Upregulation of the long noncoding RNA FOXD2-AS1 promotes carcinogenesis by epigenetically silencing EphB3 through EZH2 and LSD1, and predicts poor prognosis in gastric cancer.

Accumulating data indicate that long noncoding RNAs (lncRNAs) serve as important modulators in biological processes and are dysregulated in diverse tumors. The function of FOXD2-AS1 in gastric cancer (GC) progression and related biological mechanisms remain undefined. A comprehensive analysis identified that FOXD2-AS1 enrichment was upregulated markedly in GC and positively correlated with a large tumor size, a later pathologic stage, and a poor prognosis. Gene-set enrichment analysis (GSEA) in GEO datasets uncovered that cell cycle and DNA replication associated genes were enriched in patients with high FOXD2-AS1 expression. Loss of FOXD2-AS1 function inhibited cell growth via inhibiting the cell cycle in GC, whereas upregulation of FOXD2-AS1 expression promoted cancer progression. The enhancer of zeste homolog 2 (EZH2) and lysine (K)-specific demethylase 1A (LSD1) proteins were found to serve as binding partners of FOXD2-AS1 and mediators of FOXD2-AS1 function. Mechanically, FOXD2-AS1 promoted GC tumorigenesis partly through EZH2 and LSD1 mediated EphB3 downregulation. The present results revealed that FOXD2-AS1 acted as a tumor inducer in GC partly through EphB3 inhibition by direct interaction with EZH2 and LSD1, and may prove to be a potential biomarker of carcinogenesis.

The pseudogene derived long noncoding RNA DUXAP8 promotes gastric cancer cell proliferation and migration via epigenetically silencing PLEKHO1 expression.

Gastric cancer (GC) is the third leading cause of cancer death due to its poor prognosis and limited treatment options. Evidence indicates that pseudogene-derived long noncoding RNAs (lncRNAs) may be important players in human cancer progression, including GC. In this paper, we report that a newly discovered pseudogene-derived lncRNA named DUXAP8, a 2107-bp RNA, was remarkably upregulated in GC. Additionally, a higher level of DUXAP8 expression in GC was significantly associated with greater tumor size, advanced clinical stage, and lymphatic metastasis. Patients with a higher level of DUXAP8 expression had a relatively poor prognosis. Further experiments revealed that knockdown of DUXAP8 significantly inhibited cell proliferation and migration, as documented in the SGC7901 and BGC823 cell lines. Furthermore, RNA immunoprecipitation and chromatin immunoprecipitation assays demonstrated that DUXAP8 could epigenetically suppress the expression of PLEKHO1 by binding to EZH2 and SUZ12 (two key components of PRC2), thus promoting GC development. Taken together, our findings suggest that the pseudogene-derived lncRNA DUXAP8 promotes the progression of GC and is a potential therapeutic target for GC intervention.

E2F1 induces TINCR transcriptional activity and accelerates gastric cancer progression via activation of TINCR/STAU1/CDKN2B signaling axis.

Recent evidence indicates that E2F1 transcription factor have pivotal roles in the regulation of cellular processes, and is found to be dysregulated in a variety of cancers. Long non-coding RNAs (lncRNAs) are also reported to exert important effect on tumorigenesis. E2F1 is aberrantly expressed in gastric cancer (GC), and biology functions of E2F1 in GC are controversial. The biological characteristics of E2F1 and correlation between E2F1 and lncRNAs in GC remain to be found. In this study, integrated analysis revealed that E2F1 expression was significantly increased in GC cases and its expression was positively correlated with the poor pathologic stage, large tumor size and poor prognosis. Forced E2F1 expression promotes proliferation, whereas loss of E2F1 function decreased cell proliferation by blocking of cell cycle in GC cells. Mechanistic analyses indicated that E2F1 accelerates GC growth partly through induces TINCR transcription. TINCR could bind to STAU1 (staufen1) protein, and influence CDKN2B mRNA stability and expression, thereby affecting the proliferation of GC cells. Together, our findings suggest that E2F1/TINCR/STAU1/CDKN2B signaling axis contributes to the oncogenic potential of GC and may constitute a potential therapeutic target in this disease.

Long Noncoding RNA PVT1 Promotes Non-Small Cell Lung Cancer Cell Proliferation through Epigenetically Regulating LATS2 Expression.

Long noncoding RNAs (lncRNA) are a novel class of transcripts with no protein coding capacity, but with diverse functions in cancer cell proliferation, apoptosis, and metastasis. The lncRNA PVT1 is 1,716 nt in length and located in the chr8q24.21 region, which also contains the myelocytomatosis (MYC) oncogene. Previous studies demonstrated that MYC promotes PVT1 expression in primary human cancers. However, the expression pattern and potential biologic function of PVT1 in non-small cell lung cancer (NSCLC) is still unclear. Here, we found that PVT1 was upregulated in 105 human NSCLC tissues compared with normal samples. High expression of PVT1 was associated with a higher tumor-node-metastasis stage and tumor size, as well as poorer overall survival. Functional analysis revealed that knockdown of PVT1 inhibited NSCLC cell proliferation and induced apoptosis both in vitro and in vivo RNA immunoprecipitation and chromatin immunoprecipitation assays demonstrated that PVT1 recruits EZH2 to the large tumor suppressor kinase 2 (LATS2) promoter and represses LATS2 transcription. Furthermore, ectopic expression of LATS2 increased apoptosis and repressed lung adenocarcinoma cell proliferation by regulating the Mdm2-p53 pathway. Taken together, our findings indicated that PVT1/EZH2/LATS2 interactions might serve as new target for lung adenocarcinoma diagnosis and therapy. Mol Cancer Ther; 15(5); 1082-94. ©2016 AACR.

Long intergenic non-coding RNA 00152 promotes tumor cell cycle progression by binding to EZH2 and repressing p15 and p21 in gastric cancer.

Long noncoding RNAs (lncRNAs) play important regulatory roles in several human cancers. Integrated analysis revealed that expression of long intergenic non-coding RNA 152 (LINC00152) was significantly upregulated in gastric cancer (GC). Further analysis in a cohort of 97 GC patients revealed that LINC00152 expression was positively correlated with tumor invasion depth, lymph node metastasis, higher TNM stage, and poor survival. Gene set enrichment analysis revealed that cell proliferation and cell cycle progression were increased in patients with high LINC00152 expression. In both GC cell lines and xenograft systems, LINC00152 overexpression facilitated GC cell proliferation by accelerating the cell cycle, whereas LINC00152 knockdown had the opposite effect. Moreover, by binding to enhancer of zeste homolog 2 (EZH2), LINC00152 promotes GC tumor cell cycle progression by silencing the expression of p15 and p21. These findings suggest that LINC00152 may play contribute to the progression of GC and may be an effective therapeutic target.

Long non-coding RNA ANRIL is upregulated in hepatocellular carcinoma and regulates cell apoptosis by epigenetic silencing of KLF2.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death, especially in China. And the mechanism of its progression remains poorly understood. Growing evidence indicates that long non-coding RNAs (lncRNAs) are found to be dysregulated in many cancers, including HCC. ANRIL, a lncRNA co-clustered mainly with p14/ARF has been reported to be dysregulated in gastric cancer, esophageal squamous cell carcinoma, and lung cancer. However, its clinical significance and potential role in HCC are still not documented. METHODS AND RESULTS: In this study, expression of ANRIL was analyzed in 77 HCC tissues and matched normal tissues by using quantitative polymerase chain reaction (qRT-PCR). ANRIL expression was upregulated in HCC tissues, and the higher expression of ANRIL was significantly correlated with tumor size and Barcelona Clinic Liver Cancer (BCLC) stage. Moreover, taking advantage of loss-of-function experiments in HCC cells, we found that knockdown of ANRIL expression could impair cell proliferation and invasion and induce cell apoptosis both in vitro and in vivo. We also found that ANRIL could epigenetically repress Kruppel-like factor 2 (KLF2) transcription in HCC cells by binding with PRC2 and recruiting it to the KLF2 promoter region. We also found that SP1 could regulate the expression of ANRIL. CONCLUSION: Our results suggest that lncRNA ANRIL, as a growth regulator, may serve as a new biomarker and target for therapy in HCC.

Long noncoding RNA PVT1 indicates a poor prognosis of gastric cancer and promotes cell proliferation through epigenetically regulating p15 and p16.

BACKGROUND: Mounting evidence indicates that long noncoding RNAs (lncRNAs) could play a pivotal role in cancer biology. However, the overall biological role and clinical significance of PVT1 in gastric carcinogenesis remains largely unknown. METHODS: Expression of PVT1 was analyzed in 80 GC tissues and cell lines by qRT-PCR. The effect of PVT1 on proliferation was evaluated by MTT and colony formation assays, and cell apoptosis was evaluated by Flow-cytometric analysis. GC cells transfected with shPVT1 were injected into nude mice to study the effect of PVT1 on tumorigenesis in vivo. RIP was performed to confirm the interaction between PVT1 and EZH2. ChIP was used to study the promoter region of related genes. RESULTS: The higher expression of PVT1 was significantly correlated with deeper invasion depth and advanced TNM stage. Multivariate analyses revealed that PVT1 expression served as an independent predictor for overall survival (p = 0.031). Further experiments demonstrated that PVT1 knockdown significantly inhibited the proliferation both in vitro and in vivo. Importantly, we also showed that PVT1 played a key role in G1 arrest. Moreover, we further confirmed that PVT1 was associated with enhancer of zeste homolog 2 (EZH2) and that this association was required for the repression of p15 and p16. To our knowledge, this is the first report showed that the role and the mechanism of PVT1 in the progression of gastric cancer. CONCLUSIONS: Together, these results suggest that lncRNA PVT1 may serve as a candidate prognostic biomarker and target for new therapies in human gastric cancer.

Downregulation of lncRNA TUG1 affects apoptosis and insulin secretion in mouse pancreatic ß cells.

BACKGROUND: Increasing evidence indicates that long noncoding RNAs (IncRNAs) perform specific biological functions in diverse processes. Recent studies have reported that IncRNAs may be involved in ß cell function. The aim of this study was to characterize the role of IncRNA TUG1 in mouse pancreatic ß cell functioning both in vitro and in vivo. METHODS: qRT-PCR analyses were performed to detect the expression of lncRNA TUG1 in different tissues. RNAi, MTT, TUNEL and Annexin V-FITC assays and western blot, GSIS, ELISA and immunochemistry analyses were performed to detect the effect of lncRNA TUG1 on cell apoptosis and insulin secretion in vitro and in vivo. RESULTS: lncRNA TUG1 was highly expressed in pancreatic tissue compared with other organ tissues, and expression was dynamically regulated by glucose in Nit-1 cells. Knockdown of lncRNA TUG1 expression resulted in an increased apoptosis ratio and decreased insulin secretion in ß cells both in vitro and in vivo . Immunochemistry analyses suggested decreased relative islet area after treatment with lncRNA TUG1 siRNA. CONCLUSION: Downregulation of lncRNA TUG1 expression affected apoptosis and insulin secretion in pancreatic ß cells in vitro and in vivo. lncRNA TUG1 may represent a factor that regulates the function of pancreatic ß cells.

Antisense Long Noncoding RNA HIF1A-AS2 Is Upregulated in Gastric Cancer and Associated with Poor Prognosis.

BACKGROUND: Long noncoding RNAs (lncRNAs) have been recently shown to play important regulatory roles in fundamental biological processes, and many of them are deregulated in several human cancers. LncRNA hypoxia-inducible factor 1alpha antisense RNA-2 (HIF1A-AS2) is overexpressed in nonpapillary clear-cell renal carcinomas and involved in cancer progression. AIM: This study was to evaluate the expression of HIF1A-AS2 in gastric cancer (GC) and further explore its biological function in GC cells. MATERIALS AND METHODS: Quantitative real-time polymerase chain reaction was used to detect the expression level of HIF1A-AS2 in GC tissues. The correlation of its expression with clinicopathological features was analyzed. Area under receiver operating characteristic curve (ROC(AUC)) was constructed to evaluate the diagnostic value of HIF1A-AS2. Besides, tumor cell proliferation was assessed following knockdown of HIF1A-AS2, by MTT and colony formation assay in vitro, and tumor formation assay in a nude mouse model in vivo. RESULTS: The expression of HIF1A-AS2 was upregulated in GC tumorous tissues compared with the adjacent normal tissues (P < 0.001). Its overexpression was correlated with TNM stages (P = 0.008), tumor invasion (P = 0.016), lymph node metastasis (P = 0.042), and poor prognosis (P = 0.001). In addition, ROC(AUC) of HIF1A-AS2 was up to 0.673 (95 % CI 0.596-0.744, P < 0.001). Moreover, knockdown of HIF1A-AS2 expression by siRNA could inhibit cell proliferation in vitro and tumorigenesis in vivo. CONCLUSIONS: HIF1A-AS2 is overexpressed in GC and may play a pivotal role in tumor cell proliferation. It can be used as a potential diagnostic and prognostic biomarker for GC.

A novel long noncoding RNA IRAIN regulates cell proliferation in non small cell lung cancer.

Long non-coding RNAs (lncRNAs) are a novel class of RNA molecules defined as transcripts longer than 200 nucleotides that lack protein coding potential. LncRNA IRAIN has been verified that it is related to acute myeloid leukemia (AML) and breast cancer. However, there was no study to clarify whether it is involved in non-small cell lung cancer (NSCLC). Here, we demonstrated IRAIN as a tumor promoter in NSCLC. Its expression level was remarkably upregulated in NSCLC tissues and connected with tumor size and smoking status. Knockdown of IRAIN suppressed NSCLC cells proliferation in vitro. These data identify IRAIN as a novel promoting gene, which plays a vital role in tumorigenesis of NSCLC.

Long non-coding RNA ANRIL is upregulated in hepatocellular carcinoma and regulates cell proliferation by epigenetic silencing of KLF2.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death, especially in China. And the mechanism of its progression remains poorly understood. Growing evidence indicates that long non-coding RNAs (lncRNAs) are found to be dysregulated in many cancers, including HCC. CDKN2B antisense RNA1 (ANRIL), a lncRNA, coclustered mainly with p14/ARF has been reported to be dysregulated in gastric cancer, esophageal squamous cell carcinoma, and lung cancer. However, its clinical significance and potential role in HCC is still not documented. METHODS AND RESULTS: In this study, expression of ANRIL was analyzed in 77 HCC tissues and matched normal tissues by using quantitative real-time polymerase chain reaction (qRT-PCR). ANRIL expression was up-regulated in HCC tissues, and the higher expression of ANRIL was significantly correlated with tumor size and Barcelona Clinic Liver Cancer (BCLC) stage. Moreover, taking advantage of loss of function experiments in HCC cells, we found that knockdown of ANRIL expression could impair cell proliferation and invasion and induce cell apoptosis both in vitro and in vivo. We also found that ANRIL could epigenetically repress KLF2 transcription in HCC cells by binding with PRC2 and recruiting it to KLF2 promoter region. We also found that Sp1 could regulate the expression of ANRIL. CONCLUSION: Our results suggest that lncRNA ANRIL, as a growth regulator, may serve as a new biomarker and target for therapy in HCC.

Long noncoding RNA ANRIL promotes non-small cell lung cancer cell proliferation and inhibits apoptosis by silencing KLF2 and P21 expression.

Recent evidence highlights long noncoding RNAs (lncRNA) as crucial regulators of cancer biology that contribute to essential cancer cell functions such as cell proliferation, apoptosis, and metastasis. In non-small cell lung cancer (NSCLC), several lncRNAs' expressions are misregulated and have been nominated as critical actors in NSCLC tumorigenesis. LncRNA ANRIL was first found to be required for the PRC2 recruitment to and silencing of p15(INK4B), the expression of which is induced by the ATM-E2F1 signaling pathway. Our previous study showed that ANRIL was significantly upregulated in gastric cancer, and it could promote cell proliferation and inhibit cell apoptosis by silencing of miR99a and miR449a transcription. However, its clinical significance and potential role in NSCLC is still not documented. In this study, we reported that ANRIL expression was increased in NSCLC tissues, and its expression level was significantly correlated with tumor-node-metastasis stages and tumor size. Moreover, patients with high levels of ANRIL expression had a relatively poor prognosis. In addition, taking advantage of loss-of-function experiments in NSCLC cells, we found that knockdown of ANRIL expression could impair cell proliferation and induce cell apoptosis both in vitro and vivo. Furthermore, we uncover that ANRIL could not repress p15 expression in PC9 cells, but through silencing of KLF2 and P21 transcription. Thus, we conclusively demonstrate that lncRNA ANRIL plays a key role in NSCLC development by associating its expression with survival in patients with NSCLC, providing novel insights on the function of lncRNA-driven tumorigenesis.

Downregulation of Kruppel-like factor 2 is associated with poor prognosis for nonsmall-cell lung cancer.

Kruppel-like factor 2 (KLF2) expression is diminished in many malignancies. However, its expression and role in nonsmall-cell lung cancer (NSCLC) remain unknown. In this study, we found that KLF2 levels were decreased in NSCLC tissues compared with adjacent normal tissues. Its expression level was significantly correlated with TNM stages, tumor size, and lymph node metastasis. Moreover, patients with low levels of KLF2 expression had a relatively poor prognosis. Furthermore, knockdown of KLF2 expression by siRNA could promote cell proliferation, while ectopic expression of KLF2 inhibited cell proliferation and promoted apoptosis in NSCLC cells partly via regulating CDKN1A/p21 and CDKN2B/p15 protein expression. Our findings present that decreased KLF2 could be identified as a poor prognostic biomarker in NSCLC and regulate cell proliferation and apoptosis.

Decreased expression of the long non-coding RNA FENDRR is associated with poor prognosis in gastric cancer and FENDRR regulates gastric cancer cell metastasis by affecting fibronectin1 expression.

BACKGROUND: FENDRR is a long non-coding RNAs (lncRNA) that binds to polycomb repressive complexe 2 (PRC2) to epigenetically regulate the expression of its target gene. The clinical role of FENDRR in carcinomas remains yet to be found. METHOD: Real-time polymerase chain reaction (PCR) was used to examine FENDRR expression in gastric cancer cell lines/tissues compared with normal epithelial cells/adjacent non-tumorous tissues. Cell proliferation assays, Wound healing assays, and in vitro and in vivo invasion and migration assays were performed to detect the biological effects of FENDRR in gastric cancer cells. Real-time PCR, western-blot and immunohistochemistry were used to evaluate the mRNA and protein expression of fibronectin1 (FN1). Secreted matrix metalloproteinase (MMP) activities were detected and characterized using gelatin zymography assay. RESULTS: FENDRR was downregulated in gastric cancer cell lines and cancerous tissues, as compared with normal gastric epithelial cells and adjacent noncancerous tissue samples. Low FENDRR expression was correlated with deeper tumor invasion (p < 0.001), higher tumor stage (p = 0.001), and lymphatic metastasis (p = 0.007). Univariate and multivariate analyses indicated that low FENDRR expression predicted poor prognosis. Histone deacetylation was involved in the downregulation of FENDRR in gastric cancer cells. FENDER overexpression suppressed invasion and migration by gastric cancer cells in vitro, by downregulating FN1 and MMP2/MMP9 expression. CONCLUSION: Low expression of the lncRNA FENDRR occurs in gastric cancer and is associated with poor prognosis. Thus, FENDRR plays an important role in the progression and metastasis of gastric cancer.

Decreased expression of long noncoding RNA GAS5 indicates a poor prognosis and promotes cell proliferation in gastric cancer.

BACKGROUND: Gastric cancer is the second leading cause of cancer death and remains a major clinical challenge due to poor prognosis and limited treatment options. Long noncoding RNAs (lncRNAs) have emerged recently as major players in tumor biology and may be used for cancer diagnosis, prognosis, and potential therapeutic targets. Although downregulation of lncRNA GAS5 (Growth Arrest-Specific Transcript) in several cancers has been studied, its role in gastric cancer remains unknown. Our studies were designed to investigate the expression, biological role and clinical significance of GAS5 in gastric cancer. METHODS: Expression of GAS5 was analyzed in 89 gastric cancer tissues and five gastric cancer cell lines by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Over-expression and RNA interference (RNAi) approaches were used to investigate the biological functions of GAS5. The effect of GAS5 on proliferation was evaluated by MTT and colony formation assays, and cell apoptosis was evaluated by hochest stainning. Gastric cancer cells transfected with pCDNA3.1 -GAS5 were injected into nude mice to study the effect of GAS5 on tumorigenesis in vivo. Protein levels of GAS5 targets were determined by western blot analysis. Differences between groups were tested for significance using Student's t-test (two-tailed). RESULTS: We found that GAS5 expression was markedly downregulated in gastric cancer tissues, and associated with larger tumor size and advanced pathologic stage. Patients with low GAS5 expression level had poorer disease-free survival (DFS; P = 0.001) and overall survival (OS; P < 0.001) than those with high GAS5 expression. Further multivariable Cox regression analysis suggested that decreased GAS5 was an independent prognostic indicator for this disease (P = 0.006, HR = 0.412; 95%CI = 2.218-0.766). Moreover, ectopic expression of GAS5 was demonstrated to decrease gastric cancer cell proliferation and induce apoptosis in vitro and in vivo, while downregulation of endogenous GAS5 could promote cell proliferation. Finally, we found that GAS5 could influence gastric cancer cells proliferation, partly via regulating E2F1 and P21 expression. CONCLUSION: Our study presents that GAS5 is significantly downregulated in gastric cancer tissues and may represent a new marker of poor prognosis and a potential therapeutic target for gastric cancer intervention.

Long noncoding RNA ANRIL indicates a poor prognosis of gastric cancer and promotes tumor growth by epigenetically silencing of miR-99a/miR-449a.

Long noncoding RNAs are involved in diseases including cancer. Here, we reported that ANRIL (CDKN2B-AS1), a 3.8-kb long noncoding RNA, recruiting and binding to PRC2, was generally upregulated in human gastric cancer (GC) tissues. In a cohort of 120 GC patients, the higher expression of ANRIL was significantly correlated with a higher TNM stage (P=0.041) and tumor size (P=0.001). Multivariate analyses revealed that ANRIL expression served as an independent predictor for overall survival (P=0.036). Further experiments revealed that ANRIL knockdown significantly repressed the proliferation both in vitro and in vivo. We also showed that E2F1 could induce ANRIL and ANRIL-mediated growth promotion is in part due to epigenetic repression of miR-99a/miR-449a in Trans (controlling the targets--mTOR and CDK6/E2F1 pathway) by binding to PRC2, thus forming a positive feedback loop, continuing to promote GC cell proliferation. To our knowledge, this is the first report showed that the role of ANRIL in the progression of GC and ANRIL could crosstalk with microRNAs in epigenetic level. Our results suggest that ANRIL, as a growth regulator, may serve as a candidate prognostic biomarker and target for new therapies in human gastric cancer.

Lnc RNA HOTAIR functions as a competing endogenous RNA to regulate HER2 expression by sponging miR-331-3p in gastric cancer.

BACKGROUND: Accumulating evidence indicates that the long non-coding RNA HOTAIR plays a critical role in cancer progression and metastasis. However, the overall biological role and clinical significance of HOTAIR in gastric carcinogenesis remains largely unknown. METHODS: HOTAIR expression was measured in 78 paired cancerous and noncancerous tissue samples by real-time PCR. The effects of HOTAIR on gastric cancer cells were studied by overexpression and RNA interference approaches in vitro and in vivo. Insights of the mechanism of competitive endogenous RNAs (ceRNAs) were gained from bioinformatic analysis, luciferase assays and RNA binding protein immunoprecipitation (RIP). The positive HOTAIR/HER2 interaction was identified and verified by immunohistochemistry assay and bivariate correlation analysis. RESULTS: HOTAIR upregulation was associated with larger tumor size, advanced pathological stage and extensive metastasis, and also correlated with shorter overall survival of gastric cancer patients. Furthermore, HOTAIR overexpression promoted the proliferation, migration and invasion of gastric carcinoma cells, while HOTAIR depletion inhibited both cell invasion and cell viability, and induced growth arrest in vitro and in vivo. In particular, HOTAIR may act as a ceRNA, effectively becoming a sink for miR-331-3p, thereby modulating the derepression of HER2 and imposing an additional level of post-transcriptional regulation. Finally, the positive HOTAIR/HER2 correlation was significantly associated with advanced gastric cancers. CONCLUSIONS: HOTAIR overexpression represents a biomarker of poor prognosis in gastric cancer, and may confer malignant phenotype to tumor cells. The ceRNA regulatory network involving HOTAIR and the positive interaction between HOTAIR and HER2 may contribute to a better understanding of gastric cancer pathogenesis and facilitate the development of lncRNA-directed diagnostics and therapeutics against this disease.

Downregulation of BRAF activated non-coding RNA is associated with poor prognosis for non-small cell lung cancer and promotes metastasis by affecting epithelial-mesenchymal transition.

BACKGROUND: Recent evidence indicates that long noncoding RNAs (lncRNAs) play a critical role in the regulation of cellular processes, such as differentiation, proliferation and metastasis. These lncRNAs are found to be dysregulated in a variety of cancers. BRAF activated non-coding RNA (BANCR) is a 693-bp transcript on chromosome 9 with a potential functional role in melanoma cell migration. The clinical significance of BANCR, and its' molecular mechanisms controlling cancer cell migration and metastasis are unclear. METHODS: Expression of BANCR was analyzed in 113 non-small cell lung cancer (NSCLC) tissues and seven NSCLC cell lines using quantitative polymerase chain reaction (qPCR) assays. Gain and loss of function approaches were used to investigate the biological role of BANCR in NSCLC cells. The effects of BANCR on cell viability were evaluated by MTT and colony formation assays. Apoptosis was evaluated by Hoechst staining and flow cytometry. Nude mice were used to examine the effects of BANCR on tumor cell metastasis in vivo. Protein levels of BANCR targets were determined by western blotting and fluorescent immunohistochemistry. RESULTS: BANCR expression was significantly decreased in 113 NSCLC tumor tissues compared with normal tissues. Additionally, reduced BANCR expression was associated with larger tumor size, advanced pathological stage, metastasis distance, and shorter overall survival of NSCLC patients. Reduced BANCR expression was found to be an independent prognostic factor for NSCLC. Histone deacetylation was involved in the downregulation of BANCR in NSCLC cells. Ectopic expression of BANCR impaired cell viability and invasion, leading to the inhibition of metastasis in vitro and in vivo. However, knockdown of BANCR expression promoted cell migration and invasion in vitro. Overexpression of BANCR was found to play a key role in epithelial-mesenchymal transition (EMT) through the regulation of E-cadherin, N-cadherin and Vimentin expression. CONCLUSION: We determined that BANCR actively functions as a regulator of EMT during NSCLC metastasis, suggesting that BANCR could be a biomarker for poor prognosis of NSCLC.

c-Myc-induced, long, noncoding H19 affects cell proliferation and predicts a poor prognosis in patients with gastric cancer.

Gastric cancer (GC) is one of the most frequent cancers worldwide. Recent studies have shown that long noncoding RNAs (lncRNAs) play critical roles in multiple biological processes, including oncogenesis. The present study aimed to evaluate the potential role of lncRNA H19 in GC. qRT-PCR was performed to investigate the expression of H19 in tumor tissues and corresponding non-tumor lung tissues from 80 patients with GC and in GC cell lines. The Kaplan-Meier method and Cox proportional hazards analysis were used to evaluate the association between H19 expression and overall survival time (OS). The biological significance of H19 was evaluated using siRNAs in vitro. We also constructed a c-Myc plasmid to investigate the cause of the altered expression of H19 in the progression of GC. The results show that lncRNA H19 is overexpressed in tumor tissues compared with adjacent normal tissues. An advanced tumor-node-metastasis stage was positively correlated with increased H19 expression (P < 0.001), and a high H19 expression was associated with poor OS and can be regarded as an independent predictor of the OS of GC patients (P = 0.042). MTT and colony formation assays confirmed that H19 expression affects GC cell proliferation in vitro. Furthermore, exogenous c-Myc significantly induces H19 expression, and the expression of H19 was positively correlated with the c-Myc levels in the 80 samples used in our study (Pearson correlation coefficient = -0.687). In conclusion, our study demonstrates that the altered expression of lncRNA H19, which is induced by c-Myc, is involved in the development and progression of GC by regulating cell proliferation and shows that H19 may be a potential diagnostic and prognostic target in patients with GC.