title: Fenretinide: induction of apoptosis and endogenous transforming growth factor beta in PC-3 prostate cancer cells.
abstract: N-(4-Hydroxyphenyl)retinamide (4-HPR, Fenretinide) is a retinoid derivative with antineoplastic activity in various tumor types including prostate carcinoma. The mechanism of action of 4-HPR toxicity is unknown. 4-HPR induces apoptosis in leukemia- and lymphoma-derived cells, neuroblastoma, and small cell lung cancers. The present study was designed to investigate: (a) the mechanism of 4-HPR cytotoxicity in prostate cancer cells; and (b) correlate increased expression of transforming growth factor beta 1 (TGF beta 1) with induction of apoptosis. 4-HPR exposure to PC-3 cells in vitro was associated with apoptosis as evidenced by increased incidence of hypodiploid nuclei in propidium iodide fluorescence histograms and DNA fragmentation. An increase in the percentage of nuclei in the G1 phase of the cell cycle preceded induction of apoptosis. TGF beta 1-increased expression was noted in mRNA levels and in secretion of active TGF beta 1 into culture media. TGF beta 1 and TGF-beta receptor type II detected immunohistochemically were increased in 4-HPR-treated PC-3 cells. Furthermore, 4-HPR-induced cytotoxicity in PC-3 cells was abrogated by the addition of anti-TGF beta 1 antibody. In BT-20 cells, a 4-HPR-resistant breast carcinoma cell line, apoptosis was not observed after exposure to 4-HPR nor was TGF beta 1 expression enhanced in stained cells or in conditioned media. It is concluded that 4-HPR induces the expression of TGF beta 1 in association with the induction of apoptosis.
authors.affiliation: Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Roberson
authors.forename: S N
authors.initials: SN
authors.lastname: Penland
authors.forename: G M
authors.initials: GM
authors.lastname: Padilla
authors.forename: R S
authors.initials: RS
authors.lastname: Selvan
authors.forename: C S
authors.initials: CS
authors.lastname: Kim
authors.forename: R L
authors.initials: RL
authors.lastname: Fine
authors.forename: C N
authors.initials: CN
authors.lastname: Robertson
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000473:pathology; D005260:Female; D017313:Fenretinide / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology*; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D017313:Fenretinide; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II