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.

Seasonal variations of symptoms and occurrence of human bladder carcinomas.

A longitudinal study of transitional cell carcinomas of the urinary bladder has been performed in a region of Western Norway. Hematuria and infection were the first symptoms of neoplasia of the urinary bladder, showing marked and reproducible seasonal variations. Most of the tumours showed the first symptom at the end of the year. They also had a higher histological grade (WHO) than those occurring at other times of the year. This indicates that environmental factors dependent on the season may be of importance for the manifestation of malignant growth of the urinary bladder.

DNA aberrations of bladder mucosa in patients with transitional cell carcinomas.

DNA aberrations in bladder mucosa have been investigated in altogether 26 patients with aneuploid WHO grade 2 and 3 tumours (transitional cell carcinomas; TCC). In about 1/4 of the patients aneuploid cells were found only in the tumour. Hypotetraploid tumours showed the lowest frequency of involvement of the normal appearing mucosa of the trigone (43%). In hypertriploid tumours the corresponding value was 71%. In altogether 14 of the patients, the same type of aneuploid cells was found in the normal appearing mucosa as in the tumour. This indicates frequent involvement of the whole bladder mucosa in the tumour disease. In about 1/4 of the cases other types of ploidy aberrations were found in the normal appearing mucosa than in the tumour. This is indicative of preneoplastic changes in the mucosa, of which only one type of aberrations is associated with tumour growth. In some cases with multiple tumours of the bladder, all the tumours had the same aneuploid stemline, while in other cases the tumours were of different aneuploid stemlines. This is conformal with other reports of atypia in the surrounding mucosa in TCC and with the concept that recurrence of high grade tumours is the consequence of neoplastic involvement of the whole bladder.