Cytotoxicity of the bioreductive agent RH1 and its lack of interaction with radiation.

2.50
Hdl Handle:
http://hdl.handle.net/10541/78111
Title:
Cytotoxicity of the bioreductive agent RH1 and its lack of interaction with radiation.
Authors:
Kim, Joo-Young; West, Catharine M L; Valentine, Helen R; Ward, Timothy H; Patterson, Adam V; Stratford, Ian J; Roberts, Stephen A; Hendry, Jolyon H
Abstract:
BACKGROUND AND PURPOSE: RH1 is a new bioreductive agent that was developed as a cytotoxic agent with selectivity for tumour cells expressing high levels of the enzyme DT-diaphorase (DTD). The aim of the present study was to investigate the cytotoxicity of RH1 in relation to cellular levels of reducing enzymes and any interaction of RH1 with ionizing radiation under oxic and hypoxic conditions. PATIENTS AND METHODS: The MB-MDA231 human breast cancer cell line (WT) and WT cells transfected with the NQO1 gene encoding DTD (the D7 cell line) were used to examine the dependency of RH1's cytotoxicity on cellular DTD activity. The role of the 1-electron reducing enzyme P450 reductase was also studied using a P450 reductase-transfected isogenic cell line (R4). A clonogenic assay was used to investigate the cytotoxicity of RH1 with and without irradiation in air and in nitrogen. In all cases drug exposure was for 3 h. RESULTS: DTD levels were around 300-fold higher in D7 compared to WT and R4 cells. RH1 was cytotoxic at nanomolar concentrations to all the cell lines, and was 2-3 times more toxic in the D7 cells with high DTD than in the other two cell lines. Doses of RH1 was around 2-fold more effective in hypoxic than in oxic WT cells, but not by as much in D7 cells. RH1 did not radiosensitise the cells but showed an additive effect when combined with irradiation under oxic and hypoxic conditions. CONCLUSIONS: RH1 shows high clonogenic cytotoxicity to MDA231 cells with high DTD activity but its selectivity based on the presence of DTD is much less than as shown in previous reports. RH1 showed an additive cell killing effect when combined with irradiation under both oxic and hypoxic conditions.
Affiliation:
Cancer Research UK Groups of Experimental Radiation Oncology, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester, UK.
Citation:
Cytotoxicity of the bioreductive agent RH1 and its lack of interaction with radiation. 2004, 70 (3):311-7 Radiother Oncol
Journal:
Radiotherapy and Oncology
Issue Date:
Mar-2004
URI:
http://hdl.handle.net/10541/78111
DOI:
10.1016/j.radonc.2003.12.008
PubMed ID:
15064018
Type:
Article
Language:
en
ISSN:
0167-8140
Appears in Collections:
All Christie Publications ; All Paterson Institute for Cancer Research

Full metadata record

DC FieldValue Language
dc.contributor.authorKim, Joo-Young-
dc.contributor.authorWest, Catharine M L-
dc.contributor.authorValentine, Helen R-
dc.contributor.authorWard, Timothy H-
dc.contributor.authorPatterson, Adam V-
dc.contributor.authorStratford, Ian J-
dc.contributor.authorRoberts, Stephen A-
dc.contributor.authorHendry, Jolyon H-
dc.date.accessioned2009-08-21T10:04:02Z-
dc.date.available2009-08-21T10:04:02Z-
dc.date.issued2004-03-
dc.identifier.citationCytotoxicity of the bioreductive agent RH1 and its lack of interaction with radiation. 2004, 70 (3):311-7 Radiother Oncolen
dc.identifier.issn0167-8140-
dc.identifier.pmid15064018-
dc.identifier.doi10.1016/j.radonc.2003.12.008-
dc.identifier.urihttp://hdl.handle.net/10541/78111-
dc.description.abstractBACKGROUND AND PURPOSE: RH1 is a new bioreductive agent that was developed as a cytotoxic agent with selectivity for tumour cells expressing high levels of the enzyme DT-diaphorase (DTD). The aim of the present study was to investigate the cytotoxicity of RH1 in relation to cellular levels of reducing enzymes and any interaction of RH1 with ionizing radiation under oxic and hypoxic conditions. PATIENTS AND METHODS: The MB-MDA231 human breast cancer cell line (WT) and WT cells transfected with the NQO1 gene encoding DTD (the D7 cell line) were used to examine the dependency of RH1's cytotoxicity on cellular DTD activity. The role of the 1-electron reducing enzyme P450 reductase was also studied using a P450 reductase-transfected isogenic cell line (R4). A clonogenic assay was used to investigate the cytotoxicity of RH1 with and without irradiation in air and in nitrogen. In all cases drug exposure was for 3 h. RESULTS: DTD levels were around 300-fold higher in D7 compared to WT and R4 cells. RH1 was cytotoxic at nanomolar concentrations to all the cell lines, and was 2-3 times more toxic in the D7 cells with high DTD than in the other two cell lines. Doses of RH1 was around 2-fold more effective in hypoxic than in oxic WT cells, but not by as much in D7 cells. RH1 did not radiosensitise the cells but showed an additive effect when combined with irradiation under oxic and hypoxic conditions. CONCLUSIONS: RH1 shows high clonogenic cytotoxicity to MDA231 cells with high DTD activity but its selectivity based on the presence of DTD is much less than as shown in previous reports. RH1 showed an additive cell killing effect when combined with irradiation under both oxic and hypoxic conditions.en
dc.language.isoenen
dc.subjectCell Line Tumouren
dc.subjectMammary Canceren
dc.subjectTumour Stem Cell Assayen
dc.subject.meshAntineoplastic Agents-
dc.subject.meshAziridines-
dc.subject.meshBenzoquinones-
dc.subject.meshCell Line, Tumor-
dc.subject.meshDrug Evaluation, Preclinical-
dc.subject.meshHumans-
dc.subject.meshMammary Neoplasms, Experimental-
dc.subject.meshNAD(P)H Dehydrogenase (Quinone)-
dc.subject.meshNADPH-Ferrihemoprotein Reductase-
dc.subject.meshRadiation-Sensitizing Agents-
dc.subject.meshTransfection-
dc.subject.meshTumor Stem Cell Assay-
dc.titleCytotoxicity of the bioreductive agent RH1 and its lack of interaction with radiation.en
dc.typeArticleen
dc.contributor.departmentCancer Research UK Groups of Experimental Radiation Oncology, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester, UK.en
dc.identifier.journalRadiotherapy and Oncologyen

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