IMP-1 inhibits renal cell carcinoma 786-O cell growth by targeting EphrinB2 signaling pathway

Abstract EphrinB2 plays a critical role in tumor growth. In this study, we studied the antitumor activity of imperatorin derivative IMP-1 in renal cell carcinoma (RCC) by regulating EphrinB2 pathway.. Results showed that IMP-1 inhibited the proliferation of 786-O cells in a dose- and time-dependent manner. More importantly, knockdown and transfection of EphrinB2 altered the inhibitory effect of IMP-1 on the activity of 786-O cells. IMP-1 arrested 786-O cell cycle at G0/G1 phase by decreasing the expression of cyclin D1 and cyclin E. Moreover, IMP-1 regulated Bcl-2 family proteins' expression, thus inducing apoptosis of 786-O cells. IMP-1 down-regulated the expression of EphrinB2, Syntenin1 and PICK1. Then, IMP-1 decreased the phosphorylation of Erk1/2 and AKT. In all, IMP-1 could regulate the EphrinB2 pathway in order to inhibit 786-O cell growth by arresting the cell cycle at G0/G1 phase and inducing cell apoptosis. Thus, IMP-1 may present as a potential strategy for RCC treatment.

Expression of autophagy related gene 5 and cyclin E in coronary heart disease and its clinical significance / 中南大学学报(医学版)

OBJECTIVES@#To explore the expression of autophagy related genes 5 (ATG5) and cyclin E in coronary heart disease (CHD) and its clinical significance.@*METHODS@#From April 2018 to August 2018, 80 patients diagnosed with CHD in the Second Xiangya Hospital, Central South University were selected as an observation group, and another 80 healthy subjects were selected as a control group. The expression of ATG5 and cyclin E mRNA in nucleate cells and the plasma protein in the 2 groups were detected and analyzed. The model of macrophage-derived foam cells induced by oxidized low density lipoprotein (ox-LDL) was used to simulate atherosclerosis. The proliferation of macrophage- derived foam cells and the protein levels of ATG5 and cyclin E induced by ox-LDL at different concentrations were examined.@*RESULTS@#Compared with the control group, the levels of ATG5 mRNA and protein in the blood in the observation group were decreased, and the cyclin E mRNA and protein levels were increased, there were statistically difference (both <0.05). Receiver operating characteristic (ROC) curve showed that the area under curve (AUC) of ATG5 mRNA, cyclin E mRNA, ATG5 protein and cyclin E protein were 0.739, 0.780, 0.671 and 0.807, respectively. Pearson analysis showed that the ATG5 mRNA was negatively correlated with the cyclin E mRNA (=-0.734, <0.05),while the plasma ATG5 protein was negatively correlated with the plasma cyclin E protein (=-0.746, <0.05). Macrophage-derived foam cell model induced by ox-LDL showed that the proliferation of foam cells and the expression levels of cyclin E protein were increased in a concentration and time-dependent manner, and the expression levels of ATG5 protein were decreased in a concentration-dependent manner.@*CONCLUSIONS@#The levels of ATG5 mRNA and protein are lowly expressed while the levels of cyclin E mRNA and protein are highly expressed in the patients with CHD.The ATG5 protein levels are lowly expressed in ox-LDL-treated macrophage-derived foam cells while the cyclin E protein levels are highly expressed in ox-LDL-treated macrophage-derived foam cells. Based on these observations, we conclude that ATG5 inhibits the degradation of the cyclin E and promotes the proliferation of macrophages, involving in the occurrence and development of CHD.

Cyclic RNA Molecule circ_0007766 Promotes the Proliferation of Lung Adenocarcinoma Cells by Up-regulating the Expression of Cyclin D1/CyclinE1/CDK4 / 中国肺癌杂志

BACKGROUND@#Cyclic RNA (circRNA) is a new type of non-coding RNA (ncRNA) which is different from traditional linear RNA. More and more studies suggest that circRNA can be used as a biological marker of many malignant tumors and becomes a potential target for treatment. Therefore, searching for new molecular targets of lung adenocarcinoma from the circRNA will help to reveal the new mechanism of the occurrence and development of lung adenocarcinoma, and provide new ideas for clinical diagnosis and treatment. In this study, the biological function of circ_0007766, a highly expressed circRNA found in a screen of lung adenocarcinoma tissue, was verified and analyzed in vitro, so as to preliminarily explore the mechanism of circ_0007766 in promoting the proliferation of lung adenocarcinoma.@*METHODS@#The expression level of circ_0007766 in lung adenocarcinoma cells was detected by qPCR. Then siRNA was used to knock down the expression of circ_0007766. The effects of knockdown of circ_0007766 on proliferation, cell cycle and apoptosis of lung adenocarcinoma cells were detected by CCK8, scratch test, PI staining and Annexin V/PI double staining. In addition, the biological mechanism of circ_0007766 in lung adenocarcinoma was preliminarily studied by qPCR and Western blots.@*RESULTS@#The expression of circ_0007766 in lung adenocarcinoma cell lines was detected by qPCR. The expression of circ_0007766 was interfered in SPCA-1 cells. The proliferation and migration abilities of cells were inhibited. The cell cycle was arrested in G0/G1 phase, but the apoptosis was not affected. The deletion of circ_0007766 did not affect the expression of ERBB2, but influenced the mRNA and protein expression of Cyclin D1/Cyclin E1/CDK4.@*CONCLUSIONS@#In vitro functional studies have shown that circ_0007766 may promote the proliferation and migration of lung adenocarcinoma cells. Further molecular mechanism studies have found that circ_0007766 can up-regulate the expression of Cyclin D1/Cyclin E1/CDK4, which are the key proteins of cell cycle, and thus promote the malignant proliferation of lung adenocarcinoma. From the perspective of circRNA, this study will provide new clues for the pathogenesis, development and prognosis of lung adenocarcinoma, and provide new target for clinical treatment.

β-carotene Inhibits Expression of c-Myc and Cyclin E in Helicobacter pylori-infected Gastric Epithelial Cells

BACKGROUND: Helicobacter pylori infection is a major risk factor in the development of gastric cancer. H. pylori infection of gastric epithelial cells increases the levels of reactive oxygen species (ROS), activates oncogenes, and leads to β-catenin-mediated hyper-proliferation. β-Carotene reduces ROS levels, inhibits oxidant-mediated activation of inflammatory signaling and exhibits anticancer properties. The present study was carried out to determine if β-carotene inhibits H. pylori-induced cell proliferation and the expression of oncogenes c-myc and cyclin E by reducing the levels of β-catenin and phosphorylated glycogen synthase kinase 3β (p-GSK3β). METHODS: Gastric epithelial AGS cells were pre-treated with β-carotene (5 and 10 μM) for 2 hours prior to H. pylori infection and cultured for 6 hours (for determination of the levels of p-GSK3β, GSK3β, and β-catenin) and 24 hours (for determination of cell viability and protein levels of c-myc and cyclin E). Cell viability was determined by the MTT assay and protein levels were determined via western blot-based analysis. RESULTS: β-Carotene inhibited H. pylori-induced increases in the percentage of viable cells, phosphorylated GSK3β (p-GSK3β), and the levels of β-catenin, c-myc and cyclin E. CONCLUSIONS: β-Carotene inhibits H. pylori-induced hyper-proliferation of gastric epithelial cells by suppressing β-catenin signaling and oncogene expression.

Induction of Melanoma Cell-Selective Apoptosis Using Anti-HER2 Antibody-Conjugated Gold Nanoparticles

PURPOSE: This study was conducted to verify the induction and mechanism of selective apoptosis in G361 melanoma cells using anti-HER2 antibody-conjugated gold nanoparticles (GNP-HER2). MATERIALS AND METHODS: Following GNP-HER2 treatment of G361 cells, cell cycle arrest and apoptosis were measured by WST-1 assay, Hemacolor staining, Hoechst staining, immunofluorescence staining, fluorescence-activated cell sorting analysis, and Western blotting.

Knockdown of Chloride Channel-3 Inhibits Breast Cancer Growth In Vitro and In Vivo / 한국유방암학회지

PURPOSE: Chloride channel-3 (ClC-3) is a member of the chloride channel family and plays a critical role in a variety of cellular activities. The aim of the present study is to explore the molecular mechanisms underlying the antitumor effect of silencing ClC-3 in breast cancer. METHODS: Human breast cancer cell lines MDA-MB-231 and MCF-7 were used in the experiments. Messenger RNA and protein expression were examined by quantitative real-time polymerase chain reaction and western blot analysis. Cell proliferation was measured by the bromodeoxyuridine method, and the cell cycle was evaluated using fluorescence-activated cell sorting. Protein interaction in cells was analyzed by co-immunoprecipitation. Tumor tissues were stained with hematoxylin-eosin and tumor burden was measured using the Metamorph software. RESULTS: Breast cancer tissues collected from patients showed an increase in ClC-3 expression. Knockdown of ClC-3 inhibited the secretion of insulin-like growth factor (IGF)-1, cell proliferation, and G1/S transition in breast cancer cells. In the mouse xenograft model of human breast carcinoma, tumor growth was significantly slower in animals injected with ClC-3-deficient cells compared with the growth of normal human breast cancer cells. In addition, silencing of ClC-3 attenuated the expression of proliferating cell nuclear antigen, Ki-67, cyclin D1, and cyclin E, as well as the activation of extracellular signal-regulated protein kinases (ERK) 1/2, both in vitro and in vivo. CONCLUSION: Together, our data suggest that upregulation of ClC-3 by IGF-1 contributes to cell proliferation and tumor growth in breast cancer, and ClC-3 deficiency suppresses cell proliferation and tumor growth via the IGF/IGF receptor/ERK pathway.

Anti-proliferative Effect of 15,16-Dihydrotanshinone I Through Cell Cycle Arrest and the Regulation of AMP-activated Protein Kinase/Akt/mTOR and Mitogen-activated Protein Kinase Signaling Pathway in Human Hepatocellular Carcinoma Cells

BACKGROUND: 15,16-dihydrotanshinone I (DHTS) is a natural abietane diterpenoid that is mainly found in the roots of Salvia miltiorrhiza Bunge (Labiatae). DHTS exhibits a potential anti-proliferative effect in various human cancer cells. However, the mechanisms of action of DHTS as an anti-cancer agent have not been fully elucidated. Therefore, the present study investigated the anti-cancer effect of DHTS in terms of cell cycle regulation and the regulation of the AMP-activated protein kinase (AMPK)/Akt/mTOR signaling pathway in SK-HEP-1 human hepatocellular carcinoma cells. METHODS: The anti-proliferative effects of DHTS were evaluated by the sulforhodamine B assay in SK-HEP-1 cells. Cell cycle distribution was analyzed by flow cytometry. The elucidation of mechanisms of action such as the AMPK/AKT/mTOR and mitogen-activated protein kinase (MAPK) pathway was assessed by Western blot analysis. RESULTS: DHTS showed a significant anti-proliferative activity against SK-HEP-1 cells. DHTS induced cell cycle arrest in the G0/G1 phase, which was mediated by downregulation of cyclin D1, cyclin A, cyclin E, CDK4, CDK2, c-Myc and p-Rb expression and with increased expression of the CDK inhibitor p21. DHTS also activated the AMPK signaling. In addition, DHTS downregulated the Akt/mTOR and MAPK signaling pathways. CONCLUSIONS: Our results suggest that the anti-proliferative activity of DHTS might be associated with the induction of G0/G1 phase cell cycle arrest and regulation of AMPK/Akt/mTOR and MAPK signaling pathways in SK-HEP-1 cells.

Cellular Prion Protein Enhances Drug Resistance of Colorectal Cancer Cells via Regulation of a Survival Signal Pathway

Anti-cancer drug resistance is a major problem in colorectal cancer (CRC) research. Although several studies have revealed the mechanism of cancer drug resistance, molecular targets for chemotherapeutic combinations remain elusive. To address this issue, we focused on the expression of cellular prion protein (PrPC) in 5-FU-resistant CRC cells. In 5-FU-resistant CRC cells, PrPC expression is significantly increased, compared with that in normal CRC cells. In the presence of 5-FU, PrPC increased CRC cell survival and proliferation by maintaining the activation of the PI3K-Akt signaling pathway and the expression of cell cycle-associated proteins, including cyclin E, CDK2, cyclin D1, and CDK4. In addition, PrPC inhibited the activation of the stress-associated proteins p38, JNK, and p53. Moreover, after treatment of 5-FU-resistant CRC cells with 5-FU, silencing of PrPC triggered apoptosis via the activation of caspase-3. These results indicate that PrPC plays a key role in CRC drug resistance. The novel strategy of combining chemotherapy with PrPC targeting may yield efficacious treatments of colorectal cancer.

O papel da ciclina E1 no estresse replicativo e na instabilidade genômica em células epiteliais da mama / [The role of cyclin E1 in replicative stress and genomic instability in breast epithelial cells]

A ciclina E, juntamente com Cdk2, é um regulador importante da transição das fases G1/S do ciclo celular, promovendo o início e a progressão da síntese de DNA. Em alguns tipos de câncer, como o câncer de mama, os níveis de ciclina E se encontram desregulados, correlacionando com um estágio avançado do tumor e mau prognóstico. Níveis elevados de ciclina E interferem com a montagem de complexos pré-replicativos e retardam a progressão das forquilhas de replicação, levando ao fenômeno de estresse replicativo e eventualmente a instabilidade genômica. No entanto, as alterações genômicas causadas pela desregulação da ciclina E ainda não foram totalmente investigadas. Dados anteriores do nosso grupo demonstraram que altos níveis de ciclina E1 retardam a progressão pela fase S, permitindo que células entrem em mitose antes do término da replicação do DNA. A replicação incompleta do DNA induz aberrações cromossômicas em regiões genômicas específicas, como sítios frágeis. O objetivo deste projeto é avaliar o efeito da desregulação de ciclina E1 na instabilidade genômica de células epiteliais da mama ao longo da proliferação celular. Para estabelecer o modelo de estresse replicativo, células do epitélio da mama humana imortalizadas (HME1) foram transduzidas com adenovírus controle (Adv-Controle) ou com adenovírus que codifica o cDNA de ciclina E1 humana (Adv-Ciclina E1). Como controle positivo, foram utilizadas as linhagens celulares de câncer da mama SUM149PT e MDA-MB-157, que têm níveis aumentados de ciclina E1. Nossos resultados indicam que altos níveis de ciclina E1 não interferem com a proliferação de células HME1. Contudo, análises de citometria de fluxo indicam que altos níveis de ciclina E1 reduzem o número de células na fase G1, reduzem a progressão pela fase S e atrasam a entrada nas fases G2/M ao longo de 7 dias. A desregulação de ciclina E1 não induz a morte celular, mas induz eventos de poliploidia. Células HME1 tratadas com a afidicolina, um inibidor de DNA polimerase, progridem mais lentamente pela fase S, mas não apresentam alterações na morte celular ou poliploidia. Além disso, células HME1 com desregulação de ciclina E1 apresentam aberrações cromossômicas, como endorreduplicação, hiperfragmentação cromossômica e separação prematura de cromátides irmãs quando comparadas com células controle. No momento, estamos avaliando a instabilidade de sítios frágeis específicos em células HME1 com altos níveis de ciclina E1 usando Hibridização Fluorescente In Situ (FISH). Além disso, células HME1 com níveis elevados de ciclina E1 serão analisadas através de cariótipo por bandeamento G. O objetivo deste projeto é contribuir para a caracterização das alterações genéticas mediadas por ciclina E1 durante a carcinogênese da mama.

TRIM29 Overexpression Promotes Proliferation and Survival of Bladder Cancer Cells through NF-κB Signaling / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: TRIM29 overexpression has been reported in several human malignancies and showed correlation with cancer cell malignancy. The aim of the current study is to examine its clinical significance and biological roles in human bladder cancer tissues and cell lines. MATERIALS AND METHODS: A total of 102 cases of bladder cancer tissues were examined for TRIM29 expression by immunohistochemistry. siRNA and plasmid transfection were performed in 5637 and BIU-87 cell lines. Cell Counting Kit-8, flow cytometry, western blot, and real-time polymerase chain reaction were performed to examine its biological roles and mechanism in bladder cancer cells. RESULTS: We found that TRIM29 overexpression showed correlation with invading depth (p=0.0087). Knockdown of TRIM29 expression in bladder cancer cell line 5637 inhibited cell growth rate and cell cycle transition while its overexpression in BIU-87 cells accelerated cell proliferation and cell cycle progression. TRIM29 overexpression also inhibited cell apoptosis induced by cisplatin. In addition, we demonstrated that TRIM29 depletion decreased while its overexpression led to upregulated expression of cyclin D1, cyclin E, and Bcl-2. We also showed that TRIM29 knockdown inhibited protein kinase C (PKC) and nuclear factor κB (NF-κB) signaling while its overexpression stimulated the PKC and NF-κB pathways. BAY 11-7082 (NF-κB inhibitor) partly attenuated the effect of TRIM29 on expression of cyclin and Bcl-2. Treatment with PKC inhibitor staurosporine resulted in ameliorated TRIM29 induced activation of NF-κB. CONCLUSION: The current study demonstrated that TRIM29 upregulates cyclin and Bcl family proteins level to facilitate malignant cell growth and inhibit drug-induced apoptosis in bladder cancer, possibly through PKC–NF-κB signaling pathways.

Acadesine Inhibits the Proliferation of K562 Cells and Enhances their Sensitivity to Imatinib / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of AMPK agonist Acadesine (AICAR) on growth inhibition of K562 cells and their sensitivity to imatinib (IM).</p><p><b>METHODS</b>K562 cells were cultured with different concentrations of AICAR alone or its combination with IM for 48 hours, the CCK-8 assay was used to detect cell proliferation, the cell cycle distribution and apoptosis were analyzed by flow cytometry. The expression levels of Cyclin D1, Cyclin E1 and Caspase 3 protein were determined by Western blot.</p><p><b>RESULTS</b>AICAR inhibited the proliferation of K562 cells in dose-dependent manner, and their IC50 value was 0.45 mmol/L at 48 hours. AICAR could induce arrest of K562 cells in G1 phase and down-regulated the protein expression levels of Cyclin D1 and Cyclin E1; whereas it didn't influence the cell apoptosis. Additionally, the growth inhibition of cells induced by IM was enhanced by AICAR.</p><p><b>CONCLUSION</b>AICAR can inhibit the proliferation of K562 cells by arresting the cell cycle and enhancing the sensitivity of K562 cells to IM.</p>

High Glucose Causes Human Cardiac Progenitor Cell Dysfunction by Promoting Mitochondrial Fission: Role of a GLUT1 Blocker

Cardiovascular disease is the most common cause of death in diabetic patients. Hyperglycemia is the primary characteristic of diabetes and is associated with many complications. The role of hyperglycemia in the dysfunction of human cardiac progenitor cells that can regenerate damaged cardiac tissue has been investigated, but the exact mechanism underlying this association is not clear. Thus, we examined whether hyperglycemia could regulate mitochondrial dynamics and lead to cardiac progenitor cell dysfunction, and whether blocking glucose uptake could rescue this dysfunction. High glucose in cardiac progenitor cells results in reduced cell viability and decreased expression of cell cycle-related molecules, including CDK2 and cyclin E. A tube formation assay revealed that hyperglycemia led to a significant decrease in the tube-forming ability of cardiac progenitor cells. Fluorescent labeling of cardiac progenitor cell mitochondria revealed that hyperglycemia alters mitochondrial dynamics and increases expression of fission-related proteins, including Fis1 and Drp1. Moreover, we showed that specific blockage of GLUT1 improved cell viability, tube formation, and regulation of mitochondrial dynamics in cardiac progenitor cells. To our knowledge, this study is the first to demonstrate that high glucose leads to cardiac progenitor cell dysfunction through an increase in mitochondrial fission, and that a GLUT1 blocker can rescue cardiac progenitor cell dysfunction and downregulation of mitochondrial fission. Combined therapy with cardiac progenitor cells and a GLUT1 blocker may provide a novel strategy for cardiac progenitor cell therapy in cardiovascular disease patients with diabetes.

beta-TrCP1 degradation is a novel action mechanism of PI3K/mTOR inhibitors in triple-negative breast cancer cells

An F-box protein, beta-TrCP recognizes substrate proteins and destabilizes them through ubiquitin-dependent proteolysis. It regulates the stability of diverse proteins and functions as either a tumor suppressor or an oncogene. Although the regulation by beta-TrCP has been widely studied, the regulation of beta-TrCP itself is not well understood yet. In this study, we found that the level of beta-TrCP1 is downregulated by various protein kinase inhibitors in triple-negative breast cancer (TNBC) cells. A PI3K/mTOR inhibitor PI-103 reduced the level of beta-TrCP1 in a wide range of TNBC cells in a proteasome-dependent manner. Concomitantly, the levels of c-Myc and cyclin E were also downregulated by PI-103. PI-103 reduced the phosphorylation of beta-TrCP1 prior to its degradation. In addition, knockdown of beta-TrCP1 inhibited the proliferation of TNBC cells. We further identified that pharmacological inhibition of mTORC2 was sufficient to reduce the beta-TrCP1 and c-Myc levels. These results suggest that mTORC2 regulates the stability of beta-TrCP1 in TNBC cells and targeting beta-TrCP1 is a potential approach to treat human TNBC.

Effect of Pin1 inhibitor juglone on proliferation, migration and angiogenic ability of breast cancer cell line MCF7Adr / 华中科技大学学报（医学）（英德文版）

This study aimed to evaluate the effects of Pin1 inhibitor Juglone on proliferation, migration and the angiogenic ability of breast cancer cell line MCF7Adr. MCF7Adr cells were cultured and separately treated with Pin1 inhibitor Juglone (treatment group) and DMEM without drug (control group). The cell cycle was examined by flow cytometry. Cell migration was measured by wound-healing assay. Cyclin E protein content was detected by Western blotting. The angiogenesis factor vascular endothelial growth factor (VEGF) in cell media was determined by enzyme linked immunosorbent assay. The results showed that the percentage of cells in G2/M phase in treatment group was significantly higher than that in control group (25.5% vs. 10.1%, P<0.05), and that in G0/G1 phase and S stage in treatment group was significantly lower than that in control group (40.5% vs. 48.2%, and 33.7% vs. 41.7%, P<0.05). Cyclin E protein content in treatment group was significantly lower than that in control group (39.2 ± 7.4 vs. 100 ± 23.1, P<0.05). (A0-A24)/A0 value in treatment group was significantly lower than that in control group (23.9 ± 3.8 vs. 100 ± 14.4, P<0.05). VEGF-A, -B, and -C contents in cell media of treatment group were significantly lower than those in control group (P<0.05). It was suggested that Pin1 inhibitor Juglone can effectively inhibit the proliferation, migration and the angiogenic ability of MCF7Adr cells, and can be used as an alternative drug therapy for breast cancer.

Knockdown of Bmi1 inhibits bladder cancer cell growth both in vitro and in vivo by blocking cell cycle at G1 phase and inducing apoptosis / 华中科技大学学报（医学）（英德文版）

Bmi1 is a member of the polycomb group family of proteins, and it drives the carcinogenesis of various cancers and governs the self-renewal of multiple types of stem cells. However, its role in the initiation and progression of bladder cancer is not clearly known. The present study aimed to investigate the function of Bmi1 in the development of bladder cancer. Bmi1 expression was detected in human bladder cancer tissues and their adjacent normal tissues (n=10) by immunohistochemistry, qRT-PCR and Western blotting, respectively. Bmi1 small interference RNA (siRNA) was synthesized and transfected into human bladder carcinoma cells (EJ) by lipofectamine 2000. The Bmil expression at mRNA and protein levels was measured in EJ cells transfected with Bmil siRNA (0, 80, 160 nmol/L) by qRT-PCR and Western blotting, respectively. Cell viability and Ki67 expression (a marker of cell proliferation) were determined in Bmi1 siRNA-transfected cells by CCK-8 assay and qRT-PCR, respectively. Cell cycle of transfected cells was flow-cytometrically determined. Immunofluorescence and Western blotting were used to detect the expression levels of cell cycle-associated proteins cyclin D1 and cyclin E in the cells. Pro-apoptotic proteins Bax and caspase 3 and anti-apoptotic protein Bcl-2 were detected by Western blotting as well. Additionally, xenograft tumor models were established by inoculation of EJ cells (infected with Bmil shRNA/pLKO.1 lentivirus or not) into nude mice. The tumor volumes were measured every other day for 14 days. The results showed that the Bmil expression was significantly increased in bladder tumor tissues when compared with that in normal tissues (P<0.05). Perturbation of Bmi1 expression by using siRNA could significantly inhibit the proliferation of EJ cells (P<0.05). Bmi1 siRNA-transfected EJ cells were accumulated in G1 phase and the expression levels of cyclin D1 and cyclin E were down-regulated. Bax and caspase-3 expression levels were significantly increased and Bcl-2 levels decreased after Bmi1 knockdown. Tumor volume was conspicuously reduced in mice injected with EJ cells with Bmi1 knockdown. Our findings indicate that Bmi1 is a potential driver oncogene of bladder cancer and it may become a potential treatment target for human bladder cancer.

Murrayafoline A Induces a G0/G1-Phase Arrest in Platelet-Derived Growth Factor-Stimulated Vascular Smooth Muscle Cells

The increased potential for vascular smooth muscle cell (VSMC) growth is a key abnormality in the development of atherosclerosis and post-angioplasty restenosis. Abnormally high activity of platelet-derived growth factor (PDGF) is believed to play a central role in the etiology of these pathophysiological situations. Here, we investigated the anti-proliferative effects and possible mechanism(s) of murrayafoline A, a carbazole alkaloid isolated from Glycosmis stenocarpa Guillamin (Rutaceae), on PDGF-BB-stimulated VSMCs. Murrayafoline A inhibited the PDGF-BB-stimulated proliferation of VSMCs in a concentration-dependent manner, as measured using a non-radioactive colorimetric WST-1 assay and direct cell counting. Furthermore, murrayafoline A suppressed the PDGF-BB-stimulated progression through G0/G1 to S phase of the cell cycle, as measured by [3H]-thymidine incorporation assay and cell cycle progression analysis. This anti-proliferative action of murrayafoline A, arresting cell cycle progression at G0/G1 phase in PDGF-BB-stimulated VSMCs, was mediated via down-regulation of the expression of cyclin D1, cyclin E, cyclin-dependent kinase (CDK)2, CDK4, and proliferating cell nuclear antigen (PCNA), and the phosphorylation of retinoblastoma protein (pRb). These results indicate that murrayafoline A may be useful in preventing the progression of vascular complications such as restenosis after percutaneous transluminal coronary angioplasty and atherosclerosis.

Effect of emodin on proliferation and cell cycle of human oral squamous carcinoma Tca8113 cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of emodin on proliferation and cell cycle distribution of human oral squamous carcinoma cells in vitro.</p><p><b>METHODS</b>Cultured human oral squamous carcinoma Tca8113 cells were treated with 2.5, 5, 10, 20, 40, 60 and 80 µmol/L emodin for 24, 48 or 72 h, with the cells treated with 0.1% DMSO as control. MTT assay and flow cytometry were used to evaluate the changes in cell proliferation and cell cycle distribution, respectively. Western blotting was employed to analyze the changes in the expression levels of the cell cycle-related proteins CDK2, cyclin E and P21 after emodin treatment.</p><p><b>RESULTS</b>Emodin significantly inhibited the growth and proliferation of Tca8113 cells within 72 h in a time- and dose-dependent manner, and caused cell cycle arrest in G0-G1 phase. Western blotting revealed that emodin treatment significantly lowered the expression levels of CDK2, cyclin E and P21 proteins in Tca8113 cells (P<0.05).</p><p><b>CONCLUSION</b>Emodin can inhibit the proliferation of Tca8113 cells and affect their cell cycle distribution possibly by inhibiting the signaling pathways of cell cycle regulation.</p>

Effect of COX-2 inhibitor celecoxib on proliferation, apoptosis of HL-60 cells and its mechanism / 中国实验血液学杂志

This study was aimed to investigate the effect of COX-2 inhibitor celecoxib on proliferation, apoptosis of human acute myeloid leukemia cell line HL-60 and its mechanism. HL-60 cells were cultured with different concentrations of celecoxib for 24 h. Cell proliferation was analyzed by CCK-8 assay, cell apoptosis and cell cycle distribution were detected by flow cytometry. Cyclin D1, cyclin E1 and COX-2 mRNA expressions were determined by RT-PCR. The results showed that after the HL-60 cells were treated with different concentrations of celecoxib for 24 h, the cell growth was significantly inhibited in a dose-dependent manner(r = 0.955), IC50 was 63.037 µmol/L of celecoxib. Celecoxib could effectively induce apoptosis in HL-60 cells also in dose-dependent manner(r = 0.988), blocked the HL-60 cells in the G0/G1 phase. The expression of cyclin D1, cyclin E1 and COX-2 mRNA were downregulated. It is concluded that celecoxib can inhibit the proliferation of HL-60 cells in dose-dependent manner, celecoxib causes cell G0/G1 arrest and induces cell apoptosis possibly through down-regulation of the cyclin D1 and cyclin E1 expression, and down-regulation of COX-2 expression respectively.

Effect of AZD8330 on proliferation and apoptosis of multiple myeloma cells / 中国实验血液学杂志

This study was aimed to investigate the effect of MEK inhibitor AZD8330 on proliferation and apoptosis of multiple myeloma IM9 and NCI-H929 cell lines and its possible mechanism. These two cell line cells were exposed to different concentrations of AZD8330 for 48 h. The CCK-8 assay was used to detect cell viability and the IC50 value at 48 h. These above-mentioned IM9 and NCI-H929 cells were treated with 5,10 and 100 nmol/L of AZD8330, then the change of cell cycle was analysed by flow cytometry with PI staining. The Wester blot was used to detect the expression levels of cyclin D and cyclin E, and multiple myeloma cells were treated with 10, 100, 1000 and 2000 nmol/L of AZD8330, the AnnexinV/7-AAD double staining was used to analyse cell apoptosis and the Western blot was used to detect the expression level of caspase-3. The results showed that AZD8330 could significantly inhibit the cell viability of IM9 and NCI-H929 cell lines in a time-and dose-dependent manner, the IC50 value (48 h) of IM9 and NCI-H929 were 19.88 ± 2.7 nmol/L and 29.3 ± 2.03 nmol/L respectively, these two cell lines were arrested on G1 phase of cell cycle, the apoptosis cells increased along with enhancement of AZD8330 concentration, and the expression level of cleaved caspase-3 protein was up-regulated. It is concluded that AZD8330 can efficiently inhibit the proliferation of NCI-H929 and IM9 cell lines, and induce apoptosis, suggesting that the AZD8330 may be a potential chemotherapeutic candidate for multiple myeloma therapy.

Effect of honokiol on proliferation and apoptosis in HL-60 cells and its potential mechanism / 中国实验血液学杂志

This study was aimed to investigate the effect of Honokiol (HNK) on proliferation and apoptosis of acute myeloid leukemia HL-60 cells and its potential mechanism. Inhibitory effect of HNK on the HL-60 cell proliferation was detected by MTT assay. Flow cytometry was used to detect the change of cell cycle and AnnexinV/PI staining was used to detect apoptosis. Western blot was applied to analyze the cell cycle protein (cyclins), cyclin-dependent kinase (CDK), P53, P21, P27, BCL-2, BCL-XL, Bax, caspase-3/9 and proteins for MAPK signal pathway. The results showed that HNK could inhibit the proliferation of HL-60 cells in time- and dose dependent ways. HNK arrested HL-60 cells in G0/G1 phase, and S phase cells decreased significantly (P < 0.05). The expression of cyclin D1, cyclin A, cyclin E and CDK2/4/6 were significantly down-regulated (P < 0.05), the expression of P53 and P21 was significantly upregulated after treating for 24 h with HNK (P < 0.05). After 24 h treatment with HNK, HL-60 cell apoptosis increased significantly with the upregulation of activated caspase-3, -9, BAX expression and the downregulation of BCL-2, BCL-XL expression. The MAPK subfamily, P38 and JNK were not significantly changed, but the expression of MEK1/2-ERK1/2 was significantly downregulated (P < 0.05). It is concluded that HNK arrestes the cells at G0/G1 phase and induces HL-60 cell apoptosis through the intervention of MEK1/2-ERK1/2 signaling pathway.