Abstract 3780: Bio-competition-based smart NanoVelcro Chip for isolation and gene expression analysis of circulating tumor cells from prostate cancer patients
Authors: Chen Jie-Fu , Shen Mo-Yuan , Luo Chun-Hao , Cheng Shirley , Lee Sangjun , Hou Shuang , Posadas Edwin M. , Tseng Hsian-Rong , Yu Hsiao-Hua 
Published: July 2017

Introduction and Objective: Circulating tumor cells (CTCs) are being used in efforts to identify important transcriptomic features such as androgen receptor (AR) splicing variants in prostate cancer (PCa) and other malignancies. The low abundance of CTCs and the fragility of the genetic materials create a need for tools that obtain high-quality signals with great efficiency. Poly(3,4-ethylenedioxythiophene) (PEDOT) is a stimulation-responsive nanomaterial which allows for rapid and gentle cell purification through the use of bio-competition between pheylboronic acid and carbohydrates. We hypothesized that a combination of PEDOT with the NanoVelcro cell affinity assay (NanoVelcro-PBA Chip) would yield a tool that could minimize contamination from white blood cells and maximize cell viably and molecular intactness. In this study, we benchmarked the efficiency of this platform for purification of CTCs from blood specimens and the feasibility of using this approach for detection of PCa-related RNA signatures from purified CTCs.

Methods: The capture and release efficiency of NanoVelcro-PBA Chip was tested using PCa cell lines (LNCaP, PC3, 22Rv1) and artificial blood samples with PCa cells mixed with healthy donor blood. Variations on operating conditions were tested including the capturing antibodies on the NanoVelcro substrate, incubation time, sorbitol concentration, and bio-competition time. Impact was measured on process efficacy and cell viability. Blood specimens from 17 PCa patients were processed using NanoVelcro-PBA chip. Analysis focused detection of full length AR (AR-FL), AR splicing variant 7 (AR-V7), KLK3 (prostate-specific antigen, PSA), FOLH1 (prostate-specific membrane antigen, PSMA), and long-noncoding RNA SChLAP1 (second chromosome locus associated with prostate-1) using quantitative RT-PCR method.

Results: The combination of NanoVelcro substrate, PEDOT nanomaterial, and capturing antibody exhibits the highest cell capture efficiency (up to 80%). The highest cell release efficiency and viability was achieved by bio-competition with 100 μmol/200μL sorbitol solution for 30 minutes. PCa-related RNA signals were detected in 16/17 CTC(+) PCa patients, and was detected more frequently in patients with metastatic disease and with higher expression level.

Conclusions: We have developed a novel CTC purification platform, NanoVelcro-PBA Chip. This platform is capable of purifying CTCs with high efficiency and while retaining cell viability and molecular integrity. This in turn allows for detection of disease-relevant RNA signals. Further this new tool is being moved into clinical studies that will validate its performance in CTC purification and subsequent RNA detection.

Citation Format: Jie-Fu Chen, Mo-Yuan Shen, Chun-Hao Luo, Shirley Cheng, Sangjun Lee, Shuang Hou, Edwin M. Posadas, Hsian-Rong Tseng, Hsiao-Hua Yu. Bio-competition-based smart NanoVelcro Chip for isolation and gene expression analysis of circulating tumor cells from prostate cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3780. doi:10.1158/1538-7445.AM2017-3780