[Combined effects of alpha-interferon and anticancer drugs against renal cell carcinoma]

The direct antitumor effects of combined administration of alpha-interferon and chemotherapeutic agents against the human tumor cell line derived from renal cell carcinoma were examined in vivo as xenograft in nude mice. The administration regimen was as follows: Human lymphoblastoid interferon (HLBI) was injected intramuscularly (1 x 10(5) IU/mouse/day) every day for 14 days. Peplomycin (PEP), adriamycin (ADM), or 5-fluorouracil (5-FU) was also administered at a dose of one third of their LD50. We evaluated the effect 20 days after initial administration using the ratio of mean tumor weight. Combined administration of HLBI and PEP or ADM was determined effective and inhibited tumor growth more strongly than HLBI alone or control. Furthermore, the histopathological examination suggested that the effect of combined administration was cytostatic rather than cytolytic.