Abstract：
OBJECTIVE: The absence of melanoma 2 (AIM2) protein triggers the activation of the inflammasome cascade. It is unclear whether AIM2 plays a role in hepatocellular carcinoma (HCC) and radiofrequency ablation (RFA), which uses radiofrequency waves to treat tumors. In this study, we investigated if RFA could induce pyroptosis, also called cell inflammatory necrosis, in HCC through AIM2-inflammasome signaling in vivo and in vitro.
METHODS: BALB/c nude mice were used to generate HepG2 or SMMC-7721 cell-derived tumor xenografts. HCC cells with knockdown or overexpression of AIM2 were created using short hairpin RNA (shRNA) and expression vector transfection, respectively, for functional and mechanistic studies. Downstream effects were examined using flow cytometry, qRT-PCR, ELISAs, and other molecular assays.
RESULTS: RFA significantly suppressed tumor growth in HCC cell xenografts. Flow cytometry analysis revealed that RFA could induce pyroptosis. Furthermore, AIM2, NLRP3, caspase-1, γ-H2AX, and DNA-PKc had significantly greater expression levels in liver tissues from mice treated with RFA compared with those of the controls. Additionally, interleukin (IL)-1β and IL-18 expression levels were significantly higher in the HCC cell-derived xenograft mice treated with RFA compared with those without RFA. Notably, a significantly greater effect was achieved in the RFA complete ablation group versus the partial ablation group. Knockdown or overexpression of AIM2 in HCC cells demonstrated that AIM2 exerted a role in RFA-induced pyroptosis.
CONCLUSIONS: RFA can suppress HCC tumor growth by inducing pyroptosis via AIM2. Therefore, therapeutically intervening with AIM2-mediated inflammasome signaling may help improve RFA treatment outcomes for HCC patients.
METHODS: BALB/c nude mice were used to generate HepG2 or SMMC-7721 cell-derived tumor xenografts. HCC cells with knockdown or overexpression of AIM2 were created using short hairpin RNA (shRNA) and expression vector transfection, respectively, for functional and mechanistic studies. Downstream effects were examined using flow cytometry, qRT-PCR, ELISAs, and other molecular assays.
RESULTS: RFA significantly suppressed tumor growth in HCC cell xenografts. Flow cytometry analysis revealed that RFA could induce pyroptosis. Furthermore, AIM2, NLRP3, caspase-1, γ-H2AX, and DNA-PKc had significantly greater expression levels in liver tissues from mice treated with RFA compared with those of the controls. Additionally, interleukin (IL)-1β and IL-18 expression levels were significantly higher in the HCC cell-derived xenograft mice treated with RFA compared with those without RFA. Notably, a significantly greater effect was achieved in the RFA complete ablation group versus the partial ablation group. Knockdown or overexpression of AIM2 in HCC cells demonstrated that AIM2 exerted a role in RFA-induced pyroptosis.
CONCLUSIONS: RFA can suppress HCC tumor growth by inducing pyroptosis via AIM2. Therefore, therapeutically intervening with AIM2-mediated inflammasome signaling may help improve RFA treatment outcomes for HCC patients.
摘要：
目的：黑色素瘤2（AIM2）蛋白的缺失会触发炎症小体级联的激活。目前尚不清楚AIM2是否在肝细胞癌（HCC）和射频消融（RFA）中发挥作用，使用射频波来治疗肿瘤。在这项研究中,我们调查了RFA是否可以诱导焦亡，也称为细胞炎性坏死，在肝癌中通过AIM2-炎症小体信号在体内和体外。
方法:BALB/c裸鼠用于产生HepG2或SMMC-7721细胞来源的肿瘤异种移植物。用短发夹RNA(shRNA)和表达载体转染,分别,用于功能和机械研究。使用流式细胞术检查下游效应，qRT-PCR,ELISAs,和其他分子检测。
结果：RFA显著抑制肝癌细胞移植瘤的生长。流式细胞术分析显示RFA可诱导焦亡。此外，AIM2,NLRP3,caspase-1,γ-H2AX,与对照组相比，RFA处理的小鼠肝组织中DNA-PKc的表达水平明显更高。此外,白细胞介素（IL）-1β和IL-18的表达水平在肝癌细胞来源的异种移植小鼠中明显高于那些没有RFA治疗。值得注意的是,RFA完全消融组的疗效明显高于部分消融组.HCC细胞中AIM2的敲低或过表达表明AIM2在RFA诱导的焦亡中起作用。
结论：RFA可以通过AIM2诱导细胞凋亡来抑制HCC肿瘤的生长。因此,对AIM2介导的炎症小体信号进行治疗干预可能有助于改善HCC患者的RFA治疗结果。
方法:BALB/c裸鼠用于产生HepG2或SMMC-7721细胞来源的肿瘤异种移植物。用短发夹RNA(shRNA)和表达载体转染,分别,用于功能和机械研究。使用流式细胞术检查下游效应，qRT-PCR,ELISAs,和其他分子检测。
结果：RFA显著抑制肝癌细胞移植瘤的生长。流式细胞术分析显示RFA可诱导焦亡。此外，AIM2,NLRP3,caspase-1,γ-H2AX,与对照组相比，RFA处理的小鼠肝组织中DNA-PKc的表达水平明显更高。此外,白细胞介素（IL）-1β和IL-18的表达水平在肝癌细胞来源的异种移植小鼠中明显高于那些没有RFA治疗。值得注意的是,RFA完全消融组的疗效明显高于部分消融组.HCC细胞中AIM2的敲低或过表达表明AIM2在RFA诱导的焦亡中起作用。
结论：RFA可以通过AIM2诱导细胞凋亡来抑制HCC肿瘤的生长。因此,对AIM2介导的炎症小体信号进行治疗干预可能有助于改善HCC患者的RFA治疗结果。
