September 21, 2007
admission is free
5:30 - 7:00pm
Mackenzie Building 4359
There is considerable controversy surrounding the biological effects of radiofrequency (RF) fields, as emitted by mobile phones. Previous work from our laboratory has shown no effect related to the exposure of 1.9 GHz pulse-modulated RF fields on the expression of 22,000 genes in a human glioblastoma derived cell-line (U87MG) at 6 h following a 4 h RF field exposure period. As a follow-up to this study, we have now examined the effect of RF field exposure on the possible expression of late onset genes in U87MG cells after a 24 h RF exposure period. In addition, a human monocyte-derived cell-line (Mono-Mac-6, MM6) was exposed to intermittent (5 min ON, 10 min OFF) RF fields for 6 h and then gene expression was assessed immediately after exposure and at 18 h post-exposure. Both cell lines were exposed to 1.9 GHz pulse-modulated RF fields for 6 or 24 h at specific absorption rates (SARs) of 0.1 - 10.0 W/kg. In support of our previous results, we found no evidence that non-thermal RF field exposure could alter gene expression in either cultured U87MG or MM6 cells, relative to non-irradiated control groups. However, exposure of both cell-lines to heat-shock conditions (43oC for 1 h) caused an alteration in the expression of a number of well characterized heat shock proteins.
Vinita Chauhan1, Sami S. Qutob1, Stephanie Lui1, Anu Mariampillai1, Pascale V. Bellier1, Carole L. Yauk2, George R. Douglas2, Andrew Williams3, and James P. McNamee*1
1Consumer and Clinical Radiation Protection Bureau, Healthy Environment and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada, K1A 1C1.
2Mutagenesis Section, Environmental Health Science Bureau, Healthy Environment and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada, K1A 0L2.
3Biostatistics and Epidemiology Division, Healthy Environment and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada, K1A 0L2.
In 1995, Dr. Qutob completed an Honors thesis in physiology at the University of Western Ontario based on the characterization of sacroplasmic reticulum proteins in the AT-1 mouse atrial tumor cell line. Following this, he sought a M.Sc. degree in physiology at the same institution studying the effects of insulin on vitamin C uptake by osteoblastic and astroglial cells employing many biochemical and cell culture techniques. Since that time he has been actively involved in a range of projects, especially in the field of non-ionizing and ionizing radiation biology research. During his doctoral studies, at the Ottawa Regional Cancer Center, he examined the genetic factors that govern cellular radioresponsiveness as well as addressing the ability of exogenous factors (i.e. chemo-drugs) to modulate ionizing radiation sensitivity. Collaboration with Dr Qing Yan Liu and Dr. P. Roy Walker at the Neurogenomics Group, Institute for Biological Sciences, National Research Council of Canada (NRC) has enabled Dr. Qutob to gain valuable experience in the area of genomics research particularly in the area of cDNA microarray technology. Following completion of his Ph. D. studies, this expertise was further utilized where he spent a year at Health Canada performing Postdoctural fellowship research. During this time, the candidate examined the effects of non-ionizing 1.9 GHz pulse-modulated radiofrequency fields on microarray gene expression of a human glioblastoma cell line. Since April 1st, 2004, Dr. Qutob has led a Health Canada partnership with the Radiological Analysis and Defence Group at Defence Research and Development Canada (DRDC Ottawa) in a project funded by the Chemical, Biological, Radiological and Nuclear (CRBN) Research and Technology Initiative (CRTI). This collaboration involved several federal and industry partners for the purpose of identifying possible biomarkers of ionizing radiation exposure and developing a National Biological Dosimetry Response Plan (NBDRP) in response to a large-scale radiological event. Data obtained from a number of CRTI sub-projects has shown promise and may possibly lead to the development of a prototype fieldable biodosimeter for rapid triage of potentially exposed individuals. As of January, 2007, the candidate has returned to Health Canada as a principle investigator (P.I.), examining the mechanisms of hormesis, radioadaptation, and combined biological effects of radiation in order to provide new information on radiation safety, consistent with Health Canada’s mandate. He is a member of the Bioelectromagnetics Society and Radiation Research Society.
Last modified 07-08-24