Triple-negative breast cancer (TNBC) is a highly aggressive tumor subtype associated with a poor prognosis. The mechanism involved in TNBC progression remains largely unknown. To date, there are no effective therapeutic targets for this tumor subtype. In this study, by performing quantitative proteomic analyses in highly metastatic and parental breast cancer cell line, we found that RAB1B, a member of the RAS oncogene family, was significantly down-regulated in highly metastatic breast cancer cells. Moreover, down-regulation of RAB1B was also found to promote the proliferation and migration of TNBC cells in vitro and in vivo. Mechanistically, loss of RAB1B resulted in elevated expression of TGF-β receptor 1 (TβR1) through decreased degradation of ubiquitin, increased levels of phosphorylated SMAD3 and TGF-β-induced epithelial-mesenchymal transition (EMT). Furthermore, low RAB1B expression correlated with poor prognosis in breast cancer patients. Taken together, our findings reveal that RAB1B acts as a metastasis suppressor in TNBC by regulating the TGF-β/SMAD signaling pathway and RAB1B may serve as a novel biomarker of prognosis and the response to anti-tumor therapeutics for patients with TNBC.

The robust and reliable detection of small microRNAs (miRNAs) is important to understand the functional significance of miRNAs. Several methods can be used to quantify miRNAs. Selectively quantifying mature miRNAs among miRNA precursors, pri-miRNAs, and other miRNA-like sequences is challenging because of the short length of miRNAs. In this study, we developed a two-step miRNA quantification system based on pincer probe capture and real-time PCR amplification. The performance of the method was tested using synthetic mature miRNAs and clinical RNA samples. Results showed that the method demonstrated dynamic range of seven orders of magnitude and sensitivity of detection of hundreds of copies of miRNA molecules. The use of pincer probes allowed excellent discrimination of mature miRNAs from their precursors with five Cq (quantification cycle) values difference. The developed method also showed good discrimination of highly homologous family members with cross reaction less than 5%. The pincer probe-based approach is a potential alternative to currently used methods for mature miRNA quantification.

Deficiency or mutation in the p53 tumor suppressor gene commonly occurs in human cancer and can contribute to disease progression and chemotherapy resistance. Currently, although the pro-survival or pro-death effect of autophagy remains a controversial issue, increasing data seem to support the idea that autophagy facilitates cancer cell resistance to chemotherapy treatment. Here we report that 5-FU treatment causes aberrant autophagosome accumulation in HCT116 p53(-/-) and HT-29 cancer cells. Specific inhibition of autophagy by 3-MA, CQ or small interfering RNA treatment targeting Atg5 or Beclin 1 can potentiate the re-sensitization of these resistant cancer cells to 5-FU. In further analysis, we show that JNK activation and phosphorylation of Bcl-2 are key determinants in 5-FU-induced autophagy. Inhibition of JNK by the compound SP600125 or JNK siRNA suppressed autophagy and phosphorylation of c-Jun and Bcl-2 but increased 5-FU-induced apoptosis in both HCT116 p53(-/-) and HT29 cells. Taken together, our results suggest that JNK activation confers 5-FU resistance in HCT116 p53(-/-) and HT29 cells by promoting autophagy as a pro-survival effect, likely via inducing Bcl-2 phosphorylation. These results provide a promising strategy to improve the efficacy of 5-FU-based chemotherapy for colorectal cancer patients harboring a p53 gene mutation.

Androgen receptor (AR) plays an important role in many kinds of cancers. However, the molecular mechanisms of AR in gastric cancer (GC) are poorly characterized. Here, we investigated the role of AR in GC cell migration, invasion and metastatic potential. Our data showed that AR expression was positively correlated with lymph node metastasis and late TNM stages. These findings were accompanied by activation of AKT and upregulation of matrix metalloproteinase 9 (MMP9). AR overexpression induced increases in GC cell migration, invasion and proliferation in vitro and in vivo. These effects were attenuated by inhibition of AKT, AR and MMP9. AR overexpression upregulated MMP9 protein levels, whereas this effect was counteracted by AR siRNA. Inhibition of AKT by siRNA or an inhibitor (MK-2206 2HC) decreased AR protein expression in both stably transfected and parental SGC-7901 cells. Luciferase reporter and chromatin immunoprecipitation assays demonstrated that AR bound to the AR-binding sites of the MMP9 promoter. In summary, AR overexpression induced by AKT phosphorylation upregulated MMP9 by binding to its promoter region to promote gastric carcinogenesis. The AKT/AR/MMP9 pathway plays an important role in GC metastasis and may be a novel therapeutic target for GC treatment.

Elevated MELK expression is featured in multiple tumors and correlated with tumorigenesis and tumor development. This study is aimed to investigate the mechanisms of MELK-mediated development of gastric cancer.

China accounts for almost half of the total number of liver cancer cases and deaths worldwide, and hepatocellular carcinoma (HCC) is the most primary liver cancer. Snail family transcriptional repressor 2 (SNAI2) is known as an epithelial to mesenchymal transition-inducing transcription factor that drives neoplastic epithelial cells into mesenchymal phenotype. However, the roles of endogenous SNAI2 remain controversial in different types of malignant tumors. Herein, we surprisingly identify that anchorage-independent growth, including the formation of tumor sphere and soft agar colony, is significantly increased when SNAI2 expression is inhibited by shRNAs in HCC cells. Suppression of SNAI2 suffices to up-regulate several cancer stem genes. Although unrelated to the metastatic ability, SNAI2 inhibition does increase the efflux of Hoechst 33342 and enhance multidrug resistance in vitro and in vivo. In agreement with this data, we demonstrate for the first time that decreasing SNAI2 level can transcriptionally upregulate several ATP binding cassette (ABC) transporter genes such as ABCB1. Moreover, ABC transporters' inhibitor verapamil can rescue the multidrug resistance induced by SNAI2 inhibition. Our results implicate that SNAI2 behaves as a tumor suppressor by inhibiting multidrug resistance via suppressing ABC transporter genes in HCC cells.

The myogenic regulatory factors (MRFs) and myocyte enhancer factor 2 (MEF2) transcription factors have been extensively studied as key transcription factors that regulate myogenic gene expression. However, few reports on the molecular mechanism that modulates chromatin remodeling during skeletal muscle differentiation are available. We reported here that the expression of the H3-K9 methyltransferase Suv39h1 was decreased during myoblast differentiation. Ectopic expression of Suv39h1 could inhibit myoblast differentiation, increasing H3-K9 methylation levels, whereas knockdown of Suv39h1 stimulated myoblast differentiation. Furthermore, Suv39h1 interacted with MEF2C directly and inhibited MEF2 transcription activity in a dose-dependent manner. Together, our studies revealed a molecular mechanism wherein Suv39h1 modulated myogenic gene expression and activation during skeletal muscle differentiation.

Several studies suggest that mesenchymal stem cells (MSCs) possess antitumor properties; however, the exact mechanisms remain unclear. Recently, microvesicles (MVs) are considered as a novel avenue intercellular communication, which may be a mediator in MSCs-related antitumor effect. In the present study, we evaluated whether MVs derived from human umbilical cord Wharton's jelly mesenchymal stem cells (hWJMSCs) may inhibit bladder tumor T24 cells growth using cell culture and the BALB/c nu/nu mice xenograft model. CCK-8 assay and Ki-67 immunostaining were performed to estimate cell proliferation in vitro and in vivo. Flow cytometry and TUNEL assay were used to assess cell cycle and apoptosis. To study the conceivable mechanism by which hWJMSC-MVs attenuate bladder tumor T24 cells, we estimated the expression of Akt/p-Akt, p-p53, p21 and cleaved Caspase 3 by Western blot technique after exposing T24 cells to hWJMSC-MVs for 24, 48 and 72h. Our data indicated that hWJMSC-MVs can inhibit T24 cells proliferative viability via cell cycle arrest and induce apoptosis in T24 cells in vitro and in vivo. This study showed that hWJMSC-MVs down-regulated phosphorylation of Akt protein kinase and up-regulated cleaved Caspase 3 during the process of anti-proliferation and pro-apoptosis in T24 cells. These results demonstrate that hWJMSC-MVs play a vital role in hWJMSC-induced antitumor effect and may be a novel tool for cancer therapy as a new mechanism of cell-to-cell communication.

Despite advances in basic and clinical research, metastasis remains the leading cause of death in breast cancer patients. Genetic abnormalities in mitochondria, including mutations affecting complex I and oxidative phosphorylation, are found in breast cancers and might facilitate metastasis. Genes encoding complex I components have significant breast cancer prognostic value. In this study, we used quantitative proteomic analyses to compare a highly metastatic cancer cell line and a parental breast cancer cell line; and observed that NDUFB9, an accessory subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (complex I), was down-regulated in highly metastatic breast cancer cells. Furthermore, we demonstrated that loss of NDUFB9 promotes MDA-MB-231 cells proliferation, migration, and invasion because of elevated levels of mtROS, disturbance of the NAD+/NADH balance, and depletion of mtDNA. We also showed that, the Akt/mTOR/p70S6K signaling pathway and EMT might be involved in this mechanism. Thus, our findings contribute novel data to support the hypothesis that misregulation of mitochondrial complex I NADH dehydrogenase activity can profoundly enhance the aggressiveness of human breast cancer cells, suggesting that complex I deficiency is a potential and important biomarker for further basic research or clinical application.

The present study was aimed at screening the key genes associated with abdominal aortic aneurysm (AAA) in the neck, and to investigate the molecular mechanism underlying the development of AAA. The gene expression profile, GSE47472, including 14 AAA neck samples and eight donor controls, was downloaded from the Gene Expression Omnibus database. The total AAA samples were grouped into two types to avoid bias. Differentially expressed genes (DEGs) were screened in patients with AAA and subsequently compared with donor controls using linear models for microarray data, or the Limma package in R, followed by gene ontology enrichment analysis. Furthermore, a protein‑protein interaction (PPI) network based on the DEGs was constructed to detect highly connected regions using a Cytoscape plugin. In total, 388 DEGs in the AAA samples were identified. These DEGs were predominantly associated with limb development, including embryonic limb development and appendage development. Nuclear receptor co‑repressor 1 (NCOR1), histone 4 (H4), E2F transcription factor 4 (E2F4) and hepatocyte nuclear factor 4α (HNF4A) were the four transcription factors associated with AAA. Furthermore, HNF4A indirectly interacted with the other three transcription factors. Additionally, six clusters were selected from the PPI network. The DEG screening process and the construction of an interaction network enabled an understanding of the mechanism of AAA to be gleaned. HNF4A may exert an important role in AAA development through its interactions with the three other transcription factors (E2F4, NCOR1 and H4), and the mechanism of this coordinated regulation of the transcription factors in AAA may provide a suitable target for the development of therapeutic intervention strategies.

COX5B, a peripheral subunit of the cytochrome c oxidase complex, has previously been reported to maintain the stability of this complex. However, its functions and mechanisms involved in breast cancer progression remain unclear. Here, by performing SILAC assays in breast cancer cell models and detecting COX5B expression in tissues, we found that COX5B expression was elevated in breast cancer. Down-regulation of COX5B in breast cancer cell lines can suppress cell proliferation and induced cell senescence which was accompanied by elevating production of IL-8 and other cytokines. Interestingly, conditioned medium from COX5B knockdown cells could promote breast cancer cell migration. Mechanistic studies reveal that COX5B silence induces an increase in production of ROS, depolarization of MMP and a decrease in ATP. What's more, silence of COX5B leads to metabolic disorders, such as increased glucose uptake and decreased lactate secretion. Collectively, our study shows that loss of COX5B induces mitochondrial dysfunction and subsequently leads to cell growth suppression and cell senescence. Cytokines such as IL-8 secreted by senescent cells may in turn alter the microenvironment which could enhance cell migration. These findings may provide a novel paradigm for the treatment which combined anti-cancer drugs with particular cytokine inhibitors such as IL-8 blockers.

Acquired radioresistance of cancer cells remains a fundamental barrier to attaining the maximal efficacy of radiotherapy for the treatment of breast cancer. Anti-apoptotic proteins, such as Bcl-2 and Bcl-xL, play an important role in the radioresistance of cancer cells. In the present study, we aimed to determine if ABT-737, a BH3-only mimic, could reverse the acquired radioresistance of the breast cancer cell line MDA-MB-231R by targeting Bcl-2 and Bcl-xL.

Via sequencing the genes of apelin/angiotensin receptor-like 1 (apelin/APJ) pathway, we have recently identified and validated four common polymorphisms (rs3761581, rs56204867, rs7119375, and rs10501367) implicated in the development of hypertension. Extending these findings, we, in Chinese hypertensive patients, sought to investigate the association of these four polymorphisms and one additional promising candidate (rs9943582) from this pathway with the risk of developing coronary artery disease (CAD).

Anthracycline daunorubicin (DNR) is one of the major antitumor agents widely used in the treatment of myeloid leukemia. Unfortunately, the clinical efficacy of DNR was limited because of its cytotoxity at high dosage. As a novel cytoprotective mechanism for tumor cell to survive under unfavorable conditions, autophagy has been proposed to play a role in drug resistance of tumor cells. Whether DNR can activate to impair the sensitivity of cancer cells remains unknown. Here, we first report that DNR can induce a high level of autophagy, which was associated with the activation of extracellular signal-regulated kinase 1/2 (ERK1/2). Moreover, cell death induced by DNR was greatly enhanced after autophagy inhibition by the pharmacological inhibitor chloroquine (CQ) and siRNAs targeting Atg5 and Atg7, the most important components for the formation of autophagosome. In conclusion, we found that DNR can induce cytoprotective autophagy by activation of ERK in myeloid leukemia cells. Autophagy inhibition thus represents a promising approach to improve the efficacy of DNR in the treatment of patients with myeloid leukemia.

Photoinduced space-charges in organic optoelectronic devices, which are usually caused by poor mobility and charge injection imbalance, always limit the device performance. Here we demonstrate that photoinduced space-charge layers, accumulated at organic semiconductor-insulator interfaces, can also play a role for photocurrent generation. Photocurrent transients from organic devices, with insulator-semiconductor interfaces, were systematically studied by using the double-layer model with an equivalent circuit. Results indicated that the electric fields in photoinduced space-charge layers can be utilized for charge generation and can even induce a photovoltage reversal. Such an operational process of light harvesting would be promising for photoelectric conversion in organic devices.

Left ventricular diastolic dysfunction (LVDD) is a central perturbation in heart failure with preserved ejection fraction, and there are currently no effective remedies to improve LVDD in clinical practice. The β3-adrenergic receptor (ADRB3) was reported to play protective effects on inhibiting myocardial fibrosis in response to hemodynamic stress. However, the effects of ADRB3 on LVDD and its underlying mechanisms are still undefined. In the current study, the role of ADRB3 in LVDD was identified in ADRB3-knockout mice. Echocardiography parameters showed that depletion of ADRB3 had little effect on cardiac systolic function but obviously led to cardiac diastolic dysfunction in vivo. Proteomics (including the global proteome, phosphorylated and acetylated proteome) and bioinformatics analysis (including GO analysis, KEGG pathway analysis, GO-Tree network, Pathway-Act network, and protein-protein interaction network) were performed on cardiac specimens of ADRB3-KO mice and wild-type mice. The results showed that the cardiac energy metabolism (especially the citrate cycle), actin cytoskeleton organization, and cardiac muscle contraction (related to mitogen-activated protein kinase, toll-like receptor, and ErbB signalling pathway) were potential core mechanisms underlying ADRB3-KO-induced LVDD. In addition, the protein-protein interaction network indicated that the core proteins associated with ADRB3-KO-induced LVDD were FGG, ALDH1A1, FGA, APOC3, SLC4A1, SERPINF2, HP, CTNNB1, and TKT. In conclusion, the absence of ADRB3 leads to LVDD, which is potentially associated with the regulation of cardiac energy metabolism, actin cytoskeleton organization, and cardiac muscle contraction.

The expression of microRNA-505 (miR-505) has been investigated in various cancers; however, its effect and mechanism in relation to gastric cancer (GC) are yet to be determined. Thus, the current evaluation aimed to examine the expression and potential role of miR-505 in GC.

T follicular regulatory (Tfr) cells are a new subset of regulatory T (T reg) cells localized in the germinal center to limit the humoral response. Until now, the physiological function of Tfr cells has been largely unknown. In this study, we developed a Bcl6fl/flFoxp3Cre mouse to analyze the function of Tfr cells in immune and autoimmune responses. These mice exhibited enhanced immunity to influenza virus; moreover, Bcl6fl/flFoxp3Cre/Cre mice developed late-onset spontaneous autoimmune diseases, affecting the salivary glands with lymphocyte infiltration and antibody deposition. In a mouse experimental Sjögren's syndrome model, ablation of Bcl6 in T reg cells greatly enhanced disease development. Conversely, Bcl6fl/flCd4Cre mice were protected in the model. Thus, our study indicates that Tfr cells control autoimmune diseases and can be targeted in infectious and autoimmune disease.

Myocardial infarction (MI), characterized by interruption of blood and oxygen to myocardium, is a common yet fatal cardiovascular event that causes progressive damage to myocardial tissue and eventually leads to heart failure. Previous studies have shown increased expression of microRNA-223 (miR-223) in infarcted myocardial tissues of humans and in rat models of MI. However, the role of miR-223 in cell survival during MI has not been elucidated. Thus, we aimed to investigate whether miR-223 participates in the regulation of cardiac ischemia-induced injury and to elucidate the underlying mechanisms of this process. qRT-PCR revealed that miR-223 expression levels are significantly upregulated in the myocardial tissues of rats with post-MI heart failure and in hypoxia-treated neonatal rat cardiomyocytes (NRCMs) and H9c2 cells, which indicates that miR-223 may be associated with chronic ischemia. We also transfected NRCMs and H9c2 cells with miR-223 mimics or inhibitors in vitro, and the results revealed that increasing miR-223 expression protected cells from hypoxia-induced apoptosis and excessive autophagy, whereas decreasing miR-223 expression had contrasting effects. Further exploration of the mechanism showed that poly(ADP-ribose) polymerase 1 (PARP-1) is a target gene of miR-223 and that silencing PARP-1 prevented hypoxia-induced cell injury; additionally, silencing PARP-1 blocked the aggravated impact of miR-223 inhibitors. Thus, PARP-1 mediates the protective effects of miR-223 in hypoxia-treated cardiomyocytes. We also investigated the involvement of the Akt/mTOR pathway in the above phenomena. We found that miR-223 overexpression and PARP-1 silencing positively regulated the Akt/mTOR pathway and that treating cells with NVP-BEZ235 (BEZ235), a novel dual Akt/mTOR inhibitor, could reverse the inhibitory effects of both the miR-223 mimics and PARP-1 siRNA on hypoxia-induced apoptosis and autophagy. Taken together, our findings showed that miR-223 protects NRCMs and H9c2 cells from hypoxia-induced apoptosis and excessive autophagy via the Akt/mTOR pathway by targeting PARP-1; thus, miR-223 may be a potential target in the treatment of MI in the future.

The shRNA lentiviral vector was constructed to silence c-Ski expression in cardiac mus- cle cells, with the aim of exploring the role of c-Ski in transforming growth factor b1 (TGF-b1)-induced epithelial-mesenchymal transitions (EMT) in H9C2 cells.