Diet, genetic susceptibility and human cancer etiology

Epidemiology, risk areas and macro determinants of gastric cancer: a study based on geospatial analysis

BACKGROUND

Both incidence and mortality of gastric cancer in Gansu rank first in china, this study aimed to describe the recent prevalence of gastric cancer and explore the social and environmental determinants of gastric cancer in Gansu Province.

METHODS

The incidence of gastric cancer in each city of Gansu Province was calculated by utilizing clinical data from patients with gastric cancer (2013-2021) sourced from the medical big data platform of the Gansu Province Health Commission, and demographic data provided by the Gansu Province Bureau of Statistics. Subsequently, we conducted joinpoint regression analysis, spatial auto-correlation analysis, space-time scanning analysis, as well as an exploration into the correlation between social and environmental factors and GC incidence in Gansu Province with Joinpoint_5.0, ArcGIS_10.8, GeoDa, SaTScanTM_10.1.1 and GeoDetector_2018.

RESULTS

A total of 75,522 cases of gastric cancer were included in this study. Our findings suggested a significant upward trend in the incidence of gastric cancer over the past nine years. Notably, Wuwei, Zhangye and Jinchang had the highest incidence rates while Longnan, Qingyang and Jiayuguan had the lowest. In spatial analysis, we have identified significant high-high cluster areas and delineated two high-risk regions as well as one low-risk region for gastric cancer in Gansu. Furthermore, our findings suggested that several social and environmental determinants such as medical resource allocation, regional economic development and climate conditions exerted significant influence on the incidence of gastric cancer.

CONCLUSIONS

Gastric cancer remains an enormous threat to people in Gansu Province, the significant risk areas, social and environmental determinants were observed in this study, which may improve our understanding of gastric cancer epidemiology and help guide public health interventions in Gansu Province.

Bioactive Compounds and Metabolites from Grapes and Red Wine in Breast Cancer Chemoprevention and Therapy

Phytochemicals and their metabolites are not considered essential nutrients in humans, although an increasing number of well-conducted studies are linking their higher intake with a lower incidence of non-communicable diseases, including cancer. This review summarizes the current findings concerning the molecular mechanisms of bioactive compounds from grapes and red wine and their metabolites on breast cancer-the most commonly occurring cancer in women-chemoprevention and treatment. Flavonoid compounds like flavonols, monomeric catechins, proanthocyanidins, anthocyanins, anthocyanidins and non-flavonoid phenolic compounds, such as resveratrol, as well as their metabolites, are discussed with respect to structure and metabolism/bioavailability. In addition, a broad discussion regarding in vitro, in vivo and clinical trials about the chemoprevention and therapy using these molecules is presented.

Effects of Dietary Protein from Different Sources on Biotransformation, Antioxidation, and Inflammation in the Rat Liver

In this work, the effects of different sources of meat protein on liver metabolic enzymes were investigated. Rats were fed for 90 days with semisynthetic diets in which casein was fully replaced by isolated soybean, fish, chicken, pork, or beef proteins. Then, liver proteomics was performed using iTRAQ and LC-ESI-MS/MS. The results indicated that intake of meat protein diets significantly reduced the protein levels of CYP450s, GSTs, UGTs, and SULTs compared to those of the casein and soybean protein diet groups. The total antioxidant capacity and lipid peroxidation values did not differ between four meat protein diet groups and the casein diet group. However, GSH activity in the fish, chicken, and beef protein groups was significantly higher than those of the casein and soybean protein groups. The beef protein diet significantly upregulated the expression of immune-related proteins. The Keap1-Nrf2-ARE signaling pathway was suggested to involve the diet-mediated regulation of biotransformation, inflammation, and redox status.

Purple grape juice supplementation in smokers and antioxidant status according to different types of GST polymorphisms

DNA damages and antioxidant status was assessed after 8 weeks of purple grape juice supplementation in male smokers depending on the glutathione S-transferase polymorphisms. Ninety-five smokers consumed 480 ml of purple grape juice for 8 weeks. The blood samples were collected before and after supplementation to measure lymphocyte DNA damages, plasma antioxidants, conjugated diene, and the erythrocyte antioxidant enzymes. The diastolic pressure, lymphocyte DNA damage, and plasma conjugated diene were significantly decreased but the plasma γ-tocopherol was increased in GSTM1-null genotype, while increased blood glutathione and decreased lymphocyte DNA damage were observed in GSTM1-present genotype. In case of GSTT1 on the other hand, the decrease in diastolic pressure and lymphocyte DNA damage was observed in both null types and present types, but the erythrocyte catalase activity was decreased in GSTT1-null type and the plasma vitamin C level was increased in GSTT1-present type, suggesting that, the antioxidant effect of grape juice was greater in GSTT1-present type compared to GSTT1-null type. The intakes of 8-week purple grape juice affected diastolic blood pressures, DNA damage reductions and antioxidant status in smokers, mainly greater in GSTM1-null type and GSTT1-present type.

Purple grape juice supplementation in smokers and antioxidant status according to different types of GST polymorphisms

DNA damages and antioxidant status was assessed after 8 weeks of purple grape juice supplementation in male smokers depending on the glutathione S-transferase polymorphisms. Ninety-five smokers consumed 480 ml of purple grape juice for 8 weeks. The blood samples were collected before and after supplementation to measure lymphocyte DNA damages, plasma antioxidants, conjugated diene, and the erythrocyte antioxidant enzymes. The diastolic pressure, lymphocyte DNA damage, and plasma conjugated diene were significantly decreased but the plasma γ-tocopherol was increased in GSTM1-null genotype, while increased blood glutathione and decreased lymphocyte DNA damage were observed in GSTM1-present genotype. In case of GSTT1 on the other hand, the decrease in diastolic pressure and lymphocyte DNA damage was observed in both null types and present types, but the erythrocyte catalase activity was decreased in GSTT1-null type and the plasma vitamin C level was increased in GSTT1-present type, suggesting that, the antioxidant effect of grape juice was greater in GSTT1-present type compared to GSTT1-null type. The intakes of 8-week purple grape juice affected diastolic blood pressures, DNA damage reductions and antioxidant status in smokers, mainly greater in GSTM1-null type and GSTT1-present type.

Polymorphisms in xenobiotic metabolizing genes, intakes of heterocyclic amines and red meat, and postmenopausal breast cancer

Heterocyclic amines (HCAs) are mutagenic compounds generated when meats are cooked at high temperature and for long duration. The findings from previous studies on the relation between HCAs and breast cancer are inconsistent, possibly because of genetic variations in the enzymes metabolizing HCAs. To evaluate whether the associations of intakes of estimated HCAs, meat-derived mutagenicity (MDM), and red meat with risk of postmenopausal breast cancer were modified by N-acetyltransferase 2 (NAT2) acetylator genotype or cytochrome P450 1A2-164 A/C (CYP1A2) polymorphism, we conducted a nested case-control study with 579 cases and 981 controls within a prospective cohort, the Nurses' Health Study. HCAs and MDM intakes were derived using a cooking method questionnaire administered in 1996. NAT2acetylator genotype, the CYP1A2 polymorphism, and intakes of HCAs, MDM, and red meat were not associated with risk of postmenopausal breast cancer. There was also no interaction between NAT2 acetylator genotype or CYP1A2 polymorphism and HCAs and MDM and red meat intake in relation to breast cancer. These results do not support the hypothesis that genetic polymorphisms of xenobiotic enzymes involved in the metabolism of HCAs may modify the associations between intakes of red meat or meat-related mutagens and breast cancer risk.

Antioxidant defense markers modulated by glutathione S-transferase genetic polymorphism: results of lung cancer case-control study

Oxidative stress and xenobiotic metabolizing enzymes are suspected to be related to carcinogenesis by different cellular mechanisms. Hence, our study aimed at identifying potential relationships between antioxidant defense parameters measured in blood and glutathione S-transferase (GST) genetic polymorphisms of four GST izoenzymes in lung cancer patients and reference individuals. The case-control study included 404 lung cancer patients and 410 non-cancer subjects as controls, matched by age, gender and place of living (central Poland). In control subjects with GSTM3*A/*A, GSTT1 null, GSTM1 null + GSTT1 null, GSTM3*A/*A + GSTT1 null genotype, glutathione peroxidase activity was significantly higher (P < 0.05) than in controls possessing respective potential protective GST genotypes. Controls with GSTM3*A/*A + GSTP1*B genotype presented significantly higher ceruloplasmin activity (P < 0.05) than GSTM3*B + GSTP1*A/*A carriers. Zinc level was significantly higher (P < 0.05) in controls and cases with GSTP1*B + GSTT1 null genotype and in cases with GSTM1 null + GSTP1*B genotype, when compared with respective potential protective GST genotypes. This case-control study indicates that particular defective GST genotypes may enhance the defense against oxidative stress. The potential relationship between the investigated antioxidative enzymes and microelements, and common functional genetic polymorphism of GST was observed mostly in control subjects.

Resveratrol and breast cancer chemoprevention: molecular mechanisms

Despite years of intensive research, breast cancer remains a major cause of death among women. New strategies to combat breast cancer are being developed, one of the most exciting of which is the use of chemopreventive agents. Resveratrol (RES) is a polyphenolic compound found in plants that seems to have a wide spectrum of biological activity. RES has been shown to afford protection against several types of cancer. This review summarizes the chemopreventive effects of RES at the three major stages of breast carcinogenesis: initiation, promotion, and progression. It has anti-oxidant and anti-inflammatory properties, and may induce apoptosis as well as modulate cell cycle and estrogen receptor function in breast cancer cell lines. Although RES has shown remarkable promise as a potent chemopreventive agent in breast cancer, further studies are needed to etablish its usefulness.

Occurrence of heterocyclic amines in several home-cooked meat dishes of the Spanish diet

Heterocyclic amines (HAs) were determined in several of the most frequently eaten meat dishes in Spain such as fried beef hamburger, fried pork loin, fried chicken breast, fried pork sausages, griddled chicken breast, griddled lamb steak and griddled beef steak. All of the products tested were household cooked. The HAs were analysed in the selected meat dishes using an analytical method based on solid-phase extraction followed by liquid chromatography coupled to tandem mass spectrometry. DMIP, MeIQx, 4,8-DiMeIQx, Norharman, Harman, PhIP, Trp-P-1, AalphaC and MeAalphaC were the amines most frequently found at concentrations of up to 47 ng g(-1) of cooked meat. Glu-P-2, IQ, MeIQ, Glu-P-1, 7,8-DiMeIQx and Trp-P-2 were only found in a few of the meat dishes and their concentrations were lower than 1 ng g(-1) of cooked meat. The highest amounts of HAs, especially PhIP and DMIP, were formed in fried chicken breast and the lowest were formed in fried beef hamburger and in fried pork sausages. Daily intake of HAs in Spain was estimated at 606 ng of mutagenic HAs per capita and day, DMIP and PhIP being the main contributors.

Aggregation of stomach cancer history in parents and offspring in comparison with other sites

BACKGROUND

The aim of this study is to evaluate the magnitude of the aggregation of a stomach cancer history in parents and their offspring in comparison with that of a history at other sites.

METHODS

We used the baseline data from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study), which was initiated during 1988-1990 in Japan. Association of the cancer history of the subjects' parents with that of the subjects themselves and any of the subjects' siblings was evaluated with odds ratios (OR) by the crude and generalized estimating equations (GEE) technique for four sites: stomach, colorectum, liver, and lung/bronchus.

RESULTS

The aggregation of a history of stomach cancer between parents and their offspring was evident with significant OR >2.5. The magnitude of the parent-offspring association of a disease history of the colorectum and liver was found to be greater than that for stomach cancer. Conversely, lung and bronchus cancer failed to demonstrate a significant aggregation.

CONCLUSIONS

The hereditary and environmental influences shared by parents and offspring are likely to play a strong aetiological role in colorectal or liver cancer versus a weaker but still significant role in stomach cancer. In contrast, the aetiological role of familial predisposition to lung cancer was indeterminate, which suggests a predominant role of non-familial factors in the development of lung cancer.

Gastric cancer and other organ cancer history in the parents of patients with gastric cancer

A case-control study in a population from the Eastern Black Sea region of Turkey was performed to evaluate the risk of gastric cancer development in patients with gastric cancer reporting gastric cancer or other organ cancer history in their parents. Gastric cancer and/or other organ cancer history in the parents were found in 215 of 1240 patients with gastric cancer versus 73 of 1240 controls (odds ratio (OR) 3.35, P<0.001). The frequency of gastric cancer history among the parents was significantly different between the patients and the controls (148 versus 25, respectively; OR 6.59, P<0.001). The frequency of other organ cancer history was not significantly different between the patients and the controls (63 versus 48, respectively; OR 1.33, P>0.05). The frequency of gastric cancer history was significantly higher than the frequency of other organ cancer history in the parents of the patients (OR 4.51, P<0.001). Gastric cancer history was significantly higher in first- to third-degree relatives of the patients reporting gastric cancer and/or other organ cancer history in their parents than in the controls (OR 14.72, P<0.001). Familial clustering of gastric cancer defined by the presence of at least four cancer cases in family members, including parents, was reported by 12% of the patients. Overall, the result of this study of gastric cancer and other organ cancer history in the parents of patients with gastric cancer may suggest a genetic susceptibility for gastric carcinoma. A high risk of gastric cancer occurred in subjects reporting a gastric cancer history in their parents, and there was a higher predisposition to gastric cancer compared with other organ cancer in relatives and a familial clustering of the disease.

Effects of extracts of Coriolus versicolor (I'm-Yunity) on cell-cycle progression and expression of interleukins-1 beta,-6, and -8 in promyelocytic HL-60 leukemic cells and mitogenically stimulated and nonstimulated human lymphocytes

OBJECTIVE

The goal of this in vitro study was to test the cytostatic and cytotoxic activities of extracts derived from the polysaccharopeptide (PSP), I'm-Yunity (Integrated Chinese Medicine Holdings Ltd., Kowloon, Hong Kong) prepared from strain Cov-1 of the mushroom Coriolus versicolor.

DESIGN

Different volumes of 70% ethanol and water extracts of I'm-Yunity were incubated with cultures of human promyelocytic leukemic HL-60 cells, and compared to nontreated control cells. At various times after treatment, cells were harvested and analyzed with respect to: (1). proliferation and cell cycle phase distribution, (2). induction of apoptosis, and (3). changes in expression of the immunomodulating cytokines interleukin (IL)-1 beta, IL-6, and IL-8. To test whether extracts also affected normal cells, similar experiments were also performed using isolated peripheral blood lymphocytes from healthy volunteers, with and without stimulation by the mitogen phytohemagglutinin (PHA). The ability of extracts to affect the secretion of IL-1 beta, IL-6, and IL-8 were assessed by enzyme-linked immunosorbent assay.

RESULTS

HL-60 cells incubated with various amounts (1, 3, 5, 7.5, and 10 micro l/mL) of the extracts for 1-3 days showed dose-dependent, time-dependent growth suppression and decrease in cell viability. Flow cytometric analysis revealed partial cell arrest in the G(1) phase at less than 5 micro L/mL and induction of apoptosis at 10 micro L/mL or more of ethanol and water extracts, with the latter exhibiting more pronounced inhibition than the former. Experiments performed with lymphocytes demonstrated that extracts of I'm-Yunity alone were without effect; moreover, they also did not affect the lymphocyte response to PHA. Water extract of I'm-Yunity also significantly increased IL-1 beta and IL-6 while substantially lowering IL-8.

CONCLUSIONS

I'm-Yunity acts selectively in HL-60 leukemic cells, resulting in cell cycle restriction through the G(1)/S checkpoint and the induction of apoptosis.

Variability in aflatoxin B(1)-macromolecular binding and relationship to biotransformation enzyme expression in human prenatal and adult liver

Studies of transplacental transfer of aflatoxin B(1) (AFB(1)) suggest that the developing human fetus may be a sensitive target for AFB(1) injury. Because AFB(1) requires metabolic activation to the reactive AFB(1)-8,9-exo-epoxide (AFBO) to exert its carcinogenic effects, ontogenic and interindividual differences in AFB(1) biotransformation enzymes may underlie susceptibility to AFB(1)-induced cell injury. The present study was initiated to compare the rates of in vitro AFB(1)-DNA and AFB(1)-protein adduct formation among a panel of 10 adult and 10 second-trimester prenatal livers and to examine the relationship among AFB(1) metabolizing enzyme expression and AFB(1) binding. Mixtures of cytosolic and microsomal proteins from prenatal and adult livers catalyzed the formation of AFB(1)-DNA and AFB(1)-protein adducts at relatively similar rates, although greater individual variability in AFB(1) adduct formation was observed in adult tissues. Extensive interindividual variation among adult tissues was observed in the expression of the AFB(1) activation enzymes cytochrome P4501A2 (CYP1A2), CYP3A4/5, and lipoxygenase (LO). Prenatal CYP3A7 expression was also highly variable. LO expression was eightfold higher in prenatal liver tissues than adults, whereas the expression of the AFBO detoxification enzyme microsomal epoxide hydrolase was twofold higher in adult liver. The levels of the polymorphic glutathione S-transferase M1 (hGSTM1-1), which may potentially protect against AFBO injury, were higher in the hGSTM1-1-expressing tissues of adults in relation to prenatal livers. In general, there was not a strong relationship among AFB(1)-DNA or AFB(1)-protein adduct formation and expression levels of individual AFB(1) metabolizing enzymes. In summary, despite the presence of marked individual and ontogenic differences in the expression of AFB(1) metabolizing enzymes, human second trimester prenatal liver tissues compared to adults do not exhibit a marked sensitivity to the in vitro formation of macromolecular AFB(1) adducts.

Diet and cancer prevention

Research from several sources provides strong evidence that vegetables, fruits, and whole grains, dietary fibre, certain micronutrients, some fatty acids and physical activity protect against some cancers. In contrast, other factors, such as obesity, alcohol, some fatty acids and food preparation methods may increase risks. Unravelling the multitude of plausible mechanisms for the effects of dietary factors on cancer risk will likely necessitate that nutrition research moves beyond traditional epidemiological and metabolic studies. Nutritional sciences must build on recent advances in molecular biology and genetics to move the discipline from being largely 'observational' to focusing on 'cause and effect'. Such basic research is fundamental to cancer prevention strategies that incorporate effective dietary interventions for target populations.

Nutrition, genetics, and risks of cancer

Dietary patterns, nutrients, and other constituents of food are major components of the environmental influences that contribute to risk for cancer, and the study of interactions between nutritional and genetic factors is a new and important area or research. This review describes the concepts and principles underlying this area of study and types of relationships between nutritional and genetic factors, and it provides examples of specific diet-gene interactions that are of current interest, with an emphasis on implications for cancer prevention and public health. Polymorphisms exist in the genes for the activating and conjugating metabolizing enzymes, and the induction of metabolizing enzyme activity by nutritional factors may result in either the activation of a carcinogen or the detoxification of a reactive intermediate metabolite. The relationship between the methylenetetrahydrofolate reductase gene and dietary folate is an example of a diet-gene interaction that involves a polymorphism in a vitamin metabolism gene, and the presence of the variant appears to influence both risk for cancer and folate requirements. Diet-gene interactions likely contribute considerably to the observed inter-individual variations in cancer risk in response to exposures to the nutritional factors that have the potential to promote or protect against cancer. Insights into mechanisms by which nutritional factors affect the process of carcinogenesis are provided by knowledge of the targeted gene function and enzyme activity. Increased knowledge in this area will allow a more refined approach to reducing risk for cancer, with diet interventions targeted toward individuals and subgroups that are genetically susceptible and responsive to the effects of nutritional factors.

Vaccine-associated sarcomas in cats: a unique cancer model

Epidemiologic evidence supports a relationship between vaccination of cats for rabies and feline leukemia virus with the development of soft tissue sarcomas at the site of administration. These tumors are locally invasive and histologically aggressive. As with high-grade soft tissue sarcoma in humans, combination treatment with radiation therapy and surgery provides for optimum tumor control. Feline vaccine-associated sarcoma has become a difficult issue for the veterinary profession for legal, ethical, and clinical reasons. Although most research efforts have focused on therapeutic intervention, this tumor has great potential to provide an informative model for carcinogenesis and genetic susceptibility applicable to cancer in all species, including humans.

Creating a new paradigm in nutrition research within the National Cancer Institute

Almost two decades after Doll and Peto (1981) provided evidence that one third of cancer deaths are related to diet, it remains unclear which dietary components may be key in cancer prevention. Although the complexity of the diet can become overwhelming, the National Cancer Institute (NCI) of the National Institutes of Health (NIH) has remained steadfast in its commitment to defining the roles that diet and nutrition have in the development of cancer and has provided increased research and training support to assist in unraveling this interrelationship. Evidence for this sustained commitment is highlighted by a fourfold increase in NCI expenditures for nutrition research and training from 1983 to 1998; this substantial increase reflects a trend that is occurring in some universities and the private sector. More than one third of the nutrition-related NCI research is funded by the Division of Cancer Prevention. Supported investigations cover the gamut from basic mechanisms of action of dietary constituents, methodology development, human metabolic studies, clinical trials of dietary modification and the chemopreventive potential of individual nutrients to population-based studies.

Stomach cancer history in the siblings of patients with gastric carcinoma

A case-control study in the population of the Eastern Black Sea region of Turkey was conducted to learn the incidence of stomach cancer in the siblings of patients with gastric carcinoma. Among 1240 patients with gastric carcinoma, 168 had sibling(s) with a history of stomach cancer versus 19 cases in the control group matched according to age and gender (OR 10.07, P < 0.0001). The frequency of a history of stomach cancers and cancer of other organs in first- to third-degree relatives was 60.7% and 38.0%, respectively, of 168 sibling cases with gastric carcinoma (P < 0.0001). Fifty-two point three per cent of sibling cases having a history of cancer in other organs in their relatives also reported stomach cancer in the same-degree relatives. The number of stomach cancers in the first- to third-degree relatives of sibling cases was higher than the number of other organ cancers in the same-degree relatives (P < 0.01). Familial clustering of stomach cancer was reported in 12.5% of sibling cases. The study of stomach cancer history in the siblings suggests: the presence of a genetic susceptibility, high risk of the disease occurrence in the siblings of patients, higher predisposition to gastric than to other organ cancers in the relatives, and not infrequent familial clustering.

Separation of heteroaromatic amines in food products

In recent years, many studies have dealt with the role of certain heteroaromatic amines (HAs) as mutagenic compounds, and their occurrence in foodstuffs. Here we examine the determination of HAs, focusing on the analytical strategies for their extraction and preconcentration from several matrices. We summarise the properties of heteroaromatic amines and the main drawbacks involved in their analysis, and then concentrate on the separation procedures, sorbents and solvents used in the sample treatment. We discuss the requirements of the analytical techniques and the strategies most frequently followed to achieve accurate results.

The genetic revolution: change and challenge for the dietetics profession

Advances in genetics are occurring at a pace that challenges our ability to understand and respond to the implications. Soon we will be able to define more precisely the molecular mechanisms underlying human health and disease; subdivide diseases and conditions (e.g., obesity) that are clinically indistinguishable into more distinct entities, thereby improving our ability to choose rational preventive and treatment measures; identify genotypic markers that predict metabolic responses to dietary interventions; stratify the population into groups at higher or lower risk for chronic diseases such as cancer, thus allowing dietary intervention to be appropriately targeted; and develop dietary recommendations that take into account genetically determined taste preferences. Dietetics leaders, teachers, practitioners, and researchers must act now to ensure that dietetics professionals are prepared for practice in this new era. In this article we introduce the Human Genome Project, review the fundamentals of molecular genetics, discuss genetics and disease risk, and define and give examples of diet-gene interactions. We also discuss issues relevant to dietary counseling of healthy people with genetic susceptibility to chronic disease. To foster the growth of knowledge regarding this new biology among dietitians, The American Dietetic Association should take the following steps: require course work on diet-gene interactions and include human genetics as a topic area on dietetic registration examinations, form a practice group on this topic, develop an Internet-based communication and information hub for dietetics professionals, sponsor a session on human genetics at annual meetings, begin a dialogue regarding a new practice specialty in diet and genetic counseling, and encourage a health care system in which personal counseling on diet-gene interactions is valued and reimbursed.