Metastasis of breast cancer cells to distant tissue sites is responsible for the majority of deaths associated with breast cancer. Previously we have examined the role of class I myosin motor protein, myosin 1e (myo1e), in cancer metastasis using the Mouse Mammary Tumor Virus-Polyoma Middle T Antigen (MMTV-PyMT) mouse model. Mice deficient in myo1e formed tumors with a more differentiated phenotype relative to the wild-type mice and formed no detectable lung metastases. In the current study, we investigated how the absence of myo1e affects cell migration and invasion in vitro, using the highly invasive and migratory breast cancer cell line, 4T1. 4T1 cells deficient in myo1e exhibited an altered morphology and slower rates of migration in the wound-healing and transwell migration assays compared to the WT 4T1 cells. While integrin trafficking and Golgi reorientation did not appear to be altered upon myo1e loss, we observed lower rates of focal adhesion disassembly in myo1e-deficient cells, which could help explain the cell migration defect.

中文翻译：

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肌球蛋白1e缺乏影响4T1乳腺癌细胞的迁移

乳腺癌细胞向远处组织部位的转移是大多数与乳腺癌相关的死亡的原因。此前，我们使用小鼠乳腺肿瘤病毒-多瘤中 T 抗原 (MMTV-PyMT) 小鼠模型研究了 I 类肌球蛋白运动蛋白肌球蛋白 1e (myo1e) 在癌症转移中的作用。与野生型小鼠相比，myo1e 缺陷的小鼠形成的肿瘤具有更加分化的表型，并且没有形成可检测到的肺转移。在当前的研究中，我们使用高度侵袭性和迁移性乳腺癌细胞系 4T1，研究了 myo1e 的缺失如何影响体外细胞迁移和侵袭。与 WT 4T1 细胞相比，缺乏 myo1e 的 4T1 细胞在伤口愈合和 Transwell 迁移测定中表现出形态改变和迁移速率减慢。虽然整合素运输和高尔基体重新定向似乎没有因 myo1e 损失而改变，但我们观察到 myo1e 缺陷细胞中粘着斑分解率较低，这可能有助于解释细胞迁移缺陷。