Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2008-2-18
pubmed:abstractText
Calcitriol (1alpha,25-dihydroxyvitamin D(3)), the active metabolite of vitamin D, has recently emerged as a promising therapeutic agent in the treatment of prostate cancer, the second most common cause of cancer death in American males. In the present study, we have analyzed the effects of calcitriol treatment on the expression and activity of the UDP-glucuronosyltransferase (UGT) 2B15 and 2B17 in prostate cancer LNCaP and 22Rv1 cells. These two enzymes share a crucial role in the inactivation of androgens in the human prostate. We report that calcitriol treatment results in lower glucuronide conjugation of the active androgen dihydrotestosterone and its reduced metabolites androstane-3alpha-diol and androsterone in LNCaP cells. The same treatment also drastically decreased the mRNA and protein levels of UGT2B15 and UGT2B17 in LNCaP and 22Rv1 cells. Using casodex, an androgen receptor (AR) antagonist, and AR-specific small interfering RNA probes, we show that calcitriol requires a functional AR to inhibit the expression of the UGT2B17 gene in LNCaP cells. By contrast, transient transfection and site-directed mutagenesis experiments revealed that calcitriol down-regulates UGT2B15 promoter activity through a responsive region between positions -171 and -113 bp. In conclusion, the present study identifies the vitamin D receptor activator calcitriol as a negative regulator of the UGT2B15- and UGT2B17-dependent inactivation of androgens in prostate cancer LNCaP cells. Androgens promote prostate cancer cell proliferation; thus, the reduction of their inactivation could have a limiting effect of the calcitriol antiproliferative properties in prostate cancer cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1535-7163
pubmed:author
pubmed:issnType
Print
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
380-90
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Calcitrol (1alpha,25-dihydroxyvitamin D3) inhibits androgen glucuronidation in prostate cancer cells.
pubmed:affiliation
Centre Hospitalier Universitaire de Québec-Laval University Hospital Centre Research Center, Laval university, Sainte-Foy, Quebec, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't