Unknown

Dataset Information

0

A pharmacodynamic study of rapamycin in men with intermediate- to high-risk localized prostate cancer.


ABSTRACT: PURPOSE:Given discrepancies between preclinical and clinical observations of mammalian target of rapamycin (mTOR) inhibition in prostate cancer, we sought to determine the pharmacodynamic effects of the mTOR/TORC1 inhibitor rapamycin in men with intermediate- to high-risk prostate cancer undergoing radical prostatectomy. EXPERIMENTAL DESIGN:Rapamycin was given at 3 or 6 mg orally for 14 days before radical prostatectomy in men with multifocal Gleason sum > or =7 prostate cancer; 10 untreated control subjects were included. The primary outcome was inhibition of phosphorylation of ribosomal S6 in posttreatment radical prostatectomy versus pretreatment biopsy tumor tissue, evaluated using a Simon two-stage design for pharmacodynamic efficacy. RESULTS:Thirty-two subjects were accrued: 20 at 3 mg, 2 at 6 mg, and 10 controls. No dose-limiting toxicities were observed at 3 mg; however, two of two men enrolled at 6 mg experienced dose-limiting toxicities including thrombocytopenia and fever with grade 3 stomatitis. Adverse events observed at 3 mg included stomatitis, rash, ileus, and neutropenia. Pharmacodynamic studies showed tumor S6 phosphorylation inhibition in 50% of 10 evaluable rapamycin-treated men with sufficient paired tissue [median 58% inhibition (P = 0.049) versus 2% inhibition in controls (P = 0.75)] with no significant effect on AKT activity. We observed no change in Ki-67 or caspase-3 cleavage but noted a reduction in cytoplasmic p27 staining with increased nuclear localization with rapamycin treatment. Prostate tissue rapamycin concentrations were 3- to 4-fold higher than blood. CONCLUSIONS:At 3 mg daily, rapamycin successfully and safely inhibited prostate cancer S6 phosphorylation and achieved relatively high prostate tissue concentrations. No effect on AKT phosphorylation, tumor proliferation, or apoptosis was observed.

SUBMITTER: Armstrong AJ 

PROVIDER: S-EPMC3035576 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature

altmetric image

Publications

A pharmacodynamic study of rapamycin in men with intermediate- to high-risk localized prostate cancer.

Armstrong Andrew J AJ   Netto George J GJ   Rudek Michelle A MA   Halabi Susan S   Wood David P DP   Creel Patricia A PA   Mundy Kelly K   Davis S Lindsay SL   Wang Ting T   Albadine Roula R   Schultz Luciana L   Partin Alan W AW   Jimeno Antonio A   Fedor Helen H   Febbo Phillip G PG   George Daniel J DJ   Gurganus Robin R   De Marzo Angelo M AM   Carducci Michael A MA  

Clinical cancer research : an official journal of the American Association for Cancer Research 20100525 11


<h4>Purpose</h4>Given discrepancies between preclinical and clinical observations of mammalian target of rapamycin (mTOR) inhibition in prostate cancer, we sought to determine the pharmacodynamic effects of the mTOR/TORC1 inhibitor rapamycin in men with intermediate- to high-risk prostate cancer undergoing radical prostatectomy.<h4>Experimental design</h4>Rapamycin was given at 3 or 6 mg orally for 14 days before radical prostatectomy in men with multifocal Gleason sum > or =7 prostate cancer; 1  ...[more]

Similar Datasets

| S-EPMC5732797 | biostudies-literature
| S-EPMC11342134 | biostudies-literature
| S-EPMC9235523 | biostudies-literature
| S-EPMC8411278 | biostudies-literature
| S-EPMC5518616 | biostudies-literature
| S-EPMC3830644 | biostudies-literature
| S-EPMC9329530 | biostudies-literature
| S-EPMC3945953 | biostudies-literature
| S-EPMC5065713 | biostudies-literature
| S-EPMC6538141 | biostudies-literature