A long-term tissue culture cell line has been derived from a human prostate adenocarcinoma metastatic to the brain. The cell line, DU 145, has been passaged 90 times in vitro over a period of 2 years. The cells are epithelial, grow in isolated islands on plastic Petri dishes, and form colonies in soft agar suspension culture. Karyotypic analysis demonstrates an aneuploid human karyotype with a modal chromosome number of 64. Distinctive marker chromosomes (a translocation Y chromosome, metacentric minute chromosomes and three large acrocentic chromosomes) have been identified. Electron microscopy of the original tumor tissue and of the tissue culture cell line show a remarkable similarity in cell organelle structure.

Information on suspected risk factors for prostate cancer was obtained from in-person interviews as part of a case-control study of tissue sex hormone receptors and serum hormone levels. The risk factors examined were medical history (including venereal disease), sexual history, smoking, alcohol consumption, and occupational exposures. Study subjects were 40 prostate cancer patients and 64 benign prostatic hyperplasia controls who were newly diagnosed during 1984-1985 at North Carolina Memorial Hospital in Chapel Hill. Subjects were white and black men aged 50 years and older. Comparisons of cases' and controls' past medical histories did not support a venereal disease hypothesis of prostate cancer etiology. The most prominent finding is an association with farming employment: 75% of cases compared to 38% of controls reported farmwork occupations. Exposures to pesticides and herbicides, while more common among the patients, did not account for the association detected for farming. No relationship was observed with cadmium exposure, the most frequently cited occupational risk factor for prostate cancer.

Four longterm murine bladder tumor cell lines were established in vitro. The 4 lines were initiated from primary N-[4-(5-nitro-2-furyl)-2-thiazolyl] formamide (FANFT) induced murine bladder tumors arising in C3H/He mice. Each was maintained as a solid tumor in syngeneic mice for at least 30 generations before initiation in tissue culture. The cell lines MBT-2, MBT-8, MBT-409 and MBT-683, have been subcultured over 75 times in vitro for 18 months. They are all epithelial, grow in islands on plastic Petri dishes before confluent growth and form colonies in soft agar suspension culture. Morphologic studies indicate that all 4 lines have epithelial characteristics and karyotypic studies indicate that all lines have polyploidy and marker chromosomes. Population doubling times range from 10 to 26 hours and are consistent for each line.