芡实壳醇提物抑制人胃癌SGC7901细胞和人肝癌HepG2细胞增殖并促进其凋亡

为明确芡实壳醇提物对SGC7901及HepG2细胞体外抑制作用及机制。该研究采用75%乙醇对芡实壳超声提取,采用福林酚法测定醇提物总酚含量,采用CCK-8法检测醇提物对SGC7901和HepG2细胞的增殖作用抑制率并计算IC50值,使用流式细胞仪检测细胞凋亡、细胞周期、细胞线粒体膜电位及胞内钙离子浓度。结果表明,醇提物对SGC7901和HePG2细胞具有增殖抑制作用,浓度为200 μg/mL的醇提物作用细胞48 h后,抑制率分别为92.63%和72.40%。细胞周期检测表明,浓度为200~800 μg/mL的醇提物可使SGC7901细胞阻滞于G0/G1期;浓度为50~200 μg/mL的醇提物可使HepG2细胞阻滞于S期。细胞线粒体膜电位测定表明,醇提物可使SGC7901和HePG2细胞线粒体膜电位下降且具浓度依赖性,醇提物浓度为200 μg/mL时,细胞线粒体膜电位相较对照组分别下降21.92%和53.81%。细胞钙离子浓度测定表明,醇提物可使SGC7901和HePG2细胞内钙离子浓度升高且具浓度依赖性,醇提物浓度为200 μg/mL时,胞内钙离子浓度相较对照组分别上升21.85%和14.14%。实验表明芡实壳醇提物可抑制SGC7901和HepG2细胞增殖并诱导其凋亡,其作用机制可能与细胞线粒体膜电位降低及胞内钙离子浓度升高有关。     

麒麟菜多糖对H22肝癌移植瘤的抑制作用研究

以常温稀碱法提取的麒麟菜多糖(Eucheuma gelatinae polysaccharides,EGP)饲喂H22荷瘤小鼠,探讨其对小鼠移植性实体瘤的抑制作用。实验考察了肿瘤抑制率和免疫器官指数,分析荷瘤小鼠的脾淋巴细胞(T淋巴细胞与B淋巴细胞)增殖能力、脾NK细胞杀伤活性和腹腔巨噬细胞吞噬能力等免疫指标,并对外周血淋巴细胞亚群进行流式(FCM)检测。研究结果表明,以麒麟菜多糖灌胃荷瘤小鼠能够显著抑制小鼠体内肿瘤的生长,至实验期结束时,麒麟菜多糖低剂量组[300 mg/(kg·d)]及高剂量组[600mg/(kg·d)]的抑瘤率分别达到31.17%及59.67%。与模型组相比,麒麟菜多糖还能够显著增强荷瘤小鼠脾淋巴细胞的增殖能力和NK细胞的杀伤活性,并显著提高腹腔巨噬细胞的吞噬活性。此外,麒麟菜多糖高剂量组能显著提高荷瘤小鼠CD3+和CD8+细胞比例(p0.05)。麒麟菜多糖能够改善荷瘤小鼠机体的免疫水平,具有显著的抗肿瘤作用。     

Reversal effect of low‐intensity ultrasound on adriamycin‐resistant human hepatoma cells in vitro and in vivo

The aim of this study was to determine whether the ultrasound, with a dosage that did not lead to acute and delayed inhibition, could potentiate the cytotoxicity of adriamycin to human hepatoma resistant cell line HepG2 both in vitro and in vivo. In order to determine whether low‐intensity ultrasound could reverse resistance in adriamycin‐resistant human hepatoma cell line HepG2/ADM in vitro, cells were subjected to a variable level of ultrasound. The results showed that survival rates were decreased in groups in which ultrasound and adriamycin were exerted. The same effect of low‐intensity ultrasound was also observed in the xenograft tumor experiment. Furthermore, transmission electron microscope revealed the cavitation effects play the determining role in accelerating transmembrane transportation, suggesting that low‐intensity ultrasound altered the cell membrane thus resulting in change in adriamycin uptake into HepG2/ADM cells. Further investigation of the underlying mechanisms showed that the reversal effect of low‐intensity ultrasound on adriamycin‐resistant human hepatoma cells was attributed to the downregulation of the multidrug resistant genes, MDR1 and MRP1, in both mRNA and protein expression. In addition, downregulation of MDR1 and MRP1 was detected in HepG2/ADM xenograft tumor treated with adriamycin and ultrasound. These observations suggest the use of ultrasound could increase cytotoxicity attributable to adriamycin in chemoresistant human hepatoma cancer cells. Ultrasound is a promising therapeutic modality for refractory hepatoma patients.     

Anticancer Activity and Mechanisms of Action of New Chimeric EGFR/HDAC-Inhibitors

New chimeric inhibitors targeting the epidermal growth factor (EGFR) and histone deacetylases (HDACs) were synthesized and tested for antineoplastic efficiency in solid cancer (prostate and hepatocellular carcinoma) and leukemia/lymphoma cell models. The most promising compounds, 3BrQuin-SAHA and 3ClQuin-SAHA, showed strong inhibition of tumor cell growth at one-digit micromolar concentrations with IC₅₀ values similar to or lower than those of clinically established reference compounds SAHA and gefitinib. Target-specific EGFR and HDAC inhibition was demonstrated in cell-free kinase assays and Western blot analyses, while unspecific cytotoxic effects could not be observed in LDH release measurements. Proapoptotic formation of reactive oxygen species and caspase-3 activity induction in PCa and HCC cell lines DU145 and Hep-G2 seem to be further aspects of the modes of action. Antiangiogenic potency was recognized after applying the chimeric inhibitors on strongly vascularized chorioallantoic membranes of fertilized chicken eggs (CAM assay). The novel combination of two drug pharmacophores against the EGFR and HDACs in one single molecule was shown to have pronounced antineoplastic effects on tumor growth in both solid and leukemia/lymphoma cell models. The promising results merit further investigations to further decipher the underlying modes of action of the novel chimeric inhibitors and their suitability for new clinical approaches in tumor treatment.     

巴莲莲子生物碱提取物对人肝癌细胞HepG2的体外抗癌效果

本研究对巴莲莲子生物碱提取物的体外抗癌效果进行研究,以证实巴莲莲子生物碱提取物的生理活性作用。采用噻唑蓝法、4’,6-二脒基-2-苯基吲哚染色法和实时荧光定量聚合酶链式反应法检测巴莲莲子生物碱对人肝癌细胞HepG2的体外增殖抑制作用和凋亡诱导作用。巴莲莲子生物碱可以抑制HepG2细胞的体外增殖,但是对正常肝细胞L02无毒性,不影响其增殖。通过对癌细胞形态的观察发现随着巴莲莲子生物碱质量浓度的提高,更多的癌细胞被诱导凋亡从而死亡。同时,巴莲莲子生物碱能上调HepG2细胞的Bax、caspase-3、caspase-8、caspase-9、p53、p21基因表达和下调Bcl-2、Bcl-x L基因表达,从而促进癌细胞凋亡。巴莲莲子生物碱是一类生物活性成分,实验条件下具有较好的体外抗癌效果。     

血卟啉单甲醚介导的光动力作用对小鼠肝癌细胞生长抑制的初步研究

目的：观察血卟啉单甲醚介导的光动力作用对小鼠肝癌H22细胞生长的抑制作用。方法：采用倒置显微镜观察和MTT法检测血卟啉单甲醚介导的光动力作用后小鼠肝癌H22细胞的生长情况。结果：血卟啉单甲醚介导的光动力作用显著抑制小鼠肝癌H22细胞的生长,在一定光能密度条件下,细胞生长抑制作用跟血卟啉单甲醚浓度间呈剂量依赖关系。倒置显微镜下观察到光动力作用组癌细胞数量显著减少,细胞固缩,而单纯光照组,单纯血卟啉单甲醚组和假照射组三组间无明显差异;MTT法示光动力组细胞抑制率显著高于单纯光照组、单纯血卟啉单甲醚组和假照射组（P〈0.05）,单纯血卟啉单甲醚组和假照射组间无明显差异（P〉0.05）。结论：血卟啉单甲醚光动力学作用对小鼠肝癌细胞H22生长抑制作用确切。     

Large‐scale submerged fermentation of Antrodia cinnamomea for anti‐hepatoma activity

BACKGROUND: Submerged cultivation of Antrodia cinnamomea was carried out for manufacturing the fermentation product with anti‐hepatoma activity. The fermentation process was optimized for different parameters at shake flask level to obtain products with high inhibition potency against Hep G2 hepatoma cells. Scale‐up of the fermentation process was then achieved from 250 mL shake flask to 5 L, 500 L and 5‐ton fermenters. RESULTS: Glucose and malt extract were found to be the best carbon and nitrogen sources, respectively. The initial pH of 5.0 and an operating temperature of 22 °C were the best for a product with lowest IC₅₀ value. A shorter cultivation time was required when the scale of fermentation increased from 5 L to 5 tons. The reducing sugar and solids contents of the broth filtrate were correlated exponentially with the IC₅₀ of the ethanolic extract of mycelium for hepatoma cells, and the level of ergosterol in the mycelium extract follows the same profile as the increase in Hep G2 cells inhibition. CONCLUSION: When Antrodia cinnamomea is cultured in a 5‐ton fermenter, 4 weeks are required for the fermentation product to reach the highest anti‐hepatoma activity. The solid and reducing sugar contents of the broth filtrate as well as the ergosterol content in the ethanol extract of mycelium can serve as the marker during fermentation for manufacturing product with anti‐hepatoma activity. Copyright © 2008 Society of Chemical Industry