人脑胶质瘤新生血管的细胞来源与血液流通功能的初步评价

目的 探讨胶质瘤中部分新生血管是否源于胶质瘤干细胞转分化,并初步评价其血液运输功能.方法 将SHG44人脑胶质瘤细胞系接种于30只NC裸小鼠皮下和20只NC裸小鼠脑内尾状核,将SU-2细胞接种于12只表达绿色荧光蛋白的NC/C57BL/6J-绿色荧光蛋白裸小鼠的尾状核内.取移植瘤组织,石蜡切片后,分别进行CD34-PAS双染及CD31、CD34、CD133、胶质纤维酸性蛋白(GFAP)、人类白细胞抗原(Ki67)、HLA免疫组化染色,并结合HLA免疫荧光共聚焦显微成像对移植瘤血管进行分类,对肿瘤血管起源细胞进行鉴定.每组取3只荷瘤鼠,以活性炭颗粒混悬液行心脏灌注,对移植瘤切片进行相应的免疫组化染色,并在光镜下观察炭颗粒在肿瘤血管中的分布.结果 裸小鼠移植瘤中,同时存在CD34-PAS双阳性的内皮细胞依赖型血管、CD34ˉPAS+的血管生成拟态和由肿瘤细胞与CD34+细胞嵌合而成的马赛克血管,炭颗粒随机分布在这些血管腔内.在人脑胶质瘤于细胞移植瘤中,CD31+细胞依附于血管壁腔侧面;CD34+细胞亦沿血管分布,但在形态上介于肿瘤细胞与内皮细胞之间;在血管壁上可见HLA+和人Ki67+细胞,提示构成血管壁的这些细胞来自人源细胞.HLA免疫荧光共聚焦显微成像可见,移植瘤中的血管以表达HLA(红色)的人源肿瘤细胞为主,兼有表达GFP(绿色)的宿主细胞,或人鼠融合细胞.结论 在移植性人脑胶质瘤组织中存在具有血液运输功能的内皮细胞依赖型血管、血管生成拟态和马赛克血管3类血管,人脑胶质瘤干祖细胞有通过分化和转分化机制自主形成后两类肿瘤血管的潜能.     

人肺腺癌脑转移动物模型建立及显像的研究

背景与目的肺癌脑转移是临床常见的严重并发症,由于脑部结构和功能的特殊性、脑转移检测方法的局限性,预后很差。本研究旨在筛选人肺腺癌脑转移细胞株CPA-Yang1-BR以及建立裸小鼠动物模型和检测方法。方法将人肺腺癌细胞株CPA-Yang1-GFP接种于裸小鼠左心室,约7周-8周后比较三种小动物显像方法:microPET/CT显像,X线、放射性核素、荧光(三合一)活体成像系统和小动物线圈MRI显像,实验证明MRI显像是最准确的小鼠脑转移病灶检测方法。脑核磁共振成像(magnaticresonanceimaging,MRI)显像找到脑转移灶,深麻醉处死裸小鼠取出脑转移病灶,部分病理验证,部分行原代培养后获得人肺腺癌脑转移细胞,再次接种裸小鼠,用上述方法重复以上体内外循环4次,观察脑转移形成情况。结果获得人肺腺癌脑转移细胞株CPA-Yang1-BR及其裸小鼠模型。结论 CPA-Yang1细胞经反复裸小鼠脑组织内外筛选的方法可获得具有高转移潜能的裸小鼠脑转移模型,为肺癌脑转移的生物学研究提供了一个良好的技术平台。小动物线圈MRI或microMRI活体显像是检测小鼠肺癌脑转移敏感、准确、无创伤的显像方法。     

外源性IFN-β基因对裸鼠SHG44胶质瘤的诱导凋亡研究

目的:探讨β干扰素基因对人脑胶质瘤的诱导凋亡作用,以及人β干扰素裸DNA治疗人脑胶质瘤的可行性和作用机制.方法:建立裸鼠SHG44胶质瘤模型,用脂质体包埋法将IFN-β基因的真核表达载体pSV2IFNβ注入裸鼠皮下SHG44脑胶质瘤,观察肿瘤生长情况并计算肿瘤体积,通过免疫组化、TUNEL染色以及电镜,了解IFN-β基因诱导人脑胶质瘤细胞凋亡的作用.结果:IFN-β在荷瘤裸鼠瘤体内获得表达,裸鼠皮下胶质瘤生长受到抑制,并诱导SHG44胶质瘤细胞凋亡.结论:IFN-β裸DNA能够抑制人脑胶质瘤生长并诱导胶质瘤细胞凋亡,该实验为IFN-β基因治疗人脑胶质瘤的应用奠定了初步基础.     

人脑胶质瘤裸小鼠模型实验化疗的研究(摘要)

我们利用本室建立的人脑胶质瘤体外细胞系裸小鼠实体瘤模型NHG—1(中华肿瘤杂志,1987.9(4):269)进行了一些实验性化疗的研究,报告如下: 一、常用药物的实验治疗:将第22代移植瘤剪成1mm~3小块,通过套管针直接穿刺接     

不同免疫背景小鼠G422胶质瘤颅内移植瘤模型的建立

背景与目的：胶质瘤治疗效果差,是神经外科领域研究的难点。本研究建立正常免疫（Bal b／c小鼠）、T细胞免疫缺陷（裸小鼠）和补体功能缺陷（补体C3基因敲除小鼠）三种不同免疫背景的小鼠G422胶质瘤颅内移植瘤模型。并观察肿瘤的生长特点。方法：将小鼠源性G422胶质瘤细胞种植入Bat b／c小鼠、裸小鼠和补体C3基因敲除小鼠脑内．观察肿瘤种植后三种小鼠的生存期、成瘤率、肿瘤生长情况及病理学特性。结果：Bal b／c鼠、裸小鼠、补体C3基因敲除小鼠三种小鼠脑内种植G422胶质瘤细胞后,成瘤率分别为90％、100％、100％。Bal b／c荷瘤鼠平均生存期最长[（44．3±6．0）d],裸小鼠次之[（24．8±4．8）d],补体C3基因敲除小鼠最短[（18．6±5．2）d]．肿瘤体积增大至34．29mm^3需要的时间分别为35d、21d、14d;组织病理学观察显示G422胶质瘤细胞脑内种植后可保持胶质瘤的肿瘤特征。结论：采用G422小鼠胶质瘤细胞种植入Bal b／c小鼠、裸小鼠、补体C3基因敲除小鼠脑内．可建立具有不同免疫背景的胶质瘤动物模型。     

鼠脑胶质瘤模型制作方法的改良

 目的　建立简单易行、稳定的鼠C6脑胶质瘤模型。方法　SD鼠 2 0只 ,脑立体定向仪定向注射C6细胞至鼠脑尾状核 ,接种后 1、2、3、4周MRI测量肿瘤大小 ,每日观察鼠体重变化 ,处死后大体解剖和病理组织学检查。结果　MRI平扫见脑组织水肿明显 ,MRI增强可见肿瘤组织明显强化 ,中线移位 ,侧脑室受压或消失。颅内接种后星形细胞胶质瘤呈Ⅰ、Ⅱ、Ⅲ、Ⅳ级不等。结论　静脉注射套管针接种C6细胞 ,取材方便 ,简单易行 ,腹腔注射造影剂可获得较好的增强效果。     

胶质瘤干祖细胞可诱导宿主脑胶质细胞癌变

目的 探讨可移植性人癌组织重构过程中,肿瘤干细胞植入方与宿主受体间的关系.方法 将红色荧光蛋白(RFP)基因稳定转染于已建株的胶质瘤干祖细胞SU3,再将建立的SU3-RFP细胞接种于表达绿色荧光蛋白(GFP)的裸小鼠脑内.取移植瘤组织,筛选高增殖力GFP细胞,单克隆化后,鉴定细胞类型,测定其DNA含量,行染色体显带分析.并将建系的GFP细胞H1和H9分别接种于裸小鼠腋下和颅内,观察致瘤率和癌性表型.结果 在可移植性肿瘤组织中,RFP、GFP和RFP/GFP细胞的比例分别为(88.99±1.46)％、(5.59±1.00)％和(4.11±1.02)％.经2次单克隆化的宿主GFP细胞株H1和H9,在体外表现出无限增殖、接触抑制消失、超四倍体等癌细胞特征,并表达少突胶质细胞特异性标志蛋白2’,3’-环腺苷酸-3’-磷酸二酯酶(CNP).H1和H2细胞的体内致瘤率均为100％,肿瘤均向接种周围组织呈广泛侵袭性生长.结论 在可移植性胶质瘤模型中的肿瘤细胞,并非像传统观点那样均由移植的肿瘤干祖细胞产生,被接种的肿瘤干细胞侵袭的宿主脑细胞也可以转化为肿瘤细胞.     

胶质瘤干祖细胞诱导裸小鼠脉络丛细胞癌变的研究

背景与目的：探讨胶质瘤干祖细胞经荧光裸小鼠脑内移植后定居在脉络丛细胞并诱导其上皮细胞癌变的可能性及细胞融合在其中发挥的作用。方法：将人胶质瘤干细胞SU-3和标记红色荧光染料CM—Dil的鼠脑胶质瘤细胞系C6移植于表达绿色荧光蛋白（GFP）的裸小鼠脑内,用传统病理、分子免疫病理和荧光示踪技术对肿瘤细胞在宿主脑内侵袭对不同部位形成的肿瘤团块进行病理学分析。结果：接受尾状核移植的35只鼠和小脑移植的15只鼠全部致瘤．有6只尾状核移植鼠在侧脑室和第三脑室脉络丛见到肿瘤,有5只尾状核移植鼠在第三脑室脉络丛见到肿瘤,有5只小脑移植者在第四脑室脉络丛见到肿瘤。传统病理：肿瘤细胞和组织结构异形十分明显-细胞高度增生,一类是脉络丛结构基本保留,另一类是完全消失。荧光示踪：肿瘤团块中的细胞成分分为源于接种的肿瘤细胞（红色）、源于宿主的细胞（绿色）和两者的融合细胞（黄）。分子病理：肿瘤细胞高表达Nestin、Ki一67、角蛋白和GFAP。结论：根据癌干细胞（cancer stem cells,CSCs）定居于不同部位的形态学特征,尤其在脉络丛上形成的能表达相关标志蛋白的脉络丛癌样结构肿块,表明胶质瘤干细胞在特定环境下可诱导宿主细胞癌变．这一过程可能是通过细胞融合实现的,这对进一步研究胶质瘤干细胞分化走向和与宿主组织重构受定居地微生态环境影响有重要意义。     

影响人大肠癌裸小鼠移植瘤生长的因素分析

目的:探索影响人大肠癌移植瘤裸小鼠肿瘤生长的相关因素.方法:12只BALB/C裸小鼠建立人大肠癌原位移植瘤模型,于接种后8周处死.观察记录裸小鼠瘤质重、瘤体积,并采用RT-PCR或免疫组化法检测肿瘤组织AP-1、NF-kb、COX-2、PGE2、VEGF、EGFR,以及STAT3、Bcl-2、Survivin、Caspase9、Caspase8和Caspase3等与细胞凋亡相关的因子表达.采用多元逐步回归模型分析各指标与肿瘤生长(瘤质重和瘤体积)的关系.结果:经多元逐步回归模型分析,瘤体积以及肿瘤组织Caspase3、VEGF、COX-2的表达与瘤质重有关.瘤质重以及肿瘤组织Caspase 8、STAT3、EGFR、VEGF的表达与瘤体积相关.结论:人移植瘤裸小鼠的生长与包括凋亡因子、COX-2、VEGF、EGFR在内的多种因子有密切关系,大肠癌的发生发展是一个多因子、多信号通路参与的过程.     

蒿甲醚抗SD大鼠原位脑胶质瘤血管生成的 实验

 目的探讨蒿甲醚（Artemether）抗SD大鼠原位脑胶质瘤血管生成作用。方法采用四甲基偶氮唑蓝(MTT)法测定不同浓度蒿甲醚对大鼠C6脑胶质瘤细胞株的生长抑制作用,计算半数抑制浓度(IC₅₀)。采用立体定位仪在SD大鼠大脑皮质层接种C6脑胶质瘤细胞（1×10⁶/μl）40只,雌、雄各半;随机分为5组,每组8只。在接种第3天后,各组采用灌胃给药法连续给药10天。于接种后的第20天解剖大鼠,经活体左心室灌注4%多聚甲醛,固定肿瘤的全脑标本。在大鼠脑部接种穿刺点做冠状切口,按垂直和水平方向测量肿瘤大小。肿瘤体积=a²bπ∕6(a为肿瘤的短径,b为肿瘤的长径)。全脑标本用4%多聚甲醛固定,肿瘤组织做病理观察,免疫组化方法检测移植瘤组织微血管密度。结果各实验组血管计数分别为Ⅰ组（39±4）,Ⅱ组（29±6）,Ⅲ组（12±8）,Ⅳ组（10±5）,生理盐水组为（52±7）。各实验组血管计数均明显少于生理盐水对照组,差异有统计学意义(分别P<0.05, P<0.01)。各实验组SD大鼠原位脑胶质瘤体积较对照组显著减小。结论在一定剂量范围内,蒿甲醚具有明显抑制SD大鼠原位脑胶质瘤血管生成作用;蒿甲醚抑制原位脑胶质瘤生长和转移的机制之一是透过血脑屏障抑制脑胶质瘤血管生成。     

采用OB胶粘贴法建立人胃癌裸鼠原位种植转移模型

背景与目的建立理想的动物肿瘤移植模型是进行肿瘤防治研究的重要前提,目前公认的胃癌造模的方法为采用完整组织块的“皮下移植法”、“胃囊法”,但传统的造模方法目前尚存在操作复杂、成活率低等缺点,本研究拟采用“OB胶粘贴法”更简便地建立人胃癌裸鼠原位移植模型。方法以反复接种传代于裸鼠皮下的SGC鄄7901人胃癌细胞株建立的移植瘤组织块为材料,将其用生物吻合“OB胶”原位粘贴于裸鼠胃壁,并与传统“胃囊法”、“皮下移植法”比较观察移植肿瘤的生长情况、移植成功率和自发转移的发生率。结果“OB胶粘贴法”组原位移植成功率为100%,局部淋巴结转移率为100%,肺转移发生率为62.5%,肝转移发生率为87.5%,腹膜转移发生率为87.5%,较之胃囊法(分别为100%、100%、50.0%、50.0%和33.3%),除腹膜转移率升高外,远处脏器转移差异无显著性,但成活率高。皮下移植组未发生局部浸润及远处转移。结论“OB胶粘贴法"能更简便地建立人胃癌高转移模型,重现临床转移过程。     

利用α-氰基丙烯酸烷基酯医用胶建立人肝癌裸鼠皮下-肝原位移植瘤模型的实验研究

 目的 使用α-氰基丙烯酸烷基酯建立人肝癌-裸鼠皮下肝原位移植瘤模型。方法 将BEL-7402人肝癌细胞接种于裸鼠皮下，建立皮下模型 。形成皮下移植瘤后再移植于裸鼠肝内，利用α-氰基丙烯酸烷基酯建立肝原位移植瘤模型（间接肝原位移植瘤模型）。结果 成功的利用α-氰基丙烯酸烷基酯建立了间接肝原位移植瘤模型。移植瘤存活率达95.8 %。结论 与传统的肝原位移植瘤模型比较，利用α-氰基丙烯酸烷基酯建立间接肝原位移植瘤模型方法简便，成功率高，便于推广使用。     

人膀胱癌裸鼠原位移植瘤动物模型的建立和MRI检测

Objective:To establish an orthotopic bladder cancer model bearing human bladder cancer for experimental research, and monitor tumor progression by magnetic resonance imaging (MRI). Methods: The mucosa was mechanically damaged transurethrally under direct vision, and then human bladder cancer cell line T24 was inoculated into the bladders of BALB/c nude mice to establish orthotopic bladder cancer model. To find a suitable concentration of Gd-DTPA for this research. MRI was performed weekly to assess tumor growth, using Gd-DTPA as contrast agent. The pathologic morphology of the bladders and other specimens were observed with HE stain. Results: All the 25 mice developed bladder cancer after inoculation. The best concentration of Gd-DTPAwas 1.408 mg/mL. On MRI, no change in the bladders was observed on day 7 after inoculation, filling defect in the bladders, accordant to actual tumor size, was detected on days 14, 21 and 28. Pathologic examination showed that tumor grew in the mucosa or superficial muscle of bladder on day 7, confined in muscle layer on days 14-28, and invaded serosa on day 35. Conclusion: Transurethrally damaged bladder mucosa under direct vision and instilled bladder cancer cell T24, we successfully established an orthotopic bladder cancer model. Tumor growth simulated the progression of human bladder cancer approximately. MRI was a reliable way for dynamic detection of murine orthotopic bladder tumor.     

Establishment of orthotopic transplantation model of human bladder cancer and detection by MRI

Objective： To establish an orthotopic bladder cancer model bearing human bladder cancer for experimental research, and monitor tumor progression by magnetic resonance imaging （MRI）. Methods： The mucosa was mechanically damaged transurethrally under direct vision, and then human bladder cancer cell line T24 was inoculated into the bladders of BALB/c nude mice to establish orthotopic bladder cancer model. To find a suitable concentration of Gd-DTPA for this research. MRI was performed weekly to assess tumor growth, using Gd-DTPA as contrast agent. The pathologic morphology of the bladders and other specimens were observed with HE stain. Results： All the 25 mice developed bladder cancer after inoculation. The best concentration of Gd-DTPA was 1.408 mg/mL. On MRI, no change in the bladders was observed on day 7 after inoculation, filling defect in the bladders, accordant to actual tumor size, was detected on days 14, 21 and 28. Pathologic examination showed that tumor grew in the mucosa or superficial muscle of bladder on day 7, confined in muscle layer on days 14-28, and invaded serosa on day 35. Conclusion： Transurethrally damaged bladder mucosa under direct vision and instilled bladder cancer cell T24, we successfully established an orthotopic bladder cancer model. Tumor growth simulated the progression of human bladder cancer approximately. MRI was a reliable way for dynamic detection of murine orthotopic bladder tumor.     

Characterization of a novel transplantable orthotopic murine xenograft model of a human bladder transitional cell tumor (BIU-87)

For the evaluation of anti-human bladder cancer immunotoxin approaches, the orthotopic nude murine model that mimics the human counterpart is essential for preclinical evaluation of new treatment modalities. The objective of this study was to develop and characterize such a model. To accomplish this, the established human bladder transitional cell carcinoma (TCC) cell line, BIU-87, was transplanted orthotopically into immunodeficient nude mice. BIU-87 TCC cells were grown in monolayer cell culture and instilled intravesically as single cell suspensions into bladders that had been conditioned with mild acid washing. Tumor growth was assessed weekly by subjecting the mice to magnetic resonance imaging (MRI). At intervals following implantation and MRI tumor detection, the animals were sacrificed for necropsy, histological examination and immunocytochemical studies. The overall tumor establishment was 93% (52/56 mice) at 7-36 days, while in a subgroup of animals sacrificed at 12-13 days, 40 out of 42 animals (95%) developed TCC, the majority of which was superficial. Tumor stage was assessed by gross pathology and light microscopy. Histological examination of the tumor specimens confirmed the presence of grade II-III TCC. Immunocytochemistry confirmed that the tumor model maintained the features of BIU-87 cells. The changes seen on MRI correlated well with the extent of tumor invasion identified histologically. Carcinoma in situ could be detected histologically 7-9 days post-inoculation, and progressed to papillary tumor or invasive disease thereafter. The orthotopic BIU-87 TCC model is highly reproducible and is ideal for preclinical studies on experimental intravesical therapies.     

人胃癌组织块裸鼠原位移植/转移模型的建立

 目的　用肿瘤组织块原位移植 ,建立人胃癌裸小鼠原位移植 /转移模型。方法　以人胃低分化腺癌细胞系接种于裸小鼠皮下 ,形成稳定传代的皮下移植瘤 ,再取该肿瘤组织块原位移植于裸鼠胃壁 ,观察移植肿瘤的生长状况、移植成功率和自发转移的发生率。结果　原位移植成功率 (成瘤率 )为 1 0 0 %、局部淋巴结转移率 1 0 0 %、远处淋巴结转移率 90 %、肝转移发生率为 75%。荷瘤鼠的中位生存期为 1 4周 ,晚期出现消瘦和全身衰竭。结论　该裸小鼠原位移植 /转移模型的生物学行为与人胃癌自然生长和转移过程相似 ,可作为一种有价值的工具用于胃癌转移机理和抗转移实验治疗的研究。     

尿β-HCG测定对人卵巢癌裸小鼠原位移植模型的监测

背景与目的：肿瘤原位移植模型已成为肿瘤实验动物学的主要载体。但目前尚缺乏方便可靠的方法监测模型体内肿瘤的生长变化,本文评价β-人绒毛膜促性腺激素（βhuman chorionic gonadotropin,β-HCG）系统对肿瘤原位模型内肿瘤生长的监测作用。方法：将pclone-β-HCG质粒稳定转染的人卵巢癌细胞系A2780-CG制成裸小鼠原位移植模型。通过连续检测鼠尿中β-HCG/肌酐值,绘制曲线,间接了解小鼠体内肿瘤生长规律,以及顺铂腹腔化疗后,该比值对顺铂抗瘤效果的监测。作用。结果：β-HCG系统转染瘤细胞A2780-CG的成瘤时间和母代相同,小鼠尿中β-HCG/肌肝值与体内瘤重量呈正相关（r=0.98);顺铂腹腔化疗后,β-HCG/肌酐值呈进行性下降。结论：β-HCG系统可无创,敏感地监测卵巢癌原位移植模型中肿瘤生长规律。为该模型在肿瘤治疗中的应用提供简便的监测手段。     

Establishment of nude mouse transplantable model of a human adenoid cystic carcinoma of the oral floor showing metastasis to the lymph node and lung

Adenoid cystic carcinoma (ACC) is a generally slow-growing but highly malignant salivary gland neoplasm with remarkable capacities for local invasion and lung metastasis. The precise characteristics of ACC are not fully understood because there was no suitable animal model. We have successfully established a new human tumor line (ACCI) derived from ACC of the oral floor, which showed a cribriform pattern histologically and serially transplantable into nude mice. This tumor developed spontaneous metastasis to the neck at the second passage level, and the histological feature changed from ACC to undifferentiated carcinoma (ACCIM). ACCIM caused spontaneous metastasis to the lung at high incidence when transplanted subcutaneously in nude mice. In this study, we examined the characteristics of this interesting human ACC metastatic line. Tumor fragments were subcutaneously transplanted into nude mice and tumor growth was measured at 1-week intervals. Histological and immunohistochemical examinations were performed. As a result, the tumor growth rate of ACCIM increased as compared to that of ACCI, and the PCNA labeling index was elevated. Furthermore, ACCIM produced multiple metastases to lymph nodes and lungs 5 months after transplantation, and all mice died within 6 months. These multiple metastases were also confirmed in orthotopic transplantation to the tongue. RT-PCR analysis revealed that ACCIM expressed human beta-actin, indicating its human origin. From these findings, ACCIM transplanted into nude mice would provide a useful model for investigating the biological behaviour of ACC.     

蟾毒灵对裸鼠大肠癌原位移植瘤的抗肿瘤作用及其对凋亡相关基因Bcl-xL、Bax表达的影响

目的探讨蟾毒灵对裸鼠大肠癌原位移植瘤的抗肿瘤作用及其可能诱导凋亡的机制。方法将60只人结肠癌细胞株HCT-116建立的裸鼠原位移植瘤模型随机分为生理盐水（NS）组、5-Fu组、蟾毒灵低（BL）、中(BM)、高(BH)5组,每组12只,腹腔注射给药持续7d。用药结束后第24天每组分别处死6只裸鼠,完整取出肿瘤,测量肿瘤大小,计算肿瘤抑制率;剩余裸鼠观察带瘤生存期;TUNEL法检测原位移植瘤细胞的凋亡指数;实时荧光定量PCR法和Western blot法检测凋亡相关基因Bcl-x_L、Bax mRNA和蛋白的表达。结果5-Fu组、BL组、BM组、BH组的肿瘤抑制率分别为69.6%、45.6%、56.2%、58.5%,肿瘤体积与NS组比较明显缩小（P＜0.01);BL组、BM组带瘤生存期与NS组相比较明显延长(P< 0.05)。TUNEL结果显示蟾毒灵用药组的凋亡指数明显高于NS组(P＜0.01）;荧光定量PCR和Western结果显示蟾毒灵可抑制Bcl-x_L基因表达,促进Bax基因表达（P＜0.05）。结论蟾毒灵对裸鼠大肠癌原位移植瘤有显著的抗肿瘤作用,能够抑制Bcl-xL基因和促进Bax基因表达,诱导肿瘤细胞凋亡可能是蟾毒灵抗肿瘤的重要机制之一。     

Magnetic resonance and fluorescence-protein imaging of the anti-angiogenic and anti-tumor efficacy of selenium in an orthotopic model of human colon cancer

Tumor progression and angiogenesis are intimately related. To understand the interrelationship between these two processes, real-time imaging can make a major contribution. In this report, fluorescent protein imaging (FPI) and magnetic resonance imaging (MRI) were utilized to demonstrate the effects of selenium on tumor progression and angiogenesis in an orthotopic model of human colon cancer. GEO (well-differentiated human colon carcinoma) cells transfected with green fluorescent protein (GFP) were implanted orthotopically into the colon of athymic nude mice. Beginning at five days post implantation, whole-body FPI was performed to monitor tumor growth in vivo. Upon successful visualization of tumor growth by FPI, animals were randomly assigned to either a control group or a treatment group. Treatment consisted of daily oral administration of the organoselenium compound, methyl-selenocysteine (MSC; 0.2 mg/day × five weeks). Dynamic contrast-enhanced MRI was performed to examine the change in tumor blood volume following treatment. CD31 immunostaining of tumor sections was also performed to quantify microvessel density (MVD). While T1- and T2-weighted MRI provided adequate contrast and volumetric assessment of GEO tumor growth, GFP imaging allowed for high-throughput visualization of tumor progression in vivo. Selenium treatment resulted in a significant reduction in blood volume and microvessel density of GEO tumors. A significant inhibition of tumor growth was also observed in selenium-treated animals compared to untreated control animals. Together, these results highlight the usefulness of multimodal imaging approaches to demonstrate antitumor and anti-angiogenesis efficacy and the promise of selenium treatment of colon cancer.