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.     

安徽庐江鸭乙型肝炎病毒LJ-76转染细胞系的建立

为建立鸭乙型肝炎病毒ＬＪ－７６的转染细胞系,将ＬＪ－７６病毒ＤＮＡ插入到ｐＵＣ１９的ＥｃｏＲⅠ位点上,分离得到含有双拷贝ＬＪ－７６ＤＮＡ的重组质粒．通过磷酸钙沉淀方法,将经ＣｓＣｌ等密度离心纯化的ＬＪ－７６ＤＮＡ双体导入到人肝癌细胞ＢＥＬ７４０２中．收集转染细胞的培养液进行蔗糖密度梯度离心,所得沉淀经检测发现含有ＬＪ－７６ＤＮＡ并具有特异性ＤＨＢＶ内源性ＤＮＡ多聚酶活性;对上述样品通过ＤｏｔＥＩＡ检测ＤＨＢＶ核心抗原及表面抗原结果为阳性．Ｓｏｕｔｈｅｒｎｂｌｏｔ分析表明转染细胞内存在病毒ＤＮＡ复制中间体ｃｃｃＤＮＡ、ｓｓＤＮＡ和ｒｃＤＮＡ,而ｃｃｃＤＮＡ被认为是复制活动较为活跃的标志．电镜观察转染细胞的上清发现有病毒颗粒的存在．     

Effects of basic fibroblast growth factor on angiogenin expression and cell proliferation in H7402 human hepatoma cells

Hepatocellular carcinoma （HCC） is one of the most common cancers worldwide. Basic fibroblast growth factor （bFGF）, which is highly expressed in developing tissues and malignant cells, regulates cell growth, differentiation, and migration. Its expression is essential for the progression and metastasis of HCC. This study aims to investigate the effects of bFGF on the expression of angiogenin, another growth factor, which plays an important role in tumor angiogenesis, and on cell proliferation in H7402 human hepatoma cells. The bFGF sense cDNA or antisense cDNA was stably transfected into H7402 cells. Genomic DNA PCR analysis demonstrated that human bFGF sense cDNA or antisense cDNA was inserted into the genome. Furthermore, the expression of bFGF and angiogenin was examined by RT-PCR and Western blot assays. MTT and colony formation assays were employed to determine cell proliferation. Stable bFGF over-expressing and under-expressing transfectants were successfully established. Expression of angiogenin was decreased in the over-expressing bFGF cells （sense transfectants） and was increased in the under-expressing bFGF cells （antisense transfectants）. Cell proliferation increased in the bFGF sense transfectants and decreased in the bFGF antisense transfectants. These results demonstrated that the endogenous bFGF may not only negatively regulate the angiogenin expression but also contribute to the overall cell proliferation in H7402 human hepatoma cells. This study may be helpful in finding a potential therapeutic approach to HCC.     

Arylpropionic acid-derived NSAIDs: New insights on derivatization,anticancer activity and potential mechanism of action

NSAIDs displayed chemopreventive and anticancer effects against several types of cancers. Moreover, combination of NSAIDs with anticancer agents resulted in enhanced anticancer activity. These findings have attracted much attention of researchers working in this field. The 2-arylpropionic acid-derived NSAIDs represent one of the most widely used anti-inflammatory agents. Additionally, they displayed antiproliferative activities against different types of cancer cells. Large volume of research was performed to identify molecular targets responsible for this activity. However, the exact mechanism underlying the anticancer activity of profens is still unclear. In this review article, the anticancer potential, structure activity relationship and synthesis of selected profen derivatives were summarized. This review is focused also on non-COX targets which can mediate the anticancer activity of this derivatives. The data in this review highlighted profens as promising lead compounds in future research to develop potent and safe anticancer agents.     

4-PA对BEL-7402细胞的生长调控和诱导凋亡作用的研究

应用ＭＴＴ、流式细胞术研究了新型肿瘤诱导分化剂４－ ＰＡ 对人肝癌细胞系ＢＥＬ－ ７４０２ 细胞的生长调控、诱导凋亡作用。结果表明： ４ － ＰＡ 对ＢＥＬ－ ７４０２ 细胞增殖抑制的ＩＣ５０ 为４ －９ｍ ｍｏｌ／Ｌ,随着作用时间的增加,ＩＣ５０ 增加。作用效果迅速,在０ ．５ 小时就有效地抑制了细胞增殖,抑制率随４－ ＰＡ 浓度的增加和作用时间的延长而增加,在达到最大抑制率后出现饱和。流式细胞仪对细胞周期和细胞凋亡的分析发现：４ － ＰＡ 对细胞增殖期（Ｓ期、Ｇ２ 期） 有较强的抑制和逆转作用,使细胞群截止在Ｇ１ 期。随着作用时间的延长和４ － ＰＡ 浓度的增加,细胞凋亡的比例增加,凋亡细胞多来自于细胞增殖期（Ｓ 期、Ｇ２ 期） 。诱导凋亡和使细胞截止于细胞静息期是４ － ＰＡ 抑制细胞增殖的主要途径。     

细胞内F-actin的聚合与解聚对肝癌Bel-7402细胞的影响

目的：为探讨癌细胞内F—actin的解聚与聚合对癌细胞的形态、迁移、侵入的影响。方法：利用激光共聚焦显微镜对贴附培养的人肝癌：Bel-7402细胞形态及其细胞内F-actin进行观察;使用流式细胞仪对贴附的Bel一7402细胞及其脱落细胞与Cyt—B处理后Bel-7402细胞内F-actin的含量进行分析。结果：Bel-7402细胞在培养的过程中,癌细胞形态伸展,出现侵入性生长,细胞内F-actin聚合形成粗大的贯通细胞内的F-actin束,F-acfin含量增高;癌细胞在生长过程中,常出现重叠生长,细胞变圆,F_actin解聚变短,F-acfin小体增高,细胞有脱落的趋势,其脱落细胞内的F-actin含量低于贴附细胞。结论：人肝癌：Bel-7402细胞内F-actin的聚合可增加癌细胞的贴附和侵入性：细胞内F-actin的解聚,及Gactin重新聚合形成F-aefin小体可影响到癌细胞脱落及迁移。     

利用稻瘟霉分生孢子筛选抗肿瘤放线菌

利用稻瘟霉分生孢子萌发时菌丝形变为指示,从150余株放线菌中筛选到一株抗肿瘤活性很强的菌株JXJ-0108,并从其发酵液中纯化到一个抗肿瘤活性较强的化合物JXJ-0108-1,该化合物在治疗胃癌和肝癌的药物研制中具有潜在的价值。四氮唑盐酶还原法(MTT)体外研究表明,JXJ-0108-1对人肝癌细胞BEL-7402和人胃癌细胞BGC-823的IC50分别为1.63和0.95 ug/mL;流式细胞仪分析表明,分别从0.50和0.30 ug/mL的化合物作用浓度开始,与空白对照组相比,肝癌细胞BEL-7402和胃癌细胞BGC-823的G0/G1、S和G2/M期细胞比例有极显著差异,其中G0/G1和S期细胞比例降低,G2/M期细胞比例上升。本文为抗肿瘤放线菌的筛选及活性成分的跟踪分离提供了一个快速简便的有效方法。     

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。