title: Hypoxia in the androgen-dependent Shionogi model for prostate cancer at three stages.
abstract: The objective of this study was to investigate a possible relationship between androgen status and hypoxia in the Shionogi murine prostate tumor model, which is widely used to study the effects of androgen withdrawal on hormone resistance and radiation response. Binding of the nitroimidazole hypoxia marker EF5 was assessed using the Cy3-tagged monoclonal antibody ELK3-51. Three hours after injection of EF5 (30 mg/kg), tumors from the following three stages were excised: androgen-dependent, regressed tumors 7 days after castration, and androgen-independent. Half of each tumor was disaggregated for analysis by flow cytometry and the remainder was flash frozen. Statistically significant differences (P < 0.01) were found between androgen-dependent, regressed and androgen-dependent tumors: approximately 30, approximately 2 and approximately 50% hypoxic cells, respectively. Frozen sections from androgen-dependent tumors exhibited highly variable EF5 binding; regressed tumors showed very little or no binding; each section from androgen-dependent tumors showed high levels and uniformly distributed binding of EF5. There was no correlation between the degree of hypoxia and tumor weight (P > 0.1). The results from this preliminary study indicate that hypoxia may play an important role with respect to the timing of irradiation in prostate cancer treatments and possibly may be a useful prognostic tool. In addition, hypoxia may also be relevant to progression in this disease after androgen ablation.
authors.affiliation: Advanced Therapeutics, BC Cancer Research Centre, Vancouver, British Columbia, V5Z 1L3, Canada.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Skov
authors.forename: Hans
authors.initials: H
authors.lastname: Adomat
authors.forename: Mary
authors.initials: M
authors.lastname: Bowden
authors.forename: Wieslawa
authors.initials: W
authors.lastname: Dragowska
authors.forename: Martin
authors.initials: M
authors.lastname: Gleave
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: Koch
authors.forename: Janet
authors.initials: J
authors.lastname: Woo
authors.forename: Donald T T
authors.initials: DT
authors.lastname: Yapp
mesh_terms: D000728:Androgens / Q000378:metabolism*; D000818:Animals; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D018450:Disease Progression; D005434:Flow Cytometry; D000860:Hypoxia; D019044:Image Cytometry; D008297:Male; D015674:Mammary Neoplasms, Animal / Q000473:pathology; D051379:Mice; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000473:pathology; D009376:Neoplasms, Hormone-Dependent / Q000473:pathology*; D009593:Nitroimidazoles / Q000494:pharmacology; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000473:pathology*; D011485:Protein Binding; D013997:Time Factors; D047368:Tumor Burden
chemical_list: D000728:Androgens; D009593:Nitroimidazoles