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.

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.

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.

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.