STUDIES OF E26 AVIAN V-ETS AND ITS CELLULAR HOMOLOGUE IN MOUSE CELLS

一株复制缺陷小鼠逆转录病毒的致癌特性 构建表达人GAG-MYB-ETS融合癌基因的ME26 对禽急性白血病病毒E26进行了分析。感染了这种病毒 病毒消除NIH3T3成纤维细胞生长对血清的依赖 培养，并在新生小鼠中诱导白血病 两性假型。 为了确定ME26的不同结构域的功能作用 癌基因，突变结构已经产生，它们的生物学 已分析活动。已经证明，包含以下内容的构造 小鼠c-myb仍能诱导3T3细胞对血清的依赖 成纤维细胞和c-myb基因突变导致E26病毒 对转变的温度敏感似乎也会诱导 NIH3T3成纤维细胞的温度依赖性和血清依赖性生长。 然而，人雌激素受体结合域与C-受体结合域的融合 P135编码区的末端并不影响 诱导3T3细胞增殖的构建物 诱导荷尔蒙。这些结果与先前的观察结果一致。 C-末端v-myb和v-ETS序列是有效的 生长行为的改变，以及这一区域以外的改变 对低血清生长表型影响不大。 还尝试使用制备的消减cDNA文库 从表达ME26诱导能力的3T3细胞的正常3T3 RNA 在低血清中生长以确定ME26基因的遗传靶点 这些细胞。几个克隆，它们在ME26中的表达较高- 被感染的细胞，已被检测到，并将进一步表征。

The oncogenic properties of a replication-defective murine retrovirus construct, ME26, which expresses the gag-myb-ets fusion oncogene of the avian acute leukemia virus, E26, has been analyzed. Infection with this virus abrogates the serum dependence of NIH3T3 fibroblasts for growth in culture, and induces leukemia in newborn mice when introduced as an amphotropic pseudotype. In order to determine the functional role of different domains of the ME26 oncogene, mutant constructs have been generated and their biological activity analyzed. It has been demonstrated that constructs containing murine c-myb can still induce the abrogation of serum dependence in 3T3 fibroblasts and that a mutation in c-myb known to render E26 virus temperature-sensitive for transformation also appears to induce a temperature-dependent, serum-dependent growth in NIH3T3 fibroblasts. However, fusion of the human estrogen receptor binding domain to the C- terminus of the p135 coding region did not affect the ability of the resulting construct to induce proliferation of 3T3 cells in the absence of inducing hormone. These results are consistent with earlier observations that C-terminal v-myb and v-ets sequences are required for efficient alteration of growth behavior, and that alterations outside this region have little effect on the low-serum growth phenotype. Attempts have also been made to use subtractive cDNA libraries prepared from normal 3T3 RNA from 3T3 cells expressing the ME26-induced capacity to grow in low serum in order to identify the genetic targets of ME26 in these cells. Several clones, whose expression appears higher in ME26- infected cells, have been detected and will be characterized further.