title: Bcl-2 family proteins and cytoskeleton changes involved in DM-1 cytotoxic effect on melanoma cells.
abstract: Melanoma is one of the most aggressive types of skin cancer and its incidence rate is still increasing. All existing treatments are minimally effective. Consequently, new therapeutic agents for melanoma treatment should be developed. The DM-1 compound is a curcumin analog that possesses several curcumin characteristics, such as antiproliferative, antitumor, and anti-metastatic properties. The aim of this study was to evaluate the different signaling pathways involved in the cytotoxic effect of DM-1 on melanoma cells. The apoptotic process and cytoskeletal changes were evaluated by immunoblotting and immunofluorescence, respectively, in melanoma cells. After DM-1 treatment, SK-MEL-5 melanoma cells showed actin filament disorganization with spicule formation throughout the cytoskeleton and significant reduction of focal adhesion as well as they were present only at cell extremities, conferring a poor connection between the cell and the substrate. Besides this, there was significant filopodium retraction and loss of typical cytoskeleton scaffold. These modifications contributed to cell detachment followed by cell death. Furthermore, DM-1-induced apoptosis was triggered by multiple Bcl-2 proteins involved in both the extrinsic and the intrinsic apoptotic pathways. SK-MEL-5 cells showed a death mechanism mainly by Bcl-2/Bax ratio decrease, whereas A375 cells presented apoptosis induction by Mcl-1 and Bcl-xL downregulation. In SK-MEL-5 and A375 melanoma cells, there was a significant increase in the active form of caspase 9, and the inactive form of the effector caspase 3 was decreased in both cell lines. Expression of cleaved poly ADP ribose polymerase was increased after DM-1 treatment in these melanoma cell lines, demonstrating that the apoptotic process occurred. Altogether, these data elucidate the cellular and molecular mechanisms involved in the cytotoxicity induced by the antitumor agent DM-1 in melanoma cells.
authors: Laboratory of Biochemistry and Biophysics, Butantan Institute, 1500 Vital Brasil Avenue, São Paulo, 05503-900, Brazil. feflor@uol.com.br
authors: Fernanda
authors: F
authors: Faião-Flores
authors: José Agustín Quincoces
authors: JA
authors: Suarez
authors: Vanessa
authors: V
authors: Soto-Cerrato
authors: Margarita
authors: M
authors: Espona-Fiedler
authors: Ricardo
authors: R
authors: Pérez-Tomás
authors: Durvanei Augusto
authors: DA
authors: Maria
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008453:Maytansine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008545:Melanoma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D012878:Skin Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D014407:Tumor Cells, Cultured; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D051020:bcl-X Protein / Q000378:metabolism
chemical_list: C494826:BAX protein, human; C494811:BCL2L1 protein, human; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; D008453:Maytansine; D011065:Poly(ADP-ribose) Polymerases