gastrin-17 and Glioblastoma

This study aims to investigate the role of gastrin-17 (G17) on angiogenesis features in gliomas both in vitro and in vivo.. The influences of G17 and G17 receptor antagonists were characterized in vitro in terms of angiogenesis on human umbilical vein endothelial cell (HUVEC) tubulogenesis processes on Matrigel and in vivo with respect to U373 orthotopic glioma xenografts. The influence of phosphatidylinositol 3'-kinase, protein kinase C, and nuclear factor-kappaB inhibitors was characterized in vitro on G17-mediated HUVEC tubulogenesis. G17-mediated release of interleukin (IL)-8 from HUVECs and G17-induced modifications in nuclear factor-kappaB DNA binding activity were characterized by means of specific enzyme-linked immunosorbent assays. The influence of G17 on E- and P-selectin expression was determined by means of computer-assisted microscopy, whereas the influence of E- and P-selectin on HUVEC migration was approached by means of antisense oligonucleotides. The chemotactic influence of G17 and IL-8 on HUVEC migration was characterized by means of computer-assisted videomicroscopy with Dunn chambers.. Messenger RNAs for cholecystokinin (CCK)A, CCKB, and CCKC receptors were present in HUVECs and microvessels dissected from a human glioblastoma. Whereas G17 significantly increased the levels of angiogenesis in vivo in the U373 experimental glioma model and in vitro in the HUVECs, the CCKB receptor antagonist L365,260 significantly counteracted the G17-mediated proangiogenic effects. G17 chemoattracted HUVECs, whereas IL-8 failed to do so. IL-8 receptor alpha (CXCR1) and IL-8 receptor beta (CXCR2) mRNAs were not detected in these endothelial cells. Gastrin significantly (but only transiently) decreased the level of expression of E-selectin, but not P-selectin, whereas IL-8 increased the expression of E-selectin. Specific antisense oligonucleotides against E- and P-selectin significantly decreased HUVEC tubulogenesis processes in vitro on Matrigel.. The present study shows that gastrin has marked proangiogenic effects in vivo on experimental gliomas and in vitro on HUVECs. This effect depends in part on the level of E-selectin activation, but not on IL-8 expression/release by HUVECs.

Topics: Animals; Benzodiazepinones; Brain Neoplasms; Cell Movement; Collagen; Drug Combinations; E-Selectin; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Female; Gastrins; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; In Vitro Techniques; Interleukin-8; Laminin; Mice; Mice, Nude; Neovascularization, Pathologic; NF-kappa B; P-Selectin; Phenylurea Compounds; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase C; Proteoglycans; Rats; Rats, Nude; Receptors, Cholecystokinin; Receptors, Interleukin-8A; Receptors, Interleukin-8B; Transplantation, Heterologous; Tumor Cells, Cultured; Umbilical Veins

Astrocytic tumors are the most common and the most malignant primary tumors of the central nervous system. We had previously observed that gastrin could significantly modulate both cell proliferation and migration of astrocytoma cells. We have investigated in the present study which genes could be targeted by gastrin in tumor astrocyte migration. Using a subtractive hybridization PCR technique we have cloned genes differentially over-expressed in human astrocytoma U373 cells treated or not with gastrin. We found about 70 genes over-expressed by gastrin. Among the genes overexpressed by gastrin, we paid particular attention to tenascin-C, S100A6 and MLCK genes because their direct involvement in cell migration features. Their gastrin-induced overexpression was quantitatively determined by competitive RT-PCR technique. We also showed by means of a reporter gene system that S100A6 and tenascin-C respective promoters were upregulated after gastrin treatment. These data show that gastrin-mediated effects in glioblastoma cells occur through activation of a number of genes involved in cell migration and suggest that gastrin could be a target in new therapeutic strategies against malignant gliomas.

Topics: Actins; Amino Acid Sequence; Biopolymers; Brain Neoplasms; Cell Cycle Proteins; Cell Movement; DNA, Complementary; Gastrins; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Genes, Reporter; Glioblastoma; Humans; Molecular Sequence Data; Myosin-Light-Chain Kinase; Neoplasm Invasiveness; Neoplasm Proteins; Promoter Regions, Genetic; Protein Biosynthesis; Proteins; Reverse Transcriptase Polymerase Chain Reaction; rhoA GTP-Binding Protein; RNA, Messenger; RNA, Neoplasm; S100 Calcium Binding Protein A6; S100 Proteins; Stress Fibers; Subtraction Technique; Tenascin; Transfection; Tumor Cells, Cultured; Wiskott-Aldrich Syndrome Protein Family