Suzuki N, Suzuki H, Ishizuka T, Yamamori H, Ino H
Department of Biochemistry, School of Medicine, Chiba University, Japan.
Mutat Res. 1997 Feb 3;373(2):251-6. doi: 10.1016/s0027-5107(96)00204-7.
K-ras gene sequences mutant at codon 12 were recovered following differential dot-blot hybridization of genomic DNA from human RSa cells up to 12 days after the cells had been irradiated with far-UV (principally 254 nm). By contrast, no mutant codon 12 sequences were recovered from cells which had been treated with 50 IU/ml human interferon (HuIFN)-alpha for 24 h prior to their UV exposure. HuIFN-alpha treatment in combination with anti-HuIFN-alpha antibody did not lead to the loss of mutant sequences. However, culture of interferon-pretreated cells with medium containing the protease inhibitor antipain (0.01 mM) for 6 h immediately after UV irradiation led to the recovery of mutant codon 12 sequences. Thus, while treatment with HuIFN-alpha appeared to prevent any UV-induced mutations affecting codon 12 of the K-ras gene from being recovered, the putative antipain-sensitive protease responsible for this suppressive affect appeared to be significantly affected by the protease inhibitor antipain.
在人RSa细胞经远紫外线（主要为254nm）照射长达12天后，通过对基因组DNA进行差异点杂交，回收了密码子12处发生突变的K-ras基因序列。相比之下，在紫外线照射前先用50IU/ml人α干扰素（HuIFN-α）处理24小时的细胞中，未回收得到密码子12处的突变序列。HuIFN-α处理与抗HuIFN-α抗体联合使用并未导致突变序列的丢失。然而，在紫外线照射后立即用含有蛋白酶抑制剂抗痛素（0.01mM）的培养基培养经干扰素预处理的细胞6小时，导致回收了密码子12处的突变序列。因此，虽然用HuIFN-α处理似乎可防止回收任何受紫外线诱导且影响K-ras基因密码子12的突变，但负责这种抑制作用的假定抗痛素敏感蛋白酶似乎受到蛋白酶抑制剂抗痛素的显著影响。
