Ll210マウス白血病組織培養樹立株の浮遊培養を用いた癌実験化学療法の研究

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臨床効果の高い予言性を示すことが知られているL1210マウス白血病の組織培養樹立株浮遊培養細胞と初代培養細胞を用いて,各種制癌剤の試験管内作用様式を検討し,併せてこれら薬剤の生体内効果と比較を行なった結果,各種の薬剤はin vitroにおける作用の時間依存性や,対数増殖期と定常期細胞に対する効果およびin vivoにおける投与量の相違の点から分類されることを見出した。すなわち5-fluorouracil, methotrexate, cytosine arabinosideなどのデオキシリボヌクレオチド生合成を阻害する代謝拮抗剤およびvinblastine, vincristineなどの分裂阻害植物アルカロイドは時間依存性が強く,対数期細胞には低濃度で作用するが,定常期細胞には作用が著しく弱かった。一方nitromin, thio-TEPA, carbazilquinone,BCNUなどのアルキル化剤やmitomycin CのようにDNA2重鎖間に架橋形成を行なう薬剤およびchromomycin A_3, actinomycin D, daunomycin, adriamycinなど鋳型DNAに作用する抗生物質は時間依存性は弱く,細胞増殖時期による効果に差があまりなかった。またin vitro(ED_80)とin vivo(i.P., per mouse per day)の有効量を比較してみると,代謝拮抗剤,植物アルカロイドではその比は約1:1,700〜5,000,アルキル化剤,抗生物質では約1:4〜100と著しい差があった。このようにしてL1210細胞の試験管内浮遊培養系は,制癌剤の簡易な微量測定や,作様様式を予測するうえにすこぶる有用であり,制癌物質のスクリーニングへの応用は極めて能率性を高められるものと考えられた。さらにin vitroの成績は制癌剤の生体への投与法にも示唆を与えているものと思われた。

Studies were undertaken to elucidate the action modes of various antitumor agents employing mouse leukemia L 1210 cells. In vitro activity of test compounds was determined using both a suspension culture of established cell line and a primary culture of L 1210 cells.According to the experimental results, it was concluded that the antimetabolites such as 5-fiuorouracil, methotrexate, cytosine arabinoside and vinca alkaloids, vincristine and vinblastine, showed time dependency in their effects and were only effective on the exponentially growing cells but almost inactive against cells in stationary phase of growth. On the other hand, the effects of alkylating agents, i.e., nitrogen mustard-N-oxide, thio TEPA, carbazilquinone, BCNU as well as antibiotics, i. e., mitomycin C, chromomycin A_3, actinomycin D, daunorubicin, adriamycin were not dependent on incubation time. The latter compounds were also found to be active against the cultured cells not only in logarithmic phase but also in stationary phase. When the minimum effective doses (intraperitoneal injection, per mouse per day) in vivo and ED_80 in vitro were compared, it was revealed that the ratio varied from 1,700 to 5,000 with antimetabolites and vinca alkaloids, while they were within the range of 4 to 100 with alkylating agents and antibiotics. Above results also suggested that the suspension culture of established cell line of mouse leukemia L 1210 is highly useful for the estimation of action mechanisms in the primary stage of screening antitumor compounds and for the design of clinical treatment.