Growth inhibitory activity of bone morphogenetic protein 4 in human glioblastoma cell lines is heterogeneous and dependent on reduced SOX2 expression.
骨形态发生蛋白 4 在人胶质母细胞瘤细胞系中的生长抑制活性是异质性的，依赖于降低的 SOX2 表达。
- 作者列表："Dalmo E","Johansson P","Niklasson M","Gustavsson I","Nelander S","Westermark B
:Glioblastoma multiforme (GBM) continues to have a dismal prognosis. Even though detailed information on the genetic aberrations in cell signaling and cell cycle checkpoint control is available, no effective targeted treatment has been developed. Despite the advanced molecular defects, glioblastoma cells may have remnants of normal growth inhibitory pathways, such as the bone morphogenetic protein (BMP) signaling pathway. We have evaluated the growth inhibitory effect of BMP4 across a broad spectrum of patient samples, using a panel of 40 human glioblastoma initiating cell (GIC) cultures. A wide range of responsiveness was observed. BMP4 sensitivity was positively correlated with a proneural mRNA expression profile, high SOX2 activity, and BMP4-dependent up-regulation of genes associated with inhibition of the MAPK pathway, as demonstrated by gene set enrichment analysis (GSEA). BMP4 response in sensitive cells was mediated by the canonical BMP receptor pathway involving SMAD1/5/9 phosphorylation and SMAD4 expression. SOX2 was consistently down-regulated in BMP4-treated cells. Forced expression of SOX2 attenuated the BMP4 sensitivity including a reduced up-regulation of MAPK inhibitory genes, implying a functional relationship between SOX2 down-regulation and sensitivity. The results show an extensive heterogeneity in BMP4 responsiveness among GICs, and identify a BMP4 sensitive subgroup, in which SOX2 is a mediator of the response. Implications: Development of agonists targeting the BMP signaling pathway in glioblastoma remains an attractive avenue towards a better treatment - our study may help find biomarkers that predict the outcome of such treatment and help stratification of patients.
: 多形性胶质母细胞瘤 (GBM) 的预后仍然很差。尽管关于细胞信号传导和细胞周期检查点控制中的遗传畸变的详细信息可用，但尚未开发有效的靶向治疗。尽管存在先进的分子缺陷，胶质母细胞瘤细胞可能有正常生长抑制途径的残余，如骨形态发生蛋白 (BMP) 信号通路。我们使用一组 40 种人胶质母细胞瘤起始细胞 (GIC) 培养物，评估了 BMP4 在广谱患者样本中的生长抑制作用。观察到广泛的反应性。BMP4 敏感性与前神经 mRNA 表达谱、高 SOX2 活性和 BMP4-dependent MAPK 通路抑制相关基因上调呈正相关,如基因集富集分析 (GSEA) 所示。敏感细胞中的 BMP4 反应由涉及 SMAD1/5/9 磷酸化和 SMAD4 表达的经典 BMP 受体通路介导。SOX2 在 BMP4-treated 细胞中持续下调。SOX2 的强制表达减弱了 BMP4 的敏感性，包括 MAPK 抑制基因的上调减少，这意味着 SOX2 下调与敏感性之间存在功能关系。结果显示 GICs 中 BMP4 反应性存在广泛的异质性，并确定了一个 BMP4 敏感亚组，其中 SOX2 是反应的中介因子。意义: 开发靶向胶质母细胞瘤中 BMP 信号通路的激动剂仍然是更好治疗的一个有吸引力的途径 -- 我们的研究可能有助于找到预测此类治疗结果的生物标志物，并有助于对患者进行分层。
METHODS:PURPOSE:To generate a preclinical model of isocitrate dehydrogenase (IDH) mutant gliomas from glioma patients and design a MRS method to test the compatibility of 2-hydroxyglutarate (2HG) production between the preclinical model and patients. METHODS:Five patient-derived xenograft (PDX) mice were generated from two glioma patients with IDH1 R132H mutation. A PRESS sequence was tailored at 9.4 T, with computer simulation and phantom analyses, for improving 2HG detection in mice. 2HG and other metabolites in the PDX mice were measured using the optimized MRS at 9.4 T and compared with 3 T MRS measurements of the metabolites in the parental-tumor patients. Spectral fitting was performed with LCModel using in-house basis spectra. Metabolite levels were quantified with reference to water. RESULTS:The PRESS TE was optimized to be 96 ms, at which the 2HG 2.25 ppm signal was narrow and inverted, thereby leading to unequivocal separation of the 2HG resonance from adjacent signals from other metabolites. The optimized MRS provided precise detection of 2HG in mice compared to short-TE MRS at 9.4 T. The 2HG estimates in PDX mice were in excellent agreement with the 2HG measurements in the patients. CONCLUSION:The similarity of 2HG production between PDX models and parental-tumor patients indicates that PDX tumors retain the parental IDH metabolic fingerprint and can serve as a preclinical model for improving our understanding of the IDH-mutation associated metabolic reprogramming.
METHODS:BACKGROUND:Gliomas consist of a heterogeneous group of tumors. This study aimed to report the incidences of O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation, 1p19q co-deletion, isocitrate dehydrogenase (IDH) gene mutations, and inactivating mutations of alpha-thalassemia/mental retardation syndrome X-linked (ATRX) in high-grade gliomas in an ethnically diverse population. METHODS:Records of patients who underwent surgery for high-grade gliomas from January 2013 to March 2017 at our institution were obtained. The patients' age, gender, ethnicity, Karnofsky Performance Scale (KPS) score, ability to perform activities of daily living (ADLs), tumor location and biomarkers status were recorded. Data were analyzed using chi-square and Mann-Whitney U tests, Kaplan-Meier estimates and log-rank test. RESULTS:181 patients were selected (56 with grade III gliomas, 125 with grade IV gliomas). In the grade III group, 55% had MGMT promoter methylation, 41% had 1p19q co-deletion, 35% had IDH1 mutation and none had ATRX loss. In the grade IV group, 30% had MGMT promoter methylation, 2% had 1p19q co-deletion, 15% had IDH1 mutation and 8% had ATRX loss. After adjusting for effects of age, surgery and pre-operative ADL statuses, only MGMT promoter methylation was found to be significantly associated with longer overall survival time in grade III (p = 0.024) and IV patients (p = 0.006). CONCLUSIONS:The incidences of MGMT promoter methylation and IDH1 mutation were found to be comparable to globally reported rates, but those of 1p19q co-deletion and ATRX loss seemed to be lower in our cohort. MGMT promoter methylation was associated with increased overall survival in our cohort and might serve as favorable prognostic factor.
METHODS:BACKGROUND:Glioblastoma multiforme is a CNS cancer characterized by diffuse infiltrative growth, aggressive clinical behavior and very poor prognosis. The state-of-art clinical approach to this disease consists of surgical resection followed by radiotherapy plus concurrent and adjuvant chemotherapy with temozolomide. Tumor recurrence occurs in virtually all cases, therefore, despite any treatment, the median survival is very low (14.6 months), which makes the approach to these patients a challenging clinical issue. MAIN BODY:The escalating costs and times required for new medications to reach the bedside make repurposing or repositioning of old drugs, when scientific bases allow their use in other pathologies, an appealing strategy. Here, we analyze a number of literature data concerning the antipsychotic chlorpromazine, the founder of the phenothiazines class of drugs, a medication widely used in the clinics for approximately 60 years. The drug exerts its effects on psychiatric patients by interfering with the dopamine receptor D2, although more recent pharmacodynamics studies ascribe chlorpromazine a series of biological effects on cancer cells, all converging in hindering also glioblastoma survival capabilities. SHORT CONCLUSIONS:On these bases, and assisted by the information on the well-established chlorpromazine toxicity and dosage in humans, we designed a Phase II clinical trial involving the combination of chlorpromazine with the standard treatment, temozolomide, in the adjuvant phase of the therapeutic protocol. Patients displaying hypo-methylation of the MGMT gene, and thus intrinsically resistant to temozolomide, will be enrolled. The endpoints of this study are the analysis of toxicity and clinical activity, as evaluated in terms of Progression-Free Survival, of the association of chlorpromazine with the first-line treatment for this very serious form of cancer.