PROGRESSION OF INTERLEUKIN-2 (IL-2)-DEPENDENT RAT T-CELL LYMPHOMA LINES TO IL-2-INDEPENDENT GROWTH FOLLOWING ACTIVATION OF A GENE (GFI-1) ENCODING A NOVEL ZINC FINGER PROTEIN
PROGRESSION OF INTERLEUKIN-2 (IL-2)-DEPENDENT RAT T-CELL LYMPHOMA LINES TO IL-2-INDEPENDENT GROWTH FOLLOWING ACTIVATION OF A GENE (GFI-1) ENCODING A NOVEL ZINC FINGER PROTEIN
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DOI：
10.1128/mcb.13.3.1759
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发表时间：
1993-03-01
影响因子：
5.3
通讯作者：
TSICHLIS, PN
中科院分区：
文献类型：
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作者：
GILKS, CB;BEAR, SE;TSICHLIS, PN
在莫洛尼鼠白血病病毒（Mo-MuLV）诱导的大鼠T细胞淋巴瘤的进展过程中，生长选择导致携带越来越多的整合前病毒的细胞克隆扩增。这些新的前病毒插入可重复地有助于增强生长，从而允许从最初的异质肿瘤细胞群中出现细胞克隆。将Mo-MuLV诱导的大鼠T细胞淋巴瘤系2780 d和5675 d置于无IL-2培养基中以选择IL-2非依赖性（IL-2 i）突变体，所述细胞系在培养物中生长依赖于白细胞介素-2（IL-2）（IL-2d）。Southern印迹分析的基因组DNA从这些突变体，这是杂交到一个Mo-MuLV长末端重复探针，揭示了所有的突变体进行新的前病毒插入（从一个到四个新的前病毒每个细胞系）。通过克隆在IL-2 i突变体之一2780i.5中检测到的单个新前病毒鉴定的整合位点被发现是在24个测试的另外1个IL-2 i细胞系中的前病毒插入的靶标。克隆了在2780i.5细胞中通过插入启动子激活的基因（生长因子独立性-1 [Gfi-1]）的全长cDNA，并显示其编码一种新的锌指蛋白。Gfi-1在含IL-2的培养基中培养的IL-2d细胞系中以低水平表达，而在大多数IL-2 i细胞系中以高水平表达，包括在该基因座携带前病毒的两种细胞系。在成年动物中，Gfi-1的表达仅限于胸腺、脾脏和睾丸。在有丝分裂原刺激的脾细胞中，Gfi-1表达在刺激后12小时开始上升，并在50小时后达到非常高的水平，这表明它可能在功能上参与了IL-2与其受体相互作用后发生的事件，可能是在细胞周期从G1期到S期的过渡期间。与此一致，Gfi-1不会诱导IL-2的表达。在转移Gfi-1/LXSN逆转录病毒构建体后，Gfi-1在2780 d细胞中的表达有助于IL-2 i表型的出现。
During progression of Moloney murine leukemia virus (Mo-MuLV)-induced rat T cell lymphomas, growth selection results in the expansion of cell clones carrying increasing numbers of integrated proviruses. These new provirus insertions reproducibly contribute to enhanced growth, allowing the emergence of cell clones from the initially heterogeneous population of tumor cells. The Mo-MuLV-induced rat T cell lymphoma lines 2780d and 5675d, which are dependent on interleukin-2 (IL-2) for growth in culture (IL-2d), were placed in IL-2-free medium to select for IL-2-independent (IL-2i) mutants. Southern blot analysis of genomic DNA from these mutants, which was hybridized to a Mo-MuLV long terminal repeat probe, revealed that all mutants carried new provirus insertions (from one to four new proviruses per cell line). A locus of integration identified through cloning of the single new provirus detected in one of the IL-2i mutants, 2780i.5, was found to be the target of provirus insertion in 1 additional IL-2i cell line of 24 tested. A full-length cDNA of a gene (growth factor independence-1 [Gfi-1]) activated by promoter insertion in the 2780i.5 cells was cloned and shown to encode a novel zinc finger protein. Gfi-1 is expressed at low levels in IL-2d cell lines cultured in IL-2-containing medium and at high levels in most IL-2i cell lines, including the two harboring a provirus at this locus. Gfi-1 expression in adult animals is restricted to the thymus, spleen, and testis. In mitogen-stimulated splenocytes, Gfi-1 expression begins to rise at 12 h after stimulation and reaches very high levels after 50 h, suggesting that it may be functionally involved in events occurring after the interaction of IL-2 with its receptor, perhaps during the transition from the G1 to the S phase of the cell cycle. In agreement with this, Gfi-1 does not induce the expression of IL-2. Expression of Gfi-1 in 2780d cells following transfer of a Gfi-1/LXSN retrovirus construct contributes to the emergence of the IL-2i phenotype.