The real role of prediagnostic high-density lipoprotein cholesterol and the cancer risk: a concise review

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.

Association between total cholesterol levels and all-cause mortality among newly diagnosed patients with cancer

We aimed to determine the association between cholesterol values and the risk of all-cause mortality in newly diagnosed patients with cancer in a large-scale longitudinal cohort. Newly diagnosed patients with cancer were reviewed retrospectively. Cox proportional hazards regression models determined the association between baseline levels of total cholesterol (TC), triglycerides, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol and the risk of all-cause mortality. A restricted cubic spline curve was used to identify the association between total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol with the risk of death on a continuous scale and to present the lowest values of lipid measurements associated with death. The median follow-up duration of the study was 5.77 years. Of the 59,217 patients with cancer, 12,624 patients were expired. The multivariable adjusted hazard ratio (aHR) for all-cause mortality in patients with cancer with 1st-5th (≤ 97 mg/dL) and 96th-100th (> 233 mg/dL) in TC levels was 1.54 (95% CI 1.43-1.66) and 1.28 (95% CI 1.16-1.41), respectively, compared to 61st-80th (172-196 mg/dL). The TC level associated with the lowest mortality risk in the multivariable model was 181 mg/dL. In comparison with LDL-C levels in the 61st-80th (115-136 mg/dL), the multivariable aHR for all-cause mortality in cancer patients with LDL-C levels in the 1st-5th (≤ 57 mg/dL) and 96th-100th (> 167 mg/dL) was 1.38 (95% CI 1.14-1.68) and 0.94 (95% CI 0.69-1.28), respectively. The 142 mg/dL of LDL cholesterol showed the lowest mortality risk. We demonstrated a U-shaped relationship between TC levels at baseline and risk of mortality in newly diagnosed patients with cancer. Low LDL levels corresponded to an increased risk of all-cause death.

Dietary fats and serum lipids in relation to the risk of ovarian cancer: a meta-analysis of observational studies

Although numerous epidemiological studies investigated the association between dietary fat intakes or serum lipid levels and ovarian cancer risk, a consistent and explicit conclusion for specific dietary fats or serum lipids that increase the risk of ovarian cancer is not available. In this study, a systematic review and meta-analysis were conducted to assess the key dietary fats and serum lipids that increased the risk of ovarian cancer. Databases such as PubMed, Web of Science, and EMBASE were searched for observational studies. A total of 41 studies met the inclusion criteria, including 18 cohort and 23 case-control studies (109,507 patients with ovarian cancer and 2,558,182 control/non-ovarian cancer participants). Higher dietary intakes of total fat (RR = 1.19, 95% CI = 1.06-1.33, I2 = 60.3%), cholesterol (RR = 1.14, 95% CI = 1.03-1.26, I2 = 19.4%), saturated fat (RR = 1.13, 95% CI = 1.04-1.22, I2 = 13.4%), and animal fat (RR = 1.21, 95% CI = 1.01-1.43, I2 = 70.5%) were significantly associated with a higher risk of ovarian cancer. A higher level of serum triglycerides was accompanied by a higher risk of ovarian cancer (RR = 1.33, 95% CI = 1.02-1.72, I2 = 89.3%). This meta-analysis indicated that a higher daily intake of total fat, saturated fat, animal fat, and cholesterol and higher levels of serum triglycerides were significantly associated with an increased risk of ovarian cancer.

Synergistic Effect of Huangqin Decoction Combined Treatment With Radix Actinidiae chinensis on DSS and AOM-Induced Colorectal Cancer

Objective: To demonstrate the effectiveness of Huangqin decoction (Huangqin Tang in Chinese, HQT) combined with Radix Actinidiae chinensis (Tengligen in Chinese, TLG) under the guidance of “dampness–heat theory” in preventing and treating colorectal cancer (CRC) with dampness–heat accumulation and to preliminarily reveal its mechanism.

Methods: The mice model of CRC was established by intraperitoneal injection of AOM combined with consumption of 2.5% DSS solution, and celecoxib, HQT, TLG, and their combination (HQT + TLG) were administered at the same time. The physical signs and death of the mice were observed daily. At the end of the experiment, the colorectal tissue was dissected, and the tumor was observed and counted. HE staining and Masson’s staining were used to observe the histopathological changes of colon. Expression levels of TNF-α, IL-6, and IL-10 in colorectal tissue were detected by ELISA, and the expression of TNF-α was observed by immunofluorescence. TUNEL assay was used to observe the apoptosis of tumor tissues, and immunohistochemistry was used to observe the expression of Ki-67 and occludin. The mRNA expression levels of claudin-1, occludin, ZO-1, and IL-6 and IL-17 were detected by RT-PCR, and occludin, ZO-1, NF-κB, and STAT3 protein levels were detected by Western blot. The composition of intestinal flora was analyzed by 16S rRNA.

Results: HQT + TLG could significantly reduce the mortality of model mice and improve the intestinal mucosal inflammatory cell infiltration and high-grade intraepithelial neoplasia in model mice. All administration groups show a great reduction in the levels of IL-6 and TNF-α in the colorectal tissues of model mice, and increase in the level of IL-10, the total number of CD3⁺ T cells, the proportion of CD3⁺CD4⁺ T cells, and the ratio of CD4/CD8. HQT and HQT + TLG could significantly change the composition of intestinal flora and increase the abundance of Firmicutes and Patescibacteria.

Conclusion: HQT and TLG combination has a good effect on inhibiting AOM-DSS-induced CRC. This function may be related to improving the composition of the intestinal flora, regulating the proportion of T-cell subsets in colorectal lymphoid tissue to improve inflammatory response, and downregulating the expression of claudin-1, inhibiting the activation of IL-6/STAT3 signaling pathway to improving abnormal hyperplasia.

Identification of a Novel Immune-Related lncRNA CTD-2288O8.1 Regulating Cisplatin Resistance in Ovarian Cancer Based on Integrated Analysis

Ovarian cancer (OC) is the most lethal gynecological malignancy, in which chemoresistance is a crucial factor leading to the poor prognosis. Recently, immunotherapy has brought new light for the treatment of solid tumors. Hence, as a kind of immunologically active cancer, it is reasonably necessary to explore the potential mechanism between immune characteristics and cisplatin resistance in OC. Our study focused on the important role of cisplatin resistance-related lncRNAs on mediating the OC tumor immune microenvironment (TIME) using an integrative analysis based on the Cancer Genome Atlas (TCGA) database. First, the cisplatin resistance-related differentially expressed lncRNAs (DELs) and mRNAs (DEMs) were preliminarily screened to construct a DEL–DEM co-expression network. Next, the protein–protein interaction (PPI) network and pivot analysis were performed to reveal the relevance of these lncRNAs with tumor immune response. Second, the novel lncRNA CTD-2288O8.1 was identified as a key gene for the OC cisplatin resistance formation by qRT-PCR and survival analysis. Gain- and loss-of-function assays (Cell Counting Kit-8 (CCK-8) assay, wound-healing scratch assay, transwell assay, and colony formation assay) further verified the activity of CTD-2288O8.1 in OC progression as well. Third, gene set enrichment analysis (GSEA) was applied along with the correlation analyses of CTD-2288O8.1 with ImmuneScore, tumor-infiltrating immune cells (TICs), and immune inhibitory checkpoint molecules, illustrating that CTD-2288O8.1 was strongly associated with the TIME and has the potential to predict the effect of OC immunotherapy. In addition, basic experiments demonstrated that the expression of CTD-2288O8.1 impacted the EGFR/AKT signal pathway activity of OC tumor cells. Of greater significance, it promoted the M2 polarization of macrophage, which is a type of the most important components of the TIME in solid tumor. Taking together, our study revealed cisplatin resistance-related lncRNAs closely linked with tumor immunity in OC, underscoring the potential mechanism of the TIME in conferring cisplatin resistance, which provided the research basis for further clinical treatment. CTD-2288O8.1 was identified to mediate cisplatin resistance and affect the response of immunotherapy, which could serve as a promising biomarker for guiding clinical treatment and improving prognosis in OC.

Predictive value of a reduction in the level of high-density lipoprotein-cholesterol in patients with non-small-cell lung cancer undergoing radical resection and adjuvant chemotherapy: a retrospective observational study

Background

Cancer patients often exhibit chemotherapy-associated changes in serum lipid profiles, however, their prognostic value before and after adjuvant chemotherapy on survival among non-small-cell lung cancer (NSCLC) patients is unknown.

Methods

NSCLC patients undergoing radical resection and subsequent adjuvant chemotherapy from 2013 to 2017 at Sun Yat-sen University Cancer Center were retrospectively reviewed. Fasted serum lipid levels were measured before and after chemotherapy. The optimal lipid cut-off values at baseline and fluctuation were determined using X-tile™. The fluctuations in serum lipid levels and disease-free survival (DFS) were assessed.

Results

Serum cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), triglyceride, apolipoprotein (Apo) A-I, and ApoB all significantly increased after adjuvant chemotherapy. X-tile determined 1.52 mmol/L of HDL-C and 0.74 g/L of ApoB as the optimal cut-off values before chemotherapy. Patients with HDL-C ≥ 1.52 mmol/L (median DFS: not reached vs. 26.30 months, P = 0.0005) and a decreased HDL-C level after adjuvant chemotherapy (median DFS: 80.43 vs. 26.12 months, P = 0.0204) had a longer DFS. An HDL-C level that increased by ≥ 0.32 mmol/L after chemotherapy indicated a worse DFS. A high baseline ApoB level were associated with a superior DFS. In the univariate analysis and the multivariate Cox analyses, a high baseline HDL-C level and a HDL-C reduction after adjuvant chemotherapy were independent indicators for superior DFS. High baseline HDL-C was related to N0-1 stage (χ² = 6.413, P = 0.011), and HDL-C fluctuation was significantly correlated with specific chemotherapy regimens (χ² = 5.002, P = 0.025).

Conclusions

Adjuvant chemotherapy increased various lipid levels in resected NSCLC patients. A higher HDL-C level before chemotherapy and a reduced HDL-C level after adjuvant chemotherapy were independent predictors of longer DFS in patients with curable NSCLC.

Predicting the effect of statins on cancer risk using genetic variants from a Mendelian randomization study in the UK Biobank

Laboratory studies have suggested oncogenic roles of lipids, as well as anticarcinogenic effects of statins. Here we assess the potential effect of statin therapy on cancer risk using evidence from human genetics. We obtained associations of lipid-related genetic variants with the risk of overall and 22 site-specific cancers for 367,703 individuals in the UK Biobank. In total, 75,037 individuals had a cancer event. Variants in the HMGCR gene region, which represent proxies for statin treatment, were associated with overall cancer risk (odds ratio [OR] per one standard deviation decrease in low-density lipoprotein [LDL] cholesterol 0.76, 95% confidence interval [CI] 0.65-0.88, p=0.0003) but variants in gene regions representing alternative lipid-lowering treatment targets (PCSK9, LDLR, NPC1L1, APOC3, LPL) were not. Genetically predicted LDL-cholesterol was not associated with overall cancer risk (OR per standard deviation increase 1.01, 95% CI 0.98-1.05, p=0.50). Our results predict that statins reduce cancer risk but other lipid-lowering treatments do not. This suggests that statins reduce cancer risk through a cholesterol independent pathway.

Evaluation of oxidative stress levels in obesity and diabetes by the free oxygen radical test and free oxygen radical defence assays and correlations with anthropometric and laboratory parameters

BACKGROUND

Obesity and diabetes are associated with high levels of oxidative stress. In Romanian patients with obesity and (or) diabetes, this association has not been sufficiently explored.

AIM

To evaluate oxidative stress in obese and (or) diabetic subjects and to investigate the possible correlations between oxidative stress and anthropometric/biochemical parameters.

METHODS

Oxidative stress was evaluated from a single drop of capillary blood. Reactive oxygen species (ROS) were evaluated using the free oxygen radical test (FORT). The free oxygen radical defence (FORD) assay was used to measure antioxidant levels.

RESULTS

FORT levels were higher in obese subjects (3.04 ± 0.36 mmol/L H₂O₂) vs controls (2.03 ± 0.14 mmol/L H₂O₂) (P < 0.0001). FORD levels were lower in obese subjects (1.27 ± 0.13 mmol/L Trolox) vs controls (1.87 ± 1.20 mmol/L Trolox) (P = 0.0072). Obese diabetic subjects had higher FORT values (3.16 ± 0.39 mmol/L H₂O₂) vs non-diabetic counterparts (2.99 ± 0.33 mmol/L H₂O₂) (P = 0.0233). In obese subjects, FORT values correlated positively with body mass index (BMI) (r = 0.48, P = 0.0000), waist circumference (WC) (r = 0.31, P = 0.0018), fasting plasma glucose (FPG) (r = 0.31, P = 0.0017), total cholesterol (TC) (r = 0.27, P = 0.0068) and uric acid (r = 0.36, P = 0.0001). FORD values correlated negatively with BMI (r = -0.43, P = 0.00001), WC (r = -0.28, P = 0.0049), FPG (r = -0.25, P = 0.0130), TC (r = -0.23, P = 0.0198) and uric acid (r = -0.35, P = 0.0002). In obese diabetic subjects, FORT values correlated positively with BMI (r = 0.49, P = 0.0034) and TC (r = 0.54, P = 0.0217). FORD values were negatively associated with BMI (r = -0.54, P = 0.0217) and TC (r = -0.58, P = 0.0121).

CONCLUSION

Oxidative stress levels, as measured by the FORT and FORD assays, were higher in obese subjects vs controls. ROS levels were elevated in diabetic obese patients vs obese non-diabetic patients and controls.

Chronic disease comorbidity in patients with oral leukoplakia: A matched case-control study

OBJECTIVE

The purpose of this study was to investigate the presence of chronic diseases in patients with oral leukoplakia (OL) compared to controls matched for age group, gender, smoking and alcohol use.

SUBJECTS AND METHODS

This case-control study examined the general demographics, medical and social histories of 105 OL cases and 391 controls matched for age group, gender, tobacco and alcohol use. All OL cases were diagnosed based on both clinical and histopathological findings.

RESULTS

Chronic diseases were significantly associated with OL, namely dyslipidaemia (p < .0001), musculoskeletal diseases (p = .0101) and asthma (p = .0052). The use of ACE inhibitors (p = .0177), opioid analgesics (p = .0300), anticoagulants (p = .0055) and statins (p = .0010) was significantly associated with OL. Dyslipidaemia (p < .0001; odds ratio [95% CI]: 6.4 [3.5-11.6]) and asthma (p = .0110; odds ratio [95% CI]: 2.2 [1.2-4.0]) were identified as independent predictors of OL in multivariate analysis, both of which were significantly more common amongst cases than controls.

CONCLUSIONS

Results from this first Australian study suggest that dyslipidaemia and asthma may constitute independent predictors for the presence of OL. However, longitudinal studies are needed to ascertain the temporal relationship between OL and chronic disease comorbidity and the mechanisms underlying these associations.

SR-BI as a target of natural products and its significance in cancer

Scavenger receptor class B type I (SR-BI) protein is an integral membrane glycoprotein. SR-BI is emerging as a multifunctional protein, which regulates autophagy, efferocytosis, cell survival and inflammation. It is well known that SR-BI plays a critical role in lipoprotein metabolism by mediating cholesteryl esters selective uptake and the bi-directional flux of free cholesterol. Recently, SR-BI has also been identified as a potential marker for cancer diagnosis, prognosis, or even a treatment target. Natural products are a promising source for the discovery of new drug leads. Multiple natural products were identified to regulate SR-BI protein expression. There are still a number of challenges in modulating SR-BI expression in cancer and in using natural products for modulation of such protein expression. In this review, our purpose is to discuss the relationship between SR-BI protein and cancer, and the molecular mechanisms regulating SR-BI expression, as well as to provide an overview of natural products that regulate SR-BI expression.

Relationship between plasma Atherogenic index and final pathology of Bosniak III-IV renal masses: a retrospective, single-center study

Background

There is an increased incidence of renal cell carcinoma (RCC) in patients with metabolic syndrome who usually have high levels of serum triglyceride (TG) and low high-density lipoprotein-cholesterol (HDL-C). Plasma atherogenic index (PAI) is the logarithmic ratio of serum TG level to HDL-C and related to cardiovascular diseases. In this study, we aimed to determine the accuracy of PAI in determining renal malignancy in localized renal masses preoperatively.

Methods

Totally 169 patients who were diagnosed with Bosniak III-IV lesions by imaging modalities and treated in our hospital with partial or radical nephrectomy were retrospectively analyzed using institutional renal cancer database between 2013 and 2018. Preoperative images were evaluated by two experienced radiologists. The patients were divided into two groups according to their postoperative pathological diagnosis as malignant or benign tumors. The PAI of each patient was calculated and the statistical significance of PAI in predicting malignancy for renal masses was analyzed using uni- and multivariable analyses.

Results

Of patients, 109 (64.5%) were males and 60 (35.5%) were females with a median age of 61 (33–84) years. Median tumor size was 6.5 (2–18) cm. Pathological diagnosis was malignant in 145 (85.8%) and benign in 24 (14.2%) patients. There was no statistically significant difference in serum TG levels between malignant and benign cases (p > 0.05). The HDL-C levels were significantly lower in malignant cases (p = 0.001). Median PAI value was 0.63 (0.34–1.58) and significantly higher in malignant cases (p = 0.003). The PAI cut-off value for malignancy was ≥0.34. The sensitivity was calculated as 88.2% and specificity as 45.8%, the positive predictive value as 90.8, negative predictive value as 39.3, and odds ratio as 6.37 (95% CI: 2.466–16.458). In multivariable analysis, gender, smoking status, and hypertension had no effect on malignancy, whereas PAI and HDL-C were independent risk factors (p = 0.003 and p = 0.003, respectively). The risk of malignancy was 5.019 times higher, when PAI was > 0.34 (95% CI: 1.744–14.445) in multivariable logistic regression analysis.

Conclusions

The PAI can be used as a predictive tool in suspicion of malignant renal masses. In case of a benign pathology, PAI levels may be encouraging for surgeons for nephron-sparing surgery.

High-density lipoprotein lipid peroxidation as a molecular signature of the risk for developing cardiovascular disease: Results from MASHAD cohort

High-density lipoprotein (HDL) function rather than level may better predict cardiovascular disease (CVD). However, the contribution of the impaired antioxidant function of HDL that is associated with increased HDL lipid peroxidation (HDLox) to the development of clinical CVD remains unclear. We have investigated the association between serum HDLox with incident CVD outcomes in Mashhad cohort. Three-hundred and thirty individuals who had a median follow-up period of 7 years were recruited as part of the cohort. The primary end point was cardiovascular event, including myocardial infarction, stable angina, unstable angina, or coronary revascularization. In both univariate/multivariate analyses adjusted for traditional CVD risk factors, HDLox was an independent risk factor for CVD (odds ratio, 1.62; 95% confidence interval, 1.41-1.86; p < 0.001). For every increase in HDLox by 0.1 unit, there was an increase in CVD risk by 1.62-fold. In an adjusted analysis, there was a >2.5-fold increase in cardiovascular risk in individuals with HDLox higher than cutoff point of 1.06 compared to those with lower scores, suggesting HDLox > 1.06 is related to the impaired HDL oxidant function and in turn exposed to elevated risk of CVD outcomes (hazard ratio, 2.72; 95% CI, 1.88-3.94). Higher HDLox is a surrogate measure of reduced HDL antioxidant function that positively associated with cardiovascular events in a population-based cohort.

Associations of cholesteryl ester transfer protein (CETP) gene variants with pituitary adenoma

AIM

The aim was to evaluate the association of CETP (rs5882 and rs708272) single nucleotide polymorphisms with the presence, invasiveness, hormonal activity and recurrence of pituitary adenoma (PA).

METHODS

The study group included 142 patients with PA and the control group, 753 healthy subjects. The genotyping of CETP (rs5882 and rs708272) was performed using a real-time PCR method.

RESULTS

After statistical analysis we found that CETP rs708272 genotype G/A under the over-dominant model was associated with the decreased odds of PA (OR=0.637; 95%CI: 0.443-0.917; P=0.015), active PA (OR=0.538; 95%CI: 0.335-0.865; P =0.01) and non-recurrent PA (OR=0.602; 95% CI: 0.402 - 0.902; P =0.014). When compared to controls, the rs708272 genotype G/A was less frequent in the active PA subgroup (37.5% vs 52.7%, P =0.009) and the non-recurrent PA subgroup (40.2% vs 52.7%, P=0.013), while the rs5882 genotype A/A was less frequent in the non-recurrent PA subgroup (37.5% vs 46.2%, P=0.015).

CONCLUSION

Our study showed that CETP rs708272 genotype G/A may be associated with a decreased risk of PA.

Effect of serum triglyceride level on the prognosis of patients with hepatocellular carcinoma in the absence of cirrhosis

Background

The liver plays an important role in the metabolism of lipid and lipoprotein. Dyslipidemia has been demonstrated to be related with several cancers, but the association between serum lipid and hepatocellular carcinoma (HCC) in the absence of cirrhosis remains unclear.

Methods

A total of 2528 patients with HCC at the Beijing Ditan Hospital between February 2008 and December 2017 were retrospectively included in the study. We identified 200 patients with HCC without cirrhosis by histopathology, imaging, endoscopic findings, and laboratory tests. Multivariate regression analysis was performed to determine the independent characteristics associated with HCC without cirrhosis and its prognosis.

Results

In the logistics regression analysis, compared to patients with HCC with cirrhosis, patients with HCC without cirrhosis were more likely to have elevated triglyceride (TG) levels (OR = 2.66; 95% CI, 1.18–6.01; P = 0.019). The Kaplan-Meier analysis revealed that a lower TG level was a risk factor regardless of the presence of cirrhosis. The results of the Cox proportional hazard regression analysis showed that a decreased TG level was significantly related to a worse overall survival (HR = 0.51; 95% CI, 0.29–0.89; P = 0.017).

Conclusion

Serum TG level may be an independent factor to predict the prognosis of patients with HCC in the absence of cirrhosis.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0898-y) contains supplementary material, which is available to authorized users.

High-density lipoprotein functionality and breast cancer: A potential therapeutic target

Breast cancer is a major cause of death globally, and particularly in developed countries. Breast cancer is influenced by cholesterol membrane content, by affecting the signaling pathways modulating cell growth, adherence, and migration. Furthermore, steroid hormones are derived from cholesterol and these play a key role in the pathogenesis of breast cancer. Although most findings have reported an inverse association between serum high-density lipoprotein (HDL)-cholesterol level and the risk of breast cancer, there have been some reports of the opposite, and the association therefore remains unclear. HDL is principally known for participating in reverse cholesterol transport and has an inverse relationship with the cardiovascular risk. HDL is heterogeneous, with particles varying in composition, size, and structure, which can be altered under different circumstances, such as inflammation, aging, and certain diseases. It has also been proposed that HDL functionality might have a bearing on the breast cancer. Owing to the potential role of cholesterol in cancer, its reduction using statins, and particularly as an adjuvant during chemotherapy may be useful in the anticancer treatment, and may also be related to the decline in cancer mortality. Reconstituted HDLs have the ability to release chemotherapeutic drugs inside the cell. As a consequence, this may be a novel way to improve therapeutic targeting for the breast cancer on the basis of detrimental impacts of oxidized HDL on cancer development.

Cancer Incidence in Europe: An Ecological Analysis of Nutritional and Other Environmental Factors

The aim of this work was to offer an ecological alternative to conventional observational studies and identify factors potentially associated with cancer incidence in Europe. The incidence of 24 types of cancer in 39 European countries (2012) was compared with a long-term mean supply of 68 food items from the FAOSTAT database (1993-2011) and some other variables such as smoking, body mass index, raised cholesterol, and socioeconomic indicators. In addition to simple Pearson linear correlations, the data were analyzed via factor analyses and penalized regression methods. This comparison identified two main groups of cancers that are characteristically associated with the same variables. The first group consists of cancers of the prostate, breast, white blood cells, and melanoma. Their incidence increases with rising gross domestic product (GDP) per capita, a prevalence of raised cholesterol and a high intake of animal products. The second group includes primarily cancers of the digestive tract and is most consistently correlated with alcoholic beverages, lard, and eggs. In addition, we found specific correlations between certain variables and some other types of cancer (smoking-lung and larynx cancer; low GDP per capita and high carbohydrate consumption-stomach and cervical cancer; tea drinking-esophageal cancer; maize consumption and wine drinking-liver cancer). The documented findings often remarkably agree with the current scientific consensus, and when combined with evidence based on different methodologies, they can further extend our knowledge of the etiology of cancer. In addition, our study also identifies several foods with possible preventive effects and indicates that various dairy products may markedly differ in their relationship to cancer incidence. All these data can potentially be of fundamental importance for clinical practice and the survival of cancer patients.

Associations between serum lipids and breast cancer incidence and survival in the E3N prospective cohort study

PURPOSE

Several mechanistic studies support a role of cholesterol or its metabolites in breast cancer etiology, but associations have been inconsistent in epidemiological studies. In observational studies, possible reverse causation must be accounted for using a prospective design. We investigated prospective associations between pre-diagnostic serum lipid concentrations [total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides], and both breast cancer risk and survival in the E3N cohort study.

METHODS

Analyses were performed on 583 cases from the E3N prospective cohort diagnosed between 1994 and 2005, and 1,043 controls matched on date, age, recruitment center and menopausal status at blood collection. Odds ratios (OR) and 95% confidence intervals were estimated using conditional logistic regression. Risks of recurrence were estimated among cases using Cox proportional hazards model. Models were adjusted for lifestyle risk factors and mutually adjusted for lipid concentrations. Survival analyses were additionally adjusted for tumor characteristics.

RESULTS

Overall, there was no association between any serum lipid and breast cancer risk or survival. In stratified analyses, statistically significant interaction was observed between TC and menopausal status (P interaction = 0.05) and between TC and waist circumference (P interaction = 0.03), although the ORs did not reach statistical significance in any of the strata. There was no statistically significant effect modification by BMI, time between blood donation and diagnosis or ER status.

CONCLUSIONS

Our results suggest that serum lipids are not associated with breast cancer risk overall, but that menopausal status and waist circumference should be considered in further studies.

Identification of CETP as a molecular target for estrogen positive breast cancer cell death by cholesterol depleting agents

Cholesterol and its metabolites act as steroid hormone precursors, which promote estrogen receptor positive (ER+) breast cancer (BC) progression. Development of cholesterol targeting anticancer drugs has been hindered due to the lack of knowledge of viable molecular targets. Till now, Cholesteryl ester transfer protein (CETP) has been envisaged as a feasible molecular target in atherosclerosis, but for the first time, we show that CETP contributes to BC cell survival when challenged with cholesterol depleting agents. We show that MCF-7 CETP knockout BC cells pose less resistance towards cytotoxic compounds (Tamoxifen and Acetyl Plumbagin (AP)), and were more susceptible to intrinsic apoptosis. Analysis of differentially expressed genes using Ingenuity Pathway Analysis (IPA), in vivo tumor inhibition, and in vitro phenotypic responses to AP revealed a unique CETP-centric cholesterol pathway involved in sensitizing ER+ BC cells to intrinsic mitochondrial apoptosis. Furthermore, analysis of cell line, tissue and patient data available in publicly available databases linked elevated CETP expression to cancer, cancer relapse and overall poor survival. Overall, our findings highlight CETP as a pharmacologically relevant and unexploited cellular target in BC. The work also highlights AP as a promising chemical entity for preclinical investigations as a cholesterol depleting anticancer therapeutic agent.

Predictive value of chemotherapy-related high-density lipoprotein cholesterol (HDL) elevation in patients with colorectal cancer receiving adjuvant chemotherapy: an exploratory analysis of 851 cases

BACKGROUND

The phenomenon of chemotherapy-related lipid alterations has been reported based on a small number of patients and varies among different cancers. However, little is known about these alterations in colorectal cancer (CRC) patients.

RESULTS

Patients in cohort 1, but not in cohort 2, exhibited significantly increased cholesterol, triglyceride, HDL-C, and ApoA-I levels, and decreased LDL-C and ApoB levels after adjuvant chemotherapy. Patients with chemotherapy-related HDL-C elevation exhibited better 3-year DFS (84.5% vs. 73%, P = 0.001) and 7-year OS (82% vs. 70%, P = 0.002) than those without. Similarly, the 3-year DFS (83.3% vs. 77.6%, P = 0.008) and 7-year OS (81% vs. 74.6%, P = 0.040) were superior in chemotherapy-related ApoA-I elevation patients. However, only HDL-C elevation remained an independent prognostic value in the multivariate Cox model.

METHODS

Eight hundred fifty-one CRC patients with curative-intent resection were retrospectively analyzed. Six hundred sixty-seven receiving fluoropyrimidine-based adjuvant chemotherapy for more than 3 months were enrolled in cohort 1. The lipid alterations before and after chemotherapy were studied. Simultaneously, 184 patients not treated with chemotherapy (cohort 2) were included as a control for the comparisons of lipids alterations within 1 month after resection and at half-year follow-up. Furthermore, these significant alterations were investigated with respect to the prognostic value of disease-free survival (DFS) and overall survival (OS). An internal validation was performed.

CONCLUSION

We observed significant changes in the levels of various lipids in CRC patients receiving adjuvant chemotherapy. Furthermore, chemotherapy-related HDL-C elevation was determined to be an independent prognostic indicator for superior DFS and OS.

High scavenger receptor class B type I expression is related to tumor aggressiveness and poor prognosis in breast cancer

Scavenger receptor class B type I (SR-BI) has been linked to the development and progression of breast cancer. However, its clinical significance in breast cancer remains unclear. Here, we evaluated SR-BI expression in a well-characterized breast cancer tissue microarray by immunohistochemistry. High SR-BI expression was observed in 54 % of all breast cancer cases and was significantly associated with advanced pTNM stage (P = 0.002), larger tumor size (P = 0.023), lymph node metastasis (P = 0.012), and the absence of ER (P = 0.014). The Kaplan-Meier survival analysis revealed that patients with high SR-BI expression had significantly shorter overall survival (OS) (P = 0.004). Moreover, multivariate analysis with adjustment for other prognostic factors confirmed that SR-BI was an independent prognostic factor for patient outcome (P = 0.017). Overall, our study demonstrated that high SR-BI expression was related to conventional parameters indicative of more aggressive tumor type and may serve as a new prognostic marker for poor clinical outcome in human breast cancer.

Alteration of serum lipid profile and its prognostic value in head and neck squamous cell carcinoma

BACKGROUND

Several serum lipid components have been implicated in the development of cancer. However, the prognostic significance of serum lipid components in head and neck squamous cell carcinoma is unknown. Here, we investigated the predictive value of serum lipid profile at diagnosis and in the overall survival of the patients.

METHODS

The study population consists of 136 pathologically confirmed head and neck squamous cell carcinoma cases diagnosed between years 2009 and 2014 at a tertiary medical center. Levels of preoperative serum lipid component's total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, apolipoprotein A, apolipoprotein B, and lipoprotein (a) were compared between patients and normal controls matched for age and gender. Serum lipid profiles and their association with clinical parameters were analyzed. The effects of the serum lipid components on survival were examined using the proportional hazards regression model to estimate hazard ratio.

RESULTS

Significant lower levels of cholesterol, low-density lipoprotein, apolipoprotein A, and apolipoprotein B were found in patients with oral cancer (P < 0.0001). However, a significantly higher level of lipoprotein (a) was found in the cancer group (P < 0.0001). Patients with higher lipoprotein (a) had significantly shorter overall survival than those with lower lipoprotein (a) (P = 0.0042). Multivariate analysis showed that both higher lipoprotein (a) and lymph node metastasis are independent prognostic factors in the patient population (P < 0.01).

CONCLUSION

A higher lipoprotein (a) was associated with poorer prognosis and might be a novel marker in patients with head and neck squamous cell carcinoma.

Scavenger Receptors: Emerging Roles in Cancer Biology and Immunology

Scavenger receptors constitute a large family of evolutionally conserved protein molecules that are structurally and functionally diverse. Although scavenger receptors were originally identified based on their capacity to scavenge modified lipoproteins, these molecules have been shown to recognize and bind to a broad spectrum of ligands, including modified and unmodified host-derived molecules or microbial components. As a major subset of innate pattern recognition receptors, scavenger receptors are mainly expressed on myeloid cells and function in a wide range of biological processes, such as endocytosis, adhesion, lipid transport, antigen presentation, and pathogen clearance. In addition to playing a crucial role in maintenance of host homeostasis, scavenger receptors have been implicated in the pathogenesis of a number of diseases, e.g., atherosclerosis, neurodegeneration, or metabolic disorders. Emerging evidence has begun to reveal these receptor molecules as important regulators of tumor behavior and host immune responses to cancer. This review summarizes our current understanding on the newly identified, distinct functions of scavenger receptors in cancer biology and immunology. The potential of scavenger receptors as diagnostic biomarkers and novel targets for therapeutic interventions to treat malignancies is also highlighted.

Epidemiology: disease associations and modulators of HDL-related biomarkers

Epidemiological studies have shown an inverse association between high-density lipoprotein cholesterol (HDL-C) levels and risk of ischemic heart disease. In addition, a low level of HDL-C has been shown to be a risk factor for other diseases not related to atherosclerosis. However, recent studies have not supported a causal effect of HDL-C in the development of atherosclerosis. Furthermore, new drugs markedly elevating HDL-C levels have been disappointing with respect to clinical endpoints. Earlier, most studies have focused almost exclusively on the total HDL-C without regard to the chemical composition or multiple subclasses of HDL particles. Recently, there have been efforts to dissect the HDL fraction into as many well-defined subfractions and individual molecules of HDL particles as possible. On the other hand, the focus is shifting from the structure and composition to the function of HDL particles. Biomarkers and mechanisms that could potentially explain the beneficial characteristics of HDL particles unrelated to their cholesterol content have been sought with sophisticated methods such as proteomics, lipidomics, metabonomics, and function studies including efflux capacity. These new approaches have been used in order to resolve the complex effects of diseases, conditions, environmental factors, and genes in relation to the protective role of HDL but high-throughput methods are still needed for large-scale epidemiological studies.

Impact of gastrectomy on high-density lipoprotein cholesterol elevation in nonobese patients during a 10-year follow-up

AIM

The role of gastrectomy in glycemic control has been established in the current era of bariatric surgery for obesity. Gastrectomy in obese patients is associated with increased levels of high-density lipoprotein cholesterol (HDL-C). However, limited data on the effects of gastrectomy in nonobese patients are available. We herein investigated the long-term plasma lipid changes in nonobese patients who had undergone gastrectomy.

METHODS

Patients were enrolled as part of routine healthcare examinations from 1984 to 2003. Preoperative and postoperative data from patients who had undergone curative gastrectomy were analyzed for up to 10 years postoperatively. Three age- and sex-matched controls were assigned to each case.

RESULTS

Sixty-four nonobese patients without diabetes mellitus or a history of having taken lipid-lowering drugs who underwent curative gastrectomy during the study period were enrolled (60 subtotal gastrectomies, four total gastrectomies). The median follow-up period was 7.6 years. The mean body mass index was 9.6% lower one year after gastrectomy (p < 0.01), then plateaued with a slight recovery. Intriguingly, the preoperative HDL-C level was 21% higher one year after gastrectomy (p < 0.01), increased by another 30% six years after gastrectomy and remained at this level for the rest of the follow-up period. No significant changes in the HDL-C level were observed in the controls. The degree of HDL-C elevation was consistently significant, irrespective of the baseline triglyceride level, HDL-C level or body weight.

CONCLUSIONS

Gastrectomy in nonobese patients was associated with consistent and distinct long-term HDL-C elevations and body mass index reductions.

Use of statins and risk of AIDS-defining and non-AIDS-defining malignancies among HIV-1 infected patients on antiretroviral therapy

OBJECTIVE

Previous studies have shown that statins use is associated with a lower mortality risk or occurrence of non-Hodgkin's lymphoma or non-AIDS-defining malignancies (NADMs) in HIV-positive patients. We evaluated the effect of statin therapy on the occurrence of all AIDS-defining malignancy (ADM) and NADM among HIV-positive patients.

DESIGN

A chart study on HIV-1 infected patients attending the Infectious Diseases Department of the San Raffaele Scientific Institute, Italy.

METHODS

Incident malignancies diagnosed since antiretroviral treatment (ART) initiation until October 2012 among treated patients not taking statins at ART initiation. Statin therapy had to precede cancer diagnosis, if it occurred. Malignancies that occurred before ART or statin initiation were excluded. Follow-up was calculated since ART initiation until the first cancer diagnosis or loss to follow-up or death or last available visit, whichever occurred first. Results are described as median (interquartile range, IQR).

RESULTS

Five thousand, three hundred and fifty-seven HIV-1 treated patients were included. During 52 663 person-years, 740 (14%) patients had a history of statin use; 375 malignancies occurred: 12 (1.6%) malignancies (0 ADM; 12 NADM, crude incidence rate, 1.3/1000 person-years) among statin users and 363 (7.9%) malignancies (194 ADM; 169 NADM, crude incidence rate, 8.4/1000 person-years) among non-statin users. By multivariate Fine-Gray regression, statin use was associated with a lower risk of cancer [adjusted hazard ratio (95% confidence interval) for ever use: 0.45 (0.17-0.71)].

CONCLUSION

Among HIV-1 treated patients, statin use was associated with a lower risk of cancer; the benefit was mainly related to AIDS-defining malignancies. Confirmatory studies are needed to consider the residual confounding likely present in this study.

Oxidized lipids and lysophosphatidylcholine induce the chemotaxis, up-regulate the expression of CCR9 and CXCR4 and abrogate the release of IL-6 in human monocytes

Lipids through regulation of chronic inflammation play key roles in the development of various diseases. Here, we report that a mixed population of human primary monocytes migrated towards LPC, as well as oxidized linoleic acid isoforms 9-S-HODE, 9-R-HODE and 13-R-HODE. Incubation with 9-R-HODE, 13-R-HODE and LPC resulted in increased expression of CXCR4, the receptor for SDF-1α/CXCL12, correlated with increased monocyte migration towards SDF-1α/CXCL12. Further, we report increased expression of CCR9, the receptor for TECK/CCL25, after stimulation with these lipids. Upon examining the migratory response towards TECK/CCL25, it was observed that an increase in CCR9 expression upon pre-treatment with 9-S-HODE, 9-R-HODE, 13-R-HODE and LPC resulted in increased migration of monocytes expressing CCR9. Only LPC but not any other lipid examined increased the influx of intracellular Ca²⁺ in monocytes. Finally, 9-S-HODE, 9-R-HODE, 13-R-HODE, or LPC inhibited the release of IL-6 from monocytes suggesting that these lipids may play important role in controlling inflammatory responses.