Molecular Impact of Platinum Drugs on the Proteasome and SQSTM1_P62 Complexes_A Paradigm Shift in Resistance

铂类药物对蛋白酶体和 SQSTM1_P62 复合物的分子影响_耐药范式转变

• 批准号: 10051382
• 负责人: Rajagopal Ramesh
• 金额: --
• 依托单位: OKLAHOMA CITY VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10051382
• 关键词: 26S proteasome; Address; Alcohol consumption; Amino Acids; Antineoplastic Agents; Archives; Area; Autophagocytosis; Biological; Brain; Cancer cell line; Carboplatin; Cell Death; Cell Line; Cell Survival; Cells; Cellular Stress; Cessation of life; Chemoresistance; Cisplatin; Clinical; Complex; Diagnosis; Disease; Drug resistance; Endoplasmic Reticulum; Environmental Carcinogens; Exposure to; Failure; GTF2H1 gene; Gene Proteins; Human; In Vitro; Incidence; Innovative Therapy; Investigation; Knowledge; Laboratories; Lung Neoplasms; Malignant Neoplasms; Malignant neoplasm of lung; Military Personnel; Modeling; Molecular; Molecular Target; Nano delivery; Nature; Neoplasm Metastasis; Normal Cell; Outcome; Pathology; Patients; Pharmaceutical Preparations; Platinum; Platinum Compounds; Play; Primary Neoplasm; Proteins; Recurrence; Recurrent disease; Recycling; Reporting; Research; Resistance; Resistance development; Role; Scaffolding Protein; Services; Signal Transduction; Smoking; Specimen; Testing; Thoracic Oncology; Translational Research; Tumor Tissue; base; cancer cell; cancer stem cell; cancer therapy; chemotherapy; clinically relevant; drug development; improved; in vivo; ineffective therapies; innovation; interest; knock-down; military veteran; mortality; multicatalytic endopeptidase complex; nanoformulation; nanoparticle; novel; novel therapeutic intervention; novel therapeutics; overexpression; patient derived xenograft model; pre-clinical; prevent; protein expression; resistance mechanism; response; restoration; statistics; stem; stem cells; targeted treatment; treatment response; treatment strategy; tumor; tumor xenograft

Lung cancer-related death is primarily due to disease recurrence, drug resistance, and metastasis. Platinum compounds such as cisplatin (CDDP) and carboplatin (CBDCA) and their derivatives are widely used in the treatment of lung cancer. Although the tumors initially respond to platinum drugs, they adeptly develop resistance thereby escaping therapy. Therefore, understanding the mechanisms by which cancer cells evade therapy and develop resistance is essential for developing new therapeutic approaches for lung cancer. This application addresses a highly innovative and high-impact area of translational research that focuses on investigating how platinum-based drugs impact the proteasome and sequestosome (SQSTM1)/P62 function in cancer cells to produce drug resistance in lung cancer. Further, a nanodelivery approach targeted towards the proteasome and SQSTM1/P62 in combination with CDDP for overcoming resistance is proposed. Our interest in testing the proteasome and SQSTM1/P62 in chemoresistance stems from a serendipitous observation made in the laboratory. We observed beta 5 (β5) expression, a subunit of the large 26S proteasome complex was markedly reduced in cisplatin-resistant (CDDPR) cancer cell lines when compared to its isogenic cisplatin-sensitive (CDDPS) cell lines. β5 is the chymotryptic component of the proteasome that is required for degrading ubiquitinated proteins and recycling of amino-acids for synthesis of new proteins in the cell. Associated with reduced β5 expression in the CDDPR cells was the intracellular accumulation of proteins. Investigation into how the cellular stress induced by intracellular accumulation of proteins is overcome by the cells revealed a role for SQSTM1/P62. The primary function of SQSTM1/P62, a scaffolding protein that is activated in response to cellular stress, is to prevent cell death by aggregating intracellular accumulated polyubiquitinated proteins into aggresomes and directing towards autophagy, thereby promoting cell survival. Further, analysis for P62 expression in a subset of human lung tumor tissues showed that chemoexperienced lung tumors had higher P62 expression compared to chemonaive tumors. Although, reduced proteasome function and increased SQSTM1/P62 expression have previously been reported in cancer cells and in stem cells, the impact of chemotherapy drugs on these cellular machineries and their role in contributing to resistance has not been previously investigated and is the basis of this innovative proposal. Based on our preliminary results, we hypothesize that alterations in the proteasome and SQSTM1/p62 function in cancer cells contributes to platinum resistance. To test our hypothesis we have identified three specific aims. Aim 1. Investigate how modulating the proteasome and SQSTM1/P62 in CDDPR and CDDPS cancer cells and in normal cells alters the therapeutic response to platinum drugs in vitro. In this aim, the requirement of beta-5 subunit of the proteasome and SQSTM1/P62 to platinum sensitivity and cross-resistance to other anticancer drugs will be investigated using isogenic human cancer cell lines and compared to normal cells. Aim 2. Demonstrate restoring beta-5 subunit of the proteasome with simultaneous knock-down of SQSTM1/p62 using multifunctional nanoparticle reverts CDDPR lung tumor sensitivity to cisplatin in vivo. In this aim, we will use lung tumor xenograft and patient-derived xenograft models (PDX) to test a) whether restoration of beta-5 with simultaneous silencing of P62 in CDDPR tumors restores platinum sensitivity and b) knock-down of beta-5 with concomitant overexpression of P62 in CDDPS tumors results in platinum resistance. Aim 3. Determine the biological significance of beta-5 and SQSTM1/P62 protein expression in chemonaïve and chemotreated human lung tumor tissue specimens with clinical benefit. In this aim, archival lung tumor specimens representing primary and metastatic tumor will be examined for beta-5 and SQSTM1/P62 expression and correlate with clinical benefit.

肺癌相关死亡主要是由于疾病复发、耐药和转移。 顺铂（CDDP）和卡铂（CBDCA）等化合物及其衍生物广泛用于 尽管肿瘤最初对铂类药物有反应，但它们会迅速发展。 因此，了解癌细胞逃避治疗的机制。 治疗和产生耐药性对于开发肺癌新治疗方法至关重要。 该应用程序涉及高度创新和高影响力的转化研究领域，重点关注 研究铂类药物如何影响蛋白酶体和多螯体 (SQSTM1)/P62 功能 此外，一种针对肺癌的纳米递送方法。 建议将蛋白酶体和 SQSTM1/P62 与 CDDP 结合来克服耐药性。 我们对测试蛋白酶体和 SQSTM1/P62 的化疗耐药性的兴趣源于一次偶然的机会 我们在实验室进行了观察，观察到了 β5 (β5) 的表达，它是大 26S 的一个亚基。 与相比，顺铂耐药（CDDPR）癌细胞系中的蛋白酶体复合物显着减少 其同基因顺铂敏感 (CDDPS) 细胞系 β5 是蛋白酶体的胰凝乳蛋白酶成分。 降解泛素化蛋白质和回收氨基酸以合成新蛋白质所需的 与 CDDPR 细胞中 β5 表达减少相关的是细胞内蛋白质的积累。 研究如何克服细胞内蛋白质积累引起的细胞应激 细胞揭示了 SQSTM1/P62 的作用 SQSTM1/P62 是一种支架蛋白。 响应细胞应激而激活，通过聚集细胞内积累的物质来防止细胞死亡 多泛素化蛋白形成聚集体并引导自噬，从而促进细胞存活。 此外，对人类肺肿瘤组织子集中 P62 表达的分析表明，经过化疗的 与化疗肿瘤相比，肺部肿瘤具有更高的 P62 表达，但蛋白酶体减少。 先前已报道在癌细胞和干细胞中增强 SQSTM1/P62 的功能和表达增加 细胞，化疗药物对这些细胞机器的影响及其在促进 此前尚未对阻力进行过研究，这是这一创新提案的基础。 根据我们的初步结果，我们捕获了蛋白酶体和 SQSTM1/p62 功能的改变 为了检验我们的假设，我们确定了三个具体目标。 目标 1. 研究如何调节 CDDPR 和 CDDPS 癌细胞中的蛋白酶体和 SQSTM1/P62 在正常细胞中改变对铂类药物的体外治疗反应。 在此目标中，蛋白酶体的 β-5 亚基和 SQSTM1/P62 对铂敏感性的要求 将使用同基因人类癌细胞系研究对其他抗癌药物的交叉耐药性 与正常细胞相比。 目标 2. 展示恢复蛋白酶体的 β-5 亚基，同时敲低 使用多功能纳米颗粒的 SQSTM1/p62 可在体内恢复 CDDPR 肺部肿瘤对顺铂的敏感性。 为此，我们将使用肺肿瘤异种移植模型和患者来源的异种移植模型（PDX）来测试： 在 CDDPR 肿瘤中恢复 beta-5 并同时沉默 P62 可恢复铂敏感性，b) CDDPS 肿瘤中 β-5 的敲除伴随 P62 的过度表达会导致铂耐药。 目标 3. 确定化疗中 β-5 和 SQSTM1/P62 蛋白表达的生物学意义 以及经过化学处理的人肺肿瘤组织标本，具有临床益处。 为此，将对代表原发性和转移性肿瘤的存档肺肿瘤标本进行检查 beta-5 和 SQSTM1/P62 表达并与临床获益相关。