Evaluation of a rabbit rectal VX2 carcinoma model using computed tomography and magnetic resonance imaging

AIM： To establish a rabbit rectal VX2 carcinoma model for the study of rectal carcinoma.METHODS： A suspension of VX2 cells was injected into the rectum wall under the guidance of X-ray fluoroscopy. Computed tomography （CT） and magnetic resonance imaging （MRI） were used to observe tumorgrowth and metastasis at different phases. Pathological changes and spontaneous survival time of the rabbits were recorded.RESULTS： Two weeks after VX2 cell implantation, the tumor diameter ranged 4.1-5.8 mm and the success implantation rate was 81.8%. CT scanning showed low-density loci of the tumor in the rectum wail, while enhanced CT scanning demonstrated a symmetrical intensification in tumor loci. MRI scanning showed alow signal of the tumor on T1-weighted imaging anda high signal of the tumor on T2-weighted imaging.Both types of signals were intensified with enhanced MRI. Metastases to the liver and lung could beobserved 6 wk after VX2 cell implantation, and a largearea of necrosis appeared in the primary tumor. The spontaneous survival time of rabbits with cachexia and multiple organ failure was about 7 wk after VX2 cell implantation.CONCLUSION： The rabbit rectal VX2 carcinoma model we established has a high stability, and can be used in the study of rectal carcinoma.

Establishment of VX2 breast carcinoma model in rabbit by injecting tumor mass suspension

Objective: To establish a stable model of VX2 breast carcinoma in rabbit and select the optimal way. Methods: Thirty female New Zealand rabbits were randomly divided into 3 groups with 10 in each. Tumor cell suspensions or tumor mass suspensions were injected into breast tissues of rabbits of group A and B, respectively. Tumor blocks were surgically implanted in rabbit breasts of group C. Tumor formation rate, tumor growth rate, and tumor-bearing survival time was compared, and the histological feature of tumor was observed. Results: Models were established conveniently and successfully in rabbits received injection of tumor mass suspensions. Tumor proliferated rapidly with the biological feature of squamous cell carcinoma. Conclusion: VX2 breast carcinoma model in rabbit was established successfully. Intramammary injection of tumor mass suspension is the best method.

Role of MR-DWI and MR-PWI in the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbits

Objective： To detect the activity of tumor cells and tumor blood flow before and after the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbit models by using magnetic resonance diffusion-weighted imaging（MR-DWI） and magnetic resonance perfusion weighted imaging（MR-PWI）, and to evaluate the effectiveness and safety of the radiotherapy based on the changes in the MR-DWI and MR-PWI parameters at different treatment stages.Methods： A total of 56 rabbit models with implanted pulmonary VX-2 carcinoma were established, and then equally divided into treatment group and control group. MR-DWI and MR-PWI were separately performed using a Philips Acheiva 1.5T MRI machine（Philips, Netherland）. MRI image processing was performed using special perfusion software and the WORKSPACE advanced workstation for MRI. MRDWI was applied for the observation of tumor signals and the measurement of apparent diffusion coefficient（ADC） values; whereas MR-PWI was used for the measurement of wash in rate（WIR）, wash out rate（WOR）, and maximum enhancement rate（MER）. The radiation treatment was performed using Siemens PRIMUS linear accelerator. In the treatment group, the radiotherapy was performed 21 days later on a once weekly dosage of 1,000 c Gy to yield a total dosage of 5,000 c Gy.Results： The ADC parameters in the region of interest on DWI were as follows： on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values at the center and the edge of the lesions were 1.352 and 1.461 in the treatment group and control group（P〉0.05）. During weeks 0-1 after treatment, the t values at the center and the edge of the lesions were 1.336 and 1.137（P〉0.05）. During weeks 1-2, the t values were 1.731 and 1.736（P〈0.05）. During weeks 2-3, the t values were 1.742 and 1.749（P〈0.05）. During weeks 3-4, the t values were 2.050 and 2.127（P〈0.05）. During weeks 4-5, the t values were 2.764 and 2.985（P〈0.05）. The ADC values in the treatment group were significantly higher than in the control group. After the radiotherapy（5,000 c Gy）, the tumors remarkably shrank, along with low signal on DWI, decreased signal on ADC map, and remarkably increased ADC values. As shown on PWI, on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values of the WIR, WOR, and MER at the center of the lesions were 1.05, 1.31, and 1.33 in the treatment group and control group（P〉0.05）; in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.35, 1.07, and 1.51（P〉0.05）. During weeks 0-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 1.821, 1.856, and 1.931（P〈0.05）; in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.799, 2.016, and 2.137（P〈0.05）. During weeks 1-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.574, 2.156, and 2.059（P〈0.05） and the t values of the WIR, WOR, and MER at the edge of the lesions were 1.869, 2.058, and 2.057（P〈0.05）. During weeks 2-3 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.461, 2.098, and 2.739（P〈0.05） and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.951, 2.625, and 2.154（P〈0.05）. During weeks 3-4 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.584, 2.107, and 2.869（P〈0.05） and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.057, 2.637, and 2.951（P〈0.05）. During weeks 4-5 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.894, 2.827, and 3.285（P〈0.05） and the t values of the WIR, WOR, andMER at the edge of the lesions were 3.45, 3.246, and 3.614（P〈0.05）. After the radiotherapy（500 c Gy）, the tumors shrank on the T1 WI, WIR, WOR, and MER; meanwhile, the PWI parameter gradually decreased and reached its minimum value.Conclusions： MR-DWI and MR-PWI can accurately and directly reflect the inactivation of tumor cells and the tumor hemodynamics in rabbit models with implanted pulmonary VX-2 carcinoma, and thus provide theoretical evidences for judging the clinical effectiveness of radiotherapy for the squamous cell carcinoma of the lung.

Radiosensitivity of β-elemene on rabbit VX2 renal transplant carcinoma model

Objective To investigate the effects of low dosage of β-elemene on the radiosensitivity of rabbit VX2 renal transplant carcinoma model. Methods We took the rabbit VX2 renal transplant carcinoma as the model. Experimental rabbits were divided into three groups: the control group, the radiation group, and the radiation +β-elemene (radiosensitivity) group. The change of tumor was observed by Spiral CT and B ultrasound to compare its regrowth period. The tumor was measured by light microscopy and electron microscopy. Results The tumor in radiosensitivity group was restrained obviously and the sensitization enhancement ratio (SER) of β-elemene was 1.89. Different apoptosis was observed under transmission electron microscopy. Conclusion Low dosage β-elemene can enhance the radiosensitivity of rabbit VX2 renal transplant carcinoma model and induce the apoptosis of tumor cells, but the mechanism needs further study. It promotes apoptosis in mechanisms in vitro.

Effect of hydroxyapatite nanoparticles on the growth and p53/c-Myc protein expression of implanted hepatic VX_2 tumor in rabbits by intravenous injection

AIM： To evaluate the effect of hydroxyapatite nano- particles （Nano HAP） by intravenous injection on the inhibition of implanted hepatic VX2 tumor growth in rabbits and cell p53/c-Myc protein expression. METHODS： 60 hepatic VX2 tumor-bearing rabbits was randomly divided into five groups. Nano HAP collosol 20 mglkg, 40 mg/kg, 5-FU solutions 20 mg/mL, mixed liquor of 5-FU solution 20 mg/mL and Nano HAP collosol 20 mg/kg were infused by vein, normal saline conducted as the control. The general state, weight, liver function and gross tumor volume were detected dynamically. The expression of p53 and c-Myc gene protein in tumor tissue was detected by immunohistochemistry methods. RESULTS： The growth of implanted hepatic VX2 tumors was significantly inhibited in all therapy groups, 3 wk after the injection, the tumor control rates in Nano HAP collosol groups were 25.5% and 32.5% respectively, and the gross tumor volumes were obviously less than that of control group. （24.81 ± 5.17 and 22.73 ± 4.23 vs 33.32 ± 5.26, P 〈 0.05）. The tumor control rate of 5-FU group was 43.7% （18.74 4± 4.40 vs 33.32 ± 5.26, P 〈 0.05）, but the general state of the animals after injection aggravated; and the adverse reaction in the drug combination group obviously decreased. Due to the effect of Nano HAP, the positive expression of tumor associated the mutated p53 and c-Myc in tumor tissue was decreased obviously compared with the control group. CONCLUSION： Nano HAP has evident inhibitory action on rabbit implanted hepatic VX2 tumor in vivo, which may be the result of decreasing the expression of the mutated p53 and c-myc, and drug combination can obviously decrease the adverse reaction of 5-FU.

Adriamycin Thermotherapy through the Hepatic Artery Using VX2 Carcinoma in Rabbit Liver as a Model

OBJECTIVE It has been reported that heating can enhance sensitivity of rabbit VX2 cells to adriamycin and increase the intracellular concentration of adriamycin. This study was designed to evaluate the anti-tumor effect of interventional hyperthermia and interventional thermochemotherapy on VX2 carcinoma in rabbit liver. METHODS VX2 carcinoma cells were surgically implanted into the right liver lobe of 60 male New Zealand white rabbits, which were randomly divided into 4 groups (15 per group). The 4 groups (designated as 1, 2, 3, 4 respectively) were injected with 10 ml of the following via the hepatic artery: physiological saline (37℃); adriamycin (37℃); physiological saline (60℃); adriamycin (60℃). One week later, the tumor volume, serum level of aspartate transaminase (AST) and the survival of the rabbits bearing VX2 were observed and compared among the different treated groups. RESULTS The tumor growth rate in group 4 (ADM 60℃) (0.53±0.21)% was significantly lower than that in group 1 (3.48±1.17)%, in group 2 (1.09±0.26)% and group 3 (3.32±1.28)% (P<0.05, P<0.05, P<0.01, respectively). The days of survival days for group 4 (87.0±2.0) were significantly more than that in group 1 (40.0±3.0). Group 4 showed a significantly higher increase in serum AST compared to group 1 (P<0.05), but without significant differences compared to the other groups (P>0.05). CONCLUSION Adriamycin treatment at 60℃ significantly deceased the tumor growth, prolonged the survival period and resulted in reversible liver damage.

Sphere-forming-like cells(squamospheres) with cancer stem-like cell traits from VX2 rabbit buccal squamous cell carcinoma

Previous studies have demonstrated that spheroid type cells grown under suspension culture conditions have cancer stem cell（CSC） traits in a number of cancers, but this phenomenon has not yet been reported in the VX2 rabbit oral cancer model. Hence, this study aimed to study the spheroid cells from VX2 rabbit buccal squamous cell carcinomas（SCCs） and assess their CSC characteristics. Five adult male New Zealand white outbred rabbits were used to generate VX2 rabbit buccal SCC. Sphere-forming cell culture was performed for the VX2 rabbit buccal SCC specimens. The self-renewal capability; cluster of designation（CD） 44, CD133, acetaldehyde dehydrogenase 1（ALDH1）, B cell-specific Moloney murine leukemia virus integration site 1（Bmi-1）, Nestin, octamer-binding transcription factor 4（Oct4）and reduced expression protein-1（Rex-1） expression with reverse transcription-polymerase chain reaction（RT-PCR）; chemoresistance to cisplatin and 5-fluorouracil; and in vivo tumorigenicity of spheroid cell transplantation in nude mice were evaluated to determine the CSC characteristics of the resulting spheroid cells. We successfully obtained spheroid cells from the VX2 rabbit OSCC tissues. The spheroid cells exhibited CSC traits, including the expression of CSC and stem cell markers（CD44, Bmi-1, Nestin, Oct4 and Rex-1）, capacity to generate new spheroid colonies within 1 week of reseeding from single-dissociated spheroid cells, chemoresistance capacity and generation of tumour xenografts（with histological features resembling those of the original VX2 rabbit buccal SCC） from the transplantation of 103 undifferentiated spheroid cells into nude mice. In summary, we demonstrated that spheroid cells with CSC cell traits can be derived from VX2 rabbit buccal SCCs, indicating that this animal cancer model is applicable for studying CSCs in human oral cancers.

兔肝Vx-2移植癌改良模型的建立

目的 建立稳定的兔Vx 2移植性肝癌模型 ,探讨不同植瘤方式的成功率。方法 将 60只新西兰白兔随机分 3组 ,每组 2 0只。观察 :①不同方式的成活率 ;②B超监测肿瘤生长 ,并计算肿瘤生长率 ;③瘤组织形态特征。结果 ①改良组植瘤成活率最高 (P <0 .0 5 ) ,瘤体呈指数性生长 ;②该瘤在肝组织中呈浸润式生长 ,其性状与移植于兔其他部位的Vx 2鳞状细胞癌特征相似。结论 成功建立了兔Vx 2移植性肝癌模型 ,瘤组织块种植方式成功率明显高于其他方法。

组织块悬液注射法制作兔VX_2乳腺癌模型

目的 :建立稳定的兔VX2 乳腺癌模型 ,选择最佳的模型制作方法。方法 :3 0只兔随机分为 3组 ,每组10只 ,分别采用乳腺内瘤细胞液注射法、组织块悬液注射法、组织块种植法制作兔VX2 乳腺癌模型 ,比较各组的种植成活率、肿瘤生长率、荷瘤兔存活时间 ,并观察肿瘤的生物学形态。结果 :组织块悬液注射法操作简便 ,成瘤率高 ,肿瘤增殖旺盛 ,生物学特征符合乳腺鳞状细胞癌。结论 :成功建立了兔VX2 乳腺癌模型 。

兔肝Vx-2移植癌改良模型的建立

目的 培养、建立稳定的兔肝 ＶＸ－２移植癌模型，探讨不同植瘤方式的成功率。方法 ６０只新西兰白兔随机分 ３组，每组 ２０只。分别以不同的方式将 Ｖｘ－２瘤细胞植入兔的肝脏。观察：１．不同方式植瘤的成活率；２．Ｂ超测定肝内肿瘤 ７ｄ、１０ｄ、１４ｄ、１７ｄ、２１ｄ时的大小，并计算肿瘤生长率；３．大体及镜下（光镜和电镜）瘤组织形态特征。结果 １．三组植瘤成活率分别为 ７／２０、１０／２０、１９／２０，改良组植瘤成活率最高（Ｐ＜０．０５），瘤体呈指数性生长；２．病理学及ＣＴ表明该瘤在肝组织中呈浸润式生长，其性状与移植于兔其它部位的Ｖｘ－２鳞状细胞癌特征相似。结论 成功建立了兔肝Ｖｘ－２移植癌模型，瘤组织块种植方式成功率明显高于其它两组方式，为肝癌介入治疗的基础及临床研究，提供了成熟的大型实验动物模型。

兔转移性乳腺癌模型:肿瘤生长及转移

目的:建立移植性兔VX2乳腺癌模型,观察肿瘤生长及转移进程。方法:采用组织块悬液注射法制作兔VX2乳腺癌模型 28只,测量并记录瘤体大小变化,触诊检查有无腋窝淋巴结转移,影像学方法检查有无远处组织或器官转移,记录荷瘤生存时间,兔死亡后解剖并做病理检查。结果: 28只兔植瘤后 1周均在注射部位形成可触及的实体瘤。除去 5只中途意外死亡兔,共有 23只兔进入研究。全部模型肿瘤增长迅速,腋窝淋巴结转移发生率21 /23(91. 3% ),纵隔淋巴结转移发生率 5 /23(21. 7% ),腹腔淋巴结转移发生率 2 /23 (8. 7% ),肺转移发生率 6 /23(26. 1% ),肝转移发生率 3 /23(13. 0% ),骨转移发生率 1 /23(4. 3% )。肿瘤局部浸润侵犯胸膜腔 2 /23(8. 7% ),胃2 /23(8. 7% )。荷瘤兔平均生存时间(51. 2±8. 6)天,瘤灶病理切片检查符合乳腺鳞状细胞癌。结论:兔VX2乳腺癌模型的生物学行为和病程进展与人类转移性乳腺癌相似,是进行人类晚期乳腺癌实验研究的理想动物模型。

B超引导瘤块移植法建立兔肾Vx-2移植癌模型

目的 探讨建立兔肾Vx 2移植瘤模型 ,并观察其成功率、病理学和影像学 (DSA)表现 ,为介入实验研究提供大型动物肾肿瘤模型。方法 10只新西兰白兔 ,B超引导下将瘤组织块 (约含 10 6～ 10 8个瘤细胞 )经皮穿刺注入左肾下极。观察移植成功率、肿瘤生长率、瘤组织形态学、影像学表现。结果 1.植瘤成活率 8/ 10 ,10、14、17、2 1d生长率依次为 2 2 1.2 %、84 .6 %、4 4 .5 %、38.6 % ;2 .病理学表明该瘤为实体瘤 ,在肾组织中呈浸润式生长 ;3.DSA影像示移植性肾肿瘤具有丰富的血供 ,呈实体瘤表现。结论 B超引导瘤块移植方式成功建立了兔肾Vx 2移植癌模型 ,为实体瘤介入治疗的实验研究提供了容易复制的大型动物模型。

兔舌不同部位VX-2鳞癌与颈淋巴结转移模型的生物学特性

目的:制作兔舌不同部位VX-2鳞癌和颈淋巴结转移模型,并对其生物学特性进行研究,为舌癌多学科治疗提供研究平台。方法:将新西兰白兔20只,随机分为4组,每组5只,分别植入VX-2鳞癌瘤块。观察瘤块植入后肿瘤生长、体积变化、成瘤率、颈淋巴结转移率、转移的部位、数目以及兔生存期等指标。数据采用SPSS11.5软件包进行游程检验、独立样本t检验和χ2检验。结果:总成瘤率75%,其中舌缘80%,舌中线区70%,颈淋巴结转移率均70%,舌缘转移至同侧颈淋巴结,舌中线区转移至双侧颈淋巴结。平均生存期为舌缘(33.25±6.20)d,舌中线区(39.00±3.74)d。各区间无统计学意义(P>0.05),舌癌和颈部转移淋巴结均为低分化鳞癌。结论:瘤块移植法能成功制作不同部位兔舌VX-2鳞癌模型,成瘤率和转移率均较高,生存期为4～6周。其生物学特性与人舌癌基本一致,生长迅速,容易转移,是研究舌癌较理想的动物模型。

兔肝Vx-2移植癌改良模型的建立

【目的】建立稳定的兔Vx-2移植性肝癌模型,探讨不同植瘤方式的成功率。【方法】60只新西兰白兔随机分3组,每组20只。第1组,将Vx-2瘤细胞(5×107个)经肝动脉灌注入兔的肝脏;第2组,将Vx-2瘤细胞(5×107个)经肝包膜接种于2组兔的肝左叶;第3组,将瘤组织块(约含106-108个瘤细胞)经肝包膜植入肝左叶。观察:1.不同方式植瘤的成活率;2.B超测定肝内肿瘤7、10、14、17、21 d时的大小,并计算肿瘤生长率;3.大体及镜下(光镜和电镜)瘤组织形态特征。【结果】3组植瘤成活率分别为7/20、10/20、19/20,改良组植瘤成活率最高(P<0.05),瘤体呈指数性生长。病理学表明该瘤在肝组织中呈浸润式生长,其性状与移植于兔其它部位的Vx-2鳞状细胞癌特征相似。【结论】成功建立了兔Vx-2移植性肝癌模型,瘤组织块种植方式成功率明显高于动脉途径和细胞液注射方式,为肝癌介入治疗的基础及临床研究提供了成熟的大型实验动物模型。

经兔肝动脉灌注As_2O_3对肝移植瘤作用的实验研究

目的 探讨经兔肝动脉灌注As2 O3对肝移植瘤的抑制作用。方法 采用不同浓度As2 O3经肝动脉插管灌注治疗兔肝脏Vx 2移植瘤 ,连续 7d ,观察肿瘤平均质量、平均瘤重抑制率、肿瘤细胞形态学变化 ,检测bcl 2 bax基因表达和VEGF表达。结果 实验组的平均瘤重分别为 7 99、6 5 0、4 87g ,平均瘤重抑制率分别为 5 0 3 1%、5 9 5 8%和 69 71%,实验组移植瘤瘤重低于阴性对照组 (P <0 .0 5 )。随着As2 O3的剂量增加 ,实验组的瘤重减轻而平均瘤重抑制率增加 (P <0 .0 5 )。实验组内移植瘤组织bax基因表达显著上调 ,bcl 2基因表达、VEGF表达显著下调 (P <0 .0 5 )。而bcl 2基因、VEGF表达下调无差异性(P =1 0 0 )。电镜观察实验组各组均有典型的瘤细胞凋亡形态学改变。结论 经肝动脉灌注As2 O3治疗兔Vx 2肝移植瘤 ,有显著的抗肿瘤作用 ,并具有剂量依赖特点。

兔VX-2肝移植肿瘤的制作方法研究

目的探索应用不同方法制作VX-2兔移植性肝癌模型,评价原位成瘤率。方法新西兰白兔38只,采用VX-2瘤株动物自身接种传代。A组15只采用超声引导瘤组织混悬液注射法;B组13只采用开腹瘤组织混悬液注射法;C组10只采用瘤组织块包埋法,均接种于肝左叶。各组分别于接种后1周、2周、3周、4周、5周行CT平扫、增强扫描及MR I平扫。计算各组的原位成瘤率。结果A、B组各种植成功10只,C组种植成功7只,分别为66.7%、76.9%、70%,无统计学意义。结论三组制作方法都有较高的原位成瘤率,实验周期短,均可用于兔VX-2肝癌模型的制作。

不同途径灌注白花蛇舌草注射液对兔舌VX-2鳞癌化疗敏感性的比较研究

目的比较全身静脉及靶向舌动脉灌注白花蛇舌草注射液(Hedyotis Diffusa Willd Injection,HDI)对兔舌VX-2鳞癌化疗的敏作用。方法将兔舌VX-2鳞癌模型随机分为3组,均为舌动脉灌注紫杉醇化疗。其中,A组舌动脉灌注白花蛇舌草注射液,B组耳缘静脉灌注白花蛇舌草注射液,C组为单纯化疗组。化疗后第7天切除舌癌原发灶,SP免疫组织化学法检测VEGF、NF-κ B/p65;Western blot检测P-gp、MRP2、p-STAT3;RT-PCR检测MDR1、ABCC2的mRNA相对表达量。结果 NF-κ B/p65表达率为A<B<C组(P<0.05);VEGF表达率为A/B<C组(P<0.05);P-gp表达率为A<B<C组(P>0.05);MRP2表达率为A<B<C组(P<0.05);p-STAT3、MDR1、ABCC2表达率均为A/B<C组(P<0.05)。结论舌动脉灌注白花蛇舌草注射液对兔舌VX-2鳞癌化疗敏作用明显优于全身静脉灌注。

兔VX-2原位肾癌模型的建立

目的通过两种方法构建兔VX-2移植性原位。肾癌模型，并对其进行评估。方法将30只新西兰白兔随机分2组，每组15只。A组采用开放手术下VX-2肿瘤组织块包埋种植法建模；B组采用经皮超声引导下VX-2肿瘤组织悬液经皮注射种植法建模，通过连续的CT及病理观察与评估模型的稳定性。结果两组建模均成功。A组模型所有肿瘤均为单发，呈外生性肿瘤，形状规则。B组模型有2只出现腹壁种植，占13．3％，肾脏肿瘤生长多形状不规则，常较早突破包膜，沿人针处向肾外生长，部分肾脏肿瘤为完全内生型肿瘤，早期即侵犯集合系统。结论采用开放手术下VX-2肿瘤组织块包埋种植法建模，肿瘤具有单发、呈外生性生长、形状规则等特点，有利于肾癌如射频消融等微创治疗的实验研究，为其提供稳定的动物模型。