Molecular pathways: sterols and receptor signaling in cancer

Diet predisposes to pancreatic cancer through cellular nutrient sensing pathways

Pancreatic cancer is a lethal disease with limited effective treatments. A deeper understanding of its molecular mechanisms is crucial to reduce incidence and mortality. Epidemiological evidence suggests a link between diet and disease risk, though dietary recommendations for at-risk individuals remain debated. Here, we propose that cell-intrinsic nutrient sensing pathways respond to specific diet-derived cues to facilitate oncogenic transformation of pancreatic epithelial cells. This review explores how diet influences pancreatic cancer predisposition through nutrient sensing and downstream consequences for (pre-)cancer cell biology. We also examine experimental evidence connecting specific food intake to pancreatic cancer progression, highlighting nutrient sensing as a promising target for therapeutic development to mitigate disease risk.

Prevalence and impact of metabolic associated fatty liver disease in non-metastatic breast cancer women at initial diagnosis: a cross-sectional study in China

PURPOSE

The epidemiologic data of metabolic associated fatty liver disease (MAFLD) in breast cancer (BC) patients remains limited. We aimed to investigate the prevalence and clinicopathological characteristics of hepatic steatosis (HS) and MAFLD in Chinese BC women at initial diagnosis.

METHODS

3217 non-metastatic primary BC women with MAFLD evaluation indexes at initial diagnosis and 32,170 age-matched (in a 1:10 ratio) contemporaneous health check-up women were enrolled.

RESULTS

The prevalence of HS (21.5% vs. 19.7%, p = 0.013) and MAFLD (20.8% vs. 18.6%, p = 0.002) were significantly higher in BC women than in health check-ups, respectively. Meanwhile, the prevalence of HS/MAFLD among elderly BC women (≥ 60 years) was significantly higher than the health check-ups (38.7%/37.6% vs 31.9%/30.8%), respectively. In BC women with HS/MAFLD, the prevalence of overweight/obesity was up to 85.7%/88.6%, dyslipidemia and elevated blood pressure were 63.2%/63.7% and 59.7%/61.7%, respectively. No statistical significance of the expressions of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor 2 (HER-2) and Ki67 were found between BC women with HS/MAFLD and BC women without HS/MAFLD. After adjustment, BC women with HS showed significantly higher risk of lymph node metastasis than BC women without HS. Subjects with HS/MAFLD had higher risks of overweight/obesity, dyslipidemia, elevated blood pressure, hyperuricemia, and elevated enzymes than those without HS/MAFLD.

CONCLUSIONS

Compared with health check-ups, BC patients have higher prevalence of HS/MAFLD. HS/MAFLD coexist with high prevalence of metabolic complications, and the risk of lymph node metastasis was significantly higher in BC women with HS than in BC women without HS.

Why make it if you can take it: review on extracellular cholesterol uptake and its importance in breast and ovarian cancers

Cholesterol homeostasis is essential for healthy mammalian cells and dysregulation of cholesterol metabolism contributes to the pathogenesis of various diseases including cancer. Cancer cells are dependent on cholesterol. Malignant progression is associated with high cellular demand for cholesterol, and extracellular cholesterol uptake is often elevated in cancer cell to meet its metabolic needs. Tumors take up cholesterol from the blood stream through their vasculature. Breast cancer grows in, and ovarian cancer metastasizes into fatty tissue that provides them with an additional source of cholesterol. High levels of extracellular cholesterol are beneficial for tumors whose cancer cells master the uptake of extracellular cholesterol. In this review we concentrate on cholesterol uptake mechanisms, receptor-mediated endocytosis and macropinocytosis, and how these are utilized and manipulated by cancer cells to overcome their possible intrinsic or pharmacological limitations in cholesterol synthesis. We focus especially on the involvement of lysosomes in cholesterol uptake. Identifying the vulnerabilities of cholesterol metabolism and manipulating them could provide novel efficient therapeutic strategies for treatment of cancers that manifest dependency for extracellular cholesterol.

Cholesterol Metabolism and Urinary System Tumors

Cancers of the urinary system account for 13.1% of new cancer cases and 7.9% of cancer-related deaths. Of them, renal cancer, bladder cancer, and prostate cancer are most prevalent and pose a substantial threat to human health and the quality of life. Prostate cancer is the most common malignant tumor in the male urinary system. It is the second most common type of malignant tumor in men, with lung cancer surpassing its incidence and mortality. Bladder cancer has one of the highest incidences and is sex-related, with men reporting a significantly higher incidence than women. Tumor development in the urinary system is associated with factors, such as smoking, obesity, high blood pressure, diet, occupational exposure, and genetics. The treatment strategies primarily involve surgery, radiation therapy, and chemotherapy. Cholesterol metabolism is a crucial physiological process associated with developing and progressing urinary system tumors. High cholesterol levels are closely associated with tumor occurrence, invasion, and metastasis. This warrants thoroughly investigating the role of cholesterol metabolism in urinary system tumors and identifying novel treatment methods for the prevention, early diagnosis, targeted treatment, and drug resistance of urinary system tumors.

Adherence to a Cholesterol-Lowering Diet and the Risk of Pancreatic Cancer: A Case-Control Study

BACKGROUND

Pancreatic cancer risk has been associated with increased serum cholesterol level, which is in turn partially influenced by diet. This study aimed at evaluating the association between pancreatic cancer risk and the adherence to a plant-based cholesterol-lowering diet.

METHODS

Data were derived from an Italian case-control study including 258 pancreatic cancer patients and 551 controls. The cholesterol-lowering diet score was based on seven components: high intakes of (i) non-cellulosic polysaccharides (a proxy of viscous fibers), (ii) monounsaturated fatty acids, (iii) legumes, and (iv) seeds/corn oils (a proxy of phytosterols); and low intakes of (v) saturated fatty acids, (vi) dietary cholesterol, and (vii) food with a high glycemic index. The score was calculated adding one point for each fulfilled component, thus ranging from zero (no adherence) to seven (complete adherence). The odds ratios (ORs) and 95% confidence intervals (CIs) were estimated through the logistic regression model.

RESULTS

Scores 5-7 were associated with reduced cancer risk (OR = 0.30; 95% CI: 0.18-0.52) compared to scores 0-2.

CONCLUSIONS

Adherence to a plant-based cholesterol-lowering diet was associated with a reduced risk of pancreatic cancer.

Metabolic syndrome, its components, and gastrointestinal cancer risk: a meta-analysis of 31 prospective cohorts and Mendelian randomization study

BACKGROUND AND AIM

Cohort studies have linked metabolic syndrome (MetS) to gastrointestinal (GI) cancer risk. We aimed to evaluate the associations between MetS, its components, and combinations of MetS components with eight GI cancers risk.

METHODS

We conducted a systematic search of prospective cohort studies and performed a meta-analysis. Subgroup analyses regarding diagnostic criteria, sex, cancer sites, histological subtypes, ethnic groups, and studies adjusted for alcohol consumption were carried out. Mendelian randomization (MR) was employed to evaluate the causality between 17 MetS-related traits and eight GI cancers among Europeans and Asians separately.

RESULTS

Meta-analyses of 31 prospective studies indicated that MetS was significantly associated with an increased risk of colorectal cancer (CRC) (RR [95% CI] = 1.13 [1.12-1.15]), esophageal cancer (EC) (RR [95% CI] = 1.17 [1.03-1.32]), gallbladder cancer (GBC) (RR [95% CI] = 1.37[1.10-1.71]), liver cancer (LC) (RR [95% CI] = 1.46 [1.29-1.64]), and pancreatic cancer (PaC) (RR [95% CI] = 1.25 [1.20-1.30]), but not gastric cancer (GC) (RR [95% CI] = 1.11 [0.96-1.28]). Regarding the associations between MetS components and GI cancers risk, the following associations showed statistical significance: obesity-CRC/LC/EC/, hypertriglyceridemia-LC/PaC, reduced high-density lipoprotein (HDL)-CRC/LC/GC/PaC, hyperglycemia-CRC/LC/PaC, and hypertension-CRC/LC/EC/PaC. Sex-specific associations were observed between individual MetS components on GI cancers risk. Among the top three common combinations in both sexes, obesity + HTN + hyperglycemia had the strongest association with CRC risk (RR [95% CI] = 1.54 [1.49-1.61] for males and 1.27 [1.21-1.33] for females). MR analyses revealed causality in 16 exposure-outcome pairs: waist-to-hip ratio/BMI/HbA1c-CRC; BMI/childhood obesity/waist circumference/T2DM/glucose-EC; BMI/waist circumference/cholesterol-LC; cholesterol/childhood obesity/waist circumference/HbA1c-PaC; and HbA1c-GBC. These results were robust against sensitivity analyses.

CONCLUSIONS

Since MetS is reversible, lifestyle changes or medical interventions targeting MetS patients might be potential prevention strategies for GI cancers.

Research status and hotspots on the mechanisms of liver X receptor in cancer progression: A bibliometric analysis

BACKGROUND

The mechanism of liver X receptor in cancer has been gradually revealed in recent years. This study is committed to analyzing the current research status of the mechanism of liver × receptor in cancer progression by using bibliometric methods and to explore the development trend of liver × receptor related research in the future, in order to provide some reference for further exploration in this field.

METHODS

The Web of Science core collection database was used to carry out the original data retrieval. Excel software was used for data statistics. Vosviewer and CiteSpace software were used to analyze the publication situation, cooperation network, reference co-citation, keyword and term co-occurrence, term bursts, and cluster analysis, and draw visual maps.

RESULTS

A total of 631 publications meeting the research criteria were included by December 2022, with an average of 32.5 citations per paper. The main research fields were molecular biology, oncology and cell biology, and the papers were mainly published in journals about molecular, biology and immunology. Cell is the journal with the highest citation. The United States is the most influential country, the University of California, Los Angeles is the main research institution, and Gustafsson, Jan-ake is the author with the highest output. In reference co-citation clustering, cluster#2 "cancer development" is the main cluster, and the period from 2014 to 2018 is an important stage of relevant theoretical progress. "Tumor microenvironment" with high burst and novelty became the most noteworthy term in term burst.

CONCLUSION

Using bibliometric methods to reveal the current status of LXR and cancer mechanisms, and making predictions of possible future hotspots based on the analysis of the current situation, the translation of LXR anti-cancer research to clinical applications, the impact on the tumor microenvironment as a whole and more immune pathways, and the formation of a systematic cognition of the effects of more cancer cell lines and oncogenic signaling crosstalk, which is a possible direction for future research.

Identification and validation of DHCR7 as a diagnostic biomarker involved in the proliferation and mitochondrial function of breast cancer

BACKGROUND

Energy metabolism has a complex intersection with pathogenesis and development of breast cancer (BC). This allows for the possibility of identifying energy-metabolism-related genes (EMRGs) as novel prognostic biomarkers for BC. 7-dehydrocholesterol reductase (DHCR7) is a key enzyme of cholesterol biosynthesis involved in many cancers, and in this paper, we investigate the effects of DHCR7 on the proliferation and mitochondrial function of BC.

METHODS

EMRGs were identified from the Gene Expression Omnibus (GEO) and MSigDB databases using bioinformatics methods. Key EMRGs of BC were then identified and validated by functional enrichment analysis, interaction analysis, weighted gene co-expression network analysis (WGCNA), least absolute shrinkage and selection operator (LASSO) regression, Cox analysis, and immune infiltration. Western blot, qRT-PCR, immunohistochemistry (IHC), MTT assay, colony formation assay and flow cytometry assay were then used to analyze DHCR7 expression and its biological effects on BC cells.

RESULTS

We identified 31 EMRGs in BC. These 31 EMRGs and related transcription factors (TFs), miRNAs, and drugs were enriched in glycerophospholipid metabolism, glycoprotein metabolic process, breast cancer, and cell cycle. Crucially, DHCR7 was a key EMRG in BC identified and validated by WGCNA, LASSO regression and receiver operating characteristic (ROC) curve analysis. High DHCR7 expression was significantly associated with tumor immune infiltration level, pathological M, and poor prognosis in BC. In addition, DHCR7 knockdown inhibited cell proliferation, induced apoptosis and affected mitochondrial function in BC cells.

CONCLUSIONS

DHCR7 was found to be a key EMRG up-regulated in BC cells. This study is the first to our knowledge to report that DHCR7 acts as an oncogene in BC, which might become a novel therapeutic target for BC patients.

Pilot study of treatment of patients with deep infiltrative endometriosis with methotrexate carried in lipid nanoparticles

OBJECTIVE

Previously, lipid nanoparticles (LDE) injected in women with endometriosis were shown to concentrate in the lesions. Here, the safety and feasibility of LDE carrying methotrexate (MTX) to treat deep infiltrating endometriosis was tested.

DESIGN

Prospective pilot study.

SETTING

Perola Byington Hospital Reference for Women's Health.

SUBJECTS

Eleven volunteers (aged 30-47 years, BMI 26.15 ± 6.50 kg/m2) with endometriosis with visual analog scale pelvic pain scores (VAS) > 7 and rectosigmoid lesions were enrolled in the study.

INTERVENTION

Three patients were treated with LDE-MTX at single intravenous 25 mg/m2 dose of MTX and eight patients with two 25 mg/m2 doses with 1-week interval.

MAIN OUTCOME MEASURES

Clinical complaints, blood count, and biochemistry were analyzed before treatment and on days 90, 120, and 180 after LDE-MTX administration. Endometriotic lesions were evaluated by pelvic and transvaginal ultrasound (TVUS) before treatment and on days 30 and 180 after LDE-MTX administration.

RESULTS

No clinical complaints related with LDE-MTX treatment were reported by the patients, and no hematologic, renal, or hepatic toxicities were observed in the laboratorial exams. FSH, LH, TSH, free T4, anti-Müllerian hormone, and prolactin levels were also within normal ranges during the observation period. Scores for deep dyspareunia (p < 0.001), chronic pelvic pain (p = 0.008), and dyschezia (p = 0.025) were improved over the 180-day observation period. There was a non-significant trend for reduction of VAS scores for dysmenorrhea. Bowel lesions by TVUS were unchanged. No clear differences between the two dose levels in therapeutic responses were observed.

CONCLUSION

Results support the safety and feasibility of using LDE-MTX in women with deep infiltrating endometriosis as a novel and promising therapy for the disease. More prolonged treatment schemes should be tested in future placebo-controlled studies aiming to establish the usefulness of this novel nanomedicine approach.

Targeting NPC1 in Renal Cell Carcinoma

Rapidly proliferating cancer cells have a greater requirement for cholesterol than normal cells. Tumor cells are largely dependent on exogenous lipids given that their growth requirements are not fully met by endogenous pathways. Our current study shows that ccRCC cells have redundant mechanisms of cholesterol acquisition. We demonstrate that all major lipoproteins (i.e., LDL, HDL, and VLDL) have a comparable ability to support the growth of ccRCC cells and are equally effective in counteracting the antitumor activities of TKIs. The intracellular trafficking of exogenous lipoprotein-derived cholesterol appears to be distinct from the movement of endogenously synthesized cholesterol. De novo synthetized cholesterol is transported from the endoplasmic reticulum directly to the plasma membrane and to the acyl-CoA: cholesterol acyltransferase, whereas lipoprotein-derived cholesterol is distributed through the NPC1-dependent endosomal trafficking system. Expression of NPC1 is increased in ccRCC at mRNA and protein levels, and high expression of NPC1 is associated with poor prognosis. Our current findings show that ccRCC cells are particularly sensitive to the inhibition of endolysosomal cholesterol export and underline the therapeutic potential of targeting NPC1 in ccRCC.

Trogocytosis of cancer-associated fibroblasts promotes pancreatic cancer growth and immune suppression via phospholipid scramblase anoctamin 6 (ANO6)

In pancreatic ductal adenocarcinoma (PDAC), the fibroblastic stroma constitutes most of the tumor mass and is remarkably devoid of functional blood vessels. This raises an unresolved question of how PDAC cells obtain essential metabolites and water-insoluble lipids. We have found a critical role for cancer-associated fibroblasts (CAFs) in obtaining and transferring lipids from blood-borne particles to PDAC cells via trogocytosis of CAF plasma membranes. We have also determined that CAF-expressed phospholipid scramblase anoctamin 6 (ANO6) is an essential CAF trogocytosis regulator required to promote PDAC cell survival. During trogocytosis, cancer cells and CAFs form synapse-like plasma membranes contacts that induce cytosolic calcium influx in CAFs via Orai channels. This influx activates ANO6 and results in phosphatidylserine exposure on CAF plasma membrane initiating trogocytosis and transfer of membrane lipids, including cholesterol, to PDAC cells. Importantly, ANO6-dependent trogocytosis also supports the immunosuppressive function of pancreatic CAFs towards cytotoxic T cells by promoting transfer of excessive amounts of cholesterol. Further, blockade of ANO6 antagonizes tumor growth via disruption of delivery of exogenous cholesterol to cancer cells and reverses immune suppression suggesting a potential new strategy for PDAC therapy.

GREM1 is a potential biomarker for the progression and prognosis of bladder cancer

BACKGROUND

Gremlin-1 (GREM1) is a protein closely related to tumor growth, although its function in bladder cancer (BCa) is currently unknown. Our first objective was to study the GREM1 treatment potential in BCa.

METHODS

BCa tissue samples were collected for the detection of GREM1 expression using Western blot analysis and Immunofluorescence staining. Association of GREM1 expression with clinicopathology and prognosis as detected by TCGA (The Cancer Genome Atlas) database. The functional investigation was tested by qRT-PCR, western blot analysis, CCK-8, cell apoptosis, wound healing, and transwell assays. The interaction between GREM1 and the downstream PI3K/AKT signaling pathway was assessed by Western blot analysis.

RESULTS

GREM1 exhibited high expression in BCa tissues and was linked to poor prognosis. Stable knockdown of GREM1 significantly inhibited BCa cell (T24 and 5637) proliferation, apoptosis, migratory, invasive, as well as epithelial-mesenchymal transition (EMT) abilities. GREM1 promotes the progression in BCa via PI3K/AKT signaling pathway.

CONCLUSION

Findings demonstrate that the progression-promoting effect of GREM1 in BCa, providing a novel biomarker for BCa-targeted therapy.

Exploration of the damage and mechanisms of BPS exposure on the uterus and ovary of adult female mice

Bisphenol S (BPS) has been followed with interest for its endocrine disrupting effects, but exploration on the reproductive system of adult females is lack of deep investigation. In the present study, adult female CD-1 mice were treated with BPS for 28 days at 300 μg/kg/day. After that, uteruses and ovaries were harvested for histopathological examination, RNA-seq analysis, and diseases risk prediction. Hematoxylin-eosin (H&E) staining results showed significant histological alterations in the uterus and ovary of the BPS-exposed mice. Bioinformatics analysis of the RNA-seq screened a certain number of differentially expressed genes (DEGs) in both uterus and ovary between BPS group and their corresponding vehicle control groups (Veh), respectively. Functional enrichment analysis of DEGs found that hormone metabolism and immunoinflammatory related pathways were enriched. Disease risk evaluation of the hub genes was performed and the results indicated that diseases associated with uterus and ovary were mainly related to tumors and cancers. Further pan cancer and ovarian cancer survival analysis based on human diseases database pointed out, Foxa1, Gata3, S100a8 and Shh for uterus, Itgam, Dhcr7, Fdps, Hmgcr, Hsd11b1, Hsd3b1, Ptges, F3, Fn1, Ptger4 and Srd5a1 for ovary were significant correlation with cancer. The findings suggest that BPS causes some histopathological changes, alters the expressions of hub genes, enhances uterine and ovarian tumors or even cancer risks.

Predictive value of Controlling Nutritional Status score and Prognostic Nutritional Index for systemic inflammatory response syndrome/sepsis after percutaneous nephrolithotomy

PURPOSE

Our aim was to investigate the predictive value of Controlling Nutritional Status (CONUT) score and Prognostic Nutritional Index (PNI) for systemic inflammatory response syndrome (SIRS)/sepsis after percutaneous nephrolithotomy (PNL).

METHODS

Demographic and clinical data of 422 patients who underwent PNL were evaluated. The CONUT score was calculated from lymphocyte count, serum albumin, and cholesterol, while the PNI was calculated using lymphocyte count and serum albumin. Spearman's correlation coefficient was used to evaluate the relationship between nutritional scores and systemic inflammation markers. Logistic regression analysis was performed to determine the risk factors for SIRS/sepsis development after PNL.

RESULTS

Patients with SIRS/sepsis had a significantly higher preoperative CONUT score and lower PNI compared with the SIRS/sepsis (-) group. A positive significant correlation between CONUT score and CRP (rho = 0.75), CONUT score and procalcitonin (rho = 0.36), and CONUT score and WBC (rho = 0.23) were determined. Additionally, a negative significant correlation was shown between PNI and procalcitonin (rho = - 0.30) and PNI and CRP (rho = - 0.64). The ROC curve analysis showed that the cut-off values for the CONUT score and PNI were 4 (AUC = 0.827) and 42 (AUC = 0.734), respectively. Age, stone size, history of pyelonephritis, residual stone, presence of infection stone, CONUT score ≥ 4, and PNI ≤ 42 were found to be independent predictors for postoperative SIRS/sepsis in multivariate analysis.

CONCLUSION

Our results demonstrated that preoperative CONUT score and PNI are potential predictive factors for SIRS/sepsis development after PNL. Therefore, patients with CONUT score ≥ 4 and PNI ≤ 42 are suggested to be closely monitoring due to the risk of post-PNL SIRS/sepsis.

The Sigma Enigma: A Narrative Review of Sigma Receptors

The sigma-1 and sigma-2 receptors were first discovered in the 1960s and were thought to be a form of opioid receptors initially. Over time, more was gradually learned about these receptors, which are actually protein chaperones, and many of their unique or unusual properties can contribute to a range of important new therapeutic applications. These sigma receptors translocate in the body and regulate calcium homeostasis and mitochondrial bioenergetics and they also have neuroprotective effects. The ligands to which these sigma receptors respond are several and dissimilar, including neurosteroids, neuroleptics, and cocaine. There is controversy as to their endogenous ligands. Sigma receptors are also involved in the complex processes of cholesterol homeostasis and protein folding. While previous work on this topic has been limited, research has been conducted in multiple disease states, such as addiction, aging. Alzheimer's disease, cancer, psychiatric disorders, pain and neuropathic pain, Parkinson's disease, and others. There is currently increasing interest in sigma-1 and sigma-2 receptors as they provide potential therapeutic targets for many disease indications.

Screening for Coronary Artery Disease in Cancer Survivors: JACC: CardioOncology State-of-the-Art Review

Coronary artery disease (CAD) is an important contributor to the cardiovascular burden in cancer survivors. This review identifies features that could help guide decisions about the benefit of screening to assess the risk or presence of subclinical CAD. Screening may be appropriate in selected survivors based on risk factors and inflammatory burden. In cancer survivors who have undergone genetic testing, polygenic risk scores and clonal hematopoiesis markers may become useful CAD risk prediction tools in the future. The type of cancer (especially breast, hematological, gastrointestinal, and genitourinary) and the nature of treatment (radiotherapy, platinum agents, fluorouracil, hormonal therapy, tyrosine kinase inhibitors, endothelial growth factor inhibitors, and immune checkpoint inhibitors) are also important in determining risk. Therapeutic implications of positive screening include lifestyle and atherosclerosis interventions, and in specific instances, revascularization may be indicated.

DHCR7 promotes tumorigenesis via activating PI3K/AKT/mTOR signalling pathway in bladder cancer

Bladder cancer (BCa) is a common malignancy with uncertain molecular mechanism. 7-dehydrocholesterol reductase (DHCR7), the enzyme of mammalian sterol biosynthesis, plays important roles in several types of cancers but its specific function in BCa is still unknown. The current study aimed to determine the bioinformatic characteristics and biological functions of DHCR7 in BCa. Sequencing results and clinical data from online public databases, human BCa tissues and matched noncancerous tissues, xenograft nude mice, DHCR7 deficiency and overexpression BCa cell (T24 and EJ) models were used. Several bioinformatics analyses were made, qRT-PCR, Western-blotting, flow cytometry, immunohistochemistry (IHC), MTT assay, wound healing and cell invasion assays were performed. It was found that DHCR7 was upregulated in BCa as an independent risk factor, and the expression of DHCR7 was associated with BCa grade and stage, finally resulted in poor prognosis. We further demonstrated that DHCR7 overexpression could accelerate the G0/G1 phase to accelerate the growth of tumor cells, antagonize cell apoptosis, and enhance the invasion and migration capacity, as well as EMT process via PI3K/AKT/mTOR signalling pathway, which could be completely reversed by DHCR7 knockdown. Finally, DHCR7 deficiency significantly decreased tumorigenesis in vivo. Our novel data demonstrated that DHCR7 could modulate BCa tumorigenesis in vitro and in vivo via PI3K/AKT/mTOR signalling pathway. It is suggested that DHCR7 might become a molecular target for the diagnosis and treatment of BCa.

Integrated multi-dimensional analysis highlights DHCR7 mutations involving in cholesterol biosynthesis and contributing therapy of gastric cancer

BACKGROUND

Genetic background plays an important role in the occurrence and development of gastric cancer (GC). With the application of genome-wide association study (GWAS), an increasing number of tumor susceptibility genes in gastric cancer have been discovered. While little of them can be further applicated in clinical diagnosis and treatment due to the lack of in-depth analysis.

METHODS

A GWAS of peripheral blood leukocytes from GC patients was performed to identify and obtain genetic background data. In combination with a clinical investigation, key SNP mutations and mutated genes were screened. Via in vitro and in vivo experiments, the function of the mutated gene was verified in GC. Via a combination of molecular function studies and amino acid network analysis, co-mutations were discovered and further identified as potential therapeutic targets.

RESULTS

At the genetic level, the G allele of rs104886038 in DHCR7 was a protective factor identified by the GWAS. Clinical investigation showed that patients with the rs104886038 A/G genotype, age ≥ 60, smoking ≥ 10 cigarettes/day, heavy drinking and H. pylori infection were independent risk factors for GC, with odds ratios of 12.33 (95% CI, 2.10 ~ 72.54), 20.42 (95% CI, 2.46 ~ 169.83), and 11.39 (95% CI, 1.82 ~ 71.21), respectively. Then molecular function studies indicated that DHCR7 regulated cell proliferation, migration, and invasion as well as apoptosis resistance via cellular cholesterol biosynthesis pathway. Further amino acid network analysis based on the predicted structure of DHCR7 and experimental verification indicated that rs104886035 and rs104886038 co-mutation reduced the stability of DHCR7 and induced its degradation. DHCR7 mutation suppressed the malignant behaviour of GC cells and induced apoptosis via inhibition on cell cholesterol biosynthesis.

CONCLUSION

In this work, we provided a comprehensive multi-dimensional analysis strategy which can be applied to in-depth exploration of GWAS data. DHCR7 and its mutation sites identified by this strategy are potential theratic targets of GC via inhibition of cholesterol biosynthesis.

The Role of Dietary Lipids in Cognitive Health: Implications for Neurodegenerative Disease

Neurodegenerative diseases are a group of disorders characterised by progressive loss of brain function. The most common of these is Alzheimer's disease, a form of dementia. Intake of macro- and micro-nutrients impacts brain function, including memory, learning, mood, and behaviour. Lipids, particularly phospholipids and sphingolipids, are crucial structural components of neural tissues and significantly affect cognitive function. The importance of functional foods in preventing cardiovascular disease is well-documented in the current literature. However, the significance of such foods for central nervous system health and neurodegenerative diseases is less recognized. Gut microbiome composition affects cognitive health and function, and dietary lipids are known to influence gut health. Thus, this review will discuss different sources of dietary lipids and their effect on cognitive functioning and their interaction with the gut microbiome in the context of neurodegenerative disease.

Pathogenic role of 25-hydroxycholesterol in cancer development and progression

Cholesterol is an essential lipid that serves several important functions, including maintaining the homeostasis of cells, acting as a precursor to bile acid and steroid hormones and preserving the stability of membrane lipid rafts. 25-hydroxycholesterol (25-HC) is a cholesterol derivative that may be formed from cholesterol. 25-HC is a crucial component in various biological activities, including cholesterol metabolism. In recent years, growing evidence has shown that 25-HC performs a critical function in the etiology of cancer, infectious diseases and autoimmune disorders. This review will summarize the latest findings regarding 25-HC, including its biogenesis, immunomodulatory properties and role in innate/adaptive immunity, inflammation and the development of various types of cancer.

Temporal Association of Total Serum Cholesterol and Pancreatic Cancer Incidence

Previous studies have suggested a “cholesterol-lowering effect” of preclinical pancreatic cancer, suggesting lower total cholesterol as a potential diagnostic marker. Leveraging repeated measurements of total cholesterol, this study aims to examine the temporal association of total cholesterol and pancreatic cancer incidence. We conducted a nested case-control study based on a Korean National Health Insurance Service−Health Screening Cohort, including 215 pancreatic cancer cases and 645 controls matched on age and sex. Conditional logistic regression was applied to estimate the odds ratio (OR) and 95% confidence interval (CI) for the associations of pancreatic cancer incidence with total cholesterol levels across different time windows over 11 years before pancreatic cancer diagnosis (recent, mid, distant). We found that, compared to participants with total cholesterol < 200 mg/dL in the recent 3 years prior to diagnosis, those having total cholesterol ≥ 240 mg/dL showed a significantly lower pancreatic cancer incidence (OR = 0.50 (0.27−0.93)). No significant association was found in relation to total cholesterol measured in the mid and distant past. When changes in total cholesterol over the three time periods were analyzed, compared with those with total cholesterol levels consistently below 240 mg/dL over the entire period, the OR of pancreatic cancer was 0.45 (0.20−1.03) for participants with recent-onset hypercholesterolemia, 1.89 (0.95−3.75) for recent-resolved hypercholesterolemia, and 0.71 (0.30−1.66) for consistent hypercholesterolemia. In conclusion, while high total cholesterol in the recent past may indicate a lower pancreatic cancer incidence, a recent decrease in total cholesterol may suggest an elevated incidence of pancreatic cancer.

Prospects for the use of statins in the treatment of neurofibromatosis type 1

Neurofibromatosis type 1 is caused by a germline mutation in the NF1 gene encoding the tumor suppressor neurofibromin. Deficiency of this protein causes hyperactivation of Ras proto-oncogenes. This leads to the development of tumors. Ras proteins undergo prenylation, which is inhibited by inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme-A reductase. Therefore, statins can be proposed as anticancer drugs in the complex treatment of neurofibromatosis type 1. Clinical studies have proven the effectiveness of statins in the treatment of sporadic malignant neoplasms, in the pathogenesis of which mutations in the NF1 gene play an important role. Various pathways of the influence of these drugs on the development of tumors are described, including the activation of autophagy, ferroptosis, suppression of proliferation, stimulation of antitumor immunity, and effects on the microenvironment of neoplasms. Data on the effect of statins on the development and progression of neurofibromas in patients with neurofibromatosis type 1 are not presented in the scientific literature. However, it was found that statins enhance the effect of anticancer drugs, the use of which in monotherapy against malignant neoplasms associated with neurofibromatosis is ineffective. In this regard, despite the inefficiency of statins in cognitive disorders in patients with neurofibromatosis type 1, the introduction of these drugs into clinical practice in combination with other drugs could provide a pleiotropic effect, affect various links in the pathogenesis of the disease. 

High-affinity SOAT1 ligands remodeled cholesterol metabolism program to inhibit tumor growth

BACKGROUND

Although cholesterol metabolism is a common pathway for the development of antitumor drugs, there are no specific targets and drugs for clinical use. Here, based on our previous study of sterol O-acyltransferase 1 (SOAT1) in hepatocelluar carcinoma, we sought to screen an effective targeted drug for precise treatment of hepatocelluar carcinoma and, from the perspective of cholesterol metabolism, clarify the relationship between cholesterol regulation and tumorigenesis and development.

METHODS

In this study, we developed a virtual screening integrated affinity screening technology for target protein drug screening. A series of in vitro and in vivo experiments were used for drug activity verification. Multi-omics analysis and flow cytometry analysis were used to explore antitumor mechanisms. Comparative analysis of proteome and transcriptome combined with survival follow-up information of patients reveals the clinical therapeutic potential of screened drugs.

RESULTS

We screened three compounds, nilotinib, ABT-737, and evacetrapib, that exhibited optimal binding with SOAT1. In particular, nilotinib displayed a high affinity for SOAT1 protein and significantly inhibited tumor activity both in vitro and in vivo. Multi-omics analysis and flow cytometry analysis indicated that SOAT1-targeting compounds reprogrammed the cholesterol metabolism in tumors and enhanced CD8⁺ T cells and neutrophils to suppress tumor growth.

CONCLUSIONS

Taken together, we reported several high-affinity SOAT1 ligands and demonstrated their clinical potential in the precision therapy of liver cancer, and also reveal the potential antitumor mechanism of SOAT1-targeting compounds.

Linking Late Endosomal Cholesterol with Cancer Progression and Anticancer Drug Resistance

Cancer cells undergo drastic metabolic adaptions to cover increased bioenergetic needs, contributing to resistance to therapies. This includes a higher demand for cholesterol, which often coincides with elevated cholesterol uptake from low-density lipoproteins (LDL) and overexpression of the LDL receptor in many cancers. This implies the need for cancer cells to accommodate an increased delivery of LDL along the endocytic pathway to late endosomes/lysosomes (LE/Lys), providing a rapid and effective distribution of LDL-derived cholesterol from LE/Lys to other organelles for cholesterol to foster cancer growth and spread. LDL-cholesterol exported from LE/Lys is facilitated by Niemann–Pick Type C1/2 (NPC1/2) proteins, members of the steroidogenic acute regulatory-related lipid transfer domain (StARD) and oxysterol-binding protein (OSBP) families. In addition, lysosomal membrane proteins, small Rab GTPases as well as scaffolding proteins, including annexin A6 (AnxA6), contribute to regulating cholesterol egress from LE/Lys. Here, we summarize current knowledge that links upregulated activity and expression of cholesterol transporters and related proteins in LE/Lys with cancer growth, progression and treatment outcomes. Several mechanisms on how cellular distribution of LDL-derived cholesterol from LE/Lys influences cancer cell behavior are reviewed, some of those providing opportunities for treatment strategies to reduce cancer progression and anticancer drug resistance.

Lipid Metabolism Regulation Based on Nanotechnology for Enhancement of Tumor Immunity

The hallmarks of cancer include dysregulated metabolism and immune evasion. As a basic way of metabolism, lipid metabolism is reprogrammed for the rapid energy and nutrient supply in the occurrence and development of tumors. Lipid metabolism alterations that occur in the tumor microenvironment (TME) affect the antitumor responses of immune cells and cause immune evasion. Therefore, targeting lipid metabolism in the TME for enhancing the antitumor effect of immune cells is a promising direction for cancer treatment. Cancer nanomedicine has great potential in regulating tumor metabolism and tumor immunity. This review summarizes the nanotechnology-based strategies for lipid metabolism regulation in the TME for enhanced anticancer immune responses.

Discovery and development of brain-penetrant 18F-labeled radioligands for neuroimaging of the sigma-2 receptors

We have discovered and synthesized a series of indole-based derivatives as novel sigma-2 (σ ₂) receptor ligands. Two ligands with high σ ₂ receptor affinity and subtype selectivity were then radiolabeled with F-18 in good radiochemical yields and purities, and evaluated in rodents. In biodistribution studies in male ICR mice, radioligand [¹⁸F]9, or 1-(4-(5,6-dimethoxyisoindolin-2-yl)butyl)-4-(2-[¹⁸F]fluoroethoxy)-1H-indole, was found to display high brain uptake and high brain-to-blood ratio. Pretreatment of animals with the selective σ ₂ receptor ligand CM398 led to significant reductions in both brain uptake (29%-54%) and brain-to-blood ratio (60%-88%) of the radioligand in a dose-dependent manner, indicating high and saturable specific binding of [¹⁸F]9 to σ ₂ receptors in the brain. Further, ex vivo autoradiography in male ICR mice demonstrated regionally heterogeneous specific binding of [¹⁸F]9 in the brain that is consistent with the distribution pattern of σ ₂ receptors. Dynamic positron emission tomography imaging confirmed regionally distinct distribution and high levels of specific binding for [¹⁸F]9 in the rat brain, along with appropriate tissue kinetics. Taken together, results from our current study indicated the novel radioligand [¹⁸F]9 as the first highly specific and promising imaging agent for σ ₂ receptors in the brain.

Close interactions between lncRNAs, lipid metabolism and ferroptosis in cancer

Abnormal lipid metabolism including synthesis, uptake, modification, degradation and transport has been considered a hallmark of malignant tumors and contributes to the supply of substances and energy for rapid cell growth. Meanwhile, abnormal lipid metabolism is also associated with lipid peroxidation, which plays an important role in a newly discovered type of regulated cell death termed ferroptosis. Long noncoding RNAs (lncRNAs) have been proven to be associated with the occurrence and progression of cancer. Growing evidence indicates that lncRNAs are key regulators of abnormal lipid metabolism and ferroptosis in cancer. In this review, we mainly summarized the mechanism by which lncRNAs regulate aberrant lipid metabolism in cancer, illustrated that lipid metabolism can also influence the expression of lncRNAs, and discussed the mechanism by which lncRNAs affect ferroptosis. A comprehensive understanding of the interactions between lncRNAs, lipid metabolism and ferroptosis could help us to develop novel strategies for precise cancer treatment in the future.

Surface modification with cholesteryl acetyl carnitine, a novel cationic agent, elevates cancer cell uptake of the PEGylated liposomes

The present study aimed to synthesize cholesteryl acetyl carnitine (CAC), and surface modify the PEGylated liposomes with the intention of enhanced cancer cell uptake. For this, CAC synthesis was performed in amine-free esterification conditions and then four liposomal formulations of unmodified, CAC/PEG, and CAC + PEG-modified were prepared by ethanol injection method. Cytotoxicity of the liposomes was investigated in A549 cells, followed by cellular uptake assessments of coumarin 6 (C6)-loaded liposomes. The results of ATR-FTIR, ¹HNMR, and ¹³CNMR demonstrated successful formation of CAC. A molecular docking study showed efficient binding affinities rather than carnitine to the active site of four carnitine transporters. Liposomal formulations possessed spherical morphology with a mean particle size range of 112-138 nm, narrow size distribution, and negative surface charge. All formulations had low cytotoxicity at 0.5 mg/ml, but high cytotoxicity at around 2.5 mg/ml. The lowest IC50 was obtained for CAC modified liposomes. CAC + PEG-modified liposomes had the highest cellular uptake. In conclusion, CAC + PEG modification of liposomes is an effective approach for increasing A549 cellular uptake, with low cytotoxicity at commonly applied liposome concentrations. The elevated uptake may be due to the involvement of the organic cation transporter, cationic structure, and the metabolic preference of CAC in cancer cells.

Lipid metabolism in cancer progression and therapeutic strategies

Dysregulated lipid metabolism represents an important metabolic alteration in cancer. Fatty acids, cholesterol, and phospholipid are the three most prevalent lipids that act as energy producers, signaling molecules, and source material for the biogenesis of cell membranes. The enhanced synthesis, storage, and uptake of lipids contribute to cancer progression. The rewiring of lipid metabolism in cancer has been linked to the activation of oncogenic signaling pathways and cross talk with the tumor microenvironment. The resulting activity favors the survival and proliferation of tumor cells in the harsh conditions within the tumor. Lipid metabolism also plays a vital role in tumor immunogenicity via effects on the function of the noncancer cells within the tumor microenvironment, especially immune‐associated cells. Targeting altered lipid metabolism pathways has shown potential as a promising anticancer therapy. Here, we review recent evidence implicating the contribution of lipid metabolic reprogramming in cancer to cancer progression, and discuss the molecular mechanisms underlying lipid metabolism rewiring in cancer, and potential therapeutic strategies directed toward lipid metabolism in cancer. This review sheds new light to fully understanding of the role of lipid metabolic reprogramming in the context of cancer and provides valuable clues on therapeutic strategies targeting lipid metabolism in cancer.

Targeting the Tumor Microenvironment: A Literature Review of the Novel Anti-Tumor Mechanism of Statins

Statins is widely used in clinical practice as lipid-lowering drugs and has been proven to be effective in the treatment of cardiovascular, endocrine, metabolic syndrome and other diseases. The latest preclinical evidence shows that statins have anti-proliferation, pro-apoptotic, anti-invasion and radiotherapy sensitization effects on tumor cells, suggesting that statins may become a new type of anti-tumor drugs. For a long time, mevalonate pathway has been proved to play a supporting role in the development of tumor cells. As an effective inhibitor of mevalonate pathway, statins have been proved to have a direct auxiliary anti-tumor effect in a large number of studies. In addition, anti-tumor effects of statins through ferroptosis, pyroptosis, autophagy and tumor microenvironment (TME) have also been gradually discovered. However, the specific mechanism of the antitumor effect of statins in the tumor microenvironment has not been clearly elucidated. Herein, we reviewed the antitumor effects of statins in tumor microenvironment, focusing on hypoxia microenvironment, immune microenvironment, metabolic microenvironment, acid microenvironment and mechanical microenvironment.

Autophagy is induced and modulated by cholesterol depletion through transcription of autophagy-related genes and attenuation of flux

Perturbations to cellular homeostasis, including reduction of the cholesterol level, induce autophagy, a self-digestion process of cellular constituents through an autophagosomal-lysosomal pathway. In accord with its function as a membrane organizer and metabolic sentinel, the cellular response to cholesterol depletion comprises multiple phenomena, including the activation of transcriptional responses, accumulation of reactive oxygen species (ROS), and activation of stress-related signaling pathways. However, the molecular mechanisms by which cholesterol depletion regulates autophagy and the putative involvement of transcriptional responses, ROS and/or stress-related signaling in autophagy regulation in this biological context are not fully understood. Here, we find that cholesterol depletion regulates autophagy at three different levels. First, employing RNA-seq, we show that cholesterol depletion increases the expression of autophagy-related genes independent of ROS or JNK activity. Second, analysis of LC3 lipidation and intracellular localization, and of p62 levels and degradation kinetics, reveals that cholesterol depletion mediates autophagy induction while interfering with autophagic flux. Of note, only the latter depends on ROS accumulation and JNK activity. In view of the common use of cholesterol-reducing drugs as therapeutic agents, our findings have important implications for multiple cellular settings in which autophagy plays a prominent role.

Untargeted Lipidomics of Non-Small Cell Lung Carcinoma Demonstrates Differentially Abundant Lipid Classes in Cancer vs. Non-Cancer Tissue

Lung cancer remains the leading cause of cancer death worldwide and non-small cell lung carcinoma (NSCLC) represents 85% of newly diagnosed lung cancers. In this study, we utilized our untargeted assignment tool Small Molecule Isotope Resolved Formula Enumerator (SMIRFE) and ultra-high-resolution Fourier transform mass spectrometry to examine lipid profile differences between paired cancerous and non-cancerous lung tissue samples from 86 patients with suspected stage I or IIA primary NSCLC. Correlation and co-occurrence analysis revealed significant lipid profile differences between cancer and non-cancer samples. Further analysis of machine-learned lipid categories for the differentially abundant molecular formulas identified a high abundance sterol, high abundance and high m/z sphingolipid, and low abundance glycerophospholipid metabolic phenotype across the NSCLC samples. At the class level, higher abundances of sterol esters and lower abundances of cardiolipins were observed suggesting altered stearoyl-CoA desaturase 1 (SCD1) or acetyl-CoA acetyltransferase (ACAT1) activity and altered human cardiolipin synthase 1 or lysocardiolipin acyltransferase activity respectively, the latter of which is known to confer apoptotic resistance. The presence of a shared metabolic phenotype across a variety of genetically distinct NSCLC subtypes suggests that this phenotype is necessary for NSCLC development and may result from multiple distinct genetic lesions. Thus, targeting the shared affected pathways may be beneficial for a variety of genetically distinct NSCLC subtypes.

Prostate Cancer-Focus on Cholesterol

Prostate cancer (PC) is the most common malignancy in men. Common characteristic involved in PC pathogenesis are disturbed lipid metabolism and abnormal cholesterol accumulation. Cholesterol can be further utilized for membrane or hormone synthesis while cholesterol biosynthesis intermediates are important for oncogene membrane anchoring, nucleotide synthesis and mitochondrial electron transport. Since cholesterol and its biosynthesis intermediates influence numerous cellular processes, in this review we have described cholesterol homeostasis in a normal cell. Additionally, we have illustrated how commonly deregulated signaling pathways in PC (PI3K/AKT/MTOR, MAPK, AR and p53) are linked with cholesterol homeostasis regulation.

The 3-beta-hydroxysteroid-Delta(8), Delta(7)-isomerase EBP inhibits cholesterylation of Smoothened

Hedgehog (Hh) pathway plays a central role in vertebrate embryonic development and carcinogenesis. The G-protein coupled receptor-like protein Smoothened (SMO) is one of the major members in Hh pathway. Covalent modification of cholesterol on the 95th asparagine (D95) of human SMO, which is regulated by Hh and PTCH1, is critical for SMO activation. However, it is not known whether SMO cholesterylation is regulated by other proteins. In this study, we identified Emopamil binding protein (EBP, also known as 3-beta-hydroxysteroid-Delta(8),Delta(7)-isomerase) as a SMO-interacting protein. Overexpression of EBP suppressed SMO cholesterylation and Hh pathway activity, whereas genetic disruption of EBP enhanced SMO cholesterylation and the downstream signaling. EBP-mediated inhibition of SMO cholesterylation was independent of its isomerase activity, but dependent on the C-terminus of EBP that was required for SMO binding. The X-linked dominant chondrodysplasia punctate 2 (CDPX2)-associated EBP mutants inhibited SMO cholesterylation too. Together, this study shows that EBP modulates SMO cholesterylation through direct binding and suggests a possible mechanism of CDPX2 pathogenesis.

Development of a New Recurrence-Free Survival Prediction Nomogram for Patients with Primary Non-Muscle-Invasive Bladder Cancer Based on Preoperative Controlling Nutritional Status Score

Background

Bladder cancer is the second most prevalent neoplasm in the urogenital system in terms of morbidity and mortality, and there is an urgent need for a more accurate assessment of individual prognosis in patients with primary non-muscle-invasive bladder cancer (NMIBC). The Controlling Nutritional Status (CONUT) score is an emerging biomarker score which has been confirmed to have prognostic value in various malignant tumors. The study attempted to systematically identify the prognostic role of preoperative CONUT score on posttreatment recurrence-free survival (RFS) in patients with NMIBC, and determine the predictive value and feasibility of the new prognostic prediction model.

Methods

A total of 94 patients with NMIBC were analyzed retrospectively between January 2011 and December 2015. Statistical analysis was conducted using the nonparametric method. The Kaplan-–Meier method was used to assess recurrence-free survival (RFS), and Log rank tests was used to analyze the equivalences of survival curves. We used univariate and multivariate Cox proportional hazards regression model to identify important predictors of RFS. Discrimination of nomogram was measured by the concordance index. Predictive accuracy of the model was evaluated using the internal validation.

Results

In univariate analysis, age, history of smoking, pathological T stage, tumor grade, tumor size, and CONUT score were significantly correlated with RFS. Multivariate analysis indicated that CONUT score (HR =3.855, 95% CI 1.242–11.970, p=0.020) was an independent predictor of RFS in patients with NMIBC. Based on significant parameters in multivariate analysis and reliable recurrence predictors determined in predictive models and relevant guidelines, a new age-, history of smoking-, pathologic factors- and the CONUT score-based scoring model was developed to predict recurrence of NMBIC. In addition, we internally validated the nomogram using the consistency index and calibration plots, which demonstrated that the model has high prediction accuracy (c-index= 0.851).

Conclusion

The development of a new nomogram based on CONUT score could increase the accuracy of recurrence prediction and improve individualized treatment plans for patients with NMIBC.

Enzymes in the Cholesterol Synthesis Pathway: Interactomics in the Cancer Context

A global protein interactome ensures the maintenance of regulatory, signaling and structural processes in cells, but at the same time, aberrations in the repertoire of protein-protein interactions usually cause a disease onset. Many metabolic enzymes catalyze multistage transformation of cholesterol precursors in the cholesterol biosynthesis pathway. Cancer-associated deregulation of these enzymes through various molecular mechanisms results in pathological cholesterol accumulation (its precursors) which can be disease risk factors. This work is aimed at systematization and bioinformatic analysis of the available interactomics data on seventeen enzymes in the cholesterol pathway, encoded by HMGCR, MVK, PMVK, MVD, FDPS, FDFT1, SQLE, LSS, DHCR24, CYP51A1, TM7SF2, MSMO1, NSDHL, HSD17B7, EBP, SC5D, DHCR7 genes. The spectrum of 165 unique and 21 common protein partners that physically interact with target enzymes was selected from several interatomic resources. Among them there were 47 modifying proteins from different protein kinases/phosphatases and ubiquitin-protein ligases/deubiquitinases families. A literature search, enrichment and gene co-expression analysis showed that about a quarter of the identified protein partners was associated with cancer hallmarks and over-represented in cancer pathways. Our results allow to update the current fundamental view on protein-protein interactions and regulatory aspects of the cholesterol synthesis enzymes and annotate of their sub-interactomes in term of possible involvement in cancers that will contribute to prioritization of protein targets for future drug development.

mTOR-Rictor-EGFR axis in oncogenesis and diagnosis of glioblastoma multiforme

Glioblastoma multiforme (GBM) is one of the aggressive brain cancers with patients having less survival period upto 12-15 months. Mammalian target of rapamycin (mTOR) is a serine/threonine kinase, belongs to the phosphatidylinositol 3-kinases (PI3K) pathway and is involved in various cellular processes of cancer cells. Cancer metabolism is regulated by mTOR and its components. mTOR forms two complexes as mTORC1 and mTORC2. Studies have identified the key component of the mTORC2 complex, Rapamycin-insensitive companion of mammalian target of rapamycin (Rictor) plays a prominent role in the regulation of cancer cell proliferation and metabolism. Apart, growth factor receptor signaling such as epidermal growth factor signaling mediated by epidermal growth factor receptor (EGFR) regulates cancer-related processes. In EGFR signaling various other signaling cascades such as phosphatidyl-inositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR pathway) and Ras/Raf/mitogen-activated protein kinase/ERK kinase (MEK)/extracellular-signal-regulated kinase (ERK) -dependent signaling cross-talk each other. From various studies about GBM, it is very well established that Rictor and EGFR mediated signaling pathways majorly playing a pivotal role in chemoresistance and tumor aggressiveness. Recent studies have shown that non-coding RNAs such as microRNAs (miRs) and long non-coding RNAs (lncRNAs) regulate the EGFR and Rictor and sensitize the cells towards chemotherapeutic agents. Thus, understanding of microRNA mediated regulation of EGFR and Rictor will help in cancer prevention and management as well as a future therapy.

The Natural Products and Extracts: Anti-Triple-Negative Breast Cancer in Vitro

Triple-negative breast cancer (TNBC) makes up 15 % to 20 % of all breast cancer (BC) cases, and represents one of the most challenging malignancies to treat. For many years, chemotherapy has been the main treatment option for TNBC. Natural products isolated from marine organisms and terrestrial organisms with great structural diversity and high biochemical specificity form a compound library for the assessment and discovery of new drugs. In this review, we mainly focused on natural compounds and extracts (from marine and terrestrial environments) with strong anti-TNBC activities (IC₅₀ <100 μM) and their possible mechanisms reported in the past six years (2015-2021).

PCSK9 and cancer: Rethinking the link

BACKGROUND

Cancer is emerging as a major problem globally, as it accounts for the second cause of death despite medical advances. According to epidemiological and basic studies, cholesterol is involved in cancer progression and there are abnormalities in cholesterol metabolism of cancer cells including prostate, breast, and colorectal carcinomas. However, the importance of cholesterol in carcinogenesis and thereby the role of cholesterol homeostasis as a therapeutic target is still a debated area in cancer therapy. Proprotein convertase subtilisin/kexin type-9 (PCSK9), a serine protease, modulates cholesterol metabolism by attachment to the LDL receptor (LDLR) and reducing its recycling by targeting the receptor for lysosomal destruction. Published research has shown that PCSK9 is also involved in degradation of other LDLR family members namely very-low-density-lipoprotein receptor (VLDLR), lipoprotein receptor-related protein 1 (LRP-1), and apolipoprotein E receptor 2 (ApoER2). As a result, this protein represents an interesting therapeutic target for the treatment of hypercholesterolemia. Interestingly, clinical trials on PCSK9-specific monoclonal antibodies have reported promising results with high efficacy in lowering LDL-C and in turn reducing cardiovascular complications. It is important to note that PCSK9 mediates several other pathways apart from its role in lipid homeostasis, including antiviral activity, hepatic regeneration, neuronal apoptosis, and modulation of various signaling pathways. Furthermore, recent literature has illustrated that PCSK9 is closely associated with incidence and progression of several cancers. In a number of studies, PCSK9 siRNA was shown to effectively suppress the proliferation and invasion of the several studied tumor cells. Hence, a novel application of PCSK9 inhibitors/silencers in cancer/metastasis could be considered. However, due to poor data on effectiveness and safety of PCSK9 inhibitors in cancer, the impact of PCSK9 inhibition in these pathological conditions is still unknown.

SEARCH METHODS

A vast literature search was conducted to find intended studies from 1956 up to 2020, and inclusion criteria were original peer-reviewed publications.

PURPOSE OF REVIEW

To date, PCSK9 has been scantly investigated in cancer. The question that needs to be discussed is "How does PCSK9 act in cancer pathophysiology and what are the risks or benefits associated to its inhibition?". We reviewed the available publications highlighting the contribution of this proprotein convertase in pathways related to cancer, with focus on the potential implications of its long-term pharmacological inhibition in cancer therapy.

The Correlation between Lipid Metabolism Disorders and Prostate Cancer

Prostate cancer is the second most common cancer affecting the male population all over the world. The existence of a correlation between lipid metabolism disorders and cancer of the prostate gland has been widely known for a long time. According to hypotheses, cholesterol may contribute to prostate cancer progression as a result of its participation as a signaling molecule in prostate growth and differentiation via numerous biologic mechanisms including Akt signaling and de novo steroidogenesis. The results of some studies suggest that increased cholesterol levels may be associated with a higher risk of a more aggressive course of the disease. The aforementioned alterations in the synthesis of fatty acids are a unique feature of cancer and, therefore, constitute an attractive target for therapeutic intervention in the treatment of prostate cancer. Pharmacological or gene therapy aims to reduce the activity of enzymes involved in de novo synthesis of fatty acids, FASN, ACLY (ATP citrate lyase) or SCD-1 (Stearoyl-CoA Desaturase) in particular, that may result in cells growth arrest. Nevertheless, not all cancers are unequivocally associated with hypocholesterolaemia. It cannot be ruled out that the relationship between prostate cancer and lipid disorders is not a direct quantitative correlation between carcinogenesis and the amount of circulating cholesterol. Perhaps the correspondence is more sophisticated and connected to the distribution of cholesterol fractions or even sub-fractions of e.g. HDL cholesterol.

Can non-cholesterol sterols indicate the presence of specific dysregulation of cholesterol metabolism in patients with colorectal cancer?

Colorectal cancer (CRC) is a highly prevalent malignancy. Previous studies suggested that cholesterol might play a signficant role in malignant transformation and proliferation. Non-cholesterol sterols (NCS), which are transported by serum lipoproteins alongside cholesterol, are regarded as cholesterol synthesis and absorption markers. Quantification of NCS in serum and HDL fraction (NCS_HDL), could provide a better insight into the cholesterol metabolism. The aim of this study was to examine the status of cholesterol synthesis and cholesterol absorption markers in serum and HDL fraction and explore their interrelation in CRC patients. Current study was designed as observational, case-control study. The study included 73 CRC patients and 95 healthy subjects. NCS and NCS_HDL concentrations were determined by HPLC-MS/MS. Based on NCS and NCS_HDL concentrations, different cholesterol homeostasis indices were calculated. Patients had significantly lower NCS (P<0.001) and NCS_HDL concentrations (P<0.001 for desmosterol_HDL; P<0.05 for lathosterol_HDL, P=0.001 for campesterol_HDL, P<0.001 for β-sitosterol_HDL). NCS_HDL/NCS (P<0.005 for desmosterol_HDL/desmosterol; P<0.05 for lathosterol_HDL/lathosterol; P<0.001 for both β-sitosterol_HDL/β-sitosterol and campesterol_HDL/campesterol) and synthesis to absorption ratio (CSI/CAI) (P<0.005) were increased in CRC patients. Additionally, low serum concentrations of desmosterol (P<0.001; OR=0.329; 95%CI (0.199-0.542)) and campesterol (P<0.001; OR=0.540; 95%CI (0.424-0.687)) were independent predictors of CRC presence. Our data suggest that cholesterol homeostasis in CRC is shifted towards increased synthesis. Relative abundance of NCS in HDL particles is increased, suggesting the possible overproduction of cholesterol precursors in peripheral tissues.

Circulating 27-hydroxycholesterol and Risk of Colorectal Adenomas and Serrated Polyps

The oxysterol 27-hydroxycholesterol (27-OHC) is an endogenous selective estrogen receptor modulator implicated in breast cancer etiology. It is unknown whether circulating 27-OHC is associated with colorectal neoplasia risk. Circulating 27-OHC was measured using LC/MS in fasting plasma collected at baseline from participants of the Vitamin D/Calcium Polyp Prevention Study, a completed randomized clinical trial. Participants were between 45 and 75 years old, recently diagnosed with ≥1 colorectal adenoma, and followed for new colorectal polyps during colonoscopic surveillance. Adjusted risk ratios (RR) with 95% confidence intervals (CI) of new colorectal polyps were estimated for quartiles of circulating 27-OHC using log-linear regression for repeated outcomes. Polyp phenotypes included any adenomas, advanced adenomas, hyperplastic polyps, and sessile serrated adenomas/polyps. Circulating 27-OHC was measured at baseline for 1,246 participants. Compared with participants with circulating 27-OHC below the first quartile (<138 ng/mL), those with circulating 27-OHC at or above the fourth quartile (≥201 ng/mL) had 24% higher risk of adenomas (RR, 1.24; 95% CI, 1.05-1.47) and 89% higher risk of advanced adenomas (RR, 1.89; 95% CI, 1.17-3.06). Stronger associations were observed among participants with advanced adenomas at baseline. Circulating 27-OHC was not associated with risk of hyperplastic polyps (RR, 0.90; 95% CI, 0.66-1.22) or sessile serrated adenomas/polyps (RR, 1.02; 95% CI, 0.50-2.07). Circulating 27-OHC may be a risk factor for colorectal adenomas but not serrated polyps. PREVENTION RELEVANCE: This study found that plasma concentration of 27-hydroxycholesterol, a metabolite of cholesterol that regulates lipid metabolism and acts as a selective estrogen receptor modulator, is associated with the risk of developing precursor lesions for colorectal cancer.

Cholesterol Activates Cyclic AMP Signaling in Metaplastic Acinar Cells

Cholesterol is a non-essential metabolite that exerts both structural and signaling functions. However, cholesterol biosynthesis is elevated, and actively supports, pancreatic carcinogenesis. Our previous work showed that statins block the reprogramming of mutant KRAS-expressing acinar cells, that spontaneously undergo a metaplastic event termed acinar-to-ductal metaplasia (ADM) to initiate carcinogenesis. Here we tested the impact of cholesterol supplementation on isolated primary wild-type acinar cells and observed enhanced ductal transdifferentiation, associated with generation of the second messenger cyclic adenosine monophosphate (cAMP) and the induction of downstream protein kinase A (PKA). Inhibition of PKA suppresses cholesterol-induced ADM ex vivo. Live imaging using fluorescent biosensors dissected the temporal and spatial dynamics of PKA activation upon cholesterol addition and showed uneven activation both in the cytosol and on the outer mitochondrial membrane of primary pancreatic acinar cells. The ability of cholesterol to activate cAMP signaling is lost in tumor cells. Qualitative examination of multiple normal and transformed cell lines supports the notion that the cAMP/PKA axis plays different roles during multi-step pancreatic carcinogenesis. Collectively, our findings describe the impact of cholesterol availability on the cyclic AMP/PKA axis and plasticity of pancreatic acinar cells.

Elucidating the impact of cottonseed hydrolysates on CHO cell culture performance through transcriptomic analysis

In order to evaluate the impact of plant-based hydrolysates on CHO cells, a transcriptomic study was undertaken using cottonseed hydrolysate and Illumina's NextSeq transcriptomics profiling for 2 days of a batch cell culture. While cottonseed hydrolysate extended cell growth and increased antibody titer, significant effects were seen on transcriptomic signatures of supplemented cultures when compared to untreated cultures, evaluated using fold change, gene ontology (GO), and KEGG pathway analysis. Transcription and other factors commonly associated with cell growth such as those of the Atf family and homeobox proteins were upregulated while genes in the Hippo signaling pathway were downregulated. Genes involved in anabolic pathways such as gluconeogenesis and those involving protein folding and translation elongation were upregulated. GO analysis of biological processes for cottonseed-supplemented cultures indicated enrichments in DNA replication, protein processing, and unfolded protein response while molecular functions associated with growth such as GTPases, ATP binding, and aminoacyl t-RNA ligase activity were also enriched. Cellular components associated with structural integrity such as actin cytoskeleton, microtubules, mitochondrion, and Lewy body were enriched. Enriched KEGG pathways include growth-associated pathways such as cell cycle, pI3K-AKT-mTOR, and cancer-related pathways as well as those enhancing glycan metabolism, purine metabolism, amino acid biosynthesis, and protein processing in the endoplasmic reticulum (ER). These transcriptomic profiles provide insights into the roles that hydrolysates such as cottonseed can play in altering CHO cell growth and other physiological characteristics as well as suggesting ways in which CHO cell culture may be modified for enhancing performance in biotechnology applications. KEY POINTS: • Hydrolysate-supplemented cultures increased mammalian cell growth and productivity. • Fold-change analysis revealed upregulation in transcription and translation. • Enriched GOs and KEGG pathways including cell cycle and metabolism were observed.

Inference of Subpathway Activity Profiles Reveals Metabolism Abnormal Subpathway Regions in Glioblastoma Multiforme

Glioblastoma, also known as glioblastoma multiforme (GBM), is the most malignant form of glioma and represents 81% of malignant brain and central nervous system (CNS) tumors. Like most cancers, GBM causes metabolic recombination to promote cell survival, proliferation, and invasion of cancer cells. In this study, we propose a method for constructing the metabolic subpathway activity score matrix to accurately identify abnormal targets of GBM metabolism. By integrating gene expression data from different sequencing methods, our method identified 25 metabolic subpathways that were significantly abnormal in the GBM patient population, and most of these subpathways have been reported to have an effect on GBM. Through the analysis of 25 GBM-related metabolic subpathways, we found that (S)-2,3-Epoxysqualene, which was at the central region of the sterol biosynthesis subpathway, may have a greater impact on the entire pathway, suggesting a potential high association with GBM. Analysis of CCK8 cell activity indicated that (S)-2,3-Epoxysqualene can indeed inhibit the activity of U87-MG cells. By flow cytometry, we demonstrated that (S)-2,3-Epoxysqualene not only arrested the U87-MG cell cycle in the G0/G1 phase but also induced cell apoptosis. These results confirm the reliability of our proposed metabolic subpathway identification method and suggest that (S)-2,3-Epoxysqualene has potential therapeutic value for GBM. In order to make the method more broadly applicable, we have developed an R system package crmSubpathway to perform disease-related metabolic subpathway identification and it is freely available on the GitHub (https://github.com/hanjunwei-lab/crmSubpathway).

Prognostic value of hypocholesterolemia in patients with gastric cancer

BACKGROUND

According to previous studies, low serum total cholesterol (TC) is associated with higher cancer incidence and mortality. However, the prognostic implications of preoperative TC in patients with gastric cancer (GC) remain to be determined.

METHODS

A total of 1251 patients with GC, who underwent radical gastrectomy between 2005 and 2008, were recruited. Propensity score weighting (PSW) based on a generalized boosted method (GBM) was used to control for selection bias.

RESULTS

After balancing the preoperative and operative covariates, low TC was associated with high incidence of complications (severe complication rate: 15.2% (Low TC) vs. 4.7% (Normal TC) vs 5.5% (High TC); p = 0.004). In multivariable analysis, lowering TC was associated with poor OS and RFS in weighted population. [OS: hazard ratio (HR) = 0.92; 95% CI = 0.867-0.980; P = 0.009 and RFS: HR = 0.93; 95% CI = 0.873-0.988; P = 0.02].

CONCLUSIONS

Preoperative TC is a useful predictor of postoperative survival and postoperative complications in patients with stage I-III GC and may help to identify high-risk patients for rational therapy, including nutritional support, and timely follow-up.

20(S)-Rg3 upregulates FDFT1 via reducing miR-4425 to inhibit ovarian cancer progression

We previously found that ginsenoside 20(S)-Rg3 diminishes the proliferative and invasive capacities of ovarian cancer cells by decreasing miR-4425 level. Yet the mechanism of action of miR-4425 in ovarian cancer remains unclear. Here we report that miR-4425 is upregulated in ovarian cancer tissues relative to normal ovarian tissues, and transfection of miR-4425 inhibitor impairs the proliferation, migration and invasion of SKOV3 and 3AO ovarian cancer cells. Further, miR-4425 antagomiR reduces cell proliferation in a subcutaneous SKOV3 xenograft model using BALB/c nude mice. We identifies farnesyl-diphosphate farnesyltransferase 1 (FDFT1) as a direct target of miR-4425 by Western blotting and a luciferase reporter assay. Forced expression of FDFT1 via transfection of an FDFT1-expressing plasmid into ovarian cancer cells not only retards cell proliferation, motility and invasiveness, but also negates the tumorigenic properties of a miR-4425 mimic. By contrast, silencing of FDFT1 by siRNAs abrogates suppression of the proliferation, migration and invasion of ovarian cancer cells treated with a miR-4425 inhibitor. Finally, transfection of either a miR-4425 mimic or FDFT1 siRNAs into 20(S)-Rg3-treated ovarian cancer cells counteracts the tumor-inhibitory activity of the ginsenoside. In conclusion, 20(S)-Rg3 exerts anti-ovarian cancer activity by downregulating oncogenic miR-4425 that inhibits the expression of the tumor suppressor gene FDFT1. These results expand our current understanding of the molecular pathways leading to ovarian cancer progression, and unveil the mechanism of action of 20(S)-Rg3 in ovarian cancer inhibition.

Gender Differential Transcriptome in Gastric and Thyroid Cancers

Cancer has an important and considerable gender differential susceptibility confirmed by several epidemiological studies. Gastric (GC) and thyroid cancer (TC) are examples of malignancies with a higher incidence in males and females, respectively. Beyond environmental predisposing factors, it is expected that gender-specific gene deregulation contributes to this differential incidence. We performed a detailed characterization of the transcriptomic differences between genders in normal and tumor tissues from stomach and thyroid using Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) data. We found hundreds of sex-biased genes (SBGs). Most of the SBGs shared by normal and tumor belong to sexual chromosomes, while the normal and tumor-specific tend to be found in the autosomes. Expression of several cancer-associated genes is also found to differ between sexes in both types of tissue. Thousands of differentially expressed genes (DEGs) between paired tumor-normal tissues were identified in GC and TC. For both cancers, in the most susceptible gender, the DEGs were mostly under-expressed in the tumor tissue, with an enrichment for tumor-suppressor genes (TSGs). Moreover, we found gene networks preferentially associated to males in GC and to females in TC and correlated with cancer histological subtypes. Our results shed light on the molecular differences and commonalities between genders and provide novel insights in the differential risk underlying these cancers.

The Biological Function of Sigma-2 Receptor/TMEM97 and Its Utility in PET Imaging Studies in Cancer

The sigma-2 receptor was originally defined pharmacologically and recently identified as TMEM97. TMEM97 has been validated as a biomarker of proliferative status and the radioligand of TMEM97, [18F]ISO-1, has been developed and validated as a PET imaging biomarker of proliferative status of tumors and as a predictor of the cancer therapy response. [18F]ISO-1 PET imaging should be useful to guide treatment for cancer patients. TMEM97 is a membrane-bound protein and localizes in multiple subcellular organelles including endoplasmic reticulum and lysosomes. TMEM97 plays distinct roles in cancer. It is reported that TMEM97 is upregulated in some tumors but downregulated in other tumors and it is required for cell proliferation in certain tumor cells. TMEM97 plays important roles in cholesterol homeostasis. TMEM97 expression is regulated by cholesterol-regulating signals such as sterol depletion and SREBP expression levels. TMEM97 regulates cholesterol trafficking processes such as low density lipoprotein (LDL) uptake by forming complexes with PGRMC1 and low density lipoprotein receptor (LDLR), as well as cholesterol transport out of lysosome by interacting with and regulating NPC1 protein. Understanding molecular functions of TMEM97 in proliferation and cholesterol metabolism will be important to develop strategies to diagnose and treat cancer and cholesterol disorders using a rich collection of TMEM97 radiotracers and ligands.

Lipid metabolism alteration contributes to and maintains the properties of cancer stem cells

Lipids, the basic components of the cell membrane, execute fundamental roles in almost all the cell activities including cell-cell recognition, signalling transduction and energy supplies. Lipid metabolism is elementary for life sustentation that balances activity between synthesis and degradation. An accumulating amount of data has indicated abnormal lipid metabolism in cancer stem cells (CSCs), and that the alteration of lipid metabolism exerts a great impact on CSCs' properties such as the capability of self-renewal, differentiation, invasion, metastasis, and drug sensitivity and resistance. CSCs' formation and maintenance cannot do without the regulation of fatty acids and cholesterol. In normal cells and embryonic development, fatty acids and cholesterol metabolism are regulated by some important signalling pathways (such as Hedgehog, Notch, Wnt signalling pathways); these signalling pathways also play crucial roles in initiating and/or maintaining CSCs' properties, and such signalling is shown to be commonly modulated by the abnormal lipid metabolism in CSCs; on the other hand, the altered lipid metabolism in turn modifies the cell signalling and generates additional impacts on CSCs. Metabolic rewiring is considered as an ideal hallmark of CSCs, and metabolic alterations would be promising therapeutic targets of CSCs for aggressive tumors. In this review, we summarize the most updated findings of lipid metabolic abnormalities in CSCs and prospect the potential applications of targeting lipid metabolism for anticancer treatment.