甲基莲心碱抗乳腺癌 MCF-7细胞的研究

目的:观察甲基莲心碱对乳腺癌细胞系MCF-7增殖和凋亡的影响,并探讨其诱导乳腺癌细胞系MCF-7凋亡的可能作用机制。方法:采用体外培养人乳腺癌细胞系MCF-7,CCK-8实验检测不同浓度甲基莲心碱对MCF-7细胞增殖抑制作用;乳酸脱氢酶(LDH)试剂盒(微板法)检测细胞上清液LDH含量;流式细胞术分析甲基莲心碱对MCF-7细胞周期及凋亡的影响;实时定量PCR(RT-PCR)检测线粒体凋亡相关基因Bax和Bcl-2的表达水平。结果:CCK-8、LDH结果显示甲基莲心碱以时间、浓度依耐性的方式抑制乳腺癌MCF-7细胞的增殖及促进细胞毒性的增加;流式细胞术结果表明不同甲基莲心碱作用下MCF-7的平均凋亡率分别为(15.44±0.52)、(18.81±2.24)、(24.26±2.84)、(36.90±3.15)、(59.27±5.86),且使其周期阻滞于G0/G1期;RT-PCR检测结果证明甲基莲心碱可上调乳腺癌细胞中促凋亡基因Bax的表达,而下调抑制凋亡基因Bcl-2。结论:甲基莲心碱以时间和浓度依赖的方式抑制乳腺癌细胞增殖、细胞毒性增加,导致细胞周期于G0/G1阻滞并促进癌细胞凋亡。甲基莲心碱抗乳腺癌的可能作用机制是激活线粒体凋亡途径。     

新型鬼臼毒素衍生物诱导人肺腺癌A549细胞凋亡及其机制研究

目的探讨新型鬼臼毒素衍生物10Ⅲg诱导人肺腺癌细胞A549细胞凋亡及其调控机制。方法采用四甲基偶氮唑蓝（MTr）比色法、流式细胞术测定细胞周期细胞凋亡率,DNA琼脂糖凝胶电泳和微管蛋白组化染色,Western印迹法检测凋亡蛋白Bax、Caspase-3的表达。结果新型鬼臼毒素衍生物10m。对A549细胞增殖具有明显的剂量和时间依赖性抑制作用,细胞周期分析显示S期细胞数明显增多,出现G2／M期阻滞;10Ⅲg作用48h后DNA电泳可见明显的梯状条带;10Ⅲg能破坏A549细胞的细胞骨架,与依托泊苷相比有明显促进微管解聚现象;10Ⅲg浓度为10^-6mol/L时能显著促进Bax、Caspase-3蛋白的表达。结论新型鬼臼毒素衍生物10Ⅲg通过诱导A549细胞发生G2／M期阻滞而抑制其增殖,其机制可能与抑制细胞微管解聚及诱导细胞凋亡有关。     

G6PD通过细胞周期蛋白D1/D2调控人黑色素瘤细胞周期的进程

葡萄糖-6-磷酸脱氢酶(G6PD)在人皮肤黑色素瘤A375细胞中处于高表达与高活性状态, 但G6PD在黑色素瘤发生发展过程中的作用及其具体机制尚不明确.本文在前期运用 siRNA方法构建G6PD敲减的黑色素瘤A375稳转细胞(A375-G6PDΔ)基础上,构建表达载体pBabe-puro-G6PDWT在A375-G6PDΔ细胞中过表达野生型的G6PD基因,从而构建G6PD表达恢复的稳转细胞(A375-G6PDΔ-G6PDWT).3株细胞A375-WT、A375-G6PDΔ和 A375-G6PDΔ-G6PDWT经G6PD酶活性测定、MTT测定、克隆形成实验、流式细胞仪分析细胞周期和Western 印迹检测.结果显示,A375-G6PDΔ-G6PDWT细胞的G6PD蛋白表达量 (0.847 ± 0.080)及其活性(0.394 ± 0.029)分别是A375-G6PDΔ的3.28倍(P＜0.01) 和7.34倍(P＜0.01),分别是A375-WT细胞的91-57%和2.12倍(P＜0.05).与A375-WT细 胞相比,A375-G6PDΔ细胞G0/G1期细胞数增加,S期细胞数减少,增殖指数PI降低了25-70%（P＜0.05）,细胞周期蛋白D1/D2、细胞周期蛋白E表达分别下降37.4%、54.3% (P＜0.01)和17.3%;而A375-G6PDΔ-G6PDWT细胞呈现G1/S期阻滞解除,细胞周期蛋白D1/D2蛋白分别恢复到A375-WT细胞的89.5%和87.6%,细胞周期蛋白E表达未见 恢复,呈现生长增殖和克隆形成率的恢复并接近于A375-WT细胞. 结果提示,G6PD通 过细胞周期蛋白D1/D2调控人皮肤黑色素瘤A375细胞G1期向S期转换的进程,这为黑色 素瘤发病机制的研究提供了新的思路.     

加味苇茎汤及其成分芹菜素对肺腺癌A549细胞增殖、周期与凋亡的影响

探讨加味苇茎汤含药血清及成分芹菜素对肺腺癌A549细胞增殖、细胞周期及凋亡的影响,选用肺癌A549细胞体外培养,在不同浓度含药血清及芹菜素作用下,用MTT法检测细胞生长抑制率、流式细胞术检测细胞周期及凋亡率、hoechst33342染色检测细胞凋亡形态。结果显示,加味苇茎汤含药血清及芹菜素对A549的生长抑制率:24 h分别为31%、34%,48 h分别为45%、53%;流式细胞术检测细胞周期发现A549细胞经加味苇茎汤含药血清处理后主要阻滞在G2期,而芹菜素能明显引起细胞凋亡。荧光显微镜下观察到较典型的细胞凋亡形态甚至细胞脱落,视野内细胞核数明显减少。该研究结果显示,加味苇茎汤含药血清及芹菜素能明显抑制A549细胞的增殖,引起细胞周期阻滞、诱导其凋亡。     

槲皮素通过G4调控癌基因表达影响肿瘤细胞增殖与凋亡

该研究采用CCK-8法、流式细胞术、免疫印迹法、实时定量PCR和体外结合实验等方法检测了槲皮素对Hep-2和MCF-7细胞生长和凋亡,以及对受G4调控基因表达的影响。结果显示,槲皮素对Hep-2和MCF-7细胞生长具有明显抑制作用,并诱导细胞周期停滞在S期;槲皮素诱导Hep-2和MCF-7细胞凋亡,表现出磷脂酰丝氨酸外翻、细胞膜通透性增加、染色质凝集、caspase活化等凋亡特征;槲皮素显著抑制c-Myc、KRAS、YY1等受G4调控基因的表达;槲皮素促进c-Myc启动子区G4形成序列Pu27形成G4结构并抑制核蛋白与其结合。以上结果表明,槲皮素可能通过促进细胞内G4形成序列形成稳定G4结构并抑制G4解旋酶对其解旋,引起受G4调控的肿瘤相关基因表达降低,最终抑制肿瘤细胞生长并诱导细胞凋亡。     

维甲酸对A549细胞增殖和凋亡及Skp2、p27^kip1蛋白表达的影响

目的探讨维甲酸对A549细胞增殖和凋亡及相关基因表达的影响。方法MTT法观察ATRA对A549细胞增殖的抑制作用;流式细胞仪、AO/EB荧光双染法检测细胞凋亡;免疫细胞化学检测ATRA处理前后A549细胞Skp2、p27^kip1蛋白表达的情况。结果ATRA处理后①MTT法结果显示ATRA对A549细胞具有增殖抑制作用,在一定范围内呈时间-剂量依赖性。②AO/EB荧光双染色法观察到ATRA 25μmol/L作用A549细胞48h后,即可发现典型的凋亡形态学改变。③流式细胞仪结果出现凋亡峰,与对照组细胞相比,实验组细胞周期延长,主要表现为G0/G1期细胞比例增加,同时S期细胞比例减少。④免疫细胞化学结果显示,ATRA 25μmol/L处理细胞48h后,维甲酸处理组Skp2有明显下调,p27^kip1则明显上调。结论ATRA具有抑制肺腺癌A549细胞增殖,诱导细胞凋亡的作用,其机制可能与下调Skp2,上调p27^kip1蛋白的表达水平有关。     

miR-200a逆转人乳腺癌耐阿霉素细胞株MCF-7/ADR耐药性的功能研究

[目的]研究在人乳腺癌耐阿霉素细胞株MCF-7/ADR细胞中高表达miR-200a后对阿霉素耐药性的功能的影响。[方法]利用阳离子脂质体把miR-200a模拟物(miR-200a mimics,简称miR-200a)与阴性对照组模拟物(mimics negative control,简称NC)转染到MCF-7/ADR细胞中;WST-1法检测MCF-7/ADR细胞的增殖情况;流式细胞术检测MCF-7/ADR细胞的凋亡与周期情况。[结果]与MCF-7细胞的IC_(50)(1.97±0.33μg/mL)相比,MCF-7/ADR细胞的IC_(50)(586.73±2.65μg/mL)更高;转染miR-200a后的MCF-7/ADR细胞的IC_(50)(280.51±1.47μg/mL)则显著低于MCF-7/ADR细胞的IC_(50);在MCF-7/ADR高表达miR-200a后,MCF-7/ADR细胞凋亡率(16.52±1.42)%较空白组(3.24±0.48)%与NC组(4.47±0.61)%的高,而细胞周期分布在G0/G1期的比例(50.94±0.74)%较空白组(44.73±0.53)%与NC组(45.88±0.74)%的高,差异均有统计学意义。[结论]上调miR-200a的表达水平可使MCF-7/ADR细胞具有部分逆转阿霉素的耐药性的能力,并抑制细胞增殖,促进其凋亡以及阻滞其细胞周期分布于G0/G1期。     

川楝素诱导人肺癌A549细胞凋亡

该研究旨在探讨川楝素诱导人肺癌A549细胞凋亡作用及其作用机制。通过不同浓度的川楝素作用于A549细胞48 h后,采用MTT法检测细胞活性;光学显微镜及荧光显微镜下观察细胞形态结构;流式细胞术检测细胞凋亡率、线粒体膜电位(ΔΨm)和细胞周期;实时定量RTPCR和Western blot分别检测Bax、Bcl-2、Fas、Cycs(细胞色素C)和Caspase-3基因m RNA和蛋白质水平。结果显示,在一定浓度范围内,川楝素能抑制A549细胞增殖,诱导细胞凋亡,且呈剂量依赖性。川楝素作用48 h的最佳药物浓度是40μmol/L,增殖抑制率为46.73%±1.47%,细胞凋亡率为13.18%±0.41%,线粒体膜电位(ΔΨm)显著下降(P0.01),细胞阻滞于G2期和S期;Bcl-2的表达显著降低,Bax、Fas、Cycs和Caspase-3的表达显著增加(P0.01),提示川楝素可能通过上调Bax、Fas、Cycs和Caspase-3基因和下调Bcl-2基因诱导人肺癌A549细胞凋亡。     

miR-34c逆转乳腺癌耐药细胞株MCF-7/DOX耐药性的研究

miR-34在肿瘤发生发展中起着至关重要的作用,然而,mi R-34在肿瘤耐药中的作用研究不多。该研究将合成的mi R-34c成熟序列转染乳腺癌阿霉素(doxorubicin,DOX)耐药细胞MCF-7/DOX,探讨mi R-34c体外逆转MCF-7/DOX细胞耐药性作用及其可能的机制。采用Real-time RT-PCR检测mi R-34c在乳腺癌耐药细胞株MCF-7/DOX中的表达,MTS法检测miR-34c对MCF-7/DOX细胞阿霉素耐药性的影响,流式细胞术检测miR-34c对MCF-7/DOX细胞周期和凋亡的影响,Real-time RT-PCR和Western blot法检测多药耐药相关蛋白MDR、MRP以及细胞周期与凋亡相关蛋白Bcl-2、E2F3的表达。结果显示,mi R-34c在乳腺癌MCF-7/DOX耐药细胞中低表达,转染mi R-34c可明显增加耐药细胞对阿霉素的敏感性;流式分析发现,miR-34c可以促进耐药细胞G2期细胞周期阻滞和凋亡;与对照组相比较,miR-34c转染组细胞MDR、MRP蛋白表达无明显变化,而Bcl-2、E2F3 mRNA和蛋白表达均明显下调。研究表明,miR-34c直接靶向抑制Bcl-2和E2F3的表达,诱导细胞周期G2期阻滞和凋亡,进而增强MCF-7/DOX耐药细胞对阿霉素的敏感性。     

基于RNA干扰CMTM7 对肺腺癌A549细胞凋亡的影响

目的:探讨基于RNA干扰CMTM7对肺腺癌A549细胞凋亡的影响。方法:选择肺腺癌A549细胞株分为si RNA组、阴性对照组与空白对照组,在对数生长的A549细胞中转染RNA干扰CMTM7载体、脂质体空载体和不进行转染,观察A549细胞的生长、凋亡与细胞周期状况。结果:MTT实验显示si RNA转染组的抑制率明显高于阴性对照组和空白对照组(P0.05),阴性对照组与空白对照组的对比无明显差异(P0.05)。流式细胞术实验表明si RNA转染组的细胞凋亡率明显高于阴性对照组和空白对照组(P0.05),阴性对照组与空白对照组的对比无明显差异(P0.05)。流式细胞术实验表明si RNA转染组的G0/G1期细胞数目较阴性对照组和空白对照组增多明显(P0.05),同时si RNA转染组的S、G2/M期细胞数目较阴性对照组和空白对照组明显减少(P0.05),阴性对照组和空白对照组对比差异无统计学意义(P0.05)。结论:RNA干扰CMTM7能够促进肺腺癌A549细胞凋亡,抑制肿瘤细胞的生长,其作用机制可能通过干扰细胞周期而实现。     

Inhibition of ATP-sensitive potassium channels causes reversible cell-cycle arrest of human breast cancer cells in tissue culture

The purpose of this study was to determine if potassium channel activity is required for the proliferation of MCF-7 human mammary carcinoma cells. We examined the sensitivities of proliferation and progress through the cell cycle to each of nine potassium channel antagonists. Five of the potassium channel antagonists produced a concentration-dependent inhibition of cell proliferation with no evidence of cytotoxicity following a 3-day or 5-day exposure to drug. The IC₅₀ values for these five drugs, quinidine (25 μM), glibenclamide (50 μM), linogliride (770 μM), 4-aminopyridine (1.6 mM), and tetraethylammmonium (5.8 mM) were estimated from their respective concentration-response curves. Four other potassium channel blockers were tested at supra-maximal channel blocking concentrations, including charybdotoxin (200 nM), iberiotoxin (100 nM), margatoxin (10 nM), and apamin (500 nM), and they had no effect on MCF-7 cell proliferation, viability, or cell cycle distribution. Of the five drugs that inhibited proliferation, only quinidine, glibenclamide, and linogliride also affected the cell cycle distribution. Cell populations exposed to each of these drugs for 3 days showed a statistically significant accumulation in GO/G1 phase and a significant proportional reduction in S phase and G2/M phase cells. The inhibition of cell proliferation correlated significantly with the extent of cell accumulation in GO/G1 phase, and the threshold concentrations for inhibition of growth and GO/G1 arrest were similar. The GO/G1 arrest produced by quinidine and glibenclamide was reversed by removing the drug, and cells released from arrest entered S phase synchronously with a lag period of ～24 hours. Based on the differential sensitivity of cell proliferation and cell cycle progression to the nine potassium channel antagonists, we conclude that inhibition of ATP-sensitive potassium channels in these human mammary carcinoma cells reversibly arrests the cells in the GO/G1 phase of the cell cycle, resulting in an inhibition of cell proliferation. © 1995 Wiley-Liss, Inc.     

Synthesis and antitumor activity of (−)-bassianolide in MDA-MB 231 breast cancer cells through cell cycle arrest

The high level of interest in the cyclodepsipeptides family in the natural products stems from their diverse range of biological activities. One of the cyclodepsipeptides, (−)-bassianolide, represents rich pharmacophores with diverse biological activities including potential cytotoxicity to various cancer cells. Efficient total synthesis of (−)-bassianolide was designed and achieved in nine steps, with significant improvements in the overall yield of 46.8% (vs. 7.2% yield in previous synthesis) using Ghosez’s chloroenamine reagent under mild conditions. The cytotoxicity of the (−)-bassianolide was evaluated against five human tumor cells, and the results showed that the (−)-bassianolide displayed significant cytotoxicity against A549, SK-OV-3, HepG2, HCT-15, MCF-7 and MDA-MB 231 cell lines with IC₅₀ values of 7.24, 8.44, 15.39, 6.40, 11.42 and 3.98 μg/mL respectively. Specifically, (−)-bassianolide induced G0/G1 arrest associated with a decrease of cyclin A, D1 and an increase of p53, MDM2, and p21 expression in MDA-MB 231 cells. These results demonstrate that (−)-bassianolide possesses antitumor activities via arresting of the cell cycle and the synthetic approach features an efficient and mild method for the formation of amide bonds through three inter- and intramolecular coupling reactions.     

A novel disintegrin protein from Naja naja venom induces cytotoxicity and apoptosis in human cancer cell lines in vitro

Animal venoms and toxins are potential bioresources that have been known to mankind as a therapeutic tool for more than a century through folk and traditional medicine. The purified “disintegrin protein” (64 kDa) from the venom of the Indian cobra snake (Naja naja) exhibited cytotoxic effects of various types of human cancer cell lines such as breast cancer (MCF-7), lung cancer (A549) and liver cancer (HepG2). In vitro cytotoxicity, DNA fragmentation, an apoptotic assay and a cell cycle analysis were performed to evaluate the anticancer activity of disintegrin against the above cell lines. The IC₅₀ value of disintegrin was determined to be 2.5 ± 0.5 μg/mL, 3.5 ± 0.5 μg/mL, and 3 ± 0.5 μg/mL for the MCF-7, A549 and HepG2 cell lines respectively. Moreover, the increased distribution of G0/G1 and S phase led to decreased populations of cells in the G2/M phase of MCF-7, HepG2 and A549 cells.     

Synthesis of 1,2,4-triazole-linked urea/thiourea conjugates as cytotoxic and apoptosis inducing agents

A new series of 1,2,4-triazole-linked urea and thiourea conjugates have been synthesized and evaluated for their in vitro cytotoxicity against selected human cancer cell lines namely, breast (MCF-7, MDA-MB-231), lung (A549) prostate (DU145) and one mouse melanoma (B16-F10) cell line and compared with reference drug. The compound 5t showed significant cytotoxicity on MCF-7 breast cancer cell line with a IC₅₀ value of 7.22?±?0.47?µM among all the tested compounds. Notably, induction of apoptosis by compound 5t on MCF-7 cells was evaluated using different staining techniques such as acridine orange/ethidium bromide (AO/EB), annexin V-FITC/PI, and DAPI. Further, clonogenic assay indicates the inhibition of colony formation on MCF-7 cells by compound 5t. Moreover, the flow-cytometric analysis also revealed that compound 5t caused the arrest of cells at G0/G1 phase of cell cycle. In addition, the compounds when tested on normal human cells (L-132) were found to be safer with low cytotoxicity profile.     

Melatonin increases p53 and p21WAF1 expression in MCF-7 human breast cancer cells in vitro.

The aim of the present work was to study whether melatonin, at physiological concentrations, exerts its antiproliferative effects on MCF-7 human breast cancer cells by inducing the expression of some of the proteins involved in the control of the cell cycle. MCF-7 cells were cultured for 48 h in DMEM media containing either melatonin (1 nM) or the diluent (0.001% ethanol). At this concentration, after 48 hours of incubation, melatonin reduced the number of viable cells in relation to controls. The decreased cell proliferation was coincident with a significant increase in the expression of p53 as well as p21WAF1 proteins. These results demonstrate that melatonin inhibits MCF-7 cell proliferation by inducing an arrest of cell cycle dependent on an increased expression of p21WAF1 protein, which is mediated by the p53 pathway.     

Antitumor agents 201. Cytotoxicity of harmine and beta-carboline analogs

Twenty-six beta-carbolines were evaluated for in vitro cytotoxicity in a human tumor cell line panel. Harmine (3) showed significant activity against several cell lines including three drug-resistant KB sublines with various resistance mechanisms. Alpha-(4-nitrobenzylidine) harmine (16) had a broad cytotoxicity spectrum (ED50 values from 0.3-1.2 microg/mL against 1A9, KB, SaOS-2, A549, SK-MEL-2, U-87-MG, and MCF-7 cells).     

ROS-Mediated Antitumor Activity,Apoptosis, and Molecular Docking Studies of Platinum(II) Coordination Complexes Bearing 2-(Diphenylphosphino)pyridine Ligands

Platinum-based drugs have been widely used in cancer treatment. However, their severe side effects have limited their use. So, researchers have been striving to find compounds with fewer side effects and greater efficacy, to overcome these drawbacks. Here, the cytotoxicity of platinum(II) complexes containing 2-(diphenylphosphino)pyridine ligands have been studied on human lung (A549), ovarian (SKOV3), breast (MCF-7) cancer, and normal breast (MCF-10A) cell lines. The most potent compound exhibits a marked cell growth-inhibitory effect against ovarian and lung cancer cells with IC₅₀ values of 9.41 and 5.58 μM, respectively, which were significantly better than that observed for cisplatin (19.02, and 8.64 μM). Additionally, all complexes achieved significantly lower cytotoxicity towards MCF-10A. To investigate the interaction of complexes with DNA, an electrophoresis mobility shift assay was conducted, which indicated that complexes bind to DNA and affect its electrophoretic mobility. An analysis of apoptosis in A549 cells supported the conclusion that they inhibits cell proliferation via induction of apoptosis in a concentration-dependent manner. Molecular docking was also used to investigate the interactions of compounds with different DNA structures. These compounds have the ability to be a suitable pharmaceutical compound with further investigations in the field of cancer research.     

Design, synthesis and biological evaluation of novel chalcone derivatives as antitubulin agents

A series of novel chalcone derivatives have been designed and synthesized, and their biological activities were also evaluated as potential inhibitors of tubulin. These compounds were assayed for growth-inhibitory activity against MCF-7 and A549 cell lines in vitro. Compound 3d showed the most potent antiproliferative activity against MCF-7 and A549 cell lines with IC(50) values of 0.03 and 0.95 μg/mL and exhibited the most potent tubulin inhibitory activity with IC(50) of 1.42 μg/mL. Docking simulation was performed to insert compound 3d into the crystal structure of tubulin at colchicines binding site to determine the probable binding model. Based on the preliminary results, compound 3d with potent inhibitory activity in tumor growth may be a potential anticancer agent.     

Insulin-like factor binding protein-3 promotes the G1 cell cycle arrest in several cancer cell lines

Insulin-like growth factor binding protein-3 (IGFBP-3) is a multi-functional protein known to induce apoptosis of various cancer cells in an insulin-like growth factor (IGF)-dependent and IGF-independent manner. In our previous study, we found that IGFBP-3 induced apoptosis through the activation of caspases in 786-O cells. In this study, we further examined that whether IGFBP-3 induced apoptosis through the induction of cell cycle arrest in 786-O, A549 and MCF-7 cells. Our results showed that overexpressed IGFBP-3 resulted in typical apoptotic ultrastructures in A549 cells under transmission electron microscope. The result of flow cytometry analysis indicated that IGFBP-3 arrested the cell cycle at G1-S phase in 786-O, A549 and MCF-7 cells. In A549 cells, quantitative real-time PCR and Western blot analysis showed a significant change in the expression of cell cycle-regulated proteins—a decrease in cyclin E1 expression, an increase in p21 expression. These results indicate a possible mechanism for G1 cell cycle arrest by IGFBP-3. Taken together, cyclin E1 and p21 may play important roles in the IGFBP-3-inducing G1 cell cycle arrest and apoptosis in several human cancer cells.