Induction of apoptosis by magnolol via the mitochondrial pathway and cell cycle arrest in renal carcinoma cells

Magnolol (Mag), an effective natural compound isolated from the stem bark of Magnolia officinalis, was found to have the potential for antitumor activity by inducing apoptosis in tumor cells. However, the effect of Mag on renal carcinoma cells and its molecular mechanism are unexplored. Our study provided evidence that Mag induced apoptosis in 786-O and OS-RC-2?cell lines via the mitochondrial pathway and cell cycle arrest. In this work, we found that Mag induced morphological changes and inhibited the proliferation of 786-O and OS-RC-2?cells in a dose- and time-dependent manner but exerted no notable inhibitory effects on normal human renal proximal tubular (HK-2) cells. Treatment with Mag suppressed the migration and invasion ability of renal carcinoma cells. Moreover, Mag caused the openness of mPTP, the accumulation of intracellular ROS and decreased △Ψm, leading to mitochondrial dysfunction. However, pretreatment with the antioxidant N-acetyl cysteine (NAC) reversed the apoptosis induced by Mag and decreased the generation of ROS. In addition, the increased proportion of the G1/G0 phase indicated that Mag caused cell cycle arrest. Further analyses suggested that magnolol-induced apoptosis was related to the abnormal expression of p53, Bax, Bcl-2, cytochrome c and caspase activation. Together, the results above revealed that Mag had antitumor effects in renal carcinoma cells via ROS production as well as cell cycle arrest and the apoptotic mitochondrial pathway was suppressed in part by NAC.     

Tetramethoxychalcone,a Chalcone Derivative,Suppresses Proliferation,Blocks Cell Cycle Progression,and Induces Apoptosis of Human Ovarian Cancer Cells

In the present study, we investigated the in vitro antitumor functions of a synthetic chalcone derivative 4,3′,4′,5′- tetramethoxychalcone (TMOC) in ovarian cancer cells. We found that TMOC inhibited the proliferation and colony formation of cisplatin sensitive cell line A2780 and resistant cell line A2780/CDDP, as well as ovarian cancer cell line SKOV3 in a time- and dose-dependent manner. Treatment of A2780 cells with TMOC resulted in G₀/G₁ cell cycle arrest through the down-regulation of cyclin D1 and CDK4, and the up-regulation of p16, p21 and p27 proteins. We demonstrated that TMOC might induce cell apoptosis through suppressing Bcl-2 and Bcl-xL, but enhancing the expression of Bax and the cleavage of PARP-1. Treatment of TMOC also reduced the invasion and migration of A2780 cells. Finally, we found that TMOC inhibited the constitutive activation of STAT3 signaling pathway and induced the expression of the tumor suppressor PTEN regardless of the p53 status in cell lines. These data suggest that TMOC may be developed as a potential chemotherapeutic agent to effectively treat certain cancers including ovarian cancer.     

Abieslactone Induces Cell Cycle Arrest and Apoptosis in Human Hepatocellular Carcinomas through the Mitochondrial Pathway and the Generation of Reactive Oxygen Species

Abieslactone is a triterpenoid lactone isolated from Abies plants. Previous studies have demonstrated that its derivative abiesenonic acid methyl ester possesses anti-tumor-promoting activity in vitro and in vivo. In the present study, cell viability assay demonstrated that abieslactone had selective cytotoxicity against human hepatoma cell lines. Immunostaining experiments revealed that abieslactone induced HepG2 and SMMC7721 cell apoptosis. Flow cytometry and western blot analysis showed that the apoptosis was associated with cell cycle arrest during the G₁ phase, up-regulation of p53 and p21, and down-regulation of CDK2 and cyclin D1. Furthermore, our results revealed that induction of apoptosis through a mitochondrial pathway led to upregulation of Bax, down-regulation of Bcl-2, mitochondrial release of cytochrome c, reduction of mitochondrial membrane potential (MMP), and activation of caspase cascades (Casp-9 and -3). Activation of caspase cascades also resulted in the cleavage of PARP fragment. Involvement of the caspase apoptosis pathway was confirmed using caspase inhibitor Z-VAD-FMK pretreatment. Recent studies have shown that ROS is upstream of Akt signal in mitochondria-mediated hepatoma cell apoptosis. Our results showed that the accumulation of ROS was detected in HepG2 cells when treated with abieslactone, and ROS scavenger partly blocked the effects of abieslactone-induced HepG2 cell death. In addition, inactivation of total and phosphorylated Akt activities was found to be involved in abieslactone-induced HepG2 cell apoptosis. Therefore, our findings suggested that abieslactone induced G₁ cell cycle arrest and caspase-dependent apoptosis via the mitochondrial pathway and the ROS/Akt pathway in HepG2 cells.     

XJW20, a novel oxoindole derivative,induces G2/M arrest and apoptosis selectively in K562 leukemia cell line

In comparison with four tumor cell lines and three non transformed cell types, chronic myeloid leukemia K562 cells were selectively sensitive to proliferation inhibition by the oxoindole derivative XJW20, as determined by the MTT assay. Further investigation revealed that XJW20 selectively induced G2/M arrest and apoptosis in K562 cells. At the molecular level, XJW20-induced G2/M arrest was accompanied by up-regulation of cyclin B1 and phospho (p)-Cdc25C (Ser216) and down-regulation of CDK1. There is no change in the expression of CDK2. The increased apoptotic activity by XJW20 was characterized by an increase in reactive oxygen species (ROS) generation, the mitochondrial transmembrane potential (ΔΨ_m) dissipation, cytochrome C releasing, apoptotic nuclei (AO/EB double staining) and nuclei condensation (DAPI-staining). The down-regulation of phosphorylated ERK was also found in XJW20-treated K562 cells. These molecular events induced by XJW20 may provide insight into the mechanism of action that led to growth arrest and apoptosis.     

Molecular mechanisms of survival and apoptosis in RAW 264.7 macrophages under oxidative stress

Organisms living in an aerobic environment are continuously exposed to reactive oxygen species (ROS). Apoptosis of cells can be induced by ROS and cells also develop negative feedback mechanisms to limit ROS induced cell death. In this study, RAW264.7 murine macrophage cells were treated with H₂O₂ and cDNA microarray technique was used to produce gene expression profiles. We found that H₂O₂ treatment caused up-regulation of stress, survival and apoptosis related genes, and down-regulation of growth and cell cycle promoting genes. Numerous genes of metabolism pathways showed special expression patterns under oxidative stress: glycolysis and lipid synthesis related genes were down-regulated whereas the genes of lipid catabolism and protein synthesis were up-regulated. We also identified several signaling molecules as ROS-responsive, including p53, Akt, NF- B, ERK, JNK, p38, PKC and INF- . They played important roles in the process of apoptosis or cell survival. Finally, an interactive pathway involved in cellular response to oxidative stress was proposed to provide some insight into the molecular events of apoptosis induced by ROS and the feedback mechanisms involved in cell survival.Y. Zhang and C.C. Fong contributed equally to this work.     

LYG-202 inhibits the proliferation of human colorectal carcinoma HCT-116 cells through induction of G1/S cell cycle arrest and apoptosis via p53 and p21(WAF1/Cip1) expression

We recently established that LYG-202, a new flavonoid with a piperazine substitution, exerts an anti-tumor effect in vivo and in vitro. In the present study, we demonstrate that LYG-202 induces G1/S phase arrest and apoptosis in human colorectal carcinoma HCT-116 cells. Data showed that the blockade of the cell cycle was associated with increased p21(WAF1/Cip1) and Rb levels and reduced expression of cyclin D1, cyclin E, and CDK4. Moreover, PARP cleavage, activation of caspase-3, caspase-8, and caspase-9, and an increased ratio of Bax/Bcl-2 were detected in LYG-202-induced apoptosis. Additionally, activation of p53 resulted in the up-regulation of its downstream targets PUMA and p21(WAF1/Cip1), as well as the down-regulation of its negative regulator MDM2, suggesting that the p53 pathway may play a crucial role in LYG-202-induced cell cycle arrest and apoptosis. Furthermore, siRNA knockdown of p53 attenuated the G1 cell cycle arrest and apoptosis induced by LYG-202, as the effects of LYG-202 on up-regulation of p21(WAF1/Cip1) and down-regulation of Bcl-2 and pro-caspase-3 were partly inhibited in p53 siRNA transfected cells compared with control siRNA transfected cells. Collectively, these data indicate that LYG-202 exerts its anti-tumor potency by activating the p53-p21 pathway for G1/S cell cycle arrest and apoptosis in colorectal cancer cells.     

Oxidative stress and NF-κB signaling are involved in LPS induced pulmonary dysplasia in chick embryos

Inflammation or dysbacteriosis-derived lipopolysaccharides (LPS) adversely influence the embryonic development of respiratory system. However, the precise pathological mechanisms still remain to be elucidated. In this study, we demonstrated that LPS exposure caused lung maldevelopment in chick embryos, including higher embryo mortality, increased thickness of alveolar gas exchange zone, and accumulation of PAS⁺ immature pulmonary cells, accompanied with reduced expression of alveolar epithelial cell markers and lamellar body count. Upon LPS exposure, pulmonary cell proliferation was significantly altered and cell apoptosis was inhibited as well, indicating a delayed progress of pulmonary development. LPS treatment also resulted in reduced CAV-1 expression and up-regulation of Collagen I, suggesting increased lung fibrosis, which was verified by Masson staining. Moreover, LPS induced enhanced Nrf2 expression in E18 lungs, and the increased reactive oxygen species (ROS) production was confirmed in MLE-12 cells in vitro. Antioxidant vitamin C restored the LPS induced down-regulation of ABCA3, SP-C and GATA-6 in MLE-12 cells. Furthermore, LPS induced activation of NF-κB signaling in MLE-12 cells, and the LPS-induced decrease in SP-C expression was partially abrogated by blocking NF-κB signaling with Bay-11–7082. Bay-11–7082 also inhibited LPS-induced increases of ROS and Nrf2 expression. Taken together, we have demonstrated that oxidative stress and NF-κB signaling are involved in LPS induced disruption of pulmonary cell development in chick embryos.     

Effects of Camphorquinone on Cytotoxicity,Cell Cycle Regulation and Prostaglandin E2 Production of Dental Pulp Cells: Role of ROS,ATM/Chk2, MEK/ERK and Hemeoxygenase-1

Camphorquinone (CQ) is a popularly-used photosensitizer in composite resin restoration. In this study, the effects of CQ on cytotoxicity and inflammation-related genes and proteins expression of pulp cells were investigated. The role of reactive oxygen species (ROS), ATM/Chk2/p53 and hemeoxygenase-1 (HO-1) and MEK/ERK signaling was also evaluated. We found that ROS and free radicals may play important role in CQ toxicity. CQ (1 and 2 mM) decreased the viability of pulp cells to about 70% and 50% of control, respectively. CQ also induced G₂/M cell cycle arrest and apoptosis of pulp cells. The expression of type I collagen, cdc2, cyclin B, and cdc25C was inhibited, while p21, HO-1 and cyclooxygenase-2 (COX-2) were stimulated by CQ. CQ also activated ATM, Chk2, and p53 phosphorylation and GADD45α expression. Besides, exposure to CQ increased cellular ROS level and 8-isoprostane production. CQ also stimulated COX-2 expression and PGE₂ production of pulp cells. The reduction of cell viability caused by CQ can be attenuated by N-acetyl-L-cysteine (NAC), catalase and superoxide dismutase (SOD), but can be promoted by Zinc protoporphyin (ZnPP). CQ stimulated ERK1/2 phosphorylation, and U0126 prevented the CQ-induced COX-2 expression and prostaglandin E₂ (PGE₂) production. These results indicate that CQ may cause cytotoxicity, cell cycle arrest, apoptosis, and PGE₂ production of pulp cells. These events could be due to stimulation of ROS and 8-isoprostane production, ATM/Chk2/p53 signaling, HO-1, COX-2 and p21 expression, as well as the inhibition of cdc2, cdc25C and cyclin B1. These results are important for understanding the role of ROS in pathogenesis of pulp necrosis and pulpal inflammation after clinical composite resin filling.     

Condurango-glycoside-A fraction of Gonolobus condurango induces DNA damage associated senescence and apoptosis via ROS-dependent p53 signalling pathway in HeLa cells

Gonolobus condurango plant extract is used as an anticancer drug in some traditional systems of medicine including homeopathy, but it apparently lacks any scientific validation. Further, no detailed study is available to suggest whether condurango-glycoside-A (CGA), a major ingredient of condurango serves as a potent anticancer compound. Therefore, we investigated apoptosis-inducing ability of CGA against cervix carcinoma cells (HeLa). β-galactosidase-activity and DNA damage were critically studied at different time points; while induced DNA-damage was observed at 9–12th hours, senescence of cells appeared at a later stage (18th hour after CGA treatment), implicating thereby a possible role of DNA damage in inducing pre-mature cell senescence. Concurrently, the number of cells undergoing apoptosis increased along with increase in reactive oxygen species (ROS) generation. Expression of p53 was also up-regulated, indicating that apoptosis could have been mediated through p53 pathway. DCHFDA (4′,6-Diamidino-2-phenylindole dihydrochloride) assay, acridine orange/ethidium bromide staining and annexin V/PI assay results collectively confirmed that apoptosis was induced by increased ROS generation. Reduction in proliferation of cells was further evidenced by the cell cycle arrest at G0/G1 stage. Expression profiles of certain relevant genes and proteins like p53, Akt, Bcl-2, Bax, cytochrome c and caspase 3 also provided evidence of ROS mediated p53 up-regulation and further boost in Bax expression and followed by cytochrome c release and activation of caspase 3. Overall results suggest that CGA initiates ROS generation, promoting up-regulation of p53 expression, thus resulting in apoptosis and pre-mature senescence associated with DNA damage.     

Triptolide Induces Growth Inhibition and Apoptosis of Human Laryngocarcinoma Cells by Enhancing p53 Activities and Suppressing E6-Mediated p53 Degradation

Triptolide, an active compound extracted from Chinese herb Leigongteng (Tripterygium wilfordii Hook F.), shows a broad-spectrum of anticancer activity through its cytotoxicity. However, the efficacy of triptolide on laryngocarcinoma rarely been evaluated, and the mechanism by which triptolide-induced cellular apoptosis is still not well understood. In this study, we found that triptolide significantly inhibited the laryngocarcinoma HEp-2 cells proliferation, migration and survivability. Triptolide induces HEp-2 cell cycle arrest at the G1 phase and apoptosis through intrinsic and extrinsic pathways since both caspase-8 and -9 are activated. Moreover, triptolide enhances p53 expression by increasing its stability via down-regulation of E6 and E6AP. Increased p53 transactivates down-stream target genes to initiate apoptosis. In addition, we found that short time treatment with triptolide induced DNA damage, which was consistent with the increase in p53. Furthermore, the cytotoxicity of triptolide is decreased by p53 knockdown or use of caspases inhibitor. In conclusion, our results demonstrated that triptolide inhibits cell proliferation and induces apoptosis in laryngocarcinoma cells by enhancing p53 expression and activating p53 functions through induction of DNA damage and suppression of E6 mediated p53 degradation. These studies indicate that triptolide is a potential anti-laryngocarcinoma drug.     

Melissa officinalis extract induces apoptosis and inhibits proliferation in colon cancer cells through formation of reactive oxygen species

PurposeEfficient strategies for the prevention of colon cancer are extensively being explored, including dietary intervention and the development of novel phytopharmaceuticals. Safe extracts of edible plants contain structurally diverse molecules that can effectively interfere with multi-factorial diseases such as colon cancer. In this study, we describe the antiproliferative and proapoptotic effects of ethanolic lemon balm (Melissa officinalis) leaves extract in human colon carcinoma cells. We further investigated the role of extra- and intracellular reactive oxygen species (ROS).MethodsAntitumor effects of lemon balm extract (LBE) were investigated in HT-29 and T84 human colon carcinoma cells. Inhibition of proliferation was analyzed by DNA quantification. The causal cell cycle arrest was determined by flow cytometry of propidium iodide-stained cells and by immunoblotting of cell cycle regulator proteins. To investigate apoptosis, cleavage of caspases 3 and 7 was detected by immunoblotting and fluorescence microscopy. Phosphatidylserine externalization was measured by Annexin V assays. Mechanistic insights were gained by measurement of ROS using the indicator dyes CM-H₂DCFDA and Cell ROX Green.ResultsAfter 3 and 4 days of treatment, LBE inhibited the proliferation of HT-29 and T84 colon carcinoma cells with an inhibitory concentration (IC₅₀) of 346 and 120 µg/ml, respectively. Antiproliferative effects were associated with a G2/M cell cycle arrest and reduced protein expression of cyclin dependent kinases (CDK) 2, 4, 6, cyclin D3, and induced expression of cyclin-dependent kinase inhibitor 2C (p18) and 1A (p21). LBE (600 µg/ml) induced cleavage of caspases 3 and 7 and phosphatidylserine externalization. LBE-induced apoptosis was further associated with formation of ROS, whereas quenching of ROS by antioxidants completely rescued the colon carcinoma cells from LBE-induced apoptosis.ConclusionsLemon balm (Melissa officinalis) extract inhibits the proliferation of colon carcinoma cells and induces apoptosis through formation of ROS. Taken together, LBE or subfractions thereof could be used for the prevention of colon cancer.     

Curcumin inhibits the growth of triple‐negative breast cancer cells by silencing EZH2 and restoring DLC1 expression

Enhancer of zeste homolog 2 (EZH2), an oncogene, is a commonly up‐regulated epigenetic factor in human cancer. Hepatocellular carcinoma deletion gene 1 (DLC1) is an antioncogene that is either expressed at low levels or not expressed in many malignant tumours. Curcumin is a promising anticancer drug that has antitumour effects in many tumours, but its mechanism of action is unclear. Our research demonstrated that EZH2 was up‐regulated in breast cancer (BC) tissues and cells, whereas DLC1 was down‐regulated, and the expression of EZH2 and DLC1 was negatively correlated in BC. By analysing the characteristics of clinical cases, we found that positive expression of EZH2 and negative expression of DLC1 may be predictors of poor prognosis in patients with triple‐negative breast cancer (TNBC). Moreover, knockdown of EZH2 expression restored the expression of DLC1 and inhibited the migration, invasion and proliferation, promoted the apoptosis, and blocked the cell cycle of MDA‐MB‐231 cells. Furthermore, we found that curcumin restored the expression of DLC1 by inhibiting EZH2; it also inhibited the migration, invasion and proliferation of MDA‐MB‐231 cells, promoted their apoptosis and blocked the cell cycle. Finally, xenograft tumour models were used to demonstrate that curcumin restored DLC1 expression by inhibiting EZH2 and also inhibited the growth and promoted the apoptosis of TNBC cells. In conclusion, our results suggest that curcumin can inhibit the migration, invasion and proliferation, promote the apoptosis, block the cycle of TNBC cells and restore the expression of DLC1 by inhibiting the expression of EZH2.     

Molecular mechanism of diallyl disulfide in cell cycle arrest and apoptosis in HCT‐116 colon cancer cells

Diallyl disulfide (DADS) is the most prevalent oil‐soluble sulfur compound in garlic and inhibits cell proliferation in many cancer cell lines. Here we examined DADS cytotoxicity in a redox‐mediated process, involving reactive oxygen species (ROS) production. In the present study, p53‐independent cell cycle arrest at G2/M phase was observed with DADS treatment, along with time‐dependent increase of cyclin B1. In addition, apoptosis was also observed upon 24‐h DADS treatment accompanied by activation of p53. In HCT‐116 cells, DADS application induced a dose‐dependent increase and time‐dependent changes in ROS production. Scavenging of DADS‐induced ROS by N‐acetyl cysteine or reduced glutathione inhibited cell cycle arrest, apoptosis and p53 activation by DADS. These results suggest that ROS trigger the DADS‐induced cell cycle arrest and apoptosis and that ROS are involved in stress‐induced signaling upstream of p53 activation. Transfection of p53 small interfering RNA prevents the accumulation of cleaved poly(ADP‐ribose) polymerase and sub‐G1 cell population by 65% and 35%, respectively. Moreover, DADS‐induced apoptosis was also prevented by treatment with oligomycin, which is known to prevent p53‐dependent apoptosis by reducing ROS levels in mitochondria. These results suggest that mitochondrial ROS may serve as second messengers in DADS‐induced apoptosis, which requires activation of p53. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:71–79, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/jbt.20266     

Surfactin Induces Apoptosis and G<Subscript>2</Subscript>/M Arrest in Human Breast Cancer MCF-7 Cells Through Cell Cycle Factor Regulation

Surfactin, purified from Bacillus subtilis natto TK-1, inhibited proliferation of human breast cancer MCF-7 cells in a dose- and time-dependent manner, with IC₅₀ at 24, 48, and 72 h of 82.6, 27.3, and 14.8 μM, respectively. Surfactin-induced cell death was considered to be apoptotic by observing the typical apoptotic morphological change by acridine orange/ethidium bromide staining and Transferase-mediated dUTP Nick End-labeling assay. [Ca²⁺]i measurement revealed that surfactin induced a sustained increase in concentration of intracellular [Ca²⁺]i. Flow cytometric analysis also demonstrated that surfactin caused time-dependent apoptosis of MCF-7 cells through cell arrest at G₂/M phase. Western blot revealed that surfactin induced accumulation of the tumor suppressor p53 and cyclin kinase inhibitor p21^waf1/cip1, and inhibited the activity of the G₂-specific kinase, cyclin B1/p34^cdc2. Based on our findings, surfactin inhibited proliferation in MCF-7 cells by inducing apoptosis and the elevation of [Ca²⁺]i may play an important role in the apoptosis. The mechanism which surfactin caused G₂/M arrest seems to be through cell cycle factor regulation.     

Astragaloside IV enhances taxol chemosensitivity of breast cancer via caveolin-1-targeting oxidant damage

Accumulating evidence suggests that caveolin-1 (CAV-1) is a stress-related oncotarget and closely correlated to chemoresistance. Targeting CAV-1 might be a promising strategy to improve chemosensitivity for breast cancer treatment. Astragaloside IV (AS-IV), a bioactive compound purified from Astragalus membranaceus, has been shown to exhibit multiple bioactivities, including anticancer. However, the involved molecular targets are still ambiguous. In this study, we investigated the critical role of CAV-1 in mediating the chemosensitizing effects of AS-IV to Taxol on breast cancer. We found that AS-IV could enhance the chemosensitivity of Taxol with minimal direct cytotoxicity on breast cancer cell lines MCF-7 and MDA-MB-231, as well as the nontumor mammary epithelial cell line MCF-10A. AS-IV was further demonstrated to aggravate Taxol-induced apoptosis and G2/M checkpoint arrest. The phosphorylation of mitogen-activated protein kinase (MAPK) signaling extracellular signal-regulated kinase (ERK) and c-Jun N-terminal Kinase (JNK), except p38, was also abrogated by a synergistic interaction between AS-IV and Taxol. Moreover, AS-IV inhibited CAV-1 expression in a dose-dependent manner and reversed CAV-1 upregulation induced by Taxol administration. Mechanism study further demonstrated that AS-IV treatment triggered the eNOS/NO/ONOO⁻ pathway via inhibiting CAV-1, which led to intense oxidant damage. CAV-1 overexpression abolished the chemosensitizing effects of AS-IV to Taxol by inhibiting oxidative stress. In vivo experiments further validated that AS-IV increased Taxol chemosensitivity on breast cancer via inhibiting CAV-1 expression, followed by activation of the eNOS/NO/ONOO⁻ pathway. Taken together, our findings not only suggested the potential of AS-IV as a promising candidate to enhance chemosensitivity, but also highlighted the significance of CAV-1 as the target to reverse cancer drug resistance.     

Anti-tumor potential of ethanol extract of Curcuma phaeocaulis Valeton against breast cancer cells

Curcuma phaeocaulis Valeton is a commonly prescribed Chinese medical herb for tumor therapy. In this study, an extract of Curcuma phaeocaulis Valeton referred as Cpv was prepared and its anti-tumor effect was evaluated with MCF-7 and MDA-MB-231 cells. Curcuma phaeocaulis Valeton power was extracted with ethanol and the main components of the extract (Cpv) were analyzed with HPLC. The effect of Cpv on MCF-7 cells proliferation, intracellular reactive oxygen species (ROS) formation, mitochondrial membrane potential (ΔΨm), apoptosis, apoptotic related proteins, MDA-MB-231 cell migration, and integrins expression were determined. Furthermore, the effect of Cpv on some key signal transduction molecules was also investigated. Furanodienone, germacrone and furanodiene were identified as the main components of Cpv. Cpv treatment significantly inhibited cell proliferation, increased LDH release, induced intracellular ROS formation, and decreased ΔΨm in a dose-dependent manner in MCF-7 cells. Cpv induced apoptosis without affecting cell migration. Cpv increased protein expression of Bax, PARP, cleaved PARP, caspase-3, 7, JNK1, p-p42/44MAPK, NF-κB, IKKα, IKKβ, decreased protein expression of Bcl-2, Bcl-xL, Bim, Bik, Bad, integrin β5, p42/44MAPK without affecting integrin α5, β1, and p38MAPK protein expression. We concluded that Cpv inhibited MCF-7 cells proliferation by inducing apoptosis mediated by increasing ROS formation, decreasing ΔΨm, regulating Bcl-2 family proteins expression, and activating caspases. Cpv treatment also modulated several signaling transduction pathways. These results might provide some molecular basis for the anti-tumor activity of Curcuma phaeocaulis Valeton.     

DNA损伤诱导的长链非编码RNA-UCA1促进HeLa细胞增殖

尿路上皮癌抗原1 (UCA1)是一种长链非编码RNA,在多种肿瘤内高表达.然而,其在宫颈癌细胞和组织中的表达报告颇不一致,且功能尚未确定.本文探索UCA1在宫颈癌HeLa细胞中的生物学功能.实时定量PCR（qRT-PCR）结果显示,UCA1、p21和p53 mRNA在阿霉素（doxorubicin,DOX）或γ射线照射的HeLa细胞中表达上调|相反,敲减p53表达则可抑制DOX诱导的UCA1上调.表明DNA损伤诱导的UCA1可能与p53有关.转染结合CCK8检测HeLa细胞增殖活力结果显示,与对照比较,过表达UCA1促进HeLa细胞增殖,干扰UCA1表达则减缓细胞增殖.此外,流式细胞术结果显示,过表达UCA1导致阿霉素诱导的凋亡率下降;siRNA抑制UCA1表达后引起细胞G2/M期比例上升,S期下降,且阿霉素诱导的细胞凋亡率上升.上述结果说明,DNA损伤诱导的UCA1可促进HeLa细胞增殖,减少细胞凋亡.然而,是否DNA损伤诱导的UCA1上调依赖p53尚需进一步实验证明.     

A novel compound derived from danshensu inhibits apoptosis via upregulation of heme oxygenase-1 expression in SH-SY5Y cells

Background

Heme oxygenase-1 (HO-1) has potential anti-apoptotic properties. A novel compound [4-(2-acetoxy-3-((R)-3-(benzylthio)-1-methoxy-1-oxopropan-2- ylamino)-3-oxopropyl)-1,2-phenylene diacetate (DSC)] was synthesized by joining danshensu and cysteine through an appropriate linker. This study investigated if the cytoprotective properties of DSC involved the induction of HO-1.

Methods

We evaluated the cytoprotective effects of DSC on H₂O₂-induced cell damage, apoptosis, intracellular and mitochondrial reactive oxygen species (ROS) production, mitochondrial membrane potential (ΔΨ_m) loss, and apoptosis-related proteins expression and its underlying mechanisms.

Results

DSC concentration-dependently attenuated cell death, lactate dehydrogenase release, intracellular and mitochondrial ROS production, and ΔΨ_m collapse, modulated apoptosis-related proteins (Bcl-2, Bax, caspase-3, p53, and cleaved PARP) expression, and inhibited phosphorylation of extracellular signal-regulated kinase 1/2 in SH-SY5Y cells induced by H₂O₂. In addition, DSC concentration-dependently induced HO-1 expression associated with nuclear translocation of nuclear factor-erythroid 2 related factor 2 (Nrf-2), while the effect of DSC was inhibited by a phosphoinositide 3-kinase (PI3K) inhibitor LY294002. Furthermore, the protective effect of DSC on H₂O₂-induced cell death was abolished by HO-1 inhibitor ZnPP, but was mimicked by carbon monoxide-releasing moiety CORM-3 or HO-1 by-product bilirubin. Finally, DSC inhibited H₂O₂-induced changes of Bcl-2, Bax, and caspase-3 expression, and all of these effects were reversed by HO-1 silencing.

Conclusions

Induction of HO-1 may be, at least in part, responsible for the anti-apoptotic property of DSC, an effect that involved the activation of PI3K/Akt/Nrf-2 axis.

General significance

DSC might have the potential for beneficial therapeutic interventions for neurodegenerative diseases.     

Sanguinarine exhibits antitumor activity via up‐regulation of Fas‐associated factor 1 in non‐small cell lung cancer

Lung cancer is the most common type of malignancy and one of the leading causes of cancer‐related deaths in the world. Non‐small cell lung carcinomas (NSCLC) account for 85% cases of lung cancer. Sanguinarine (SNG) is a benzophenanthridine alkaloid isolated from plants of the Papaveraceae family that possess diverse biological activities. SNG exhibits antitumor effects in several cancer cells. However, the effects of SAN on NSCLC proliferation, invasion, and migration and the mechanisms remain to be clarified. We showed that SNG concentration‐ and time‐dependently decreased the cell proliferation, viability, and induced a marked increase in cell death in A549 cells. SNG inhibited invasion and migration and induced S phase cell cycle arrest and apoptosis. SNG resulted in a significant increase of E‐cadherin expression and a marked decrease of the expression of N‐cadherin, Vimentin, Smad2/3, and Snail and the phosphorylation of Smad2. SNG increased Fas‐associated factor 1 (FAF1) expression and upregulation of FAF1 inhibited cell proliferation, invasion, and migration and induced cell cycle arrest and apoptosis in NSCLC cells. Knockdown of FAF1 suppressed SNG‐induced inhibition of cell proliferation, invasion, and migration and induction of cell cycle arrest and apoptosis in NSCLC cells. SNG also inhibited implanted tumor growth and increased FAF1 expression in tumors in vivo. Our findings highlight FAF1 as a novel therapeutic target and provide a new insight in the potential use of SNG for the inhibition of NSCLC.