Hong Xiaoting, Sin Wun Chey, Harris Andrew L, Naus Christian C
Department of Cellular and Physiological Sciences, The Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, V6T1Z3, Canada.
Department of Pharmacology & Physiology, New Jersey Medical School, Rutgers University, Newark, New Jersey, 07103, USA.
Oncotarget. 2015 Jun 20;6(17):15566-77. doi: 10.18632/oncotarget.3904.
The invasiveness of high-grade glioma is the primary reason for poor survival following treatment. Interaction between glioma cells and surrounding astrocytes are crucial to invasion. We investigated the role of gap junction mediated miRNA transfer in this context. By manipulating gap junctions with a gap junction inhibitor, siRNAs, and a dominant negative connexin mutant, we showed that functional glioma-glioma gap junctions suppress glioma invasion while glioma-astrocyte and astrocyte-astrocyte gap junctions promote it in an in vitro transwell invasion assay. After demonstrating that glioma-astrocyte gap junctions are permeable to microRNA, we compared the microRNA profiles of astrocytes before and after co-culture with glioma cells, identifying specific microRNAs as candidates for transfer through gap junctions from glioma cells to astrocytes. Further analysis showed that transfer of miR-5096 from glioma cells to astrocytes is through gap junctions; this transfer is responsible, in part, for the pro-invasive effect. Our results establish a role for glioma-astrocyte gap junction mediated microRNA signaling in modulation of glioma invasive behavior, and that gap junction coupling among astrocytes magnifies the pro-invasive signaling. Our findings reveal the potential for therapeutic interventions based on abolishing alteration of stromal cells by tumor cells via manipulation of microRNA and gap junction channel activity.
高级别胶质瘤的侵袭性是治疗后生存率低的主要原因。胶质瘤细胞与周围星形胶质细胞之间的相互作用对侵袭至关重要。在此背景下，我们研究了间隙连接介导的微小RNA转移的作用。通过用间隙连接抑制剂、小干扰RNA和显性负性连接蛋白突变体来操纵间隙连接，我们发现在体外Transwell侵袭试验中，功能性胶质瘤-胶质瘤间隙连接抑制胶质瘤侵袭，而胶质瘤-星形胶质细胞和星形胶质细胞-星形胶质细胞间隙连接则促进其侵袭。在证明胶质瘤-星形胶质细胞间隙连接对微小RNA具有通透性后，我们比较了与胶质瘤细胞共培养前后星形胶质细胞的微小RNA谱，确定了特定的微小RNA作为通过间隙连接从胶质瘤细胞转移到星形胶质细胞的候选物。进一步分析表明，miR-5096从胶质瘤细胞到星形胶质细胞的转移是通过间隙连接进行的；这种转移部分地导致了促侵袭作用。我们的结果确立了胶质瘤-星形胶质细胞间隙连接介导的微小RNA信号在调节胶质瘤侵袭行为中的作用，并且星形胶质细胞之间的间隙连接耦联放大了促侵袭信号。我们的发现揭示了基于通过操纵微小RNA和间隙连接通道活性来消除肿瘤细胞对基质细胞的改变进行治疗干预的潜力。
