The -786T>C promoter polymorphism of the NOS3 gene is associated with prostate cancer progression.
BACKGROUND
There is no biological or epidemiological data on the association between NOS3 promoter polymorphisms and prostate cancer. The polymorphisms in the promoter region of NOS3 gene may be responsible for variations in the plasma NO, which may promote cancer progression by providing a selective growth advantage to tumor cells by angiogenic stimulus and by direct DNA damage.


METHODS
This study aimed evaluating the NOS3 promoter polymorphisms by PCR-SSCP and sequencing, associating genotypes and haplotypes with NOS3 expression levels through semi-quantitative RT-PCR, and with PCA3 mRNA detection, a specific tumor biomarker, in the peripheral blood of pre-surgical samples from 177 patients; 83 PCa and 94 BPH.


RESULTS
Three novel SNPs were identified -764A>G, -714G>T and -649G>A in the NOS3 gene promoter region, which together with the -786T>C generated four haplotypes (N, T, C, A). NOS3 gene expression levels were affected by the -786T>C polymorphism, and there was a 2-fold increase in NOS3 levels favored by the incorporation of each C allele. NOS3 levels higher than 80% of the constitutive gene expression level (B2M) presented a 4-fold increase in PCa occurrence.


CONCLUSIONS
The -786T>C polymorphism was the most important promoter alteration of the NOS3 gene that may affect the PCa progression, but not its occurrence, and the incorporation of the C allele is associated with increased levels of NOS3 transcripts. The NOS3 transcript levels presented a bimodal behavior in tumor development and may be used as a biomarker together with the PCA3 marker for molecular staging of the prostate cancer.
Marangoni
Karina
K
Federal University of Uberlândia, Institute of Genetics and Biochemistry, Molecular Genetics Laboratory, Campus Umuarama, Block 2E, Room 24, 38400-902, Uberlândia, MG, Brazil. kmarangoni@yahoo.com.br
Araújo
Thaíse G
TG
Neves
Adriana F
AF
Goulart
Luiz R
LR
D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics; D016009:Chi-Square Distribution; D003720:Densitometry; D018450:Disease Progression; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D052250:Nitric Oxide Synthase Type III / Q000235:genetics*; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology; D012044:Regression Analysis; D018709:Statistics, Nonparametric; D001613:beta 2-Microglobulin / Q000235:genetics
D014408:Biomarkers, Tumor; D001613:beta 2-Microglobulin; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III