乏氧诱导因子预测肺鳞癌放疗敏感性研究

Hypoxia-inducible factor in predicting the sensitivity of radiotherapy for lung squamous cell carcinoma

目的探讨乏氧诱导因子(hypoxia-inducible factor-1α,HIF-1α)预测肺鳞癌放疗敏感性的价值。方法对数期人肺鳞癌细胞,按放疗照射时间分为24h组和48h组,2组分别采用0、2、10Gy照射剂量单次X线照射24h和48h。照射后采用Western blot检测肺鳞癌细胞HIF-1α蛋白表达情况,采用逆转录PCR检测肺鳞癌细胞HIF-1α基因表达情况,比较2组肺鳞癌细胞放疗前、后HIF-1α阳性表达率、微血管密度和细胞凋亡率。结果 48h组肺鳞癌细胞在照射0、2、10Gy剂量时HIF-1αmRNA((14±2)%、(37±2)%、(69±3)%)和蛋白表达量((16±1)%、(70±5)%、(97±13)%)均明显高于24h组((10±1)%、(29±5)%、(41±6)%,(13±2)%、(65±4)%、(89±10)%),且10Gy剂量时高于0、2Gy剂量,2Gy剂量高于0Gy剂量(P<0.05);放疗前24h组肺鳞癌细胞HIF-1α阳性表达率(12.5%)、微血管密度(40.78±5.25)和细胞凋亡率((2.10±0.43)%)与48h组(12.5%、42.90±7.54、(2.08±0.39)%)比较差异均无统计学意义(P>0.05),放疗后48h组肺鳞癌细胞HIF-1α阳性表达率(87.5%)、微血管密度(83.31±4.67)和细胞凋亡率((4.04±1.22)%)均高于24h组(62.5%、61.22±9.48、(2.23±0.57)%)(P<0.05),2组放疗后均较放疗前明显增高(P<0.05)。结论放射剂量越大、放射时间越长,肺鳞癌中HIF-1α阳性表达量越高,对放疗越不敏感;HIF-1α与微血管密度、细胞凋亡密切相关。

Objective To investigate the value of hypoxia-inducible factor-1α（HIF-1α）to predicting the sensitivity of radiotherapy for lung squamous cell carcinoma（LSCC）.Methods LSCC cells in logarithmic growth phase were divided into 24-hour group and 48-hour group according to radiation exposure time,receiving X-ray radiation in a dose of 0,2and10 Gy for 24 and 48hours respectively.HIF-1αprotein expression was detected by Western blot after radiation,and HIF-1αgene expression was detected by RT-PCR.The expression of HIF-1α,microvessel density and apoptosis rate were compared before and after radiation between two groups.Results The expression levels of HIF-1αmRNA（（14±2）%,（37±2）%,（69±3）%）and protein（（16±1）%,（70±5）%,（97±13）%）were higher in doses of 0,2and 10 Gy in 48-hour group than those in 24-hour group（（10±1）%,（29±5）%,（41±6）%;（13±2）%,（65±4）%,（89±10）%）,and were the highest in dose of 10 Gy,followed by 2Gy and 0Gy（P〈0.05）.The positive rate of HIF-1α（87.5%）,microvessel density（83.31±4.67）and apoptosis rate（（4.04±1.22）%）were higher in 48-hour group than those in 24-hour group（62.5%,61.22±9.48,（2.23±0.57）%）after radiation（P〈0.05）,showed no significant differences before radiation between 24-hour group（12.5%,40.78±5.25,（2.10±0.43）%）and 48-hour group（12.5%,42.90±7.54,（2.08±0.39）%）（P〉0.05）,and were higher after radiation than those before radiation in both two groups（P〈0.05）.Conclusion The large radiation dose and the long radiation time cause high expression of HIF-1αin LSCC and reduce the sensitivity to radiotherapy.HIF-1αis closely correlated with microvessel density and apoptosis.