Gene Summary

Gene:APOB; apolipoprotein B
Aliases: FLDB, FCHL2, LDLCQ4, apoB-48, apoB-100
Summary:This gene product is the main apolipoprotein of chylomicrons and low density lipoproteins. It occurs in plasma as two main isoforms, apoB-48 and apoB-100: the former is synthesized exclusively in the gut and the latter in the liver. The intestinal and the hepatic forms of apoB are encoded by a single gene from a single, very long mRNA. The two isoforms share a common N-terminal sequence. The shorter apoB-48 protein is produced after RNA editing of the apoB-100 transcript at residue 2180 (CAA->UAA), resulting in the creation of a stop codon, and early translation termination. Mutations in this gene or its regulatory region cause hypobetalipoproteinemia, normotriglyceridemic hypobetalipoproteinemia, and hypercholesterolemia due to ligand-defective apoB, diseases affecting plasma cholesterol and apoB levels. [provided by RefSeq, Jul 2008]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:apolipoprotein B-100
Source:NCBIAccessed: 01 September, 2019


What does this gene/protein do?
Show (59)

Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 01 September 2019 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Messenger RNA
  • Chromosome 2
  • Mutation
  • Homologous Transplantat
  • Colorectal Cancer
  • APOBEC-1 Deaminase
  • Breast Cancer
  • Gene Expression Regulation
  • Polymorphism
  • Genetic Predisposition
  • Liver
  • p53 Protein
  • RNA Editing
  • Biomarkers, Tumor
  • Tumor Virus Infections
  • Regression Analysis
  • Molecular Sequence Data
  • Apolipoproteins B
  • Hepatocellular Carcinoma
  • Lipoproteins, VLDL
  • Transcription
  • Adolescents
  • Cytidine Deaminase
  • Apolipoproteins A
  • Single Nucleotide Polymorphism
  • Apolipoprotein B-100
  • Lipid Metabolism
  • Cholesterol
  • Cancer Gene Expression Regulation
  • Asian Continental Ancestry Group
  • Triglycerides
  • Risk Factors
  • Polymerase Chain Reaction
  • Sex Factors
  • Case-Control Studies
  • Liver Cancer
  • Uridine
  • Genotype
  • Base Sequence
  • Alleles
  • Uterine Cancer
  • Ultraviolet Rays
Tag cloud generated 01 September, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: APOB (cancer-related)

Zhang T, Guo J, Gu J, et al.
Identifying the key genes and microRNAs in colorectal cancer liver metastasis by bioinformatics analysis and in vitro experiments.
Oncol Rep. 2019; 41(1):279-291 [PubMed] Free Access to Full Article Related Publications
Colorectal cancer (CRC) is one of the principal causes of cancer‑associated mortality worldwide. The high incidence of liver metastasis is the leading risk factor of mortality in patients with CRC, and the mechanisms of CRC liver metastasis are poorly understood. In the present study, 7 datasets, including 3 gene expression profile datasets and 4 microRNA (miRNA) expression profile datasets were downloaded from the NCBI Gene Expression Omnibus (GEO) database to identify potential key genes and miRNAs, which may be candidate biomarkers for CRC liver metastasis. Differentially expressed (DE) genes (DEGs) and DE miRNAs of primary CRC tumor tissues and liver metastatic CRC tumor tissues were selected using the GEO2R tool. Gene Ontology and Kyoto Encyclopedia of Gene and Genome pathway enrichment analyses were conducted using the Database for Annotation, Visualization and Integrated Discovery online database. Furthermore, Cytoscape with cytoHubba and the Molecular Complex Detection (MCODE) plug‑in were used to visualize a protein‑protein interaction (PPI) network for these DEGs, and to screen hub genes and gene modules in the PPI network. In addition, the online databases, TargetScan, miRanda, PITA, miRWalk and miRDB, were used to identify the target genes of the DE miRNAs. In the present study, 141 DEGs (97 upregulated and 44 downregulated) and 3 DE miRNAs (2 upregulated and 1 downregulated) were screened from the 3 gene expression microarray datasets and 4 miRNA expression microarray datasets, respectively. In total, 10 hub genes with a high degree of connectivity were selected from the PPI network, including albumin (ALB), coagulation factor II (F2), thrombin, apolipoprotein H (APOH), serpin family C member 1 (SERPINC1), apolipoprotein A1 (APOA1), α‑1‑microglobulin/bikunin precursor (AMBP), apolipoprotein C3 (APOC3), plasminogen (PLG), α‑2 HS glycoprotein (AHSG) and apolipoprotein B (APOB). The most important module was detected in the PPI network using the MCODE plug‑in. A total of 20 DEGs were identified to be potential target genes of these DE miRNAs, and novel miRNA‑DEGs regulatory axes were constructed. In vitro experiments were performed to demonstrate that miR‑885 promoted CRC cell migration by, at least partially, decreasing the expression of von Willebrand factor (vWF) and insulin‑like growth factor binding protein 5 (IGFBP5). In conclusion, by using integrated bioinformatics analysis and in vitro experiments, key candidate genes were identified and novel miRNA‑mRNA regulatory axes in CRC liver metastasis were constructed, which may improve understanding of the molecular mechanisms underlying CRC liver metastasis.

Lee G, Jeong YS, Kim DW, et al.
Clinical significance of APOB inactivation in hepatocellular carcinoma.
Exp Mol Med. 2018; 50(11):147 [PubMed] Free Access to Full Article Related Publications
Recent findings from The Cancer Genome Atlas project have provided a comprehensive map of genomic alterations that occur in hepatocellular carcinoma (HCC), including unexpected mutations in apolipoprotein B (APOB). We aimed to determine the clinical significance of this non-oncogenetic mutation in HCC. An Apob gene signature was derived from genes that differed between control mice and mice treated with siRNA specific for Apob (1.5-fold difference; P < 0.005). Human gene expression data were collected from four independent HCC cohorts (n = 941). A prediction model was constructed using Bayesian compound covariate prediction, and the robustness of the APOB gene signature was validated in HCC cohorts. The correlation of the APOB signature with previously validated gene signatures was performed, and network analysis was conducted using ingenuity pathway analysis. APOB inactivation was associated with poor prognosis when the APOB gene signature was applied in all human HCC cohorts. Poor prognosis with APOB inactivation was consistently observed through cross-validation with previously reported gene signatures (NCIP A, HS, high-recurrence SNUR, and high RS subtypes). Knowledge-based gene network analysis using genes that differed between low-APOB and high-APOB groups in all four cohorts revealed that low-APOB activity was associated with upregulation of oncogenic and metastatic regulators, such as HGF, MTIF, ERBB2, FOXM1, and CD44, and inhibition of tumor suppressors, such as TP53 and PTEN. In conclusion, APOB inactivation is associated with poor outcome in patients with HCC, and APOB may play a role in regulating multiple genes involved in HCC development.

Gao J, Choudhry H, Cao W
Apolipoprotein B mRNA editing enzyme catalytic polypeptide-like family genes activation and regulation during tumorigenesis.
Cancer Sci. 2018; 109(8):2375-2382 [PubMed] Free Access to Full Article Related Publications
Cancer is currently viewed as a disease of evolving genomic instability and abnormal epigenomic modifications. Most solid cancers harbor oncogenic gene mutations driven by both extrinsic and intrinsic factors. Apolipoprotein B mRNA editing catalytic polypeptide-like family (APOBEC) enzymes have an intrinsic deamination activity to convert cytosine to uracil during RNA editing and retrovirus or retrotransposon restriction. Beyond their natural defense in innate immunity, compelling evidence showed that a subclass of APOBEC3 can cause high mutation burden in various types of cancer genomes, and high expression subtypes of APOBEC3 may contribute to drug resistance and associate with clinical outcomes. The underlying molecular mechanisms of APOBEC-mediated hypermutation phenotype are poorly understood. In this review, we discuss the linkage of activation-induced deaminase (AID)/APOBEC3 enzymes to tumorigenesis, highlight the dysregulatory mechanisms of APOBEC3 activities during cancer development, and propose potential approaches to targeting APOBEC3-mediated mutagenesis for cancer interventions.

Zhang R, Liu Q, Liu H, et al.
Effects of apoC1 genotypes on the hormonal levels, metabolic profile and PAF-AH activity in Chinese women with polycystic ovary syndrome.
Lipids Health Dis. 2018; 17(1):77 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Elevated serum levels of apolipoprotein (apo) C1 may be an early protein marker of metabolic abnormality in women with polycystic ovary syndrome (PCOS). It is not clear, however, whether there are any relationships between the apoC1 rs4420638A/G and -317deletion (H1)/insertion (H2) polymorphisms and PCOS. We investigated the relationship between these two variants and the risk of PCOS, evaluated the genotypic effects on clinical, hormonal and metabolic indexes and plasma platelet-activating factor acetylhydrolase (PAF-AH) activity, and defined the association of apoC1 gene variants with apoE ε2/ε3/ε4 polymorphisms.
METHODS: This is a cross-sectional study of 877 women with PCOS and 761 controls. The apoC1 rs4420638A/G genotype was determined by a Taqman real-time PCR allelic discrimination assay. The apoC1-317H1/H2 and apoE ε2/ε3/ε4 genotypes were measured using PCR and restriction fragment length polymorphism analysis. The clinical, hormonal and metabolic parameters and PAF-AH activity were measured.
RESULTS: The frequencies of apoC1 rs4420638A/G and -317H1/H2 genotypes and alleles were similar between PCOS and control groups (P > 0.05). However, the rs4420638 G allele was related to increased serum luteinizing hormone, cholesterol and apoB levels, and the ratio of apoB to apoA1 (P < 0.05), and the -317H1H1 genotype was associated with a higher acne grade score and a higher ratio of apoB-PAF-AH to H-PAF-AH activity (P < 0.05) in patients with PCOS. We also demonstrated that the apoC1 rs4420638A/G and -317H1/H2 gene variants existed in moderate to reasonably high linkage disequilibrium with apoE ε2/ε3/ε4 polymorphisms in Chinese women.
CONCLUSION: The apoC1 rs4420638A/G and -317H1/H2 gene variants might be involved in endocrine abnormalities of reproductive axis, metabolic abnormalities and chronic inflammation in PCOS, although no association was observed between the apoC1 genetic variants and the risk of PCOS in Chinese women.

Lu X, Lu J, Liao B, et al.
Driver pattern identification over the gene co-expression of drug response in ovarian cancer by integrating high throughput genomics data.
Sci Rep. 2017; 7(1):16188 [PubMed] Free Access to Full Article Related Publications
Multiple types of high throughput genomics data create a potential opportunity to identify driver patterns in ovarian cancer, which will acquire some novel and clinical biomarkers for appropriate diagnosis and treatment to cancer patients. To identify candidate driver genes and the corresponding driving patterns for resistant and sensitive tumors from the heterogeneous data, we combined gene co-expression modules with mutation modulators and proposed the method to identify driver patterns. Firstly, co-expression network analysis is applied to explore gene modules for gene expression profiles through weighted correlation network analysis (WGCNA). Secondly, mutation matrix is generated by integrating the CNV data and somatic mutation data, and a mutation network is constructed from the mutation matrix. Thirdly, candidate modulators are selected from significant genes by clustering vertexs of the mutation network. Finally, a regression tree model is utilized for module network learning, in which the obtained gene modules and candidate modulators are trained for the driving pattern identification and modulators regulatory exploration. Many identified candidate modulators are known to be involved in biological meaningful processes associated with ovarian cancer, such as CCL11, CCL16, CCL18, CCL23, CCL8, CCL5, APOB, BRCA1, SLC18A1, FGF22, GADD45B, GNA15, GNA11, and so on.

England J, Drouin S, Beaulieu P, et al.
Genomic determinants of long-term cardiometabolic complications in childhood acute lymphoblastic leukemia survivors.
BMC Cancer. 2017; 17(1):751 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: While cure rates for childhood acute lymphoblastic leukemia (cALL) now exceed 80%, over 60% of survivors will face treatment-related long-term sequelae, including cardiometabolic complications such as obesity, insulin resistance, dyslipidemia and hypertension. Although genetic susceptibility contributes to the development of these problems, there are very few studies that have so far addressed this issue in a cALL survivorship context.
METHODS: In this study, we aimed at evaluating the associations between common and rare genetic variants and long-term cardiometabolic complications in survivors of cALL. We examined the cardiometabolic profile and performed whole-exome sequencing in 209 cALL survivors from the PETALE cohort. Variants associated with cardiometabolic outcomes were identified using PLINK (common) or SKAT (common and rare) and a logistic regression was used to evaluate their impact in multivariate models.
RESULTS: Our results showed that rare and common variants in the BAD and FCRL3 genes were associated (p<0.05) with an extreme cardiometabolic phenotype (3 or more cardiometabolic risk factors). Common variants in OGFOD3 and APOB as well as rare and common BAD variants were significantly (p<0.05) associated with dyslipidemia. Common BAD and SERPINA6 variants were associated (p<0.05) with obesity and insulin resistance, respectively.
CONCLUSIONS: In summary, we identified genetic susceptibility loci as contributing factors to the development of late treatment-related cardiometabolic complications in cALL survivors. These biomarkers could be used as early detection strategies to identify susceptible individuals and implement appropriate measures and follow-up to prevent the development of risk factors in this high-risk population.

Wippel HH, Santos MDM, Clasen MA, et al.
Comparing intestinal versus diffuse gastric cancer using a PEFF-oriented proteomic pipeline.
J Proteomics. 2018; 171:63-72 [PubMed] Related Publications
Gastric cancer is the fifth most common malignant neoplasia and the third leading cause of cancer death worldwide. Mac-Cormick et al. recently showed the importance of considering the anatomical region of the tumor in proteomic gastric cancer studies; more differences were found between distinct anatomical regions than when comparing healthy versus diseased tissue. Thus, failing to consider the anatomical region could lead to differential proteins that are not disease specific. With this as motivation, we compared the proteomic profiles of intestinal and diffuse adenocarcinoma from the same anatomical region, the corpus. To achieve this, we used isobaric labeling (iTRAQ) of peptides, a 10-step HILIC fractionation, and reversed-phase nano-chromatography coupled online with a Q-Exactive Plus mass spectrometer. We updated PatternLab to take advantage of the new Comet-PEFF search engine that enables identifying post-translational modifications and mutations included in neXtProt's PSI Extended FASTA Format (PEFF) metadata. Our pipeline then uses a text-mining tool that automatically extracts PubMed IDs from the proteomic result metadata and drills down keywords from manuscripts related with the biological processes at hand. Our results disclose important proteins such as apolipoprotein B-100, S100 and 14-3-3 proteins, among many others, highlighting the different pathways enriched by each cancer type.
SIGNIFICANCE: Gastric cancer is a heterogeneous and multifactorial disease responsible for a significant number of deaths every year. Despite the constant improvement of surgical techniques and multimodal treatments, survival rates are low, mostly due to limited diagnostic techniques and late symptoms. Intestinal and diffuse types of gastric cancer have distinct clinical and pathological characteristics; yet little is known about the molecular mechanisms regulating these two types of gastric tumors. Here we compared the proteomic profile of diffuse and intestinal types of gastric cancer from the same anatomical location, the corpus, from four male patients. This methodological design aimed to eliminate proteomic variations resulting from comparison of tumors from distinct anatomical regions. Our PEFF-tailored proteomic pipeline significantly increased the identifications as when compared to previous versions of PatternLab.

Comprehensive and Integrative Genomic Characterization of Hepatocellular Carcinoma.
Cell. 2017; 169(7):1327-1341.e23 [PubMed] Free Access to Full Article Related Publications
Liver cancer has the second highest worldwide cancer mortality rate and has limited therapeutic options. We analyzed 363 hepatocellular carcinoma (HCC) cases by whole-exome sequencing and DNA copy number analyses, and we analyzed 196 HCC cases by DNA methylation, RNA, miRNA, and proteomic expression also. DNA sequencing and mutation analysis identified significantly mutated genes, including LZTR1, EEF1A1, SF3B1, and SMARCA4. Significant alterations by mutation or downregulation by hypermethylation in genes likely to result in HCC metabolic reprogramming (ALB, APOB, and CPS1) were observed. Integrative molecular HCC subtyping incorporating unsupervised clustering of five data platforms identified three subtypes, one of which was associated with poorer prognosis in three HCC cohorts. Integrated analyses enabled development of a p53 target gene expression signature correlating with poor survival. Potential therapeutic targets for which inhibitors exist include WNT signaling, MDM4, MET, VEGFA, MCL1, IDH1, TERT, and immune checkpoint proteins CTLA-4, PD-1, and PD-L1.

Zhang R, Song Q, Liu H, et al.
Effect of the R92H and A379V genotypes of platelet-activating factor acetylhydrolase on its enzyme activity, oxidative stress and metabolic profile in Chinese women with polycystic ovary syndrome.
Lipids Health Dis. 2017; 16(1):57 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The G994T polymorphism in platelet-activating factor acetylhydrolase (PAF-AH) gene is associated with the risk of polycystic ovary syndrome (PCOS). The aim of this study was to investigate the relationship between R92H and A379V variants of the PAF-AH gene and the risk of PCOS and to evaluate the effects of the genotypes on PAF-AH activities and clinical, metabolic and oxidative stress indexes in Chinese women.
METHODS: A total of 862 patients with PCOS based on the Rotterdam consensus criteria and 750 control women from a population of Chinese Han nationality in the Chengdu area were studied from 2006-2015. PAF-AH genotypes were determined by PCR and restriction fragment length polymorphism analysis. Plasma PAF-AH, high-density lipoprotein (HDL)-associated PAF-AH (H-PAF-AH) and apolipoprotein (apo) B-containing lipoprotein-associated PAF-AH (apoB-PAF-AH) activities were measured using the trichloroacetic acid precipitation procedure with PAF C-16 as a substrate. Circulating markers of oxidative stress, including serum total oxidant status, total antioxidant capacity, oxidative stress index and malondialdehyde levels, and clinical and metabolic parameters were also analyzed.
RESULTS: No significant differences were observed in the frequencies of R92H and A379V genotypes and alleles of the PAF-AH gene between PCOS and control groups (P > 0.05). Compared with patients with the 92RR genotype, patients with H allele of R92H (RH + HH genotype) had significantly higher plasma PAF-AH and apoB-PAF-AH activities (P < 0.05) and tended to exhibit increased H-PAF-AH activity (P = 0.063) after adjusted for age and BMI. However, when serum LDL-C, HDL-C, TG and HOMA index were added as covariates, the comparisons no longer remained statistical significance (P > 0.05). There were no significant differences in clinical, hormonal, metabolic and circulating oxidative stress parameters and the frequencies of PAF-AH G449T genotype according to PAF-AH R92H or A379V genotyping in patients with PCOS and control women.
CONCLUSIONS: There were no significant associations between R92H and A379V variants of PAF-AH gene and risk of PCOS in Chinese women. The increased plasma PAF-AH and apoB-PAF-AH activities in patients with H allele of R92H are related to the R92 → H variation, changes in plasma lipoprotein levels, insulin resistance, aging, and gaining weight and thus may be involved in the pathogenesis of PCOS and the increased risks of future cardiovascular diseases.

Sharma M, Tuaine J, McLaren B, et al.
Chemotherapy Agents Alter Plasma Lipids in Breast Cancer Patients and Show Differential Effects on Lipid Metabolism Genes in Liver Cells.
PLoS One. 2016; 11(1):e0148049 [PubMed] Free Access to Full Article Related Publications
Cardiovascular complications have emerged as a major concern for cancer patients. Many chemotherapy agents are cardiotoxic and some appear to also alter lipid profiles, although the mechanism for this is unknown. We studied plasma lipid levels in 12 breast cancer patients throughout their chemotherapy. Patients received either four cycles of doxorubicin and cyclophosphamide followed by weekly paclitaxel or three cycles of epirubicin, cyclophosphamide and 5'-fluorouracil followed by three cycles of docetaxel. Patients demonstrated a significant reduction (0.32 mmol/L) in high density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 (apoA1) levels (0.18 g/L) and an elevation in apolipoprotein B (apoB) levels (0.15 g/L) after treatment. Investigation of the individual chemotherapy agents for their effect on genes involved in lipoprotein metabolism in liver cells showed that doxorubicin decreased ATP binding cassette transporter A1 (ABCA1) via a downregulation of the peroxisomal proliferator activated receptor γ (PPARγ) and liver X receptor α (LXRα) transcription factors. In contrast, ABCA1 levels were not affected by cyclophosphamide or paclitaxel. Likewise, apoA1 levels were reduced by doxorubicin and remained unaffected by cyclophosphamide and paclitaxel. Doxorubicin and paclitaxel both increased apoB protein levels and paclitaxel also decreased low density lipoprotein receptor (LDLR) protein levels. These findings correlate with the observed reduction in HDL-C and apoA1 and increase in apoB levels seen in these patients. The unfavourable lipid profiles produced by some chemotherapy agents may be detrimental in the longer term to cancer patients, especially those already at risk of cardiovascular disease (CVD). This knowledge may be useful in tailoring effective follow-up care plans for cancer survivors.

Roberts JL, He B, Erickson A, Moreau R
Improvement of mTORC1-driven overproduction of apoB-containing triacylglyceride-rich lipoproteins by short-chain fatty acids, 4-phenylbutyric acid and (R)-α-lipoic acid, in human hepatocellular carcinoma cells.
Biochim Biophys Acta. 2016; 1861(3):166-76 [PubMed] Related Publications
The activation of hepatic kinase mechanistic target of rapamycin complex 1 (mTORC1) is implicated in the development of obesity-related metabolic disorders. This study investigated the metabolic sequelae of mTORC1 hyperactivation in human hepatoma cells and the lipid-regulating mechanisms of two short-chain fatty acids: 4-phenylbutyric acid (PBA) and (R)-α-lipoic acid (LA). We created three stable cell lines that exhibit low, normal, or high mTORC1 activity. mTORC1 hyperactivation induced the expression of lipogenic (DGAT1 and DGAT2) and lipoprotein assembly (MTP and APOB) genes, thereby raising cellular triacylglyceride (TG) and exacerbating secretion of apoB-containing TG-rich lipoproteins. LYS6K2, a specific inhibitor of the p70 S6 kinase branch of mTORC1 signaling, reversed these effects. PBA and LA decreased secreted TG through distinct mechanisms. PBA repressed apoB expression (both mRNA and protein) and lowered secreted TG without mitigation of mTORC1 hyperactivity or activation of AMPK. LA decreased cellular and secreted TG by attenuating mTORC1 signaling in an AMPK-independent manner. LA did not regulate apoB expression but led to the secretion of apoB-containing TG-poor lipoproteins by repressing the expression of lipogenic genes, FASN, DGAT1, and DGAT2. Our studies provide new mechanistic insight into the hypolipidemic activity of PBA and LA in the context of mTORC1 hyperactivation and suggest that the short-chain fatty acids may aid in the prevention and treatment of hypertriglyceridemia.

Asaba J, Bandyopadhyay M, Kindy M, Dasgupta S
Estrogen receptor signal in regulation of B cell activation during diverse immune responses.
Int J Biochem Cell Biol. 2015; 68:42-7 [PubMed] Related Publications
The role of signalling through oestrogen receptors (ERs) in the regulation of B cell activation is an area of growing importance not only in terms protective immunity but also in the determination of the mechanisms of the onset of autoimmune disorders and cancers. The mode of signalling action of this single chain nuclear receptor protein molecule depends on its ability to bind to the promoters of Pax5, HOXC4 and apolipoprotein B RNA-editing enzyme activation-induced cytidine deaminase (AID) genes. ER-mediated transcriptional regulation induces class switch recombination of the immunoglobulin heavy chain variable (VH) to DH-JH genes and somatic hypermutation in developing B cells. The mode of action of ER is associated with BCR-signal pathways that involve the regulator proteins BAFF and APRIL. Additionally, the plasma membrane-bound G protein-coupled oestrogen receptor-1 (GEPR1) directs diverse cell signalling events in B cells that involve the MAPK pathways. These signals are immensely important during progenitor and precursor B cell activation. We have focused our goals on the medicinal aspects of ER-signalling mechanisms and their effects on polyclonal B cell activation.

Fukuhara T, Wada M, Nakamura S, et al.
Amphipathic α-helices in apolipoproteins are crucial to the formation of infectious hepatitis C virus particles.
PLoS Pathog. 2014; 10(12):e1004534 [PubMed] Free Access to Full Article Related Publications
Apolipoprotein B (ApoB) and ApoE have been shown to participate in the particle formation and the tissue tropism of hepatitis C virus (HCV), but their precise roles remain uncertain. Here we show that amphipathic α-helices in the apolipoproteins participate in the HCV particle formation by using zinc finger nucleases-mediated apolipoprotein B (ApoB) and/or ApoE gene knockout Huh7 cells. Although Huh7 cells deficient in either ApoB or ApoE gene exhibited slight reduction of particles formation, knockout of both ApoB and ApoE genes in Huh7 (DKO) cells severely impaired the formation of infectious HCV particles, suggesting that ApoB and ApoE have redundant roles in the formation of infectious HCV particles. cDNA microarray analyses revealed that ApoB and ApoE are dominantly expressed in Huh7 cells, in contrast to the high level expression of all of the exchangeable apolipoproteins, including ApoA1, ApoA2, ApoC1, ApoC2 and ApoC3 in human liver tissues. The exogenous expression of not only ApoE, but also other exchangeable apolipoproteins rescued the infectious particle formation of HCV in DKO cells. In addition, expression of these apolipoproteins facilitated the formation of infectious particles of genotype 1b and 3a chimeric viruses. Furthermore, expression of amphipathic α-helices in the exchangeable apolipoproteins facilitated the particle formation in DKO cells through an interaction with viral particles. These results suggest that amphipathic α-helices in the exchangeable apolipoproteins play crucial roles in the infectious particle formation of HCV and provide clues to the understanding of life cycle of HCV and the development of novel anti-HCV therapeutics targeting for viral assembly.

Hattori Y, Arai S, Okamoto R, et al.
Sequential intravenous injection of anionic polymer and cationic lipoplex of siRNA could effectively deliver siRNA to the liver.
Int J Pharm. 2014; 476(1-2):289-98 [PubMed] Related Publications
In this study, we developed novel siRNA transfer method to the liver by sequential intravenous injection of anionic polymer and cationic liposome/cholesterol-modified siRNA complex (cationic lipoplex). When cationic lipoplex was intravenously injected into mice, the accumulation of siRNA was mainly observed in the lungs. In contrast, when cationic lipoplex was intravenously injected at 1 min after intravenous injection of poly-L-glutamic acid (PGA) or chondroitin sulfate C (CS), siRNA was accumulated in the liver. In terms of suppression of gene expression in vivo, apolipoprotein B (ApoB) mRNA in the liver and low-density-lipoprotein (LDL) and very low-density-lipoprotein (VLDL) cholesterol level in serum were reduced at 48 h after single sequential injection of PGA or CS plus cationic lipoplex of cholesterol-modified ApoB siRNA. Furthermore, sequential injections of PGA plus cationic lipoplex of cholesterol-modified luciferase siRNA could reduce luciferase activity in tumor xenografts bearing liver metastasis of human breast tumor MCF-7-Luc. From these findings, sequential injection of anionic polymer and cationic lipoplex of siRNA might produce a systemic vector of siRNA to the liver.

Welty FK
Hypobetalipoproteinemia and abetalipoproteinemia.
Curr Opin Lipidol. 2014; 25(3):161-8 [PubMed] Free Access to Full Article Related Publications
PURPOSE OF REVIEW: Several mutations in the apoB, proprotein convertase subtilisin/kexin type 9 (PCSK9), and MTP genes result in low or absent levels of apoB and LDL-cholesterol in plasma, which cause familial hypobetalipoproteinemia and abetalipoproteinemia. Mutations in the ANGPTL3 gene cause familial combined hypolipidemia. Clinical manifestations range from none to severe, debilitating, and life-threatening disorders. This review summarizes recent genetic, metabolic, and clinical findings and presents an update on management strategies.
RECENT FINDINGS: Cases of cirrhosis and hepatocellular carcinoma have now been identified in heterozygous familial hypobetalipoproteinemia probably because of decreased triglyceride transport capacity from the liver. ANGPTL3 mutations cause low levels of LDL-cholesterol and low HDL-cholesterol in compound heterozygotes and homozygous individuals, decrease reverse cholesterol transport, and lower glucose levels. The effect on atherosclerosis is unknown; however, severe fatty liver has been identified. Loss-of-function mutations in PCSK9 cause familial hypobetalipoproteinemia, which appears to lower risk for coronary artery disease and has no adverse sequelae. Phase III clinical trials are now underway examining the effect of PCSK9 inhibitors on cardiovascular events in combination with statin drugs.
SUMMARY: Mutations causing low LDL-cholesterol and apoB have provided insight into lipid metabolism, disease associations, and the basis for drug development to lower LDL-cholesterol in disorders causing high levels of cholesterol. Early diagnosis and treatment are necessary to prevent adverse sequelae from familial hypobetalipoproteinemia and abetalipoproteinemia.

He X, Wang Y, Zhang W, et al.
Screening differential expression of serum proteins in AFP-negative HBV-related hepatocellular carcinoma using iTRAQ -MALDI-MS/MS.
Neoplasma. 2014; 61(1):17-26 [PubMed] Related Publications
Hepatocellular carcinoma(HCC) is serious condition associated with a high morbidity and mortality. Therefore is an urgent need to develop novel noninvasive techniques for early diagnosis, particularly for patients with AFP-negative [AFP(-)] HCC. In this study, iTRAQ-MALDI-MS/MS was used to identify differentially expressed proteins in AFP(-) HBV-related HCC compared with non-cancerous hepatitis B virus (HBV) and healthy controls subjects.Serum was obtained from 18 patients with AFP(-) HBV-related HCC, 18 matched patients with HBV without HCC and 18 healthy control subjects. High abundance proteins were removed from serum and the differentially expressed proteins from the three groups were screened out using iTRAQ-MALDI-MS/MS. The Gene Ontology (GO) function and the interaction networks of differentially expressed proteins were then analyzed. A total of 24 expressed differential proteins associated with AFP(-) HBV-related HCC were screened out, 15 proteins were up-regulated and 9 down-regulated. The most common molecular function of the 24 differentially expressed proteins was enzyme inhibition. Interaction network of the 24 differentially expressed proteins showed that 14 proteins (C5, KNG1, FN1, LRG1, HRG, SERPINC1, CRP, APOB, SAA1, APCS, C4BPA, CFI, CFB and GSN) were central to the functional network. The expression levels of the GSN protein were down-regulated in AFP(-) HBV-related HCC subjects compared with healthy controls and the HBV group (p<0.01), consistent with the iTRAQ results.The 14 proteins from the serum of AFP(-) HBV-related HCC appeared at the fulcrum of the functional network and were differentially expressed compare to HBV and healthy controls suggesting a possible association with HCC progression.

Cefalù AB, Pirruccello JP, Noto D, et al.
A novel APOB mutation identified by exome sequencing cosegregates with steatosis, liver cancer, and hypocholesterolemia.
Arterioscler Thromb Vasc Biol. 2013; 33(8):2021-5 [PubMed] Free Access to Full Article Related Publications
OBJECTIVE: In familial hypobetalipoproteinemia, fatty liver is a characteristic feature, and there are several reports of associated cirrhosis and hepatocarcinoma. We investigated a large kindred in which low-density lipoprotein cholesterol, fatty liver, and hepatocarcinoma displayed an autosomal dominant pattern of inheritance.
APPROACH AND RESULTS: The proband was a 25-year-old female with low plasma cholesterol and hepatic steatosis. Low plasma levels of total cholesterol and fatty liver were observed in 10 more family members; 1 member was affected by liver cirrhosis, and 4 more subjects died of either hepatocarcinoma or carcinoma on cirrhosis. To identify the causal mutation in this family, we performed exome sequencing in 2 participants with hypocholesterolemia and fatty liver. Approximately 22 400 single nucleotide variants were identified in each sample. After variant filtering, 300 novel shared variants remained. A nonsense variant, p.K2240X, attributable to an A>T mutation in exon 26 of APOB (c.6718A>T) was identified, and this variant was confirmed by Sanger sequencing. The gentotypic analysis of 16 family members in total showed that this mutation segregated with the low cholesterol trait. In addition, genotyping of the PNPLA3 p.I148M did not show significant frequency differences between carriers and noncarriers of the c.6718A>T APOB gene mutation.
CONCLUSIONS: We used exome sequencing to discover a novel nonsense mutation in exon 26 of APOB (p.K2240X) responsible for low cholesterol and fatty liver in a large kindred. This mutation may also be responsible for cirrhosis and liver cancer in this family.

Gong Y, Zhang L, Bie P, Wang H
Roles of ApoB-100 gene polymorphisms and the risks of gallstones and gallbladder cancer: a meta-analysis.
PLoS One. 2013; 8(4):e61456 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Gallstones (GS) is the major manifestation of gallbladder disease, and is the most common risk factor for gallbladder cancer (GBC). Previous studies investigating the association between ApoB-100 gene polymorphisms and the risks of GS and GBC have yielded conflicting results. Therefore, we performed a meta-analysis to clarify the effects of ApoB-100 gene polymorphisms on the risks of GS and GBC.
METHODS: A computerized literature search was conducted to identify the relevant studies from PubMed and Embase. Fixed or random effects model was selected based on heterogeneity test. Publication bias was estimated using Begg's funnel plots and Egger's regression test.
RESULTS: A total of 10, 3, and 3 studies were included in the analyses of the association between ApoB-100 XbaI, EcoRI, or insertion/deletion (ID) polymorphisms and the GS risks, respectively, while 3 studies were included in the analysis for the association between XbaI polymorphism and GBC risk. The combined results showed a significant association in Chinese (X+ vs. X-, OR = 2.37, 95%CI 1.52-3.70; X+X+/X+X- vs. X+X+, OR = 2.47, 95%CI 1.55-3.92), but not in Indians or Caucasians. Null association was observed between EcoRI or ID polymorphisms and GS risks. With regard to the association between XbaI polymorphism and GBC risk, a significant association was detected when GBC patients were compared with healthy persons and when GBC patients were compared with GS patients. A significant association was still detected when GBC patients (with GS) were compared with the GS patients (X+X+ vs. X-X-, OR = 0.33, 95%CI 0.12-0.90).
CONCLUSION: The results of this meta-analysis suggest that the ApoB-100 X+ allele might be associated with increased risk of GS in Chinese but not in other populations, while the ApoB-100 X+X+ genotype might be associated with reduced risk of GBC. Further studies with larger sample sizes are needed to confirm these results.

Liu X, Wang Y, Qu H, et al.
Associations of polymorphisms of rs693 and rs1042031 in apolipoprotein B gene with risk of breast cancer in Chinese.
Jpn J Clin Oncol. 2013; 43(4):362-8 [PubMed] Related Publications
BACKGROUND: Lipid synthesis is an integrated result of genetic, epigenetic and environmental factors, and also can promote growth and survival of cancer cells. Apolipoprotein B plays a central role in lipid metabolism as the major protein component of very-low-density lipoprotein and low-density lipoprotein.
METHODS: We investigated the associations of polymorphisms of rs693 (-7673C>T) and rs1042031 (-12669 G>A) in the APOB gene with risk of breast cancer in 675 blood-unrelated Chinese patients with breast cancer and 712 healthy controls.
RESULTS: Polymorphisms of -12669 G>A and -7673C>T in the APOB gene were significantly associated with an increased risk of breast cancer (P = 0.000), especially for postmenopausal women (P = 0.000, 0.023). The positive associations still remained after further analysis of the two polymorphisms' distribution according to body mass index. However, no statistical associations were found between -12669 G>A and -7673C>T polymorphisms and other clinical characteristics, including tumor size, lymph node metastasis, histological grade, estrogen and progesterone receptor status and Her-2 status.
CONCLUSIONS: rs693 and rs1042031 polymorphisms in the APOB gene increased the risk of breast cancer in Chinese, and this role of the two polymorphisms in connection with breast cancer was not dependent on body mass index.

Liu T, Huang Y, Liu J, et al.
MicroRNA-122 influences the development of sperm abnormalities from human induced pluripotent stem cells by regulating TNP2 expression.
Stem Cells Dev. 2013; 22(12):1839-50 [PubMed] Free Access to Full Article Related Publications
Sperm abnormalities are one of the main factors responsible for male infertility; however, their pathogenesis remains unclear. The role of microRNAs in the development of sperm abnormalities in infertile men has not yet been investigated. Here, we used human induced pluripotent stem cells to investigate the influence of miR-122 expression on the differentiation of these cells into spermatozoa-like cells in vitro. After induction, mutant miR-122-transfected cells formed spermatozoa-like cells. Flow cytometry of DNA content revealed a significant increase in the haploid cell population in spermatozoa-like cells derived from mutant miR-122-transfected cells as compared to those derived from miR-122-transfected cells. During induction, TNP2 and protamine mRNA and protein levels were significantly higher in mutant miR-122-transfected cells than in miR-122-transfected cells. High-throughput isobaric tags for relative and absolute quantification were used to identify and quantify the different protein expression levels in miR-122- and mutant miR-122-transfected cells. Among all the proteins analyzed, the expression of lipoproteins, for example, APOB and APOA1, showed the most significant difference between the two groups. This study illustrates that miR-122 expression is associated with abnormal sperm development. MiR-122 may influence spermatozoa-like cells by suppressing TNP2 expression and inhibiting the expression of proteins associated with sperm development.

Zhang J, Fan P, Liu H, et al.
Apolipoprotein A-I and B levels, dyslipidemia and metabolic syndrome in south-west Chinese women with PCOS.
Hum Reprod. 2012; 27(8):2484-93 [PubMed] Related Publications
STUDY QUESTION: What are the relationships between apolipoprotein (apo) A-I and apoB concentrations, the apoB/apoA-I ratio and the prevalences of dyslipidemia and metabolic syndrome (MS) in south-west Chinese women with polycystic ovary syndrome (PCOS).
SUMMARY ANSWER: There is a relatively high incidence of dyslipidemia and MS in south-west Chinese women with PCOS, especially in patients without hyperandrogenism. Patients with dyslipidemia are more obese, and have a more adverse glucose and lipid metabolic profile and higher apoB levels and apoB/apoA-I ratio. The increased apoB levels and apoB/A1 ratio and the MS are strongly associated with PCOS, suggesting that there is an increased risk of cardiovascular diseases in these patients.
WHAT IS KNOWN AND WHAT THIS PAPER ADDS: Dyslipidemia and MS have been widely studied in women with PCOS, but to date no data from south-west Chinese subjects have been available. The apoB/apoA-I ratio has been reported to be strongly associated with MS and insulin resistance (IR) and to be a reliable parameter that reflects lipid disturbances and the potential to develop atherosclerosis, but its relationship with PCOS is unclear. DESIGN This case-control study included 406 patients with PCOS and 342 control women between 17 and 40 years of age from a population in south-west China during 2006-2011.
PARTICIPANTS AND SETTING: The diagnosis of PCOS was based on the revised 2003 Rotterdam criteria. The control group, consisting of women with infertility due to a Fallopian obstruction or the husband's infertility, women undergoing a pre-pregnancy check and healthy volunteers, was recruited from the same hospital during the same period. All women were not taking any medication known to affect carbohydrate or lipid or hormone metabolism for at least 3 months prior to the study, and were studied during the follicular phase of their menstrual cycle. MS was assessed by the National Cholesterol Education Program-Adult treatment Panel (NCEP-ATP) III criteria modified for Asian populations. Dyslipidemia was defined by one or more of the following conditions: fasting total cholesterol≥5.7 mmol/l, fasting triglycerides (TG)≥1.7 mmol/l, fasting high-density lipoprotein cholesterol (HDL-C)<1.29 mmol/l or fasting low-density lipoprotein cholesterol (LDL-C)≥3.6 mmol/l.
MAIN RESULTS AND THE ROLE OF CHANCE: The prevalence of dyslipidemia in patients with PCOS was 52.96%, about two times than that in the controls, 28.95%. The most common components of dyslipidemia in patients with PCOS were decreased HDL-C (41.13%) and increased TG (24.14%). PCOS patients with dyslipidemia had significantly higher TG/HDL-C ratios, and lower HDL-C and apoA-I levels when compared with the controls or patients without dyslipidemia, and had significantly higher BMIs, fasting insulin concentrations, 2-h insulin and glucose levels, homeostatic model assessment IR, TG levels, LDL-C levels, atherogenic indexes, apoB concentrations and apoB/apoA-I ratios when compared with all of the control women, with or without dyslipidemia and patients without dyslipidemia. The frequency of MS in patients with PCOS was 25.62%, more than five times than that in the controls. The main two risk factors were increased waist circumference and low HDL-C levels. In the four PCOS phenotypes based on the Rotterdam criteria, the oligo- and/or anovulation+PCO presented the highest prevalence of dyslipidemia (66.14%) and MS (34.65%). Binary logistic regression analysis showed that increased apoB levels, an increased apoB/apoA-I ratio and MS was strongly associated with PCOS (odds ratio=17.41, 27.16 and 7.66, 95% confidence interval: 6.93-43.74, 9.46-77.93 and 4.32-13.57, respectively) after adjustment for age.
BIAS, CONFOUNDING AND OTHER REASONS FOR CAUTION: The relatively minor limitations of this study are discussed within the paper. GENERALISABILITY TO OTHER POPULATIONS: The metabolic patterns found in south-west Chinese with PCOS are compared with that of other populations.
STUDY FUNDING/COMPETING INTEREST(S): This work was supported by Chinese National Natural Science Foundation (81070463), Program for Changjiang Scholars and Innovative Research Team in University (IRT0935), and Research Seed Fund from West China Second Hospital of Sichuan University (to H.B.). There are no any competing interests.

Hyung SW, Lee MY, Yu JH, et al.
A serum protein profile predictive of the resistance to neoadjuvant chemotherapy in advanced breast cancers.
Mol Cell Proteomics. 2011; 10(10):M111.011023 [PubMed] Free Access to Full Article Related Publications
Prediction of the responses to neoadjuvant chemotherapy (NACT) can improve the treatment of patients with advanced breast cancer. Genes and proteins predictive of chemoresistance have been extensively studied in breast cancer tissues. However, noninvasive serum biomarkers capable of such prediction have been rarely exploited. Here, we performed profiling of N-glycosylated proteins in serum from fifteen advanced breast cancer patients (ten patients sensitive to and five patients resistant to NACT) to discover serum biomarkers of chemoresistance using a label-free liquid chromatography-tandem MS method. By performing a series of statistical analyses of the proteomic data, we selected thirteen biomarker candidates and tested their differential serum levels by Western blotting in 13 independent samples (eight patients sensitive to and five patients resistant to NACT). Among the candidates, we then selected the final set of six potential serum biomarkers (AHSG, APOB, C3, C9, CP, and ORM1) whose differential expression was confirmed in the independent samples. Finally, we demonstrated that a multivariate classification model using the six proteins could predict responses to NACT and further predict relapse-free survival of patients. In summary, global N-glycoproteome profile in serum revealed a protein pattern predictive of the responses to NACT, which can be further validated in large clinical studies.

Zaiden N, Yap WN, Ong S, et al.
Gamma delta tocotrienols reduce hepatic triglyceride synthesis and VLDL secretion.
J Atheroscler Thromb. 2010; 17(10):1019-32 [PubMed] Related Publications
AIM: Present study aimed to elucidate the suppression of serum lipids by gamma- and delta-tocotrienol (γδT3).
METHODS: The lipid-lowering effects of γδT3 were investigated using HepG2 liver cell line, hypercholesterolemic mice and borderline-high cholesterol patients.
RESULTS: In-vitro results demonstrated two modes of action. First, γδT3 suppressed the upstream regulators of lipid homeostasis genes (DGAT2, APOB100, SREBP1/2 and HMGCR) leading to the suppression of triglycerides, cholesterol and VLDL biosyntheses. Second, γδT3 enhanced LDL efflux through induction of LDL receptor (LDLr) expression. Treatment of LDLr-deficient mice with 1 mg/day (50 mg/kg/day) γδT3 for one-month showed 28%, 19% reduction in cholesterol and triglyceride levels respectively, whereas HDL level was unaltered. The lipid-lowering effects were not affected by alpha-tocopherol (αTP). In a placebo-controlled human trial using 120 mg/day γδT3, only serum triglycerides were lowered by 28% followed by concomitant reduction in the triglyceride-rich VLDL and chylomicrons. In contrast, total cholesterol, LDL and HDL remained unchanged in treated and placebo groups. The discrepancies between in-vitro, in-vivo and human studies may be attributed to the differential rates of post-absorptive γδT3 degradation and LDL metabolism.
CONCLUSION: Reduction in triglycerides synthesis and transport may be the primary benefit caused by ingesting γδT3 in human.

Liu FL, Lu WB, Niu WX
XbaI polymorphisms of apolipoprotein B gene: another risk factor of gallstone formation after radical gastrectomy.
World J Gastroenterol. 2010; 16(20):2549-53 [PubMed] Free Access to Full Article Related Publications
AIM: To prospectively investigate the association between the XbaI polymorphisms of apolipoprotein B (APOB) gene and gallstone formation following gastrectomy.
METHODS: The study was conducted between January 2005 and December 2006. A total of 186 gastric cancer patients who had undergone radical gastrectomy were grouped according to XbaI polymorphisms of APOB gene (X(+)X(-) group, n = 24 and X(-)X(-) group, n = 162) and compared. The XbaI polymorphisms of APOB gene were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).
RESULTS: The incidence of gallstone was significantly higher in the X(+)X(-) group than in the X(-)X(-) group [54.2% vs 9.3%, RR = 5.85 (2.23-15.32), P < 0.001]. The serum levels of total cholesterol (TC) and low-density lipoprotein (LDL) were higher in the X(+)X(-) than in the X(-)X(-) group (4.02 +/- 1.12 vs 3.48 +/- 0.88, P = 0.004 before surgery and 3.88 +/- 1.09 vs 3.40 +/- 0.86, P = 0.008 after surgery). LDL was 2.21 +/- 0.96 vs 1.89 +/- 0.84 (P = 0.042) before surgery and 2.09 +/- 0.95 vs 1.72 +/- 0.85 (P = 0.029) after surgery in the two groups. No relationship was found between XbaI polymorphisms and gallbladder motility.
CONCLUSION: In Chinese patients after radical gastrectomy, X(+) allele of APOB gene is another risk factor for the development of gallstone besides the gallbladder motility disorder after surgery.

Báez S, Tsuchiya Y, Calvo A, et al.
Genetic variants involved in gallstone formation and capsaicin metabolism, and the risk of gallbladder cancer in Chilean women.
World J Gastroenterol. 2010; 16(3):372-8 [PubMed] Free Access to Full Article Related Publications
AIM: To determine the effects of genetic variants associated with gallstone formation and capsaicin (a pungent component of chili pepper) metabolism on the risk of gallbladder cancer (GBC).
METHODS: A total of 57 patients with GBC, 119 patients with gallstones, and 70 controls were enrolled in this study. DNA was extracted from their blood or paraffin block sample using standard commercial kits. The statuses of the genetic variants were assayed using Taqman SNP Genotyping Assays or Custom Taqman SNP Genotyping Assays.
RESULTS: The non-ancestral T/T genotype of apolipoprotein B rs693 polymorphism was associated with a decreased risk of GBC (OR: 0.14, 95% CI: 0.03-0.63). The T/T genotype of cholesteryl ester transfer protein (CETP) rs708272 polymorphism was associated with an increased risk of GBC (OR: 5.04, 95% CI: 1.43-17.8).
CONCLUSION: Genetic variants involved in gallstone formation such as the apolipoprotein B rs693 and CETP rs708272 polymorphisms may be related to the risk of developing GBC in Chilean women.

Skarda J, Amariglio N, Rechavi G
RNA editing in human cancer: review.
APMIS. 2009; 117(8):551-7 [PubMed] Related Publications
In eukaryotes mRNA transcripts are extensively processed by different post-transcriptional events such as alternative splicing and RNA editing in order to generate many different mRNAs from the same gene, increasing the transcriptome and then the proteome diversity. The most frequent RNA editing mechanism in mammals involves the conversion of specific adenosines into inosines by the ADAR family of enzymes. This editing event can alter the sequence and the secondary structure of RNA molecules, with consequences for final proteins and regulatory RNAs. Alteration in RNA editing has been connected to tumor progression and many other important human diseases. Analysis of many editing sites in various cancer types is expected to provide new diagnostic and prognostic markers and might contribute to early detection of cancer, the monitoring of response to therapy, and to the detection of minimal residual disease.

Mochizuki Y, Maebuchi M, Kohno M, et al.
Changes in lipid metabolism by soy beta-conglycinin-derived peptides in HepG2 cells.
J Agric Food Chem. 2009; 57(4):1473-80 [PubMed] Related Publications
In this study, HepG2 cells were treated with short peptides (7S-peptides) derived from highly purified soybean beta-conglycinin (7S), which was free from lipophilic protein, and the effect of the peptide treatment on lipid metabolism was determined. 7S-peptide treatment suppressed the secretion of apolipoprotein B-100 from HepG2 cells into the medium. The 7S-peptides also suppressed the incorporation of (3)H-glycerol and (14)C-acetate into triacylglyceride but not into major phospholipids, such as phosphatidylcholine and phosphatidylethanolamine. Additionally, the synthesis of cholesterol esters was dramatically decreased for 2 h after the addition of the 7S-peptides, whereas the synthesis of cholesterol remained unchanged by 4 h and increased by 8 h after the addition of the 7S-peptides. The cleaved nuclear form of SREBP-2 increased 8 h after the addition of the 7S peptides, suggesting a decrease in intracellular cholesterol levels. Analysis of changes in mRNA expression after 7S-peptide treatment suggested that the 7S-peptides lower the level of cholesterol in the endoplasmic reticulum, increase the mRNA of genes related to beta-oxidation of fatty acids, and increase the synthesis of cholesterol. From these results, it may be concluded that the peptides derived from 7S altered the lipid metabolism to decrease secretion of apolipoprotein B-100-containing lipoprotein from HepG2 cells.

Han CZ, Du LL, Jing JX, et al.
Associations among lipids, leptin, and leptin receptor gene Gin223Arg polymorphisms and breast cancer in China.
Biol Trace Elem Res. 2008; 126(1-3):38-48 [PubMed] Related Publications
We evaluated the relationship among the leptin receptor (LEPR) gene Gln223Arg polymorphism, body mass index (BMI), waist and hip circumference ratio (WHR), dietary structure, lifestyle, and other biomarkers with breast cancer and determined whether they could be effective for the prevention and treatment of breast cancer. The Gln223Arg polymorphisms in the LEPR gene were investigated in blood deoxyribonucleic acid (DNA) available for 240 breast cancer cases and 500 controls. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism. Leptin, insulin were determined by enzyme-linked immunosorbent assays. We found that the serum levels of leptin, insulin, triglyceride (TG), free cholesterol (FCH), apolipoprotain (APO) A1, and BMI were significantly higher in breast cancer cases than the controls, while physical activity was clearly less in breast cancer cases (P < 0.02 approximately P < 0.001, respectively). Moreover, there were significant association between the Gln223Arg genotype and breast cancer risk; homozygotes for AA and heterozygotes for AG,AG + GG genotypes had been proved to increase the risk of breast cancer, and their corresponding odds ratio were 7.14 (95% confidence interval [CI] = 1.92-25.64), 1.33(95% CI = 1.03-2.70), and 2.04 (95% CI = 1.09-3.82). Interestingly, logistic regression analysis showed that LEPR gene Gln223Arg polymorphism and elevated leptin, insulin, TG, FCH, APOA1, WHR, and reduced APOB increased the risk of developing breast cancer, respectively. And, it also suggested that LEPR gene Gln223Arg polymorphisms, elevated leptin, insulin, TG, FCH, APOA1, WHR, and reduced APOB should play a major role in the development of breast cancer.

Kamdem LK, Hamilton L, Cheng C, et al.
Genetic predictors of glucocorticoid-induced hypertension in children with acute lymphoblastic leukemia.
Pharmacogenet Genomics. 2008; 18(6):507-14 [PubMed] Related Publications
OBJECTIVE: Glucocorticoids are used universally in the remission induction therapy for acute lymphoblastic leukemia (ALL). One of the adverse effects of glucocorticoids is hypertension. Our aim was to define the frequency of and clinical and genetic risk factors for steroid-induced hypertension.
METHODS: We determined the genotypes for 203 candidate polymorphisms in genes previously linked to hypertension or to the pharmacokinetics or pharmacodynamics of antileukemic agents. Hypertension was defined according to the guidelines of the American Academy of Pediatrics; patients were evaluated during the 28-day period of prednisone at 40 mg/m2/day during remission induction of childhood ALL.
RESULTS: Of the 602 children with newly diagnosed ALL who were normotensive pretherapy, 270 (45%) developed hypertension during remission induction. None of the putative risk factors (age, sex, race, white blood cell count, risk group, body mass index, or serum creatinine) was associated with hypertension. Among the polymorphisms genotyped, we identified eight genes (CNTNAP2, LEPR, CRHR1, NTAN1, SLC12A3, ALPL, BGLAP, and APOB) containing variants that were associated with hypertension (chi2 P values 0.002-0.048), several of which interact with the hypothalamus-pituitary-adrenal axis. Polymorphisms in CYP3A4 and CYP3A5 were not associated with hypertension.
CONCLUSION: Hypertension is common during ALL remission induction and is related to germline genetic variation.

Nahmias Y, Goldwasser J, Casali M, et al.
Apolipoprotein B-dependent hepatitis C virus secretion is inhibited by the grapefruit flavonoid naringenin.
Hepatology. 2008; 47(5):1437-45 [PubMed] Free Access to Full Article Related Publications
UNLABELLED: Hepatitis C virus (HCV) infects over 3% of the world population and is the leading cause of chronic liver disease worldwide. HCV has long been known to associate with circulating lipoproteins, and its interactions with the cholesterol and lipid pathways have been recently described. In this work, we demonstrate that HCV is actively secreted by infected cells through a Golgi-dependent mechanism while bound to very low density lipoprotein (vLDL). Silencing apolipoprotein B (ApoB) messenger RNA in infected cells causes a 70% reduction in the secretion of both ApoB-100 and HCV. More importantly, we demonstrate that the grapefruit flavonoid naringenin, previously shown to inhibit vLDL secretion both in vivo and in vitro, inhibits the microsomal triglyceride transfer protein activity as well as the transcription of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase and acyl-coenzyme A:cholesterol acyltransferase 2 in infected cells. Stimulation with naringenin reduces HCV secretion in infected cells by 80%. Moreover, we find that naringenin is effective at concentrations that are an order of magnitude below the toxic threshold in primary human hepatocytes and in mice.
CONCLUSION: These results suggest a novel therapeutic approach for the treatment of HCV infection.

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