Nuñez Rebeca E, Del Valle Miguel Mayol, Ortiz Kyle, Almodovar Luis, Kucheryavykh Lilia
Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR 00956, USA.
Department of Surgery, Neurosurgery Section, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00936, USA.
Cancers (Basel). 2021 Dec 7;13(24):6160. doi: 10.3390/cancers13246160.
Glioblastoma is the most aggressive brain tumor in adults. Multiple lines of evidence suggest that microglia create a microenvironment favoring glioma invasion and proliferation. Our previous studies and literature reports indicated the involvement of focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (Pyk2) in glioma cell proliferation and invasion, stimulated by tumor-infiltrating microglia. However, the specific microglia-released factors that modulate Pyk2 and FAK signaling in glioma cells are unknown. In this study, 20 human glioblastoma specimens were evaluated with the use of RT-PCR and western blotting. A Pierson correlation test demonstrated a correlation (0.6-1.0) between the gene expression levels for platelet-derived growth factor β(PDGFβ), stromal-derived factor 1α (SDF-1α), IL-6, IL-8, and epidermal growth factor (EGF) in tumor-purified microglia and levels of p-Pyk2 (Y579/Y580) and p-FAK(Y925) in glioma cells. siRNA knockdown against Pyk2 or FAK in three primary glioblastoma cell lines, developed from the investigated specimens, in combination with the cytokine receptor inhibitors gefitinib (1 μM), DMPQ (200 nM), and burixafor (1 μM) identified EGF, PDGFβ, and SDF-1α as key extracellular factors in the Pyk2- and FAK-dependent activation of invadopodia formation and the migration of glioma cells. EGF and IL-6 were identified as regulators of the Pyk2- and FAK-dependent activation of cell viability and mitosis.
胶质母细胞瘤是成人中最具侵袭性的脑肿瘤。多条证据表明，小胶质细胞营造了有利于胶质瘤侵袭和增殖的微环境。我们之前的研究及文献报道指出，在肿瘤浸润性小胶质细胞的刺激下，粘着斑激酶（FAK）和富含脯氨酸的酪氨酸激酶2（Pyk2）参与了胶质瘤细胞的增殖和侵袭。然而，在胶质瘤细胞中调节Pyk2和FAK信号传导的小胶质细胞特异性释放因子尚不清楚。在本研究中，我们使用逆转录聚合酶链反应（RT-PCR）和蛋白质免疫印迹法对20例人类胶质母细胞瘤标本进行了评估。皮尔逊相关性检验表明，肿瘤纯化小胶质细胞中血小板衍生生长因子β（PDGFβ）、基质细胞衍生因子1α（SDF-1α）、白细胞介素-6（IL-6）、白细胞介素-8（IL-8）和表皮生长因子（EGF）的基因表达水平与胶质瘤细胞中磷酸化Pyk2（Y579/Y580）和磷酸化FAK（Y925）的水平之间存在相关性（0.6 - 1.0）。针对从所研究标本中培养出的三种原发性胶质母细胞瘤细胞系中的Pyk2或FAK进行小干扰RNA（siRNA）敲低，并联合细胞因子受体抑制剂吉非替尼（1 μM）、二甲基哌嗪（DMPQ，200 nM）和布立尼布（1 μM），确定了EGF、PDGFβ和SDF-1α是小胶质细胞依赖性激活侵袭伪足形成和胶质瘤细胞迁移过程中Pyk2和FAK的关键细胞外因子。EGF和IL-6被确定为小胶质细胞依赖性激活细胞活力和有丝分裂过程中Pyk2和FAK的调节因子。
