Breast cancer is the most common and highly heterogeneous disease in women worldwide. Given the challenges in the treatment of advanced metastatic breast cancer, it is necessary to understand the molecular mechanisms related to disease progression. Exosomes play various roles in the progression of tumors, including promoting the invasion and advancing the distant metastasis. To study the molecular mechanisms related to the progression of luminal androgen receptor (LAR) breast cancer, we first isolated exosomes of MDA-MB-453 cells, a representative cell line of LAR. Through quantitative proteomic analysis, we identified 180 proteins specifically enriched in exosomes after comparing with those in cells, microvesicles, and the 150K supernatant. Among these, CD151, a protein involved in the regulation of cell motility was the most enriched one. CD151-knockdown exosomes reduced the invasion ability of the recipient breast cancer cell and lowered the phosphorylation level of tyrosine-protein kinase Lck, indicating that the invasion of LAR breast cancer may be due to CD151-enriched exosomes. Our work reports for the first time that CD151 was highly abundant in the exosomes of MDA-MB-453 cells and expands the understanding of the development process of LAR subtype, suggesting CD151 may be a potential candidate for the treatment of LAR breast cancer.

乳腺癌是全世界女性中最常见和高度异质性的疾病。鉴于晚期转移性乳腺癌治疗的挑战，有必要了解与疾病进展相关的分子机制。外泌体在肿瘤的进展中发挥着多种作用，包括促进侵袭和促进远处转移。为了研究与管腔雄激素受体 (LAR) 乳腺癌进展相关的分子机制，我们首先分离了 LAR 的代表性细胞系 MDA-MB-453 细胞的外泌体。通过定量蛋白质组学分析，在与细胞、微泡和 150K 上清液中的蛋白质进行比较后，我们确定了 180 种蛋白质在外泌体中特异性富集。其中，CD151，一种参与细胞运动调节的蛋白质是最丰富的。CD151-knockdown外泌体降低了受体乳腺癌细胞的侵袭能力，降低了酪氨酸蛋白激酶Lck的磷酸化水平，表明LAR乳腺癌的侵袭可能是由于富含CD151的外泌体。我们的工作首次报告 CD151 在 MDA-MB-453 细胞的外泌体中高度丰富，并扩展了对 LAR 亚型发展过程的理解，表明 CD151 可能是治疗 LAR 乳腺癌的潜在候选者。