A Mendelian randomization study of the effects of blood lipids on breast cancer risk

The association between oxidized low-density lipoprotein and cancer: An emerging targeted therapeutic approach?

Lipids play an important role in varying vital cellular processes including cell growth and division. Elevated levels of low-density lipoprotein (LDL) and oxidized-LDL (ox-LDL), and overexpression of the corresponding receptors including LDL receptor (LDLR), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), and cluster of differentiation 36 (CD36), have shown strong correlations with different facets of carcinogenesis including proliferation, invasion, and angiogenesis. Furthermore, a high serum level of LOX-1 is considered as a poor prognostic factor in many types of cancer including colorectal cancer. Ox-LDL could contribute to cancer progression and metastasis through endothelial-to-mesenchymal transition (EMT) and autophagy. Thus, many studies have shed light on the significant role of ox-LDL as a potential therapeutic target for cancer therapy. In various repurposing approaches, anti-dyslipidemia agents, phytochemicals, autophagy modulators as well as recently developed ldl-like nanoparticles have been investigated as potential tumor therapeutic agents by targeting oxidized-LDL/LOX-1 pathways. Herein, we reviewed the role of oxidized-LDL and LOX-1 in cancer progression, invasion, metastasis, and also cancer-associated angiogenesis. Moreover, we addressed therapeutic utility of several compounds that proved to be capable of targeting the metabolic moieties in cancer. This review provides insights on the potential impact of targeting LDL and ox-LDL in cancer therapy and their future biomedical implementations.

Comparing the effects of CETP in East Asian and European ancestries: a Mendelian randomization study

CETP inhibitors are a class of lipid-lowering drugs in development for treatment of coronary heart disease (CHD). Genetic studies in East Asian ancestry have interpreted the lack of CETP signal with low-density lipoprotein cholesterol (LDL-C) and lack of drug target Mendelian randomization (MR) effect on CHD as evidence that CETP inhibitors might not be effective in East Asian participants. Capitalizing on recent increases in sample size of East Asian genetic studies, we conducted a drug target MR analysis, scaled to a standard deviation increase in high-density lipoprotein cholesterol. Despite finding evidence for possible neutral effects of lower CETP levels on LDL-C, systolic blood pressure and pulse pressure in East Asians (interaction p-values < 1.6 × 10-3), effects on cardiovascular outcomes were similarly protective in both ancestry groups. In conclusion, on-target inhibition of CETP is anticipated to decrease cardiovascular disease in individuals of both European and East Asian ancestries.

Circulating lipids, lipid-lowering drug targets, and breast cancer risk: Comprehensive evidence from Mendelian randomization and summary data-based Mendelian randomization

BACKGROUND

Breast cancer (BC) is the most common and fatal cancer among women, yet the causal relationship between circulating lipids, lipid-lowering drugs, and BC remains unclear.

METHODS

Mendelian randomization (MR) and summary data-based MR (SMR) analysis are used to explore the causal relationship between plasma lipids, lipid-lowering drug targets, and BC.

RESULTS

The result of MR suggested that per mg/dL higher levels of LDL-C (OR = 1.045, FDR = 0.023), HDL-C (OR = 1.079, FDR = 0.003), TC (OR = 1.043, FDR = 0.026), and APOA-I (OR = 1.085, FDR = 2.64E-04) were associated with increased BC risk, while TG was associated with reduced BC risk (OR = 0.926, FDR = 0.003). Per mg/dL higher levels of HDL-C (OR = 1.080, FDR = 0.011) and APOA-I (OR = 1.083, FDR = 0.002) were associated with increased ER+BC risk, while TG was associated with reduced ER+BC risk (OR = 0.909, FDR = 0.002). For every per 1 mg/dL decrease in LDL, HMGCR (OR: 0.839; FDR = 0.016), NPC1L1 (OR: 0.702; FDR = 0.004), and PCSK9 (OR: 0.916; FDR = 0.026) inhibition were associated with reduced BC risk, whereas CETP inhibition (OR: 1.194; FDR = 0.026) was associated with increased BC risk. For every per 1 mg/dL decrease in LDL, HMGCR (OR: 0.822; FDR = 0.023), NPC1L1 (OR: 0.633; FDR = 2.37E-03), and APOB inhibition (OR: 0.816; FDR = 1.98E-03) were associated with decreased ER-BC risk, while CETP inhibition (OR: 1.465; FDR = 0.011) was associated with increased ER-BC risk. SMR analysis indicated that HMGCR was associated with increased BC risk (OR: 1.112; p = 0.044).

CONCLUSION

Lipids are associated with the BC risk, and lipid-lowering drugs targets HMGCR, NPC1L1, PCSK9, and APOB may be effective strategies for preventing BC. However, lipid-lowering drugs target CETP may potentially increase BC risk.

Lipid Profile and Atherogenic Risk Assessment in Nigerian Breast Cancer Patients - A Cross-Sectional Study

BACKGROUND

The lipid profile and atherogenic risk indices in Nigerian breast cancer patients are largely unknown. This study evaluated the lipid profile and atherogenic risk indices of breast cancer patients in Nigeria.

METHODS

This study involved 45 primarily diagnosed breast cancer patients and 50 normal control subjects. Total cholesterol, triglyceride, and High-density lipoprotein cholesterol (HDL-C) were measured. Low-density lipoprotein cholesterol (LDL-C) was calculated according to Friedewald formula. Atherogenic index of plasma (AIP), Atherogenic coefficient (AC), TC/HDL-C (Castelli I) and LDL-C/HDL-C (Castelli II) risk indices were all calculated. The Framingham risk assessment was calculated and categorized.

RESULTS

The study group had significantly higher triglycerides (TG), and atherogenic indices than the control group (p < 0.001), while HDL-Cholesterol (HDL-C) was significantly lower in the study group (p < 0.001). Total cholesterol and LDL-Cholesterol (LDL-C) had a significant positive correlation with age (r = 0.283, p < 0.018; r = 0.272, p < 0.023); TG was significantly positively correlated with systolic and diastolic blood pressure (r = 0.320. p < 0.007; r = 0.334, p < 0.005); HDL-C had a significant negative correlation with BMI, systolic and diastolic blood pressure (r = -0.252, p < 0.035; r = -0.29, p < 0.015; r = -0.329, p < 0.005). The lipid ratios (TC/HDL-C, LDL-C/HDL-C) were significantly positively correlated with body mass index (BMI), systolic and diastolic blood pressure. The Framingham Risk Score showed that only 2 subjects in the study group (4.4%) were at a high risk of having a cardiovascular event.

CONCLUSION

Breast cancer patients have a higher prevalence of dyslipidaemia, and cardiovascular risk than the normal population.

Causal association between lipid-lowering drugs and cancers: A drug target Mendelian randomization study

Accumulating evidences have indicated that lipid-lowering drugs have effect for the treatment of cancers. However, causal associations between lipid-lowering drugs and the risk of cancers are still unclear. In our study, we utilized single nucleotide polymorphisms of proprotein convertase subtilis kexin 9 (PCSK9) inhibitors and 3-hydroxy-3-methylglutaryl-assisted enzyme A reductase (HMGCR) inhibitors and performed a drug target Mendelian randomization to explore the causal association between lipid-lowering drugs and the risk of cancers. Five regression methods were carried out, including inverse variance weighted (IVW) method, MR Egger, weighted median, simple mode and weighted mode methods, of which IVW method was considered as the main analysis. Our outcome dataset contained the risk of breast cancer (BC), colorectal cancer, endometrial cancer, gastric cancer (GC), hepatocellular carcinoma (HCC), lung cancer, esophageal cancer, prostate cancer (PC), and skin cancer (SC). Our results demonstrated that PCSK9 inhibitors were significant associated with a decreased effect of GC [IVW: OR = 0.482, 95% CI: 0.264-0.879, P = .017]. Besides, genetic inhibitions of HMGCR were significant correlated with an increased effect of BC [IVW: OR = 1.421, 95% CI: 1.056-1.911, P = .020], PC [IVW: OR = 1.617, 95% CI: 1.234-2.120, P = .0005] and SC [IVW: OR = 1.266, 95% CI: 1.022-1.569, P = .031]. For GC [IVW: OR = 0.559, 95% CI: 0.382-0.820, P = .0029] and HCC [IVW: OR = 0.241, 95% CI: 0.085-0.686, P = .0077], HMGCR inhibitors had a protective risk. Our method suggested that PCSK9 inhibitors were significant associated with a protective effect of GC. Genetic inhibitions of HMGCR were significant correlated with an increased effect of BC, PC and SC. Meanwhile, HMGCR inhibitors had a protective risk of GC and HCC. Subsequent studies still needed to assess potential effects between lipid-lowering drugs and the risk of cancers with clinical trials.

The causal associations of circulating lipids with Barrett's Esophagus and Esophageal Cancer: a bi-directional, two sample mendelian randomization analysis

OBJECTIVE

The causal associations of circulating lipids with Barrett's Esophagus (BE) and Esophageal Cancer (EC) has been a topic of debate. This study sought to elucidate the causality between circulating lipids and the risk of BE and EC.

METHODS

We conducted two-sample Mendelian randomization (MR) analyses using single nucleotide polymorphisms (SNPs) of circulating lipids (n = 94,595 - 431,167 individuals), BE (218,792 individuals), and EC (190,190 individuals) obtained from the publicly available IEU OpenGWAS database. The robustness and reliability of the results were ensured by employing inverse-variance weighted (IVW), weighted median, MR-Egger, and MR-PRESSO methods. The presence of horizontal pleiotropy, heterogeneities, and stability of instrumental variables were assessed through MR-Egger intercept test, Cochran's Q test, and leave-one-out sensitivity analysis. Additionally, bidirectional MR and multivariable MR (MVMR) were performed to explore reverse causality and adjust for known confounders, respectively.

RESULTS

None of the testing methods revealed statistically significant horizontal pleiotropy, directional pleiotropy, or heterogeneity. Univariate MR analyses using IVW indicated a robust causal relationship between increased triglycerides and BE (odds ratio [OR] = 1.79, p-value = 0.009), while no significant association with EC was observed. Inverse MR analysis indicated no evidence of reverse causality in the aforementioned outcomes. In MVMR analyses, elevated triglycerides (TRG) were significantly and positively associated with BE risk (OR = 1.79, p-value = 0.041).

CONCLUSION

This MR study suggested that genetically increased triglycerides were closely related to an elevated risk of BE, potentially serving as a biomarker for the diagnosis of BE in the future.

Cardiovascular disease and cancer: shared risk factors and mechanisms

Cardiovascular disease (CVD) and cancer are among the leading causes of morbidity and mortality globally, and these conditions are increasingly recognized to be fundamentally interconnected. In this Review, we present the current epidemiological data for each of the modifiable risk factors shared by the two diseases, including hypertension, hyperlipidaemia, diabetes mellitus, obesity, smoking, diet, physical activity and the social determinants of health. We then review the epidemiological data demonstrating the increased risk of CVD in patients with cancer, as well as the increased risk of cancer in patients with CVD. We also discuss the shared mechanisms implicated in the development of these conditions, highlighting their inherent bidirectional relationship. We conclude with a perspective on future research directions for the field of cardio-oncology to advance the care of patients with CVD and cancer.

Cancer and Cardiovascular Disease: The Conjoined Twins

Cancer and cardiovascular disease are the two most common causes of death worldwide. As the fields of cardiovascular medicine and oncology continue to expand, the area of overlap is becoming more prominent demanding dedicated attention and individualized patient care. We have come to realize that both fields are inextricably intertwined in several aspects, so much so that the mere presence of one, with its resultant downstream implications, has an impact on the other. Nonetheless, cardiovascular disease and cancer are generally approached independently. The focus that is granted to the predominant pathological entity (either cardiovascular disease or cancer), does not allow for optimal medical care for the other. As a result, ample opportunities for improvement in overall health care are being overlooked. Herein, we hope to shed light on the interconnected relationship between cardiovascular disease and cancer and uncover some of the unintentionally neglected intricacies of common cardiovascular therapeutics from an oncologic standpoint.

Prognostic Value of PCSK9 Levels in Premenopausal Women at Risk of Breast Cancer-Evidence from a 17-Year Follow-Up Study

BACKGROUND AND AIM

The involvement of cholesterol in cancer development remains a topic of debate, and its association with breast cancer has yet to be consistently demonstrated. Considering that circulating cholesterol levels depend on several concomitant processes, we tested the liability of plasma levels of proprotein convertase subtilisin/kexin type 9 (PCSK9), one of the key regulators of cholesterol levels, as a prognostic biomarker in the context of breast neoplastic events.

METHODS

Within a prospective randomized breast cancer prevention trial we measured baseline plasma levels of PCSK9. A total of 235 at-risk premenopausal women were randomized and followed up for 17 years. Participants enrolled in this placebo-controlled, phase II, double-blind trial were randomly assigned to receive either tamoxifen 5 mg/d or fenretinide 200 mg/d, both agents, or placebo for 2 years. The associations with breast cancer events were evaluated through competing risk and Cox regression survival models, adjusted for randomization strata (5-year Gail risk ≥ 1.3% vs. intraepithelial neoplasia or small invasive breast cancer of favorable prognosis), age, and treatment allocation. PCSK9 associations with biomarkers linked to breast cancer risk were assessed on blood samples collected at baseline.

RESULTS

The plasmatic PCSK9 median and interquartile range were 207 ng/mL and 170-252 ng/mL, respectively. Over a median follow-up period of 17 years and 89 breast neoplastic events, disease-free survival curves showed a hazard ratio of 1.002 (95% CI: 0.999-1.005, p = 0.22) for women with PCSK9 plasma levels ≥ 207 ng/mL compared to women with levels below 207 ng/mL. No differences between randomization strata were observed. We found a negative correlation between PCSK9 and estradiol (r = -0.305), maintained even after partial adjustment for BMI and age (r = -0.287). Cholesterol (r = 0.266), LDL-C (r = 0.207), non-HDL-C (r = 0.246), remnant cholesterol (r = 0.233), and triglycerides (r = 0.233) also correlated with PCSK9.

CONCLUSIONS

In premenopausal women at risk of early-stage breast cancer, PCSK9 did not appear to have a role as a prognostic biomarker of breast neoplastic events. Larger studies are warranted investigating patients in different settings.

Circulating levels of biomarkers and risk of ductal carcinoma in situ of the breast in the UK Biobank study

Observational studies have shown associations between circulating levels of various biomarkers (eg, total cholesterol [TC], low-density lipoprotein cholesterol [LDL], insulin-like growth factor-1 [IGF-1], C-reactive protein [CRP] and glycated hemoglobin-1c [HbA1c]) and the risk of invasive breast cancer (IBC). Ductal carcinoma in situ of the breast (DCIS) is a nonobligate precursor of IBC and shares several risk factors with it. However, the relationship between these biomarkers and DCIS risk remains unexplored. We studied the association between circulating levels of TC, LDL-C, high-density lipoprotein cholesterol (HDL-C), Lipoprotein (a) (Lp-(a)), IGF-1, CRP and HbA1c, with the risk of DCIS in 156801women aged 40 to 69 years and breast cancer-free at enrolment when blood samples and information on demographic and health-related factors were collected. Incident cases of DCIS were ascertained during the follow-up via linkage to the UK cancer registries Multivariable-adjusted Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations of interest. In all, 969 DCIS incident cases were diagnosed during 11.4 years of follow-up. Total cholesterol was inversely associated with the risk of DCIS (HRquintile(Q)5vsQ1  = 0.47, 95% CI: 0.27-0.82, Ptrend  = .008). Conversely, LDL-C was positively associated with DCIS risk (HRQ3vsQ1  = 1.43, 95% CI: 1.01-2.04, HRQ4vsQ1  = 1.60, 95% CI: 1.04-2.47, HRQ5vsQ1  = 2.29, 95% CI: 1.36-3.88, Ptrend  = .004). In postmenopausal women, CRP had a weak positive association with DCIS risk, while HbA1c showed a nonlinear association with the risk. These results, in conjunction with those from previous studies on IBC, provide support for the association of several biomarkers with the risk of an early stage of breast cancer.

Blood lipid profile, HbA1c, fasting glucose, and diabetes: a cohort study and a two-sample Mendelian randomization analysis

PURPOSE

The prevalence of diabetes is increasing worldwide. The associations between the lipid profile and glycated hemoglobin (HbA1c), fasting glucose, and diabetes remain unclear, so we aimed to perform a cohort study and a two-sample Mendelian randomization (MR) study to investigate the causality between blood lipid profile and HbA1c, fasting glucose, and diabetes.

METHODS

A total of 25,171 participants from the Taiwan Biobank were enrolled. We applied a cohort study and an MR study to assess the association between blood lipid profile and HbA1c, fasting glucose, and diabetes. The summary statistics were obtained from the Asian Genetic Epidemiology Network (AGEN), and the estimates between the instrumental variables (IVs) and outcomes were calculated using the inverse-variance weighted (IVW) method. A series of sensitivity analyses were performed.

RESULTS

In the cohort study, high-density lipoprotein cholesterol (HDL-C) was negatively associated with HbA1c, fasting glucose, and diabetes, while the causal associations between HDL-C and HbA1c (βIVW = - 0.098, p = 0.003) and diabetes (βIVW = - 0.594, p < 0.001) were also observed. Furthermore, there was no pleiotropy effect in this study using the MR-Egger intercept test and MR-PRESSO global test.

CONCLUSIONS

Our results support the hypothesis that a genetically determined increase in HDL-C is causally related to a reduction in HbA1c and a lower risk of diabetes.

Low-Density Lipoproteins Increase Proliferation, Invasion, and Chemoresistance via an Exosome Autocrine Mechanism in MDA-MB-231 Chemoresistant Cells

Dyslipidemias involving high concentrations of low-density lipoproteins (LDLs) increase the risk of developing triple-negative breast cancer (TNBC), wherein cholesterol metabolism and protein translation initiation mechanisms have been linked with chemoresistance. Doxorubicin (Dox) treatment, a member of the anthracycline family, represents a typical therapeutic strategy; however, chemoresistance remains a significant challenge. Exosomes (Exs) secreted by tumoral cells have been implicated in cell communication pathways and chemoresistance mechanisms; the content of exosomes is an outcome of cellular cholesterol metabolism. We previously induced Dox resistance in TNBC cell models, characterizing a variant denominated as variant B cells. Our results suggest that LDL internalization in parental and chemoresistant variant B cells is associated with increased cell proliferation, migration, invasion, and spheroid growth. We identified the role of eIF4F translation initiation factor and the down-regulation of tumor suppressor gene PDCD4, an inhibitor of eIF4A, in chemoresistant variant B cells. In addition, the exomes secreted by variant B cells were characterized by the protein content, electronic microscopy, and cell internalization assays. Critically, exosomes purified from LDL-treated variant B cell promoted cell proliferation, migration, and an increment in lactate concentration. Our results suggest that an autocrine phenomenon induced by exosomes in chemoresistant cells may induce modifications on signaling mechanisms of the p53/Mdm2 axis and activation of p70 ribosomal protein kinase S6. Moreover, the specific down-regulated profile of chaperones Hsp90 and Hsp70 secretion inside the exosomes of the chemoresistant variant could be associated with this phenomenon. Therefore, autocrine activation mediated by exosomes and the effect of LDL internalization may influence changes in exosome chaperone content and modulate proliferative signaling pathways, increasing the aggressiveness of MDA-MB-231 chemoresistant cells.

MS3 Imaging Enables the Simultaneous Analysis of Phospholipid C═C and sn-Position Isomers in Tissues

Mass spectrometry (MS) imaging of lipids in tissues with high structure specificity is challenging in the effective fragmentation of position-selective structures and the sensitive detection of multiple lipid isomers. Herein, we develop an MS3 imaging method for the simultaneous analysis of phospholipid C═C and sn-position isomers by on-tissue photochemical derivatization, nanospray desorption electrospray ionization (nano-DESI), and a dual-linear ion trap MS system. A novel laser-based sensing probe is developed for the real-time adjustment of the probe-to-surface distance for nano-DESI. This method is validated in mouse brain and kidney sections, showing its capability of sensitive resolving and imaging of the fatty acyl chain composition, the sn-position, and the C═C location of phospholipids in an MS3 scan. MS3 imaging of phospholipids has shown the capability of differentiation of cancerous, fibrosis, and adjacent normal regions in liver cancer tissues.

Association evaluations of oral anticoagulants with dementia risk based on genomic and real-world data

BACKGROUND

Several observational studies have suggested that oral anticoagulants (OACs) might reduce the risk of dementia in the elderly, but the evidence is inconclusive. And the consistency of this relationship across different OAC classes and dementia subtypes is still uncertain.

METHODS

To comprehensively evaluate this association, we applied Mendelian randomization (MR) combined with pharmacovigilance analysis. MR was used to assess the associations between genetic proxies for three target genes of OACs (VKORC1, F2, and F10) and dementia, including Alzheimer's disease (AD) and vascular dementia (VaD). This genetic analysis was supplemented with real-world pharmacovigilance data, employing disproportionality analysis for more reliable causal inference.

RESULTS

Increased expression of the VKORC1 gene was strongly associated with increased risk of dementia, especially for AD (OR = 1.28, 95% CI = 1.14-1.43; p value < 0.001). Based on pharmacovigilance data, vitamin K antagonists (VKAs, inhibitors targeting VKORC1) exhibited a protective effect against dementia risk (ROR = 0.43, 95% CI = 0.28-0.67). Additional sensitivity analyses, including different MR models and cohorts, supported these results. Conversely, no strong causal associations of genetically proxied F2 and F10 target genes with dementia and its subtypes were found.

CONCLUSIONS

This study reveals that the inhibition of genetically proxied VKORC1 expression or VKAs exposure is associated with a reduced risk of Alzheimer's dementia. However, there is little evidence to support similar associations with direct oral anticoagulants (F2 inhibitors and F10 inhibitors). Further research is warranted to clinically validate our findings.

Genetically determined blood pressure, antihypertensive medications, and risk of intracranial aneurysms and aneurysmal subarachnoid hemorrhage: A Mendelian randomization study

INTRODUCTION

Observational studies suggest that different classes of antihypertensive drugs may have different effects on the occurrence of intracranial aneurysms (IA) and subarachnoid hemorrhage (SAH). However, the reported results in previous studies are inconsistent, and randomized data are absent. We performed a two-sample Mendelian randomization (MR) analysis to study the causal effects of genetically determined blood pressure (BP) and genetic proxies for antihypertensive drug classes on the risk of IA and SAH.

MATERIALS AND METHODS

Genetic instruments and outcome data were obtained from independent genome-wide association studies (GWAS) or published data, which were exclusively restricted to European ancestry. Causal relationships were identified using inverse-variance weighted MR analyses and a series of statistical sensitivity analyses. The FinnGen consortium was used for repeated analysis to verify results obtained from the above GWAS.

RESULTS

Two-sample MR analysis showed that genetically determined Systolic BP, Dystolic BP, and Pulse Pressure were related to a higher risk of IA and SAH. Based on identified single nucleotide polymorphisms (SNPs) that influence the effect of calcium channel blockers (CCB, 42 SNPs), beta-blockers (BB, 8 SNPs), angiotensin-converting enzyme inhibitors (ACEI, 2 SNPs), angiotensin receptor blockers (ARB, 1 SNPs), and thiazides (5 SNPs), genetically determined effect of CCBs was associated with a higher risk of IA (OR, 1.07 [95% CI, 1.03-1.10], p = 5.02 × 10-5) and SAH (OR, 1.06 [95% CI, 1.03-1.09], p = 1.84 × 10-3). No associations were found between other antihypertensive drugs and the risk of IA or SAH. The effect of CCBs on SAH was confirmed in FinnGenconsortium samples (OR, 1.04 [95% CI, 1.00-1.08], p = 0.042).

DISCUSSION AND CONCLUSION

This MR analysis supports the role of elevated blood pressure in the occurrence of intracranial aneurysms and subarachnoid hemorrhage. However, genetic proxies for calcium channel blockers were associated with an increased risk of intracranial aneurysms and subarachnoid hemorrhage. Further studies are required to confirm these findings and investigate the underlying mechanisms.

Discovery and Exploration of Lipid-Modifying Drug Targets for ALS by Mendelian Randomization

Observational studies have faced challenges in identifying replicable causes for amyotrophic lateral sclerosis (ALS). To address this, we employed an unbiased and data-driven approach to discover and explore potential causal exposures using two-sample Mendelian randomization (MR) analyses. In the phenotype discovery stage, we assessed 3948 environmental exposures from the UK Biobank and utilized ALS summary statistics (Europeans, 20,806 cases, 59,804 controls) as the outcome within a phenome-wide MR pipeline. Through a range of sensitivity analyses, two medication traits were identified to be protective for ALS. In the target exploration stage, we further conducted drug target MR analyses using the latest and trans-ethnic summary data on lipid-related traits and ALS (Europeans, 27,205 cases, 110,881 controls; East Asians, 1234 cases, 2850 controls). Our aim was to explore potential causal drug targets through six lipid-modifying effects. These comprehensive analyses revealed significant findings. Specifically, "cholesterol-lowering medication" and "atorvastatin" survived predefined criteria in the phenotype discovery stage and exhibited a protective effect on ALS. Further in the target exploration stage, we demonstrated that the therapeutic effect of APOB through LDL-lowering was associated with reduced ALS liability in Europeans (OR = 0.835, P = 5.61E - 5). Additionally, the therapeutic effect of APOA1 and LDLR through TC-lowering was associated with reduced ALS liability in East Asians (APOA1, OR = 0.859, P = 5.38E - 4; LDLR, OR = 0.910, P = 2.73E - 5). Overall, we propose potential protective effects of cholesterol-lowering drugs or statins on ALS risk from thousands of exposures. Our research also suggests APOB, APOA1, and LDLR as novel therapeutic targets for ALS and supports their potential protective mechanisms may be mediated by LDL-lowering or TC-lowering effects.

Association of serum lipids and abnormal lipid score with cancer risk: a population-based prospective study

BACKGROUND

Serum lipid levels are associated with cancer risk. However, there still have uncertainties about the single and combined effects of low lipid levels on cancer risk.

METHODS

A prospective cohort study of 33,773 adults in Shanghai between 2016 and 2017 was conducted. Total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels were measured. Cox proportional hazard models were used to assess the association of single and combined lipids with overall, lung, colon, rectal, thyroid gland, stomach, and female breast cancers. The effect of the combination of abnormal lipid score and lifestyle on cancer was also estimated.

RESULTS

A total of 926 incident cancer cases were identified. In the RCS analysis, hazard ratios (HRs) of overall cancer for individuals with TC < 5.18 mmol/L or with LDL-C < 3.40 mmol/L were higher. Low TC was associated with higher colorectal cancer risk (HR [95% CI] = 1.76 [1.09-2.84]) and low HDL-C increased thyroid cancer risk by 90%. Abnormal lipid score was linearly and positively associated with cancer risk, and smokers with high abnormal lipid scores had a higher cancer risk, compared to non-smokers with low abnormal lipid scores (P < 0.05).

CONCLUSIONS

Low TC levels were associated with an increased risk of overall and colorectal cancer. More attention should be paid to participants with high abnormal lipid scores and unhealthy lifestyles who may have a higher risk of developing cancer. Determining the specific and comprehensive lipid combinations that affect tumorigenesis remains a valuable challenge.

Inhibition of tumor migration and invasion by fenofibrate via suppressing epithelial-mesenchymal transition in breast cancers

The recurrence and metastasis in breast cancer within 3 years after the chemotherapies or surgery leads to poor prognosis with approximately 1-year overall survival. Large-scale scanning research studies have shown that taking lipid-lowering drugs may assist to reduce the risk of death from many cancers, since cholesterol in lipid rafts are essential for maintain integral membrane structure and functional signaling regulation. In this study, we examined five lipid-lowering drugs: swertiamarin, gemfibrozil, clofibrate, bezafibrate, and fenofibrate in triple-negative breast cancer, which is the most migration-prone subtype. Using human and murine triple-negative breast cancer cell lines (Hs 578 t and 4 T1), we found that fenofibrate displays the highest potential in inhibiting the colony formation, wound healing, and transwell migration. We further discovered that fenofibrate reduces the activity of pro-metastatic enzymes, matrix metalloproteinases (MMP)-9 and MMP-2. In addition, epithelial markers including E-cadherin and Zonula occludens-1 are increased, whereas mesenchymal markers including Snail, Twist and α-smooth muscle actin are attenuated. Furthermore, we found that fenofibrate downregulates ubiquitin-dependent GDF-15 degradation, which leads to enhanced GDF-15 expression that inhibits cell migration. Besides, nuclear translocation of FOXO1 is also upregulated by fenofibrate, which may responsible for GDF-15 expression. In summary, fenofibrate with anti-cancer ability hinders TNBC from migration and invasion, and may be beneficial to repurposing use of fenofibrate.

The Impact of Different Intensities of Physical Activity on Serum Urate and Gout: A Mendelian Randomization Study

Physical activity is a potential protective factor against gout, but the role of exercise intensity in this context remains unclear. To overcome the limitations of observational studies in causal inference, this study employed a two-sample Mendelian randomization approach to explore the impact of different genetically proxied/predicted intensities of physical activity on serum urate concentration and the incidence of gout. Our data related to physical activity, serum urate, and gout were obtained from the UK Biobank, the Global Urate Genetics Consortium (GUGC), and the FinnGen dataset, respectively. Walking was included as representative of typical low-intensity physical activity in the analysis, and the other two types were moderate and vigorous physical activities. The estimation methods we used included the inverse-variance-weighted (IVW) method, MR-Egger regression, weighted-median method, simple-mode method, and weighted-mode method. Sensitivity analyses involved Rucker's framework, Cochran's Q test, funnel plots, MR-PRESSO outlier correction, and leave-one-out analysis. We found suggestive evidence from the inverse-variance-weighted method that moderate physical activity was a potential factor in reducing the incidence of gout (OR = 0.628, p = 0.034), and this association became more substantial in our subsequent sensitivity analysis (OR = 0.555, p = 0.006). However, we observed no distinctive effects of physical activity on serum urate concentration. In conclusion, our study supports some findings from observational studies and emphasizes the preventive role of moderate physical activity against gout. Given the limitations of the existing datasets, we call for future reexamination and expansion of our findings using new GWAS data.

Blood Lipid Metabolic Profiles and Causal Links to Site-Specific Cancer Risks: A Mendelian Randomization Study

Observational and Mendelian randomization (MR) studies have established links between dyslipidemia and select cancer susceptibilities. However, there is a lack of comprehensive exploration of causal relationships spanning diverse cancer types. Here, we conducted a two-sample MR analysis to elucidate the causative connections between 9 blood lipid metabolic profiles (namely, adiponectin, leptin, lipoprotein A, apolipoprotein A1, apolipoprotein B, cholesterol, triglycerides, LDL-cholesterol, and HDL-cholesterol) and 21 site-specific cancer risks. Our findings reveal genetically predicted adiponectin levels to be associated with a reduced ovarian cancer risk, while genetically determined leptin increases bladder cancer risk but decreases prostate cancer risk. Lipoprotein A elevates risk of prostate cancer while diminishing risk of endometrial cancer, while apolipoprotein A1 heightens risks of breast and cervical cancers. Furthermore, elevated levels of cholesterol are positively correlated with kidney cancer, and triglycerides demonstrate a positive association with non-melanoma skin cancer but a negative association with breast cancer. Protective effects of genetically predicted LDL-cholesterol on endometrial cancer and adverse effects of HDL-cholesterol on breast cancer are also observed. Our study conclusively establishes that blood lipid metabolic profiles exert causal effects on cancer susceptibility, providing more robust evidence for cancer prevention and prompting contemplation regarding the future health of the human populace.

Application of Metabolomics to Epidemiologic Studies of Breast Cancer: New Perspectives for Etiology and Prevention

PURPOSE

To provide an overview on how the application of metabolomics (high-throughput characterization of metabolites from cells, organs, tissues, or biofluids) to population-based studies may inform our understanding of breast cancer etiology.

METHODS

We evaluated studies that applied metabolomic analyses to prediagnostic blood samples from prospective epidemiologic studies to identify circulating metabolites associated with breast cancer risk, overall and by breast cancer subtype and menopausal status. We provide some important considerations for the application and interpretation of metabolomics approaches in this context.

RESULTS

Overall, specific lipids and amino acids were indicated as the most common metabolite classes associated with breast cancer development. However, comparison of results across studies is challenging because of heterogeneity in laboratory techniques, analytical methods, sample size, and applied statistical methods.

CONCLUSION

Metabolomics is being increasingly applied to population-based studies for the identification of new etiologic hypotheses and/or mechanisms related to breast cancer development. Despite its success in applications to epidemiology, studies of larger sample size with detailed information on menopausal status, breast cancer subtypes, and repeated biologic samples collected over time are needed to improve comparison of results between studies and enhance validation of results, allowing potential clinical translation of findings.

Association between blood pressure and different antihypertensive drugs with outcome after ischemic stroke: A Mendelian randomization study

BACKGROUND

Observational studies suggest an association between blood pressure (BP) and functional outcomes in ischemic stroke patients but whether this is causal or due to confounding is uncertain. We used Mendelian randomization (MR) to assess causality, and also explore whether particular classes of anti-hypertensives were associated with a better outcome after ischemic stroke.

METHODS

We selected genetic variants associated with systolic and diastolic BP and BP-lowering variants in genes encoding antihypertensive drugs from genome-wide association studies (GWAS) on 757,601 individuals. The primary outcome was 3-month dependence or death defined as a modified Rankin Scale (mRS) of 3-6. The secondary outcome was disability or death after 90 days defined as mRS 2-6. Cochran's Q statistic in the inverse variance weighted (IVW) model, the weighted median, MR-Egger regression, leave-one-single-nucleotide polymorphism (SNP)-out analysis, MR-Pleiotropy Residual Sum and Outlier methods were adopted as sensitivity analyses. To validate our primary results, we performed independent repeat analyses and Bi-directional MR analyses.

RESULTS

Genetic predisposition to higher systolic and diastolic BP was associated with disability or death after ischemic stroke in univariable IVW MR analysis (odds ratio (OR) 1.29, 95% confidence interval (CI): 1.05-1.59, p = 0.014; OR 1.27, 95% CI: 1.07-1.51, p = 0.006, respectively). Pulse pressure was associated with both dependence or death and disability or death after ischemic stroke (OR = 1.05, 95% CI: 1.02-1.08, p = 0.002; OR = 1.04, 95% CI = 1.01-1.07, p = 0.009, respectively). Angiotensin-converting enzyme inhibitor (ACEI) and calcium channel blocker (CCB) were significantly associated with improved functional outcomes (dependence or death, OR 0.76, 95% CI: 0.62-0.94, p = 0.009; OR 0.89, 95% CI: 0.83-0.97, p = 0.005). Proxies for β-blockers, angiotensin receptor blockers (ARB), and thiazides failed to show associations with functional outcomes (p > 0.05).

CONCLUSION

We provide evidence for an association of genetic predisposition to higher BP with a higher risk of 3-month functional dependence after ischemic stroke. Our findings support ACEI and CCB as promising antihypertensive drugs for improving functional outcomes in ischemic stroke.

A bibliometric analysis of PCSK9 inhibitors from 2007 to 2022

Background

Since the approval of the proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibodies for marketing in 2015, PCSK9 inhibitors have attracted significant interest in the field of cardiovascular endocrinology. A large number of clinical trials have confirmed the efficacy and safety of PCSK9 inhibitors in reducing cholesterol and the risk of cardiovascular events. No bibliometric analysis of PCSK9 inhibitors has been performed as of yet. This study aims to analyze the research trends and hotspots of PCSK9 inhibitors through bibliometric analysis.

Methods

We searched the Web of Science Core Collection (WoSCC) database for PCSK9 inhibitor-related publications from 2007 to 2022. Data visualization analysis was performed using CiteSpace software. Microsoft Excel and Graphpad software were used for the drawing of some tables and figures.

Results

A total of 1072 pieces of literature were retrieved between 2007 and 2022. The number of publications concerning PCSK9 inhibitors is growing annually. The top five countries with the most articles published were the United States, England, Canada, Italy, and France. Harvard University, Amgen, Brigham & Women's Hospital, Harvard Medical School, and Imperial College London are the five institutions with the highest output. The Journal of Clinical Lipidology is the most popular journal in this field. The most frequently cited journal is the New England Journal of Medicine. As for authors, Sabatine MS and Giugliano RP from Brigham & Women's Hospital have the highest number of published articles. Amgen is the funding agency for most of the research. According to keyword analysis, "low density lipoprotein", "familial hypercholesterolemia", "PCSK9 inhibitor", "PCSK9", and "efficacy" are the five keywords with the highest frequency of co-occurrence.

Conclusion

The past 15 years have witnessed a rapid and fruitful development of PCSK9 inhibitors. The research trend and focus for PCSK9 inhibitors are from the mechanism of reducing low-density lipoprotein cholesterol to related clinical trials. Developed countries such as the United States have contributed prominently in this area. Coronary artery and inflammation are currently at the forefront of research in the field and are in an explosion period.

The causal relationship between physical activity, sedentary time and idiopathic pulmonary fibrosis risk: a Mendelian randomization study

BACKGROUND

Several observational studies have found that physical inactivity and sedentary time are associated with idiopathic pulmonary fibrosis (IPF) risk. However, the causality between them still requires further investigation. Therefore, our study aimed to investigate the causal effect of physical activity (PA) and sedentary time on the risk of IPF via two-sample Mendelian randomization (MR) analysis.

METHODS

Multiple genome-wide association study (GWAS) data involving individuals of European ancestry were analyzed. The datasets encompassed published UK Biobank data (91,105-377,234 participants) and IPF data (2018 cases and 373,064 controls) from FinnGen Biobank. The inverse variance weighting (IVW) method was the primary approach for our analysis. Sensitivity analyses were implemented with Cochran's Q test, MR-Egger regression, MR-PRESSO global test, and leave-one-out analysis.

RESULTS

Genetically predicted self-reported PA was associated with lower IPF risk [OR = 0.27; 95% CI 0.09-0.82; P = 0.02]. No causal effects of accelerometry-based PA or sedentary time on the risk of IPF were observed.

CONCLUSIONS

Our findings supported a protective relationship between self-reported PA and the risk for IPF. The results suggested that enhancing PA may be an effective preventive strategy for IPF.

Mendelian Randomization Study of Lipid Metabolites Reveals Causal Associations with Heel Bone Mineral Density

BACKGROUND

Osteoporosis, which is a bone disease, is characterized by low bone mineral density and an increased risk of fractures. The heel bone mineral density is often used as a representative measure of overall bone mineral density. Lipid metabolism, which includes processes such as fatty acid metabolism, glycerol metabolism, inositol metabolism, bile acid metabolism, carnitine metabolism, ketone body metabolism, sterol and steroid metabolism, etc., may have an impact on changes in bone mineral density. While some studies have reported correlations between lipid metabolism and heel bone mineral density, the overall causal relationship between metabolites and heel bone mineral density remains unclear.

OBJECTIVE

to investigate the causal relationship between lipid metabolites and heel bone mineral density using two-sample Mendelian randomization analysis.

METHODS

Summary-level data from large-scale genome-wide association studies were extracted to identify genetic variants linked to lipid metabolite levels. These genetic variants were subsequently employed as instrumental variables in Mendelian randomization analysis to estimate the causal effects of each lipid metabolite on heel bone mineral density. Furthermore, metabolites that could potentially be influenced by causal relationships with bone mineral density were extracted from the KEGG and WikiPathways databases. The causal associations between these downstream metabolites and heel bone mineral density were then examined. Lastly, a sensitivity analysis was conducted to evaluate the robustness of the results and address potential sources of bias.

RESULTS

A total of 130 lipid metabolites were analyzed, and it was found that acetylcarnitine, propionylcarnitine, hexadecanedioate, tetradecanedioate, myo-inositol, 1-arachidonoylglycerophosphorine, 1-linoleoylglycerophoethanolamine, and epiandrosterone sulfate had a causal relationship with heel bone mineral density (p < 0.05). Furthermore, our findings also indicate an absence of causal association between the downstream metabolites associated with the aforementioned metabolites identified in the KEGG and WikiPathways databases and heel bone mineral density.

CONCLUSION

This work supports the hypothesis that lipid metabolites have an impact on bone health through demonstrating a causal relationship between specific lipid metabolites and heel bone mineral density. This study has significant implications for the development of new strategies to osteoporosis prevention and treatment.

Targeting PCSK9 to tackle cardiovascular disease

Lowering blood cholesterol levels efficiently reduces the risk of developing atherosclerotic cardiovascular disease (ASCVD), including coronary artery disease (CAD), which is the main cause of death worldwide. CAD is caused by plaque formation, comprising cholesterol deposits in the coronary arteries. Proprotein convertase subtilisin kexin/type 9 (PCSK9) was discovered in the early 2000s and later identified as a key regulator of cholesterol metabolism. PCSK9 induces lysosomal degradation of the low-density lipoprotein (LDL) receptor in the liver, which is responsible for clearing LDL-cholesterol (LDL-C) from the circulation. Accordingly, gain-of-function PCSK9 mutations are causative of familial hypercholesterolemia, a severe condition with extremely high plasma cholesterol levels and increased ASCVD risk, whereas loss-of-function PCSK9 mutations are associated with very low LDL-C levels and protection against CAD. Since the discovery of PCSK9, extensive investigations in developing PCSK9 targeting therapies have been performed. The combined delineation of clear biology, genetic risk variants, and PCSK9 crystal structures have been major drivers in developing antagonistic molecules. Today, two antibody-based PCSK9 inhibitors have successfully progressed to clinical application and shown to be effective in reducing cholesterol levels and mitigating the risk of ASCVD events, including myocardial infarction, stroke, and death, without any major adverse effects. A third siRNA-based inhibitor has been FDA-approved but awaits cardiovascular outcome data. In this review, we outline the PCSK9 biology, focusing on the structure and nonsynonymous mutations reported in the PCSK9 gene and elaborate on PCSK9-lowering strategies under development. Finally, we discuss future perspectives with PCSK9 inhibition in other severe disorders beyond cardiovascular disease.

Mendelian randomization analysis revealed potential metabolic causal factors for breast cancer

Observational studies showed that metabolic phenotypes were associated with the risk of developing breast cancer (BC). However, those results are inconsistent regarding the magnitude of the association, particularly by subtypes of breast cancer. Furthermore, the mechanisms of the association remain unclear. We performed two-sample Mendelian randomization (MR) analyses to evaluate the causal effect of metabolic risk factors on breast cancer in the European population. Assessed individually using MR, body mass index (BMI) (odds ratio [OR] 0.94, 95% Confidence interval [CI] 0.90-0.98, P = 0.007), high-density lipoprotein cholesterol (HDL-C) (OR 1.10, 95% CI 1.07-1.13, P = 6.10 × 10-11) and triglycerides (TG) (OR 0.92, 95% CI 0.90-0.96, P = 1.58 × 10-6) were causally related to breast cancer risk. In multivariable MR, only HDL-C (OR 1.08; 95% CI 1.02-1.14; P = 0.02) retained a robust effect, suggesting that the genetic association between BMI, HDL-C and TG with breast cancer risk in univariable analysis was explained via HDL-C. These findings suggest a possible causal role of HDL-C in breast cancer etiology.

Increased Expression of miR-223-3p and miR-375-3p and Anti-Inflammatory Activity in HDL of Newly Diagnosed Women in Advanced Stages of Breast Cancer

The expression of inflammation-related miRs bound to high-density lipoproteins (HDLs), the anti-inflammatory activity of HDLs isolated from individuals with breast cancer, and controls were determined. Forty newly diagnosed women with breast cancer naïve of treatment and 10 control participants were included. Cholesterol-loaded bone-marrow-derived macrophages were incubated with HDL from both groups and challenged with lipopolysaccharide (LPS). Interleukin 6 (IL6) and tumor necrosis factor (TNF) in the medium were quantified. The miRs in HDLs were determined by RT-qPCR. Age, body mass index, menopausal status, plasma lipids, and HDL composition were similar between groups. The ability of HDL to inhibit IL6 and TNF production was higher in breast cancer compared to controls, especially in advanced stages of the disease. The miR-223-3p and 375-3p were higher in the HDLs of breast cancer independent of the histological type of the tumor and had a high discriminatory power between breast cancer and controls. The miR-375-3p was greater in the advanced stages of the disease and was inversely correlated with the secretion of inflammatory cytokines. Inflammation-related miRs and the anti-inflammatory role of HDLs may have a significant impact on breast cancer pathophysiology.

Activation of invasion by oncogenic reprogramming of cholesterol metabolism via increased NPC1 expression and macropinocytosis

Cancer cells are dependent on cholesterol, and they possess strictly controlled cholesterol homeostasis mechanisms. These allow them to smoothly switch between cholesterol synthesis and uptake to fulfill their needs and to adapt environmental changes. Here we describe a mechanism of how cancer cells employ oncogenic growth factor signaling to promote uptake and utilization of extracellular cholesterol via Myeloid Zinc Finger 1 (MZF1)-mediated Niemann Pick C1 (NPC1) expression and upregulated macropinocytosis. Expression of p95ErbB2, highly oncogenic, standard-treatment resistant form of ErbB2 mobilizes lysosomes and activates EGFR, invasion and macropinocytosis. This is connected to a metabolic shift from cholesterol synthesis to uptake due to macropinocytosis-enabled flow of extracellular cholesterol. NPC1 increase facilitates extracellular cholesterol uptake and is necessary for the invasion of ErbB2 expressing breast cancer spheroids and ovarian cancer organoids, indicating a regulatory role for NPC1 in the process. The ability to obtain cholesterol as a byproduct of increased macropinocytosis allows cancer cells to direct the resources needed for the energy-consuming cholesterol synthesis towards other activities such as invasion. These results demonstrate that macropinocytosis is not only an alternative energy source for cancer cells but also an efficient way to provide building material, such as cholesterol, for its macromolecules and membranes.

Genetic variations in HMGCR and PCSK9 and kidney function: a Mendelian randomization study

BACKGROUND

The genetically predicted lipid-lowering effect of HMGCR or PCSK9 variant can be used to assess drug proxy effects on kidney function.

METHODS

Mendelian randomization (MR) analysis-identified HMGCR and PCSK9 genetic variants were used to predict the low-density lipoprotein (LDL) cholesterol-lowering effects of medications targeting related molecules. Primary summary-level outcome data for log-estimated glomerular filtration rate (eGFR; creatinine) were provided by the CKDGen Consortium (n = 1,004,040 European) from a meta-analysis of CKDGen and UK Biobank data. We also conducted a separate investigation of summary-level data from CKDGen (n = 567,460, log-eGFR [creatinine]) and UK Biobank (n = 436,581, log-eGFR [cystatin C]) samples. Summary-level MRs using an inverse variance weighted method and pleiotropy-robust methods were performed.

RESULTS

Summary-level MR analysis indicated that the LDL-lowering effect predicted genetically by HMGCR variants (50-mg/dL decrease) was significantly associated with a decrease in eGFR (-1.67%; 95% confidence interval [CI], -2.20% to -1.13%). Similar significance was found in results from the pleiotropy-robust MR methods when the CKDGen and UK Biobank data were analyzed separately. However, the LDL-lowering effect predicted genetically by PCSK9 variants was significantly associated with an increase in eGFR (+1.17%; 95% CI, 0.10%-2.25%). The results were similarly supported by the weighted median method and in each CKDGen and UK Biobank dataset, but the significance obtained by MR-Egger regression was attenuated.

CONCLUSION

Genetically predicted HMG-CoA reductase inhibition was associated with low eGFR, while genetically predicted PCSK9 inhibition was associated with high eGFR. Clinicians should consider that the direct effect of different types of lipid-lowering medication on kidney function can vary.

Prognostic value of perioperative serum low-density lipoprotein cholesterol level for postoperative prognosis of pancreatic cancer: a retrospective study

BACKGROUND

As a common malignant tumour, pancreatic cancer (PC) has the worst clinical outcome. Early evaluation of the postoperative prognosis has certain clinical value. Low-density lipoprotein cholesterol (LDL-c), which is mainly composed of cholesteryl esters, phospholipids, and proteins, plays an important role in transporting cholesterol into peripheral tissues. LDL-c has also been reported to be correlated with the occurrence and progression of malignant tumours and can predict postoperative prognosis in various tumours.

AIMS

To determine correlation between serum LDL-c level and clinical outcome in PC patients after surgery.

METHODS

Data of PC patients that received surgery at our department from January 2015 to December 2021 were retrospectively analysed. Receiver operating characteristic (ROC) curves between perioperative serum LDL-c at different timepoints and survival rate at postoperative 1-year were drawn, and the optimal cut-off value was calculated. Patients were categorized into low and high LDL-c groups, and their clinical data and outcome were compared. Univariate and multivariate analyses were applied to screen out risk markers for poor prognosis of PC patients after surgery.

RESULTS

The area under the ROC curve of serum LDL-c at 4 weeks after surgery and prognosis was 0.669 (95% CI: 0.581-0.757), and the optimal cut-off value was 1.515 mmol/L. The median disease-free survival (DFS) rates of low and high LDL-c groups were 9 months and 16 months, respectively, and the 1-, 2- and 3-year DFS rates were 42.6%, 21.1% and 11.7% in low LDL-c group, respectively, and, 60.2%, 35.3% and 26.2% in high LDL-c group, respectively (P = 0.005). The median overall survival (OS) rates of low and high LDL-c groups were 12 months and 22 months, respectively, and the 1-, 2- and 3-year OS rates were 46.8%, 22.6% and 15.8% in low LDL-c group, respectively, and 77.9%, 46.8% and 30.4% in high LDL-c group, respectively (P = 0.004). Multivariate analysis confirmed low postoperative 4-week serum LDL-c as independent risk marker for early tumour recrudesce and poor clinical outcome in PC patients.

CONCLUSION

High postoperative 4-week serum LDL-c is a prognostic marker for prolonged DFS and OS time in PC patients.

A pan-cancer analysis of the oncogenic and immunological roles of apolipoprotein F (APOF) in human cancer

BACKGROUND

Apolipoprotein F (APOF) has been less studied in cancers. Thus, we aimed to perform a pan-cancer analysis of the oncogenic and immunological effects of APOF on human cancer.

METHODS

A standardized TCGA pan-cancer dataset was downloaded. Differential expression, clinical prognosis, genetic mutations, immune infiltration, epigenetic modifications, tumor stemness and heterogeneity were analyzed. We conducted all analyses through software R (version 3.6.3) and its suitable packages.

RESULTS

Overall, we found that the common cancers differentially expressed between tumor and normal samples and prognostic-associated were BRCA, PRAD, KIRP, and LIHC in terms of overall survival (OS), disease-free survival (DFS) and progression-free survival (PFS). The pan-cancer Spearman analysis showed that the mRNA expression of APOF was negatively correlated with four tumor stemness indexes (DMPss, DNAss, ENHss, and EREG-METHss) with statistical significance for PRAD and was positively correlated for LIHC. In terms of BRCA and PRAD patients, we found negative correlation of APOF with TMB, MSI, neo, HRD and LOH. The mutation frequencies of BRCA and LIHC were 0.3%. APOF expression was negatively correlated with immune infiltration and positively correlated with tumor purity for PRAD patients. The mRNA expression of APOF was negatively associated with most TILs for LIHC, B cells, CD4+ T cells, neutrophils, macrophages and dendritic cells, but was positively associated with CD8+ T cells.

CONCLUSIONS

Our pan-cancer study offered a relatively comprehensive understanding of the roles of APOF on BRCA, PRAD, KIRP, and LIHC.

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.

Hypertension, antihypertensive drugs, and age at onset of Huntington's disease

BACKGROUND

Associations between blood pressure (BP) with age at onset of Huntington's disease (HD) have reported inconsistent findings. We used Mendelian randomization (MR) to assess effects of BP and lowering systolic BP (SBP) via the genes encoding targets of antihypertensive drugs on age at onset of HD.

METHODS

Genetic variants from genome-wide association studies(GWAS) of BP traits and BP-lowering variants in genes encoding antihypertensive drugs targets were extracted. Summary statistics for age at onset of HD were retrieved from the GWAS meta-analysis of HD residual age at onset from the GEM-HD Consortium included 9064 HD patients of European ancestry (4417 males and 4,647 females). MR estimates were calculated using the inverse variance weighted method, supplemented by MR-Egger, weighted median, and MR-PRESSO methods.

RESULTS

Genetically predicted SBP or diastolic BP increase was associated with a later age at onset of HD. However, after SBP/DBP was present as a covariate using multivariable MR method, no significant causal association was suggested. A 10-mm Hg reduction in SBP through variants in genes encoding targets of calcium channel blockers (CCB) was associated with an earlier age at onset of HD (β=-0.220 years, 95% CI =-0.337 to -0.102, P = 2.42 × 10^- 4). We did not find a causal association between angiotensin converting enzyme inhibitors and β-blockers with the earlier HD onset. No heterogeneity and horizontal pleiotropy were identified.

CONCLUSIONS

This MR analysis provided evidence that genetically determined SBP lowering through antihypertensive drugs might be associated with an earlier age at onset of HD. The results may have a potential impact on management of hypertension in the pre-motor-manifest HD population.

The Ratio of Monocyte to Apolipoprotein A1 is an Independent Predictor of Breast Cancer: A Retrospective Study

Objective

To explore the predictive value of the ratio of monocyte to apolipoprotein A1 (MAR) (a new index related to inflammation and lipid in breast cancer (BC)) and its relationship with clinicopathological staging.

Methods

The hematological test results of 394 patients with breast diseases, including 276 cases of BC, 118 cases of benign breast disease (BBD), and 219 healthy volunteers (HV), were retrospectively collected. The clinical value of MAR was analyzed with binary logistic regression.

Results

Using statistical software analysis, the results showed that MAR level (P<0.001) was the largest in the BC group, followed by BBD, and the lowest in the HV group, and it was found to be an indicator to distinguish BC from BBD, also an independent risk factor for BC. The increase in MAR level showed that the risk of BC was 3.733 times higher than that of HV (P<0.001). In addition, there was a notable difference in MAR between early, middle and late stages of BC patients (P=0.047), with the highest MAR level in late stage (0.510±0.078) and the lowest MAR level in early stage (0.392±0.011); the MAR level of those with tumor invasion depth of Phase 4 was the highest (0.484±0.072), and that of Phase 1/2 was the lowest (0.379±0.010), with a statistically significant difference (P<0.001). MAR was positively correlated with tumor invasion depth (P<0.001, r=0.210), that's, the size of MAR increased when there was more deeper tumor invasion.

Conclusion

MAR is a new indicator for the auxiliary differential diagnosis of benign and malignant breast diseases, and is also an independent risk factor for BC. High-level MAR is closely related to late staging and tumor invasion depth of BC. It can be seen that MAR is a potentially valuable predictor of BC, and this is the first study to explore the clinical value of MAR in BC.

Nuclear magnetic resonance-determined lipoprotein profile and risk of breast cancer: a Mendelian randomization study

PURPOSE

While crudely quantified lipoproteins have been reported to affect the risk of breast cancer, the effects of subclass lipoproteins characterized by particle size, particle number, and lipidomes remain unknown.

METHODS

Utilizing nuclear magnetic resonance-based GWAS of 85 lipoprotein traits, we performed two-sample univariable Mendelian randomization (MR) to evaluate the causal relationship between each trait with breast cancer (Ncase/control = 133,384/113,789) and with its estrogen receptor (ER) subtypes. Then, we applied multivariable MR to investigate the independent effects considering both general and central obesity.

RESULTS

In univariable MR, a heterogeneous effect of subclass high-density lipoproteins (HDL) was observed, in which small HDL traits (ORs ranged from 0.89 to 0.94) were associated with a decreased risk of breast cancer while non-small HDLs traits (OR ranged from 1.04 to 1.08) were associated with an increased risk of breast cancer. Very-low-density lipoproteins (VLDL) traits and serum total triglycerides (TG) were associated with a decreased risk of breast cancer (ORs ranged from 0.88 to 0.94). Similar association patterns were found for ER + subtype. In multivariable MR, only the protective effects of small HDL, VLDL and TG on ER + subtype remained significant.

CONCLUSION

We identified a heterogeneous effect of subclass HDLs and a consistent protective effect of VLDL on breast cancer. Only the effects of small HDL and VLDL on ER + subtype remained robust after controlling for obesity. These findings provide new insight into the causal pathway underlying lipoproteins and breast cancer.

Cholesterol and breast cancer risk: a cohort study using health insurance claims and health checkup databases

PURPOSE

This study aimed to investigate the association between serum cholesterol and triglyceride levels and breast cancer risk in Japanese women.

METHODS

We retrospectively evaluated the association between the levels of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TGs) and the incidence of breast cancer in a cohort study by using the health insurance claims and health checkup data from a database provided by JMDC Inc. We included 956,390 women who were insured between April 2008 and June 2019, identified breast cancer cases by using validated definitions, and estimated the risk of breast cancer by using multivariable Cox proportional hazards regression models adjusted for potential confounders.

RESULTS

During the 2,832,277 person-years observation period (median 2.4 years), 6284 participants were diagnosed with breast cancer. There was marginally significant association between LDL-C and breast cancer risk when comparing the highest and lowest quintiles and at the clinical cutoff values for diagnosing hyperlipidemia. HDL-C was not associated with breast cancer. However, when stratified by age groups (< 50 and ≥ 50), HDL-C was inversely associated with breast cancer risk in women over 50 years old. TG was not associated with breast cancer risk.

CONCLUSION

In this population, there was a modest association of LDL-C at the clinical cutoff values for diagnosing hyperlipidemia (140 mg/mL), and there were no associations of HDL-C and TG with breast cancer risk.

High-density lipoprotein cholesterol and carcinogenesis

High-density lipoprotein cholesterol (HDLC) has been recognized to be associated with atherosclerosis. In the past few years many studies have found that HDLC is also related to tumor development and progression. Despite some opposing views, a large number of studies support a negative association between HDLC and tumor incidence. Measuring serum HDLC concentrations may facilitate assessment of the prognosis of cancer patients and provide a biomarker for tumors. However, there is a lack of molecular mechanism studies on the link between HDLC and tumors. In this review we discuss the impact of HDLC on the incidence and prognosis of cancer in different systems, as well as prospects for the prediction and treatment of cancer in the future.

Causal relationship between polycystic ovary syndrome and chronic kidney disease: A Mendelian randomization study

Objective

Polycystic ovary syndrome is one of the most common endocrine disorders among women of childbearing age. The relationship between polycystic ovary syndrome and chronic kidney disease remains unclear and controversial. In this study, we investigated the causal role of polycystic ovary syndrome in the development of chronic kidney disease using the two-sample Mendelian randomization method.

Methods

Public shared summary-level data was acquired from European-ancestry genome wide association studies. We finally obtained 12 single nucleotide polymorphisms as instrumental variables, which were associated with polycystic ovary syndrome in European at genome-wide significance (P < 5 × 10-8). Inverse-variance weighted method was employed in the Mendelian randomization analysis and multiple sensitivity analyses were implemented. Outcome data were obtained from the Open GWAS database.

Results

A positive causal association was observed between polycystic ovary syndrome and chronic kidney disease (odds ratio [OR]=1.180, 95% confidence interval [CI]: 1.038-1.342; P=0.010). Further analyses clarified that causal relationship exist between polycystic ovary syndrome and some serological indicators of chronic kidney disease (fibroblast growth factor 23: OR= 1.205, 95% CI: 1.031-1.409, P=0.019; creatinine: OR= 1.012, 95% CI: 1.001-1.023, P=0.035; cystatin C: OR= 1.024, 95% CI: 1.006-1.042, P=0.009). However, there was no causal association of polycystic ovary syndrome with other factors in the data sources we employed.

Conclusions

Our results indicate an important role of polycystic ovary syndrome in the development of chronic kidney disease. This study suggests that regular follow-up of renal function in patients with polycystic ovary syndrome is necessary for the early treatment of chronic kidney disease.

The increased antioxidant action of HDL is independent of HDL cholesterol plasma levels in triple-negative breast cancer

Introduction

The association between high-density lipoprotein cholesterol (HDLc) with the incidence and progression of breast cancer (BC) is controversial. HDL removes excess cholesterol from cells and acts as an antioxidant and anti-inflammatory. BC is a heterogeneous disease, and its molecular classification is important in the prediction of clinical and therapeutic evolution. Triple-negative breast cancer (TNBC) presents higher malignancy, lower therapeutic response, and survival rate. In the present investigation, the composition and antioxidant activity of isolated HDL was assessed in women with TNBC compared to controls.

Methods

Twenty-seven women with a recent diagnosis of TNBC, without prior treatment, and 27 healthy women (control group) paired by age and body mass index (BMI) were included in the study. HDL and low-density lipoprotein (LDL) were isolated from plasma by discontinuous density gradient ultracentrifugation. Plasma lipid profile and HDL composition (total cholesterol, TC; triglycerides, TG; HDLc; phospholipids, PL) were determined by enzymatic colorimetric methods. ApoB and apo A-I were quantified by immunoturbidimetry. The antioxidant activity of HDL was determined by measuring the lag time phase for LDL oxidation and the maximal rate of conjugated dienes formation in LDL incubated with copper sulfate solution. The absorbance (234 nm) was monitored at 37°C, for 4 h, at 3 min intervals.

Results

The control group was similar to the TNBC concerning menopausal status, concentrations, and ratios of plasma lipids. The composition of the HDL particle in TC, TG, PL, and apo A-I was also similar between the groups. The ability of HDL to retard LDL oxidation was 22% greater in the TNBC group as compared to the control and positively correlated with apoA-I in HDL. Moreover, the antioxidant activity of HDL was greater in the advanced stages of TNBC (stages III and IV) compared to the control group. The maximum rate of formation of conjugated dienes was similar between groups and the clinical stages of the disease.

Discussion

The results highlight the role of HDL as an antioxidant defense in TNBC independently of HDLc plasma levels. The improved antioxidant activity of HDL, reflected by retardation in LDL oxidation, could contribute to limiting oxidative and inflammatory stress in advanced stages of TNBC.

Low expression of HIF1AN accompanied by less immune infiltration is associated with poor prognosis in breast cancer

Background

Hypoxia-inducible factor 1-alpha (HIF-1α) stability and transcriptional action are reduced by the hypoxia-inducible factor 1-alpha subunit suppressor (HIF1AN). Its inappropriate expression is associated with the development of cancer and immune control. It is yet unknown how HIF1AN, clinical outcomes, and immune involvement in breast cancer (BC) are related.

Methods

Using the GEPIA, UALCAN, TIMER, Kaplan-Meier plotter, and TISIDB datasets, a thorough analysis of HIF1AN differential expression, medical prognosis, and the relationship between HIF1AN and tumor-infiltrating immune cells in BC was conducted. Quantitative real-time PCR (qRT-PCR) analysis of BC cells were used for external validation.

Results

The findings revealed that, as compared to standard specimens, BC cells had significantly lower levels of HIF1AN expression. Good overall survival (OS) for BC was associated with higher HIF1AN expression. Additionally, in BC, the expression of HIF1AN was closely associated with the chemokines and immune cell infiltration, including neutrophils, macrophages, T helper cells, B cells, Tregs, monocytes, dendritic cells, and NK cells. A high correlation between HIF1AN expression and several immunological indicators of T-cell exhaustion was particularly revealed by the bioinformatic study.

Conclusions

HIF1AN is a predictive indicator for breast tumors, and it is useful for predicting survival rates.

Can Intelligence Affect Alcohol-, Smoking-, and Physical Activity-Related Behaviors? A Mendelian Randomization Study

People with high levels of intelligence are more aware of risk factors, therefore choosing a healthier lifestyle. This assumption seems reasonable, but is it true? Previous studies appear to agree and disagree. To cope with the uncertainty, we designed a mendelian randomization (MR) study to examine the causal effects of genetically proxied intelligence on alcohol-, smoking-, and physical activity (PA)-related behaviors. We obtained genome-wide association study (GWAS) datasets concerning these variables from separate studies or biobanks and used inverse-variance weighted (IVW) or MR-Egger estimator to evaluate the causal effects according to an MR protocol. The MR-Egger intercept test, MR-PRESSO, and funnel plots were employed for horizontal pleiotropy diagnosis. The Steiger test (with reliability test), Cochran's Q test, MR-PRESSO, and leave-one-out method were employed for sensitivity analysis. We found significant or potential effects of intelligence on alcohol dependence (OR = 0.749, p = 0.003), mental and behavioral disorders due to alcohol (OR = 0.814, p = 0.009), smoking (OR = 0.585, p = 0.005), and smoking cessation (OR = 1.334, p = 0.001). Meanwhile, we found significant or potential effects on walking duration (B = -0.066, p < 0.001), walking frequency (B = -0.055, p = 0.031), moderate PA frequency (B = -0.131, p < 0.001), and vigorous PA frequency (B = -0.070, p = 0.001), but all in a negative direction. In conclusion, our findings reinforce some existing knowledge, indicate the complexity of the health impacts of human intelligence, and underline the value of smoking and alcohol prevention in less intelligent populations. Given the existing limitations in this study, particularly the potential reverse causality in some estimations, re-examinations are warranted in future research.

Visualization and Quantification of the Association Between Breast Cancer and Cholesterol in the All of Us Research Program

Epidemiologic evidence for the association of cholesterol and breast cancer is inconsistent. Several factors may contribute to this inconsistency, including limited sample sizes, confounding effects of antihyperlipidemic treatment, age, and body mass index, and the assumption that the association follows a simple linear function. Here, we aimed to address these factors by combining visualization and quantification a large-scale contemporary electronic health record database (the All of Us Research Program). We find clear visual and quantitative evidence that breast cancer is strongly, positively, and near-linearly associated with total cholesterol and low-density lipoprotein cholesterol, but not associated with triglycerides. The association of breast cancer with high-density lipoprotein cholesterol was non-linear and age dependent. Standardized odds ratios were 2.12 (95% confidence interval 1.9-2.48), P = 5.6 × 10^-31 for total cholesterol; 1.99 (1.75-2.26), P = 2.6 × 10^-26 for low-density lipoprotein cholesterol; 1.69 (1.3-2.2), P = 9.0 × 10^-5 for high-density lipoprotein cholesterol at age < 56; and 0.65 (0.55-0.78), P = 1.2 × 10^-6 for high-density lipoprotein cholesterol at age ⩾ 56. The inclusion of the lipid levels measured after antihyperlipidemic treatment in the analysis results in erroneous associations. We demonstrate that the use of the logistic regression without inspecting risk variable linearity and accounting for confounding effects may lead to inconsistent results.

Protective effect of antihypertensive drugs on the risk of Parkinson's disease lacks causal evidence from mendelian randomization

Background: Evidence from observational studies concerning the causal role of blood pressure (BP) and antihypertensive medications (AHM) on Parkinson's disease (PD) remains inconclusive. A two-sample Mendelian randomization (MR) study was performed to evaluate the unconfounded association of genetic proxies for BP and first-line AHMs with PD. Methods: Instrumental variables (IV) from the genome-wide association study (GWAS) for BP traits were used to proxy systolic BP (SBP), diastolic BP, and pulse pressure. SBP-associated variants either located within encoding regions or associated with the expression of AHM targets were selected and then scaled to proxy therapeutic inhibition of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, calcium channel blockers, and thiazides. Positive control analyses on coronary heart disease (CHD) and stroke were conducted to validate the IV selection. Summary data from GWAS for PD risk and PD age at onset (AAO) were used as outcomes. Results: In positive control analyses, genetically determined BP traits and AHMs closely mimicked the observed causal effect on CHD and stroke, confirming the validity of IV selection methodology. In primary analyses, although genetic proxies identified by "encoding region-based method" for β-blockers were suggestively associated with a delayed PD AAO (Beta: 0.115; 95% CI: 0.021, 0.208; p = 1.63E-2; per 10-mmHg lower), sensitivity analyses failed to support this association. Additionally, MR analyses found little evidence that genetically predicted BP traits, overall AHM, or other AHMs affected PD risk or AAO. Conclusion: Our data suggest that BP and commonly prescribed AHMs may not have a prominent role in PD etiology.

Association between genetically proxied PCSK9 inhibition and prostate cancer risk: A Mendelian randomisation study

BACKGROUND

Prostate cancer (PrCa) is the second most prevalent malignancy in men worldwide. Observational studies have linked the use of low-density lipoprotein cholesterol (LDL-c) lowering therapies with reduced risk of PrCa, which may potentially be attributable to confounding factors. In this study, we performed a drug target Mendelian randomisation (MR) analysis to evaluate the association of genetically proxied inhibition of LDL-c-lowering drug targets on risk of PrCa.

METHODS AND FINDINGS

Single-nucleotide polymorphisms (SNPs) associated with LDL-c (P < 5 × 10-8) from the Global Lipids Genetics Consortium genome-wide association study (GWAS) (N = 1,320,016) and located in and around the HMGCR, NPC1L1, and PCSK9 genes were used to proxy the therapeutic inhibition of these targets. Summary-level data regarding the risk of total, advanced, and early-onset PrCa were obtained from the PRACTICAL consortium. Validation analyses were performed using genetic instruments from an LDL-c GWAS conducted on male UK Biobank participants of European ancestry (N = 201,678), as well as instruments selected based on liver-derived gene expression and circulation plasma levels of targets. We also investigated whether putative mediators may play a role in findings for traits previously implicated in PrCa risk (i.e., lipoprotein a (Lp(a)), body mass index (BMI), and testosterone). Applying two-sample MR using the inverse-variance weighted approach provided strong evidence supporting an effect of genetically proxied inhibition of PCSK9 (equivalent to a standard deviation (SD) reduction in LDL-c) on lower risk of total PrCa (odds ratio (OR) = 0.85, 95% confidence interval (CI) = 0.76 to 0.96, P = 9.15 × 10-3) and early-onset PrCa (OR = 0.70, 95% CI = 0.52 to 0.95, P = 0.023). Genetically proxied HMGCR inhibition provided a similar central effect estimate on PrCa risk, although with a wider 95% CI (OR = 0.83, 95% CI = 0.62 to 1.13, P = 0.244), whereas genetically proxied NPC1L1 inhibition had an effect on higher PrCa risk with a 95% CI that likewise included the null (OR = 1.34, 95% CI = 0.87 to 2.04, P = 0.180). Analyses using male-stratified instruments provided consistent results. Secondary MR analyses supported a genetically proxied effect of liver-specific PCSK9 expression (OR = 0.90 per SD reduction in PCSK9 expression, 95% CI = 0.86 to 0.95, P = 5.50 × 10-5) and circulating plasma levels of PCSK9 (OR = 0.93 per SD reduction in PCSK9 protein levels, 95% CI = 0.87 to 0.997, P = 0.04) on PrCa risk. Colocalization analyses identified strong evidence (posterior probability (PPA) = 81.3%) of a shared genetic variant (rs553741) between liver-derived PCSK9 expression and PrCa risk, whereas weak evidence was found for HMGCR (PPA = 0.33%) and NPC1L1 expression (PPA = 0.38%). Moreover, genetically proxied PCSK9 inhibition was strongly associated with Lp(a) levels (Beta = -0.08, 95% CI = -0.12 to -0.05, P = 1.00 × 10-5), but not BMI or testosterone, indicating a possible role for Lp(a) in the biological mechanism underlying the association between PCSK9 and PrCa. Notably, we emphasise that our estimates are based on a lifelong exposure that makes direct comparisons with trial results challenging.

CONCLUSIONS

Our study supports a strong association between genetically proxied inhibition of PCSK9 and a lower risk of total and early-onset PrCa, potentially through an alternative mechanism other than the on-target effect on LDL-c. Further evidence from clinical studies is needed to confirm this finding as well as the putative mediatory role of Lp(a).

Role of Serum Lipids, Blood Glucose and Blood Pressure in Breast Cancer Risk for Women with Type 2 Diabetes Mellitus

PURPOSE

Women with type 2 diabetes mellitus (T2DM) have an increased risk of breast cancer. We aimed to determine the contribution of lipids, glucose and blood pressure to this risk based on the multifactorial nature of T2DM.

PATIENTS AND METHODS

This population-based cohort study used data from a Dutch database (the Groningen Initiative to Analyse Type 2 Diabetes Treatment) for the period 2004-2013. The cohort included women diagnosed with T2DM, aged 30-80 years, with no history of breast cancer and with follow-up data for at least 1 year. We used Cox proportional hazards models to estimate the associations of exposures with breast cancer occurrence, reporting adjusted hazard ratios (aHR) with 95% confidence intervals (CI). Exposures of interest included total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides, glycated hemoglobin A (HbA1c) and systolic blood pressure (SBP).

RESULTS

During a median of 4.45 years' follow-up, 183 of 10,183 included women received a breast cancer diagnosis. We observed U-shaped associations with breast cancer incidence for total cholesterol and HDL-C at baseline. Compared with moderate elevations, women had significantly higher breast cancer risks associated with high total cholesterol (aHR, 95% CI: 1.72, 1.15-2.55) and HDL-C (aHR, 95% CI: 1.74, 1.18-2.58) levels, while low total cholesterol (aHR, 95% CI: 1.43, 0.94-2.19) and HDL-C (aHR, 95% CI: 1.44, 0.95-2.17) levels produced marginal effects without significance. Women with high LDL-C levels more often received a breast cancer diagnosis than those with medium levels (aHR, 95% CI: 1.56, 1.03-2.35).

CONCLUSION

This real-world dataset highlights the importance of balancing lipid profiles, particularly total cholesterol and HDL-C. Dysregulation of the lipid profile, not the glucose or blood pressure profiles, may increase the risk of breast cancer in women with T2DM.

The crosstalk within the breast tumor microenvironment in type II diabetes: Implications for cancer disparities

Obesity-driven (type 2) diabetes (T2D), the most common metabolic disorder, both increases the incidence of all molecular subtypes of breast cancer and decreases survival in postmenopausal women. Despite this clear link, T2D and the associated dysfunction of diverse tissues is often not considered during the standard of care practices in oncology and, moreover, is treated as exclusion criteria for many emerging clinical trials. These guidelines have caused the biological mechanisms that associate T2D and breast cancer to be understudied. Recently, it has been illustrated that the breast tumor microenvironment (TME) composition and architecture, specifically the surrounding cellular and extracellular structures, dictate tumor progression and are directly relevant for clinical outcomes. In addition to the epithelial cancer cell fraction, the breast TME is predominantly made up of cancer-associated fibroblasts, adipocytes, and is often infiltrated by immune cells. During T2D, signal transduction among these cell types is aberrant, resulting in a dysfunctional breast TME that communicates with nearby cancer cells to promote oncogenic processes, cancer stem-like cell formation, pro-metastatic behavior and increase the risk of recurrence. As these cells are non-malignant, despite their signaling abnormalities, data concerning their function is never captured in DNA mutational databases, thus we have limited insight into mechanism from publicly available datasets. We suggest that abnormal adipocyte and immune cell exhaustion within the breast TME in patients with obesity and metabolic disease may elicit greater transcriptional plasticity and cellular heterogeneity within the expanding population of malignant epithelial cells, compared to the breast TME of a non-obese, metabolically normal patient. These challenges are particularly relevant to cancer disparities settings where the fraction of patients seen within the breast medical oncology practice also present with co-morbid obesity and metabolic disease. Within this review, we characterize the changes to the breast TME during T2D and raise urgent molecular, cellular and translational questions that warrant further study, considering the growing prevalence of T2D worldwide.

Serum cholesterol and the risk of developing hormonally driven cancers: A narrative review

Although cholesterol has been hypothesized to promote cancer development through several potential pathways, its role in the risk of developing hormonally driven cancer is controversial. This literature review summarizes evidence from the highest quality studies to examine the consistency and strength of the relationship between serum cholesterol parameters and incidence of hormonally driven cancer. Articles were identified using EMBASE. Longitudinal observational studies published between January 2000 and December 2020 were considered for inclusion. The endpoint of interest was incident prostate, ovary, breast, endometrium, and uterine cancers. In total, 2732 reports were identified and screened; 41 studies were included in the review. No associations were found for ovarian cancer. Most endometrial cancer studies were null. The majority (76.9%) of studies reported no association between cholesterol and prostate cancer. Data on breast cancer were conflicting, associations limited, and effect sizes modest. Our results do not provide evidence for a clear association between cholesterol and different types of incident, hormonally driven reproductive cancers. Future studies should investigate the impact of lipid-lowering therapy.

Circulating levels of PCSK9, ANGPTL3 and Lp(a) in stage III breast cancers

Background / synopsis

Cholesterol and lipids play an important role in sustaining tumor growth and metastasis in a large variety of cancers. ANGPTL3 and PCSK9 modify circulating cholesterol levels, thus availability of lipids to peripheral cells. Little is known on the role, if any, of circulating lipid-related factors such as PCSK9, ANGPTL3 and lipoprotein (a) in cancers.

Objective/purpose

To compare circulating levels of PCSK9, ANGPTL3, and Lp(a) in women with stage III breast cancer versus women with premalignant or benign breast lesions.

Methods

Twenty-three plasma samples from women diagnosed with a stage III breast cancer (ductal, lobular or mixed) were matched for age with twenty-three plasma samples from women bearing premalignant (stage 0, n = 9) or benign (n = 14) breast lesions. The lipid profile (Apo B, total cholesterol, HDL cholesterol and triglycerides levels) and Lp(a) were measured on a Roche Modular analytical platform, whereas LDL levels were calculated with the Friedewald formula. ANGPTL3 and PCSK9 plasma levels were quantitated by ELISA. All statistical analyses were performed using SAS software version 9.4.

Results

PCSK9 levels were significantly higher in women with stage III breast cancer compared to age-matched counterparts presenting a benign lesion (95.9 ± 27.1 ng/mL vs. 78.5 ± 19.3 ng/mL, p < 0.05, n = 14). Moreover, PCSK9 levels positively correlated with breast disease severity (benign, stage 0, stage III) (Rho = 0.34, p < 0.05, n = 46). In contrast, ANGPTL3 and Lp(a) plasma levels did not display any association with breast disease status and lipids did not correlate with disease severity.

Conclusion

In this small cohort of 46 women, PCSK9 levels tended to increase with the severity of the breast disease. Given that PCSK9 plays an important role in maintaining cholesterolemia, and a potential role in tumor evasion, present results warrant further investigation into a possible association between PCSK9 levels and breast cancer severity in larger cohorts of women.