Design and Development of Aptamer Targeting C-type Lectin-like Molecule-1 as a Biomarker for Acute Myeloid Leukemia: a SELEX Approach

Yiwen ChenQinhang LiShifeng LouHanqing ZengShu Chen^*

• Second Affiliated Hospital, Chongqing Medical University, Chongqing, China

Acute myeloid leukemia (AML) is an important public health issue as a hematologic malignancy. It is a resultant of abnormal proliferation of immatured myeloid cells. Despite the advancements of diagnostic procedures applied, the early identification of AML remains as a significant clinical challenge marking a distinctive niche for newer theranostic approaches to ameliorate diagnosis and treatment. Aptamers are single-stranded oligonucleotides capable of specific binding with high target affinity that have emerged as one of the promising candidates for molecular recognition in diagnostics and targeted therapy. In this study we aimed to select and characterize a high-affinity aptamer for C-type lectin-like molecule-1 (CLL-1), an important cell surface marker for AML. CLL-1-specific aptamers were enriched in the context of iterative positive and negative rounds of selections in a systematic SELEX approach. In the following, flow cytometry assessment demonstrated progression of enrichment and then, confirmed their performance. The high-throughput sequencing supported the enrichment of 5 candidate aptamers among others. Besides, flow cytometry and specificity assays determined that aptamer-2 specifically bound to CLL-1 with an exceedingly high degree of specificity (94.3%) compared with negative controls and other aptamers. The Surface Plasmon Resonance (SPR) valuation revealed that aptamer-2 has a Kd (1.55 × 10⁻⁸ M), which indicates a high affinity of binding to CLL-1. In the following, Docking analysis reveals a stable and specific interaction between aptamer-2 and CLL-1, highlighting key binding regions and molecular contacts that may underpin targeted recognition. Taken together, the results put forward aptamer-2 as a candidate for highly specific and high affinity candidate for targeting CLL-1. This study opens the prospect of using this aptamer for diagnostic approaches for AML. Further in vivo and translational studies on its efficacy and efficiency are needed to elucidate its performance in real-world scenarios.