Department of Neurosurgery, Philipps University Marburg, Baldingerstr, Marburg, 35033, Germany.
Department of Anesthesiology, Intensive Care, and Pain Medicine, University of Münster, Albert-Schweitzer Campus 1, Münster, 48149, Germany.
Int J Cancer. 2018 Feb 15;142(4):779-791. doi: 10.1002/ijc.31090. Epub 2017 Oct 31.
Metastatic breast cancer affects long-term survival and is a major cause of cancer death for women worldwide. The Metalloprotease-Disintegrin ADAM8 promotes breast cancer development and brain metastasis in a mouse breast cancer model. Here, abundant ADAM8 expression was detected in primary human breast tumors and associated brain metastases. To investigate the function of ADAM8 in metastasis, MB-231 breast cancer cells with ADAM8 knockdown (MB-231_shA8) and scramble control cells (MB-231_shCtrl) were analyzed for their capability to develop metastases. In vitro, formation of metastatic complexes in hanging drops is dependent on ADAM8 and blocked by ADAM8 inhibition. MB-231_shA8 in contrast to MB-231_shCtrl cells were impaired in transmigration through an endothelial and a reconstituted blood-brain barrier. Out of 23 MMP and 22 ADAM genes, only the MMP-9 gene was affected by ADAM8 knockdown in MB-231_shA8 cells. Following re-expression of wild-type ADAM8 in contrast to ADAM8 lacking the cytoplasmic domain in MB-231_shA8 cells caused increased levels of activated pERK1/2 and pCREB (S133) that were associated with elevated MMP-9 transcription. Application of ADAM8 and MMP-9 antibodies reduced transmigration of MB-231 cells suggesting that ADAM8 affects transmigration of breast cancer cells by MMP-9 regulation. ADAM8-dependent transmigration was confirmed in Hs578t cells overexpressing ADAM8. Moreover, transmigration of MB-231 and Hs578t cells was significantly reduced for cells treated with an antibody directed against P-selectin glycoprotein ligand (PSGL-1), a substrate of ADAM8. From these data we conclude that ADAM8 promotes early metastatic processes such as transendothelial migration by upregulation of MMP-9 and shedding of PSGL-1 from breast cancer cells.
转移性乳腺癌影响长期生存，是全球女性癌症死亡的主要原因。金属蛋白酶-解整合素 ADAM8 在小鼠乳腺癌模型中促进乳腺癌的发展和脑转移。在这里，在原发性人乳腺癌肿瘤和相关脑转移中检测到丰富的 ADAM8 表达。为了研究 ADAM8 在转移中的功能，用 ADAM8 敲低（MB-231_shA8）和对照细胞（MB-231_shCtrl）的 MB-231 乳腺癌细胞分析其形成转移的能力。在体外，在悬滴中形成转移性复合物依赖于 ADAM8，并被 ADAM8 抑制阻断。与 MB-231_shCtrl 细胞相比，MB-231_shA8 细胞在穿过内皮和重建血脑屏障方面受到损害。在 23 种 MMP 和 22 种 ADAM 基因中，只有 MMP-9 基因在 MB-231_shA8 细胞中受到 ADAM8 敲低的影响。与 MB-231_shA8 细胞中缺乏细胞质结构域的 ADAM8 相反，野生型 ADAM8 的重新表达导致激活的 pERK1/2 和 pCREB（S133）水平升高，这与 MMP-9 转录水平升高有关。ADAM8 和 MMP-9 抗体的应用减少了 MB-231 细胞的迁移，表明 ADAM8 通过 MMP-9 调节影响乳腺癌细胞的迁移。在过表达 ADAM8 的 Hs578t 细胞中证实了 ADAM8 依赖的迁移。此外，用针对 P-选择素糖蛋白配体（PSGL-1）的抗体处理 MB-231 和 Hs578t 细胞后，细胞的迁移明显减少，PSGL-1 是 ADAM8 的底物。从这些数据中，我们得出结论，ADAM8 通过上调 MMP-9 和从乳腺癌细胞上脱落 PSGL-1，促进早期转移过程，如跨内皮迁移。
