Chemotherapy is an effective treatment for invasive breast cancer. Paradoxically, many recently published findings showed that the first-line chemotherapeutic agent paclitaxel (PTX) showed pro-metastatic effects in the progress of treating breast cancer. Xiao-Ai-Ping (XAP) injection, composed of a traditional herbal medicine, Marsdenia tenacissimae extract, is known to exert antitumor effects on various cancers. However, there are few experimental studies on breast cancer. The underlying mechanism of the antitumor effect of XAP combined with chemotherapy agents has not been fully understood. In the present study, we sought to find the antitumor effects of XAP combined with PTX in vitro and in vivo. The data demonstrated that the combination of XAP with PTX resulted in remarkable enhancement of the pro-apoptotic, migration-inhibiting, and anti-invasive effects of PTX in vitro. Significantly, further study showed the overexpression of ATF3 in PTX-treated cell, while XAP counteracted the change of ATF3 induced by PTX. Moreover, it showed that combination treatment could promote the inhibition of tumor growth in MDA-MB-231 cell xenograft mouse model. Compared with PTX treatment, the downregulation of ATF3 indicated that ATF3 played a pivotal role in the combination of XAP with PTX to exert a synergistic effect. Overall, it is expected that PTX combined with XAP may serve as an effective agent for antitumor treatment, and dampening ATF3 maybe a potential strategy to improve the efficacy of PTX.

中文翻译：

---

小爱平注射液通过激活转录因子3增强紫杉醇抑制乳腺癌的增殖和转移的作用。

化学疗法是浸润性乳腺癌的有效治疗方法。矛盾的是，最近发表的许多发现表明，一线化疗剂紫杉醇（PTX）在治疗乳腺癌的过程中显示出促转移作用。小艾平（XAP）注射剂由传统草药Marsdenia tenacissimae提取物组成，已知对多种癌症具有抗肿瘤作用。但是，关于乳腺癌的实验研究很少。XAP联合化疗药物抗肿瘤作用的潜在机制尚未完全了解。在本研究中，我们试图发现XAP与PTX联合在体内外的抗肿瘤作用。数据表明，XAP与PTX的组合可显着增强促凋亡，抑制迁移，和PTX的体外抗侵袭作用。值得注意的是，进一步的研究表明，PTX处理的​​细胞中ATF3过表达，而XAP抵消了PTX诱导的ATF3的变化。而且，表明联合治疗可以促进对MDA-MB-231细胞异种移植小鼠模型中肿瘤生长的抑制。与PTX治疗相比，ATF3的下调表明ATF3在XAP与PTX联合应用中起关键作用。总体而言，预计PTX与XAP结合可作为抗肿瘤治疗的有效药物，而抑制ATF3可能是提高PTX疗效的潜在策略。结果表明，联合治疗可促进对MDA-MB-231细胞异种移植小鼠模型肿瘤生长的抑制。与PTX治疗相比，ATF3的下调表明ATF3在XAP与PTX联合使用中起关键作用。总体而言，预计PTX与XAP结合可作为抗肿瘤治疗的有效药物，而抑制ATF3可能是提高PTX疗效的潜在策略。结果表明，联合治疗可促进对MDA-MB-231细胞异种移植小鼠模型肿瘤生长的抑制。与PTX治疗相比，ATF3的下调表明ATF3在XAP与PTX联合使用中起关键作用。总体而言，预计PTX与XAP结合可作为抗肿瘤治疗的有效药物，而抑制ATF3可能是提高PTX疗效的潜在策略。