Oncogene-targeted antisense oligodeoxynucleotides combined with chemotherapy or immunotherapy: a new approach for tumor treatment?

Synthetic oligodeoxynucleotides (antisenses) complementary to bcr/abl breakpoint junction transcript on Philadelphia chromosome, or c-myb protooncogene inhibit partially the proliferation of Philadelphia positive leukemic cells (antisenses against bcr/abl and c-myb) and other tumor cells (antisenses against c-myb). This phenomenon is accompanied by specific downregulation of mRNA level of the particular gene. To develop a more effective procedure of tumor treatment the combination of low dose of cytostatic and bcr/abl or c-myb antisenses against Philadelphia chromosome positive cell line BV173, and the combination of anti-tumor cytotoxic T lymphocytes (CTL) and c-myb antisenses against melanoma cell line MM-28, were tested in vitro. Our results indicate that the combinations of conventional chemotherapeutic agent and antisense against bcr/abl or c-myb or tumor specific CTL and antisense against c-myb, are highly effective in killing of tumor cells and sparing normal cells. This creates the possibility to develop a more selective and effective treatment of neoplasia.