Wan Quanyuan, Zeng Zihua, Qi Jianjun, Zhao Yingxin, Liu Xiaohui, Chen Zhenghu, Zhou Haijun, Zu Youli
Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, TX 77030, USA.
Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA.
Cancers (Basel). 2022 Mar 18;14(6):1570. doi: 10.3390/cancers14061570.
Although targeted cancer therapy can induce higher therapeutic efficacy and cause fewer side effects in patients, the lack of targetable biomarkers on triple-negative breast cancer (TNBC) cells limits the development of targeted therapies by antibody technology. Therefore, we investigated an alternative approach to target TNBC by using the PDGC21T aptamer, which selectively binds to poorly differentiated carcinoma cells and tumor tissues, although the cellular target is still unknown. We found that synthetic aptamer probes specifically bound cultured TNBC cells in vitro and selectively targeted TNBC xenografts in vivo. Subsequently, to identify the target molecule on TNBC cells, we performed aptamer-mediated immunoprecipitation in lysed cell membranes followed by liquid chromatography tandem mass spectrometry (LC-MS/MS). Sequencing analysis revealed a highly conserved peptide sequence consistent with the cell surface protein CD49c (integrin α3). For target validation, we stained cultured TNBC and non-TNBC cells with an aptamer probe or a CD49c antibody and found similar cell staining patterns. Finally, competition cell-binding assays using both aptamer and anti-CD49c antibody revealed that CD49c is the biomarker targeted by the PDGC21T aptamer on TNBC cells. Our findings provide a molecular foundation for the development of targeted TNBC therapy using the PDGC21T aptamer as a targeting ligand.
尽管靶向癌症治疗可以在患者中诱导更高的治疗效果并产生更少的副作用，但三阴性乳腺癌（TNBC）细胞上缺乏可靶向的生物标志物限制了通过抗体技术开发靶向疗法。因此，我们研究了一种使用PDGC21T适体靶向TNBC的替代方法，该适体选择性地结合低分化癌细胞和肿瘤组织，尽管细胞靶点仍然未知。我们发现合成的适体探针在体外特异性结合培养的TNBC细胞，并在体内选择性靶向TNBC异种移植瘤。随后，为了鉴定TNBC细胞上的靶分子，我们在裂解的细胞膜中进行了适体介导的免疫沉淀，然后进行液相色谱串联质谱（LC-MS/MS）分析。测序分析揭示了一个与细胞表面蛋白CD49c（整合素α3）一致的高度保守的肽序列。为了进行靶点验证，我们用适体探针或CD49c抗体对培养的TNBC和非TNBC细胞进行染色，发现了相似的细胞染色模式。最后，使用适体和抗CD49c抗体进行的竞争细胞结合试验表明，CD49c是PDGC21T适体在TNBC细胞上靶向的生物标志物。我们的研究结果为使用PDGC21T适体作为靶向配体开发靶向TNBC治疗提供了分子基础。
