Molecular Targeting of Bcl-xL Pathway in Cancer

癌症中 Bcl-xL 通路的分子靶向

基本信息

批准号：
7404555
负责人：
SUBRATA HALDAR
金额：
$ 26.5万
依托单位：
CASE WESTERN RESERVE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-07-01 至 2011-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7404555
关键词：
2-methoxyestradiol Antineoplastic Agents Apoptosis Apoptotic B-Cell Development B-Lymphocytes BAD gene BCL-Xs protein Bad protein Binding Biochemical Cell Line Cells Cytoplasm Development Family Family member Genes Germ Lines Growth Human Implant In Vitro Inhibition of Apoptosis Lymphocyte M Phase Arrest Malignant Neoplasms Malignant neoplasm of prostate Measures Microtubules Mitosis Modeling Molecular Target Mus Nude Mice Outcome Paclitaxel Pathology Pathway interactions Peptidylprolyl Isomerase Pharmaceutical Preparations Phosphorylation Post-Translational Protein Processing Process Prognostic Factor Proline Prostatic Neoplasms Protein Overexpression Proteins Regulation Role Serine Signal Transduction Site Small Interfering RNA Structure Therapeutic Transgenic Organisms Tubulin cancer cell cancer type docetaxel in vivo member mouse model mutant neoplastic cell novel prospective tumor tumor xenograft

项目摘要

DESCRIPTION (provided by applicant): The identification of the Bcl2 as well as lAP family members has suggested that excessive inhibition of apoptosis may constitute a common feature of all known human cancers -the ability to influence their onset, progression and outcome. The crystal structure of BCl-xL (a member of Bcl2 family) has contributed to a better understanding of its functional domains including the discovery of an unstructured "loop region" (LR) near the N-terminus exposed to the cytoplasm. The regulation of phosphorylation of Bcl-xL on Serine 62 residue in this "LR" by tubulin-binding anticancer drugs at mitosis has been defined. Importantly, the expression of a phosphorylation null (Ser 62 Ala) mutant Bcl-xL enhanced the growth of an established prostate tumor cell line in vitro by reducing the apoptotic threshold. Further in vitro studies indicate a novel downstream interaction of phosphorylated Bcl-xL with Pin1, a member of peptidyl prolyl isomerase family. To comprehend the significance of their association, elaborative studies will be undertaken in cancer cells, where the Pin1 gene will be post-transcriptionally silenced by a siRNA approach. To the other end, the importance of Bcl-xL expression during B cell development is demonstrated by the expansion of the pro-pre-B cell compartment. Placing the phosphomimetic and phosphorylation-defective mutant of Bcl-xL transgenically into the germ line of mice will provide a prospective opportunity to observe the effects of phosphorylation during the development of lymphocytes. Besides, the effect of microtubule-damaging drugs, such as Taxol or 2-Methoxyestradiol (2-ME), will be examined in tumor xenografts developed in athymic mice by implanting prostate cancer cells overexpressing phosphomimetic and phosphorylation-defective mutant of Bcl-xL. The following specific aims are proposed. Aim 1: To determine the outcome of the association between phospho-BCl-xL and Pin1. Aim 2: In vivo function of Bcl2 phosphorylation in regulating B lymphocyte development using a transgenic mouse model. Aim 3: To study the effect of Taxol or 2-ME on the tumors developed by prostate cancer cells overexpressing wild, phosphomimetic and phosphorylation-defective mutant of Bcl-xL in athymic (nude) mice. The understanding yielded from the proposed studies might be helpful to target a prospective therapy for a subpopulation of cancer cells in which Bcl-xL overexpression is a key prognostic factor.

描述（由申请人提供）：Bcl2以及lAP家族成员的鉴定表明，细胞凋亡的过度抑制可能构成所有已知人类癌症的共同特征——影响其发生、进展和结果的能力。 BCl-xL（Bcl2 家族成员）的晶体结构有助于更好地理解其功能域，包括在暴露于细胞质的 N 末端附近发现非结构化“环区”(LR)。有丝分裂时微管蛋白结合抗癌药物对该“LR”中丝氨酸 62 残基上的 Bcl-xL 磷酸化的调节已被定义。重要的是，磷酸化无效（Ser 62 Ala）突变体 Bcl-xL 的表达通过降低细胞凋亡阈值增强了体外已建立的前列腺肿瘤细胞系的生长。进一步的体外研究表明磷酸化 Bcl-xL 与 Pin1（肽基脯氨酰异构酶家族的成员）存在新型下游相互作用。为了理解它们之间关联的重要性，我们将在癌细胞中进行详细研究，其中 Pin1 基因将通过 siRNA 方法进行转录后沉默。另一方面，B 细胞前体区室的扩张证明了 Bcl-xL 表达在 B 细胞发育过程中的重要性。将 Bcl-xL 的磷酸化和磷酸化缺陷突变体转基因放入小鼠种系中，将为观察淋巴细胞发育过程中磷酸化的影响提供一个前瞻性的机会。此外，通过植入过度表达磷酸化和磷酸化缺陷型 Bcl-xL 突变体的前列腺癌细胞，在无胸腺小鼠中开发的肿瘤异种移植物中检查微管损伤药物（例如紫杉醇或 2-甲氧基雌二醇 (2-ME)）的作用。提出以下具体目标。目标 1：确定磷酸化 BCl-xL 和 Pin1 之间关联的结果。目标 2：使用转基因小鼠模型研究 Bcl2 磷酸化在调节 B 淋巴细胞发育中的体内功能。目标 3：研究紫杉醇或 2-ME 对无胸腺（裸）小鼠中过度表达 Bcl-xL 野生型、拟磷酸化和磷酸化缺陷突变体的前列腺癌细胞产生的肿瘤的影响。从拟议的研究中获得的理解可能有助于针对癌细胞亚群进行前瞻性治疗，其中 Bcl-xL 过度表达是关键的预后因素。