MDA-MB-231细胞在乏氧条件下通过外泌体传递miR-221、miR-222增强乳腺癌细胞侵袭和迁移能力

目的探讨乳腺癌细胞MDA-MB-231在乏氧条件下分泌的外泌体对肿瘤细胞侵袭和迁移的影响。方法利用差速离心法分离外泌体,并通过动态光散射和透射电镜对外泌体的粒径、形态进行表征。通过对外泌体进行PKH26染色,进而观察肿瘤细胞对外泌体的摄取情况。应用qRT-PCR法检测肿瘤细胞及外泌体中miR-221、miR-222的含量。Transwell侵袭实验和细胞划痕实验检测MDA-MB-231细胞的侵袭和迁移能力。Western blot法检测MDA-MB-231细胞中上皮细胞-间质转化(epithelial-mesenchymal transition,EMT)相关蛋白(E-cadherin、N-cadherin和vimentin)的表达。结果MDA-MB-231细胞经乏氧处理后,其侵袭和迁移能力增强,并且N-cadherin和vimentin的表达上调;乏氧处理的肿瘤细胞分泌的外泌体通过传递miR-221、miR-222,促进MDA-MB-231细胞的EMT进展。结论MDA-MB-231细胞在乏氧条件下,可以通过外泌体传递miR-221、miR-222增加癌细胞侵袭和迁移能力。

Exosome secreted by MDA-MB-231 cells deliver miR-221,miR-222 to enhance the invasion and migration of breast cancer cells under hypoxia conditions

Purpose To explore the effect of exosomes secreted by MDA-MB-231 in hypoxic on the invasion and migration of breast cancer cells under hypoxia conditions.Methods Exosomes were isolated by differential centrifugation and characterized by dynamic light scattering(DLS)and transmission electron microscopy(TEM).The exosome uptake of tumor cells was observed by PKH26 staining.The content of miR-221,miR-222 in tumor cells and exosomes was detected by qRT-PCR.Invasion and migration of MDA-MB-231 cells were detected by Transwell invasion and wound healing assay.The expression of EMT-related proteins(E-cadherin,N-cadherin and vimentin)in MDA-MB-231 cells was detected by Western blot.Results After hypoxic treatment,the invasion and migration of MDA-MB-231 cells were enhanced,and the expression of N-cadherin and vimentin was up-regulated.Exosomes secreted by hypoxic tumor cells promoted EMT progression in MDA-MB-231 cells by delivering miR-221,miR-222.Conclusion Under hypoxia conditions,MDA-MB-231 cells can deliver miR-221,miR-222 through exosomes to increase the invasion and migration ability of cancer cells.