CLINICAL CORRELATIVE STUDIES IN GERM CELL TUMORS

描述：（申请人摘要）在此竞争性续期申请中， 本申请人将详述其显示TP 53突变的观察， 广泛变异的p53蛋白表达，bcl-2蛋白表达， 缺陷性凋亡 以上结果提示生殖细胞耐药性与生殖细胞的耐药有关， 肿瘤（GCT）的发生部分与细胞死亡途径的缺陷有关。 gcts 对化疗异常敏感 只有20%到30%的肿瘤 对顺铂化疗有抵抗力 GCT也显示体细胞 分化（畸胎瘤，通常是组织学良性）。 因此，畸胎瘤 也有"抗药性"，但化疗后出现畸胎瘤 很少会导致病人死亡 因此，两种形式的耐药性 都在场 因此，申请人将研究相关的遗传事件， 药物敏感（患者治愈）未分化的耐药性 GCT，耐药（患者复发或死于疾病）未分化 GCT和耐药分化GCT（畸胎瘤）。 具体目标 1，将估计GCT中TP53突变的频率。 他 初步数据显示TP53突变存在于一些耐药GCT中。 在特异性目标2中，凋亡反应和 p53依赖性凋亡或细胞周期调节蛋白（例如，bax，bcl-2， p21将被评估。 他在两个GCT细胞系（一个 药物敏感（TP53野生型）和一种药物抗性（TP53突变型））显示 未能上调p21，TP53突变体中凋亡率无变化 暴露于顺铂时与野生型相比的线，并标记 p53、bax和bcl-2蛋白表达在敏感性和 耐药GCT。 比较基因组杂交（CGH） 将用于评价GCT中基因组过量或损失受限区域 to drug药物resistant抗药性tumors肿瘤. 他的初步数据显示 五个不同染色体臂上的扩增区域。 在这些 具体目标，他将进一步确定是否存在一个协会， 遗传事件（标志物）和临床终点之间的单变量分析 (e.g.,治愈与死亡），最初使用比值比作为衡量 关联，然后进行多变量分析，以建立更好的方法 治疗计划。 对每个肿瘤进行SSCP和测序 TP53突变;对bax、bcl-2和p21进行免疫组化 表达和TUNEL检测凋亡率; CGH进行区域搜索 基因组失衡 从这些数据中，申请人将开始剖析 耐药途径，可能鉴定出与GCT相关的新基因 耐药性，并确定他们是否有独立的临床 预测值。

DESCRIPTION: (Applicant's Abstract) In this competing renewal application, the applicant will expand on his observations which show mutations in TP53, widely variable p53 protein expression, bcl-2 protein expression, and defective apoptosis. All of these suggest that drug resistance in germ cell tumors (GCTs) is partly related to defects in the cell death pathway. GCTs display unusual sensitivity to chemotherapy. Only 20% to 30% of tumors are resistant to cisplatin-based chemotherapy. GCTs also display somatic differentiation (teratoma, usually histologically benign). Thus, teratomas are also "drug resistant", but the presence of teratoma after chemotherapy rarely leads to a patient's death. Therefore, two forms of drug resistance are present. Thus, the applicant will study the genetic events associated with drug resistance in drug-sensitive (patient cured) undifferentiated GCTs, drug-resistant (patient relapsed or dead of disease) undifferentiated GCTs, and drug-resistant differentiated GCTs (teratomas). In Specific Aim 1, the frequency of TP53 mutations in GCTs will be estimated. His preliminary data show that TP53 mutations exist in some drug-resistant GCTs. In Specific Aim 2, the apoptotic response and the expression of p53-dependent apoptosis or cell cycle regulatory proteins (e.g., bax, bcl-2, p21) will be assessed. His preliminary data in two GCT cell lines (one drug-sensitive (TP53 wild-type) and one drug-resistant (TP53 mutant)) show failure to upregulate p21, no change in apoptotic rate in the TP53 mutant line compared to the wild-type when exposed to cisplatin, and marked differences in p53, bax, and bcl-2 protein expression in sensitive and resistant GCTs. In Specific Aim 3, comparative genomic hybridization (CGH) will be used to evaluate GCTs for regions of genomic excess or loss limited to drug-resistant tumors. His preliminary data have identified six amplified regions on five different chromosome arms. In each of these specific aims, he will further determine whether an association exists in univariate analysis between genetic events (markers) and clinical endpoints (e.g., cured vs. dead), initially using the odds-ratio as the measure of association, followed by multivariable analysis to establish better methods of treatment planning. On each tumor, SSCP and sequencing will be performed for TP53 mutations; immunohistochemistry performed for bax, bcl-2, and p21 expression and TUNEL for apoptotic rate; and CGH performed seeking regions of genomic imbalance. From these data, the applicant will begin to dissect the resistance pathway(s), possibly identify new genes associated with GCT drug resistance, and determine whether they have independent clinical predictor value.