Targeting PYK2 mediates microenvironment-specific cell death in multiple myeloma.
Targeting PYK2 mediates microenvironment-specific cell death in multiple myeloma.
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作者：
Meads MB;Fang B;Mathews L;Gemmer J;Nong L;Rosado-Lopez I;Nguyen T;Ring JE;Matsui W;MacLeod AR;Pachter JA;Hazlehurst LA;Koomen JM;Shain KH
多发性骨髓瘤（MM）仍然是一种无法治愈的恶性肿瘤，部分原因是骨髓微环境对生存和药物反应的影响。识别微环境特异性生存信号决定因子对于合理设计治疗和消除MM至关重要。以前，我们已经表明β1整合素介导的与纤连蛋白的粘附和白细胞介素-6之间的协同信号传导通过信号转导和转录激活因子3（STAT 3）激活的扩增赋予更恶性的表型。在这些条件下与定量磷酸酪氨酸分析的事件调制的进一步表征确定了193差异磷酸化的肽。77个磷酸化在粘附后上调，包括PYK 2/FAK 2、Paxillin、CASL和p130 CAS，与粘着斑（FA）形成一致。我们假设β1整合素和gp 130（IL-6 β受体，IL-6信号转导子）之间的协同信号传导是由FA形成和富含脯氨酸的酪氨酸激酶2（PYK 2）活性介导的。PYK 2的药理学和分子靶向都减弱了共刺激条件下STAT 3磷酸化的扩增。MM细胞与患者骨髓基质细胞（BMSC）的共培养显示PYK 2和STAT 3信号传导的β1整合素特异性增强相似。PYK 2的分子和药理学靶向特异性诱导BMSC粘附性骨髓瘤细胞系、乙醛脱氢酶阳性MM癌症干细胞和患者标本中的细胞死亡并减少克隆形成生长。最后，PYK 2抑制在体内类似地减弱MM进展。这些数据在微环境线索的背景下确定了MM细胞和MM癌症干细胞中新型PYK 2介导的存活途径，为临床阶段FAK/PYK 2抑制剂用于治疗MM提供了临床前支持，特别是在微小残留疾病环境中。
Multiple myeloma (MM) remains an incurable malignancy due, in part, to the influence of the bone marrow microenvironment on survival and drug response. Identification of microenvironment-specific survival signaling determinants is critical for the rational design of therapy and elimination of MM. Previously, we have shown that collaborative signaling between β1 integrin-mediated adhesion to fibronectin and interleukin-6 confers a more malignant phenotype via amplification of signal transducer and activator of transcription 3 (STAT3) activation. Further characterization of the events modulated under these conditions with quantitative phosphotyrosine profiling identified 193 differentially phosphorylated peptides. Seventy-seven phosphorylations were upregulated upon adhesion, including PYK2/FAK2, Paxillin, CASL and p130CAS consistent with focal adhesion (FA) formation. We hypothesized that the collaborative signaling between β1 integrin and gp130 (IL-6 beta receptor, IL-6 signal transducer) was mediated by FA formation and proline-rich tyrosine kinase 2 (PYK2) activity. Both pharmacological and molecular targeting of PYK2 attenuated the amplification of STAT3 phosphorylation under co-stimulatory conditions. Co-culture of MM cells with patient bone marrow stromal cells (BMSC) showed similar β1 integrin-specific enhancement of PYK2 and STAT3 signaling. Molecular and pharmacological targeting of PYK2 specifically induced cell death and reduced clonogenic growth in BMSC-adherent myeloma cell lines, aldehyde dehydrogenase-positive MM cancer stem cells and patient specimens. Finally, PYK2 inhibition similarly attenuated MM progression in vivo. These data identify a novel PYK2-mediated survival pathway in MM cells and MM cancer stem cells within the context of microenvironmental cues, providing preclinical support for the use of the clinical stage FAK/PYK2 inhibitors for treatment of MM, especially in a minimal residual disease setting.