己糖激酶 II (HK) 的上调改变了葡萄糖代谢并破坏了导致利妥昔单抗化疗耐药的侵袭性 B 细胞淋巴瘤的线粒体潜能，是未来治疗发展的临床相关靶点,Blood

当前位置： X-MOL 学术 › Blood › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

己糖激酶 II (HK) 的上调改变了葡萄糖代谢并破坏了导致利妥昔单抗化疗耐药的侵袭性 B 细胞淋巴瘤的线粒体潜能，是未来治疗发展的临床相关靶点
Blood ( IF 21.0 ) Pub Date : 2014-12-06 , DOI: 10.1182/blood.v124.21.1767.1767
Juan J Gu ₁ , Anil Singh ₁ , Cory Mavis ₁ , Vivek Yanamadala ₁ , Kai Xue ₂ , Michael Grau ₃ , Peter Lenz ₃ , Georg Lenz ₄ , Myron S. Czuczman ₁ , Francisco Hernandez ₁

Affiliation

复发性侵袭性淋巴瘤 (CORAL) 研究的前瞻性多中心 III 期合作试验的结果强调需要确定与不良临床结果相关的细胞通路，并为复发性/难治性侵袭性淋巴瘤开发新的治疗策略。为此，我们生成了几种利妥昔单抗耐药的临床前模型，之前报道过，利妥昔单抗耐药的获得与葡萄糖代谢失调和导致化疗耐药的凋亡阈值增加有关。己糖激酶 (HK) 是糖酵解途径的第一步限速酶，介导葡萄糖磷酸化为 6-磷酸葡萄糖 (G-6-P)，促进糖酵解途径。HK的四种同工型已被表征。己糖激酶 II (HKII), 在癌细胞中过表达的主要同种型具有催化域和结合域。HKII 的催化域促进糖酵解，而结合域保护肿瘤细胞免受线粒体外膜通透性 (MOMP) 的影响并抑制线粒体介导的细胞凋亡。在我们目前的工作中，我们进一步研究了 HKII 在侵袭性 B 细胞淋巴瘤中表达的生物学和临床意义。首先，我们分析了一组利妥昔单抗化疗敏感 (RSCL) 或耐药 (RRCL) 弥漫性大 B 细胞淋巴瘤 (DLBCL) 和伯基特淋巴瘤 (BL) 细胞系中 HKII 基因和蛋白质表达的差异。通过 qRT-PCR 和蛋白质印迹确定 RRCL 具有更高的 HKII mRNA 和蛋白质水平。线粒体和细胞质的亚细胞分离显示大部分 HKII 位于 RRCL 的线粒体中。此外，免疫沉淀研究表明 HKII 与电压依赖性阴离子通道 (VDAC) 结合。有趣的是，通过使用 1) 竞争性底物抑制剂 (2DG)、2) 激酶抑制剂 (氯尼达明)、3) 破坏其与 VDAC 的相互作用（HKII/VADC 竞争性结合肽测定）或 4) 完全沉默HKII（使用 HKII siRNA 干扰或二甲双胍）导致线粒体膜电位 (MMP) 降低、ATP 产生减少、细胞活力降低以及 RRCL 对化疗药物重新敏感。为了在更临床相关的环境中进一步评估 HKII 对利妥昔单抗/化疗耐药性的贡献，我们分析了 401 名接受 CHOP（N=181）或 R+CHOP（N=220）作为一线治疗的 DLBCL 患者的基因表达谱数据。高水平的 HKII 与 DLBCL 患者的不良预后相关。在接受 CHOP 化疗的患者中，高水平的 HKII 与较短的总生存期 (OS) 相关（P=0.0012）。同样，在 R-CHOP 治疗的 DLBCL 中，高 HKII mRNA 水平与较短的无进展生存期 (PFS) (P=0.039) 和 OS (P=0.043) 相关。我们的数据表明，HKII 的过度表达有助于在 DLBCL B 细胞淋巴瘤中获得对利妥昔单抗和化疗药物的耐药性。似乎 HKII 与 VDAC 和较小程度的 HKII 催化结构域的结合有助于淋巴瘤临床前模型的治疗抵抗。临床上，在利妥昔单抗之前和之后的时代，较高水平的 HKII 与先前未经治疗的 DLBCL 中较短的 PFS 和 OS 相关。靶向 HKII 似乎是一种具有挑战性但有吸引力的策略，可以增强目前可用的单克隆抗体或化疗药物在侵袭性淋巴瘤中的抗肿瘤活性。（部分研究得到了授予罗斯威尔公园癌症研究所和尤金和康妮科拉桑蒂淋巴瘤研究基金的 NIH 赠款 R01 CA136907-01A1 的支持）披露没有需要声明的相关利益冲突。

"点击查看英文标题和摘要"

Up-Regulation of Hexokinase II (HK) Alters the Glucose Metabolism and Disrupts the Mitochondrial Potential in Aggressive B-Cell Lymphoma Contributing to Rituximab-Chemotherapy Resistance and Is a Clinically Relevant Target for Future Therapeutic Development

The results of the prospective multicenter phase III Collaborative trial in relapsed aggressive lymphoma (CORAL) study stressed the need to identify cellular pathways associated with poor clinical outcomes and to develop novel therapeutic strategies for relapsed/refractory aggressive lymphoma. To this end, we generated several pre-clinical models of rituximab resistance and previously reported that the acquirement of rituximab resistant was associated with a deregulation in the glucose metabolism and an increase in the apoptotic threshold leading to chemotherapy resistance. Hexokinase (HK) is the first step rate-limiting enzyme of the glycolytic pathway and mediates the phosphorylation of glucose to glucose-6-phosphate (G-6-P), promoting the glycolic pathway. Four isoforms of HK had been characterized. Hexokinase II (HKII), the predominant isoform overexpressed in cancer cells, has a catalytic and a biding domain. The catalytic domain of HKII promotes glycolysis while the binding domain protects tumor cell from mitochondrial outer membrane permeability (MOMP) and inhibits mitochondrial-mediated apoptosis. In our current work, we further study the biological and clinical significance of HKII expression in aggressive B-cell lymphoma. First, we analyzed differences in HKII gene and protein expression in a panel of rituximab-chemotherapy sensitive (RSCL) or resistant (RRCL) diffuse large B-cell lymphoma (DLBCL) and Burkitt’s lymphoma (BL) cell lines. RRCL were found to have higher HKII mRNA and protein levels as determined by qRT-PCR and Western blotting. Subcellular fractionation of the mitochondria and cytoplasm revealed that most of the HKII was localized in the mitochondria in RRCL. Moreover, immunoprecipitation studies demonstrated that HKII was bound to the voltage dependent anion channel (VDAC). Of interest, by targeting HKII using either 1) a competitive substrate inhibitor (2DG), 2) a kinase inhibitor (lonidamine), 3) disruption its interaction with VDAC (HKII/VADC competitive binding peptide assay), or 4) complete silencing of HKII (using HKII siRNA interference or metformin) resulted in a decrease in the mitochondrial membrane potential (MMP), reduction in ATP production, decrease in cell viability and re-sensitization of RRCL to chemotherapy agents. To further assess the contribution of HKII to rituximab/chemotherapy resistance in a more clinically relevant setting, we analyzed gene expression profiling data from 401 patients with DLBCL treated with CHOP (N=181) or R+CHOP (N=220) as front-line therapy. High levels of HKII correlated with a poor prognosis in DLBCL patients. In patients receiving CHOP chemotherapy, high levels of HKII correlated with a shorter overall survival (OS) (P=0.0012). Similarly, high-HKII mRNA levels were associated with a shorter progression free survival (PFS) (P=0.039) and OS (P=0.043) in R-CHOP treated DLBCL. Our data suggest that over-expression of HKII contribute to the acquirement of resistance to rituximab and chemotherapy agents in DLBCL B-cell lymphoma. It appears that HKII binding to VDAC and to a lesser degree HKII catalytic domain, contribute to therapy resistance in lymphoma pre-clinical models. Clinically, higher levels of HKII correlate with a shorter PFS and OS in previously untreated DLBCL in the pre- and post-rituximab era. Targeting HKII appears to be a challenging but attractive strategy to potentiate the anti-tumor activity of current available monoclonal antibodies or chemotherapy agents in aggressive lymphoma. (Research, in part, supported by a NIH grant R01 CA136907-01A1 awarded to Roswell Park Cancer Institute and The Eugene and Connie Corasanti Lymphoma Research Fund) Disclosures No relevant conflicts of interest to declare.

更新日期：2014-12-06

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文本刊介绍/投稿指南