Document Server@UHasselt >
Research >
Research publications >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/17032

Title: Nucleoside-catabolizing Enzymes in Mycoplasma-infected Tumor Cell Cultures Compromise the Cytostatic Activity of the Anticancer Drug Gemcitabine
Authors: Vande Voorde, Johan
Sabuncuoglu, Suna
Noppen, Sam
Hofer, Anders
Ranjbarian, Farahnaz
FIEUWS, Steffen
Balzarini, Jan
Liekens, Sandra
Issue Date: 2014
Citation: JOURNAL OF BIOLOGICAL CHEMISTRY, 289 (19), p. 13054-13065
Abstract: The intracellular metabolism and cytostatic activity of the anticancer drug gemcitabine (2′,2′-difluoro-2′-deoxycytidine; dFdC) was severely compromised in Mycoplasma hyorhinis-infected tumor cell cultures. Pronounced deamination of dFdC to its less cytostatic metabolite 2′,2′-difluoro-2′-deoxyuridine was observed, both in cell extracts and spent culture medium (i.e. tumor cell-free but mycoplasma-containing) of mycoplasma-infected tumor cells. This indicates that the decreased antiproliferative activity of dFdC in such cells is attributed to a mycoplasma cytidine deaminase causing rapid drug catabolism. Indeed, the cytostatic activity of gemcitabine could be restored by the co-administration of tetrahydrouridine (a potent cytidine deaminase inhibitor). Additionally, mycoplasma-derived pyrimidine nucleoside phosphorylase (PyNP) activity indirectly potentiated deamination of dFdC: the natural pyrimidine nucleosides uridine, 2′-deoxyuridine and thymidine inhibited mycoplasma-associated dFdC deamination but were efficiently catabolized (removed) by mycoplasma PyNP. The markedly lower anabolism and related cytostatic activity of dFdC in mycoplasma-infected tumor cells was therefore also (partially) restored by a specific TP/PyNP inhibitor (TPI), or by exogenous thymidine. Consequently, no effect on the cytostatic activity of dFdC was observed in tumor cell cultures infected with a PyNP-deficient Mycoplasma pneumoniae strain. Because it has been reported that some commensal mycoplasma species (including M. hyorhinis) preferentially colonize tumor tissue in cancer patients, our findings suggest that the presence of mycoplasmas in the tumor microenvironment could be a limiting factor for the anticancer efficiency of dFdC-based chemotherapy. Accordingly, a significantly decreased antitumor effect of dFdC was observed in mice bearing M. hyorhinis-infected murine mammary FM3A tumors compared with uninfected tumors.
Notes: Balzarini, J (reprint author),Katholieke Univ Leuven, Rega Inst Med Res, Minderbroedersstr 10,Blok X Bus 1030, B-3000 Louvain, Belgium jan.balzarini@rega.kuleuven.be
URI: http://hdl.handle.net/1942/17032
DOI: 10.1074/jbc.M114.558924
ISI #: 000335522800009
ISSN: 0021-9258
Category: A1
Type: Journal Contribution
Validation: ecoom, 2015
Appears in Collections: Research publications

Files in This Item:

Description SizeFormat
published version3.57 MBAdobe PDF

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.