Comparison of organochlorine chemical body burdens of female breast cancer cases with cancer free women in Rio Grande do Sul, Brazil--Pilot Study

This pilot study collected preliminary data to examine known and suspected breast cancer risk factors among women living in rural and urban areas in the state of Rio Grande do Sul, Brazil by questionnaire. In addition, the body burden levels of a panel of organochlorines was measured in a small clinic-based prospective sample

Relationship between intratumoral expression of genes coding for xenobiotic-metabolizing enzymes and benefit from adjuvant tamoxifen in estrogen receptor alpha-positive postmenopausal breast carcinoma

INTRODUCTION: Little is known of the function and clinical significance of intratumoral dysregulation of xenobiotic-metabolizing enzyme expression in breast cancer. One molecular mechanism proposed to explain tamoxifen resistance is altered tamoxifen metabolism and bioavailability. METHODS: To test this hypothesis, we used real-time quantitative RT-PCR to quantify the mRNA expression of a large panel of genes coding for the major xenobiotic-metabolizing enzymes (12 phase I enzymes, 12 phase II enzymes and three members of the ABC transporter family) in a small series of normal breast (and liver) tissues, and in estrogen receptor alpha (ERα)-negative and ERα-positive breast tumors. Relevant genes were further investigated in a well-defined cohort of 97 ERα-positive postmenopausal breast cancer patients treated with primary surgery followed by adjuvant tamoxifen alone. RESULTS: Seven of the 27 genes showed very weak or undetectable expression in both normal and tumoral breast tissues. Among the 20 remaining genes, seven genes (CYP2A6, CYP2B6, FMO5, NAT1, SULT2B1, GSTM3 and ABCC11) showed significantly higher mRNA levels in ERα-positive breast tumors than in normal breast tissue, or showed higher mRNA levels in ERα-positive breast tumors than in ERα-negative breast tumors. In the 97 ERα-positive breast tumor series, most alterations of these seven genes corresponded to upregulations as compared with normal breast tissue, with an incidence ranging from 25% (CYP2A6) to 79% (NAT1). Downregulation was rare. CYP2A6, CYP2B6, FMO5 and NAT1 emerged as new putative ERα-responsive genes in human breast cancer. Relapse-free survival was longer among patients with FMO5-overexpressing tumors or NAT1-overexpressing tumors (P = 0.0066 and P = 0.000052, respectively), but only NAT1 status retained prognostic significance in Cox multivariate regression analysis (P = 0.0013). CONCLUSIONS: Taken together, these data point to a role of genes coding for xenobiotic-metabolizing enzymes in breast tumorigenesis, NAT1 being an attractive candidate molecular predictor of antiestrogen responsiveness

Interindividual variation in CYP1A1 expression in breast tissue and the role of genetic polymorphism.

The cytochrome P4501A1 (CYP1A1) enzyme is regulated at the transcriptional level and its expression is influenced by genetic factors, polymorphisms in the structural and regulatory genes, and by environmental factors such as exposure to polycyclic aromatic hydrocarbons (PAHs). To investigate the role of CYP1A1 in breast cancer, we studied CYP1A1 expression in breast tissue, thereby taking all possible modifying factors into account. We measured CYP1A1 expression in 58 non-tumor breast tissue specimens from both breast cancer patients (n = 26) and cancer-free individuals (n = 32) using a newly developed reverse transcription-polymerase chain reaction assay. CYP1A1 expression varied between specimens approximately 400-fold and was independent of age. CYP1A1 expression was somewhat higher in tissue from breast cancer patients than in that from cancer-free individuals, but this difference was not statistically significant. Analysis for CYP1A1 genetic polymorphisms revealed eight variants, seven in the cancer-free group and one in the patient group. The variant genotype was not a good predictor of expression level. We conclude that high CYP1A1 expression could be a risk factor for breast cancer and that the known CYP1A1 polymorphisms are not good predictors of CYP1A1 expression

Interindividual variation in CYP1A1 expression in breast tissue and the role of genetic polymorphism.

The cytochrome P4501A1 (CYP1A1) enzyme is regulated at the transcriptional level and its expression is influenced by genetic factors, polymorphisms in the structural and regulatory genes, and by environmental factors such as exposure to polycyclic aromatic hydrocarbons (PAHs). To investigate the role of CYP1A1 in breast cancer, we studied CYP1A1 expression in breast tissue, thereby taking all possible modifying factors into account. We measured CYP1A1 expression in 58 non-tumor breast tissue specimens from both breast cancer patients (n = 26) and cancer-free individuals (n = 32) using a newly developed reverse transcription-polymerase chain reaction assay. CYP1A1 expression varied between specimens approximately 400-fold and was independent of age. CYP1A1 expression was somewhat higher in tissue from breast cancer patients than in that from cancer-free individuals, but this difference was not statistically significant. Analysis for CYP1A1 genetic polymorphisms revealed eight variants, seven in the cancer-free group and one in the patient group. The variant genotype was not a good predictor of expression level. We conclude that high CYP1A1 expression could be a risk factor for breast cancer and that the known CYP1A1 polymorphisms are not good predictors of CYP1A1 expression

Interindividual variation in CYP1A1 expression in breast tissue and the role of genetic polymorphism.

The cytochrome P4501A1 (CYP1A1) enzyme is regulated at the transcriptional level and its expression is influenced by genetic factors, polymorphisms in the structural and regulatory genes, and by environmental factors such as exposure to polycyclic aromatic hydrocarbons (PAHs). To investigate the role of CYP1A1 in breast cancer, we studied CYP1A1 expression in breast tissue, thereby taking all possible modifying factors into account. We measured CYP1A1 expression in 58 non-tumor breast tissue specimens from both breast cancer patients (n = 26) and cancer-free individuals (n = 32) using a newly developed reverse transcription-polymerase chain reaction assay. CYP1A1 expression varied between specimens approximately 400-fold and was independent of age. CYP1A1 expression was somewhat higher in tissue from breast cancer patients than in that from cancer-free individuals, but this difference was not statistically significant. Analysis for CYP1A1 genetic polymorphisms revealed eight variants, seven in the cancer-free group and one in the patient group. The variant genotype was not a good predictor of expression level. We conclude that high CYP1A1 expression could be a risk factor for breast cancer and that the known CYP1A1 polymorphisms are not good predictors of CYP1A1 expression

Method for measuring the size distribution of airborne rhinovirus

About 50% of viral-induced respiratory illnesses are caused by the human rhinovirus (HRV). Measurements of the concentrations and sizes of bioaerosols are critical for research on building characteristics, aerosol transport, and mitigation measures. We developed a quantitative reverse transcription-coupled polymerase chain reaction (RT-PCR) assay for HRV and verified that this assay detects HRV in nasal lavage samples. A quantitation standard was used to determine a detection limit of 5 fg of HRV RNA with a linear range over 1000-fold. To measure the size distribution of HRV aerosols, volunteers with a head cold spent two hours in a ventilated research chamber. Airborne particles from the chamber were collected using an Andersen Six-Stage Cascade Impactor. Each stage of the impactor was analyzed by quantitative RT-PCR for HRV. For the first two volunteers with confirmed HRV infection, but with mild symptoms, we were unable to detect HRV on any stage of the impactor

Interindividual variation in CYP1A1 expression in breast tissue and the role of genetic polymorphism.

The cytochrome P4501A1 (CYP1A1) enzyme is regulated at the transcriptional level and its expression is influenced by genetic factors, polymorphisms in the structural and regulatory genes, and by environmental factors such as exposure to polycyclic aromatic hydrocarbons (PAHs). To investigate the role of CYP1A1 in breast cancer, we studied CYP1A1 expression in breast tissue, thereby taking all possible modifying factors into account. We measured CYP1A1 expression in 58 non-tumor breast tissue specimens from both breast cancer patients (n = 26) and cancer-free individuals (n = 32) using a newly developed reverse transcription-polymerase chain reaction assay. CYP1A1 expression varied between specimens approximately 400-fold and was independent of age. CYP1A1 expression was somewhat higher in tissue from breast cancer patients than in that from cancer-free individuals, but this difference was not statistically significant. Analysis for CYP1A1 genetic polymorphisms revealed eight variants, seven in the cancer-free group and one in the patient group. The variant genotype was not a good predictor of expression level. We conclude that high CYP1A1 expression could be a risk factor for breast cancer and that the known CYP1A1 polymorphisms are not good predictors of CYP1A1 expression