linc-UBC1 physically associates with polycomb repressive complex 2 (PRC2) and acts as a negative prognostic factor for lymph node metastasis and survival in bladder cancer.

The human genome encodes many long intergenic noncoding RNAs (lincRNAs). However, their biological functions, molecular mechanisms and prognostic values associated with bladder cancer remain to be elucidated. Here we investigated a lincRNA termed linc-UBC1 (Up-regulated in bladder cancer 1) and evaluated its prognostic value in bladder cancer patients. Expression of linc-UBC1 was evaluated by quantitative reverse transcription PCR (qRT-PCR) in 102 bladder cancer tissue samples and normal adjacent tissues. The functions of linc-UBC1 on cell proliferation, migration, invasion, colony formation, tumorigenicity and metastatic potential were evaluated by knockdown strategy in vitro and in vivo. RNA immunoprecipitation (RIP) was performed to confirm that linc-UBC1 physically associates with EZH2 and SUZ12, core components of polycomb repressive complex 2 (PRC2). Chromatin immunoprecipitation (ChIP) was conducted to examine histone modification status. qRT-PCR confirmed that linc-UBC1 expression is up-regulated in 60 cases (58.8%) in bladder cancer tissues compared with normal adjacent tissues, and its overexpression correlates with lymph node metastasis and poor survival. Further functional analysis demonstrated that knockdown of linc-UBC1 attenuates bladder cancer cell proliferation, motility, invasion, colony formation ability, tumorigenicity and metastatic potential. Importantly, the inhibitory effect of linc-UBC1 on cell proliferation was also observed in primary bladder cancer cells obtained from patients. RIP and ChIP assay confirmed that linc-UBC1 physically associates with PRC2 complex and regulates histone modification status of target genes. Frequently overexpressed linc-UBC1 physically associates with PRC2 complex, and acts as a negative prognostic factor for lymph node metastasis and survival in bladder cancer.

He W ，Cai Q ，Sun F ，Zhong G ，Wang P ，Liu H ，Luo J ，Yu H ，Huang J ，Lin T ... -  《-》

lncRNA Up-Regulated in Nonmuscle Invasive Bladder Cancer Facilitates Tumor Growth and Acts as a Negative Prognostic Factor of Recurrence.

While lncRNAs (long noncoding RNAs) have been shown to have critical regulatory roles in cancer biology, the biological functions and prognostic values in nonmuscle invasive bladder cancer remain largely unknown. We identified a lncRNA termed lncRNA-UNMIBC (up-regulated in nonmuscle invasive bladder cancer) and evaluated its prognostic value in patients with primary nonmuscle invasive bladder cancer. We analyzed the expression of lncRNA-UNMIBC in the tissues of 75 cases of primary nonmuscle invasive bladder cancer and adjacent normal mucosa by quantitative real-time polymerase chain reaction. Data were compared with clinicopathological parameters using the Kaplan-Meier method and multivariate Cox regression analysis. The functions of lncRNA-UNMIBC were assessed by silencing the lncRNA in vitro and in vivo. RNA immunoprecipitation was performed to assay whether lncRNA-UNMIBC could be physically associated with EZH2 (enhancer of zeste homolog 2) and SUZ12 (SUZ12 polycomb repressive complex 2 subunit), which are core components of PRC2 (polycomb repressive complex 2). Chromatin immunoprecipitation was done to examine histone modification status. The expression level of lncRNA-UNMIBC was up-regulated in the tissues of 45 cases of primary nonmuscle invasive bladder cancer compared with normal mucosa. Kaplan-Meier estimates showed that lncRNA-UNMIBC expression was significantly associated with recurrence (log rank test p = 0.0151). We also found that lncRNA-UNMIBC had a key role in G0/G1 arrest. Furthermore, RNA and chromatin immunoprecipitation assays demonstrated that lncRNA-UNMIBC was physically associated with EZH2 and SUZ12, leading to an altered histone H3 lysine 27 methylation status of target genes. These findings indicate that lncRNA-UNMIBC can facilitate tumor growth and may act as a negative prognostic factor of recurrence.

Zhang S ，Zhong G ，He W ，Yu H ，Huang J ，Lin T ... -  《-》

Long noncoding RNA linc-UBC1 is negative prognostic factor and exhibits tumor pro-oncogenic activity in gastric cancer.

Hu Y ，Pan J ，Wang Y ，Li L ，Huang Y ... -  《-》

Increased levels of the long intergenic non-protein coding RNA POU3F3 promote DNA methylation in esophageal squamous cell carcinoma cells.

Thousands of long intergenic non-protein coding RNAs (lincRNAs) have been identified in mammals via genome-wide sequencing studies. Many are functional, but are expressed aberrantly by cancer cells. We investigated whether levels of lincRNAs are altered during the development of esophageal squamous cell carcinoma (ESCC). We used quantitative real-time polymerase chain reaction to measure levels of 26 highly conserved lincRNAs in ESCC and surrounding nontumor tissues. A total of 182 ESCC and paired adjacent nontumor tissue samples were collected from patients undergoing tylectomy at The First Affiliate Hospital of Soochow University from 2001 through 2009; another 178 ESCC tissue pairs were collected from Guangzhou Medical University from 2002 through 2009. LincRNAs were expressed from lentiviral vectors or knocked down with small hairpin RNAs in Eca-109 and TE-1 cells. Levels of a lincRNA encoded by a gene located next to POU3F3 (linc-POU3F3) were significantly higher in ESCC than neighboring nontumor tissues. In RNA immunoprecipitation assays, linc-POU3F3 was associated with the EZH2 messenger RNA (mRNA). Overexpression of linc-POU3F3 in cell lines increased their proliferation and ability to form colonies, and reduced the expression of POU3F3 mRNA, whereas knockdown of linc-POU3F3 increased the levels of POU3F3 mRNA. CpG islands in POU3F3 were densely hypermethylated in cell lines that overexpressed linc-POU3F3; methylation at these sites was reduced by knockdown of linc-POU3F3. Pharmacologic inhibition of EZH2 increased the levels of POU3F3 mRNA and significantly reduced binding of DNA methyltransferase (DNMT)1, DNMT3A, and DNMT3B to POU3F3. ESCC cells with knockdown of linc-POU3F3 formed xenograft tumors more slowly in mice than control ESCC cells. Levels of linc-POU3F3 are increased in ESCC samples from patients compared with nontumor tissues. This noncoding RNA contributes to the development of ESCC by interacting with EZH2 to promote methylation of POU3F3, which encodes a transcription factor.

Li W ，Zheng J ，Deng J ，You Y ，Wu H ，Li N ，Lu J ，Zhou Y ... -  《-》

Long noncoding RNA linc-UBC1 promotes tumor invasion and metastasis by regulating EZH2 and repressing E-cadherin in esophageal squamous cell carcinoma.

Niu G ，Zhuang H ，Li B ，Cao G ... -  《-》