Treatment response assessment with (R)-[11CPAQ PET in the MMTV-PyMT mouse model of breast cancer
作者:T. Tegnebratt、L. Lu、S. Eksborg、A. Chireh、P. Damberg、S. Nikkhou-Aski、T. Foukakis、H. Rundqvist、S. Holmin、R. V. Kuiper、E. Samen
DOI:10.1186/s13550-018-0380-x
日期:2018.12
The goal of the study was to assess the potential of the vascular endothelial growth factor receptor (VEGFR)-2-targeting carbon-11 labeled (R)-N-(4-bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3-piperidinyl)methoxy)-4-quinazolineamine ((R)-[11C]PAQ) as a positron emission tomography (PET) imaging biomarker for evaluation of the efficacy of anticancer drugs in preclinical models. MMTV-PyMT mice were treated with vehicle alone (VEH), murine anti-VEGFA antibody (B20-4.1.1), and paclitaxel (PTX) in combination or as single agents. The treatment response was measured with (R)-[11C]PAQ PET as standardized uptake value (SUV)mean, SUVmax relative changes at the baseline (day 0) and follow-up (day 4) time points, and magnetic resonance imaging (MRI)-derived PyMT mammary tumor volume (TV) changes. Expression of Ki67, VEGFR-2, and CD31 in tumor tissue was determined by immunohistochemistry (IHC). Non-parametric statistical tests were used to evaluate the relation between (R)-[11C]PAQ radiotracer uptake and therapy response biomarkers. The (R)-[11C]PAQ SUVmax in tumors was significantly reduced after 4 days in the B20-4.1.1/PTX combinational and B20-4.1.1 monotherapy groups (p < 0.0005 and p < 0.003, respectively). No significant change was observed in the PTX monotherapy group. There was a significant difference in the SUVmax change between the VEH group and B20-4.1.1/PTX combinational group, as well as between the VEH group and the B20-4.1.1 monotherapy group (p < 0.05). MRI revealed significant decreases in TV in the B20-4.1.1/PTX treatment group (p < 0.005) but not the other therapy groups. A positive trend was observed between the (R)-[11C]PAQ SUVmax change and TV reduction in the B20-4.1.1/PTX group. Statistical testing showed a significant difference in the blood vessel density between the B20-4.1.1/PTX combinational group and the VEH group (p < 0.05) but no significant difference in the Ki67 positive signal between treatment groups. The results of this study are promising. However, additional studies are necessary before (R)-[11C]PAQ can be approved as a predictive radiotracer for cancer therapy response.
这项研究的目的是评估血管内皮生长因子受体(VEGFR)-2 靶向碳-11标记的(R)-N-(4-溴-2-氟苯基)-6-甲氧基-7-((1-甲基-3-哌啶基)甲氧基)-4-喹唑啉胺((R)-[11C]PAQ)作为正电子发射断层扫描(PET)成像生物标记物的潜力,以评估临床前模型中抗癌药物的疗效。对 MMTV-PyMT 小鼠单独使用载体(VEH)、小鼠抗 VEGFA 抗体(B20-4.1.1)和紫杉醇(PTX)进行联合或单药治疗。用(R)-[11C]PAQ PET测量治疗反应,即标准化摄取值(SUV)平均值、基线(第0天)和随访(第4天)时间点的SUVmax相对变化以及磁共振成像(MRI)得出的PyMT乳腺肿瘤体积(TV)变化。肿瘤组织中 Ki67、VEGFR-2 和 CD31 的表达通过免疫组织化学(IHC)测定。采用非参数统计检验来评估(R)-[11C]PAQ放射性示踪剂摄取与治疗反应生物标志物之间的关系。4天后,B20-4.1.1/PTX联合治疗组和B20-4.1.1单药治疗组肿瘤的(R)-[11C]PAQ SUVmax显著降低(分别为p < 0.0005和p < 0.003)。PTX单药治疗组未观察到明显变化。VEH组与B20-4.1.1/PTX联合治疗组之间以及VEH组与B20-4.1.1单药治疗组之间的SUVmax变化有明显差异(p < 0.05)。核磁共振成像显示,B20-4.1.1/PTX治疗组的TV明显下降(p < 0.005),而其他治疗组则没有。在B20-4.1.1/PTX治疗组中,(R)-[11C]PAQ SUVmax的变化与TV的减少呈正相关趋势。统计检测显示,B20-4.1.1/PTX 联合治疗组与 VEH 组的血管密度有显著差异(P < 0.05),但治疗组间的 Ki67 阳性信号无显著差异。这项研究的结果很有希望。然而,在(R)-[11C]PAQ被批准作为预测癌症治疗反应的放射性示踪剂之前,还需要进行更多的研究。