Biophysical and biochemical characterization of a liposarcoma-derived recombinant MnSOD protein acting as an anticancer agent.

Abstract

A recombinant MnSOD (rMnSOD) synthesized by specific cDNA clones derived from a liposarcoma cell line was shown to have the same sequence as the wild-type MnSOD expressed in the human myeloid leukaemia cell line U937, except for the presence of the leader peptide at the N-terminus. These results were fully confirmed by the molecular mass of rMnSOD as evaluated by ES/MS analysis (26662.7 Da) and the nucleotide sequence of the MnSOD cDNA. The role of the leader peptide in rMnSOD was investigated using a fluorescent and/or (68)Gallium-labelled synthetic peptide. The labelled peptide permeated MCF-7 cells and uptake could be inhibited in the presence of an excess of oestrogen. In vivo it was taken up by the tumour, suggesting that the molecule can be used for both therapy and diagnosis. The in vitro and in vivo pharmacology tests confirmed that rMnSOD is only oncotoxic for tumour cells expressing oestrogen receptors. Pharmacokinetic studies in animals performed with (125)I- and (131)I-labelled proteins confirmed that, when administered systemically, rMnSOD selectively reached the tumour, where its presence was unambiguously demonstrated by scintigraphic and PET scans. PCR analysis revealed that Bax gene expression was increased and the Bcl2 gene was down regulated in MCF7 cells treated with rMnSOD, which suggests that the protein induces a pro-apoptotic mechanism.

• Authors: Aldo Mancini, Antonella Borrelli, Antonella Schiattarella, Luigi Aloj, Michela Aurilio, Franco Morelli, Alessandra Pica, Antonella Occhiello, Roberto Lorizio, Roberto Mancini, Alessandro Sica, Lelio Mazzarella, Filomena Sica, Paolo Grieco, Ettore Novellino, Daniela Pagnozzi, Piero Pucci, Jean Rommelaere
• Journal: International journal of cancer (Int J Cancer) Vol. 123 Issue 11 Pg. 2684-95 (Dec 01 2008) ISSN: 1097-0215 [Electronic] United States
• PMID: 18798256 (Publication Type: Journal Article)
• Copyright: (c) 2008 Wiley-Liss, Inc.

Chemical References

• Antineoplastic Agents
• Recombinant Proteins
• Estradiol
• Hydrogen Peroxide
• Superoxide Dismutase

Topics

• Amino Acid Sequence
• Animals
• Antineoplastic Agents (pharmacology, therapeutic use)
• Base Sequence
• Biochemical Phenomena
• Biochemistry
• Biophysical Phenomena
• Biophysics
• Cell Line, Tumor
• Chromatography, Affinity
• Circular Dichroism
• Estradiol (pharmacology)
• Health
• Humans
• Hydrogen Peroxide (metabolism)
• Liposarcoma (drug therapy, enzymology, pathology)
• Mice
• Mice, Nude
• Molecular Sequence Data
• Peptide Mapping
• Recombinant Proteins (chemistry, isolation & purification, metabolism, pharmacology)
• Sequence Analysis
• Spectrometry, Mass, Electrospray Ionization
• Superoxide Dismutase (chemistry, isolation & purification, metabolism, pharmacology)
• Xenograft Model Antitumor Assays