title: False-positive TUNEL staining observed in SV40 based transgenic murine prostate cancer models.
abstract: The TRAMP (Transgenic Adenocarcinoma of the Mouse Prostate) and LADY (Probasin-large T antigen transgenic mouse) mice are widely used autochthonous models of prostate cancer. Both models utilise probasin promoters to direct androgen-regulated expression of oncogenic SV40 specifically to epithelial cells of the mouse prostate. The oncogenic processes and phenotypes which result mimic many features of human prostate cancer, making these transgenic mouse models useful experimental systems. The terminal deoxynucleotidyl transferase (Tdt)-mediated dUTP in situ nick end labelling (TUNEL) assay is a commonly used method for the detection of cells undergoing apoptosis. In this study, we demonstrate false-positive TUNEL staining in frozen prostate tissue from TRAMP and LADY mice, which was not observed in non-transgenic control animals and is not due to non-specific binding of labelled-dUTP substrate. The false-positive signal co-localised with large SV40 T-antigen expression. False-positive signal was apparent using multiple commercial TUNEL kits with different detection systems. These results caution against the use of the TUNEL assay for detection of apoptosis in frozen prostate tissue of large T-antigen based autochthonous transgenic models of prostate cancer.
authors: Department of Haematology and Genetic Pathology, Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Flinders Drive, Bedford Park, Adelaide, South Australia, 5042, Australia.
authors: M D
authors: MD
authors: Lawrence
authors: B J
authors: BJ
authors: Blyth
authors: R J
authors: RJ
authors: Ormsby
authors: W D
authors: WD
authors: Tilley
authors: P J
authors: PJ
authors: Sykes
mesh_terms: D000727:Androgen-Binding Protein / Q000235:genetics; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D015925:Cryopreservation; D004195:Disease Models, Animal; D005189:False Positive Reactions; D005453:Fluorescence; D006657:Histones / Q000378:metabolism; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling / Q000379:methods*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D011471:Prostatic Neoplasms / Q000378:metabolism*; D053219:Receptors, Tumor Necrosis Factor, Member 25 / Q000235:genetics
chemical_list: D000727:Androgen-Binding Protein; D000952:Antigens, Polyomavirus Transforming; D006657:Histones; D053219:Receptors, Tumor Necrosis Factor, Member 25; C506034:Tnfrsf25 protein, mouse; C475961:gamma-H2AX protein, mouse; C027519:probasin; C505409:Casp3 protein, mouse; D053148:Caspase 3