与放疗抵抗相关的长链非编码RNA在不同放疗敏感性结直肠癌细胞株中的表达

Expression of long non-coding RNA associated with radiotherapy-resistance in colorectal cancer cell lines with different radiosensitivity

目的 筛选与结直肠癌细胞放疗敏感性相关的长链非编码RNA（lncRNA）.方法 将HT29、SW480、RKO、Lovo和HCT116等5株结直肠癌细胞梯度照光后行克隆形成实验,通过细胞存活率（SF2值）来检测5株细胞的放疗敏感性差异;利用高通量lncRNA芯片筛选在SW480、RKO和Lovo细胞株中两两比较表达差异均大于2倍的lncRNA,并通过实时定量PCR进一步检测所选lncRNA在5株结直肠癌细胞中的表达差异.结果 5株结直肠癌细胞放疗敏感性由低至高（即SF2值由高至低）依次为HT29 （0.83±0.03）、SW480 （0.69±0.02）、RKO （0.53±0.02）、Lovo （0.47±0.05）和HCT116（0.32±0.03）（P＜0.01）.lncRNA芯片筛选得到5种与结直肠癌细胞放疗敏感性相关的lncRNA基因,其中R05532、NR_015441和NR_033374基因表达水平与细胞放疗抵抗呈正相关（均P＜0.01）,而NR_073156和AA745020基因表达水平与细胞放疗抵抗无明显相关性（均P＞0.05）.结论 R05532、NR_015441和NR_033374三种lncRNA可能成为结直肠癌细胞放疗敏感性的预测分子,其高表达提示放疗抵抗。

Objective To screen long non-coding RNA（lncRNA） associated with radiosensitivity in colorectal carcinoma cell lines.Methods Colony formation assay was performed in colorectal cancer cell lines HT29,SW480,RKO,Lovo and HCT116 after irradiation with different radiation doses.Radiation sensitivity of these 5 cell lines was detected through survival fraction at 2 Gy （SF2 value）.High-throughput lncRNA chip was used to screen lncRNA genes with expression differences more than 2 folds among SW480,RKO and Lovo.Further experiment on the expression differences of lncRNAs selected was conducted by realtime PCR.Results The radiosensitivity order of these 5 cell lines from low to high （SF2 value from high to low） was HT29 （0.83±0.03）,SW480 （0.69±0.02）,RKO （0.53± 0.02）,Lovo （0.47±0.05）,HCT116 （0.32±0.03）（P〈0.01）.Five lncRNAs associated with radiation sensitivity were screened.Among them,expression levels of R05532,NR_015441,and NR_033374 were positively correlated with radiation resistance （all P〈0.01）,and expression levels of the other 2 lncRNAs,NR_073156 and AA745020,were not correlated with radiation resistance of colorectal cancer cells （both P〉0.05）.Conclusions lncRNA R05532,NR_015441 and NR_033374 may be used as the predictiv marker of radiosensitivity of colorectal cancer cells.Higher expression of these genes shows radiation resistance.