The roles of TRAF2 and RIP1 in breast cancer cell survival

TRAF2 和 RIP1 在乳腺癌细胞存活中的作用

• 批准号: 10619506
• 负责人: HASEM HABELHAH
• 金额: $ 34.51万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-15 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10619506
• 关键词: AKT inhibition; Affect; Apoptosis; Bioinformatics; Biological Assay; Biological Models; Breast Cancer Cell; Breast Cancer cell line; Breast Cancer therapy; Cancer Etiology; Cancer cell line; Cause of Death; Cell Line; Cell Survival; Cell physiology; Cellular Stress; Cessation of life; Clinical Trials; Data; Development; Diagnosis; Disease; Drug resistance; Exhibits; Genes; Goals; Growth; Growth Factor; Harvest; Histopathology; Homologous Gene; In Vitro; Induction of Apoptosis; Malignant Neoplasms; Maps; Mediating; Modeling; Mus; Neoplasm Metastasis; PIK3CG gene; PTEN gene; Pathway interactions; Patient-derived xenograft models of breast cancer; Peptides; Phosphorylation; Phosphorylation Site; Phosphotransferases; Play; Pre-Clinical Model; Prognosis; Protein-Serine-Threonine Kinases; Proto-Oncogene Proteins c-akt; RIPK1 gene; Recurrent disease; Reporting; Resistance; Resistance development; Role; Series; Serine; Signal Transduction; Small Interfering RNA; Solid Neoplasm; TBK1 gene; TNF gene; TRAF2 gene; Testing; Therapeutic; Treatment Efficacy; Ubiquitination; Woman; Xenograft Model; Xenograft procedure; anticancer research; biomarker identification; cancer cell; derepression; glycogen synthase kinase 3 beta; in vivo; inhibitor; kinase inhibitor; knock-down; malignant breast neoplasm; mortality; novel therapeutic intervention; overexpression; patient derived xenograft model; predictive marker; recruit; response; synergism; tool; treatment response; tumor; tumor growth; tumor xenograft; ubiquitin-protein ligase

Breast cancer (BC) is the most frequently diagnosed malignancy and the second leading cause of cancer mortality in Western women. As is the case for most other solid tumors, metastasis and drug resistance are the main causes of death. In ~80% of BC cases, the PI3K-AKT pathway is aberrantly activated, due to the alterations in genes encoding the pathway components, such as Ras, Her2, PTEN, PIK3C and AKT. This pathway regulates multiple cellular processes to promote BC development, growth, metastasis, and drug resistance. Consequently, over 100 clinical trials are currently underway worldwide to evaluate the therapeutic efficacy of PI3K and AKT inhibitors in BC; however, initial data revealed that inhibition of this pathway is either not effective or often results in development of resistance and relapse of the disease. Thus, identification of additional targets and therapeutic combinations are urgently needed. We previously mapped TRAF2 phosphorylation sites and reported that TRAF2 Ser-11 phosphorylation enhances NF-κB activation to promote cancer cell survival under conditions of cellular stresses. Recently, we discovered that inhibition of AKT in BC cells leads to increased phosphorylation of TRAF2 by TBK1, and that inhibition of both AKT and TBK1 synergistically induces apoptosis in BC cell lines in vitro and significantly suppresses xenograft BC tumor growth in vivo. TBK1 and its close homologue IKKε are serine/threonine kinases overexpressed in 65-70% of BC and play critical roles in BC cell survival mainly by direct phosphorylation of TRAF2 at Ser-11. In cancer cells, TRAF2 constitutively recruits potent E3 ligases cIAP1 and cIAP2 (cIAPs) to RIP1 to catalyze its noncanonical ubiquitination, which is not only essential for NF-κB activation but also for the suppression of RIP1-dependent apoptosis and necroptosis. Through a series of functional assays, we identified a peptide (Tp-14) that blocks TRAF2 interaction with RIP1 and synergizes with AKT inhibition to induce apoptosis in BC cells that overexpress RIP1. Bioinformatic analyses revealed that TRAF2 and RIP1 are overexpressed in invasive BC, and significantly correlate with poor prognosis. Thus, we hypothesize that combined inhibition of AKT and TRAF2 phosphorylation or interaction with RIP1 synergistically induce apoptosis in BC cells that overexpress TRAF2 and RIP1. To test this hypothesis, we propose the following specific aims. Aim-1. Determine the mechanisms of signaling crosstalks between the PI3K-AKT and TBK1-TRAF2 pathways and identify biomarkers that predict BC cell response to combined AKT and TBK1 inhibition. Aim-2. Evaluate the therapeutic efficacy of combined AKT and TBK1 inhibition in BC xenograft models. Aim-3. Determine how blockade of TRAF2 interaction with RIP1 affects BC cell survival in vitro and xenograft tumor growth in vivo. Our proposals will shed new lights on the mechanisms underlying BC cell resistance to AKT inhibition and identify biomarkers for combined inhibition of AKT and TRAF2 phosphorylation or interaction with RIP1 for BC therapy.

乳腺癌是最常见的恶性肿瘤，也是第二大致癌原因。 西方妇女的死亡率。与大多数其他实体肿瘤的情况一样，转移和耐药性是 主要死因。在约80%的BC病例中，PI3K-AKT通路异常激活，原因是 编码Ras、Her2、PTEN、PIK3C和AKT等途径成分的基因发生变化。这 途径调节多种细胞过程以促进BC的发展、生长、转移和药物 抵抗。因此，目前全世界正在进行100多项临床试验，以评估这种治疗方法 PI3K和AKT抑制剂在BC中的疗效；然而，初步数据显示，抑制这一途径是 无效或经常导致抗药性的发展和疾病的复发。因此，确定 迫切需要更多的靶点和治疗组合。我们之前映射了TRAF2 并报道TRAF2Ser-11磷酸化促进NF-κB活化促进 癌细胞在细胞应激条件下的存活。最近，我们发现在BC中抑制AKT 细胞内TRAF2被TBK1磷酸化增强，AKT和TBK1均被抑制 协同诱导BC细胞株的凋亡并显著抑制移植瘤的生长 在活体内。Tbk1及其同源物IKKε是丝氨酸/苏氨酸激酶，在65-70%的BC和 在BC细胞存活中起关键作用，主要是通过直接磷酸化Ser-11上的TRAF2。在癌细胞中， TRAF2结构性地招募强大的E3连接酶cIAP1和cIAP2(CIAPs)到RIP1以催化其非规范的 泛素化，这不仅对NF-κB的激活至关重要，而且对抑制RIP1依赖也是必不可少的 细胞凋亡和坏死性下垂。通过一系列功能分析，我们确定了一种能阻断 TRAF2与RIP1相互作用并与AKT抑制协同诱导BC细胞凋亡 过表达RIP1。生物信息学分析表明，TRAF2和RIP1在侵袭性BC中高表达， 与预后不良密切相关。因此，我们假设AKT和AKT的联合抑制 TRAF2磷酸化或与RIP1相互作用协同诱导过表达的BC细胞凋亡 TRAF2和RIP1。为了验证这一假设，我们提出了以下具体目标。AIM-1。确定 PI3K-AKT和TBK1-TRAF2信号通路之间的信号串扰机制及识别生物标志物 预测BC细胞对AKT和TBK1联合抑制的反应。AIM-2。评价其治疗效果。 AKT和TBK1对BC异种移植模型的联合抑制作用。AIM-3。确定如何封锁TRAF2 与RIP1的相互作用影响BC细胞的体外存活和体内移植瘤的生长。我们的建议将会有所改变 BC细胞对AKT抑制耐药机制的新进展和确定AKT抑制的生物标志物 联合抑制AKT和TRAF2的磷酸化或与RIP1相互作用治疗BC。