Viruses as an aid to cancer therapy: regression of solid and ascites tumors in rodents after treatment with bovine enterovirus.

Treatment of ascites and solid tumors in mice (Sarcoma-1 and Ehrlich ascites carcinoma) with bovine enterovirus-1 resulted in regression of the tumors without any pathological effect on the animals. Death of mice with lymphatic-leukemia L4946 was delayed after such treatment. The oncolytic specificity of the virus does not appear to involve the production of interferon, but requires specific adsorption of virus to the tumor cells. The specificity of killing extends to cells in culture, since viral-transformed cells and oncogenic cells are susceptible to the virus, in contrast to cells of untransformed lines and cells of primary cultures, which are resistant. The possibility of utilizing the specificity of nonvirulent viruses in therapeutic treatment of human cancers is considered.