Burtey Anne, Wagner Marek, Hodneland Erlend, Skaftnesmo Kai Ove, Schoelermann Julia, Mondragon Ivan Rios, Espedal Heidi, Golebiewska Anna, Niclou Simone P, Bjerkvig Rolf, Kögel Tanja, Gerdes Hans-Hermann
*Department of Biomedicine, Biomaterials, Department of Clinical Dentistry, and K. G. Jebsen Brain Tumour Research Center, University of Bergen, Bergen, Norway; Department of Pathology and Department of Clinical Medicine, Haukeland University Hospital, Bergen, Norway; and NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health (LIH), Luxembourg, Luxembourg
*Department of Biomedicine, Biomaterials, Department of Clinical Dentistry, and K. G. Jebsen Brain Tumour Research Center, University of Bergen, Bergen, Norway; Department of Pathology and Department of Clinical Medicine, Haukeland University Hospital, Bergen, Norway; and NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health (LIH), Luxembourg, Luxembourg.
FASEB J. 2015 Nov;29(11):4695-712. doi: 10.1096/fj.14-268615. Epub 2015 Jul 28.
Intercellular communication between cancer cells, especially between cancer and stromal cells, plays an important role in disease progression. We examined the intercellular transfer of organelles and proteins in vitro and in vivo and the role of tunneling nanotubes (TNTs) in this process. TNTs are membrane bridges that facilitate intercellular transfer of organelles of unclear origin. Using 3-dimensional quantitative and qualitative confocal microscopy, we showed that TNTs contain green fluorescent protein (GFP)-early endosome antigen (EEA) 1, GFP Rab5, GFP Rab11, GFP Rab8, transferrin (Tf), and Tf receptor (Tf-R) fused to mCherry (Tf-RmCherry). Tf-RmCherry was transferred between cancer cells by a contact-dependent but secretion-independent mechanism. Live cell imaging showed TNT formation preceding the transfer of Tf-RmCherry and involving the function of the small guanosine triphosphatase (GTPase) Rab8, which colocalized with Tf-RmCherry in the TNTs and was cotransferred to acceptor cells. Tf-RmCherry was transferred from cancer cells to fibroblasts, a noteworthy finding that suggests that this process occurs between tumor and stromal cells in vivo. We strengthened this hypothesis in a xenograft model of breast cancer using enhanced (e)GFP-expressing mice. Tf-RmCherry transferred from tumor to stromal cells and this process correlated with an increased opposite transfer of eGFP from stromal to tumor cells, together pointing toward complex intercellular communication at the tumor site.
癌细胞之间的细胞间通讯，尤其是癌症细胞与基质细胞之间的通讯，在疾病进展中起着重要作用。我们在体外和体内研究了细胞器和蛋白质的细胞间转移以及隧道纳米管（TNTs）在此过程中的作用。TNTs是促进来源不明的细胞器进行细胞间转移的膜桥。使用三维定量和定性共聚焦显微镜，我们发现TNTs含有绿色荧光蛋白（GFP）-早期内体抗原（EEA）1、GFP Rab5、GFP Rab11、GFP Rab8、转铁蛋白（Tf）以及与mCherry融合的转铁蛋白受体（Tf-R）（Tf-RmCherry）。Tf-RmCherry通过一种依赖接触但不依赖分泌的机制在癌细胞之间转移。活细胞成像显示，Tf-RmCherry转移之前会形成TNT，这涉及小GTP酶（GTPase）Rab8的功能，Rab8与Tf-RmCherry在TNTs中共定位，并共同转移到受体细胞。Tf-RmCherry从癌细胞转移到成纤维细胞，这一值得注意的发现表明该过程在体内肿瘤细胞与基质细胞之间发生。我们使用表达增强型（e）GFP的小鼠在乳腺癌异种移植模型中强化了这一假设。Tf-RmCherry从肿瘤细胞转移到基质细胞，这一过程与eGFP从基质细胞到肿瘤细胞的反向转移增加相关，共同指向肿瘤部位复杂的细胞间通讯。
