Association of apolipoprotein E and myeloperoxidase genotypes to clinical course of familial and sporadic multiple sclerosis

The importance of apolipoprotein E (ApoE) and myeloperoxidase (MPO) genotypes in the clinical characteristics of multiple sclerosis (MS) has been recently emphasized. In a large group of Polish patients we have tested the hypothesis that polymorphism in ApoE and MPO genes may influence the course of the disease. G enotypes were determined in 117 MS patients (74 females and 43 males; 99 sporadic and 18 familial cases) with mean EDSS of 3.6, mean age of 44.1 years, mean duration of the disease 12.8 years and mean onset of MS at 31.2 years, and in 100 healthy controls. The relationship between ApoE and MPO genes’ polymorphism and the MS activity as well as the defect of remyelination (diffuse demyelination) and brain atrophy on MRI were analysed. The ApoE o4 allele was not related to the disease course or the ApoE o2 to the intensity of demyelination on MRI. The genotype MPO G/G was found in all familial MS and in 57% (56/99) of sporadic cases. This genotype was also related to more pronounced brain atrophy on MRI. The MPO G/G subpopulation was characterized by a significantly higher proportion of patients with secondary progressive MS (PB- 0.05) and by a higher value of EDSS. A ccording to our results the MPO G allele is frequently found (in 96% of cases) among Polish patients with MS. More severe nervous tissue damage in the MPO G/G form can be explained by the mechanism of accelerated oxidative stress. It seems that MPO G/G genotype may be one of the genetic factors influencing the progression rate of disability in MS patients.

Genetic variants associated with physical and mental characteristics of the elite athletes in the Polish population

The aim of the study was to assess whether selected genetic variants are associated with elite athlete performance in a group of 413 elite athletes and 451 sedentary controls. Polymorphisms in ACE, ACTN3, AGT, NRF-2, PGC1A, PPARG, and TFAM implicated in physical performance traits were analyzed. Additionally, polymorphisms in CHRNB3 and FAAH coding for proteins modulating activity of brain's emotion centers were included. The results of univariate analyses indicated that the elite athletic performance is associated with four polymorphisms: ACE (rs4341, P = 0.0095), NRF-2 (rs12594956, P = 0.011), TFAM (rs2306604, P = 0.049), and FAAH (rs324420, P = 0.0041). The multivariate analysis adjusted for age and gender confirmed this association. The higher number of ACE D alleles (P = 0.0021) and the presence of NRF-2 rs12594956 A allele (P = 0.0067) are positive predictors, whereas TFAM rs2306604 GG genotype (P = 0.031) and FAAH rs324420 AA genotype (P = 0.0084) negatively affect the elite athletic performance. The CHRNB3 variant (rs4950, G allele) is significantly more frequent in the endurance athletes compared with the power ones (P = 0.025). Multivariate analysis demonstrated that the presence of rs4950 G allele contributes to endurance performance (P = 0.0047). Our results suggest that genetic inheritance of psychological traits should be taken into consideration while trying to decipher a genetic profile of top athletic performance.

Abstract P3-12-05: Genetic Variation in Prolactin and Prolactin Receptor, and Relationships with Serum Prolactin Levels and Breast Cancer Risk

Background: Studies support the hypothesis that high circulating levels of the hormone prolactin increase breast cancer risk. It remains unclear if genetic factors are associated with interindividual variation in circulating prolactin and subsequent breast cancer risk. We examined the relationship between single nucleotide polymorphisms (SNPs) in prolactin (PRL) and prolactin receptor (PRLR), serum prolactin levels and breast cancer risk in a population based case-control study.

Methods: We genotyped 8 PRL and 20 PRLR tag SNPs in 1943 cases and 2229 controls (82% and 89% of enrolled, respectively). Cases were women 20-74 years old, diagnosed with in situ or invasive breast cancer between 2000 and 2003, and living in Warsaw or Lodz, Poland. Controls were cancer-free women selected from a population registry, matched to cases on age and city. Blood samples were provided at the study interview. Serum prolactin levels were measured in a subset of 773 controls using the Bayer Advia Centaur immunoassay. Odds ratios and 95% CIs for genotype-breast cancer associations were estimated using unconditional logistic regression, adjusting for age and city. Geometric mean prolactin levels and 95% confidence intervals (CI) were estimated using linear regression, adjusting for age, city, blood collection time, and day of menstrual cycle (premenopausal). Log-additive model Wald P-values were used to test for linear trends. Analyses were stratified by menopausal status, and all statistical tests were 2-sided (alpha=0.05). To account for multiple comparisons, P-values were adjusted using the Benjamini and Hochberg method.

Results: Three PRLR SNPs were nominally associated with breast cancer: in premenopausal women, rs249537 (per-allele OR 1.39, 95% CI 1.07 - 1.82, P=0.0140); and in postmenopausal women, rs7718468 (per-allele OR 1.16, 95% CI 1.03 — 1.30, P=0.0137) and rs13436213 (per-allele OR 1.13 95% CI 1.01 — 1.26, P=0.0397). We examined serum prolactin levels by genotype for these three SNPs to determine whether the potential risk alleles were associated with increased circulating prolactin, but mean serum prolactin levels were similar by genotype in controls: rs249537 TT=3.83 ng/ml, CT=5.51 ng/ml, CC=5.50 ng/ml, P-trend=0.8381; rs7718468 CC=6.41 ng/ml, CT=6.86 ng/ml, TT=6.47 ng/ml, P-trend=0.5643; and rs13436213 AA=6.48 ng/ml, AG=6.52 ng/ml, GG=6.29 ng/ml, P-trend=0.4766. None of the nominal associations between PRLR genotypes and breast cancer risk were significant after adjusting for multiple comparisons (multiple comparison adjusted P-values: rs249537 P=0.4340; rs7718468 P=0.4340; rs13436213 P=0.8205). PRL SNPs were not associated with breast cancer risk in premenopausal or postmenopausal women. Discussion: Our data do not support an association between PRL or PRLR tag SNPs and breast cancer. Though some associations were nominally significant, these results may be due to random error and require further study. Furthermore, data do not support a relationship between riskassociated SNPs and differences in prolactin levels. Future research should focus on non-genetic factors that affect circulating prolactin levels.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-12-05.

Prolactin serum levels and breast cancer: relationships with risk factors and tumour characteristics among pre- and postmenopausal women in a population-based case-control study from Poland

Background:

Previous prospective studies have found an association between prolactin (PRL) levels and increased risk of breast cancer. Using data from a population-based breast cancer case–control study conducted in two cities in Poland (2000–2003), we examined the association of PRL levels with breast cancer risk factors among controls and with tumour characteristics among the cases.

Methods:

We analysed PRL serum levels among 773 controls without breast cancer matched on age and residence to 776 invasive breast cancer cases with available pretreatment serum. Tumours were centrally reviewed and prepared as tissue microarrays for immunohistochemical analysis. Breast cancer risk factors, assessed by interview, were related to serum PRL levels among controls using analysis of variance. Mean serum PRL levels by tumour characteristics are reported. These associations also were evaluated using polytomous logistic regression.

Results:

Prolactin levels were associated with nulliparity in premenopausal (P=0.05) but not in postmenopausal women. Associations in postmenopausal women included an inverse association with increasing body mass index (P=0.0008) and direct association with use of recent/current hormone therapy (P=0.0006). In case-only analyses, higher PRL levels were more strongly associated with lobular compared with ductal carcinoma among postmenopausal women (P=0.02). Levels were not different by tumour size, grade, node involvement or oestrogen receptor, progesterone receptor, or human epidermal growth factor receptor 2 status.

Conclusions:

Our analysis demonstrates that PRL levels are higher among premenopausal nulliparous as compared with parous women. Among postmenopausal women, levels were higher among hormone users and lower among obese women. These results may have value in understanding the mechanisms underlying several breast cancer risk factor associations.

Elaboration of a quantitative job-exposure matrix for historical exposure to airborne exposures in the Polish rubber industry

BACKGROUND

A job-exposure matrix (JEM) for inhalable aerosols, aromatic amines, and cyclohexane soluble matter (CSM) was elaborated based on measurements collected routinely between 1981 and 1996.

METHODS

The data were grouped based on similarities in exposure levels and time trends in different departments, and were analyzed using smoothing splines and mixed effects models.

RESULTS

Although higher than in western European countries, inhalable aerosol exposure decreased after changes in production volume and implementation of exposure reduction measures in mid-1980s. Aromatic amines concentrations first increased following the factory's production volume, but subsequently decreased in more recent years. CSM concentrations were uniformly distributed between departments.

CONCLUSIONS

This JEM provides an overview of historical exposure levels in a large Polish rubber factory and will enable estimation of lifetime exposure for individual workers in a Polish rubber workers cohort and further investigation of the associations between specific exposures and cancer risk.

Neurocognition of centenarians: neuropsychological study of élite centenarians

OBJECTIVE

The aim of this study was to evaluate the cognitive state of highly selected Polish centenarians and analyze the mechanisms of their functioning.

METHODS

The selected centenarian group (10 persons) and a reference group (20 persons) who started aging (65 years) were examined with a sensitive set of neuropsychological tests and tasks in clinical-experimental assessment.

RESULTS

As expected, the centenarians' cognitive functions were different from those of the subjects who started aging, however, not in all aspects. For instance, the former scored significantly lower in the area of linguistic functions but the ability to plan and controlled perform complex visuospatial task with use of simultaneous and sequential strategies was preserved despite unfavorable symptoms of natural aging such as permanence attention as well as prolonged action time.

CONCLUSIONS

The results suggest that the studied centenarians show a dominant right-hemispheric pattern functioning not only in relation to perception, but also to planning and executing complex activities. The study and description of preserved neurocognition of centenarians was possible due to introducing a special procedure sensitive to the preserved functions.

Genetic variation in five genes important in telomere biology and risk for breast cancer

Telomeres, consisting of TTAGGG nucleotide repeats and a protein complex at chromosome ends, are critical for maintaining chromosomal stability. Genomic instability, following telomere crisis, may contribute to breast cancer pathogenesis. Many genes critical in telomere biology have limited nucleotide diversity, thus, single nucleotide polymorphisms (SNPs) in this pathway could contribute to breast cancer risk. In a population-based study of 1995 breast cancer cases and 2296 controls from Poland, 24 SNPs representing common variation in POT1, TEP1, TERF1, TERF2 and TERT were genotyped. We did not identify any significant associations between individual SNPs or haplotypes and breast cancer risk; however, data suggested that three correlated SNPs in TERT (−1381C>T, −244C>T, and Ex2-659G>A) may be associated with reduced risk of breast cancer among individuals with a family history of breast cancer (odds ratios 0.73, 0.66, and 0.57, 95% confidence intervals 0.53–1.00, 0.46–0.95 and 0.39–0.84, respectively). In conclusion, our data do not support substantial overall associations between SNPs in telomere pathway genes and breast cancer risk. Intriguing associations with variants in TERT among women with a family history of breast cancer warrant follow-up in independent studies.

The rate of conversion of mild cognitive impairment to dementia: predictive role of depression

BACKGROUND

Mild cognitive impairment (MCI) is a condition referring to the persons with cognitive deficits measurable in some form or another, but not meeting criteria for dementia, and who have an increased risk of becoming demented.

OBJECTIVE

To establish the rate of progression to dementia in MCI, to investigate the risk of conversion for amnestic vs multiple-domains subtypes, and to identify the predictors of progression.

METHODS

MCI (n = 105) individuals enrolled in a longitudinal study received annual clinical and psychometric examinations for up to a mean of 3 years. The diagnosis of MCI according to Mayo Clinic Petersen's Criteria was conducted by a panel of specialists.

RESULTS

After 3 years of follow-up, 23 of 105 subjects with MCI were diagnosed with dementia. 40 showed cognitive decline not dementia, 34 were stable and showed no cognitive decline or improvement, while eight showed cognitive improvement.

CONCLUSIONS

We conclude that conversion rate from MCI to DSM-IIIR dementia was 21.9% over a period of 3 years. The occurrence of depressive symptoms may constitute a predictor for those who are more likely to progress to dementia. The risk of conversion to dementia was higher among the subjects with an evidence of impairment extending beyond memory than with those who suffered only from memory deficits, and the subjects who converted to dementia in this subtype had significantly higher baseline plasma total homocysteine levels than non-converters.

Reproductive risk factors for endometrial cancer among Polish women

We conducted a population-based case-control study of reproductive factors in Warsaw and Lódź, Poland, in 551 incident endometrial cancer cases and 1925 controls. The reproductive variable most strongly related to risk was multiparity, with subjects with three or more births having a 70% lower risk than the nulliparous women. The reduced risk was particularly strong below 55 years of age. Subjects with older ages at a first birth were also at reduced risk even after adjustment for number of births. Ages at last birth or intervals since last birth were not strongly related to risk. Spontaneous abortions were unrelated to risk, but induced abortions were associated with slight risk increases (odds ratios=1.28, 95% confidence intervals 0.8-2.1 for 3+ vs no abortions). The absence of effects on risk of later ages at, or short intervals since, a last birth fails to support the view that endometrial cancer is influenced by mechanical clearance of initiated cells. Alternative explanations for reproductive effects should be sought, including alterations in endogenous hormones.

Occupational exposure to NDMA and NMor in the European rubber industry

Many nitrosamines are suspected of being human carcinogens, with the highest concentrations in the environment being measured in the rubber industry. Time trends of personal exposure to N-nitrosodimethylamine (NDMA) and to N-nitrosomorpholine (NMor) during the past two decades in the German rubber industry were analysed and compared with cross-sectional studies in the same period in the Netherlands, Poland, the UK and Sweden. In the majority of the surveyed departments exposures reduced over time, but considerable heterogeneity was present between departments and sectors. Significant reductions were primarily found in curing and post-treating departments and ranged from -3% year(-1) to -19% year(-1). In contrast, NDMA levels increased (+13% year(-1)) in maintenance and engineering in the tyres industry. Average NDMA-levels in general rubber goods (GRG) and NMor-levels in tyre production in Germany did not decrease significantly in the past two decades, whereas NDMA-levels in tyre production (-10% year(-1)) and NMor-levels in GRG (-7% year(-1)) declined significantly after the introduction of an exposure limit for total nitrosamines in Germany in 1988. Confidence intervals of average exposures in other studied countries largely overlap trends observed in Germany. Exposure to N-nitrosamines decreased on average two-to-five fold in the German rubber industry with comparable concentration levels in other European countries. Although average levels are well below the current limits exposure has not been eliminated, and incidental high exposures do still occur.

Hyperhomocysteinemia and methylenetetrahydrofolate reductase polymorphism in patients with Parkinson's disease

Elevated levels of homocysteine have been observed in Parkinson's disease (PD) patients treated with levodopa. However, it is not studied if duration of PD or PD per se is associated with hyperhomocysteinemia. In the present study, the levels of homocysteine in 99 levodopa-treated PD patients, 15 untreated PD patients and 100 controls were examined. We focused on the influence of levodopa dose, duration of therapy and disease as well as genetic (C677T methylenetetrahydrofolate reductase (MTHFR) polymorphism) and environmental factors. We found that levodopa-treated PD patients had elevated homocysteine plasma levels as compared to controls (p < 0.05), but the levels did not depend on levodopa doses. Another factor influencing homocysteine level was the duration of PD (p < 0.001). The frequency of allele C677T of MTHFR gene did not differ between PD and controls. In conclusion, hyperhomocysteinemia is associated with the duration of PD and levodopa treatment and possibly also with PD per se.

Established breast cancer risk factors by clinically important tumour characteristics

Breast cancer is a morphologically and clinically heterogeneous disease; however, it is less clear how risk factors relate to tumour features. We evaluated risk factors by tumour characteristics (histopathologic type, grade, size, and nodal status) in a population-based case-control of 2386 breast cancers and 2502 controls in Poland. Use of a novel extension of the polytomous logistic regression permitted simultaneous modelling of multiple tumour characteristics. Late age at first full-term birth was associated with increased risk of large (> 2 cm) tumours (odds ratios (95% confidence intervals) 1.19 (1.07-1.33) for a 5-year increase in age), but not smaller tumours (P for heterogeneity adjusting for other tumour features (Phet) = 0.007). On the other hand, multiparity was associated with reduced risk for small tumours (0.76 (0.68-0.86) per additional birth; Phet = 0.004). Consideration of all tumour characteristics simultaneously revealed that current or recent use of combined hormone replacement therapy was associated with risk of small (2.29 (1.66-3.15)) and grade 1 (3.36 (2.22-5.08)) tumours (Phet = 0.05 for size and 0.0008 for grade 1 vs 3), rather than specific histopathologic types (Phet = 0.63 for ductal vs lobular). Finally, elevated body mass index was associated with larger tumour size among both pre- and postmenopausal women (Phet = 0.05 and 0.0001, respectively). None of these relationships were explained by hormone receptor status of the tumours. In conclusion, these data support distinctive risk factor relationships by tumour characteristics of prognostic relevance. These findings might be useful in developing targeted prevention efforts.

Skewed X chromosome inactivation and early-onset breast cancer

BACKGROUND

Skewed X chromosome inactivation may be more common in women with epithelial ovarian cancer and early-onset breast cancer. We tested this hypothesis in a group of 235 breast cancer patients and 253 controls (mean age 45.8 years) from a larger population based case control study.

METHODS

We measured X chromosome inactivation with the AR gene assay in lymphocyte DNA digested with the methylation specific enzyme HpaII. We judged skewness using an adjusted measure (relative to the undigested sample) with a cut point of 75%, and an unadjusted measure where skewed was defined as > 90% of the signal from one allele in the HpaII digested sample.

RESULTS

There were no significant differences in any of the skewing measures between cases and controls. Using the adjusted skewing measure among pre-menopausal subjects under the age of 50, 14% of cases versus 11% of controls were skewed, OR = 1.2, 95% CI 0.6 to 2.3; using the unadjusted measure, OR = 0.9, 95% CI 0.4 to 2.0.

CONCLUSIONS

While we cannot rule out a subtle difference of approximately twofold or less, we have failed to find a significant difference in the prevalence of skewed X chromosome inactivation in younger women with breast cancer compared to controls.

Polymorphisms within the prion (PrP) and prion-like protein (Doppel) genes in AD

The authors present a study on the association of PRNP and PRND gene polymorphisms with the occurrence and age at onset of Alzheimer's disease (AD). DNA from 79 Polish patients with probable AD and 107 healthy control subjects was studied. The PRNP codon 129 homozygosity seemed to be associated with the occurrence of AD: In AD patients, the percentage of Val/Val and Met/Met genotypes was higher than in the control subjects. A significant difference appeared also between early-onset (<70 years) and late-onset (> or = 70 years) AD patients in the PRND genotypes.

Homocysteine, apolipoproteine E and methylenetetrahydrofolate reductase in Alzheimer's disease and mild cognitive impairment

BACKGROUND

Alzheimer's disease (AD) is the most common dementia disorder in elderly people. Currently, the only known genetic factor associated with the development of sporadic AD is the apolipoprotein E (ApoE) 4 allele. There is a need to identify other environmental and genetic risk factors that could modulate the risk of developing sporadic AD.

OBJECTIVE

To analyse the correlation between the ApoE and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and plasma homocysteine levels and vitamins (B(12) and folic acid) concentrations in serum from patients with AD and mild cognitive impairment (MCI) as compared with control group.

METHODS

The study was carried out in 99 AD patients, 98 subjects with MCI and 100 healthy subjects. Diagnosis of probable AD was made according to the NINCDS-ADRDA and DSM-IV criteria. The following factors were analysed: age, gender, duration of disease, concentration of plasma total homocysteine, folic acid and vitamin B(12) in the serum and the polymorphism of MTHRF and ApoE genes. The results obtained were analysed by multivariate analysis of regression.

RESULTS

We found that plasma total homocysteine is increased in AD patients (p < 0.0001) and depended on the MTHFR T/T genotype in the presence of low folate levels (p < 0.05). The increased frequency of ApoE4 allele in the AD population was independent of homocysteine, folic acid and vitamin B(12) levels and MTHFR status.

CONCLUSIONS

We conclude that the concentration of plasma total homocysteine is increased in AD patients. This may be associated with the T/T genotype in the MTHFR gene; however, the distribution of the MTHRF C677T polymorphism in the Polish population does not differ in AD and controls.

Behavioural pathology in Alzheimer's disease with special reference to apolipoprotein E genotype

The aim of this study was to define the co-occurrence of behavioural symptoms and Alzheimer's disease (AD) in relation to apolipoprotein E (APOE) genotype. Probable AD patients from the Alzheimer's Day Clinic (n = 139) were assessed with the 'Behavioural Pathology in Alzheimer's Disease' rating scale, and their APOE genotype was determined. This study demonstrated no relationship between presence of the APOE epsilon4 allele and any of the behavioural symptoms assessed, including delusions, hallucinations, depression, activity disturbances, aggressiveness and anxiety. Activity disturbances, delusions, hallucinations and aggressiveness paralleled the severity of AD, increasing in frequency with the severity of the dementia. The prevalence of delusions, hallucinations, aggressiveness and depression were found to be associated with lower levels of education.