scholarly journals circHMGCS1–016 reshapes immune environment by sponging miR-1236-3p to regulate CD73 and GAL-8 expression in intrahepatic cholangiocarcinoma

Author(s):  
Ya-Ping Xu ◽  
Ze-Ning Dong ◽  
Si-Wei Wang ◽  
Yi-Min Zheng ◽  
Chi Zhang ◽  
...  

Abstract Background Accumulating evidence indicates that circRNAs may serve as essential regulators in the progression of several human cancers, but the function and mechanism of circRNAs in intrahepatic cholangiocarcinoma (ICC) are largely unknown. Methods RNA-seq was used to assess differentially expressed circRNAs between 4 ICC and peritumor tissues. Quantitative RT-PCR and in situ hybridization were used to determine the circHMGCS1–016 expression in ICC tissues. The function and mechanism of circHMGCS1–016 were further identified via in vivo experiments. The clinical characteristics and prognostic significance of circHMGCS1–016 were analyzed by a retrospective study. The functions of circHMGCS1–016 were assessed via modifying circRNA expression in ICC cells. Moreover, the molecular mechanisms of circHMGCS1–016 in ICC cells were explored by circRNA precipitation, miRNA immunoprecipitation, SILAC and luciferase reporter assays. Results We identified that compared with peritumor tissues, ICC tissues expressed hsa_circ_0008621 (circHMGCS1–016) high by RNA-seq, which was further identified by qRT-PCR and in situ hybridization. Moreover, the expression of circHMGCS1–016 was revealed to be associated with survival and recurrence of ICC patients. By regulating circHMGCS1–016 expression, we found that elevated circHMGCS1–016 promoted ICC development both in vitro and in vivo. By SILAC and circRNA-pull down, we demonstrated that circHMGCS1–016 induced ICC cell invasion and reshaped the tumor immune microenvironment via the miR-1236-3p/CD73 and GAL-8 axis. In ICC tissues, we uncovered that a high level of circHMGCS1–016 was positively associated with CD73 and GAL-8 expression and negatively related to the CD8+ T cells infiltration, which was further validated by establishing a humanized mouse tumor model. Importantly, we displayed that ICC patients with high levels of circHMGCS1–016 in tumor tissues benefited less from anti-PD1 treatment compared to those with low levels of circHMGCS1–016. Conclusions CircHMGCS1–016 is a forceful contributor in ICC development and immune tolerance via miR-1236-3p/CD73 and GAL-8 axis. CircHMGCS1–016 can be explored as a new potential biomarker and therapeutic target for PD1-resistant ICC.

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Xiaosong Wang ◽  
Lei Xing ◽  
Rui Yang ◽  
Hang Chen ◽  
Min Wang ◽  
...  

Abstract Background Recent studies have revealed that circular RNAs (circRNAs) play significant roles in the occurrence and development of many kinds of cancers including breast cancer (BC). However, the potential functions of most circRNAs and the molecular mechanisms underlying progression of BC remain elusive. Method Here, Circular RNA microarray was executed in 4 pairs of breast cancer tissues and para-cancer tissues. The expression and prognostic significance of circACTN4 in BC cells and tissues were determined by qRT-PCR and in situ hybridization. Gain-and loss-of-function experiments were implemented to observe the impacts of circACTN4 on the growth, invasion, and metastasis of BC cells in vitro and in vivo. Mechanistically, chromatin immunoprecipitation, luciferase reporter, RNA pulldown, mass spectrum, RNA immunoprecipitation, fluorescence in situ hybridization and co-immunoprecipitation assays were executed. Results CircACTN4 was significantly upregulated in breast cancer tissues and cells, its expression was correlated with clinical stage and poor prognosis of patients with BC. Ectopic expression of circACTN4 strikingly facilitated the growth, invasion, and metastasis of breast cancer cells in vitro and in vivo. Whereas knockdown of circACTN4 revealed opposite roles. CircACTN4 was mainly distributed in the nucleus. Further mechanistic research proved that circACTN4 could competitively bind to far upstream element binding protein 1 (FUBP1) to prevent the combination between FUBP1 and FIR, thereby activating MYC transcription and facilitating tumor progression of breast cancer. Furthermore, we found that upstream transcription factor 2 (USF2) might promote the biogenesis of circACTN4. Conclusion Our findings uncover a pivotal mechanism that circACTN4 mediated by USF2 might interact with FUBP1 to promote the occurrence and development of breast cancer via enhancing the expression of MYC. CircACTN4 could be a novel potential target for diagnosis and treatment of breast cancer.


2020 ◽  
Author(s):  
Wei Zhang ◽  
Bo Wang ◽  
Yang Yang ◽  
Zhen Zhang ◽  
Quan Wang ◽  
...  

Abstract Background circular RNAs (circRNAs) recently have been emerged as vital regulators for involvement of initiation and progression of diverse kinds of human cancers. This study aimed to investigate the role of circRNAs in colorectal cancer (CRC). Methods The expression profile of circRNAs in 5 pairs of CRC tissues and adjacent normal tissues were analyzed by Microarray. Quantitative real-time PCR and in situ hybridization and Base Scope Assay were used to determine the level and prognostic values of hsa_circ_0000231. Then, functional experiments in vitro and in vivo were performed to investigate the effects of hsa_circ_0000231 on cell proliferation. Mechanistically, fluorescent in situ hybridization, dual luciferase reporter assay, RNA pull-down and RNA immunoprecipitation experiments were performed to confirm the interaction between hsa_circ_0000231 and IGF2BP3 or has_miR-375. Results hsa_circ_0000231 was evidently up-regulated in CRC primary tissues, which was indicated to poor prognosis of CRC patients. The results demonstrated that hsa_circ_0000231 could promote CRC cell proliferation as well as tumorigenesis in vitro and in vivo. Mechanistic analysis showed that hsa_circ_0000231 might on the one hand act as a ceRNA (competing endogenous RNA) of miR-375 to regulate cyclin D2 (CCND2), and on the other hand bind to IGF2BP3 protein to protect CCND2 from being degraded. Conclusion Our findings suggest that hsa_circ_0000231 facilitated CRC progression by sponging miR-375 or binding to IGF2BP3 to modulate CCND2. This discovery implied that has_circ_0000231 may be a potential new diagnostic and therapeutic biomarker for CRC.


2020 ◽  
Author(s):  
Dan Zhang ◽  
Zhiwei He ◽  
Yiyi Shen ◽  
Jie wang ◽  
Tao Liu ◽  
...  

Abstract Background: Malignant proliferation and chemotherapy resistance are some of the causes of high mortality in pancreatic cancer. MicroRNAs have long been a hot spot in cancer research and are involved in tumor formation and metabolic stress responses. miR-489-3p is involved in inhibiting the growth of many tumors, but its relationship with the growth and metabolism of pancreatic cancer is not clear. Methods:We used RNA in situ hybridization to analyze the differential expression of miR-489-3p in pancreatic cancer tissues and adjacent tissues. The qRT-PCR experiment detected the content of miR-489-3p in pancreatic cancer cell lines and ordinary pancreatic ductal epithelial cells. Then we did experiments in vivo (subcutaneous tumor formation in nude mice) and in vitro (plate cloning, transwell, glycolysis related experiments) experiments to verify that miR-489-3p can continue the invasion and metastasis of pancreatic cancer and glucose metabolism. Furthermore, we confirmed that LDHA and PKM2 are the two targets of miR-489-3p through dual luciferase reporter gene experiments. Finally, several reply experiments were done to verify the regulation mechanism of miR-489-3p.Results: We determined that miR-489-3p is under-expressed in pancreatic cancer tissues by RNA in situ hybridization, and the function acquisition and deletion experiments and glycolysis experiments confirmed that miR-489-3p can inhibit the proliferation and invasion of Glycolysis. We then analyzed the website to find that miR-489-3p can target LDHA and PKM, and then we verified this finding with a luciferase report experiment. Therefore, we proceeded with recovery experiments on LDHA and PKM2, and concluded that miR-489-3p performs its function by targeting LDHA and PKM2. Finally, in vivo experiments confirmed that highly expressed miR-489-3p inhibited the growth of pancreatic cancer. Conclusion: In short, we identified miR-489-3p as a novel chemotherapy target for pancreatic cancer, and its diagnostic value deserves further study.


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.


Author(s):  
Xiaojian Zhu ◽  
Fanqin Bu ◽  
Ting Tan ◽  
Qilin Luo ◽  
Jinfeng Zhu ◽  
...  

Abstract Background Accumulating evidence indicates that long non-coding RNAs (lncRNAs) acting as crucial regulators in tumorigenesis. However, its biological functions of lncRNAs in colorectal cancer (CRC) have not been systematically clarified. Methods An unbiased screening was performed to identify disregulated lncRNAs revealed to be implicated in CRC carcinogenesis according to an online-available data dataset. In situ hybridization (ISH), RT-qPCR and RNA fluorescence in situ hybridization (RNA-FISH) were applied to detect RP11-757G1.5 expression in CRC tissues and cell lines. The associations of RP11-757G1.5 with clinicopathological characteristics were analyzed. Their effects on prognosis were analyzed by the Kaplan-Meier analysis, Log-rank test, Univariate and Multivariate Cox regression analysis. The potential biological function of RP11-757G1.5 in CRC was investigated by Colony formation, Edu cell proliferation, Flow cytometry, Wound healing and Transwell assays. Bioinformatics binding site analysis, Luciferase reporter assay, Ago2 immunoprecipitation assays, RNA pull-down assay, RT-qPCR and Western blotting were utilized to demonstrate the mechanism of RP11-757G1.5 acts as a molecular sponge of miR-139-5p to regulate the expression of YAP1. Finally, we further explore the potential role of RP11-757G1.5 in CRC orthotopic xenografts in vivo. Results We discovered a novel oncogenic lncRNA RP11-757G1.5, that was overexpressed in CRC tissues, especially in aggressive cases. Moreover, up-regulation of RP11-757G1.5 strongly correlated with poor clinical outcomes of patients with CRC. Functional analyses revealed that RP11-757G1.5 promoted cell proliferation in vitro and in vivo. Furthermore, RP11-757G1.5 stimulated cell migration and invasion in vitro and in vivo. Mechanistic studies illustrated that RP11-757G1.5 regulated the expression of YAP1 through sponging miR-139-5p and inhibiting its activity thereby promoting CRC progression and development. Conclusions Altogether, these results reveal a novel RP11-757G1.5/miR-139-5p/YAP1 regulatory axis that participates in CRC carcinogenesis and progression.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Yaxin Guo ◽  
Yuying Guo ◽  
Chen Chen ◽  
Dandan Fan ◽  
Xiaoke Wu ◽  
...  

Abstract Background Colorectal cancer (CRC) is one of the most common malignant tumours. The recurrence and metastasis of CRC seriously affect the survival rate of patients. Angiogenesis is an extremely important cause of tumour growth and metastasis. Circular RNAs (circRNAs) have been emerged as vital regulators for tumour progression. However, the regulatory role, clinical significance and underlying mechanisms still remain largely unknown. Methods High-throughput sequencing was used to analyse differential circRNAs expression in tumour and non-tumour tissues of CRC. In situ hybridization (ISH) and qRT-PCR were used to determine the level of circ3823 in CRC tissues and serum samples. Then, functional experiments in vitro and in vivo were performed to investigate the effects of circ3823 on tumour growth, metastasis and angiogenesis in CRC. Sanger sequencing, RNase R and Actinomycin D assay were used to verify the ring structure of circ3823. Mechanistically, dual luciferase reporter assay, fluorescent in situ hybridization (FISH), RNA immunoprecipitation (RIP) and RNA pull-down experiments were performed to confirm the underlying mechanisms of circ3823. Results Circ3823 was evidently highly expressed in CRC and high circ3823 expression predicted a worse prognosis of CRC patients. Receiver operating characteristic curves (ROCs) indicated that the expression of circ3823 in serum showed high sensitivity and specificity for detecting CRC which means circ3823 have the potential to be used as diagnostic biomarkers. Functional experiments in vitro and in vivo indicated that circ3823 promote CRC cell proliferation, metastasis and angiogenesis. Mechanism analysis showed that circ3823 act as a competing endogenous RNA of miR-30c-5p to relieve the repressive effect of miR-30c-5p on its target TCF7 which upregulates MYC and CCND1, and finally facilitates CRC progression. In addition, we found that N6-methyladenosine (m6A) modification exists on circ3823. And the m6A modification is involved in regulating the degradation of circ3823. Conclusions Our findings suggest that circ3823 promotes CRC growth, metastasis and angiogenesis through circ3823/miR-30c-5p/TCF7 axis and it may serve as a new diagnostic marker or target for treatment of CRC patients. In addition, m6A modification is involved in regulating the degradation of circ3823.


2021 ◽  
Author(s):  
Juan Cai ◽  
Zhiqiang Chen ◽  
Yao Zhang ◽  
Jinguo Wang ◽  
Junfeng Wang ◽  
...  

Abstract Background Metabolic rewiring of cancer cells reshapes the tumor microenvironment, thereby restricting the response to immunotherapy. Circular RNAs (circRNAs) can influence various cellular processes and have been implicated in hepatocellular carcinoma (HCC). Here, we investigated the role of a novel circRNA circRHBDD1 in HCC metabolic transformation and immunotherapy resistance. Methods CircRNA sequencing was performed to determine the differentially expressed circRNA profile in HCC. RT-qPCR and in situ hybridization were used to verify the dysregulation of circRHBDD1 in two independent HCC cohorts. Univariate and multivariate survival analyses were employed to assess the prognostic significance of circRHBDD1. Loss- and gain-of-function approaches were adopted to evaluate the effects of circRHBDD1 on glycolysis and glutaminolysis. Patient-derived xenograft models were used for in vivo evaluation. RNA pull-down, mass spectrometry, RNA immunoprecipitation, fluorescence in situ hybridization, polysome profiling, and meRIP assays were utilized to explore the molecular mechanisms of circRHBDD1 in HCC. Results We found that circRHBDD1 was significantly upregulated in HCC and associated with unfavorable clinicopathological characteristics and poor survival outcomes. In vitro and in vivo experiments showed that circRHBDD1 facilitated HCC glycolysis and glutaminolysis. Mechanistic studies revealed that circRHBDD1 could recruit YTHDF1 to PIK3R1 mRNA and augment PIK3R1 translation in an m6A-dependent manner, leading to activation of the PI3K/AKT signaling. EIF4A3-mediated exon back-splicing contributed to the upregulation of circRHBDD1. Moreover, targeting of circRHBDD1 was able to improve anti-PD-1 therapy resulting in prolonged survival. Conclusion We identified that the circRHBDD1/YTHDF1/PIK3R1 axis was crucial to metabolic reprogramming of HCC. Suppression of circRHBDD1 could potentially sensitize HCC cells to anti-PD-1 therapy.


2020 ◽  
Author(s):  
xiaojian zhu ◽  
Fanqin Bu ◽  
Ting Tan ◽  
Qilin Luo ◽  
Jingfeng Zhu ◽  
...  

Abstract Background: Accumulating evidence indicates that long non-coding RNAs (lncRNAs) acting as crucial regulators in tumorigenesis. However, its biological functions of lncRNAs in colorectal cancer (CRC) have not been systematically clarified. Methods: An unbiased screening was performed to identify disregulated lncRNAs revealed to be implicated in CRC carcinogenesis according to an online-available data dataset. In situ hybridization (ISH), RT-qPCR and RNA fluorescence in situ hybridization (RNA-FISH) were applied to detect RP11-757G1.5 expression in CRC tissues and cell lines. The associations of RP11-757G1.5 with clinicopathological characteristics were analyzed. Their effects on prognosis were analyzed by the Kaplan-Meier analysis, Log-rank test, Univariate and Multivariate Cox regression analysis. The potential biological function of RP11-757G1.5 in CRC was investigated by Colony formation, Edu cell proliferation, Flow cytometry, Wound healing and Transwell assays. Bioinformatics binding site analysis, Luciferase reporter assay, Ago2 immunoprecipitation assays, RNA pull-down assay, RT-qPCR and Western blotting were utilized to demonstrate the mechanism of RP11-757G1.5 acts as a molecular sponge of miR-139-5p to regulate the expression of YAP1. Finally, we further explore the potential role of RP11-757G1.5 in CRC orthotopic xenografts in vivio . Results: We discovered a novel oncogenic lncRNA RP11-757G1.5, that was overexpressed in CRC tissues, especially in aggressive cases. Moreover, up-regulation of RP11-757G1.5 strongly correlated with poor clinical outcomes of patients with CRC. Functional analyses revealed that RP11-757G1.5 promoted cell proliferation in vitro and in vivo . Furthermore, RP11-757G1.5 stimulated cell migration and invasion in vitro and in vivo . Mechanistic studies illustrated that RP11-757G1.5 regulated the expression of YAP1 through sponging miR-139-5p and inhibiting its activity thereby promoting CRC progression and development. Conclusions: Altogether, these results reveal a novel RP11-757G1.5/miR-139-5p/YAP1 regulatory axis that participates in CRC carcinogenesis and progression.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yahang Liang ◽  
Jingbo Shi ◽  
Qingsi He ◽  
Guorui Sun ◽  
Lei Gao ◽  
...  

Abstract Background Colorectal cancer (CRC) is one of the most common cancers worldwide. Circular RNAs (circRNAs), a novel class of non-coding RNAs, have been confirmed to be key regulators of many diseases. With many scholars devoted to studying the biological function and mechanism of circRNAs, their mysterious veil is gradually being revealed. In our research, we explored a new circRNA, hsa_circ_0026416, which was identified as upregulated in CRC with the largest fold change (logFC = 3.70) of the evaluated circRNAs via analysing expression profiling data by high throughput sequencing of members of the GEO dataset (GSE77661) to explore the molecular mechanisms of CRC. Methods qRT-PCR and western blot analysis were utilized to assess the expression of hsa_circ_0026416, miR-346 and Nuclear Factor I/B (NFIB). CCK-8 and transwell assays were utilized to examine cell proliferation, migration and invasion in vitro, respectively. A luciferase reporter assay was used to verify the combination of hsa_circ_0026416, miR-346 and NFIB. A nude mouse xenograft model was also utilized to determine the role of hsa_circ_0026416 in CRC cell growth in vivo. Results Hsa_circ_0026416 was markedly upregulated in CRC patient tissues and plasma and was a poor prognosis in CRC patients. In addition, the area under the curve (AUC) of hsa_circ_0026416 (0.767) was greater than the AUC of CEA (0.670), CA19-9 (0.592) and CA72-4 (0.575). Functionally, hsa_circ_0026416 promotes cell proliferation, migration and invasion both in vitro and in vivo. Mechanistically, hsa_circ_0026416 may function as a ceRNA via competitively absorbing miR-346 to upregulate the expression of NFIB. Conclusions In summary, our findings demonstrate that hsa_circ_0026416 is an oncogene in CRC. Hsa_circ_0026416 promotes the progression of CRC via the miR-346/NFIB axis and may represent a potential biomarker for diagnosis and therapy in CRC.


2021 ◽  
Author(s):  
Jiahui Guo ◽  
Tingting Liu ◽  
Zhongyan Shan ◽  
Weiping Teng

Abstract Background: Circular RNA (circRNA) has been reported to play multiple roles in a variety of cancers. However, the role of circRNA in papillary thyroid carcinoma (PTC) remains mostly unknown. Methods: The expression, function and potential molecular mechanisms of hsa_circ_0000839 in PTC in vitro were evaluated by quantitative RT-PCR, western blot, flow cytometry, CCK8, Edu, RNA-sequencing, luciferase reporter, and RNA immunoprecipitation assay. The function of hsa_circ_0000839 in PTC in vivo was evaluated by xenograft tumors assay.Results: Hsa_circ_0000839 was significantly downregulated in PTC tissues and plasma from patients with PTC, and its downregulation was correlated with larger tumor size in patients with PTC. The role of hsa_circ_0000839 in the proliferation of PTC cell lines was evaluated in both vitro and in vivo. Mechanistically, hsa_circ_0000839 regulated the level of CDC27 via sponging miR-149-5p in PTC. Conclusions: Hsa_circ_0000839 might act as a tumor suppressor of PTC through the hsa_circ_0000839/miR-149-5p/CDC27 axis. Hsa_circ_0000839 could serve as a potential biomarker and therapeutic target for patients with PTC.


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