Flavonoids have been shown to inhibit colon cancer cell proliferation in vitro and protect against colorectal carcinogenesis in animal models. However, epidemiological evidence on the potential role of flavonoid intake in colorectal cancer (CRC) development remains sparse and inconsistent. We evaluated the association between dietary intakes of total flavonoids and their subclasses and risk of development of CRC, within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. A cohort of 477,312 adult men and women were recruited in 10 European countries. At baseline, dietary intakes of total flavonoids and individual subclasses were estimated using centre-specific validated dietary questionnaires and composition data from the Phenol-Explorer database. During an average of 11 years of follow-up, 4,517 new cases of primary CRC were identified, of which 2,869 were colon (proximal = 1,298 and distal = 1,266) and 1,648 rectal tumours. No association was found between total flavonoid intake and the risk of overall CRC (HR for comparison of extreme quintiles 1.05, 95% CI 0.93-1.18; p-trend = 0.58) or any CRC subtype. No association was also observed with any intake of individual flavonoid subclasses. Similar results were observed for flavonoid intake expressed as glycosides or aglycone equivalents. Intake of total flavonoids and flavonoid subclasses, as estimated from dietary questionnaires, did not show any association with risk of CRC development.
Recent studies from high-risk countries such as the US, Denmark and Ireland have shown rising incidence rates of hormone receptor (HR)-positive and falling rates of HR-negative breast cancers (BC). However, it remains unclear whether a similar pattern occurs in low-risk countries. Detailed clinical and risk factor data were collected from 2,977 female invasive BC patients (≥20 years) in Sarawak General Hospital, Malaysia, representing 93% of the population. The population-at-risk was obtained from the Department of Statistics Malaysia. Secular trends in age-standardized incidence rates were assessed using estimated average annual percent changes. Associations between established BC risk factors and tumor subtypes defined by HR or joint human epidermal growth factor receptor 2 (HR/HER2) status were examined by case-case comparisons using logistic regression. From 2006 to 2015, incidence rates increased for HR-positive cancers by 4.46%/year (95% CI = 2.19-6.78) and decreased for HR-negative cancers by 2.29%/year (95% CI = -4.31 to -0.24). When further stratified by HER2, the most contrasting difference in linear trends was observed between HR+/HER2- and HR-/HER2- subtypes. After controlling for potential confounders, cases with excess body weight (ORoverweight vs. normal = 0.82; 95% CI = 0.69-0.98; ORobese vs. normal = 0.62; 95% CI = 0.48-0.80), later age at first birth (OR≥26 years vs. <23 years = 0.82; 95% CI = 0.66-1.02), nulliparity (ORnulliparous vs. <23 years = 0.74; 95% CI = 0.59-0.94) and never-breastfeeding (ORnever vs. ever = 0.73; 95% CI = 0.55-0.97) were less frequent among HR-negative cases than among HR-positive cases. Diverging incidence trends by HR expression were similar in Sarawak and Western countries, possibly reflecting changes in the prevalence of risk factors with opposing effects by tumor subtypes in low- and high-risk populations.
Pancreatic ductal adenocarcinoma (PDAC) is a very aggressive tumor with a five-year survival of less than 6%. Chronic pancreatitis (CP), an inflammatory process in of the pancreas, is a strong risk factor for PDAC. Several genetic polymorphisms have been discovered as susceptibility loci for both CP and PDAC. Since CP and PDAC share a consistent number of epidemiologic risk factors, the aim of this study was to investigate whether specific CP risk loci also contribute to PDAC susceptibility. We selected five common SNPs (rs11988997, rs379742, rs10273639, rs2995271 and rs12688220) that were identified as susceptibility markers for CP and analyzed them in 2,914 PDAC cases, 356 CP cases and 5,596 controls retrospectively collected in the context of the international PANDoRA consortium. We found a weak association between the minor allele of the PRSS1-PRSS2-rs10273639 and an increased risk of developing PDAC (ORhomozygous = 1.19, 95% CI 1.02-1.38, p = 0.023). Additionally all the SNPs confirmed statistically significant associations with risk of developing CP, the strongest being PRSS1-PRSS2-rs10273639 (ORheterozygous = 0.51, 95% CI 0.39-0.67, p = 1.10 × 10-6 ) and MORC4-rs 12837024 (ORhomozygous = 2.07 (1.55-2.77, ptrend = 0.7 × 10-11 ). Taken together, the results from our study do not support variants rs11988997, rs379742, rs10273639, rs2995271 and rs12688220 as strong predictors of PDAC risk, but further support the role of these SNPs in CP susceptibility. Our study suggests that CP and PDAC probably do not share genetic susceptibility, at least in terms of high frequency variants.
Isolation of single cells permits analysis of DNA or RNA from individual cells among heterogeneous populations. This technique is particularly useful in the study of classical Hodgkin's lymphoma (cHL) due to the scarcity of H/RS tumor cells among large numbers of reactive leukocytes. In a previous study, we found a high frequency of dual LMP-1 variant (concurrent presence of deleted and nondeleted variants) in cHL from whole-tissue sections. For the present study, we applied a single-cell isolation technique to determine the LMP-1 oncogene variant in EBV-associated H/RS cells. Five cases of EBV-infected cHL, containing nondeleted (n=1), deleted (n=1) and dual infection (n=3) based on whole-tissue section analysis, were selected for study. Paraffin-embedded tissue sections were stained with antibody to LMP-1 and positively stained H/RS cells isolated using a semiautomated micromanipulator. Each isolated single cell was subjected to PCR for amplification of the LMP-1 gene flanking the 30 bp deletion region and Xho1 restriction site. Cases with either nondeleted variant or the deleted variant showed similar LMP-1 variant expression in isolated single H/RS cells. However, 1 of the 3 cases with dual variants showed only the deleted variant in H/RS cells. The other 2 cases showed mixed patterns of deleted, nondeleted and dual LMP-1 variants in isolated single H/RS cells. All cases showed loss of the Xho1 restriction site, with the exception of the case with nondeleted LMP-1. Results of single-H/RS cell analysis of the Xho1 restriction site concur with those of whole-tissue section amplification. A mixed pattern of LMP-1 variants was observed in isolated H/RS cells, and it is speculated that this is due to the accumulation of mutation and deletion events.
Oestrogen is important in the development of breast cancer. Oestrogen receptor positive breast cancers are associated with a better prognosis than oestrogen-receptor negative breast cancers since they are more responsive to hormonal treatment. Oestrone sulphate acts as a huge reservoir for oestrogens in the breast. It is converted to the potent oestrogen, oestradiol (E(2)) by the enzymes oestrone sulphatase and oestradiol-17beta hydroxysteroid dehydrogenase (E(2)DH). Retinoic acid and carotenoids have been shown to have chemopreventive activity against some cancers. The aim of our study was to determine and compare the effects of retinoic acid and palm oil carotenoids on growth of and oestrone sulphatase and E(2)DH activities in the oestrogen receptor positive, MCF-7 and oestrogen receptor negative, MDA-MB-231 breast cancer cell lines. Retinoic acid and carotenoids inhibited MCF-7 cell growth but had no effect on MDA-MB-231 cell growth. Both retinoic acid and carotenoids stimulated oestrone sulphatase activity in the MCF-7 cell line. E(1) to E(2) conversion was inhibited by 10(-7) M carotenoids but was stimulated at 10(-6) M in the MCF-7 cell line. Retinoic acid had no effect on E(1) to E(2) conversion at 10(-7) M but stimulated E(1) to E(2) conversion at 10(-6) M. Retinoic acid and carotenoids had no effect on E(2) to E(1) conversion in the MCF-7 cell line. Retinoic acid stimulated E(1) to E(2) conversion in the MDA-MB-231 cell line but had no effect on oestrone sulphatase activity or E(2) to E(1) conversion in this cell line. Both oestrone sulphatase and E(2)DH activity were not affected by carotenoids in the MDA-MB-231 cell line. In conclusion, retinoic acid and carotenoids may prevent the development of hormone-dependent breast cancers since they inhibit the growth of the MCF-7 cell line.
Endometrial cancer risk prediction models including lifestyle, anthropometric and reproductive factors have limited discrimination. Adding biomarker data to these models may improve predictive capacity; to our knowledge, this has not been investigated for endometrial cancer. Using a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, we investigated the improvement in discrimination gained by adding serum biomarker concentrations to risk estimates derived from an existing risk prediction model based on epidemiologic factors. Serum concentrations of sex steroid hormones, metabolic markers, growth factors, adipokines and cytokines were evaluated in a step-wise backward selection process; biomarkers were retained at p
Incidence rates of differentiated thyroid carcinoma (TC) have increased in many countries. Adiposity and dietary risk factors may play a role, but little is known on the influence of energy intake and macronutrient composition. The aim of this study was to investigate the associations between TC and the intake of energy, macronutrients, glycemic index (GI) and glycemic load in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. The study included 477,274 middle-age participants (70.2% women) from ten European countries. Dietary data were collected using country-specific validated dietary questionnaires. Total carbohydrates, proteins, fats, saturated, monounsaturated and polyunsaturated fats (PUFA), starch, sugar, and fiber were computed as g/1,000 kcal. Multivariable Cox regression was used to calculate multivariable adjusted hazard ratios (HR) and 95% confidence interval (CI) by intake quartile (Q). After a mean follow-up time of 11 years, differentiated TC was diagnosed in 556 participants (90% women). Overall, we found significant associations only with total energy (HRQ4 vs .Q1 , 1.29; 95% CI, 1.00-1.68) and PUFA intakes (HRQ4 vs .Q1 , 0.74; 95% CI, 0.57-0.95). However, the associations with starch and sugar intake and GI were significantly heterogeneous across body mass index (BMI) groups, i.e., positive associations with starch and GI were found in participants with a BMI ≥ 25 and with sugar intake in those with BMI
Epstein-Barr virus (EBV) type B, a less potent transformer of B lymphocytes than type A, has rarely been detected in EBV-associated neoplasms except in AIDS-related lymphomas, in which about 50% of the cases contained this sub-type. In this study we analyzed the association of EBV and the distribution of virus sub-types in Asian non-Hodgkin's lymphoma (NHL) of the upper aerodigestive tract. We studied archival material of 29 NHL cases from Malaysia. B- and T-cell associated antigens were demonstrated by immunohistochemistry, and EBV early RNA EBER-1 was demonstrated using the RNA in situ hybridization technique. EBV was detected in the majority of tumour cells in 11/13 T-NHL but in only 1/16 B-NHL. EBV was sub-typed by single-step polymerase chain reaction of the EBNA-2 gene. This was successful in 9/10 cases of EBER-1-positive tumours and all contained type-A virus only. Our results showed a preponderance of T-cell lymphoma of the upper aerodigestive tract in the ethnic Chinese group of Malaysian patients, and EBV was strongly associated with T-NHL but not with B-NHL. Our results suggest that type-A EBV is the prevalent sub-type in Asian NHL of the upper aerodigestive tract, similarly to findings in Asian nasopharyngeal carcinoma.
Evidence suggests an influence of sex hormones on cutaneous melanoma risk, but epidemiologic findings are conflicting. We examined the associations between use of oral contraceptives (OCs) and menopausal hormone therapy (MHT) and melanoma risk in women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). EPIC is a prospective cohort study initiated in 1992 in 10 European countries. Information on exogenous hormone use at baseline was derived from country-specific self-administered questionnaires. We used Cox proportional hazards regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Over 1992-2015, 1,696 melanoma cases were identified among 334,483 women, whereof 770 cases among 134,758 postmenopausal women. There was a positive, borderline-significant association between OC use and melanoma risk (HR = 1.12, 95% CI = 1.00-1.26), with no detected heterogeneity across countries (phomogeneity = 0.42). This risk increased linearly with duration of use (ptrend = 0.01). Among postmenopausal women, ever use of MHT was associated with a nonsignificant increase in melanoma risk overall (HR = 1.14, 95% CI = 0.97-1.43), which was heterogeneous across countries (phomogeneity = 0.05). Our findings do not support a strong and direct association between exogenous hormone use and melanoma risk. In order to better understand these relations, further research should be performed using prospectively collected data including detailed information on types of hormone, and on sun exposure, which may act as an important confounder or effect modifier on these relations.
Expression of the Epstein-Barr virus (EBV) encoded nuclear antigens (EBNA 1 to 6) and membrane-associated protein (LMP) was investigated by immunoblotting in 83 nasopharyngeal carcinoma (NPC) biopsies and 25 other tumor and normal tissue specimens from the head and neck region. Fifty-eight of the 83 NPC biopsies were large enough to yield parallel data on virus DNA and viral expression. All 16 cases of clinically diagnosed and histologically confirmed NPCs from North Africa contained EBV DNA and expressed EBNA-1. Of 31 clinically diagnosed NPCs from China, 29 contained EBV DNA and 25 of these expressed EBNA-1. One control tissue biopsy from the oropharynx of NPC patients contained EBV DNA, but none expressed EBNA-1. The latent membrane protein (LMP) was detected in 22/31 of the Chinese and in 10/16 of the North African NPC biopsies. None of the NPC biopsies or control tissues expressed detectable amounts of EBNA 2 or any of the other 4 nuclear antigens which are invariably expressed in EBV-transformed B cells. A smaller number of tumors from Malaysia and East Africa exhibited a similar pattern of expression. EBV was rescued from a nude-mouse-passaged North African NPC tumor by co-cultivation of the tumor cells with umbilical cord blood lymphocytes. The tumor expressed EBNA 1 and LMP, but not EBNA 2 or the other 4 EBNAs. The resulting LCLs expressed all 6 nuclear antigens, EBNA 1 to 6 and LMP. Our data suggest that expression of the EBV genome is regulated in a tissue-specific fashion.
Alcohol intake has been related to an increased risk of breast cancer (BC) while dietary fiber intake has been inversely associated to BC risk. A beneficial effect of fibers on ethanol carcinogenesis through their impact on estrogen levels is still controversial. We investigated the role of dietary fiber as a modifying factor of the association of alcohol and BC using data from the European Prospective Investigation into Cancer and Nutrition (EPIC). This study included 334,850 women aged 35-70 years at baseline enrolled in the ten countries of the EPIC study and followed up for 11.0 years on average. Information on fiber and alcohol intake at baseline and average lifetime alcohol intake were calculated from country-specific dietary and lifestyle questionnaires. Hazard ratios (HR) of developing invasive BC according to different levels of alcohol and fiber intake were computed. During 3,670,439 person-years, 11,576 incident BC cases were diagnosed. For subjects with low intake of fiber (<18.5 g/day), the risk of BC per 10 g/day of alcohol intake was 1.06 (1.03-1.08) while among subjects with high intake of fiber (>24.2 g/day) the risk of BC was 1.02 (0.99-1.05) (test for interaction p = 0.011). This modulating effect was stronger for fiber from vegetables. Our results suggest that fiber intake may modulate the positive association of alcohol intake and BC. Alcohol is well known to increase the risk for BC, while a fiber-rich diet has the opposite effect. Here the authors find a significant interaction between both lifestyle factors indicating that high fiber intake can ease the adverse effects associated with alcohol consumption. Consequently, women with high alcohol intake and low fiber intake (<18.5 g/day) had the highest risk for BC. Specific benefits were associated with fibers from vegetable, warranting further investigations into specific fiber sources and their mechanistic interactions with alcohol-induced BC risk.
Previous genome-wide association studies among women of European ancestry identified two independent breast cancer susceptibility loci represented by single nucleotide polymorphisms (SNPs) rs13281615 and rs11780156 at 8q24. A fine-mapping study across 2.06 Mb (chr8:127,561,724-129,624,067, hg19) in 55,540 breast cancer cases and 51,168 controls within the Breast Cancer Association Consortium was conducted. Three additional independent association signals in women of European ancestry, represented by rs35961416 (OR = 0.95, 95% CI = 0.93-0.97, conditional p = 5.8 × 10(-6) ), rs7815245 (OR = 0.94, 95% CI = 0.91-0.96, conditional p = 1.1 × 10(-6) ) and rs2033101 (OR = 1.05, 95% CI = 1.02-1.07, conditional p = 1.1 × 10(-4) ) were found. Integrative analysis using functional genomic data from the Roadmap Epigenomics, the Encyclopedia of DNA Elements project, the Cancer Genome Atlas and other public resources implied that SNPs rs7815245 in Signal 3, and rs1121948 in Signal 5 (in linkage disequilibrium with rs11780156, r(2) = 0.77), were putatively functional variants for two of the five independent association signals. The results highlighted multiple 8q24 variants associated with breast cancer susceptibility in women of European ancestry.
Despite the potential cancer preventive effects of flavonoids and lignans, their ability to reduce pancreatic cancer risk has not been demonstrated in epidemiological studies. Our aim was to examine the association between dietary intakes of flavonoids and lignans and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. A total of 865 exocrine pancreatic cancer cases occurred after 11.3 years of follow-up of 477,309 cohort members. Dietary flavonoid and lignan intake was estimated through validated dietary questionnaires and the US Department of Agriculture (USDA) and Phenol Explorer databases. Hazard ratios (HR) and 95% confidence intervals (CIs) were calculated using age, sex and center-stratified Cox proportional hazards models, adjusted for energy intake, body mass index (BMI), smoking, alcohol and diabetes status. Our results showed that neither overall dietary intake of flavonoids nor of lignans were associated with pancreatic cancer risk (multivariable-adjusted HR for a doubling of intake = 1.03, 95% CI: 0.95-1.11 and 1.02; 95% CI: 0.89-1.17, respectively). Statistically significant associations were also not observed by flavonoid subclasses. An inverse association between intake of flavanones and pancreatic cancer risk was apparent, without reaching statistical significance, in microscopically confirmed cases (HR for a doubling of intake = 0.96, 95% CI: 0.91-1.00). In conclusion, we did not observe an association between intake of flavonoids, flavonoid subclasses or lignans and pancreatic cancer risk in the EPIC cohort.
Several dietary factors have been studied in relation to prostate cancer; however, most studies have not reported on subtypes of fruit and vegetables or tumor characteristics, and results obtained so far are inconclusive. This study aimed to examine the prospective association of total and subtypes of fruit and vegetable intake with the incidence of prostate cancer overall, by grade and stage of disease, and prostate cancer death. Lifestyle information for 142,239 men participating in the European Prospective Investigation into Cancer and Nutrition from 8 European countries was collected at baseline. Multivariable Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). After an average follow-up time of 13.9 years, 7,036 prostate cancer cases were identified. Compared with the lowest fifth, those in the highest fifth of total fruit intake had a significantly reduced prostate cancer risk (HR = 0.91; 95% CI = 0.83-0.99; p-trend = 0.01). No associations between fruit subtypes and prostate cancer risk were observed, except for citrus fruits, where a significant trend was found (HR = 0.94; 95% CI = 0.86-1.02; p-trend = 0.01). No associations between total and subtypes of vegetables and prostate cancer risk were observed. We found no evidence of heterogeneity in these associations by tumor grade and stage, with the exception of significant heterogeneity by tumor grade (pheterogeneity <0.001) for leafy vegetables. No significant associations with prostate cancer death were observed. The main finding of this prospective study was that a higher fruit intake was associated with a small reduction in prostate cancer risk. Whether this association is causal remains unclear.
While the association between fruit consumption and bladder cancer risk has been extensively reported, studies have had inadequate statistical power to investigate associations between types of fruit and bladder cancer risk satisfactorily. Fruit consumption in relation to bladder cancer risk was investigated by pooling individual data from 13 cohort studies. Cox regression models with attained age as time scale were used to estimate hazard ratios (HRs) for intakes of total fruit and citrus fruits, soft fruits, stone fruits, tropical fruits, pome fruits and fruit products. Analyses were stratified by sex, smoking status and bladder cancer subtype. During on average 11.2 years of follow-up, 2836 individuals developed incident bladder cancer. Increasing fruit consumption (by 100 g/day) was inversely associated with the risk of bladder cancer in women (HR = 0.92; 95% CI 0.85-0.99). Although in women the association with fruit consumption was most evident for higher-risk nonmuscle invasive bladder cancer (NMIBC; HR = 0.72; 95% CI 0.56-0.92), the test for heterogeneity by bladder cancer subtype was nonsignificant (P-heterogeneity = .14). Increasing fruit consumption (by 100 g/day) was not associated with bladder cancer risk in men (HR = 0.99; 95% CI 0.94-1.03), never smokers (HR = 0.96; 95% CI 0.88-1.05), former smokers (HR = 0.98; 95% CI 0.92-1.05) or current smokers (HR = 0.95; 95% CI 0.89-1.01). The consumption of any type of fruit was not found to be associated with bladder cancer risk (P values > .05). Our study supports no evidence that the consumption of specific types of fruit reduces the risk of bladder cancer. However, increasing total fruit consumption may reduce bladder cancer risk in women.
Gallstones, a common gastrointestinal condition, can lead to several digestive complications and can result in inflammation. Risk factors for gallstones include obesity, diabetes, smoking and physical inactivity, all of which are known risk factors for colorectal cancer (CRC), as is inflammation. However, it is unclear whether gallstones are a risk factor for CRC. We examined the association between history of gallstones and CRC in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, a prospective cohort of over half a million participants from ten European countries. History of gallstones was assessed at baseline using a self-reported questionnaire. The analytic cohort included 334,986 participants; a history of gallstones was reported by 3,917 men and 19,836 women, and incident CRC was diagnosed among 1,832 men and 2,178 women (mean follow-up: 13.6 years). Hazard ratios (HR) and 95% confidence intervals (CI) for the association between gallstones and CRC were estimated using Cox proportional hazards regression models, stratified by sex, study centre and age at recruitment. The models were adjusted for body mass index, diabetes, alcohol intake and physical activity. A positive, marginally significant association was detected between gallstones and CRC among women in multivariable analyses (HR = 1.14, 95%CI 0.99-1.31, p = 0.077). The relationship between gallstones and CRC among men was inverse but not significant (HR = 0.81, 95%CI 0.63-1.04, p = 0.10). Additional adjustment for details of reproductive history or waist circumference yielded minimal changes to the observed associations. Further research is required to confirm the nature of the association between gallstones and CRC by sex.
General obesity, as reflected by BMI, is an established risk factor for esophageal adenocarcinoma (EAC), a suspected risk factor for gastric cardia adenocarcinoma (GCC) and appears unrelated to gastric non-cardia adenocarcinoma (GNCC). How abdominal obesity, as commonly measured by waist circumference (WC), relates to these cancers remains largely unexplored. Using measured anthropometric data from 391,456 individuals from the European Prospective Investigation into Cancer and Nutrition (EPIC) study and 11 years of follow-up, we comprehensively assessed the association of anthropometric measures with risk of EAC, GCC and GNCC using multivariable proportional hazards regression. One hundred twenty-four incident EAC, 193 GCC and 224 GNCC were accrued. After mutual adjustment, BMI was unrelated to EAC, while WC showed a strong positive association (highest vs. lowest quintile HR = 1.19; 95% CI, 0.63-2.22 and HR = 3.76; 1.72-8.22, respectively). Hip circumference (HC) was inversely related to EAC after controlling for WC, while WC remained positively associated (HR = 0.35; 0.18-0.68, and HR=4.10; 1.94-8.63, respectively). BMI was not associated with GCC or GNCC. WC was related to higher risks of GCC after adjustment for BMI and more strongly after adjustment for HC (highest vs. lowest quintile HR = 1.91; 1.09-3.37, and HR = 2.23; 1.28-3.90, respectively). Our study demonstrates that abdominal, rather than general, obesity is an indisputable risk factor for EAC and also provides evidence for a protective effect of gluteofemoral (subcutaneous) adipose tissue in EAC. Our study further shows that general obesity is not a risk factor for GCC and GNCC, while the role of abdominal obesity in GCC needs further investigation.
A panel of monoclonal antibodies specific to Hong Kong Chinese nasopharyngeal carcinoma (NPC)-associated Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) variants has been generated. These monoclonal antibodies not only differentiate the Hong Kong Chinese NPC-associated LMP1 variants from the prototype B95-8 LMP1, derived from Caucasian infectious mononucleosis, but also differentiate the 2 highly homologous LMP1 deletion variants commonly found in Hong Kong primary NPC. The predominant deletion type variant, DV-Asp335, is characterized by an aspartic acid at residue 335 located in the cytoplasmic C-terminal region, whereas the other minor deletion variant, DV-Gly335, has a glycine in the same residue position. 335D is hitherto found predominantly in LMP1 of the China 1 strain in association with NPC in the Chinese populations located in southern China and Malaysia. These antibodies, which are applicable in ELISA, immunofluorescence, immunoprecipitation, immunoblotting and immunohistochemistry on paraffin sections, are the first variant-specific anti-LMP1 monoclonal antibodies produced, and will be useful in investigating the functional significance of 335D in NPC.
Telomere deregulation is a hallmark of cancer. Telomere length measured in lymphocytes (LTL) has been shown to be a risk marker for several cancers. For pancreatic ductal adenocarcinoma (PDAC) consensus is lacking whether risk is associated with long or short telomeres. Mendelian randomization approaches have shown that a score built from SNPs associated with LTL could be used as a robust risk marker. We explored this approach in a large scale study within the PANcreatic Disease ReseArch (PANDoRA) consortium. We analyzed 10 SNPs (ZNF676-rs409627, TERT-rs2736100, CTC1-rs3027234, DHX35-rs6028466, PXK-rs6772228, NAF1-rs7675998, ZNF208-rs8105767, OBFC1-rs9420907, ACYP2-rs11125529 and TERC-rs10936599) alone and combined in a LTL genetic score ("teloscore", which explains 2.2% of the telomere variability) in relation to PDAC risk in 2,374 cases and 4,326 controls. We identified several associations with PDAC risk, among which the strongest were with the TERT-rs2736100 SNP (OR = 1.54; 95%CI 1.35-1.76; p = 1.54 × 10-10 ) and a novel one with the NAF1-rs7675998 SNP (OR = 0.80; 95%CI 0.73-0.88; p = 1.87 × 10-6 , ptrend = 3.27 × 10-7 ). The association of short LTL, measured by the teloscore, with PDAC risk reached genome-wide significance (p = 2.98 × 10-9 for highest vs. lowest quintile; p = 1.82 × 10-10 as a continuous variable). In conclusion, we present a novel genome-wide candidate SNP for PDAC risk (TERT-rs2736100), a completely new signal (NAF1-rs7675998) approaching genome-wide significance and we report a strong association between the teloscore and risk of pancreatic cancer, suggesting that telomeres are a potential risk factor for pancreatic cancer.
A 30-kb deletion that eliminates the coding region of APOBEC3B (A3B) is >5 times more common in women of Asian descent compared to European descent. This polymorphism creates a chimera with the APOBEC3A (A3A) coding region and A3B 3'UTR, and it is associated with an increased risk for breast cancer in Asian women. Here, we explored the relationship between the A3B deletion polymorphism with tumour characteristics in Asian women. Using whole exome and whole transcriptome sequencing data of 527 breast tumours, we report that germline A3B deletion polymorphism leads to expression of the A3A-B hybrid isoform and increased APOBEC-associated somatic hypermutation. Hypermutated tumours, regardless of A3B germline status, were associated with the Her2 molecular subtype and PIK3CA mutations. Compared to nonhypermutated tumours, hypermutated tumours also had higher neoantigen burden, tumour heterogeneity and immune activation. Taken together, our results suggest that the germline A3B deletion polymorphism, via the A3A-B hybrid isoform, contributes to APOBEC mutagenesis in a significant proportion of Asian breast cancers. In addition, APOBEC somatic hypermutation, regardless of A3B background, may be an important clinical biomarker for Asian breast cancers.