Establishment and characterization of a new human urinary bladder carcinoma cell line (PS-1).

An epithelioid cell line (PS-1) has been established from a transitional cell cancer derived from human urinary bladder. Subcutaneous injection of the epithelioid cells into weanling athymic nude mice induced solid tumors histologically similar to the original tumor. A cell line was also established from a tumor induced in the athymic nude mouse (PS-1, T-1). Both cell lines exhibited essentially identical growth characteristics and formed a monolayer growth of epithelioid cells in culture. Electron microscopic studies confirmed epithelioid morphology. No fibroblastoid elements were observed. Chromosomal analysis revealed heteroploidy with persistent marker chromosomes; all cells contained a Y chromosome. The presence of tumor-specific antigen(s) in PS-1 cells was suggested by microcytotoxicity assays with peripheral allogeneic lymphocytes from other transitional cancer cell patients. Sera of urinary bladder cancer patients reacted with nuclear antigens of the established cells.

Immune response of prostatic cancer patients to cytomegalovirus-infected and -transformed human cells.

The indirect immunofluorescent test was used to determine the prevalence of humoral immunity to cytomegalovirus (CMV)-induced antigens in prostatic cancer patients as compared to age-matched controls. Significantly more prostatic cancer patients demonstrated high CMV-antibody titers than did the benign prostatic hyperplasia and nonurogenital cancer groups; however, no significant difference in reactivity was found between paients with prostatic cancer and transitional cell carcinoma of the urinary bladder. When screened against CMV-transformed human cell lines, the reactivity of the sera followed the rate of expression of CMV-related antigens of cell lines used in these tests.

Alterations in biological properties of different lines of cytomegalorivus-transformed human embryo lung cells following in vitro cultivation.

Diverse alterations in biological properties of CMV-transformed cell lines were observed during prolonged in vitro cultivation. In the CMV-Mj-HEL-2 parent line there was a gradual decrease in the number of cells expressing CMV-related antigens; at the same time, an increase in oncogenicity was observed. One tumour line, designated CMV-Mj-HEL-2,T-1, however, retained the original ratio of cells expressing CMV-related antigens for over 100 in vitro passages. The cells lost their original moderate oncogenicity during this period. A later increase in the ratio of cells without CMV antigenic markers was accompanied by the return of moderate tumorigenicity and karyotypic changes. Both cell lines were studied to determine sensitivity to superinfection with herpesviruses, induction of immune response in nude mice, and release of infectious virus.

Evidence for the association of cytomegalovirus with carcinoma of the prostate.

A human genital isolate of cytomegalovirus is shown to have transformed human embryonic lung cells in vitro. These cells produce tumors when injected into athymic nude mice. Two cell lines derived from tissue from human prostatic carcinoma have survived more than 20 passages in vitro and demonstrate cytomegalovirus-specific membrane antigen. Significant humoral antibody titers against cytomegalovirus have been demonstrated. Cell-mediated lymphocytotoxicity against these transformed cells has been demonstrated in patients with urinary tract tumors. This evidence indicates that an association between cytomegalovirus and human prostatic cancer may be more than coincidental.