Bradykinin enhances invasion of malignant glioma into the brain parenchyma by inducing cells to undergo amoeboid migration

Abstract

Key pointsr Glioma multiforme is a fast expanding and aggressive type of brain tumour that invades healthy brain tissue by migration of single glioma cells along blood vessels.r We show that bradykinin, a neuropeptide of the vasculature, induces the formation of small bleb-like protrusions at the plasma membrane of glioma cells in vitro, which are regulated by intracellular Ca 2+ , resulting in contraction of the cytoskeleton, cytoplasmatic flow and activation of Ca 2+ -dependent K + and Cl − channels.r From our in vitro experiments we conclude that bradykinin facilitates glioma invasion by stimulating an amoeboid phenotype of migration.r In situ experiments confirmed that bradykinin increases the speed of glioma cell migration, which we have been able to block with blebbistatin, an inhibitor of membrane blebbing, and with the B2 receptor agonist Hoe-140.r The study reveals novel mechanisms of bradykinin-induced glioma migration and suggests pharmacological targets to reduce glioma invasion.Abstract The molecular and cellular mechanisms governing cell motility and directed migration in response to the neuropeptide bradykinin are largely unknown. Here, we demonstrate that human glioma cells whose migration is guided by bradykinin generate bleb-like protrusions. We found that activation of the B2 receptor leads to a rise in free Ca 2+ from internal stores that activates actomyosin contraction and subsequent cytoplasmic flow into protrusions forming membrane blebs. Furthermore Ca 2+ activates Ca 2+ -dependent K + and Cl − channels, which participate in bleb regulation. Treatment of gliomas with bradykinin in situ increased glioma growth by increasing the speed of cell migration at the periphery of the tumour mass. To test if bleb formation is related to bradykinin-promoted glioma invasion we blocked glioma migration with blebbistatin, a blocker of myosin kinase II, which is necessary for proper bleb retraction. Our findings suggest a pivotal role of bradykinin during glioma invasion by stimulating amoeboid migration of glioma cells.

Glioblastoma‐mesenchymal stem cell communication modulates expression patterns of kinin receptors: Possible involvement of bradykinin in information flow

“…In vivo studies on kinin B1 (B1R) and B2 receptors (B2R) revealed that B2R was increasingly expressed with augmenting malignancy of glioma (16) and GBM cells (26). Reportedly, B1R was not relevant for GBM cell invasion (15); however, B1R expression upregulation in GBM cells was confirmed by Lu et al (27). In GBM tissue, B1R expression may be induced by high levels of inflammatory cytokines produced by tumor infiltrating immune cells (28).…”

“…With respect to the underlying mechanism, Montana and Sontheimer (16) showed that bradykinin via B2R-induced [Ca 21 ] i transients enhanced and directed invasion of glioma cells toward blood vessels. Moreover, Seifert and Sontheimer (15) recently revealed that bradykinin through [Ca 21 ] i transients in GBM cells in vitro induced the formation of small bleb-like protrusions at the plasma membrane, which stimulated an amoeboid phenotype of cell migration.…”

“…At the same time, recent studies demonstrate the influence of kinin B1 (B1R) and B2 receptors (B2R) on proliferation, chemotaxis, and tumor invasion (11), such as in melanoma (12), bladder cancer (13,14), and glioblastoma (15,16 (17) recently reported that the human GBM cell line U373 produced and bound kininogens, synthesized kallikreins, as well as carboxypeptidases M and E, resulting in the production of B1R and B2-activating kinins, affecting cell invasion. Therefore, considering the effects of GBM-MSC interaction and of kinin receptor activation on proliferation, chemotaxis, and tumor invasion of glioma cells, here we investigate whether direct and indirect co-cultures of bone marrow derived MSC with malignant GBM cells U87-MG would affect B1R and B2R expression, as well as consider possible inductions of protease mediated increase in GBM progression and invasion.…”

Molecular Mechanisms of Glioma Cell Motility

“…It is a critical attractor of glioma cells toward the vasculature, and an activator of ion channels (127,129). Binding of bradykinin to B 2 R leads to increases in intracellular Ca 2 + which induces the opening of the KCa3.1 and ClC-3 channels, resulting in the efflux of Cl − , K + , and water (16,127,130). As a result, the glioma cells shrink which enable them to migrate through the narrow space of the brain.…”

Novel delivery methods bypassing the blood-brain and blood-tumor barriers

“…63,71,109 Effectiveness of the RMP-7 and carboplatin regimen was investigated in Phase I (2001) and Phase II (2006) clinical trials, which concluded that this combination was ineffective. 164,165 Recent research indicates that glioma invasion can be achieved through a bradykinin-mediated chemotactic process, 112,144 and this finding questions the overall efficacy of using a kinin agent. Nevertheless, kinin agents continue to remain an active area of translational research, 46 particularly because of the advantage of preferential BTB disruption observed with these vasoactive compounds.…”