Apolipoprotein E genotype, serum lipids, and colorectal adenomas in Japanese men

Therapeutic role of biogenic silver and gold nanoparticles against a DMH-induced colon cancer model

Colorectal cancer (CRC) ranks third among fatal diseases afflicting mankind globally due to the shortage of primary detection methods and appropriate choice of drugs. Moreover, current treatments such as chemo drugs and radiotherapies create adverse effects and lead to drug resistance. In this context, recent advances in nanomedicine offer novel clinical solutions for colon cancer therapy. The current study denotes the therapeutic roles of biogenic Abutilon indicum silver and gold nanoparticles (AIAgNPs and AIAuNPs) against a 1, 2-dimethyl hydrazine (DMH)-induced CRC in Wistar rats. Following treatment of nanoparticles (NPs), the CRC rats showed great localization of AIAgNPs and AIAuNPs in colon tumors shown by ICP-OES, indicating their bioavailability. The AIAgNPs and AIAuNPs significantly enhanced cellular antioxidant enzyme levels including catalase, SOD, GSH, GPx and reduced lipid peroxidation (LPO) compared to the standard drug paclitaxel. AIAgNPs and AIAuNPs revealed significant protection against metastasis compared to paclitaxel shown in the histopathological study. The important CRC signaling molecules of the Wnt pathway, the β-catenin and Tcf-4 levels were significantly downregulated in AIAgNPs and AIAuNPs treated CRC rats compared to paclitaxel. Furthermore, the expression levels of cleaved apoptotic caspase-9, -8, and - 3 and lamins were significantly upregulated in AIAgNPs and AIAuNPs treated CRC rats compared to paclitaxel. This preclinical study provides substantial insights into the anti-colon cancer roles of biogenic NPs and gives an idea for targeting different cancers.

Effects of APOE gene ε4 allele on serum lipid profiles and risk of cardiovascular disease and tumorigenesis in southern Chinese population

Background

Human apolipoprotein E (APOE) polymorphisms are attributable to the presence of three common alleles, namely, ε2, ε3, and ε4, which generate six genotypes, viz, E2/E2, E2/E3, E3/E3, E3/E4, E4/E4, and E2/E4. APOE polymorphisms are associated with all types of tumors and cardiovascular diseases (CVD). However, the relationship between the type of APOE polymorphisms and tumorigenesis remains debatable. Therefore, we aimed to investigate the role of APOE polymorphisms on the tumor with or without CVD in southern China.

Methods

A total of 1438 participants were categorized into 4 groups: 409 patients with tumor, 369 patients with CVD, 338 patients with both tumor and CVD, and 322 controls. APOE polymorphisms were determined by genotyping assay. The factors influencing tumor patients with or without CVD were also analyzed by logistic regression analysis.

Results

The present study involved different types of solid tumors. Lung cancer was the most common cancer (20.2%, 151/747), followed by colorectal (17%, 127/747), esophageal (9.8%, 73/747), and liver (8.7%, 65/747) cancers. E3/E3 was the most frequent genotype, and ɛ3 was the greatest allele frequency in our study population. The frequencies of the E3/E3, E3/E4, E2/E3, E2/E4, E4/E4, and E2/E2 genotypes in tumor patients were 76.97% (575/747), 14.19% (106/747), 6.83% (51/747), 1.2% (9/747), 0.4% (3/747), and 0.4% (3/747), respectively. Tumor patients carrying ε3 with or without CVD showed higher levels of TG, TC, and LDL-C and lower levels of HDL-C compared to the controls carrying ε3. On the other hand, the tumor patients carrying ε4 with or without CVD showed higher levels of TG and LDL-C and lower levels of HDL-C (all P < 0.05). The frequency of APOE ε4 allele and the E3/E4 genotype was relatively greater in tumor or CVD patients (P < 0.001). In addition, ε4 allele acted as an independent risk factor for tumor patients group (P = 0.037, adjusted OR = 1.92, 95% CI 1.04–3.55) and tumor + CVD patients group (P = 0.012, adjusted OR = 2.53, 95% CI 1.22–5.23).

Conclusions

Individuals carrying ε4 are at a higher risk of tumor with or without CVD, and APOE polymorphisms affect the serum lipid profiles.

The Relationship Between Colorectal Polyps and Serum Lipid Levels: A Systematic Review and Meta-analysis

Colorectal polyp has been considered as the precancerous lesion of colorectal cancer, to which serum lipid levels are closely related. At present, there is no consensus on the relationship between colorectal polyps and serum lipid levels. We performed a meta-analysis to explore the effects of lipid levels on colorectal polyps. Relevant articles published from 2000 to 2020 were searched in PubMed, Web of Science, EMBASE, and Cochrane Library databases. The mean value and SD of serum lipid indexes and body mass index in colorectal polyps groups and control groups were extracted from the included articles. Combined weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated to assess the effect size of serum lipid levels on colorectal polyps. The publication bias of the included studies were assessed based on the Egger test. Thirty-seven articles containing 19,464 cases and 63,979 controls were included. There were no significant publication bias. The levels of high-density lipoprotein cholesterol in the cases were lower than those in the controls (WMD: -2.589 mg/dL, 95% CI: -3.273, -1.906). While the levels of triglyceride (WMD: 16.933 mg/dL, 95% CI: 13.131, 20.736), total cholesterol (WMD: 5.561 mg/dL, 95% CI: 3.477, 7.645), low-density lipoprotein cholesterol (WMD: 3.109 mg/dL, 95% CI: 0.859, 5.359) and body mass index (WMD: 0.747 mg/dL, 95% CI: 0.588, 0.906) were higher in the cases. Colorectal polyps were associated with serum lipid levels and obesity. Hyperlipidemia and obesity may be the risk factors for colorectal polyps.

APOE and metabolic dysfunction in Alzheimer's disease

The strongest genetic risk factor for sporadic Alzheimer's disease (AD) is carriage of the E4 allele of APOE. Metabolic dysfunction also increases risk of dementia and AD. Facing a need for effective therapies and an aging global population, studies aimed at uncovering new therapeutic targets for AD have become critical. Insight into the biology underlying the effects of E4 and metabolic impairment on the brain may lead to novel therapies to reduce AD risk. An understudied hallmark of both AD patients and E4 individuals is a common metabolic impairment-cerebral glucose hypometabolism. This is a robust and replicated finding in humans, and begins decades prior to cognitive decline. Possession of E4 also appears to alter several other aspects of cerebral glucose metabolism, fatty acid metabolism, and management of oxidative stress through the pentose phosphate pathway. A critical knowledge gap in AD is the mechanism by which APOE alters cerebral metabolism and clarification as to its relevance to AD risk. Facing a need for effective therapies, studies aimed at uncovering new therapeutic targets have become critical. One such approach is to gain a better understanding of the metabolic mechanisms that may underlie E4-associated cognitive dysfunction and AD risk.

Apolipoprotein: prospective biomarkers in digestive tract cancer

Digestive tract cancer, which is characterized by high morbidity and mortality, seriously affects the quality of life of patients worldwide. The digestive tract has abundant blood supply and nutriment, providing a suitable environment for tumor cells. Under chemical, physical, and biological stimuli, the activated cancer-related genes promote tumorigenesis. The synthesis of apolipoprotein occurs in the liver, intestine, and other digestive organs. However, the functions of apolipoproteins are not limited to lipid metabolism. An increasing number of studies have revealed that apolipoproteins take part in the regulation of tumor behavior. Apolipoprotein A (apoA) has recently been acknowledged as a beneficial indicator of several cancers, including colon, hepatocellular, and pancreatic cancer. Apolipoprotein E (apoE) can affect tumor susceptibility on account of genetic polymorphism. Levels of apolipoprotein C (apoC), B (apoB), and D (apoD) also impact tumor progression and the prognosis of patients. However, because of individual, racial, and genetic differences, a consensus has not yet been reached. Based on clinical data and analysis, apolipoproteins could be a novel target and marker in tumor therapy and prevention.

Comparison of biomarker expression between proximal and distal colorectal adenomas: The Tennessee-Indiana Adenoma Recurrence Study

It is unclear if proximal and distal traditional adenomas present with differences in molecular events which contribute to cancer heterogeneity by tumor anatomical subsite. Participants from a colonoscopy-based study (n = 380) were divided into subgroups based on the location of their most advanced adenoma: proximal, distal, or "equivalent both sides." Eight biomarkers in the most advanced adenomas were evaluated by immunohistochemistry (Ki-67, COX-2, TGFβRII, EGFR, β-catenin, cyclin D1, c-Myc) or TUNEL (apoptosis). After an adjustment for pathological features, there were no significant differences between proximal and distal adenomas for any biomarker. Conversely, expression levels did vary by other features, such as their size, villous component, and synchronousness. Large adenomas had higher expression levels of Ki-67(P < 0.001), TGFβRII (P < 0.0001), c-Myc (P < 0.001), and cyclin D1 (P < 0.001) in comparison to small adenomas, and tubulovillous/villous adenomas also were more likely to have similar higher expression levels in comparison to tubular adenomas. Adenoma location is not a major determinant of the expression of these biomarkers outside of other pathological features. This study suggests similarly important roles of Wnt/β-catenin and TGF-β pathways in carcinogenesis in both the proximal and distal colorectum. © 2016 Wiley Periodicals, Inc.

Blood Lipid Concentrations and Colorectal Adenomas: A Systematic Review and Meta-Analysis of Colonoscopy Studies in Asia, 2000-2014

It is unclear whether dyslipidemia is associated with risk of colorectal neoplasia. The incidence of both conditions is increasing in Asia, motivating a number of new studies from this region. We performed a systematic literature search of Asian colonoscopy-based studies that collected blood lipid concentrations at the time of endoscopy. Persons found to have colorectal adenoma were considered cases, and those found to be adenoma-free were considered controls. Seventeen studies published between 2000 and 2014 met inclusion criteria, collectively enrolling 17,387 cases and 30,427 controls. Mean differences and adjusted odds ratios were summarized with random-effects meta-analyses. Compared with controls, cases had higher total cholesterol (mean difference (MD) = 2.4 mg/dL, 95% confidence interval (CI): 0.2, 4.6), higher low-density lipoprotein cholesterol (MD = 1.3 mg/dL, 95% CI: 0.1, 2.6), higher triglyceride (MD = 16.4 mg/dL, 95% CI: 11.2, 21.5), and lower high-density lipoprotein (HDL) cholesterol (MD = -2.1 mg/dL, 95% CI: -2.7, -1.6) concentrations. Based on adjusted odds ratios, associations for 40-mg/dL-higher triglyceride levels (odds ratio = 1.13, 95% CI: 1.05, 1.21) and 10-mg/dL-higher HDL cholesterol levels (odds ratio = 0.96, 95% CI: 0.92, 1.00) achieved statistical significance. Persons with adenoma were more likely to have unfavorable cholesterol profiles at the time of colonoscopy than those without adenoma. The most convincing evidence for an association between dyslipidemia and colorectal neoplasia was observed for hypertriglyceridemia.

Apolipoprotein E polymorphism and colorectal neoplasm: results from a meta-analysis

To investigate the relationship of Apolipoprotein E (APOE) gene polymorphism to colorectal neoplasia (CRN), we performed a systematic review and meta-analysis. Eligible studies were identified through a systematic literature review from PubMed, EMBASE, and the Science Citation Index up to February 2014. A combined analysis was performed, followed by a subgroup analyses stratified by the study design. We used data collected from 8 prospective studies involving respectively a total of 9243 participants and 4310 CRN cases which including 438 patients with colorectal adenoma (CRA), and 3873 patients with colorectal carcinoma (CRC). The pooled data from this meta-analysis indicated there was no significant association between APOE polymorphism and CRN (ε2: P = 0.51, OR 1.04 95% CI 0.93 to 1.16; ε4: P = 0.72, OR 0.98 95% CI 0.90 to 1.07). Interestingly, subgroup analysis demonstrated there was a significant decreased risk for proximal CRN in patients with APOE ε4 (P = 0.0007, OR 0.52 95% CI 0.35 to 0.76). Data showed no significant association between APOE genotype and overall CRN. However, compared with those carry APOE ε3 alleles, persons with APOE ε4 genotype have significant decreased risk suffering from proximal CRN but not from distal CRN.

Lipid levels in serum and cancerous tissues of colorectal cancer patients

AIM: To investigate the correlations between lipid metabolism disorder and the occurrence and development of colorectal cancer by monitoring the alterations in lipid levels in cancerous tissue and serum in patients with colorectal cancer.

METHODS: The levels of total and free cholesterol (TCH and FCH), triglycerides (TG), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein- cholesterol (HDL-C), apolipoprotein A1 (ApoA-1) and ApoB in serum of 206 patients with colorectal cancer, 70 patients with benign colorectal disease and 300 healthy participants, and in the cancerous tissue and paracancerous tissue of 152 patients with colorectal cancer were measured with an Olympus 600 auto-biochemical analyzer. The obtained data were statistically analyzed.

RESULTS: Serum FCH level was significantly higher (1.9 ± 0.4 mmol/L vs 1.3 ± 0.3 mmol/L, 1.9 ± 0.4 mmol/L vs 1.2 ± 0.4 mmol/L, P < 0.05), whereas serum levels of TCH, LDL-C, ApoA-I and ApoB were significantly lower in patients with colorectal cancer than in patients with benign colorectal disease and healthy controls. The levels of FCH and TG in cancerous tissue were significantly lower (14.5 ± 9.6 μmol/g vs 19.3 ± 13.9 μmol/g, P < 0.05; 16.3 ± 19.8 μmol/g vs 44.1 ± 38.1 μmol/g, P < 0.05), whereas HDL-C level was significantly higher (7.9 ± 4.5 μmol/g vs 5.7 ± 3.9 μmol/g, P < 0.01) in cancerous tissue than in paracancerous tissue. The levels of TCH and TG in serum and the levels of TCH and HDL-C in cancerous tissue in patients with colorectal cancer were significantly correlated with TNM stage. The levels of TCH and LDL-C in serum were significantly lower, whereas HDL-C level in cancerous tissue was significantly higher in patients with lymph node metastasis than in patients without lymph node metastasis. The levels of TCH, FCH, TG, HDL-C and LDL-C in cancerous tissue were not significantly different from those in paracancerous tissue. The serum levels of FCH and TG were significantly higher, whereas serum HDL-C levels were significantly lower in patients with rectum cancer than in patients with colon cancer.

CONCLUSION: The disordered and abnormally altered levels of lipids in cancerous tissue and serum of patients with colorectal cancer may be correlated with the occurrence and development of colorectal cancer.

The association of serum lipids with colorectal adenomas

OBJECTIVES

There is suggestive but sparse evidence that dyslipidemia is associated with colorectal neoplasms. We investigated the association of serum lipid and apolipoprotein concentrations with the prevalence of colorectal adenomas.

METHODS

Cross-sectional study of 19,281 consecutive participants aged 40-79 years undergoing screening colonoscopy at the Center for Health Promotion of the Samsung Medical Center in Korea from January 2006 to June 2009.

RESULTS

We identified 5,958 participants with colorectal adenomas (30.9%), including 5,504 (28.5%) with non-advanced adenomas and 454 (2.4%) with advanced adenomas. The adjusted relative prevalence ratios (aRPRs) comparing the fourth with the first quartiles of serum triglycerides were 1.35 (95% confidence interval (CI) 1.20-1.52; P trend<0.001) for non-advanced adenomas and 1.45 (95% CI 1.02-2.06; P trend=0.005) for advanced adenomas. Higher levels of high-density lipoprotein (HDL) cholesterol and apolipoprotein A-1 (ApoA-1) were significantly associated with 12% (Q4 vs. Q1 aRPR 1.12; 95% CI 1.00-1.26; P trend=0.049) and 17% (Q4 vs. Q1 aRPR 1.17; 95% CI 1.04-1.31; P trend=0.004) higher prevalence of non-advanced adenoma. There was also a non-significant association between higher levels of low-density lipoprotein (LDL) cholesterol (Q4 vs. Q1 aRPR 1.22; 95% CI 0.91-1.66; P trend= 0.12) and apolipoprotein B (ApoB) (Q4 vs. Q1 aRPR 1.32; 95% CI 0.94-1.83; P trend=0.07) with higher prevalence of advanced adenoma. There was no association between total cholesterol levels with colorectal adenoma.

CONCLUSIONS

In this large cross-sectional study, higher levels of serum triglycerides were significantly associated with an increasing prevalence of both non-advanced and advanced colorectal adenomas, while higher levels of ApoA-1 and HDL cholesterol were significantly associated with an increasing prevalence of non-advanced adenomas.

Metabolic syndrome: a novel high-risk state for colorectal cancer

Metabolic syndrome (MS) and related disorders, including cancer, are steadily increasing in most countries of the world. However, mechanisms underlying the link between MS and colon carcinogenesis have yet to be fully elucidated. In this review article we focus on the relationships between various individual associated conditions (obesity, dyslipidemia, diabetes mellitus type 2 and hypertension) and colon cancer development, and demonstrate probable related factors revealed by in vivo and in vitro studies. Furthermore, molecules suggested to be involved in cancer promotion are addressed, and the potential for cancer prevention by targeting these molecules is discussed.

Lipoprotein lipase as a candidate target for cancer prevention/therapy

Epidemiological studies have shown that serum triglyceride (TG) levels are linked with risk of development of cancer, including colorectal and pancreatic cancers, and their precancerous lesions. Thus, it is assumed that serum TG plays an important role in carcinogenesis, and the key enzyme lipoprotein lipase (LPL), which catalyzes the hydrolysis of plasma TG, may therefore be involved. Dysregulation of LPL has been reported to contribute to many human diseases, such as atherosclerosis, chylomicronaemia, obesity, and type 2 diabetes. Recently, it has been reported that LPL gene deficiency, such as due to chromosome 8p22 loss, LPL gene polymorphism, and epigenetic changes in its promoter region gene, increases cancer risk, especially in the prostate. In animal experiments, high serum TG levels seem to promote sporadic/carcinogen-induced genesis of colorectal and pancreatic cancers. Interestingly, tumor suppressive effects of LPL inducers, such as PPAR ligands, NO-1886, and indomethacin, have been demonstrated in animal models. Moreover, recent evidence that LPL plays important roles in inflammation and obesity implies that it is an appropriate general target for chemopreventive and chemotherapeutic agents.

Trade-off in the effects of the apolipoprotein E polymorphism on the ages at onset of CVD and cancer influences human lifespan

Progress in unraveling the genetic origins of healthy aging is tempered, in part, by a lack of replication of effects, which is often considered a signature of false-positive findings. We convincingly demonstrate that the lack of genetic effects on an aging-related trait can be because of trade-offs in the gene action. We focus on the well-studied apolipoprotein E (APOE) e2/3/4 polymorphism and on lifespan and ages at onset of cardiovascular diseases (CVD) and cancer, using data on 3924 participants of the Framingham Heart Study Offspring cohort. Kaplan-Meier estimates show that the e4 allele carriers live shorter lives than the non-e4 allele carriers (log rank = 0.016). The adverse effect was attributed to the poor survival of the e4 homozygotes, whereas the effect of the common e3/4 genotype was insignificant. The e3/4 genotype, however, was antagonistically associated with onsets of those diseases predisposing to an earlier onset of CVD and a later onset of cancer compared to the non-e4 allele genotypes. This trade-off explains the lack of a significant effect of the e3/4 genotype on survival; adjustment for it in the Cox regression model makes the detrimental effect of the e4 allele highly significant (P = 0.002). This trade-off is likely caused by the lipid-metabolism-related (for CVD) and nonrelated (for cancer) mechanisms. An evolutionary rationale suggests that genetic trade-offs should not be an exception in studies of aging-related traits. Deeper insights into biological mechanisms mediating gene action are critical for understanding the genetic regulation of a healthy lifespan and for personalizing medical care.

Functional polymorphisms to modulate luminal lipid exposure and risk of colorectal cancer

PURPOSE

Fat absorption may play a crucial role in colorectal carcinogenesis by determining intra-colonic exposure to potentially carcinogenic lipid metabolites.

METHODS

We conducted a population-based case-control study that included 1163 cases and 1501 controls to examine whether individuals who carry genetic variants associated with lower lipid absorption have a higher risk of colorectal cancer. Using Taqman assay, we determined FABP2 alanine (A)/threonine (T) polymorphism at codon 54 in exon-2 and APOE isoforms. Multivariable odds ratios (OR) and 95% confidence intervals (CI) were calculated by unconditional logistic regression models, assuming FABP2 A54 and APO non-E4 as high risk alleles.

RESULTS

We found no associations with either of the polymorphisms. The OR associated with FABP2 A54 homozygotes compared with the others was 1.01 (95% CI; 0.86-1.45) and that for non-ApoE4 carriers compared with carries was 0.95 (95% CI; 0.80-1.13). However, there was a statistically significant negative interaction between total fat intake and FABP2 AA genotypes (p=0.025), indicating that the risk of colorectal cancer associated with this polymorphism is higher in the subjects with lower fat intake.

CONCLUSIONS

These results suggest that these SNPs may not be useful in predicting colorectal cancer risk in populations with high fat intake.

Polymorphisms of apolipoprotein e and methylenetetrahydrofolate reductase in the Japanese population

AIM

The aim of this study is to analyze the effect of apolipoprotein E (apo E) and methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms on serum lipid and homocysteine levels in the general Japanese population.

METHODS

We analyzed the polymorphisms in individuals randomly selected from among participants of Serum Lipid Survey 2000.

RESULTS

The frequency of the epsilon2, epsilon3, and epsilon4 alleles of APOE was 4.2, 85.3, and 10.5%, respectively. Individuals with the genotype epsilon4/epsilon4 had the highest total and low-density lipoprotein (LDL) cholesterol levels, while those with epsilon2/epsilon2 had the lowest. Individuals with the epsilon2/epsilon2 and epsilon2/epsilon4 genotypes had higher remnant-like particles (RLP)-cholesterol levels than those with epsilon2epsilon3, epsilon3epsilon3, and epsilon3epsilon4. There was a trend for individuals with the epsilon2/epsilon4 and epsilon2/epsilon2 genotypes to have higher triglyceride levels, although the difference was not significant. The presence of the T allele in a MTHFR polymorphism (C667T) was associated with higher homocysteine levels, which is more prominent in men than in women.

CONCLUSION

Thus in our large-scale analysis we have shown that RLP-cholesterol is better associated with, APOE genotype than triglyceride and the effect of the T allele on MTHFR polymorphism (C667T) homocysteine levels is more prominent in men than in women among Japanese.

Serum triglycerides and colorectal adenoma in a case-control study among cancer screening examinees (Japan)

OBJECTIVE

Most epidemiologic studies have shown serum triglycerides to be associated with colorectal adenoma. However, whether the association can be modified by smoking is unknown. We cross-sectionally investigated the association of serum triglycerides with the risk of adenoma by smoking status.

METHODS

We identified 782 newly diagnosed adenoma cases from the examinees of a colorectal cancer screening program. All cases were diagnosed by a magnifying colonoscopy with dye spreading. We determined 738 controls without present illness or past history of adenoma from among the examinees. They provided their lifestyle information and fasting blood samples to measure their serum triglycerides. We calculated odds ratios (OR) and 95% confidence intervals (CI) of colorectal adenoma for serum triglycerides.

RESULTS

High serum triglycerides were associated with colorectal adenoma (OR 1.5; 95% CI 1.1-2.0 for the highest versus the lowest quartile, P (trend, )0.030). A stronger association was observed between three or more adenoma cases and study controls (OR 2.3; 95% CI 1.3-4.2, P (trend,) < 0.0010). After classifying the study subjects by smoking status, a significant linear risk trend was found in ever-smokers (P (trend), 0.0018) but not in never-smokers (P (trend), 0.94; P (interaction), 0.067).

CONCLUSIONS

Our results suggested that a higher serum triglyceride level may be related to a larger number of adenomas. Adenoma development involving an elevated serum triglyceride level may be modified by smoking.

Fatty acid metabolism pathway play an important role in carcinogenesis of human colorectal cancers by Microarray-Bioinformatics analysis

The present study systematically explored metabolic pathways and altered expressions of genes speculatively participating in colorectal carcinogenesis by using a Microarray-Bioinformatic analysis methods. The results revealed that 157 genes were up-regulated and 281 genes were down-regulated in colorectal cancer (CRC). Gene Ontology (GO) and relevant bioinformatics tools indicated that the functional category to which 438 genes (12%; 438/3800) of the most frequent alteration belonged was metabolism. The analysis of 10 colorectal cancer tissue specimens demonstrated that genes involved in fatty acid metabolic pathways had high rates of overexpression. In addition, we stimulated CRL-1790 cell line with linoleic acid (a polyunsaturated fatty acid) for 12, 24, 48 and 72 h. Cell proliferation was elevated by 5, 25, 28 and 31% (P<0.05), respectively. Further analyses revealed that the genes increasingly expressed in the cell line included enoyl-Coenzyme A, hydratase/3-hydroxyacyl Coenzyme A dehydrogenase (EHHADH), enoyl Coenzyme A hydratase, short chain, 1, mitochondrial (ECHS1); glutaryl-Coenzyme A dehydrogenase (GCDH), acyl-Coenzyme A oxidase 2, branched chain (ACOX2); acyl-Coenzyme A dehydrogenase, C-2 to C-3 short chain precursor (ACADS); carnitine palmitoyltransferase 1B (CPT1B), acyl-CoA synthetase long-chain family member 5 (ACSL5), and cytochrome P450, family 4, subfamily A, and polypeptide 11 (CYP4A11) genes. This indicated that the stimulating effect of linoleic acid on cell proliferation was due to interference with the metabolic pathway of fatty acid metabolism. In conclusion, genes with altered expression levels in CRC were mainly associated with fatty acid metabolic pathways speculated to have an important role linked to carcinogenesis.

Associations between apoE genotype and colon and rectal cancer

Apolipoprotein E (apoE) plays a major role in the metabolism of bile acids, cholesterol and triglycerides, and has recently been proposed as being involved in the carcinogenic process. Given the potential role of bile acids in colorectal cancer etiology, it is reasonable that colorectal cancer risk might be modified by apoE genotype. We used data collected from a case-control study of colon cancer (n=1556 cases and 1948 controls) and rectal cancer (n=777 cases and 988 controls). The absence of an e3 apoE allele significantly increased the risk of colon cancer (OR=1.37 95% CI 1.00-1.87), particularly among those diagnosed when older than 64 years (OR=1.88 95% CI 1.17-3.04; P interaction between age and apoE genotype equal to 0.05). A significant three-way interaction was detected for family history of colorectal cancer, age at diagnosis and apoE genotype (P = 0.05), in those diagnosed when older, not having an e3 allele and having a significantly increased risk of colon cancer with family history of colorectal cancer (OR=3.93 95% CI 1.23-12.6). This was compared with the risk associated with family history of colorectal cancer among those diagnosed when older, with an e3 allele of 1.61 (95% CI 1.17-2.23) or those diagnosed when younger without an e3 allele (OR=2.40 95% CI 0.56-10.3). Among those diagnosed when older than 64 years, associations of BMI and prudent diet with colon cancer were stronger among individuals without an e3 allele, although the P for interaction was not significant. We did not detect any significant associations between apoE genotype and rectal cancer, survival after diagnosis with colorectal cancer, stage of disease at diagnosis or type of tumor mutation. These findings suggest those apoE genotypes that do not include the e3 allele, the same genotypes that are associated with increased risk of coronary heart disease, may influence development of colon cancer among those who are older at diagnosis.

Apolipoprotein E polymorphism modifies the alcohol-HDL association observed in the National Heart, Lung, and Blood Institute Family Heart Study

BACKGROUND

The apolipoprotein E gene (APOE) allele epsilon4 is associated with an increased risk of cardiovascular disease. The presence of the epsilon4 allele has been associated with lower concentrations of HDL cholesterol, but it is not known whether the epsilon4 allele modifies the association between alcohol consumption and HDL-cholesterol concentrations.

OBJECTIVE

The objective of the study was to assess whether the epsilon4 allele modifies the association between alcohol consumption and HDL-cholesterol concentrations.

DESIGN

In a cross-sectional design, we studied 670 men and women aged 26-78 y who participated in the National Heart, Lung, and Blood Institute Family Heart Study to assess whether the epsilon4 allele of the gene APOE modifies the association between alcohol consumption and HDL-cholesterol concentrations. Alcohol data were self-reported, and we used multivariate, generalized estimating equations to assess interactions.

RESULTS

In a model with adjustment for age, sex, body mass index, smoking, exercise, waist-hip ratio, TV viewing, and study site, there was a significant effect of the interaction between the epsilon4 allele and alcohol consumption on HDL cholesterol (P=0.0001). In the absence of the epsilon4 allele, multivariate adjusted means of HDL were 1.24, 1.36, and 1.54 mmol/L among subjects who never drank and those who currently drink 0.1-12 and >12 g alcohol/d, respectively; in the presence of the epsilon4 allele, the corresponding values were 1.19, 1.27, and 1.25 mmol/L.

CONCLUSION

Our data show a significant effect of the interaction between the epsilon4 allele and alcohol consumption on HDL. The increase in HDL associated with alcohol appears to be stronger in subjects without the epsilon4 allele than in those with the epsilon4 allele.

Association between polymorphisms of apolipoprotein E, bone mineral density of the lower forearm, quantitative ultrasound of the calcaneus and osteoporotic fractures in postmenopausal women with hip or lower forearm fracture

A genetic contribution to the development of osteoporosis is well documented. Although the association between the common allelic variation of apolipoprotein E (APOE), fracture risk, bone loss and bone mineral density (BMD) has been examined in several studies, the results of these investigations are contradictory. The aim of this study was to examine the association between polymorphisms of APOE, BMD of the lower forearm, quantitative ultrasound of the calcaneus and osteoporotic fractures in a population of postmenopausal women with hip or lower forearm fractures admitted to a department of orthopaedic surgery and age-matched controls from the population register. The APOE genotypes of 327 women were studied: 73 with lower forearm fractures, 43 with hip fractures and 211 age-matched controls. The participants were not receiving antiosteoporotic treatment. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) was used to detect the APOE genotypes. Quantitative ultrasound was measured at the calcaneus. Bone mineral density (BMD) of the lower forearm was measured with dual-energy X-ray absorptiometry. The distributions of genotype frequencies in this study were: E2/E2: 0.3%; E2/E3: 16.5%; E2/E4: 2.5%; E3/E3: 54.7%; E3/E4: 24.2%; E4/E4: 1.8%. All subpopulations were in Hardy-Weinburg equilibrium. There was no association between bone mass parameters and the APOE allele groups. Logistic regression analysis did not show any association between fractures and APOE allele groups. In conclusion, this study showed no association between bone mass parameters (BMD, speed of sound (SOS), broadband ultrasound attenuation (BUA)), hip or lower forearm fracture and APOE genotypes in a population of postmenopausal women and age-matched controls.

Apolipoprotein E and the Risk of Breast Cancer in African-American and Non-Hispanic White Women

The apolipoprotein genetic polymorphism (APO E) is part of a broader paradigm, highlighting the role of gene-environment interactions as risk factors for human diseases such as cardiovascular disease, Alzheimer’s disease, dementia, atherosclerosis, multiple sclerosis, peripheral artery disease, diabetes, stroke, and most recently, cancer. APO E, a normal constituent of very-low-density lipoproteins and high-density lipoproteins, is involved in many functions, including lipid metabolism, cholesterol transport, tissue repair, immune response and regulation, as well as cell growth and differentiation. The location, frequency and functional effects of this gene have been reviewed elsewhere in terms of cardiovascular disease, Alzheimer’s disease, neuromuscular disease, multiple sclerosis, stroke and diabetes. However, while the majority of studies have examined the significance of APO E as a molecular marker for a variety of diseases in multiethnic populations, few evaluate its role as a putative marker of cancer susceptibility. Fewer explore the importance of APO E on the risk of breast cancer, although some report an association. None have been designed to study its relevance as a marker of breast cancer risk in multiethnic populations. The purpose of this review was to evaluate the association between APO E and the risk for breast cancer in non-Hispanic white and African-American women.