The human prostate cancer cell line LNCaP bears functional membrane testosterone receptors that increase PSA secretion and modify actin cytoskeleton.

Abstract

Recent findings have shown that, in addition to the genomic action of steroids, through intracellular receptors, short-time effects could be mediated through binding to membrane sites. In the present study of prostate cancer LNCaP cells, we report that dihydrotestosterone and the non-internalizable analog testosterone-BSA increase rapidly the release of prostate-specific antigen (PSA) in the culture medium. Membrane testosterone binding sites were identified through ligand binding on membrane preparations, flow cytometry, and confocal laser microscopy of the non-internalizable fluorescent analog testosterone-BSA-FITC, on whole cells. Binding on these sites is time- and concentration-dependent and specific for testosterone, presenting a KD of 10.9 nM and a number of 144 sites/mg protein (approximately 13000 sites/cell). Membrane sites differ immunologically for intracellular androgen receptors. The secretion of PSA after membrane testosterone receptor stimulation was inhibited after pretreatment with the actin cytoskeleton disrupting agent cytochalasin B. In addition, membrane testosterone binding modifies the intracellular dynamic equilibrium of monomeric to filamentous actin and remodels profoundly the actin cytoskeleton organization. These results are discussed in the context of a possible involvement of these sites in cancer chemotherapy.

• Authors: Maeilena Kampa, Evangelia A Papakonstanti, Anastassia Hatzoglou, Efstathios N Stathopoulos, Christos Stournaras, Elias Castanas
• Journal: FASEB journal : official publication of the Federation of American Societies for Experimental Biology (FASEB J) Vol. 16 Issue 11 Pg. 1429-31 (Sep 2002) ISSN: 1530-6860 [Electronic] United States
• PMID: 12205037 (Publication Type: Journal Article)

Chemical References

• Receptors, Androgen
• Receptors, Cell Surface
• Dihydrotestosterone
• Testosterone
• Prostate-Specific Antigen

Topics

• Actin Cytoskeleton (drug effects, metabolism, ultrastructure)
• Binding Sites
• Biological Transport
• Cell Membrane (metabolism)
• Dihydrotestosterone (pharmacology)
• Humans
• Male
• Models, Biological
• Prostate-Specific Antigen (metabolism)
• Prostatic Neoplasms (metabolism, ultrastructure)
• Receptors, Androgen (physiology)
• Receptors, Cell Surface (physiology)
• Testosterone (metabolism, pharmacology)
• Tumor Cells, Cultured