Frequency of common CYP1B1 polymorphic variations in Delhi population of Northern India

CYP1B1 G199T Polymorphism Affects Prognosis of NSCLC Patients with the Potential to Be an Indicator and Target for Precise Drug Intervention

CYP1B1 gene single nucleotide polymorphisms G119T, C432G, and A453G were tested among 164 NSCLC patients treated by Video-Assisted Thoracoscopic Surgery. After a follow-up period of 5 years, it was found that CYP1B1 G119T mutant genotypes were related to a higher risk of tumor recurrence and death after surgical resection. However, C432G and A453G genotypes had no influence on long-term prognosis of the study cohort. Thus, G199T alleles are supposed to be an auxiliary predictor for prognosis of NSCLC patients and a potential target for precise drug intervention, as well as a candidate for further anticancer drug research.

The association of Asn453Ser polymorphism in CYP1B1 gene with selected somatic and biochemical variables in Slovak women of different menopause status

OBJECTIVE

The aim of this study was to determine the relationship between the CYP1B1 Asn453Ser polymorphism and selected somatic and biochemical variables, and atherogenic indices in premenopausal and postmenopausal Slovak women.

METHODS

The studied sample consisted of 334 women; 188 premenopausal (mean age 45.73 ± 3.77 y) and 146 postmenopausal women (mean age 53.51 ± 4.52 y). The participants were interviewed during their medical examination. They provided a blood sample for biochemical analysis and DNA genotyping.

RESULTS

The frequency of rare allele Ser (CYP1B14) was equal to 0.125 in premenopausal and 0.168 in postmenopausal women. The observed genotype frequencies were in the Hardy-Weinberg equilibrium. The Asn453Ser genotype showed statistically significant associations with a high-density lipoprotein (HDL-cholesterol) and apolipoprotein A1 levels in postmenopausal women. The mean values of the above mentioned variables were significantly higher in women carrying the Ser/Ser genotype. The general linear model analysis confirmed the results of the additive genetic model in postmenopausal women and demonstrated significant association of the Asn453Ser polymorphism with HDL-cholesterol levels also in premenopausal women (P = 0.041).

CONCLUSIONS

This pilot study revealed a significant association of the CYP1B1 Asn453Ser genotypes with the plasma levels of HDL-cholesterol and of apolipoprotein A1 in postmenopausal women and less unequivocal findings in premenopausal women. Because of study limitations, these results need to be examined in a larger study.

Interethnic differences of cytochrome P450 gene polymorphisms may influence outcome of taxane therapy in Roma and Hungarian populations

Taxanes are widely used microtubule-stabilizing chemotherapeutic agents in the treatment of cancers. Several cytochrome P450 gene variants have been proven to influence taxane metabolism and therapy. The purpose of this work was to determine the distribution of genetic variations of CYP1B1, CYP2C8 and CYP3A5 genes as the first report on taxane metabolizer cytochrome P450 gene polymorphisms in Roma and Hungarian populations. A total of 397 Roma and 412 Hungarian healthy subjects were genotyped for CYP1B1 c.4326C > G, CYP2C8 c.792C > G and CYP3A5 c.6986A > G variant alleles by PCR-RFLP assay and direct sequencing. We found significant differences in the frequencies of homozygous variant genotypes of CYP1B1 4326 GG (p = 0.002) and CYP3A5 6986 GG (p < 0.001) between Roma and Hungarian populations. Regarding minor allele frequencies, for CYP2C8 a significantly increased prevalence was found in 792G allele frequency in the Hungarian population compared to the Roma population (5.83% vs. 2.14%, p = 0.001). Our results can be used as possible predictive factors in population specific treatment algorithms to developing effective programs for a better outcome in patients treated with taxanes.

Association of CYP1A1, CYP1B1 and CYP17 gene polymorphisms and organochlorine pesticides with benign prostatic hyperplasia

It is well established that steroidal hormones (testosterone and estrogen) increase benign prostatic hyperplasia (BPH) risk. Cytochrome P450 (CYP) enzymes especially CYP1A1, CYP1B1 and CYP17 metabolize these hormones. Apart from that, several endocrine disrupting organochlorine pesticides (OCPs) are reported to mimic the activity of these steroidal hormones. Therefore, functional polymorphisms in these genes and exposure to such pesticides may increase BPH risk further. Our study included 100 newly diagnosed BPH subjects and 100 age-matched healthy male controls. CYP1A1, CYP1B1 and CYP17 polymorphisms were studied using PCR-RFLP and allele-specific PCR method. OCP levels in blood were analyzed by gas chromatography (GC). Levels of p,p'-DDE and endosulfan α were found to be significantly higher amongst BPH subjects as compared to controls (p-values=0.001 and 0.03 respectively) and CYP17 polymorphism was observed to be significantly associated with BPH subjects as compared to controls (p-values=0.03), indicating that these factors may be important risk factors for BPH. However, further studies are required before unequivocal conclusion.

Polymorphic variation of CYP1A1 and CYP1B1 genes in a Haryana population

Cytochrome P450 (CYP) 1A1 and CYP1B1 are important phase I xenobiotic metabolizing enzymes involved in the metabolism of numbers of toxins, endogenous hormones, and pharmaceutical drugs. Polymorphisms in these phase I genes can alter enzyme activity and are known to be associated with cancer susceptibility related to environmental toxins and hormone exposure. Their genotypes may also display ethnicity-dependent population frequencies. The present study was aimed to determine the frequencies of commonly known functional polymorphisms of CYP1A1 and CYP1B1 genes in a Haryana state population of North India. The allelic frequency of CYP1A1 polymorphism m1 (MspI) was 29.65% and m2 (Ile(462)Val) was 24.85%. The frequency of CYP1B1 polymorphism m1 (Val(432)Leu) was 45.85% and m2 (Asn(453)Ser) was 16.2%. We observed inter- and intra-ethnic variation in the frequency distribution of these polymorphisms. Analysis of polymorphisms in these genes might help in predicting the risk of cancer. Our results emphasize the need for more such studies in high-risk populations.

CYP1A1 and CYP3A4 polymorphic variations in Delhi population of Northern India

Cytochrome P450 (CYP) 1A1 and CYP3A4 are important phase I xenobiotic metabolizing enzymes involved in the metabolism of numbers of toxins, endogenous hormones and pharmaceutical drugs. Polymorphisms in these phase I genes can alter enzyme activity and are known to be associated with cancer susceptibility related to environmental toxins and hormone exposure. Their genotypes may also display ethnicity dependent population frequencies. The present study was aimed to determine the frequencies of commonly known functional polymorphisms of CYP1A1 and CYP3A4 in North Indian population. Allelic frequency of CYP1A1 polymorphisms, m1, m2 and m4 were observed to be 40.3, 31.2 and 0% respectively. Frequency of CYP3A4*1B polymorphism was 0%. We observed inter as well as intra ethnic variation in the distribution of frequency of these polymorphisms. Analysis of polymorphisms in these genes might help in predicting the risk of cancer. Our results emphasize the need for more such studies in "high risk populations".