PTENP1 has been demonstrated to function as a tumor suppressor in several cancer cells. However, its expression and biological roles in gastric cancer (GC) have not yet been investigated. In this study, we demonstrated that PTENP1 was frequently decreased in GC tissues and cell lines, which might be partly associated with DNA hypermethylation, and lower PTENP1 expression was associated with larger tumor size, more advanced stage, deeper invasion depth and lymphatic metastasis. In addition, our data suggested that PTENP1 could regulate GC cell proliferation, apoptosis, migration and invasion in vitro. Furthermore, we demonstrated that PTENP1 could modulate the PTEN protein expression. Taken together, these results suggest that PTENP1 functions as a novel tumor suppressor in GC and its suppressive ability may be involved in the modulation of PTEN.

By investigating the migration and invasion ability in pancreatic cancer, this study probed into the lncRNA MALAT1 molecular mechanism on Hippo-YAP signaling. The expression of lncRNA MALAT1 in PC tissues and cells was detected by qRT-PCR and Western blot. The effect of si-MALAT1 on proliferation was determined by CCK-8 assay. Cell apoptosis, migration, and invasion were respectively detected by flow cytometry assay, wound healing assay, and transwell assay. Western blot and immunohistochemistry were successively used for detecting LATS1 and YAP1 expression in pancreatic cancer tissues. The microarray analysis determined that lncRNA MALAT1 in pancreatic cancer was highly expressed. LncRNA MALAT1 presented an extremely high expression level in pancreatic cancer tissues and cells. After transfected with si-MALAT1, the proliferation of AsPC-1 cells decreased, induce apoptosis of AsPC-1 cells, and migration and invasion ability were reduced. The tendency of LATS1 expression level was down-regulated and YAP1 show the opposite trend in the Hippo-YAP signaling. The in vivo assay was found that the tumor to be small in size and volume, and the expression of Ki-67 was decreased. High expression of lncRNA MALAT1 in PC disorder the proliferation, apoptosis, and migration and invasion ability via influence Hippo-YAP signaling pathway.

Introduction: As it is not clear whether growth arrest-specific 5 (GAS5) inhibits gastric cancer (GC) cell proliferation by regulating cell cycle, we analyzed the effect of GAS5 on cell cycle regulation of GC cells and explored the underlying mechanism. Methods: We measured GAS5 levels in GC tissues and corresponding normal tissues, and analyzed the role of GAS5 in regulation of cell proliferation and cell cycle in GC cells using CCK-8 assay and flow cytometry. We also measured the expression of P21 and CDK6 proteins after transfection of AGS and MGC-803 cells with pLJM-GAS5 and GAS5 siRNA, respectively, by western blotting. Results: GAS5 expression was significantly lower in GC tissues relative to normal tissues, and its lower expression was correlated with larger tumor size and a more advanced clinical stage of GC. GAS5 induced growth arrest of GC cells through inhibition of G1-S phase translation. The action of GAS5 may be mediated by upregulation of P21 and suppression of CDK6. Conclusion: These data enhance our understanding of the important role that GAS5 plays in the molecular etiology of GC and suggest a potential of GAS5 as a new therapeutic target for GC treatment.

Tristetraprolin (TTP) is an adenine/uridine (AU)-rich element (ARE)-binding protein that can induce degradation of mRNAs. In this study, we report that TTP suppresses the expression of interleukin-33 (IL-33), a tumor-promoting inflammatory cytokine, and thereby inhibits the progression of gastric cancer (GC). Overexpression of TTP decreased the level of IL-33, whereas knockdown of TTP increased IL-33 levels. We also discovered that TTP inhibited the proliferation, migration, and invasion of GC cell lines through regulation of IL-33. Furthermore, TTP RNA and protein levels were remarkably reduced in GC and inversely correlated with IL-33 level, and they were also closely associated with depth of invasion, lymph node metastasis, advanced TNM stage, as well as survival rate. Taken together, these findings identified TTP as a downregulator of IL-33, and further suggest that TTP can serve as a novel biomarker for the diagnosis of GC and as a potential therapeutic target for GC treatment.

No abstract

The desire to develop artificial cells to imitate living cells in synthetic vesicle platforms has continuously increased over the past few decades. In particular, heterogeneous synthetic vesicles made from two or more building blocks have attracted attention for artificial cell applications based on their multifunctional modules with asymmetric structures. In addition to the traditional liposomes or polymersomes, polypeptides and proteins have recently been highlighted as potential building blocks to construct artificial cells owing to their specific biological functionalities. Incorporating one or more functionally folded, globular protein into synthetic vesicles enables more cell-like functions mediated by proteins. This Review highlights the recent research about synthetic vesicles toward artificial cell models, from traditional synthetic vesicles to protein-assembled vesicles with asymmetric structures. We aim to provide fundamental and practical insights into applying knowledge on molecular selfassembly to the bottom-up construction of artificial cell platforms with heterogeneous building blocks.

No abstract

Underexpression of the gene runt-related transcription factor 3 (RUNX3), an important tumor suppressor, is known to contribute to gastric cancer progression. However, the mechanism underlying aberrant RUNX3 expression has not been fully elucidated. We investigated the role of microRNA-148a (miR-148a) and DNA methyltransferases (DNMTs) in RUNX3 promoter methylation and gene expression. RUNX3 mRNA, RUNX3 protein, and methylation levels were assayed in human gastric cancer tissues and matched normal tissues, and AGS and BGC-823 cells by real-time reverse transcription PCR, Western blot, and methylation-specific PCR, respectively. A correlation between RUNX3 mRNA levels and that of miR-148a was also investigated in gastric cancer tissues. We found that RUNX3 mRNA levels were significantly downregulated in gastric cancer tissues compared with their matched normal tissues, and were closely associated with miR-148a expression. After treatment of human gastric cancer AGS and BGC-823 cells with the DNA methylation inhibitor 5-aza-2'-deoxycytidine, a significant increase in RUNX3 mRNA, RUNX3 protein, and the non-methylated form of the RUNX3 promoter were observed relative to untreated cells. Enforced expression of miR-148a, which can modulate DNMT1 and DNMT3B, also increased the expression of RUNX3 in gastric cancer cells. Knockdown of DNMT1 was associated with increased levels of RUNX3 mRNA and RUNX3 protein, while knockdown of DNMT3B did not have any effect on these in BGC-823 cells. Our results show that miR-148a may regulate RUNX3 expression through modulation of DNMT1-dependent DNA methylation in gastric cancer and highlight a miRNA-epigenetics regulation mechanism of gene expression.