白屈菜碱对KB细胞株的抗肿瘤作用机制探讨

目的:探讨白屈菜碱(chelidonine)对人口腔上皮样癌细胞KB细胞株的抗肿瘤作用机制。方法:以不同浓度的白屈菜碱作用于体外培养的KB细胞株24、48、72 h,应用MTT检测细胞生长抑制率;Transwell小室检测肿瘤细胞的侵袭作用;流式细胞仪检测细胞凋亡率;免疫印迹实验分析Caspase-3、Bax、Bcl-2、MMP-2、MMP-9信号通路相关蛋白的表达水平。结果:MTT结果显示白屈菜碱对KB细胞株的增殖具有明显的抑制作用,且呈时间剂量依赖性;侵袭试验结果表明,白屈菜碱能够抑制KB细胞侵袭作用,且随着浓度的增大,抑制侵袭作用增强;流式双染检测白屈菜碱作用KB细胞24 h后细胞的凋亡率,与对照组相比差异有统计学意义;蛋白免疫印迹试验显示白屈菜碱组的Caspase-3、Bax表达明显上调,Bcl-2、MMP-2、MMP-9表达下调,与对照组相比差异有统计学意义。结论:白屈菜碱对KB细胞具有明显的抑制增殖、侵袭和促进凋亡的作用;其抗肿瘤机制可能与下调Bcl-2、MMP-2、MMP-9,上调Caspase-3、Bax的表达有关。     

苦参碱对KB及其多药耐药细胞KBv200增殖与凋亡影响的对比研究

目的: 研究中药苦参提取物苦参碱对体外培养的口腔上皮癌KB细胞和具有多药耐药特征的KBv200细胞增殖和凋亡的影响. 方法: 以MTT法对比观察苦参碱对细胞存活率的影响;以吖啶橙/溴乙啶(AO/EB)双荧光染色检测细胞凋亡率;流式细胞术分析苦参碱对细胞周期的影响;扫描电镜观察苦参碱作用后的细胞形态学变化. 结果: 苦参碱浓度在0.50、1.00、1.50、2.00mg/ml时,均有抑制KB及KBv200增殖的作用,其半数抑制浓度(IC50)分别为1.35mg/ml和1.43mg/ml;双荧光染色及流式细胞术提示苦参碱可诱导KB及KBv200细胞凋亡,使细胞生长停滞在S期;扫描电镜观察发现不同浓度的苦参碱作用24h后,细胞出现体积缩小、细胞质空泡化、细胞核碎裂等凋亡现象.苦参碱对两种细胞增殖和凋亡的影响均未见明显差异(P>0.05). 结论: 苦参碱对KB及多药耐药的KBv200细胞均具有抑制增殖和诱导凋亡的作用.提示苦参碱可克服肿瘤的多药耐药现象,故有可能成为一种理想的中药抗肿瘤制剂.     

Anti-proliferative and apoptosis induction activities of extracts from Thai medicinal plant recipes selected from MANOSROI II database

Ethonopharmacological relevances

Traditional medicines have long been used by the Thai people. Several medicinal recipes prepared from a mixture of plants are often used by traditional medicinal practitioners for the treatment of many diseases including cancer. The recipes collected from the Thai medicinal text books were recorded in MANOSROI II database. Anticancer recipes were searched and selected by a computer program using the recipe indication keywords including Ma-reng and San which means cancer in Thai, from the database for anticancer activity investigation.

Aim of study

To investigate anti-cancer activities of the Thai medicinal plant recipes selected from the “MANOSROI II” database.

Materials and methods

Anti-proliferative and apoptotic activities of extracts from 121 recipes selected from 56,137 recipes in the Thai medicinal plant recipe “MANOSROI II” database were investigated in two cancer cell lines including human mouth epidermal carcinoma (KB) and human colon adenocarcinoma (HT-29) cell lines using sulforhodamine B (SRB) assay and acridine orange (AO) and ethidium bromide (EB) staining technique, respectively.

Results and conclusions

In the SRB assay, recipes NE028 and, S003 gave the highest anti-proliferation activity on KB and HT29 with the IC₅₀ values of 2.48 ± 0.24 and 6.92 ± 0.49 μg/ml, respectively. In the AO/EB staining assay, recipes S016 and NE028 exhibited the highest apoptotic induction in KB and HT-29 cell lines, respectively. This study has demonstrated that the three Thai medicinal plant recipes selected from “MANOSROI II” database (NE028, S003 and S016) gave active anti-cancer activities according to the NCI classification which can be further developed for anti-cancer treatment.     

石杉碱甲对D-半乳糖诱导老年性聋的局部抗炎作用

目的研究石杉碱甲对D-半乳糖诱导的老年性聋大鼠的局部抗炎作用。方法将30只SD雄性大鼠随机平均分为3组,均行颈背部皮下连续注射8周：D-gal组予5％D-半乳糖（200mg／kg）;D-gal＋HupA组予同体积的5％D-半乳糖（200mg／kg）和石杉碱甲（0．1mg／kg）,对照组予同体积生理盐水。利用免疫组织化学检测耳蜗组织中的施万细胞和NF-κB的活化情况;通过定量RT-PCR分析检测耳蜗组织中的炎症因子IL-1β、IL-6、TNF-α。结果与对照组相比,D-gal组的施万细胞被激活、NF-KB活化,而D-gal＋HupA组的施万细胞和NF-κB变化无差别;同时D-gal组和D-gal＋HupA组相比,D-gal＋HupA组耳蜗组织内IL-1p、IL-6、TNF-d的含量明显低于D-gal组,差异具有统计学意义（P〈0．05）。结论石杉碱甲可以抑制D-半乳糖诱导老年性聋大鼠的耳蜗组织内的施万细胞的激活和NF-KB活化,进而抑制炎症因子的释放,起到局部抗炎作用。     

Antitumor effect of folate-targeted liposomal doxorubicin in KB tumor-bearing mice after intravenous administration

The effect of folate-targeted liposomal doxorubicin (FTL-Dox) has been well characterized in folate receptor (FR) overexpressing tumors in vitro, particularly in KB human carcinoma cells. However, there are few studies evaluating the in vivo efficacy of FTL-Dox in KB murine xenograft models. In this study, we investigated the antitumor activity of FTL-Dox injected intravenously in mice bearing KB tumors. Folate ligands comprising of folate-polyethyleneglycol-distearoylphosphatidylethanolamine (FA-PEG-DSPE) were synthesized with different MW PEG. To design an optimum FTL-Dox formulation for therapeutic studies, we prepared various FTLs and characterized their in vitro targeting and in vivo tissue biodistribution. Mice were administered a single intravenous injection of free Dox, nontargeted PEGylated liposomal Dox (PL-Dox), or FTL-Dox. FTLs and PLs accumulated similarly in tumor tissue, despite FTLs’ faster clearance from circulation. Mice treated with FTL-Dox 20?mg/kg had a slightly greater tumor growth inhibition and almost a 50% increase in life span than mice receiving PL-Dox 20?mg/kg (P?=?0.0121; log-rank test). We conclude that FTLs administered systemically have the potential to enhance the delivery of anticancer drugs in vivo; however, their removal by FR expressing normal tissues may have to be blocked if the benefits of tumor targeting are to be realized.     

COX-2与NF-κB在食管癌组织中的表达及关系

目的 研究NF-κB与COX-2在食管癌组织中的表达及关系。方法　取经手术病理证实的食管癌及癌旁组织80例,采用免疫组化法检测食管癌及癌旁组织中NF-κB和COX-2的表达情况。结果 食管癌组织中NF-κB和COX-2的表达率分别为58.75％和61.25％,癌旁组织NF-κB和COX-2的表达率分别为3.75％和13.75％。NF-κB主要表达于胞核和胞浆,COX-2主要表达于胞浆。COX-2的表达和NF-κB的表达呈止相关(P<0.05)。结论 NF-κB和COX-2在食管癌组织中均有高水平的表达,NF-κB和COX-2有可能参与食管癌的发生发展,其可能机制是NF-κB促进了COX-2的表达。     

Smartwatch Algorithm for Automated Detection of Atrial Fibrillation

Background

The Kardia Band (KB) is a novel technology that enables patients to record a rhythm strip using an Apple Watch (Apple, Cupertino, California). The band is paired with an app providing automated detection of atrial fibrillation (AF).

4-NQO induces apoptosis via p53-dependent mitochondrial signaling pathway

4-Nitroquinoline N-oxide (4-NQO) as an UV-mimetic agent leading to DNA damage is a potent mutagen and carcinogen, and can induce apoptosis in various types of cells. However, the mechanism of apoptosis induced by 4-NQO is still not quite clarified. In this study we found that 4-NQO could not only induce apoptosis in KB cells, but also caused considerable damage to the mitochondrial membrane. Therefore, we inferred that 4-NQO might induce apoptosis through the mitochondrial signaling pathway resulting from DNA damage. Further investigation showed that the apoptosis induced by 4-NQO was p53-dependent. Furthermore, the expression levels of bax and bcl-2, closely related to mitochondrial signaling pathway, were up- and down-regulated, respectively. Meanwhile, the activity of caspase-9 and -3, lying in downstream of mitochondrial, was also enhanced. At the same time, the expression level of p21 also was increased by 4-NQO exposure, leading to the cell cycle arrested in G₁ phase. The results indicated that 4-NQO arrested cell cycle in G₁ phase, thus allowing enough time for DNA repair; on the other hand, if the cellular DNA were not repaired, apoptosis may follow through the p53-dependent mitochondrial signaling pathway, and mechanism of apoptosis induced by 4-NQO is not exactly the same that induced by UV radiation, as the later induces apoptosis through death receptors and mitochondrial signaling pathway.     

Inhibitory mechanisms of heterocyclic carboxaldehyde thiosemicabazones for two forms of human ribonucleotide reductase

Two forms of ribonucleotide reductase (RR), consisting of M1 with M2 subunits and M1 with p53R2 subunits, are involved in DNA replication and damage repair, respectively. 3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3AP), one of the heterocyclic carboxaldehyde thiosemicabazones (HCTs), is a potent RR inhibitor in clinical trial for cancer treatment. In this study, 3AP and its 7 derivatives showed 100-1000-fold higher inhibitory potency on KB nasopharyngeal carcinoma cells than hydroxyurea and were fully active against hydroxyurea- and gemcitabine-resistant KB cells. In vitro RR assays using two recombinant RRs showed that all 8 HCTs decreased the activity of both RRs in a dose-dependent manner and the efficiency was compatible with that on cell proliferation inhibition. Iron has different impact on the behavior of the compounds toward RRs. In the absence of iron, the HCTs showed more selective inhibition for p53R2-M1 than M2-M1, while addition of iron increased their activity but reduced their selectivity for two RRs. Radioligand binding assays showed that [³H]3AP directly bounded to the small subunits. Electron paramagnetic resonance measurements demonstrated that these HCTs generated reactive oxygen species with ferrous iron, which quenched the diiron-tyrosyl radical co-factor of the small subunits and hence the enzyme activity. While the ROS may be a common mediator responsible for the potent activity of the HCTs, the different characteristics of the small subunit proteins are probably associated with the subunit-selectivity of inhibition. Better understanding of the mechanism of action of RR inhibition may improve design of new potent and subunit-selective RR inhibitors for cancer therapy.     

Gambogic Acid通过影响NF-κB信号通路诱导A549细胞凋亡

目的:研究Gambogic Acid（GA）对人非小细胞肺癌A549细胞系中NF-κB信号通路的影响及其对细胞凋亡的促进作用。方法:Western blot法和共聚焦显微镜成像技术检测GA对NF-κB的信号通路的影响,MTT及流式细胞（FCM）术检测GA对A549细胞的促凋亡作用。结果:Western blot发现GA能显著抵抗TNF-α诱导导致的IκB磷酸化水平上升及IκB的降解;共聚焦显微镜成像进一步发现GA有效阻止了NF-κB入核;MTT结果显示GA能显著抑制A549细胞的增殖,当药物浓度为5.0μmol/L时抑制率可达到（93.5±6.5）％（P<0.05),IC50值为1.2±0.4 μmol/L;凋亡检测结果显示A549细胞在0.0、0.5、1.0、2.0、3.0及5.0 μmol/L药物处理下细胞凋亡率分别是（6.0±0.7）%、（15.5±2.3）%、（35.0±3.6）%、（43.5±2.7）%、（43.0±3.8）%及（53.7±2.6）%（P<0.05);结论:实验表明,GA能有效地抑制A549细胞增殖和诱导其凋亡,其机制可能是通过影响NF-κB信号通路而发生作用。