The in vitro influences of neurotensin on the motility characteristics of human U373 glioblastoma cells

Abstract

Astrocytic tumours are associated with dismal prognoses due to their pronounced ability to diffusely invade the brain parenchyma. Various neuropeptides, including gastrin, are able to modulate tumour astrocyte migration. While neurotensin has been shown to influence the proliferation of glioma cells and the migratory ability of a large set of other cell types, its role in glioma cell migration has never been investigated. Neurotensin-induced modifications to the motility features of human U373 glioblastoma cells therefore constitute the topic of the present study. We evidenced that three subtypes of neurotensin receptors (NTR1, NTR2 and NTR3) are expressed in U373 glioblastoma cells, at least as far as their mRNAs are concerned. Treating U373 tumour cells with 10 nM neurotensin markedly modified the morphological patterns of these cells and also profoundly altered the organization of their actin cytoskeletons. Pull-down assays revealed that neurotensin induced the activation in U373 cells of both Racl and Cdc42 but not RhoA. Scratch wound assays evidenced that neurotensin (0.1 and 10 nM) very significantly inhibited wound colonization by U373 cells cultured in the absence of serum. In addition, quantitative phase-contrast videomicroscopy analyses showed that neurotensin decreases the motility levels of U373 glioblastoma cells when these cells are cultured on plastic. In sharp contrast, neurotensin stimulates the motility of U373 cells when they are cultured on laminin, which is a pro-adhesive extracellular matrix component ubiquitously secreted by glioma cells. Our data thus strongly suggest that, in addition to gastrin, neurotensin is a neuropeptide capable of modulating tumour astrocyte migration into the brain parenchyma.

Diverse expression patterns and tumorigenic role of neurotensin signaling components in colorectal cancer cells

“…3B, right). In addition to cell proliferation, NTSR1 activation influences cell migration and invasion in some cancers including breast and NET (13, 16, 23). On the basis of these studies, we next assessed the migratory activity of CRC cells transfected with NTSR1 siRNA using a wound-healing migration assay.…”

“…It has been reported that NTS and/or NTSR1 are over expressed in some types of cancers and many cancer cell lines, and that inhibition of NTS signaling can suppress the oncogenic activities in several cancer cell lines (10–14, 16, 23, 24). Moreover, there is accumulating evidence that NTSR1 activation is linked with poor prognosis, cancer progression and a higher incidence of metastases in lung and breast cancers (13,14).…”

Molecular Mechanisms of Glioma Cell Motility

“…EGFRvIII, a truncated and constitutively active EGF receptor, and Platelet Growth Factor Receptor alpha (PDGFRa) activate RAC-1-mediated migration through tyrosine protein kinase SRC-dependent DOCK180 phosphorylation (103,104). RAC-1 is also activated by the IQ-domain GTPase-Activating Protein (IQGAP)-1/ADP-Ribosylation Factor 6 (ARF6), neurotensin, and ephrinB3 signaling (105)(106)(107). RAC-1 activity is further modulated by CDC42 (104,108) as well as by axonal guidance molecules (see the section "Axonal Guidance Molecules").…”

ELMO1 and Dock180, a Bipartite Rac1 Guanine Nucleotide Exchange Factor, Promote Human Glioma Cell Invasion

“…Rac1, a member of the Rho GTPase family, is a key regulator of actin cytoskeletal dynamics and relays signals from various stimuli such as growth factors, cytokines, and adhesion molecules to downstream effectors modulating cell migration and invasion (3). Importantly, Rac1 has been shown to promote glioma cell migration (4)(5)(6)(7)(8)(9)(10). The activation of Rac1 is through a GDP/GTP exchange mechanism catalyzed by the guanine nucleotide exchange factors (GEF) resulting in an active, GTP-bound state (11).…”