Hoang-Minh Lan B, Deleyrolle Loic P, Siebzehnrubl Dorit, Ugartemendia George, Futch Hunter, Griffith Benjamin, Breunig Joshua J, De Leon Gabriel, Mitchell Duane A, Semple-Rowland Susan, Reynolds Brent A, Sarkisian Matthew R
Department of Neuroscience, University of Florida College of Medicine, McKnight Brain Institute, Gainesville, Florida, USA.
Preston A. Wells, Jr. Center for Brain Tumor Therapy, University of Florida College of Medicine, McKnight Brain Institute, Gainesville, Florida, USA.
Oncotarget. 2016 Feb 9;7(6):7029-43. doi: 10.18632/oncotarget.6854.
KIF3A, a component of the kinesin-2 motor, is necessary for the progression of diverse tumor types. This is partly due to its role in regulating ciliogenesis and cell responsiveness to sonic hedgehog (SHH). Notably, primary cilia have been detected in human glioblastoma multiforme (GBM) tumor biopsies and derived cell lines. Here, we asked whether disrupting KIF3A in GBM cells affected ciliogenesis, in vitro growth and responsiveness to SHH, or tumorigenic behavior in vivo. We used a lentiviral vector to create three patient-derived GBM cell lines expressing a dominant negative, motorless form of Kif3a (dnKif3a). In all unmodified lines, we found that most GBM cells were capable of producing ciliated progeny and that dnKif3a expression in these cells ablated ciliogenesis. Interestingly, unmodified and dnKif3a-expressing cell lines displayed differential sensitivities and pathway activation to SHH and variable tumor-associated survival following mouse xenografts. In one cell line, SHH-induced cell proliferation was prevented in vitro by either expressing dnKif3a or inhibiting SMO signaling using cyclopamine, and the survival times of mice implanted with dnKif3a-expressing cells were increased. In a second line, expression of dnKif3a increased the cells' baseline proliferation while, surprisingly, sensitizing them to SHH-induced cell death. The survival times of mice implanted with these dnKif3a-expressing cells were decreased. Finally, expression of dnKif3a in a third cell line had no effect on cell proliferation, SHH sensitivity, or mouse survival times. These findings indicate that KIF3A is essential for GBM cell ciliogenesis, but its role in modulating GBM cell behavior is highly variable.
驱动蛋白-2分子马达的组成部分KIF3A对于多种肿瘤类型的进展是必需的。部分原因在于它在调节纤毛发生以及细胞对音猬因子（SHH）的反应性方面所起的作用。值得注意的是，在多形性胶质母细胞瘤（GBM）肿瘤活检组织及其衍生的细胞系中已检测到初级纤毛。在此，我们探究了在GBM细胞中破坏KIF3A是否会影响纤毛发生、体外生长以及对SHH的反应性，或者体内致瘤行为。我们使用慢病毒载体构建了三种源自患者的GBM细胞系，这些细胞系表达一种显性负性、无运动功能形式的Kif3a（dnKif3a）。在所有未修饰的细胞系中，我们发现大多数GBM细胞能够产生有纤毛的子代细胞，并且这些细胞中dnKif3a的表达消除了纤毛发生。有趣的是，未修饰的和表达dnKif3a的细胞系对SHH表现出不同的敏感性和信号通路激活情况，并且在小鼠异种移植后具有不同的肿瘤相关生存率。在一个细胞系中，通过表达dnKif3a或使用环杷明抑制SMO信号传导，均可在体外阻止SHH诱导的细胞增殖，并且植入表达dnKif3a细胞的小鼠存活时间延长。在第二个细胞系中，dnKif3a的表达增加了细胞的基础增殖，而令人惊讶的是，使它们对SHH诱导的细胞死亡敏感。植入这些表达dnKif3a细胞的小鼠存活时间缩短。最后，在第三个细胞系中dnKif3a的表达对细胞增殖、SHH敏感性或小鼠存活时间没有影响。这些发现表明，KIF3A对于GBM细胞的纤毛发生至关重要，但其在调节GBM细胞行为方面的作用高度可变。
