Cholesterol and prostate cancer

A hypoxia-derived gene signature to suggest cisplatin-based therapeutic responses in patients with cervical cancer

Cervical cancer remains a significant global public health concern, often exhibits cisplatin resistance in clinical settings. Hypoxia, a characteristic of cervical cancer, substantially contributes to cisplatin resistance. To evaluate the therapeutic efficacy of cisplatin in patients with cervical cancer and to identify potential effective drugs against cisplatin resistance, we established a hypoxia-inducible factor-1 (HIF-1)-related risk score (HRRS) model using clinical data from patients treated with cisplatin. Cox and LASSO regression analyses were used to stratify patient risks and prognosis. Through qRT-PCR, we validated nine potential prognostic HIF-1 genes that successfully predict cisplatin responsiveness in patients and cell lines. Subsequently, we identified fostamatinib, an FDA-approved spleen tyrosine kinase inhibitor, as a promising drug for targeting the HRRS-high group. We observed a positive correlation between the IC50 values of fostamatinib and HRRS in cervical cancer cell lines. Moreover, fostamatinib exhibited potent anticancer effects on high HRRS groups in vitro and in vivo. In summary, we developed a hypoxia-related gene signature that suggests cisplatin response prediction in cervical cancer and identified fostamatinib as a potential novel treatment approach for resistant cases.

Rapid Lifestyle Recommendations to Improve Urologic, Heart and Overall Health

PURPOSE OF REVIEW

This literature review is intended to highlight recent correlations between urologic, heart and overall health by emphasizing healthy eating patterns, physical activity, alcohol minimization and tobacco elimination, healthy sleep, weight, cholesterol, blood sugar, blood pressure management, and mental health awareness.

RECENT FINDINGS

Meta-analyses, systematic reviews, and clinical studies espouse a unified message for prevention, reducing the risk of disease recurrence, progression, complementing conventional medical intervention efficacy, and mitigating treatment side effects. Limiting or eliminating alcohol consumption could be considered an independent recommendation and adding a mental health and miscellaneous (genetic risk and lifestyle, planetary health, HPV or other vaccination awareness, spirituality, etc.) category could allow for individualized educational opportunities, synergism appreciation, and self-improvement. Urologic healthcare professionals have the potential to strengthen the collective public health goal of improving the quality and quantity of the lives of patients able to adhere to these heart healthy recommendations.

Statin Concentration in Prostatic Tissue is Subtype- and Dose-dependent

OBJECTIVE

To evaluate for the first time, comparative serum and prostate tissue concentrations of lipophilic and hydrophilic statins.

METHODS

After reviewing all patients who underwent radical prostatectomy between 1993 and 2019, we selected 80 patients taking atorvastatin (lipophilic) or rosuvastatin (hydrophilic) for cholesterol control and with available banked fresh-frozen tissue from the prostatectomy. Primary endpoint was serum and prostate statin concentration measured by HPLC-mass spectrometry analysis. Serum/prostate statin concentrations were compared between patients on atorvastatin and rosuvastatin, and patients receiving high- and low-dose statin, using the Mann-Whitney U test.

RESULTS

In total, 39 patients were taking atorvastatin and 41 were taking rosuvastatin. Thirty-eight and 42 were taking high- and low-dose statin, respectively. Statin concentration was measurable in the prostatic tissue of 15 patients (38.4%) taking atorvastatin (33.3% high-dose vs 42.8% low-dose) compared to 22 (53.6%) taking rosuvastatin (55% high-dose vs 52.3% low-dose). Median tissue concentration of rosuvastatin was greater than atorvastatin (3.98 ng/g vs 0.96 ng/g, P <.001). Dose-dependency was observed: median prostate concentration was higher in those taking high-dose versus low-dose statin for both atorvastatin (1.22 ng/g vs 0.79 ng/g, P = .69) and rosuvastatin (5.21 ng/g vs 1.99 ng/g, P <.001).

CONCLUSION

We have shown, for the first time, that lipophilic and hydrophilic statins can be measured in the prostate of patients with prostate cancer and that the concentrations are dependent on dose. Moreover, rosuvastatin, a hydrophilic statin, achieves a 4-fold higher concentration in the prostate.

Increased plasma lipids in triple-negative breast cancer and impairment in HDL functionality in advanced stages of tumors

The association between plasma lipids and breast cancer (BC) has been extensively explored although results are still conflicting especially regarding the relationship with high-density lipoprotein cholesterol (HDLc) levels. HDL mediates cholesterol and oxysterol removal from cells limiting sterols necessary for tumor growth, inflammation, and metastasis and this may not be reflected by measuring HDLc. We addressed recently diagnosed, treatment-naïve BC women (n = 163), classified according to molecular types of tumors and clinical stages of the disease, in comparison to control women (CTR; n = 150) regarding plasma lipids and lipoproteins, HDL functionality and composition in lipids, oxysterols, and apo A-I. HDL was isolated by plasma discontinuous density gradient ultracentrifugation. Lipids (total cholesterol, TC; triglycerides, TG; and phospholipids, PL) were determined by enzymatic assays, apo A-I by immunoturbidimetry, and oxysterols (27, 25, and 24-hydroxycholesterol), by gas chromatography coupled with mass spectrometry. HDL-mediated cell cholesterol removal was determined in macrophages previously overloaded with cholesterol and ¹⁴C-cholesterol. Lipid profile was similar between CTR and BC groups after adjustment per age. In the BC group, lower concentrations of TC (84%), TG (93%), PL (89%), and 27-hydroxicholesterol (61%) were observed in HDL, although the lipoprotein ability in removing cell cholesterol was similar to HDL from CRT. Triple-negative (TN) BC cases presented higher levels of TC, TG, apoB, and non-HDLc when compared to other molecular types. Impaired HDL functionality was observed in more advanced BC cases (stages III and IV), as cholesterol efflux was around 28% lower as compared to stages I and II. The altered lipid profile in TN cases may contribute to channeling lipids to tumor development in a hystotype with a more aggressive clinical history. Moreover, findings reinforce the dissociation between plasma levels of HDLc and HDL functionality in determining BC outcomes.

Pseurotin A Validation as a Metastatic Castration-Resistant Prostate Cancer Recurrence-Suppressing Lead via PCSK9-LDLR Axis Modulation

Metastatic castration-resistant prostate cancer (mCRPC) cells can de novo biosynthesize their own cholesterol and overexpress proprotein convertase subtilisin/kexin type 9 (PCSK9). PCSK9 proved to contribute to mCRPC cell motility since PCSK9 knockdown (KD) in mCRPC CWR-R1ca cells led to notable reductions in cell migration and colony formation. Human tissue microarray results proved a higher immunohistoscore in patients ≥ 65 years old, and PCSK9 proved to be expressed higher at an early Gleason score of ≤7. The fermentation product pseurotin A (PS) suppressed PCSK9 expression, protein-protein interactions with LDLR, and breast and prostate cancer recurrences. PS suppressed migration and colony formation of the CWR-R1ca cells. The progression and metastasis of the CWR-R1ca-Luc cells subcutaneously (sc) xenografted into male nude mice fed a high-fat diet (HFD, 11% fat content) showed nearly 2-fold tumor volume, metastasis, serum cholesterol, low-density lipoprotein cholesterol (LDL-C), prostate-specific antigen (PSA), and PCSK9 levels versus mice fed a regular chow diet. Daily oral PS 10 mg/kg treatments prevented the locoregional and distant tumor recurrence of CWR-R1ca-Luc engrafted into nude mice after primary tumor surgical excision. PS-treated mice showed a significant reduction in serum cholesterol, LDL-C, PCSK9, and PSA levels. These results comprehensively validate PS as an mCRPC recurrence-suppressive lead by modulating the PCSK9-LDLR axis.

Cholelithiasis increased prostate cancer risk: evidence from a case-control study and a meta-analysis

Introduction

Cholelithiasis represents a known risk factor for digestive system neoplasm. Few studies reported the association between cholelithiasis and the risk of prostate cancer (PCa), and the results were controversial.

Methods

We reviewed the medical records of the Second Affiliated Hospital of Chongqing Medical University Hospital to perform a retrospective matched case–control study, which included newly diagnosed 221 PCa patients and 219 matched controls. Logistic regression was applied to compare cholelithiasis exposure and adjusted for confounding factors. Additionally, we conducted a meta-analysis pooling this and published studies further to evaluate the association between cholelithiasis and PCa risk. Related ratio (RR) and 95% confidence interval (95%CI) were used to assess the strength of associations.

Results

Our case–control study showed that cholelithiasis was associated with a higher incidence of PCa (OR = 1.87, 95% CI: 1.06–3.31) after multivariable adjustment for covariates. The incidence of PCa was increased in patients with gallstones but not cholecystectomy. 7 studies involving 80,403 individuals were included in the meta-analysis. Similarly, the results demonstrated that cholelithiasis was associated with an increased risk of PCa (RR = 1.35, 95%CI: 1.17–1.56) with moderate-quality evidence. Cholelithiasis patients with low BMI increased the PCa incidence. Moreover, Subgroup analysis based on region showed that cholelithiasis was associated with PCa in Europe (RR = 1.24, 95%CI 1.03–1.51) and Asia (RR = 1.32, 95%CI 1.24–1.41).

Conclusions

The results suggested an association between cholelithiasis and the risk of PCa. There was no significant relationship between cholecystectomy therapy and PCa risk. Further cohort studies should be conducted to demonstrate the results better.

Egg Consumption and Risk of All-Cause and Cause-Specific Mortality: A Systematic Review and Dose-Response Meta-analysis of Prospective Studies

The association between egg consumption and mortality is extremely debatable. This study aimed to investigate the potential dose-response association of egg consumption with risk of mortality from all causes and cause-specific in the general population. The primary comprehensive literature search was conducted in PubMed/Medline, Scopus, ISI Web of Science, and Embase up to March 2021, as well as reference lists of relevant original papers and key journals. We calculated summary RRs and their 95% CIs for the highest and lowest categories, as well as the linear trend estimation of egg intake, using the random-effects model. Thirty-three (32 publications) cohort studies were included. These studies enrolled 2,216,720 participants and recorded 232,408 deaths from all causes. Comparing highest versus lowest egg intake categories was not associated with the risk of mortality from all causes (RR: 1.02; 95% CI: 0.94, 1.11; n = 25), cardiovascular disease (CVD) (RR: 1.04; 95% CI: 0.87, 1.23, n = 11), coronary heart disease (CHD) (RR: 0.98; 95% CI: 0.84, 1.16; n = 10), stroke (RR: 0.81; 95% CI: 0.64, 1.02; n = 9), and respiratory disease (RR: 0.96; 95% CI: 0.53, 1.71; n = 3); however, it was associated with a higher risk of cancer mortality (RR: 1.20; 95% CI: 1.04, 1.39; n = 13). In the linear dose-response analysis, an additional intake of 1 egg per week was associated with a 2% and 4% increased risk of all-cause and cancer mortality, respectively, and a 4% decreased risk of stroke mortality. The certainty of the evidence was rated as low to moderate. Higher egg consumption was not associated with an increased risk of mortality from all causes, CVD, CHD, stroke, or respiratory disease, whereas an elevated risk was observed for cancer mortality. These findings suggest that eggs be consumed in low to moderate amounts (≤1 egg/d) as part of a healthy diet.

Using the Method of "Optical Biopsy" of Prostatic Tissue to Diagnose Prostate Cancer

Simple Summary

Analytical discrimination models of Raman spectra of prostate cancer tissue were constructed by using the projections onto latent structures data analysis (PLS-DA) method for different wavelengths of exciting radiation—532 and 785 nm. These models allowed us to divide the Raman spectra of prostate cancer and the spectra of hyperplasia sites for validation datasets with the accuracy of 70–80%, depending on the specificity value. Meanwhile, for the calibration datasets, the accuracy values reached 100% for the excitation of a laser with a wavelength of 785 nm. Due to the registration of Raman “fingerprints”, the main features of cellular metabolism occurring in the tissue of a malignant prostate tumor were confirmed, namely the absence of aerobic glycolysis, over-expression of markers, and a strong increase in the concentration of cholesterol and its esters, as well as fatty acids and glutamic acid.

Abstract

The possibilities of using optical spectroscopy methods in the differential diagnosis of prostate cancer were investigated. Analytical discrimination models of Raman spectra of prostate tissue were constructed by using the projections onto latent structures data analysis(PLS-DA) method for different wavelengths of exciting radiation—532 and 785 nm. These models allowed us to divide the Raman spectra of prostate cancer and the spectra of hyperplasia sites for validation datasets with the accuracy of 70–80%, depending on the specificity value. Meanwhile, for the calibration datasets, the accuracy values reached 100% for the excitation of a laser with a wavelength of 785 nm. Due to the registration of Raman “fingerprints”, the main features of cellular metabolism occurring in the tissue of a malignant prostate tumor were confirmed, namely the absence of aerobic glycolysis, over-expression of markers (FASN, SREBP1, stearoyl-CoA desaturase, etc.), and a strong increase in the concentration of cholesterol and its esters, as well as fatty acids and glutamic acid. The presence of an ensemble of Raman peaks with increased intensity, inherent in fatty acid, beta-glucose, glutamic acid, and cholesterol, is a fundamental factor for the identification of prostate cancer.

Uncovering temperature-dependent extracellular vesicle secretion in breast cancer

In all living things, temperature is a key factor to maintain function and survive. Animals and plants need to adapt temperature change with optimizing their behaviour and growth by sensing temperature. Similarly, tumour cells must adapt continuously to fluctuations in external conditions including temperature. To find a better environment, cancer cells promote growth and metastasis, which contributes to tumour malignancy. Pathological studies in breast cancer have implied that temperature is associated with disease progression. However, no clear mechanisms have emerged for how thermal changes affect tumour cells and their gene regulation in tumour development and malignancy. Here we discovered the temperature-dependent extracellular vesicle (EV) secretion in breast cancer. Cancer cell growth and EV secretion increased in a temperature-dependent manner, which indicated that temperatures were associated with poor prognosis in breast cancer patients. We also found that low-density lipoprotein receptor (LDLR), a responsible gene for temperature-dependent EV secretion, was upregulated with the increase in temperature. Consistent with our results, LDLR gene has been characterized and identified as a key factor for malignancy in a wide range of cancers. Our findings shed new light on tumour aggressiveness and therapeutic strategies for breast cancer, especially regarding EV formation and secretion, thus providing a new relationship between cancer and EV biology in the light of temperature.

The interactions of a number of steroid-metabolizing cytochromes P450 with abiraterone D4A metabolite: spectral analysis and molecular docking

The interactions of pharmacologically active 3-keto-Δ4-metabolite of anticancer drug abiraterone (D4A) with steroid-metabolizing cytochromes P450 (CYP51A1, CYP11A1, CYP19A1) was studied by absorption spectroscopy and molecular docking. Both abiraterone and D4A induce type I spectral changes of CYP51A1, one of the enzymes of cholesterol biosynthesis. We have revealed that D4A did not induce spectral changes of CYP11A1, the key enzyme of pregnenolone biosynthesis, unlike abiraterone (type II ligand of CYP11A1). On the contrary, D4A interacts with the active site of CYP19A1, the key enzyme of estrogen biosynthesis, inducing type II spectral changes, while abiraterone does not. Spectral analysis allowed us to calculate spectral dissociation constant (K_S) for each complex of cytochrome P450 with respective ligands. The data were supported by molecular docking. The obtained results broaden understanding of interactions of D4A with some of the key steroid-metabolizing cytochromes P450 and allow one to predict possible disproportions of steroid metabolism.

How unsaturated fatty acids and plant stanols affect sterols plasma level and cellular membranes? Review on model studies involving the Langmuir monolayer technique

The Langmuir monolayer technique has long been known for its usefulness to study the interaction between molecules and mimic cellular membranes to understand the mechanism of action of biologically relevant molecules. In this review we summarize the results that provided insight into the potential mechanism for lowering the plasma level of cholesterol by hypocholesterolemic substances (unsaturated fatty acids (UFAs) and phytocompounds) - in the aspect of prevention of atherosclerosis - and their effects on model biomembranes. The results on UFAs/cholesterol (oxysterols) interactions indicate that these systems are miscible and strongly interacting, contrary to immiscible systems containing saturated fatty acids. Lowering of cholesterol plasma level by UFAs was attributed to the strong affinity between UFAs and sterols, resulting in the formation of high stability complexes, in which sterols were bound and eliminated from the body. Studies on the effect of UFAs and plant sterols/stanols on simplified biomembranes (modeled as cholesterol/DPPC system) indicated that the studied hypocholesterolemic substances modify the biophysical properties of model membrane, affecting its fluidity and interactions between membrane components. Both UFAs and plant sterols/stanols were found to loosen interactions between DPPC and cholesterol and decrease membrane rigidity caused by the excess cholesterol in biomembrane, thus compensating strong condensing effect of cholesterol and restoring proper membrane fluidity, which is of utmost importance for normal cells functioning. The agreement between model - in vitro - studies and biological results prove the usefulness of the Langmuir monolayer technique, which helps in understanding the mode of action of biologically relevant substances.

Obesity and Cancer: 27-Hydroxycholesterol, the Missing Link

Obesity is currently affecting more than 40% of the Americans, and if it progresses with this rate, soon one out of two Americans will be obese. Obesity is an important risk factor for several disorders including cardiovascular disease, the first cause of death in the United States. Cancer follows as the second deadliest disease, and a link between obesity and cancer has been suggested. However, it is very hard to establish an exact connection between obesity and cancers due to the multifactorial nature of obesity. Hypercholesterolemia is a comorbidity of obesity and also linked to several cancers. Recently a cholesterol metabolite 27-hydroxycholesterol (27HC) was found to be an endogenous selective estrogen receptor modulator (SERM), which opened new doors toward several interesting studies on the role of this molecule in biological disorders. It is speculated that 27HC might be the missing link in the obesity and cancer chain. Here, we explored the effects of 27-hydroxycholesterol on obesity and cancers with a focus on the SERM capacity of 27HC.

Plasma metabolomic profile in prostatic intraepithelial neoplasia and prostate cancer and associations with the prostate-specific antigen and the Gleason score

INTRODUCTION

The metabolic alterations reflecting the influence of prostate cancer cells can be captured through metabolomic profiling.

OBJECTIVE

To characterize the plasma metabolomic profile in prostatic intraepithelial neoplasia (PIN) and prostate cancer (PCa).

METHODS

Metabolomics analyses were performed in plasma samples from individuals classified as non-cancerous control (n = 36), with PIN (n = 16), or PCa (n = 27). Untargeted [26 moieties identified after pre-processing by gas chromatography/mass spectrometry (GC/MS)] and targeted [46 amino acids, carbohydrates, organic acids and fatty acids by GC/MS, and 16 nucleosides and amino acids by ultra performance liquid chromatography-triple quadrupole/mass spectrometry (UPLC-TQ/MS)] analyses were performed. Prostate specific antigen (PSA) concentrations were measured in all samples. In PCa patients, the Gleason scores were determined.

RESULTS

The metabolites that were best discriminated (p < 0.05, FDR < 0.2) for the Kruskal-Wallis test with Dunn's post-hoc comparing the control versus the PIN and PCa groups included isoleucine, serine, threonine, cysteine, sarcosine, glyceric acid, among several others. PIN was mainly characterized by alterations on steroidogenesis, glycine and serine metabolism, methionine metabolism and arachidonic acid metabolism, among others. In the case of PCa, the most predominant metabolic alterations were ubiquinone biosynthesis, catecholamine biosynthesis, thyroid hormone synthesis, porphyrin and purine metabolism. In addition, we identified metabolites that were correlated to the PSA [i.e. hypoxanthine (r = - 0.60, p < 0.05; r = - 0.54, p < 0.01) and uridine (r = - 0.58, p < 0.05; r = - 0.50, p < 0.01) in PIN and PCa groups, respectively] and metabolites that were significantly different in PCa patients with Gleason score < 7 and ≥ 7 [i.e. arachidonic acid, median (P25-P75) = 883.0 (619.8-956.4) versus 570.8 (505.6-651.8), respectively (p < 0.01)].

CONCLUSIONS

This human plasma metabolomic assessment contributes to the understanding of the unique metabolic features exhibited in PIN and PCa and provides a list of metabolites that can have the potential to be used as biomarkers for early detection of disease progression and management.

Lapatinib-induced annexin A6 upregulation as an adaptive response of triple-negative breast cancer cells to EGFR tyrosine kinase inhibitors

The epidermal growth factor receptor (EGFR) is a major oncogene in triple-negative breast cancer (TNBC), but the use of EGFR-targeted tyrosine kinase inhibitors (TKI) and therapeutic monoclonal antibodies is associated with poor response and acquired resistance. Understanding the basis for the acquired resistance to these drugs and identifying biomarkers to monitor the ensuing resistance remain a major challenge. We previously showed that reduced expression of annexin A6 (AnxA6), a calcium-dependent membrane-binding tumor suppressor, not only promoted the internalization and degradation of activated EGFR but also sensitized TNBC cells to EGFR-TKIs. Here, we demonstrate that prolong (>3 days) treatment of AnxA6-low TNBC cells with lapatinib led to AnxA6 upregulation and accumulation of cholesterol in late endosomes. Basal extracellular signal-regulated kinase 1 and 2 (ERK1/2) activation was EGFR independent and significantly higher in lapatinib-resistant MDA-MB-468 (LAP-R) cells. These cells were more sensitive to cholesterol depletion than untreated control cells. Inhibition of lapatinib-induced upregulation of AnxA6 by RNA interference (A6sh) or withdrawal lapatinib from LAP-R cells not only reversed the accumulation of cholesterol in late endosomes but also led to enrichment of plasma membranes with cholesterol, restored EGFR-dependent activation of ERK1/2 and sensitized the cells to lapatinib. These data suggest that lapatinib-induced AnxA6 expression and accumulation of cholesterol in late endosomes constitute an adaptive mechanism for EGFR-expressing TNBC cells to overcome prolong treatment with EGFR-targeted TKIs and can be exploited as an option to inhibit and/or monitor the frequently observed acquired resistance to these drugs.

SUMOylation in the control of cholesterol homeostasis

SUMOylation—protein modification by the small ubiquitin-related modifier (SUMO)—affects several cellular processes by modulating the activity, stability, interactions or subcellular localization of a variety of substrates. SUMO modification is involved in most cellular processes required for the maintenance of metabolic homeostasis. Cholesterol is one of the main lipids required to preserve the correct cellular function, contributing to the composition of the plasma membrane and participating in transmembrane receptor signalling. Besides these functions, cholesterol is required for the synthesis of steroid hormones, bile acids, oxysterols and vitamin D. Cholesterol levels need to be tightly regulated: in excess, it is toxic to the cell, and the disruption of its homeostasis is associated with various disorders like atherosclerosis and cardiovascular diseases. This review focuses on the role of SUMO in the regulation of proteins involved in the metabolism of cholesterol.

Calcitonin receptor is required for T-antigen-induced prostate carcinogenesis

Expression of calcitonin (CT) and its receptor (CTR) is frequently elevated in prostate cancer (PC) and activation of CT–CTR axis in non- invasive PC cells induces an invasive phenotype. However, the role of CT-CTR axis in prostate carcinogenesis has not been investigated. We employed a transgenic mouse prostate cancer model that uses long probasin promoter to target the expression of T-antigen in the prostate gland (LPB-Tag) along with CTR knock-out mice (CTRKO) to address this question. We cross-bred LPB-Tag mice with CTRKO to obtain four groups of mice. Prostates of these mice were obtained at the age of 90 days, fixed, paraffin-embedded, and used either for the extraction of RNA or for immunofluorescence. Prostate RNAs from different groups were reverse transcribed and used either for transcription profiling or for qRT-PCR. As expected, prostates of mice with LPB-Tag genotype displayed well-grown tumors with histologic features such as loss of normal morphology and nuclear atypia. WT as well as CTRKO mice displayed normal prostate morphology. Interestingly, LPB-Tag-CTRKO prostates also displayed relatively normal morphology which was indistinguishable from the WT. Microarray analysis as well as qRT-PCR suggested that CTRKO genotype reversed T-antigen-induced silencing of RB and PTEN gene expression as well as T-antigen-induced expression of several enzymes associated with lipid metabolism/ cholesterol biosynthesis, several cancer-related and androgen-regulated genes. The results for the first time identify mechanisms associated CTR-induced prostate carcinogenesis, and raise an exciting possibility of using a potent CT antagonist to attenuate progression of prostate cancer.

Association of Cholecystectomy with the Risk of Prostate Cancer in Patients with Gallstones

Objectives: To assess the association of cholecystectomy with the risk of prostate cancer in patients with gallstones. Methods: This nationwide population-based cohort study was conducted by retrieving the Longitudinal Health Insurance Research Database (LHID2000) for inpatient claims in the Taiwan National Health Insurance (NHI) program. The study cohort consisted of 72,606 men aged ≥ 20 years with gallstones undergoing cholecystectomy between 2000 and 2010. The control cohort consisted of the men with gallstones, but without cholecystectomy, by 1:1 propensity score matching with the study cohort based on age, sex, urbanization, occupation, comorbidities, and the index date. We compared the hazard ratio of prostate cancer between both of the cohorts. Results: The incidence of prostate cancer was 0.76/1000 person-years for the non-cholecystectomy cohort and 1.28/1000 person-years for the cholecystectomy cohort [aHR (adjusted hazard ratio) = 1.67, 95% confidence interval (CI = 1.45–1.92), respectively (p < 0.001). When compared with the non-cholecystectomy cohort, the hazard ratio of prostate cancer for the cholecystectomy cohort was 1.49-fold greater (95% CI = 1.04–2.11) for follow-up ≤ 1 year, 1.52-fold greater (95% CI = 1.24–1.86) for follow-up 1–5 years, and 1.99-fold greater (95% CI = 1.56–2.53) for follow-up > 5 years, respectively. Conclusions: Cholecystectomy is associated with an increased hazard ratio of prostate cancer in gallstones patients, and the risk increases with an incremental period of follow-up. This observational study cannot ascertain the detrimental mechanisms of cholecystectomy for the development of prostate cancer, and cholecystectomy is not recommended for the prevention of prostate cancer based on our study.

Modelling of interactions between Aβ(25-35) peptide and phospholipid bilayers: effects of cholesterol and lipid saturation

Aggregation of amyloid beta (Aβ) peptides in neuronal membranes is a known promoter of Alzheimer’s disease. To gain insight into the molecular details of Aβ peptide aggregation and its effect on model neuronal membranes, we carried out molecular dynamics simulations of the Aβ(25–35) fragment of the amyloid precursor protein in phospholipid bilayers composed of either fully saturated or highly unsaturated lipids, in the presence or absence of cholesterol. It was found that the peptide does not penetrate through any of the considered membranes, but can reside in the headgroup region and upper part of the lipid tails showing a clear preference to a polyunsaturated cholesterol-free membrane. Due to the ordering and condensing effect upon addition of cholesterol, membranes become more rigid facilitating peptide aggregation on the surface. Except for the case of the cholesterol-free saturated lipid bilayer, the peptides have a small effect on the membrane structure and ordering. It was also found that the most “active” amino-acid for peptide–lipid and peptide–cholesterol interaction is methionine-35, followed by asparagine-27 and serine-26, which form hydrogen bonds between peptides and polar atoms of lipid headgroups. These amino acids are also primarily responsible for peptide aggregation. This work will be relevant for designing strategies to develop drugs to combat Alzheimer’s disease.

Molecular dynamics simulations of Aβ(25–35) peptides in phospholipid bilayers are carried out to investigate the effect of polyunsaturated lipids and cholesterol on aggregation of the peptides.

Validation of Human Sterol 14α-Demethylase (CYP51) Druggability: Structure-Guided Design, Synthesis, and Evaluation of Stoichiometric, Functionally Irreversible Inhibitors

Sterol 14α-demethylases (CYP51) are the cytochrome P450 enzymes required for biosynthesis of sterols in eukaryotes, the major targets for antifungal agents and prospective targets for treatment of protozoan infections. Human CYP51 could be and, for a while, was considered as a potential target for cholesterol-lowering drugs (the role that is now played by statins, which are also in clinical trials for cancer) but revealed high intrinsic resistance to inhibition. While microbial CYP51 enzymes are often inhibited stoichiometrically and functionally irreversibly, no strong inhibitors have been identified for human CYP51. In this study, we used comparative structure/functional analysis of CYP51 orthologs from different biological kingdoms and employed site-directed mutagenesis to elucidate the molecular basis for the resistance of the human enzyme to inhibition and also designed, synthesized, and characterized new compounds. Two of them inhibit human CYP51 functionally irreversibly with their potency approaching the potencies of azole drugs currently used to inhibit microbial CYP51.

Effect of selected B-ring-substituted oxysterols on artificial model erythrocyte membrane and isolated red blood cells

In this paper, systematic studies concerning the influence of selected oxysterols on the structure and fluidity of human erythrocyte membrane modeled as Langmuir monolayers have been performed. Three oxidized cholesterol derivatives, namely 7α-hydroxycholesterol (7α-OH) 7β-hydroxycholesterol (7β-OH) and 7-ketocholesterol (7-K) have been incorporated in two different proportions (10 and 50%) into artificial erythrocyte membrane, modeled as two-component (cholesterol:POPC) Langmuir monolayer. All the studied oxysterols were found to alter membrane fluidity and the effect was more pronounced for higher oxysterol content. 7α-OH increased membrane fluidity while opposite effect was observed for 7β-OH and 7-K. Experiments performed on model systems have been verified in biological studies on red blood cells (RBC). Consistent results have been found, i.e. under the influence of 7α-OH, the elasticity of erythrocytes increased, and in the presence of other investigated oxysterols - decreased. The strongest effect was noticed for 7-K. Change of membrane elasticity was associated with the change of erythrocytes shape, being most noticeable under the influence of 7-K.

Penfluridol as a Candidate of Drug Repurposing for Anticancer Agent

Penfluridol has robust antipsychotic efficacy and is a first-generation diphenylbutylpiperidine. Its effects last for several days after a single oral dose and it can be administered once a week to provide better compliance and symptom control. Recently; strong antitumour effects for penfluridol were discovered in various cancer cell lines; such as breast; pancreatic; glioblastoma; and lung cancer cells via several distinct mechanisms. Therefore; penfluridol has drawn much attention as a potentially novel anti-tumour agent. In addition; the anti-cancer effects of penfluridol have been demonstrated in vivo: results showed slight changes in the volume and weight of organs at doses tested in animals. This paper outlines the potential for penfluridol to be developed as a next-generation anticancer drug.

Lipid Status During Combined Treatment in Prostate Cancer Patients

The aim of this study was to provide a specific review of current medical literature regarding the lipid profile during prostate carcinoma (PCa) treatment. The main aim was to analyze the results presented by different authors and to find a commonality in the changes occurring during the treatment-hormonotherapy. The levels of total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol were measured before and after the follow-up treatment. The manuscripts reviewed came from the period between 2008 and 2016. The size of the studies ranged from 16 participants to 310. The mean age was from 65 to 74 years in all studies. The Q test was used to attain all lipid parameters and to specify heterogeneity (p < .0001). After 12 months of androgen deprivation therapy (ADT), the patients had a significantly higher level serum TC and TG.

Anti-cancer effect of doxorubicin is mediated by downregulation of HMG-Co A reductase via inhibition of EGFR/Src pathway

Doxorubicin is a widely used DNA damage-inducing anti-cancer drug. However, its use is limited by its dose-dependent side effects, such as cardiac toxicity. Cholesterol-lowering statin drugs increase the efficacy of some anti-cancer drugs. Cholesterol is important for cell growth and a critical component of lipid rafts, which are plasma membrane microdomains important for cell signaling. 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMG-CR) is a critical enzyme in cholesterol synthesis. Here, we show that doxorubicin downregulated HMG-CR protein levels and thus reduced levels of cholesterol and lipid rafts. Cholesterol addition attenuated doxorubicin-induced cell death, and cholesterol depletion enhanced it. Reduction of HMG-CR activity by simvastatin, a statin that acts as an HMG-CR inhibitor, or by siRNA-mediated HMG-CR knockdown enhanced doxorubicin cytotoxicity. Doxorubicin-induced HMG-CR downregulation was associated with inactivation of the EGFR-Src pathway. Furthermore, a high-cholesterol-diet attenuated the anti-cancer activity of doxorubicin in a tumor xenograft mouse model. In a multivulva model of Caenorhabditis elegans expressing an active-EGFR mutant, doxorubicin decreased hyperplasia more efficiently in the absence than in the presence of cholesterol. These data indicate that EGFR/Src/HMG-CR is a new pathway mediating doxorubicin-induced cell death and that cholesterol control could be combined with doxorubicin treatment to enhance efficacy and thus reduce side effects.

Cholesterol Sulfotransferase SULT2B1b Modulates Sensitivity to Death Receptor Ligand TNFα in Castration-Resistant Prostate Cancer

Cholesterol sulfotransferase, SULT2B1b, has been demonstrated to modulate both androgen receptor activity and cell growth properties. However, the mechanism(s) by which SULT2B1b alters these properties within prostate cancer cells has not been described. Furthermore, specific advantages of SULT2B1b expression in prostate cancer cells are not understood. In these studies, single-cell mRNA sequencing was conducted to compare the transcriptomes of SULT2B1b knockdown (KD) versus Control KD LNCaP cells. Over 2,000 differentially expressed genes were identified along with alterations in numerous canonical pathways, including the death receptor signaling pathway. The studies herein demonstrate that SULT2B1b KD increases TNFα expression in prostate cancer cells and results in NF-κB activation in a TNF-dependent manner. More importantly, SULT2B1b KD significantly enhances TNF-mediated apoptosis in both TNF-sensitive LNCaP cells and TNF-resistant C4-2 cells. Overexpression of SULT2B1b in LNCaP cells also decreases sensitivity to TNF-mediated cell death, suggesting that SULT2B1b modulates pathways dictating the TNF sensitivity capacity of prostate cancer cells. Probing human prostate cancer patient datasets further supports this work by providing evidence that SULT2B1b expression is inversely correlated with TNF-related genes, including TNF, CD40LG, FADD, and NFKB1. Together, these data provide evidence that SULT2B1b expression in prostate cancer cells enhances resistance to TNF and may provide a growth advantage. In addition, targeting SULT2B1b may induce an enhanced therapeutic response to TNF treatment in advanced prostate cancer. IMPLICATIONS: These data suggest that SULT2B1b expression enhances resistance to TNF and may promote prostate cancer.

Accounting for biological variation with linear mixed-effects modelling improves the quality of clinical metabolomics data

Metabolite profiles from biological samples suffer from both technical variations and subject-specific variants. To improve the quality of metabolomics data, conventional data processing methods can be employed to remove technical variations. These methods do not consider sources of subject variation as separate factors from biological factors of interest. This can be a significant issue when performing quantitative metabolomics in clinical trials or screening for a potential biomarker in early-stage disease, because changes in metabolism or a desired-metabolite signal are small compared to the total metabolite signals. As a result, inter-individual variability can interfere subsequent statistical analyses. Here, we propose an additional data processing step using linear mixed-effects modelling to readjust an individual metabolite signal prior to multivariate analyses. Published clinical metabolomics data was used to demonstrate and evaluate the proposed method. We observed a substantial reduction in variation of each metabolite signal after model fitting. A comparison with other strategies showed that our proposed method contributed to improved classification accuracy, precision, sensitivity and specificity. Moreover, we highlight the importance of patient metadata as it contains rich information of subject characteristics, which can be used to model and normalize metabolite abundances. The proposed method is available as an R package lmm2met.

Is low cholesterol a risk factor for cancer mortality?

Although a large number of studies have shown the associations of high plasma lipid profile levels with cancer, few studies demonstrate the association between low serum cholesterol (<160 mg/dl) and risk for cancer mortality. The aim of this study was to determine the association of low serum cholesterol level as a risk factor for mortality in cancer. The prospective cohort studies were conducted on 19 of 52 cohort studies including 30 179 male and 26 005 female participants who were followed up for 9 years. Cox proportion hazard model was applied to analyze these data. The associations are presented as hazard ratios (HRs) with 95% confidence intervals (CI). The statistical package for the social sciences software was used for analysis. The multivariate analysis results showed risk associations with low serum cholesterol for the first decile among male participants (cancer: HR=1.52, 95% CI: 1.06-2.18; noncancer liver dysfunction: HR=10.73, 95% CI: 3.74-30.18) and female participants (cancer: HR=1.03, 95% CI: 0.52-2.05; noncancer liver dysfunction: HR=25.8, 95% CI: 3.09-217.70). Furthermore, in the second decile, this association among male patients (noncancer liver dysfunction: HR=3.73, 95% CI: 1.16-11.95) had a statistically significant result. For the remaining deciles in both sexes, cancer and noncancer liver dysfunction has some risk or protective association, although not significant. Findings of this study indicated an inverse association between low serum cholesterol and cancer and noncancer liver dysfunction mortality.

Cholesterol Induces Epithelial-to-Mesenchymal Transition of Prostate Cancer Cells by Suppressing Degradation of EGFR through APMAP

Cholesterol increases the risk of aggressive prostate cancer and has emerged as a potential therapeutic target for prostate cancer. The functional roles of cholesterol in prostate cancer metastasis are not fully understood. Here, we found that cholesterol induces the epithelial-to-mesenchymal transition (EMT) through extracellular-regulated protein kinases 1/2 pathway activation, which is mediated by EGFR and adipocyte plasma membrane-associated protein (APMAP) accumulation in cholesterol-induced lipid rafts. Mechanistically, APMAP increases the interaction with EGFR substrate 15-related protein (EPS15R) to inhibit the endocytosis of EGFR by cholesterol, thus promoting cholesterol-induced EMT. Both the mRNA and protein levels of APMAP are upregulated in clinical prostate cancer samples. Together, these findings shed light onto an APMAP/EPS15R/EGFR axis that mediates cholesterol-induced EMT of prostate cancer cells. SIGNIFICANCE: This study delineates the molecular mechanisms by which cholesterol increases prostate cancer progression and demonstrates that the binding of cholesterol-induced APMAP with EPS15R inhibits EGFR internalization and activates ERK1/2 to promote EMT. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/12/3063/F1.large.jpg.

Cholesterol in phospholipid bilayers: positions and orientations inside membranes with different unsaturation degrees

Cholesterol is an essential component of all animal cell membranes and plays an important role in maintaining the membrane structure and physical-chemical properties necessary for correct cell functioning. The presence of cholesterol is believed to be responsible for domain formation (lipid rafts) due to different interactions of cholesterol with saturated and unsaturated lipids. In order to get detailed atomistic insight into the behaviour of cholesterol in bilayers composed of lipids with varying degrees of unsaturation, we have carried out a series of molecular dynamics simulations of saturated and polyunsaturated lipid bilayers with different contents of cholesterol, as well as well-tempered metadynamics simulations with a single cholesterol molecule in these bilayers. From these simulations we have determined distributions of cholesterol across the bilayer, its orientational properties, free energy profiles, and specific interactions of molecular groups able to form hydrogen bonds. Both molecular dynamics and metadynamics simulations showed that the most unsaturated bilayer with 22:6 fatty acid chains shows behaviour which is most different from other lipids. In this bilayer, cholesterol is relatively often found in a "flipped" configuration with the hydroxyl group oriented towards the membrane middle plane. This bilayer has also the highest (least negative) binding free energy among liquid phase bilayers, and the lowest reorientation barrier. Furthermore, cholesterol molecules in this bilayer are often found to form head-to-tail contacts which may lead to specific clustering behaviour. Overall, our simulations support ideas that there can be a subtle interconnection between the contents of highly unsaturated fatty acids and cholesterol, deficiency or excess of each of them is related to many human afflictions and diseases.

Perturbing the Dynamics and Organization of Cell Membrane Components: A New Paradigm for Cancer-Targeted Therapies

Cancer is a multi-process disease where different mechanisms exist in parallel to ensure cell survival and constant adaptation to the extracellular environment. To adapt rapidly, cancer cells re-arrange their plasma membranes to sustain proliferation, avoid apoptosis and resist anticancer drugs. In this review, we discuss novel approaches based on the modifications and manipulations that new classes of molecules can exert in the plasma membrane lateral organization and order of cancer cells, affecting growth factor signaling, invasiveness, and drug resistance. Furthermore, we present azurin, an anticancer protein from bacterial origin, as a new approach in the development of therapeutic strategies that target the cell membrane to improve the existing standard therapies.

Characterization of farnesyl diphosphate farnesyl transferase 1 (FDFT1) expression in cancer

AIM

To help characterize the FDFT1 gene and protein expression in cancer. Cholesterol represents an important structural component of lipid rafts. These specializations can be involved in pathways stimulating cell growth, survival and other processes active in cancer. This cellular compartment can be expanded by acquisition of cholesterol from the circulation or by its synthesis in a metabolic pathway regulated by the FDFT1 enzyme. Given the critical role this might play in carcinogenesis and in the behavior of cancers, we have examined the level of this enzyme in various types of human cancer. Our demonstration of elevated levels of FDFT1 mRNA and protein in some tumors relative to surrounding normal tissue identifies this as a possible biomarker for disease development and progression, and as a potential new target for the treatment of cancer.

Metabolic Vulnerabilities of Prostate Cancer: Diagnostic and Therapeutic Opportunities

Cancer cells hijack metabolic pathways to support bioenergetics and biosynthetic requirements for their uncontrolled growth. Thus, cancer can be considered as a metabolic disease. In this review, we discuss the main metabolic features of prostate cancer with a particular focus on the link between oncogene-directed cancer metabolic regulation, metabolism rewiring, and epigenetic regulation. The potential of using metabolic profiling as a means to predict disease behavior and to identify novel therapeutic targets and new diagnostic markers will be addressed as well as the current challenges in metabolomics analyses. Finally, diagnostic and prognostic metabolic imaging approaches, including positron emission tomography, mass spectrometry, nuclear magnetic resonance, and their translational applications, will be discussed. Here, we emphasize how targeting metabolic vulnerabilities in prostate cancer may pave the way for novel personalized diagnostic and therapeutic interventions.

Cholesterol synthesis pathway genes in prostate cancer are transcriptionally downregulated when tissue confounding is minimized

BACKGROUND

The relationship between cholesterol and prostate cancer has been extensively studied for decades, where high levels of cellular cholesterol are generally associated with cancer progression and less favorable outcomes. However, the role of in vivo cellular cholesterol synthesis in this process is unclear, and data on the transcriptional activity of cholesterol synthesis pathway genes in tissue from prostate cancer patients are inconsistent.

METHODS

A common problem with cancer tissue data from patient cohorts is the presence of heterogeneous tissue which confounds molecular analysis of the samples. In this study we present a general method to minimize systematic confounding from stroma tissue in any prostate cancer cohort comparing prostate cancer and normal samples. In particular we use samples assessed by histopathology to identify genes enriched and depleted in prostate stroma. These genes are then used to assess stroma content in tissue samples from other prostate cancer cohorts where no histopathology is available. Differential expression analysis is performed by comparing cancer and normal samples where the average stroma content has been balanced between the sample groups. In total we analyzed seven patient cohorts with prostate cancer consisting of 1713 prostate cancer and 230 normal tissue samples.

RESULTS

When stroma confounding was minimized, differential gene expression analysis over all cohorts showed robust and consistent downregulation of nearly all genes in the cholesterol synthesis pathway. Additional Gene Ontology analysis also identified cholesterol synthesis as the most significantly altered metabolic pathway in prostate cancer at the transcriptional level.

CONCLUSION

The surprising observation that cholesterol synthesis genes are downregulated in prostate cancer is important for our understanding of how prostate cancer cells regulate cholesterol levels in vivo. Moreover, we show that tissue heterogeneity explains the lack of consistency in previous expression analysis of cholesterol synthesis genes in prostate cancer.

Identification of race-associated metabolite biomarkers for hepatocellular carcinoma in patients with liver cirrhosis and hepatitis C virus infection

Disparities in hepatocellular carcinoma (HCC) incidence and survival have been observed between ethnic groups including African-Americans (AA) and European-Americans (EA). The evaluation of the changes in the levels of metabolites in samples stratified by race could provide a snapshot of ethnically diverse disease related pathways and identify reliable biomarkers. In this study, we considered AA and EA to investigate metabolites that may be associated with HCC in a race-specific manner. The levels of 46 metabolites in plasma samples, collected from patients recruited at MedStar Georgetown University Hospital, were analyzed by Agilent GC-qMS in selected ion monitoring (SIM) mode. A least absolute shrinkage and selection operator (LASSO) regression model was applied to select metabolites with significant changes in HCC vs. cirrhosis in three groups: (1) AA and EA combined; (2) AA separately; and (3) EA separately. In addition, metabolites that distinguish HCC cases from cirrhosis in these three groups were selected by excluding those without HCV infection. The performances of the metabolites selected by LASSO in each group were evaluated through a leave-one-out cross-validation. We identified race-specific metabolites that differentiated HCC cases from cirrhotic controls, yielding better area under the receiver operating characteristics (ROC) curve (AUC) compared to alpha-fetoprotein (AFP), the serological marker widely used for the diagnosis of HCC. This study sheds light on metabolites that could potentially be used as biomarkers for HCC by monitoring their levels in high-risk population of cirrhotic patients in a race-specific manner.

Hyperlipidemia is associated with an increased risk of clinical benign prostatic hyperplasia

BACKGROUND

A high fat diet is associated with risk of benign prostatic hyperplasia (BPH). However, whether hyperlipidemia is associated with BPH remains unclear. This population-based cohort study elucidated whether hyperlipidemia is associated with an increased risk of BPH.

METHODS

We used a new-exposure design and analyzed data retrieved from the Taiwan National Health Insurance Database between January 1, 2000 and December 31, 2013. The cohort of men with newly diagnosed hyperlipidemia and the age- and index-date-matched (1:3) nonhyperlipidemia cohort were tracked for incidence of BPH during a 1- to 14-year follow-up. Diagnosis of BPH using the International Classification of Diseases, Ninth Revision, Clinical Modification codes, and the occurrence of BPH diagnosis plus the use of alpha-blockers or 5-alpha reductase inhibitors or receipt of transurethral resection of the prostate were the primary and secondary endpoints, respectively. The confounders in this study were diabetes mellitus, hypertension, coronary heart disease, obesity, liver cirrhosis, nonsteroidal anti-inflammatory drugs, metformin, aspirin, and number of urologist visits. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using a multivariate Cox proportional hazards regression model adjusted for the propensity score.

RESULTS

A total of 35 860 subjects (aged 40-99 years)-including the hyperlipidemia cohort (n = 8,965) and nonhyperlipidemia cohort (n = 26 895)-were identified. Our data revealed that the hyperlipidemia cohort had significantly higher incidences of developing BPH (24.6% vs 12.3%, P < 0.001) and treated BPH (13% vs 5.7%, P < 0.001) compared with the nonhyperlipidemia cohort. The risk of developing BPH in the hyperlipidemia cohort was significantly higher than that in the nonhyperlipidemia cohort (HR = 1.73, 95% CI = 1.63-1.83, P < 0.001) after adjustment for the propensity score.

CONCLUSIONS

Hyperlipidemia is associated with an increased risk of clinical BPH.

Cholesterol and Cholesterol-Rich Membranes in Prostate Cancer: An Update

Cells maintain normal structure and function by responding appropriately to cues from the surrounding milieu. Extracellular stimuli are transduced from the surface through the plasma membrane by a complex series of interactions between ligands, their receptors and intracellular signaling partners (e.g., kinases, G proteins). Cholesterol-enriched membrane microdomains, generally referred to as “lipid rafts”, exist within the lipid bilayer of all mammalian cells and play an important role in signaling from the cell surface to various subcellular compartments. Lipid rafts have also been implicated in tumor growth and aggressiveness. Epidemiological evidence suggests that the modern Western diet, which contains substantial levels of cholesterol and other fatty substances, promotes prostate cancer progression. Consistent with this idea, prolonged inhibition of the cholesterol synthesis pathway by pharmacologic intervention in men has recently been associated with reduction in risk of advanced prostate cancer. In this review, we discuss the possibility that membrane cholesterol promotes prostate cancer progression by a mechanism that involves dysregulation of lipid raft-resident signaling complexes. This hypothesis provides new avenues for mechanistic studies as well as therapeutic intervention.

ATP-binding cassette transporter-2 (ABCA2) as a therapeutic target

The ATP binding cassette transporter ABCA2 is primarily an endolysosomal membrane protein that demonstrates pleiotropic functionalities, coalescing around the maintenance of homeostasis of sterols, sphingolipids and cholesterol. It is most highly expressed in brain tissue and ABCA2 knockout mice express neurological defects consistent with aberrant myelination. Increased expression of the transporter has been linked with resistance to cancer drugs, particularly those possessing a steroid backbone and gene expression (in concert with other genes involved in cholesterol metabolism) was found to be regulated by sterols. Moreover, in macrophages ABCA2 is influenced by sterols and has a role in regulating cholesterol sequestration, potentially important in cardiovascular disease. Accumulating data indicate the critical importance of ABCA2 in mediating movement of sphingolipids within cellular compartments and these have been implicated in various aspects of cholesterol trafficking. Perhaps because the functions of ABCA2 are linked with membrane building blocks, there are reports linking it with human pathologies, including, cholesterolemias and cardiovascular disease, Alzheimer's and cancer. The present review addresses whether there is now sufficient information to consider ABCA2 as a plausible therapeutic target.

The Comparison and Estimation of the Prognostic Value of Lipid Profiles in Patients With Prostate Cancer Depends on Cancer Stage Advancement

Lipid profiles and prostate cancer have a controversial relationship, and the predictive ability of lipids in determining cancer risk estimation is still questionable. This study demonstrates a significance assessment of the plasma lipid profiles of subjects with prostate cancer. Locoregional subjects irradiated with external beam therapy were compared to prostate cancer subjects with bone metastases. The histopathologic diagnosis of 103 subjects (71 locoregional [Group 1] and 32 palliative [Group 2]) were analyzed and compared using their blood samples, total cholesterol (CHL), triglycerides (TG), high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol. The HDL/CHL, LDL/CHL, and TG/HDL ratios were used for better fit and comparison. Subjects were grouped according to their cancer stages and assessed using statins in both groups. In this study, serum HDL/CHL was significantly increased in Group 1 compared to Group 2 ( p = .02), and time-statin factor in relation was statistically significant ( p = .02). For Group 2, this index decreased with each day after radiotherapy ( p = .07), which means the CHL was increased. Negative effects were noticed at the time of observation of the LDL/HDL ratio with an approximate increase of 0.0025 each day in palliative subjects. This ratio showed a statically significant elevation ( p = .04). There was not a statistically significant difference in the value of the TG/HDL ratio between both groups. As the survival of cancer subjects increases, frequent control of the lipid profile gains importance.

27-hydroxycholesterol: A novel player in molecular carcinogenesis of breast and prostate cancer

Several studies have suggested an etiological role for hypercholesterolemia in the pathogenesis of breast cancer and prostate cancer (PCa). However, the molecular mechanisms that underlie and mediate the hypercholesterolemia-fostered increased risk for breast cancer and PCa are yet to be determined. The discovery that the most abundant cholesterol oxidized metabolite in the plasma, 27 hydroxycholesterol (27-OHC), is a selective estrogen receptor modulator (SERM) and an agonist of Liver X receptors (LXR) partially fills the void in our understanding and knowledge of the mechanisms that may link hypercholesterolemia to development and progression of breast cancer and PCa. The wide spectrum and repertoire of SERM and LXR-dependent effects of 27-OHC in the context of all facets and aspects of breast cancer and prostate cancer biology are reviewed in this manuscript in a very comprehensive manner. This review highlights recent findings pertaining to the role of 27-OHC in breast cancer and PCa and delineates the signaling mechanisms involved in the governing of different facets of tumor biology, that include tumor cell proliferation, epithelial-mesenchymal transition (EMT), as well as tumor cell invasion, migration, and metastasis. We also discuss the limitations of contemporary studies and lack of our comprehension of the entire gamut of effects exerted by 27-OHC that may be relevant to the pathogenesis of breast cancer and PCa. We unveil and propose potential future directions of research that may further our understanding of the role of 27-OHC in breast cancer and PCa and help design therapeutic interventions against endocrine therapy-resistant breast cancer and PCa.

Possible protective effect of royal jelly against cyclophosphamide induced prostatic damage in male albino rats; a biochemical, histological and immuno-histo-chemical study

Almost all the chemotherapy treat many cancer types effectively, but it leads to severe side effects. Chemotherapy like cyclophosphamide (CP) not works only on the active cells, such as cancer cells, but also acts on the healthy cells. Royal jelly (RJ) was reported to have a lot of therapeutic effects besides being an anti-oxidant and anti-cancer agent. The purpose of this study was to assess the possible protective role of RJ in ameliorating the toxic effects of CP overdose in the rat prostatic tissue. The rats were separated into 4 groups; control group, RJ group, CP group and RJ with CP group. Prostatic specimens were processed for biochemical, histological and immune-histo-chemical studies. The mean area fractions of eNOS and Bax expression were measured in all groups, and statistical analysis was carried out. The results showed that in CP treated group, there were marked biological changes in the form of significant increase in prostatic malondialdehyde (MDA) and C - reactive protein (CRP). Additionally there was a significant decrease in glutathione peroxidase (GPx) in prostatic tissue if compared with the control group. Furthermore, the histological changes showed marked acinar and stromal prostatic degeneration. Most prostatic acini showed less PAS reaction and more (eNOS and Bax) expression if compared with the control group. Concomitant administration of RJ with CP revealed a noticeable amelioration of these biochemical and histological changes. In conclusion, RJ provided biochemical and histo-pathological improvement in CP induced prostatic tissue toxicity. These findings revealed that this improvement was associated with a decrease in the tissue oxidative damage and apoptosis.

SR-BI: Linking Cholesterol and Lipoprotein Metabolism with Breast and Prostate Cancer

Studies have demonstrated the significant role of cholesterol and lipoprotein metabolism in the progression of cancer. The SCARB1 gene encodes the scavenger receptor class B type I (SR-BI), which is an 82-kDa glycoprotein with two transmembrane domains separated by a large extracellular loop. SR-BI plays an important role in the regulation of cholesterol exchange between cells and high-density lipoproteins. Accordingly, hepatic SR-BI has been shown to play an essential role in the regulation of the reverse cholesterol transport pathway, which promotes the removal and excretion of excess body cholesterol. In the context of atherosclerosis, SR-BI has been implicated in the regulation of intracellular signaling, lipid accumulation, foam cell formation, and cellular apoptosis. Furthermore, since lipid metabolism is a relevant target for cancer treatment, recent studies have focused on examining the role of SR-BI in this pathology. While signaling pathways have initially been explored in non-tumoral cells, studies with cancer cells have now demonstrated SR-BI's function in tumor progression. In this review, we will discuss the role of SR-BI during tumor development and malignant progression. In addition, we will provide insights into the transcriptional and post-transcriptional regulation of the SCARB1 gene. Overall, studying the role of SR-BI in tumor development and progression should allow us to gain useful information for the development of new therapeutic strategies.

Cholesterol Sulfonation Enzyme, SULT2B1b, Modulates AR and Cell Growth Properties in Prostate Cancer

Cholesterol accumulates in prostate lesions and has been linked to prostate cancer incidence and progression. However, how accumulated cholesterol contributes to prostate cancer development and progression is not completely understood. Cholesterol sulfate (CS), the primary sulfonation product of cholesterol sulfotransferase (SULT2B1b), accumulates in human prostate adenocarcinoma and precancerous prostatic intraepithelial neoplasia (PIN) lesions compared with normal regions of the same tissue sample. Given the enhanced accumulation of CS in these lesions, it was hypothesized that SULT2B1b-mediated production of CS provides a growth advantage to these cells. To address this, prostate cancer cells with RNAi-mediated knockdown (KD) of SULT2B1b were used to assess the impact on cell growth and survival. SULT2B1b is expressed and functional in a variety of prostate cells, and the data demonstrate that SULT2B1b KD, in LNCaP and other androgen-responsive (VCaP and C4-2) cells, results in decreased cell growth/viability and induces cell death. SULT2B1b KD also decreases androgen receptor (AR) activity and expression at mRNA and protein levels. While AR overexpression has no impact on SULT2B1b KD-mediated cell death, the addition of exogenous androgen is able to partially rescue the growth inhibition induced by SULT2B1b KD in LNCaP cells. These results suggest that SULT2B1b positively regulates the AR either through alterations in ligand availability or by interaction with critical coregulators that influence AR activity.

IMPLICATIONS

These findings provide evidence that SULT2B1b is a novel regulator of AR activity and cell growth in prostate cancer and should be further investigated for therapeutic potential. Mol Cancer Res; 14(9); 776-86. ©2016 AACR.

Human sterol 14α-demethylase as a target for anticancer chemotherapy: towards structure-aided drug design

Rapidly multiplying cancer cells synthesize greater amounts of cholesterol to build their membranes. Cholesterol-lowering drugs (statins) are currently in clinical trials for anticancer chemotherapy. However, given at higher doses, statins cause serious side effects by inhibiting the formation of other biologically important molecules derived from mevalonate. Sterol 14α-demethylase (CYP51), which acts 10 steps downstream, is potentially a more specific drug target because this portion of the pathway is fully committed to cholesterol production. However, screening a variety of commercial and experimental inhibitors of microbial CYP51 orthologs revealed that most of them (including all clinical antifungals) weakly inhibit human CYP51 activity, even if they display high apparent spectral binding affinity. Only one relatively potent compound, (R)-N-(1-(3,4'-difluorobiphenyl-4-yl)-2-(1H-imidazol-1-yl)ethyl)-4-(5-phenyl-1,3,4-oxadiazol-2-yl)benzamide (VFV), was identified. VFV has been further tested in cellular experiments and found to decrease proliferation of different cancer cell types. The crystal structures of human CYP51-VFV complexes (2.0 and 2.5 Å) both display a 2:1 inhibitor/enzyme stoichiometry, provide molecular insights regarding a broader substrate profile, faster catalysis, and weaker susceptibility of human CYP51 to inhibition, and outline directions for the development of more potent inhibitors.

Hypercholesterolemia Is Associated with a Shorter Time to Castration-Resistant Prostate Cancer in Patients Who Have Undergone Androgen Deprivation Therapy

Purpose

The goal of this study was to investigate the association between hypercholesterolemia and the time required for progression to castration-resistant prostate cancer (CRPC) in patients who have undergone androgen deprivation therapy (ADT).

Materials and Methods

Data from 154 patients with prostate cancer between 2005 and 2012 were reviewed retrospectively. ADT was employed as a treatment modality for these patients either due to multiple bone metastases at the time of diagnosis or due to old age in combination with other morbidities. Serum cholesterol levels and statin use were reviewed. We analyzed the factors associated with the development of CRPC after ADT treatment. The mean follow-up period was 34.8 months.

Results

The mean age of the patients was 71.3 years old and their mean prostate-specific antigen level was 141.8±212.6 ng/mL. Their mean cholesterol level was 175.9±37.7 mg/dL, and 14 patients (9.1%) were statin users. CRPC developed in 44 patients (28.6%), and the mean duration from ADT treatment to CRPC was 24.1 months. In a multivariate analysis, hypercholesterolemia was associated with the development of CRPC (hazard ratio [HR]=1.017, p<0.001), depending on clinical T stage (p=0.005) and the presence of bone metastasis (p<0.001). A subanalysis showed that hypercholesterolemia was associated with the development of CRPC in patients with bone metastasis (HR=1.032, p<0.001), but not in patients without bone metastasis.

Conclusions

Hypercholesterolemia may be associated with the development of CRPC after ADT in patients with bone metastasis. Further studies with longer follow-up periods and larger samples are needed to validate this finding.

Involvement of cholesterol in Campylobacter jejuni cytolethal distending toxin-induced pathogenesis

AIM

The aim of this study was to investigate whether cholesterol plays a pivotal role in cytolethal distending toxin (CDT) mediated pathogenic effects in hosts.

MATERIALS & METHODS

The molecular mechanisms underlying cholesterol sequestering conferred resistance to CDT-induced DNA double-strand breaks (DSBs) and cell cycle arrest were investigated. Histopathological analysis was conducted for evaluating CDT-induced intestinal inflammation in mouse.

RESULTS

CDT actions were attenuated by treatment of cells with methyl-β-cyclodextrin (MβCD). Severe intestinal inflammation induced by CDT treatment was observed in high-cholesterol diet-fed mice, but not in normal diet-fed mice, indicating that cholesterol is essential for CDT intoxication.

CONCLUSION

Our findings demonstrate a molecular link between Campylobacter jejuni CDT and cholesterol, which is crucial to facilitate CDT-induced pathogenesis in hosts.

[Lipid metabolism in patients with hematologic cancers]

It is considered that hypercholesterolemia is life-threatening and low cholesterol levels are a positive factor. However, taking into consideration the fact that cholesterol plays a key role in cell proliferation, it should be remembered that its low blood level may be linked to high cholesterol demands from neoplastic cells. The literature review analyzes the results of recent investigations of lipid metabolism in patients with hematologic cancers and their other types. All given investigations show a significant reduction in the serum levels of total cholesterol and high-density lipoproteins in patients with hematological disease at its onset. The data for other indicators of the lipid transport system are ambiguous. Such changes have been elucidated to be associated with the accumulation of cholesterol in the leukemia cells due to enhanced synthesis de novo, a more active absorption from circulation and blocked release of its surplus. If the disease runs a favorable course, lipid metabolic parameters become normalized and, in case of remission, correspond to those seen in healthy individuals. They continue to decline in patients with disease progression. This allows the consideration of cholesterol, its fractions, and apolipoproteins as biochemical prognostic markers in hematological cancer patients and as indicators for assessment of treatment results. In addition, there is evidence for the effect of chemotherapeutic agents on lipid metabolism. Recent attempts to elaborate new treatment strategies, by using the current knowledge on the role of lipid metabolism in cancers, are considered.