Department of Chemistry, The University of Kansas, Lawrence, KS 66047, USA.
Center of Bio-Modular Multiscale Systems for Precision Medicine (CBM2), The University of Kansas, Lawrence, KS 66047, USA.
Cells. 2023 Sep 13;12(18):2266. doi: 10.3390/cells12182266.
There is a high clinical unmet need to improve outcomes for pancreatic ductal adenocarcinoma (PDAC) patients, either with the discovery of new therapies or biomarkers that can track response to treatment more efficiently than imaging. We report an innovative approach that will generate renewed interest in using circulating tumor cells (CTCs) to monitor treatment efficacy, which, in this case, used PDAC patients receiving an exploratory new therapy, poly ADP-ribose polymerase inhibitor (PARPi)-niraparib-as a case study. CTCs were enumerated from whole blood using a microfluidic approach that affinity captures epithelial and mesenchymal CTCs using anti-EpCAM and anti-FAPα monoclonal antibodies, respectively. These antibodies were poised on the surface of two separate microfluidic devices to discretely capture each subpopulation for interrogation. The isolated CTCs were enumerated using immunophenotyping to produce a numerical ratio consisting of the number of mesenchymal to epithelial CTCs (denoted "Φ"), which was used as an indicator of response to therapy, as determined using computed tomography (CT). A decreasing value of Φ during treatment was indicative of tumor response to the PARPi and was observed in 88% of the enrolled patients (n = 31). Changes in Φ during longitudinal testing were a better predictor of treatment response than the current standard CA19-9. We were able to differentiate between responders and non-responders using ΔΦ ( = 0.0093) with higher confidence than CA19-9 ( = 0.033). For CA19-9 non-producers, ΔΦ correctly predicted the outcome in 72% of the PDAC patients. Sequencing of the gDNA extracted from affinity-selected CTC subpopulations provided information that could be used for patient enrollment into the clinical trial based on their tumor mutational status in DNA repair genes.
目前，提高胰腺导管腺癌（PDAC）患者的治疗效果存在巨大的临床需求，无论是发现新的治疗方法还是生物标志物，都需要比影像学更有效地跟踪治疗反应。我们报告了一种创新方法，它将重新激发人们使用循环肿瘤细胞（CTC）来监测治疗效果的兴趣，在这种情况下，我们使用接受探索性新疗法多聚 ADP-核糖聚合酶抑制剂（PARPi）尼拉帕尼的 PDAC 患者作为案例研究。我们使用微流控方法从全血中计数 CTC，该方法分别使用抗 EpCAM 和抗 FAPα单克隆抗体亲和捕获上皮和间充质 CTC。这些抗体分别位于两个独立的微流控设备的表面，以分别捕获每个亚群进行检测。使用免疫表型对分离的 CTC 进行计数，产生一个由间充质 CTC 与上皮 CTC 数量组成的数值比（表示为“Φ”），作为对治疗反应的指示，使用计算机断层扫描（CT）确定。在治疗过程中Φ值的降低表明肿瘤对 PARPi 的反应，在 88%的入组患者（n=31）中观察到。在纵向测试过程中Φ值的变化是治疗反应的更好预测指标，优于当前的标准 CA19-9。我们能够使用 ΔΦ（=0.0093）比 CA19-9（=0.033）更有信心地区分应答者和非应答者。对于 CA19-9 非生产者，ΔΦ 在 72%的 PDAC 患者中正确预测了结果。从亲和选择的 CTC 亚群中提取的 gDNA 进行测序，提供了可用于根据肿瘤突变状态在 DNA 修复基因中招募患者进入临床试验的信息。
