AntiCancer, Inc., San Diego, California; Department of Surgery, University of California, San Diego, California; Department of Orthopaedic Surgery, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan.
J Cell Biochem. 2013 Nov;114(11):2493-9. doi: 10.1002/jcb.24599.
We have previously demonstrated that the ultraviolet (UV) light is effective against a variety of cancer cells in vivo as well as in vitro. In the present report, we imaged the DNA damage repair response of minimal cancer after UVC irradiation. DNA-damage repair response to UV irradiation was imaged on tumors growing in 3D culture and in superficial tumors grown in vivo. UV-induced DNA damage repair was imaged with GFP fused to the DNA damage response (DDR)-related chromatin-binding protein 53BP1 in MiaPaCa-2 human pancreatic cancer cells. Three-dimensional Gelfoam® histocultures and confocal imaging enabled 53BP1-GFP nuclear foci to be observed within 1 h after UVC irradiation, indicating the onset of DNA damage repair response. A clonogenic assay showed that UVC inhibited MiaPaCa-2 cell proliferation in a dose-dependent manner, while UVA and UVB showed little effect on cell proliferation. Induction of UV-induced 53BP1-GFP focus formation was limited up to a depth of 40 µm in 3D-culture of MiaPaCa-2 cells. The MiaPaCa-2 cells irradiated by UVC light in a skin-flap mouse model had a significant decrease of tumor growth compared to untreated controls. Our results also demonstrate that 53BP1-GFP is an imageable marker of UV-induced DNA damage repair response of minimal cancer and that UVC is a useful tool for the treatment of residual cancer since UVC can kill superficial cancer cells without damage to deep tissue.
我们之前已经证明，紫外线 (UV) 光对体内和体外的多种癌细胞都有效。在本报告中，我们对 UVC 照射后微小癌症的 DNA 损伤修复反应进行了成像。在 3D 培养物中生长的肿瘤和体内生长的浅表肿瘤中，对 UV 照射的 DNA 损伤修复反应进行了成像。用 GFP 融合到与 DNA 损伤反应 (DDR) 相关的染色质结合蛋白 53BP1 来成像 UV 诱导的 DNA 损伤修复。三维 Gelfoam®组织培养物和共聚焦成像使我们能够在 UVC 照射后 1 小时内观察到 53BP1-GFP 核焦点，表明 DNA 损伤修复反应的开始。克隆形成测定表明，UVC 以剂量依赖性方式抑制 MiaPaCa-2 细胞的增殖，而 UVA 和 UVB 对细胞增殖几乎没有影响。在 MiaPaCa-2 细胞的 3D 培养物中，诱导的 UV 诱导的 53BP1-GFP 焦点形成的深度限制在 40µm 以内。与未处理的对照组相比，在皮瓣小鼠模型中用 UVC 光照射的 MiaPaCa-2 细胞的肿瘤生长明显减少。我们的结果还表明，53BP1-GFP 是微小癌症 UV 诱导的 DNA 损伤修复反应的可成像标志物，UVC 是治疗残留癌症的有用工具，因为 UVC 可以杀死浅表癌细胞而不会对深部组织造成损伤。
