title: Parthenolide generates reactive oxygen species and autophagy in MDA-MB231 cells. A soluble parthenolide analogue inhibits tumour growth and metastasis in a xenograft model of breast cancer.
abstract: Triple-negative breast cancers (TNBCs) are clinically aggressive forms associated with a poor prognosis. We evaluated the cytotoxic effect exerted on triple-negative MDA-MB231 breast cancer cells both by parthenolide and its soluble analogue dimethylamino parthenolide (DMAPT) and explored the underlying molecular mechanism. The drugs induced a dose- and time-dependent decrement in cell viability, which was not prevented by the caspase inhibitor z-VAD-fmk. In particular in the first hours of treatment (1-3 h), parthenolide and DMAPT strongly stimulated reactive oxygen species (ROS) generation. The drugs induced production of superoxide anion by activating NADPH oxidase. ROS generation caused depletion of thiol groups and glutathione, activation of c-Jun N-terminal kinase (JNK) and downregulation of nuclear factor kB (NF-kB). During this first phase, parthenolide and DMAPT also stimulated autophagic process, as suggested by the enhanced expression of beclin-1, the conversion of microtubule-associated protein light chain 3-I (LC3-I) to LC3-II and the increase in the number of cells positive to monodansylcadaverine. Finally, the drugs increased RIP-1 expression. This effect was accompanied by a decrement of pro-caspase 8, while its cleaved form was not detected and the expression of c-FLIPS markedly increased. Prolonging the treatment (5-20 h) ROS generation favoured dissipation of mitochondrial membrane potential and the appearance of necrotic events, as suggested by the increased number of cells positive to propidium iodide staining. The administration of DMAPT in nude mice bearing xenografts of MDA-MB231 cells resulted in a significant inhibition of tumour growth, an increment of animal survival and a marked reduction of the lung area invaded by metastasis. Immunohistochemistry data revealed that treatment with DMAPT reduced the levels of NF-kB, metalloproteinase-2 and -9 and vascular endothelial growth factor, while induced upregulation of phosphorylated JNK. Taken together, our data suggest a possible use of parthenolide for the treatment of TNBCs.
authors.affiliation: Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, Polyclinic, Laboratory of Biochemistry, University of Palermo, Via del Vespro 129, Palermo, Italy.
authors.forename: A
authors.initials: A
authors.lastname: D'Anneo
authors.forename: D
authors.initials: D
authors.lastname: Carlisi
authors.forename: M
authors.initials: M
authors.lastname: Lauricella
authors.forename: R
authors.initials: R
authors.lastname: Puleio
authors.forename: R
authors.initials: R
authors.lastname: Martinez
authors.forename: S
authors.initials: S
authors.lastname: Di Bella
authors.forename: P
authors.initials: P
authors.lastname: Di Marco
authors.forename: S
authors.initials: S
authors.lastname: Emanuele
authors.forename: R
authors.initials: R
authors.lastname: Di Fiore
authors.forename: A
authors.initials: A
authors.lastname: Guercio
authors.forename: R
authors.initials: R
authors.lastname: Vento
authors.forename: G
authors.initials: G
authors.lastname: Tesoriere
mesh_terms: D000818:Animals; D001343:Autophagy / Q000187:drug effects*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D053200:Fas-Associated Death Domain Protein / Q000378:metabolism; D005260:Female; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012717:Sesquiterpenes / Q000494:pharmacology* / Q000627:therapeutic use; D023041:Xenograft Model Antitumor Assays
chemical_list: C119724:AGFG1 protein, human; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; C505533:FADD protein, human; D053200:Fas-Associated Death Domain Protein; C524858:LC-1 compound; D016328:NF-kappa B; D028861:Nuclear Pore Complex Proteins; D016601:RNA-Binding Proteins; D017382:Reactive Oxygen Species; D012717:Sesquiterpenes; C002669:parthenolide; D002118:Calcium