Application of the anti-HER2 drug trastuzumab has significantly improved the prognosis of patients with the HER2-positive subtype of breast cancer. However, 50% of patients with HER2 amplification relapse due to trastuzumab resistance. Accumulating evidence indicates that breast cancer is driven by a small subset of cancer-initiating cells or breast cancer stem cells (BCSCs), which have the capacity to self-renew and differentiate to regenerate the tumor cell hierarchy. Increasing data suggest that BCSCs are resistant to conventional therapy, including chemotherapy, radiotherapy, and endocrine therapy, which drives distant metastasis and breast cancer relapse. In recent years, the trastuzumab resistance of breast cancer has been closely related to the prevalence of BCSCs. Here, our primary focus is to discuss the role of epithelial-mesenchymal transition (EMT) of BCSCs in the setting of trastuzumab resistance and approaches of reducing or eradicating BCSCs in HER2-positive breast cancer.

中文翻译：

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癌症干细胞靶向治疗方法克服 HER2 阳性乳腺癌的曲妥珠单抗耐药性

抗HER2药物曲妥珠单抗的应用显着改善了HER2阳性亚型乳腺癌患者的预后。然而，50% 的HER2患者曲妥珠单抗耐药导致的扩增复发。越来越多的证据表明，乳腺癌是由一小部分癌症起始细胞或乳腺癌干细胞 (BCSC) 驱动的，这些细胞具有自我更新和分化以再生肿瘤细胞层次的能力。越来越多的数据表明，BCSCs 对常规疗法（包括化学疗法、放射疗法和内分泌疗法）具有抗性，这会导致远处转移和乳腺癌复发。近年来，乳腺癌的曲妥珠单抗耐药与BCSCs的患病率密切相关。在这里，我们的主要焦点是讨论 BCSCs 的上皮间质转化 (EMT) 在曲妥珠单抗耐药中的作用以及在 HER2 阳性乳腺癌中减少或根除 BCSCs 的方法。