摘要
目的观察^32P-磷酸铬-聚三-乳酸（CP—PLLA）粒子瘤体植入后对荷人前列腺癌裸鼠移植瘤的抑瘤效应和体内药物分布。方法采用雄性BALB／c裸小鼠建立人前列腺癌PC-3M细胞株的裸鼠皮下移植瘤模型，按随机数字表法分为4组，每组8只，即空白对照组和低、中、高剂量组（各植入3．7、7．4和18．5MBq粒子1枚）。植入后第2天每组各处死3只小鼠，取瘤体标本，采用原位末端标记法（TUNEL）观察肿瘤细胞凋亡并计算凋亡率。另5只裸鼠每2天测量肿瘤体积。植入后1h、2h、1d、2d、4d和8d对裸鼠行放射性核素显像，观察^32P—CP—PLLA粒子的放射性动态分布。植入后第14天处死小鼠，测量瘤体放射性活度和质量，计算放射性滞留率和抑瘤率，行常规病理检查观察瘤体和主要脏器病理变化，计算瘤细胞坏死率。免疫组织化学法检测肿瘤微血管密度（MVD）的表达。抑瘤率、瘤细胞坏死率和MVD组间差异采用单因素方差分析和SNK—q检验。结果放射性核素显像示放射性高度浓聚在植入靶位，并且瘤内弥散。粒子植入后第14天，各活度组肿瘤体积差异有统计学意义（F=212．820，P〈0．01）；瘤体病理示坏死性改变，TUNEL检测示肿瘤细胞大量凋亡，凋亡率[第2天分别为（1．66±0．56）％、（34．51±6．68）％、（42．45±6．09）％和（57．01±3．13）％]、瘤细胞坏死率[（4．86±4．12）％、（65．43±8．06）％、（76．18±6．35）％、（85．85±3．05）％I和抑瘤率[（60．82±3．81）％、（73．17±4．55）％、（81．80±4．74）％]均随给药剂量增加而同步增高。低、中和高剂量组瘤体放射性滞留率分别为（34．36±5．78）％、（41．16±5．26）％和（44．70±3．83）％（F=6．311，P〈0．05）；空白对照组、低、中和高剂量组MVD分别为62．00±5．40、38．16±4．16、23．50±4．59和15．80±3．92（q：14．31、23．11、27．74、8．80、13．43和4．62，均P〈0．01）。肝、脾等主要脏器未见明显病理学异常。结论^32P—CP—PLLA粒子植入后靶向浓聚，持续释放，具有杀伤、诱导凋亡和抑制肿瘤血管生成作用，且抑瘤效应和瘤内药物滞留率均存在一定的剂量一效应关系。
Objective To investigate the anti-tumor effects and distribution of 32P-chromic-phosphate poly(L-lactide)(CP-PLLA) in nude mice bearing the prostate cancer cell line PC-3M.Methods Tumor xenograft models were established with PC-3M prostate cancer cell line in male BALB/c nude mice.Based on the implanted dosage of 32P-CP-PLLA particles,the mice were randomly divided into four groups:control group (n =8,0 MBq),low-dose group (n =8,3.7 MBq),middle-dose group (n =8,7.4 MBq) and high-dose group (n =8,18.5 MBq).Three mice from each group were sacrificed 2 d after the 32P-CPPLLA particles were implanted into the tumor.Cell apoptosis was analyzed by a terminal oxynucleotidyl transferase mediated dUTP biotin nick and labeling (TUNEL) method,upon which the apoptotic rate was calculated.Tumor volume was measured every two days.The in vivo distribution of 32P-CP-PLLA was observed by SPECT.Mice in each group (n =5) were sacrificed on the 14th day.The weight and radioactivity of tumors were measured,so that the radioactive retention ratio and tumor growth inhibition rate could be calculated.The pathological changes of tumors and livers were observed,allowing the tumor necrotic rate to be calculated.The intratumoral microvessel density (MVD) was evaluated by an immunohistochemical method.Statistical analysis was performed by one-way analysis of variance and SNK-q analysis.Results 32P mainly accumulated in the tumor.Significant differences were noted in the tumor volumes among all groups on the 14th day (F =212.820,P ＜ 0.01).Massive tumor necrosis was observed by pathologic examination.After exposure to 0,3.7,7.4 and 18.5 MBq 32P-CP-PLLA,the apoptotic rates of tumors on the 2nd day were (1.66 ±0.56)％,(34.51 ±6.68)％,(42.45 ±6.09)％ and (57.01 ±3.13)％,respectively.On the 14th day,the tumor necrotic rates were (4.86 ±4.12)％,(65.43 ±8.06)％,(76.18 ±6.35)％ and (85.85 ±3.05)％,respectively and the tumor growth inhibition rates were (60.82 ± 3.81) ％,(73.17 ± 4.55) ％,(8 1.80 ± 4.74) ％,respectively.The apoptotic rate,tumor necrotic rate and tumor growth inhibition rate all showed a dose-effect relationship.When the dose was 3.7,7.4 and 18.5 MBq,the radioactive retention ratios in the tumors were (34.36 ±5.78)％,(41.16 ±5.26) ％ and (44.70 ± 3.83) ％,respectively (F =6.311,P ＜ 0.05).When the dose was 0,3.7,7.4 and 18.5 MBq,the MVD was 62.00 ±5.40,38.16 ±4.16,23.50 ±4.59 and 15.80 ±3.92,respectively (F=128.613,q=14.31,23.11,27.74,8.80,13.43,4.62,all P＜0.01).No pathological changes were observed in the liver or spleen.Conclusions The 32P-CP-PLLA particles released in the tumor and accumulated significantly at the implantation site.It shows apparent antitumor effects,including inducing apoptosis and inhibiting angiogenesis.In addition,a dose-effect relationship is noted between the antitumor effects and radioactive retention ratios of the tumors.
出处
《中华核医学与分子影像杂志》
CSCD
北大核心
2012年第6期457-462,共6页
Chinese Journal of Nuclear Medicine and Molecular Imaging
基金
国家自然科学基金
