禽白血病病毒J亚组(ALV-J)诱导骨髓细胞瘤,可以转移到病鸡的多个器官。虽然转移是这种情况下死亡的主要原因,其机制尚不清楚。这里,我们发现ALV-J表面蛋白(SU)和双皮质素样激酶1(DCLK1)之间的相互作用促进上皮-间质转化(EMT)和细胞增殖.我们发现ALV-J可以激活感染细胞中的EMT。随后,蛋白质组学分析显示,DCLK1是一种公认的肿瘤干细胞标志物,在ALV-J感染的DF-1细胞和鸡中高表达,可能是介导EMT的潜在因素。此外,使用免疫荧光和免疫沉淀,我们验证了SU与DCLK1相互作用。功能研究表明,DCLK1的过表达通过加速细胞从G0/G1期到S期的细胞周期进程来增加病毒复制并促进细胞增殖。而在ALV-J感染的细胞中,DCLK1的RNA干扰通过延缓细胞周期从G1期晚期进入S期来减少病毒复制并阻止细胞增殖.此外,我们证明DCLK1的积累增加通过增加N-cadherin的表达促进EMT,波形蛋白,MMP2和转录因子Snail1降低上皮标志物E-cadherin的表达。这些结果表明,ALV-JSU与DCLK1相互作用,并加速细胞增殖,导致病毒复制增加并最终激活EMT,这为肿瘤转移铺平了道路。重要性肿瘤转移是癌症研究的主要挑战,因为其系统性和播散性肿瘤细胞对现有治疗剂的抗性。据估计,来自癌症的>90%的死亡率归因于转移。我们发现ALV-J能激活EMT,在癌症转移中起着至关重要的作用。随后,我们确定了肿瘤干细胞标记物,DCLK1,在ALV-J感染的细胞中,与ALV-J的表面蛋白(SU)相互作用以促进病毒复制,激活EMT,并加速细胞增殖,使ALV-J获得转移能力。了解ALV-J参与EMT的过程和转移途径将有助于阐明病毒诱导肿瘤转移的机制,并有助于确定有希望的分子靶标和ALV-J控制和临床技术发展的关键障碍。
Avian leukosis virus subgroup J (ALV-J) induces myelocytomas, which can metastasize to multiple organs in diseased chickens. Although metastasis is the primary cause of death in such cases, the mechanism for it remains unclear. Here, we found that interaction between ALV-J surface protein (SU) and doublecortin-like kinase 1 (DCLK1) promotes epithelial-mesenchymal transition (EMT) and cell proliferation. We found that ALV-J can activate EMT in infected cells. Subsequently, proteomics analysis revealed that DCLK1, a well-established putative tumor stem cell marker, which is highly expressed in ALV-J-infected DF-1 cells and chickens, might be a potential factor mediating EMT. Furthermore, using immunofluorescence and immunoprecipitation, we verified that SU interacts with DCLK1. Functional studies suggested that overexpression of DCLK1 increased viral replication and promoted cell proliferation by accelerating the progression of cells from the G0/G1 phase to the S phase of cell cycle, whereas RNA interference of DCLK1 reduced viral replication and arrested cell proliferation by retarding cell cycle progression from the late G1 phase into the S phase in ALV-J-infected cells. Moreover, we demonstrate that the increased accumulation of DCLK1 promotes EMT by increasing the expression of N-cadherin, vimentin, MMP2, and transcription factor Snail1 and decreasing the expression of epithelial marker E-cadherin. These results suggest that ALV-J SU interacts with DCLK1, and accelerates cell proliferation, leading to increased viral replication and ultimately activating EMT, which paves the way for tumor metastasis. IMPORTANCE Tumor metastasis is a major challenge in cancer research, because of its systemic nature and the resistance of disseminated tumor cells to existing therapeutic agents. It is estimated that >90% of mortality from cancer is attributable to metastases. We found that ALV-J can activate EMT, which plays a critical role in cancer metastasis. Subsequently, we identified a tumor stem cell marker, DCLK1, in ALV-J infected cells, which interacts with surface protein (SU) of ALV-J to promote virus replication, activate EMT, and accelerate cell proliferation enabling ALV-J to obtain metastatic ability. Understanding the process of participation of ALV-J in EMT and the route of metastasis will help elucidate the mechanism of virus-induced tumor metastasis and help identify promising molecular targets and key obstacles for ALV-J control and clinical technology development.