Differential sensitivity of mouse epithelial tissues to the polyomavirus middle T oncogene.
To determine how different epithelial cell types respond to the same oncogenic stimulation, we have used a modified human keratin 18 gene to conditionally express the polyomavirus middle T antigen (PyMT) oncogene in simple epithelial tissues of transgenic mice. Activation of PyMT expression by transgenic Cre recombinase in mammary epithelial cells resulted in carcinomas in all bitransgenic females. PyMT expression induced by K18-driven Cre in internal epithelial organs resulted in pancreatic acinar metaplasia and ductal dysplasia with remarkable desmoplastic stromal responses in all 25 bitransgenic mice. Hepatoma formation with altered lipid metabolism and gastric adenocarcinoma occurred in 96 and 54% of these mice, respectively. Elevated PyMT RNA expression also correlated with intraepithelial neoplasia in the prostate. Activated Erk2 was found in mammary tumors, pancreatic tissues, and affected livers. Hes1 RNA, a target of Notch signaling that has been implicated downstream of Ras pathway activation, was elevated in pancreatic and liver lesions. The variety of responses of different epithelia to PyMT demonstrates the importance of the differentiated state in interpreting oncogenic signals.
Cecena
Grace
G
Oncodevelopmental Biology Program, Cancer Research Center, The Burnham Institute, La Jolla, CA 92037, USA.
Wen
Fang
F
Cardiff
Robert D
RD
Oshima
Robert G
RG
D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D015139:Blotting, Southern; D002471:Cell Transformation, Neoplastic / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005260:Female; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D053538:Keratin-18; D007633:Keratins / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D009857:Oncogenes / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000072056:Transcription Factor HES-1
D000952:Antigens, Polyomavirus Transforming; D051792:Basic Helix-Loop-Helix Proteins; D048049:Extracellular Signal-Regulated MAP Kinases; D018398:Homeodomain Proteins; D053538:Keratin-18; D007633:Keratins; D012333:RNA, Messenger; D000072056:Transcription Factor HES-1; C489734:Hes1 protein, mouse; C488421:KRT18 protein, human