Prognostic role of EGR1 in breast cancer : A systematic review

Funding Information: This study was supported by grants from the National Research Foundation (NRF) funded by the Korean government (grant no. 2015R1A5A1009701 and 2019M3A9H1030682); and, in part by the National Research Foundation of Korea-Grant funded by the Korean Government (Ministry of Science and ICT)-NRF-2017R1A2B2012337. In addition, this paper was written as part of Konkuk University's research support program for its faculty on sabbatical leave in 2019-2020.Peer reviewedPublisher PD

Mining Prognostic Significance of MEG3 in Human Breast Cancer Using Bioinformatics Analysis

Background/Aims: Maternally expressed gene 3 (MEG3) is an imprinted gene with maternal expression, which may function as a tumor suppressor by inhibiting angiogenesis. To identify the prognostic value of MEG3 in breast cancer, systematic analysis was performed in this study. Methods: To evaluate gene alteration during breast carcinogenesis, we explored MEG3 expression using the Serial Analysis of Gene Expression Genie suite and Oncomine analysis. The prognostic roles of MEG3 in breast cancer were investigated using the PrognoScan database. The heat map and methylation status of MEG3 were determined using the UCSC Genome Browser. Results: We found that MEG3 was more frequently downregulated in breast cancer than in normal tissues and this correlated with prognosis. However, estrogen receptor and progesterone receptor status were found to be positively correlated with MEG3 expression. Conversely, basal-like status, triple-negative breast cancer status, and Scarff Bloom & Richardson grade criterion were negatively correlated with MEG3 expression. Following data mining in multiple big data databases, we confirmed a positive correlation between MEG3 and heparan sulfate proteoglycan 2 (HSPG2) expression in breast cancer tissues. Conclusion: MEG3 could be adopted as a marker to predict the prognosis of breast cancer with HSPG2. However, large-scale and comprehensive research is needed to clarify our results

MicroRNA-based regulation of Aurora A kinase in breast cancer

The involvement of non-coding RNAs (ncRNAs) in cellular physiology and disease pathogenesis is becoming increasingly relevant in recent years specifically in cancer research. Breast cancer (BC) has become a health concern and accounts for most of the cancer-related incidences and mortalities reported amongst females. In spite of the presence of promising tools for BC therapy, the mortality rate of metastatic BC cases is still high. Therefore, the genomic exploration of the BC subtype and the use of ncRNAs for possible regulation is pivotal. The expression and prognostic values of AURKA gene were assessed by Oncomine, GEPIA, KM-plotter, and bc-GenExMiner v4.4, respectively. Associated proteins and functional enrichment were evaluated by Cytoscape and DAVID databases. Additionally, molecular docking approach was employed to investigate the regulatory role of hsa-miR-32-3p assisted argonaute (AGO) protein of AURKA gene in BC. AURKA gene was highly expressed in patients with BC relative to normal counterpart and significantly correlated with poor survival. The docking result suggested that AURKA could be regulated by hsa-miR-32-3p as confirmed by the reported binding energy and specific interactions. The study gives some insights into role of AURKA and its regulation by microRNAs through AGO protein. It also provides exciting opportunities for cancer therapeutic intervention. © 2020 Fadaka et al

microRNA regulation of mammalian target of rapamycin expression and activity controls estrogen receptor function and RAD001 sensitivity

Background: The AKT/mammalian target of rapamycin (mTOR) signaling pathway is regulated by 17 α -estradiol (E2) signaling and mediates E2-induced proliferation and progesterone receptor (PgR) expression in breast cancer. Methods and results: Here we use deep sequencing analysis of previously published data from The Cancer Genome Atlas to demonstrate that expression of a key component of mTOR signaling, rapamycin-insensitive companion of mTOR (Rictor), positively correlated with an estrogen receptor- α positive (ER α + ) breast tumor signature. Through increased microRNA-155 (miR-155) expression in the ER α + breast cancer cells we demonstrate repression of Rictor enhanced activation of mTOR complex 1 (mTORC1) signaling with both qPCR and western blot. miR-155-mediated mTOR signaling resulted in deregulated ER α signalingbothinculturedcells in vitro and in xenografts in vivo in addition to repressed PgR expression and act ivity.FurthermoreweobservedthatmiR-155 enhanced mTORC1 signaling (observed through western blot for increased phosphorylation on mTOR S2448) and induced inhibition of mTORC2 signaling (evident through repressed Rictor and tuberous sclerosis 1 (TSC1) gene expression). mTORC1 induced deregulation of E2 signaling was confirmed using qPCR and the mTORC1-specific inhibitor RAD001. Co-treatment of MCF7 breast cancer cells stably overexpressing miR-155 with RAD001 and E2 restored E2-induced PgR gene expression. RAD001 treatment of SCID/CB17 mice inhibited E2-induced tumorigenesis of the MCF7 miR-155 overexpressing cell line. Finally we demonstrated a strong positive correlation between Rictor and PgR expression and a negative correlation with Raptor expression in Luminal B breast cancer samples, a breast cancer histological subtype known for having an altered ER α -signaling pathway. Conclusions: miRNA mediated alterations in mTOR and ER α signaling establishes a new mechanism for altered estrogen responses independent of growth factor stimulation

Mapping of Genomic Vulnerabilities in the Post-Translational Ubiquitination, SUMOylation and Neddylation Machinery in Breast Cancer

© 2021 by the authors.The dysregulation of post-translational modifications (PTM) transversally impacts cancer hallmarks and constitutes an appealing vulnerability for drug development. In breast cancer there is growing preclinical evidence of the role of ubiquitin and ubiquitin-like SUMO and Nedd8 peptide conjugation to the proteome in tumorigenesis and drug resistance, particularly through their interplay with estrogen receptor signaling and DNA repair. Herein we explored genomic alterations in these processes using RNA-seq and mutation data from TCGA and METABRIC datasets, and analyzed them using a bioinformatic pipeline in search of those with prognostic and predictive capability which could qualify as subjects of drug research. Amplification of UBE2T, UBE2C, and BIRC5 conferred a worse prognosis in luminal A/B and basal-like tumors, luminal A/B tumors, and luminal A tumors, respectively. Higher UBE2T expression levels were predictive of a lower rate of pathological complete response in triple negative breast cancer patients following neoadjuvant chemotherapy, whereas UBE2C and BIRC5 expression was higher in luminal A patients with tumor relapse within 5 years of endocrine therapy or chemotherapy. The transcriptomic signatures of USP9X and USP7 gene mutations also conferred worse prognosis in luminal A, HER2-enriched, and basal-like tumors, and in luminal A tumors, respectively. In conclusion, we identified and characterized the clinical value of a group of genomic alterations in ubiquitination, SUMOylation, and neddylation enzymes, with potential for drug development in breast cancer.Work in Alberto Ocaña’s lab is supported by the Instituto de Salud Carlos III (ISCIII, PI19/00808); ACEPAIN; Diputación de Albacete; and the CRIS Cancer Foundation. Work in Atanasio Pandiella’s lab is supported by the Ministry of Economy and Competitiveness of Spain (BFU2015- 71371-R, the Junta de Castilla y León (CSI146P20), and the CRIS Foundation. Balázs Györffy is financed by the 2018-2.1.17-TET-KR-00001 grant and by the Higher Education Institutional Excellence Programme of the Ministry for Innovation and Technology (MIT) in Hungary, within the framework of the Bionic thematic programme of the Semmelweis University

\u3ci\u3eITGA2\u3c/i\u3e Promotes Expression of \u3ci\u3eACLY\u3c/i\u3e and \u3ci\u3eCCND1\u3c/i\u3e in Enhancing Breast Cancer Stemness and Metastasis

Cancer metastasis is largely incurable and accounts for 90% of breast cancer deaths, especially for the aggressive basal-like or triple negative breast cancer (TNBC). Combining patient database analyses and functional studies, we examined the association of integrin family members with clinical outcomes as well as their connection with previously identified microRNA regulators of metastasis, such as miR-206 that inhibits stemness and metastasis of TNBC. Here we report that the integrin receptor CD49b-encoding ITGA2, a direct target of miR-206, promotes breast cancer stemness and metastasis. ITGA2 knockdown suppressed self-renewal related mammosphere formation and pluripotency marker expression, inhibited cell cycling, compromised migration and invasion, and therefore decreased lung metastasis of breast cancer. ITGA2 overexpression reversed miR-206-caused cell cycle arrest in G1. RNA sequencing analyses revealed that ITGA2 knockdown inhibits genes related to cell cycle regulation and lipid metabolism, including CCND1 and ACLY as representative targets, respectively. Knockdown of CCND1 or ACLY inhibits mammosphere formation of breast cancer cells. Overexpression of CCND1 rescues the phenotype of ITGA2 knockdown-induced cell cycle arrest. ACLY-encoded ATP citrate lyase is essential to maintain cellular acetyl-CoA levels. CCND1 knockdown further mimics ITGA2 knockdown in abolishing lung colonization of breast cancer cells. We identified that the low levels of miR-206 as well as high expression levels of ITGA2, ACLY and CCND1 are associated with an unfavorable relapse-free survival of the patients with estrogen receptor-negative or high grade breast cancer, especially basal-like or TNBC, possibly serving as potential biomarkers of cancer stemness and therapeutic targets of breast cancer metastasis

Spheroid-Induced Epithelial-Mesenchymal Transition Provokes Global Alterations of Breast Cancer Lipidome: A Multi-Layered Omics Analysis

Metabolic rewiring has been recognized as an important feature to the progression of cancer. However, the essential components and functions of lipid metabolic networks in breast cancer progression are not fully understood. In this study, we investigated the roles of altered lipid metabolism in the malignant phenotype of breast cancer. Using a spheroid-induced epithelial-mesenchymal transition (EMT) model, we conducted multi-layered lipidomic and transcriptomic analysis to comprehensively describe the rewiring of the breast cancer lipidome during the malignant transformation. A tremendous homeostatic disturbance of various complex lipid species including ceramide, sphingomyelin, ether-linked phosphatidylcholines, and ether-linked phosphatidylethanolamine was found in the mesenchymal state of cancer cells. Noticeably, polyunsaturated fatty acids composition in spheroid cells was significantly decreased, accordingly with the gene expression patterns observed in the transcriptomic analysis of associated regulators. For instance, the up-regulation of SCD, ACOX3, and FADS1 and the down-regulation of PTPLB, PECR, and ELOVL2 were found among other lipid metabolic regulators. Significantly, the ratio of C22:6n3 (docosahexaenoic acid, DHA) to C22:5n3 was dramatically reduced in spheroid cells analogously to the down-regulation of ELOVL2. Following mechanistic study confirmed the up-regulation of SCD and down-regulation of PTPLB, PECR, ELOVL2, and ELOVL3 in the spheroid cells. Furthermore, the depletion of ELOVL2 induced metastatic characteristics in breast cancer cells via the SREBPs axis. A subsequent large-scale analysis using 51 breast cancer cell lines demonstrated the reduced expression of ELOVL2 in basal-like phenotypes. Breast cancer patients with low ELOVL2 expression exhibited poor prognoses (HR = 0.76, CI = 0.67–0.86). Collectively, ELOVL2 expression is associated with the malignant phenotypes and appear to be a novel prognostic biomarker in breast cancer. In conclusion, the present study demonstrates that there is a global alteration of the lipid composition during EMT and suggests the down-regulation of ELOVL2 induces lipid metabolism reprogramming in breast cancer and contributes to their malignant phenotypes

The Role of EHD2 in Triple-Negative Breast Cancer Tumorigenesis and Progression

Triple-negative breast cancer (TNBC) comprises 10%-15% of all breast cancer cases, yet is clinically challenging due to lack of targeted therapies which leads to higher mortality. Molecular subtyping has identified the most aggressive subclasses of breast cancer to be enriched in components of caveolae. While caveolae have been linked to many biological processes, their precise role in TNBC is still poorly understood. EHD2, a member of the C-terminal EPS15-Homology Domain-containing (EHD) protein family, has emerged as a new regulator of caveolae dynamics and is essential to maintain a stable membrane pool of caveolae. Studies in model cells demonstrate that caveolae facilitate repair of plasma membrane injuries incurred under stressful conditions. Importantly, new evidence suggests the invasiveness of tumor cells makes them vulnerable to plasma membrane injuries and hence a robust repair mechanism is essential to protect injured tumor cells from cell death. EHD2 is found to be highly expressed within the basal myoepithelial layer throughout mammary gland development. High EHD2 mRNA and protein expression was observed in human TNBC cell lines and positively correlated with Caveolin-1 and Caveolin-2 expression. Furthermore, by analyzing publicly available gene expression databases, we found that high expression of EHD2 mRNA correlated with lower probability of survival in TNBC patients. This led us to hypothesize that EHD2 is a marker and crucial regulator of tumorigenicity in TNBC. Using a cohort of 840 highly-annotated human breast cancer tissue samples, we discovered that high cytoplasmic expression of EHD2 marked TNBC cases, and served as a robust prognostic indicator of metastasis and lower patient survival. ShRNA-mediated knockdown of EHD2 in TNBC cell lines reduced invasiveness, growth under anchorage-independent conditions, and membrane repair ability in vitro. Using orthotopic implantation of human breast cancer cell lines in mouse mammary gland, we observed a dramatic abrogation of tumor growth and a reduction in metastasis of TNBC cell lines with EHD2 knockdown compared to their controls. These findings indicate that EHD2 is a novel clinical biomarker of poor prognosis in TNBC, and serves a novel role as a positive regulator of caveolae-dependent protection of plasma membrane against injury, enabling tumorigenicity and metastasis in TNBC. Our results support the potential of targeting EHD2 to develop therapeutic approaches against TNBC

The Age-Dependent Characterization of the ER-Alpha Positive Breast Cancer Tumor Microenvironment

In disease states such as cancer, endocrine and paracrine signals from adipose tissue contribute to cancer progression and drug resistance. Young individuals diagnosed with estrogen receptor-alpha positive (ER-a+) breast cancer have an observed increase in resistance to endocrine therapies. This suggests that an alternative estrogen signaling pathway is active within these tumors. Despite this, the effects of stromal age on the endocrine response in breast cancer is not well known. Here, we review and highlight the involvement of the stromal age in both tumorigenesis and physiological wound healing. To identify specific differences between young and aged ER-a+ breast tumors, RNA sequencing data was obtained from The Cancer Genome Atlas (TCGA). Analysis revealed enrichment of matrix and paracrine factors in young (old) patients compared to aged (\u3e65 years old) tumor samples. Analyzing cell infiltrate of young and aged ER-a+ breast tumors revealed significant differences in several immune cell populations, however, there were no differences in MSC and adipocyte infiltrate between young and aged tumors. Based on these results, we next sought to determine if stromal cells exhibited age-dependent differences. To determine if the age of tumor stroma differentially regulated the ER-a+ tumor microenvironment (TME), adipose-derived stem/stromal cells (ASCs) from healthy young and aged donors were evaluated for alterations in matrix production and paracrine factors. Results demonstrated that young and aged ASCs were neither phenotypically different, nor did they demonstrate alterations in matrix production. Analysis of paracrine factors demonstrated that young and aged ASCs had differences in pro-inflammatory cytokines. Paracrine factors from young ASCs enhanced the ER-a regulated genes progesterone receptor (PR) and stromal-derived factor 1 (SDF-1) in the MCF-7 ER-a+ breast cancer cell line. Additionally, western blot analysis demonstrated increased activation of p-ER ser167 in the MCF-7 cell line treated with young ASC paracrine factors. These results are important in understanding the mechanisms of estrogen receptor signaling in young breast cancer patients, as well as unveiling underlying factors that contribute to the unique TME in young breast cancer patients