Li Jing, Wu Dong-Ming, Han Rong, Yu Ye, Deng Shi-Hua, Liu Teng, Zhang Ting, Xu Ying
Clinical Laboratory, The First Affiliated Hospital, Collaborative Innovation Center of Sichuan for Elderly Care and Health of Chengdu Medical College, Chengdu, Sichuan 610041, People's Republic of China.
Onco Targets Ther. 2020 Apr 29;13:3619-3629. doi: 10.2147/OTT.S243914. eCollection 2020.
Radiation has well-known and well-characterized direct toxic effects on cells and tissues. However, low-dose ionizing irradiation (LDIR) can also enhance the invasion and migration of tumor cells, and the mechanisms underlying these effects remain unclear. The present study aimed to investigate changes induced in the migration and invasion of A549 cells after LDIR and to explore the potential molecular mechanism.
A549 cells were irradiated with X-rays at different doses (0, 2, 4, and 6 Gy) and cultured for 24 or 48 h. Apoptosis and proliferation were evaluated by lactate dehydrogenase release, CCK8, colony formation, and flow cytometry assays. Wound-healing and transwell assays were performed to detect migration and invasion ability. CXCL1 or p65 were knocked down using lentivirus-mediated siRNA in A549 cell lines. Knockdown efficiency of CXCL1 and p65 was assessed by RT-qPCR. Western blotting and immunofluorescence were used to determine the changes in protein levels.
In cells irradiated with a dose of 6 Gy, after 48 h, apoptosis was clearly induced while proliferation was inhibited. Irradiation with 4 Gy resulted in the upregulation of CXCL1 expression and activation of the NF-κB signaling pathway. Moreover, upon 4 Gy irradiation, migration, invasion, and epithelial-mesenchymal transition (EMT) were significantly enhanced in A549 cells. Importantly, CXCL1 or p65 knockdown inhibited radiation-induced migration, invasion, and EMT.
Low-dose radiation upregulates CXCL1 expression and activates the NF-κB signaling to regulate EMT in A549 cells, thereby promoting invasion and migration. These results provide new insights into the prevention of tumor invasion and metastasis induced by radiotherapy.
辐射对细胞和组织具有众所周知且特征明确的直接毒性作用。然而，低剂量电离辐射（LDIR）也可增强肿瘤细胞的侵袭和迁移能力，其作用机制尚不清楚。本研究旨在探讨LDIR后A549细胞迁移和侵袭的变化，并探索潜在的分子机制。
用不同剂量（0、2、4和6 Gy）的X射线照射A549细胞，并培养24或48小时。通过乳酸脱氢酶释放、CCK8、集落形成和流式细胞术检测评估细胞凋亡和增殖。进行划痕实验和Transwell实验以检测迁移和侵袭能力。在A549细胞系中使用慢病毒介导的siRNA敲低CXCL1或p65。通过RT-qPCR评估CXCL1和p65的敲低效率。采用蛋白质免疫印迹法和免疫荧光法测定蛋白水平的变化。
在接受6 Gy剂量照射的细胞中，48小时后明显诱导了细胞凋亡，同时抑制了细胞增殖。4 Gy照射导致CXCL1表达上调和NF-κB信号通路激活。此外，4 Gy照射后，A549细胞的迁移、侵袭和上皮-间质转化（EMT）显著增强。重要的是，敲低CXCL1或p65可抑制辐射诱导的迁移、侵袭和EMT。
低剂量辐射上调A549细胞中CXCL1的表达并激活NF-κB信号通路以调节EMT，从而促进侵袭和迁移。这些结果为预防放疗诱导的肿瘤侵袭和转移提供了新的见解。
