title: Cytoskeleton alterations induced by Geodia corticostylifera depsipeptides in breast cancer cells.
abstract: Crude extracts of the marine sponge Geodia corticostylifera from Brazilian Coast have previously shown antibacterial, antifungal, cytotoxic, haemolytic and neurotoxic activities. The present work describes the isolation of the cyclic peptides geodiamolides A, B, H and I (1-4) from G. corticostylifera and their anti-proliferative effects against sea urchin eggs and human breast cancer cell lineages. Its structure-activity relationship is discussed as well. In an initial series of experiments these peptides inhibited the first cleavage of sea urchin eggs (Lytechinus variegatus). Duplication of nuclei without complete egg cell division indicated the mechanism of action might be related to microfilament disruption. Further studies showed that the geodiamolides have anti-proliferative activity against human breast cancer cell lines (T47D and MCF7). Using fluorescence techniques and confocal microscopy, we found evidence that the geodiamolides A, B, H and I act by disorganizing actin filaments of T47D and MCF7 cancer cells, in a way similar to other depsipeptides (such as jaspamide 5 and dolastatins), keeping the normal microtubule organization. Normal cells lines (primary culture human fibroblasts and BRL3A rat liver epithelial cells) were not affected by the treatment as tumor cells were, thus indicating the biomedical potential of these compounds.
authors.affiliation: Department of Physiology, Biosciences Institute, University of Sao Paulo, São Paulo 05508-900, Brazil. mrangel@butantan.gov.br
authors.forename: Marisa
authors.initials: M
authors.lastname: Rangel
authors.forename: Marisa P
authors.initials: MP
authors.lastname: Prado
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Konno
authors.forename: Hideo
authors.initials: H
authors.lastname: Naoki
authors.forename: José C
authors.initials: JC
authors.lastname: Freitas
authors.forename: Glaucia M
authors.initials: GM
authors.lastname: Machado-Santelli
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000648:ultrastructure; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D003599:Cytoskeleton / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D047630:Depsipeptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D047231:Geodia / Q000378:metabolism; D006801:Humans; D018613:Microscopy, Confocal; D010456:Peptides, Cyclic / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D047630:Depsipeptides; D010456:Peptides, Cyclic; C514601:geodiamolide B; C514602:geodiamolide H; C514603:geodiamolide I; C076171:geodiamolide A