INHIBITION OF HUMAN ONCOGENE EXPRESSION BY INTERFERON

长效α/β干扰素（IFN-α/β）或重组 IFN-β处理由长时间的IFN-β转化的RS485、NIH 3 T3细胞 末端重复激活的Ha-ras原癌基因导致 回复突变体在IFN后很长时间保持非转化表型 停止治疗。 克隆持久回复突变体 (PRs)产生了大量的ras编码的p21， 通过EJras DNA转化和通过转化 携带v-Ha-ras、v-Ki-ras、v-abl或v-fes的逆转录病毒 癌基因 体外或体内瞬时治疗， 通过抑制DNA而改变基因表达的胞苷类似物 甲基化导致PR的转化，但不导致NIH 3 T3的转化 细胞 我们希望研究这种持续存在的 逆转 我们希望能证明基因表达模式的改变， 通过在cDNA文库细胞中鉴定持久回复突变体 在PR和RS485中差异表达的信息。 的 这些cDNA影响RS485表型的潜力，或 通过检测这些细胞， 细胞与结构，将允许过表达 消息或反义消息。 差异表达基因组克隆 也将获得表达的基因，并且侧翼调控基因 区域分析。 我们还希望研究共同转化的可能作用， 癌基因，内源性IFN产生，和DNA甲基化 持续逆转现象中的调节位点， 进一步研究PR对各种再转化的抵抗力 病毒和细胞癌基因。

Prolonged alpha/beta interferon (IFN-alpha/beta) or recombinant IFN-beta treatment of RS485, NIH 3T3 cells transformed by a long terminal repeat-activated Ha-ras proto-oncogene resulted in revertants that maintain a non-transformed phenotype long after IFN treatment had been discontinued. Cloned persistent revertants (PRs) produced large amounts of the ras-encoded p21 and were refractile to transformation by EJras DNA and by transforming retroviruses which carried the v-Ha-ras, v-Ki-ras, v-abl, or v-fes oncogene. Transient treatment either in vitro or in vivo with cytidine analogs that alter gene expression by inhibiting DNA methylation resulted in transformation of PR, but not of NIH 3T3 cells. We wish to study the mechanisms involved in this persistent reversion. We hope to demonstrate altered patterns of gene expression in the persistent revertants by identifying in cDNA libraries cell messages that are differentially expressed in PRs and RS485s. The potential of these cDNAs to affect the phenotype of RS485 or persistent revertant cells will be evaluated by transfecting these cells with constructs that will allow the over-expression of either message or anti-sense message. Genomic clones of differentially expressed gene will also be obtained and the flanking regulatory regions analyzed. We also wish to investigate the possible roles of co-transforming oncogenes, endogenous IFN production, and DNA methylation of regulatory sites in the phenomenon of persistent reversion, and to study further the resistance of PRs to re-transformation by various viral and cellular oncogenes.