scholarly journals Long noncoding RNA LINC00261 upregulates ITIH5 to impair tumorigenic ability of pancreatic cancer stem cells

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Lijuan Zou ◽  
Hengpeng He ◽  
Zhiguo Li ◽  
Ou Chen ◽  
Xiukun Jia ◽  
...  

AbstractLong noncoding RNAs (lncRNAs) are implicated tumor development in a range of different cancers, including pancreatic cancer (PC). Cancer stem cells (CSCs), a drug-resistant cancer cell subset, drive tumor progression in PC. In this work, we aimed to investigate the mechanism by which lncRNA LINC00261 affects the biological functions of CSCs during the progression of PC. Microarray analysis of differentially expressed genes and lncRNAs suggested that LINC00261 is downregulated in PC. Both LINC00261 and ITIH5 were confirmed to be downregulated in PC cells and PC stem cells. Gain-of-function and loss-of-function investigations were performed to analyze their effects on cell proliferation, drug resistance, cell cycle distribution, self-renewal, invasion, and ultimately overall tumorigenicity. These experiments revealed that the expression of stem cell markers was reduced, and cell proliferation, self-renewal ability, cell invasion, drug resistance, and tumorigenicity were all suppressed by upregulation of LINC00261 or ITIH5. The results of dual-luciferase reporter gene, ChIP, and RIP assays indicated that LINC00261 binds directly to GATA6, increasing its activity at the ITIH5 promoter. The presence of LINC00261 and GATA6 inhibited the self-renewal and tumorigenesis of PC stem cells, while silence of ITIH5 rescued those functions. Collectively, this study identifies the tumor suppressive activity of LINC00261 in PC, showing that this lncRNA limits the functions of PC stem through an ITIH5/GATA6 regulatory pathway.

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yu-Shui Ma ◽  
Xiao-Li Yang ◽  
Yu-Shan Liu ◽  
Hua Ding ◽  
Jian-Jun Wu ◽  
...  

Abstract Background Cancer stem cells (CSCs) are key regulators in the processes of tumor initiation, progression, and recurrence. The mechanism that maintains their stemness remains enigmatic, although the role of several long noncoding RNAs (lncRNAs) has been highlighted in the pancreatic cancer stem cells (PCSCs). In this study, we first established that PCSCs overexpressing lncRNA NORAD, and then investigated the effects of NORAD on the maintenance of PCSC stemness. Methods Expression of lncRNA NORAD, miR-202-5p and ANP32E in PC tissues and cell lines was quantified after RNA isolation. Dual-luciferase reporter assay, RNA pull-down and RIP assays were performed to verify the interactions among NORAD, miR-202-5p and ANP32E. We then carried out gain- and loss-of function of miR-202-5p, ANP32E and NORAD in PANC-1 cell line, followed by measurement of the aldehyde dehydrogenase activity, cell viability, apoptosis, cell cycle distribution, colony formation, self-renewal ability and tumorigenicity of PC cells. Results LncRNA NORAD and ANP32E were upregulated in PC tissues and cells, whereas the miR-202-5p level was down-regulated. LncRNA NORAD competitively bound to miR-202-5p, and promoted the expression of the miR-202-5p target gene ANP32E thereby promoting PC cell viability, proliferation, and self-renewal ability in vitro, as well as facilitating tumorigenesis of PCSCs in vivo. Conclusion Overall, lncRNA NORAD upregulates ANP32E expression by competitively binding to miR-202-5, which accelerates the proliferation and self-renewal of PCSCs.


2013 ◽  
Author(s):  
Yumi Miyazaki ◽  
Qiang Ding ◽  
Makoto Yoshimitsu ◽  
Toru Obara ◽  
Koichirou Tsukasa ◽  
...  

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13543-e13543
Author(s):  
Monal Mehta ◽  
Atif J. Khan ◽  
Hatem E. Sabaawy ◽  
Bruce George Haffty

e13543 Background: Glioblastoma (GBM) is the most frequent and deadly brain cancer. Despite tolerance doses of radiation, control of tumor growth within the brain remains a formidable failure. Since the identification of brain cancer stem cells (BCSCs), efforts are underway to target the pathways regulating these cells. The role of Bmi-1 (B-cell specific MMLV insertion site-1), a polycomb member of chromatin-remodeling complex, in BCSCs self-renewal was elucidated. Here we utilize shRNA targeting or pharmacological inhibition of Bmi-1 in GBM cell lines and primary cells as a radiosensitizer to examine the effects of combination therapy on cell death and BCSCs differentiation. Methods: Cells were pre-treated with a Bmi-1 inhibitor before being irradiated. Serial neurosphere assay, a measure of self-renewal potential, was employed to study the effects of radiation, Bmi-1 inhibition, or the combination on BCSCs. The efficacy of this combination on cell death was assessed with MTT and clonogenic assays. Next, the abilities of the inhibitor and radiation to induce differentiation in GBM cell lines and primary cells were quantified. Further, by utilizing a novel zebrafish orthotropic xenograft model, small molecules targeting Bmi-1 and other BCSC pathways can be identified, and used to predict response to combination therapies. Results: Targeting of Bmi-1 in combination with radiation, specifically as a radiosensitizer, induced significant cell death in GBM cells, and was five-fold more effective than radiation only. Importantly, the neurosphere forming ability of BCSCs was severely compromised when the cells were treated with the combination, indicating a potent effect on the stem cell constituency. These effects may be due to loss of BCSC self-renewal potential, increased differentiation, and/or apoptosis as cells treated with the combination exhibited decreased expression of neural stem cell markers and abnormal phenotypes compared to single treatment. Conclusions: Targeting of Bmi-1 may eliminate the subpopulation of radioresistant BCSCs. Bmi-1 inhibition when combined with radiotherapy might provide an effective therapy for GBM patients specifically through its effect on BCSCs by affecting their survival, proliferation, and stem cell features.


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