School of Medicine, St. James's University Hospital, University of Leeds, Beckett St., Leeds, LS9 7TF, UK.
School of Medicine, St. James's University Hospital, University of Leeds, Beckett St., Leeds, LS9 7TF, UK.
Photodiagnosis Photodyn Ther. 2018 Sep;23:221-229. doi: 10.1016/j.pdpdt.2018.06.027. Epub 2018 Jun 30.
Photodynamic Therapy (PDT) is an attractive modality for treating solid cancers. This study evaluates the efficacy of Hypericin-PDT as a cytotoxic therapy in colorectal cancer (CRC), using 2D cell cultures and 3D multicellular tumour spheroids.
Spheroids were generated through forced-floating and agitation-based techniques. 2D and spheroid models of HT29 and HCT116 CRC cells were incubated with Hypericin (0-200 nM) for 16 h. Cultures were irradiated with light (1 J/cm) and cytotoxicity assessed using Propidium Iodide fluorescence. Expression of ABCG2 protein was assessed by immunoassays in 2D and spheroid cultures. The effect of ABCG2 inhibition, using 10 μM Ko143, on cytotoxicity following Hypericin-PDT was evaluated.
Hypericin-PDT produced a significant reduction in HT29 (p < 0.0001) and HCT116 (p < 0.0001) cell viability in 2D cultures, with negligible non-phototoxicity. Spheroids were more resistant than 2D cultures to Hypericin-PDT (HT29: p = 0.003, HCT116: p = 0.006) and had a greater expression of ABCG2. Inhibition of ABCG2 in spheroids with Ko143 resulted in an enhanced Hypericin-PDT effect compared to Hypericin-PDT alone (HT29: p = 0.04, HCT116: p = 0.01).
Hypericin-PDT has reduced efficacy in CRC spheroids as compared to 2D cultures, which may be attributable through upregulation in ABCG2. The clinical efficacy of Hypericin-PDT may be enhanced by ABCG2 inhibition.
光动力疗法（PDT）是治疗实体瘤的一种有吸引力的方法。本研究通过 2D 细胞培养和 3D 多细胞肿瘤球体评估 Hypericin-PDT 作为结直肠癌（CRC）细胞毒性治疗的疗效。
通过强制浮法和基于搅拌的技术生成球体。将 HT29 和 HCT116 CRC 细胞的 2D 和球体模型与 Hypericin（0-200nm）孵育 16 小时。用光照（1J/cm）照射培养物，并使用碘化丙啶荧光评估细胞毒性。通过 2D 和球体培养物中的免疫测定评估 ABCG2 蛋白的表达。用 10µM Ko143 评估 ABCG2 抑制对 Hypericin-PDT 后细胞毒性的影响。
Hypericin-PDT 显著降低 HT29（p<0.0001）和 HCT116（p<0.0001）2D 培养物中的细胞活力，而光毒性可忽略不计。与 2D 培养物相比，球体对 Hypericin-PDT 的抗性更强（HT29：p=0.003，HCT116：p=0.006），并且 ABCG2 的表达更高。用 Ko143 抑制球体中的 ABCG2 导致与单独使用 Hypericin-PDT 相比，Hypericin-PDT 的效果增强（HT29：p=0.04，HCT116：p=0.01）。
与 2D 培养物相比，CRC 球体中的 Hypericin-PDT 疗效降低，这可能归因于 ABCG2 的上调。通过 ABCG2 抑制可增强 Hypericin-PDT 的临床疗效。
