Adjuvant Treatment with Chemotherapeutic Agents and Polyadenylic-Polyuridylic Acid in Operable Stomach Cancers: I. Enhancement of Natural Killer Cell Activity

ABSTRACT

Natural Killer (NK) cell activity of 47 operable stomach cancer patients was sequentially studied before and after chemotherapy in association with polyadenylic. polyuridylic acid [poly(A).poly(U)]. NK activity was determined by an in vitro 4 h chromium release assay using nonadherent mononuclear cells isolated from peripheral bloods as effectors and human myeloblastic cells (K562) as targets. The following results were obtained: 1) The mean NK activity of the 47 patients tested before chemotherapy was significantly lower than that of 14 healthy controls. 2) The patents who received chemotherapy consisting of 5 FU (12 mg/kg) and adriamycin (40 mg/M2) showed an increase in NK activity 5 days after injection as compared to that of the same patients tested before chemotherapy. 3) In these patients, an additional administration of poly(A) poly(U) (100mg) resulted in a further significant increase of NK activity 2 days later, whereas the control patients who received placebo showed no change of NK activity.