Nodality Inc., South San Francisco, California, United States of America.
PLoS One. 2011;6(10):e24592. doi: 10.1371/journal.pone.0024592. Epub 2011 Oct 10.
Chronic lymphocytic leukemia (CLL) is a B cell malignancy with a variable clinical course and unpredictable response to therapeutic agents. Single cell network profiling (SCNP) utilizing flow cytometry measures alterations in signaling biology in the context of molecular changes occurring in malignancies. In this study SCNP was used to identify proteomic profiles associated with in vitro apoptotic responsiveness of CLL B cells to fludarabine, as a basis for ultimately linking these with clinical outcome.
METHODOLOGY/PRINCIPAL FINDING: SCNP was used to quantify modulated-signaling of B cell receptor (BCR) network proteins and in vitro F-ara-A mediated apoptosis in 23 CLL samples. Of the modulators studied the reactive oxygen species, hydrogen peroxide (H₂O₂), a known intracellular second messenger and a general tyrosine phosphatase inhibitor stratified CLL samples into two sub-groups based on the percentage of B cells in a CLL sample with increased phosphorylation of BCR network proteins. Separately, in the same patient samples, in vitro exposure to F-ara-A also identified two sub-groups with B cells showing competence or refractoriness to apoptotic induction. Statistical analysis showed that in vitro F-ara-A apoptotic proficiency was highly associated with the proficiency of CLL B cells to undergo H₂O₂-augmented signaling.
CONCLUSIONS/SIGNIFICANCE: This linkage in CLL B cells among the mechanisms governing chemotherapy-induced apoptosis increased signaling of BCR network proteins and a likely role of phosphatase activity suggests a means of stratifying patients for their response to F-ara-A based regimens. Future studies will examine the clinical applicability of these findings and also the utility of this approach in relating mechanism to function of therapeutic agents.
慢性淋巴细胞白血病（CLL）是一种 B 细胞恶性肿瘤，其临床病程多变，对治疗药物的反应不可预测。单细胞网络分析（SCNP）利用流式细胞术测量信号生物学的改变，同时也测量发生在恶性肿瘤中的分子变化。在这项研究中，SCNP 用于识别与 CLL B 细胞对氟达拉滨的体外凋亡反应相关的蛋白质组学特征，作为最终将这些特征与临床结果联系起来的基础。
方法/主要发现：SCNP 用于量化 23 例 CLL 样本中 B 细胞受体（BCR）网络蛋白的调节信号和体外 F-ara-A 介导的凋亡。在研究的调节剂中，活性氧、过氧化氢（H₂O₂）是一种已知的细胞内第二信使和一种通用的酪氨酸磷酸酶抑制剂，根据 CLL 样本中 BCR 网络蛋白磷酸化增加的 B 细胞比例，将 CLL 样本分为两个亚组。另外，在相同的患者样本中，体外暴露于 F-ara-A 也鉴定出两个亚组，其中 B 细胞对凋亡诱导具有能力或抗性。统计分析表明，体外 F-ara-A 凋亡能力与 CLL B 细胞发生 H₂O₂增强信号的能力高度相关。
结论/意义：在 CLL B 细胞中，调节化疗诱导凋亡的机制之间存在联系，包括 BCR 网络蛋白的信号增强和磷酸酶活性的可能作用，这提示了一种分层患者对基于 F-ara-A 的方案反应的方法。未来的研究将检验这些发现的临床适用性，以及这种方法在将机制与治疗药物的功能联系起来的效用。
