title: Sanguinarine cytotoxicity on mouse melanoma K1735-M2 cells--nuclear vs. mitochondrial effects.
abstract: Sanguinarine (SANG) is an alkaloid recognized to have anti-proliferative activity against various human tumour cell lines. No data is available on the susceptibility of advanced malignant melanoma to SANG, although this disease has a very poor prognosis if not detected in time due to the resistance to conventional chemotherapy. The present work was designed to study the nuclear and mitochondrial involvement in the pro-apoptotic effect of SANG in an invasive mouse melanoma cell line. The results obtained show that SANG is primarily accumulated by the cell nuclei, causing inhibition of cell proliferation and inducing cell death, as confirmed by an increase in sub-G1 peaks. At low concentrations, SANG induces mitochondrial depolarization in a sub-population of melanoma cells, which also generally displayed strong nuclear labelling of phosphorylated histone H2AX. Western blotting revealed an increase in p53, but not Bax protein, in both whole-cell extracts and in mitochondrial fractions. Isolated hepatic mitochondrial fractions revealed that SANG affects the mitochondrial respiratory chain, and has dual effects on mitochondrial calcium loading capacity. We suggest that SANG is able to induce apoptosis in metastatic melanoma cells. The knowledge of mitochondrial vs. nuclear effects of SANG is important in the development of this promising compound for clinical use against aggressive melanoma.
authors.affiliation: Center for Neurosciences and Cell Biology, Department of Zoology, University of Coimbra, P-3004-517 Coimbra, Portugal.
authors.forename: Teresa L
authors.initials: TL
authors.lastname: Serafim
authors.forename: Júlio A C
authors.initials: JA
authors.lastname: Matos
authors.forename: Vilma A
authors.initials: VA
authors.lastname: Sardão
authors.forename: Gonçalo C
authors.initials: GC
authors.lastname: Pereira
authors.forename: Ana F
authors.initials: AF
authors.lastname: Branco
authors.forename: Sandro L
authors.initials: SL
authors.lastname: Pereira
authors.forename: Donna
authors.initials: D
authors.lastname: Parke
authors.forename: Edward L
authors.initials: EL
authors.lastname: Perkins
authors.forename: António J M
authors.initials: AJ
authors.lastname: Moreno
authors.forename: Jon
authors.initials: J
authors.lastname: Holy
authors.forename: Paulo J
authors.initials: PJ
authors.lastname: Oliveira
mesh_terms: D000818:Animals; D053119:Benzophenanthridines / Q000494:pharmacology*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000187:drug effects*; D049109:Cell Proliferation; D004354:Drug Screening Assays, Antitumor; D006657:Histones / Q000378:metabolism; D007546:Isoquinolines / Q000494:pharmacology*; D008546:Melanoma, Experimental / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D051379:Mice; D008928:Mitochondria / Q000187:drug effects*; D010766:Phosphorylation; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D053119:Benzophenanthridines; D006657:Histones; D007546:Isoquinolines; C005705:sanguinarine