Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue (NE-50), Cleveland, OH 44195, USA.
Breast Cancer Res Treat. 2012 Feb;131(3):849-58. doi: 10.1007/s10549-011-1500-8. Epub 2011 Apr 9.
Breast cancer is a genetically heterogenous disease with subtypes differing in prognosis and chemosensitivity. The basal-like breast cancer (BLBC) molecular subtype is associated with poorer outcomes, but is more responsive to taxane-based chemotherapy. Kinesins are intracellular transport proteins that interact with microtubules, which are also the mechanistic target for taxanes. We investigated the relationship between taxane resistance in BLBC and kinesins using both expression and functional studies. Kinesin (KIF) expression was evaluated in three settings in relation to taxane resistance: (i) the NCI-60 cancer cell lines, (ii) pre-treatment samples from four BLBC patient cohorts receiving neoadjuvant chemotherapy regimens with and without taxanes, and (iii) post-treatment samples from residual breast cancer following neoadjuvant taxane-containing chemotherapy. We used a novel functional approach to gene modification, validation-based insertional mutagenesis, to select kinesin-overexpressing clones of BLBC cells for evaluation of related mechanisms of taxane resistance. In the NCI-60 cell line dataset, overexpression of the kinesin KIFC3 is significantly correlated with resistance to both docetaxel (P < 0.001) and paclitaxel (P < 0.001), but not to platinum-based chemotherapy, including carboplatin (P = 0.49) and cisplatin (P = 0.10). Overexpression of KIFC3 and KIF5A in pre-chemotherapy samples similarly predicted resistance to paclitaxel in the MDACC cohorts (P = 0.01); no KIF predicted resistance to fluorouracil-epirubicin-cyclophosphamide or cisplatin in BLBC patient cohorts treated without taxanes. KIF12 is the most overexpressed KIF gene in post-chemotherapy taxane-resistant residual breast cancers (2.8-fold-change). Functional studies established that overexpression of KIFC3, KIF5A, and KIF12 were specific in mediating resistance to docetaxel and not vincristine or doxorubicin. Mutation of the ATP-binding domain of a kinesin abolished its ability to mediate docetaxel resistance. Overall, kinesin overexpression correlates with specific taxane resistance in BLBC cell lines and tissues. Our results suggest a novel approach for drug development to overcome taxane resistance in breast cancer through concurrent or sequential use of kinesin inhibitors.
乳腺癌是一种遗传异质性疾病，其亚型在预后和化疗敏感性方面存在差异。基底样乳腺癌（BLBC）分子亚型与较差的预后相关，但对基于紫杉烷的化疗更敏感。驱动蛋白是与微管相互作用的细胞内运输蛋白，也是紫杉烷类药物的作用机制靶点。我们使用表达和功能研究来研究 BLBC 中紫杉烷耐药与驱动蛋白之间的关系。在与紫杉烷耐药相关的三个方面评估了驱动蛋白（KIF）的表达：（i）NCI-60 癌细胞系，（ii）接受无紫杉烷和有紫杉烷新辅助化疗方案的 4 个 BLBC 患者队列的治疗前样本，以及（iii）新辅助含紫杉烷化疗后残留乳腺癌的治疗后样本。我们使用一种新的基因修饰方法，基于验证的插入诱变，选择 BLBC 细胞中过表达驱动蛋白的克隆，以评估与紫杉烷耐药相关的相关机制。在 NCI-60 细胞系数据集，驱动蛋白 KIFC3 的过表达与多西紫杉醇（P<0.001）和紫杉醇（P<0.001）的耐药显著相关，但与铂类化疗药物（包括卡铂（P=0.49）和顺铂（P=0.10））无关。化疗前样本中 KIFC3 和 KIF5A 的过表达也同样预测了 MDACC 队列中紫杉醇的耐药（P=0.01）；在未接受紫杉烷治疗的 BLBC 患者队列中，没有 KIF 预测氟尿嘧啶-表柔比星-环磷酰胺或顺铂的耐药。化疗后紫杉烷耐药残留乳腺癌中 KIF12 是过表达最多的 KIF 基因（2.8 倍变化）。功能研究证实，KIFC3、KIF5A 和 KIF12 的过表达特异性介导多西紫杉醇耐药，而不是长春新碱或阿霉素耐药。驱动蛋白的 ATP 结合域突变使其丧失介导多西紫杉醇耐药的能力。总的来说，在 BLBC 细胞系和组织中，驱动蛋白过表达与特定的紫杉烷耐药相关。我们的结果表明，通过同时或序贯使用驱动蛋白抑制剂，为克服乳腺癌中的紫杉烷耐药提供了一种新的药物开发方法。
