APOPTOSIS MEDIATED REGRESSION OF TRANSPLANTABLE LS LYMPHOSARCOMA IN CBA MICE TREATED WITH ACVP (ADRIAMICINE, CYCLOPHOSPHAMIDE, VINCRISTINE, PREDNISOLONE) OR CYCLOPHOSPHAMIDE ALONE

Kaledin V.I., Nikolin V.P., Timofeeva O.A., Filipenko M.L., Baymak T.Yu., Galyamova M.R., Popova N.A.

The antitumor activity of a four-drug combination, cyclophosphamide (CP), adriamycin, vincristine, and prednisolone, was studied on a transplantable lymphosarcoma LS in CBA mice. A single injection of the drug mixture produced a complete regression of the tumor transplants in all animals. The effect was found to be elicited by CP, not by any other constituent of the mixture. Morphological analyses of tumor slices and DNA electrophoresis evidenced that tumors regressed by apoptosis. The depth and duration of remission caused by CP were dose-dependent. Glucocorticoids and ionizing radiation, known apoptosis inducers, did not evoke total tumor regression. The obtained data show that there may be complete tumor regression due to apoptosis induced by a single constituent of the drug mixture.