Taiwan cobra cardiotoxin III inhibits Src kinase leading to apoptosis and cell cycle arrest of oral squamous cell carcinoma Ca9-22 cells

Cardiotoxin III (CTX III), a basic polypeptide with 60-amino acid residues isolated from Naja naja atra venom, has been reported to have cytotoxic activity. CTX III exerted cytotoxicity with the S-phase cell cycle arrest, correlated with a marked decrease in the expression levels of cyclin A, cyclin B, and cyclin-dependent kinase 1 (CDK1), and apoptosis, accompanied with Bax and Bad up-regulation, and the down-regulation of Bcl-2, p-Bad, and X-linked inhibitor of apoptosis (XIAP) with cytochrome c release and sequential activation of caspase-9 and caspase-3 in Ca9-22 cells. Mechanistic studies showed that CTX III suppressed the phosphorylation of Src, EGFR, STAT3, STAT5, Akt, and activation of PI3 K (p110). Moreover, Src inactivation was observed earlier than that of the EGFR and the Src inhibitor PP2 suppressed the levels of phospho-EGFR, phospho-STAT3, phospho-STAT5, phospho-Akt, and PI3 K(p110). The PP2 also caused the S-phase arrest and apoptosis, and led to down-regulation of Bcl-2, p-Bad, XIAP, cyclin A, cyclin B, and CDK1, and up-regulation of Bax and Bad, similar to that observed in CTX III treatment. Taken together, these results indicate that CTX III induces apoptosis and S-phase arrest in Ca9-22 cells via concomitant inactivation of the Src, EGFR, STAT3, STAT5, PI3 K(p110), and Akt signaling pathways.     

姜黄素对人鼻咽癌株CNE-2Z细胞凋亡的影响及机制研究

目的探讨姜黄素(CU)对人鼻咽癌株CNE-2Z细胞凋亡的影响及机制。方法体外培养CNE-2Z细胞在梯度浓度CU(0、20、40、80μmol/L)干预48 h后,采用MTT法检测其对CNE-2Z抑制增殖的作用,ELISA法检测8-羟基-2-脱氧鸟苷(8-OHdG)水平,Hoechst33342染色检测细胞形态学的变化,Western blotting法检测PI3K和Akt磷酸化水平。结果与空白对照组(0μmol/L)比较,CU干预后明显抑制CNE-2Z的细胞增殖(P<0.01),同时减少内源性的8-OHdG生成(P<0.01)。此外,CU干预可有效促进癌细胞凋亡,下调p-PI3K和p-Akt的表达。结论姜黄素具有良好的抗肿瘤作用,其机制与抑制癌细胞增殖、诱导细胞凋亡及抑制PI3K/Akt通路有关。     

GL-V9, a newly synthetic flavonoid derivative, induces mitochondrial-mediated apoptosis and G2/M cell cycle arrest in human hepatocellular carcinoma HepG2 cells

We recently established that GL-V9, a newly synthetic flavonoid derivative, is an active cytotoxic component. In this study, we demonstrated that GL-V9 inhibited cells growth via inducing apoptosis and G2/M cell cycle arrest in human hepatocellular carcinoma HepG2 cells. Following the treatment of HepG2 cells with GL-V9, we observed poly (ADP-ribose) polymerase (PARP) cleavage and activation of caspase-3 and caspase-9, while caspase-8 remained unchanged. The expression ratio of Bcl-2/Bax was also decreased in GL-V9-treated cells. Meanwhile, the cell cycle-related proteins, such as cyclin B1, CDK1 and cdc25 were down-regulated in GL-V9-induced G2/M cell cycle arrest. Furthermore, we showed that GL-V9-induced apoptosis in HepG2 cells was achieved through mitochondrial pathway. It also regulated changes of mitochondrial membrane potential and increased the production of intracellular reactive oxygen species. Besides, the growth inhibitory effect of GL-V9 was examined in vivo using murine implanted tumor model. These studies indicate that GL-V9 shows promise as a therapeutic agent against human heptoma.     

Effect of active fraction of Eriocaulon sieboldianum on human leukemia K562 cells via proliferation inhibition,cell cycle arrest and apoptosis induction

Eriocaulon sieboldianum (Sieb. & Zucc. ex Steud.), a genus of Eriocaulon in the Eriocaulaceae family, is an edible and medicinal plant used in traditional Chinese medicine. It was processed into healthcare beverages for expelling wind-heat, protecting eyes, and reducing blood fat. Also, it has been used with other herbs as Traditional Chinese herbal compound to treat cancer as adjuvants in tumor therapy in China. However, the active fractions and precise cellular mechanisms of E. sieboldianum extract remain to be illustrated. The goal of this study was to investigate the effects of the active fraction of E. sieboldianum on the growth of K562 cells and understand the possible mechanisms of its action. Our findings suggested that the fraction E3 of E. sieboldianum could effectively inhibit the activity of Aurora kinase and induce apoptosis via blocking cell cycle, up-regulating the expression of proapoptotic proteins including p53 and Bax and reducing the expression of Bcl-2. The levels of Cytochrome C, cleaved caspase-9, cleaved caspase-3 and cleaved PARP were also found to be increased after treatment with fraction E3 of E. sieboldianum.This study could improve the development of E. sieboldianum and raise its application value in cancer adjuvant therapy. Considering it is both a dietary supplement and a traditional Chinese herbal medicine which exhibits anticancer activities, it can be developed into functional food.     

2'-chloro-4'-aminoflavone derivatives selectively targeting hepatocarcinoma cells: convenient synthetic process, G(2)/M cell cycle arrest and apoptosis triggers

A series of 2'-chloro-4'-nitroflavone and 2'-chloro-4'-aminoflavone derivatives were synthesized by a convenient synthetic process. The in vitro anti-proliferation ability of these compounds was evaluated against hepatocarcinoma cells (HepG2), breast adenocarcinoma cells (MCF-7), and human chronic myelogenous leukemia cells (K562). Most of synthetic compounds possessed notable anti-proliferation activity against HepG2 cells and little activity against MCF-7 cells and K562 cells. In particular, compounds 4c and 4e exhibited high anti-proliferation activity against HepG2 cells with IC(50) at about 2.0 μM. Further toxicity screening toward normal human hepatocytes indicated that some compounds had low toxicity against normal liver cells, among which 4e displayed very weak effects on QSG7701 and HL7702 cells, with IC(50) values >100 and 50 μM, respectively. Compound 4c, with the best anti-proliferation activity in amino-substituted flavones (IC(50) = 2.0 μM), was selected for further evaluation of its effects on apoptosis and the cell cycle. HepG2 cells were exposed to this compound at 10 μM, which induced nuclear disassembly and DNA fragmentation. Flow cytometry analysis suggested that the population of apoptotic cells greatly increased in the 4c-treated HepG2 cells, and the cell cycle was arrested at the G(2)/M phase.     

Ciprofloxacin-mediated induction of S-phase cell cycle arrest and apoptosis in COLO829 melanoma cells

Background

Low effectiveness of anti-melanoma therapies makes it necessary to search for new drugs that could improve or replace the standard chemotherapy. Fluoroquinolones are a group of synthetic antibiotics, used in the treatment of wide range of bacterial infections. Moreover, this class of antibiotics has shown promising anti-tumor activity in several cancer cell lines. The aim of this study was to examine the effect of ciprofloxacin on cell viability, apoptosis and cell cycle distribution in COLO829 melanoma cells.

Tetrandrine triggers apoptosis and cell cycle arrest in human renal cell carcinoma cells

Tetrandrine is a cytotoxic compound capable of exerting remarkable antitumor activity against many cancer cells in vitro and in vivo. However, little is known about its effect on human renal cell carcinoma (RCC). In the present study, using RCC 786-O, 769-P and ACHN cell lines as the model system, we demonstrated the anticancer effect of tetrandrine against RCC and clarified its underlying mechanisms. Tetrandrine treatment showed growth inhibitory effects on RCC cells in a time- and dose-dependent manner. Additionally, flow cytometric studies revealed that tetrandrine was capable of inducing G1 cell cycle arrest and apoptosis in RCC cells. Mechanically, activation of caspase-8, caspase-9, and caspase-3 and increasing expression of cell cycle regulatory protein p21^WAF1/CIP1 and p27^KIP1 were observed in tetrandrine-treated RCC cells. This study provides the first evidence that tetrandrine triggered apoptosis and cell cycle arrest in RCC 786-O, 769-P and ACHN cells in vitro; these events are associated with caspase cascade activation and upregulation of p21 and p27. Our results thus provide rational evidence supporting the application of tetrandrine as a novel therapeutic agent against RCC in the clinical setting.     

Osthole induces G2/M cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells

Context: Osthole [7-methoxy-8-(3-methyl-2-butenyl) coumarin] isolated from the fruit of Cnidium monnieri (L.) Cuss, one of the commonly used Chinese medicines listed in the Shennong’s Classic of Materia Medica in the Han Dynasty, had remarkable antiproliferative activity against human hepatocellular carcinoma HepG2 cells in culture.

Objectives: This study evaluated the effects of osthole on cell growth, nuclear morphology, cell cycle distribution, and expression of apoptosis-related proteins in HepG2 cells.

Materials and methods: Cytotoxic activity of osthole was determined by the MTT assay at various concentrations ranging from 0.004 to 1.0?µmol/ml in HepG2 cells. Cell morphology was assessed by Hoechst staining and fluorescence microscopy. Apoptosis and cell-cycle distribution was determined by annexin V staining and flow cytometry. Apoptotic protein levels were assessed by Western blot.

Results: Osthole exhibited significant inhibition of the survival of HepG2 cells and the half inhibitory concentration (IC₅₀) values were 0.186, 0.158 and 0.123?µmol/ml at 24, 48 and 72?h, respectively. Cells treated with osthole at concentrations of 0, 0.004, 0.02, 0.1 and 0.5?μmol/ml showed a statistically significant increase in the G2/M fraction accompanied by a decrease in the G0/G1 fraction. The increase of apoptosis induced by osthole was correlated with down-regulation expression of anti-apoptotic Bcl-2 protein and up-regulation expression of pro-apoptotic Bax and p53 proteins.

Conclusion: Osthole had significant growth inhibitory activity and the pro-apoptotic effect of osthole is mediated through the activation of caspases and mitochondria in HepG2 cells. Results suggest that osthole has promising therapeutic potential against hepatocellular carcinoma.     

Luteolin induced G2 phase cell cycle arrest and apoptosis on non-small cell lung cancer cells

In this study, we investigated the underlying molecular mechanism for the potent cell cycle inhibition and pro-apoptotic effect of luteolin (2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-4-chromenone) on human non-small-cell lung carcinoma cell line A549. MTT assay showed that luteolin had obvious cytotoxicity on A549 with IC₅₀ of 40.2 μM at 48 h. Pro-apoptotic effect of luteolin on A549 cells was demonstrated by Hoechst 33258 staining assay and annexin V-FITC/PI double staining analysis. A great quantity of apoptotic cells and increasing G2 phase cells were observed by flow cytometry. Western blotting assay revealed that luteolin activated JNK, increased Bax, promoted procaspase-9 cleavage and activated caspase-3 at last. Assay using TNFα, an active agent of NF-κB, showed that pretreatment of A549 cells with luteolin could inhibit TNFα induced trans-nuclear of NF-κB. In summary, luteolin displayed a significant cytotoxic effect through cell cycle arrest and apoptosis induction in A549 cells. Pro-apoptotic effect was implemented via activating JNK and inhibiting translocation of NF-κB (p65). These results suggested that luteolin might have therapeutic potential against NSCLC.     

Diallyl trisulfide-induced apoptosis of bladder cancer cells is caspase-dependent and regulated by PI3K/Akt and JNK pathways

Diallyl trisulfide (DATS) is one of the major organosulfur components of garlic (Allium sativum L.), which inhibits the proliferation of various cancer cells, but the exact mechanisms of this action in human bladder cancer cells still remain largely unresolved. In this study, we investigated how DATS induces apoptosis in T24 human bladder cancer cells in vitro. Treatment of T24 cells with DATS resulted in potent anti-proliferative activity. Additionally, some typical apoptotic characteristics, such as chromatin condensation and an increase in the population of sub-G1 hypodiploid cells, were observed. With respect to the mechanism underlying the induction of apoptosis, DATS reduced the expression of anti-apoptotic Bcl-2 and Bcl-xL, and inhibitor of apoptosis protein family proteins, but the expression of pro-apoptotic Bax and death receptor-related proteins was increased compared with the controls. DATS also activated caspase-8 and -9, the respective initiator caspases of the extrinsic and the intrinsic apoptotic pathways. The increase in mitochondrial membrane depolarization was correlated with activation of effector caspase-3 and cleavage of poly-ADP-ribose polymerase, a vital substrate of activated caspase-3. Blockage of caspase activation through treatment with a pan-caspase inhibitor consistently inhibited apoptosis and abrogated growth inhibition in DATS-treated T24 cells. The study further investigated the roles of the phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinases (MAPKs) pathways with respect to the apoptotic effect of DATS, and showed that DATS deactivates Akt. Additionally, DATS activates extracellular signal-regulated kinase (ERK) and c-Jun N-terminal protein kinase (JNK), but not p38 MAPK, in T24 cells. Unlike ERK, JNK inhibitors reversed DATS-induced apoptosis and growth inhibition; however, inhibition of PI3K/Akt notably enhanced the apoptotic action of DATS. The results suggest that the pro-apoptotic activity of DATS is probably regulated by a caspase-dependent cascade through the activation of both intrinsic and extrinsic signaling pathways, which is mediated through the blocking of PI3K/Akt and the activation of the JNK pathway.     

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.     

Antiproliferative effects of quercetin through cell cycle arrest and apoptosis in human breast cancer MDA-MB-453 cells

To explore the anticancer effects of the flavonoid quercetin on human breast cancer MDA-MB-453 cells via cell cycle regulation and the induction of apoptosis, the antiproliferative effect of quercetin was first examined by MTT assay. When MDA-MB-453 cells were treated with quercetin for various periods of time (3–24 hrs) and at various doses (1–100 μM), cell growth decreased significantly in a time-and dose-dependent manner. To elucidate the mechanism underlying the antiproliferative effect of quercetin, cell cycle progression and the induction of apoptosis in MDA-MB-453 cells exposed to 100 μM quercetin for 24 hrs were investigated. Quercetin caused a remarkable increase in the number of sub-G1 phase cells, and an Annexin-V assay revealed that exposure to quercetin affected apoptosis. Moreover, treatment with quercetin increased Bax expression but decreased Bcl-2 expression. Cleaved caspase-3 and PARP expression was also increased by quercetin. Thus, quercetin has probable anticancer activity. Our results suggest the existence of multiple pathways for the induction of cell cycle arrest and apoptosis by quercetin.     

Effects of ginsenoside compound K combined with cisplatin on the proliferation,apoptosis and epithelial mesenchymal transition in MCF-7 cells of human breast cancer

Context: Breast cancer seriously harms the health of women and there are currently few therapeutic options for patients with breast cancer.

Objective: Effects of ginsenoside compound K (CK) in combination with cisplatin (DDP) on the proliferation, apoptosis, and epithelial mesenchymal transition (EMT) of MCF-7 cells were studied.

Materials and methods: MCF-7 cells were divided into CK (50?μmol/L) group, DDP (10?mg/L) group, CK (50?μmol/L)?+DDP (10?mg/L) group, and control (CON) group. The cells in the CON group were not treated with any drugs. Proliferation, apoptosis, expression of E-cadherin, N-cadherin, vimentin, protein kinase B (Akt), phosphorylated Akt (p-Akt), and level of fibronectin (FN) in MCF-7 cells were detected by methyl thiazolyl tetrazolium (MTT), flow cytometry, western blotting, and enzyme-linked immuno sorbent assay (ELISA), respectively.

Results: The proliferation inhibition rates in CK, DDP, and CK?+?DDP groups at 48?h were 19.18?±?2.25, 21.34?±?2.84, and 43.37?±?5.62, respectively. The apoptosis rates were 2.85?±?0.56, 13.37?±?2.28, 20.04?±?2.92, and 30.78?±?4.64 at 24?h and 3.14?±?0.72, 20.36?±?3.28, 27.58?±?4.09, and 41.62?±?5.83 at 48?h in CON, CK, DDP, and CK?+?DDP groups, respectively. CK or DDP alone and their combination all could reduce the levels of N-cadherin, vimentin, p-Akt/Akt, and FN and elevate level of E-cadherin.

Discussion and conclusion: Both CK and DDP can inhibit the proliferation, EMT, and induce the apoptosis in MCF-7 cells, which may be related to the PI3K/Akt pathway. In addition, the combination of CK with DDP can produce a better effect.     

紫草素促进食管癌细胞凋亡及细胞周期阻滞的作用机制研究

目的研究紫草素促进食管癌细胞凋亡及细胞周期阻滞的作用及机制。方法 2019年 1月至 2020年 6月期间开展细胞实验,培养食管癌 Eca109细胞,分为不含药物杜氏改良 Eagle培养基( DMEM)处理的对照组,含不同剂量紫草素 DMEM处理的紫草素组,含 2.0 μmol/L紫草素和 10 μg/L胰岛素样生长因子 -1(IGF-1)DMEM处理的 2.0 μmol/L紫草素 +10μg/L IGF-1组。检测细胞凋亡率、细胞周期及凋亡基因活化的胱天蛋白酶 -3(cleaved caspase-3)、细胞周期蛋白 D1(cyclin D1)、磷酸化磷酸肌醇 3激酶( PI3K)、蛋白激酶 B(AKT)的表达量。结果 0.5 μmol/L紫草素组、 1.0 μmol/L紫草素组、 2.0 μmol/L紫草素组的细胞凋亡率、细胞周期 G1期比例、 cleaved caspase-3的表达量［ 0.5 μmol/L紫草素组( 0.64±0.14)、 1.0 μmol/L紫草素组( 0.81±0.19)、2.0 μmol/L紫草素组( 1.02±0.24)］高于对照组 0.41±0.07,细胞周期 S期、 G2期比例及 cyclin D1［0.5 μmol/L紫草素组( 0.80±0.16)、 1.0 μmol/L紫草素组( 0.68±0.13)、 2.0 μmol/L紫草素组( 0.45±0.09)］、 p-PI3K、p-AKT表达量低于对照组［ cyclin D1表达量(0.91±0.18)］(P<0.05); 2.0 μmol/L紫草素 +10 μg/L IGF-1组的细胞凋亡率、细胞周期 G1期比例、 cleaved caspase-3的表达量低于 2.0 μmol/L紫草素组,细胞周期 G2期比例及 cyclin D1、p-PI3K、p-AKT表达量高于 2.0 μmol/L紫草素组( P<0.05)。结论紫草素具有促进食管癌细胞凋亡及细胞周期阻滞的作用,该作用与抑制 PI3K/AKT通路激活有关。     

Synthetic polysulfane derivatives induce cell cycle arrest and apoptotic cell death in human hematopoietic cancer cells

Natural polysulfanes including diallyltrisulfide (DATS) and diallyltetrasulfide (DATTS) from garlic possess antimicrobial, chemopreventive and anticancer properties. However these compounds exhibit chemical instability and reduced solubility, which prevents their potential clinical applicability. We synthesized six DATS and DATTS derivatives, based on the polysulfane motif, expected to exhibit improved physical and chemical properties and verified their biological activity on human leukemia cells.We identified four novel cytotoxic compounds (IC₅₀ values: compound 1, 24.96 ± 12.37 μM; compound 2, 22.82 ± 4.20 μM; compound 3, 3.86 ± 1.64 μM and compound 5, 40.62 ± 10.07 μM, compared to DATTS: IC₅₀: 9.33 ± 3.86 μM). These polysulfanes possess excellent differential toxicity, as they did not affect proliferating mononuclear blood cells from healthy donors.We further demonstrated ability of active compounds to induce apoptosis in leukemia cells by analysis of nuclear fragmentation and of cleavage of effector and executioner caspases. Apoptosis was preceded by accumulation of cells in G2/M phase with a pro-metaphase-like nuclear pattern as well as microtubular alterations. Prolonged and persistent arrest of cancer cells in early mitosis by the benzyl derivative identifies this compound as the most stable and effective one for further mechanistic and in vivo studies.     

Effect of bisphenol-A on the expression of selected genes involved in cell cycle and apoptosis in the OVCAR-3 cell line

To support the argument that bisphenol-A (BPA) poses a risk for ovarian cancer, OVCAR-3 cell line was exposed to environmentally relevant concentration of BPA. Expression of selected genes involved in cell cycle and apoptosis were evaluated by real-time PCR. In a dose-dependent manner, BPA increased OVCAR-3 cell proliferation and decreased caspase-3 activity, but it had no effect on DNA fragmentation. We noted 1.2-1.5-fold induction of genes responsible for inducing cell proliferation and 1.2-46-fold suppression of genes responsible for inhibition of proliferation. Moreover, 1.6-8-fold suppression of genes involved in the extrinsic apoptotic pathway was observed. In parallel, 1.3-2.5-fold suppression pro-apoptotic genes and 1.6-51-fold induction of pro-survival genes involved in the intrinsic apoptotic pathway were observed. Additionally, 1.7-fold induction of p53 and 5-fold induction of endonuclease G genes involved in CAD-independent DNA fragmentation were noted under the influence of BPA.In conclusion, we hypothesize that induction of p53 and suppression of caspase-3 and 7 gene expression observed in this study activate the DNA repair process. Therefore, despite the observed induction of endo G gene expression, the action of BPA on DNA fragmentation was not observed.     

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.     

Additive effect of zinc oxide nanoparticles and isoorientin on apoptosis in human hepatoma cell line

Metal nanomaterial could effectively decrease tumour resistance to anti-cancer drugs. In this paper, we have explored the synergistic effect and mechanisms of zinc oxide nanoparticles (ZnO Nps) and isoorientin (ISO) on cytotoxicity in human hepatoma (HepG2) cells. The results showed that ZnO Nps could exert dose- and time-dependent cytotoxicity in HepG2 cells, and the combining treatment resulted in a greater cytotoxicity than single treatment. ZnO Nps could synergistically potentiate ISO to induce apoptosis through resulting in mitochondrial dysfunction, inhibiting the phosphorylation of Akt and ERK1/2, and enhancing the phosphorylation of JNK and P38. Additionally, ZnO Nps were uptaked by cells through endocytic pathway and it enhanced the cellular uptake of ISO, while no significant injury was found in normal liver cells after the combined treatment. These results suggest that the combination of metal nanoparticle with anti-cancer drugs may provide a promising alternative for novel cancer treatments.     

帕唑帕尼对甲状腺癌细胞和血管内皮细胞增殖的影响及其作用机制

目的 研究新型酪氨酸激酶抑制剂帕唑帕尼对甲状腺癌细胞株SW579和血管内皮细胞株HUVEC增殖的影响及作用机制.方法 将SW579和HUVEC暴露于不同浓度（1、2、4、8和16 μmoL/L）的帕唑帕尼至72 h,无药物处理的细胞作为对照.采用细胞活度测定、图像分析技术及分裂细胞荧光免疫染色观察评价帕唑帕尼对细胞增殖的影响,应用流式细胞仪进行细胞周期时相分析.结果 细胞活度测定显示,帕唑帕尼对SW579和HUVEC细胞的生长增殖均有明显的抑制作用,并呈浓度依赖性及时间依赖性,其半数抑制浓度（IC50）分别约为2和4μmol/L.图像分析显示,在IC50作用下,帕唑帕尼使两种细胞的细胞密度降低,分裂指数下降.帕唑帕尼作用48 h时,SW579细胞分裂指数（0.9％）明显低于其对照细胞（2.2％）,差异有统计学意义（P＜0.01）;HUVEC细胞分裂指数（1.9％）亦明显低于其对照细胞（4.0％）,差异有统计学意义（P＜0.01）.细胞周期时相分析表明,帕唑帕尼可使SW579和HUVEC发生细胞周期休止,分别休止于G1期和S期.帕唑帕尼作用24、48 h时,SW579在G1期的比例均明显高于其对照组细胞[（60.4±2.2）％比（49.2±1.6）％,（70.4±1.6）％比（58.6±3.3）％],差异有统计学意义（P＜0.01）;HUVEC细胞在S期的比例均明显高于其对照组细胞[（47.3±2.7）％比（39.5±0.6）％,（43.5±1.6）％比（28.8±4.2）％],差异有统计学意义（P＜0.01）.结论 帕唑帕尼对甲状腺癌细胞和血管内皮细胞的增殖均有明显的抑制效应,其作用是藉细胞周期休止作用而实现,但在两种细胞细胞周期休止时相不同.