The long non-coding RNA rhabdomyosarcoma 2-associated transcript exerts anti-tumor effects on lung adenocarcinoma via ubiquitination of SOX9.

BACKGROUND: Long non-coding RNAs (lncRNAs) play an important role in the post-translational modification of proteins, but the importance of lncRNAs in protein ubiquitination remains unclear. This study investigated to role of the lncRNA rhabdomyosarcoma 2-associated transcript (RMST) in lung adenocarcinoma (LUAD). METHODS: The expression of RMST was analyzed in LUAD samples and normal lung tissues using data from The Cancer Genome Atlas (TCGA) and The Genotype-Tissue Expression (GTEx) public databases. Colony formation and transwell assays were used to determine the anti-tumor effects of RMST in human LUAD progression. RNA pull-down assays, RNA immunoprecipitation assays, and mass spectrometry were used to determine the mechanisms by which RMST induces the ubiquitination of SRY-box transcription factor 9 (SOX9). Furthermore, animal models were used to determine the effects of RMST on LUAD tumorigenicity in vivo. RESULTS: Compared with normal tissues, RMST expression was significantly downregulated in LUAD samples. This abnormal expression of RMST led to significant changes in the proliferation and migration of LUAD cells both in vitro and in vivo. The experiments demonstrated that RMST binds directly to the SOX9 protein, resulting in the ubiquitination of SOX9 and this was mediated by F-box and WD repeat domain-containing 7 (FBW7). Clinically, RMST expression was shown to be positively correlated with the overall survival of LUAD patients. CONCLUSIONS: These findings revealed that RMST suppressed the SOX9 signaling pathway to inhibit LUAD growth and metastasis. The RMST-induced ubiquitination of SOX9 via FBW7 may be a potential therapeutic target for the treatment of patients with LUAD.

Antitumor effects of flavokawain-B flavonoid in gemcitabine-resistant lung cancer cells are mediated via mitochondrial-mediated apoptosis, ROS production, cell migration and cell invasion inhibition and blocking of PI3K/AKT Signaling pathway.

The Editors of JBUON issue an Expression of Concern to 'Antitumor effects of flavokawain-B flavonoid in gemcitabine resistant lung cancer cells are mediated via mitochondrial mediated apoptosis, ROS production, cell migration and cell invasion inhibition and blocking of PI3K/AKT Signaling pathway', by Rong Hua, Yaofei Pei, Haiyong Gu, Yifeng Sun, Yi He, JBUON 2020;25(1):262-267; PMID: 32277640. Following the publication of the above article, readers drew to our attention that part of the data was possibly unreliable. We sent emails to the authors with a request to provide the raw data to prove the originality, but received no reply. Therefore, as we continue to work through the issues raised, we advise readers to interpret the information presented in the article with due caution. We thank the readers for bringing this matter to our attention. We apologize for any inconvenience it may cause.

Antitumor effects of flavokawain-B flavonoid in gemcitabine-resistant lung cancer cells are mediated via mitochondrial-mediated apoptosis, ROS production, cell migration and cell invasion inhibition and blocking of PI3K/AKT Signaling pathway.

PURPOSE: Drug resistance in lung cancer is a growing and challenging problem affecting the overall treatment and quality of the patient's life. The main purpose of the current study was to investigate the anticancer effects of flavokawain-B in gemcitabine-resistant non-small lung cancer cells (NSCLC) along with evaluating its mode of action by studying its effects on programmed cell death, ROS production, cell migration and invasion and PI3K/AKT signalling pathway. METHODS: Cell proliferation rate was studied using MTS cell viability assay while apoptosis induction by flavokawain-B was studied by fluorescence microscopy using DAPI staining as well as flow cytometry using Annexin V-FITC/propidium iodide (PI). Effects on mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) were studied by flow cytometry using Rh-123 and DCH-DA dyes respectively. Effects on cell migration and cell invasion were examined by in vitro wound healing assay and transwell assay respectively. Changes in PI3K/AKT protein expressions were evaluated by western blot. RESULTS: Flavokawain-B selectively inhibited the viability of the human NSCLC cell line A549, indicating lower toxicity compared with normal lung cancer (NLC) CCL-151 cells and both showed dose-dependent inhibition. DAPI and annexin V-FITC/PI staining showed that flavokawain-B led to a dose-dependent onset of apoptosis in lung cancer cells characterized by shrunken cells, fragmented nuclei and chromatin condensation. Western blot showed that flavokawain-B resulted in downregulation of Bcl-2 and upregulation of Bax in a dose dependent manner. Flavokawain-B treatment led to increase of intracellular ROS concentration and decrease of mitochondrial membrane potential (MMP) both showing dose-dependence. It also led to suppression of cell migration and invasion along with blocking PI3K/AKT signalling pathway. CONCLUSIONS: Flavokawain-B targets gemcitabine-resistant NSCLC cells selectively without inducing any significant toxicity in normal cells and these effects are mediated via apoptosis induction, ROS production, loss of MMP, suppression of cell migration and invasion and blocking PI3K/AKT signalling pathway.

The Crosstalk between lncRNA-SNHG7/miRNA-181/cbx7 Modulates Malignant Character in Lung Adenocarcinoma.

Lung adenocarcinoma (LUAD) is a malignant tumor with poor patient survival and high patient mortality. Long noncoding RNA is profoundly involved in the tumorigenesis of LUAD. The present study explores the effect of small nucleolar RNA host gene 7 (SNHG7) on the progression of LUAD and its underlying mechanisms. SNHG7 was found to be down-regulated in LUAD tissues compared with normal tissues. Altered SNHG7 expression induced changes in cell proliferation and migration both in vitro and in vivo. Mechanistically, it was found that SNHG7 interacted with microRNA mir-181 and sequentially up-regulated cbx7. cbx7, which suppresses the Wnt/ß-catenin pathway in LUAD, was found to be a direct target of mir-181. Taken together, loss of SNHG7 in LUAD up-regulated mir-181 and then down-regulated the tumor suppressor cbx7.

Silencing of LAMC2 Reverses Epithelial-Mesenchymal Transition and Inhibits Angiogenesis in Cholangiocarcinoma via Inactivation of the Epidermal Growth Factor Receptor Signaling Pathway.

Cholangiocarcinoma (CCA) is a malignant cancer that is associated with high mortality rates. The relationship between laminin γ 2 chain gene (LAMC2) and epidermal growth factor receptor (EGFR) has been previously documented in gastric cancer and oral squamous cell carcinoma. This study investigates the role of LAMC2 in epithelial-mesenchymal transition (EMT) and angiogenesis in CCA and explores the underlying mechanism(s). Differentially expressed genes related to CCA were initially screened using a microarray analysis, and the interaction between LAMC2 and the EGFR signaling pathway was identified. To determine the regulatory effects of LAMC2 on CCA progression, LAMC2 was silenced or overexpressed and the EGFR signaling pathway was activated or blocked. Subsequently, the regulation effects of LAMC2 were evaluated on the expression of EMT markers, invasion and migration of CCA cells, as well as microvessel density in nude mice. Microarray analysis demonstrated that highly expressed LAMC2 is linked to CCA development, which involves the EGFR signaling pathway. When LAMC2 expression was increased, the EGFR signaling pathway and EMT were activated in CCA tissues. Silencing of LAMC2 as well as EGFR signaling pathway inhibition led to suppression of EMT, cell invasion, and migration abilities in vitro, as well as angiogenesis in vivo. This study demonstrates that LAMC2 silencing suppresses the activity of the EGFR signaling pathway, thus functioning as a tumor suppressor in CCA.

Methyl-CpG Binding Domain Protein 2 Inhibits the Malignant Characteristic of Lung Adenocarcinoma through the Epigenetic Modulation of 10 to 11 Translocation 1 and miR-200s.

It has been reported that disorders of epigenetic modulation play a critical role in carcinogenesis. Methyl-CpG binding domain protein 2 (MBD2) is known to act as an epigenetic modulator in various types of tumors; however, the role of MBD2 in lung adenocarcinoma (LUAD) remains unclear. Herein, we demonstrated the down-regulation of MBD2 in LUAD compared with adjacent nontumor tissues. The down-regulation of MBD2 in LUAD was correlated with metastasis and poor survival. In addition, MBD2 inhibited tumor metastasis by maintaining the expression of the miR-200s, which suppressed the invasive properties of tumors. Also, MBD2 positively correlated with 5-hydroxymethylcytosine content in the promoter of miR-200s. The conventional view is that MBD2 acts as a transcriptional suppressor. However, the data revealed that MBD2 may act as a transcriptional activator by recruiting 10 to 11 translocation 1 (TET1) and forming a chromatin-remodeling complex. The MBD2-TET1 complex locates to the TET1 promoter and removes the methyl residues in this region, thereby activating TET1 transcription. TET1 also acted as a tumor suppressor in LUAD. Taken together, the data demonstrate the correlation between MBD2, miR-200s, and TET1, and tumor suppressive effect of MBD2 through up-regulation of TET1 and the miR-200s.

TOP2A induces malignant character of pancreatic cancer through activating ß-catenin signaling pathway.

It has been reported that Topoisomerase II alpha (TOP2A) could induce tumor development and progression in many cancer types. Herein, through analysis of different independent cohorts, we found TOP2A was up-regulated in pancreatic cancer as compared with non-tumor tissues. Moreover, the up-regulation of TOP2A was significantly correlated with tumor metastasis and shorter survival in patients with pancreatic cancer. Knockdown of TOP2A in pancreatic cancer cell lines inhibited cell proliferation and migration. Furthermore, bioinformatics analysis revealed TOP2A activatesß-catenin pathway in pancreatic cancer. Mechanistically, we demonstrated TOP2A acts as a co-activator ofß-catenin and activates EMT process. Further investigation showed TOP2A was a direct target of mir-139, which was validated by dual-luciferase reporter gene assay. The effects of mir-139 on pancreatic cancer were also mechanistically, functionally and clinically investigated. Taken together, our research identified a novel miR-139\TOP2A\ß-catenin axis driving the malignant progression of pancreatic cancer.

Correction: Inhibition of neddylation regulates dendritic cell functions via Deptor accumulation driven mTOR inactivation.

[This corrects the article DOI: 10.18632/oncotarget.9543.].

Hypermethylation of the CHRDL1 promoter induces proliferation and metastasis by activating Akt and Erk in gastric cancer.

CHRDL1 (Chordin-like 1) is a secreted protein that acts as an antagonist of bone morphogenetic protein (BMP). BMP plays a role as an activator of BMP receptor II (BMPR II), which mediates extracellular to intracellular signal transmission and is involved in carcinogenesis and metastasis. Herein, we report that CHRDL1 expression was significantly down-regulated in gastric cancer tissues and associated with poor survival. Clinic-pathological parameters demonstrated a close relationship between low CHRDL1 expression and metastasis. In vitro, CHRDL1 knockdown promoted tumor cell proliferation and migration through BMPR II by activating Akt, Erk and ß-catenin. Furthermore, we observed the hypermethylation of the CHRDL1 promoter in gastric cancer, which induced low expression of CHRDL1 and decreased its secretion to the supernatant. Finally, in vivo experiments confirmed that CHRDL1 acted as a tumor suppressor gene in suppressing tumor growth and metastasis.

MiR-29a promotes cell proliferation and EMT in breast cancer by targeting ten eleven translocation 1.

Increasing evidence has shown that microRNAs played an important role in regulating carcinogenesis. However, the role of miR-29a in breast cancer is still unclear. Herein, we showed that miR-29a was significantly up-regulated in breast cancer as compared with non-tumor tissues. Moreover, the up-regulation of miR-29a was significantly correlated with tumor metastasis and shorter overall survival in breast cancer patients. Knockdown of miR-29a in breast cancer cell lines inhibited cell proliferation and migration. Furthermore, data from bioinformatic analysis validated by dual-luciferase reporter gene assay showed that ten eleven translocation 1 (TET1) was a direct target of miR-29a, and over-expression of TET1 inhibited cell proliferation and migration which could be induced by the up-regulation of miR-29a. TET1 silencing promoted cell growth and migration in breast cancer. MiR-29a over-expression had the same effect. MiR-29a targets TET1, down regulates its expression and thus promotes EMT in breast cancer. Altogether, we demonstrate that miR-29a acts as a tumor activator by targeting TET1 and induces cell proliferation and EMT in breast cancer.

Correction: mTOR Inhibition Attenuates Dextran Sulfate Sodium-Induced Colitis by Suppressing T Cell Proliferation and Balancing TH1/TH17/Treg Profile.

[This corrects the article DOI: 10.1371/journal.pone.0154564.].

Inhibition of neddylation regulates dendritic cell functions via Deptor accumulation driven mTOR inactivation.

Neddylation, a newly identified post-translational modification, is significant for the activity and stability of target proteins. The exact role of neddylation in the pathogenesis of inflammatory bowel disease, specifically those mediated by dendritic cells (DCs), was still rarely reported. Here, we showed that inhibition of neddylation protected mice from mucosal inflammation. Targeting neddylation also inhibited DC maturation characterized by reduced cytokine production, down-regulated costimulatory molecules and suppressed capacity in allogeneic T cell stimulation. Additionally, inactivation of neddylation promotes caspase dependent apoptosis of DCs. These phenomena were attributed to the inactivation of mTOR, which was caused by Cullin-1 deneddylation induced Deptor accumulation. Together, our findings revealed that neddylation inhibition suppressed DC functions through mTOR signaling pathway and provided a potential therapeutic opportunity in inflammatory bowel diseases.

mTOR Inhibition Attenuates Dextran Sulfate Sodium-Induced Colitis by Suppressing T Cell Proliferation and Balancing TH1/TH17/Treg Profile.

It has been established that mammalian target of Rapamycin (mTOR) inhibitors have anti-inflammatory effects in models of experimental colitis. However, the underlying mechanism is largely unknown. In this research, we investigate the anti-inflammatory effects of AZD8055, a potent mTOR inhibitor, on T cell response in dextran sulfate sodium (DSS)-induced colitis in mice, a commonly used animal model of inflammatory bowel diseases (IBD). Severity of colitis is evaluated by changing of body weight, bloody stool, fecal consistency, histology evaluation and cytokine expression. We find that AZD8055 treatment attenuates DSS-induced body weight loss, colon length shortening and pathological damage of the colon. And AZD8055 treatment decreases colonic expression of genes encoding the pro-inflammatory cytokines interferon-γ, interleukin (IL)-17A, IL-1ß,IL-6 and tumor necrosis factor(TNF)-a and increases colonic expression of anti-inflammatory cytokines IL-10. We show that AZD8055 treatment decreases the percentages of CD4+ T cells and CD8+ T cells in spleen, lymph nodes and peripheral blood of mice. We also find that AZD8055 treatment significantly reduces the number of T helper 1(TH1) cells and TH17 cells and increases regulatory T (Treg) cells in the lamina propria and mesenteric lymph nodes. Furthermore, we demonstrates that AZD8055 suppresses the proliferation of CD4+ and CD8+ T cells and the differentiation of TH1/TH17 cells and expands Treg cells in vitro. The results suggest that, in experimental colitis, AZD8055 exerts anti-inflammatory effect by regulating T helper cell polarization and proliferation.

TET1 inhibits gastric cancer growth and metastasis by PTEN demethylation and re-expression.

Ten-Eleven Translocation 1 (TET1) is a member of ten eleven translocation enzymes, which convert 5-methylcytosine (5-mC) to 5-hydroxymethylcytosine (5-hmC). TET1 can promote CpG islands demethylation in specific genes and often absent in various cancers. Herein, we found that TET1 expression and 5-hmC content were low in gastric tumors compared to its adjacent non-tumor tissues. Cell proliferation, migration and invasion were enhanced upon TET1 knockdown in gastric cancer cells in vitro. This phenomenon was confirmed by an animal xeongraft model. We also found that TET1 directly binds to the promoter region of PTEN and activates its transcription through demethylation of CpG islands. TET1 knockdown activated AKT and FAK pathways, which were suppressed by PTEN. The activation of AKT and FAK facilitated tumor migration, invasion and accelerated cell growth. In conclusion, we found a novel mechanism that TET1 suppresses tumor cell growth, migration and invasion through demethylation of CpG island in PTEN promoter by increasing 5-hmC content. The re-expressed PTEN subsequently down regulates AKT and FAK activity.

Role of liver in modulating the release of inflammatory cytokines involved in lung and multiple organ dysfunction in severe acute pancreatitis.

The objective of this study was to understand the role of liver in modulating remote organ dysfunction during severe acute pancreatitis (SAP). We used sodium taurocholate and endotoxin to induce SAP in the rats and confirmed the development of this condition by measuring serum and ascite levels of the biomarkers of liver and lung damage. Our results showed that expression of tumor necrosis factor (TNF)-α was up-regulated sequentially, first in the gut, then in the liver, and finally in lung. Moreover, the SAP-induced increase in the expressions of TNF-α and IL-6 occurring in gut, liver, and lung was directly related to the increase in time. However, in liver and lung, the transcriptional activity of NF-κB and expression of TNF-α at 4 and 8 h were not increased. The distribution sequence of the pro-inflammatory cytokines to various organs was determined by their detection in the blood from portal vein and inferior vena cava. Although liver received TNF-α during 0.5-8 h of the SAP induction, the release of this cytokine into vena cava was not increased in this period of time. In conclusion, our results suggest that the aggravation of SAP leading to development of MODS exhibited the gut-liver-lung cytokine axis. Furthermore, this study indicates that liver performs both protective and stimulatory activities in the modulation of pro-inflammatory cytokine generation and their distribution to remote organs, such as lungs.

Clinical operational tolerance in liver transplantation: state-of-the-art perspective and future prospects.

BACKGROUND: Liver transplantation is the definite treatment for end-stage liver diseases with satisfactory results. However, untoward effects of life-long immunosuppression prevent the development of alternative strategies to achieve better long-term outcome. Achieving clinical operational tolerance is the ultimate goal. DATA SOURCES: A PubMed and Google Scholar search using terms: "immune tolerance", "liver transplantation", "clinical trial", "operational tolerance" and "immunosuppression withdrawal" was performed, and relevant articles published in English in the past decade were reviewed. Full-text publications relevant to the field were selected and relevant articles from reference lists were also included. Priority was given to those articles which are relevant to the review. RESULTS: Because of the inherent tolerogenic property, around 20%-30% of liver transplantation recipients develop spontaneous operational tolerance after immunosuppression withdrawal, and the percentage may be even higher in pediatric living donor liver transplantation recipients. Several natural killer and gammadeltaT cell related markers have been identified to be associated with the tolerant state in liver transplantation patients. Despite the progress, clinical operational tolerance is still rare in liver transplantation. Reprogramming the recipient immune system by creating chimerism and regulatory cell therapies is among newer promising means to achieve clinical liver transplantation tolerance in the future. CONCLUSION: Although clinical operational tolerance is still rare in liver transplantation recipients, ongoing basic research and collaborative clinical trials may help to decipher the mystery of transplantation tolerance and extend the potential benefits of drug withdrawal to an increasing number of patients in a more predictable fashion.