Drivers of MAPK-redundant resistance to BRAF inhibition in melanoma

黑色素瘤中 MAPK 冗余对 BRAF 抑制产生耐药性的驱动因素

• 批准号: 9909750
• 负责人: Eliot Zhu
• 金额: $ 3.05万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9909750
• 关键词: Actins; Address; BRAF gene; Biochemistry; Caring; Cell Line; Cells; Cessation of life; ChIP-seq; Complex; Cutaneous Melanoma; Drug resistance; Gene Expression Profile; Generations; Genetic; Genetic Screening; Genetic Transcription; Goals; Growth; Homo; Individual; Integrins; Knowledge; MAP Kinase Gene; MAP Kinase Modules; Malignant Neoplasms; Mediator of activation protein; Medical Oncologist; Melanoma Cell; Mitogen-Activated Protein Kinases; Mutation; Oncogenic; Outcome; PDGFRB gene; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacology; Phenotype; Protein Family; Proteins; Recurrence; Reporting; Research; Resistance; Signal Transduction; Skin Cancer; Sleeping Beauty; System; Testing; Transcription Factor AP-1; Work; activating transcription factor; base; dimer; drug development; effective therapy; genetic manipulation; genome-wide; improved; in vitro Assay; in vivo; inhibitor/antagonist; insight; melanoma; member; mutant; next generation; novel; programs; raf Kinases; resistance mechanism; therapeutic target; therapy development; transcriptome; transcriptome sequencing; transcriptomics; treatment strategy

PROJECT SUMMARY Cutaneous melanoma is an aggressive form of skin cancer. In the US alone, approximately 90,000 new cases and 9,000 deaths due to melanoma were reported in 2017. Selective inhibitors of BRAFV600E/K work potently against melanomas driven by oncogenic BRAF. Unfortunately, drug resistance is ubiquitous, and most patients will progress within two years of therapy. Large-scale genome- and transcriptome- profiling reveal that resistance to MAPK inhibition (MAPKi) is either MAPK- dependent or redundant. MAPK-dependent (resistance ~50%) resistance is characterized by the reactivation of MAPK typically through mutations that augment MAPK signaling. These MAPKi-resistant melanomas are nearly identical at the transcriptome level to their respective parental cancers, which further support these cancers simply restore MAPK. By contrast, MAPK-redundant resistance (remaining 50%) is characterized by extensive transcriptional reprogramming and is often devoid of recurrent mutations. Mechanistically, MAPK-dependent resistance is centered on the formation of Raf homo- or heter- dimers that are resistant to current generation Raf inhibitors but sensitive to next-generation Raf inhibitors that have dimer activity. However, MAPK-redundant resistance is not uniform, not well-understood, and lacks a common therapeutic target. This knowledge is important as there are no current treatment options for melanomas with MAPK-redundant resistance. To address this critical gap, we performed a forward genetic screen to identify novel mechanisms that drive resistance to MAPKi. This screen was performed using our well-established Sleeping Beauty Transposon system. The outcome of this screen was that SFKs and PDGFRβ were the preferred MAPK-redundant mechanisms of resistance for BRAFV600E melanomas A375 and SKMEL28. However the precise mechanisms by which SFKs and PDGFRβ drive MAPK-redundant resistance are unknown. In Aim 1, I will elucidate the mechanism of SFKs- and PDGFRβ- driven resistance to MAPKi by testing the hypothesis that actin remodeling is central to MAPKi resistance that is driven by both SFKs or PDGFRβ and that integrins are critical upstream of the SFKs resistance program and Akt is a critical downstream meditator of the PDGFR resistance program. In Aim 2 I will test the hypothesis that SFKs and PDGFRβ promotes MAPKi resistance by activating the Yap/Taz/TEAD/AP-1 transcriptional complex. The central hypothesis is that actin remodeling and the YAP/TAZ/AP-1 complex are critical mediators of the SFKs- and PDGFRβ- resistance programs.

项目概要 皮肤黑色素瘤是一种侵袭性皮肤癌。仅在美国就有约 90,000 例新病例 2017 年报告了 9,000 人因黑色素瘤死亡。BRAFV600E/K 的选择性抑制剂发挥作用 对抗由致癌 BRAF 驱动的黑色素瘤。不幸的是，耐药性普遍存在，大多数患者 将在治疗两年内取得进展。大规模基因组和转录组分析揭示了耐药性 MAPK 抑制 (MAPKi) 要么依赖于 MAPK，要么是多余的。 MAPK 依赖性（耐药性 ~50%） 耐药性的特点是通常通过增强 MAPK 的突变重新激活 MAPK 发信号。这些 MAPKi 抗性黑色素瘤在转录组水平上与其各自的几乎相同 亲代癌症，进一步支持这些癌症只是恢复 MAPK。相比之下，MAPK 冗余 耐药性（剩余 50%）的特点是广泛的转录重编程，并且通常缺乏 反复发生的突变。从机制上讲，MAPK 依赖性耐药性集中于 Raf 同型或异型的形成。 对当前一代 Raf 抑制剂具有抗性但对下一代 Raf 抑制剂敏感的异二聚体 具有二聚体活性。然而，MAPK 冗余抗性并不统一，也没有得到很好的理解，并且缺乏 共同的治疗目标。这些知识很重要，因为目前没有治疗方案 具有 MAPK 冗余耐药性的黑色素瘤。 为了解决这一关键差距，我们进行了正向遗传筛选，以确定新的机制 驱动对 MAPKi 的抵抗。该筛选是使用我们成熟的睡美人转座子进行的 系统。该筛选的结果是 SFK 和 PDGFRβ 是首选的 MAPK 冗余 BRAFV600E 黑色素瘤 A375 和 SKMEL28 的耐药机制。然而，精确的机制 哪些 SFK 和 PDGFRβ 驱动 MAPK 冗余耐药尚不清楚。在目标 1 中，我将阐明 通过检验肌动蛋白重塑的假设，研究 SFK 和 PDGFRβ 驱动的 MAPKi 抗性机制 是由 SFK 或 PDGFRβ 驱动的 MAPKi 耐药性的核心，并且整合素是 SFK 或 PDGFRβ 的关键上游 SFKs 抵抗计划，Akt 是 PDGFR 抵抗计划的关键下游冥想者。在 目标 2 我将检验以下假设：SFK 和 PDGFRβ 通过激活 Yap/Taz/TEAD/AP-1 转录复合物。中心假设是肌动蛋白重塑和 YAP/TAZ/AP-1 复合物是 SFK 和 PDGFRβ 抗性程序的关键介质。