Small, novel proteins from the mistletoe Phoradendron tomentosum exhibit highly selective cytotoxicity to human breast cancer cells
2003 (English)In: Cellular and Molecular Life Sciences (CMLS), ISSN 1420-682X, Vol. 60, no 1, 165-175 p.Article in journal (Refereed) Published
Four novel proteins (phoratoxins C-F) have been isolated from the North American mistletoe Phoradendron tomentosum. The amino acid sequences of these phoratoxins were determined unambiguously using a combination of Edman degradation and trypsin enzymatic digestion, and by electrospray ionization tandem mass spectrometry sequencing. Phoratoxins C, E and F consist of 46 amino acid residues; and phoratoxin D of 41. All proteins had six cysteines, similar to the earlier described phoratoxins A and B, which are thionins. The cytotoxicity of each protein was evaluated in a human cell line panel that represented several cytotoxic drug-resistance mechanisms. For the half-maximal inhibitory concentrations (IC50 values) of the different cell lines in the panel, correlation with those of standard drugs was low. The most potent cytotoxic phoratoxin C was further tested on primary cultures of human tumor cells from patients. The solid tumor samples from breast cancer cells were 18 times more sensitive to phoratoxin C than the tested hematological tumor samples.
Place, publisher, year, edition, pages
2003. Vol. 60, no 1, 165-175 p.
Breast cancer, cytotoxicity drug screening, mistletoe proteins, Phoradendron tomentosum, phoratoxins, thionins, tumor cell lines
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-64178DOI: 10.1007/s000180300011PubMedID: 12613665OAI: oai:DiVA.org:uu-64178DiVA: diva2:92089