Association of Angiotensin I Converting Enzyme Insertion/287 bp Deletion Polymorphisms and Proliferative Prostatic Diseases among Lebanese Men.

BACKGROUND: Angiotensin I converting enzyme (ACE) insertion (I) and 287 bp Alu repeat DNA fragment deletion (D) polymorphisms have been indicated in various cancers. Here, we investigated I/D polymorphisms in prostate cancer (PCa) and benign prostate hyperplasia (BPH) among Lebanese men. METHODS: Blood DNA extracted from 69 control subjects, 69 subjects with clinically confirmed PCa, and 69 subjects with clinical BPH, all the subjects were aged 50 years or older, was subjected to the polymerase chain reaction. The PCR products were resolved in polyacrylamide gels to determine II, ID, and DD genotypes. The odds ratios (OR), 95% confidence intervals (CI), and p values of the allele frequencies and genotype ratios were calculated for establishing possible association of the alleles and/or genotypes and PCa and/or BPH. RESULTS: The proportions of II, ID, and DD genotypes were significantly different from Hardy-Weinberg equilibrium for BPH and PCa groups (but not the control group), mostly due to overabundance of the ID genotypes. There was no significant difference in the I and D allele frequencies between the control groups and the affected groups. The ratio of (DD + ID)/II is significantly lower among the control group compared to the BPH group (RR = 8.92, p values of the allele frequencies and genotype ratios were calculated for establishing possible association of the alleles and/or genotypes and PCa and/or BPH. p values of the allele frequencies and genotype ratios were calculated for establishing possible association of the alleles and/or genotypes and PCa and/or BPH. CONCLUSIONS: Our data indicate that the D allele of the I/D polymorphisms of the ACE gene is associated with increased risk of BPH, and the ID genotype is a risk factor for both BPH and PCa among Lebanese males.

Association of Some Polymorphisms in the VDR Gene, CYP17 Gene and SRD5A2 Gene and Prostate Cancer among Lebanese Men

Aims: The goal of the study was to investigate possible association of some single nucleotide polymorphisms (SNPs) in the VDR gene (the FokI, BsmI, ApaI and TaqαI loci), and the CYP17 gene (the MspA1I locus), and 0 or 9 TA repeats in the SRD5A2 gene, and prostate cancer (PCa) among Lebanese men. Materials and Methods: Blood DNA of 69 subjects with confirmed PCa and 69 controls, all about 50 years of age or older, was subjected to PCR or PCR-restriction fragment-length polymorphism (PCR-RFLP) analyses, and the risk-bearing and the protective alleles were identified. The odds ratio (OR) of having a genotype and the relative risk (RR) of developing PCa were calculated. In addition, the distributions of homozygosis and heterozygosis in the risk-bearing alleles and the protective alleles among the control and the PCa groups were compared. Results: The f allele of the VDR FokI locus and the (TA) 9 repeat allele of the SRD5A2 gene were found to be associated with increased risks of PCa (p = 0.006 and 0.050, respectively). Homozygosis in the risk-bearing alleles was rare both in the control and the PCa groups. A higher fraction of the controls compared to the PCa group was double-homozygous in the two protective alleles (52.2% for controls, 24.6% for PCa group, p = <0.001). Conclusions: To the best of our knowledge, this is the first genetic study demonstrating the association of certain polymorphisms of the VDR gene and the SDR5A2 gene and increased risk of PCa among Lebanese men. Our study also indicates that the overall polymorphism profile of all genes involved in the prostate physiology is likely to be a better indicator for PCa risk than the polymorphisms in the individual genes.

Long-term stability of thyroid hormones and DNA in blood spots kept under varying storage conditions.

BACKGROUND: Congenital hypothyroidism is screened using blood spotted on filter paper that may be transported from remote areas to central testing facilities. However, storage conditions and transportation may affect sample quality. METHODS: We examined long-term stability of thyroid-stimulating hormone (TSH) and thyroxin (TT4) in blood spotted on filter paper, which was stored at room temperature (RT), 4°C and -20°C under continuous or intermittent power supply (six hours on and six hours off around the clock.) Hormone levels in the discs were measured periodically for up to ten years. Extraction of DNA from blood spots and polymerase chain reaction were performed. RESULTS: Our results showed that TT4 was stable for up to 6.1, 5.34 and 5.16 years when stored at -20°C, 4°C and RT, respectively. TSH was stable for up to 2.7 years at RT, and for up to 6.5 and 4.1 years when stored at -20°C and 4°C, respectively, under continuous power supply. However, under intermittent power supply, TSH was stable for up to 3.8 and 2.5 years when stored at 4°C and -20°C, respectively. Mitochondrial cytochrome oxidase and sex-determining region of Y chromosome genes were successfully amplified from DNA extracted from the blood spots. CONCLUSION: Our data indicate that TT4 and TSH are most stable in blood spots stored at -20°C under continuous power supply. However, they can be stored at RT or at 4°C and -20°C under interrupted power supply for at least 2.5 years. Moreover, the DNA extracted from the blood spots was intact and suitable for genetic studies.

Stability of total and free prostate specific antigen in serum submitted to intermittent cold storage conditions.

The goal of this study was to determine the stability of Total Prostrate Specific antigen (PSA-T) and Free Prostrate Specific Antigen (PSA-F) in archival serum stored at 4°C and -20°C and subjected to temperature shift due to interruption in power supply. Our study showed that PSA-T was stable up to 285 days and PSA-F was stable for 158 days under these conditions. Since power supply interruption is an unavoidable problem in developing nations, our study has implication on the validity of measurement of PSA-T and PSA-F in serum that was not properly stored due to emergency situations and for certain types of retrospective studies.