MicroRNAs (miRNAs) are a class of endogenous small noncoding RNAs that regulate gene expression after transcription. Aberrant expression of miRNAs has been shown to be involved in tumorigenesis. We showed that miR-21 was one of the most frequently overexpressed miRNA in human glioblastoma (GBM) cell lines. To explore whether miR-21 can serve as a therapeutic target for glioblastoma, we downregulated miR-21 with a specific antisense oligonucleotide and found that apoptosis was induced and cell-cycle progression was inhibited in vitro in U251 (PTEN mutant) and LN229 (PTEN wildtype) GBM cells; xenograft tumors from antisense-treated U251 cells were suppressed in vivo. Antisense-miR-21-treated cells showed a decreased expression of EGFR, activated Akt, cyclin D, and Bcl-2. Although miR-21 is known to regulate PTEN and downregulation of miR-21 led to increased PTEN expression both endogenously and in a reporter gene assay, the GBM suppressor effect of antisense-miR-21 is most likely independent of PTEN regulation because U251 has mutant PTEN. Microarray analysis showed that the knockdown of miR-21 significantly altered expression of 169 genes involved in nine cell-cycle and signaling pathways. Taken together, our studies provide evidence that miR-21 may serve as a novel therapeutic target for malignant gliomas independent of PTEN status. Malignant gliomas are the most common primary brain tumors with high mortality and morbidity. The prognosis for malignant gliomas has not significantly improved in the last four decades. A recent meta-analysis of 12 randomized clinical trials showed that the overall survival rate of highgrade gliomas was 40% at 1 year after surgical removal and only slightly higher, 46%, after combined radiotherapy and chemotherapy. 1 To develop more optimized and effective treatment strategies for malignant gliomas, it is critical to gain deeper understanding of the molecular mechanisms underlying gliomagenesis and to identify targets for therapeutic intervention.The microRNAs (miRNAs) are a class of highly conserved small non-coding RNAs, approximately 22 nucleotides in length, that control gene expression through binding to the seed sequence at the 3 0 -UTR (untranslated region) of target mRNAs, resulting in translational repression or mRNA degradation. 2 This regulatory mechanism was first shown in the developmental processes in worms, flies, and plants. [3][4][5] Subsequently, miRNAs have been shown to have important roles in many physiological processes of mammalian systems by influencing cell apoptosis, proliferation, differentiation, development, and metabolism through regulation of critical signaling molecules including cytokines, growth factors, transcription factors, and pro-apoptotic and anti-apoptotic proteins. [6][7][8] Increasing number of miRNAs have been identified in the human genome and they are collectively called the miRNome. 9 Accumulating evidence shows the potential

C53/LZAP (also named as Cdk5rap3) is a putative tumor suppressor that plays important roles in multiple cell signaling pathways, including DNA damage response and NF-B signaling. Yet how its function is regulated remains largely unclear. Here we report the isolation and characterization of two novel C53/LZAP-interacting proteins, RCAD (Regulator of C53/ LZAP and DDRGK1) and DDRGK1 (DDRGK domain-containing protein 1). Our co-immunoprecipitation assays confirmed their interactions, while gel filtration assay indicated that C53/ LZAP and RCAD may form a large protein complex. Intriguingly, we found that RCAD knockdown led to dramatic reduction of C53/LZAP and DDRGK1 proteins. We also found that C53/LZAP and DDRGK1 became more susceptible to the proteasome-mediated degradation in RCAD knockdown cells, whereas their ubiquitination was significantly attenuated by RCAD overexpression. In addition, we found that RCAD, like C53/LZAP, also plays an important role in regulation of NF-B signaling and cell invasion. Taken together, our findings strongly suggest that RCAD is a novel regulator of C53/LZAP tumor suppressor and NF-B signaling.C53/LZAP is a highly conserved protein that has been shown to be involved in multiple cell signaling pathways. We originally found that C53/LZAP overexpression potentiated DNA damage-induced cell death by modulating the G2/M checkpoint (1). Furthermore, we demonstrated that by antagonizing checkpoint kinase 1 (Chk1), C53/LZAP modulated the activation of cyclin-dependent kinase 1 (Cdk1), thereby influencing the DNA damage response and mitotic entry during the cell cycle progression (2). Meanwhile, Wang et al. (3) elegantly demonstrated that C53/LZAP functions as a novel tumor suppressor in primary head and neck cancers by specifically inhibiting NF-B signaling. They found that decreased C53/LZAP expression promoted cellular transformation, xenograft tumor growth, and xenograft tumor vascularity. Loss of C53/LZAP increased cellular invasion, and NF-B transcriptional activity. At the molecular level, C53/LZAP directly bound to RelA, impaired serine 536 phosphorylation of RelA and increased HDAC association with RelA, thereby inhibiting basal and stimulated NF-B transcriptional activity. Interestingly, they found that C53/LZAP protein level was markedly decreased in one third of primary human head and neck squamous cell carcinomas (HNSCCs) and decreased C53/LZAP level in primary HNSCC correlated with increased expression of the NF-Bregulated genes IL-8 and I〉␣.C53/LZAP appears to play important roles in cell signaling pathways that are involved in tumorigenesis and cancer metastasis, yet the mechanism to regulate its activity remains completely unknown. To further elucidate its biological functions and the molecular mechanism that regulates its activity, we attempted to identify and characterize its interacting partners. Here we report the isolation and characterization of a novel C53/LZAP-interacting protein that regulates its protein stability. EXPERIMENTAL PROCEDURESTissue Culture Cells and ...

The prognosis of advanced oral squamous cell carcinoma (OSCC) patients remains dismal, and a better understanding of the underlying mechanisms is critical for identifying effective targets with therapeutic potential to improve the survival of patients with OSCC. This study aims to clarify the clinical and biological significance of metastasis-associated long non-coding RNA, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in OSCC. We found that MALAT1 is overexpressed in OSCC tissues compared to normal oral mucosa by real-time PCR. MALAT1 served as a new prognostic factor in OSCC patients. When knockdown by small interfering RNA (siRNA) in OSCC cell lines TSCCA and Tca8113, MALAT1 was shown to be required for maintaining epithelial-mesenchymal transition (EMT) mediated cell migration and invasion. Western blot and immunofluorescence staining showed that MALAT1 knockdown significantly suppressed N-cadherin and Vimentin expression but induced E-cadherin expression in vitro. Meanwhile, both nucleus and cytoplasm levels of β-catenin and NF-κB were attenuated, while elevated MALAT1 level triggered the expression of β-catenin and NF-κB. More importantly, targeting MALAT1 inhibited TSCCA cell-induced xenograft tumor growth in vivo. Therefore, these findings provide mechanistic insight into the role of MALAT1 in regulating OSCC metastasis, suggesting that MALAT1 is an important prognostic factor and therapeutic target for OSCC.

COVID-19 has rapidly become a global challenge. 1 We read with interest the article by Bezzio et al 1 that reported the characteristics and outcomes of COVID-19 patients with pre-existing IBD. Patients with pre-existing cirrhosis, who have immune dysfunction and poorer outcomes from acute respiratory distress syndrome (ARDS) than patients without cirrhosis, are also considered a high-risk population for COVID-19. 2 3 In previous studies, the proportion of COVID-19 patients with pre-existing liver conditions ranged from 2% to 11%. 2 However, the clinical course and risk factors for mortality in these patients has not yet been reported. This retrospective multicentre study (COVID-Cirrhosis-CHESS, ClinicalTrials. gov NCT04329559) included consecutive adult patients with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and pre-existing cirrhosis from 16 designated hospitals in China between 31 December 2019 and 24 March 2020. Patient characteristics are summarised in table 1. Twenty-one COVID-19 patients with preexisting cirrhosis (Child-Pugh class A, B and C in 16, 3 and 2 patients, respectively) were included in the analysis. The median age was 68 years; 11 (52.4%) were male. Most patients had compensated cirrhosis (81.0%) and chronic HBV infection was the most common aetiology (57.1%). Comorbidities other than cirrhosis were present in most patients (66.7%). In previous studies, older age, male sex and pre-existing comorbidities were associated with higher risk of mortality for COVID-19. 4 5 Here, there were no significant differences between survivors (n=16) and non-survivors (n=5) in age, sex, comorbidities, aetiology of cirrhosis, stage of cirrhosis, Child-Pugh class, Model for End-stage Liver Disease (MELD) score, interval between onset and admission, or onset symptoms of COVID-19. Comorbidities have been associated with adverse outcomes in cirrhosis, 6 but our analysis did not show clear prognostic associations-possibly due to the small size and narrow composition of the study population.

BackgroundSubstantial data indicate that the oncogene microRNA 21 (miR-21) is significantly elevated in glioblastoma multiforme (GBM) and regulates multiple genes associated with cancer cell proliferation, apoptosis, and invasiveness. Thus, miR-21 can theoretically become a target to enhance the chemotherapeutic effect in cancer therapy. So far, the effect of downregulating miR-21 to enhance the chemotherapeutic effect to taxol has not been studied in human GBM.MethodsHuman glioblastoma U251 (PTEN-mutant) and LN229 (PTEN wild-type) cells were treated with taxol and the miR-21 inhibitor (in a poly (amidoamine) (PAMAM) dendrimer), alone or in combination. The 50% inhibitory concentration and cell viability were determined by the MTT assay. The mechanism between the miR-21 inhibitor and the anticancer drug taxol was analyzed using the Zheng-Jun Jin method. Annexin V/PI staining was performed, and apoptosis and the cell cycle were evaluated by flow cytometry analysis. Expression of miR-21 was investigated by RT-PCR, and western blotting was performed to evaluate malignancy related protein alteration.ResultsIC(50) values were dramatically decreased in cells treated with miR-21 inhibitor combine with taxol, to a greater extent than those treated with taxol alone. Furthermore, the miR-21 inhibitor significantly enhanced apoptosis in both U251 cells and LN229 cells, and cell invasiveness was obviously weakened. Interestingly, the above data suggested that in both the PTEN mutant and the wild-type GBM cells, miR-21 blockage increased the chemosensitivity to taxol. It is worth noting that the miR-21 inhibitor additively interacted with taxol on U251cells and synergistically on LN229 cells. Thus, the miR-21 inhibitor might interrupt the activity of EGFR pathways, independently of PTEN status. Meanwhile, the expression of STAT3 and p-STAT3 decreased to relatively low levels after miR-21 inhibitor and taxol treatment. The data strongly suggested that a regulatory loop between miR-21 and STAT3 might provide an insight into the mechanism of modulating EGFR/STAT3 signaling.ConclusionsTaken together, the miR-21 inhibitor could enhance the chemo-sensitivity of human glioblastoma cells to taxol. A combination of miR-21 inhibitor and taxol could be an effective therapeutic strategy for controlling the growth of GBM by inhibiting STAT3 expression and phosphorylation.

BackgroundThe communication between carcinoma associated fibroblasts (CAFs) and cancer cells facilitate tumor metastasis. In this study, we further underlying the epigenetic mechanisms of CAFs feed the cancer cells and the molecular mediators involved in these processes.MethodsMCF-7 and MDA-MB-231 cells were treated with CAFs culture conditioned medium, respectively. Cytokine antibody array, enzyme-linked immunosorbent assay, western blotting and immunofluorescence were used to identify the key chemokines. Chromatin immunoprecipitation and luciferase reporter assay were performed to explore the transactivation of target LncRNA by CAFs. A series of in vitro assays was performed with RNAi-mediated knockdown to elucidate the function of LncRNA. An orthotopic mouse model of MDA-MB-231 was conducted to confirm the mechanism in vivo.ResultsHere we reported that TGF-β1 was top one highest level of cytokine secreted by CAFs as revealed by cytokine antibody array. Paracrine TGF-β1 was essential for CAFs induced EMT and metastasis in breast cancer cells, which is a crucial mediator of the interaction between stromal and cancer cells. CAF-CM significantly enhanced the HOTAIR expression to promote EMT, whereas treatment with small-molecule inhibitors of TGF-β1 attenuated the activation of HOTAIR. Most importantly, SMAD2/3/4 directly bound the promoter site of HOTAIR, located between nucleotides -386 and -398, -440 and -452, suggesting that HOTAIR was a directly transcriptional target of SMAD2/3/4. Additionally, CAFs mediated EMT by targeting CDK5 signaling through H3K27 tri-methylation. Depletion of HOTAIR inhibited CAFs-induced tumor growth and lung metastasis in MDA-MB-231 orthotopic animal model.ConclusionsOur findings demonstrated that CAFs promoted the metastatic activity of breast cancer cells by activating the transcription of HOTAIR via TGF-β1 secretion, supporting the pursuit of the TGF-β1/HOTAIR axis as a target in breast cancer treatment.Electronic supplementary materialThe online version of this article (10.1186/s12943-018-0758-4) contains supplementary material, which is available to authorized users.

The Golgi apparatus lies at the heart of the secretory pathway where it is required for secretory trafficking and cargo modification. Disruption of Golgi architecture and function has been widely observed in neurodegenerative disease, but whether Golgi dysfunction is causal with regard to the neurodegenerative process, or is simply a manifestation of neuronal death, remains unclear. Here we report that targeted loss of the golgin GM130 leads to a profound neurological phenotype in mice. Global KO of mouse GM130 results in developmental delay, severe ataxia, and postnatal death. We further show that selective deletion of GM130 in neurons causes fragmentation and defective positioning of the Golgi apparatus, impaired secretory trafficking, and dendritic atrophy in Purkinje cells. These cellular defects manifest as reduced cerebellar size and Purkinje cell number, leading to ataxia. Purkinje cell loss and ataxia first appear during postnatal development but progressively worsen with age. Our data therefore indicate that targeted disruption of the mammalian Golgi apparatus and secretory traffic results in neuronal degeneration in vivo, supporting the view that Golgi dysfunction can play a causative role in neurodegeneration.GM130 | Golgi apparatus | polarized secretion | Purkinje cell | ataxia

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