lncRNA UCA1 induced by SP1 and SP3 forms a positive feedback loop to facilitate malignant phenotypes of colorectal cancer via targeting miR-495.

Long noncoding RNA (LncRNA) urothelial cancer associated 1 (UCA1) was dysregulated in colorectal cancers (CRC) and promoted tumor progression of CRC. The aims of this study are to further investigate the underlying mechanism. Short hairpin RNAs (shRNAs) were applied for gene knockdown. microRNA mimic and pcDNA-UCA1 plasmids were transfected for miR-495 and UCA1 overexpression, respectively. MTT was applied to determine cell viability and sensitivity of 5-fluorouracil (FU). Transwell assays were performed to evaluate cell migration/invasion. Angiogenesis was evaluated by tube formation. Western blotting and quantitative PCR were utilized for protein and mRNA detection, respectively. The interaction of UCA1, miR-495 and SP1/SP3 were explored by dual-luciferase assay. RNA pulldown was adopted to determine the UCA1/miR-495 interaction. UCA1 was significantly upregulated in CRC tissues. UCA1 enhanced cell proliferation, migration/invasion, angiogenesis, epithelial-mesenchymal transition, and resistance to 5-FU in CRC cell lines. MiR-495 was inversely correlated to the expression of UCA1. The results indicated that UCA1 sponged miR-495, leading to the disinhibition of SP1/SP3 expression. SP1/SP3 induced the expression of DNA methyltransferases and, in turn, contributed to UCA1 mediated tumor-promoting actions. Reduction of SP1/SP3 exerted anti-cancer effects, which can be reversed by forced expression of UCA1. UCA1-miR-495-SP1/SP3 axis is dysregulated in CRC and contributed to malignant phenotypes of CRC. UCA1-SP1/SP3 may form a positive feedback loop in CRC.

Liu SJ ，Li ZQ ，Wang XY ，Liu F ，Xiao ZM ，Zhang DC ... -  《-》

Transcription factor SP1-induced microRNA-146b-3p facilitates the progression and metastasis of colorectal cancer via regulating FAM107A.

Recent studies have provided compelling evidence regarding the association of microRNAs (miRNAs) with the progression and development of tumors. Among the miRNAs, the dysregulation of miR-146b-3p expression has been reported in several cancers, however, its effect on colorectal cancer (CRC) remains unexplored. Many studies have suggested a close correlation between the transcription factor (TF)-miRNA signal and cancer. The present study explored the effects of TF-miR-146b-3p axis on CRC and elucidated its downstream regulatory molecule. The expression levels of miR-146b-3p in CRC tissues and cell lines were assessed via quantitative real-time polymerase chain reaction (qRT-PCR). The impact of miR-146b-3p on CRC cell proliferation, migration, and invasion were analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cell proliferation assay and transwell migration and invasion assay. Additionally, the impact of miR-146b-3p on CRC cell cycle and apoptosis was investigated using flow cytometry. The targets of miR-146b-3p, predicted by miRWalk database, were verified using a dual-luciferase reporter system. The expression levels of TFs were detected using qRT-PCR. The effects of miR-146b-3p and SP1 on FAM107A expression were assessed by performing qRT-PCR and western blotting. Chromatin Immunoprecipitation (ChIP) Assay was performed and JASPAR database was utilized to explore the regulatory relationship between the SP1 and miR-146b-3p. Increased expression of miR-146b-3p in CRC tissues and cell lines correlated with poor overall survival (OS). Upregulation of miR-146b-3p expression remarkably promoted the proliferation, migration, and invasion of CRC cells and suppressed their apoptosis. Furthermore, SP1 overexpression significantly elevated the miR-146b-3p expression, decreased the FAM107A expression, and promoted the G1/S transition. The miR-146b-3p overexpression also enhanced the effects of SP1 overexpression on CRC cell proliferation, migration, and invasion, whereas miR-146b-3p knockdown led to the opposite results. Mechanistically, miR-146b-3p functions as an oncogene by directly targeting FAM107A. Our results highlight the critical regulatory role played by SP1-induced miR-146b-3p expression in CRC development. Our results suggest that SP1/miR-146b-3p/FAM107A axis may be a potential therapeutic target for CRC.

Wang D ，Feng M ，Ma X ，Tao K ，Wang G ... -  《-》

Downregulated lncRNA UCA1 acts as ceRNA to adsorb microRNA-498 to repress proliferation, invasion and epithelial mesenchymal transition of esophageal cancer cells by decreasing ZEB2 expression.

Wang P ，Liu X ，Han G ，Dai S ，Ni Q ，Xiao S ，Huang J ... -  《-》

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 ... -  《-》

Knockdown of long noncoding RNA urothelial carcinoma-associated 1 inhibits cell viability, migration, and invasion by regulating microRNA-182 in gastric carcinoma.

Long noncoding RNA urothelial carcinoma-associated 1 (UCA1) has been reported to be a vital mediator in various cancers. But, in terms of gastric cancer (GC), the effects of UCA1 on GC cell proliferation, migration, invasion, and apoptosis remain unclear. This study aimed to uncover the potential regulatory mechanism of UCA1 in GC cells. The expression level of UCA1 was first examined in the five different cell lines of HEK293, CCL-153, HUVEC, SUN-216, and SGC-7901 using a reverse-transcriptase quantitative polymerase chain reaction. Then, the vectors of short hairpin UCA1, the microRNA-182 (miR-182) mimic/inhibitor, and the pEX-tissue inhibitor of metalloproteinases 2 (TIMP2)/small interfering TIMP2 were transfected into SUN-216 and SGC-7901 cells to alter UCA1, miR-182, and TIMP2 expression. To investigate the biological functions, cell viability, migration, invasion, and apoptosis were examined by Cell Counting Kit-8, Transwell, and flow cytometry. The key factors of apoptosis and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/glycogen synthase kinase 3β (GSK3β) and nuclear factor κB (NF-κB) signal pathways were determined by Western blot analysis. UCA1 was upregulated in SUN-216 and SGC-7901 cells than in the other three cell lines of HEK293, CCL-153, and HUVEC. Knockdown of UCA1 significantly suppressed cell viability, migration, and invasion, and promoted apoptosis by regulating B-cell lymphoma 2, Bax, and cleaved-caspase-3/9 expressions. However, miR-182 overexpression markedly reversed the regulatory effect of UCA1 knockdown on SUN-216 and SGC-7901 cells. TIMP2 was a direct target gene of miR-182, and TIMP2 overexpression exhibited the same effect of UCA1 knockdown on cell viability, migration, invasion, and apoptosis. Besides, miR-182 activated PI3K/AKT/GSK3β and NF-κB signal pathways by regulation of TIMP2. Knockdown of UCA1 exerts an anticancer effect on GC cells by regulating miR-182.

Qin L ，Jia Z ，Xie D ，Liu Z ... -  《-》