Effect of human alpha-fetoprotein on DNA, RNA, and protein synthesis, and viability of tumor cells in vitro

Effect of human alpha-fetoprotein (AFP) on the synthesis of RNA, DNA, and protein in tissue cultures of tumor cells (mastocytoma P815 from DBA/2 mice and erythromyeloleukosis K562) was investigated by radioisotope method. It was determined that AFP provided direct anti-proliferative effect on tumor cells in vitro via involvement of non-immune mechanisms of membrane toxicity and blockade of RNA, DNA, and protein synthesis. Within dose range from 153 to 1250 g/ml AFP exhibited an expressed cytotoxic effect on cells of murine mastocytoma P815; it impeded DNA synthesis in cells of erythromyeloleukosis K562 in the doses 640, 320, and 80 g/ml; and it decreased the level of protein synthesis in cells of erythromyeloleukosis K562 in doses 640, 320, and 160 g/ml. Under the additional examination AFP inhibited RNA synthesis in cells of human erythromyeloleukosis K562 and murine mastocytoma P815 in doses 165 and 82 g/ml. AFP within dose range from 40 to 100 g/ml (72 h incubation) exhibited an expressed cytotoxic effect on cells of human erythromyeloleukosis K562 from 55 % to 100 %.