model, the protein and mRNA levels of Soat2 were significantly increased. Following avasimibe administration, there was a decrease in serum amylase levels, reduction in pancreatic tissue pathological damage, and attenuation of inflammatory cell infiltration. Furthermore, avasimibe administration resulted in downregulation of ferroptosis-related indicators. In conclusion, our findings suggest that the Soat2 inhibitor avasimibe protects against AP in mice through inhibition of the ferroptosis.

The Landscape of Lipid Metabolism in Lung Cancer: The Role of Structural Profiling

The aim of this study was to explore the relationship between lipids with different structural features and lung cancer (LC) risk and identify prospective biomarkers of LC. Univariate and multivariate analysis methods were used to screen for differential lipids, and two machine learning methods were used to define combined lipid biomarkers. A lipid score (LS) based on lipid biomarkers was calculated, and a mediation analysis was performed. A total of 605 lipid species spanning 20 individual lipid classes were identified in the plasma lipidome. Higher carbon atoms with dihydroceramide (DCER), phosphatidylethanolamine (PE), and phosphoinositols (PI) presented a significant negative correlation with LC. Point estimates revealed the inverse associated with LC for the n-3 PUFA score. Ten lipids were identified as markers with an area under the curve (AUC) value of 0.947 (95%, CI: 0.879-0.989). In this study, we summarized the potential relationship between lipid molecules with different structural features and LC risk, identified a panel of LC biomarkers, and demonstrated that the n-3 PUFA of the acyl chain of lipids was a protective factor for LC.

Patterns of Somatic Variants in Colorectal Adenoma and Carcinoma Tissue and Matched Plasma Samples from the Hungarian Oncogenome Program

Analysis of circulating cell-free DNA (cfDNA) of colorectal adenoma (AD) and cancer (CRC) patients provides a minimally invasive approach that is able to explore genetic alterations. It is unknown whether there are specific genetic variants that could explain the high prevalence of CRC in Hungary. Whole-exome sequencing (WES) was performed on colon tissues (27 AD, 51 CRC) and matched cfDNAs (17 AD, 33 CRC); furthermore, targeted panel sequencing was performed on a subset of cfDNA samples. The most frequently mutated genes were APC, KRAS, and FBN3 in AD, while APC, TP53, TTN, and KRAS were the most frequently mutated in CRC tissue. Variants in KRAS codons 12 (AD: 8/27, CRC: 11/51 (0.216)) and 13 (CRC: 3/51 (0.06)) were the most frequent in our sample set, with G12V (5/27) dominance in ADs and G12D (5/51 (0.098)) in CRCs. In terms of the cfDNA WES results, tumor somatic variants were found in 6/33 of CRC cases. Panel sequencing revealed somatic variants in 8 out of the 12 enrolled patients, identifying 12/20 tumor somatic variants falling on its targeted regions, while WES recovered only 20% in the respective regions in cfDNA of the same patients. In liquid biopsy analyses, WES is less efficient compared to the targeted panel sequencing with a higher coverage depth that can hold a relevant clinical potential to be applied in everyday practice in the future.

Curcumin suppresses cell proliferation and reduces cholesterol absorption in Caco-2 cells by activating the TRPA1 channel

BACKGROUND

Curcumin (Cur) is a bioactive dietary polyphenol of turmeric with various biological activities against several cancers. Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths. Intestinal cholesterol homeostasis is associated with CRC. Chemotherapy for CRC is related to varied adverse effects. Therefore, natural products with anti-cancer properties represent a potential strategy for primary prevention of CRC.

METHODS

The present study used Cur as a therapeutic approach against CRC using the Caco-2 cell line. The cells were treated with different concentrations of Cur for different duration of time and then the proliferation ability of cells was assessed using Cell Counting Kit-8 and 5-Ethynyl-2'-deoxyuridine assays. Oil red O staining and cholesterol assay kit were used to evaluate cellular lipid content and cholesterol outward transportation. Finally, the protein expressions of cholesterol transport-related protein and signal transduction molecules were assessed using Western blot assay.

RESULTS

Cur inhibited cell proliferation in Caco-2 cells in a dose- and time-dependent manner by activating the transient receptor potential cation channel subfamily A member 1 (TRPA1) channel. Activation of the TRPA1 channel led to increased intracellular calcium, peroxisome proliferator-activated receptor gamma (PPARγ) upregulation, and the subsequent downregulation of the specificity protein-1 (SP-1)/sterol regulatory element-binding protein-2 (SREBP-2)/Niemann-Pick C1-like 1 (NPC1L1) signaling pathway-related proteins, and finally reduced cholesterol absorption in Caco-2 cells.

CONCLUSIONS

Cur inhibits cell proliferation and reduces cholesterol absorption in Caco-2 cells through the Ca²⁺/PPARγ/SP-1/SREBP-2/NPC1L1 signaling by activating the TRPA1 channel, suggesting that Cur can be used as a dietary supplement for the primary prevention of CRC. In Caco-2 cells, Cur first stimulates calcium influx by activating the TRPA1 channel, further upregulates PPARγ and downregulates SP-1/SREBP-2/NPC1L1 signaling pathway, and finally inhibits the absorption of cholesterol. TRPA1, transient receptor potential cation channel subfamily A member 1; NPC1L1, Niemann-Pick C1-like 1; PPARγ, peroxisome proliferator-activated receptor gamma; SP-1, specificity protein-1; SREBP-2, sterol regulatory element-binding protein-2; Cur, curcumin.

Targeting Sterol O-Acyltransferase/Acyl-CoA:Cholesterol Acyltransferase (ACAT): A Perspective on Small-Molecule Inhibitors and Their Therapeutic Potential

Sterol O-acyltransferase (SOAT) is a membrane-bound enzyme that aids the esterification of cholesterol and fatty acids to cholesterol esters. SOAT has been studied extensively as a potential drug target, since its inhibition can serve as an alternative to statin therapy. Two SOAT isozymes that have discrete functions in the human body, namely, SOAT1 and SOAT2, have been characterized. Over three decades of research has focused on candidate SOAT1 inhibitors with unsatisfactory results in clinical trials. Recent research has focused on targeting SOAT2 selectively. In this perspective, we summarize the literature covering various SOAT inhibitory agents and discuss the design, structural requirements, and mode of action of SOAT inhibitors.

Amino acid metabolism genes associated with immunotherapy responses and clinical prognosis of colorectal cancer

Based on amino acid metabolism-related genes (AAMRGs), this study aimed at screening out key prognosis-related genes and finding the underlying correlation between the amino acid metabolism and tumor immune microenvironment of colorectal cancer. A total of 448 amino acid metabolism-related genes were obtained from MsigDB. The risk signature was built based on differential expression genes, univariate Cox, and LASSO analyses with 403 patients’ data downloaded from the TCGA database. Survival analysis and independence tests were performed to confirm the validity of the risk signature. Single-sample gene set enrichment analysis (ssGSEA), tumor mutation burden (TMB), the score of tumor immune dysfunction and exclusion (TIDE), the immunophenoscore obtained from The Cancer Immunome Atlas database, and the IC50 of drugs were used to find the relationship among the risk signature, immune status, immunotherapy response, and drug sensitivity of colorectal cancer. We identified five amino acid metabolism-related genes for the construction of the risk signature, including ENOPH1, ACAT1, ALDH4A1, FAS, and ASPG. The low-risk group was significantly associated with a better prognosis (p < 0.0001). In the entire set, the area under the curve (AUC) for 1, 3, and 5 years was 0.717, 0.734, and 0.764, respectively. We also discovered that the low-risk subgroup was related to more activity of immune cells, had higher expression of some immune checkpoints, and was more likely to benefit from immunotherapy. ssGSEA revealed that except the processes of glutamine histidine, lysine, tyrosine, and L-phenylalanine metabolism, the other amino acid metabolism pathways were more active in the samples with the low risk scores, whereas the activities of synthesis and transportation of most amino acids were similar. Hedgehog signaling, WNT/β-catenin signaling, mitotic, notch signaling, and TGF-β signaling were the top five pathways positively associated with the risk score. To sum up, AAMRGs were associated with the immune microenvironment of CRC patients and could be applied as biomarkers to predict the prognosis and immunotherapy response of patients.

KIAA1363-A Multifunctional Enzyme in Xenobiotic Detoxification and Lipid Ester Hydrolysis

KIAA1363, annotated as neutral cholesterol ester hydrolase 1 (NCEH1), is a member of the arylacetamide deacetylase (AADAC) protein family. The name-giving enzyme, AADAC, is known to hydrolyze amide and ester bonds of a number of xenobiotic substances, as well as clinical drugs and of endogenous lipid substrates such as diglycerides, respectively. Similarly, KIAA1363, annotated as the first AADAC-like protein, exhibits enzymatic activities for a diverse substrate range including the xenobiotic insecticide chlorpyrifos oxon and endogenous substrates, acetyl monoalkylglycerol ether, cholesterol ester, and retinyl ester. Two independent knockout mouse models have been generated and characterized. However, apart from reduced acetyl monoalkylglycerol ether and cholesterol ester hydrolase activity in specific tissues and cell types, no gross-phenotype has been reported. This raises the question of its physiological role and whether it functions as drug detoxifying enzyme and/or as hydrolase/lipase of endogenous substrates. This review delineates the current knowledge about the structure, function and of the physiological role of KIAA1363, as evident from the phenotypical changes inflicted by pharmacological inhibition or by silencing as well as knockout of KIAA1363 gene expression in cells, as well as mouse models, respectively.