Tyroserleutide tripeptide affects calcium homeostasis of human hepatocarcinoma BEL-7402 cells

This study aimed to observe the effects of tyroserleutide (tyrosyl-seryl-leucine, YSL) on the growth of human hepatocarcinoma BEL-7402 that was transplanted into nude mice, and explore its anti-tumor mechanism preliminarily. YSL, at doses of 80 μg-kg^-1 · d^-1, 160 μg·kg^-1 ·d^-1 and 320 μg · kg^-1 · d^-1 significantly inhibited the growth of the human hepatocarcinoma BEL-7402 tumor in nude mice, producing inhibition of 21.66%, 41.34%, and 34.78%, respectively. Ultra structure of BEL-7402 tumor in nude mice showed that YSL could induce tumor cells apoptosis and necrosis, cell organelle mitochondria and endoplasmic reticulum damage, and calcium overload. By confocal laser scanning microscopy and flow cytometry, we found that 10 μg/mL YSL rapidly induced an increase of the concentration of cytoplasmic free calcium in BEL-7402 cells in vitro, and maintained high concentrations of cytoplasmic free calcium for 1 h. Then the calcium concentration began to decrease after 2 h, and was lower than that of the control group at 4 h and 24 h (P< 0.05). YSL also decreased the mitochondrial transmembrane potential of BEL-7402 cells in vitro, but had no effect on the calcium homeostasis or mitochondrial transmembrane potential of Chang liver hepatocytes. So affecting calcium homeostasis, then inducing apoptosis and necrosis may be a mechanism by which YSL inhibits the tumor growth in animal model.     

The effect of tripeptide tyroserleutide (YSL) on animal models of hepatocarcinoma

This study aimed to observe the effects of tyroserleutide (tyrosyl-seryl-leucine, YSL) on the survival time of mice transplanted with the ascitic fluid-type hepatocarcinoma H22, as well as the inhibitory effect of tyroserleutide on the human hepatocarcinoma Bel-7402 that was transplanted into nude mice. At doses of 80, 20 and 5 microg/kg/d, tyroserleutide significantly prolonged the survival of mice transplanted with H22 tumor cells, producing survival rates of 89%, 39% and 49%, respectively, which were statistically significantly different from the saline group (P < 0.05). YSL, at doses of 80, 160 and 320 microg/kg/d significantly inhibited the growth of the human hepatocarcinoma Bel-7402 tumor in nude mice, producing inhibition of 40%, 64% and 59%, respectively; this inhibition was significantly greater than that by saline (P < 0.05). HE staining and electron microscopy of the pathological changes of the tumor in nude mice showed that YSL changed the structure Bel-7402 tumor cells that were transplanted into nude mice, and also induced tumor cell apoptosis and necrosis, which could be a mechanism by which YSL inhibits the tumor growth in animal models.     

Inhibition by tyroserleutide (YSL) on the invasion and adhesion of the mouse melanoma cell

Tyroserleutide (YSL) is an active, low-molecular-weight polypeptide, comprised of three amino acids, that has shown antitumor effects on human hepatocarcinoma BEL-7402 in vitro and in vivo. In this study, we evaluated the inhibition of YSL on invasion and adhesion of the mouse B16-F10 melanoma cell line by injecting B16-F10 cells into the tail veins of C57BL/6 mice to establish an experimental lung metastasis model. YSL inhibited B16-F10 cell metastasis to lung, reducing the number and area of metastasis lesions. When we treated B16-F10 cells with YSL (0.01, 0.1, 1, 10, or 100 microg/mL) in vitro, we found that YSL inhibited the proliferation of B16-F10 cells with a 28.11% rate of inhibition. YSL significantly decreased the adhesiveness of B16-F10 cells to Matrigel with a 29.15% inhibition rate; YSL also significantly inhibited the invasion of B16-F10 cells, producing an inhibition of 35.31%. By analyses with Western blot and real-time RT-PCR, we found that YSL markedly inhibited the expression of ICAM-1 in B16-F10 cells. These data suggest that YSL inhibits the growth, invasion, and adhesion of B16-F10 cells.     

Tripeptide tyroserleutide enhances the antitumor effects of macrophages and stimulates macrophage secretion of IL-1β, TNF-α, and NO in vitro

Tyroserleutide (YSL) is a type of active, low molecular weight polypeptide, comprised of three amino acids, which has antitumor effects. YSL has various advantages over the other bioactive peptides such as its low molecular weight, simple construction, nonimmunogenicity, specificity, few side effects, and ease of synthesis. However, the biological activities contributing to it’s antitumor effects are not yet known. We studied the effects of YSL on the in vitro cytotoxic activity of BALB/c mice peritoneal macrophages (PEMφ) against the target tumor cell lines BEL-7402 and B16-F10. We also measured the concentrations of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and nitric oxide (NO) produced by YSL-activated Mφ, and we determined the concentrations of IL-1β and NO secreted by YSL-activated murine macrophage RAW264.7 cells. YSL activated Mφ in vitro, inhibited BEL-7402 proliferation, enhanced PEMφ antitumor effects, and stimulated IL-1β, TNF-α, and NO production by RAW264.7 cells. These data suggest that YSL activates the monocyte–macrophage system, which enhances Mφ antitumor effects against BEL-7402 and B16-F10 cells and stimulates the secretion by Mφ of cytotoxic effectors such as IL-1β, TNF-α, and NO.     

酪丝亮肽荧光标记物的合成及其在肿瘤治疗靶点研究中的应用

酪丝亮肽是一种具有抗肿瘤活性的小分子三肽,它可以诱导造成肝癌细胞发生凋亡坏死,从而杀伤肿瘤细胞,但是酪丝亮肽在肝癌细胞的亚细胞定位尚不十分明确．为了达到对酪丝亮肽进行示踪进而观察其亚细胞定位的目的,使用荧光物质（5（6）－羧基叫甲基罗丹明琥珀酰业胺酯,5（6）－TAMRASE）对酪丝亮肽进行丫标记,应用非变性聚丙烯酰胺凝胶电泳、毛细管电泳和荧光分光光度法对标记酪丝亮肽进行纯化和鉴定．并在激光扫描共聚焦显微镜下观察了荧光标记酪丝亮肽在人肝癌BEL－7402细胞中的分布．结果显示,合成的酪丝亮肽荧光标记物性质稳定,标记的酪丝亮肽在人肝癌BEL－7402细胞的胞浆中呈聚集分布．     

Synthesis and antitumor activity of cholest-4 alpha-methyl-7-en-3beta-ol derivatives

Cholest-4 alpha-methyl-7-en-3beta-ol (1) has potent inhibitory activity against pc 12 tumor with 0.5043 ratio (10 microg/mL). This paper describes a series of structural modification of this compound, which focus on 3beta-hydroxyl group and 7(8)-double bond. The synthesized derivatives of 1 were tested for human cancer cell lines including colon cancer (HCT-8), liver cancer (BEL-7402) and nasopharyngeal cancer (KB) cells. The results showed that cholest-4 alpha-methyl-8-en-3beta,7 alpha-diol 6a inhibits KB cell significantly with IC(50) 1.32 x 10(-9)microg/mL. In addition, the cytotoxic properties of this compound against HCT-8 and BEL-7402 are excellent with IC(50) 1.2 microg/mL.     

BIX-01294对肝癌细胞周期、凋亡及移植瘤的影响

目的:探究组蛋白甲基转移酶G9a抑制剂(BIX-01294)对肝癌细胞周期、凋亡及移植瘤的影响.方法:将SMMC-7721、BEL-7402、HL-7702原始细胞株传代培养后,分为空白对照组和不同浓度(1 μM、5 μM、10 μM、20 μM)BIX-01294处理组.应用Western-blot法检测G9a及肝癌...     

Effects of tyroserleutide on gene expression of calmodulin and PI3K in hepatocellular carcinoma

Tyroserleutide (YSL) is a tripeptide compound that has exhibited inhibitory effects on hepatocellular carcinoma in our previous research. The mechanism of this antitumor activity involves the second messenger, Ca(2+). Ca(2+) influences cell function through the Ca(2+)/calmodulin (CaM) pathway, and abnormality of the Ca(2+)/CaM system correlates closely with the occurrence of tumors. In addition, CaM associates with phosphatidylinositol 3 kinase (PI3K), thereby enhancing the activity of PI3K, which promotes cell proliferation. In order to investigate its anti-tumor mechanism, we studied the effects of YSL on CaM protein expression and mRNA level, PI3K activity, PI3K regulatory subunit p85 protein expression and mRNA level, and the mRNA level of PI3K catalytic subunits p110alpha and p110gamma in human hepatocellular carcinoma BEL-7402 xenograft tumors in nude mice. Our results showed that YSL decreased the mRNA level and protein expression of CaM, inhibited the activity of PI3K, and reduced the mRNA level and protein expression of the PI3K regulatory subunit p85 and mRNA level of PI3K catalytic subunits p110alpha and p110gamma. Accordingly, it is suggestive that the anti-tumor effects of YSL may be mediated by down regulation of CaM and PI3K subunits p85 and p110, influencing the signal transduction pathway in the tumor cells and perhaps overcoming the dysfunctional PI3K activity in tumors.     

人肝癌细胞BEL-7402中热休克蛋白70相伴甲胎蛋白的实验研究

为研究人肝癌细胞BEL-7402中热休克蛋白70(HSP70)与甲胎蛋白(AFP)的相互作用,采用免疫化学和免疫荧光检测HSP70和AFP在肝癌细胞中的表达和定位.HSP70与AFP的相互关系通过免疫共沉淀和蛋白印迹杂交进行分析.结果免疫化学显示人肝癌细胞BEL-7402中存在高水平的HSP70和AFP共表达,均定位于细胞浆.AFP存在于HSP70单抗的免疫沉淀中,而HSP70则存在于AFP单抗的免疫沉淀中.结果表明人肝癌细胞BEL-7402中HSP70与AFP相伴.两者之间的相互关系研究将成为探讨肝癌的发生和免疫治疗的新途径.     

胡桃醌不同给药途径对人肝癌细胞BEL-7402裸鼠皮下移植瘤生长的影响

目的采用裸鼠皮下移植瘤模型,通过不同给药途径对胡桃醌抗肿瘤活性和毒性进行评价。方法建立人肝癌BEL-7402细胞裸鼠皮下移植瘤模型,通过腹腔注射和局部注射两个给药途径观察胡桃醌抑制肿瘤生长的效果。结果①以600、300和150μg/kg胡桃醌腹腔注射于人肝癌BEL-7402细胞裸鼠皮下移植瘤模型,发现该剂量胡桃醌对肿瘤生长没有明显的影响;NK细胞活性检测发现,600、300μg/kg胡桃醌对裸鼠免疫功能有影响(P均<0.01),150μg/kg胡桃醌则没有影响(P>0.05);与阳性对照组(5-Fu)相比,600μg/kg胡桃醌组NK细胞活性差异无显著性(P>0.05),300和150μg/kg胡桃醌组NK细胞活性差异有显著性(P<0.05,P<0.01),结果提示胡桃醌对小鼠免疫系统有一定的损伤作用。②以4.5、3和1.5 mg/kg胡桃醌腹腔注射于人肝癌BEL-7402细胞裸鼠皮下移植瘤模型,抑瘤率分别为为78.24%、66.57%、48.94%;4.5、3 mg/kg胡桃醌的抑瘤作用可与阳性对照组比拟(P均>0.05)。但4.5 mg/kg胡桃醌组裸鼠出现明显的皮下脂肪减少、消瘦,并有死亡现象。③以pH 7.4和pH 4.0的600、300和150μg/kg胡桃醌人肝癌BEL-7402细胞裸鼠皮下移植瘤模型局部给药,结果发现不同pH(pH 7.4或4.0)600、300μg/kg的胡桃醌局部注射抑瘤作用与阳性对照组(5-Fu)组差异无显著性(P>0.05),而不同pH的150μg/kg胡桃醌抑瘤作用不明显。同一浓度不同pH药物的抑瘤作用差异无显著性(P均>0.05),但pH 4.0的胡桃醌组肿瘤细胞肝转移较少。结论胡桃醌不同给药途径均可抑制人肝癌BEL-7402细胞裸鼠皮下移植瘤的生长,但有一定的毒副作用,药物安全范围较小。     

白花蛇舌草豆甾醇对肝癌细胞的体内外抑制作用及对其增殖周期、凋亡的影响

目的:研究白花蛇舌草豆甾醇(stigmasterol from Hedyotis diffusa willd.,SHD)对人肝癌细胞SMMC-7721、BEL-7402的体外抑制作用,对肝癌H22的体内抑制作用及对其增殖周期、凋亡的影响。方法:MTT法评价SHD对人肝癌细胞SMMC-7721、BEL-7402的抑制率变化规律。昆明雄性小鼠60只,随机取10只为正常对照组,余接种H22瘤株,随机分为模型对照组、5-FU阳性对照组(30mg/kg)和高中低剂量SHD给药组(剂量分别为15、30、60mg/kg),腹腔给药10 d后,比较各组瘤重抑制率、H22细胞周期分布、凋亡率。结果:SHD对SMMC-7721、BEL-7402细胞具有体外抑制作用;SHD显著抑制H22肿瘤,增加G0-G1期细胞比例,降低G2/M期细胞比例,促进肿瘤细胞凋亡。结论:SHD在体外、体内均具有抑制肝癌细胞的作用,此作用与阻滞肿瘤细胞增殖周期,促进肿瘤细胞凋亡有关。     

Antitumor activity of Pulsatilla chinensis (Bunge) Regel saponins in human liver tumor 7402 cells in vitro and in vivo

Pulsatilla chinensis (Bunge) Regel is a Chinese medicinal herb for "blood-cooling" and detoxification. Now it is used for the treatment of malignant tumor, but the antitumor mechanisms and toxic side effects of P. chinensis are unclear. The present study was undertaken to investigate if P. chinensis saponins (PRS) possesses anticancer effects and toxic side effects in human liver tumor 7402 cells in vitro and vivo. 7402 cells were treated with different concentrations of PRS for 24h. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was assessed by flow cytometry. The in vivo effect of PRS on 7402 tumor cells transplanted in athymic nude mice was investigated. 15 saponins were isolated and identified from PRS. PRS inhibited the proliferation of human liver tumor 7402 cells in vitro by apoptosis. 19 days after administration of PRS (100, 200mg/kg), the weight of tumor mass was markly decreased in nude mice. The anti-tumor effect of PRS in vivo was associated with a significant increase in the 7402 apoptosis rate. Although PRS inhibited the weight of mice, it showed almost no effect on leukocyte number, liver and spleen weight index. Light microscopic histopathological examination showed that PRS had no specific lesion in organ. These results suggested that P. chinensis saponins exert potential anticancer activity in treating tumors in nude mice and no toxic side effects.     

Musca Domestica Larva Lectin Induces Apoptosis in BEL-7402 Cells Through a Ca2+/JNK-mediated Mitochondrial Pathway

Although Musca domestica larvae lectin (MLL) is able to inhibit cancer cell proliferation and to induce cancer cell apoptosis, the molecular mechanism(s) responsible for these processes remain elusive. In the current study, the signaling network underlying the MLL-induced apoptosis of human hepatoma BEL-7402 cell was investigated. Our data found out that MLL causes a sustained increase of the intracellular Ca²⁺ and this process was prevented by the intracellular calcium chelator, BAPTA-AM, suggesting the involvement of intracellular Ca²⁺ in MLL-induced cell apoptosis. MLL also causes the production of reactive oxygen species and elevates the phosphorylation status of JNK, processes associated with the increased cytoplasmic Ca²⁺. The mitochondrial permeability transition pore (MPTP) opening study showed that MLL treatment of BEL-7402 cells results in the opening of MPTP and a reduction of mitochondrial transmembrane potential. In such condition, cytochrome-c was detected to be released from mitochondria to cytoplasm through the MPTP. This eventually activates caspase-3 and thus results in apoptosis of the tested BEL-7402 cells. According to a comprehensive review of all the evidence, it is concluded that MLL induces apoptosis of BEL-7402 cells through a Ca²⁺/JNK-mediated MPTP pathway.     

IL—6诱导肝癌细胞BEL—7402细胞凋亡及其Ca^2＋转导机制

白细胞介素－6（interleukin-6,IL-6）具有直接或间接的抗肿瘤活性,本组在以前的体内外实验中证明其具有明显的抑制肝癌作用。本文主要报告应用流式细胞仪和共聚焦显微镜检测IL－6对肝癌细胞（BEL－7402）凋亡的作用和该过程中Ca^2 转导机制。生长曲线描绘以及MTT分析结果表明,IL－6（6000u/ml）作用于BEL－7402细胞24小时后,生长抑制率达12％左右,而流式细胞仪结果显示IL－60（6000u/ml）作用于BEL－7402细胞24小时后,BEL－7402细胞凋亡率达8.2％。流式细胞仪分析还表明,IL－60（6000u/ml）作用于BEL－7402细胞24小时后,对照组平均FTTC荧光值为1.03而IL－60（6000u/ml）组为0.759,也就是说,IL－6引起了bcl－2基因表达下降。激光共聚焦显微镜测定表明,IL－60（6000u/ml）作用于BEL－7402细胞后,胞浆[Ca^2 ]c升高达2倍。若事先加入TC（thapsigargin),15min后再加入IL－6,则抑制了胞浆内[Ca^2 ]c升高;事先10min或5min分别加入EGTA和普鲁卡因（procaine）也有同样的抑制作用。上述结果表明,IL－6在一定剂量下可以诱导肝癌细胞BEL－7402发生细胞凋亡,该凋亡过程可能与Ca^2 转导及bcl-2基因表达下调有关。     

Retrovirus—mediated herpes simplex virus thymidine kinase gene therapy approach for hepatocellular carcinoma

INTRODUCTI0NHepatocellularcarcinoma(HCC)is0ne0fthem0stc0mm0nhumanmalignancies,causinganestimatedl,250,OOOdeatht0llperyearworldwide[1].Thep0orprognosisencounteredintreatment0fsuchcarcinomaismainlycausedbylatediagn0sisandinsufficiency0feffectivestrategies,especiallyforadvanced-stagedpatients.However,recentknowledge0fpathogenesisofHCCatm0lecularlevelprovidesanalternativeappr0achwhenc0nsideringgenetherapyastreatmelltf0rHCC.Am0ngthevari0usgenetherapystrategiesincancer)itwaJsrep0rtedthatth…     

In vivo regulation of Na/Ca exchanger expression by adrenergic effectors

The Na/Ca exchanger encoded by the NCX1 gene plays an important role in calcium homeostasis in cardiac muscle. We previously identified three in vitro signaling pathways that are of major importance in the regulation of Na/Ca exchanger gene expression in neonatal cardiac myocytes, the protein kinase A (PKA) and protein kinase C (PKC) pathways, and intracellular Ca(2+). To determine whether these pathways are important in vivo, we stimulated the PKA and PKC pathways and examined functional expression of the Na/Ca exchanger in adult rat heart. After a 3- and 7-day treatment, norepinephrine (200 microg x kg(-1) x h(-1)), isoproterenol (150 microg x kg(-1) x h(-1)), and phenylephrine (200 microg x kg(-1) x h(-1)) each stimulated a significant increase in NCX1 mRNA levels (35-85%, P < 0.05). Norepinephrine also stimulated a 35% increase in protein abundance (P < 0.05), a 20% decrease in relaxation duration (P < 0.05), and a 25% reduction in the fluorescence decay constant (P < 0.05) after a 7-day treatment. We conclude that a 7-day treatment of alpha- and beta-adrenergic agonists increases the expression of functional Na/Ca exchangers in adult rat heart.     

Gene silencing of Toll-like receptor 2 inhibits proliferation of human liver cancer cells and secretion of inflammatory cytokines

Background

Toll-like receptors (TLRs) are key factors in the innate immune system and initiate the inflammatory response to foreign pathogens such as bacteria, fungi and viruses. In the microenvironment of tumorigenesis, TLRs can promote inflammation and cell survival. Toll-like receptor 2/6 (TLR2/6) signaling in tumor cells is regarded as one of the mechanisms of chronic inflammation but it can also mediate tumor cell immune escape and tumor progression. However, the expression of TLR2 and its biological function in the development and progression of hepatocarcinoma have not been investigated. This study aimed to determine the expression of TLRs 1–10 in the established human hepatocellular carcinoma cell line BLE-7402, to investigate the biological effect of TLR2 on cell growth and survival.

Methods

TLR expression in BLE-7402 cells was assayed by RT-PCR, real-time PCR and flow cytometry (FCM). To further investigate the function of TLR2 in hepatocarcinoma growth, BLE-7402 cells were transfected with recombinant plasmids expressing one of three forms of TLR2 siRNA (sh-TLR2 RNAi(A, B and C)). TLR2 knockdown was confirmed using RT-PCR, real-time PCR and fluorescence microscopy. Tumor cell proliferation was monitored by MTT assay and secreted cytokines in the supernatant of transfected cells were measured by bead-based FCM, the function of TLR2 siRNA was also investigated in vivo.

Results

The BLE-7402 cell line expressed TLRs 2 to 10 at both mRNA and protein levels. TLR2 was the most highly expressed TLR. While all the three siRNAs inhibited TLR2 mRNA and protein expression, sh-TLR2 RNAi(B) had the strongest knockdown effect. TLR2 knockdown with sh-TLR2 RNAi(B) reduced cell proliferation. Furthermore, secretion of IL-6 and IL-8 was also reduced. The result showed a drastic reduction in tumor volume in mice treated with sh-TLR2 RNAi(B).

Discussion

These results suggest that TLR2 knockdown inhibit proliferation of cultured hepatocarcinoma cells and decrease the secretion of cytokines. It is suggested that TLR2 silencing may worth further investigations for siRNA based gene therapy in treatment of hepatocarcinoma.     

Potential new antitumor agents from an innovative combination of camphorato, a ramification of traditional Chinese medicine, with a platinum moiety

Eight new camphorato platinum complexes have been synthesized and evaluated for their in vitro cytotoxicity against HL-60 human leukemia, 3AO human ovarian carcinoma, BEL-7402 human hepatocarcinoma, and A549 human lung carcinoma cell lines. Most complexes showed good cytotoxic activity against the above-selected cell lines. Among the complexes, two compounds were assayed for their in vivo antitumor activity against LS-174T human colon carcinoma cells implanted in mice. One complex exhibited not only higher in vivo antitumor activity, but also less toxicity than oxaliplatin when it was administered intravenously at a dose of 6 mg/kg three times.     

荧光素酶标的人肝癌细胞裸鼠异种移植瘤模型的生物发光成像和PET-CT成像比较

目的利用荧光素酶基因标记的人肝癌细胞株BEL-7402建立裸鼠肝原位移植模型,及小鼠肝原位移植模型的生物发光和小动物PET-CT成像的比较。方法构建表达荧光素酶基因的真核表达载体并将其转入人肝癌细胞BEL-7402,经梯度浓度G418筛选获得稳定表达荧光素酶基因的细胞克隆并扩大培养。BALB/cA-nu裸鼠肝门静脉接种5×105个发光细胞使其成瘤,活体荧光成像和小动物PET-CT成像系统观察肿瘤的生长情况。结果获得了稳定表达Luc的人肝癌细胞株,将其接种到裸鼠体内,活体荧光成像系统观察发现能够成瘤,小动物PET-CT影像观察发现小鼠肝脏边缘对18 F-FDG有高摄取区域。结论利用荧光素酶基因标记的人肝癌细胞BEL-7402成功建立了原位肝癌裸鼠模型,小动物活体成像结合小动物PET-CT技术为原位肿瘤模型的建立提供了一种新的可靠的技术,为进一步研究肝癌生长转移机制和药物开发提供了新的有用工具。