mir-193a and MVP in colon cancer metastasis

Proposed model for the mechanism of colon cancer metastasis to the liver involves exporting miR-193a via exosomes sorted by major vault protein (MVP). In pre-metastatic cells miR-193a suppresses mouse colon cancer progression by directly targeting Caprin1, which is known to positively regulate the cell cycle and cell proliferation. Higher levels of miR-193a in tumor cells causes of cell cycle G1 arrest and cell proliferation repression through reduction of Caprin1 expression. In metatstatic cells, increased levels of MVP leads to MVP-mediated selective sorting of tumor suppressor miRNA into exosomes, which promotes tumor progression.

所提出的模型针对结肠癌肝转移机制，涉及通过主要隔室蛋白（MVP）分选的细胞外囊泡（exosomes）输出miR-193a。在转移前细胞中，miR-193a通过直接靶向Caprin1（已知其正调控细胞周期和细胞增殖）来抑制小鼠结肠癌的进展。肿瘤细胞中miR-193a水平的升高，通过降低Caprin1的表达，导致细胞周期G1期阻滞和细胞增殖抑制。在转移细胞中，MVP水平的增加导致MVP介导的肿瘤抑制性miRNA的选择性分选入细胞外囊泡，从而促进肿瘤的进展。