New insights into ATR inhibition in muscle invasive bladder cancer:The role of apolipoprotein B mRNA editing catalytic subunit 3B

Background:Apolipoprotein B mRNA editing catalytic polypeptide(APOBEC),an endogenous mutator,induces DNA damage and activates the ataxia telangiectasia and Rad3-related(ATR)-checkpoint kinase 1(Chk1)pathway.Although cisplatin-based therapy is the mainstay for muscle-invasive bladder cancer(MIBC),it has a poor survival rate.Therefore,this study aimed to evaluate the efficacy of an ATR inhibitor combined with cisplatin in the treatment of APOBEC catalytic subunit 3B(APOBEC3B)expressing MIBC.Methods:Immunohistochemical staining was performed to analyze an association between APOBEC3B and ATR in patients with MIBC.The APOBEC3B expression in MIBC cell lines was assessed using real-time polymerase chain reaction and western blot analysis.Western blot analysis was performed to confirm differences in phosphorylated Chk1(pChk1)expression according to the APOBEC3B expression.Cell viability and apoptosis analyses were performed to examine the anti-tumor activity of ATR inhibitors combined with cisplatin.Results:There was a significant association between APOBEC3B and ATR expression in the tumor tissues obtained from patients with MIBC.Cells with higher APOBEC3B expression showed higher pChk1 expression than cells expressing low APOBEC3B levels.Combination treatment of ATR inhibitor and cisplatin inhibited cell growth in MIBC cells with a higher APOBEC3B expression.Compared to cisplatin single treatment,combination treatment induced more apoptotic cell death in the cells with higher APOBEC3B expression.Conclusion:Our study shows that APOBEC3B’s higher expression status can enhance the sensitivity of MIBC to cisplatin upon ATR inhibition.This result provides new insight into appropriate patient selection for the effective application of ATR inhibitors in MIBC.

XbaⅠpolymorphisms of apolipoprotein B gene:Another risk factor of gallstone formation after radical gastrectomy

AIM:To prospectively investigate the association between the XbaⅠpolymorphisms 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 XbaⅠpolymorphisms of APOB gene(X+X-group,n=24 and X-X-group,n =162)and compared.The XbaⅠpolymorphisms of APOB gene were detected by polymerase chain reaction-restriction fragment length polymorphism(PCRRFLP).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 XbaⅠpolymorphisms 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.

Genetic variants involved in gallstone formation and capsaicin metabolism,and the risk of gallbladder cancer in Chilean women

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 paraffi n 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 rs 708272 polymorphisms may be related to the risk of developing GBC in Chilean women.

Retinopathy in non diabetics, diabetic retinopathy and oxidative stress: a new phenotype in Central Africa?

AIM:To evaluate the rates of retinopathy without diabetes and diabetic retinopathy(DR),associated with some markers of oxidative stress,antioxidants and cardiometabolic risk factors.METHODS:We determined the prevalence of DR in 150type 2 diabetes mellitus(T2DM)patients,that of retinopathy in 50 non diabetics,the levels of body mass index(BMI),waist circumference(WC),blood pressure,lipids,8-isoprostane,8-hydroxydeoxyguanosine(8-oHdG),gamma-glutamyl transferase(GGT),oxidized low density lipoprotein(LDL)(OxLDL),thiobarbituric acid reacting substances(TBARS),reduced glutathione(GSH),superoxide dismutase(SOD),uric acid,creatinine,albumin,total antioxidant status(TAOS),zinc,selenium,magnesium,vitamin C,vitamin D,vitamin E,glucose,apolipoprotein B(ApoB).RESULTS:The prevalences of DR at 53y and Rtp at62y were 44%(n=66)and 10%(n=5),respectively.Thehighest levels of 8-isoprostane,8-OHdG,TBARS,SOD,and OxLDL were in DR.The lowest levels of vitamin D,vitamin C,TAOS,and vitamin E were in DR.In the casecontrol study discriminant analysis,the levels of vitamin C,vitamin D,ApoB,8-OHdG,creatinine,Zn,vitamin E,and WC distinguished significantly non-diabetics without DR(controls),T2DM patients without DR and T2DM patients with DR.CONCLUSION:Anticipation of DR onset is significantly associated with the exageration of oxidative stress biomarkers or decrease of antioxidants in African type 2diabetics.Prevention of oxidative stress and abdominal obesity is needed.Supplementation in vitamin C,D,and E should be recommended as complement therapies of T2DM.

THE ASSOCIATION OF POLYMORPHISMS AT A VNTR LOCUS 3’TO THE APOLIPOPROTEIN B GENE WITH CORONARY HEART DISEASE IN CHINESE POPULATION

The polymorphisms of variable number of tandem repeats (VNTR) 3’to the apolipoprotein B (apo B) gene were investigated using polymerase chain reaction (PCR) in a sample of 103 patients with documented coronary heart disease (CHD) and 100 healthy individuals selected from Chinese Han nationality.Twelve segregating alleles (3’β29 -51) were observed in the pooled total of 203 subjects. The most common allele was 3’β 37. followed by 3’β39 with frequencies of 0. 362 and 0. 296, respectively. This model of allele distribution was coincident with the results form different ethnic groups, but the relative frequencies of alleles were different. In comparison with the allele frequencies between the patients and controls,alleles bigger than 3’β39 (3’VNTR-B) were significantly more common among the patients than among the controls (P<0. 001). Moreover. in the CHD group patients with plasma levels of TC≥3.88 mmol/L,LDL-C≥2. 59 mmol/L and HDL-C<l. 16mmol/L had significantly higher frequencies of 3’ VNTR-B allele (P<0. 01). Therefore,it is suggested that 3’ VNTR-B allele might be involved in the development of coronary atherosclerosis, presumably through their influences on lipid metabolism.This study supported by “8. 5” grant from Ministry of PublicHealth.

N-terminal and C-terminal cytosine deaminase domain of APOBEC3G inhibit hepatitis B virus replication

AIM: To investigate the effect of human apolipoprotein B mRNA-editing enzyme catalytic-polypeptide 3G (APOBEC3G) and its N-terminal or C-terminal cytosine deaminase domain-mediated antiviral activity against hepatitis B virus (HBV) in vitro and in vivo. METHODS: The mammalian hepatoma cells HepG2 and HuH7 were cotransfected with APOBEC3G and its N-terminal or C-terminal cytosine deaminase domain expression vector and 1.3-fold-overlength HBV DNA as well as the linear monomeric HBV of genotype B and C. For in vivo study, an HBV vector-based mouse model was used in which APOBEC3G and its N-terminal or C-terminal cytosine deaminase domain expression vectors were co-delivered with 1.3-fold-overlength HBV DNA via high-volume tail vein injection. Levels of hepatitis B virus surface antigen (HBsAg) and hepatitis B virus e antigen (HBeAg) in the media of the transfected cells and in the sera of mice were determined by ELISA.The expression of hepatitis B virus core antigen (HBcAg) in the transfected cells was determined by Western blot analysis. Core-associated HBV DNA was examined by Southern blot analysis. Levels of HBV DNA in the sera of mice as well as HBV core-associated RNA in the liver of mice were determined by quantitative PCR and quantitative RT-PCR analysis, respectively. RESULTS: Human APOBEC3G exerted an anti-HBV activity in a dose-dependent manner in HepG2 cells, and comparable suppressive effects were observed on genotype B and C as that of genotype A. Interestingly, the N-terminal or C-terminal cytosine deaminase domain alone could also inhibit HBV replication in HepG2 cells as well as Huh7 cells. Consistent with in vitro results, the levels of HBsAg in the sera of mice were dramatically decreased, with more than 50 times decrease in the levels of serum HBV DNA and core-associated RNA in the liver of mice treated with APOBEC3G and its N-terminal or C-terminal cytosine deaminase domain as compared to the controls. CONCLUSION: Our findings provide probably the first evidence showing that APOBEC3G and its N-terminal or C-terminal cytosine deaminase domain could suppress HBV replication in vitro and in vivo.

Apolipoprotein B100 quality control and the regulation of hepatic very low density lipoprotein secretion

Apolipoprotein B （apoB） is the main protein component of very low density lipoprotein （VLDL） and is necessary for the assembly and secretion of these triglyceride （TG）-rich particles. Following release from the liver, VLDL is converted to low density lipoprotein （LDL） in the plasma and increased production of VLDL can therefore play a detrimental role in cardiovascular disease. Increasing evidence has helped to establish VLDL assembly as a target for the treatment of dyslipidemias. Multiple factors are involved in the folding of the apoB protein and the formation of a secretion-competent VLDL particle. Failed VLDL assembly can initiate quality control mechanisms in the hepatocyte that target apoB for degradation. ApoB is a substrate for endoplasmic reticulum associated degradation （ERAD） by the ubiquitin proteasome system and for autophagy. Efficient targeting and disposal of apoB is a regu- lated process that modulates VLDL secretion and partitioning of TG. Emerging evidence suggests that significant overlap exists between these degradative pathways. For example, the insulin-mediated targeting of apoB to autop- hagy and postprandial activation of the unfolded protein response （UPR） may employ the same cellular machinery and regulatory cues. Changes in the quality control mechanisms for apoB impact hepatic physiology and pathology states, including insulin resistance and fatty liver. Insulin signaling, lipid metabolism and the hepatic UPR may impact VLDL production, particularly during the postprandial state. In this review we summarize our current understanding of VLDL assembly, apoB degradation, quality control mechanisms and the role of these processes in liver physiology and in pathologic states.

Novel parameter based on lipid indicators ratio improves prognostic value of plasma lipid levels in resectable colorectal cancer patients

BACKGROUND At present,the value of lipid indicators in evaluating the prognosis of colorectal cancer is still relatively limited.AIM To evaluate the value of a novel parameter for colorectal cancer(CRC)prognosis scoring based on preoperative serum lipid levels.METHODS Four key serum lipid factors,namely,high-density lipoprotein cholesterol(HDLC),low-density lipoprotein cholesterol(LDL-C),apolipoprotein A1(Apo A1),and apolipoprotein B(Apo B),were detected.Two representative ratios,HDL-C-LDLC ratio(HLR)and Apo A1-Apo B ratio(ABR)were calculated.The relationship of these parameters with the prognosis of CRC patients including progression-free survival(PFS)and overall survival(OS)was analyzed by Kaplan-Meier plot and Cox proportional hazards regression.A novel lipoprotein cholesterol-apolipoprotein(LA)score based on HLR and ABR was established and its value in prognosis evaluation for CRC patients was explored.RESULTS Multivariate Cox proportional hazards regression analysis of PFS and OS showed that HDL-C,Apo A1,HLR,and ABR were positively associated with the prognosis of CRC patients.LA score was independently associated with a good prognosis in resectable CRC patients.Data processing of a dummy variable showed that the prognosis of patients with higher LA scores is better than that with lower LA scores.CONCLUSION The newly established LA score might serve as a better predictor of the prognosis of resectable CRC patients.

Apolipoprotein B Is a Good Tool for Screening Dyslipidaemia in Apparently Healthy Population

Dyslipidaemia is the major risk factor for cardiovascular disease (CVD) which is the leading cause of death in the world. Even though several lipid parameters are used, currently apolipoprotein B (apoB) is considered as the best predictor of CVD. Thus this study was carried out to find out the association between conventional lipid parameters and apoB in apparently healthy subjects. A descriptive cross-sectional study was carried out in 170 apparently healthy volunteers who were not diagnosed with dyslipidaemia. After 12 hours overnight fast venous blood was obtained and Total cholesterol (TC), Triglyceride (TG), High density lipoprotein cholesterol (HDL-C) were measured by enzymatic kit method. Low density lipoprotein cholesterol (LDL-C) was calculated by Friedewald formula and apoB was analyzed by immune turbid metry using a Konelab® auto analyzer. Among the participants, majority (63.5%) were females. The mean value of apoB concentration of the population was 103 ± 42 mg/dL which was similar and not significantly different between the genders (Males, 102 ± 37 mg/dL and Females, 104 ± 45 mg/dL). All lipid parameters showed a positive correlation with apoB concentration whereas HDL-C had a negative correlation (r = -0.165). HDL-C significantly (p < 0.05) decreased with increase in apoB concentration while LDL-C, TC/HDL-C and non-HDL-C significantly (p < 0.05) increased with an increase in apoB concentration. Present study suggests that serum apoB has better correlations and associations with the parameters that are used in conventional lipid profile and with markers recommended for diagnosing dyslipidaemia. Hence apoB could be used as a single marker for screening dyslipidaemia in apparently healthy people.

Improving Cardiovascular Risk Assessment to Optimize Therapy

Background: Quantifying ten-year cardiovascular risk can be challenging. Different online risk calculators provide different risk estimates and online risk calculators use only one point in time. However, risk factors occur over the lifetime of the individual. Purpose: This manuscript provides three solutions to improving ten-year cardiovascular risk assessment in individuals at intermediate risk. Methods: Measuring Lipoprotein(a)—Lp(a) is recommended for assessing cardiovascular risk in all individuals who are in the intermediate risk category by standard online risk calculators. Lp(a) is primarily determined by genetic inheritance. It has the undesirable properties of being proatherosclerotic, proinflammatory, and prothrombotic. Measuring apolipoprotein B (apo B) provides a good index of the number of atherosclerotic particles present. Studies have demonstrated that small, dense LDL cholesterol particles are more atherogenic than larger, less dense LDL cholesterol particles. Measuring high sensitivity C-reactive protein (hsCRP) provides a good estimation of the degree of inflammation in the vascular system. Inflammation is a critical component of heart attacks and strokes. It is increased in diabetes and obesity. Treatment to reduce inflammation results in a reduction of cardiovascular events, independent of lipid values. Results: The above three risk factors should be measured in all patients with an intermediate risk score. Routine assays are readily available at a reasonable cost. They are independent risk factors for cardiovascular disease. Their recommendation is based on the pathophysiology of atherosclerotic cardiovascular disease. Successful therapy will result in the decrease of each of these risk factors. Conclusion: The recommended approach will improve the assessment of cardiovascular risk and guide the physician and patient to the correct treatment recommendations.

Effects of Red Palm Oil on Serum Lipids and Plasma Carotenoids Level in Chinese Male Adults

Objective Effects of red palm oil on major plasma carotenoids, tocopherol, retinol and serum lipids were evaluated when used in Chinese diet. Methods Red palm oil group (RPO) composed of 20 male subjects(aged 18-32) and soybean oil group (SBO) composed of 22 male subjects (aged 18-32). Dietary fat provided about 28% of total calories, and the test oil accounted for about 60% of total dietary fat. In the 3 weeks of pretest period, diets were prepared with soybean oil, and then in the next 6 weeks subjects in each group consumed the diet prepared by test oil. Results Plasma α-carotene, β-carotene and lycopene concentration of RPO group significantly increased at the time of interim (21 days) and of the end (42 days) (P<0.05), and α-tocopherol concentration significantly increased at the time of the end (42 days) in this study. Though Chinese plasma retinol level was relatively low when compared with that of Westerners, red palm oil diet showed no significant effect on adult Chinese plasma retinol level. Serum concentration of total cholesterol, triglyceride, high density lipoprotein cholesterol, apolipoprotein AI and apolipoprotein B of all subjects showed no significant changes in RPO group during the study. Conclusions The data in our study suggest that red palm oil is a good source of carotenoids and vitamin E when used in Chinese diet preparation, and it can significantly increase plasma concentration of a-carotene, α-carotene, lycopene and β-tocopherol.

FOLR1-induced folate deficiency reduces viral replication via modulating APOBEC3 family expression

Folate receptor alpha(FOLR1)is vital for cells ingesting folate(FA).FA plays an indispensable role in cell pro-liferation and survival.However,it is not clear whether the axis of FOLR1/FA has a similar function in viral replication.In this study,we used vesicular stomatitis virus(VSV)to investigate the relationship between FOLR1-mediated FA deficiency and viral replication,as well as the underlying mechanisms.We discovered that FOLR1 upregulation led to the deficiency of FA in HeLa cells and mice.Meanwhile,VSV replication was notably sup-pressed by FOLR1 overexpression,and this antiviral activity was related to FA deficiency.Mechanistically,FA deficiency mainly upregulated apolipoprotein B mRNA editing enzyme catalytic subunit 3B(APOBEC3B)expression,which suppressed VSV replication in vitro and in vivo.In addition,methotrexate(MTX),an FA metabolism inhibitor,effectively inhibited VSV replication by enhancing the expression of APOBEC3B in vitro and in vivo.Overall,our present study provided a new perspective for the role of FA metabolism in viral infections and highlights the potential of MTX as a broad-spectrum antiviral agent against RNA viruses.

The Relationship between Apolipoprotein B Gene Loci Polymorphisms and Coronary Heart Disease.

The authors utilized the polymerase chain reaction to rapidly and accurately type a variable number of tandemly repeated loci (VNTR loci) of the 3’ flanking region of apolipoprotein B (apo B) gene, and studied the relationship between this loci polymorphisms and coronary heart disease (CAD); comparisons were made with relative diseases and

Apolipoprotein B/Apolipoprotein A1 ratio is associated with sex hormone binding globulin and may be an indicator of metabolic syndrome in PCOS women

Objective To identify significant factors related to the apolipoprotein B/apolipoprotein A1 （apoB/A1） ratio and investigate the association between the apoB/A1 ratio and metabolic syndrome （MS） in polycystic ovary syndrome （PCOS） women. Methods Totally 307 subjects with PCOS were collected and recruited fulfilling the revised 2003 Rotterdam diagnostic criteria. MS was diagnosed by the National Cholesterol Education Program-Adult treatment Panel （NCEP-ATP） III criteria. Results The prevalence of MS in PCOS women was 31.6%, whose average age was 26.2 ___＋ 5.2 years. The apoB/A1 ratio was significantly correlated with age, body mass index （BM1）, waist circumference （WC）, hip circumference, waist-to-hip ratio, blood pressure, metabolic abnormalities, sex hormone binding globulin （SHBG）, and free androgen index. In addition, SHBG had a significant association with all five component risk of MS. The increasing apoB/A1 ratio was associated with the prevalence of MS and was one of the risk factors of MS. Conclusion SHBG was considered as an additional potential factor in predicting the metabolic abnormity in PCOS women. The apoB/A1 ratio is associated with SHBG and might be an indicator of MS in PCOS women.

Structure and function of alleles in the 3' end region of human apoB gene

Objective To study the structure of alleles in the 3' end of the apoB gene in Han, Mongolian and Tibetan populations in China as well as the roles in the regulation of gene expression. Methods DNA were obtained from human leukocytes by phenol chloroform extraction and ethanol precipitation. PCR were carried out in a 50 μl volume containing 50 ng genomic DNA as template. The Ssp1 digested products were loaded on a gradient acrylamide gel and run for 3 hours. The constructs containing alleles were tested in cultured HepG2 and HeLa cells using transient assays. Results Sixteen alleles with different repeat number were characterized. All of the alleles varying from HVE22 to HVE52, allele HVE34 was the most common (58.4%), followed by allele HVE36 (13.8%) and HVE32 (10.5%). 258 PCR products were digested with Ssp1 and run in 4-12% PAGE. We detected the fragments of 266bp, 91bp, 61bp and 39bp in almost all samples. The small alleles (including HVE22, HVE24, HVE26 and HVE36) decreased the expressive activity of the luciferase reporter, in contrary, the large alleles (including HVE44, HVE46 and HVE48) elevated obviously the expressive activity of the luciferase reporter. Conclusions More alleles with different number of tandem repeats in 3' end of apoB gene exist in the Chinese populations. The alleles in 3' end minisatellite of human apoB gene could control the expression of the gene itself.

The Study of Apolipoprotein B Gene Polymorphisms by Polymerase Chain Reaction.

Two polymorphic sites of apolipoprotein B（apoB） gene-Xbal and EcoRI were examined in a sample of 103 patients with documented coronary heart disease （CHD） and 100 healthy individuals. It was demonstrated: （1） The frequencies of rare Xallele （presence of Xbal cutting site） and E-allele （absence of cutting site） were significantly higher in CHD patients than those in controls. It was suggested that these genetic variations were associated with CHD. （2） The patients with genotype of XXhad significantly lower

Relation of combined non-high density lipoprotein cholesterol and apolipoprotein B with Gensini Score of coronary atherosclerosis in non-diabetic acute coronary syndrome

Background Non-high-density lipoprotein cholesterol （non-HDL-C） and Apolipoprotein B （apoB） increase car- diovascular disease （CVD） risk, but few studies have explored the correlations of non-HDL-C and apoB with cor- onary atherosclerosis in non-diabetes acute coronary syndrome （ACS）. Methods The study enrolled 443 sub- jects with non-diabetic ACS, and all subject check coronary angiography, and coronary atherosclerosis were eval- uated using Gensini Score （GS） scale including small （GS 1-15）, middle （GS16-43）, and severe （GS≥44）. All sub- jects were classified into 4 groups： High apoB （≥90 mg/dL） and High non-HDL-C （≥130 mg/dL）, High non-HDL -C alone, High apoB alone, and normal apoB and non-HDL-C. Results After adjusted for risk factors, non-HDL -C and apoB were positively correlated with GS （ r = 0.075, P = 0.002 and r = 0.092, P 〈 0.001）. In the GS 0-15, high non-HDL-C ＋ high apoB group 29.3% and high apoB alone group 28.2% were significantly lower than nor- mal non-HDL-C＋ normal apoB group 48% （p = 0.010）. In the GS 16-43, high non-HDL-C alone group 50.4% and high apoB alone group 47.6% were significantly more than high non-HDL-C＋ high apoB group 34.1% （P = 0.036）. In the GS ≥44, high non-HDL-C＋ high apoB group 36.6% was significantly higher than high non-HDL- C alone group 16% and normal non-HDL-C＋ normal apoB 14.2%（P 〈 0.001）. Conclusions The high non-HDL- C and apoB are the risk factors for coronary artery atherosclerosis in non-diabetic ACS.