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 (BC) 是最常诊断的恶性肿瘤，也是癌症的第二大原因 西方女性的死亡率。与大多数其他实体瘤的情况一样，转移和耐药性是关键 死亡的主要原因。在约 80% 的 BC 病例中，PI3K-AKT 通路被异常激活，这是由于 编码途径成分的基因发生改变，例如 Ras、Her2、PTEN、PIK3C 和 AKT。这 途径调节多种细胞过程，促进 BC 的发生、生长、转移和药物 反抗。因此，目前全球正在进行 100 多项临床试验来评估治疗效果 PI3K 和 AKT 抑制剂在 BC 中的功效；然而，初步数据显示，抑制该途径是 无效或经常导致耐药性的产生和疾病的复发。因此，识别 迫切需要额外的靶点和治疗组合。我们之前绘制了 TRAF2 磷酸化位点并报道 TRAF2 Ser-11 磷酸化增强 NF-κB 激活以促进 癌细胞在细胞应激条件下存活。最近，我们发现 BC 中 AKT 的抑制 细胞导致 TBK1 对 TRAF2 的磷酸化增加，并且抑制 AKT 和 TBK1 体外协同诱导 BC 细胞系凋亡并显着抑制异种移植 BC 肿瘤生长 体内。 TBK1 及其密切同源物 IKKε 是丝氨酸/苏氨酸激酶，在 65-70% 的 BC 和 主要通过 TRAF2 Ser-11 的直接磷酸化在 BC 细胞存活中发挥关键作用。在癌细胞中， TRAF2 组成型招募有效的 E3 连接酶 cIAP1 和 cIAP2 (cIAP) 到 RIP1 以催化其非规范 泛素化，不仅对于 NF-κB 激活至关重要，而且对于抑制 RIP1 依赖性 细胞凋亡和坏死性凋亡。通过一系列的功能测定，我们鉴定出一种肽 (Tp-14)，它可以阻断 TRAF2 与 RIP1 相互作用并与 AKT 抑制协同作用诱导 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 中过度表达， 并与不良预后显着相关。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度表达的 BC 细胞凋亡 TRAF2 和 RIP1。为了检验这一假设，我们提出以下具体目标。目标-1。确定 PI3K-AKT 和 TBK1-TRAF2 通路之间的信号串扰机制并识别生物标志物 预测 BC 细胞对 AKT 和 TBK1 联合抑制的反应。目标2。评估治疗效果 在 BC 异种移植模型中联合抑制 AKT 和 TBK1。目标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异种移植肿瘤的生长。我们的建议将流淌 BC 细胞抵抗 AKT 抑制的机制有了新的认识，并确定了生物标志物 联合抑制 AKT 和 TRAF2 磷酸化或与 RIP1 相互作用进行 BC 治疗。