Kohsaka Shinji, Hinohara Kunihiko, Wang Lei, Nishimura Tatsunori, Urushido Masana, Yachi Kazuhiro, Tsuda Masumi, Tanino Mishie, Kimura Taichi, Nishihara Hiroshi, Gotoh Noriko, Tanaka Shinya
Neuro Oncol. 2014 Jul;16(7):960-70. doi: 10.1093/neuonc/not315.
Glioblastoma multiforme (GBM) is one of the most aggressive human tumors, and the establishment of an effective therapeutic reagent is a pressing priority. Recently, it has been shown that the tumor tissue consists of heterogeneous components and that a highly aggressive population should be the therapeutic target.
Through a single subcutaneous passage of GBM cell lines LN443 and U373 in mice, we have developed highly aggressive variants of these cells named LN443X, U373X1, and U373X2, which showed increased tumor growth, colony-forming potential, sphere-forming potential, and invasion ability. We further investigated using microarray analysis comparing malignant cells with their parental cells and mRNA expression analysis in grades II to IV glioma samples.
Adipocyte enhancer binding protein 1, epiregulin (EREG), and microfibrillar associated protein 5 were identified as candidate genes associated with higher tumor grade and poor prognosis. Immunohistochemical analysis also indicated a correlation of a strong expression of EREG with short overall survival. Furthermore, both EREG stimulation and EREG introduction of GBM cell lines were found to increase phosphorylation of epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase and resulted in the promotion of colony formation, sphere formation, and in vivo tumor formation. Gefitinib treatment inhibited phosphorylation of EGFR and extracellular signal-regulated kinase and led to tumor regression in U373-overexpressed EREG.
These results suggested that EREG is one of the molecules involved in glioma malignancy, and EGFR inhibitors may be a candidate therapeutic agent for EREG-overexpressing GBM patients.
多形性胶质母细胞瘤（GBM）是最具侵袭性的人类肿瘤之一，建立有效的治疗试剂是当务之急。最近的研究表明，肿瘤组织由异质性成分组成，高侵袭性群体应作为治疗靶点。
通过将GBM细胞系LN443和U373在小鼠体内进行单次皮下传代，我们获得了这些细胞的高侵袭性变体，命名为LN443X、U373X1和U373X2，它们表现出肿瘤生长增加、集落形成潜力、成球潜力和侵袭能力增强。我们进一步使用微阵列分析比较恶性细胞与其亲本细胞，并对II至IV级胶质瘤样本进行mRNA表达分析。
脂肪细胞增强子结合蛋白1、表皮调节素（EREG）和微原纤维相关蛋白5被确定为与肿瘤分级较高和预后不良相关的候选基因。免疫组织化学分析还表明EREG的强表达与总生存期短相关。此外，发现EREG刺激和GBM细胞系中EREG的导入均增加表皮生长因子受体（EGFR）和细胞外信号调节激酶的磷酸化，并导致集落形成、成球和体内肿瘤形成的促进。吉非替尼治疗抑制EGFR和细胞外信号调节激酶的磷酸化，并导致U373过表达EREG的肿瘤消退。
这些结果表明EREG是参与胶质瘤恶性进展的分子之一，EGFR抑制剂可能是EREG过表达的GBM患者的候选治疗药物。
