Podophyllotoxin Induces ROS-Mediated Apoptosis and Cell Cycle Arrest in Human Colorectal Cancer Cells via p38 MAPK Signaling

Podophyllotoxin (PT), a lignan compound from the roots and rhizomes of Podophyllum peltatum, has diverse pharmacological activities including anticancer effect in several types of cancer. The molecular mechanism of the anticancer effects of PT on colorectal cancer cells has not been reported yet. In this study, we sought to evaluate the anticancer effect of PT on human colorectal cancer HCT116 cells and identify the detailed molecular mechanism. PT inhibited the growth of cells and colony formation in a concentration-dependent manner and induced apoptosis as determined by the annexin V/7-aminoactinomycin D double staining assay. PT-induced apoptosis was accompanied by cell cycle arrest in the G2/M phase and an increase in the generation of reactive oxygen species (ROS). The effects of PT on the induction of ROS and apoptosis were prevented by pretreatment with N-acetyl-L-cysteine (NAC), indicating that an increase in ROS generation mediates the apoptosis of HCT116 cells induced by PT. Furthermore, Western blot analysis showed that PT upregulated the level of phospho (p)-p38 mitogen-activated protein kinase (MAPK). The treatment of SB203580, a p38 inhibitor, strongly prevented the apoptosis induced by PT, suggesting that PT-induced apoptosis involved the p38 MAPK signaling pathway. In addition, PT induced the loss of mitochondrial membrane potential and multi-caspase activation. The results suggested that PT induced cell cycle arrest in the G2/M phase and apoptosis through the p38 MAPK signaling pathway by upregulating ROS in HCT116 cells.     

Synthetic Homoisoflavane Derivatives of Cremastranone Suppress Growth of Colorectal Cancer Cells through Cell Cycle Arrest and Induction of Apoptosis

Colorectal cancer is diagnosed as the third most prevalent cancer; thus, effective therapeutic agents are urgently required. In this study, we synthesized six homoisoflavane derivatives of cremastranone and investigated their cytotoxic effects on the human colorectal cancer cell lines HCT116 and LoVo. We further examined the related mechanisms of action using two of the potent compounds, SH-19027 and SHA-035. They substantially reduced the cell viability and proliferation in a dose-dependent manner. Treatment with SH-19027 and SHA-035 induced cell cycle arrest at the G2/M phase and increased expression of p21 both of which are implicated in cell cycle control. In addition, the apoptotic cell population and apoptosis-associated marker expression were accordingly increased. These results suggest that the synthesized cremastranone derivatives have anticancer effects through the suppression of cell proliferation and induction of apoptosis. Therefore, the synthesized cremastranone derivatives could be applied as novel therapeutic agents against colorectal cancer.     

Ethanol Elicits Inhibitory Effect on the Growth and Proliferation of Tongue Carcinoma Cells by Inducing Cell Cycle Arrest

Cellular effects of ethanol in YD-15 tongue carcinoma cells were assessed by MTT assay, caspase activity assay, Western blotting and flow cytometry. Ethanol inhibited the growth and proliferation of YD-15 cells in a dose- and time-dependent manner in an MTT assay. The effects of ethanol on cell cycle control at low percent range of ethanol concentration (0 to 1.5%), the condition not inducing YD-15 cell death, was investigated after exposing cells to alcohol for a certain period of time. Western blotting on the expression of cell cycle inhibitors showed that p21 and p27 was up-regulated as ethanol concentration increases from 0 to 1.5% whilst the cell cycle regulators, cdk1, cdk2, and cdk4 as well as Cyclin A, Cyclin B1 and Cyclin E1, were gradually down-regulated. Flow cytometric analysis of cell cycle distribution revealed that YD-15 cells exposed to 1.5% ethanol for 24 h was mainly arrested at G2/M phase. However, ethanol induced apoptosis in YD-15 cells exposed to 2.5% or higher percent of ethanol. The cleaved PARP, a marker of caspase-3 mediated apoptosis, and the activation of caspase-3 and -7 were detected by caspase activity assay or Western blotting. Our results suggest that ethanol elicits inhibitory effect on the growth and proliferation of YD-15 tongue carcinoma cells by mediating cell cycle arrest at G2/M at low concentration range and ultimately induces apoptosis under the condition of high concentration.     

Gallic Acid Hindered Lung Cancer Progression by Inducing Cell Cycle Arrest and Apoptosis in A549 Lung Cancer Cells via PI3K/Akt Pathway

This study elucidates the anti-cancer potential of gallic acid (GA) as a promising therapeutic agent that exerts its effect by regulating the PI3K/Akt pathway. To prove our research rationale, we used diverse experimental methods such as cell viability assay, colony formation assay, tumor spheroid formation assay, cell cycle analysis, TUNEL assay, Western blot analysis, xenograft mouse model and histological analysis. Treatment with GA inhibited cell proliferation in dose-dependent manner as measured by cell viability assay at 48 h. GA and cisplatin (CDDP) also inhibited colony formation and tumor spheroid formation. In addition, GA and CDDP induced apoptosis, as determined by the distribution of early and late apoptotic cells and DNA fragmentation. Western blot analysis revealed that inhibition of the PI3K/Akt pathway induced upregulation of p53 (tumor suppressor protein), which in turn regulated cell cycle related proteins such as p21, p27, Cyclin D1 and E1, and intrinsic apoptotic proteins such as Bax, Bcl-2 and cleaved caspase-3. The anti-cancer effect of GA was further confirmed in an in vivo mouse model. Intraperitoneal injection with GA for 4 weeks in an A549-derived tumor xenograft model reduced the size of tumor mass. Injection of them downregulated the expression of proliferating cell nuclear antigen and p-Akt, but upregulated the expression of cleaved caspase-3 in tumor tissues. Taken together, these results indicated that GA hindered lung cancer progression by inducing cell cycle arrest and apoptosis, suggesting that GA would be a potential therapeutic agent against non-small cell lung cancer.     

Heme Oxygenase-1 Induced by Aprotinin Inhibits Vascular Smooth Muscle Cell Proliferation Through Cell Cycle Arrest in Hypertensive Rats

Spontaneous hypertensive rats (SHR) are an established model of genetic hypertension. Vascular smooth muscle cells (VSMC) from SHR proliferate faster than those of control rats (Wistar-Kyoto rats; WKY). We tested the hypothesis that induction of heme oxygenase (HO)-1 induced by aprotinin inhibits VSMC proliferation through cell cycle arrest in hypertensive rats. Aprotinin treatment inhibited VSMC proliferation in SHR more than in normotensive rats. These inhibitory effects were associated with cell cycle arrest in the G1 phase. Tin protoporphyrin IX (SnPPIX) reversed the anti-proliferative effect of aprotinin in VSMC from SHR. The level of cyclin D was higher in VSMC of SHR than those of WKY. Aprotinin treatment downregulated the cell cycle regulator, cyclin D, but upregulated the cyclin-dependent kinase inhibitor, p21, in VSMC of SHR. Aprotinin induced HO-1 in VSMC of SHR, but not in those of control rats. Furthermore, aprotinin-induced HO-1 inhibited VSMC proliferation of SHR. Consistently, VSMC proliferation in SHR was significantly inhibited by transfection with the HO-1 gene. These results indicate that induction of HO-1 by aprotinin inhibits VSMC proliferation through cell cycle arrest in hypertensive rats.     

染料木素对人宫颈癌Siha细胞增殖凋亡和周期的影响

［摘要］目的探讨染料木素对人宫颈癌Siha细胞增殖、凋亡和周期的影响及机制。方法50 mol•mL 1染料木素处理Siha细胞,用噻唑蓝（MTT）法检测细胞生长抑制率,用流式细胞术（FCM）检测细胞凋亡、周期及周期蛋白cyclin A和cyclin B表达的变化。结果染料木素作用于Siha细胞后,增殖抑制率比对照组明显升高（P＜0.05）;染料木素处理48 h后,实验组凋亡率较对照组升高,分别为（67.45±1.54）%和（45.37±1.65）%（P＜0.01）。染料木素处理后的Siha细胞G2/M期的细胞比例显著上升,由（9.55±0.71）%升至（79.54±1.09）%（P＜0.01）;cyclin A和cyclin B表达上调,分别由（1.84±0.11）%升至（37.38±0.71）%（P＜0.01）,由（69.44±1.84）%升至（97.70±1.20）%（P＜0.01）。结论染料木素在体外可有效抑制人宫颈癌细胞生长,其抗肿瘤机制可能是上调cyclin A和cyclin B蛋白表达和引起G2/M期细胞周期阻滞。     

复元胶囊对硝普钠诱导的软骨细胞凋亡与细胞周期作用的实验研究

目的:研究复元胶囊含药血清对硝普钠(SNP)诱导的软骨细胞凋亡与细胞周期的作用。方法:雄性3周龄SD大鼠,用于分离培养软骨细胞;雄性成年SD大鼠,用于制备含药血清。将第2代的软骨细胞进行分组实验。透射电镜观察软骨细胞凋亡的超微结构,流式细胞仪检测细胞周期百分率及细胞凋亡率,硝酸还原酶法检测培养液中NO含量。结果:复元胶囊含药血清可使SNP诱导的软骨细胞处于G0/G1期的百分比减少,S期及G2/M期的百分比增加(P<0.05,P<0.01);可使细胞凋亡率显著降低(P<0.05或P<0.01),培养上清中NO含量显著降低(P<0.05)。结论:复元胶囊含药血清能显著降低SNP诱导的软骨细胞凋亡率,促进细胞增殖,并降低培养液中NO的含量,这可能是复元胶囊防治骨性关节炎的作用机制之一。     

华蟾素注射液对人肝癌HepG-2细胞增殖及周期的影响

目的探讨华蟾素注射液对人肝癌HepG-2细胞增殖及周期的影响。方法应用噻唑蓝还原法(MTT)检测华蟾素注射液对HepG-2细胞增殖的影响;应用流式细胞术(FCM)检测HepG-2细胞周期分布;采用逆转录-多聚酶链反应技术(RT-PCR)检测华蟾素注射液对HepG-2细胞CyclinA和CDK2 mRNA表达水平的影响;应用比色定量法检测华蟾素注射液对HepG-2细胞内CDK2及CyclinA活性的影响。结果华蟾素注射液可以抑制HepG-2细胞增殖,其抑制作用具有时间和剂量依赖性;可将HepG2细胞阻滞于S期;抑制HepG-2细胞CDK2、CyclinAmRNA水平表达;使HepG-2细胞CyclinA、CDK2活性降低。结论华蟾素注射液能够抑制人肝癌HepG-2细胞增殖,并将细胞阻滞于S期,诱导细胞凋亡,机制可能是通过影响CyclinA、CDK2活性,下调CDK2、CyclinAmRNA水平表达实现的。     

Eriocalyxin B induces apoptosis and cell cycle arrest in pancreatic adenocarcinoma cells through caspase- and p53-dependent pathways

Pancreatic cancer is difficult to detect early and responds poorly to chemotherapy. A breakthrough in the development of new therapeutic agents is urgently needed. Eriocalyxin B (EriB), isolated from the Isodon eriocalyx plant, is an ent-kaurane diterpenoid with promise as a broad-spectrum anti-cancer agent. The anti-leukemic activity of EriB, including the underlying mechanisms involved, has been particularly well documented. In this study, we demonstrated for the first time EriB's potent cytotoxicity against four pancreatic adenocarcinoma cell lines, namely PANC-1, SW1990, CAPAN-1, and CAPAN-2. The effects were comparable to that of the chemotherapeutic camptothecin (CAM), but with much lower toxicity against normal human liver WRL68 cells. EriB's cytoxicity against CAPAN-2 cells was found to involve caspase-dependent apoptosis and cell cycle arrest at the G2/M phase. Moreover, the p53 pathway was found to be activated by EriB in these cells. Furthermore, in vivo studies showed that EriB inhibited the growth of human pancreatic tumor xenografts in BALB/c nude mice without significant secondary adverse effects. These results suggest that EriB should be considered a candidate for pancreatic cancer treatment.     

LY294002对多药耐药急性白血病细胞株HL60/VCR的凋亡及细胞周期的影响研究

目的:研究磷脂酰肌醇-3-激酶(PI3K)抑制剂LY294002对多药耐药急性白血病细胞株HL60/VCR凋亡与细胞周期的影响及可能机制。方法:取耐长春新碱(VCR)的HL60/VCR多药耐药急性白血病细胞株分为未加药的对照组及加入不同浓度的LY294002(其终浓度为1.0、2.5、5.0、10μmol.L-1)组,MTT法检测2种细胞的半数抑制浓度(IC50),流式细胞仪检测细胞凋亡及细胞周期分布,半定量逆转录-聚合酶链反应(RT-PCR)检测抗凋亡蛋白Bcl-2、细胞周期调控分子CyclinD1mRNA表达。结果:与对照组比较,LY294002可明显降低HL60/VCR对VCR的IC50(P<0.05),且与剂量相关;LY294002可显著增加HL60/VCR细胞凋亡率,阻滞细胞于G0/G1期,降低HL60/VCR细胞的Bcl-2、CyclinD1mRNA的表达(P均<0.05)。结论:LY294002可能是通过影响Bcl-2及CyclinD1基因的表达,从而促进HL60/VCR细胞凋亡及抑制细胞增殖。     

Licochalcone H Induces Cell Cycle Arrest and Apoptosis in Human Skin Cancer Cells by Modulating JAK2/STAT3 Signaling

Licochalcone H (LCH) is a phenolic compound synthetically derived from licochalcone C (LCC) that exerts anticancer activity. In this study, we investigated the anticancer activity of LCH in human skin cancer A375 and A431 cells. The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) cell viability assay was used to evaluate the antiproliferative activity of LCH. Cell cycle distribution and the induction of apoptosis were analyzed by flow cytometry. Western blotting assays were performed to detect the levels of proteins involved in cell cycle progression, apoptosis, and the JAK2/STAT3 signaling pathway. LCH inhibited the growth of cells in dose- and time-dependent manners. The annexin V/propidium iodide double staining assay revealed that LCH induced apoptosis, and the LCH-induced apoptosis was accompanied by cell cycle arrest in the G1 phase. Western blot analysis showed that the phosphorylation of JAK2 and STAT3 was decreased by treatment with LCH. The inhibition of the JAK2/STAT3 signaling pathway by pharmacological inhibitors against JAK2/STAT3 (cryptotanshinone (CTS) and S3I-201) simulated the antiproliferative effect of LCH suggesting that LCH induced apoptosis by modulating JAK2/STAT3 signaling.     

冬凌草甲素诱导胃癌BGC-823细胞凋亡及G2／M细胞周期阻滞作用研究

目的研究冬凌草甲素体外诱导胃癌BGC-823细胞凋亡和细胞周期阻滞的作用，阐明其作用机理，为临床应用提供科学依据。方法用MTT方法测定冬凌草甲素体外抑制BGC-823细胞生长的作用。用共聚焦荧光显微镜和流式细胞仪分别观察诱导凋亡的情况。线粒体膜电位和细胞内钙离子浓度分别用荧光探针标记后流式细胞仪测定。凋亡和细胞周期相关蛋白的表达用Westem blotting进行测定。结果冬凌草甲素对BGC-823细胞的半数生长抑制浓度IC50值为22．21μmol.L^-1，并诱导细胞凋亡，呈现浓度依赖性。此外，能够降低线粒体膜电位，升高细胞内钙离子浓度，激活caspase-3前体。同时，冬凌草甲素能够使得BGC-823细胞阻滞在细胞周期的G2／M期，伴随有cyclin A蛋白的表达下降。在发生凋亡和细胞阻滞之前，观察到p53蛋白的表达增加。结论冬凌草甲素能够诱导BGC-823细胞产生凋亡，并使细胞周期阻滞在G2／M期。其凋亡机理与caspase-3的激活，p53蛋白表达上调及cyclin A表达下调相关。     

苦参碱诱导胰腺癌细胞凋亡的实验研究

目的 探讨苦参碱对胰腺癌细胞SW 1990生长抑制和诱导凋亡作用.方法 将不同浓度的苦参碱作用于培养的SW1990细胞,通过MTT比色法、流式细胞仪和DNA凝胶电泳、电子显微镜技术观察检测细胞凋亡,研究分析其对SW1990细胞的生长抑制和诱导凋亡作用.结果 苦参碱浓度为0.5、1.0、1.5g/L时,细胞生长抑制率分别为14.3%、24.8%、41.6%;流式细胞术测定RD横纹肌肉瘤细胞的凋亡率分别为10.3%、18.3%、27.5%;DNA电泳见DNA"梯形"图谱;电镜显示肿瘤细胞的凋亡形态.结论 苦参碱能抑制SW1990细胞增殖,诱导其凋亡.     

茵陈素对肺癌细胞增殖和细胞周期的影响

目的：探讨茵陈素（6，7-二甲基香豆素）对肺癌细胞增殖和细胞周期的影响。应用光镜、四氮甲唑蓝（MTT）方法和流式细胞术分析茵陈素对肺癌细胞的增殖，并呈剂量依赖性，以160цg/mL抑制作用最明显，抑制率达52.4%。细胞被阻滞于Go/G1期，不能进入S及G2/M期，增殖指数明显下降。结论：茵陈素在体外对肺癌细胞具有抑制作用，通过抑制DNA合成，将细胞阻滞于G0/G1期，从而抑制细胞增殖。     

Arctigenin induces cell cycle arrest by blocking the phosphorylation of Rb via the modulation of cell cycle regulatory proteins in human gastric cancer cells

Gastric cancer is a leading cause of cancer-related deaths, worldwide being second only to lung cancer as a cause of death. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms of arctigenin for anti-tumor effect on gastric cancer have not been examined. This study examined the biological effects of arctigenin on the human gastric cancer cell line SNU-1 and AGS. Cell proliferation was determined by MTT assay. In MTT assay, the proliferation of SNU-1 and AGS cells was significantly inhibited by arctigenin in a time and dose dependent manner, as compared with SNU-1 and AGS cells cultured in the absence of arctigenin. Inhibition of cell proliferation by arctigenin was in part associated with apoptotic cell death, as shown by changes in the expression ratio of Bcl-2 to Bax by arctigenin. Also, arctigenin blocked cell cycle arrest from G₁ to S phase by regulating the expression of cell cycle regulatory proteins such as Rb, cyclin D1, cyclin E, CDK4, CDK2, p21Waf1/Cip1 and p15 INK4b. The antiproliferative effect of arctigenin on SNU-1 and AGS gastric cancer cells revealed in this study suggests that arctigenin has intriguing potential as a chemopreventive or chemotherapeutic agent.     

羟基喜树碱对胃癌细胞凋亡和细胞周期的影响

目的 探讨羟基喜树碱诱导胃癌细胞凋亡与细胞周期变化的关系.方法 用MTT法测定不同浓度的HCPT对胃癌细胞的生长抑制作用,用流式细胞仪测定一定浓度下不同作用时间细胞凋亡率和细胞周期的变化.结果 在3.125～50.0 μg/ml浓度范围内药物对细胞的抑制率随浓度的增加而增加;在相同浓度下,随时间的延长细胞的凋亡率也逐渐增加,0、12、24、48h的凋亡率为2.8%、8.5%、10.2%,13.3%,在24h内S期细胞减少而G0/G1细胞增多,第二个24h S期和G2/M的阻滞.结论羟基喜树碱可诱导胃癌细胞凋亡,其细胞凋亡与细胞周期分布有关.