Enhanced tumor suppressor gene therapy via replication-deficient adenovirus vectors expressing an N-terminal truncated retinoblastoma protein.

The preclinical studies presented here demonstrate that treatment of human non-small cell lung carcinoma and bladder carcinoma cells by a recombinant adenovirus vector, AdCMVpRB94, expressing the N-terminal truncated retinoblastoma (RB) protein (pRB94) completely suppressed the tumorigenicity of the treated tumor cells in nude mice. Furthermore, gene therapy of established human RB- and RB+ bladder xenograft cancers in nude mice by AdCMVpRB94 resulted in regression of the treated tumors. Of note, although both the full-length and the truncated forms of the RB protein, when overexpressed in tumor cells via replication-deficient adenovirus vectors, were capable of suppression of tumor growth, the pRB94 was evidently more potent than the full-length RB protein.