Expression of the retinoblastoma gene product in bladder carcinoma cells associates with a low frequency of tumor formation

• Published in: Cancer research (Baltimore) Vol. 52; no. 7; pp. 1968 - 1973
• Main Authors: GOODFICH, D. W, CHEN, Y, SCULLY, P, WEN-HWA LEE
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 01.04.1992
• Subjects: Alleles; Biological and medical sciences; Blotting, Western; Cell Division; Cell Line; Gene Expression; Genes, Retinoblastoma; Humans; Kidneys; Kinetics; Medical sciences; Molecular Weight; Nephrology. Urinary tract diseases; Retinoblastoma Protein - analysis; Retinoblastoma Protein - genetics; Tumor Cells, Cultured; Tumors of the urinary system; Urinary Bladder Neoplasms - chemistry; Urinary Bladder Neoplasms - genetics; Urinary Bladder Neoplasms - pathology; Human; Cell proliferation; Urinary system disease; Carcinoma; Pathogenesis; Tumorigenicity; Malignant tumor; Genetic transfer; Phenotype; Urinary bladder; Established cell line; Inhibition; Tumor suppressor gene
• ISSN: 0008-5472; 1538-7445

Upon inactivation of both alleles of the retinoblastoma gene (RB), individuals develop the intraocular eye tumor, retinoblastoma. The gene encodes a Mr 110,000 phosphorylated nuclear protein that may be involved in regulation of the cell cycle. Besides retinoblastoma, mutations of the gene have been detected in several other types of tumors, including bladder carcinoma. Up to one-third of bladder carcinomas may contain mutations of the RB gene. Introducing the retinoblastoma gene into single retinoblastoma, osteosarcoma, or prostate carcinoma cell lines suppresses their tumorigenicity as assayed in nude mice. We have sought to extend these results by introducing the retinoblastoma gene into multiple bladder carcinoma lines, and analyzing several of the resulting, cloned lines. We have found that inhibition of tumorigenicity, as assayed by tumor growth in nude mice or growth of cells in soft agar, is the only consistent phenotype observed upon re-expression of RB in all bladder carcinoma cells examined. The effect of RB expression on growth and cellular morphology varied depending on the particular parental cell line. We conclude that RB expression generally correlates with reduced tumorigenicity, but not reduced growth rate, in bladder carcinoma cells.