Total Antioxidant Capacity of Saliva and Its Correlation with pH Levels among Dental Students under Different Stressful Conditions.

(1) Background: This cross-sectional study conducted at the Faculty of Dental Medicine, Timisoara, Romania, between December 2022 and February 2023 aims to assess salivary total antioxidant capacity and pH levels in dental students experiencing non-stressful and stressful situations and explore potential correlations between these factors. (2) Methods: Saliva samples were collected during two different periods: before an Oral Health course and before the Oral Health exam, under stressful conditions. Ethical principles were followed, and informed consent was obtained. Data on age, gender, health status, drug use, smoking habits, and anxiety levels were recorded. Saliva was collected using the draining method and pH was measured using indicator paper strips. Total antioxidant capacity (TAC) was determined using a commercial assay kit. Statistical analysis involved descriptive statistics, Student's t-test to compare pH and TAC between study groups, and Pearson's correlation coefficient to analyze the correlation between salivary pH and TAC within each group, with p < 0.05 indicating significance. (3) Results: This study involved 80 participants, comprising 26 males and 54 females, all enrolled in the 5th year of the Oral Health course, with ages ranging from 20 to 53 and a mean age of 23.62 (±4.19) years. Pearson's correlation results show a statistically significant negative relationship between the STAI test and TAC during the stress-free period (-0.02 **, N = 80, p < 0.01). (4) Conclusions: There are variations in saliva's antioxidant capacity in response to different stress conditions. Dental students experienced a higher level of stress before academic assessments compared to the non-stress period during the course.

Link between Oral Health, Periodontal Disease, Smoking, and Systemic Diseases in Romanian Patients.

(1) Background: The link between oral and systemic health is becoming increasingly obvious. Oral diseases, particularly periodontitis, have been linked to various diseases including diabetes and cardiovascular disease, among others. This survey aimed to assess the oral health condition of individuals, considering both their overall health and periodontal status, by performing oral examinations and collecting data using questionnaires. (2) Methods: After obtaining approval from the University's Ethics Committee, the study was carried out from 2021 to 2022 at the Department of Oral Health, located in the Emergency Municipal Hospital in Timisoara, Timis County, Romania. Bivariate correlations were performed using nonparametric Spearman's Rho using SPPS software version 23. To assess the importance of smoking frequency related to the severity of periodontitis diagnosis, the ANOVA Simple test (one-way) and Hochberg GT2 post hoc analysis were utilized. The chi-squared test was employed for nominal variables. A significance level of 0.05 (alpha = 0.05) was adopted for all statistical tests. (3) Results: There is a significant positive association between the frequency of systemic disease and the severity of the periodontitis diagnosis taken as a total, Rho (242) = 0.151, p < 0.05, and taken as a stage, Rho (242) = 0.199, p < 0.01, thus as the severity of the diagnosis increases, the patient presents comorbidities. Hochberg GT2 post hoc analysis indicates that the non-smoking group has statistically significantly lower diagnostic severity (Mdif = -0.81, p = 0.01), with a strong effect size (Cohen's d = 0.73). (4) Conclusions: The findings are increasingly indicating a potential association between oral diseases and a range of systemic diseases. The impact of periodontal disease on the quality of life is significant, especially in individuals with associated systemic conditions and present risk factors.

Enhancing the Antimicrobial Effect of Ozone with Mentha piperita Essential Oil.

This study aimed to obtain and analyse Mentha piperita essential oil (MpEO) for the prospect of being used as an enhancement agent for the antimicrobial potential of ozone against gram-positive and gram-negative bacteria and fungi. The research was done for different exposure times, and it gained time-dose relationships and time-effect correlations. Mentha piperita (Mp) essential oil (MpEO) was obtained via hydrodistillation and further analysed by using GC-MS. The broth microdilution assay was used to determine the strain inhibition/strain mass growth by using spectrophotometric optical density reading (OD). The bacterial/mycelium growth rates (BGR/MGR) and the bacterial/mycelium inhibition rates (BIR/MIR) after ozone treatment in the presence and absence of MpEO on the ATTC strains were calculated; the minimum inhibition concentration (MIC) and statistical interpretations of the time-dose relationship and specific t-test correlations were determined. The effect of ozone on the following tested strains at maximum efficiency was observed after 55 s of single ozone exposure, in order of effect strength: S. aureus > P. aeruginosa > E. coli > C. albicans > S. mutans. For ozone with the addition of 2% MpEO (MIC), maximum efficacy was recorded at 5 s for these strains, in order of effect strength: C. albicans > E. coli > P. aeruginosa > S. aureus > S. mutans. The results suggest a new development and affinity regarding the cell membrane of the different microorganisms tested. In conclusion, the use of ozone, combined with MpEO, is sustained as an alternative therapy in plaque biofilm and suggested as helpful in controlling oral disease-causing microorganisms in medicine.

Impact of Dentistry Materials on Chemical Remineralisation/Infiltration versus Salivary Remineralisation of Enamel-In Vitro Study.

The aim of this study is to evaluate salivary remineralisation versus chemical remineralisation/infiltration of enamel, using different dentistry materials. The enamel changes were studied using confocal laser scanning microscopy (CLSM), and the depth of lesions and demineralisation/remineralisation/infiltration percentage were calculated. Additionally, the macro elemental composition of the teeth was performed using atomic absorption spectroscopy (AAS). Two studies were performed: (i) demineralisation of enamel in 3% citric acid and infiltration treatment with infiltration resin (Icon, DMG), remineralisation with Fluor Protector (Ivoclar Vivadent) and artificial saliva pH 8; and (ii) enamel demineralisation in saliva at pH 3 and remineralisation at salivary pH 8. The results showed that, firstly, for the remineralisation of demineralised enamel samples, Fluor Protector (Ivoclar Vivadent) was very effective for medium demineralised lesions followed by saliva remineralisation. In cases of deep demineralisation lesions where fluoride could not penetrate, low viscosity resin (Icon, DMG, Hamburg) effectively infiltrated to stop the demineralisation process. Secondly, remineralisation in salivary conditions needed supplementary study over a longer period, to analyse the habits, diet and nutrition of patients in detail. Finally, demineralisation/remineralisation processes were found to influence the macro elemental composition of enamel demineralisation, with natural saliva proving to be less aggressive in terms of decreasing Ca and Mg content.

The Impact of Parental Education on Schoolchildren's Oral Health-A Multicenter Cross-Sectional Study in Romania.

The present study is part of the first national oral health survey for children in Romania. The aim of this study was to determine caries prevalence in correlation with the level of the parents' education, preventive behavior, and socioeconomic parameters in 11-14-year-old schoolchildren in Romania. A cross-sectional epidemiological survey was designed and conducted in 2019-2020. The sampled children were selected from 49 schools distributed in rural and urban areas of Romania, including its capital. Data were collected using the Oral Health Questionnaire for Children developed by the World Health Organization and described in the WHO Oral Health Surveys-Basic Methods, 5th edition, 2013, after positive informed consent. To express prevalence and severity of carious lesions, International Caries Detection and Assessment System (ICDAS) criteria were recorded in school for 814 schoolchildren (388 boys and 426 girls) aged between 11 and 14 years old (mean age 12.29 ± 0.6). Elements regarding the specificity of the child (gender, age, and parental education) were tabulated against preventive behavior. The parents' education was correlated with three clinical indices in order to assess the existence or lack of certain significant differences among schoolchildren in Romania. In terms of correlation between the mother's education and preventive behavior, results showed a significant positive correlation in case of dental check-ups (rs = 0.08 *, p < 0.05), brushing (rs = 0.02 **, p < 0.01), and use of different types of dental hygiene aids (rs = 0.06 **, p < 0.01) and a negative correlation with tooth pain or discomfort (rs = -0.01 **, p < 0.01). A statistically significant positive relationship was highlighted between the mother's education and the presence of restorations (rs = -0.09 **, p < 0.01). Regarding the father's education, there was a positive relationship with oral hygiene behavior (rs = 0.18 **, p < 0.01) but a negative relationship with the D3T index (rs = -0.18 **, p < 0.01). In conclusion, there was a strong correlation between the parents' education, preventive behavior, and oral health status of Romanian schoolchildren.

Dental Caries, Oral Health Behavior, and Living Conditions in 6-8-Year-Old Romanian School Children.

Dental caries still have a high prevalence in Romania. The aim of this paper is to determine the prevalence of caries in children (aged 6 to 8 years) correlated with individual-level predictors and socio-economic variables. A stratified, randomized nationally representative sample was established, taking into consideration the total number of preschool children and based on administrative units and residence. Self-assessment was performed by means of the Oral Health Questionnaire for Children (WHO). Examinations were conducted by 10 standardized examiners, with International Caries Detection and Assessment System (ICDAS) caries codes higher than 3 considered as dentinal caries, missing teeth as MT, and restorations as FT. DMFT and SiC indexes were calculated accordingly. The dataset for each outcome variable was analyzed by the Hurdle approach analyzed. The gender distribution was similar (47.22% male and 52.78% female), with 42.65% residing in rural areas. The mean DMFT value for the sample was 4.89 and SiC index 9.83. A negative association could be seen between DMFT and the father's level of education (ß = −0.33, SE = 0.07, p < 0.01) as well as the mother's education (ß = −0.25, SE = 0.07, p < 0.01). In conclusion, caries prevalence is very high in Romania as compared to the World Health Organization (WHO) recommendation for this age group in correlation with socio-economic factors and oral health behavior.

Caries Prevalence Associated with Oral Health-Related Behaviors among Romanian Schoolchildren.

Oral health-related behaviors and living conditions play an important role in general and oral health. This study aimed to evaluate caries prevalence and severity in schoolchildren residing in rural and urban areas of Romania, and to correlate these with oral health-related behaviors. An estimation of the required sample size was conducted (sampling error of ±3% at a 95% confidence level), followed by the stratification of administrative units and then the selection of 49 schools. The Hurdle approach was used to analyze the dataset, requiring two sets of analyses for each outcome variable: a multilevel binary model to predict prevalence, and a multilevel Poisson analysis using only non-zero values. The mean and standard deviation (SD) for the dentinal caries index was 4.96 (5.33). Girls were more likely to have non-zero restoration codes (ß = 0.14, SE = 0.08, p < 0.05). Low education levels of each parent were associated with an increased likelihood of having non-zero carious tooth surfaces (ß = 0.23, SE = 0.06, p = 0.01; ß = 0.22, SE = 0.06, p < 0.01). The presence of cavities was predicted by the consumption of carbonated soft drinks (ß = 0.19, SE = 0.07, p < 0.01), candies (ß = 0.13, SE = 0.06, p < 0.01), sweetened milk (ß = 0.12, SE = 0.06, p < 0.05), tea (ß = 0.16, SE = 0.08, p < 0.05), or cocoa (ß = 0.13, SE = 0.06, p < 0.05). Furthermore, the non-zero values of the dentinal caries index were more likely in rural schools (ß = -0.37, SE = 0.11, p < 0.01), and a negative association between the county development index and the fillings/restorations index (ß = -0.01, SE = 0.01, p < 0.05) was also established. The outcome of this research highlights that the presence of caries (dentinal caries index) in Romanian schoolchildren is influenced by their socioeconomic background, as well as their specific consumption behaviors.

Early Epigenetic Markers for Precision Medicine.

Over the last years, epigenetic changes, including DNA methylation and histone modifications detected in early tumorigenesis and cancer progression, have been proposed as biomarkers for cancer detection, tumor prognosis, and prediction to treatment response. Importantly for the clinical use of DNA methylation biomarkers, specific methylation signatures can be detected in many body fluids including serum/plasma samples. Several of these potential epigenetic biomarkers detected in women's cancers, colorectal cancers, prostate, pancreatic, gastric, and lung cancers are discussed. Studies conducted in breast cancer, for example, found that aberrant methylation detection of several genes in serum DNA and genome-wide epigenetic change could be used for early breast cancer diagnosis and prediction of breast cancer risk. In colorectal cancers, numerous studies have been conducted to identify specific methylation markers important for CRC detection and in fact clinical assays evaluating the methylation status of SEPT19 gene and vimentin, became commercially available. Furthermore, some epigenetic changes detected in gastric washes have been suggested as potential circulating noninvasive biomarkers for the early detection of gastric cancers. For the early detection of prostate cancer, few epigenetic markers have shown a better sensitivity and specificity than serum PSA, indicating that the inclusion of these markers together with current screening tools, could improve early diagnosis and may reduce unnecessary repeat biopsies. Similarly, in pancreatic cancers, abnormal DNA methylation of several genes including NPTX2, have been suggested as a diagnostic biomarker. Epigenetic dysregulation was also observed in several tumor suppressor genes and miRNAs in lung cancer patients, suggesting the important role of these changes in cancer initiation and progression. In conclusion, epigenetic changes detected in biological fluids could play an essential role in the early detection of several cancer types and this may have a great impact for the cancer precision medicine field.

Interplay Between Genetic and Epigenetic Changes in Breast Cancer Subtypes.

Breast cancer is the most common cancer among women and represents one of the top five leading causes of cancer-related mortality. Inherited and acquired genetic mutations as well as epigenetic aberrations are known to be important contributors to the development and progression of breast cancer. Recent developments in high-throughput technologies have increased our understanding of the molecular changes in breast cancer, leading to the identification of distinctive genetic and epigenetic modifications in different breast cancer molecular subtypes. These genetic and epigenetic changes in luminal A, luminal B, ERBB2/HER2-enriched, basal-like, and normal-like breast cancer subtypes are discussed in this chapter. Furthermore, recent epigenome studies provided more information about further stratification of breast cancer subtypes, with essential role in the appropriate diagnosis and treatment of breast cancer. Thus, the inclusion of both genetic and epigenetic information in breast cancer clinical care could provide critical scientific base for precision medicine in breast cancer.

MicroRNAs Role in Prostate Cancer.

Prostate cancer still represents a major health problem for men worldwide. Due to the specific limitation of the currently used clinical biomarkers for prostate cancer, there is a need to identify new and more accurate prostate-specific biomarkers, both for diagnosis and prediction. Small noncoding species of RNAs called microRNAs (miRNAs) have emerged as possible biomarkers in cancer tissues as well as biological fluids, including for prostate cancer. Moreover, it has been shown that miRNAs could be used as therapeutic targets in different cancer types, including prostate cancer, playing an important role in improving diagnosis and prognosis; and miRNAs have the potential to be clinically useful as predictors of response to personalized cancer therapy and as predictors of prognosis. The analysis of miRNAs in prostate tissue is rather straightforward and has been routinely done on fresh tissue. In addition, due to the more stable nature of miRNAs, they are amenable to be analyzed in archived formalin fixed paraffin embedded tissue as well, and also in serum, plasma and urine, using various analytical platforms including microarrays, next generation sequencing and real time PCR. Moreover, although the existence or prostasomes (microvesicles secreted by prostate cells including prostate cancer cells) has been known for years and they were studied as a source of biomarkers for prostate cancer, only recently it has been described that these vesicles also contain miRNAs that could be used as biomarkers in prostate cancer. This chapter underscores the feasibility of current technologies for miRNA analysis and their importance in prostate cancer biology. Moreover, elucidating the specific alteration of miRNA expression and how to modulate it in prostate tissue will open new avenues for developing therapeutic strategies for prostate cancer treatment.

Alcohol-Induced Epigenetic Changes in Cancer.

Chronic, heavy alcohol consumption is associated with serious negative health effects, including the development of several cancer types. One of the pathways affected by alcohol toxicity is the one-carbon metabolism. The alcohol-induced impairment of this metabolic pathway results in epigenetic changes associated with cancer development. These epigenetic changes are induced by folate deficiency and by products of the ethanol metabolism. The changes induced by long-term heavy ethanol consumption result in elevations of homocysteine and S-adenosyl-homocysteine (SAH) and reductions in S-adenosylmethionine (SAM) and antioxidant glutathione (GSH) levels, leading to abnormal promoter gene hypermethylation, global hypomethylation, and metabolic insufficiency of antioxidant defense mechanisms. In addition, reactive oxygen species (ROS) generated during the ethanol metabolism induce alterations in DNA methylation patterns that play a critical role in cancer development. Specific epigenetic changes in esophageal, hepatic, and colorectal cancers have been detected in blood samples and proposed to be used clinically as epigenetic biomarkers for diagnosis and prognosis of these cancers. Also, genetic variants of genes involved in one-carbon metabolism and ethanol metabolism were found to modulate the relationship between alcohol-induced epigenetic changes and cancer risk. Furthermore, alcohol metabolism products have been associated with an increase in NADH levels, which lead to histone modifications and changes in gene expression that in turn influence cancer susceptibility. Chronic excessive use of alcohol also affects selected members of the family of microRNAs, and as miRNAs could act as epigenetic regulators, this may play an important role in carcinogenesis. In conclusion, targeting alcohol-induced epigenetic changes in several cancer types could make available clinical tools for the diagnosis, prognosis, and treatment of these cancers, with an important role in precision medicine.

Discovery and replication of microRNAs for breast cancer risk using genome-wide profiling.

BACKGROUND: Genome-wide miRNA expression may be useful for predicting breast cancer risk and/or for the early detection of breast cancer. RESULTS: A 41-miRNA model distinguished breast cancer risk in the discovery study (accuracy of 83.3%), which was replicated in the independent study (accuracy = 63.4%, P=0.09). Among the 41 miRNA, 20 miRNAs were detectable in serum, and predicted breast cancer occurrence within 18 months of blood draw (accuracy 53%, P=0.06). These risk-related miRNAs were enriched for HER-2 and estrogen-dependent breast cancer signaling. MATERIALS AND METHODS: MiRNAs were assessed in two cross-sectional studies of women without breast cancer and a nested case-control study of breast cancer. Using breast tissues, a multivariate analysis was used to model women with high and low breast cancer risk (based upon Gail risk model) in a discovery study of women without breast cancer (n=90), and applied to an independent replication study (n=71). The model was then assessed using serum samples from the nested case-control study (n=410). CONCLUSIONS: Studying breast tissues of women without breast cancer revealed miRNAs correlated with breast cancer risk, which were then found to be altered in the serum of women who later developed breast cancer. These results serve as proof-of-principle that miRNAs in women without breast cancer may be useful for predicting breast cancer risk and/or as an adjunct for breast cancer early detection. The miRNAs identified herein may be involved in breast carcinogenic pathways because they were first identified in the breast tissues of healthy women.

Genetic variation in one-carbon metabolism in relation to genome-wide DNA methylation in breast tissue from heathy women.

Single nucleotide polymorphisms (SNPs) in one-carbon metabolism genes and lifestyle factors (alcohol drinking and breast folate) may be determinants of whole-genome methylation in the breast. DNA methylation profiling was performed using the Illumina Infinium HumanMethylation450 BeadChip in 81 normal breast tissues from women undergoing reduction mammoplasty and no history of cancer. ANCOVA, adjusting for age, race and BMI, was used to identify differentially-methylated (DM) CpGs. Gene expression, by the Affymetrix GeneChip Human Transcriptome Array 2.0, was correlated with DM. Biological networks of DM genes were assigned using Ingenuity Pathway Analysis. Fifty-seven CpG sites were DM in association with eight SNPs in FTHFD, MTHFD1, MTHFR, MTR, MTRR, and TYMS (P <5.0 x 10-5); 56% of the DM CpGs were associated with FTHFD SNPs, including DM within FTHFD. Gene expression was negatively correlated with FTHFD methylation (r=-0.25, P=0.017). Four DM CpGs identified by SNPs in MTRR, MTHFR, and FTHFD were significantly associated with alcohol consumption and/or breast folate. The top biological network of DM CpGs was associated with Energy Production, Molecular Transportation, and Nucleic Acid Metabolism. This is the first comprehensive study of the association between SNPs in one-carbon metabolism genes and genome-wide DNA methylation in normal breast tissues. These SNPs, especially FTHFD, as well as alcohol intake and folate exposure, appear to affect DM in breast tissues of healthy women. The finding that SNPs in FTHFD and MTR are associated with their own methylation is novel and highlights a role for these SNPs as cis-methylation quantitative trait loci.

Racial differences in genome-wide methylation profiling and gene expression in breast tissues from healthy women.

Breast cancer is more common in European Americans (EAs) than in African Americans (AAs) but mortality from breast cancer is higher among AAs. While there are racial differences in DNA methylation and gene expression in breast tumors, little is known whether such racial differences exist in breast tissues of healthy women. Genome-wide DNA methylation and gene expression profiling was performed in histologically normal breast tissues of healthy women. Linear regression models were used to identify differentially-methylated CpG sites (CpGs) between EAs (n = 61) and AAs (n = 22). Correlations for methylation and expression were assessed. Biological functions of the differentially-methylated genes were assigned using the Ingenuity Pathway Analysis. Among 485 differentially-methylated CpGs by race, 203 were hypermethylated in EAs, and 282 were hypermethylated in AAs. Promoter-related differentially-methylated CpGs were more frequently hypermethylated in EAs (52%) than AAs (27%) while gene body and intergenic CpGs were more frequently hypermethylated in AAs. The differentially-methylated CpGs were enriched for cancer-associated genes with roles in cell death and survival, cellular development, and cell-to-cell signaling. In a separate analysis for correlation in EAs and AAs, different patterns of correlation were found between EAs and AAs. The correlated genes showed different biological networks between EAs and AAs; networks were connected by Ubiquitin C. To our knowledge, this is the first comprehensive genome-wide study to identify differences in methylation and gene expression between EAs and AAs in breast tissues from healthy women. These findings may provide further insights regarding the contribution of epigenetic differences to racial disparities in breast cancer.

Associations between genetic variation in one-carbon metabolism and LINE-1 DNA methylation in histologically normal breast tissues.

Genome-wide DNA hypomethylation is an early event in the carcinogenic process. Percent methylation of long interspersed nucleotide element-1 (LINE-1) is a biomarker of genome-wide methylation and is a potential biomarker for breast cancer. Understanding factors associated with percent LINE-1 DNA methylation in histologically normal tissues could provide insight into early stages of carcinogenesis. In a cross-sectional study of 121 healthy women with no prior history of cancer who underwent reduction mammoplasty, we examined associations between plasma and breast folate, genetic variation in one-carbon metabolism, and percent LINE-1 methylation using multivariable regression models (adjusting for race, oral contraceptive use, and alcohol use). Results are expressed as the ratio of LINE-1 methylation relative to that of the referent group, with the corresponding 95% confidence intervals (CI). We found no significant associations between plasma or breast folate and percent LINE-1 methylation. Variation in MTHFR, MTR, and MTRR were significantly associated with percent LINE-1 methylation. Variant allele carriers of MTHFR A1289C had 4% lower LINE-1 methylation (Ratio 0.96, 95% CI 0.93-0.98), while variant allele carriers of MTR A2756G (Ratio 1.03, 95% CI 1.01-1.06) and MTRR A66G (Ratio 1.03, 95% CI 1.01-1.06) had 3% higher LINE-1 methylation, compared to those carrying the more common genotypes of these SNPs. DNA methylation of LINE-1 elements in histologically normal breast tissues is influenced by polymorphisms in genes in the one-carbon metabolism pathway. Future studies are needed to investigate the sociodemographic, environmental and additional genetic determinants of DNA methylation in breast tissues and the impact on breast cancer susceptibility.

Relationships among folate, alcohol consumption, gene variants in one-carbon metabolism and p16INK4a methylation and expression in healthy breast tissues.

p16(INK4a) is a tumor suppressor gene, frequently hypermethylated in breast cancer; this epigenetic silencing of p16(INK4a) occurs early in carcinogenesis. The risk factors and functional consequences of p16(INK4a) methylation are unknown. Alcohol consumption, a breast cancer risk factor, impedes folate metabolism and may thereby alter gene methylation since folate plays a pivotal role in DNA methylation. In a cross-sectional study of 138 women with no history of breast cancer who underwent reduction mammoplasty, we studied breast cancer risk factors, plasma and breast folate concentrations, variation in one-carbon metabolism genes, p16(INK4a) promoter methylation and P16 protein expression. Logistic regression was used to estimate multivariable-adjusted odds ratios (OR) and 95% confidence intervals (CI). p16(INK4a) methylation was negatively correlated with P16 expression (r = -0.28; P = 0.002). Alcohol consumption was associated with lower breast folate (P = 0.03), higher p16(INK4a) promoter methylation (P = 0.007) and less P16 expression (P = 0.002). Higher breast folate concentrations were associated with lower p16(INK4a) promoter methylation (P = 0.06). Genetic variation in MTRR (rs1801394) and MTHFD1 (rs1950902) was associated with higher p16 (INK4a) promoter methylation (OR = 2.66, 95% CI: 1.11-6.42 and OR = 2.72, 95% CI: 1.12-6.66, respectively), whereas variation in TYMS (rs502396) was associated with less P16 protein expression (OR = 0.22, 95% CI: 0.05-0.99). Given that this is the first study to indicate that alcohol consumption, breast folate and variation in one-carbon metabolism genes are associated with p16(INK4a) promoter methylation and P16 protein expression in healthy tissues; these findings require replication.

Genetic variation in adipokine genes and associations with adiponectin and leptin concentrations in plasma and breast tissue.

BACKGROUND: Circulating adipokines may be associated with breast cancer risk. Genetic variants governing adipokines and adipokine receptors may also predict risk, but their effect on breast adipokine concentrations is unknown. METHODS: We conducted a cross-sectional analysis of functional SNPs in 5 adipokine genes [adiponectin, leptin (LEP), and their receptors] among 85 cancer-free women who were undergoing reduction mammoplasty. RESULTS: In multivariable-adjusted regression models, compared with the common GG genotype, the AA genotype of the LEP A19G SNP was associated with 27% lower plasma adiponectin [ratio, 0.73; 95% confidence interval (CI), 0.54-0.98] and leptin (ratio, 0.73; 95% CI, 0.55-0.96). Women with the AG genotype of LEP A19G had 39% lower breast leptin (ratio, 0.61; 95% CI, 0.39-0.97) compared with those with the GG genotype. No associations were observed for SNPs in the remaining genes. CONCLUSIONS: Genetic variation in LEP may alter endogenous adipokine concentrations in circulation and in breast tissues. IMPACT: These preliminary findings may support the hypothesis that genetic variation in adipokine genes modifies circulating adipokine concentrations and possibly leptin concentrations in local breast tissues, which may be associated with breast cancer risk.

Plasma IGF-1 and IGFBP-3 may be imprecise surrogates for breast concentrations: an analysis of healthy women.

We investigated insulin-like growth factor (IGF)-1 and IGF binding protein (IGFBP)-3 concentrations in histologically normal breast tissues and assessed their association with plasma concentrations, and breast cancer risk factors. IGF-1 and IGFBP-3 were assessed in plasma and breast tissues of 90 women with no history of any cancer and undergoing reduction mammoplasty. Pearson correlations and ANOVAs were used to describe plasma-breast associations and biomarker differences by breast cancer risk factors, respectively. Multivariable regression models were used to determine associations between risk factors, and breast IGF-1 and IGFBP-3. The mean age of the study sample was 37.3 years, 58 % were white, and generally these women were obese (mean BMI = 30.8 kg/m(2)). We observed no plasma-breast correlation for IGF-1, IGFBP-3, or IGF-1/IGFBP-3 (r = -0.08, r = 0.14, and r = 0.03, respectively; p-values >0.05). Through age- and BMI-adjusted analysis, BMI and years of oral contraceptive (OC) use were inversely associated with breast IGF-1 (p-values = 0.02 and 0.003, respectively) and age was associated with breast IGFBP-3 (p = 0.01), while breast IGF-1/IGFBP-3 was higher in blacks than whites (1.08 vs. 0.68, p = 0.04) and associated with age and BMI (p-values = 0.03 and 0.002, respectively). In multivariable-adjusted models, some breast cancer risk factors studied herein explained 24, 10, and 15 % of the variation in breast IGF-1, IGFBP-3, and IGF-1/IGFBP-3, respectively. While reasons for the lack of plasma-breast hormone correlations in these cancer-free women are unknown, several factors were shown to be associated with breast concentrations. The lack of correlation between blood and tissue IGF-1 and IGFBP-3 suggests that studies of breast cancer risk assessing blood IGF-1 and IGFBP-3 may have important limitations in understanding their role in breast carcinogenesis.

Adipokines in plasma and breast tissues: associations with breast cancer risk factors.

BACKGROUND: Blood adipokines are associated with breast cancer risk; however, blood-breast adipokine correlations and factors that explain variation in adipokines are unknown. METHODS: Plasma (n = 155) and breast (n = 85) leptin and adiponectin were assessed by immunoassays in women with no history of cancer. Multivariable-adjusted regression models were used to determine breast adipokine associations. RESULTS: Through body mass index (BMI)-adjusted analyses, we initially observed positive plasma-breast correlations for leptin (r = 0.41, P = 0.0002) and adiponectin (r = 0.23, P = 0.05). The positive plasma-breast correlation for leptin was strongest among normal weight women (r = 0.62), whereas the correlation for adiponectin was strongest among obese women (r = 0.31). In multivariable models, adjusting for BMI, demographic, reproductive, and lifestyle factors, plasma leptin was not associated with breast leptin, and only the highest quartile of plasma adiponectin was associated with tissue levels. Of the risk factors investigated, those that contributed most to the variation in breast tissue adipokines were BMI and race for leptin, oral contraceptive use and smoking status for adiponectin. CONCLUSIONS: Although we report positive plasma-breast adipokine correlations overall, plasma adipokine concentrations may not be good surrogates for breast concentrations among all women. Predictors of breast adipokines vary, depending on subject characteristics, possibly explaining inconsistent epidemiologic results and they implicate differing pathways toward carcinogenesis. IMPACT: A clearer understanding of the relationships between plasma adipokines and their levels within the target organ is necessary to better understand the impact of these hormones on breast cancer risk. Future studies are needed to identify additional factors associated with breast adipokines in target tissues.

Epigenetic markers of early tumor development.

Cancer patients' outcome and survival depends on the early diagnosis of malignant lesions. Several investigation methods used for the prevention and early detection strategies have specific limitations. More recently, epigenetic changes have been considered one of the most promising tools for the early diagnosis of cancer. Some of these epigenetic alterations including promoter hypermethylation of genes like P16INK4a, BRCA1, BRCA2, ERα and RARß2, APC, and RASSF1A have been associated with early stages of mammary gland tumorigenesis and have been suggested to be included in the models that evaluate individual breast cancer risk. In lung cancer, P16INK4a and MGMT gene hypermethylation was observed in sputum years before clinical manifestation of the squamous cell carcinoma among smokers. Loss of GSTP1 function by DNA hypermethylation together with changes in the methylation levels of repetitive elements like LINE-1 and Sat2 was reported in prostatic preneoplastic lesions. Also, DNA hypermethylation for hMLH1 and MGMT DNA repair genes was reported in precursor lesions to colorectal cancer. These epigenetic alterations may be influenced by factors such as xenoestrogens, folate, and multivitamins. Detection of these changes may help determining cancer susceptibility and early diagnosis.