腎細胞癌化学療法のin vitroでの実験的研究 1.細胞回転からみた各種制癌剤の併用効果について

Abstract

1)従来のin vitroにおける制癌剤感受性試験に若干の工夫を加え, 写真撮影法により, 薬剤接触後の増殖動態を観察し, 短時間で比較的増殖能を忠実に反映する感受性試験を考案した.2)検討した8種類の薬剤のうち, vincristine (VCR), adriamycin (ADM), carboquone (CQ)の3剤が, 腎細胞癌由来のNC-65細胞に対し強い増殖抑制効果を示した.3)上記3例のcell cycleに及ぼす効果をFCMを用いて調べた.3剤とも, 単独で50%増殖を抑制する濃度までは, 12時間後にS期からG2-M期の蓄積を示し, 24時間後には, 逆にG1期の増加, S, G2-Mの減少を示し, その後は部分的な同調を示しつつ細胞回転は進行し, 72時間後には対照とほぼ同様の波形に復した.4) 2剤の同時併用による効果では, ADMとCQの同時接触で比較的強い併用効果を示した.時間差接触では, CQ投与後のVCR投与が, 有効な投与法であることが示唆され, 細胞回転を考慮した併用では, VCRやCQによりS, G2-M期に蓄積した細胞集団に対し, ADMの有効性が示された

To establish a useful combination chemotherapy of advanced renal cell carcinoma, I determined the optimal design of therapeutic schedules with an in vitro experimental model. At first, I determined the chemosensitivity of the NC-65 cell line established from human renal cell carcinoma. The method used is an original growth inhibition test which traces the cell growth in the same area by photography. This method can be completed in a short term and cell growth inhibition rate evaluated sequentially and precisely as well. Among 8 tested drugs, vincristine (VCR), adriamycin (ADM) and carboquone (CQ) were the most effective drugs. The effect of these three drugs on cell cycle traverse was estimated by flow cytometry. With all of these three drugs, at a concentration which inhibits cell growth less than 50%, an accumulation of cells in the S and G2-M phases was observed 12 hours after the exposure to the drugs. Although 24 hours later, the histogram showed the increase in cells of a G1 phase and decrease in G2-M cells, followed by the cell progression partially synchronized. The tendency was the most characteristic in VCR although it was not so significant in CQ. Effectiveness of the simultaneous or sequential combination of two-drugs was compared to the calculated expected effect using the t-test. At a low concentration which inhibits cell growth 32% (IC 32), most of the combination groups showed a weak effect. Sequential treatment at 12-hour intervals such as with VCR-ADM, CQ-VCR, CQ-ADM, were considered more effective than that of a 24-hour interval. In the medium concentration which inhibits cell growth 50% (IC 50), simultaneous administration of ADM and CQ showed a relatively high inhibition rate. Sequential treatment of CQ followed by VCR was the most cytotoxic. Comparison of sequential administration schedules, administration at 12-hour intervals showed a higher inhibition rate than that of a 24-hour interval, in the combination of VCR-ADM, CQ-ADM.