中文摘要：

目的研究2、4GyX射线照射后人肺腺癌细胞miR-424＊体内、外表达以及非小细胞肺癌患者肺组织及血清中miR-424＊的表达变化及其意义。方法2、4Gyx射线分别照射体外培养的A549细胞，以实时定量PER（tit—qPCR）法检测A549细胞中miR-424＊表达水平；用照射后的A549细胞制备裸鼠肺转移动物模型，检测裸鼠肺组织及血清中rniR-424。的表达水平；收集肺癌患者肺组织及血清样本，检测miR-424＊表达水平。结果2、4GyX射线照射后1、2、12、24及48h，miR-424＊表达均显著升高（2Gy：t=-45．886～-6．709，P〈0．05；4Gy：t=-29．087～-7．833，P〈0．05）；0、2、4Gy照射后，miR-424＊在裸鼠肺及血清中表达水平分别为空白对照组的9．72、8．58及4．7与11．93、9．22及8．99倍（t=-13．243～-3．052，P〈0．05）。6／11例（54．5％）患者肺癌组织中高表达miR-424＊，腺癌、鳞癌病理类型间检出率差异无统计学意义（P〉0．05）；43／84例（51．20％）肺癌患者与健康志愿者相比，血清miR-424＊表达升高1．97—17．71倍，其中腺癌患者血清检出率为39．1％（18／46），鳞癌患者血清检出率为65．8％（25／38），两种病理类型检出率差异有统计学意义（t=5．919，P〈0．05）；此外，84例肺癌患者中，miR-424＊在未接受放疗的肺癌患者血清中的阳性检出率为41．5％（22／53），显著低于接受放疗的肺癌患者血清的阳性检出率67．7％（21／31）（t=5．387，P〈0．05）。结论2、4GyX射线照射可增加A549细胞miRNA-424＊的体内、外表达水平，可能与增强A549细胞体内、外侵袭转移能力有关。肺癌患者中50％以上的肺癌组织及肺癌患者血清中miR-424＊表达水平显著升高，可能与肺癌的病理类型及放疗相关。

英文摘要：

Objective To investigate the expression of miR-424 ＊ in 2 and 4 Gy X-ray irradiated A549 ceils in vitro and in vivo, as well as in clinical lung tissues and serum sample of non-small cell lung cancer（NSCLC） patients, and to explore its potential role in the diagnosis and prognosis of lung cancer. Methods A549 ceils were irradiated with 2 and 4 Gy X-rays, and some of irradiated cells were injected into nude mice through tail vein. Real time quantitative PCR （RT-qPCR） assay was employed to detect the expression of miR-424 ＊ in 2 and 4 Gy X-ray irradiated A549 cells in vitro and in vivo, as well as in clinical lung tissues and serum sample of lung cancer patients. Results Compared with the control group, the expression of miR-424＊ was up-regulated significantly in X-ray irradiated A549 cells at 1, 2, 12, 24 and 48 hpost irradiation, respectively （2 Gy： t = -45.886 - -6.709,P〈0.05; 4 Gy： t = -29.087 - - 7. 833 ,P 〈 0.05 ）. Furthermore, the expression of miR-424 ＊ was up-regulated in the lung and serum of nude mice with injection of 0, 2 and 4 Gy X-ray irradiated A549 cells, compared with control group （fold change was 9.72, 8.58 and 4. 7 with 2 Gy irradiation and I i. 93, 9.22 and 8.99 with 4 Gy irradiation, t= -13.243, -12.409, -9.833 in lung and t= -6.436, -3.052, -3.609 in serum, respectively, P 〈0.05）. Out of 11 tissue samples of NSCLC patients, 6 were detected with up-regulated miR-424＊ expression, and no significant discrepancy of miR-424＊ expression was detected in two type of NSCLC tissue samples. On the contrary, 43 serum samples were detected with up-regulated miR-424＊ expression out of 84 serum samples （51.20%） of NSCLC patients （fold change range 1.97 to 17.71 ）, and significant discrepancy of milR-424 ＊ expression was shown in two subtypes of NSCLC serum samples [ adenocarcinoma： 39. 10% （18/46） and sqoamous carcinoma： 65.8% （25/38）], as well as in serum samples of NSCLC patients with radiotherapy [ 41.5% （22/53） ] and without radiotherap