scholarly journals A novel hypoxic long noncoding RNA KB-1980E6.3 maintains breast cancer stem cell stemness via interacting with IGF2BP1 to facilitate c-Myc mRNA stability

Oncogene ◽  
2021 ◽  
Author(s):  
Pengpeng Zhu ◽  
Fang He ◽  
Yixuan Hou ◽  
Gang Tu ◽  
Qiao Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Underlying Mechanism ◽  
Rapid Expansion ◽  
Breast Cancer Patients ◽  
Coding Region ◽  
Signaling Axis

AbstractThe hostile hypoxic microenvironment takes primary responsibility for the rapid expansion of breast cancer tumors. However, the underlying mechanism is not fully understood. Here, using RNA sequencing (RNA-seq) analysis, we identified a hypoxia-induced long noncoding RNA (lncRNA) KB-1980E6.3, which is aberrantly upregulated in clinical breast cancer tissues and closely correlated with poor prognosis of breast cancer patients. The enhanced lncRNA KB-1980E6.3 facilitates breast cancer stem cells (BCSCs) self-renewal and tumorigenesis under hypoxic microenvironment both in vitro and in vivo. Mechanistically, lncRNA KB-1980E6.3 recruited insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) to form a lncRNA KB-1980E6.3/IGF2BP1/c-Myc signaling axis that retained the stability of c-Myc mRNA through increasing binding of IGF2BP1 with m6A-modified c-Myc coding region instability determinant (CRD) mRNA. In conclusion, we confirm that lncRNA KB-1980E6.3 maintains the stemness of BCSCs through lncRNA KB-1980E6.3/IGF2BP1/c-Myc axis and suggest that disrupting this axis might provide a new therapeutic target for refractory hypoxic tumors.

scholarly journals Long noncoding RNA RP11-70C1.3 confers chemoresistance of breast cancer cells through miR-6736-3p/NRP-1 axis

2021 ◽  
Author(s):  
Lansheng Zhang ◽  
Xia Zheng ◽  
Anqi Shen ◽  
Daojin Hua ◽  
Panrong Zhu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Noncoding Rna ◽  
Breast Cancer Cells ◽  
Underlying Mechanism ◽  
Breast Cancer Patients ◽  
Potential Therapeutic Target ◽  
Cancer Chemoresistance

Chemoresistance remains a major obstacle for improving the clinical outcome of patients with breast cancer. Recently, long noncoding RNAs (lncRNAs) have been implicated in breast cancer chemoresistance. However, the function and underlying mechanism are still largely unknown. Using lncRNA microarray, we identified 122 upregulated and 475 downregulated lncRNAs that might be related to the breast cancer chemoresistance. Among them, RP11-70C1.3 was one of the most highly expressed lncRNAs. In breast cancer patients, high RP11-70C1.3 expression predicted poor prognosis. Knockdown of RP11-70C1.3 inhibited the multidrug resistance of breast cancer cells in vitro and in vivo. Further investigations revealed that RP11-70C1.3 functioned as a competing endogenous RNA (ceRNA) for miR-6736-3p to increase NRP-1 expression. Notably, the rescue experiments showed that both miR-6736-3p inhibitor and NRP-1 overexpression could partly reverse the suppressive influence of RP11-70C1.3 knockdown on breast cancer chemoresistance. In conclusion, our study indicated that lncRNA RP11-70C1.3 regulated NRP-1 expression by sponging miR-6736-3p to confer chemoresistance of breast cancer cells. RP11-70C1.3 might be a potential therapeutic target in enhancing the clinical efficacy of chemotherapy in breast cancer.

scholarly journals Long noncoding RNA SNHG1 promotes TERT expression by sponging miR-18b-5p in breast cancer

2021 ◽  
Author(s):  
yujuan Kang ◽  
Lin Wan ◽  
Qin Wang ◽  
Yanling Yin ◽  
Jiena Liu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Malignant Tumors ◽  
Positive Role ◽  
Nucleolar Rna ◽  
Human Malignant Tumors ◽  
Tert Expression

Abstract Background: Long noncoding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) plays a positive role in the progression of human malignant tumors. However, the molecular mechanism of SNHG1 remains elusive in breast cancer. Results: LncRNA SNHG1 was upregulated and had a positive relationship with poor prognosis according to bioinformatics analysis. Silencing SNHG1 inhibited tumorigenesis in breast cancer both in vitro and in vivo. Mechanistically, SNHG1 functioned as a ceRNA to promote TERT expression by sponging miR-18b-5p. Moreover, miR-18b-5p acted as a tumor repressor in breast cancer. Finally, E2F1, a transcription factor, enhanced SNHG1 transcription.Conclusions: Our results provide a comprehensive understanding of the oncogenic mechanism of lncRNA SNHG1 in breast cancer. Importantly, we identified a novel E2F1–SNHG1–miR-18b-5p–TERT axis, which may be a potential therapeutic target for breast cancer.

scholarly journals Long noncoding RNA SNHG1 promotes TERT expression by sponging miR-18b-5p in breast cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yujuan Kang ◽  
Lin Wan ◽  
Qin Wang ◽  
Yanling Yin ◽  
Jiena Liu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Malignant Tumors ◽  
Inhibitory Effect ◽  
Positive Role ◽  
Breast Cancer Growth ◽  
Tert Expression

Abstract Background Long noncoding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) plays a positive role in the progression of human malignant tumors. However, the molecular mechanism of SNHG1 remains elusive in breast cancer. Results LncRNA SNHG1 was upregulated and had a positive relationship with poor prognosis according to bioinformatics analysis in pan-cancer including breast cancer. Silencing SNHG1 inhibited tumorigenesis in breast cancer both in vitro and in vivo. Mechanistically, SNHG1 functioned as a competing endogenous RNA (ceRNA) to promote TERT expression by sponging miR-18b-5p in breast cancer. miR-18b-5p acted as a tumor repressor in breast cancer. Moreover, the combination of SNHG1 knockdown and TERT inhibitor administration showed a synergistic inhibitory effect on breast cancer growth in vivo. Finally, E2F1 as a transcription factor, binding to SNHG1 promoter and enhanced SNHG1 transcription in breast cancer. Conclusions Our results provide a comprehensive understanding of the oncogenic mechanism of lncRNA SNHG1 in breast cancer. Importantly, we identified a novel E2F1–SNHG1–miR-18b-5p–TERT axis, which may be a potential therapeutic target for breast cancer. Our results also provided a potential treatment for breast cancer when knockdown SNHG1 and TERT inhibitor administration simultaneously.

scholarly journals Bisphenol-A and diethylstilbestrol exposure induces the expression of breast cancer associated long noncoding RNA HOTAIR in vitro and in vivo

2014 ◽  
Vol 141 ◽  
pp. 160-170 ◽  
Author(s):  
Arunoday Bhan ◽  
Imran Hussain ◽  
Khairul I. Ansari ◽  
Samara A.M. Bobzean ◽  
Linda I. Perrotti ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Bisphenol A ◽  
Long Noncoding Rna ◽  
Noncoding Rna

scholarly journals Long Noncoding RNA SNHG1 Promotes TERT Expression by Sponging miR-18b-5p in Breast Cancer

2021 ◽  
Author(s):  
Yujuan Kang ◽  
Lin Wan ◽  
Qin Wang ◽  
Yanling Yin ◽  
Jiena Liu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Transcription Factor ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Malignant Tumors ◽  
The Cancer Genome Atlas ◽  
Luciferase Reporter ◽  
Tert Expression

Abstract Background: Long noncoding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) plays a positive role in the progression of human malignant tumors. However, the molecular mechanism of SNHG1 remains elusive in breast cancer. Methods: The Cancer Genome Atlas data were used to examine the differential expression of SNHG1 in tumor and normal tissues, as well as the relationship between SNHG1 expression and prognosis. Oncogenic role of SNHG1 in breast cancer was studied both in vitro and in vivo. Animal experiments along with colony counting kit-8, colony formation, wound healing, and Transwell invasion assays were used to verify that SNHG1 was an oncogene in breast cancer. Furthermore, reverse transcription-polymerase chain reaction, western blotting analysis, subcellular RNA fractionation, and dual-luciferase reporter assay were performed to prove the competing endogenous RNA (ceRNA) mechanism of SNHG1, miR-18b-5p, and telomerase reverse transcriptase (TERT). Finally, chromatin immunoprecipitation was performed to confirm that the transcription factor E2F1 could enhance SNHG1 transcription.Results: LncRNA SNHG1 was upregulated and had a positive relationship with poor prognosis according to bioinformatics analysis. Silencing SNHG1 inhibited tumorigenesis in breast cancer both in vitro and in vivo. Mechanistically, SNHG1 functioned as a ceRNA to promote TERT expression by sponging miR-18b-5p. Moreover, miR-18b-5p acted as a tumor repressor in breast cancer. Finally, E2F1, a transcription factor, enhanced SNHG1 transcription.Conclusions: Our results provide a comprehensive understanding of the oncogenic mechanism of lncRNA SNHG1 in breast cancer. Importantly, we identified a novel E2F1–SNHG1–miR-18b-5p–TERT axis, which may be a potential therapeutic target for breast cancer.

scholarly journals GCH1 induces immunosuppression through metabolic reprogramming and IDO1 upregulation in triple-negative breast cancer

2021 ◽  
Vol 9 (7) ◽  
pp. e002383
Author(s):  
Jin-Li Wei ◽  
Si-Yu Wu ◽  
Yun-Song Yang ◽  
Yi Xiao ◽  
Xi Jin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Molecular Taxonomy ◽  
Underlying Mechanism ◽  
Metabolic Reprogramming ◽  
Sequencing Data ◽  
Aryl Hydrocarbon

PurposeRegulatory T cells (Tregs) heavily infiltrate triple-negative breast cancer (TNBC), and their accumulation is affected by the metabolic reprogramming in cancer cells. In the present study, we sought to identify cancer cell-intrinsic metabolic modulators correlating with Tregs infiltration in TNBC.Experimental designUsing the RNA-sequencing data from our institute (n=360) and the Molecular Taxonomy of Breast Cancer International Consortium TNBC cohort (n=320), we calculated the abundance of Tregs in each sample and evaluated the correlation between gene expression levels and Tregs infiltration. Then, in vivo and in vitro experiments were performed to verify the correlation and explore the underlying mechanism.ResultsWe revealed that GTP cyclohydrolase 1 (GCH1) expression was positively correlated with Tregs infiltration and high GCH1 expression was associated with reduced overall survival in TNBC. In vivo and in vitro experiments showed that GCH1 increased Tregs infiltration, decreased apoptosis, and elevated the programmed cell death-1 (PD-1)-positive fraction. Metabolomics analysis indicated that GCH1 overexpression reprogrammed tryptophan metabolism, resulting in L-5-hydroxytryptophan (5-HTP) accumulation in the cytoplasm accompanied by kynurenine accumulation and tryptophan reduction in the supernatant. Subsequently, aryl hydrocarbon receptor, activated by 5-HTP, bound to the promoter of indoleamine 2,3-dioxygenase 1 (IDO1) and thus enhanced the transcription of IDO1. Furthermore, the inhibition of GCH1 by 2,4-diamino-6-hydroxypyrimidine (DAHP) decreased IDO1 expression, attenuated tumor growth, and enhanced the tumor response to PD-1 blockade immunotherapy.ConclusionsTumor-cell-intrinsic GCH1 induced immunosuppression through metabolic reprogramming and IDO1 upregulation in TNBC. Inhibition of GCH1 by DAHP serves as a potential immunometabolic strategy in TNBC.

Targeting PKM2 promotes chemosensitivity of breast cancer cells in vitro and in vivo

2021 ◽  
pp. 1-10
Author(s):  
Yu Wang ◽  
Han Zhao ◽  
Ping Zhao ◽  
Xingang Wang
Keyword(s):  
Breast Cancer ◽  
Neoadjuvant Chemotherapy ◽  
Cancer Cells ◽  
Cancer Patients ◽  
Poor Prognosis ◽  
Breast Cancer Cells ◽  
Breast Cancer Patients ◽  
Cancer Tissues

BACKGROUND: Pyruvate kinase M2 (PKM2) was overexpressed in many cancers, and high PKM2 expression was related with poor prognosis and chemoresistance. OBJECTIVE: We investigated the expression of PKM2 in breast cancer and analyzed the relation of PKM2 expression with chemotherapy resistance to the neoadjuvant chemotherapy (NAC). We also investigated whether PKM2 could reverse chemoresistance in breast cancer cells in vitro and in vivo. METHODS: Immunohistochemistry (IHC) was performed in 130 surgical resected breast cancer tissues. 78 core needle biopsies were collected from breast cancer patients before neoadjuvant chemotherapy. The relation of PKM2 expression and multi-drug resistance to NAC was compared. The effect of PKM2 silencing or overexpression on Doxorubicin (DOX) sensitivity in the MCF-7 cells in vitro and in vivo was compared. RESULTS: PKM2 was intensively expressed in breast cancer tissues compared to adjacent normal tissues. In addition, high expression of PKM2 was associated with poor prognosis in breast cancer patients. The NAC patients with high PKM2 expression had short survival. PKM2 was an independent prognostic predictor for surgical resected breast cancer and NAC patients. High PKM2 expression was correlated with neoadjuvant treatment resistance. High PKM2 expression significantly distinguished chemoresistant patients from chemosensitive patients. In vitro and in vivo knockdown of PKM2 expression decreases the resistance to DOX in breast cancer cells in vitro and tumors in vivo. CONCLUSION: PKM2 expression was associated with chemoresistance of breast cancers, and could be used to predict the chemosensitivity. Furthermore, targeting PKM2 could reverse chemoresistance, which provides an effective treatment methods for patients with breast cancer.

scholarly journals Integrin alpha5 in human breast cancer is a mediator of bone metastasis and a therapeutic target for the treatment of osteolytic lesions

Oncogene ◽  
2021 ◽  
Author(s):  
Francesco Pantano ◽  
Martine Croset ◽  
Keltouma Driouch ◽  
Natalia Bednarz-Knoll ◽  
Michele Iuliani ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Bone Marrow ◽  
Bone Metastasis ◽  
Tumor Cell ◽  
Cancer Patients ◽  
Breast Cancer Patients ◽  
Osteolytic Lesions ◽  
Cell Colonization

AbstractBone metastasis remains a major cause of mortality and morbidity in breast cancer. Therefore, there is an urgent need to better select high-risk patients in order to adapt patient’s treatment and prevent bone recurrence. Here, we found that integrin alpha5 (ITGA5) was highly expressed in bone metastases, compared to lung, liver, or brain metastases. High ITGA5 expression in primary tumors correlated with the presence of disseminated tumor cells in bone marrow aspirates from early stage breast cancer patients (n = 268; p = 0.039). ITGA5 was also predictive of poor bone metastasis-free survival in two separate clinical data sets (n = 855, HR = 1.36, p = 0.018 and n = 427, HR = 1.62, p = 0.024). This prognostic value remained significant in multivariate analysis (p = 0.028). Experimentally, ITGA5 silencing impaired tumor cell adhesion to fibronectin, migration, and survival. ITGA5 silencing also reduced tumor cell colonization of the bone marrow and formation of osteolytic lesions in vivo. Conversely, ITGA5 overexpression promoted bone metastasis. Pharmacological inhibition of ITGA5 with humanized monoclonal antibody M200 (volociximab) recapitulated inhibitory effects of ITGA5 silencing on tumor cell functions in vitro and tumor cell colonization of the bone marrow in vivo. M200 also markedly reduced tumor outgrowth in experimental models of bone metastasis or tumorigenesis, and blunted cancer-associated bone destruction. ITGA5 was not only expressed by tumor cells but also osteoclasts. In this respect, M200 decreased human osteoclast-mediated bone resorption in vitro. Overall, this study identifies ITGA5 as a mediator of breast-to-bone metastasis and raises the possibility that volociximab/M200 could be repurposed for the treatment of ITGA5-positive breast cancer patients with bone metastases.

scholarly journals Cardiac pathologies in mouse loss of imprinting models are due to misexpression of H19 long noncoding RNA

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Ki-Sun Park ◽  
Beenish Rahat ◽  
Hyung Chul Lee ◽  
Zu-Xi Yu ◽  
Jacob Noeker ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ventricular Function ◽  
Mouse Models ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Relative Importance ◽  
Maternal Loss ◽  
Loss Of Imprinting

Maternal loss of imprinting (LOI) at the H19/IGF2 locus results in biallelic IGF2 and reduced H19 expression and is associated with Beckwith-Wiedemann syndrome (BWS). We use mouse models for LOI to understand the relative importance of Igf2 and H19 mis-expression in BWS phenotypes. Here we focus on cardiovascular phenotypes and show that neonatal cardiomegaly is exclusively dependent on increased Igf2. Circulating IGF2 binds cardiomyocyte receptors to hyperactivate mTOR signaling, resulting in cellular hyperplasia and hypertrophy. These Igf2-dependent phenotypes are transient: cardiac size returns to normal once Igf2 expression is suppressed postnatally. However, reduced H19 expression is sufficient to cause progressive heart pathologies including fibrosis and reduced ventricular function. In the heart, H19 expression is primarily in endothelial cells (ECs) and regulates EC differentiation both, in vivo and in vitro. Finally, we establish novel mouse models to show that cardiac phenotypes depend on H19 lncRNA interactions with Mirlet7 microRNAs.

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.

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