Specific Binding of Interferon-γ and-α_<2a> to Tumor Cells and Their Antitumor Activities

概要

論文の詳細を見る
Binding activities of a recombinant human interferon-γ (IFN-γ) preparation with 5 human tumor cell lines, including lung large cell carcinoma PC-13,lung small cell carcinoma QG-90,amelanotic melanoma HMV-1,renal carcinoma ACHN and Burkitt lymphoma Daudi, were compared with those of IFN-α_<2a>. Three out of five human tumor cell lines, ACHN, HMV-1,and QG-90,were highly susceptible to IFN-γ : the concentrations required to inhibit 50% of the growth of cells (IC_<50>) of ACHN, HMV-1,and QG-90 were 26,11 and 7 pM, respectively. IFN-α_<2a> also markedly inhibited the growth of ACHN, HMV-1 and Daudi cells : the values of IC_<50> for the former and latter cells were 20,31 and 0.8 pM, respectively. With these susceptible cells, larger amounts of IFN_-γ were bound than with resistant cells. On the other hand, IFN-α_<2a> bound all cell lines, irrespective of the susceptibilities of cells. The values of the apparent dissociation constant (K_d) of binding of both IFNs ranged from 1.3 to 7.3×10^<-10>M. The competitive binding test revealed that the binding properties of IFN_-γ were different from those of IFN-α_<2a>. Under the present experimental condition, it could be said that, with IFN_-γ, the susceptibilities of cells were linked of the expression of the receptors, but there were some exceptions with IFN-α_<2a>.
公益社団法人日本薬学会の論文