Department of Oncology Radiotherapy 2, Yantai Yantaishan Hospital, Yantai, Shandong, China.
Kaohsiung J Med Sci. 2021 Aug;37(8):654-663. doi: 10.1002/kjm2.12387. Epub 2021 May 6.
This study aims to investigate if the radiosensitivity of non-small cell lung cancer (NSCLC) cells can be regulated by long noncoding RNA (lncRNA) colon cancer associated transcript1 (CCAT1). CCAT1 was detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in NSCLC cells (A549, H1299, SK-MES1, H460, and H647) and human bronchial epithelial cells (16HBE). H460 and A549 cells were then selected for the determination of CCAT1 expression after exposure to radiation (0, 2, 4, 6 Gy) at different time points (0, 6, 12, 24 h). Colony forming assay was performed to evaluate the effects of CCAT1 siRNA or pcDNA3.1-CCAT1 vector on the radiosensitivity of H460 and A549 cells. Then, flow cytometry, western blotting and qRT-PCR were also conducted. CCAT1 was increased in NSCLC cells when compared with 16HBE cells, which was declined in a time- and dosage-dependent manner after exposure to radiation. The H460 and A549 cell colonies were decreased and the γ-H2AX expression was elevated with the increase of radiation dosage, which was more obvious in those transfected with CCAT1 siRNA. CCAT1 downregulation arrested NSCLC cells at G2/M phase. Moreover, the enhanced apoptosis of radiotherapy-treated NSCLC cells with reductions of p-p38/p38, p-ERK/ERK, and p-JNK/JNK was promoted by siCCAT1, but it was reversed by pcDNA3.1-CCAT1 vector. Inhibiting CCAT1 regulated cell cycle, DNA damage and apoptosis of NSCLC cells, and affected MAPK pathway, eventually improving the radiosensitivity of NSCLC.
本研究旨在探讨长链非编码 RNA（lncRNA）结肠癌相关转录本 1（CCAT1）是否可以调节非小细胞肺癌（NSCLC）细胞的放射敏感性。通过定量逆转录聚合酶链反应（qRT-PCR）检测 NSCLC 细胞（A549、H1299、SK-MES1、H460 和 H647）和人支气管上皮细胞（16HBE）中的 CCAT1。然后选择 H460 和 A549 细胞，在不同时间点（0、6、12、24 h）暴露于不同剂量（0、2、4、6 Gy）的辐射后，确定 CCAT1 的表达。集落形成试验用于评估 CCAT1 siRNA 或 pcDNA3.1-CCAT1 载体对 H460 和 A549 细胞放射敏感性的影响。然后进行流式细胞术、Western blot 和 qRT-PCR。与 16HBE 细胞相比，NSCLC 细胞中 CCAT1 增加，暴露于辐射后呈时间和剂量依赖性下降。随着辐射剂量的增加，H460 和 A549 细胞集落减少，γ-H2AX 表达增加，转染 CCAT1 siRNA 后更为明显。CCAT1 下调使 NSCLC 细胞停滞在 G2/M 期。此外，siCCAT1 增强了放疗后 NSCLC 细胞的凋亡，降低了 p-p38/p38、p-ERK/ERK 和 p-JNK/JNK，而 pcDNA3.1-CCAT1 载体则逆转了这一过程。抑制 CCAT1 调节 NSCLC 细胞的细胞周期、DNA 损伤和凋亡，并影响 MAPK 通路，最终提高 NSCLC 的放射敏感性。
