Cell Commun Signal. 2014 Oct 14;12:64. doi: 10.1186/s12964-014-0064-8.
Human cells release nano-sized vesicles called exosomes, containing mRNA, miRNA and specific proteins. Exosomes from one cell can be taken up by another cell, which is a recently discovered cell-to-cell communication mechanism. Also, exosomes can be taken up by different types of cancer cells, but the potential functional effects of mast cell exosomes on tumor cells remain unknown.
Exosomes were isolated from the human mast cell line, HMC-1, and uptake of PKH67-labelled exosomes by the lung epithelial cell line, A549, was examined using flow cytometry and fluorescence microscopy. The RNA cargo of the exosomes was analyzed with a Bioanalyzer and absence or presence of the c-KIT mRNA was determined by RT-PCR. The cell proliferation was determined in a BrdU incorporation assay, and proteins in the KIT-SCF signaling pathway were detected by Western blot. Our result demonstrates that exosomes from mast cells can be taken up by lung cancer cells. Furthermore, HMC-1 exosomes contain and transfer KIT protein, but not the c-KIT mRNA to A549 cells and subsequently activate KIT-SCF signal transduction, which increase cyclin D1 expression and accelerate the proliferation in the human lung adenocarcinoma cells.
Our results indicate that exosomes can transfer KIT as a protein to tumor cells, which can affect recipient cell signaling events through receptor-ligand interactions.
人类细胞会释放一种称为外泌体的纳米级囊泡，其中包含 mRNA、miRNA 和特定蛋白质。一个细胞的外泌体可以被另一个细胞摄取，这是一种最近发现的细胞间通讯机制。此外，外泌体可以被不同类型的癌细胞摄取，但肥大细胞外泌体对肿瘤细胞的潜在功能影响尚不清楚。
从人肥大细胞瘤系 HMC-1 中分离出外泌体，并使用流式细胞术和荧光显微镜检查 PKH67 标记的外泌体被肺上皮细胞系 A549 摄取的情况。使用 Bioanalyzer 分析外泌体的 RNA 货物，并通过 RT-PCR 确定 c-KIT mRNA 的存在或不存在。通过 BrdU 掺入测定法测定细胞增殖，通过 Western blot 检测 KIT-SCF 信号通路中的蛋白质。我们的结果表明，肥大细胞的外泌体可以被肺癌细胞摄取。此外，HMC-1 外泌体含有并向 A549 细胞转移 KIT 蛋白，但不转移 c-KIT mRNA，随后激活 KIT-SCF 信号转导，增加 cyclin D1 的表达并加速人肺腺癌细胞的增殖。
我们的结果表明，外泌体可以将 KIT 作为一种蛋白质转移到肿瘤细胞中，通过受体-配体相互作用影响受体细胞的信号事件。
