Induction of G1 cell cycle arrest and cyclin D1 down-regulation in response to pericarp extract of Baneh in human breast cancer T47D cells

Background and the purpose of the study

Natural products from plants have an important role in the development and production of new drugs mainly for cancer therapy. More recently, we have shown that the pericarp methanolic extract of Pistacia atlantica sub kurdica (with local name of Baneh) as a rich source of active biological components with high antioxidant and radical scavenging activities, has ability to cease proliferation and induce apoptosis in T47D human breast cancer cells. The present study aimed to clarify whether Baneh extract able to alter cell cycle progression of T47D cells or not.

Methods

In order to study the possible effect of Baneh extract on cell cycle of T47D cells, we evaluated cell cycle distribution and its regulatory proteins by flow cytometry and western blot analysis respectively.

Results

Baneh extract induced G₀/G₁ cell cycle arrest in conjunction with a marked decrease in expression of cyclin D1 and cdk4 that was strongly dependent on time of exposure. In parallel, Dox-treated T47D cells in early time points were accumulated on S phase, but after 48 h cell cycle progression was inhibited on G₂/M. Dox promoted striking accumulation of cyclin B1 rapidly and enhanced cyclin A abundance.

Conclusion

Taken together, our results establish that the antitumor activity of the pericarp extract of Baneh partly is mediated via cell cycle arrest and downregulation of cyclin D1 and cdk4 expression. These findings warrant further evaluation regarding the mechanism(s) of action of this promising anticancer agent.     

多柔比星联合索拉非尼治疗晚期肝癌与多柔比星单药疗效比较

3背景 肝癌是世界范围内最常见的第六大恶性肿瘤。每年将近有600000新发病例,晚期患者的中位生存期仅为数月。多柔比星作为肝癌的常规治疗药物,尽管缺少明确的生存获益,     

TRAIL及联合阿霉素治疗骨肉瘤的动物实验研究

目的 探讨肿瘤坏死因子相关凋亡诱导配体(TRAIL)以及TRAIL联合阿霉素(ADM)对裸鼠移植性骨肉瘤的治疗作用及机制.方法 取对数生长的MG-63骨肉瘤细胞,以5×10~6/ml浓度的细胞悬液0.2 ml接种于裸鼠下肢外侧皮下,建立裸鼠肿瘤模型随机分组.各以1、2 μg TRAIL,15 μg ADM,1μ,g TRAIL+15μg ADM和100 μl生理盐水腹腔注射,观察肿瘤生长速度,处死裸鼠取血清,应用血清碱性磷酸酶(ALP)试剂盒检测血清ALP的活性,取下瘤体应用TUNEL技术检测瘤体中细胞凋亡情况,应用免疫组化法检测Bax基因的表达,应用RT-PCR技术分析TRAIL受体表达的情况.结果 肿瘤生长曲线显示:腹腔注射TRAIL蛋白组与注射生理盐水组相比,裸鼠皮下移植瘤生长更慢,且2 μg TRAIL组的抑制作用强于1μg TRAIL组;TRAIL与ADM联用较两种药物单用具备更强的抑瘤作用.各实验组间ALP活性差异统计学意义.细胞凋亡的TUNEL检测显示TRAIL与ADM联用组较两种药物单用组有更多的凋亡细胞出现.免疫组化检测Bax基因的表达显示TRAIL与ADM联用出现Bax蛋白表达量上调.RT-PCR检测显示TRAIL与ADM联用出现TRAIL-R2的mRNA表达上调.结论 在活体水平TRAIL具有促进骨肉瘤细胞凋亡、抑制肿瘤生长的作用,且这种作用一定范围内随药物的剂量提高而增强.TRAIL与ADM联用具备协同效应,其机制与TRAIL-R2的mRNA和Bax基因的表达上调有关.     

阿霉素纳米脂质体制备工艺研究

目的 本实验尝试制备阿霉素纳米脂质体并测定其包封率,探求其最佳制备工艺.方法 采用薄膜分散高压均质法制备阿霉素纳米脂质体,高效液相色谱法检测阿霉素包封率.结果 制得的阿霉素纳米脂质体大小均匀、分散性好、粒径在180nm左右、包封率为71.46%,4℃保存3个月稳定.阿霉素在0.54μg/mL～21.60μg/mL范围内线性良好(r=0.9997),回归方程为Y=46632x+19140.结论 该法制备的阿霉素纳米脂质体,工艺简单易行,质量可控.     

Systemic administration of doxorubicin impairs aversively motivated memory in rats

There is growing clinical evidence of cognitive impairment in cancer patients treated with chemotherapy, especially in women treated with drug combinations for breast cancer. Clinical studies have a difficult task of defining which drugs individually are responsible for the cognitive changes and published papers evaluating single agents in experimental models are scanty. In the present study we have investigated the effect of single escalating doses of doxorubicin (DOX) on memory for inhibitory avoidance conditioning (IA) in rats. The doses used were comparable to those applied in the clinic. When given systemically before training, higher doses of DOX impaired IA memory retention measured 24 h and 7 days, but not 3 h after training. DOX did not affect IA retention when given either before or after training in a multiple-trial IA training protocol. Control experiments showed that DOX produced a decrease in exploratory behavior assessed by the number of rearings performed during exploration of an open field. The results indicate that a single systemic administration of DOX might impair long-term aversive learning.     

New iron chelators in anthracycline-induced cardiotoxicity

The use of anthracycline anticancer drugs is limited by a cumulative, dose-dependent cardiac toxicity. Iron chelation has long been considered as a promising strategy to limit this unfavorable side effect, either by restoring the disturbed cellular iron homeostasis or by removing redox-active iron, which may promote anthracycline-induced oxidative stress. Aroylhydrazone lipophilic iron chelators have shown promising results in the rabbit model of daunorubicin-induced cardiomyopathy as well as in cellular models. The lack of interference with the antiproliferative effects of the anthracyclines also favors their use in clinical settings. The dose, however, should be carefully titrated to prevent iron depletion, which apparently also applies for other strong iron chelators. We have shown that a mere ability of a compound to chelate iron is not the sole determinant of a good cardioprotector and the protective potential does not directly correlate with the ability of the chelators to prevent hydroxyl radical formation. These findings, however, do not weaken the role of iron in doxorubicin cardiotoxicity as such, they rather appeal for further investigations into the molecular mechanisms how anthracyclines interact with iron and how iron chelation may interfere with these processes.     

Adriamycin-induced interference with cardiac mitochondrial calcium homeostasis

Adriamycin (doxorubicin) is a potent and broad-spectrum antineoplastic agent, the clinical utility of which is limited by the development of a cumulative and irreversible cardiomyopathy. Although the drug affects numerous structures in different cell types, the mitochondrion appears to a principal subcellular target for the development of cardiomyopathy. This review describes evidence demonstrating that adriamycin redox cycles on complex I of the mitochondrial electron transport chain to liberate highly reactive free radical species of molecular oxygen. The primary effect of adriamycin on mitochondrial performance is the interference with oxidative phosphorylation and inhibition of ATP synthesis. Free radicals liberated from adriamycin redox cycling are thought to be responsible for many of the secondary effects of adriamycin, including lipid peroxidation, the oxidation of both proteins and DNA, and the depletion of glutathione and pyridine nucleotide reducing equivalents in the cell. It is this altered redox status that is believed to cause assorted changes in intracellular regulation, including the induction of the mitochondrial permeability transition and complete loss of mitochondrial integrity and function. Associated with this is the interference with mitochondrial-mediated cell calcium signaling, which is implicated as essential to the capacity of mitochondria to participate in bioenergetic regulation in response to external signals reflecting changes in metabolic demand. If taken to an extreme, this loss of mitochondrial plasticity may manifest in the liberation of signals mediating either oncotic or necrotic cell death, further perpetuating the cardiac failure associated with adriamycin-induced mitochondrial cardiomyopathy.     

Iron signaling and oxidant damage

In this brief essay we discuss the interrelationship between the cellular signaling effects induced by extracellular and intracellular ROS and nitric oxide in the context of doxorubicin (DOX) toxicity.     

环氧合酶-2抑制剂对白血病细胞HL-60的化疗增敏作用及机制

 目的　观察环氧合酶-2（COX-2）抑制剂塞来昔布对白血病细胞株HL-60的化疗增敏作用,并对其机制进行初步探讨。方法　MTT法评估塞来昔布、多柔比星及二者联合对HL-60细胞的生长抑制效应;流式细胞术（FCM）检测细胞的凋亡;反转录聚合酶链反应（RT-PCR）检测Survivin基因的表达;Western blotting检测Survivin蛋白的表达。结果　多柔比星联合塞来昔布5和10 μmol／L对HL-60细胞的半数抑制浓度（IC50）分别为0.25及0.16 μg／ml,明显低于多柔比星单用的IC50（0.48 μg／ml）;多柔比星0.10 μg／ml联合10 μmol／L塞来昔布下调Survivin基因mRNA及蛋白的表达;联合塞来昔布5和10 μmol／L的凋亡率[分别为（13.07±1.66）%及（22.36±1.84）%]较多柔比星0.10 μg／ml单用[（5.72±1.25）%]明显增加（P＜0.01）。结论　COX-2抑制剂塞来昔布对白血病细胞株HL-60具有明显的化疗增敏作用,其初步机制涉及下调Survivin的表达,增加细胞凋亡。