Functional Mechanism of Resveratrol in Inhabiting Growth of Cells ls174t and Its Mechanism in Subcutaneously Transplanted Tumor of Nude Mice

To explore the functional mechanism of Resveratrol against colon cancer cells ls174t and the growth of colon cancer tissue of tumor-bearing mice, MTT method was used to observe the functions of resveratrol for inhibition against cells ls174t in vitro. Transmission electron microscope was used to observe the cell apoptosis. FCM assay was performed to measure the change of the cell apoptosis rate and of cell cycle. RT-PCR method was used to detect the expressions of bcl-2 and bax mRNA. Western blot method was used to detect the expressions of bcl-2 and bax protein. Ceils ls174t were transplanted subcutaneously to nude mice to observe the effect of resveratrol on the growth of subcutaneously transplanted tumor, RT-PCR method was used to detect the expressions of bcl-2 and bax mRNA in the tumor tissue. Western blot method was used to detect the expressions of bcl-2 and bax protein in the tumor tissue. Resveratrol has an effect of inhibiting proliferation of cells ls174t in vitro（P〈0.01）. It is able to induce the apoptosis of cells ls174t, causing the decrease in the expression of bcl-2 and the increase in the expression of bax. Resveratrol could inhibit the growth of subcutaneously transplanted tumor of nude mice（P〈0.05）, causing the decrease in the expression of bcl-2 and the increase in the expression of bax. Resveratrol can inhibit the growth of cells 174t and the growth of subcutaneously transplanted tumor. The mechanism is possibly related to the induction of the cell apoptosis and the regulation of bcl-2/bax expression.

Effects of epidermal growth factor on the growth of human gastric cancer cell and the implanted tumor of nude mice

AIM: Epidermal growth factor (EGF) plays an important role in the regulation of gastrointestinal tissue growth and development, and it can stimulate epithelial proliferation, cell differentiation and growth. It has been established that the EGF can promote gastric cytoprotection and ulcer healing. But the potential ability of EGF to regulate the gastric cancer growth is unknown. This study is to investigate the influence of EGF on human gastric cancer cell and the implanted tumor growth of nude mice. METHODS: The cell growth rates of human gastric adenocarcinoma cell lines MKN-28, MKN-45, SGC-7901 and normal human gastric epithelial cells 3T3 were assessed when incubated with recombinant human EGF (rhEGF, 0.05, 0.1, 0.5, 1.0, 10, 50, 100 mg.L(-1)) using MTT method. The cells of MKN-28, MKN-45, SGC-7901 (gastric cancer tissue 1.5mm(3)) were implanted in the BALB/cA nude mice for 10 days.The EGF was given intraperitoneally (15, 30, 60 microg.kg(-1)) for 3 weeks. The body weights of the tumor-bearing animals and their tumor mass were measured afterwards to assess the mitogenic effect of rhEGF in the nude mice. RESULTS: Within the concentration range of 0.05-100mg.L(-1), rhEGF could increase the cell growth of normal 3T3 cells (cell growth rate 100% vs 102.8%, P【0.05), but partially restrain the gastric cancer cell growth. The latter effect was related to cell differentiation. In 15-60 microg/kg rhEGF groups, the mean implanted tumor mass of MKN-28 cell were 1.75 g, 1.91 g, 2.08 g/NS group 1.97 g (P】0.05), the mean tumor mass of SGC-7901 cell were 1.53 g, 1.07 g, 1.20 g/NS group 1.07 g (P】0.05), and for MKN-45 cell, the tumor mass were respectively 1.92 g, 1.29 g, 1.77 /NS group 1.82 g (P】0.05). So rhEGF had no obvious effect on implanted MKN-28, SGC-7901 and MKN-45 tumor growth. CONCLUSION: EGF has no stimulating effect on the human gastric cancer cell growth neither in vitro nor in vivo.

The recruitment of exogenous endothelial progenitor cells in lung tumor model of nude mice

Background and Objective: Endothelial progenitor cells (EPCs) play an important role in hypoxia-triggered tumor vasculogenesis. However, the homing of exogenous EPCs in tumors is still unclear. In this study, we investigated the recruitment of exogenous EPCs in human lung adenocarcinoma model of nude mice. Methods: EPCs labeled with green fluorescence protein (GFP) were transplanted into nude mice bearing human lung adenocarcinoma. The growth of tumor was observed. After the mice were killed, GFP-EPCs in different tissues were examined by fluorescence. The tumor tissues were stained for CD133, hypoxia-inducible factor-1alpha (HIF-1α), stromal cell-derived factor-1α (SDF-1α), and vascular endothelial growth factor receptor (KDR). Real-time polymerase chain reaction of CD133, HIF-1α, SDF-1α, and VEGF-1 were also performed. Results: The growth of tumor in EPC group was significantly faster than that in saline solution group (P < 0.05). Under fluorescence microscope, GFP-EPCs were strongly expressed in both tumor and bone marrow. EPCs were recruited to the tumor periphery to participate in tumor vasculogenesis. The expression of CD133, HIF-1α, and SDF-1 mRNA in tumor and bone marrow were significantly higher than that in the liver, spleen, and skin (P < 0.05). Conclusions: Exogenous EPCs can be recruited to tumor and accelerate tumor growth. Except tumor, bone marrow can also recruit EPCs.

INVESTIGATION OF TUMORIGENIC EFFECT ON ULTRAWEAK LUMINESCENCE FROM NUDE MOUSE FOR ANIMAL MODEL

With nude mouse for animal model, this paper has investigated its whole body luminescence after or before it was inoculated with tumor, and the relationship between tumorigenesis and the luminescence, then, studied the luminescence difference from different mouse organs and find out sensitive luminescence organs. Furthermore, it has tested possibie luminescence mechanism with beta- carotene, NaN3 and D2O. This paper is supposed to provide a new feasible method for cancer diagnosis.

Evaluation of Tumor Formation of Three Bladder Cancer Cell Lines in Nude Mice

This study examined the differences in tumor formation of three bladder tumor cell lines （BIU-87, T24 and EJ） after subcutaneously transplanted into nude mice, in order to find the best technique for establishing in vivo bladder tumor model. BIU-87, T24 and EJ cells at logarithmic phase were re-suspended in serum-free medium. The cells suspensions of the identical concentration were subcutaneously transplanted into nude mice and then the success rate and tumor growth were compared among the three cell groups. The results of tumor formation were pathologically evaluated. Lung, liver and kidney tissues were also pathologically examined for distant metastasis. The proliferation of the three cells were determined by immunohistochemically detecting the PCNA expression in the tumors. The results showed that the success rates of EJ and T24 cells were significantly higher than that of BIU-87 cells and no distant metastasis was noted among the three groups. The proliferation levels of EJ and T24 cells was significantly higher than that of BIU-87. But at the later stage of tumor formation, as compared with T24 cells, EJ grew more vigorously, soon resulting in the central necrosis of tumor, which affected the measurement of the actual size of the tumors. Moreover, PCNA staining exhibited that the proliferation of EJ and T24 was significantly higher than that of BIU-87 cells. It is concluded that as compared with BIU-87 cells, EJ and T24 cells had higher success rates, with not significant differences in death rate and distant metastasis found among them. There existed no significant difference in tumor formation between EJ and T24 cells and T24 cells do not rupture easily, which makes it a better cell line for the establishment of in vivo bladder tumor model.

Kanglaite combined Gemcitabine inhibits growth of nude mouse subcutaneous transplantation tumor of human PC-3 pancreatic cancer cell

Objective:To study the mechanisms of pancreatic cancer treatment with Kanglaite combined Gemcitabine by investigating the relationship between the apoptosis and the expression of bcl-2, Bax and VEGF in pancreatic cancer cells.Methods:Nude mouse subcutaneous transplantation tumor model of Human PC-3 pancreatic cancer was established; the expressions of bcl-2, Bax and VEGF of transplantation tumor cell were determined; the earlier apoptosis rate of pancreatic cancer cell and the gross tumor volume were determined. Results:Kanglaite combined Gemcitabine remarkably decreased the protein expression of bcl-2,raised the expression of Bax,increased the apoptosis rate of the pancreatic cancer and contract the gross tumor volume. Kanglaite greatly decreased the protein expression of VEGF of the tumor cell. Conclusion:Therapeutic efficacy of Kanglaite combined Gemcitabine is far better than separate use of the two medicines in the pancreatic cancer transplantation tumor treatment.

靶向FOLR1的脱氧核酶提高鼻咽癌移植瘤对紫杉醇的敏感性

目的:探讨裸鼠鼻咽癌移植瘤能否通过靶向FOLR1的脱氧核酶(DrzE)提高其对紫杉醇的敏感性。方法:取CNE-1鼻咽癌亲本细胞及CNE-1/taxol紫杉醇耐药细胞进行裸鼠成瘤实验,分别予靶向FOLR1的“10-23”型DrzE单用和紫杉醇单用及紫杉醇-DrzE联用后比较各组鼻咽癌移植瘤体的抑制情况。RT-qPCR及Western blot检测用药前后各组瘤体FOLR1 mRNA及蛋白的表达。结果:CNE-1瘤体较CNE-1/taxol瘤体生长速度快,瘤体体积更大(P<0.05);CNE-1瘤体生长能被紫杉醇单药抑制,但紫杉醇对CNE-1/taxol瘤体无效;两种瘤体生长均能被DrzE单药抑制,其中耐药瘤体更显著(P<0.05);紫杉醇与DrzE联用较分别单用两药对移植瘤的抑制作用更显著(P<0.05);给药前CNE-1/taxol移植瘤中FOLR1的表达量显著高于CNE-1(P<0.01),用药后DrzE单药组及紫杉醇与DrzE联用组中两种移植瘤体FOLR1表达量均显著低于对照组(P<0.05)。结论:靶向FOLR1的脱氧核酶DrzE转染裸鼠移植瘤体后可减慢鼻咽癌瘤体的生长,提高鼻咽癌耐药移植瘤体对紫杉醇的敏感性。

超声造影评估裸鼠食管癌移植瘤血管生成情况的实验研究

目的探讨超声造影(CEUS)对裸鼠食管癌移植瘤血管生成情况的评估价值。方法选取18只裸鼠,于其背部皮下注射人食管癌细胞株建立食管癌移植瘤模型,分别于移植后4、6、8周均随机选取6只裸鼠,先应用二维超声观察移植瘤回声、形态和边界,再行CEUS检查并获取时间-强度曲线(TIC)。然后处死所有裸鼠,使用HE染色观察移植瘤细胞结构和组织形态,免疫组化观察移植瘤组织血管内皮生长因子(VEGF)蛋白表达和微血管密度(MVD),比较移植后不同时间移植瘤CEUS表现、TIC定量参数及病理学检查结果的差异。Pearson相关分析法分析TIC定量参数与VEGF蛋白表达、MVD的相关性。结果所有裸鼠食管癌移植瘤模型均成功建立,未出现死亡。移植后4周,移植瘤二维超声表现为类椭圆形低回声肿块,边界清晰,内部回声不均匀,CEUS表现为移植瘤内部呈均匀增强;移植后6周,移植瘤二维超声表现为肿块边界欠清晰,内部回声不均匀,CEUS表现为移植瘤内部呈不均匀高增强;移植后8周,移植瘤二维超声表现为肿块边界不清晰,内部回声不均匀,CEUS表现为移植瘤内部出现灌注缺损。移植后4、6、8周移植瘤峰值强度(PI)、曲线下流入面积(AWI)及曲线下流出面积(AWO)比较,差异均有统计学意义(均P<0.05);与移植后4周比较,移植后6、8周移植瘤PI、AWI和AWO均升高(均P<0.05);与移植后6周比较,移植后8周移植瘤PI和AWO均升高(均P<0.05)。HE染色显示,移植后4周移植瘤见角化珠且细胞间见细胞间桥;移植后6周移植瘤角化珠和细胞间桥均稍减少,毛细血管增多;移植后8周,移植瘤角化珠和细胞间桥均明显减少,毛细血管增多,可见病理性核裂变。免疫组化显示,移植后4、6、8周MVD和VEGF蛋白表达比较,差异均有统计学意义(均P<0.05);与移植后4周比较,移植后6、8周移植瘤MVD均升高,移植后8周移植瘤VEGF蛋白表达升高,差异均有统计学意义(均P<0.05)。相关性分析显示,移植瘤PI、AWI、AWO与MVD、VEGF蛋白表达均呈正相关(均P<0.001)。结论CEUS能够有效观察裸鼠食管癌移植瘤内部血流灌注情况,TIC定量参数PI、AWI、AWO随着移植瘤的生长而逐渐升高,其与移植瘤MVD、VEGF蛋白表达均呈正相关,可以较好地评估移植瘤血管生成情况。

miR-20a-5p调控NFKBIB对人肾母细胞瘤细胞WiT49裸鼠移植瘤增殖的影响

目的探讨miR-20a-5p对人肾母细胞瘤细胞系WiT49裸鼠移植瘤的影响及作用机制。方法从GEO数据库下载基因表达芯片,应用GEO2R获得差异基因miR-20a-5p;通过cBioPortal数据库获得与miR-20a-5p表达具有正相关关系的NF-κB基因;通过targetscan数据库预测miR-20a-5p靶基因可能为NF-κB转录因子抑制蛋白家族的NFKBIB,并使用双荧光素酶实验进行验证;体外培养肾母细胞瘤细胞系WiT49,采用miR-20a-5p模拟物及其抑制基因构建慢病毒载体分别转染至WiT49细胞;将12只裸鼠随机分为3组,WiT49模型组、WiT49-miR-20a-5p过表达组、WiT49-miR-20a-5p敲低组;裸鼠成瘤实验检测各组瘤块质量及体积;应用实时荧光定量聚合酶链反应(qRT-PCR)检测各组瘤块中miR-20a-5p、NFKBIB及NF-κB表达情况;通过CCK-8细胞增殖实验验证各组瘤细胞增殖情况。结果miR-20a-5p在肾母细胞瘤中高表达,且与NF-κB表达呈正相关,miR-20a-5p与NFKBIB具有相互结合位点且存在结合作用;裸鼠成瘤实验中,WiT49-miR-20a-5p过表达组瘤块体积及质量较WiT49模型组均明显增加,差异有统计学意义(P<0.05);qRT-PCR实验中,WiT49-miR-20a-5p过表达组中miR-20a-5p及NF-κB表达均高于WiT49模型组,WiT49-miR-20a-5p过表达组中NFKBIB表达低于WiT49模型组,差异有统计学意义(P<0.05)。CCK-8细胞增殖实验中WiT49-miR-20a-5p过表达组细胞24及48 h吸光度高于WiT49模型组,WiT49-miR-20a-5p敲低组细胞24、48及72 h吸光度均低于WiT49模型组,差异有统计学意义(P<0.05)。结论miR-20a-5p可能是通过调控NFKBIB激活NF-κB通路促进人肾母细胞瘤细胞WiT49裸鼠移植瘤生长。

基质金属蛋白酶12在胃癌组织、细胞中的表达及对裸鼠移植瘤生长的影响实验研究

目的:观察基质金属蛋白酶12(MMP-12)在胃癌组织和胃癌细胞株SGC-7901中的表达及对裸鼠移植瘤生长的影响。方法:收集胃癌患者42例,手术后留取肿瘤组织和距肿瘤边缘>3 cm的正常胃黏膜组织,应用免疫组化EnVision法检测MMP-12的表达。合成sh-MMP12质粒,应用慢病毒载体转染胃癌细胞株SGC-7901,设为sh-MMP12组,同时设立未行任何干预的细胞为空白对照组(NC组),应用Western blot法检测MMP-12和增殖细胞核抗原(PCNA)蛋白的表达,应用实时荧光定量PCR(RT-qPCR)检测MMP-12和PCNA mRNA的表达。选择4~5周龄的BALB/C雌性裸鼠5只,分别将sh-MMP12组和NC组细胞悬液注射于同一只裸鼠的左右两侧腋下(左侧为sh-MMP12组,右侧为NC组),间隔7 d测量并记录肿瘤体积,28 d后处死小鼠对瘤体称重。结果:免疫组化结果显示,胃癌组织MMP-12阳性率高于正常胃黏膜组织,胃癌组织MMP-12和PCNA表达呈正相关(均P<0.05)。Western blot结果显示,sh-MMP12组MMP-12和PCNA蛋白表达量于NC组(均P<0.05)。RT-qPCR结果显示,sh-MMP12组MMP-12和PCNA mRNA表达量低于NC组(均P<0.05)。裸鼠移植瘤实验结果显示,sh-MMP 12组肿瘤体积在7、14 d时与NC组比较无统计学差异(均P>0.05),而在21、28 d时与NC组比较明显缩小(均P<0.05);28 d后,sh-MMP12组腋下肿瘤重量低于NC组(P<0.05)。结论:胃癌组织和细胞株SGC-7901中MMP-12表达升高,抑制MMP-12可减缓裸鼠移植瘤生长。

灵菌红素对耐阿霉素人乳腺癌细胞MCF-7/ADR的作用研究

目的探讨灵菌红素对耐阿霉素人乳腺癌细胞MCF-7/ADR的作用。方法采用平板发酵粘质沙雷氏菌WA12-1-18生产灵菌红素,CCK-8测定灵菌红素的体外活性及MCF-7/ADR的耐药指数。构建裸鼠皮下移植瘤模型,灵菌红素高、低剂量组分别腹腔注射5.0、2.5 mg/kg灵菌红素,生理盐水对照位腹腔注射等体积生理盐水,每4天1次,连续用药24 d,观察移植瘤的体积、质量及裸鼠体质量,HE染色观察移植瘤组织及裸鼠主要脏器的病理情况,免疫组织化学检测移植瘤Ki-67的表达。结果获得的灵菌红素质量分数为95.18%,对MCF-7和MCF-7/ADR的IC50分别为0.484μg/mL和0.264μg/mL。MCF-7/ADR耐药指数13,符合细胞耐药株的要求。灵菌红素处理组裸鼠移植瘤增长速度较生理盐水组慢,肿瘤细胞排列稀疏,核小且着色较浅,Ki-67染色后棕色明显减少。灵菌红素2.5 mg/kg组和灵菌红素5 mg/kg组,在荷MCF-7/ADR裸鼠中抑瘤率分别为37.23%和53.72%。另外,各组裸鼠体质量差异无统计学意义,主要脏器无明显病理变化。结论灵菌红素可抑制裸鼠体内耐阿霉素人乳腺癌细胞MCF-7/ADR的生长,对心、肝、脾、肺和肾等主要脏器无明显毒副作用,为灵菌红素在耐阿霉素乳腺癌的临床应用提供了实验依据。

芒柄花黄素对裸鼠人胃癌细胞SGC7901移植瘤生长的影响及其机制

目的 :探究芒柄花黄素(Form onone tin,Form)对注射人胃癌细胞系SGC7901细胞悬液裸鼠的保护作用和具体机制。方法:建模成功后将裸鼠分为对照组,低、中、高浓度(10、20、40 mg/kg)芒柄花黄素处理组。观察皮下肿瘤,称量湿重,计算出肿瘤湿重抑制率及体积抑制率。Western blot法检测β-catenin、p-β-catenin、CyclinD1、CDK4以及p-Akt、Akt、Bcl-2、Bax、Caspase3蛋白的相对表达量;免疫组织化学方法测定各组裸鼠肿瘤组织中β-catenin、p-β-catenin、CyclinD1、CDK4、Caspase 3、Caspase 9蛋白表达情况。结果 :免疫组织化学方法结果显示β-cate nin、p-β-cate nin、CyclinD1、CDK4表达情况随Form干预浓度增加而减弱;Caspase3、Caspase 9表达随Form干预浓度增加而增强。Western blot结果显示β-Catenin、p-β-Catenin、CyclinD1、CDK4以及p-Akt、Akt、Bcl-2等蛋白的相对表达量随Form干预浓度增加而降低;Caspase3、Bax等蛋白的相对表达量随Form干预浓度增加而上升。结论:Form可以通过抑制Wnt/β-catenin信号通路而抑制胃癌细胞的增殖,同时还可以上调Caspase3来促进胃癌细胞的凋亡。

壮药白花蛇舌草水提物对MDA-MB-231乳腺癌裸鼠移植瘤的抑制及免疫调节作用研究

目的观察白花蛇舌草水提物对MDA-MB-231乳腺癌裸鼠移植瘤的抑制及免疫调节作用,并探讨其作用机制。方法取6只正常BALB/c-nu雌性裸鼠作为正常组;取30只BALB/c-nu雌性裸鼠复制MDA-MB-231乳腺癌移植瘤模型,将造模成功裸鼠随机分为模型组、环磷酰胺组及白花蛇舌草水提物低、高剂量组,每组6只。环磷酰胺组给予环磷酰胺25 mg/kg腹腔注射,每7 d注射1次;白花蛇舌草水提物低、高剂量组分别按照1500 mg/(kg·d)、6000 mg/(kg·d)灌胃白花蛇舌草水提物溶液,正常组和模型组灌胃等体积灭菌注射用水,均1次/d。各组均连续干预21 d,监测裸鼠活动状况,每间隔2 d测量1次肿瘤大小。干预结束后,测量体重、瘤重与脾重,计算脾脏指数、抑瘤率;HE染色观察移植瘤的病理学形态;脾淋巴细胞增殖试验评价脾脏中T淋巴细胞和B淋巴细胞的增殖能力;血液分析仪测定外周血中白细胞数目和淋巴细胞占比;ELISA法检测血清中白细胞介素-2(IL-2)、白细胞介素-6(IL-6)、γ干扰素(IFN-γ)、肿瘤坏死因子-α(TNF-α)水平;Western blot法测定模型组和白花蛇舌草水提物低、高剂量组裸鼠肿瘤组织中磷脂酰肌醇3-激酶(PI3K)/蛋白激B(Akt)/哺乳动物雷帕霉素靶蛋白(mTOR)通路蛋白及凋亡相关蛋白[B细胞淋巴瘤/白血病-2蛋白(Bcl-2)、Bcl-2相关X蛋白(Bax)、半胱天冬氨酸蛋白酶-7(Caspase-7)、半胱天冬氨酸蛋白酶-9(Caspase-9)]表达情况。结果与正常组比较,模型组裸鼠脾脏指数、外周血中白细胞数量均明显升高(P均<0.05),脾脏T淋巴细胞和B淋巴细胞增殖能力指数、外周血淋巴细胞占比及血清中IL-2、IL-6、IFN-γ、TNF-α水平均明显降低(P均<0.05);肿瘤组织中肿瘤细胞密集丰富排列无序,肿瘤细胞异型性明显。与模型组比较,白花蛇舌草水提物高、低剂量组裸鼠脾脏指数、脾脏T淋巴细胞和B淋巴细胞增殖能力指数、外周血淋巴细胞占比及血清中IL-2、IL-6、IFN-γ、TNF-α水平均明显升高(P均<0.05),瘤重、外周血中白细胞数量均明显降低(P均<0.05);肿瘤组织中肿瘤细胞数目大量减少,细胞凋亡,组织结构破损;肿瘤组织中p-PI3K、PI3K、p-Akt、Akt、mTOR、Bcl-2蛋白相对表达量均明显降低(P均<0.05),Bax、Caspase-7、Caspase-9蛋白相对表达量均明显升高(P均<0.05)。环磷酰胺组裸鼠脾脏指数、瘤重、脾脏T淋巴细胞和B淋巴细胞增殖能力指数、外周血白细胞数量和淋巴细胞占比均明显低于模型组(P均<0.05);肿瘤组织中肿瘤细胞数量明显减少。结论白花蛇舌草水提物可显著抑制MDA-MB-231乳腺癌裸鼠移植瘤生长,诱导乳腺癌细胞发生凋亡,增强移植瘤裸鼠免疫功能,其机制可能与抑制PI3K/Akt/mTOR通路激活,下调凋亡相关蛋白表达、上调促凋亡蛋白表达相关。

OB glue paste technique for establishing nude mouse human gastric cancer orthotopic transplantation models

AIM： To establish nude mouse human gastric cancer orthotopic transplantation models using OB glue paste technique. METHODS： Using OB glue paste technique, orthtopic transplantation models were established by implanting SGC-7901 and NKN-45 human gastric cancer cell strains into the gastric wall of nude mice. Biological features, growth of the implanted tumors, the success rate of transplantation and the rate of auto-metastasis of the two models were observed. RESULTS： The success rates of orthotopic transplanration of the two models were 94.20% and 96%. The rates of hepatic metastasis, pulmonary metastasis, peritoneal metastasis, lymphocytic metastasis and splenic metastasis were 42.13% and 94.20%, 48.43% and 57.97%, 30.83% and 36.96%, 67.30% and 84.06%, and 59.75% and 10.53%, respectively. The occurrence of ascites was 47.80% and 36.96%. CONCLUSION： OB glue paste technique is easy to follow. The biological behaviors of the nude mouse human gastric cancer orthotopic transplantation models established with this technique are similar to the natural processes of growth and metastasis of human gastric cancer, and, therefore, can be used as an ideal model for experimental research of proliferative metastasis of tumors.

Inhibition of KIT RNAi mediated with adenovirus in gastrointestinal stromal tumor xenograft

AIM: To investigate a therapeutic method for gastrointestinal stromal tumor (GIST) based on KIT RNA interference (RNAi) with AdMax adenovirus. METHODS: KIT short hairpin RNA (shRNA), whose lateral sides were decorated with restriction endonuclease sequences, was designed. T 4 DNA ligase catalyzed the joint of the KIT shRNA and the green fluorescent protein-containing PDC316-EGFP-U6 to form PDC316EGFP-U6-KIT. Homologous recombination of AdEGFPU6-KIT was performed with the AdMax system. Heterotopically transplanted GISTs were established in nude mice. AdEGFP-U6-KIT was intratumorally injected. The volume, inhibition ratio of tumor and CD117 expression of GIST graft tumor in nude mice were compared between test and control groups. RESULTS: The length of KIT shRNA was determined to be about 50bp by agarose electrophoresis. Gene se-quencing detected the designed KIT RNAi sequence in PDC316-EGFP-U6-KIT. After transfection with AdEGFPU6-KIT, 293 cells displayed green fluorescence. The physical and infective titers of AdEGFP-U6-KIT were 5 × 10 11 viral particles/mL and 5.67 × 10 7 plaque forming units/mL, respectively. The mean volume of the grafted tumor was significantly smaller in test mice than in control mice (75.3 ± 22.9 mm 3 vs 988.6 ± 30.5 mm 3 , t = -18.132, P < 0.05). The inhibition ratio of the tumors was 59.6% in the test group. CD117 positive expression was evident in two cases (20%) in the test group and 10 cases (100%) in the control group (χ 2 = 10.2083, P < 0.005). CONCLUSION: AdEGFP-U6-KIT is successfully constructed, and KIT RNAi mediated with Admax vector system can effectively inhibit the expression of the KIT gene and the growth of GIST in nude mice.

Establishment of an orthotopic transplantation tumor model of hepatocellular carcinoma in mice

AIM:To improve the outcome of orthotopic transplantation in a mouse model,we used an absorbable gelatin sponge(AGS) in nude mice to establish an orthotopic implantation tumor model.METHODS:MHCC-97L hepatocellular carcinoma(HCC)cells stably expressing the luciferase gene were injected into the subcutaneous region of nude mice.One week later,the ectopic tumors were harvested and transplanted into the left liver lobe of nude mice.The AGS was used to establish the nude mouse orthotopic implantation tumor model.The tumor suppressor gene,paired box gene 5(PAX5),which is a tumor suppressor in HCC,was transfected into HCC cells to validate the model.Tumor growth was measured by bioluminescence imaging technology.Semi-quantitative reverse transcription polymerase chain reaction(RT-PCR) and histopathology were used to confirm the tumorigenicity of the implanted tumor from the MHCC-97L cell line.RESULTS:We successfully developed an orthotopic transplantation tumor model in nude mice with the use of an AGS.The success rate of tumor transplantation was improved from 60% in the control group to 100% in the experimental group using AGS.The detection of fluorescent signals showed that tumors grew in all live nude mice.The mice were divided into 3 groups:AGS-,AGS+/PAX5-and AGS+/PAX5 +.Tumor size was significantly smaller in PAX5 transfected nude mice compared to control mice(P < 0.0001).These fluorescent signal results were consistent with observations made during surgery.Pathologic examination further confirmed that the tissues from the ectopic tumor were HCC.Results from RT-PCR proved that the HCC originated from MHCC-97L cells.CONCLUSION:Using an AGS is a convenient and efficient way of establishing an indirect orthotopic liver transplantation tumor model with a high success rate.

Metastatic human hepatocellular carcinoma models in nude mice and cell line with metastatic potential

Metastatic human HCC model is needed for the studies on mechanism and intervention of metastatic recurrence. By using orthotopic implantation of histologically intact tissues of 30 surgical specimens, a patient-like metastatic model of human HCC in nude mice (LCI-D20) and a low metastatic model of human HCC in nude mice (LCI-D35) have been established. All mice with transplanted LCI-D20 tumors exhibited extremely high metastatic ability including spontaneous metastasis to liver, lungs, lymph nodes and peritoneal seeding. Remarkable difference was also found in expression of some of the invasiveness related genes and growth factors between the LCI-D20 and LCI-D35 tumors. PAI-1 increased gradually following tumor progression in LCI-D20 model, and correlated with tumor size and AFP level. Phasic expression of tissue intercellular adhesion molecule-1 in this model was also observed. Using corneal micropocket model, it was demonstrated that the vascular response induced by LCI-D20 tumor was stronger than that induced by LCI-D35 tumor. Similar report on metastatic human HCC model in nude mice and human HCC cell line with metastatic potential was rarely found in the literature. This LCI-D20 model has been widely used for the studies on intervention of metastasis, including anti-angiogenesis,antisense approach, metalloproteinase inhibitor, differentiation inducer, etc. It is concluded that the establishment of metastatic human HCC model in nude mice and human HCC cell line with metastatic potential will provide important models for the in vitro and in vitro study of HCC invasiveness, angiogenesis as well as intervention of HCC recurrence.

Antitumor activities of human autologous cytokineinduced killer(CIK)cells against hepatocellular carcinoma cells in vitro and in vivo

AIM: To characterize the anticancer function of cytokine-induced killer cells (CIK) and develop an adoptive immunotherapy for the patients with primary hepatocellular carcinoma (HCC), we evaluated the proliferation rate, phenotype and the antitumor activity of human CIK cells from healthy donors and HCC patients in vitro and in vivo. METHODS: Peripheral blood mononuclear cells (PBMC) from healthy donors and patients with primary HCC were incubated in vitro and induced into CIK cells in the presence of various cytokines such as interferon-gamma (IFN-gamma), interleukin-1 (IL-1), IL-2 and monoclonal antibody (mAb) against CD3. The phenotype and characterization of CIK cells were identified by flow cytometric analysis. The cytotoxicity of CIK cells was determined by (51)Cr release assay. RESULTS: The CIK cells were shown to be a heterogeneous population with different cellular phenotypes. The percentage of CD3+/CD56+ positive cells, the dominant effector cells, in total CIK cells from healthy donors and HCC patients, significantly increased from 0.1-0.13% at day 0 to 19.0-20.5% at day 21 incubation, which suggested that the CD3+ CD56+ positive cells proliferated faster than other cell populations of CIK cells in the protocol used in this study. After 28 day in vitro incubation, the CIK cells from patients with HCC and healthy donors increased by more than 300-fold and 500-fold in proliferation cell number, respectively. CIK cells originated from HCC patients possessed a higher in vitro antitumor cytotoxic activity on autologous HCC cells than the autologous lymphokine-activated killer (LAK) cells and PBMC cells. In in vivo animal experiment, CIK cells had stronger effects on the inhibition of tumor growth in Balb/c nude mice bearing BEL-7402-producing tumor than LAK cells (mean inhibitory rate, 84.7% vs 52.8%, P【0.05) or PBMC (mean inhibitory rate, 84.7% vs 37.1%, P【0.01). CONCLUSION: Autologous CIK cells are of highly efficient cytotoxic effector cells against primary hepatocellular carcinoma cells and might serve as an alternative adoptive therapeutic strategy for HCC patients.

Effects of endostatin on expression of vascular endothelial growth factor and its receptors and neovascularization in colonic carcinoma implanted in nude mice

AIM:To investigate the antiangiogenic effects of endostatin on colonic carcinoma cell line implanted in nude mice and its mechanism. METHODS:Nude mice underwent subcutaneous injection with LS-174t colonic carcinoma cell line to generate carcinoma and were randomly separated into two groups.Mice received injection of vehicle or endostatin every day for two weeks. After the tumor was harvested,the tumor volumes were determined,and the expressions of CD34,VEGF and FIk-1 were examined by immunohistochemical method. RESULTS:Tumor volume was significantly inhibited in the endostatin group(84.17%)and tumor weight was significantly inhibited in the endostatin group(0.197±0.049) compared to the control group(1.198±0.105)(F=22.56, P=0.001),microvessel density(MVD)was significantly decreased in the treated group(31.857±3.515)compared to the control group(100.143±4.290)(F=151.62,P<0.001). Furthermore,the expression of FIk-1 was significantly inhibited in the treated group(34.29%) ompared to the control group(8.57%)(X^2=13.745,P=0.001).However no significant decrease was observed in the expression of vascular endothelial growth factor(VEGF)between these two groups(X^2=0.119,P=0.730). CONCLUSION:Endostatin can inhibit tumor growth and angiogenesis by blocking Vegf/FIk-1 pathway.This experiment provides the theory basis for developing a new anti-carcinoma drug through studying the properties of anti-angiogenesis inhibitors.

Reduction of tumorigenicity of SMMC-7721 hepatoma cells by vascular endothelial growth factor antisense gene therapy

AIM: To test the hypothesis to block VEGF expression of SMMC-7721 hepatoma cells may inhibit tumor growth using the rat hepatoma model. METHODS: Amplify the 200 VEGF cDNA fragment and insert it into human U6 gene cassette in the reverse orientation transcribing small antisense RNA which could specifically interact with VEGF165, and VEGF121 mRNA. Construct the retroviral vector containing this antisense VEGF U6 cassette and package the replication-deficient recombinant retrovirus. SMMC-7721 cells were transduced with these virus and positive clones were selected with G418. PCR and Southern blot analysis were performed to determine if U6 cassette integrated into the genomic DNA of positive clone. Transfected tumor cells were evaluated for RNA expression by ribonuclease protection assays. The VEGF protein in the supernatant of parental tumor cells and genetically modified tumor cells was determined with ELISA. In vitro and in vivo growth properties of antisense VEGF cell clone in nude mice were analyzed. RESULTS: Restriction enzyme digestion and PCR sequencing verified that the antisense VEGF RNA retroviral vector was successfully constructed.After G418 selection, resistant SMMC-7721 cell clone was picked up. PCR and Southern blot analysis suggested that U6 cassette was integrated into the cell genomic DNA. Stable SMMC-7721 cell clone transduced with U6 antisense RNA cassette could express 200 bp small antisense VEGF RNA and secrete reduced levels of VEGF in culture condition. Production of VEGF by antisense transgene-expressing cells was 65+/-10 ng/L per 10(6) cells, 42045 ng/L per 10(6) cells in sense group and 485+/-30 ng/L per 10(6) cells in the negative control group, (P【 0.05). The antisense-VEGF cell clone appeared phenotypically indistinguishable from SMMC-7721 cells and SMMC-7721 cells transfected sense VEGF. The growth rate of the antisense-VEGF cell clone was the same as the control cells. When S.C. was implanted into nude mice, growth of antisense-VEGF cell lines was greatly inhibited compared with control cells. CONCLUSION: Expression of antisense VEGF RNA in SMMC-7721 cells could decrease the tumorigenicity, and antisense-VEGF gene therapy may be an adjuvant treatment for hepatoma.