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

Abstract

The most aggressive subtype of brain tumors is glioma WHO grade IV, the glioblastoma (GBM). The present work aims to elucidate the role of kinin receptors in interactions between GBM cells and mesenchymal stem cells (MSC). The GBM cell line U87-MG was stably transfected to express dsRed protein, single cell cloned, expanded, and cultured with MSC, both in the direct co-cultures (DC) and indirect co-cultures (IC) at equal cell number ratio for 72 h. Up-and down-regulation of matrix metalloproteases (MMP)29 expression in U87-MG and MSC cells, respectively, in direct coculture points to possible MSC participation in tumor invasion. MMP9 expression is in line with significantly increased expression of kinin B1 (B1R) and B2 receptor (B2R) in U87-MG cells and their decreased levels in MSC, as confirmed by quantitative assessment using flow cytometric analysis. Similarly, in indirect cultures (IC), lacking the contact between GBM and MSC cells, an increase of B1 and B2 receptor expression was again noted in U87-MG cells, and no significant changes in kinin receptors in MSC was observed. Functionality of kinin-B1 and B2 receptors was evidenced by stimulation of intracellular calcium fluxes by their respective agonists, des-Arg9-bradykinin (DBK) and bradykinin (BK). Moreover, BK showed a feedback control on kinin receptor expression in mono-cultures, direct and indirect co-cultures. The treatment with BK resulted in down-regulation of B1 and B2 receptors in MSC, with simultaneous upregulation of these receptors in U87-MG cells, suggesting that functions of BK in information flow between these cells is important for tumor progression and invasion. V C International Society for Advancement of CytometryKey terms Bradykinin; kinin-B1 receptor; kinin-B2 receptor; glioblastoma; bone-marrow mesenchymal stem cells; direct and indirect cell co-culture GLIOMAS, although classified as a rare neoplastic disease, are still the most frequent brain tumors and their most malignant form (WHO stage IV astrocytoma). Glioblastoma (GBM) has an average postoperative survival of only 14.6 or 12.1 months when treated with radio-and chemo-therapy (temozolomide) or with radiotherapy alone, respectively (1). The major characteristic of these tumors is the high infiltration rate of single cells, the so called "guerrilla" cells into the brain parenchyma, even several cm away from the bulk tumor mass. These cells are hard to target by conventional therapies. In view of that, the development of novel therapeutic strategies for successful GBM treatment targeting tumor invasiveness has turned into an aim of priority.

Mesenchymal stem cells differentially affect the invasion of distinct glioblastoma cell lines

“…Authentication of the cell lines was performed as described previously [7]. U373 cells stably expressing enhanced green fluorescent protein (U373 eGFP cells) [24] and U87 cells expressing red fluorescent protein (dsRED) were prepared as described previously [59]. …”

The Role of C1-Esterase Inhibitors in the Management of Vasogenic Edema in Glioblastoma

“…However, for patients who have increasing edema unresponsive to steroids, there are few additional medical therapies available. is, combined with recent research that supports bradykinin's role in both tumor invasion and vasogenic edema, has led to interest in the usefulness of C1INH as a potential therapy to decrease the amount of bradykinin generated by malignant glioblastoma cells [3,4,11]. Our case discusses a patient with advanced glioblastoma who had diffuse angioedema refractory to steroid therapy who responded well to plasma-derived C1INH replacement.…”

“…Prognosis is deemed as poor, with 5year survival after radiation and temozolomide chemotherapy at 9.8% [2]. It is thought that mesenchymal stem cells influence glioblastoma invasiveness through crosstalk pathways that lead to an upregulation of bradykinin, a vasoactive peptide, and its receptors: bradykinin 1 receptor (B1R) and bradykinin 2 receptor (B2R) [3,4]. B1R receptors are more highly expressed in pathological processes involving tissue damage [5], while B2R are constitutive throughout the body and when expressed on brain tissue, play a role in the regulation of the BBB [5,6].…”

Kinins and microglial responses in bipolar disorder: a neuroinflammation hypothesis

“…More recently, studies have demonstrated the role of BK in neurite outgrowth, proliferation inhibition of stem cells and their differentiation into neurons (Martins et al, 2005;Trujillo et al, 2009;Trujillo et al, 2012;Nascimento et al, 2015;Pillat et al, 2015). At a molecular level, BK and B2BKR are also involved in ERK activation, acting via tyrosine kinases Pyk2 and Src (Ca 2+ -dependent pathway), and via EGF and PKC pathway, respectively (Dikic et al, 1996;Adomeit et al, 1999).…”