Up-regulated long non-coding RNA H19 contributes to proliferation of gastric cancer cells

Long non-coding RNAs (lncRNAs) have been shown to have important regulatory roles in cancer biology, and the lncRNA H19 is up-regulated in hypoxic stress and in some tumors. However, the contributions of H19 to gastric cancer remain largely unknown. In this study, we assayed the H19 expression level in gastric cancer tissues by real-time PCR, and defined the biological functions by flow cytometry and RNA immunoprecipitation. We demonstrated that H19 levels were markedly increased in gastric cancer cells and gastric cancer tissues compared with normal controls. Moreover, ectopic expression of H19 increased cell proliferation, whereas H19 siRNA treatment contributed to cell apoptosis in AGS cell line. We further verified that H19 was associated with p53, and that this association resulted in partial p53 inactivation. These data suggest an important role for H19 in the molecular etiology of gastric cancer and potential application of H19 in gastric cancer therapy.     

Insulin induces proliferation and cardiac differentiation of P19CL6 cells in a dose‐dependent manner

Insulin is a peptide hormone produced by beta cells of the pancreas. The roles of insulin in energy metabolism have been well studied, with most of the attention focused on glucose utilization, but the roles of insulin in cell proliferation and differentiation remain unclear. In this study, we observed for the first time that 10 nmol/L insulin treatment induces cell proliferation and cardiac differentiation of P19CL6 cells, whereas 50 and 100 nmol/L insulin treatment induces P19CL6 cell apoptosis and blocks cardiac differentiation of P19CL6 cells. By using real‐time polymerase chain reaction (PCR) and Western blotting analysis, we found that the mRNA levels of cyclin D1 and α myosin heavy chain (α‐MHC) are induced upon 10 nmol/L insulin stimulation and inhibited upon 50/100 nmol/L insulin treatment, whereas the mRNA levels of BCL‐2‐antagonist of cell death (BAD) exists a reverse trend. The similar results were observed in P19CL6 cells expressing GATA‐6 or peroxisome proliferator‐activated receptor α (PPARα). Our results identified the downstream targets of insulin, cyclin D1, BAD, α‐MHC, and GATA‐4, elucidate a novel molecular mechanism of insulin in promoting cell proliferation and differentiation.     

Expression of metalloproteinases and inhibitors in the differentiation of P19CL6 cells into cardiac myocytes

P19CL6 are a clonal derivative of P19 embryonal carcinoma cells, a euploid, multipotent mouse cell line, that differentiate efficiently into cardiac myocytes, with spontaneous beating evident within 10 days, following DMSO treatment. Using real-time quantitative RT-PCR we have profiled the expression of the complete matrix metalloproteinase and tissue inhibitor of metalloproteinase gene families during P19CL6 differentiation to cardiac myocytes. The genes subdivide into eight groups based upon their expression profile. Their expression was both qualitatively and quantitatively highly homologous to that seen during mouse heart development.     

Knockdown of long noncoding RNA urothelial carcinoma associated 1 inhibits colorectal cancer cell proliferation and promotes apoptosis via modulating autophagy

Long noncoding RNA urothelial carcinoma associated 1 (UCA1) has been implicated in the growth and metastasis of colorectal cancer (CRC), and autophagy contributes to tumorigenesis and cancer cell survival. However, the regulatory role of UCA1 in CRC cell viability by modulating autophagy remains unclear. In the present study, a significant positive correlation was observed between UCA1 and microtubule-associated protein 1 light chain 3 (LC3) levels, and the elevated UCA1 was negatively correlated with the PKB/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway in 293T cells. Downregulation of UCA1 inhibited autophagy activation and cell proliferation, whereas the apoptosis was increased and the cell cycle was arrested in G2 stage. The next results showed that UCA1 was markedly upregulated in Caco-2 cells. Knockdown of UCA1 significantly decreased the LC3-II and autophagy-related gene 5 (ATG5) protein levels and resulted in an increase in p62 expression. Conversely, the autophagy activator rapamycin (RAPA) reversed the effects. Furthermore, downregulated UCA1 decreased Caco-2 cells population in the G1 phase and increased the cells number in G2 phage. The cell proliferation was inhibited, and apoptosis rate was promoted. More important, RAPA could also abrogate the changes induced by knockdown of UCA1. Collectively, these data demonstrated that downregulated UCA1 induced autophagy inhibition, resulting in suppressing cell proliferation and promoting apoptosis, which suggested that UCA1 might serve as a potential new oncogene to regulate CRC cells viability by modulating autophagy.     

Long non-coding RNA LINC00460 promotes proliferation and inhibits apoptosis of cervical cancer cells by targeting microRNA-503-5p

Molecular and Cellular Biochemistry - We reported previously that the rat submandibular gland is able to release nanovesicles capable to hydrolyse millimolar concentrations of ATP, ADP and AMP in...     

A novel long non-coding RNA LINC00355 promotes proliferation of lung adenocarcinoma cells by down-regulating miR-195 and up-regulating the expression of CCNE1

Lung adenocarcinoma is the most common subtype of non-small-cell lung cancer affecting people all over the globe. Recent studies have indicated that long non-coding RNAs (lncRNAs) possess the ability to regulate gene expression. Initially, we uncovered increased LINC00355 expressions in lung adenocarcinoma tissues and cells. Functionally, our findings demonstrated that LINC00355 silencing suppressed the proliferation in vitro and in vivo. In addition, we found that LINC00355 negatively regulated miR-195 in lung adenocarcinoma cells. Simultaneously, silencing LINC00355 by shRNA resulted in suppressed proliferation, colony formation and promoted cell cycle arrest and apoptosis via miR-195. Moreover, silencing LINC00355 by shRNA inhibited the cyclin E1 (CCNE1) gene expression via miR-195 in lung adenocarcinoma cells. Collectively, this study demonstrates the novel lncRNA LINC00355 in regulatory network of CCNE1 via miR-195 in lung adenocarcinoma, highlighting LINC00355 as a new target for the treatment of lung adenocarcinoma.     

Downregulation of EIF5A2 by miR-221-3p inhibits cell proliferation,promotes cell cycle arrest and apoptosis in medulloblastoma cells

Recently, miR-221-3p expression has been reported to be down-regulated in medulloblastoma (MB), but its functional effects remains unclear. In this study, quantitative real-time PCR (qRT-PCR) revealed significantly decreased miR-221-3p in MB cell lines. Transfection of miR-221-3p mimics reduced, or inhibitor increased cell proliferation in MB cells using MTT assay. Flow cytometry analysis indicated miR-221-3p overexpression promoted, while knockdown alleviated G0/G1 arrest and apoptosis. Luciferase reporter assay confirmed miR-221-3p directly targets the EIF5A2 gene. Moreover, restoration of EIF5A2 in the miR-221-3p-overexpressing DAOY cells significantly alleviated the suppressive effects of miR-221-3p on cell proliferation, cell cycle and apoptosis. Furthermore, miR-221-3p overexpression decreased CDK4, Cyclin D1 and Bcl-2 and increased Bad expression, which was reversed by EIF5A2 overexpression. These results uncovered the tumor suppressive role of miR-221-3p in MB cell proliferation at least in part via targeting EIF5A2, suggesting that miR-221-3p might be a potential candidate target for diagnosis and therapeutics of MB.     

Knockdown of TSP50 inhibits cell proliferation and induces apoptosis in P19 cells

Earlier studies identified testes-specific protease 50 (TSP50), which encodes a threonine protease, and showed that it was abnormally reactivated in many breast cancer biopsies. Further, it was shown to be negatively regulated by the p53 gene. However, little is known about the biological function of TSP50. In this study, we applied RNA interference to knockdown TSP50 gene expression in P19 murine embryonal carcinoma stem cells and tested whether this modulated the cell phenotype. The results showed that downregulation of TSP50 expression not only reduced cell proliferation, colony formation, and migration but also induced cell apoptosis. Further investigation revealed that knockdown of TSP50 resulted in greater sensitivity to doxorubicin-induced apoptosis and that activation of caspase-3 was involved in this process.     

Nfib promotes chondrocyte proliferation and inhibits differentiation by mildly regulating Sox9 and its downstream genes

Molecular Biology Reports - Chondrocyte proliferation and differentiation play pivotal roles in regulating cartilage formation, endochondral bone formation, and repair. Cartilage damage and...     

Long non-coding RNA MEG3 regulates CSE-induced apoptosis and inflammation via regulating miR-218 in 16HBE cells

Chronic obstructive pulmonary disease (COPD) is a prevalent disease worldwide, mainly caused by cigarette smoking. Maternally expressed gene 3 (MEG3) functions as the lncRNA and is upregulated in COPD patients and human bronchial epithelial cells after fine particulate matter (PM2.5) treatment. However, the molecular mechanism of MEG3 in COPD remains unknown. The expression of MEG3 and miR-218 in COPD tissues and cigarette smoke extract (CSE)-treated 16HBE cells was detected by RT-qPCR. The effects of MEG3 and miR-218 on proliferation and apoptosis in (CSE)-treated 16HBE cells were analyzed by CCK-8 and flow cytometry assay, respectively. The protein levels of inflammatory cytokines (IL-1β IL-6 and TNF-α) were detected in 16HBE cells by ELISA. MEG3 and miR-218 binding interaction was predicted by LncBase Predicted v.2 and further confirmed by dual luciferase reporter assay and RNA Immunoprecipitation (RIP) assay. MEG3 was upregulated in COPD tissues and inversely related to FEV1%. MEG3 was upregulated in (CSE)-treated 16HBE cells, and knockdown of MEG3 mitigated CSE-repressed proliferation and CSE-triggered apoptosis or inflammation. MiR-218 was demonstrated as a target miRNA of MEG3. MiR-218 was downregulated in COPD tissues and (CSE)-treated or MEG3 overexpressed 16HBE cells. MiR-218 overexpression attenuated CSE-blocked proliferation and CSE-induced apoptosis or inflammation. Deficiency of MEG3 counteracted CSE-blocked proliferation CSE-induced apoptotic rate and inflammatory cytokine (IL-1β IL-6 and TNF-α) levels, while introduction of anti-miR-218 reversed these effects. MEG3 regulated CSE-inhibited proliferation and CSE-induced apoptosis or inflammation by targeting miR-218, providing a possible therapeutic target for treatment of CSE-induced COPD.