125I-血管抑素的制备及生物活性研究

目的：利用^125Ⅰ标记血管抑素（angiostatin，AS），并研究标记产物^125Ⅰ-AS的体外稳定性及生物活性。方法：制备的AS经鉴定后，用Ch-T法进行标记，用纸层析法测标记率，用Sephadex-G50柱纯化，产物分别加入牛血清白蛋白（BsA）、生理盐水及不同摩尔比的半胱氨酸以观察其体外稳定性，并通过人脐静脉内皮细胞系ECV304细胞生长抑制试验来检测^125Ⅰ-AS的生物活性。结果：制备的^125Ⅰ-AS标记率可达85％，^125Ⅰ-AS在生理盐水中1、4、24h的解离率分别为2．3％、5．2％、8．0％，在10g／L BSA中1、4、24h的解离率分别为4．6％、9．1％、11．0％。在不同摩尔比半胱氨酸溶液中孵育，^125Ⅰ-AS存在不同程度的解离，摩尔比在5以下时，4h的解离率不超过11％，表明标记产物在体外较稳定。分别用不同浓度^125Ⅰ-AS和AS作用于ECV304细胞，并以6-氨基己酸作为对照，发现两者对ECV304细胞增殖均有明显的抑制作用，且^125Ⅰ-AS的作用强于单纯的AS，表明^125Ⅰ-AS具有较强的生物活性。结论：用Ch-T法进行^125Ⅰ-AS标记简单易行，^125Ⅰ-AS对ECV304细胞的生长有明显抑制作用，有较强的生物活性，标记产物在体外较稳定。     

131I-Tyr-octreotide的标记方法学及其生物学分布的研究

目的探讨131^Ⅰ采用氯胺-T氧化还原法标记生长抑素类似物Tyr-octreotide的可行性和标记物的稳定性，并研究其在正常小鼠体内的生物学分布和非小细胞肺癌荷瘤鼠SPEC3、显像。方法采用氯胺-T法制备131^Ⅰ-Tyr-octreotide，并测定标记物的放化纯、胶体含量及正常小鼠体内的生物学分布，不同时间点眼球取血后处死，测定血液及各主要脏器的放射性，计算％ID／g。对非小细胞肺癌荷瘤鼠模型进行131^Ⅰ-Tyr-octreotide显像研究。结果采用氯胺-T法131^Ⅰ标记Tyr-octreotide的最佳条件：磷酸缓冲液（0．2mol／L）0．15ml，Tyr-oetreotide（1g／L）10μl，Na131^Ⅰ（3．7MBq）0．1ml，氯胺-T（30g／L）4μl，迅速混匀反应2．5min，之后加入Na2S2O5（30g／L）5μl终止反应，放化纯可达97％，6h后放化纯可达83％，胶体含量为1．02％。小鼠体内分布实验表明，肾脏和肝脏对131^Ⅰ-Tyr-octreotide的摄取最高，胃肠消化器官次之，其他脏器摄取较少；对肿瘤组织具有较好的亲和力。结论131^Ⅰ-Tyr-octreotide采用氯胺-T法标记具有标记率高、方法简便和迅速、体外稳定性较好、无需进一步纯化等优点。在小鼠体内主要经肝、肾系统代谢，血液清除快，有望成为以生长抑素介导的生物靶向诊断和治疗非小细胞肺癌的分子药物。     

细胞电穿孔联合低浓度顺铂作用卵巢癌SKOV3细胞体外生长实验研究

目的 探讨细胞电穿孔联合低浓度顺铂对卵巢癌SKOV3细胞株体外生长作用的影响.方法 选用电场600 V/cm,脉冲个数5个,电容11μF作用于SKOV3细胞株.根据作用不同分为电穿孔＋药物（E＋M）组;电穿孔（E）组,药物（M）组和空白（C）组.每3 d一次观察处理后的生长细胞共24 d.描绘细胞生长曲线,观察各组细胞生长变化.结果 不同方式处理后细胞生长情况表明电穿孔＋药物组对SKOV3细胞的体外生长有良好抑制作用,差异显著（P〈0.01）;单纯电穿孔组对肿瘤细胞的抑制大于单纯药物组,低于电穿孔＋药物组;单纯药物组的低浓度顺铂对卵巢癌SKOV3细胞仅有微弱生长抑制.结论 以电场600 V/cm,脉冲个数5个,电容11μF作为细胞电穿孔参数并同时联合低浓度顺铂作用卵巢癌SKOV3细胞株时,有明显加强非细胞抑制剂量顺铂对体外SKOV3细胞生长的抑制作用.     

131I-17-丙烯胺基-17-去甲氧基格尔德霉素对人乳腺癌细胞生长的抑制作用

目的 探讨^131I-17-丙烯胺基-17-去甲氧基格尔德霉素（17-AAG）对人乳腺癌细胞生长的影响及其相关机制。方法 采用过氧化氢标记法制备^131I-17-AAG。细胞杀伤实验分为5组：二甲基亚砜（DMSO）对照（A）组，Na^131I370kBq（B）组，17-AAG2．5mg／L（C）组，^131I-17-AAG370kBq（D）组，^131I-17-AAG370kBq＋17-AAG2．5mg／L（E）组。用四甲基偶氮唑蓝（MTT）法检测各种药物对人乳腺癌细胞MCF-7的生长抑制作用，流式细胞术分析细胞凋亡及细胞周期变化，RT—PCR检测药物处理前后MCF-7细胞中Akt2基因的mRNA表达情况。结果 ^131I-17-AAG的标记率为83％，放化纯为96．6％，比活度为1．48×10^5MBq／μmol。各组药物对细胞的杀伤呈时间效应，随着时间的延长，细胞的抑制率都呈明显上升趋势，尤以E组趋势明显。A～E组药物作用48h后，通过亚G1峰检测MCF-7细胞凋亡率分别为（1．54±0．13）％，（5．72±1．05）％，（12．97±1．44）％，（20．65±1．36）％，（35．39±4．15）％，各组细胞凋亡率差异有统计学意义（P均〈0．05）。C组，D组及E组Akt2基因的mRNA表达均比A组降低，其中E组降低尤为明显。结论 ^131I-17AAG能够抑制MCF-7细胞的生长并促进其凋亡，且能有效抑制Akt2基因的mRNA表达，和17-AAG联合应用能够增强肿瘤细胞对放疗的敏感性。     

^131I标记人源抗HBs Fab瘤内注射荷人肝癌裸鼠的实验研究

目的： 探讨^131I标记人源抗肝表面抗原单克隆抗体Fab片段（抗HBs Fab)瘤内给药治疗荷人肝癌裸鼠移植瘤的合理性。方法 荷瘤裸鼠分为5组,分别经瘤内注射^131I-抗HBs Fab,^131I-无关Fab,^131I,PBS及腹腔注射^131I-抗HBs Fab。5d后每组各取2只作组织分布测定,其余观察3周,计算各组肿瘤生长抑制率。结果 瘤内注射^131I-抗HBs Fab组放射性计数瘤／肝比值是腹腔注射组的9倍,3周后前者肿瘤生长抑制率高于后者,分别为62．3％和46．7％。结论 采用瘤内注射^131I标记人源抗HBs Fab导向治疗肝癌,具有低毒高效的治疗作用,临床实用价值大。     

131I-BAC5和CT-BAC5联合应用对鼻咽癌CNE-2细胞微球的作用

目的 观察中华眼镜膜毒素（CT）和131I与抗鼻咽癌（NPC）单克隆抗体BAC5的偶联物，对NPC CNE－2细胞微球的抑制或破坏作用。方法 采用氯胺－T法制备131－I－BAC5，并用异型双功能交联剂（SPDP）偶联CT－BAC5，分别或联合应用于NPC CNE－2细胞微球，观察微球生长的体积变化率和评价其受抑制或受破坏的情况，结果 CT和BAC5的偶联率为32．4％，与对照组比较，CT对微球的生长无明显抑制作用（P＞0．05），CT－BAC5的偶联率为32．4％，与对照组比较，CT对微球的生长无明显抑制作用（P＞0．05），CT－BAC5有明显的抑制作用（P＜0．05），131I－BAC5，131I－BAC5＋CT－BAC5有非常明显的破坏作用（P＜0．01），结论 肿瘤多细胞微球是一种用于体外研究肿瘤治疗效果的理想模型之一，CT－BAC5和131I－BAC5联合免疫导向治疗NPC比单项治疗效果更好。     

~(131)IBAC_5和CT-BAC_5联合应用对鼻咽癌CNE-2细胞微球的作用

目的　观察中华眼镜蛇膜毒素 (CT)和131I与抗鼻咽癌 (NPC)单克隆抗体BAC5的偶联物 ,对NPCCNE 2细胞微球的抑制或破坏作用。方法　采用氯胺 T法制备131I BAC5,并用异型双功能交联剂 (SPDP)偶联CT BAC5,分别或联合应用于NPCCNE 2细胞微球 ,观察微球生长的体积变化率和评价其受抑制或受破坏的情况。结果　CT和BAC5的偶联率为 32 .4% ,与对照组比较 ,CT对微球的生长无明显抑制作用 (P >0 .0 5 ) ,CT BAC5有明显的的抑制作用 (P <0 .0 5 ) ,131I BAC5、131I BAC5 CT BAC5有非常明显的破坏作用 (P <0 .0 1)。结论　肿瘤多细胞微球是一种用于体外研究肿瘤治疗效果的理想模型之一。CT BAC5和131I BAC5联合免疫导向治疗NPC比单项治疗效果更好。     

hNIS基因的靶向性转染介导肝癌131I治疗

目的探讨鼠白蛋白基因启动子／增强子（mAlb）调控下人钠／碘同向转运体（hNIS）基因的组织特异性表达介导^131 I治疗肝癌的可行性。方法构建mAlb调控下萤光素酶表达载体和mAlb引导下hNIS/潮酶素共表达的重组逆转录病毒载体，后者用脂质体法转染包装细胞获取重组逆转录病毒颗粒感染鼠肝癌细胞MH3924A，建立稳定表达细胞系，并在体内和体外水平评价重组肝癌细胞对^125 I的摄取和流出，以及”。I对转染后肝癌细胞的杀伤作用及在移植瘤模型中的生物分布。结果体外培养条件下，hNIS基因稳定转染细胞系摄取^125 I高出野生型肝癌细胞240倍，该摄取过程可被Na^＋／K^＋-ATP酶抑制剂哇巴因（Ouabain）和NIS特异性阻断剂NaCIO4阻断。在含3．7MBq/ml^131 I的培养液中培养7h后，重组肝癌细胞和野生型肝癌细胞存活率分别下降了86％和8％。静脉注射^131I后，重组肝癌细胞移植瘤摄取量较对照高出19．2倍，静脉注射治疗剂量的^131 I后重组肝癌细胞移植瘤的生长明显受抑制。结论证实mAlb引导下hNIS基因的组织特异性表达介导^131I治疗肝癌的可能性，但疗效有待进一步提高。     

153Sm-EDTMP-纳米羟基磷灰石的生物学性能

目的研究^153Sm-乙二胺四甲撑膦酸(EDTMP)-纳米羟基磷灰石(HA)的体内外生物学性能。方法采用溶胶-凝胶法合成纳米HA并用电镜和X线衍射进行鉴定，采用独立变数法研究^153Sm-EDTMP-纳米HA的最佳标记条件并对产物进行体外稳定性分析，进行^153Sm-EDTMP-纳米HA新西兰兔显像，比较纳米HA、^153Sm-EDTMP和^153Sm-EDTMP-纳米HA对肝癌SMMC-7721和乳腺癌MCF-7细胞的体外抑制作用。结果①纳米HA为针状结晶，结晶度较好，径向10～30nm，轴向70～100nm，X线衍射证明产物为HA。②^153Sm-EDTMP-纳米HA的标记率均在95％以上。体外稳定性好，在生理盐水中放置48h后放化纯仍大于95％。③正常新西兰兔^153Sm-EDTMP-纳米HA显像对比度较好，骨骼系统显示清晰，肾脏显影，血清中放射性下降较快。④^153Sm-EDTMP-纳米HA对肝癌SMMC-7721和乳腺癌MCF-7细胞的半抑制率质量浓度分别为1．98mg／L和0．075mg／L，而纳米HA分别为3．31mg／L和0．52mg／L，^153Sm-EDTMP分别为4．32mg／L和0．67mg／L，^153Sm-EDTMP-纳米HA对肿瘤生长的抑制率明显高于纳米HA和^153Sm-EDTMP。结论^153Sm-EDTMP-纳米HA的骨组织摄取好，有明显的体外抑制肿瘤生长的作用。     

188Re-Herceptin-磁性纳米微粒的体外抗肿瘤作用

目的探讨^188Re—Herceptin-磁性纳米微粒在外置磁场下对HER-2／neu癌基因高表达的SKBR-3乳腺癌细胞的靶向结合性及抗癌作用。方法采用戊二醛交联法使人源性单克隆抗体Her—ceptin与磁性纳米微粒交联，用直接标记法制备^188Re—Herceptin及^188Re—Herceptin-磁性纳米微粒，用羰基铼标记法制备^188Re-磁性纳米微粒。肿瘤细胞体外抑制实验设4个组：^188Re—Herceptin-磁性纳米微粒组、^188Re—Herceptin组、^188Re-磁性纳米微粒组和^188ReO4^-组，各组均设3．7×10^4、18．5×10^4、37×10^4、55．5×10^4、74×10^4Bq／ml5个放射性剂量级别；另设生理盐水对照组。采用四甲基偶氮唑蓝（MTT）法测定各组的抑瘤效应，计算相对抑制率，采用半数抑制放射性浓度（IC50）对各组抑瘤作用进行比较和评价。结果^188Re—Herceptin-磁性纳米微粒和^188Re—Herceptin组对SKBR-3细胞均有较强杀伤作用，且呈剂量依赖性；而^188Re-磁性纳米微粒和^188Re04组的杀伤作用较弱0188Re—Herceptin-磁性纳米微粒组的IC50（53．1×10^4Bq／L）明显低于^188Re—Herceptin组（76．1×10^4Bq／L）；^188Re一磁性纳米微粒组和^188ReO4组的IC50分别为169×10^4和175×10^4Bq／L，明显高于前2组。结论^188Re—Herceptin-磁性纳米微粒和^188Re—Herceptin均可明显抑制体外培养的SKBR-3乳腺癌细胞增殖，且前者的抑制作用较后者强。     

Comparison of the distribution and binding of monoclonal antibodies labeled with 131-iodine or 111-indium

The distribution of two monoclonal antibodies with reactivity against human leukemia/lymphoma associated antigens (BA-1 antibody) and carcinoembryonic antigen (202 antibody) when labeled with 131I or 111In was studied in normal Balb/c mice. The BA-1 antibody of the IgM subclass was labeled with 131I by the micro iodine monochloride method at a 12:1 molar ratio and with 111In by the cyclic DTPA anhydride method at a 10:1 molar ratio. In vitro, the 131I-labeled BA-1 antibody bound 35.5% to 10(7) KM-3 leukemic cells while the 111In-labeled BA-1 antibody bound 29.9% to the same number of KM-3 cells. In vivo, the 111In-labeled BA-1 antibody showed a higher accumulation in liver, spleen, and kidney than the 131I-labeled BA-1 antibody. The 202 antibody of the IgG1 subclass was labeled with 131I at a 5:1 molar ratio and with 111In at a 7:1 molar ratio. In vitro, the 131I-labeled 202 antibody bound 30.9%, 27.4%, and 30.0% to 10(7) CO-112, WIDR, and LS-174T colon cancer cells, respectively. The 111In-labeled 202 antibody bound 20.5%, 30.2%, and 33.6%, respectively to the same number of colon cancer cells. In vivo, the 131I-labeled 202 antibody showed a higher tissue to blood ratio in liver, spleen, and kidney than the 111In-labeled 202 antibody. The data indicate that the relative distribution of 131I-labeled versus 111In-labeled monoclonal antibody may depend on the immunoglobulin subclass of the antibody and the molar ratio used in labeling.     

钾通道阻断剂四乙铵对卵巢癌细胞增殖及凋亡的影响

目的 研究钾通道阻断剂四乙铵(TEA)对卵巢癌细胞(SKOV3)凋亡的影响.方法 将浓度为2×104/ml的卵巢癌细胞分别设对照组和不同浓度(1、5、10、20mmol/L)TEA组.将TEA作用于卵巢癌细胞,用MTT法检测细胞活性,采用Hoechest33258染色检测细胞凋亡,同时通过碘化丙啶(PI)染色,采用流式细胞仪检测细胞凋亡比率.结果 在TEA浓度为1、5、10、20mmol/L时,对SKOV3细胞增殖的抑制率分别为8.61%、18.86%、46.63%和65.22%,表明TEA对SKOV3细胞的增殖有抑制作用并呈现明显的剂量依赖性,当TEA浓度=5mmol/L时,对SKOV3细胞增殖的抑制效应明显;Hoechst33258染色结果显示,TEA能诱导SKOV3细胞凋亡;流式细胞仪检测结果表明,SKOV3细胞经TEA浓度为1、5、10、20mmol/L处理后48h,其细胞凋亡率分别为9.23%、21.57%、54.22%和71.06%,与对照组(2.08%)比较,差异有显著性(P＜0.01),提示TEA可诱导SKOV3细胞凋亡,且TEA促进SKOV3细胞凋亡作用具有一定的剂量依赖性.结论 钾通道对SKOV3细胞增殖具有重要调控作用,钾通道阻断剂TEA阻断钾通道后可促进细胞凋亡.     

杆状病毒介导NIS基因放射治疗甲状腺癌的实验研究

目的探讨重组钠／碘同向转运体(NIS)基因杆状病毒介导甲状腺癌细胞放射性碘治疗的可行性。方法构建杆状病毒载体质粒(pFBNIS)并制备重组NIS杆状病毒(BacNIS)，体外感染甲状腺癌细胞，通过免疫荧光检测NIS蛋白的表达，通过动态摄碘及NaC104摄碘抑制实验观察表达蛋白的功能和特性；进行^131I杀伤细胞的克隆形成实验。结果成功构建了重组NIS杆状病毒，受巨细胞病毒(CMV)极早期基因启动子调控；BacNIS体外感染的甲状腺癌细胞表达的NIS蛋白具有摄碘功能和NaC104抑制的特性；BacNIs感染的肿瘤细胞可被^131I有效杀伤。结论BacNIS是介导肿瘤细胞摄碘的有效方法，为杆状病毒介导NIS基因治疗失分化甲状腺癌转移灶提供依据。     

Relative therapeutic efficacy of (125)I- and (131)I-labeled monoclonal antibody A33 in a human colon cancer xenograft.

A33, a monoclonal antibody that targets colon carcinomas, was labeled with (125)I or (131)I and the relative therapeutic efficacy of the 2 radiolabeled species was compared in a human colon cancer xenograft system. METHODS: Nude mice bearing human SW1222 colon carcinoma xenografts were administered escalating activities of (125)I-A33 (9.25-148 MBq) or (131)I-A33 (0.925-18.5 MBq), (125)I- and (131)I-labeled control antibodies, unlabeled antibody, or no antibody. The effects of treatment were assessed using the endpoints of tumor growth delay and cure. RESULTS: Tumor growth delay increased with administered activity for all radiolabeled antibodies. Approximately 4.5 times more activity was required for (125)I-A33 to produce therapeutic effects that were equivalent to those of (131)I-A33. This ratio was approximately 7 for a nonspecific, noninternalizing isotype-matched, radiolabeled control antibody. Unlabeled A33 antibody had no effect on tumor growth. Approximately 10 times more activity of (125)I-A33 produced toxicity similar to that of (131)I-A33, and this ratio fell to approximately 6 for radiolabeled control antibody. CONCLUSION: Treatment with (125)I-A33 resulted in a relative therapeutic gain of approximately 2 compared with (131)I-A33 in this experimental system.     

Radioimmunoscintigraphy of xenografted human thyroid carcinoma

We developed monoclonal antibodies against human thyroid cancer-associated antigen by fusing mouse myeloma cells with mouse spleen cells immunized by insoluble fraction of homogenized thyroid papillary carcinoma cells. One monoclonal antibody (KTC-3, IgM) was selected to evaluate basic usefulness for radioimmunoscintigraphy in xenografted human thyroid carcinoma. KTC-3 was labeled with 131I by Iodogen method of 20 to 1 Iodogen to IgM molar ratio. It was also labeled with 111In by cyclic DTPA anhydride method of 20 to 1 DTPA to IgM molar ratio. The labeling efficiency and specific activity for 131I labeling were 16.5% and 0.66 mCi/mg IgM respectively, and those for 111In labeling were 12.7% and 1.6 mCi/mg IgM. Imaging and biodistribution of labeled KTC-3 were evaluated in nude mice bearing thyroid anaplastic carcinoma (THC-5-JCK). The tumors were well visualized 3 and 5 days after injection of 131I KTC-3. Tumor uptake of 131I KTC-3 on day 7 was 0.52 +/- 0.27% ID/g and tumor to blood ratio was 1.98 +/- 0.76 (n = 6). Those of 111In KTC-3 were 0.88 +/- 0.09% ID/g and 5.51 +/- 3.36 (n = 6). In conclusion, KTC-3 is promising for radioimmunoscintigraphy of thyroid cancer.     

Antiepidermal growth factor variant III scFv fragment: effect of radioiodination method on tumor targeting and normal tissue clearance

INTRODUCTION: MR1-1 is a single-chain Fv (scFv) fragment that binds with high affinity to epidermal growth factor receptor variant III, which is overexpressed on gliomas and other tumors but is not present on normal tissues. The objective of this study was to evaluate four different methods for labeling MR1-1 scFv that had been previously investigated for the radioiodinating of an intact anti-epidermal growth factor receptor variant III (anti-EGFRvIII) monoclonal antibody (mAb) L8A4. METHODS: The MR1-1 scFv was labeled with (125)I/(131)I using the Iodogen method, and was also radiohalogenated with acylation agents bearing substituents that were positively charged--N-succinimidyl-3-[*I]iodo-5-pyridine carboxylate and N-succinimidyl-4-guanidinomethyl-3-[*I]iodobenzoate ([*I]SGMIB)--and negatively charged--N-succinimidyl-3-[*I]iodo-4-phosphonomethylbenzoate ([*I]SIPMB). In vitro internalization assays were performed with the U87MGDeltaEGFR cell line, and the tissue distribution of the radioiodinated scFv fragments was evaluated in athymic mice bearing subcutaneous U87MGDeltaEGFR xenografts. RESULTS AND CONCLUSION: As seen previously with the anti-EGFRvIII IgG mAb, retention of radioiodine activity in U87MGDeltaEGFR cells in the internalization assay was labeling method dependent, with SGMIB and SIPMB yielding the most prolonged retention. However, unlike the case with the intact mAb, the results of the internalization assays were not predictive of in vivo tumor localization capacity of the labeled scFv. Renal activity was dependent on the nature of the labeling method. With MR1-1 labeled using SIPMB, kidney uptake was highest and most prolonged; catabolism studies indicated that this uptake primarily was in the form of epsilon-N-3-[*I]iodo-4-phosphonomethylbenzoyl lysine.     

Radioimmunoscintigraphy of advanced gastrointestinal carcinomas employing I-131 labeled CEA-79 monoclonal antibody

CEA-79 is a murine IgG2a type monoclonal antibody (MoAb) generated using purified CEA from culture supernatants of a human colon cancer cell line, LS174T. The association constant and immunoreactivity of the I-131 labeled CEA-79 ranged from 2.0 to 3.2 ×10⁹ l/mole, and from 54 to 74 %, respectively. The purpose of this study was to evaluate the feasibility of radioimmunoscintigraphy employing MoAb CEA-79 in patients with advanced gastrointestinal carcinomas. Two mgs of MoAb CEA-79 was labeled with 111 MBq (3 mCi) of I-131, and infused intravenously in 6 stomach cancer and 16 colon cancer patients. Out of 6 patients with stomach cancer, immunoscintigraphy was able to detect the tumors in 4 cases. However, immunoscintigraphy found out tumors in all patients with colon cancer. Moreover, 1 patient with stomach cancer and 2 patients with colon cancer showed increased uptake of MoAb in the tumor lesions despite normal serum levels of CEA. We could conclude that this antibody has a potential as a new imaging agent for the diagnosis of gastrointestinal carcinoma.     

Effects of temperature on radiochemical purity and immunoreactivity of radiolabeled monoclonal antibody 1H10

OBJECTIVE: This study was undertaken to investigate the effects of temperature on preserving the radiochemical purity and immunoreactivity of 125I- and 131I-labeled monoclonal antibody (MAb) 1H10--an antibody against human cervical carcinoma cell-surface antigen. METHODS: An antibody-irrelevant human melanoma cell line, H2269, served as the control group. Iodine-125 and 131I radiolabeling of MAbs 1H10 and H2669 was performed by the chloramine-T method. All the prepared MAbs were divided into aliquots and stored at 4, -20, and -70 degrees C for 2-14 d. The radiochemical purity and immunoreactivity of the labeled antibodies in set conditions were measured by thin-layer chromatography and a modified index, respectively, after a single freeze-and-thaw cycle. RESULTS: Reduced release of free radioiodide and better preservation of immunoreactivity were observed in the radiolabeled MAbs stored at -70 degrees C than in those stored at -20 degrees C or 4 degrees C. The extent of free iodide dissociation and immunologic binding degradation of 125I-labeled MAb 1H10 appeared milder than that of 131I-labeled MAb under the same conditions. However, both 125I- and 131I-labeled MAb stored at -70 degrees C or -20 degrees C retained more than 90% radiochemical purity for at least 3d. CONCLUSION: Freezing provides an appropriate alternative for reducing radiolysis and preserving immunoreactivity of radioiodinated MAbs. MAb 1H10, labeled with either 125I or 131I and stored at temperatures of -20 degrees C or below for 3 d after labeling, appeared stable in both radiolabeling and binding studies in vitro and was still acceptable for in vivo use.     

腺病毒介导的RNA干扰ERCC1基因表达对卵巢癌顺铂化疗的增敏作用

 目的 探讨腺病毒介导的RNA干扰ERCC1基因表达对卵巢癌顺铂化疗的增敏作用。方法 采用直接感染法、台盼蓝活细胞计数、MTT、Hoechst染色法及流失细胞仪检测等方法,绘制SKOV3细胞生长曲线及倍增时间,检测SKOV3细胞感染重组病毒前后其顺铂的IC₅₀值、细胞凋亡形态及细胞各周期的分布。结果 (1)顺铂浓度与SKOV3细胞抑制率呈线性正相关,相关系数r=0.9905(P<0.05),顺铂IC₅₀值为(7.76±0.37)μg/ml;腺病毒载体介导的RNA干扰ERCC1基因表达后,SKOV3细胞的生长受到一定程度的抑制;(2)与对照组相比,梯度浓度的重组腺病毒感染后,SKOV3细胞对顺铂的敏感性分别增加了9.4%、16.4%、23.2%、33.5%,呈剂量依懒性;(3)梯度滴度重组腺病毒表达载体联合顺铂作用于SKOV3细胞株,细胞凋亡显著增高;(4)重组腺病毒表达载体感染并联合顺铂用药,G₁期细胞比例减小,S期细胞比例增大,细胞凋亡率进一步增高。结论 重组腺病毒表达载体可以通过诱导肿瘤细胞凋亡、调节肿瘤细胞周期分布等途径增加SKOV3细胞对顺铂的敏感性。     

131I-cRGD环肽对荷黑色素瘤小鼠的靶向治疗作用

目的 用131I标记环精氨酸-甘氨酸-天冬氨酸(cRGD)肽-探讨131I-cRGD对荷黑色素瘤小鼠模型瘤体生长的双重抑制作用.方法 应用氯胺T法对cRGD进行131I标记.建立荷黑色素瘤B16株小鼠模型,将20只荷瘤小鼠按完全随机化法分为4组,每组5只.即实验(131I-cRGD)组、cRGD对照组、131I-甘氨酸-甘氨酸-甘氨酸(cGGG)对照组和空白对照(PBS)组.分别经尾静脉注射相应药物,观察各组倚瘤小鼠肿瘤体积和质量的变化,利用单因素方差分析比较各组之间的差异.结果 131I-cRGD的标记率和放化纯分别达到(89.14±4.57)%及(99.14±0.72)%.治疗第2l天时.各组与PBS组肿瘤体积相比.抑瘤率分别为64.92%(131I-cRGD组)、37.70%(cRGD组)及24.78%(131I-cGGG组);治疗第28天时,处死各组小鼠,其瘤质量(含治疗第2l～28天自然死亡的4只小鼠)分别为131I-cRGD组(6.48±5.19)g、cRGD组(10.81±6.25)g、131I-cGGG组(14.21±5.91)g、PBS组(18.88±7.59)g(F=3.479,P<0.05),131I-cRGD组与PBS组之间差异有统计学意义(t=3.12,P<0.05).各组与PBS组肿瘤质量相比,抑瘤率分别为65.72%(131I-cRGD组)、42.76%(cRGD组)及24.77%(131I-cGGG组).治疗第28天时,各组小鼠净体质量(净体质量=小鼠体质量一瘤质量,含治疗第2l～28天死亡的4只小鼠)分别为(29.12±8.66)g(131I-cRGD组)、(25.89±6.49)g(cRGD组)、(24.29±2.97)g(131I-cGGG组)、(20.92±5.95)g(PBS组).差异尤统计学意义(F=1.444,P>0.05).结论 131I-cRGD能抑制荷黑色素瘤小鼠肿瘤的生长,对黑色素瘤治疗具有潜在的价值.