Biochemistry and Tumor Biology Lab, Department of Obstetrics and Gynecology, Hannover Medical School, Hannover, Germany.
Stem Cells. 2018 Jul;36(7):977-989. doi: 10.1002/stem.2819. Epub 2018 Mar 28.
Formation of hybrid cells by "accidental cell fusion" of normal and neoplastic breast epithelial cells with local tissue-associated mesenchymal stroma/stem-like cells (MSC) in an inflammatory microenvironment can generate new cancer cell populations whereby molecular signaling mechanisms of this process remain unclear. Fusions of lentiviral enhanced green fluorescent protein-labeled MSC with mcherry-labeled breast epithelial cells were quantified and effects of tumor necrosis factor alpha (TNF-α) and receptor downstream signaling were investigated. Cocultures of MSC with normal human mammary epithelial cells, with neoplastic MCF10A, or with MDA-MB-231 or MCF7 breast cancer cells demonstrated hybrid cell formation between 0.1% and about 2% of the populations within 72 hours, whereby the fusion process occurred in less than 5 minutes. Addition of the pro-inflammatory cytokine TNF-α significantly enhanced MCF10A-MSC cell fusion. Small-interfering RNA (siRNA) knockdown experiments revealed an involvement of tumor necrosis factor (TNF) receptor-1 and -2 in this process. This was also substantiated by siRNA knockdown of tumor necrosis factor receptor type 1-associated death domain which abolished TNF-α-stimulated fusion. While TNF receptor signaling can be relayed via the Mitogen-activated protein kinase 8 (MAPK8), NF-κB or cell death pathways, examination of further downstream signaling exhibited little if any effects of MAPK8 or RelA (p65) on TNF-α-mediated cell fusion, respectively. These data suggested that cell fusion between MSC and MCF10A breast epithelial cells can be stimulated by TNF-α involving TNF receptor-activated cell death pathways or additional NF-κB signaling. Stem Cells 2018;36:977-989.
在炎症微环境中，正常和肿瘤乳腺上皮细胞与局部组织相关的间充质基质/干细胞样细胞（MSC）通过“偶然细胞融合”形成杂交细胞，可以产生新的癌细胞群体，而这一过程的分子信号机制尚不清楚。我们对慢病毒增强型绿色荧光蛋白标记的 MSC 与 mcherry 标记的乳腺上皮细胞融合进行了定量，并研究了肿瘤坏死因子 α（TNF-α）和受体下游信号的影响。MSC 与正常的人乳腺上皮细胞、肿瘤 MCF10A 细胞以及 MDA-MB-231 或 MCF7 乳腺癌细胞的共培养显示，在 72 小时内，杂交细胞形成在 0.1%至约 2%的细胞群体中，融合过程发生在不到 5 分钟内。添加促炎细胞因子 TNF-α显著增强了 MCF10A-MSC 细胞融合。小干扰 RNA（siRNA）敲低实验表明肿瘤坏死因子（TNF）受体-1 和 -2 参与了这一过程。这也得到了肿瘤坏死因子受体 1 相关死亡域 siRNA 敲低的证实，该敲低消除了 TNF-α 刺激的融合。虽然 TNF 受体信号可以通过丝裂原活化蛋白激酶 8（MAPK8）、NF-κB 或细胞死亡途径进行传递，但进一步的下游信号转导研究表明，MAPK8 或 RelA（p65）对 TNF-α介导的细胞融合几乎没有影响。这些数据表明，MSC 和 MCF10A 乳腺上皮细胞之间的细胞融合可以被 TNF-α刺激，涉及 TNF 受体激活的细胞死亡途径或其他 NF-κB 信号。《干细胞》2018；36:977-989。
