Capture and selective release of multiple types of circulating tumor cells using smart DNAzyme probes.

Qianying Zhang,Jun-Jie Zhu,Tingting Tan,Wenjing Wang,Sha Yu,Jian-Rong Zhang,Shan Huang

doi:10.1039/c9sc04309h

Abstract

The effective capture, release and reanalysis of circulating tumor cells (CTCs) are of great significance to acquire tumor information and promote the progress of tumor therapy. Particularly, the selective release of multiple types of CTCs is critical to further study; however, it is still a great challenge. To meet this challenge, we designed a smart DNAzyme probe-based platform. By combining multiple targeting aptamers and multiple metal ion responsive DNAzymes, efficient capture and selective release of multiple types CTCs were realized. Sgc8c aptamer integrated Cu2+-dependent DNAzyme and TD05 aptamer integrated Mg2+-dependent DNAzyme can capture CCRF-CEM cells and Ramos cells respectively on the substrate. With the addition of Cu2+ or Mg2+, CCRF-CEM cells or Ramos cells will be released from the substrate with specific selectivity. Furthermore, our platform has been successfully demonstrated in the whole blood sample. Therefore, our capture/release platform will benefit research on the molecular analysis of CTCs after release and has great potential for cancer diagnosis and individualized treatment.

Highlights

Circulating tumor cells (CTCs) are a class of cancer cells present in peripheral blood which cast off from the primary tumor into peripheral blood.[1,2] The detection and isolation of circulating tumor cells (CTCs) are of vital importance for the early diagnosis of cancer, monitoring of therapeutic efficacy and evaluation of treatment.[3,4,5,6] Since the amount of CTCs is extremely exiguous in patients' blood,[7,8,9] there is an imperative demand to capture and enrich CTCs with high efficiency
In order to observe the cells clearly, CCRF-CEM cells were stained with calcein AM for 10 min while Ramos cells were stained with DAPI 15 min a er incubation
A er the successful release of CTCs by metal ions, we explored the viability of released CTCs with live/dead cell staining with calcein AM and propidium iodide (PI)

Summary

Introduction

Circulating tumor cells (CTCs) are a class of cancer cells present in peripheral blood which cast off from the primary tumor into peripheral blood.[1,2] The detection and isolation of CTCs are of vital importance for the early diagnosis of cancer, monitoring of therapeutic efficacy and evaluation of treatment.[3,4,5,6] Since the amount of CTCs is extremely exiguous in patients' blood,[7,8,9] there is an imperative demand to capture and enrich CTCs with high efficiency . Sgc8c aptamer integrated Cu2+-dependent DNAzyme and TD05 aptamer integrated Mg2+-dependent DNAzyme can capture CCRF-CEM cells and Ramos cells respectively on the substrate. With the addition of Cu2+ or Mg2+, CCRF-CEM cells or Ramos cells will be released from the substrate with specific selectivity.

Results

Conclusion