Curcumin reverses tumor exosomes-mediated inhibition of myeloid differentiation

姜黄素逆转肿瘤外泌体介导的骨髓分化抑制

• 批准号: 7484914
• 负责人: HUANG-GE ZHANG
• 金额: $ 35.53万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-30 至 2011-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7484914
• 关键词: Address; Antineoplastic Agents; BARD1 gene; BRCA1 Associated RING Domain 1 Protein; Biological Assay; Cancer Patient; Cell Differentiation process; Cell Line; Cells; Chemopreventive Agent; Co-Immunoprecipitations; Complex; Curcuma longa; Curcumin; Data; Doctor of Medicine; Doctor of Philosophy; Equilibrium; Growth; Guanine Nucleotide Dissociation Inhibitors; Human; ITGAM gene; Immune; Immunosuppression; In Vitro; Knock-out; Malignant Neoplasms; Mammary Neoplasms; Mediating; Modeling; Molecular; Molecular Target; Mus; Myelogenous; Myeloid Cells; Nude Mice; Pathway interactions; Patients; Phosphorylation; Phosphorylation Inhibition; Phosphotransferases; Play; Prevention; Production; Protein Dephosphorylation; Protein Overexpression; Proteomics; RNF139 gene; Research Personnel; Rhizome; Role; Screening procedure; Site; Small Interfering RNA; Spleen; T-Lymphocyte; Technology; Testing; Therapeutic immunosuppression; Treatment Efficacy; Tumor Suppressor Genes; Ubiquitination; Yeasts; attenuation; chemotherapeutic agent; clinically relevant; in vivo; malignant breast neoplasm; mouse model; neoplastic cell; novel; peripheral blood; polyphenol; prevent; programs; tumor; tumor growth; ubiquitin-protein ligase; yeast two hybrid system

DESCRIPTION (provided by applicant): The naturally occurring polyphenol, curcumin, has been shown to be a potent chemotherapeutic agent in a variety of tumor models; however, its effects on tumor-associated immunosuppression have not been investigated to any great extent. The accumulation of immature myeloid cells is a hallmark of cancer and our data indicate that exosomes produced by tumors can suppress the differentiation of immature myeloid cells (iMCs). We have now found that curcumin treatment inhibits the tumor exosome-mediated suppression of differentiation of IMCs in mice, preventing their accumulation in the spleen and delaying tumor growth. Analysis of the composition of the tumor exosomes using a proteomics approach identified CSN5 as a candidate regulatory molecule and siRNA knockdown of CSN5 resulted in attenuation of the tumor exosome- mediated induction of IMCs in the spleen, suggesting that exosomal CSN5 plays a key role in tumor exosome-mediated immune suppression. We have now found that curcumin treatment destabilizes exosomal CSN5. The exosomal CSN5 is stable when associated with phosphorylated STAM1. Curcumin treatment leads to the dephosphorylation of STAM1 permitting the recruitment of an E3 ligase BARD1/BRCA1 to the CSN5 complex, resulting in CSN5 degradation. Our in vitro kinase assay results indicate that the curcumin- mediated disassociation of STAM1 from CSN5 complex is most likely due to the inhibition of CSN5- associated kinase activity. The clinical relevance of these studies is supported by our recent data that indicate that CSN5 is packed in exosomes isolated from the peripheral blood of breast cancer patients but not healthy subjects. We propose: (1) To use siRNA technology to determine if tumor exosomal CSN5 is a primary target of curcumin in its prevention of breast tumor exosome-mediated immunosuppression; (2) To determine whether CSN5-associated kinase activity prevents BARD1/BRCA1 E3 complex degradation of CSN5 in TS/A tumor cells; and (3) To determine whether curcumin treatment of human tumor cells results in degradation of CSN5 and prevents blocking of differentiation of CD33 (equivalent to mouse GDI lb+) Grl+ cells. We will further determine if exosomes packed with CSN5 circulate in the peripheral blood of patients with breast cancer and if overproduction of exosomes is correlated with the accumulation of iMCs in patients with breast cancer. RELEVANCE: The data generated should identify a novel mechanism for the actions of curcumin and identify its molecular targets in preventing CSN5/tumor exosome-mediated blockade of myeloid cell differentiation.

描述（由申请人提供）：自然存在的多酚姜黄素已被证明是多种肿瘤模型中有效的化学治疗剂。但是，其对与肿瘤相关的免疫抑制的影响尚未在很大程度上进行研究。未成熟的髓样细胞的积累是癌症的标志，我们的数据表明，肿瘤产生的外泌体可以抑制未成熟的髓样细胞（IMC）的分化。现在，我们发现姜黄素治疗抑制了肿瘤外泌体介导的小鼠分化的抑制，从而阻止了它们在脾脏中的积累并延迟肿瘤的生长。 Analysis of the composition of the tumor exosomes using a proteomics approach identified CSN5 as a candidate regulatory molecule and siRNA knockdown of CSN5 resulted in attenuation of the tumor exosome- mediated induction of IMCs in the spleen, suggesting that exosomal CSN5 plays a key role in tumor exosome-mediated immune suppression.现在，我们发现姜黄素治疗破坏了外泌体CSN5的稳定稳定。当与磷酸化的stam1相关时，外泌体CSN5稳定。姜黄素治疗导致StAM1的去磷酸化，从而允许将E3连接酶Bard1/brca1募集到CSN5复合物中，从而导致CSN5降解。我们的体外激酶测定结果表明，姜黄素介导的STAM1与CSN5复合物的分离很可能是由于抑制了CSN5-相关的激酶活性。这些研究的临床相关性得到了我们最近的数据支持，即CSN5挤满了从乳腺癌患者的外周血中分离出来但不是健康受试者的外泌体中。我们建议：（1）使用siRNA技术来确定肿瘤外泌体CSN5是否是姜黄素预防乳腺肿瘤外部介导的免疫抑制的主要靶标； （2）确定与CSN5相关的激酶活性是否阻止了TS/A肿瘤细胞中CSN5的BARD1/BRCA1 E3复合物降解； （3）确定姜黄素治疗人肿瘤细胞是否会导致CSN5降解，并防止CD33（相当于小鼠GDI LB+）GRL+细胞的分化阻止。我们将进一步确定乳腺癌患者外周血中挤满了CSN5的外泌体是否循环，以及外泌体的过量生产与乳腺癌患者IMC的积累相关。相关性：生成的数据应确定姜黄素作用的新机制，并确定其在防止CSN5/肿瘤外泌体介导的髓样细胞分化的阻断中的分子靶标。