The adult human testis produces millions of sperm each day trough spermatogenesis
Area 4: Molecular recognition in biomolecules
Toxic effects induced by polyamine metabolites on melanoma cells: a new therapeutic approach Enzo Agostinelli
Department of Biochemical Sciences "A. Rossi Fanelli"
℡: +39 06 49910838 - @: enzo.agostinelli@uniroma1.it
The purpose of this research is to develop a new anticancer therapy against melanoma
(M14), taking advantage of the high polyamine content of tumor cells, since such polycations may become a source of cytotoxic metabolites. For their generation an enzyme, bovine serum amine oxidase (BSAO) will be employed. It is expected that by delivering BSAO into cancer cells, toxic enzymatic oxidation products could be produced intracellularly for selective killing in situ.
Several studies have been performed to overcome the drug-resistant phenotype and to
develop innovative chemotherapeutic strategies effective against multi-drug resistant (MDR) tumours. Our studies demonstrate that BSAO and spermine (SPM) addition to human M14 cells induces cell growth inhibition and overcomes the MDR phenotype (ADR2). The oxidative reaction produces polyamine metabolites (H2O2 and aldehydes) which induce
oxidative stress. Cytotoxicity induced by SPM metabolites was greater in MDR cells than in wild-type ones (WT), due to an increased mitochondrial activity. To increase the induction of cell death by toxic polyamine metabolites, we are currently investigating several drug combinations. Clonogenic experiments showed that the cytotoxicity induced by BSAO/SPM addition was enhanced by the pre-treatment of tumour cells with lysosomotropic compounds, the drug chloroquine (CQ) or MDL 72527, in both WT and MDR M14 cells.
The pre-treatment of M14 cells with CQ or MDL 72527 sensitized both WT and ADR2
cells to the subsequent exposure to SPM metabolites. Noteworthy, the apoptotic effect was higher in ADR2 cells than in their WT counterparts. The cytotoxic effect induced by the combined treatment was characterized by cytoplasmic vacuolization and mitochondrial damage, as revealed by transmission electron microscopy (TEM) (Fig. 1). We hypothesize that the release of lysosomal enzymes produces oxidative stress and apoptosis, indicating a contribution of the lysosomotropic properties of CQ to the sensitization of M14 cells to H2O2
and aldehyde(s). The findings suggest that the association of BSAO/SPM with CQ or MDL 72527, and mitochondrial alterations induced by SPM oxidation products, allow the design of a new therapeutic strategy based on the use of these combinations in human neoplasms, making this approach mainly attractive in treating MDR cancer patients.
From a therapeutic point of view the improvement of the efficacy of in situ formation of
cytotoxic polyamines metabolites is essential. Since in the present model H2O2 and
aldehydes are produced outside the cells, the main challenge will be to deliver BSAO into cancer cells in order to induce their selective killing by the cytotoxic factors produced intracellularly from endogenous polyamines. Therefore, strategies could be developed to find
Area 4: Molecular recognition in biomolecules
how the enzyme could be delivered in vivo. To this aim BSAO incorporates into liposomal vesicles and dedicated nano-scale drug delivery systems will be designed. Thus, endogenous polyamines present in high concentration in tumor cells could be targeted and oxidized by the enzyme.
Fig. 1- Ultrastructural analysis of M14 WT ( top panels) and M14 ADR2 (lower panels) cells performed by TEM. (a and b) Untreated melanoma cells; (c and d) Cells exposed to 300 µM MDL 72527 for 24 h, at 37˚C; (e and f) Cells treated for 60 min with 6.5x10-3 IU/ml BSAO and6 µM SPM at 37˚C; (g and h) Cells were first exposed for 24 h to 300 µM MDL 72527, and then treated for 60 min with 6.5x10-3 IU/ml BSAO and 6 µM SPM at 37˚C.
Publications Agostinelli E. Role of polyamines, their analogs and transglutaminases in biological and
clinical perspectives. Amino Acids 2011 Epub. doi: 10.1007/s00726-011-1129-2
Agostinelli E, Toninello A, Vianello F, Stevanato R. Do mammalian amine oxidases and the
mitochondrial polyamine transporter have similar protein structures? Amino Acids 2011 Epub. doi: 10.1007/s00726-011-0988-x.
Stevanato R, Cardillo S, Braga M, De Iuliis A, Battaglia V, Toninello A, Agostinelli E, Vianello
F. Preliminary kinetic characterization of a copper amine oxidase from rat liver mitochondria matrix. Amino Acids 2011, 40: 713–20. doi: 10.1007/s00726-010-0708-y.
Valente S, Tomassi S, Tempera G, Saccoccio S, Agostinelli E, Mai A. Novel Reversible
Monoamine Oxidase A Inhibitors: Highly Potent and Selective 3-(1H-Pyrrol-3-yl)-2- oxazolidinones. J Med Chem 2011, 54: 8228-32. Epub 2011 Nov 7. doi: 10.1021/ jm201011x.
Research Group Collaborations Paola Turini, professor; Giampiero Tempera, Annarica Calcabrini, Istituto Superiore di Nikenza Viceconte, Stefania Saccoccio, post-
Sanità, Roma; Taichi Ueshima, Wakunaga
Epilepsy in Rett syndrome – notes for talk at ORSA meeting, September 2010 This talk was part of a three-person panel discussion and had two principal 1) to describe why and how epileptic seizures develop in the human brain 2) to review the main features of epilepsy in Rett syndrome (RTT) – what kinds of seizures occur and at what age; who is more likely to develop epileptic seizures; wh
THE KILLER SMILE A Growing Problem How Do You Say That in Science-speak? As environmental pollution increases we become Toxic metals alter pro-oxidant / anti-oxidant bal-more and more vulnerable to the chronic, low-level ance, and are directly antagonistic to essential exposure to toxic metals in our air, water, food and trace elements for binding sites on transport and teeth.
Area 4: Molecular recognition in biomolecules
how the enzyme could be delivered in vivo. To this aim BSAO incorporates into liposomal