Short rare hTERT-VNTR2-2nd alleles are associated with prostate cancer susceptibility and influence gene expression.
BACKGROUND
The hTERT (human telomerase reverse transcriptase) gene contains five variable number tandem repeats (VNTR) and previous studies have described polymorphisms for hTERT-VNTR2-2nd. We investigated how allelic variation in hTERT-VNTR2-2nd may affect susceptibility to prostate cancer.


METHODS
A case-control study was performed using DNA from 421 cancer-free male controls and 329 patients with prostate cancer. In addition, to determine whether the VNTR polymorphisms have a functional consequence, we examined the transcriptional levels of a reporter gene linked to these VNTRs and driven by the hTERT promoter in cell lines.


RESULTS
Three new rare alleles were detected from this study, two of which were identified only in cancer subjects. A statistically significant association between rare hTERT-VNTR2-2nd alleles and risk of prostate cancer was observed [OR, 5.17; 95% confidence interval (CI), 1.09-24.43; P = 0.021]. Furthermore, the results indicated that these VNTRs inserted in the enhancer region could influence the expression of hTERT in prostate cancer cell lines.


CONCLUSIONS
This is the first study to report that rare hTERT VNTRs are associated with prostate cancer predisposition and that the VNTRs can induce enhanced levels of hTERT promoter activity in prostate cancer cell lines. Thus, the hTERT-VNTR2-2nd locus may function as a modifier of prostate cancer risk by affecting gene expression.
Yoon
Se-Lyun
SL
Department of Biology and Biomedical Science, Dong-A University, Busan, South Korea.
Jung
Se-Il
SI
Do
Eun-Ju
EJ
Lee
Se-Ra
SR
Lee
Sang-Yeop
SY
Chu
In-Sun
IS
Kim
Wun-Jae
WJ
Jung
Jaeil
J
Kim
Choung Soo
CS
Cheon
Sang-Hyeon
SH
Leem
Sun-Hee
SH
D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D016022:Case-Control Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D011379:Prognosis; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology; D019098:Telomerase / Q000235:genetics*
D008156:Luciferases; C509186:TERT protein, human; D019098:Telomerase