OBJECTIVETo label a human bladder cancer cell line and establish a novel human bladder cancer mouse model.

METHODST-24 cells, a human bladder transitional cell carcinoma cell line, were transfected with GFP plasmid to screen stable GFP-expressing clones. The latter were implanted into the wall of the bladder or the subcutaneous tissue of the neck of nude mice. The growth, invasion, and metastasis of the implanted tumor were observed and evaluated with whole-body optical imaging system. The findings were compared with those of HE staining on routine paraffin sections.

RESULTSGFP-labeled tumor cells displayed green fluorescence under fluorescent microscopy and showed stable GFP expression in vitro and in vivo. One week after in situ transplantation of 5 x 10(5) T24 cells, the new bladder cancer was observed and evaluated under whole-body optical imaging system. Two weeks later, the new bladder tumor could be palpated, and 4 weeks later, metastasis to regional drainage lymph nodes in the pelvic and retroperitoneal lymph nodes occurred. The growth and metastasis of the implant bladder tumor were easily observed and accurately evaluated by fluorescent microscope.

CONCLUSIONGFP-labeled tumor cells display green fluorescence under fluorescent microscopy and show stable GFP expression. GFP-labeled T-24 cells and the novel human bladder cancer model described hereby provide a simple and reliable means for studying human bladder cancer in vivo.