Dauricine inhibits human pancreatic carcinoma cell proliferation through regulating miRNAs.

Pancreatic cancer is one of the most malignant digestive tract tumors with the worst prognosis. Dauricine (Dau) can inhibit the proliferation of the pancreatic cancer cell line, and has the potential to be used as an adjuvant drug against pancreatic cancer; however, the working mechanism of Dau has not been elucidated. To unravel the effects and mechanisms of Dau on proteins and metabolic pathways, we evaluated the mRNA and microRNA expression in BxPC3 cells treated with Dau. The differences in the gene expression were compared using principal component analysis using mRNA and miRNA data to detect and analyze the sample discrimination. 187 miRNA and 907 mRNA that were significantly differentially expressed were identified using Python programming. On comparing genes and miRNAs in the DISEASES database, 79 known miRNA and 47 mRNA were found to be affected by Dau. The up-regulated and down-regulated genes were annotated with GO biological processes to determine the functional effect. Interactions between mRNA and mRNA were analyzed using the STRING database and the miRBase database was queried to obtain experimentally verified interactions between miRNA and mRNA as edges of miRNA and mRNA in the network. Finally, 413 sites and 2125 sides of the network were obtained, including 1 up-regulated and 18 down-regulated miRNAs. The expression of 19 miRNAs was identified by qPCR. The analysis of the protein-protein interaction network, using the Molecular Complex Detection (MCODE) plug-in of cytoscape, helped in identifying 12 important sub-networks. Most subnets are indirectly or directly related to specific miRNAs. This study provides evidence for the anticancer effect of Dau as a potential anticancer compound.

Long noncoding RNA H19 upregulates vascular endothelial growth factor A to enhance mesenchymal stem cells survival and angiogenic capacity by inhibiting miR-199a-5p.

BACKGROUND: Currently, the overall therapeutic efficiency of mesenchymal stem cells (MSCs) transplantation for the treatment of cardiovascular disease is not satisfactory. The low viability and angiogenic capacity of the implanted cells in the local infarct tissues restrict their further application. Evidence shows that long noncoding RNA H19 (lncRNA-H19) mediates cell survival and angiogenesis. Additionally, it is also involved in MSCs biological activities. This study aimed to explore the functional role of lncRNA-H19 in MSCs survival and angiogenic capacity as well as the underlying mechanism. METHODS: MSCs were obtained from C57BL/6 mice and cultured in vitro. Cells at the third passage were divided into the following groups: MSCs+H19, MSCs+H19 NC, MSCs+si-H19, MSCs+si-H19 NC and MSCs. The MSCs+H19 and MSCs+H19 NC groups were transfected with lncRNA-H19 and lncRNA-H19 scramble RNA respectively. The MSCs+si-H19 and MSCs+si-H19 NC groups were transfected with lncRNA-H19 siRNA and lncRNA-H19 siRNA scramble respectively. MSCs were used as the blank control. All groups were exposed to normoxia (20% O2) and hypoxia (1% O2)/serum deprivation (H/SD) conditions for 24 h. Cell proliferation, apoptosis and vascular densities were assessed. Bioinformatics and dual luciferase reporter assay were performed. Relevant biomarkers were detected in different experimental groups. RESULTS: Overexpression of lncRNA-H19 improved survival and angiogenic capacity of MSCs under both normoxia and H/SD conditions, whereas its knockdown impaired cell viability and their angiogenic potential. MicroRNA-199a-5p (miR-199a-5p) targeted and downregulated vascular endothelial growth factor A (VEGFA). MiR-199a-5p was a target of lncRNA-H19. LncRNA-H19 transfection led to a decreased level of miR-199a-5p, accompanied with an elevated expression of VEGFA. However, both miR-199a-5p and VEGFA presented inverse alterations in the condition of lncRNA-H19 knockdown. CONCLUSIONS: LncRNA-H19 enhanced MSCs survival and their angiogenic potential in vitro. It could directly upregulate VEGFA expression by inhibiting miR-199a-5p as a competing endogenous RNA. This mechanism contributes to a better understanding of MSCs biological activities and provides new insights for cell therapy based on MSCs transplantation.

Hypoxia preconditioning promotes cardiac stem cell survival and cardiogenic differentiation in vitro involving activation of the HIF-1α/apelin/APJ axis.

BACKGROUND: Cardiac stem cells (CSCs) transplantation has been regarded as an optimal therapeutic approach for cardiovascular disease. However, inferior survival and low differentiation efficiency of these cells in the local infarct site reduce their therapeutic efficacy. In this study, we investigated the influence of hypoxia preconditioning (HP) on CSCs survival and cardiogenic differentiation in vitro and explored the relevant mechanism. METHODS: CSCs were obtained from Sprague-Dawley rats and cells of the third passage were cultured in vitro and exposed to hypoxia (1% O2). Cells survival and apoptosis were evaluated by MTS assay and flow cytometry respectively. Cardiogenic differentiation was induced by using 5-azacytidine for another 24 h after the cells experienced HP. Normoxia (20% O2) was used as a negative control during the whole process. Cardiogenic differentiation was assessed 2 weeks after the induction. Relevant molecules were examined after HP and during the differentiation process. Anti-hypoxia-inducible factor-1α (HIF-1α) small interfering RNA (siRNA), anti-apelin siRNA, and anti-putative receptor protein related to the angiotensin receptor AT1 (APJ) siRNA were transfected in order to block their expression, and relevant downstream molecules were detected. RESULTS: Compared with the normoxia group, the hypoxia group presented more rapid growth at time points of 12 and 24 h (p < 0.01). Cells exhibited the highest proliferation rate at the time point of 24 h (p < 0.01). The cell apoptosis rate significantly declined after 24 h of hypoxia exposure (p < 0.01). Expression levels of HIF-1α, apelin, and APJ were all enhanced after HP. The percentage of apelin, α-SA, and cTnT positive cells was greatly increased in the HP group after 2 weeks of induction. The protein level of α-SA and cTnT was also significantly elevated at 7 and 14 days (p < 0.01). HIF-1α, apelin, and APJ were all increased at different time points during the cardiogenic differentiation process (p < 0.01). Knockdown of HIF-1α, apelin or APJ by siRNAs resulted in a significant reduction of α-SA and cTnT. HIF-1α blockage caused a remarkable decrease of apelin and APJ (p < 0.01). Expression levels of apelin and APJ were depressed after the inhibition of apelin (p < 0.01). CONCLUSION: HP could effectively promote CSCs survival and cardiogenic differentiation in vitro, and this procedure involved activation of the HIF-1α/apelin/APJ axis. This study provided a new perspective for exploring novel strategies to enhance CSCs transplantation efficiency.

ABCG2 and NCF4 polymorphisms are associated with clinical outcomes in diffuse large B-cell lymphoma patients treated with R-CHOP.

The impact of pharmacogenetics on predicting survival in diffuse large B-cell lymphoma (DLBCL) remains unclear. We tested 337 DLBCL patients treated with rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) for 9 single nucleotide polymorphisms from 6 genes (CD20, FCGR2A, NAD(P)H, ABCC2, ABCG2 and CYP3A5). Patients who carried the NCF4 rs1883112 GG genotype showed significantly shorter progression-free survival (PFS) (P = 0.023) and event-free survival (EFS) (P < 0.001) comparing with A allele. A significantly shortened PFS (P = 0.013) and EFS (P = 0.002) was also observed in the patients with ABCG2 rs2231137 GG genotype. Furthermore, the elder (> 60 years old) or male patients with ABCG2 rs2231137 GG genotype had poorer PFS and EFS than A allele. Moreover, CD20 rs2070770 CC and RAC2 rs13058338 AT genotypes were independent predictors of chemotherapy-induced toxicity. Cox proportional hazards analyses demonstrated that the GG genotype of ABCG2 rs2231137 and NCF4 rs1883112 were risk factors in DLBCL patients. In conclusion, the identified polymorphisms provide guide for the identification of DLBCL patients who are likely to benefit from chemotherapy.

Apelin promotes mesenchymal stem cells survival and vascularization under hypoxic-ischemic condition in vitro involving the upregulation of vascular endothelial growth factor.

BACKGROUND: Mesenchymal stem cells (MSCs) transplantation has been regarded as an optimal therapeutic approach for cardiovascular disease. However, the inferior survival and low vascularization potential of these cells in the local infarct site reduce the therapeutic efficacy. In this study, we investigated the influence of apelin on MSCs survival and vascularization under hypoxic-ischemic condition in vitro and explored the relevant mechanism. METHODS: MSCs were obtained from C57BL/6 mice and cultured in vitro. Cells of the third passage were divided into MSCs and MSCs+apelin groups. In the MSCs+apelin group, MSCs were stimulated with apelin-13 (5µM). The two groups experienced exposure to hypoxia (1% O2) and serum deprivation for 24h, using normoxia (20% O2) as a negative control during the process. Human umbilical vein endothelial cells (HUVECs) were used and incubated with conditioned media from both groups to promote vascularization for another 6h. Vascular densities were assessed and relevant biomarkers were detected thereafter. RESULTS: Compared with MSCs group, MSCs+apelin group presented more rapid growth. The proliferation rate was much higher. Cells apoptosis percentage was significantly declined both under normoxic and hypoxic conditions. Media produced from MSCs+apelin group triggered HUVECs to form a larger number of vascular branches on matrigel. The expression and secretion of vascular endothelial growth factor (VEGF) were significantly increased. CONCLUSION: Apelin could effectively promote MSCs survival and vascularization under hypoxic-ischemic condition in vitro, and this procedure was associated with the upregulation of VEGF. This study provides a new perspective for exploring novel approaches to enhance MSCs survival and vascularization potential.

Long noncoding RNA Braveheart promotes cardiogenic differentiation of mesenchymal stem cells in vitro.

BACKGROUND: Mesenchymal stem cells (MSCs) have limited potential of cardiogenic differentiation. In this study, we investigated the influence of long noncoding RNA Braveheart (lncRNA-Bvht) on cardiogenic differentiation of MSCs in vitro. METHODS: MSCs were obtained from C57BL/6 mice and cultured in vitro. Cells were divided into three groups: blank control, null vector control, and lncRNA-Bvht. All three groups experienced exposure to hypoxia (1% O2) and serum deprivation for 24 h, and 24 h of reoxygenation (20% O2). Cardiogenic differentiation was induced using 5-AZA for another 24 h. Normoxia (20% O2) was applied as a negative control during the whole process. Cardiogenic differentiation was assessed, and expressions of cardiac-specific transcription factors and epithelial-mesenchymal transition (EMT)-associated biomarkers were detected. Anti-mesoderm posterior1 (Mesp1) siRNA was transfected in order to block its expression, and relevant downstream molecules were examined. RESULTS: Compared with the blank control and null vector control groups, the lncRNA-Bvht group presented a higher percentage of differentiated cells of the cardiogenic phenotype in vitro both under the normal condition and after hypoxia/re-oxygenation. There was an increased level of cTnT and α-SA, and cardiac-specific transcription factors including Nkx2.5, Gata4, Gata6, and Isl-1 were significantly upregulated (P < 0.01). Expressions of EMT-associated genes including Snail, Twist and N-cadherin were much higher (P < 0.01). Mesp1 exhibited a distinct augmentation following lncRNA-Bvht transfection. Expressions of relevant cardiac-specific transcription factors and EMT-associated genes all presented a converse alteration in the condition of Mesp1 inhibition prior to lncRNA-Bvht transfection. CONCLUSION: lncRNA-Bvht could efficiently promote MSCs transdifferentation into cells with the cardiogenic phenotype in vitro. It might function via enhancing the expressions of cardiac-specific transcription factors and EMT-associated genes. Mesp1 could be a pivotal intermediary in the procedure.

Long noncoding RNAs: Novel molecules in cardiovascular biology, disease and regeneration.

Remarkable breakthroughs made in genomic technologies have facilitated the discovery of thousands of novel transcripts that do not template protein synthesis. Numerous RNAs termed as long noncoding RNAs (lncRNAs) generated from this pervasive transcription function vividly in gene regulatory networks and a variety of biological and cellular processes. Here, we make a brief description of the known and putative functions of lncRNAs in cardiovascular biology and disease. The association between lncRNAs and stem cells mediated cardiomyocytes differentiation and neovascularization is discussed then. It will provide a new clue for further studies on these novel molecules in cardiovascular disease and bring bright prospects for their future applications in cardiac regenerative medicine.

Cardiac stem cells transplantation enhances the expression of connexin 43 via the ANG II/AT1R/TGF-beta1 signaling pathway in a rat model of myocardial infarction.

BACKGROUND: In this study, we hypothesized that CSCs mediated the expression of Cx43 after transplantation post MI via the ANG II/AT1R/TGF-beta1 signaling pathway. METHODS: Myocardial infarction (MI) was induced in twenty male Sprague-Dawley rats. The rats were randomized into two groups and were then received the injection of 5 × 10(6) CSCs labeled with PKH26 in phosphate buffer solution (PBS) or equal PBS alone into the infarct anterior ventricular free wall two weeks after MI. Six weeks later, relevant signaling molecules involved were all examined. RESULTS: In the CSCs group, an increased expression of Cx43 could be observed in different zones of the left ventricle (P<0.01). There was a significant reduction of the angiotensin II (ANG II) level in plasma and different regions of the left ventricular cardiac tissues (P<0.05; P<0.01). The angiotensin II type I receptor (AT1R) was decreased accompanied with an enhanced expression of angiotensin II type II receptor (AT2R) (P<0.01). Transforming growth factor beta-1(TGF-beta1) was downregulated (P<0.01). The expression of mothers against decapentaplegic homolog (SMAD) proteins including SMAD2 and SMAD3 was attenuated whereas SMAD7 was elevated (P<0.01, P<0.01, P<0.05). In addition, the expression of mitogen-activated protein kinases (MAPKs) including extracellular kinases 1/2 (ERK1/2) and p38 was also found to be reduced (P<0.01). CONCLUSION: CSCs transplantation could enhance the level of Cx43 after MI. They might function through intervening the ANGII/AT1R/TGF-beta1 signaling pathway to regulate the expression of Cx43.

Peroxisome Proliferator-Activated Receptor Gamma Promotes Mesenchymal Stem Cells to Express Connexin43 via the Inhibition of TGF-ß1/Smads Signaling in a Rat Model of Myocardial Infarction.

BACKGROUND: In this study, we hypothesized that activation of PPAR-γ enhanced MSCs survival and their therapeutic efficacy via upregulating the expression of Cx43. METHODS: MI was induced in 50 male Sprague-Dawley rats. The rats were randomized into five groups: MI group and four intervention groups, including the MSCs group, combined therapy group (MSCs+ pioglitazone), pioglitazone group and PBS group. Two weeks later, 5 × 10(6) MSCs labeled with PKH26 in PBS were injected into the infarct anterior ventricular free wall in the MSCs and combined therapy groups, and PBS alone was injected into the infarct anterior ventricular free wall in the PBS group. Pioglitazone (3 mg/kg/day) was given to the combined therapy and pioglitazone groups by oral gavage at the same time for another 2 weeks. Myocardial function and relevant signaling molecules involved were all examined thereafter. RESULTS: Heart function was enhanced after MSCs treatment for 2 weeks post MI. A significant improvement of heart function was observed in the combined therapy group in contrast to the other three intervention groups. Compared with the MSCs group, there was a higher level of PPAR-γ in the combined therapy group; Cx43 was remarkably increased in different regions of the left ventricle; TGF-ß1 was decreased in the infarct zone and border zone. To the downstream signaling molecules, mothers against Smad proteins including Smad2 and Smad3 presented a synchronized alteration with TGF-ß1; no differences of the expressions of ERK1/2 and p38 could be discovered in the left ventricular cardiac tissue. CONCLUSIONS: MSCs transplantation combined with pioglitazone administration improved cardiac function more effectively after MI. Activation of PPAR-γ could promote MSCs to express Cx43. Inhibition of TGF-ß1/Smads signaling pathway might be involved in the process.

Reduced expression of microRNA­206 regulates cell proliferation via cyclinD2 in gliomas.

MicroRNAs are short single­stranded non­coding RNA molecules that function as regulators of tumor progression, including regulation of glioblastoma multiforme, which is a World Health Organization grade Ⅳ glioma. Based on the results of a microRNA microarray, which included 198 patients with glioma from the Chinese Glioma Genome Atlas data set, it was observed that microRNA­206 (miR­206) was downregulated in high-grade (grades Ⅲ and Ⅳ) gliomas compared with grade II gliomas. In addition, high expression of miR­206 was associated with longer overall survival time in glioma patients. The present study aimed to investigate the biological functions of miR­206 in glioma progression in vitro using the LN229 glioma cell line. Cell proliferation was observed to be inhibited subsequent to transfection with miR­206. It was suggested that miR­206 induced cell cycle G1/S phase arrest by suppressing the expression of cyclinD2. The results of the present study concluded that miR­206 inhibits glioma progression via the regulation of cyclinD2 and that miR­206 may be a novel biomarker with potential for use as a therapeutic target in gliomas.

microRNA-378 promotes mesenchymal stem cell survival and vascularization under hypoxic-ischemic conditions in vitro.

INTRODUCTION: Mesenchymal stem cells (MSCs) transplantation has been demonstrated to be an effective strategy for the treatment of cardiovascular disease. However, the low survival rate of MSCs at local diseased tissue reduces the therapeutic efficacy. We therefore investigated the influence of MicroRNA-378 (miR-378) transfection on MSCs survival and vascularization under hypoxic-ischemic condition in vitro. METHODS: MSCs were isolated from bone marrow of Sprague-Dawley rats and cultured in vitro. The third passage of MSCs were divided into the miR-378 group and control group. For the miR-378 group, cells were transfected with miR-378 mimic. Both groups experienced exposure to hypoxia (1% O2) and serum deprivation for 24 hours, using normoxia (20% O2) as a negative control during the process. After 24 hours of reoxygenation (20% O2), cell proliferation and apoptosis were evaluated. Expressions of apoptosis and angiogenesis related genes were detected. Both groups were further co-cultured with human umbilical vein endothelial cells to promote vascular differentiation for another 6 hours. Vascular density was assessed thereafter. RESULTS: Compared with the control group, MSCs transfected with miR-378 showed more rapid growth. Their proliferation rates were much higher at 72 h and 96 h under hypoxic condition (257.33% versus 246.67%, P <0.01; 406.84% versus 365.39%, P <0.05). Cell apoptosis percentage in the miR-378 group was significantly declined under normoxic and hypoxic condition (0.30 ± 0.10% versus 0.50 ± 0.10%, P <0.05; 0.60 ± 0.40% versus 1.70 ± 0.20%, P <0.01). The miR-378 group formed a larger number of vascular branches on matrigel. BCL2 level was decreased accompanied with an upregulated expression of BAX in the two experimental groups under the hypoxic environment. BAX expression was reduced in the miR-378 group under the hypoxic environment. In the miR-378 group, there was a decreased expression of tumor necrosis factor-α on protein level and a reduction of TUSC-2 under normoxic environment. Their expressions were both downregulated under hypoxic environment. For the angiogenesis related genes, enhanced expressions of vascular endothelial growth factorα, platelet derived growth factor-ß and transforming growth factor-ß1 could be detected both in normoxic and hypoxic-ischemic conditions. CONCLUSION: MiR-378 transfection could effectively promote MSCs survival and vascularization under hypoxic-ischemic condition in vitro.

MicroRNA-320a suppresses in GBM patients and modulates glioma cell functions by targeting IGF-1R.

Glioblastoma (GBM) is the most aggressive and malignant glioma. Currently, a few modern surgical and medical therapeutic strategies are applied for GBM, but the prognosis of GBM patients remains poor, and the average median survival time is only 14.6 months. In this study, we for the first time found that the levels of miR-320a were decreased in both GBM patients and glioma cells. In GBM patients, elevated miR-320a expression was associated with better prognosis. In addition, insulin-like growth factor-1 receptor (IGF-1R) was identified as a key direct target of miR-320a. Overexpression of miR-320a led to the inhibition of cell proliferation, migration, invasion, as well as tumorigenesis by targeting IGF-1R, and thus regulated the signaling pathways downstream, including PI3K/AKT and MAPK/ERK. In tumor orthotopic xenograft experiment, the tumor growth was depressed and survival time of mice model was prolonged when miR-320a was overexpressed. Therefore, our results suggested that miR-320a could suppress tumor development and growth by targeting IGF-1R, and miR-320a might serve as a new effective target for anti-cancer therapy strategies.

Integrated analysis using methylation and gene expression microarrays reveals PDE4C as a prognostic biomarker in human glioma.

Hypermethylation of tumor suppressor promoters is generally accepted to indicate poor prognosis in glioma; however, the DNA methylation patterns associated with different glioma prognoses remain to be elucidated. In the present study, promoter methylation and gene expression microarrays were used to screen candidate genes between different grades of glioma. Survival analysis was performed using the Kaplan­Meier (KM) method. Promoter methylation and protein expression of phosphodiesterase 4C (PDE4C) was examined in different grade gliomas and the correlation between PDE4C and wild-type (WT) p53 was evaluated in glioma cell lines. In addition, gene ontology and gene set variation analysis were used to examine PDE4C function. We found PDE4C exhibited promoter hypermethylation in high-grade glioma samples and hypomethylation in low-grade glioma, with PDE4C expression levels showing the reverse. This indicated PDE4C may be a candidate glioma biomarker. Through studies of PDE4C methylation and expression status in an independent cohort of 124 patient samples (56 low-grade and 63 high-grade glioma and 5 normal brain), we identified PDE4C as having significant promoter methylation and lower expression in high-grade glioma. Hypermethylation and reduced PDE4C protein expression were associated with grade progression and overall survival. In glioma cell lines, PDE4C was upregulated by demethylation treatment with 5-Aza-2'-deoxycytidine and WT p53 expression was downregulated after PDE4C siRNA suppression. Finally, we found PDE4C promoted apoptosis and inhibited migration in a U87 cell line. On the basis of these observations and the results from subset analysis, it is reasonable to conclude that PDE4C may function as a tumor suppressor by promoting apoptosis through the WT p53 pathway and inhibiting cell migration. The data show that PDE4C is downregulated through promoter hypermethylation in glioma.

Cardiac stem cells and their roles in myocardial infarction.

Myocardial infarction leads to loss of cardiomyocytes, scar formation, ventricular remodeling and eventually deterioration of heart function. Over the past decade, stem cell therapy has emerged as a novel strategy for patients with ischemic heart disease and its beneficial effects have been demonstrated by substantial preclinical and clinical studies. Efficacy of several types of stem cells in the therapy of cardiovascular diseases has already been evaluated. However, repair of injured myocardium through stem cell transplantation is restricted by critical safety issues and ethic concerns. Recently, the discovery of cardiac stem cells (CSCs) that reside in the heart itself brings new prospects for myocardial regeneration and reconstitution of cardiac tissues. CSCs are positive for various stem cell markers and have the potential of self-renewal and multilineage differentiation. They play a pivotal role in the maintenance of heart homeostasis and cardiac repair. Elucidation of their biological characteristics and functions they exert in myocardial infarction are very crucial to further investigations on them. This review will focus on the field of cardiac stem cells and discuss technical and practical issues that may involve in their clinical applications in myocardial infarction.