INHIBITION OF HUMAN ONCOGENE EXPRESSION

干扰素对小鼠NIH3T3细胞的抑制作用 哈维小鼠肉瘤病毒DNA的转化 (HA-MusSV DNA)或人类EJ/T24 c-Ha-ras癌基因。转型是 即使在转染后第8天加入干扰素，也能显著抑制细胞增殖。 此外，用干扰素治疗RS 485，已经是NIH 3T3株 由Ha-MuSV启动子激活的人c-Ha-ras基因转化 导致了这些生物特性的表型逆转 细胞。突变体RS485在以下方面与未转化的NIH3T3相似 到形态、在软琼脂中的生长和饱和密度 初步实验已经降低了裸鼠的致瘤性和 产生较少的癌基因编码蛋白(P21)与 变换，与RS-485相比。 人类癌基因表达的生物学和生化方面将是 在这些逆转株中的进一步研究包括它们的c-Ha-ras水平 特异性DNA、mRNA和p21。此外，我还将学习复归 干扰素对EJ/T24癌基因转化的RS 504细胞的作用 它有一个非病毒式的推动者。RS 485和RS 504将被共转染 在使用neo和slad进行干扰素治疗之前，通常 在小鼠细胞中表达，以检测干扰素是否诱导抑制 癌基因表达是有选择性的。我还将调查是否 观察到的癌基因表达的抑制与 细胞对干扰素的反应或在已有充分描述的作用机制中 涉及特定蛋白激酶和2‘5’寡腺苷的干扰素 系统。为了研究这些，我将测试生物反应 将突变细胞转化为干扰素，并检测基础水平和诱导水平 这些细胞中的各种干扰素相关酶。我也要学习 蛋白激酶或核酸内切酶缺陷的NIH3T3细胞的逆转 与2‘5’A系统相关联。在用干扰素治疗后，以前有些 恢复RS 485“重新转换”到转换状态；然而，伟大的 大多数回复的RS 485细胞仍处于持续的回复中 州政府。癌基因表达和干扰素诱导的生化变化也将 在再生体和持久返回体中进行研究。我希望能 证明干扰素调节人类癌基因的表达，从而 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)