Dataset Information

Microglia Activate Migration of Glioma Cells through a Pyk2 Intracellular Pathway.

ABSTRACT: Glioblastoma is one of the most aggressive and fatal brain cancers due to the highly invasive nature of glioma cells. Microglia infiltrate most glioma tumors and, therefore, make up an important component of the glioma microenvironment. In the tumor environment, microglia release factors that lead to the degradation of the extracellular matrix and stimulate signaling pathways to promote glioma cell invasion. In the present study, we demonstrated that microglia can promote glioma migration through a mechanism independent of extracellular matrix degradation. Using western blot analysis, we found upregulation of proline rich tyrosine kinase 2 (Pyk2) protein phosphorylated at Tyr579/580 in glioma cells treated with microglia conditioned medium. This upregulation occurred in rodent C6 and GL261 as well as in human glioma cell lines with varying levels of invasiveness (U-87MG, A172, and HS683). siRNA knock-down of Pyk2 protein and pharmacological blockade by the Pyk2/focal-adhesion kinase (FAK) inhibitor PF-562,271 reversed the stimulatory effect of microglia on glioma migration in all cell lines. A lower concentration of PF-562,271 that selectively inhibits FAK, but not Pyk2, did not have any effect on glioma cell migration. Moreover, with the use of the CD11b-HSVTK microglia ablation mouse model we demonstrated that elimination of microglia in the implanted tumors (GL261 glioma cells were used for brain implantation) by the local in-tumor administration of Ganciclovir, significantly reduced the phosphorylation of Pyk2 at Tyr579/580 in implanted tumor cells. Taken together, these data indicate that microglial cells activate glioma cell migration/dispersal through the pro-migratory Pyk2 signaling pathway in glioma cells.

SUBMITTER: Rolon-Reyes K

PROVIDER: S-EPMC4476590 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Microglia Activate Migration of Glioma Cells through a Pyk2 Intracellular Pathway.

Rolón-Reyes Kimberleve K Kucheryavykh Yuriy V YV Cubano Luis A LA Inyushin Mikhail M Skatchkov Serguei N SN Eaton Misty J MJ Harrison Jeffrey K JK Kucheryavykh Lilia Y LY

PloS one 20150622 6

Glioblastoma is one of the most aggressive and fatal brain cancers due to the highly invasive nature of glioma cells. Microglia infiltrate most glioma tumors and, therefore, make up an important component of the glioma microenvironment. In the tumor environment, microglia release factors that lead to the degradation of the extracellular matrix and stimulate signaling pathways to promote glioma cell invasion. In the present study, we demonstrated that microglia can promote glioma migration throug ...[more]

PMID: 26098895

Similar Datasets

Project description:BACKGROUND:Microglia are resident innate immune cells which release many factors including proinflammatory cytokines or nitric oxide (NO) when they are activated in response to immunological stimuli. Pathophysiology of Alzheimer's disease (AD) is related to the inflammatory responses mediated by microglia. Intracellular Ca2+ signaling is important for microglial functions such as release of NO and cytokines. In addition, alteration of intracellular Ca2+ signaling underlies the pathophysiology of AD, while it remains unclear how donepezil, an acetylcholinesterase inhibitor, affects intracellular Ca2+ mobilization in microglial cells. METHODS:We examined whether pretreatment with donepezil affects the intracellular Ca2+ mobilization using fura-2 imaging and tested the effects of donepezil on phagocytic activity by phagocytosis assay in rodent microglial cells. RESULTS:In this study, we observed that pretreatment with donepezil suppressed the TNFα-induced sustained intracellular Ca2+ elevation in both rat HAPI and mouse primary microglial cells. On the other hand, pretreatment with donepezil did not suppress the mRNA expression of both TNFR1 and TNFR2 in rodent microglia we used. Pretreatment with acetylcholine but not donepezil suppressed the TNFα-induced intracellular Ca2+ elevation through the nicotinic α7 receptors. In addition, sigma 1 receptors were not involved in the donepezil-induced suppression of the TNFα-mediated intracellular Ca2+ elevation. Pretreatment with donepezil suppressed the TNFα-induced intracellular Ca2+ elevation through the PI3K pathway in rodent microglial cells. Using DAF-2 imaging, we also found that pretreatment with donepezil suppressed the production of NO induced by TNFα treatment and the PI3K pathway could be important for the donepezil-induced suppression of NO production in rodent microglial cells. Finally, phagocytosis assay showed that pretreatment with donepezil promoted phagocytic activity of rodent microglial cells through the PI3K but not MAPK/ERK pathway. CONCLUSIONS:These suggest that donepezil could directly modulate the microglial function through the PI3K pathway in the rodent brain, which might be important to understand the effect of donepezil in the brain.

Project description:BackgroundSuppressor of cytokine signaling 3 (SOCS3) is considered to inhibit cytokine responses and play a negative role in migration of various cells. Proline-rich tyrosine kinase 2 (PYK2) is a non-receptor kinase and has been found crucial to cell motility. However, little is known about whether SOCS3 could regulate PYK2 pro-migratory function in lung cancer.MethodsThe methylation status of SOCS3 was investigated in HBE and A549 cell lines by methylation-specific PCR. A549 cells were either treated with a demethylation agent 5-aza-2'-deoxycytidine or transfected with three SOCS3 mutants with various functional domains deleted. Besides, cells were pretreated with a proteasome inhibitor beta-lactacystin where indicated. The effects of SOCS3 up-regulation on PYK2 expression, PYK2 and ERK1/2 phosphorylations were assessed by western blot using indicated antibodies. RT-PCR was used to estimate PYK2 mRNA levels. Transwell experiments were performed to evaluate cell migration.ResultsSOCS3 expression was found impaired in A549 cells and higher PYK2 activity was correlated with enhanced cell migration. We identified that SOCS3 was aberrantly methylated in the exon 2, and 5-aza-2'-deoxycytidine restored SOCS3 expression. Reactivation of SOCS3 attenuated PYK2 expression and phosphorylation, cell migration was inhibited as well. Transfection studies indicated that exogenous SOCS3 interacted with PYK2, and both the Src homology 2 (SH2) and the kinase inhibitory region (KIR) domains of SOCS3 contributed to PYK2 binding. Furthermore, SOCS3 was found to inhibit PYK2-associated ERK1/2 activity in A549 cells. SOCS3 possibly promoted degradation of PYK2 in a SOCS-box-dependent manner and interfered with PYK2-related signaling events, such as cell migration.ConclusionThese data indicate that SOCS3 negatively regulates cell motility and decreased SOCS3 induced by methylation may confer a migration advantage to A549 cells. These results also suggest a negative role of SOCS3 in PYK2 signaling, and a previously unidentified regulatory mechanism for PYK2 function.

Dataset Information

Microglia Activate Migration of Glioma Cells through a Pyk2 Intracellular Pathway.

Publications

Microglia Activate Migration of Glioma Cells through a Pyk2 Intracellular Pathway.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets