【作者】 刘丽娟；

【导师】 金观桥；

【作者基本信息】 广西医科大学 ， 影像医学与核医学， 2019， 硕士

【摘要】 目的:探讨本课题组以sLeX与超顺磁性纳米氧化铁颗粒(Ultrasmall Superparamagnetic Iron Oxide,USPIO)连接的磁共振分子探针USPIO-PEG-sLeX在裸鼠鼻咽癌(nasopharyngeal carcinoma,NPC)移植瘤模型中的价值。测量USPIO-PEG-sLeX在转移组与非转移组结合后造成的T2*值改变差异。用西咪替丁抑制裸鼠体内E-selectin的表达,再次使用分子探针靶向成像,判断分子探针对机体E-seletcin的靶向效果。方法:培养鼻咽癌细胞株SUNE1-亚株5-8F细。Balb/c雌性裸鼠共12只进行左侧爪垫造模。接种后8周常规麻醉,尾静脉注射USPIO-PEG-sLeX前(平扫)、注射分子探针后0h、1h、2h行磁共振T2*mapping扫描,比较分析注射前后各时间点T2*值、T2*差值(ΔT2*值)及增强后各时刻强化率(enhancement rate,ER)。扫描完成后处死裸鼠并行详细解剖检查,观察肿瘤以及有无转移情况,取移植瘤及可疑转移结节标本经福尔马林固定后常规石蜡包埋,切片,对组织行HE染色判断有无转移,行免疫组化染色分析移植瘤E-selectin表达。另皮下造模裸鼠24只,使用西咪替丁注射液抑制E-selectin的表达。造模后8周行磁共振T2*mapping扫描,分析分子探针注射前后T2*值变化。验证分子探针USPIO-PEG-sLeX对E-selectin的靶向能力。转移组与非转移组荷瘤裸鼠E-selectin相比较,转移组平均光密度值(mean optical density,MOD)明显高于非转移组(0.52±0.24 VS 0.08±0.01,P<0.05)。两组裸鼠爪垫移植瘤平扫T2*值差异无统计学意义(22.25±8.08 VS27.01±9.45,P>0.05)。两组裸鼠尾静脉注射分子探针后0h、1h和2h的三个时刻点,转移组T2*值均低于非转移组,其值分别为11.57±4.02 VS24.82±7.84、10.09±4.88 VS 24.15±8.74、12.46±5.63 VS 23.42±7.12,P值均小于0.05,差异有统计学意义。两组裸鼠尾静脉注射分子探针后0h、1h和2h三个时间点的T2*值变化,转移组ΔT2*均高于非转移组,其值分别为10.69±6.23 VS 3.86±2.20、12.17±8.67 VS 2.87±1.37、9.80±3.03 VS 4.32±2.28,P值均小于0.05,差异均有统计学意义。两组裸鼠尾静脉注射分子探针后0h、1h和2h,转移组ER均高于非转移组,其值分别为45.98±14.03 VS7.10±5.18、51.15±22.70 VS 11.04±6.01、44.05±13.92 VS 12.09±7.54,P值均小于0.05,差异有统计学意义。经西咪替丁抑制E-selectin表达后,经西咪替丁干预后裸鼠皮下移植瘤模型E-selectin表达较生理盐水对照组低(0.040±0.009VS 0.6805±0.008,P<0.05),差异有统计学意义。两组裸鼠爪垫移植瘤平扫T2*值差异无统计学意义(22.40±7.61 VS 29.54±9.52,P>0.05)。尾静脉注射分子探针USPIO-PEG-sLeX后0h、1h、2h后行MRI扫描,两组裸鼠在各时刻点T2*值差异无统计学意义(16.59±5.38 VS 16.81±6.08、13.44±4.57 VS 12.27±3.49、12.30±3.69 VS 12.18±3.98),P值均>0.05。两组裸鼠在注射造影剂0h、1h、2h各时刻点ΔT2*值差异有统计学意义(6.08±5.65 VS 13.04±9.83、8.96±6.54VS 17.28±9.52、10.11±6.07 VS 17.37±9.57),P值均<0.05。两组裸鼠在注射造影剂后0h、1h的ER差异有统计学意义(21.23±14.68 VS 40.79±20.05、36.39±20.26 VS 55.37±15.54),P值均小于0.05。两组裸鼠在注射造影剂后2h的ER差异无统计学意义(42.12±16.14 VS 55.69±16.08,P>0.05)。结果:结论:E-selectin在NPC移植瘤中高表达,且与鼻咽癌的转移密切相关,是鼻咽癌转移的重要分子标志物,可以作为分子探针目标靶点。分子探针USPIO-PEG-sLeX可以成功靶向至移植瘤E-selectin,有望成为NPC的一种特异性MRI分子探针,临床用于NPC早诊断、早发现转移灶、动态监测评估E-selectin变化情况,可为临床制定NPC治疗方案、精准治疗提供依据。更多还原

【Abstract】 Objective: To explore the value of magnetic resonance molecular probe USPIO-PEG-sLeX which was consisted of sLeX and Ultrasmall Superparamagnetic Iron Oxidem(USPIO)in a nude mouse model of nasopharyngeal carcinoma(NPC).The difference of T2* value caused by the binding of USPIO-PEG-sLeX in the metastatic group and the non-metastasis group was measured.The expression of E-selectin in nude mice was inhibited by cimetidine,and molecular imaging was again used to detect molecular probes.Targeting effect on the body E-seletcin.Methods: The nasopharyngeal carcinoma(NPC)cell 5-8F was cultured.A total of 12 Balb/c female nude mice were modeled on the left paw pad.Routine anesthesia was performed 8 weeks after inoculation.Magnetic resonance T2*mapping was performed before and after USPIO-PEG-sLeX injection 0h,1h,2h,and the time points before and after injection were compared.T2* value,T2*difference(ΔT2* value),and enhancement rate(ER)at each time after enhancement.After the scan was completed,the nude mice were sacrificed and detailed anatomical examination was performed to observe the tumor and thepresence or absence of metastasis.The specimens of transplanted tumors and suspicious metastatic nodules were embedded in formalin and sectioned.Metastasis was performed and immunohistochemical staining was used to analyze the expression of E-selectin in transplanted tumors.Another 24 nude mice were subcutaneously cast,and the expression of E-selectin was inhibited by cimetidine injection.Magnetic resonance T2*mapping was performed 8 weeks after modeling to analyze the change of T2*value before and after molecular probe injection.The ability of the molecular probe USPIO-PEG-sLeX to target E-selectin was verified.Results: Compared with the non-metastatic group of nude mice E-selectin,the mean optical density(MOD)of the metastatic group was significantly higher than that of the non-metastatic group(0.52±0.24 VS 0.08±0.01,P<0.05).There was no significant difference in the plain T2* values between the two groups of nude mice(22.25±8.08 vs 27.01±9.45,P>0.05).At the three time points of 0h,1h and 2h after the injection of molecular probes in the tail vein of the two groups,the T2* values of the metastatic group were lower than those of the non-metastasis group,and the values were 11.57±4.02 VS24.82±7.84,10.09±4.88 VS.24.15±8.74,12.46±5.63 VS 23.42±7.12,P valueswere less than 0.05,the difference was statistically significant.The T2*values of the two groups at 0h,1h and 2h after the injection of molecular probes in the tail vein of the two groups were higher than those in the non-metastasis group,which were 10.69±6.23 VS 3.86±2.20,12.17.±8.67 VS2.87±1.37,9.80±3.03 VS 4.32±2.28,P values were all less than 0.05,the difference was statistically significant.At 0h,1h and 2h after injection of molecular probes in the tail vein of the two groups,the ER in the metastatic group was higher than that in the non-metastasis group,and the values were45.98±14.03 VS 7.10±5.18,51.15±22.70 VS 11.04±6.01,44.05±13.92,respectively.VS 12.09 ± 7.54,P values were less than 0.05,the difference was statistically significant.After cimetidine inhibited the expression of E-selectin,the expression of E-selectin in subcutaneous xenograft model of nude mice was lower than that of normal saline control group(0.040±0.009 VS 0.6805±0.008,P<0.05).It is statistically significant.There was no significant difference in the plain T2*values between the two groups of nude mice(22.40±7.61 VS 29.54±9.52,P>0.05).MRI scan was performed at 0h,1h,and 2h after molecular injection of USPIO-PEG-sLeX in the tail vein.There was no significant difference in T2*between the two groups at each time point(16.59±5.38 VS 16.81±6.08,13.44±4.57).VS 12.27 ± 3.49,12.30 ± 3.69 VS 12.18 ± 3.98),P values are > 0.05.There were significant differences in ΔT2* values between the two groups of nude mice at 0h,1h,and 2h(6.08±5.65 VS 13.04±9.83,8.96±6.54 VS 17.28±9.52,10.11±6.07 VS 17.37±9.57).P values were all<0.05.The ER difference between the two groups of nude mice at 0h and 1h after injection of contrast agent was statistically significant(21.23±14.68 VS40.79±20.05,36.39±20.26 VS 55.37±15.54),P value was less than 0.05.There was no significant difference in ER between the two groups of mice at 2 h after injection of contrast agent(42.12±16.14 VS 55.69±16.08,P>0.05).Conclusions: E-selectin is highly expressed in NPC xenografts and is closely related to the metastasis of nasopharyngeal carcinoma.It is an important molecular marker for metastasis of nasopharyngeal carcinoma and can be used as a molecular probe target.The molecular probe USPIO-PEG-sLeX can be successfully targeted to the transplanted tumor E-selectin,which is expected to be a specific MRI molecular probe for NPC.It can be used for early diagnosis ofNPC,early detection of metastases,and dynamic monitoring and evaluation of E-selectin.Changes can provide a basis for clinical development of NPC treatment and precision treatment.更多还原