地塞米松对姑息性手术术后小鼠残存Lewis肺癌细胞复发的抑制作用

目的 研究地塞米松对姑息性手术术后小鼠残存Lewis肺癌细胞复发的抑制作用.方法 构建C57 BL小鼠Lewis肺癌姑息性手术切除术后模型,并采用随机数字表法将18只小鼠分为生理盐水组、地塞米松组、顺铂组,每组6只,术后第4～10天用游标卡尺(0.1 mm)测量每组小鼠皮下肿瘤结节.用石蜡免疫组织化学法检测3组小鼠术后残存Lewis肺癌细胞复发肿瘤组织中缺氧诱导因子-1α(HIF-1α)、平均微血管密度(MVD)染色情况.用实时荧光定量PCR和Western blotting检测3组小鼠术后复发肿瘤细胞中HIF-1α、血管内皮生长因子(VEGF)、增殖细胞核抗原(PCNA)基因和蛋白的表达.结果 肿瘤生长曲线显示,接受顺铂和地塞米松治疗的小鼠肿瘤体积分别为(200.34±20.94) mm3和(436.58±37.94) mm3,比生理盐水组(1 398.81±192.85) mm3明显减小,差异均有统计学意义(t=-1201.75,P＜0.001;t=-921.52,P＜0.001).石蜡免疫组织化学结果显示,地塞米松组和顺铂组HIF-1α表达(2.67 ±0.43,1.67 ±0.43)和MVD计数(17.01 ±3.24,9.89 ±2.25)都明显低于生理盐水组(4.21 ±0.35,29.75 ±5.64),差异均有统计学意义(t=-1.55,P＜0.001;t=-1.83,P＜0.001;t=-12.68,P＜0.001;t=-18.35,P＜0.001).实时定量PCR检测显示,HIF-1α(0.56±0.11)、VEGF(0.61±0.18)和PCNA(0.38±0.07) mRNA表达在地塞米松组较生理盐水组(1.21±0.13,1.13 ±0.26,1.06±0.08)明显减少,差异具有统计学意义(t=-0.55,P＜0.001;t=-0.62,P＜0.001;t=-0.69,P＜0.001);HIF-1α(0.31 ±0.12)、VEGF(0.30 ±0.13)和PCNA(0.18±0.06) mRNA表达在顺铂组较生理盐水组也明显减少,差异具有统计学意义(t=-0.73,P＜0.001;t=-0.76,P＜0.001;t=-0.81,P＜0.001).Western blotting结果显示,地塞米松组HIF-1α(85.98±20.86)、VEGF(173.28 ± 30.98)和PCNA蛋白(228.96±22.97)的表达较生理盐水组(198.98±29.89,378.98±28.98,357.98±35.98)明显减少,差异具有统计学意义(t=98.78,P＜0.001;t=85.68,P＜0.001;t=120.86,P＜0.001);顺铂组HIF-1α(65.78±18.62)、VEGF(109.43士19.86)和PCNA蛋白(176.86 ±22.76)的表达较生理盐水组明显减少,差异具有统计学意义(t=132.86,P＜0.001;t=108.68,P＜0.001;t=154.74,P＜0.001).结论 地塞米松对姑息性手术切除术后残存的Lewis肺癌细胞复发有明显抑制作用,有望为姑息性手术切除患者术后治疗提供一种新的辅助治疗方法.

Inhibitory effect of dexamethasone on residual Lewis lung cancer cells in mice after palliative surgery

Objective To investigate the inhibitory effect of dexamethasone on residual Lewis lung cancer cells in mice after palliative surgery.Methods The model of residual Lewis lung cancer cells in C57BL mice after palliative surgery were established,then accordance with the random number table,18 mice were randomly divided into 3 groups with 6 animals in each group:the normal saline group,cisplatin group,and dexamethasone group.After operation,the subcutaneous tumor nodules of each mouse were measured on days 4-10 using vernier calipers (accuracy of 0.l mm).The expressions of hypoxia induction factor-1α (HIF-1 α) and mean vascular density (MVD) in the normal saline group,cisplatin group and dexamethasone group were assessed by paraffin immunohistochemical assay.The expressions of HIF-1α,VEGF and PCNA mRNA and protein in the three groups were assessed by real-time quantitative PCR and Western blotting.Results Tumor growth curve showed that the tumor volume in cisplatin group (200.34 ± 20.94) mm3 and in dexamethasone group (436.58 ± 37.94)mm3 were obviously decreased compared with the normal saline group (1 398.81 ± 192.85) mm3,with statistically significant differences (t =-1201.75,P ＜ 0.001;t =-921.52,P ＜ 0.001).As Paraffin immunohistochemical assay showed,in cisplatin group and dexamethasone group,the expressions of HIF-1 α(2.67 ± 0.43,1.67 ± 0.43) and MVD counts (17.01 ± 3.24,9.89 ± 2.25) were decreased significantly compared with the normal saline (4.21 ± 0.35,29.75 ± 5.64),with statistically significant differences (t =-1.55,P＜0.001;t=-1.83,P＜0.001;t=-12.68,P＜0.001;t=-18.35,P＜0.001).The results of real-time quantitative PCR showed that the expressions of HIF-1α (0.56 ±0.11),VEGF (0.61 ±0.18) and PCNA mRNA (0.38 ± 0.07) in dexamethasone group were obviously reduced compared with the normal saline group (1.21 ±0.13,1.13 ± 0.26,1.06 ± 0.08),with statistically significant differences (t =-0.55,P ＜ 0.001;t=-0.62,P＜0.001;t=-0.69,P＜0.001).The expressions of HIF-1α (0.31 ±0.12),VEGF (0.30 ± 0.13) and PCNA mRNA (0.18 ± 0.06) in cisplatin group were also obviously reduced compared with the normal saline group,with statistically significant differences (t =-0.73,P ＜ 0.001;t =-0.76,P ＜ 0.001;t =-0.81,P ＜ 0.001).The results of Western blotting showed that the expressions of HIF-1α (85.98 ± 20.86),VEGF (173.28 ± 30.98) and PCNA protein (228.96 ± 22.97) in dexamethasone group were decreased significantly compared with the normal saline group (198.98 ± 29.89,378.98 ± 28.98,357.98 ± 35.98),with statistically significant differences (t =98.78,P ＜ 0.001;t =85.68,P ＜ 0.001;t =120.86,P ＜ 0.001).The expressions of HIF-1 α (65.78 ± 18.62),VEGF (109.43 ± 19.86) and PCNA protein (176.86 ± 22.76) in cisplatin group were decreased significantly compared with the normal saline group,with statistically significant differences (t =132.86,P ＜ 0.001;t =108.68,P ＜ 0.001;t =154.74,P ＜ 0.001).Conclusion Dexamethasone can effectively inhibit the growth and angiogenesis of the residual Lewis lung carcinoma after palliative surgery in mice,and may also provide a new method of postoperative adjuvant therapy for patients,especially who received palliative surgery.