Department of Radiotherapy Oncology, The Third Affiliated Hospital of Kunming Medical University (Tumor Hospital of Yunnan Province), Kunming 650118, Yunnan, China.
Department of Nuclear Medicine, The Third Affiliated Hospital of Kunming Medical University (Tumor Hospital of Yunnan Province), Kunming 650118, Yunnan, China.
Biomed Pharmacother. 2018 Jun;102:618-625. doi: 10.1016/j.biopha.2018.03.017. Epub 2018 Apr 5.
In this research, we aimed at finding out how San Yang Xue Dai (SYKT) promotes the radiosensitivity of non-small cell lung cancer (NSCLC) cell line NCI-H460.
Survival rate of NSCLC cells (A549, NCI-H460, NCI-H1650 and NCI-H1975) after the SYKT treatment or irradiation (IR) was calculated by the MTT assay. The radiosensitization of SYKT (0.5 g/mL and 1.0 g/mL) on cell line NCI-H460 and the radioresistant cell line NCI-H460R was studied by MTT assay and clone formation assay. The protein expression levels of iNOS, Cyclin B1 and CDC2 were determined by western blot, and the expression of NO was measured by Griess method. Finally, cell cycle and apoptotic rate of NSCLC cell line NCI-H460 were accessed by flow cytometry assay. BrdU staining was also applied to detect the cell proliferation after IR with or without SYKT treatment.
The IC value of SYKT for NCI-H460 cells was 1.03 g/mL. After 1.0 g/mL SYKT treatment, the radiosensitivity of NCI-H460R cells was enhanced. The level of iNOS in the cells was found decreased after IR. We also found that SYKT could enhance iNOS and NO expressions while inhibit cyclin B1 and CDC2 expressions in radiation resistant cells. Combining β-irradiation with SYKT caused cell cycle arrest in G2/M phase and increased cell apoptosis.
SYKT resensitized radioresistant NCI-H460R cells via increasing cell apoptosis and cell cycle arrest. This was due to an elevated NO level caused by accumulating iNOS and effects of SYKT on radiosensitization of NSCLC should be further investigated in clinical application.
本研究旨在探讨三阳血傣（SYKT）如何提高非小细胞肺癌（NSCLC）细胞系 NCI-H460 的放射敏感性。
采用 MTT 法检测 SYKT 处理或照射（IR）后 NSCLC 细胞（A549、NCI-H460、NCI-H1650 和 NCI-H1975）的存活率。MTT 法和集落形成实验研究 SYKT（0.5 g/ml 和 1.0 g/ml）对 NCI-H460 细胞系和耐辐射细胞系 NCI-H460R 的放射增敏作用。Western blot 检测 iNOS、Cyclin B1 和 CDC2 的蛋白表达水平，Griess 法检测 NO 的表达。最后，通过流式细胞术检测 NSCLC 细胞系 NCI-H460 的细胞周期和凋亡率。BrdU 染色也用于检测 IR 后有无 SYKT 处理时的细胞增殖。
SYKT 对 NCI-H460 细胞的 IC 值为 1.03 g/ml。经 1.0 g/ml SYKT 处理后，NCI-H460R 细胞的放射敏感性增强。IR 后细胞中 iNOS 水平降低。我们还发现，SYKT 可以增强耐辐射细胞中 iNOS 和 NO 的表达，同时抑制细胞周期蛋白 B1 和 CDC2 的表达。结合β-照射和 SYKT 导致细胞周期停滞在 G2/M 期，并增加细胞凋亡。
SYKT 通过增加细胞凋亡和细胞周期阻滞使耐辐射的 NCI-H460R 细胞重新敏感。这是由于 iNOS 积累导致的 NO 水平升高，以及 SYKT 对 NSCLC 的放射增敏作用在临床应用中需要进一步研究。
