Inhibition Of Akt Signaling Pathway Research Articles

Increased Thioredoxin-1 Expression Promotes Cancer Progression and Predicts Poor Prognosis in Patients with Gastric Cancer

Background Thioredoxin-1 (Trx-1) is a small redox protein, which plays an important role in many biological processes. Although increased expression of Trx-1 in various solid tumors has been reported, the prognostic significance and function of Trx-1 in human gastric cancer (GC) are still unclear. Here, we investigated the clinical and prognostic significance of Trx-1 expression and the function and mechanism of Trx-1 in human GC. Methods We analyzed Trx-1 mRNA expression from the GEO database and Trx-1 protein expression in 144 GC tissues using immunohistochemistry. Effects of Trx-1 on GC cell were assessed in vitro and in vivo through Trx-1 knockdown or overexpression. The antitumor effects of the Trx-1 inhibitor, PX-12, on GC cells were investigated. PTEN and p-AKT expressions were evaluated by Western blotting. Results Increased Trx-1 expression was found in GC tissues and associated with poor prognosis and aggressive clinicopathological characteristics in patients with GC. High Trx-1 expression predicted poor prognosis, and its expression was an independent prognostic factor for overall survival of GC patients. Knockdown of Trx-1 expression inhibited GC cell growth, migration, and invasion in vitro and tumor growth and lung metastasis in vivo. Conversely, overexpression of Trx-1 promoted GC cell growth, migration, and invasion. We also found that PX-12 inhibited GC cell growth, migration, and invasion. Overexpression of Trx-1 caused a decrease in PTEN and increase in p-AKT levels whereas silencing Trx-1 caused an increase in PTEN and decrease in p-AKT levels in GC cells. Inhibition of AKT signaling pathway by MK2206 also inhibited GC cell growth, migration, and invasion. Conclusion Our results indicate that Trx-1 may be a promising prognostic indicator and therapeutic target for GC patients.

Loss of cell adhesion molecule L1 like promotes tumor growth and metastasis in esophageal squamous cell carcinoma.

Esophageal squamous cells carcinoma (ESCC) is a major common thoracic tumor characterized by distinctly high incidences and mortality rates. Despite advances in multimodality therapy, the mortality rate of ESCC remains high and understanding of molecular alterations leading to the development and progression of ESCC is still very limited. In this study, a new tumor suppressor candidate, cell adhesion molecule with homology to L1CAM (CHL1), located at 3p26 which was frequently deleted in ESCC was identified. Reduced expression of CHL1 correlated with poor differentiation, increased invasion, and lymph-node metastasis, advanced tumor stage, and decreased overall survival. Methylation-specific PCR and FISH assays revealed that down-regulation of CHL1 in both ESCC cell lines and clinical samples were associated with promoter hypermethylation and loss of heterozygosity. Functional studies using lentiviral-based overexpression and knockdown systems provided direct support of CHL1 to function as an important tumor suppressor with both anti-proliferation and anti-metastasis abilities, through Merlin and SEMA3B-Np1-mediated inhibition of AKT signaling pathway. Further characterization of CHL1 may provide a novel therapeutic target in ESCC treatment.

MicroRNA-203 Acts as a Potent Suppressor in Septic Shock by Alleviating Lung Injury via Inhibition of VNN1

Background: Septic shock, the most serious complication of sepsis, is a life-threatening disease that is mainly characterized by hypoperfusion and multiple organ failure. Various aberrantly expressed microRNAs (miRNAs) have been reported to be related to septic shock. We explored the regulatory effect of microRNA-203 (miR-203) on lung injury in septic shock mice. Methods: Microarray-based gene expression profiling related to septic shock identified the differentially expressed gene vanin-1 (VNN1) and potential regulatory miR-203. miR-203 was predicted to mediate VNN1 expression, thus affecting septic shock, which was investigated by treatment with miR-203 mimic, miR-203 inhibitor, and siRNA-VNN1 in septic shock mouse models. Polymorphonuclear neutrophils (PMNs) and pulmonary alveolar macrophages in bronchoalveolar lavage fluid (BALF) as well as the wet/dry ratio of the lung were also measured to assess lung injury. Additionally, the effects of miR-203 on inflammatory cytokines, oxidative stress indexes, blood biochemical indexes, serine-threonine protein kinase (AKT) signaling pathway-related factors, and apoptosis-related factors were determined. Results: VNN1 was verified to be targeted and negatively regulated by miR-203. In mouse models of septic shock, weak expression of miR-203, high expression of VNN1, and inhibition of AKT signaling pathway were identified. In response to miR-203 mimic and VNN1 gene silencing, mouse models of septic shock displayed reduced apoptosis, MDA, ALT, and AST in lung tissues, decreased levels of TNF-α, IL-1β, IFN-γ, IL-10, and IL-6, in serum, and reduced PMN and PAM levels in BALF, in addition to elevated SOD activity. Notably, the presence of miR-203 mimic led to AKT signaling pathway activation. Conclusion:This study shows that upregulating miR-203 can alleviate lung injury through activation of the AKT signaling pathway by downregulating VNN1 in septic shock.

DUSP1 promotes senescence of retinoblastoma cell line SO-Rb5 cells by activating AKT signaling pathway.

Retinoblastoma seriously threats to human health and life. Molecular targeted therapy of retinoblastoma supplies the direction of research in the future. This study aims to investigate the impact of DUSP1 on human retinoblastoma SO-Rb5 cell senescence. Angiotensin II (AGII) was used to induce human retinoblastoma SO-Rb5 cell senescence model. DUSP1 over-expression plasmid and small interfere RNA (siRNA) were transfected into SO-Rb5 cells by Lipofectamine. Dual specificity phosphatase 1 (DUSP1), p53, p16, and protein kinase B (Akt) signaling expressions were detected with Western blot assay. SH-6 was applied to inhibit Akt signaling in SO-Rb5 cells. Cell senescence was evaluated by using β-galactosidase test. DUSP1 level increased in SO-Rb5 cells induced by AGII. Senescence protein p53 and p16 significantly upregulated in SO-Rb5 cell senescence model, together with β-galactosidase staining. DUSP1 plasmid transfection significantly enhanced DUSP expression, triggered SO-Rb5 cell senescence, and inhibited Akt signaling activation. DUSP1 siRNA exhibited the opposite effects. SH-6 significantly increased SO-Rb5 cell senescence induced by AGII through inhibiting Akt signaling. DUSP1 facilitated human retinoblastoma SO-Rb5 cell senescence induced by AGII through inhibiting Akt signaling pathway.

Gambogic acid induces cell apoptosis through endoplasmic reticulum stress triggered inhibition of Akt signaling pathways in extranodal NK/T-cell lymphoma cells

As the chemotherapeutic resistance of extranodal NK/T-cell lymphoma (ENKTL) rises year by year, searching for novel chemoprevention compounds has become imminent. Gambogic acid (GA) has recently been shown to have anti-tumor effects, but its role and underling mechanism in ENKTL are rather elusive. In the present study, we showed that GA inhibited the cell growth and potently induced the apoptosis of ENKTL cells in vitro in a time- and concentration-dependent manner. Furthermore, GA induced cell death through endoplasmic reticulum stress (ERS) mediated suppression of Akt signaling pathways and finally the release of the caspase-3 proteases. Overall, our data provided evidences supporting GA as a potential therapeutic agent for ENKTL, which may facilitate further preclinical development of anti-tumor drugs.

Propranolol increases vascular permeability through pericyte apoptosis and exacerbates oxygen-induced retinopathy

Retinopathy of prematurity (ROP) is an eye disease that causes blindness due to delayed vascular growth, retinal ischemia, and resulting abnormal angiogenesis. Nonselective β-antagonist propranolol is in clinical trials for the treatment of ROP due to its effect of reducing VEGF expression and inhibiting retinal angiogenesis in oxygen-induced ROP models (OIR), but the mechanism by which propranolol acts on ROP vessels is still unclear. In the present study, we have focused on the effect of propranolol on pericyte survival and vascular permeability. We demonstrated that propranolol increases pericyte apoptosis more sensitively than endothelial cells (ECs), thereby weakening EC tight junctions to increase endothelial permeability in co-cultures of pericytes and ECs. Mechanistically, pericyte apoptosis by propranolol was due to the inhibition of Akt signaling pathway. We also demonstrated that propranolol increases pericyte loss and vascular permeability of retinal vessels in a mouse model of OIR. These results suggest that propranolol may be negative for blood vessels in retinas of OIR, and that the efficacy of propranolol for the treatment of ROP needs to be more thoroughly verified.

Astragalus polysaccharide enhanced antitumor effects of Apatinib in gastric cancer AGS cells by inhibiting AKT signalling pathway

Apatinib has been proved effective in the treatment of advanced gastric cancer. Traditional Chinese medicine is often considered as adjuvants which could increase the effects and counteract the side effects of chemotherapy. The present study aims to explore the antitumor effects of Astragalus polysaccharide (AsPs) in combination with Apatinib in gastric cancer AGS cells. Our results demonstrated that the expression of VEGFR-2 was observed in human gastric cancer line AGS. Both Apatinib and AsPs could significantly inhibit the proliferation of AGS cells in a dose-dependent manner and Apatinib in combination with AsPs showed enhanced inhibitory effects on cell proliferation, migration and invasion compared with Apatinib monotherapy. Moreover, there was a remarkable increase in apoptosis following Apatinib treatment which could be enhanced by the addition of AsPs. Western blotting showed that the combination of Apatinib and AsPs could inhibit the expression of phosphorylated AKT (p-AKT) and MMP-9 expression. In addition, both Apatinib alone and Apatinib in combination with AsPs induced celluar autophagy which could be attenuated by the autophagy inhibitor 3-MA. The suppression of autophagy leaded to further apoptosis induction and cell proliferation suppression. In conclusion, the current study showed AsPs enhanced antitumor effects of Apatinib on AGS cells by the mechanism which includes inhibition of AKT signaling pathway. Apatinib-induced autophagy could be attenuated by 3-MA, which subsequently increased the apoptosis rate. On the basis of our study, the combination of Apatinib and AsPs could be considered as a potential candidate in the gastric cancer treatment.

Exenatide modulates metalloproteinase expression in human cardiac smooth muscle cells via the inhibition of Akt signaling pathway.

Incretin analogue drugs, a FDA-approved treatment in diabetes, has been tested for its therapeutic properties as modulators of atherosclerosis. We investigated the effects of incretin drugs on the modulation of gene expression and protein levels of matrix metalloproteinases (MMPs) as well as their inhibitors - tissue inhibitors of metalloproteinases (TIMPs) in coronary artery smooth muscle cells (hCASMC) in the context of atherosclerotic plaque formation and inflammation. TNFα-stimulated hCASMC were treated with Glucagon-like Peptide 1 (GLP-1) (10nM and 100nM) and Exendin-4 (1nM and 10nM). Messenger RNA (mRNA) levels and protein concentrations of MMP-1, MMP-2, MMP-9 and TIMP-1, TIMP-2 were measured and the effects on extracellular matrix turnover under TNFα-mediated microenvironment were evaluated. Intracellular signaling pathways were also examined. Our experiments reveal that GLP-1 receptor agonists downregulate the expression of MMP-1, MMP-2, MMP-9 in hCASMC under TNFα mediated inflammatory conditions. Signaling pathway analysis show that GLP-1 receptor agonists induced inhibition of AKT-Thr308 phosphorylation, PRAS40 and S6 proteins but not AKT-Ser473. These findings indicate that GLP-1 receptor agonists modulate the expression of MMPs through inhibition of AKT-Thr308 phosphorylation in hCASMC. These results suggest a possible role of incretin analogue drugs in therapy of coronary atherosclerosis.

Lasp1 promotes malignant phenotype of non-small-cell lung cancer via inducing phosphorylation of FAK-AKT pathway.

Lasp1 (LIM and SH3 domain protein 1) promotes tumor proliferation and invasion in multiple cancer entities including non-small cell lung cancer (NSCLC). However, the molecular mechanism is uncertain to date. In the present study, using immunohistochemistry, we found that Lasp1 expression was significantly correlated with tumor size (P=0.005), advanced TNM stage (P=0.042), positive regional lymph node metastasis (P=0.034) and poor overall survival (P<0.001). Similar results were seen in patients with squamous cell lung carcinoma (P=0.003 for larger tumor size, P=0.017 for advanced TNM stage, P=0.003 for positive lymph node metastasis and P<0.001 for poor overall survival) but not in patients with lung adenocarcinoma (P>0.05). Proliferation and invasion assay showed that Lasp1 dramatically promoted the ability of proliferation and invasion of NSCLC cells. Subsequent western blot results revealed that Lasp1 promoted the expression of Cyclin A2, CyclinB1, and Snail, and inhibited the expression of E-cadherin. Lasp1 directly interacted with FAK and facilitated the expression of phosphorylated FAK (Tyr397) and AKT (Ser473). Incorporation of both FAK inhibitor and AKT inhibitor counteracted the upregulating expression of Cyclin A2, CyclinB1, and Snail, and downregulating expression of E-cadherin expression induced by Lasp1 overexpression. Interestingly, inhibition of FAK signaling pathway attenuated the phosphorylation of AKT, but inhibition of AKT signaling pathway did not affect the phosphorylation of FAK. In conclusion, Lasp1 facilitated tumor proliferation and invasion of NSCLC through directly binding to FAK and enhancing the phosphorylation of FAK (Tyr397) and AKT (Ser473). Lasp1 may be a novel therapeutic target in the treatment of NSCLC patients.

USP39, a direct target of microRNA-133a, promotes progression of pancreatic cancer via the AKT pathway

Ubiquitin specific protease 39 (USP39) is one of the deubiquitinating enzymes without ubiquitin protease activity, which has been implicated in the progression of several cancers. However, the role of USP39 in pancreatic cancer (PC) is largely unknown. In present study, we found that USP39 expression was elevated in PC tissues than adjacent non-tumor tissues. Importantly, we demonstrated that overexpression of USP39 is closely correlated with tumor progression and poor survival in PC patients. Furthermore, high USP39 expression was observed in PC cell lines and ectopic expression of USP39 significantly enhanced in vitro cell proliferation and promoted in vivo tumor growth, whereas silencing USP39 suppressed growth of PC cells. Besides, our experimental data revealed that knockdown of USP39 induced cell apoptosis through inhibition of AKT signaling pathway in PC cells. Moreover, USP39 was a direct target of miR-133a, a microRNA that has been reported to be involved in progression of PC. Taken together, our data provide a novel PC regulatory axis that is miR-133a/USP39, the dysfunction of which drives diverse aspects of the progression of PC.

Indirubins: A Potential Therapeutic Target in Multiple Myeloma

Current drugs in the treatment of Multiple Myeloma (MM) result in cell death via a number of mechanisms including a direct effect on plasma cells as well as alteration in the BM microenvironment. Although effective to some extent, none of the drug mechanisms of action are fully targeting a biological process essential and necessary for PC survival. Among the FDA approved kinase inhibitors, few are based on natural scaffolds. 6-bromoindirubin-39-oxime (6BIO) is a potent kinase inhibitor based on the natural 6-bromoindirubin scaffold. Indirubin and 6-bromoindirubin are two natural products that have found a particular interest in dye chemistry as the main constituent of indigo and Tyrian purple dyes. Recent findings discovered that 6BIO was a promising anti-cancer agent acting on the JAK/STAT signaling pathway mediating cell proliferation. After enhancement of the chemical structure of 6BIO, further reports exposed that MLS-2438 and MLS-2384 were Akt signaling pathway inhibitor (MLS-2438) and potent c-Src kinase direct inhibitors. A library containing 2000 natural molecules was constructed using several data platforms. Each molecule was processed through different filters such as tautomeric studies, protonation and steroisomerism status in order to be used for calculations of virtual evaluation. Two approaches were followed: the structure-based virtual screening and the ligand-based virtual screening. To achieve structural based virtual screening, binding and evaluation of the chemical relation of each molecule in the crystallographic structure of the proteasome β5 subunit was performed. In the ligand-based virtual screening, calculations were made to identify the structural similarities of each molecule with the known proteasome inhibitor, bortezomib. The results of both approaches were combined, the molecules ranked, and 100 out of 2000 were identified as strong potential bioactive hits for the β5 subunit. Out of these 100 molecules, the chemical structures of high interest were the following: indole alkaloids derivatives (indirubins), flavonoids, secoiridoids, simple phenolic acids and acetophenone. A rational selection of indirubins derivatives was conducted in order to study their cytotoxic effects on MM. Fifty indirubins derivatives were selected based on different criteria: structure, known/unknown targets, chemodiversity in substitution patterns. To explore the inhibitory effects of indirubins in MM, we performed the WST1 proliferation assay in three MM cell lines (H929, JJN3, L363). Initially, all the selected indirubins (~50 indirubins) were tested at 7.5μM in L363 cell line and proliferation results from the WST1 assay extracted after 24 hours of treatment. More than half of the indirubins tested displayed more than 50% reduction of the proliferation at 7.5μM. Interestingly, 10 out of the 50 indirubins tested reduced more than 80% proliferation after 24 hours. The most active indirubins were tested in H929 and JJN3 cell lines, where similar effects were seen after 24 hours of treatment. All tested indirubins acted in a dose-dependent manner. Based on our first set of data, we suggest that indirubins have significant anti-proliferative effects on MM cell lines. Among the most active indirubins, two molecules namely 805 and 673 emerged as attractive for further development. Compound 805 is an analog of MLS-2384 while compound 673 is an analog of MLS-2438. The latter derivative represents a promising candidate displaying an IC50below the micromolar range on H929 and JJN3 cells. To determine the kind of cell death caused by one of the most active indirubins, 673, cell cycle analysis was performed before and after treatment in H929 cell line. In particular changes in RNA expression of 84 genes key to cell cycle regulation were analyzed in H929 cell line. Our results show that among other genes, the ones which have a dramatic increase in their expression (>5 fold) are mainly involved in cell cycle arrest such as GADD45A, CDC34, TP53, CHEK1 and CHEK2. A more detailed analysis of the profiler array will be presented at the meeting. In conclusion, this is the first study to show the inhibitory effects of indirubins in MM. Further investigation of these compounds may offer a therapeutic advantage that would affect MM pathogenesis and treatment. Disclosures Kastritis:Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Genesis: Consultancy, Honoraria. Terpos:Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Dimopoulos:Amgen: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees; Genesis: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees.

Augmented O-GlcNAc signaling via glucosamine attenuates oxidative stress and apoptosis following contrast-induced acute kidney injury in rats

Contrast-induced acute kidney injury (CI-AKI) is an iatrogenic renal injury and associated with substantial morbidity and mortality in susceptible individuals. Despite extensive study of a variety of agents for renal protection, limited strategies have been shown to be effective in the reduction of CI-AKI. O-linked β-N-acetylglucosamine (O-GlcNAc) is a post-translational regulatory modification of intracellular proteins and governs the function of numerous proteins, both cytosolic and nuclear. Increasing evidence suggests that O-GlcNAc levels are increased in response to stress and that acute augmentation of this reaction is cytoprotective. However, the underlying mechanisms by which augmented OGlcNAc signaling provides renoprotection against contrast media insults is still unknown. Here, we investigated the effect of augmented O-GlcNAc signaling via glucosamine on CI-AKI and explored the underlying molecular mechanisms, particularly its relationship with PI3-kinase (PI3K)/Akt signaling. We used a novel and reliable CI-AKI model consisting of 5/6 nephrectomized (NE) rats, and a low-osmolar contrast media (iohexol, 10mL/kg, 3.5gI) injected via the tail vein after dehydration for 48h. The results showed that augmented O-GlcNAc signaling by glucosamine prevented the kidneys against iohexol-induced injury characterized by the attenuation of renal dysfunction, tubular damage, apoptosis and oxidative stress. Furthermore, this renoprotection was blocked by treatment with alloxan, an O-GlcNAc transferase inhibitor. Augmented O-GlcNAc signaling also increased the protein expression levels of phospho-Akt (Ser473, but not Thr308 and Thr450), phospho-GSK-3β, Nrf2, and Bcl-2, and decreased the levels of Bax and cleaved caspase-3. Both alloxan and specific inhibitors of PI3K (Wortmannin and LY294002) blocked the protection of glucosamine via inhibiting Akt signaling pathway. We further identified O-GlcNAcylated Akt through immunoprecipitation and western blot. We confirmed that Akt was modified by O-GlcNAcylation, and glucosamine pretreatment increased the O-GlcNAcylation of Akt. Collectively, the results demonstrate that glucosamine induces renoprotection against CI-AKI through augmented O-GlcNAc and activation of PI3K/Akt signaling, making it a promising strategy for preventing CI-AKI.

Indirubins: A Potential Therapeutic Target in Multiple Myeloma

Current drugs in the treatment of Multiple Myeloma (MM) result in cell death via a number of mechanisms including a direct effect on plasma cells as well as alteration in the BM microenvironment. Although effective to some extent, none of the drug mechanisms of action are fully targeting a biological process essential and necessary for PC survival. Among the FDA approved kinase inhibitors, few are based on natural scaffolds. 6-bromoindirubin-3'-oxime (6BIO) is a potent kinase inhibitor based on the natural 6-bromoindirubin scaffold. Indirubin and 6-bromoindirubin are two natural products that have found a particular interest in dye chemistry as the main constituent of indigo and Tyrian purple dyes. Recent findings discovered that 6BIO was a promising anti-cancer agent acting on the JAK/STAT signaling pathway mediating cell proliferation. After enhancement of the chemical structure of 6BIO, further reports exposed that MLS-2438 and MLS-2384 were Akt signaling pathway inhibitor (MLS-2438) and potent c-Src kinase direct inhibitors.A library containing 2000 natural molecules was constructed using several data platforms. Each molecule was processed through different filters such as tautomeric studies, protonation and steroisomerism status in order to be used for calculations of virtual evaluation. Two approaches were followed: the structure-based virtual screening and the ligand-based virtual screening. To achieve structural based virtual screening, binding and evaluation of the chemical relation of each molecule in the crystallographic structure of the proteasome β5 subunit was performed. In the ligand-based virtual screening, calculations were made to identify the structural similarities of each molecule with the known proteasome inhibitor, bortezomib.The results of both approaches were combined, the molecules ranked, and 100 out of 2000 were identified as strong potential bioactive hits for the β5 subunit. Out of these 100 molecules, the chemical structures of high interest were the following: indole alkaloids derivatives (indirubins), flavonoids, secoiridoids, simple phenolic acids and acetophenone. A rational selection of indirubins derivatives was conducted in order to study their cytotoxic effects on MM. Fifty indirubins derivatives were selected based on different criteria: structure, known/unknown targets, chemodiversity in substitution patterns.To explore the inhibitory effects of indirubins in MM, we performed the WST1 proliferation assay in three MM cell lines (H929, JJN3, L363). Initially, all the selected indirubins (~50 indirubins) were tested at 7.5μM in L363 cell line and proliferation results from the WST1 assay extracted after 24 hours of treatment. More than half of the indirubins tested displayed more than 50% reduction of the proliferation at 7.5μM. Interestingly, 10 out of the 50 indirubins tested reduced more than 80% proliferation after 24 hours. The most active indirubins were tested in H929 and JJN3 cell lines, where similar effects were seen after 24 hours of treatment. All tested indirubins acted in a dose-dependent manner. Based on our first set of data, we suggest that indirubins have significant anti-proliferative effects on MM cell lines.Among the most active indirubins, two molecules namely 805 and 673 emerged as attractive for further development. Compound 805 is an analog of MLS-2384 while compound 673 is an analog of MLS-2438. The latter derivative represents a promising candidate displaying an IC50below the micromolar range on H929 and JJN3 cells. To determine the kind of cell death caused by one of the most active indirubins, 673, cell cycle analysis was performed before and after treatment in H929 cell line. In particular changes in RNA expression of 84 genes key to cell cycle regulation were analyzed in H929 cell line. Our results show that among other genes, the ones which have a dramatic increase in their expression (>5 fold) are mainly involved in cell cycle arrest such as GADD45A, CDC34, TP53, CHEK1 and CHEK2. A more detailed analysis of the profiler array will be presented at the meeting.In conclusion, this is the first study to show the inhibitory effects of indirubins in MM. Further investigation of these compounds may offer a therapeutic advantage that would affect MM pathogenesis and treatment. DisclosuresKastritis:Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Genesis: Consultancy, Honoraria. Terpos:Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Dimopoulos:Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genesis: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

Suppressive effect of formononetin on platelet-derived growth factor-BB-stimulated proliferation and migration of vascular smooth muscle cells.

Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) has been implicated in intimal hyperplasia, atherosclerosis and restenosis following percutaneous coronary intervention. Formononetin, a phytoestrogen extracted from the root of Astragalus membranaceus, has been widely used in Chinese tradition medicine due to its protective effects against certain symptoms of cancer, hypertension, inflammation, hypoxia-induced cytotoxicity and ovariectomy-induced bone loss. However, the effect of formononetin on platelet-derived growth factor (PDGF)-BB-induced proliferation and migration of VSMCs, as well as the underlying molecular mechanism, remains largely unclear. In the present study, treatment with formononetin significantly inhibited PDGF-BB-induced proliferation and migration of human VSMCs. Investigation into the underlying molecular mechanism revealed that the administration of formononetin suppressed PDGF-BB-stimulated switch of VSMCs to a proliferative phenotype. Furthermore, treatment with formononetin inhibited the PDGF-BB-induced upregulation of cell cycle-related proteins, matrix metalloproteinase (MMP2) and MMP9. In addition, the that administration of formononetin inhibited the phosphorylation of AKT induced by PDGF-BB in VSMCs. The present results suggest that formononetin has a suppressive effect on PDGF-BB-stimulated VSMCs proliferation and migration, which may occur partly via the inhibition of AKT signaling pathway. Therefore, formononetin may be useful for the treatment of intimal hyperplasia, atherosclerosis and restenosis.

MicroRNA-155 promotes tumor growth of human hepatocellular carcinoma by targeting ARID2.

Aberrant expression of microRNA-155 (miR-155) has been reported in several human cancers and is associated with prognosis of patients. However, the clinical significance of miR‑155 and its underlying mechanisms involved in hepatocarcinogenesis remain to be determined. In this study, we demonstrated that the expression of miR-155 was elevated in both hepatocellular carcinoma (HCC) tissues and cell lines. Clinical association analysis revealed that high expression of miR-155 was correlated with malignant clinicopathological characteristics including large tumor size, high Edmondson-Steiner grading and TNM tumor stage. Furthermore, its high expression conferred a reduced 5-year overall survival and disease-free survival of HCC patients. Gain- and loss-of function studies revealed that miR‑155 promoted cell cycle progression, cell proliferation and inhibited apoptosis. Mechanistically, we identified AT-rich interactive domain 2 (ARID2) as a direct downstream target and functional mediator of miR‑155 in HCC cells. Notably, alterations of ARID2 expression abrogated the effects of miR‑155 on HCC cell proliferation, cell cycle and apoptosis. Moreover, we demonstrated that Akt phosphorylation is essential for the functional roles of miR‑155 through altering CyclinD1 and p27, which were key components of cell cycle machinery. Finally, we disclosed that the downregulation of miR‑155 suppressed tumor growth of HCC by inhibiting Akt signaling pathway. In conclusion, our results indicate that miR‑155 promotes tumor growth of HCC by targeting ARID2-mediated Akt phosphorylation pathway, and potentially serves as a novel prognostic biomarker and therapeutic target for HCC.

The androgen receptor plays a suppressive role in epithelial- mesenchymal transition of human prostate cancer stem progenitor cells.

BackgroundTo investigate the roles of androgen receptor (AR) in epithelial- mesenchymal transition (EMT) in human prostate cancer stem progenitor (S/P) cells isolated from LNCaP cell line.MethodsThe S/P cells were obtained from LNCaP cell line through florescence-activated cell sorting (FACS). AR was overexpressed in S/P cells through lentivirus. Western blot assay was used to detect the EMT markers expression, such as E Cadherin, N Cadherin, Vimentin and Snail. MTT assay, soft agar colony formation assay, sphere formation assay and migration assay were used to investigate AR’s roles in EMT of S/P cells. Cell signaling pathways associated with proliferation and apoptosis of S/P cells were detected simultaneously. And S/P cells were treated with in vitro combinatory use of LY 294002 (inhibitor of AKT signaling molecules) with γ-TT and/or 5-AZA.ResultsOur data showed that S/P cells from LNCaP had high EMT markers expression, more tumorigenesis and strong migration ability. And in S/P cells overexpressed with AR, the expression of EMT markers decreased. In addition, these cells had less proliferation ability, tumorigenesis ability, self-renewal and migration ability. At the same time, targeting S/P cells with AKT signaling pathway inhibitor LY29004 andγ-TT and/or 5-AZA could inhibit S/P cell’s proliferation and tumorigenesis.ConclusionsOur data suggest that AR played a negative role in EMT of PCa S/P cells, by regulating AKT cell signaling pathway, which could be a new strategy to treat castration resistant prostate cancer (CRPC).

Effect of nano-structured bioceramic surface on osteogenic differentiation of adipose derived stem cells

Tissue engineering strategies to construct vascularized bone grafts potentially revolutionize the treatment of massive bone loss. The surface topography of the grafts plays critical roles on bone regeneration, while adipose derived stem cells (ASCs) are known for their capability to promote osteogenesis and angiogenesis when applied to bone defects. In the present study, the effects of hydroxyapatite (HAp) bioceramic scaffolds with nanosheet, nanorod, and micro-nano-hybrid (the hybrid of nanorod and microrod) surface topographies on attachment, proliferation and osteogenic differentiation, as well as the expression of angiogenic factors of rat ASCs were systematically investigated. The results showed that the HAp bioceramic scaffolds with the micro-/nano-topography surfaces significantly enhanced cell attachment and viability, alkaline phosphatase (ALP) activity, and mRNA expression levels of osteogenic markers and angiogenic factors of ASCs. More importantly, the biomimetic feature of the hierarchical micro-nano-hybrid surface topography showed the highest stimulatory effect. The activation in Akt signaling pathway was observed in ASCs cultured on HAp bioceramics with nanorod, and micro-nano-hybrid surface topographies. Moreover, these induction effects could be repressed by Akt signaling pathway inhibitor LY294002. Finally, the in vivo bone regeneration results of rat critical-sized calvarial defect models confirmed that the combination of the micro-nano-hybrid surface and ASCs could significantly enhance both osteogenesis and angiogenesis as compared with the control HAp bioceramic scaffold with traditional smooth surface. Our results suggest that HAp bioceramic scaffolds with micro-nano-hybrid surface can act as cell carrier for ASCs, and consequently combine with ASCs to construct vascularized tissue-engineered bone.

Methyl p-Hydroxycinnamate Suppresses Lipopolysaccharide-Induced Inflammatory Responses through Akt Phosphorylation in RAW264.7 Cells

Derivatives of caffeic acid have been reported to possess diverse pharmacological properties such as anti-inflammatory, anti-tumor, and neuroprotective effects. However, the biological activity of methyl p-hydroxycinnamate, an ester derivative of caffeic acid, has not been clearly demonstrated. This study aimed to elucidate the anti-inflammatory mechanism of methyl p-hydroxycinnamate in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. Methyl p-hydroxycinnamate significantly inhibited LPS-induced excessive production of pro-inflammatory mediators such as nitric oxide (NO) and PGE2 and the protein expression of iNOS and COX-2. Methyl p-hydroxycinnamate also suppressed LPS-induced overproduction of pro-inflammatory cytokines such as IL-1β and TNF-α. In addition, methyl p-hydroxycinnamate significantly suppressed LPS-induced degradation of IκB, which retains NF-κB in the cytoplasm, consequently inhibiting the transcription of pro-inflammatory genes by NF-κB in the nucleus. Methyl p-hydroxycinnamate exhibited significantly increased Akt phosphorylation in a concentration-dependent manner. Furthermore, inhibition of Akt signaling pathway with wortmaninn abolished methyl p-hydroxycinnamate-induced Akt phosphorylation. Taken together, the present study clearly demonstrates that methyl p-hydroxycinnamate exhibits anti-inflammatory activity through the activation of Akt signaling pathway in LPS-stimulated RAW264.7 macrophage cells.

Desmocollin 3 mediates follicle stimulating hormone-induced ovarian epithelial cancer cell proliferation by activating EGFR/Akt signaling pathway

Objective To explore whether desmocollin 3( Dsc3) mediates follicle stimulating hormone( FSH)-induced ovarian epithelial cancer cell proliferation by activating EGFR / Akt signaling pathway, thereby promoting tumor growth. Methods Immunohistochemical staining was used to detect the expression of Dsc3 in ovarian tumor tissues; Western blotting analysis was used to detect Dsc3 protein expression in 6 ovarian tumor cell lines and immortalized ovarian epithelial cells,and Dsc3,EGFR expression after FSH treatment. After knock-down Dsc3 and EGFR expression by siRNA and after treatment with PI3K / Akt signaling pathway inhibitor, Western blotting analysis was used to detect the expression of Dsc3,EGFR,Akt and pAkt; MTT assay was used to determine cellular growth. Results( 1) The positive expression rates of Dsc3 in ovarian cancer tissues and borderline ovarian tumor tissues were significantly higher than that in benign ovarian cyst tissues( P 0. 05); and the positive rates were similar between the former two tissues. The expression of Dsc3 in some ovarian cancer cells,such as Hey and HO8910 and borderline ovarian tumor cells MCV152, was higher than that in immortalized ovarian epithelial cells( Moody).( 2) FSH up-regulated expression of Dsc3 and EGFR in a doseand time-dependent manner.( 3) Inhibition of Dsc3 by RNA interference inhibited the expression of EGFR and pAkt,but not Akt. Inhibition of EGFR by RNA interference inhibited the expression of Dsc3 and pAkt,but not Akt. Inhibition of PI3K / Akt signalingpathway inhibited the expression of Dsc3 and pAkt,but not Akt. The above three methods could all reduce the regulation role of FSH for PI3K / Akt signaling pathway.( 4) Inhibition of Dsc3,EGFR and PI3K / Akt signaling pathway could significantly reduce FSHinduced cell proliferation( P 0. 05). Conclusion Dsc3 can mediate FSH-induced ovarian epithelial cancer cell proliferation by activating EGFR / Akt signaling pathway,and thereby promoting tumor growth.

The effects of urokinase-type plasminogen activator (uPA) on cell proliferation and phenotypic transformation of rat mesangial cells induced by high glucose

AimsTo investigate the effects of urokinase-type plasminogen activator (uPA) on proliferation and phenotypic transformation of rat mesangial cells (MCs) under high glucose conditions and its possible signal transduction pathway. MethodsRat MC were divided into 4 groups: the control group, the high glucose group, the high glucose and wortmannin group, and the high glucose and uPA group. MC proliferation in all groups was detected by the 3-(4,5-dimethylthiazol-)-2,5-diphenyltetrazolium bromide (MTT) method. MC cell cycle was analyzed by flow cytometry. Expression of cyclin dependent kinase 2 (CDK2), and activity of the signaling protein Akt in MC were detected by Western blot. Expression pattern and quantity of α-smooth muscle actin (α-SMA) in MC were examined using laser confocal microscopy. The expression of plasminogen activator inhibitor-1 (PAI-1), and collagen IV in renal tissues in rats was tested with immunohistochemistry and Western blotting methods. ResultsActivation of Akt induced by high glucose can be reduced significantly by wortmannin and uPA. There was no obvious change in CDK2 protein expression in different groups (P>0.05). Expression of α-SMA in MC cytoplasm increased dramatically (P<0.01). Expression of α-SMA decreased significantly in the high glucose and wortmannin group and the high glucose and uPA group compared with that of the high glucose group (P<0.01). In diabetic rats, uPA down-regulated PAI-1 and collagen IV expression in mesangial matrix (P<0.05). ConclusionuPA antagonizes cell proliferation and phenotypic transformation of MCs induced by high glucose through inhibiting Akt signaling pathway.