scholarly journals The MS-lincRNA landscape reveals a novel lincRNA BCLIN25 that contributes to tumorigenesis by upregulating ERBB2 expression via epigenetic modification and RNA–RNA interactions in breast cancer

2019 ◽  
Vol 10 (12) ◽  
Author(s):  
Shouping Xu ◽  
Hongbo Liu ◽  
Lin Wan ◽  
Weijia Zhang ◽  
Qin Wang ◽  
...  

AbstractThe landscape of molecular subtype-specific long intergenic noncoding RNAs (MS-lincRNAs) in breast cancer has not been elucidated. No study has investigated the biological function of BCLIN25, serving as a novel HER2 subtype-specific lincRNA, in human disease, especially in malignancy. Moreover, the mechanism of BCLIN25 in the regulation of ERBB2 expression remains unknown. Our present study aimed to investigate the role and underlying mechanism of BCLIN25 in the regulation of ERBB2 expression. The transcriptional landscape across five subtypes of breast cancer was investigated using RNA sequencing. Integrative transcriptomic analysis was performed to identify the landscape of novel lincRNAs. Next, WEKA was used to identify lincRNA-based subtype classification and MS-lincRNAs for breast cancer. The MS-lincRNAs were validated in 250 breast cancer samples in our cohort and datasets from The Cancer Genome Atlas and Gene Expression Omnibus. Furthermore, BCLIN25 was selected, and its role in tumorigenesis was examined in vitro and in vivo. Finally, the mechanism by which BCLIN25 regulates ERBB2 expression was investigated in detail. A total of 715 novel lincRNAs were differentially expressed across five breast cancer subtypes. Next, lincRNA-based subtype classifications and MS-lincRNAs were identified and validated using our breast cancer samples and public datasets. BCLIN25 was found to contribute to tumorigenesis in vitro and in vivo. Mechanistically, BCLIN25 was shown to increase the expression of ERBB2 by enhancing promoter CpG methylation of miR-125b, leading to miR-125b downregulation. In turn, ERBB2 mRNA degradation was found to be abolished due to decreased binding of miR-125b to the 3’-untranslated region (UTR) of ERBB2. These findings reveal the role of novel lincRNAs in breast cancer and provide a comprehensive landscape of breast cancer MS-lincRNAs, which may complement the current molecular classification system in breast cancer.

2021 ◽  
Vol 10 ◽  
Author(s):  
Hiu Yee Kwan ◽  
Qinghua Xu ◽  
Ruihong Gong ◽  
Zhaoxiang Bian ◽  
Chih-Chang Chu

Triple negative breast cancer (TNBC) has the worst overall survival among all breast cancer subtypes; 80% of TNBC harbors TP53 mutation. Gambogic acid (GA) is an herbal compound isolated from the dry brownish gamboge resin of Garcinia hanburyi. A new family of biodegradable polymer, the folate (FA)-conjugated arginine-based poly(ester urea urethane)s nanoparticles (FA-Arg-PEUU NP), was developed as nano-carrier for GA. Its anti-TNBC effects and the underlying mechanism of action were examined. The average diameters of FA-Arg-PEUU NP and GA-loaded FA-Arg-PEUU NP (NP-GA) in water are around 165 and 220nm, respectively. Rhodamine-tagged FA-Arg-PEUU NP shows that the conjugation of FA onto Arg-PEUU NPs facilitates the internalization of FA-Arg-PEUU-NP into TNBC. Compared to free-GA at the same GA concentrations, NP-GA exhibits higher cytotoxicity in both TP53-mutated and non-TP53 expressed TNBC cells by increasing intrinsic and extrinsic apoptosis. In HCC1806-bearing xenograft mouse model, the targeted delivery of GA by the FA-Arg-PEUU-NP nano-carriers to the tumor sites results in a more potent anti-TNBC effect and lower toxicity towards normal tissues and organs when compared to free GA. Furthermore, NP-GA also reduces the tumor-associated macrophage (TAM) M1/M2 ratio, suggesting that the use of Arg-based nanoparticles as carriers for GA not only makes the surface of the nanoparticles positively charged, but also confers on to the nanoparticles an ability to modulate TAM polarization. Our data clearly demonstrate that NP-GA exhibits potent anti-TNBC effects with reduced off-target toxicity, which represents novel alternative targeted therapeutics for TNBC treatment.


2021 ◽  
Vol 9 (7) ◽  
pp. e002383
Author(s):  
Jin-Li Wei ◽  
Si-Yu Wu ◽  
Yun-Song Yang ◽  
Yi Xiao ◽  
Xi Jin ◽  
...  

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.


Oncogene ◽  
2021 ◽  
Author(s):  
Pengpeng Zhu ◽  
Fang He ◽  
Yixuan Hou ◽  
Gang Tu ◽  
Qiao Li ◽  
...  

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.


2019 ◽  
Vol 100 (3) ◽  
pp. 400-413
Author(s):  
Milica Krstic ◽  
Haider M. Hassan ◽  
Bart Kolendowski ◽  
M. Nicole Hague ◽  
Pieter. H. Anborgh ◽  
...  

Abstract TBX3 is a member of the highly conserved family of T-box transcription factors involved in embryogenesis, organogenesis and tumor progression. While the functional role of TBX3 in tumorigenesis has been widely studied, less is known about the specific functions of the different isoforms (TBX3iso1 and TBX3iso2) which differ in their DNA-binding domain. We therefore sought to investigate the functional consequence of this highly conserved splice event as it relates to TBX3-induced tumorigenesis. By utilizing a nude mouse xenograft model, we have identified differential tumorigenic potential between TBX3 isoforms, with TBX3iso1 overexpression more commonly associated with invasive carcinoma and high tumor vascularity. Transcriptional analysis of signaling pathways altered by TBX3iso1 and TBX3iso2 overexpression revealed significant differences in angiogenesis-related genes. Importantly, osteopontin (OPN), a cancer-associated secreted phosphoprotein, was significantly up-regulated with TBX3iso1 (but not TBX3iso2) overexpression. This pattern was observed across three non/weakly-tumorigenic breast cancer cell lines (21PT, 21NT, and MCF7). Up-regulation of OPN in TBX3iso1 overexpressing cells was associated with induction of hyaluronan synthase 2 (HAS2) expression and increased retention of hyaluronan in pericellular matrices. These transcriptional changes were accompanied by the ability to induce endothelial cell vascular channel formation by conditioned media in vitro, which could be inhibited through addition of an OPN neutralizing antibody. Within the TCGA breast cancer cohort, we identified an 8.1-fold higher TBX3iso1 to TBX3iso2 transcript ratio in tumors relative to control, and this ratio was positively associated with high-tumor grade and an aggressive molecular subtype. Collectively, the described changes involving TBX3iso1-dependent promotion of angiogenesis may thus serve as an adaptive mechanism within breast cancer cells, potentially explaining differences in tumor formation rates between TBX3 isoforms in vivo. This study is the first of its kind to report significant functional differences between the two TBX3 isoforms, both in vitro and in vivo.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Giada Zurlo ◽  
Xijuan Liu ◽  
Mamoru Takada ◽  
Cheng Fan ◽  
Jeremy M. Simon ◽  
...  

AbstractProtein hydroxylation affects protein stability, activity, and interactome, therefore contributing to various diseases including cancers. However, the transiency of the hydroxylation reaction hinders the identification of hydroxylase substrates. By developing an enzyme-substrate trapping strategy coupled with TAP-TAG or orthogonal GST- purification followed by mass spectrometry, we identify adenylosuccinate lyase (ADSL) as an EglN2 hydroxylase substrate in triple negative breast cancer (TNBC). ADSL expression is higher in TNBC than other breast cancer subtypes or normal breast tissues. ADSL knockout impairs TNBC cell proliferation and invasiveness in vitro and in vivo. An integrated transcriptomics and metabolomics analysis reveals that ADSL activates the oncogenic cMYC pathway by regulating cMYC protein level via a mechanism requiring ADSL proline 24 hydroxylation. Hydroxylation-proficient ADSL, by affecting adenosine levels, represses the expression of the long non-coding RNA MIR22HG, thus upregulating cMYC protein level. Our findings highlight the role of ADSL hydroxylation in controlling cMYC and TNBC tumorigenesis.


2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Cui-Cui Zhao ◽  
Jing Chen ◽  
Li-Ying Zhang ◽  
Hong Liu ◽  
Chuan-Gui Zhang ◽  
...  

Abstract Triple negative breast cancer (TNBC) is a more common type of breast cancer with high distant metastasis and poor prognosis. The potential role of lamins in cancer progression has been widely revealed. However, the function of lamin B2 (LMNB2) in TNBC progression is still unclear. The present study aimed to investigate the role of LMNB2 in TNBC. The cancer genome atlas (TCGA) database analysis and immunohistochemistry (IHC) were performed to examine LMNB2 expression levels. LMNB2 short hairpin RNA plasmid or lentivirus was used to deplete the expression of LMNB2 in human TNBC cell lines including MDA-MB-468 and MDA-MB-231. Alterations in cell proliferation and apoptosis in vitro and the nude mouse tumorigenicity assay in vivo were subsequently analyzed. The human TNBC tissues shown high expression of LMNB2 according to the bioinformation analysis and IHC assays. LMNB2 expression was correlated with the clinical pathological features of TNBC patients, including pTNM stage and lymph node metastasis. Through in vitro and in vivo assays, we confirmed LMNB2 depletion suppressed the proliferation and induced the apoptosis of TNBC cells, and inhibited tumor growth of TNBC cells in mice, with the decrease in Ki67 expression or the increase in caspase-3 expression. In conclusion, LMNB2 may promote TNBC progression and could serve as a potential therapeutic target for TNBC treatment.


2021 ◽  
Author(s):  
Feng-Juan Zhou ◽  
Sen Meng ◽  
Hongmei Yong ◽  
Ping-Fu Hou ◽  
Min-Le Li ◽  
...  

Abstract Renal cell carcinoma (RCC) is one of the most prevalent cancers. Long noncoding RNAs (LncRNAs) have been indicated as a mediator acted in tumorigenesis of RCC. However, the mechanism of LINC00460 on RCC is yet to be investigated. This study aimed to investigate the potential function of LINC00460 and underlying mechanism of RCC. We detected LINC00460 expression in RCC tissues and the prognosis in RCC patients using Gene Expression Profiling Interactive Analysis (GEPIA) website and The Cancer Genome Atlas (TCGA) database. LINC00460 level in normal renal cell line and RCC cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). We study the effects of LINC00460 on proliferation, migration, invasion, apoptosis in RCC cells lines using a series of in vivo and in vitro experiments. RNA sequencing (RNA-seq) analysis for the whole transcriptome was applied to searching potential LINC00460 related signal pathway in RCC. We identified the significant up-regulated expression level of LINC00460 in RCC tissues and cell lines. Elevated LINC00460 was correlated with shorter survival of RCC patients. Overexpression of LINC00460 promoted cell viability, proliferation, invasion and migration, while down-regulation of LINC00460 exerted inhibitory effect on these activities. We crucially identified that LNC00460 promotes development of RCC by influencing the PI3K/AKT pathway. Knockdown of LNC00460 decreased the phosphorylation of AKT and mTOR. The key finding of our study provided a new evidence suggesting that LINC00460 functions as an oncogene in RCC pathogenesis by mediating the PI3K/AKT pathway, which may provide a new target for the treatment of RCC.


2020 ◽  
Vol 12 (534) ◽  
pp. eaaw8275 ◽  
Author(s):  
Johanna M. Schafer ◽  
Brian D. Lehmann ◽  
Paula I. Gonzalez-Ericsson ◽  
Clayton B. Marshall ◽  
J. Scott Beeler ◽  
...  

Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer that does not respond to endocrine therapy or human epidermal growth factor receptor 2 (HER2)–targeted therapies. Individuals with TNBC experience higher rates of relapse and shorter overall survival compared to patients with receptor-positive breast cancer subtypes. Preclinical discoveries are needed to identify, develop, and advance new drug targets to improve outcomes for patients with TNBC. Here, we report that MYCN, an oncogene typically overexpressed in tumors of the nervous system or with neuroendocrine features, is heterogeneously expressed within a substantial fraction of primary and recurrent TNBC and is expressed in an even higher fraction of TNBCs that do not display a pathological complete response after neoadjuvant chemotherapy. We performed high-throughput chemical screens on TNBC cell lines with varying amounts of MYCN expression and determined that cells with higher expression of MYCN were more sensitive to bromodomain and extraterminal motif (BET) inhibitors. Combined BET and MEK inhibition resulted in a synergistic decrease in viability, both in vitro and in vivo, using cell lines and patient-derived xenograft (PDX) models. Our preclinical data provide a rationale to advance a combination of BET and MEK inhibitors to clinical investigation for patients with advanced MYCN-expressing TNBC.


Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1564 ◽  
Author(s):  
Norihiko Saito ◽  
Nozomi Hirai ◽  
Kazuya Aoki ◽  
Sho Sato ◽  
Ryo Suzuki ◽  
...  

The Cancer Genome Atlas (TCGA) project described a robust gene expression-based molecular classification of glioblastoma (GBM), but the functional and biological significance of the subclasses has not been determined. The present comprehensive analysis of 25 glioma-initiating cell (GIC) lines classifies GIC lines into four subtypes (classical, mesenchymal, proneural, and neural) that are closely related to the TCGA GBM subclasses and display distinct lineage characteristics and differentiation behavior that recapitulate neural development. More importantly, the GIC subtypes exhibit distinct biological phenotypes in relation to self-renewal capacity, proliferation, invasiveness, and angiogenic potential in vitro and in vivo. In addition, the GIC subtypes exhibit divergent patterns of signaling pathway activation and deactivation of the Wnt, Notch, and TGF-β pathways. These results will improve drug discovery targeting certain genetic mutation in glioblastoma and improve the development of precision medicine.


2020 ◽  
Vol 19 ◽  
pp. 153473542090646 ◽  
Author(s):  
Junjun Chen ◽  
Xiangqi Zhang ◽  
Xiao Xiao ◽  
Yawei Ding ◽  
Wei Zhang ◽  
...  

Chemotherapy is an effective treatment for invasive breast cancer. Paradoxically, many recently published findings showed that the first-line chemotherapeutic agent paclitaxel (PTX) showed pro-metastatic effects in the progress of treating breast cancer. Xiao-Ai-Ping (XAP) injection, composed of a traditional herbal medicine, Marsdenia tenacissimae extract, is known to exert antitumor effects on various cancers. However, there are few experimental studies on breast cancer. The underlying mechanism of the antitumor effect of XAP combined with chemotherapy agents has not been fully understood. In the present study, we sought to find the antitumor effects of XAP combined with PTX in vitro and in vivo. The data demonstrated that the combination of XAP with PTX resulted in remarkable enhancement of the pro-apoptotic, migration-inhibiting, and anti-invasive effects of PTX in vitro. Significantly, further study showed the overexpression of ATF3 in PTX-treated cell, while XAP counteracted the change of ATF3 induced by PTX. Moreover, it showed that combination treatment could promote the inhibition of tumor growth in MDA-MB-231 cell xenograft mouse model. Compared with PTX treatment, the downregulation of ATF3 indicated that ATF3 played a pivotal role in the combination of XAP with PTX to exert a synergistic effect. Overall, it is expected that PTX combined with XAP may serve as an effective agent for antitumor treatment, and dampening ATF3 maybe a potential strategy to improve the efficacy of PTX.


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