Hyperactivation of Ha-ras oncogene, but not Ink4a/Arf deficiency, triggers bladder tumorigenesis
J. Clin. Invest. Lan Mo, et al. 117:314 doi:10.1172/JCI30062 [Go to this article.]

Figure 1
Expression of senescence-associated markers during urothelial hyperproliferation and tumorigenesis in UPII/Ha-ras-M–transgenic mice. (A–C) Expression of Ink4a gene products, p16Ink4a (p16) and p19Arf (p19), as assayed by real-time quantitative PCR (A and B) and Western blotting (C). n, number of animals assayed in each group; Normal, normal urothelia from wild-type mice; +/– S/HP, simple urothelial hyperplasia from heterozygous transgenic mice; +/– T, low-grade, noninvasive superficial papillary tumors from the heterozygous mice. The level of p16 and p19 mRNA is expressed as a ratio in reference to a simultaneously amplified internal control, GAPDH. Total urothelial proteins used for Western blotting (C) were extracted from wild-type mice exhibiting normal urothelia (lane 1); heterozygous UPII/Ha-ras-M–transgenic mice exhibiting urothelial hyperplasia (6 months old; lanes 2 and 3); and heterozygous mice exhibiting low-grade, superficial papillary tumors (15 months old; lanes 4 and 5). Urothelial proteins from UPII/SV40T-transgenic mice were used as positive controls for p16 and p19 antibodies (lanes 6 and 7). MAPK was used as a loading control. Note the marked induction of p16, but not p19, in ras-induced urothelial hyperplasia as well as in low-grade, superficial papillary tumors. (D) Histochemical detection of senescence-associated β-galactosidase activity (SA-β-gal; stained at pH 6.0) and lysosomal, non–senescence-associated β-galactosidase activity (adjacent sections stained at pH 4.0). Urothelial tissues were from wild-type mice exhibiting normal urothelium, heterozygous transgenic mice exhibiting simple urothelial hyperplasia, and transgenic mice exhibiting papillary urothelial tumors. Note the absence of senescence-associated β-galactosidase activity in all of the urothelial lesions. Original magnification, ×200.