scholarly journals Circular RNA CircEYA3 induces energy production to promote pancreatic ductal adenocarcinoma progression through the miR-1294/c-Myc axis

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Zeyin Rong ◽  
Si Shi ◽  
Zhen Tan ◽  
Jin Xu ◽  
Qingcai Meng ◽  
...  

Abstract Background Extensive studies have demonstrated the pivotal roles of circular RNAs (circRNAs) in the occurrence and development of different human cancers. However, the expression and regulatory roles of circRNAs in pancreatic ductal adenocarcinoma (PDAC) are unclear. Methods CircEYA3 was explored based on Gene Expression Omnibus (GEO) dataset analysis. qRT-PCR was applied to determine the expression of circRNAs, miRNAs and mRNAs in PDAC cells and tissues. The biological roles of circEYA3 in vitro and in vivo were determined by performing a series of functional experiments. Further, dual luciferase reporter, fluorescence in situ hybridization (FISH), RNA pull-down assays, and RNA immunoprecipitation (RIP) assays were used to confirm the interaction of circEYA3 with miR-1294. Results CircEYA3 was elevated in PDAC tissues and cells, and a higher level of circEYA3 was significantly associated with a poorer prognosis in patients with PDAC. Functionally, circEYA3 increased energy production via ATP synthesis to promote PDAC progression in vitro and in vivo. Mechanistically, circEYA3 functions as an endogenous miR-1294 sponge to elevate c-Myc expression, thus exerting its oncogenic functions. Conclusion CircEYA3 promotes the progression of PDAC through the miR-1294/c-Myc signalling axis, and circEYA3 may be an efficient molecular therapeutic target in PDAC.

Author(s):  
Taoyue Yang ◽  
Peng Shen ◽  
Qun Chen ◽  
Pengfei Wu ◽  
Hao Yuan ◽  
...  

Abstract Background Circular RNAs (circRNAs) are becoming a unique member of non-coding RNAs (ncRNAs) with emerging evidence of their regulatory roles in various cancers. However, with regards to pancreatic ductal adenocarcinoma (PDAC), circRNAs biological functions remain largely unknown and worth investigation for potential therapeutic innovation. Methods In our previous study, next-generation sequencing was used to identify differentially expressed circRNAs in 3 pairs of PDAC and adjacent normal tissues. Further validation of circRHOBTB3 expression in PDAC tissues and cell lines and gain-and-loss function experiments verified the oncogenic role of circRHOBTB3. The mechanism of circRHOBTB3 regulatory role was validated by pull-down assays, RIP, luciferase reporter assays. The autophagy response of PANC-1 and MiaPaca-2 cells were detected by mCherry-GFP-LC3B labeling and confocal microscopy, transmission electron microscopy and protein levels of LC3B or p62 via Western blot. Results circRHOBTB3 is highly expressed in PDAC cell lines and tissues, which also promotes PDAC autophagy and then progression in vitro and in vivo. Mechanistically, circRHOBTB3 directly binds to miR-600 and subsequently acts as a miRNA-sponge to maintain the expression level of miR-600-targeted gene NACC1, which facilitates the autophagy response of PDAC cells for adaptation of proliferation via Akt/mTOR pathway. Moreover, the RNA-binding protein FUS (FUS) directly binds to pre-RHOBTB3 mRNA to mediate the biogenesis of circRHOBTB3. Clinically, circRHOBTB3, miR-600 and NACC1 expression levels are correlated with the prognosis of PDAC patients and serve as independent risk factors for PDAC patients. Conclusions FUS-mediated circRHOBTB3 functions as a tumor activator to promote PDAC cell proliferation by modulating miR-600/NACC1/Akt/mTOR axis regulated autophagy.


2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Hua Guan ◽  
Wei Luo ◽  
Yuping Liu ◽  
Mingfei Li

AbstractIncreasing evidence has indicated the great diagnostic and therapeutic potentials of circular RNAs (circRNAs) in human cancers. Although the biological roles of circRNAs in pancreatic ductal adenocarcinoma (PDAC) have been partially annotated, the potential regulatory mechanism of circRNAs in PDAC tumorigenesis remains poorly understood. Here, our study found that the novel circRNA circSLIT2 was significantly upregulated in PDAC tissues and cells. Clinically, ectopic high-expression of circSLIT2 was correlated with unfavorable prognosis of PDAC patients. Functional experiments demonstrated that circSLIT2 promoted the aerobic glycolysis and proliferation of PDAC cells in vitro, and circSLIT2 knockdown inhibited tumor growth in vivo. Mechanistically, circSLIT2 acted as miRNA sponge to target miR-510-5p/c-Myc axis. Furthermore, c-Myc bound with the promoter region of lactate dehydrogenase A (LDHA) to activate the transcription. Collectively, present findings reveal that circSLIT2/miR-510-5p/c-Myc/LDHA axis participates in the aerobic glycolysis and carcinogenesis of PDAC, and may act as a promising therapeutic target.


2021 ◽  
Vol 11 ◽  
Author(s):  
Yuqiong Wang ◽  
Dan Wang ◽  
Yanmiao Dai ◽  
Xiangyu Kong ◽  
Xian Zhu ◽  
...  

It has been shown that aberrant activation of the Hedgehog (Hh) and nuclear factor-kappa B (NF-κB) signaling pathways plays an important role in the pancreatic carcinogenesis, and KRAS mutation is a hallmark of pancreatic ductal adenocarcinoma (PDAC). Until now, the role of KRAS mutation in the context of crosstalk between Hh and NF-κB signaling pathways in PDAC has not been investigated. This study was to determine whether the crosstalk between the Hh and NF-κB pathways is dependent on KRAS mutation in PDAC. The correlation between Gli1, Shh, NF-κB p65 expression and KRAS mutation in PDAC tissues was firstly examined by immunohistochemistry. Next, Western blotting, qPCR, and immunofluorescence were conducted to examine the biological effects of interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α) as NF-κB signaling agonists, Shh as an Hh ligand alone or in combination with KRAS small interfering RNA (si-KRAS) in KRAS-mutant PDAC cells (MT-KRAS; SW1990 and Panc-1), wild-type KRAS PDAC cells (WT-KRAS; BxPC-3) and mutant KRAS knock-in BxPC-3 cells in vitro as well as tumor growth in vivo. KRAS mutation-dependent crosstalk between Hh and NF-κB in PDAC cells was further assessed by Ras activity and luciferase reporter assays. The aberrant Hh and NF-κB pathway activation was found in PDAC tissues with KRAS mutation. The same findings were confirmed in MT-KRAS PDAC cells and MT-KRAS knock-in BxPC-3 cells, whereas this activation was not observed in WT-KRAS PDAC cells. However, the activation was significantly down-regulated by KRAS silencing in MT-KRAS PDAC cells. Furthermore, MT-KRAS cancer cell proliferation and survival in vitro and tumor growth after inoculation with MT-KRAS cells in vivo were promoted by NF-κB and Hh signaling activation. The pivotal factor for co-activation of NF-κB and Hh signaling is MT-KRAS protein upregulation, showing that positive crosstalk between Hh and NF-κB pathways is dependent upon KRAS mutation in PDAC.


2015 ◽  
Vol 35 (1) ◽  
pp. 184-190 ◽  
Author(s):  
Weifeng Song ◽  
Qi Li ◽  
Lei Wang ◽  
Liwei Wang

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal primary tumors in humans, with undetermined tumorigenesis. Although previous work by us, and by others, has clearly demonstrated an involvement of miR-21 in the growth of PDAC, the underlying mechanism has not been clarified. Methods: Here we analyzed the regulation of FoxO1 by miR-21 in vitro and in vivo, using luciferase-reporter assay and pancreatic intraductal infusion of antisense of miR-21, respectively. Results: We found that overexpression of miR-21 in PDAC cells decreased FoxO1 protein levels, whereas inhibition of miR-21 increased FoxO1 levels. Further, miR-21 bound to FoxO1 mRNA to prevent its translation through its 3'UTR. Moreover, administration of antisense of miR-21 through an intraductal infusion system significantly decreased miR-21 levels and increased FoxO1 levels in implanted PDAC, resulting in a significant decrease in PDAC growth. Conclusion: Taken together, our data highlight miR-21/FoxO1 axis as a novel therapeutic target for inhibiting the growth of PDAC.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Dandan Zheng ◽  
Xianxian Huang ◽  
Juanfei Peng ◽  
Yanyan Zhuang ◽  
Yuanhua Li ◽  
...  

AbstractEmerging evidence has demonstrated that circular RNAs (circRNAs) take part in the initiation and development of pancreatic ductal adenocarcinoma (PDA), a deadly neoplasm with an extremely low 5-year survival rate. Reprogrammed glucose metabolism is a key feature of tumour development, including PDA. In this research, we evaluated the role of circRNAs in reprogrammed glucose metabolism in PDA. RNA sequencing under various glucose incubation circumstances was performed. A new circMYOF was identified. Sanger sequencing and RNase R treatment confirmed its circular RNA characteristics. Real-time PCR indicated that it was highly expressed in PDA clinical specimens and cell lines. Gain-of- and loss-of-function assays showed that circMYOF induced progression in PDA. Mechanistically, RNA pull-down and luciferase reporter experiments elucidated that circMYOF, as a competing endogenous RNA for miR-4739, facilitated glycolysis via the VEGFA/PI3K/AKT pathway. Taken together, our findings indicate that circMYOF may work as a desirable biomarker and therapeutic target for PDA patients.


Author(s):  
Guangli Sun ◽  
Zheng Li ◽  
Zhongyuan He ◽  
Weizhi Wang ◽  
Sen Wang ◽  
...  

Abstract Background Cisplatin (CDDP) is the first-line chemotherapy for gastric cancer (GC). The poor prognosis of GC patients is partially due to the development of CDDP resistance. Circular RNAs (circRNAs) are a subclass of noncoding RNAs that function as microRNA (miRNA) sponges. The role of circRNAs in CDDP resistance in GC has not been evaluated. Methods RNA sequencing was used to identify the differentially expressed circRNAs between CDDP-resistant and CDDP-sensitive GC cells. qRT-PCR was used to detect the expression of circMCTP2 in GC tissues. The effects of circMCTP2 on CDDP resistance were investigated in vitro and in vivo. Pull-down assays and luciferase reporter assays were performed to confirm the interactions among circMCTP2, miR-99a-5p, and myotubularin-related protein 3 (MTMR3). The protein expression levels of MTMR3 were detected by western blotting. Autophagy was evaluated by confocal microscopy and transmission electron microscopy (TEM). Results CircMCTP2 was downregulated in CDDP-resistant GC cells and tissues compared to CDDP-sensitive GC cells and tissues. A high level of circMCTP2 was found to be a favorable factor for the prognosis of patients with GC. CircMCTP2 inhibited proliferation while promoting apoptosis of CDDP-resistant GC cells in response to CDDP treatment. CircMCTP2 was also found to reduce autophagy in CDDP-resistant GC cells. MiR-99a-5p was verified to be sponged by circMCTP2. Inhibition of miR-99a-5p could sensitize GC cells to CDDP. MTMR3 was confirmed to be a direct target of miR-99a-5p. Knockdown of MTMR3 reversed the effects of circMCTP2 on the proliferation, apoptosis and autophagy of CDDP-resistant GC cells. CircMCTP2 was also confirmed to inhibit CDDP resistance in vivo in a nude mouse xenograft model. Conclusions CircMCTP2 sensitizes GC to CDDP through the upregulation of MTMR3 by sponging miR-99a-5p. Overexpression of CircMCTP2 could be a new therapeutic strategy for counteracting CDDP resistance in GC.


2021 ◽  
Author(s):  
Penghui Xu ◽  
Xing Zhang ◽  
Jiacheng Cao ◽  
Jing Yang ◽  
Zetian Chen ◽  
...  

Abstract Background: Gastric cancer (GC) ranks third in motality among all cancers worldwide. Circular RNAs (circRNAs) play essential roles in the malignant progression and metastasis of gastric cancer. As a transcription factor, FOXP2 is involved in the progression of many tumours. However, the regulation and association between circRNAs and FOXP2 remain to be discovered. Methods: RNA sequencing was used to explore differential circRNA expression profile in gastric cancer and quantitative real-time PCR (qRT-PCR) were used to detect circST3GAL6 expression. The cellular location of circST3GAL6 was determined by fluorescence in situ hybridization (FISH). Functional experiments in circST3GAL6 knockdown and overexpression cell lines were performed in vitro and in vivo. The correlation between circST3GAL6 and miR-300 was confirmed by the RNA pull-down assay, dual-luciferase reporter assay and fluorescence in situ hybridization (FISH). The effects of circST3GAL6 on autophagy were detected by confocal microscopy and transmission electron microscopy (TEM). The mechanism of the circST3GAL6/miR-300/FOXP2 axis was verified by western blotting. The transcriptional regulation of Met by FOXP2 was proven by ChIP and luciferase reporter assays.Results: CircST3GAL6 was significantly depressed in GC tissues and cells. circST3GAL6 overexpression inhibited the proliferation, invasion and metastasis of GC cells in vitro and in vivo. Importantly, circST3GAL6 overexpression induced apoptosis and promote autophagy in GC cells. Furthermore, we found that circST3GAL6 sponged miR-300 and subsequently regulated FOXP2. We further revealed that FOXP2 suppressed the activation of the Met/AKT/mTOR axis, a classic pathway that regulates autophagy-mediated proliferation and migration.Conclusion: Our findings revealed that circST3GAL6 functions as a tumour suppressor through the miR-300/FOXP2 axis in GC, regulates apoptosis and autophagy through FOXP2-mediated transcriptional inhibition of the MET axis and may be a biomarker for GC treatment.


2018 ◽  
Vol 50 (3) ◽  
pp. 823-840 ◽  
Author(s):  
Dan-ming Wei ◽  
Yi-wu Dang ◽  
Zhen-bo Feng ◽  
Lu Liang ◽  
Lu Zhang ◽  
...  

Background/Aims: Accumulating evidence strongly suggests that microRNAs (miRNAs) modulate the expression of known tumor suppressor genes and oncogenes. In the present study, we found that the proliferation and invasion ability of pancreatic ductal adenocarcinoma (PDAC) cells were significantly suppressed by the overexpression of miR-23b-3p. In addition, there are miR-23b-3p binding sites in annexin A2 (ANXA2). Here, we investigated whether miR-23b-3p had an impact on the progression and metastasis of PDAC by targeting ANXA2. Methods: Cell proliferation, migration, and invasion, and cell cycle assays were performed to explore the effect of miR-23b-3p on various malignant phenotypes of pancreatic cancer cells. The size of tumors was observed following miR-23b-3p overexpression in an in vivo chick chorioallantoic membrane assay. Dual-luciferase reporter, quantitative real-time PCR, western blot, and immunohistochemical analyses were used to validate the relationship between miR-23b-3p and ANXA2 in vitro. Results: We observed that miR-23b-3p could bind specifically to the 3′ untranslated region of ANXA2 and inhibit its expression. MiR-23b-3p overexpression downregulated the expression of ANXA2 mRNA in PDAC cells and limited the size of tumors or even prevented tumor formation. In addition, there was a negative correlation between miR-23b-3p expression and ANXA2 protein expression in clinical specimens. Conclusion: MiR-23b-3p inhibits the development and progression of PDAC by regulating ANXA2 directly.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yixiang Huang ◽  
Wenfang Zheng ◽  
Changle Ji ◽  
Xuehui Wang ◽  
Yunhe Yu ◽  
...  

AbstractBreast cancer (BC) is one of the most fatal diseases among women all over the world. Non-coding RNAs including circular RNAs (circRNAs) have been reported to be involved in different aspects during tumorigenesis and progression. In this study, we aimed to explore the biological functions and underlying mechanism of circRPPH1 in BC. Candidate circRNAs were screened in dataset GSE101123 from Gene Expression Omnibus (GEO) database and a differentially expressed circRNA, circRPPH1, was discovered in BC. CircRPPH1 expression was higher in the cancerous tissue compared to paired adjacent tissue. Further in vitro and in vivo experiments indicated that circRPPH1 acted as an oncogene in BC. In addition, circRPPH1 was mainly localized in cytoplasm and played the role of miR-512-5p sponge. By sequestering miR-512-5p from the 3′-UTR of STAT1, circRPPH1 inhibited the suppressive role of miR-512-5p, stabilized STAT1 mRNA in BC and finally affected BC progression. In conclusion, these findings indicated that circRPPH1 acted as an oncogene and regulated BC progression via circRPPH1-miR-512-5p-STAT1 axis, which might provide a potential therapeutic target for BC treatment.


2020 ◽  
Author(s):  
Dianqi Hou ◽  
Zhenlin Wang ◽  
Haimeng Li ◽  
Juan Liu ◽  
Yaohua Liu ◽  
...  

Abstract background: Glioblastoma Multiform (GBM) is the primary malignancy with the highest incidence and worst prognosis in the adult CNS. Circular RNAs (circRNAs) are a novel and widely diverse class of endogenous non-coding RNAs that can promote or inhibit gliomagenesis. Our study aimed to explore the role of circASPM in GBM and its molecular mechanism.Methods: Levels of circASPM, miR-130b-3p and E2F1 were determined by quantitative real-time PCR (qRT-PCR) or western blotting assay. MTS, Edu, neurospheres formation and extreme limiting dilution assays were used to detect the tumorigenesis and proliferation of GSCs in vitro. The interactions between miR-130b-3p and circASPM or E2F1 was demonstrated via qPCR, western blotting, dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Xenograft experiments was used to analyze tumor growth in vivo.Results: CircASPM was overexpressed in GBM and could promote the tumorigenesis and proliferation of GSCs both in vitro and in vivo. Mechanistically, circASPM up-regulated the expression of E2F1 in GSCs via miR-130b-3p sponging. We furtherly demonstrated that circAPSM could promote the GSCs proliferation via E2F1 up-regulating. Therefore, our study identified a novel circRNA and its possible mechanism in the development and tumorigenesis of GBM.Conclusions: CircASPM can promote GBM progression via regulating miR-130b-3p/E2F1 axis, suggesting that circAPSM could provide an effective biomarker for GBM diagnosis and prognostic evaluation and possibly being used for molecular targeted therapy.


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