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

一种复制缺陷型小鼠逆转录病毒的致瘤特性 构建体ME 26，其表达大肠杆菌的gag-myb-ets融合癌基因。 禽急性白血病病毒，E26，已分析。 感染这种 病毒消除了NIH 3 T3成纤维细胞生长的血清依赖性， 培养，并诱导新生小鼠白血病时，引入作为一个 嗜热假模式。 为了确定ME 26不同结构域的功能作用， 已经产生了癌基因突变体构建体，并且它们的生物学特性 活动分析。 已经证明，包含 小鼠c-myb仍能诱导3 T3细胞血清依赖性的消除 成纤维细胞和已知使E26病毒 对温度敏感强迫转化似乎也诱导了 NIH 3 T3成纤维细胞中的温度依赖性、血清依赖性生长。 然而，人雌激素受体结合结构域与C-受体结合结构域的融合是不可能的。 p135编码区的末端并不影响p135蛋白表达的能力。 所得到的构建体在不存在下诱导3 T3细胞增殖， 诱导激素 这些结果与早期的观察结果一致 C-末端v-myb和v-ets序列是有效的 生长行为的改变，以及该区域以外的改变 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 来自表达ME 26诱导能力的3 T3细胞的正常3 T3 RNA， 在低血清中生长，以鉴定ME 26的遗传靶点， 这些细胞。 几个克隆，其表达在ME 26- 已检测到感染的细胞，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.