Overexpression of lncRNA TINCR is associated with high-grade, invasive, and recurring tumors, and facilitates proliferation in vitro and in vivo of urothelial carcinoma of the bladder.

The aberrant expression of long noncoding RNAs (lncRNAs) plays roles in cancer development. In this work, we measured the expression of lncRNA terminal differentiation-induced non-coding RNA (TINCR) in urothelial carcinoma of the bladder (UCB), determined its impact on the proliferation of UCB in vitro and in vivo and identified its possible targets. The expression levels of genes were measured by Real-Time quantitative Polymerase Chain Reaction (qPCR). Cell proliferation, cell motility, and cell apoptosis were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, wound healing assay, and ELISA, respectively. Tumor growth in vivo was determined by xenograft formation assay in nude mice. The predicted binding site between TINCR and hsa-miR-125b was confirmed by dual luciferase reporter assay. The expression levels of TINCR were higher in cancerous tissues than that in paired noncancerous tissues of UCB. Higher expression levels of TINCR were positively associated with high-grade, invasive, and recurring tumors. Depletion of TINCR retarded proliferation, decreased motility, increased apoptosis in UCB cells, and markedly reduced tumor growth in xenograft nude mice. The predicted binding site between TINCR and hsa-miR-125b was functional. TINCR downregulated hsa-miR-125b in UCB cells. Hsa-miR-125b mimic reversed the proliferation caused by TINCR up-expression in UCB cells. Up-regulation of TINCR may act as an unfavorable indicator for the diseasing status of UCB. TINCR facilitates bladder cancer proliferation in vitro and in vivo. Hsa-miR-125b is a target for TINCR in UCB.

Han Y ，Sun G 《-》

Long non-coding RNA urothelial cancer-associated 1 promotes bladder cancer cell migration and invasion by way of the hsa-miR-145-ZEB1/2-FSCN1 pathway.

Numerous studies suggest that several long non-coding RNAs (lncRNAs) play critical roles in bladder cancer development and progression. Long non-coding RNA urothelial cancer-associated 1 (lncRNA-UCA1) is highly expressed in bladder cancer tissues and cells, and it has been shown to play an important role in regulating aggressive phenotypes of bladder cancer cells. However, little is known about the molecular mechanism of lncRNA-UCA1-mediated bladder cancer cell migration and invasion. Here, we show that overexpression of lncRNA-UCA1 could induce EMT and increase the migratory and invasive abilities of bladder cancer cells. Mechanistically, lncRNA-UCA1 induced EMT of bladder cancer cells by upregulating the expression levels of zinc finger E-box binding homeobox 1 and 2 (ZEB1 and ZEB2), and regulated bladder cancer cell migration and invasion by tumor suppressive hsa-miR-145 and its target gene the actin-binding protein fascin homologue 1 (FSCN1). Furthermore, we also observed a positive correlation between lncRNA-UCA1 and ZEB1/2 expression, and a negative correlation between lncRNA-UCA1 and hsa-miR-145 expression in bladder cancer specimens. Importantly, we found that lncRNA-UCA1 repressed hsa-miR-145 expression to upregulate ZEB1/2, whereas the suppression of hsa-miR-145 could upregulate lncRNA-UCA1 expression in bladder cancer cells. Moreover, the binding site for hsa-miR-145 within exons 2 and 3 of lncRNA-UCA1 contributed to the reciprocal negative regulation of lncRNA-UCA1 and hsa-miR-145. Taken together, our results identified that lncRNA-UCA1 enhances bladder cancer cell migration and invasion in part through the hsa-miR-145/ZEB1/2/FSCN1 pathway. Therefore, lncRNA-UCA1 might act as a promising therapeutic target for the invasion and metastasis of bladder cancer.

Xue M ，Pang H ，Li X ，Li H ，Pan J ，Chen W ... -  《-》

LncRNA MIR4435-2HG drives cancer progression by modulating cell cycle regulators and mTOR signaling in stroma-enriched subtypes of urothelial carcinoma of the bladder.

The risk for recurrence and metastasis after treatment for urothelial carcinoma of the bladder (UCB) is high. Therefore, identifying efficient prognostic markers and novel therapeutic targets is urgently needed. Several long noncoding RNAs (lncRNAs) have been reported to be correlated with UCB progression. In this study, we found that the subtype-specific lncRNA MIR4435-2 host gene (MIR4435-2HG) plays a novel oncogenic role in UCB. RNA-Seq data of TCGA/BLCA were analyzed. The expression of MIR4435-2HG was measured by qRT-PCR in 16 pairs of bladder cancer tissues and adjacent normal tissues. The clinical relecance of MIR4435-2HG was validated via in situ hybridization performed on an in-house cohort of 116 UCB patient samples. RNA pull-down followed by mass spectrometry was performed to identify MIR4435-2HG-binding proteins. To identify signaling pathways involved in MIR4435-2HG activity, comprehensive in vitro and in vivo studies and RNA-Seq assays were performed using UCB cells in which MIR4435-2HG expression was knocked down or exogenously overexpressed. In addition, we performed RNA immunoprecipitation and Western blot analyses to validate the identified MIR4435-2HG-binding proteins and to determine the molecular mechanisms by which MIR4435-2HG promotes UCB progression. We found that MIR4435-2HG was significantly upregulated in the stromal-enriched subtype of UCB. Increased MIR4435-2HG expression was positively correlated with a high histological grade, advanced T stages, larger tumors, lymph node metastasis and a poor prognosis. In vitro experiments revealed that MIR4435-2HG expression silencing suppressed cell proliferation and induced apoptosis. Inhibition of MIR4434-2HG delayed xenograft tumor growth, while MIR4435-2HG overexpression reversed the MIR4435-2HG silencing-induced inhibition of UCB tumor phenotype acquisition. Mechanistically, we found that MIR4435-2HG positively regulated the expression of a variety of cell cycle regulators, including BRCA2 and CCND1. Knocking down MIR4435-2HG increased the sensitivity of tumor cells to the VEGFR inhibitor cediranib. Furthermore, we found that MIR4435-2HG regulated mTOR signaling and epithelial-mesenchymal transition (EMT) signaling pathways by modulating the phosphorylation of mTOR, 70S6K and 4EBP1. Finally, we confirmed that MIR4435-2HG enhances tumor metastasis through regulation of the EMT pathway. Our data indicate that upregulated MIR4435-2HG expression levels are significantly correlated with a poor prognosis of UCB patients. MIR4435-2HG promotes bladder cancer progression, mediates cell cycle (de)regulation and modulates mTOR signaling. MIR4435-2HG is an oncogenic lncRNA in UCB that may serve as a diagnostic and therapeutic target.

Pei L ，Yan D ，He Q ，Kong J ，Yang M ，Ruan H ，Lin Q ，Huang L ，Huang J ，Lin T ，Qin H ... -  《-》

Hsa-miR-1 downregulates long non-coding RNA urothelial cancer associated 1 in bladder cancer.

Wang T ，Yuan J ，Feng N ，Li Y ，Lin Z ，Jiang Z ，Gui Y ... -  《-》

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 ... -  《-》