PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (29)
 

Clipboard (0)
None

Select a Filter Below

Year of Publication
Document Types
1.  The VITamin D and OmegA-3 TriaL (VITAL): Rationale and Design of a Large Randomized Controlled Trial of Vitamin D and Marine Omega-3 Fatty Acid Supplements for the Primary Prevention of Cancer and Cardiovascular Disease 
Contemporary Clinical Trials  2011;33(1):159-171.
Data from laboratory studies, observational research, and/or secondary prevention trials suggest that vitamin D and marine omega-3 fatty acids may reduce risk for cancer or cardiovascular disease (CVD), but primary prevention trials with adequate dosing in general populations (i.e., unselected for disease risk) are lacking. The ongoing VITamin D and OmegA-3 TriaL (VITAL) is a large randomized, double-blind, placebo-controlled, 2×2 factorial trial of vitamin D (in the form of vitamin D3 [cholecalciferol], 2000 IU/day) and marine omega-3 fatty acid (Omacor® fish oil, eicosapentaenoic acid [EPA] + docosahexaenoic acid [DHA], 1 g/day) supplements in the primary prevention of cancer and CVD among a multi-ethnic population of 20,000 U.S. men aged ≥50 and women aged ≥55. The mean treatment period will be 5 years. Baseline blood samples will be collected in at least 16,000 participants, with follow-up blood collection in about 6000 participants. Yearly follow-up questionnaires will assess treatment compliance (plasma biomarker measures will also assess compliance in a random sample of participants), use of non-study drugs or supplements, occurence of endpoints, and cancer and vascular risk factors. Self-reported endpoints will be confirmed by medical record review by physicians blinded to treatment assignment, and deaths will be ascertained through national registries and other sources. Ancillary studies will investigate whether these agents affect risk for diabetes and glucose intolerance; hypertension; cognitive decline; depression; osteoporosis and fracture; physical disability and falls; asthma and other respiratory diseases; infections; rheumatoid arthritis, systemic lupus erythematosus, thyroid diseases, and other autoimmune disorders.
doi:10.1016/j.cct.2011.09.009
PMCID: PMC3253961  PMID: 21986389
Cancer; cardiovascular disease; cholecalciferol; primary prevention; omega-3 fatty acids; vitamin D; randomized controlled trial
2.  Sunlight exposure, vitamin D, and risk of non-Hodgkin lymphoma in the Nurses’ Health Study 
Cancer causes & control : CCC  2011;22(12):1731-1741.
Purpose
Case-control studies suggest increased sun exposure reduces non-Hodgkin lymphoma (NHL) risk. Evidence from prospective cohort studies, however, is limited and inconsistent. We evaluated the association between ambient ultraviolet radiation (UV) exposure and NHL in a nationwide cohort of women, the Nurses’ Health Study (NHS).
Methods
Between 1976 and 2006, we identified 1064 incident NHL cases among 115,482 women in the prospective NHS. Exposures assessed included average annual UV-B flux based on residence at various times during life, vitamin D intake, and predicted plasma 25-hydroxyvitamin D levels. We estimated incidence rate ratios (RRs) and 95% confidence intervals (CIs) for risk of all NHL and histologic subtypes using Cox proportional hazards models.
Results
NHL risk was increased for women residing in areas of high ambient UV radiation (UV-B flux >113 R-B count × 10−4) compared to those with lower exposure (<113), with positive linear trends at all time points. The multivariable-adjusted RR for high UV area at age 15 was 1.21 (95% CI: 1.00, 1.47; p-trend <0.01). There was no evidence of statistical heterogeneity by subtype, although power was limited for subtype analyses. We observed no association between vitamin D measures and risk of NHL overall or by subtype.
Conclusions
Our findings do not support the hypothesis of a protective effect of UV radiation exposure on NHL risk. We found no association between vitamin D and NHL risk.
doi:10.1007/s10552-011-9849-x
PMCID: PMC3240999  PMID: 21987081
non-Hodgkin lymphoma; sunlight; ultraviolet radiation; vitamin D; epidemiology
3.  N-Acetyltransferase 2 Polymorphisms, Tobacco Smoking, and Breast Cancer Risk in the Breast and Prostate Cancer Cohort Consortium 
American Journal of Epidemiology  2011;174(11):1316-1322.
Common polymorphisms in the N-acetyltransferase 2 gene (NAT2) modify the association between cigarette smoking and bladder cancer and have been hypothesized to determine whether active cigarette smoking increases breast cancer risk. The authors sought to replicate the latter hypothesis in a prospective analysis of 6,900 breast cancer cases and 9,903 matched controls drawn from 6 cohorts (1989–2006) in the National Cancer Institute’s Breast and Prostate Cancer Cohort Consortium. Standardized methods were used to genotype the 3 most common polymorphisms that define NAT2 acetylation phenotype (rs1799930, rs1799931, and rs1801280). In unconditional logistic regression analyses, breast cancer risk was higher in women with more than 20 pack-years of active cigarette smoking than in never smokers (odds ratio (OR) = 1.28, 95% confidence interval (CI): 1.17, 1.39), after controlling for established risk factors other than alcohol consumption and physical inactivity. However, associations were similar for the slow (OR = 1.25, 95% CI: 1.11, 1.39) and rapid/intermediate (OR = 1.24, 95% CI: 1.08, 1.42) acetylation phenotypes, with no evidence of interaction (P = 0.87). These results provide some support for the hypothesis that long-term cigarette smoking may be causally associated with breast cancer risk but underscore the need for caution when interpreting sparse data on gene-environment interactions.
doi:10.1093/aje/kwr257
PMCID: PMC3390163  PMID: 22074863
arylamine N-acetyltransferase; breast neoplasms; NAT2 protein, human; polymorphism, single nucleotide; smoking
4.  Interactions Between Genetic Variants and Breast Cancer Risk Factors in the Breast and Prostate Cancer Cohort Consortium 
Background
Recently, several genome-wide association studies have identified various genetic susceptibility loci for breast cancer. Relatively little is known about the possible interactions between these loci and the established risk factors for breast cancer.
Methods
To assess interactions between single-nucleotide polymorphisms (SNPs) and established risk factors, we prospectively collected DNA samples and questionnaire data from 8576 breast cancer case subjects and 11 892 control subjects nested within the National Cancer Institute’s Breast and Prostate Cancer Cohort Consortium (BPC3). We genotyped 17 germline SNPs (FGFR2-rs2981582, FGFR2-rs3750817, TNRC9-rs3803662, 2q35-rs13387042, MAP3K1-rs889312, 8q24-rs13281615, CASP8-rs1045485, LSP1-rs3817198, COL1A1-rs2075555, COX11-rs6504950, RNF146-rs2180341, 6q25-rs2046210, SLC4A7-rs4973768, NOTCH2-rs11249433, 5p12-rs4415084, 5p12-rs10941679, RAD51L1-rs999737), and odds ratios were estimated by logistic regression to confirm previously reported associations with breast cancer risk. We performed likelihood ratio test to assess interactions between 17 SNPs and nine established risk factors (age at menarche, parity, age at menopause, use of hormone replacement therapy, family history, height, body mass index, smoking status, and alcohol consumption), and a correction for multiple testing of 153 tests (adjusted P value threshold = .05/153 = 3 × 10−4) was done. Case–case comparisons were performed for possible differential associations of polymorphisms by subgroups of tumor stage, estrogen and progesterone receptor status, and age at diagnosis. All statistical tests were two-sided.
Results
We confirmed the association of 14 SNPs with breast cancer risk (Ptrend = 2.57 × 10−3 –3.96 × 10−19). Three SNPs (LSP1-rs3817198, COL1A1-rs2075555, and RNF146-rs2180341) did not show association with breast cancer risk. After accounting for multiple testing, no statistically significant interactions were detected between the 17 SNPs and the nine risk factors. We also confirmed that SNPs in FGFR2 and TNRC9 were associated with greater risk of estrogen receptor–positive than estrogen receptor–negative breast cancer (Pheterogeneity = .0016 for FGFR2-rs2981582 and Pheterogeneity = .0053 for TNRC9-rs3803662). SNP 5p12-rs10941679 was statistically significantly associated with greater risk of progesterone receptor–positive than progesterone receptor–negative breast cancer (Pheterogeneity = .0028).
Conclusion
This study does not support the hypothesis that known common breast cancer susceptibility loci strongly modify the associations between established risk factors and breast cancer.
doi:10.1093/jnci/djr265
PMCID: PMC3156803  PMID: 21791674
5.  The Aromatase Gene (CYP19A1) Variants and Circulating Hepatocyte Growth Factor in Postmenopausal Women 
PLoS ONE  2012;7(7):e42079.
Background
Estrogen and androgen have been linked to the regulation of circulating hepatocyte growth factor (HGF), an adipose tissue-derived cytokine. It is possible that the CYP19A1 gene which alters sex hormones production may influence HGF levels. We examined the association between the CYP19A1 gene variants and plasma HGF concentrations.
Design
We evaluated 45 common and putative functional variants of CYP19A1 and circulating levels of HGF among 260 postmenopausal women who later developed colorectal cancer from the Women's Health Initiative Observational Cohort. As the distribution of HGF levels was highly skewed, we transformed HGF concentrations for all women into a log-, ranked-, or normal score-scale value. Multiple linear regression with adjustment for age was used to evaluate the associations.
Results
We observed an association between the rs7172156, rs1008805, rs6493494, rs749292, and rs11636639 variants and HGF levels in ranked and normal score scales (corrected p values ≤0.02), although the association of these 5 SNPs with log-scale HGF was not significant (corrected p values ≥0.16). The associations remained unchanged after additional adjustment for hormone therapy use and estradiol levels. These 5 SNPs, which were in linkage disequilibrium (pairwise D′≥97%, r2≥56%), constituted a block with 2 common haplotypes accounting for 82% frequency. The most common haplotype, TCCCA, was associated with lower ranked- or normal score-transformed HGF levels (corrected p values ≤0.001), whereas the second most common haplotype, CTTCA, was associated with higher ranked- or normal score-transformed HGF levels (corrected p values ≤0.02).
Conclusion
Our findings of a potential association between the CYP19A1 variants and circulating HGF levels warrant confirmation in studies with larger sample size.
doi:10.1371/journal.pone.0042079
PMCID: PMC3405042  PMID: 22848710
6.  Stable silencing of β-lactoglobulin (BLG) gene by lentivirus-mediated RNAi in goat fetal fibroblasts 
Genetics and Molecular Biology  2012;35(3):680-685.
β-lactoglobulin (BLG), a dominant allergen in goat milk, is difficult to remove by traditional biochemical methods. Its elimination from goat milk by genetic modification therefore poses a major challenge for modern goat breeders. A shRNA targeting BLG mRNA with high interference efficiency was identified, with which lentiviral vectors were used for mediating stable shRNA interference in goat-fetal fibroblast cells. Apart from high efficiency in the knockdown of BLG expression in these cells, lentivector-mediated RNAi manifested stable integration into the goat genome itself. Consequently, an in vitro model for goat BLG-content control was compiled, and a goat-cell line for accompanying transgenetic goat production created.
doi:10.1590/S1415-47572012005000042
PMCID: PMC3459420  PMID: 23055809
RNAi; shRNA; lentivirus; BLG; goat
7.  EPLIN Downregulation Promotes Epithelial-Mesenchymal Transition in Prostate Cancer Cells and Correlates With Clinical Lymph Node Metastasis 
Oncogene  2011;30(50):4941-4952.
Epithelial-mesenchymal transition (EMT) is a crucial mechanism for the acquisition of migratory and invasive capabilities by epithelial cancer cells. By conducting quantitative proteomics in experimental models of human prostate cancer (PCa) metastasis, we observed strikingly decreased expression of EPLIN (epithelial protein lost in neoplasm; or LIM domain and actin binding 1, LIMA-1) upon EMT. Biochemical and functional analyses demonstrated that EPLIN is a negative regulator of EMT and invasiveness in PCa cells. EPLIN depletion resulted in the disassembly of adherens junctions, structurally distinct actin remodeling, and activation of β-catenin signaling. Microarray expression analysis identified a subset of putative EPLIN target genes associated with EMT, invasion and metastasis. By immunohistochemistry EPLIN downregulation was also demonstrated in lymph node metastases of human solid tumors including PCa, breast cancer, colorectal cancer and squamous cell carcinoma of the head and neck. This study reveals a novel molecular mechanism for converting cancer cells into a highly invasive and malignant form, and has important implications in prognosing and treating metastasis at early stages.
doi:10.1038/onc.2011.199
PMCID: PMC3165108  PMID: 21625216
EPLIN; epithelial-mesenchymal transition; prostate cancer; lymph node metastasis; cytoskeleton
8.  Prediction and Identification of Potential Immunodominant Epitopes in Glycoproteins B, C, E, G, and I of Herpes Simplex Virus Type 2 
Twenty B candidate epitopes of glycoproteins B (gB2), C (gC2), E (gE2), G (gG2), and I (gI2) of herpes simplex virus type 2 (HSV-2) were predicted using DNAstar, Biosun, and Antheprot methods combined with the polynomial method. Subsequently, the biological functions of the peptides were tested via experiments in vitro. Among the 20 epitope peptides, 17 could react with the antisera to the corresponding parent proteins in the EIA tests. In particular, five peptides, namely, gB2466–473 (EQDRKPRN), gC2216–223 (GRTDRPSA), gE2483–491 (DPPERPDSP), gG2572–579 (EPPDDDDS), and gI2286-295 (CRRRYRRPRG) had strong reaction with the antisera. All conjugates of the five peptides with the carrier protein BSA could stimulate mice into producing antibodies. The antisera to these peptides reacted strongly with the corresponding parent glycoproteins during the Western Blot tests, and the peptides reacted strongly with the antibodies against the parent glycoproteins during the EIA tests. The antisera against the five peptides could neutralize HSV-2 infection in vitro, which has not been reported until now. These results suggest that the immunodominant epitopes screened using software algorithms may be used for virus diagnosis and vaccine design against HSV-2.
doi:10.1155/2012/205313
PMCID: PMC3357521  PMID: 22649465
9.  A Phase I Clinical-Pharmacodynamic Study of the Farnesyltransferase Inhibitor Tipifarnib in Combination with the Proteasome Inhibitor Bortezomib in Advanced Acute Leukemias 
Purpose
To determine the safety, target inhibition, and signals of clinical activity of tipifarnib in combination with bortezomib in patients with advanced acute leukemias.
Experimental Design
In a 3+3 design, patients received escalating doses of tipifarnib (days 1–14) and bortezomib (days 1, 4, 8, 11) every 3 weeks until maximum tolerated dose was reached. Peripheral blood mononuclear cells (PBMCs) were collected at days 1, 8, and 22 for measurement of chymotrypsin-like and farnesyltransferase activity. Purified bone marrow leukemic blasts were collected at baseline and at day 8 for measurement of NF-kB activity.
Results
The combination was well-tolerated, and maximum tolerated dose was not reached. Dose-limiting toxicities included diarrhea, fatigue, and sensorimotor neuropathy. Chymotrypsin-like and farnesyltransferase activity within PBMCs were decreased in a majority of patients at day 8. NF-kB activity within leukemic blasts was decreased in a majority of patients at day 8. Complete response with incomplete count recovery was observed in 2 patients, and an additional 5 patients had stable disease.
Conclusions
Tipifarnib and bortezomib combination in patients with advanced leukemias was well-tolerated, demonstrated relevant target inhibition, and was associated with signals of clinical activity in patients with advanced and refractory acute leukemias. Future studies of this combination may be warranted in more selected groups of patients in whom these molecular targets are of particular importance.
doi:10.1158/1078-0432.CCR-10-1878
PMCID: PMC3049960  PMID: 21233404
acute leukemia; NF-kappa B; farnesyltransferase inhibitor; proteasome inhibitor; phase 1
10.  Complete Genome Sequence of Bordetella pertussis CS, a Chinese Pertussis Vaccine Strain ▿  
Journal of Bacteriology  2011;193(15):4017-4018.
Bordetella pertussis is the causative agent of pertussis. Here, we report the genome sequence of Bordetella pertussis strain CS, isolated from an infant patient in Beijing and widely used as a vaccine strain for production of an acellular pertussis vaccine in China.
doi:10.1128/JB.05184-11
PMCID: PMC3147532  PMID: 21622744
11.  PDGF Upregulates Mcl-1 Through Activation of β-Catenin and HIF-1α-Dependent Signaling in Human Prostate Cancer Cells 
PLoS ONE  2012;7(1):e30764.
Background
Aberrant platelet derived growth factor (PDGF) signaling has been associated with prostate cancer (PCa) progression. However, its role in the regulation of PCa cell growth and survival has not been well characterized.
Methodology/Principal Findings
Using experimental models that closely mimic clinical pathophysiology of PCa progression, we demonstrated that PDGF is a survival factor in PCa cells through upregulation of myeloid cell leukemia-1 (Mcl-1). PDGF treatment induced rapid nuclear translocation of β-catenin, presumably mediated by c-Abl and p68 signaling. Intriguingly, PDGF promoted formation of a nuclear transcriptional complex consisting of β-catenin and hypoxia-inducible factor (HIF)-1α, and its binding to Mcl-1 promoter. Deletion of a putative hypoxia response element (HRE) within the Mcl-1 promoter attenuated PDGF effects on Mcl-1 expression. Blockade of PDGF receptor (PDGFR) signaling with a pharmacological inhibitor AG-17 abrogated PDGF induction of Mcl-1, and induced apoptosis in metastatic PCa cells.
Conclusions/Significance
Our study elucidated a crucial survival mechanism in PCa cells, indicating that interruption of the PDGF-Mcl-1 survival signal may provide a novel strategy for treating PCa metastasis.
doi:10.1371/journal.pone.0030764
PMCID: PMC3262835  PMID: 22276222
12.  Intakes of vitamins A, C, and E and use of multiple vitamin supplements and risk of colon cancer: a pooled analysis of prospective cohort studies 
Cancer causes & control : CCC  2010;21(11):1745-1757.
Objective
To evaluate the associations between intakes of vitamins A, C, and E and risk of colon cancer.
Methods
Using the primary data from 13 cohort studies, we estimated study- and sex-specific relative risks (RR) with Cox proportional hazards models and subsequently pooled RRs using a random effects model.
Results
Among 676,141 men and women, 5,454 colon cancer cases were identified (7–20 years of follow-up across studies). Vitamin A, C, and E intakes from food only were not associated with colon cancer risk. For intakes from food and supplements (total), the pooled multivariate RRs (95% CI) were 0.88 (0.76–1.02, >4,000 vs. ≤1,000 μg/day) for vitamin A, 0.81 (0.71–0.92, >600 vs. ≤100 mg/day) for vitamin C, and 0.78 (0.66–0.92, >200 vs. ≤6 mg/day) for vitamin E. Adjustment for total folate intake attenuated these associations, but the inverse associations with vitamins C and E remained significant. Multivitamin use was significantly inversely associated with colon cancer risk (RR = 0.88, 95% CI: 0.81–0.96).
Conclusions
Modest inverse associations with vitamin C and E intakes may be due to high correlations with folate intake, which had a similar inverse association with colon cancer. An inverse association with multivitamin use, a major source of folate and other vitamins, deserves further study.
doi:10.1007/s10552-010-9549-y
PMCID: PMC3091388  PMID: 20820901
Vitamin A; Vitamin C; Vitamin E; Multivitamin; Colon cancer; Cohort study; Pooled analysis
13.  Risk of Colon Cancer and Coffee, Tea, and Sugar-Sweetened Soft Drink Intake: Pooled Analysis of Prospective Cohort Studies 
Background
The relationships between coffee, tea, and sugar-sweetened carbonated soft drink consumption and colon cancer risk remain unresolved.
Methods
We investigated prospectively the association between coffee, tea, and sugar-sweetened carbonated soft drink consumption and colon cancer risk in a pooled analysis of primary data from 13 cohort studies. Among 731 441 participants followed for up to 6–20 years, 5604 incident colon cancer case patients were identified. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models and then pooled using a random-effects model. All statistical tests were two-sided.
Results
Compared with nonconsumers, the pooled multivariable relative risks were 1.07 (95% CI = 0.89 to 1.30, Ptrend = .68) for coffee consumption greater than 1400 g/d (about six 8-oz cups) and 1.28 (95% CI = 1.02 to 1.61, Ptrend = .01) for tea consumption greater than 900 g/d (about four 8-oz cups). For sugar-sweetened carbonated soft drink consumption, the pooled multivariable relative risk comparing consumption greater than 550 g/d (about 18 oz) to nonconsumers was 0.94 (95% CI = 0.66 to 1.32, Ptrend = .91). No statistically significant between-studies heterogeneity was observed for the highest category of each beverage consumed (P > .20). The observed associations did not differ by sex, smoking status, alcohol consumption, body mass index, physical activity, or tumor site (P > .05).
Conclusions
Drinking coffee or sugar-sweetened carbonated soft drinks was not associated with colon cancer risk. However, a modest positive association with higher tea consumption is possible and requires further study.
doi:10.1093/jnci/djq107
PMCID: PMC2879415  PMID: 20453203
14.  Genetic variation in sex-steroid receptors and synthesizing enzymes and colorectal cancer risk in women 
Cancer causes & control : CCC  2010;21(6):897-908.
Objectives
Several lines of evidence have suggested that female hormones may lower risk for developing colorectal cancer. However, the mechanisms by which sex hormones affect colorectal cancer development remain unknown. We sought to determine whether the association may be under genetic control by evaluating genetic variation in estrogen receptors (ESR1 and ESR2), progesterone receptor (PGR), aromatase cytochrome 450 enzyme (CYP19A1) and 17 beta-hydroxysteroid dehydrogenase type 2 gene (HSD17B2).
Methods
We included 158 incident cases of colorectal cancer and 563 randomly chosen control subjects from 28,345 women in the Women's Health Study aged 45 years or older who provided blood samples and had no history of cancer or cardiovascular disease at baseline in 1993. All cases and controls were Caucasians of European descent. A total of 63 tagging and putative functional SNPs in the 5 genes were included for analysis. Unconditional logistic regression was used to estimate odds ratio (ORs) and 95% confidence intervals (CIs).
Results
There was no association between variation in ESR1, ESR2, PGR, CYP19A1 and HSD17B2 and colorectal cancer risk after correction for multiple comparisons (p values after correction ≥0.25). There was also no association with any of the haplotypes examined (p ≥0.15) and no evidence of joint effects of variants in the 5 genes (p ≥0.51).
Conclusion
Our data offer insufficient support for an association between variation in ESR1, ESR2, PGR, CYP19A1 and HSD17B2 and risk for developing colorectal cancer.
doi:10.1007/s10552-010-9518-5
PMCID: PMC2873149  PMID: 20148360
15.  Estrogen and progesterone-related gene variants and colorectal cancer risk in women 
BMC Medical Genetics  2011;12:78.
Background
Observational studies and randomized trials have suggested that estrogens and/or progesterone may lower the risk for colorectal cancer. Inherited variation in the sex-hormone genes may be one mechanism by which sex hormones affect colorectal cancer, although data are limited.
Method
We conducted a comprehensive evaluation of single nucleotide polymorphisms (SNPs) in genes encoding 3 hormone receptors (ESR1, ESR2, PGR) and 5 hormone synthesizers (CYP19A1 and CYP17A1, HSD17B1, HSD17B2, HSD17B4) among 427 women with incident colorectal cancer and 871 matched controls who were Caucasians of European ancestry from 93676 postmenopausal women enrolled in the Women's Health Initiative Observational cohort. A total of 242 haplotype-tagging and functional SNPs in the 8 genes were included for analysis. Unconditional logistic regression with adjustment for age and hysterectomy status was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).
Results
We observed a weak association between the CYP17A1 rs17724534 SNP and colorectal cancer risk (OR per risk allele (A) = 1.39, 95% CI = 1.09-1.78, corrected p-value = 0.07). In addition, a suggestive interaction between rs17724534 and rs10883782 in 2 discrete LD blocks of CYP17A1 was observed in relation to colorectal cancer (empirical p value = 0.04). Moreover, one haplotype block of CYP19A1 was associated with colorectal cancer (corrected global p value = 0.02), which likely reflected the association with the tagging SNP, rs1902584, in the block.
Conclusion
Our findings offer some support for a suggestive association of CYP17A1 and CYP19A1 variants with colorectal cancer risk.
doi:10.1186/1471-2350-12-78
PMCID: PMC3125237  PMID: 21627810
16.  Plasma homocysteine and cysteine and risk of breast cancer in women 
Cancer research  2010;70(6):2397-2405.
Homocysteine and cysteine are associated with oxidative damage and metabolic disorders, which may lead to carcinogenesis. Observational studies assessing the association between circulating homocysteine or cysteine and breast cancer are very limited and findings have been inconsistent. We prospectively evaluated plasma levels of homocysteine and cysteine in relation to breast cancer risk among 812 incident cases of invasive breast cancer and 812 individually matched control subjects from 28,345 women in the Women’s Health Study aged ≥45 years who provided blood samples and had no history of cancer or cardiovascular disease at baseline. Logistic regression controlling for matching factors and risk factors for breast cancer was used to estimate relative risks (RRs) and 95% confidence intervals (CIs). All statistical tests were two sided. Homocysteine levels were not associated with overall risk for breast cancer. However, we observed a positive association between cysteine levels and breast cancer risk; the multivariate RR for the highest quintile group relative to the lowest quintile was 1.65 (95% CI=1.04–2.61, p for trend=0.04). In addition, women with higher levels of homocysteine and cysteine were at a greater risk for developing breast cancer when their folate levels were low (p values for interaction were 0.04 and 0.002, respectively). Although our study offers little support for an association between circulating homocysteine and overall breast cancer risk, higher homocysteine levels may be associated with an increased risk for breast cancer among women with low folate status. The increased risk of breast cancer associated with high cysteine levels warrants further investigation.
doi:10.1158/0008-5472.CAN-09-3648
PMCID: PMC2840179  PMID: 20197471
17.  Plasma organochlorine levels and risk of non-Hodgkin lymphoma in a cohort of men 
Epidemiology (Cambridge, Mass.)  2010;21(2):172-180.
Background
Environmental exposure to polychlorinated biphenyls (PCBs) and p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) has been associated with the risk of non-Hodgkin lymphoma.
Methods
We conducted a case-control study nested within the Physicians’ Health Study, a prospective cohort established in 1982. We measured concentrations of PCBs and p,p′-DDE in baseline blood samples from 205 men later diagnosed with non-Hodgkin lymphoma and 409 age- and race-matched controls. Lipid-adjusted organochlorine concentrations were categorized into quintiles based on the distribution among controls. We used conditional logistic regression to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for each quintile relative to the lowest quintile. We also evaluated these associations for major histologic subtypes of non-Hodgkin lymphoma.
Results
The risk of non-Hodgkin lymphoma was positively associated with the sum of 51 PCB congeners assayed (ΣPCB); the group of immunotoxic congeners; the individual congeners 118, 138, 153, and 180; and the sum of these four congeners. The simple OR for the highest quintile of lipid-adjusted ΣPCB versus the lowest was 1.9 (95% CI = 1.1-3.2; test for trend P = 0.001), with similar trends for individual congeners and groups defined as above. Adjustment for height, body mass index, alcohol intake, smoking, and fish intake did not substantially change the effect estimates. No association was observed for p,p′-DDE. There was no evidence of statistical heterogeneity in effects by histologic subtype of lymphoma; however, this analysis was underpowered.
Conclusions
These results support the hypothesis of a positive association between PCB exposure and development of NHL in men.
doi:10.1097/EDE.0b013e3181cb610b
PMCID: PMC2957873  PMID: 20087190
18.  Effect of Vaccination on Bordetella pertussis Strains, China 
Emerging Infectious Diseases  2010;16(11):1695-1701.
Strains in China may differ from those in countries that have long histories of high vaccination coverage.
Whole-cell pertussis vaccine was introduced in China in the early 1960s. We used standard typing methods to compare 96 Bordetella pertussis isolates collected before and after introduction of vaccination, during 1953–2005. The following vaccine-type alleles of the pertussis toxin (ptx) gene were characteristic for all prevaccination strains: ptxA2, ptxA3, and ptxA4. The shift to ptxA1 occurred since 1963. All isolates collected since 1983 contained ptxA1. Pertactin (prn) allele 1, prn1, was predominant, although prn2 and prn3 have been detected since 2000. Serotypes fimbriae (Fim) 2 and Fim2,3 were found in all isolates collected before 1986. During 1997–2005, Fim3 became prevalent. Although changes in electrophoresis profiles over time were observed, the predominant profiles during 1997–2005 resembled those during the prevaccine era and those found in Europe before the 1990s. B. pertussis strains in China may differ from those in countries that have a long history of high vaccine coverage.
doi:10.3201/eid1611.100401
PMCID: PMC3294513  PMID: 21029526
China; Bordetella pertussis; whooping cough; pertussis; incidence; vaccination; genotyping; PFGE; bacteria; research
19.  Intakes of fruit, vegetables, and carotenoids and renal cell cancer risk: a pooled analysis of 13 prospective studies 
Fruit and vegetable consumption has been hypothesized to reduce the risk of renal cell cancer. We conducted a pooled analysis of 13 prospective studies, including 1,478 incident cases of renal cell cancer (709 women and 769 men) among 530,469 women and 244,483 men followed for up to 7 to 20 years. Participants completed a validated food-frequency questionnaire at baseline. Using the primary data from each study, the study-specific relative risks (RRs) were calculated using the Cox proportional hazards model and then pooled using a random effects model. We found that fruit and vegetable consumption was associated with a reduced risk of renal cell cancer. Compared with <200 g/d of fruit and vegetable intake, the pooled multivariate RR for ≥600 g/d was 0.68 (95% CI = 0.54–0.87; P value, test for between-studies heterogeneity = 0.86; P value, test for trend = 0.001). Compared with <100 g/d, the pooled multivariate RRs (95% CIs) for ≥400 g/d were 0.79 (0.63–0.99; P value, test for trend = 0.03) for total fruit, and 0.72 (0.48–1.08; P value, test for trend = 0.07) for total vegetables. For specific carotenoids, the pooled multivariate RRs (95% CIs) comparing the highest and lowest quintiles were 0.87 (0.73–1.03) for α-carotene, 0.82 (0.69–0.98) for β-carotene, 0.86 (0.73–1.01) for β-cryptoxanthin, 0.82 (0.64–1.06) for lutein/zeaxanthin, and 1.13 (0.95–1.34) for lycopene. In conclusion, increasing fruit and vegetable consumption is associated with decreasing risk of renal cell cancer; carotenoids present in fruit and vegetables may partly contribute to this protection.
doi:10.1158/1055-9965.EPI-09-0045
PMCID: PMC2883186  PMID: 19505906
20.  Modulation of lung molecular biomarkers by β-carotene in the Physicians’ Health Study 
Cancer  2009;115(5):1049-1058.
BACKGROUND
β-Carotene supplementation showed neither benefit nor harm among apparently healthy male physicians in the Physicians’ Health Study (PHS) trial. The present investigation was to evaluate how long-term β-carotene supplementation affects molecular markers of lung carcinogenesis in the PHS.
METHODS
The protein levels of total p53, cyclin D1, proliferating cellular nuclear antigen (PCNA), retinoic acid receptor β (RARβ), and cytochrome p450 enzyme 1A1 (CYP1A1) were measured using the immunohistochemical method in the 40 available archival lung tissue samples from patients diagnosed with lung cancer in the PHS. The protein levels of these markers were compared by category of β-carotene treatment assignment and other characteristics using unconditional logistic regression models.
RESULTS
The lung tumor positivity for total p53, RARβ, cyclin D1, and PCNA was nonsignificantly lower among lung cancer patients assigned to β-carotene than those assigned to β-carotene placebo. There was a borderline significant difference in the lung tumor positivity for CYP1A1 with an odds ratio of 0.2 (95% confidence interval, 0.2–1.1; P = 0.06) comparing men received β-carotene with those received β-carotene placebo.
CONCLUSIONS
The 50 mg of β-carotene supplementation on alternate days had no significant influence on molecular markers of lung carcinogenesis that we evaluated in the PHS. This finding provides mechanistic support for the main PHS trial results of β-carotene, which showed no benefit or harm on lung cancer risk.
doi:10.1002/cncr.24061
PMCID: PMC2649969  PMID: 19142877
lung cancer; β-carotene; molecular markers
21.  Vascular endothelial growth factor regulates myeloid cell leukemia-1 expression through neuropilin-1-dependent activation of c-MET signaling in human prostate cancer cells 
Molecular Cancer  2010;9:9.
Background
Myeloid cell leukemia-1 (Mcl-1) is a member of the Bcl-2 family, which inhibits cell apoptosis by sequestering pro-apoptotic proteins Bim and Bid. Mcl-1 overexpression has been associated with progression in leukemia and some solid tumors including prostate cancer (PCa). However, the regulatory mechanism for Mcl-1 expression in PCa cells remains elusive.
Results
Immunohistochemical analyses revealed that Mcl-1 expression was elevated in PCa specimens with high Gleason grades and further significantly increased in bone metastasis, suggesting a pivotal role of Mcl-1 in PCa metastasis. We further found that vascular endothelial growth factor (VEGF) is a novel regulator of Mcl-1 expression in PCa cells. Inhibition of endogenous Mcl-1 induced apoptosis, indicating that Mcl-1 is an important survival factor in PCa cells. Neuropilin-1 (NRP1), the "co-receptor" for VEGF165 isoform, was found to be highly expressed in PCa cells, and indispensible in the regulation of Mcl-1. Intriguingly, VEGF165 promoted physical interaction between NRP1 and hepatocyte growth factor (HGF) receptor c-MET, and facilitated c-MET phosphorylation via a NRP1-dependent mechanism. VEGF165 induction of Mcl-1 may involve rapid activation of Src kinases and signal transducers and activators of transcription 3 (Stat3). Importantly, NRP1 overexpression and c-MET activation were positively associated with progression and bone metastasis in human PCa specimens and xenograft tissues.
Conclusions
This study demonstrated that Mcl-1 overexpression is associated with PCa bone metastasis. Activation of VEGF165-NRP1-c-MET signaling could confer PCa cells survival advantages by up-regulating Mcl-1, contributing to PCa progression.
doi:10.1186/1476-4598-9-9
PMCID: PMC2820018  PMID: 20085644
22.  Production and characterization of recombinant pertactin, fimbriae 2 and fimbriae 3 from Bordetella pertussis 
BMC Microbiology  2009;9:274.
Background
Bordetella pertussis is a causative agent of pertussis or whooping cough in humans. Pertactin (Prn), fimbriae 2 (Fim2) and fimbriae 3 (Fim3) of B. pertussis are important virulence factors and immunogens which have been included in some acellular pertussis vaccines. In this present study, we cloned, expressed and purified Prn, Fim2 and Fim3, respectively. The immunogenicity and protective efficacy of the three recombinant proteins (rPrn, rFim2 and rFim3) were investigated in mouse model.
Results
Three recombinant proteins with amount of 12 to 25 mg/L were produced. Compared to the control mice only immunized with adjuvant, serum IgG antibody responses were significantly induced in the mice immunized with rPrn, rFim2 or rFim3 (P < 0.001 for all three proteins). Furthermore, T cell responses characteristic of increased production of IL-2 and TNF-α (only for rPrn) were elicited in the mice immunized with the three proteins (P < 0.05 for all three proteins). Immunization with rPrn, but not with rFim2 or rFim3, significantly enhanced clearance of bacteria in the lungs of mice after intranasal challenge with B. pertussis (P < 0.05). When tested in a lethal intracerebral infection model, certain protection was observed in mice immunized with rPrn.
Conclusions
We have developed an efficient method to produce large amounts of rPrn, rFim2, and rFim3 from B. pertussis. The three recombinant proteins induced both humoral and cellular immune responses in mice. Immunization with rPrn also conferred protection against pertussis in mouse infection models. Our results indicated that the recombinant proteins still retain their immunological properties and highlighted the potential of the recombinant proteins for the future development of the B. pertussis vaccines.
doi:10.1186/1471-2180-9-274
PMCID: PMC2807877  PMID: 20040101
23.  Fat, Protein, and Meat Consumption and Renal Cell Cancer Risk: A Pooled Analysis of 13 Prospective Studies 
Background
Results of several case–control studies suggest that high consumption of meat (all meat, red meat, or processed meat) is associated with an increased risk of renal cell cancer, but only a few prospective studies have examined the associations of intakes of meat, fat, and protein with renal cell cancer.
Methods
We conducted a pooled analysis of 13 prospective studies that included 530 469 women and 244 483 men and had follow-up times of up to 7–20 years to examine associations between meat, fat, and protein intakes and the risk of renal cell cancer. All participants had completed a validated food frequency questionnaire at study entry. Using the primary data from each study, we calculated the study-specific relative risks (RRs) for renal cell cancer by using Cox proportional hazards models and then pooled these RRs by using a random-effects model. All statistical tests were two-sided.
Results
A total of 1478 incident cases of renal cell cancer were identified (709 in women and 769 in men). We observed statistically significant positive associations or trends in pooled age-adjusted models for intakes of total fat, saturated fat, monounsaturated fat, polyunsaturated fat, cholesterol, total protein, and animal protein. However, these associations were attenuated and no longer statistically significant after adjusting for body mass index, fruit and vegetable intake, and alcohol intake. For example, the pooled age-adjusted RR of renal cell cancer for the highest vs the lowest quintile of intake for total fat was 1.30 (95% confidence interval [CI] = 1.08 to 1.56; Ptrend = .001) and for total protein was 1.17 (95% CI = 0.99 to 1.38; Ptrend = .02). By comparison, the pooled multivariable RR for the highest vs the lowest quintile of total fat intake was 1.10 (95% CI = 0.92 to 1.32; Ptrend = .31) and of total protein intake was 1.06 (95% CI = 0.89 to 1.26; Ptrend = .37). Intakes of red meat, processed meat, poultry, or seafood were not associated with the risk of renal cell cancer.
Conclusions
Intakes of fat and protein or their subtypes, red meat, processed meat, poultry, and seafood are not associated with risk of renal cell cancer.
doi:10.1093/jnci/djn386
PMCID: PMC2727138  PMID: 19033572
24.  Effect of Combined Folic Acid, Vitamin B6, and Vitamin B12 on Cancer Risk: Results from a Randomized Trial 
Context
Folate, vitamin B6, and vitamin B12 are thought to play an important role in cancer prevention.
Objective
To evaluate the effect of combined folic acid, vitamin B6, and vitamin B12 treatment on cancer risk in women at high risk for cardiovascular disease.
Design, Setting, and Participants
In the Women’s Antioxidant and Folic Acid Cardiovascular Study, 5442 US female health professionals aged 42 years or older with preexisting cardiovascular disease or 3 or more coronary risk factors were randomly assigned to receive either a daily combination of folic acid, vitamin B6, and vitamin B12 or placebo in April 1998, and treated through July 31, 2005 for 7.3 years.
Intervention
Daily supplementation of a combination of 2.5 mg of folic acid, 50 mg of vitamin B6, and 1 mg of vitamin B12 (n=2721) or placebo (n=2721).
Main Outcome Measures
Confirmed newly diagnosed total invasive cancer.
Results
A total of 379 women developed invasive cancer (187 in the active group and 192 in the placebo group). Compared with placebo, women receiving combined folic acid, vitamin B6, and vitamin B12 had similar risk of developing total invasive cancer (101.1/10000 person-years vs 104.3/10000 person-years for the active vs placebo group; hazard ratio, 0.97; 95% confidence interval, 0.79–1.18; P=.75), breast cancer (37.8/10000 person-years vs 45.6/10000 person-years; hazard ratio, 0.83; 95% confidence interval, 0.60–1.14; P=.24), and any cancer death (24.6/10000 person-years vs 30.1/10000 person-years; hazard ratio, 0.82; 95% confidence interval, 0.56–1.21; P=.32).
Conclusions
Combined folic acid, vitamin B6, and vitamin B12 treatment had no significant effect on overall risk of total invasive cancer or breast cancer among women during folic acid fortification era.
Trial Registration
clinicaltrials.gov Identifier: NCT00000541
doi:10.1001/jama.2008.555
PMCID: PMC2593624  PMID: 18984888
25.  Caffeine Consumption and Risk of Breast Cancer in a Large Prospective Cohort of Women 
Archives of internal medicine  2008;168(18):2022-2031.
Background
Prospective data relating caffeine consumption to breast cancer risk are limited. We evaluated the association among women enrolled in a completed cancer prevention trial.
Methods
Detailed dietary information was obtained at baseline (1992–1995) among 38,432 women aged ≥45 years and free of cancer. During an average of 10 years of follow-up, we identified 1188 invasive breast cancer cases.
Results
Consumption of caffeine and caffeinated beverages and foods was not statistically significantly associated with overall risk of breast cancer. The multivariable relative risks (RRs) of breast cancer were 1.02 (95% confidence interval [CI], 0.84–1.22) for caffeine (top vs. bottom quintile), 1.08 (95% CI, 0.89–1.30) for coffee (≥4 cups/day vs. almost never), and 1.03 (95% CI, 0.85–1.25) for tea (≥2 cups/day vs. almost never). However, among women with benign breast disease, a borderline significant positive association with breast cancer risk was observed for the highest quintile of caffeine (RR = 1.32; 95% CI, 0.99–1.76) and for the highest category of coffee (≥4 cups/day) (RR = 1.35; 95% CI, 1.01–1.80); tests for interaction were marginally significant. Caffeine consumption was also significantly positively associated with risk of developing ER−PR−breast cancer (RR = 1.68; 95% CI, 1.01–2.81) and breast tumors of >2 cm in size (RR = 1.79; 95% CI, 1.18–2.72).
Conclusions
Data show no overall association between caffeine consumption and breast cancer risk. The possibility of an increased risk among women with benign breast disease or for tumors that are ER−PR− or greater than 2 cm in size warrants further study.
doi:10.1001/archinte.168.18.2022
PMCID: PMC2574428  PMID: 18852405

Results 1-25 (29)