雌激素受体阳性（ER+）乳腺癌占了超过50％的乳腺癌病例，严重威胁着妇女的健康。然而，ER+乳腺癌的检测和靶向治疗仍然面临着挑战。为了针对ER+乳腺癌MCF-7细胞的特异性靶向，我们使用细胞-SELEX和核酸截断策略开发了一种新型核酸适配体S1-4。体外实验结果显示，适配体S1-4与MCF-7细胞结合的亲和离解常数为97.6±7.5 nM。与HER2+的乳腺细胞SK-BR-3和三阴性乳腺癌细胞MDA-MB-231相比，MCF-7细胞能够被适配体S1-4选择性识别和靶向。体内荧光示踪结果还表明，适配体S1-4选择性地靶向了MCF-7肿瘤组织的细胞膜，而不是SK-BR-3或MDB-MA-231移植小鼠上的细胞膜。这种具有高亲和力的选择性开发的新型适配体探针S1-4可以用于ER+乳腺癌的诊断和治疗。版权所有 © 2023 Elsevier B.V. 发布。

The estrogen receptor-positive (ER+) breast cancers constitute more than 50 % of breast cancers, seriously threatening the health of women. Unfortunately, the detection and targeted therapy of ER+ breast cancers remain a challenge. Here, a novel nucleic acid aptamer S1-4 was developed to specifically target ER+ breast cancer MCF-7 cells by using Cell-SELEX and nucleic acid truncation strategies. The affinity dissociation constant of the binding of aptamer S1-4 to MCF-7 cells was 97.6 ± 7.5 nM in vitro. Compared with HER2+ breast cells SK-BR-3 and triple-negative breast cancer cells MDA-MB-231, MCF-7 cells were selectively recognized and targeted by aptamer S1-4. Fluorescence tracing in vivo results also indicated that aptamer S1-4 selectively targeted the cell membrane of tumor tissues in MCF-7- but not in SK-BR3 or MDB-MA-231-bearing mice. This selectively developed novel aptamer probe S1-4 with high affinity could be used for the diagnosis and treatment of ER+ breast cancers.Copyright © 2023. Published by Elsevier B.V.