TNF-ALPHA AND ITS RECEPTORS IN PEDIATRIC ACUTE LEUKEMIA

描述：尽管儿童的治疗有了很大的进步 急性淋巴细胞白血病(ALL)，约35%的儿童 这种疾病会复发或诱导治疗失败。申请人有 观察到内源性肿瘤坏死因子-α(TNF)的产生 儿科ALL细胞可能与难治性疾病有关。白血病的生长 被测试的大多数患者的细胞被肿瘤坏死因子抑制 并呈剂量依赖关系，并伴有细胞凋亡。相比之下，细胞 产生肿瘤坏死因子，并对抑制物产生抵抗力 外源性肿瘤坏死因子的作用。产生肿瘤坏死因子的白血病细胞系， 肿瘤坏死因子抵抗细胞和不产生肿瘤坏死因子、对肿瘤坏死因子敏感的细胞 细胞保留了原代细胞对外源性肿瘤坏死因子的反应性。 肿瘤坏死因子和肿瘤坏死因子细胞系均表达p60和p80肿瘤坏死因子受体(TNFR)， 提示这些品系之间的肿瘤坏死因子反应的表型差异 不是由于肿瘤坏死因子受体的表达改变所致。初步实验 提示肿瘤坏死因子和肿瘤坏死因子-细胞在调节 基因毒性治疗后的某些细胞凋亡/存活相关基因。 此外，临床数据表明，肿瘤坏死因子表型与 难治疾病和不良预后：剩余患者的百分比 确诊后一年的完全缓解率为20%。 细胞对89%的肿瘤坏死因子-ALL。他假设内源性肿瘤坏死因子起作用 作为肿瘤坏死因子ALL细胞的生存因子，保护这些细胞免受 细胞凋亡。为了检验这一假设，他提出了以下具体目标： 1)进一步研究肿瘤坏死因子和肿瘤坏死因子-ALL细胞系对 外源性肿瘤坏死因子、阿霉素和胰岛素抵抗基因表达的差异 DNA损伤后细胞凋亡与生存基因的关系；2)确定 阻断内源性肿瘤坏死因子的产生(使用肿瘤坏死因子反义表达 构建)影响所有细胞系对外源性肿瘤坏死因子的反应， 阿霉素和IR；3)研究内源性诱导的影响 肿瘤坏死因子(使用肿瘤坏死因子表达载体)对肿瘤坏死因子-急性淋巴细胞白血病细胞系反应的影响 4)检测儿童急性淋巴细胞白血病的原代白血病细胞 肿瘤坏死因子和肿瘤坏死因子受体的表达及其相关性 对遗传毒性药物有临床反应和体外反应；5) 重组肿瘤坏死因子-假单胞菌内毒素的细胞毒性测定 (肿瘤坏死因子-PE)对TNFR ALL细胞以及在SCID模型中的作用 移植白血病。

DESCRIPTION: Despite substantial advances in the treatment of childhood acute lymphoblastic leukemia (ALL), approximately 35 percent of children with this disease will relapse or fail induction therapy. The applicant has observed that endogenous production of tumor necrosis factor-alpha (TNF) by pediatric ALL cells may be linked to refractory disease. Growth of leukemic cells by the majority of patients tested was inhibited by TNF in a dose-dependent manner and was accompanied by apoptosis. In contrast, cells from a subset of patients produced TNF and were resistant to the inhibitory effects of exogenous TNF. Leukemic cell lines derived from TNF-producing, TNF-resistant (TNF+) cells and from TNF-nonproducing, TNF sensitive (TNF-) cells retained the responsiveness of the primary cells to exogenous TNF. Both TNF+ and TNF- lines expressed p60 and p80 TNF receptors (TNFrs), suggesting that phenotypic differences in TNF response between these lines are not due to altered expression of TNFrs. Preliminary experiments indicate marked differences between TNF+ and TNF-cells in the regulation of certain apoptosis/survival associated genes after genotoxic treatments. Moreover, clinical data suggest that the TNF+ phenotype is associated with refractory disease and poor prognosis: The percentage of patients remaining in complete remission at one year post-diagnosis was 20 percent for TNF+ ALL cells vs 89 percent for TNF- ALL. He hypothesizes that endogenous TNF acts as a survival factor for TNF+ ALL cells, protecting these cells from apoptosis. To test the hypothesis, he proposes the following specific aims: 1) To further investigate the response of TNF+ and TNF- ALL cell lines to exogenous TNF, adriamycin, and IR by examining differences in expression of apoptosis vs. survival genes following DNA damage; 2) To determine if blockade of endogenous TNF production (using a TNF-antisense expression construct) affects the response of TNF+ ALL cell lines to exogenous TNF, adriamycin, and IR; 3) To investigate the effects of induction of endogenous TNF (using a TNF expression vector) on the response of TNF- ALL cell lines to these agents; 4) To examine primary leukemic cells fro pediatric ALL patients for expression of TNF and TNF receptors, and to correlate this data with clinical response and in vitro response to genotoxic agents; 5) To determine the cytotoxicity of a recombinant TNF-Pseudomonas endotoxin (TNF-PE) for TNFR+ ALL cells in vitro as well as in the SCID model for engrafted leukemia.