放疗对结肠癌细胞种植瘤血管生成的影响

目的:观察荷瘤鼠接受放疗前后,肿瘤组织内微血管密度及血管内皮生长因子表达的变化,探讨放疗对肿瘤血管生成的作用.方法:20只小鼠接种结肠癌细胞SW480,随机分为对照组和放疗组.放疗组接受总量20 Gy的照射.放疗结束后第5 d处死小鼠,免疫组化法测定肿瘤组织内微血管密度和肿瘤细胞VEGF表达阳性率,比较两组间的差异.结果:放疗组和对照组肿瘤组织内MVD值分别为8.40±4.22和14.40±4.65 (P=0.007);VEGF表达阳性率分别为2.07±0.569和1.44±0.608(P=0.028),均有明显差异.结论:放疗可减少荷瘤鼠肿瘤的血管数量,提高血管内皮生成因子的表达.     

131I标记的抗肝癌血管内皮细胞单克隆抗体对肝癌治疗的实验研究

目的运用131I标记的抗肝癌血管内皮细胞单克隆抗体,研究靶向血管内皮细胞治疗肝癌的可行性.方法 建立裸小鼠人肝细胞癌动物模型,取30只裸鼠随机分为3组,分别为实验A组、实验B组和对照组,每组各10只.实验A组在接种肝癌细胞的同时,经腹腔注射抗肝癌血管内皮细胞的单克隆抗体,每只200μg/200μl,2次/周;实验B组在接种肝癌细胞的同时,经腹腔注射同剂量的131I标记的抗肝癌血管内皮细胞的单克隆抗体;对照组在接种肝癌细胞的同时,经腹腔注射等量的生理盐水.观察肿瘤的生长情况,计算肿瘤的体积,计算抑瘤率.结果 实验A组的抑瘤率为74.55%,实验B组为86.36%;实验A、B组与对照组比较肿瘤明显受抑(P<0.05).实验B组与实验A组比较显示了明显的放疗作用(P<0.05).HE及免疫组化染色观察证实,经单抗治疗后肿瘤区微血管内血栓形成,血管内皮细胞变性、坏死,血管周围大片肿瘤细胞坏死,瘤内血管密度明显降低.结论 抗肝癌血管内皮细胞单克隆抗体在动物实验中有明显的抑瘤作用,以此抗体为载体与核素相结合,可明显提高治疗肿瘤的疗效.     

缺氧对肺腺癌细胞生长特性及血管形成的影响

目的探讨缺氧对肺腺癌肿瘤生长及血管形成的影响。方法人肺腺癌细胞株A549暴露于常氧(空气，5%CO2)、缺氧(1％O2，5％CO2，94%N2)、无氧(95％N2，5%CO2)环境48h后，将细胞接种于裸鼠皮下，观察其生长情况。通过免疫组化染色计数微血管密度，测定移植瘤组织中血管内皮细胞生长因子(VEGF)及碱性成纤维细胞生长因子(bFGF)的表达水平。结果移植10天后，缺氧组肿瘤体积显著大于常氧组。移植25天后缺氧组肿瘤体积、重量、微血管密度以及瘤组织中VEGF、bFGF水平均显著高于常氧组，而无氧组显著低于常氧组。结论适度缺氧可以刺激肺癌细胞VEGF、bFGF等生长因子的表达，促进移植瘤血管形成，提高肿瘤的生长能力；而严重缺氧损伤癌细胞，影响生长因子合成表达，阻碍血管形成，抑制肿瘤的生长。     

pSilence APE1抑制骨肉瘤生长的实验研究

的观察脱嘌呤／脱嘧啶核酸内切酶（APE1）siRNA表达载体pSilence APE1对骨肉瘤裸鼠移植瘤生长的抑制作用,探讨APE1与骨肉瘤发生、发展的关系。方法人骨肉瘤细胞9901荷瘤裸鼠20只随机分为2组：脂质体对照组（n=10）和pSilence APE1治疗组（n=10）。在实验第12天处死动物,计算抑瘤率。免疫组化SP法检测骨肉瘤细胞APE1蛋白的表达和肿瘤微血管密度、增殖指数变化;TUNEL法检测肿瘤细胞凋亡的变化。结果pSilence APE1处理组肿瘤细胞APE1表达显著降低,抑瘤率为38．23％,肿瘤微血管密度和增殖指数明显低于对照组,而肿瘤凋亡显著增加。结论靶向敲低APE1表达能显著抑制骨肉瘤的生长。     

不同磷脂补充对力竭运动小鼠心肌线粒体NO、Ca~(2+)和ATP含量的影响

目的:探讨不同磷脂补充对小鼠心肌线粒体功能的影响。方法:雄性昆明种小鼠48只,随机分为4组:安静对照组、运动对照组、大豆磷脂补充组和肝磷脂补充组。后3组每天早、晚两次灌胃,肝磷脂补充组为18mg/ml的肝磷脂悬浊液,大豆磷脂补充组为18mg/ml的大豆磷脂悬浊液,运动对照组灌胃生理盐水,共2周。饲养2周后除安静对照组外,其余各组均进行一次力竭游泳。运动后即刻分别测定小鼠心肌线粒体NO、游离Ca2+和ATP含量。结果:(1)力竭运动后运动对照组NO含量显著高于安静对照组,磷脂补充组显著低于运动对照组;3个运动组力竭运动后Ca2+和ATP含量均显著低于安静对照组,两个磷脂补充组Ca2+和ATP含量显著高于运动对照组。两磷脂补充组各指标均无明显差异。(2)两个磷脂补充组小鼠游泳力竭时间均显著长于运动对照组,且肝磷脂补充组小鼠力竭游泳时间略长于大豆磷脂补充组,但无统计学意义。结论:磷脂补充可以削弱力竭运动对线粒体的影响,使ATP生成增多,运动时间延长。两种磷脂补充效果无明显不同。     

血管内皮生长因子反义寡聚脱氧核苷酸与碘油混合栓塞治疗大鼠肝癌的实验研究

目的　观察血管内皮生长因子 (vascularendothelialgrowthfactor,VEGF)反义寡聚脱氧核苷酸 (antisenseoligodeoxynucleotides,asODN)抑制体外培养的Walker 2 5 6瘤细胞VEGF表达的情况 ,评价其与碘油混合行肝动脉栓塞对大鼠肝癌的治疗效果。方法　将反义和正义VEGF寡核苷酸加入无血清培养的Walker 2 5 6瘤细胞的培养液中 ,4 8h后酶联免疫吸附试验 (ELISA)法测定上清VEGF含量 ,并观察上清刺激血管内皮细胞 (ECV 30 4 )生长受抑情况。 30只Walker 2 5 6移植性大鼠肝癌模型数字法随机分成 3组 ,分别经肝动脉注入超液态碘油 (UFLP) 0 2ml(UFLP组 ,n =10 ) ,UFLP 0 2ml+VEGFasODN 3OD混合物 (UFLP +asODN组 ,n =10 ) ,生理盐水 0 2ml (对照组 ,n =10 )。于术前及术后第 7天行MR检查观察肿瘤的体积 ,用逆转录聚合酶链反应 (RT PCR)方法检测瘤内及瘤周VEGFmRNA含量 ,免疫组织化学法检测肿瘤组织VEGF的表达及微血管密度 (microvesseldensity ,MVD)。结果　VEGFasODN可以明显抑制培养的Walker 2 5 6瘤细胞VEGF的表达。动脉栓塞实验中 ,UFLP +asODN组肿瘤生长率明显低于UFLP组和对照组 [分别为 (14 0 1± 33 8) %、(177 9± 6 4 9) %和 (4 0 3 9±6 9 4 ) % ;F =6 0 0 2 ,P <0 0 1]。瘤内及瘤周VEGFmRNA含量     

肝动脉化疗栓塞联合动脉内灌注促肝细胞生长素对兔VX2肝癌模型的疗效研究

目的 观察肝动脉化疗栓塞(transcatheter arterial chemoembolization,TACE )联合动脉内灌注促肝细胞生长素治疗实验兔肝种植瘤灶的疗效.材料与方法30只VX2肝癌模型兔随机分为3组,A组(n=10):单纯TACE组;;B组(n =10);TACE+局部肝动脉促肝细胞生长素灌注组;C组(n=10):假手术组,经肝动脉造影并灌注生理盐水2ml.分别于术前1天及术后3,7,28天抽血检查血清丙氨酸氨基转移酶(ALT);于术前1天及术后28天测量肿瘤最大直径和最小直径(超声),计算肿瘤体积及肿瘤体积增长率,术后28天处死实验动物,行HE染色与免疫组织化学染色(抗CD34染色),计算肿瘤微血管密度(MVD).结果 介入干预前1天3组ALT水平差异无统计学意义(P>0.05);介入干预后3,7,28天3组动物ALT水平差异有统计学意义(P<0.05).术后28天3组动物肿瘤体积、肿瘤体积增长率分别为:A组(3.42±0.45)cm 3、(316.77±82.44)%;B组(4.92±0.38)cm3,(551.36±121.92)%;C组(8.11±0.52) cm3,(818.70±231.27)%.3组两两相比肿瘤体积及肿瘤增长率差异均有统计学意义(P<0.05).术后第28天A,B,C 3组肿瘤MVD分别为:75.97±11.46,85.34±4.90,63.88±10.04,3组两两相比差异均有统计学意义(P<0.05).结论 TACE联合动脉内灌注促肝细胞生长素治疗兔VX2肝癌,可明显改善TACE后肝功能的损伤;但同时也促进了TACE后残余肿瘤新生血管生成及体积的增长.     

新城疫病毒感染瘤细胞的抗瘤作用

目的 探讨了新城疫病毒感染小鼠肝癌细胞H_(22)后,制备的癌细胞瘤苗对小鼠的抗肿瘤保护作用,并检测细胞免疫原性的影响。方法 将经新城设病毒感染的小鼠肝癌细胞H_(22)为瘤苗进行免疫接种,同对照比较其对小鼠抗瘤保护作用和小鼠NK细胞活性与小鼠淋巴细胞敏感性。结果 新城疫病毒感染并杀伤的癌细胞制备的瘤苗可完全排斥再次接种未经病毒处理瘤细胞的攻击和生长,瘤苗能增强小鼠的免疫功能,免设组与对照组的NK细胞活性同淋巴细胞敏感性具有显著差异(P<0.01)。结论 新城疫病毒感染小鼠肝癌细胞后制备的癌细胞瘤苗能直接使小鼠排斥接种的癌细胞攻击,并能提高小鼠NK细胞活性和小鼠淋巴细胞敏感性。     

ACI大鼠肝细胞癌模型的免疫化疗栓塞术研究

目的:评价生物反应调节剂(BRM)经肝动脉化疗栓塞术(TACE)治疗ACI大鼠肝细胞癌的疗效。方法:在30只雄性ACI大鼠肝包膜下植入Morris Hepatom 3924A肝癌瘤块(2 mm3),移植术后13天行MRI检查,测量肿瘤体积V1;第14天时,经腹部切开术及胃十二指肠动脉逆行插管而采取以下3种介入治疗方案:①A组,0.1 mg丝裂霉素、0.1 ml碘油、7.5μg TNFα和5×103IU IL-2(n=10);②B组,0.1 mg丝裂霉素、0.1 ml碘油、0.05 mg链球菌提取物(OK-432)和5×103IU IL-2(n=10);③C组(对照组),0.1 mg丝裂霉素、0.1 ml碘油(n=10);13天后再次行MRI检查以确定肿瘤体积V2变化。比较肝肿瘤体积生长率V2/V1。结果:肿瘤治疗前和治疗后体积分别为A组0.0377 cm3和0.2752 cm3;B组0.0344 cm3和0.2233 cm3;C组0.0380 cm3和0.3398 cm3。介入治疗后肿瘤体积与治疗前肿瘤体积之比(V2/V1)分别为A组7.31、B组6.53、C组9.14。与对照组相比,采取A组的治疗方案能抑制肝肿瘤体积的生长(P=0.042),采取B组的治疗方案能明显抑制肿瘤的生长(P=0.004)。结论:采取免疫化疗栓塞术能有效抑制ACI大鼠肝细胞癌的生长。     

氟MRI监测高强度超声射频消融后的肿瘤炎症反应

目的研究高强度聚焦超声(HIFU)诱导的巨噬细胞浸润是否可以用~(19)F MRI进行定量动态监测。材料与方法将皮下接种4T1细胞的BALB/c小鼠分成3组:未治疗的小鼠(对照,n=9),HIFU处理的小鼠(HIFU,n=9)和HIFU+氯膦酸盐处理的小鼠(HIFU+Clod,n=9)。所有小鼠静脉内给予全氟化碳乳剂,并在行HIFU治疗后的第2、4、7、10和14天进行MRI检查。采用双向重复测量方差分析来检验~(19)F信号随时间的变化和组间的差异。组织学检查以确认活体内数据。结果在肿瘤边缘和消融病灶周围检测到19F信号。HIFU治疗后前4天,HIFU组小鼠的~(19)F信号明显大于对照组(0.82±0.26∶0.42±0.17,P0.001)。在HIFU治疗后第4~14天,HIFU+Clod组小鼠平均~(19)F信号显著高于对照组小鼠(0.55±0.16∶0.28±0.06,P0.05)。组织学检查显示消融病灶周围有巨噬细胞浸润。免疫荧光染色验证巨噬细胞的全氟化碳标记。结论 ~(19)F MRI可以在临床前肿瘤模型中动态捕获和定量分析HIFU诱导的巨噬细胞。     

HIF-1α基因沉默对人肺癌放射敏感性及移植瘤生长的影响

目的 探讨HIF-1α基因沉默对A549肺癌细胞放射敏感性及裸鼠移植瘤生长的影响。方法 采用克隆形成实验,评价A549/HIF-1α(-)细胞及A549细胞对X射线的敏感性。将A549/HIF-1α(-)细胞及A549细胞接种于BALB/C雄性裸小鼠,观察肿瘤生长情况。免疫组织化学法检测肿瘤内HIF-1α蛋白的表达及瘤内微血管密度。结果 HIF-1α基因沉默在常氧条件下放射增敏比 (SER) 为1.06,乏氧条件下为1.65。A549/HIF-1α(-)组移植瘤体积明显小于A549组,A549/HIF-1α(-)组肿瘤细胞HIF-1α蛋白表达显著下降, A549组肿瘤微血管密度为19.83±4.09,而A549/HIF-1α(-)组为11.61±3.04(F=15.57,P<0.05)。结论 HIF-1α基因沉默可以逆转乏氧诱导的A549肺癌细胞对X射线敏感性的降低,并延缓裸鼠移植瘤的生长,使HIF-1α蛋白表达下降和血管生成减少。     

Hepatic colorectal cancer metastases: imaging initial steps of formation in mice

PURPOSE: To prospectively use optical imaging to study the cell-specific mechanisms of entrapment and subsequent growth of two human colon cancer cell lines differing in their propensity to form hepatic metastases. MATERIALS AND METHODS: In this Animal Care Committee-approved study, intravital optical imaging was performed in exteriorized livers of three groups of mice after intrasplenic inoculation of human colon cancer cells. Group 1 mice (control group; n=12) received a cell-maintaining solution only. Groups 2 and 3 (n=12 in each) were administered poorly (MIP-101 colon cancer cells) or highly (CX-1 colon cancer cells) metastatic cells. Imaging was performed on postinoculation days 0, 1, 3, and 6 to document sites and mechanisms of tumor cell entrapment and presence and sites of endothelial cell activation and of tumor cell interactions with systemic macrophages and Kupffer cells. Fluorescence intensity of Kupffer cells was compared by using the Mann-Whitney test. Immunohistochemistry served as the reference standard for all in vivo observations. RESULTS: Whereas both MIP-101 and CX-1 colon cancer cells adhered to periportal Kupffer cells, the CX-1 cells resulted in Kupffer cell activation, evidenced in vivo by increased visible peroxidase activity (P<.05). Only CX-1 cells were associated with subsequent downstream endothelial cell activation, evidenced by in vivo expression of E-selectin. By day 6, regression of periportal MIP-101 tumor growth correlated with ingrowth of systemic macrophages, while CX-1 tumor growth, originating in the outflow venous regions, correlated with translobular migration and ingrowth of activated Kupffer cells. Conclusion: Formation of hepatic colon cancer metastases is cancer cell-type specific, with cell lines differing in their mechanisms and intrahepatic locations of initial entrapment and Kupffer cell activation and subsequent growth.     

Effect of transcatheter hepatic arterial embolization on angiogenesis in an animal model

OBJECTIVES: Transcatheter arterial embolization (TAE) is used for the treatment of patients with malignant liver tumors. However, the proangiogenesis effect of TAE-associated hypoxia has not been adequately studied. The goal of this study was to determine angiogenic activity in tumors subjected to TAE by evaluating the tumor microvessel density (MVD). MATERIALS AND METHODS: Mammary cancer 13762 NF tumor cells were inoculated into the livers of male Sprague-Dawley rats. TAE was performed 12-14 days after tumor inoculation. Rats were divided into 4 groups on the basis of treatment type. Control group animals (n = 16) were subjected to sham TAE without polyvinyl alcohol (PVA) particles. Animals in the other 3 groups were subjected to TAE with 1 (n = 11), 2 (n = 8), or 3 (n = 10) mg of PVA particles. Rats were killed 3-6 hours or 2 or 3 days after embolization, and the liver tumor tissues were dissected and frozen in liquid nitrogen. Tumor tissue slides were prepared, stained with CD-31, and evaluated for MVD. Blood samples collected just before sacrificing the animals were used to measure serum vascular endothelial growth factor (VEGF) levels. RESULTS: Tumors treated with TAE showed varying degrees of central necrosis with residual viable tumor cells in the periphery. Tumor MVD in animals treated with TAE was significantly higher than that in the control group (23.6 versus 17.5; P = 0.001). Although the MVD in animals treated with TAE using 1 mg of PVA was higher than that in the control group, this difference was not statistically significant. TAE using 2 mg of PVA resulted in a significant increase in tumor MVD (25.9 versus 17.5; P = 0.007). Use of 3 mg of PVA did not result in any further increase in MVD. There was a significant increase in tumor MVD in the animals killed 2 or 3 days after TAE compared with the control group (24.5 versus 17.5; P = 0.002). The animals treated with TAE showed a statistically significant increase in VEGF levels compared with the control group. CONCLUSIONS: TAE of hepatic tumors results in the stimulation of angiogenesis in the residual viable tumor, which could have an adverse effect on the therapeutic efficacy of TAE.     

Hepatic perfusion changes in mice livers with developing colorectal cancer metastases

PURPOSE: To evaluate whether intrahepatic flow alterations occur during formation of hepatic colorectal cancer metastases and to identify possible causes of these alterations. MATERIALS AND METHODS: Intravital imaging of exteriorized livers was performed in 72 live mice. Three groups of mice were studied: a sham-operated control group (n = 24), a group with nonmetastasizing subcutaneous gliomas (n = 24), and a group with developing hepatic CX-1 colon cancer metastases (n = 24). Microvascular flow parameters, leukocyte-endothelial interactions, and wall shear stress were directly measured in hepatic sinusoids and postsinusoidal venules at 2-day intervals prior to and during the development of metastases. The Kruskal-Wallis test was used initially to test for overall equality of medians in each data group. Single posttest comparisons of independent samples were performed with the Mann-Whitney test, with an overall statistical significance of .05. RESULTS: Prior to the development of visible colorectal cancer metastases, significant (P <.05) reductions occurred in sinusoidal and postsinusoidal flow and wall shear rates, coupled with increased leukocyte rolling and adherence. With tumor growth, flow was further compromised in 92% of tumors larger than 0.5 mm in diameter by extrinsic compression of sinusoids and portal venules and narrowing caused by adherent leukocytes. CONCLUSION: Significant intrahepatic flow alterations occur in mouse livers prior to growth of visible metastases and provide a rational explanation for elevation in the Doppler perfusion index that occurs prior to tumor formation.     

氯氧喹对Lewis肺癌细胞及荷瘤小鼠的辐射增敏作用

目的 研究氯氧喹联合X射线对Lewis肺癌细胞及荷瘤小鼠的辐射增敏作用.方法 细胞及动物实验均设置为对照组、给药组、照射组及给药+照射组(联合组)4个组别.采用体外细胞培养MTT检测及荷瘤动物模型观察方法,分别予以不同处理因素后,细胞实验用MTT法检测各组别细胞吸光度(A)值;小鼠皮下接种Lewis肺癌细胞,予以相关处理因素后,观察记录肿瘤生长情况并测量其长、宽径从而计算出肿瘤抑制率及肿瘤生长延迟.照射结束后眼静脉采血,检测各组小鼠血液标本中细胞成分数量的变化情况.结果 MTT实验结果显示,细胞照射24 h后,给药+照射组SF值较单纯照射组有一定的降低,但差异无统计学意义(P＞0.05),而照射48 h后,在10、20、40和80 mg/L浓度下,两组间差异有统计学意义(t=3.22、4.23、4.46和4.58,P＜0.05).动物实验结果显示,给药+照射组的肿瘤生长曲线明显较单纯照射组低平,但差异无统计学意义;给药+照射组的肿瘤控制率及肿瘤生长延迟远高于单独给药组及照射组(t=3.15～3.59,P＜0.05).另外,氯氧喹并未增加辐射对小鼠血液细胞成分的不良反应.结论 氯氧喹对Lewis肺癌细胞及荷瘤小鼠均具有明显的辐射增敏作用,对小鼠血液系统未见明显不良反应,值得进一步深入研究.

Abstract：

Objective To study whether Chloroxoquinoline could enhance the radiation sensitivity of Lewis lung cancer cells and xenograft tumors in tumor-bearing mice.Methods Both cell and animal experiments were divided into control group,drug group,irradiation group and combination group.MTT assay was used to detect the optical density of Lewis lung cancer cells cultured in vitro.The model of tumor-bearing mice was established first and then the tumor diameters of different groups were measured to figure out the tumor control rates and tumor growth delay.After irradiation,the blood samples in each group were collected to detect the amount of blood cells.Results MTT showed 24 hours after irradiation,the cell survival fraction of combination group was lower than that of irradiation group,but no statistical differences (P ＞ 0.05).However,48 hours later,the cell survival fraction of combination group was obviously lower than irradiation group with statistically significant differences( t = 3.22,4.23,4.46,4.58,P ＜ 0.05).Animal experiments showed the tumor growth curve of combination group was significantly lower than irradiation group.The tumor control rate and tumor growth delay of combination group was more above the other groups ( t = 3.15-3.59,P ＜ 0.05 ).Additionally,according to the analysis of blood samples,the hematological toxicity of chloroxoquinoline on mice was not found.Conclusion Chloroxoquinoline shows its radiation sensitizing effect on Lewis lung cancer cells and xenograft tumors in mice without hematological toxicity.     

IFN-γ和内皮抑素双基因联合X射线对小鼠乳腺癌及肺转移的抑瘤作用

目的 评价IFN-γ和内皮抑素(endostatin)双基因-放射治疗在小鼠转移性乳腺癌中的抑瘤效应,并探讨其可能的作用机制。方法 用脂质体包裹pEgr-IFN-γ和 pEgr-endostatin质粒转染小鼠乳腺腺癌4T1 细胞,并用X射线照射,吸收剂量为2~20 Gy。用ELISA检测细胞培养液上清中IFN-γ和内皮抑素的浓度。小鼠下肢注4T1肿瘤细胞1×10⁵个,荷瘤小鼠随机分组为对照组、空质粒组,基因治疗组、放射治疗组及基因-放射治疗组,观察小鼠肿瘤生长及肺转移情况,计算肿瘤生长率、肿瘤/体重比及荷瘤小鼠生存率, 并用流式细胞仪检测脾脏 CTL 和 NK细胞的细胞毒活性,用免疫组织化学法检测肿瘤内部的微血管密度。结果 辐射显著增强了4T1 细胞分泌IFN-γ和内皮抑素的浓度。小鼠接受基因-放射治疗与单独接受基因治疗或者接受放射治疗相比,肿瘤生长率明显降低,同时生存率明显提高(t＝8.724,P<0.05)。双基因联合放射治疗组小鼠脾中CTL 和 NK 细胞的细胞毒活性及腹腔巨噬细胞的TNF-α水平较对照组明显升高(t=2.120、22.140和5.289,P<0.05),微血管密度明显降低(t=13.294,P<0.05)。结论 IFN-γ和内皮抑素的基因-放射治疗增强了小鼠转移性乳腺癌的抑瘤效应,其机制可能与IFN-γ激活 CTL 和 NK 细胞活性及内皮抑素引起肿瘤血管生成抑制有关。     

Murine lung tumor measurement using respiratory-gated micro-computed tomography

OBJECTIVE: The authors explored micro-computed tomography (micro-CT) to quantify lung tumor number and volume in a specific genetic mouse model for lung cancer. MATERIALS AND METHODS: The authors used K-ras mice, which develop lung adenomas and adenocarcinomas through somatic activation of the K-ras oncogene. Tumor number measured using micro-CT and were compared at necropsy (n = 38 mice). Tumor volume measurement precision (n = 39 mice) and accuracy (multiple tumors from a single mouse) were evaluated. Serial lung tumor volume was assessed in a pilot group (n = 8) of mice in vivo. RESULTS: Tumor number assessed at necropsy and using micro-CT were significantly correlated. Lung tumor volume measurements were both reproducible (2% operator variability) and accurate (6% average error). Strikingly, we observed both tumor growth and shrinkage within individual mice. CONCLUSION: Serial measurements provided evidence of tumor heterogeneity, an unexpected finding given the uniformity of the initiating genetic event. Micro-CT may become a powerful tool for murine lung cancer research in vivo.     

Imaging of differential protease expression in breast cancers for detection of aggressive tumor phenotypes

PURPOSE: To determine if different expression levels of tumor cathepsin-B activity in well differentiated and undifferentiated breast cancers could be revealed in vivo with optical imaging. MATERIALS AND METHODS: A well differentiated human breast cancer (BT20, n = 8) and a highly invasive metastatic human breast cancer (DU4475, n = 8) were implanted orthotopically in athymic nude mice. Tumor-bearing animals were examined in vivo with near-infrared fluorescence (NIRF) imaging 24 hours after intravenous injection of an enzyme-sensing imaging probe. Immunohistochemistry, Western blotting (on cells and whole tumor samples), and correlative fluorescence microscopy were performed. RESULTS: Both types of breast cancers activated the NIRF probe so that tumors became readily detectable. However, in tumors of equal size, there was a 1.5-fold higher fluorescence signal in the highly invasive breast cancer (861 arbitrary units +/- 88) compared with the well differentiated lesion (566 arbitrary units +/- 36, P <.01). Western blotting confirmed a higher cathepsin-B protein content in the highly invasive breast cancer (DU4475) of about 1.4-fold (whole tumor samples) to 1.7-fold (cells). Immunohistochemistry and fluorescence microscopy findings confirmed the imaging findings. CONCLUSION: Cathepsin-B enzyme activity can be determined in vivo with NIRF optical imaging, while differences in tumoral expression may correlate with tumor aggressiveness.     

腺病毒介导VEGF启动子驱动的TK及CD融合基因系统与碘油混合栓塞治疗兔肝癌的实验研究

目的 评价携带血管内皮生长因子(VEGF)启动子调控的TK及CD融合双自杀基因重组腺病毒系统(AdVEGF-CDglyTK)与超液化碘油混合栓塞兔肝癌后的治疗效果及安全性. 资料与方法 36只荷VX2瘤兔随机分4组,LP组(单纯超液化碘油栓塞组);LP AdVEGF-CDglyTK组(超液化碘油 AdVEGF-CDglyTK栓塞混合栓塞,介入术后腹腔注射GCV 5-FC治疗组);AdVEGF-CDglyTK组(单纯灌注AdVEGF-CDglyTK,介入术后腹腔注射GCV 5-FC治疗组);NS组(生理盐水治疗组).于术前及术后第10、15天行MRI检查观察肿瘤的体积,免疫组织化学法检测肿瘤组织VEGF的表达及微血管密度(MVD). 结果 4组兔术前肿瘤体积在统计学无显著差异(P>0.05);介入治疗后10天、15天的各组之间肿瘤增长率均有显著性差异(P<0.05),LP AdVEGF-CDglyTK肿瘤增长率最小.VEGF表达方面:LP组表达较其他三组高(P<0.05).MVD:LP AdVEGF-CDglyTK组较其他组低(P<0.05). 结论 在对兔肝癌的治疗中,与单纯碘油栓塞以及单纯灌注AdVEGF-CDglyTK相比,AdVEGF-CDglyTK与碘油混合肝动脉栓塞可以明显降低肿瘤的生长率,减少肿瘤组织VEGF的表达及减少肿瘤新生血管生成.