Oroxylin A inhibits ethanol‐induced hepatocyte senescence via YAP pathway

Objectives

Oroxylin A, a natural flavonoid isolated from Scutellaria baicalensis, has been reported to have anti‐hepatic injury effects. However, the effects of oroxylin A on alcoholic liver disease (ALD) remains unclear. The aim of this study was to elucidate the effects of oroxylin A on ALD and the potential mechanisms.

Materials and methods

Male ICR mice and human hepatocyte cell line LO₂ were used. Yes‐associated protein (YAP) overexpression and knockdown were achieved using plasmid and siRNA technique. Cellular senescence was assessed by analyses of the senescence‐associated β‐galactosidase (SA‐β‐gal), senescence marker p16, p21, Hmga1, cell cycle and telomerase activity.

Results

Oroxylin A alleviated ethanol‐induced hepatocyte damage by suppressing activities of supernatant marker enzymes. We found that oroxylin A inhibited ethanol‐induced hepatocyte senescence by decreasing the number of SA‐β‐gal‐positive LO₂ cells and reducing the expression of senescence markers p16, p21 and Hmga1 in vitro. Moreover, oroxylin A affected the cell cycle and telomerase activity. Of importance, we revealed that YAP pharmacological inhibitor verteporfin or YAP siRNA eliminated the effect of oroxylin A on ethanol‐induced hepatocyte senescence in vitro, and this was further supported by the evidence in vivo experiments.

Conclusion

Therefore, these aggregated data suggested that oroxylin A relieved alcoholic liver injury possibly by inhibiting the senescence of hepatocyte, which was dependent on its activation of YAP in hepatocytes.

     

Curcumin enhances the anti‐cancer effects of Paris Saponin II in lung cancer cells

Objectives

To investigate the synergistic mechanisms of Paris Saponin II (PSII) and Curcumin (CUR) in lung cancer.

Materials and Methods

The combination changed the cellular uptake of CUR and PSII, apoptosis, cell cycle arrest and cytokine levels were analysed on different lung cancer cells.

Results

The combination displayed a synergistic anti‐cancer effect through promoting the cellular uptake of CUR on different lung cancer cells. Hoechst H33258 staining and FACS assay indicated that the combination of PSII and CUR induced cell cycle arrest and apoptosis. Western blot and cytokine antibody microarray suggested that the combination activated death receptors such as DR6, CD40/CD40L, FasL and TNF‐α to induce cancer cells apoptosis, and up‐regulated IGFBP‐1 leading to inhibition of PI3K/Akt pathway and increase of p21 and p27, which therefore induced a G2 phase arrest in NCI‐H446 cells. Meanwhile, the combination suppressed PCNA and NF‐κB pathway in 4 kinds of lung cancer cells. They activated the phosphorylation of p38 and JNK, and inhibited PI3K in NCI‐H460 and NCI‐H446 cells, enhanced the phosphorylation of JNK in NCI‐H1299 cells, and increased the phosphorylation of p38 and ERK, and suppressed PI3K in NCI‐H520 cells.

Conclusions

PSII combined with CUR had a synergistic anti‐cancer effect on lung cancer cells. These findings provided a rationale for using the combination of curcumin and PSII in the treatment of lung cancer in future.

     

Vasoactive intestinal peptide induces proliferation of human hepatocytes

Objectives

Proliferation of hepatocytes in vitro can be stimulated by growth factors such as epidermal growth factor (EGF), but the role of vasoactive intestinal peptide (VIP) remains unclear. We have investigated the effect of VIP on maintenance and proliferation of human hepatocytes.

Materials and methods

Human hepatocytes were isolated from liver specimens obtained from patients undergoing liver surgery. Treatment with VIP or EGF was started 24 h after plating and continued for 3 or 5 d. DNA replication was investigated by Bromodeoxyuridine (BrdU) incorporation and cell viability detected by MTT assay. Cell lysate was analysed by western blotting and RT‐PCR. Urea and albumin secretion into the culture supernatants were measured.

Results

VIP increased DNA replication in hepatocytes in a dose‐dependant manner, with a peak response at day 3 of treatment. VIP treatment was associated with an increase in mRNA expression of antigen identified by monoclonal antibody Ki‐67 (MKI‐67) and Histone Cluster 3 (H3) genes. Western blotting analysis showed that VIP can induce a PKA/B‐Raf dependant phosphorylation of extracellular signal‐regulated kinases (ERK). Although EGF can maintain hepatocyte functions up to day 5, no marked efffect was found with VIP.

Conclusions

VIP induces proliferation of human hepatocytes with little or no effect on hepatocyte differentiation. Further investigation of the role of VIP is required to determine if it may ultimately support therapeutic approaches of liver disease.

     

Deferoxamine promotes mesenchymal stem cell homing in noise‐induced injured cochlea through PI3K/AKT pathway

Objective

Over 5% of the world's population suffers from disabling hearing loss. Stem cell homing in target tissue is an important aspect of cell‐based therapy, which its augmentation increases cell therapy efficiency. Deferoxamine (DFO) can induce the Akt activation, and phosphorylation status of AKT (p‐AKT) upregulates CXC chemokine receptor‐4 (CXCR4) expression. We examined whether DFO can enhance mesenchymal stem cells (MSCs) homing in noise‐induced damaged cochlea by PI3K/AKT dependent mechanism.

Materials and Methods

Mesenchymal stem cells were treated with DFO. AKT, p‐AKT protein and hypoxia inducible factor 1‐ α (HIF‐1α) and CXCR4 gene and protein expression was evaluated by RT‐ PCR and Western blot analysis. For in vivo assay, rats were assigned to control, sham, noise exposure groups without any treatment or receiving normal, DFO‐treated and DFO +LY294002 (The PI3K inhibitor)‐treated MSCs. Following chronic exposure to 115 dB white noise, MSCs were injected into the rat cochlea through the round window. Number of Hoechst‐ labelled cells was determined in the endolymph after 24 hours.

Results

Deferoxamine increased P‐AKT, HIF‐1α and CXCR4 expression in MSCs compared to non‐treated cells. DFO pre‐conditioning significantly increased the homing ability of MSCs into injured ear compared to normal MSCs. These effects of DFO were blocked by LY294002.

Conclusions

Pre‐conditioning of MSCs by DFO before transplantation can improve stem cell homing in the damaged cochlea through PI3K/AKT pathway activation.

     

Replicative stress and alterations in cell cycle checkpoint controls following acetaminophen hepatotoxicity restrict liver regeneration

Objectives

Acetaminophen hepatotoxicity is a leading cause of hepatic failure with impairments in liver regeneration producing significant mortality. Multiple intracellular events, including oxidative stress, mitochondrial damage, inflammation, etc., signify acetaminophen toxicity, although how these may alter cell cycle controls has been unknown and was studied for its significance in liver regeneration.

Materials and methods

Assays were performed in HuH‐7 human hepatocellular carcinoma cells, primary human hepatocytes and tissue samples from people with acetaminophen‐induced acute liver failure. Cellular oxidative stress, DNA damage and cell proliferation events were investigated by mitochondrial membrane potential assays, flow cytometry, fluorescence staining, comet assays and spotted arrays for protein expression after acetaminophen exposures.

Results

In experimental groups with acetaminophen toxicity, impaired mitochondrial viability and substantial DNA damage were observed with rapid loss of cells in S and G2/M and cell cycle restrictions or even exit in the remainder. This resulted from altered expression of the DNA damage regulator, ATM and downstream transducers, which imposed G1/S checkpoint arrest, delayed entry into S and restricted G2 transit. Tissues from people with acute liver failure confirmed hepatic DNA damage and cell cycle‐related lesions, including restrictions of hepatocytes in aneuploid states. Remarkably, treatment of cells with a cytoprotective cytokine reversed acetaminophen‐induced restrictions to restore cycling.

Conclusions

Cell cycle lesions following mitochondrial and DNA damage led to failure of hepatic regeneration in acetaminophen toxicity but their reversibility offers molecular targets for treating acute liver failure.

     

Effects of simvastatin and rosuvastatin on RAS protein,matrix metalloproteinases and NF‐κB in lung cancer and in normal pulmonary tissues

Objectives

In this study, we have evaluated effects of 24‐hour treatments with simvastatin or rosuvastatin on RAS protein, NF‐κB and MMP expression in LC tissues obtained from 12 patients undergoing thoracic surgery.

Materials and methods

Normal and lung tumour tissues obtained from each sample were exposed to simvastatin (2.5–30 μm ) or rosuvastatin (1.25–30 μm ) and western blot analysis was then performed.

Results

We documented increased expression of proteins, MMP‐2, MMP‐9 and NF‐κB‐p65 in LC tissues, with respect to normal tissues (P < 0.01). In the malignant tissues, simvastatin and rosuvastatin significantly (P < 0.01) and dose‐dependently reduced RAS protein, MMP‐2/9 and NF‐κB‐p65 expression.

Conclusions

In conclusion, our results suggest that simvastatin and rosuvastatin could play a role in LC treatment by modulation of RAS protein, MMP‐2/9 and NF‐κB‐p65.

     

Wnt/β‐catenin signalling pathway mediates high glucose induced cell injury through activation of TRPC6 in podocytes

Objectives

Diabetic nephropathy is a major complication of diabetes and a frequent cause of end‐stage renal disease and recent studies suggest that podocyte damage may play a role in the pathogenesis of this. At early onset of diabetic nephropathy there is podocyte drop‐out, which is thought to provoke glomerular albuminuria and subsequent glomerular injury; however, the underlying molecular mechanisms of this remain poorly understood. Here we report that we tested the hypothesis that early diabetic podocyte injury is caused, at least in part, by up‐regulation of transient receptor potential cation channel 6 (TRPC6), which is regulated by the canonical Wnt signalling pathway, in mouse podocytes.

Materials and methods

Mechanism of injury initiation in mouse podocytes, by high concentration of D‐glucose (HG, 30 mM), was investigated by MTT, flow cytometry, real‐time quantitative PCR, and western blot analysis.

Results

HG induced apoptosis and reduced viability of differentiated podocytes. It caused time‐dependent up‐regulation of TRPC6 and activation of the canonical Wnt signalling pathway, in mouse podocytes. In these cells, blockade of the Wnt signalling pathway by dickkopf related protein 1 (Dkk1) resulted in effective reduction of TRPC6 up‐regulation and amelioration of podocyte apoptosis. Furthermore, reduction of cell viability induced by HG was attenuated by treatment with Dkk1.

Conclusion

These findings indicate that the Wnt/β‐catenin signalling pathway may potentially be active in pathogenesis of TRPC6‐mediated diabetic podocyte injury.

     

Protective effect of GDNF‐engineered amniotic fluid‐derived stem cells on the renal ischaemia reperfusion injury in vitro

Objectives

Amniotic fluid‐derived stem cells (AFSCs) possessing multilineage differentiation potential are proposed as a novel and accessible source for cell‐based therapy and tissue regeneration. Glial‐derived neurotrophic factor (GDNF) has been hypothesized to promote the therapeutic effect of AFSCs on markedly ameliorating renal dysfunction. The aim of this study was to investigate whether AFSCs equipped with GDNF (GDNF‐AFSCs) had capabilities of attenuating mouse renal tubular epithelial cells (mRTECs) apoptosis and evaluate its potential mechanisms.

Materials and methods

A hypoxia‐reoxygenation (H/R) model of the mRTECs was established. Injured mRTECs were co‐cultured with GDNF‐AFSCs in a transwell system. The mRNA expressions of hepatocytes growth factor (HGF) and fibroblast growth factor (bFGF) were detected by qRT‐PCR. Changes of intracelluar reactive oxygen species (ROS) and the level of superoxide dismutase (SOD) and malondialdehyde (MDA) were examined. The expressions of nitrotyrosine, Gp91‐phox, Bax, and Bcl‐2 were determined by Western blotting. Cell apoptosis was assayed by flow cytometry, and caspase‐3 activity was monitored by caspase‐3 activity assay kit.

Results

Our study revealed that expression of growth factors was increased and oxidative stress was dramatically counteracted in GDNF‐AFSCs‐treated group. Furthermore, apoptosis induced by H/R injury was inhibited in mRTECs by GDNF‐AFSCs.

Conclusions

These data indicated that GDNF‐AFSCs are beneficial to repairing damaged mRTECs significantly in vitro, which suggests GDNF‐AFSCs provide new hopes of innovative interventions in different kidney disease.

     

Fak‐Mapk,Hippo and Wnt signalling pathway expression and regulation in distraction osteogenesis

Objectives

To investigate the mechanism of mechanical stimulation in bone formation and regeneration during distraction osteogenesis.

Materials and methods

In this study, microarray technology was used to investigate the time course of bone‐related molecular changes in distraction osteogenesis in rats. Real‐time PCR and Western‐blot analyses were used to confirm the expression of genes identified in microarrays. Meanwhile, we used a lentivirus vector to inhibit Fak expression, in order to identify the osteogenic effect of Fak and Fak‐Mapk pathway during distraction osteogenesis.

Results

Several components of the Wnt and Hippo pathways were found to be up‐ or down‐regulated during distraction osteogenesis by microarray. Meanwhile, it was found that Fak, Src, Raf‐1, Erk1, Jnk and p38‐Mapk were up‐regulated during gradual distraction, compared with consolidation. To further determine whether Fak‐Mapk pathway played an important role in distraction osteogenesis, Fak was disrupted with a lentivirus vector. The expressions levels of p‐Fak, p‐Erk1/2, p‐JNK and p‐p38Mapk were decreased. Meanwhile, a poor early and late osteogenesis effect was found in the shRNA‐Fak group.

Conclusion

It was inferred that the mechanical stimulus induces increased expression of Fak and activates Fak‐Mapk pathway, by activation of Erk, Jnk and p38‐Mapk pathway, and that Fak at least, in part, plays an important role in maintaining osteogenic effect by activating Fak‐Mapk pathway during distraction osteogenesis.

     

MiR‐616‐3p modulates cell proliferation and migration through targeting tissue factor pathway inhibitor 2 in preeclampsia

Objectives

Despite improvements in diagnosis and treatment, preeclampsia (PE) continues to pose a significant risk of maternal and foetal morbidity and mortality if not addressed promptly. An increasing number of studies have suggested that tissue factor pathway inhibitor 2 (TFPI2) acts as a suppressor gene, possibly inhibiting multiple serine proteases affecting cell proliferation and migration. It plays an essential role in the occurrence and development of PE, but the pathogenesis remains unclear.

Materials and methods

In our research, we performed western blotting, immunohistochemistry and qPCR assays to investigate TFPI2 and miR‐616‐3p expression in preeclamptic placental tissues. Cell assays were performed in HTR‐8/SVneo and JEG3 cell lines. Cell proliferation and migration events were investigated by MTT, EdU and transwell assays. In conjunction with bioinformatics analysis, luciferase reporter assays were performed to elucidate the mechanism by which miR‐616‐3p binds to TFPI2 mRNA.

Results

We established that TFPI2 protein levels were significantly upregulated in PE placental tissues. In addition, we found that miR‐616‐3p binds specifically to the 3′‐UTR region of TFPI2 mRNA. Furthermore, miR‐616‐3p knockdown or TFPI2 overexpression substantially impaired cell growth and migration, whereas miR‐616‐3p upregulation or TFPI2 knockdown stimulated cell proliferation and migration. This miR‐616‐3p / TFPI2 axis was also found to affect the epithelial‐mesenchymal transition process in PE.

Conclusions

Our results demonstrated that TFPI2 plays a vital role in the progression of PE and might provide a prospective therapeutic strategy to mitigate the severity of the disorder.

     

Fluoxetine induces autophagic cell death via eEF2K‐AMPK‐mTOR‐ULK complex axis in triple negative breast cancer

Objectives

Triple negative breast cancer (TNBC) is a complex and intrinsically aggressive tumour with poor prognosis, and the discovery of targeted small‐molecule drugs for TNBC treatment still remains in its infancy. In this study, we aimed to discover a small‐molecule agent for TNBC treatment and illuminate its potential mechanisms.

Materials and methods

Cell viability was detected by using methylthiazoltetrazolium (MTT) assay. Electron microscopy, GFP‐LC3 transfection, monodansylcadaverine staining and apoptosis assay were performed to determine Fluoxetine‐induced autophagy and apoptosis. Western blotting and siRNA transfection were carried out to investigate the mechanisms of Fluoxetine‐induced autophagy. iTRAQ‐based proteomics analysis was used to explore the underlying mechanisms.

Results

We have demonstrated that Fluoxetine had remarkable anti‐proliferative activities and induced autophagic cell death in MDA‐MB‐231 and MDA‐MB‐436 cells. The mechanism for Fluoxetine‐induced autophagic cell death was associated with inhibition of eEF2K and activation of AMPK‐mTOR‐ULK complex axis. Further iTRAQ‐based proteomics and network analyses revealed that Fluoxetine‐induced mechanism was involved in BIRC6, BNIP1, SNAP29 and Bif‐1.

Conclusions

These results demonstrate that Fluoxetine induces apoptosis and autophagic cell death in TNBC, which will hold a promise for the future TNBC therapy.

     

Loss of PPM1F expression predicts tumour recurrence and is negatively regulated by miR‐590‐3p in gastric cancer

Objectives

MicroRNAs (miRNAs) as small non‐coding RNA molecules act by negatively regulating their target genes. Recent studies have shown that protein phosphatase Mg2+/Mn2+‐dependent 1F (PPM1F) plays a critical role in cancer metastasis. But, the regulation mechanisms of PPM1F by miRNAs in gastric cancer (GC) remain undefined.

Methods

The correlation of PPM1F or miR‐590‐3p (miR‐590) expression with clinicopathological features and prognosis of the patients with GC was analysed by TCGA RNA‐sequencing data. The miRNAs that target PPM1F gene were identified by bioinformatics and Spearman correlation analysis, and the binding site between miR‐590 and PPM1F 3′UTR was confirmed by dual luciferase assay. MTT and Transwell assays were conducted to evaluate the effects of miR‐590 or (and) PPM1F on cell proliferation and invasion.

Results

We found that PPM1F expression was downregulated in GC tissues and cell lines and was correlated with tumour recurrence in patients with GC. The decreased expression of PPM1F was attributed to the dysregulation of miR‐590 expression rather than its genetic or epigenetic alterations. Overexpression of miR‐590 promoted cell proliferation and invasion capability of GC cells, while knockdown of miR‐590 reversed these effects. Moreover, PPM1F was validated as a direct target of miR‐590 and counteracted the tumour‐promoting effects caused by miR‐590. The expression of miR‐590 presented the negative correlation with PPM1F expression and acted as an independent prognostic factor for tumour recurrence in patients with GC.

Conclusion

PPM1F may function as a suppressive factor and is negatively regulated by miR‐590 in GC.

     

The transient receptor potential vanilloid‐3 regulates hypoxia‐mediated pulmonary artery smooth muscle cells proliferation via PI3K/AKT signaling pathway

Objectves

Transient receptor potential vanilloid 3 (TRPV3) is a member of the TRP channels family of Ca²⁺‐permeant cation channels. In this study, we aim to investigate the role of TRPV3 in pulmonary vascular remodeling and PASMCs proliferation under hypoxia.

Materials and methods

The expression of TRPV3 was evaluated in patients with pulmonary arterial hypertension (PAH) and hypoxic rats, using hematoxylin and eosin (H&E) and immunohistochemistry. In vitro, MTT assay, flow cytometry, Western blotting and immunofluorescence were performed to investigate the effects of TRPV3 on proliferation of PASMCs.

Results

We found that, in vivo, the expression of TRPV3 was increased in patients with PAH and hypoxic rats. Right ventricular hypertrophy measurements and pulmonary pathomorphology data show that the ratio of the heart weight/tibia length (HW/TL), the right ventricle/left ventricle plus septum (RV/LV+S) and the medial width of the pulmonary artery were increased in chronic hypoxic rats. Moreover, the expression of proliferating cell nuclear antigen (PCNA), Cyclin D, Cyclin E and Cyclin A, phospho‐CaMKII (p‐CaMKII) were induced by hypoxia. In vitro, we revealed that hypoxia promoted PASMCs viability, increased the expression of PCNA, Cyclin D, Cyclin E, Cyclin A p‐CaMKII, made more cells from G₀/G₁ phase to G₂/M + S phase, enhanced the microtubule formation, and increased [Ca²⁺]_i, which could be suppressed by Ruthenium Red, an inhibitor of TRPV3, and TRPV3 silencing has similar effects. Furthermore, the up‐regulated expression of PCNA, Cyclin D, Cyclin E and Cyclin A, the increased number of cells in G₂/M and S phase, and the enhanced activation and expression of PI3K and AKT proteins induced by hypoxia and in presence of carvacrol (an agonist of TRPV3), was significantly attenuated by incubation of LY 294002, a specific inhibitor for PI3K/AKT.

Conclusions

These findings suggest that TRPV3 is involved in hypoxia‐induced pulmonary vascular remodeling and promotes proliferation of PASMCs and the effect is, at least in part, mediated via the PI3K/AKT pathway.

     

Galantamine inhibits β‐amyloid‐induced cytostatic autophagy in PC12 cells through decreasing ROS production

Objectives

Alzheimer's disease (AD) is one of the most prevalent brain diseases among the elderly, majority of which is caused by abnormal deposition of amyloid beta‐peptide (Aβ). Galantamine, currently the first‐line drug in treatment of AD, has been shown to diminish Aβ‐induced neurotoxicity and exert favourable neuroprotective effects, but the detail mechanisms remain unclear.

Materials and methods

Effects of galantamine on Aβ‐induced cytotoxicity were checked by MTT, clone formation and apoptosis assays. The protein variations and reactive oxygen species (ROS) production were measured by western blotting analysis and dichloro‐dihydro‐fluorescein diacetate assay, respectively.

Results

Galantamine reversed Aβ‐induced cell growth inhibition and apoptosis in neuron cells PC12. Aβ activated the entire autophagy flux and accumulation of autophagosomes, and the inhibition of autophagy decreased the protein level of cleaved‐caspase‐3 and Aβ‐induced cytotoxicity. Meanwhile, galantamine suppressed Aβ‐mediated autophagy flux and accumulation of autophagosomes. Moreover, Aβ upregulated ROS accumulation, while ROS scavengers N‐acetyl‐l ‐cysteine impaired Aβ‐mediated autophagy. Further investigation showed that galantamine downregulated NOX4 expression to inhibit Aβ‐mediated ROS accumulation and autophagy.

Conclusions

Galantamine inhibits Aβ‐induced cytostatic autophagy through decreasing ROS accumulation, providing new insights into deep understanding of AD progression and molecular basis of galantamine in neuroprotection.

     

Low level laser therapy induces increased viability and proliferation in isolated cancer cells

Objectives

Low level laser therapy (LLLT), which stimulates natural biological processes in the application region, is frequently used in dental treatments. The aim of our study was to evaluate the effects of LLLT which could activate precancerous cells or increase existing cancerous tissue in case of clinically undetectable situations.

Materials and methods

Saos‐2 osteoblast‐like osteosarcoma cells and A549 human lung carcinoma cells were used. Twenty‐four hours after preparation of cell culture plates, laser irradiation was performed 1, 2 and 3 times according to the test groups using Nd:YAG laser with the power output 0.5, 1, 2 and 3 W. Cell proliferation analysis was performed by MTT assay at the 24th hour following the last laser applications.

Results

Generally, it was observed that the proliferation rates increased as the number of applications increased, when compared to the controls, especially in those cases in which the irradiation was performed 2 or 3 times more.

Conclusion

The findings of this study have led to the conclusion that LLLT increases cancer cell proliferation, depending on the power output level of the laser and the number of applications. In addition to the proliferation and mitotic activity of the cancer tissue cells, we concluded that LLLT, which is frequently used in dental practice, could activate precancerous cells or increase existing cancerous tissue.

     

miR‐34c works downstream of p53 leading to dairy goat male germline stem‐cell (mGSCs) apoptosis

Objectives

Recent lines of evidence have indicated that miR‐34c can play important roles in regulation of the cell cycle, cell senescence and apoptosis of mouse and human tumour cells, spermatogenesis, and male germ‐cell apoptosis. However, there is little information on the effects of miR‐34c on proliferation and apoptosis of livestock male germ cells. The dairy goat is a convenient domestic species for biological investigation and application. The purpose of this study was to investigate the effects of miR‐34c on apoptosis and proliferation of dairy goat male germline stem cells (mGSCs), as well as to determine the relationship between p53 and miR‐34c in this species.

Materials and methods

Morphological observation, miRNA in situ hybridisation (ISH), bromodeoxyuridine staining, flow cytometry, quantitative‐RT‐PCR (Q‐RT‐PCR) and western blotting were utilized to ascertain apoptosis and proliferation of mGSCs, through transfection of miR‐34c mimics (miR‐34c), miR‐34c inhibitor (anti‐miR‐34c), miR‐34c mimics and inhibitors co‐transfected (mixture) compared to control groups.

Results

Results manifested that miR‐34c over‐expression promoted mGSCs apoptosis and suppressed their proliferation. Simultaneously, a variety of apoptosis‐related gene expression was increased while some proliferation‐related genes were downregulated. Accordingly, miR‐34c promoted apoptosis in mGSCs and reduced their proliferation; moreover, expression of miR‐34c was p53‐dependent.

Conclusions

This study is the first to provide a model for study of miRNAs and mechanisms of proliferation and apoptosis in male dairy goat germ cells.

     

Identification of novel caspase/autophagy‐related gene switch to cell fate decisions in breast cancers

Objectives

Caspases, a family of cysteine proteases with unique substrate specificities, contribute to apoptosis, whereas autophagy‐related genes (ATGs) regulate cytoprotective autophagy or autophagic cell death in cancer. Accumulating evidence has recently revealed underlying mechanisms of apoptosis and autophagy; however, their intricate relationships still remain to be clarified. Identification of caspase/ATG switches between apoptosis and autophagy may address this problem.

Materials and methods

Identification of caspase/ATG switches was carried out using a series of elegant systems biology & bioinformatics approaches, such as network construction, hub protein identification, microarray analyses, targeted microRNA prediction and molecular docking.

Results

We computationally constructed the global human network from several online databases and further modified it into the basic caspase/ATG network. On the basis of apoptotic or autophagic gene differential expressions, we identified three molecular switches [including androgen receptor, serine/threonine‐protein kinase PAK‐1 (PAK‐1) and mitogen‐activated protein kinase‐3 (MAPK‐3)] between certain caspases and ATGs in human breast carcinoma MCF‐7 cells. Subsequently, we identified microRNAs (miRNAs) able to target androgen receptor, PAK‐1 and MAPK‐3, respectively. Ultimately, we screened a range of small molecule compounds from DrugBank, able to target the three above‐mentioned molecular switches in breast cancer cells.

Conclusions

We have systematically identified novel caspase/ATG switches involved in miRNA regulation, and predicted targeted anti‐cancer drugs. These findings may uncover intricate relationships between apoptosis and autophagy and thus provide further new clues towards possible cancer drug discovery.