Invasion heterogeneity of C6 glioblastomas in rat orthotopic model

Abstract

Objective To investigate the invasion heterogeneity of C6 glioblastomas in rat orthotopic model. Methods Cells invading experiment and scratch test were used to observe the change of the invasive C6 cells respectively added epidermal growth factor(EGF) and epidermal growth factor receptor(EGFR) blockers(Gefitinib), in order to demonstrate the ability of EGFR as invasive tumor marker.With stereotactic technique, the model of rat C6 glioma cells in situconstructs was constructed.The general situation of rats after inoculation, body mass changes were observed, body mass of rats before inoculation and in the experiments were compared.In 28 days after inoculation to death and take cerebral perfusion in rats, to obtain gross and pathological section.Vimentin and microtubule protein were used to marker tumor tissue and the surrounding brain tissue.The pathological section was carried out on the pathological immunohistochemistry and immunofluorescence staining of EGFR, determined its expression whether consistent. Results The invasion number of C6 cells(74±7) and the migration distance((5 093±1 662.24) μm) were remarkably higher than control group(30±8, (1 623±515) μm, P<0.01) when EGF was added into the culture medium of C6 group, and the invasion number of C6 cells and the migration distance were reduced after EGF+ Gefitinib were added(52±8, (1 310±570) μm, P<0.01). After modling, with the extension of time the rats body mass was reduced, and drinking water, food intake was reduced, premature aging, and gross and histological section of rats by HE staining were seen tumor formation.The IHC and immunofluorescent staining results of EGFR showed that the OD of EGFR in centre of tumor, peripheral position and normal tissue were 14 123.09±9 397.98, 22 101.43±9 705.92 and 7 122.46±5 294.36, respectively.Intensity of EGFR in peripheral position of tumor was higher than that in centre of tumor and normal tissue (P<0.01). Conclusion EGFR might be a powerful biomarker to indicate the invasiveness of C6 cell line.The part of C6 rat orthotopic tumor with the most capability of invasiveness indicated by EGFR is the peripheral position of tumor. Key words: Glioma; Invasiveness; Heterogeneity; Epidermal growth factor receptor