Kallikrein-binding protein suppresses growth of hepatocellular carcinoma by anti-angiogenic activity

Effect of kallikrein-binding protein (KBP), an endogenous angiogenic inhibitor, on the growth of hepatocellular carcinoma and the possible mechanism were investigated. KBP inhibited proliferation and induced apoptosis of endothelial cells, but had no effect on the proliferation and apoptosis of hepatocarcinoma cell line HepG2. Intraperitoneal injection of KBP significantly suppressed the tumor growth and inhibited intratumoral neovascularization both in grafted hepatocarcinoma mice and xenografted hepatocarcinoma athymic mice. Moreover, KBP reduced expression of VEGF and HIF-1alpha nuclear translocation in HepG2 cells and xenografts. Down-regulation of VEGF in tumor cells through inhibiting HIF-1alpha may represent a novel mechanism for the anti-angiogenic and anti-tumor activity of KBP.     

Experimental study of the inhibition of human hepatocarcinoma Bel7402 cells by the tripeptide tyroserleutide(YSL)

Purpose: To investigate the antitumor effects of tyroserleutide (tyrosyl-seryl-leucine, YSL) on human Bel7402 hepatocarcinoma in vitro and in vivo, with preliminary exploration of its antitumor mechanism. Methods: MTT was used to observe the anticarcinogenic effects of YSL on human hepatocarcinoma Bel7402 cells in vitro. The ultrastructure of tumor cells was observed by electron microscopy. Nude mice bearing xenografts of human hepatocarcinoma Bel7402 were given daily i.p. injections of YSL or saline and an admixture of amino acids as controls, after tumor implantation. The inhibition of xenografts was determined by calculating the tumor volume and measuring tumor weight. The effects of YSL on the cell cycle and apoptosis of Bel7402 cells were determined by flow cytometry, and the effects on the ultrastructure of the cells by electron microscopy. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and proliferating-cell nuclear antigen (PCNA) immunohistochemical staining were used to investigate apoptosis in tumor tissue in nude mice. Results: In vitro YSL inhibited the proliferation of human Bel7402 tumor cells and changed their ultrastructure, resulting in the necrosis and apoptosis of the tumor cells. YSL at 80, 160, or 320 μg/kg/d inhibited tumor growth in nude mice by 40.26, 64.17, and 59.19%, respectively, which are significantly lower than the inhibition exerted by saline and an admixture of YSL amino acids (P<0.05). The ultrastructure and cell cycle of human hepatocarcinoma Bel7402 cells were changed by treatment with YSL, with a rate of apoptosis higher than that of the control group. TUNEL and PCNA analysis showed that YSL inhibited the proliferation of tumor cells and induced apoptosis at the level of the cell. Conclusions: YSL significantly inhibited human hepatocarcinoma Bel7402 growth in vitro and in vivo. The growth inhibition of the tumor may involve necrosis and apoptosis of the tumor induced by YSL. This study was supported by grants for the National High Technology Research and Development Program of China (2004AA2Z3170) (863 Program), The National Basic Research Program(2003CCA04300)(973 Program) and a project grant (03007) from the Department of Education of China.     

Preliminary investigation of the inhibitory effects of the tyroservaltide (YSV) tripeptide on human hepatocarcinoma BEL-7402

This study aimed to investigate the inhibitory effect of tyroservaltide (YSV) on the human hepatocarcinoma BEL-7402 transplanted into nude mice and to explore its possible anti-tumor mechanism. Nude mice bearing xenografts of the human BEL-7402 hepatoma were given daily i.p. injections of YSV or saline (as a control) after the tumor were transplanted. Calculating tumor volume and measuring tumor weight determined the extent of inhibition of xenografts. The ultrastructure of tumor cells was observed by electron microscopy. Proliferating cell nuclear antigen (PCNA) expression in tissues of the YSV-treated group was observed by immunohistochemistry. Apoptosis of tumor tissue cells was assayed by the terminal transferase uridyl nick end labeling (TUNEL) method. At doses of 80 microg/kg/d and 160 microg/kg/d, YSV could significantly inhibit growth of tumors transplanted into nude mice, with inhibition rates of 60% and 64%, respectively, compared with that of the controls (P < 0.05). Moreover, YSV changed the ultrastructure of tumor cells, resulting in necrosis and apoptosis of the tumor cells. Compared with the saline group, the expression of PCNA in tumor tissue decreased and the count of apoptotic cell increased. Therefore, YSV can significantly inhibit the growth of human hepatocarcinoma BEL-7402 in nude mice, decrease the expression of PCNA in tumor tissue, and induce tumor cell apoptosis.     

In vivo and in vitro evaluation of erianin, a novel anti-angiogenic agent

This study evaluated the anti-angiogenic activities of erianin in vivo and in vitro. Erianin, a natural product from Dendrobium chrysotoxum, caused moderate growth delay in xenografted human hepatoma Bel7402 and melanoma A375 and induced significant vascular shutdown within 4 h of administering 100 mg/kg of the drug. Erianin also displayed potent anti-angiogenic activities in vitro: it abrogated spontaneous or basic fibroblast growth factor-induced neovascularisation in chick embryo; it inhibited proliferation of human umbilical vein endothelial cells (EC(50) 34.1+/-12.7 nM), disrupted endothelial tube formation, and abolished migration across collagen and adhesion to fibronectin. Erianin also exerted selective inhibition toward endothelial cells, and quiescent endothelium showed more resistance than in proliferative and tumour conditions. In a cytoskeletal study, erianin depolymerised both F-actin and beta-tubulin, more significantly in proliferating endothelial cells than in confluent cells. In conclusion, erianin caused extensive tumour necrosis, growth delay and rapid vascular shutdown in hepatoma and melanoma models; it inhibited angiogenesis in vivo and in vitro and induced endothelial cytoskeletal disorganisation. These findings suggest that erianin has the therapeutic potential to inhibit angiogenesis in vivo and in vitro.     

酪丝缬肽对裸小鼠人肝癌BEL-7402移植瘤的抑制作用

目的观察酪丝缬肽对裸小鼠人肝癌BEL-7402移植瘤的抑瘤作用,并初步探讨其可能的作用机制。方法通过动物模型观察酪丝缬肽对裸小鼠人肝癌BEL-7402移植瘤肿瘤重量及体积的影响;以电镜观察肿瘤细胞超微结构的改变;以免疫组化法观察瘤组织中增殖细胞核抗原(PCNA)的表达;以利用TUNEL法检测瘤组织细胞的凋亡情况。结果给药剂量为80μg·kg~(-1)·d~(-1)和160μg·kg~(-1)·d~(-1)时,酪丝缬肽可以显著抑制裸小鼠BEL-7402移植瘤的生长,抑瘤率分别为64．02%和66．27%,与生理盐水及相应氨基酸混合物组比较,差异均有统计学意义(P＜0．05)。酪丝缬肽可引起肿瘤细胞超微结构改变,导致肿瘤细胞广泛坏死和凋亡。酪丝缬肽给药组与生理盐水组比较,肿瘤组织细胞的PCNA表达明显降低,凋亡细胞明显增多。结论酪丝缬肽可显著抑制人肝癌BEL-7402细胞在裸小鼠体内的生长,抑制肿瘤细胞增殖,促进瘤细胞凋亡。     

海胆肠提取物体外抗肿瘤活性的研究

目的 :研究海胆肠提取物对体外培养的SGC 790 1人胃腺癌细胞和Bel74 0 2人肝癌细胞系的作用 ,了解其体外抗肿瘤活性 ,并对其作用机制进行初步探讨。方法 :从海胆肠内提取水溶性多糖类成分。应用四氮唑蓝 (MTT)快速比色法测定肿瘤细胞生长抑制率。利用扫描电镜和透射电镜观察提取物对培养细胞超微结构的影响。结果 :MTT实验显示 ,海胆肠提取物对培养的SGC 790 1人胃腺癌细胞和Bel74 0 2人肝癌细胞的生长有明显的抑制作用 ,且抑制程度随浓度升高而增强 ;经海胆肠提取物作用后的细胞 ,透射电镜和扫描电镜观察均显示发生了特征性的形态学改变。结论 :海胆肠提取物在体外可显著抑制人癌细胞株生长 ,其作用机制主要是诱导肿瘤细胞凋亡     

人源化肿瘤血管移植瘤模型的建立及应用

背景与目的:目前在肿瘤内皮细胞基因功能和靶向血管治疗肿瘤的研究中仍缺乏适宜的动物模型。本研究拟建立一种新的小鼠人源化肿瘤血管移植瘤模型。方法:将人肝窦微血管内皮细胞系(humanliversinusoidendothelialcells,HLSEC)分别与人肝癌细胞系BEL7402、人结肠癌细胞系LS174T、人食管癌细胞系NEC按不同比例混合共接种NOD/SCID小鼠或BALB/c裸小鼠,以单独接种肿瘤细胞的小鼠作为对照组,观察小鼠人移植瘤生长的情况。采用绿色荧光蛋白基因(greenfluorescentprotein,GFP)转染HLSEC,结合荧光显微镜检方法观察HLSEC在共接种移植瘤中的存活及血管形成的情况。免疫组化法检测肿瘤内微血管密度(microvesseldensity,MVD)。用抗人肝癌内皮细胞单抗2B6处理人肝癌移植瘤共接种模型,观察2B6对肿瘤生长的影响。结果:HLSEC与BEL7402细胞共接种NOD/SCID小鼠时,共接种组肿瘤生长速度显著加快,平均瘤重可达肿瘤单独接种组的5.1倍。在GFP表达阳性的HLSEC与BEL7402共接种的移植瘤冰冻切片中可见HLSEC的存在,并已形成瘤内新生血管。免疫组化检测发现共接种组移植瘤中的总MVD较肿瘤细胞单独接种组增加85.7%,采用抗人vWF多抗检测结果显示共接种组人源微血管平均MVD可达10.28～29.28,约占总血管数量的41%～65%。进一步将HLSEC分别与NEC、BEL7402及LS174T细胞共接种于BALB/c裸小鼠时,共接种组的瘤重是单独接种组的3.3～6.0倍。2B6单抗能使共接种人肝癌移植瘤中人源肿瘤血管密度减少65.1%,抑制肿瘤瘤重达71.8%。结论:HLSEC与人肿瘤细胞共接种小鼠后,能在移植瘤中存活、增殖,形成大量人源化的肿瘤新生血管,并在促进肿瘤快速生长中起重要作用。该小鼠人源化肿瘤血管移植瘤模型可为肿瘤内皮细胞相关基因及靶向治疗剂的研究提供一个新的有价值的工具。     

肝癌高转移细胞株的肿瘤干细胞生物学特性研究

目的:建立高转移肝癌细胞株,研究其肿瘤干细胞生物学特征,为靶向人肝癌干细胞治疗提供有价值的细胞模型。方法:肝癌细胞系Bel7402接种裸鼠皮下,成瘤后,取小鼠肺部转移灶,通过机械分离法,获取肺部肝转移细胞,体外扩大培养后,再次接种裸鼠。如此反复接种裸鼠,获得稳定肺转移肝癌细胞株Bel7402-V13。采用无血清悬浮培养及PKH26染色确定Bel7402-V13中肿瘤干细胞的存在。流式细胞术分析亲本Bel7402和Bel7402-V13中肿瘤干细胞标志物ESA的表达情况,分选Bel7402和Bel7402-V13中ESA+细胞并进行体外生物学特征研究及裸鼠致瘤实验。结果:建立高转移Bel7402-V13细胞株,Bel7402-V13细胞无血清悬浮培养7d后形成的细胞球体中存在单个PKH26阳性细胞。与Bel7402中ESA+细胞相比,流式分析显示干细胞标志物ESA比例高转移Bel7402-V13显著提高5.67倍（17.6±0.4 vs 3.1±1.5）。Bel7402-V13中ESA+细胞具有更强的自我更新能力［成球率:（94.8±7.5）% vs （52.3±6.9）%,P<0.01］,侵袭能力提高1.51倍（397.7±79.4 vs 262.0±40.1,P<0.01）,耐药能力也显著增强（IC50:0.286 vs 0.196,P<0.01）,ESA+细胞Bel7402-V13在裸鼠皮下接种2×102个细胞3月即可致瘤（3/6）,而接种2×102个ESA+细胞Bel7402细胞3月才能致瘤（1/6）。结论:获得高转移肝癌细胞株Bel7402-V13,伴随ESA+细胞增加,其体内外功能显著增强,为肝癌干细胞的靶向治疗提供有价值的细胞模型。     

Up-Regulation of Bcl-2 in microvascular endothelial cells enhances intratumoral angiogenesis and accelerates tumor growth

Vascular endothelial growth factor (VEGF) has been shown to be a potent mediator of angiogenesis that functions as a survival factor for endothelial cells by up-regulating Bcl-2 expression. We have recently reported that human dermal microvascular endothelial cells (HDMECs) seeded in biodegradable sponges and implanted into severe combined immunodeficient (SCID) mice organize into functional human microvessels that transport mouse blood cells. In this study, we implanted sponges seeded with OSCC-3 (oral squamous cell carcinoma) or SLK (Kaposi's sarcoma) together with endothelial cells into SCID mice to generate human tumors vascularized with human microvessels. This model system was used to examine the role of both endothelial cell Bcl-2 and the proangiogenic chemokine interleukin-8 (IL-8) on tumor growth and intratumoral microvascular density. Coimplantation of HDMECs overexpressing Bcl-2 (HDMEC-Bcl-2) and tumor cells resulted in a 3-fold enhancement of tumor growth when compared with the coimplantation of control HDMECs and tumor cells. This was associated with increased intratumoral microvascular density and enhanced endothelial cell survival. To determine whether the enhanced neovascularization mediated by Bcl-2 overexpression in endothelial cells was influenced by the synthesis of endogenous mediators of angiogenesis, we screened these cells for expression of VEGF, basic fibroblast growth factor (bFGF), and IL-8 by ELISA. HDMEC-Bcl-2 cells and VEGF-treated HDMECs exhibited a 15-fold and 4-fold increase, respectively, in the expression of the proangiogenic chemokine IL-8 in vitro, whereas the expression of VEGF and bFGF remained unchanged. Transfection of antisense Bcl-2 into HDMECs blocked VEGF-mediated induction of IL-8. Conditioned media from HDMEC-Bcl-2 induced proliferation and sprouting of endothelial cells in vitro and neovascularization in rat corneas. Anti-IL-8 antibody added to HDMEC-Bcl-2 conditioned media markedly reduced the potency of these responses. SCID mice bearing VEGF-producing tumor implants that were treated with anti-lL-8 antibody exhibited a 43% reduction in microvessel density and a 50% reduction in tumor weight compared with treatment with a nonspecific antibody. These results demonstrate that the up-regulation of Bcl-2 expression in endothelial cells that constitute tumor microvessels enhances intratumoral microvascular survival and density and accelerates tumor growth. Furthermore, endothelial cells that overexpress Bcl-2 have more angiogenic potential than control cells, and IL-8-neutralizing antibodies attenuate their angiogenic activity in vitro and in vivo.     

Combined effects of soluble vascular endothelial growth factor receptor FLT-1 gene therapy and cisplatin chemotherapy in human tongue carcinoma xenografts

The aim of the present study was to assess the anti-tumor effect of a defective adenovirus that expresses soluble vascular endothelial growth factor (VEGF) receptor FLT-1 (AdsFLT-1) in combination with cisplatin (cis-diamminedichloroplatinum, DDP) on human tongue carcinoma Tca8113 cell xenografts that had been pre-established in nude mice. In vitro, Tca8113 cells secreted soluble FLT-1 (sFLT-1) after infection with AdsFLT-1, and the conditioned medium from AdsFLT-1-treated Tca8113 cells seemed to inhibit VEGF-induced proliferation of human umbilical vein endothelial cells. The combined effects of sFLT-1 gene therapy and DDP chemotherapy was then studied in well-established Tca8113 xenografts. The concentration of sFLT-1 in serum reached a peak 8 days after intratumoral injection of AdsFLT-1. In these tumors, AdsFLT-1 intratumoral injections had only a small effect. Interestingly, when the cells were also exposed to DDP chemotherapy, significantly higher (P<0.05), and possibly synergistic, anti-tumoral effects were observed that were highly correlated to a marked reduction in intratumoral vascularization and an increase in tumor-cell apoptosis. Together, these data emphasize the potential of combining an anti-angiogenic gene therapy strategy with a destructive approach directed against the tumor cells to fight human tongue carcinoma.     

Fascaplysin, a selective CDK4 inhibitor, exhibit anti-angiogenic activity in vitro and in vivo

Purpose This study was to evaluate the correlation of two important strategies, namely, cell cycle proliferation arrest and anti-angiogenesis. We chose fascaplysin, a marine natural product with selective CDK4 selective inhibition activity, to study its potential anti-angiogenesis effects in vivo and in vitro. Methods Chorioallantoic membrane (CAM) assay was initially used as an in vivo approach to evaluate anti-angiogenic activity of fascaplysin. In addition, human umbilical vein endothelial cell (HUVEC) line was used to further confirm the anti-angiogenic activity of fascaplysin in vitro. To explore the mechanism of anti-angiogenesis, we examined the effect of fascaplysin on vascular endothelial growth factor (VEGF) expression and secretion by hepatocarcinoma cells BeL-7402. Results The results of CAM assay suggested fascaplysin inhibited capillary plexus formation in a dose-dependent manner and suppressed VEGF in cross section. Moreover, the in vitro assay also confirmed that fascaplysin provided selective inhibition of endothelial cells proliferation towards tumor cells in low concentration. The immunocytochemical staining and ELISA verified fascaplysin could inhibit VEGF expression and secretion by BeL-7402. Conclusions These findings strongly suggest that fascaplysin is a natural angiogenesis inhibitor.     

Intramuscular electroporation of a plasmid encoding human plasminogen kringle 5 induces growth inhibition of Lewis lung carcinoma in mice

Tumor growth and metastasis depend critically on blood vessel formation. Antiangiogenesis, therefore, represents a promising strategy for cancer therapy. The kringle 5 (K5) domain of human plasminogen is a potent angiogenesis inhibitor. To investigate whether intramuscular electroporation (EP) of K5 has antitumor activity in mouse tumor models, we constructed a plasmid encoding K5 (pVAX1-K5). Hela cells transfected with this plasmid produced and secreted K5 that inhibited the migration of human microvascular endothelial cells. Intramuscular EP treatment of pVAX1-K5 inhibited the growth of Lewis lung carcinoma and prolonged the survival time of tumor-bearing mice. Angiogenesis was obviously inhibited, and apoptosis was induced in tumor cells of mice that received intramuscular EP of pVAX1-K5. On the contrary, intramuscular injection of pVAX1-K5 without EP failed to show the same effects. The data indicate that intramuscular EP of plasmid DNA encoding the K5 domain is an effective strategy for the experimental treatment of cancer by expressing K5.     

白细胞介素2质粒复合物治疗后小鼠肝癌的组织学变化

目的 探讨瘤体内直接注射白细胞介素2质粒／阳离子脂质体复合物治疗小鼠肝癌的效果和机制。方法 将小鼠白介素2表达质粒（VR1110）与阳离子脂质体（Transfectam)按适当比例混合而形成复合物（VR1110／Transfectam)。通过瘤体内接注射此复合物治疗小鼠肝癌模型,观察治疗后肿瘤积变化、组织学变化及表达情况。结果 瘤体内注射VR1110／Transfectam后,可在肿瘤组织中检测到小鼠IL－2mRNA的表达。VR1110／与Tansfectam治疗组肿瘤生长较其它对照组明显减慢,第1次治疗后第12天肿瘤体积明显小于其它组（P＜0．05）。治疗组小鼠均可见肿瘤组织大量坏死,炎性细胞浸润,及CD4^ 、CD8 淋巴细胞。结论 瘤体内直接注射VR1110／Transfectam复合物对小鼠肝癌的治疗作用明显,增强了小鼠机体对肝癌细胞的免疫学反应。     

Endostar, a modified recombinant human endostatin, exhibits synergistic effects with dexamethasone on angiogenesis and hepatoma growth

We evaluated the efficacy of a combination strategy, Endostar, a modified recombinant human endostatin, plus dexamethasone, against angiogenesis and hepatoma growth. By colony formation assay, synergistic effects of the combination of Endostar and dexamethasone were observed on the proliferations of human umbilical endothelial cells and hepatoma Bel-7402 cells. Endostar plus dexamethasone inhibited angiogenesis events in vitro. Examined with transwell assay, HUVECs invasion was more efficiently suppressed by combination of Endostar and dexamethasone than by the respective single drug. But the combination treatment of Endostar and dexamethasone to Bel-7402 cells did not alter the migration of HUVECs. The migration of HUVEC tended to coincident with VEGF secretion as determined by ELISA. Tube formation assay, rat aortic ring assay and chick embryo chorioallantoic membrane (CAM) assay indicated that the anti-angiogenesis effects of Endostar were significantly enhanced by dexamethasone. In mouse hepatoma H22 and human hepatoma Bel-7402 subcutaneous xenograft, Endostar plus dexamethasone presented more potent efficacy in tumor growth suppression than the single drug treatments. The above confirms the synergism of Endostar and dexamethasone on anti-angiogenesis and suppression of hepatoma growth. The potentiation effects of the combination indicate that Endostar plus dexamethasone might be a positive strategy for cancer therapy.     

Inhibitory effect of recombinant adenovirus carrying melittin gene on hepatocellular carcinoma.

OBJECTIVES: To search for a new clinical application of melittin (Mel): treating hepatocellular carcinoma with Mel gene. METHODS: Recombinant adenoviruses carrying the Mel gene and alpha-fetoprotein (AFP) promoter (Ad-rAFP-Mel) were constructed through a bacterial homologous recombinant system. The efficiency of adenovirus-mediated gene transfer and the inhibitory effect of Ad-rAFP-Mel on the proliferation of hepatocarcinoma cells were determined by X-gal stain and MTT assay, respectively. The tumorigenicity of hepatocarcinoma cells transfected by Ad-rAFP-Mel and the antitumor effect of Ad-rAFP-Mel on transplanted tumor in nude mice were detected in vivo. RESULTS: The Mel mRNA was transcribed in BEL-7402 hepatocellular carcinoma cells transducted by Ad-rAFP-Mel. The efficiency of adenovirus-mediated gene transferred to BEL-7402 cells was 100% when the multiplicity of infection of Ad-rAFP-Mel was 10 in vitro, and was also high in vivo. The inhibitive rates of Ad-rAFP-Mel and Ad-rAFP for BEL7402 cells were 66.2 +/- 2.7% and 2.9 +/- 2.3% (t=30.83, P=6.6 x 10(-6)) by MTT assay. The inhibitive rates of Ad-CMV-Mel for BEL7402, SMMC7721 and L02 cells were 58.9 +/- 9.6%, 65.9 +/- 3.8% and 31.7 +/- 1.2%, respectively, and of Ad-rAFP-Mel were 66.2 +/- 2.7%, 16.1 +/- 6.6% and 7.5 +/- 3.3%, respectively (t=1.27, P=0.27; t=11.31, P=3.5 x 10(-4); and t=12.12, P=2.7 x 10(-4) versus the Ad-CMV-Mel group in the same cells). The tumorigenicity rates of hepatocarcinoma cells transfected by Ad-rAFP-Mel were decreased. A significant antineoplastic effect was detected on transplanted tumor in nude mice by intratumoral injection of Ad-rAFP-Mel. CONCLUSIONS: Ad-rAFP-Mel can inhibit specifically proliferation of AFP-producing human hepatocarcinoma cells in vitro and in vivo. This suggests that animal toxin gene can be used as an antitumor gene.     

Expression of PTEN, p27, p21 and AKT mRNA and protein in human BEL-7402 hepatocarcinoma cells in transplanted tumors of nude mice treated with the tripeptide tyroservatide (YSV)

The tripeptide, tyroservatide (YSV), has been previously shown to have antitumor effects through unknown mechanism. In the current study, we examined whether YSV modulates the protumorigenic PI3K pathway in human BEL-7402 hepatocarcinoma cells. BEL-7402 hepatocarcinoma was transplanted into the subcutaneous tissues of nude mice, and YSV, at varying doses, was administered. RT-PCR and Western blot were used to analyze the expression of PTEN, AKT, p21 and p27. YSV at doses of 80 microg/kg/day, 160 microg/kg/day and 320 microg/kg/day markedly inhibited the growth of human BEL-7402 hepatocarcinoma (p < 0.05). YSV increased mRNA and protein expression of the tumor-suppressor genes, PTEN, p21 and p27, and inhibited the mRNA and protein expression of the oncogene AKT. Furthermore, YSV administration was associated with dephosphorylation of both PTEN (which activates PTEN) and AKT (which inhibits AKT). These results are consistent with the possibility that YSV mediates inhibition of tumor growth through inhibition of the PI3K pathway and suggests that YSV should be explored for use as an antitumor agent for hepatocarcinoma.     

白英总苷抗肿瘤作用初步研究

目的研究白英总苷体内外抗肿瘤作用。方法采用MTT法考察白英总苷体外对人肝癌BEL-7402细胞及人胃腺癌SGC-7901细胞的增殖抑制作用;以小鼠S180肉瘤及H22肝癌为模型,考察白英总苷体内对肿瘤生长的抑制作用。结果白英总苷对人肝癌BEL-7402细胞及人胃腺癌SGC-7901细胞有显著地增殖抑制作用,且均呈现良好的浓度-效应依赖关系,作用48h的IC50值分别为(180.22±6.32)μg/ml和(114.89±4.89)μg/ml;白英总苷对小鼠S180肉瘤有显著的抑制作用,且呈现良好的剂量-效应关系,三次重复实验,高剂量组的抑瘤率达到33.76%±3.24%;白英总苷各剂量对小鼠H22肝癌抑制作用均不显著。结论白英总苷体内外有一定的抗肿瘤作用。     

miR-16对人肝癌细胞BEL-7402增殖与凋亡的影响

背景与目的：miR-16和miR-15a基因复合体位于人13q14区域的DLEU2基因内含子内,是目前公认的抑癌基因之一。该基因区域的缺失与多种实体肿瘤有关,miR-16同时促进肿瘤细胞的凋亡。该研究旨在探讨miR-16对BEL-7402肝癌细胞增殖与凋亡的影响。方法：人肝癌细胞BEL-7402分为miR-16感染组(加入LV-hsamiR-16-1慢病毒)和阴性对照组(加入阴性对照病毒),采用倒置荧光显微镜观察细胞绿色荧光的强度;采用细胞计数试剂盒(cell counting kit-8,CCK-8)检测miR-16对BEL-7402肝癌细胞增殖的影响;采用流式细胞术分析miR-16对人肝癌细胞BEL-7402的细胞周期与凋亡的影响。结果：CCK-8检测结果显示,感染组细胞增殖能力明显降低(P<0.05);流式细胞术检测结果显示,阴性对照组BEL-7402细胞周期中G₁期细胞百分率数值明显下降,但S及G₂/M期细胞的百分率均明显上升(P<0.05)。miR-16促进BEL-7402肝癌细胞凋亡。结论：miR-16抑制BEL-7402肝癌细胞的增殖并促进其凋亡,miR-16有望成为临床肝癌靶向治疗的新靶点。     

Cytoplasmic alpha-fetoprotein functions as a co-repressor in RA-RAR signaling to promote the growth of human hepatoma Bel 7402 cells

The role of AFP in the retinoic acid-RAR signaling pathway was investigated in human hepatoma Bel 7402 cells. The results showed that AFP and RAR-β were co-localized and interacted in cytoplasm. AFP may inhibit translocation of RAR-β into the nucleus via competitive binding to RAR-β with ATRA, which was reversed by AFP-siRNA transfection. Our data suggest that the ATRA resistance of Bel 7402 cells is at least in part attributable to their high level of cytoplasmic AFP. Thus, by counteracting the effect of AFP, it may be possible to increase the sensitivity of tumor cells to ATRA.