INHIBITION OF HUMAN ONCOGENE EXPRESSION

用干扰素（IFN）处理小鼠NIH 3 T3， 哈维鼠肉瘤病毒DNA转染转化 （Ha-MusSV DNA）或人EJ/T24 c-Ha-ras癌基因。 改造是 即使在转染后8天加入IFN，也显著抑制。 此外，用干扰素处理RS 485，NIH 3 T3系， 由Ha-MuSV启动子激活的人c-Ha-ras基因转化 导致这些生物学特性的表型逆转， 细胞 回复突变体RS 485在以下方面类似于未转化的NIH 3 T3： 形态，软琼脂生长，饱和密度， 初步实验已经降低了裸鼠的致瘤性， 产生较少的癌基因编码蛋白（p21）， 与RS-485相比， 人类癌基因表达的生物学和生物化学方面将是 在这些回复突变体中进一步研究，包括它们的c-Ha-ras水平 特异性DNA、mRNA和p21。 此外，我还将研究以下回复： 用干扰素处理EJ/T24癌基因转化的细胞系RS 504 它有一个非病毒启动子。 RS 485和RS 504将被共转染 在用neo和SLA进行IFN治疗之前，D基因通常 在小鼠细胞中表达，以测试IFN-诱导的对 癌基因表达是选择性的。 我还将调查 观察到的癌基因表达的抑制与肿瘤细胞中 细胞对IFN的反应或良好表征的作用机制 涉及特定蛋白激酶和2 '5'寡腺苷酸的IFN 系统 为了研究这些，我将分析 转化的回复突变体细胞IFN和测试的基础和诱导水平， 这些细胞中的各种干扰素相关酶。 我也要学习 在蛋白激酶或核酸内切酶缺陷的NIH 3 T3细胞中的逆转 与2 '5'A系统相关。 IFN治疗后，一些先前 恢复RS 485“再转换”到转换状态;然而，伟大的 大多数回复突变体RS 485细胞保持在持续回复突变体中， 状态 癌基因表达和干扰素诱导的生化变化也将 在再转化体和持久回复体中进行研究。 我希望 表明IFN调节人类癌基因的表达，因此 为它们用于治疗人类癌症奠定了基础。 （十）

Treatment of mouse NIH 3T3 with interferon (IFN) inhibited their transformation by transfection with Harvey murine sarcoma virus DNA (Ha-MusSV DNA) or the human EJ/T24 c-Ha-ras oncogene. Transformation was significantly inhibited even when IFN was added 8 days after transfection. Furthermore, treatment with IFN of RS 485, an NIH 3T3 line already transformed by a human c-Ha-ras gene activated by a Ha-MuSV promoter resulted in a phenotypic reversion in the biological properties of these cells. The revertant RS 485 resembled untransformed NIH 3T3 with respect to morphology, growth in soft agar, and saturation density, and in preliminary experiments had reduced tumorigenicity in nude mice and produced less of an oncogene-coded protein (p21) associated with transformation, when compared to RS-485. The biological and biochemical aspects of human oncogene expression will be further studied in these revertants including their levels of c-Ha-ras specific DNA, mRNA, and p21. In addition I shall study reversion following IFN treatment in RS 504, a cell line transformed by the EJ/T24 oncogene that has a nonviral promoter. Both RS 485 and RS 504 will be cotransfected before IFN treatment with the neo and SLAd, genes that are usually expressed in mouse cells in order to test whether IFN-induced inhibition of oncogene expression is selective. I shall also investigate whether the observed inhibition of oncogene expression is related to changes in the response of cells to IFN or in the well-characterized mechanisms of action of IFNs that involve a specific protein kinase and the 2'5' oligoadenylate system. In order to study these I shall assay the biological responses of transformed revertant cells to IFN and test the basal and induced levels of the various IFN-associated enzymes in these cells. I shall also study reversion in NIH 3T3 cells deficient in protein kinase or the endonuclease associated with the 2'5'A system. After treatment with IFN some previously reverted RS 485 "retransform" to a transformed state; however, the great majority of revertant RS 485 cells remain in a persistently revertant state. Oncogene expression and IFN-induced biochemical changes will also be studied in retransformants and persistent revertants. I hope to demonstrate that IFNs modulate the expression of human oncogenes, thus establishing a basis for their use in treatment of human cancers. (X)