scholarly journals Circular RNA circIKBKB promotes breast cancer bone metastasis through sustaining NF-κB/bone remodeling factors signaling

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Yingru Xu ◽  
Shuxia Zhang ◽  
Xinyi Liao ◽  
Man Li ◽  
Suwen Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Bone Metastasis ◽  
Bone Remodeling ◽  
Circular Rna ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Metastatic Niche ◽  
Breast Cancer Bone Metastasis

Abstract Background Breast cancer (BC) has a marked tendency to spread to the bone, resulting in significant skeletal complications and mortality. Recently, circular RNAs (circRNAs) have been reported to contribute to cancer initiation and progression. However, the function and mechanism of circRNAs in BC bone metastasis (BC-BM) remain largely unknown. Methods Bone-metastatic circRNAs were screened using circRNAs deep sequencing and validated using in situ hybridization in BC tissues with or without bone metastasis. The role of circIKBKB in inducing bone pre-metastatic niche formation and bone metastasis was determined using osteoclastogenesis, immunofluorescence and bone resorption pit assays. The mechanism underlying circIKBKB-mediated activation of NF-κB/bone remodeling factors signaling and EIF4A3-induced circIKBKB were investigated using RNA pull-down, luciferase reporter, chromatin isolation by RNA purification and enzyme-linked immunosorbent assays. Results We identified that a novel circRNA, circIKBKB, was upregulated significantly in bone-metastatic BC tissues. Overexpressing circIKBKB enhanced the capability of BC cells to induce formation of bone pre-metastatic niche dramatically by promoting osteoclastogenesis in vivo and in vitro. Mechanically, circIKBKB activated NF-κB pathway via promoting IKKβ-mediated IκBα phosphorylation, inhibiting IκBα feedback loop and facilitating NF-κB to the promoters of multiple bone remodeling factors. Moreover, EIF4A3, acted acting as a pre-mRNA splicing factor, promoted cyclization of circIKBKB by directly binding to the circIKBKB flanking region. Importantly, treatment with inhibitor eIF4A3-IN-2 reduced circIKBKB expression and inhibited breast cancer bone metastasis effectively. Conclusion We revealed a plausible mechanism for circIKBKB-mediated NF-κB hyperactivation in bone-metastatic BC, which might represent a potential strategy to treat breast cancer bone metastasis.

scholarly journals Increased Expression of Circular RNA circ_0005230 Indicates Dismal Prognosis in Breast Cancer and Regulates Cell Proliferation and Invasion via miR-618/ CBX8 Signal Pathway

2018 ◽  
Vol 51 (4) ◽  
pp. 1710-1722 ◽  
Author(s):  
Yi Xu ◽  
Yue Yao ◽  
Kaiming Leng ◽  
Daolin Ji ◽  
Lijun Qu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Circular Rna ◽  
Clinical Severity ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Dismal Prognosis ◽  
Tumorigenesis And Progression ◽  
Tissue Specimens

Background/Aims: Circular RNAs (circRNAs) are a class of non-coding RNAs. They have been proved to be critically involved in tumorigenesis and progression of malignancies through competing endogenous RNA (ceRNA) mechanism. Nevertheless, the exploration between circRNAs and pathogenesis of breast cancer (BC) is limited. Previously, circ_0005230 was identified upregulated in BC tissues screened by circRNA microarray. In the present study, we aimed to investigate the expression pattern, functional role, and mechanism of circ_0005230 in BC. Methods: qRT-PCR was conducted to elucidate the expression levels of circ_0005230 in BC tissues and cells. Additionally, the clinical severity and prognostic value were investigated. CCK-8, colony-forming, flow cytometric assays were performed. Animal study was conducted to validate the in vitro data. What’s more, Transwell assays were induced to detect the cell metastatic properties of circ_0005230 exerts in BC cells. Luciferase reporter assay was used to measure the mechanism of circ_0005230. Results: circ_0005230 was overexpressed in BC tissue specimens and cell lines. The overexpression of circ_0005230 was related to adverse phenotypes in the patients with BC. In addition, circ_0005230 could be regarded as a prognostic predictor in BC patients. In vitro and in vivo data demonstrated the cell growth promoting role of circ_0005230. Moreover, circ_0005230 could also promote cell migratory and invasive capacities. For the mechanism investigation, circ_0005230 was proved to be a sponge of miR-618, and expression of miR-618 could regulate CBX8 expression via targeting the 3’UTR of CBX8. Rescue assays also illustrated an oncogenic function of circ_0005230 in BC via acting as a miR-618 sponge to promote CBX8 expression. Conclusion: circ_0005230/miR-618/CBX8 axis might play a key role in BC tumorigenesis and development.

scholarly journals CircWAC induces chemotherapeutic resistance in triple-negative breast cancer by targeting miR-142, upregulating WWP1 and activating the PI3K/AKT pathway

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Lei Wang ◽  
Yehui Zhou ◽  
Liang Jiang ◽  
Linlin Lu ◽  
Tiantian Dai ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Luciferase Reporter ◽  
Akt Pathway ◽  
Circular Rnas ◽  
Chemotherapeutic Resistance ◽  
Repressive Effect

Abstract Background Chemotherapeutic resistance is the main cause of clinical treatment failure and poor prognosis in triple-negative breast cancer (TNBC). There is no research on chemotherapeutic resistance in TNBC from the perspective of circular RNAs (circRNAs). Methods TNBC-related circRNAs were identified based on the GSE101124 dataset. Quantitative reverse transcription PCR was used to detect the expression level of circWAC in TNBC cells and tissues. Then, in vitro and in vivo functional experiments were performed to evaluate the effects of circWAC in TNBC. Results CircWAC was highly expressed in TNBC and was associated with worse TNBC patient prognosis. Subsequently, it was verified that downregulation of circWAC can increase the sensitivity of TNBC cells to paclitaxel (PTX) in vitro and in vivo. The expression of miR-142 was negatively correlated with circWAC in TNBC. The interaction between circWAC and miR-142 in TNBC cells was confirmed by RNA immunoprecipitation assays, luciferase reporter assays, pulldown assays, and fluorescence in situ hybridization. Mechanistically, circWAC acted as a miR-142 sponge to relieve the repressive effect of miR-142 on its target WWP1. In addition, the overall survival of TNBC patients with high expression of miR-142 was significantly better than that of patients with low expression of miR-142, and these results were verified in public databases. MiR-142 regulated the expression of WWP1 and the activity of the PI3K/AKT pathway. It was confirmed that WWP1 is highly expressed in TNBC and that the prognosis of patients with high WWP1 expression is poor. Conclusions CircWAC/miR-142/WWP1 form a competing endogenous RNA (ceRNA) network to regulate PI3K/AKT signaling activity in TNBC cells and affect the chemosensitivity of cells.

scholarly journals CircBCBM1 Promotes Breast Cancer Brain Metastasis via miR-125a/BRD4 Axis

2020 ◽  
Author(s):  
Bo Fu ◽  
Wei Liu ◽  
Peng Li ◽  
Li Pan ◽  
Ke Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Brain Metastasis ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Breast Cancer Patients ◽  
Breast Cancer Brain Metastasis ◽  
Tumorigenesis And Progression ◽  
And Migration

Abstract Background: Accumulating evidence indicates that circular RNAs (circRNAs) play critical roles in tumorigenesis and progression of various cancers. We previously identified a novel upregulated circRNA, circBCBM1 (hsa_circ_0001944), in the context of breast cancer brain metastasis. However, the potential biological function and molecular mechanism of circBCBM1 in breast cancer brain metastasis remain largely unknown.Methods: In this reserch, we validated the expression and characterization of circBCBM1 through RT-qPCR, Sanger sequencing, RNase R assay and fluorescence in situ hybridization (FISH). Functional experiments were performed to determine the effect of circBCBM1 on growth and metastasis of 231-BR cells both in vitro and in vivo. The regulatory mechanisms among circBCBM1, miR-125a (has-miR-125a-5p), and BRD4 (bromodomain containing 4) were investigated by RNA immunoprecipitation (RIP), RNA pull-down, luciferase reporter assay and western blot. Results: Our findings demonstrated that circBCBM1 is a stable and cytoplasmic circRNA. Functionally, silencing of circBCBM1 led to decreased proliferation and migration of 231-BR cells whereas elevated circBCBM1 expression showed reverse effects in vitro. These findings were confirmed in vivo in mouse models, as knockdown of circBCBM1 significantly decreased growth and brain metastases of 231-BR cells. Mechanistically, circBCBM1 functions as an endogenous miR-125a sponge to inhibit miR-125a activity, resulting in the upregulation of BRD4 expression and subsequent upregulation of MMP9 (matrix metallopeptidase 9) through Sonic hedgehog (SHH) signaling pathway. Importantly, circBCBM1 was markedly upregulated in the breast cancer brain metastasis cells and clinical tissue and plasma samples; besides, the overexpression of circBCBM1 in primary cancerous tissues was associated with shorter brain metastasis-free survival (BMFS) of breast cancer patients.Conclusions: These findings indicate that circBCBM1 is involved in breast cancer brain metastasis via circBCBM1/miR-125a/BRD4 axis, which sheds light on the pathogenic mechanism of circBCBM1 and provides translational evidence that circBCBM1 may serve as a novel diagnostic or prognostic biomarker and potential therapeutic target for breast cancer brain metastasis.

Development of a Novel 3D Bioprinted In Vitro Nano Bone Model for Breast Cancer Bone Metastasis Study

2014 ◽  
Vol 1724 ◽  
Author(s):  
Benjamin Holmes ◽  
Wei Zhu ◽  
Lijie Grace Zhang
Keyword(s):  
Breast Cancer ◽  
Bone Metastasis ◽  
Metastatic Breast ◽  
Bone Microstructure ◽  
Bone Model ◽  
Skeletal Complications ◽  
3D Printed ◽  
Breast Cancer Bone Metastasis

ABSTRACTBreast cancer (BrCa) is the second commonest cause of cancer-related deaths in women. The metastatic breast cancer exhibits a high affinity to bone, leading to debilitating skeletal complications associated with significant morbidity and poor prognosis. Traditional in vitro and in vivo BrCa bone metastasis models contain many inherent limitations with regards to controllability, reproducibility, and flexibility of design. Thus, the objective of this research is to use a 3D bioprinting system and nanomaterials to recreate a biomimetic and tunable bone model suitable for the effective simulation and study of metastatic BrCa invading and colonizing a bone environment. For this purpose, we designed and 3D printed a series of scaffolds, comprised of a bone microstructure and nano hydroxyapatites (nHA, inorganic nano components in bone). The size and geometry of the bone microstructure was varied with 250 and 150 µm pores, in repeating square and hexagon patterns, for a total of four different pore geometries. 3D bioprinted scaffolds were subsequently conjugated with nHA, using an acetylation chemical functionalization process and then characterized by scanning electron microscope (SEM). SEM imaging showed that our designed microfeatures were printable with the predesigned resolutions described above. Imaging further confirmed that acetylation effectively attached nHA to the surface of scaffolds and induced a nanoroughness. Metastatic BrCa cell 4 h adhesion and 1, 3 and 5 day proliferation were investigated in the bone model in vitro. The cell adhesion and proliferation results showed that all scaffolds are cytocompatible for BrCa cell growth; in particular the nHA scaffolds with small hexagonal pores had the highest cell density. Given this data, it can be stipulated that our 3D printed nHA scaffolds may make effective biomimetic environments for studying BrCa bone metastasis.

scholarly journals Circular RNA MCTP2 inhibits cisplatin resistance in gastric cancer by miR-99a-5p-mediated induction of MTMR3 expression

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Guangli Sun ◽  
Zheng Li ◽  
Zhongyuan He ◽  
Weizhi Wang ◽  
Sen Wang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Xenograft Model ◽  
Circular Rna ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Mouse Xenograft Model ◽  
Mirna Sponges ◽  
High Level

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.

The Therapeutic Effect of Circular RNA ST3GAL6 on Blocking GC Malignant Behaviors Through Autophagy Regulated by the FOXP2/MET/Mtor Axis

2021 ◽  
Author(s):  
Penghui Xu ◽  
Xing Zhang ◽  
Jiacheng Cao ◽  
Jing Yang ◽  
Zetian Chen ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Circular Rna ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Induced Apoptosis

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.

scholarly journals Different molecular profiles are associated with breast cancer cell homing compared with colonisation of bone: evidence using a novel bone-seeking cell line

2014 ◽  
Vol 21 (2) ◽  
pp. 327-341 ◽  
Author(s):  
Faith Nutter ◽  
Ingunn Holen ◽  
Hannah K Brown ◽  
Simon S Cross ◽  
C Alyson Evans ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Bone Metastasis ◽  
Expression Profiles ◽  
Molecular Profile ◽  
Calcium Signal ◽  
Cell Homing ◽  
Gene And Protein Expression ◽  
Breast Cancer Bone Metastasis

Advanced breast cancer is associated with the development of incurable bone metastasis. The two key processes involved, tumour cell homing to and subsequent colonisation of bone, remain to be clearly defined. Genetic studies have indicated that different genes facilitate homing and colonisation of secondary sites. To identify specific changes in gene and protein expression associated with bone-homing or colonisation, we have developed a novel bone-seeking clone of MDA-MB-231 breast cancer cells that exclusively forms tumours in long bones following i.v. injection in nude mice. Bone-homing cells were indistinguishable from parental cells in terms of growth ratein vitroand when grown subcutaneouslyin vivo. Only bone-homing ability differed between the lines; once established in bone, tumours from both lines displayed similar rates of progression and caused the same extent of lytic bone disease. By comparing the molecular profile of a panel of metastasis-associated genes, we have identified differential expression profiles associated with bone-homing or colonisation. Bone-homing cells had decreased expression of the cell adhesion molecule fibronectin and the migration and calcium signal binding protein S100A4, in addition to increased expression of interleukin 1B. Bone colonisation was associated with increased fibronectin and upregulation of molecules influencing signal transduction pathways and breakdown of extracellular matrix, including hRAS and matrix metalloproteinase 9. Our data support the hypothesis that during early stages of breast cancer bone metastasis, a specific set of genes are altered to facilitate bone-homing, and that disruption of these may be required for effective therapeutic targeting of this process.

scholarly journals Circular RNA circRPPH1 promotes breast cancer progression via circRPPH1-miR-512-5p-STAT1 axis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yixiang Huang ◽  
Wenfang Zheng ◽  
Changle Ji ◽  
Xuehui Wang ◽  
Yunhe Yu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
Underlying Mechanism ◽  
Circular Rna ◽  
Gene Expression Omnibus ◽  
Circular Rnas ◽  
In Vivo Experiments

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.

scholarly journals Circular RNA circASPM Promotes the Progression of Glioblastoma by Acting as a Competing Endogenous RNA to Regulate miR-130b–3p/E2F1 Axis

2020 ◽  
Author(s):  
Dianqi Hou ◽  
Zhenlin Wang ◽  
Haimeng Li ◽  
Juan Liu ◽  
Yaohua Liu ◽  
...  
Keyword(s):  
Western Blotting ◽  
Circular Rna ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Primary Malignancy ◽  
Rna Immunoprecipitation ◽  
Western Blotting Assay

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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