RESUMO
Antineoplastons are naturally occurring peptides and amino acid derivatives that were originally isolated from human urine. They possess a broad-spectrum antitumor activity and seem to be much safer and specific than many of the available chemotherapeutic agents. Their selectivity is likely entailed to preferential interaction with cellular components or signaling mechanisms that predominate in cancer cells. Our studies on breast cancer- cell lines and -patients indicated the efficacy of antineoplaston-A10 and its derivatives as antimitotic, immunemodulator and cytodifferentiating agents. Moreover, phase-I and phase-II clinical trials implied the utility of antineoplastons in treating neoplasms of various origins. Combination with lower doses of known chemotherapeutic agents or in conjunction with radiotherapy was a promising therapeutic strategy. Such regimens were likewise effective in cases with recurrent or drug-resistant neoplasms. Intensive research is continuing to reveal more on antineoplastons and their biologic characteristics