Department of Radiotherapy, Third Affiliated Hospital of Kunming Medical University (Yunnan Cancer Hospital, Yunnan Cancer Center), Kunming, China.
Department of Pathology, Third Affiliated Hospital of Kunming Medical University (Yunnan Cancer Hospital, Yunnan Cancer Center), Kunming, China.
Cancer Med. 2023 Aug;12(15):16386-16404. doi: 10.1002/cam4.6274. Epub 2023 Jul 1.
Breast cancer (BC) seriously threatens women's health. Aspirin plays a key role in the treatment and prognosis of BC.
To explore the effect of low-dose aspirin on BC radiotherapy through the mechanism of exosomes and natural killer (NK) cells.
BC cells were injected into the left chest wall to establish a BC model in nude mice. Tumor morphology and size were observed. Immunohistochemical staining for Ki-67 was used to observe the proliferation of tumor cells. TUNEL was used to detect the apoptosis of cancer cells. Protein levels of exosomal biogenesis- and secretion-related genes (Rab 11, Rab27a, Rab27b, CD63, and Alix) were detected by Western blot. Flow cytometry was used to detect apoptosis. Transwell assays were used to detect cell migration. A clonogenic assay was used to detect cell proliferation. Exosomes of BT549 and 4T1-Luc cells were extracted and observed by electron microscopy. After the coculture of exosomes and NK cells, the activity of NK cells was detected by CCK-8.
The protein expression of genes related to exosomal genesis and secretion (Rab 11, Rab27a, Rab27b, CD63, and Alix) in BT549 and 4T1-Luc cells was upregulated under radiotherapy treatment. Low doses of aspirin inhibited exosome release from BT549 and 4T1-Luc cells and alleviated the inhibitory effect of BC cell exosomes on NK cell proliferation. In addition, knocking down Rab27a reduced the protein levels of exosome-related and secretion-related genes in BC cells, further enhancing the promotive effect of aspirin on NK cell proliferation, while overexpressing Rab27a had the opposite effect. Aspirin was combined at a radiotherapeutic dose of 10 Gy to enhance the radiotherapy sensitivity of radiotherapy-tolerant BC cells (BT549R and 4T1-LucR). Animal experiments have also verified that aspirin can promote the killing effect of radiotherapy on cancer cells and significantly inhibit tumor growth.
Low doses of aspirin can inhibit the release of BC exosomes induced by radiotherapy and weaken their inhibition of NK cell proliferation, promoting radiotherapy resistance.
乳腺癌（BC）严重威胁着女性的健康。阿司匹林在 BC 的治疗和预后中起着关键作用。
通过外泌体和自然杀伤（NK）细胞的机制探讨低剂量阿司匹林对 BC 放疗的影响。
将 BC 细胞注入裸鼠左胸壁建立 BC 模型。观察肿瘤形态和大小。用 Ki-67 免疫组化染色观察肿瘤细胞的增殖。TUNEL 检测癌细胞的凋亡。Western blot 检测外泌体生物发生和分泌相关基因（Rab11、Rab27a、Rab27b、CD63 和 Alix）的蛋白水平。流式细胞术检测细胞凋亡。Transwell 检测细胞迁移。克隆形成实验检测细胞增殖。用电子显微镜观察 BT549 和 4T1-Luc 细胞的外泌体提取和观察。外泌体与 NK 细胞共培养后，通过 CCK-8 检测 NK 细胞的活性。
在放射治疗下，BT549 和 4T1-Luc 细胞中外泌体生成和分泌相关基因（Rab11、Rab27a、Rab27b、CD63 和 Alix）的蛋白表达上调。低剂量阿司匹林抑制 BT549 和 4T1-Luc 细胞外泌体的释放，并减轻 BC 细胞外泌体对 NK 细胞增殖的抑制作用。此外，敲低 Rab27a 降低了 BC 细胞中外泌体相关和分泌相关基因的蛋白水平，进一步增强了阿司匹林对 NK 细胞增殖的促进作用，而过表达 Rab27a 则有相反的效果。将阿司匹林与放射治疗剂量 10 Gy 联合使用，增强了放射治疗耐受的 BC 细胞（BT549R 和 4T1-LucR）的放射治疗敏感性。动物实验也验证了阿司匹林可以促进放射治疗对癌细胞的杀伤作用，显著抑制肿瘤生长。
低剂量阿司匹林可抑制放射治疗诱导的 BC 外泌体释放，减弱其对 NK 细胞增殖的抑制作用，促进放射治疗抵抗。
