DNA Aptamer Selected against Esophageal Squamous Cell Carcinoma for Tissue Imaging and Targeted Therapy with Integrin β1 as a Molecular Target

Abstract

Esophageal cancer, especially esophageal squamous cell carcinoma (ESCC), poses a serious threat to human health. It is urgently needed to develop recognition tools and discover molecular targets for early diagnosis and targeted therapy of esophageal cancer. Here, we developed several DNA aptamers that can bind to ESCC KYSE410 cells with a nanomolar range of dissociation constants by using cell-based systematic evolution of ligands by exponential enrichment (cell-SELEX). The selected A2 aptamer is found to strongly bind with multiple cancer cells, including several ESCC cell lines. Tissue imaging displayed that the A2 aptamer can specifically recognize clinical ESCC tissues but not the adjacent tissues. Moreover, we identified integrin β1 as the binding target of A2 through pulldown and RNA interference assays. Meanwhile, molecular docking and mutation assays suggested that A2 probably binds to integrin β1 through the nucleotides of DA16-DG21, and competitive binding and structural alignment assays indicated that A2 shares the overlapped binding sites with laminin and arginine−glycine−aspartate ligands. Furthermore, we engineered A2-induced targeted therapy for ESCC. By constructing A2-tethered DNA nanoassemblies carrying multiple doxorubicin (Dox) molecules as antitumor agents, inhibition of tumor cell growth in vitro and in vivo was achieved. This work provides a useful targeting tool and a potential molecular target for cancer diagnosis and targeted therapy and is helpful for understanding the integrin mechanism and developing integrin inhibitors.

Circulating Tumor Cells Adhesion: Application in Biosensors

“…These approaches enable specific interactions, are easily developed and modified, detect a variety of targets, and exhibit stability, biocompatibility, and reusability [ 129 , 133 , 134 ]. Aptamers have been extensively studied for CTC detection and the identification of new cancer biomarkers [ 63 , 135 , 136 , 137 , 138 ]. Moreover, these recognition ligands can amplify the sensor response signal, further enhancing their utility [ 52 , 60 , 61 , 117 , 129 ].…”

“…Due to its large variety of isoforms, this glycoprotein plays different roles in cell behavior, being involved in different cell functions such as cell adhesion, sensing, and signaling [ 59 ]. Despite its presence on non-tumor cells, CD44 is commonly explored as a cancer-related biomarker since it is overexpressed on the cell surfaces of major cancers, such as pancreatic [ 60 ], breast [ 61 ], prostate [ 52 ], lung [ 62 ], and gastric cancer [ 63 ].…”

The characteristics and the multiple functions of integrin β1 in human cancers

“…2 , which indicates the applicability of integrin β1 as a therapeutic target and underlines the requirement for patient stratification in future clinical studies. For example, in esophageal cancer, high expression of integrin β1 is related to worse overall survival, and targeting integrin β1 alleviates tumor metastasis and chemotherapy resistance of patients [ 89 , 90 ]. Combined inhibition of the integrin β1 and the stress-mediator JNK induces radiosensitization, which is caused by defective DNA repair associated with chromatin changes, enhanced ataxia-telangiectasia mutated phosphorylation and prolonged G2/M cell cycle arrest in glioblastoma [ 91 ].…”

Molecular Targets of Aptamers in Gastrointestinal Cancers: Cancer Detection, Therapeutic Applications, and Associated Mechanisms

“…The ectopic expression of P42 aptamers significantly reduced about 86% of the tumor mass weight and inhibited the metastasis of ESCC cells in zebrafishes 55 . A more recent study by Zhang et al 56 developed a few aptamers to detect ESCC-positive cells with cell-SELEX technology. The most successful aptamer to detect the ESCC-positive cells was an aptamer labelled A2.…”