Background/Objectives:There is increasing evidence to indicate that histotripsy treatment can enhance the host anti-tumor immune responses both locally at the targeting tumor site as well as systemically from abscopal effects. Histotripsy is a non-invasive ultrasound ablation technology that mechanically disrupts target tissue via cavitation. A key factor contributing to histotripsy-induced abscopal effects is believed to be the release of tumor-specific antigens (TSAs) or tumor-associated antigens (TAAs) that induce a systemic immune response. In this study, we studied the effect of histotripsy treatment on the release of HER2, a well-defined TAA target for cancer immunotherapy.Methods:A range of doses of histotripsy administered to HER2-postive mammary tumor cells in an in vitro cell culture system and an ex vivo tumor were applied. In addition, a single dose of histotripsy was used for an in vivo murine tumor model. The released proteins, and specifically HER2, in both tumor cell-free supernatants and tumor cell pellets were analyzed by a BCA protein assay, an ultra-performance liquid chromatography (UPLC) assay, and Western blot.Results:Our results showed that histotripsy could significantly trigger the release of HER2 proteins in the current study. The level of HER2 proteins was actually higher in tumor cell-free supernatants than in tumor cell pellets, suggesting that HER2 was released from the intracellular domain into the extracellular compartment. Furthermore, proportionally more HER2 protein was released at higher histotripsy doses, indicating free HER2 was histotripsy-dose-dependent.Conclusions:In conclusion, we have qualitatively and quantitatively demonstrated that histotripsy treatment triggers the release of HER2 from the tumor cells into the extracellular compartment. The histotripsy-mediated release of HER2 antigens provides important insights into the mechanism underlying its immunostimulation and suggests the potential of TSA/TAA-based immunotherapies in numerous cancer types.
背景/目的：越来越多的证据表明，组织粉碎治疗能够增强宿主抗肿瘤免疫反应，这种增强既发生在靶向肿瘤的局部区域，也通过远隔效应在全身范围内实现。组织粉碎是一种非侵入性超声消融技术，通过空化效应机械性破坏目标组织。引发组织粉碎远隔效应的关键因素被认为是肿瘤特异性抗原（TSA）或肿瘤相关抗原（TAA）的释放，这些抗原能够诱导全身性免疫反应。本研究探讨了组织粉碎治疗对HER2释放的影响，HER2是癌症免疫治疗中一个明确的TAA靶点。 方法：研究在体外细胞培养系统和离体肿瘤中对HER2阳性乳腺肿瘤细胞施加了一系列剂量的组织粉碎处理。此外，还在体内小鼠肿瘤模型中使用了单剂量组织粉碎。通过BCA蛋白测定、超高效液相色谱（UPLC）分析和Western blot，对肿瘤细胞上清液和肿瘤细胞沉淀中的释放蛋白，特别是HER2进行了分析。 结果：本研究结果显示，组织粉碎能够显著触发HER2蛋白的释放。实际上，肿瘤细胞上清液中的HER2蛋白水平高于肿瘤细胞沉淀，这表明HER2从细胞内区域释放到了细胞外间隙。此外，更高剂量的组织粉碎处理会按比例释放更多的HER2蛋白，表明游离HER2的释放具有组织粉碎剂量依赖性。 结论：总之，我们通过定性和定量分析证实，组织粉碎处理能够触发HER2从肿瘤细胞释放到细胞外间隙。组织粉碎介导的HER2抗原释放为了解其免疫刺激机制提供了重要见解，并提示了基于TSA/TAA的免疫疗法在多种癌症类型中的潜在应用价值。
Ultrasound-Guided Histotripsy Triggers the Release of Tumor-Associated Antigens from Breast Cancers
肿瘤(癌症)患者之家