siRNA腺病毒体内抑制Survivin基因表达诱导裸鼠肿瘤细胞凋亡的研究

目的利用腺病毒siRNA载体介导的RNA干扰技术,在免疫缺陷鼠肝癌肿瘤动物模型中通过靶向沉默细胞凋亡因子Survivin的表达,探讨其在活体动物肿瘤组织中的作用。方法利用肝癌细胞株HepG2构建裸鼠肝癌肿瘤细胞动物模型,并按照病毒注射剂量分组,将已构建的Survivin-siRNA重组腺病毒注射入裸鼠肿瘤内,观察肿瘤生长状况并绘制肿瘤生长曲线,利用TUNEL反应测定肿瘤组织细胞内DNA的片段化观察细胞凋亡。结果注射AdsiR- NA-Survivin高、低剂量组肿瘤生长明显受到抑制,且抑制程度与注射的腺病毒浓度呈正相关;TUNEL实验表明注射AdsiRNA-Survivin高、低剂量组的肿瘤组织标本可见大量细胞核呈黄褐色、核质浓缩、细胞形态不规则的凋亡细胞。高剂量组、低剂量组、AdsiRNA-U6组、PBS组凋亡细胞数依次减少。结论腺病毒siRNA载体系统可应用于活体动物试验中;AdsiRNA-Survivin对裸鼠人肝癌移植瘤有明显抑制作用,与肿瘤感染数或浓度成正比,且能促进人肝癌肿瘤细胞的凋亡。     

阿司匹林抑制肝癌生长的实验研究

目的探讨阿司匹林对人肝癌生长的影响及是否能诱导其凋亡. 方法用3H-TdR掺入、形态学观察、DNA末端原位标记法(Tunel)和流式细胞术等方法研究阿司匹林对人肝癌细胞株SMMC-7721生长及诱导凋亡的作用;建立人肝癌裸鼠原位移植瘤模型,观察阿司匹林对肝癌移植瘤生长的影响. 结果阿司匹林能显著抑制人肝癌细胞株SMMC-7721生长,当其浓度在1×10-1～1×10-7mol/L时,肝癌细胞3H-TdR掺入与浓度增加呈显著负相关(r＝-0.918,P＜0.01).经1×10-3mol/L阿司匹林作用后可见较多肝癌细胞呈典型的细胞凋亡形态学变化,凋亡指数为(8.90±1.32)%,对照组为 (0.50±0.35)%,两组比较,差异有显著性,流式细胞术也检测到其G1期前有一典型的亚二倍体凋亡峰,凋亡率为 12.79%.阿司匹林能显著抑制人肝癌裸鼠原位移植瘤生长,抑瘤率为71.62%,实验中裸鼠存活率为100%,未见消化道出血、溃疡等不良反应. 结论阿司匹林能显著抑制人肝癌生长并能诱导其凋亡.     

The antiangiogenic effects of tyroservatide on animal models of hepatocellular carcinoma

Purpose  To investigate the tumor inhibition and antiangiogenic effects of Tyroservatide (YSV, a small polypeptide composed of 3 amino acids. The chemical structure of YSV is l-tyrosine–l-serine–l-valine, molecular structure is C₁₇H₂₅N₃O₆, and molecular weight is 367.40 Da) on human hepatocarcinoma SMMC-7721 transplanted tumors in nude mice. Methods  The nude mice bearing xenografts of human hepatocarcinoma SMMC-7721 tumors were daily given intraperitoneal injection of YSV or saline as a control group after the tumor was implanted, total four groups with six mice in each. Calculating tumor volume and measuring tumor weight determined the extent of inhibition of xenografts. The microvessel density (MVD) of tumor tissue was measured by immunohistochemistry. Angiogenesis-related gene expression profile in tumor tissue was assayed by Oligo gene chip and checked by real-time PCR. The Serum concentration of selected factors was measured by ELISA. Result  YSV at 160, 320, or 640 μg/kg/day inhibited tumor growth in nude mice by 42.62, 60.66, and 27.59%, respectively, which were lower than that of control (P < 0.05). Immunohistochemical staining of the tumor tissue showed the decrease in MVD of tumor tissue after YSV injection. Comparing the 113 genes related with angiogenesis, we found that 18 genes showed the significant difference between the YSV groups and the control; vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) were the leading ones. The mRNA level as well as ELISA of VEGF and IL-8 in YSV group (320 μg/kg/day) were significantly decreased compared with the control (P < 0.05). Conclusion  YSV could inhibit the growth of human hepatocarcinoma SMMC-7721 tumor in nude mice, which might attribute to the inhibition of expression of angiogenesis-related factors in mRNA and protein level.     

Establishment and characterization of human hepatocellular carcinoma cell line FHCC-98

AIM: To establish a novel human hepatocellular carcinoma (HCC) cell line FHCC-98 from HCC tissue and to provide a suitable model for studying HCC occurrence, progress and metastasis.METHODS: Serially passaged cells were cultured and their morphologies were observed under light and electron microscope. Cytogenetic study was conducted by using flow cytometry and chromosome analysis. Expressions of tumor markers such as α-fetoprotein (AFP), cytokeratin (CK) and hepatoma metastasis-associated factor HAb18G/CD147 on the FHCC-98 cells were detected by immunocytochemistry or Western blotting. Lactic dehydrogenase (LDH) isoenzymes were detected by polyacrylamide gel electrophoresis (PAGE).Xenograft was performed by inoculating FHCC-98 cells into the flanks of nude mice.RESULTS: Morphology of FHCC-98 cells was the same as that of other malignant cells. The expressions of the cells were positive for HAb18G/CD147 and CK, and negative for AFP. Its population doubling time was 21.4 h. The cell DNA was tetraploid and the major chromosomes were triploid by cytogenetics analysis. The tumorigenicity in nude mice was 100%. PAGE showed four bands representing LDH2, LDH3,LDH4 and LDH5.CONCLUSION: FHCC-98 is a novel HCC cell line and an ideal cell model for further exploring the mechanism of hepatocellular carcinoma invasion and metastasis.     

Octreotide acts as an antitumor angiogenesis compound and suppresses tumor growth in nude mice bearing human hepatocellular carcinoma xenografts

Purpose To investigate the effect of octreotide on angiogenesis induced by human hepatocellular carcinoma (HCC) and to evaluate whether octreotide can suppress tumor growth in nude mice bearing human HCC xenografts through inhibition of angiogenesis.Methods Using MTT assay, invasion assay, migration assay, and Matrigel assay, the effects of octreotide on endothelial cells stimulated by vascular endothelial growth factor (VEGF) were evaluated in vitro. MTT assay was also used to investigate the effects of octreotide on human HCC cells with high (MHCC97-H) and low (MHCC97-L) metastatic potential that were established from the animal model of human HCC LCI-D20 in nude mice. The expression of somatostatin receptor (SSTR) subtypes in human umbilical vein endothelial cells (HUVECs), MHCC97-H, and MHCC97-L cells was detected by RT-PCR analysis. An LCI-D20 corneal micropocket model in nude mice was used to evaluate the effect of octreotide on angiogenesis induced by human HCC in vivo. Male nude mice were subcutaneously implanted with LCI-D20 tumor tissues for the tumor xenograft studies. Microvessel density was analyzed in CD34-stained tumor sections by the immunohistochemical SP method.Results In vitro, octreotide inhibited the proliferation, invasion, and differentiation of HUVECs elicited by VEGF. RT-PCR analysis demonstrated that HUVECs expressed the somatostatin receptor subtype SSTR3. In vivo, octreotide was sufficiently potent to suppress nude mice corneal neovascularization induced by tumor tissues from LCI-D20. Systemic administrations of octreotide produced a significant suppression of the growth of LCI-D20. In cell culture, MHCC97-H and MHCC97-L cells were insensitive to octreotide at concentrations that significantly inhibited endothelial cells proliferation. The HCC cells used did not express any known SSTRs. Immunohistochemical studies of tumor tissues revealed decreased microvessel density in octreotide-treated animals as compared with controls.Conclusions The present study demonstrates that the somatostatin analogue octreotide is a potent antitumor angiogenesis compound and the antiproliferative effect of octreotide on tumor growth in nude mice bearing HCC xenografts may be mediated, at least in part, by its suppressive effect on blood vessel supply. The somatostatin analogue octreotide might provide a useful and relatively nontoxic adjuvant therapy in the treatment of HCC.The work was supported by the grant from the Natural Science Foundation of Anhui and Anke Pharmaceutical Co. limited (NO.01043708)     

Inhibitory effect of interferon-α-2b on expression of cyclooxygenase-2 and vascular endothelial growth factor in human hepatocellular carcinoma inoculated in nude mice

AIM： To evaluate the effects of interferon-α-2b （IFN- α-2b） on expression of cyclooxygenase-2 （COX-2） and vascular endothelial growth factor （VEGF） in human hepatocellular carcinoma （HCC） inoculated in nude mice and to study the underlying mechanism of IFN-α- 2b against HCC growth. METHODS： Thirb/-two nude mice bearing human HCC were randomly divided into four groups （n = 8）. On the 10th day after implantation of HCC cells, the mice in test groups （groups A, B and C） received IFN-α- 2b at a serial dose （10000 IU for group A, 20000 IU for group B, 40000 IU for group C sc daily） for 35 d. The mice in control group received normal saline （NS）. The growth conditions of transplanted tumors were observed. Both genes and proteins of COX-2 and VEGF were detected by RT-PCR and Western blot. Apoptosis of tumor cells in nude mice was detected by TUNEL assay after treatment with IFN-α-2b. RESULTS： Tumors were significantly smaller and had a lower weight in the IFN-α-2b treatment groups than those in the control group （P 〈 0.01）, and the tumor growth inhibition rate in groups A, B and C was 27.78%, 65.22% and 49.64%, respectively. The expression levels of both genes and proteins of COX-2 and VEGF were much lower in the IFN-α-2b treatment groups than in the control group （P 〈 0.01）. The apoptosis index （AI） of tumor cells in the IFN-α-2b treatment groups was markedly higher than that in the control group （P 〈 0.01）. Group B had a higher inhibition rate of tumor growth, a lower expression level of COX-2 and VEGF and a higher AI than groups A and C （P 〈 0.05）, but there was no significant difference between groups A and C. CONCLUSION： The inhibitory effects of IFN-α-2b on implanted tumor growth and apoptosis may be associated with the down-regulation of COX-2 and VEGF expression. There is a dose-effect relationship. The medium dose of IFN-α-2b for inhibiting tumor growth is 20 000 IU/d.