(*) shows nucleotides at positions -1602 (A), -871 (B), -862 to -858 (C), -315 (D), and -191 (E) of thep16INK4apromoters

(*) shows nucleotides at positions -1602 (A), -871 (B), -862 to -858 (C), -315 (D), and -191 (E) of thep16INK4apromoters. results indicate that this promoter sequences of these genes differ among normal Japanese individuals and that polymorphisms can alter gene transcription activity. Keywords:Murine double minute 2, polymorphism, p16INK4a, p53, transcription == Introduction == Different populations exhibit sequence polymorphisms of the murine double minute 2 (MDM2) gene (Atwalet al., 2007), a target gene of the transcription factor p53. A promoter polymorphism of theMDM2gene, SNP309, is located in the intron 1 region of the gene and influences transcriptional regulation in a cell collection expressing wild-type p53 (Bondet al., 2004). Non-cancerous control subjects frequently have a polymorphism of p53 at codon 72 (Wuet al., 1995;Minaguchiet al., 1998), and this common polymorphism differentially alters promoter activity of theMDM2gene that contains the SNP309 polymorphism (Yanget al., 2007). Cytosine-phospho-guanine (CpG) dinucleotides are methylated by DNA methyltransferase (DNMT) (Siedlecki and Zielenkiewicz, 2006), and the methylated form interacts with methyl-CpG-binding proteins (Fan and Hutnick, 2005), which serve as modulators of gene transcription. CpG methylation in the promoter region ofp53decreases promoter activity of the gene (Schroeder and Mass, 1997). Genomic DNA obtained from blood of people exposed to arsenic has been reported to exhibit methylation at the promoter regions ofp53andp16INK4a, a cycline-dependent kinase inhibitor, and the DNA methylation status of these promoters differs among people (Chandaet al., 2006). Normal populations have polymorphisms inDNMT; a polymorphismDNMT3Laffects the ability of this gene to activate Mavoglurant racemate DNA methylation (El-Maarriet al., 2009). Nucleotide substitutions in thep53promoter at 4 mutated positions, including position -250, and in thep16INK4apromoter at positions -735, -493, and -191 are found not only in Taiwanese patients with uterine leiomyoma (Hsiehet al., 2007) and frequently in melanoma families from other populations (Harlandet al., 2000) but also in control groups;p53promoter polymorphism at position -250 andp16INK4apromoter polymorphism at position -191 are located within CpG dinucleotides. Thus, control subjects, including normal populations, exhibit gene promoter polymorphisms. However, no studies have investigated differences at other nucleotide positions inMDM2,p53, andp16INK4apromoter sequences among healthy individuals. Rabbit polyclonal to PNO1 In addition, it has not been decided Mavoglurant racemate whether known polymorphisms in the promoter sequence of these genes are present in other normal populations and alter gene promoter activity in other cell lines. A number of polymorphisms have been recognized in 10 Mavoglurant racemate ENCODE (Encyclopedia of DNA Elements) regions in the human genome of 48 individuals from 4 populations, including 8 Japanese individuals. Moreover, the frequency distributions of these polymorphisms have been investigated among different populations (International HapMap Consortium, 2005). In the present study, we sequenced theMDM2andp53promoters and thep16INK4apromoter nucleotides at positions -735, -493, and -191 from genomic DNA extracted from whole blood samples obtained from healthy Japanese individuals and decided whether these promoter polymorphisms impact gene promoter activity in cell lines expressing mutant or wild-type p53. We found that normal Japanese individuals exhibit polymorphisms in these regions of theMDM2,p53, andp16INK4agenes and that these polymorphisms alter promoter activity in some cell lines. == Materials and Methods == == Extraction of genomic DNA == Human peripheral blood was obtained from 17 healthy Japanese students, who consented to have their DNA sequenced for identification of polymorphisms. Genomic DNA was extracted from whole blood by using a QIAamp DNA Blood Mini kit (Qiagen, Hilden, Germany). DNA analysis of the samples showed that this frequency of generally known polymorphisms (Kadowakiet al., 1995;Eguchi-Ishimaeet al., 2005) was comparable to that previously recognized in control Japanese subjects. == Amplification of promoter regions by polymerase chain reaction == Promoter sequences of theMDM2genes were amplified by polymerase chain reaction (PCR) in a reaction mixture made up of genomic DNA (0.1 g) and MDM2 primers (Table 1) in the presence Mavoglurant racemate or absence of 5% dimethyl sulfoxide with DNA polymerase (KOD-Plus DNA polymerase (Takagiet Mavoglurant racemate al., 1997); Toyobo, Osaka, Japan) according to the manufacturer’s instructions. The amplification was performed in a.