Characterization of cell lines originating from an invasive transitional cell carcinoma

A reporter gene (lacZ) was introduced into a human transitional cell cancer cell line (Hu1703He) by means of liposomal transfection. The lacZ-transfected cell line induced subcutaneous tumours in nude rats and cells from one rat tumour were then established as a monolayer culture. The two lacZ-transfected cell lines both stained positive for CK7 and negative for CK14 and additionally formed spheroids in three-dimensional cultures. Insignificant genomic changes occurred in the tumour cells after incubation in nude rats, while the lacZ transfection caused alterations that probably correspond to increased invasiveness and tumourigenicity in vitro and in vivo. Most important is the observation that lacZ transfection of this human TCC cell line does not reduce its invasion potential in vitro or in vivo. The lacZ reporter gene may thus be exploited to facilitate the identification and quantification of migrating tumour cells and subsequently for studies of invasion in in vitro coculture systems. The observation that the spheroidal growth is reduced after transfection of the cell line, in contrast to increased invasion and cellular growth in monolayer, is an observation indicating that a three-dimensional arrangement mimicking the in vivo conditions offers important regulating factors to cellular growth.

A human in vitro model of bladder tumour cell invasion

To study invasion of transitional cell cancer three-dimensional coculture assay consisting of living human tissues has been developed. Multicellular spheroids initiated from an invasive human bladder tumour cell line (Hu-1703He) were confronted with precultured fragments derived from normal human bladder mucosa. The fragments consisted of a surface epithelium and a central stroma. An intact epithelium prevented adhesion of the tumour cells to the fragments. By removing the surface epithelium prior to confrontation, tumour cells rapidly adhered to, migrated on and invaded the bladder fragments. This process was demonstrated by an inverted confocal laser scanning microscope on live tissue pre-incubated with fluorescent dyes. The coculture model enables the study of factors regulating different steps of tumour invasion in human bladder.

Nonadheshive stationary organ culture of normal human urinary bladder mucosa

Cold cup biopsies from normal human bladder mucosa were taken at cystoscopy. They were cut into fragments of 300-450 microns and grown in suspension in microwells base coated with agar. Within the first 24 hours of culture the fragments were totally covered by epithelium. After 7 days of culture the fragments had a morphology mimicking normal urothelial mucosa with an epithelium resting on a basement membraned for six weeks in culture. The purpose of this study was to provide a model representative of normal human urothelial mucosa for further studies of various diseases affecting the urinary bladder.