MYC Deregulation and PTEN Loss Model Tumor and Stromal Heterogeneity of Aggressive Triple-Negative Breast Cancer
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE215071 | GEO | 2022/10/17
REPOSITORIES: GEO
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Project description:Triple-negative breast cancer (TNBC) patients have a poor prognosis and few treatment options. Mouse models of TNBC are important for development of new therapies, however, few mouse models represent the complexity of TNBC. Here, we develop a female TNBC murine model by mimicking two common TNBC mutations with high co-occurrence: amplification of the oncogene MYC and deletion of the tumor suppressor PTEN. This Myc;Ptenfl model develops heterogeneous triple-negative mammary tumors that display histological and molecular features commonly found in human TNBC. Our research involves deep molecular and spatial analyses on Myc;Ptenfl tumors including bulk and single-cell RNA-sequencing, and multiplex tissue-imaging. Through comparison with human TNBC, we demonstrate that this genetic mouse model develops mammary tumors with differential survival and therapeutic responses that closely resemble the inter- and intra-tumoral and microenvironmental heterogeneity of human TNBC, providing a pre-clinical tool for assessing the spectrum of patient TNBC biology and drug response.
2023-07-18 | GSE215070 | GEO
Project description:Triple negative breast cancer (TNBC) has poor prognostic outcome compared to other types of breast cancer1. At present the molecular and cellular mechanisms underlying TNBC pathology are not well understood1. Here we report that the transcription factor BCL11A is overexpressed in TNBC including basal-like breast cancer (BLBC) and that its genomic locus is amplified in up to 38% of BLBC tumours. BCL11A overexpression in immortalised human breast epithelial cells promotes tumour formation in xenograft models, whereas knockdown of BCL11A in TNBC cell lines suppresses their tumourigenic potential. In the DMBA-induced mouse mammary tumour model, Bcl11a is found to be essential for tumourigenesis since deletion of Bcl11a before DMBA treatment substantially decreases tumour formation, even in p53-null cells, and inactivation of Bcl11a in established tumours causes their regression. At the cellular level, BCL11A overexpression enhances clonogenicity in vitro whereas its deletion in the mouse causes a reduction in the number of mammary epithelial stem and progenitor cells. Thus, BCL11A has an important role in the genesis of TNBC and in normal mammary epithelial cells. This study highlights the importance of further investigation of BCL11A in breast cancer diagnosis and targeted therapies. [Mouse] KO is bcl11a deleted mammary stem cells. WT are mammary stem cells with intact Bcl11a. [Human] HMLE tumors overexpressing BCL11A.
2014-11-18 | E-GEOD-63386 | biostudies-arrayexpress
Project description:Triple negative breast cancer (TNBC) is an aggressive subtype that lack targeted clinical therapies. In addition, TNBC is heterogeneous and was recently further sub-classified into seven TNBC subtypes that displayed unique gene expression patterns. To develop therapeutic treatment regimens, we established seven patient-derived xenograft models from TNBC tumors. These xenograft models not only retained the histology and clinical markers of the corresponding patient tumors, but also bearing the same mutations and deletions identified in the patient tumors. Moreover, as part of evaluation of these models, we performed microarrays on the xenograft tumors to assess their TNBC subtypes. After obtaining IRB-approved informed written patient consent, breast cancer tissues were obtained fresh from Stanford Hospital and transplanted into the number 2 mammary fat pads of female NOD SCID mice (NOD.CB17-Prkdcscid/J, Jackson Laboratory West, Sacramento, CA, USA). Mice were maintained in pathogen-free animal housing. The established xenografts were subsequently passaged from mouse to mouse. Xenograft tumor tissues were frozen on dry ice for RNA isolation and microarray analysis.
2014-03-21 | E-GEOD-47079 | biostudies-arrayexpress
Project description:The MYC oncogene is frequently amplified in triple negative breast cancer (TNBC). Here, we show that MYC suppression induces immune-related hallmark gene set signatures and tumor infiltrating T cells in MYC-hyperactivated TNBCs. Mechanistically, MYC repressed stimulator of interferon genes (STING) expression via direct binding to the STING enhancer region, resulting in downregulation of the T cell chemokines CCL5, CXCL10 and CXCL11. In primary and metastatic TNBC cohorts, tumors with high MYC expression or activity exhibited low STING expression. Using a CRISPR-mediated enhancer perturbation approach, we demonstrated that MYC-driven immune evasion is mediated by STING repression. STING repression induced resistance to PD-L1 blockade in mouse models of TNBC. Finally, a small molecule inhibitor of MYC combined with PD-L1 blockade elicited a durable response in immune-cold TNBC with high MYC levels, suggesting a strategy to restore PD-L1 inhibitor sensitivity in MYC-overexpressing TNBC.
2022-03-01 | GSE196324 | GEO
Project description:The MYC oncogene is frequently amplified in triple negative breast cancer (TNBC). Here, we show that MYC suppression induces immune-related hallmark gene set signatures and tumor infiltrating T cells in MYC-hyperactivated TNBCs. Mechanistically, MYC repressed stimulator of interferon genes (STING) expression via direct binding to the STING enhancer region, resulting in downregulation of the T cell chemokines CCL5, CXCL10 and CXCL11. In primary and metastatic TNBC cohorts, tumors with high MYC expression or activity exhibited low STING expression. Using a CRISPR-mediated enhancer perturbation approach, we demonstrated that MYC-driven immune evasion is mediated by STING repression. STING repression induced resistance to PD-L1 blockade in mouse models of TNBC. Finally, a small molecule inhibitor of MYC combined with PD-L1 blockade elicited a durable response in immune-cold TNBC with high MYC levels, suggesting a strategy to restore PD-L1 inhibitor sensitivity in MYC-overexpressing TNBC.
2022-03-01 | GSE196323 | GEO
Project description:<p>In this study the investigators looked at adaptive reprogramming impact on the kinome when a MEK inhibitor called GSK1120212 (trametinib) was administered in a "window of opportunity" trial. GSK1120212 is not yet approved by the FDA for use in breast cancer patients. The investigators gave GSK1120212 for a short period of time (one week) to examine MEK and the other kinase expression in cancer cells both before and after the study drug is given. The investigators gave this drug for research purposes only. The length of time it was given is not intended to treat cancer.</p> <p>Recently researchers at UNC developed a process that can comprehensively profile the majority of the individual kinases in the kinome and examine the impact on kinase expression of kinase inhibitors (Duncan et al, Cell 2012, PMID: 22500798). This can tell us which kinases need to be concurrently blocked to augment responsiveness and prevent acquired resistance so that the investigators can design the best combinations of kinase blocking drugs for triple negative breast cancer. This is especially important for individuals with triple negative breast cancer (TNBC) because there are no targeted drugs available that can block molecules that affect tumor growth. The investigators believe that kinase-blocking drugs have the potential to be a more effective treatment for people with TNBC.</p> <p>In this recently published study (Zawistowski et al, Cancer Discovery 2017, PMID: 28108460), TNBC patients treated with trametinib for 7 days resulted in a transcriptional response characterized by significant reprogramming of the tyrosine kinome, and this adaptive bypass response in human tumors was found to be similar to that seen in preclinical models including TNBC cell lines and mouse xenografts. In this study we also examined whether reprogramming differed between TNBC molecular subtypes, finding that basal-like and claudin-low human TNBC cells and mouse tumor subtypes had different adaptive transcriptional responses to MEK-ERK inhibition. Mechanistically we found that genome-wide enhancer remodeling drove the adaptive transcriptional response, suggesting that epigenetic approaches to reprogramming may be more durable than kinase inhibitor polypharmacology.</p>
| phs001405 | dbGaP
Project description:The gene expression of 6 different mouse xenografts initiated by BPLER cells analyzed by microarray. Basal-like triple negative breast cancers (TNBC) have poor prognosis. To study the basal-like transcriptional profile of tumors transformed by defined genetic elements, the human breast epithelial cell line BPLER was injected into NOD/SCID mice. The resulting tumors were excised for expression analysis. Keywords: breast cancer, BPLER, metastasis, tumor stem cells, tumor initiating cells, breast adenocarcinoma BPLER cells were derived from human primary breast epithelial cells propagated in WIT medium (Ince et al, Cancer Cell, 2007). These cells were transformed with hTERT, SV40 early region and hRASV12 by retroviral transduction. BPLER have a TNBC-like phenotype in vitro and are highly enriched for tumor-initiating cells. To define the phenotype of BPLER-derived tumors in vivo, BPLER cells were injected in the mammary fat-pad of 6 NOD/SCID mice. Once tumors were palpable, mice were sacrificed and tumors excised. Total RNA was extracted using Trizol. The gene expression profile of each tumor was assessed by mRNA microarray analysis. Based on histology and principal component analysis of microarray data, BPLER tumors were remarkably similar to human primary TNBC encountered in the clinic (Petrocca et al, Cancer Cell, 2013).
2013-07-02 | E-GEOD-48444 | biostudies-arrayexpress
Project description:To identify novel molecular targets for triple negative breast cancer (TNBC), we have employed whole genome microarray expression profiling. We purified 30 surgically resected breast cancer tissue diagnosed triple negative by means of immunohistochemical staining and 13 normal mammary ductal cells with lasermicrobeam microdissection system (PALM MicroBeam, Carl Zeiss MicroImaging Co., Ltd), performed whole human genome microarray, and compared gene expression levels of TNBC, normal mammary ductal cells, and normal vital organs to develop molecular targets with a minimum risk. Gene expression levels of 30 TNBC, 13 normal mammary ductal cells, and 4 normal vital tissues were evaluated. to clarify the molecular mechanism involved in TNBC, we analyzed gene expression profiles of 30 TNBC as well as 13 normal epithelial ductal cells purified by laser microbeam microdissection, and identified 301 transcripts that were significantly up-regulated and 321 transcripts that were significantly down-regulated in TNBC. In addition, gene-expression profiles analysis of normal human vital organs including heart, lung, liver, and kidney allowed us to identify 90 cancer-specific genes involved in breast carcinogenesis such as NEK2, PBK, DTL, MELK and GPSM2. Among them, we focused on cell cycle regulators, asp (abnormal spindle) homolog, microcephaly associated (Drosophila) (ASPM) and centromere protein K (CENPK) as novel therapeutic targets for TNBC.
2012-12-21 | E-GEOD-38959 | biostudies-arrayexpress
Project description:Triple negative breast cancer (TNBC) has poor prognostic outcome compared to other types of breast cancer1. At present the molecular and cellular mechanisms underlying TNBC pathology are not well understood1. Here we report that the transcription factor BCL11A is overexpressed in TNBC including basal-like breast cancer (BLBC) and that its genomic locus is amplified in up to 38% of BLBC tumours. BCL11A overexpression in immortalised human breast epithelial cells promotes tumour formation in xenograft models, whereas knockdown of BCL11A in TNBC cell lines suppresses their tumourigenic potential. In the DMBA-induced mouse mammary tumour model, Bcl11a is found to be essential for tumourigenesis since deletion of Bcl11a before DMBA treatment substantially decreases tumour formation, even in p53-null cells, and inactivation of Bcl11a in established tumours causes their regression. At the cellular level, BCL11A overexpression enhances clonogenicity in vitro whereas its deletion in the mouse causes a reduction in the number of mammary epithelial stem and progenitor cells. Thus, BCL11A has an important role in the genesis of TNBC and in normal mammary epithelial cells. This study highlights the importance of further investigation of BCL11A in breast cancer diagnosis and targeted therapies.
2014-11-18 | GSE63386 | GEO
Project description:Gain-of-function mutation of PIK3CA represents one of the most common oncogenic events in human malignancy, making PI3K an attractive target for cancer therapy. Despite the great promise of targeted therapy, drug resistance is likely to develop, causing treatment failure. To elucidate resistance mechanisms to PI3K-targeted therapy, we constructed a mouse model of breast cancer conditionally expressing PIK3CA-H1047R. Surprisingly, the majority of mammary tumors induced by PIK3CA-H1047R expression recurred following PIK3CA-H1047R inactivation. Genomic analyses of recurrent tumors revealed multiple lesions, including spontaneous focal amplification of c-Met or c-Myc. While amplification of c-Met allowed tumor survival dependent on activation of endogenous PI3K, tumors with amplification of c-Myc become independent of the PI3K pathway. Functional analyses further demonstrated that c-Myc contributed to tumors’ independence of oncogene and resistance to PI3K inhibition. Together, our data suggest that MYC elevation in tumors may be a potential mechanism conferring resistance to current PI3K-targeted therapies. Affymetrix SNP array analysis was performed with Mouse Diversity Genotyping Arrays (Affymetrix) on genomic DNA extracted from frozen biopsies of 6 recurrent mouse mammary tumor samples. Copy number analysis was performed for the mouse mammary tumors using genomic DNA from normal mammary tissue as the reference for copy number inference.
2011-08-01 | E-GEOD-27691 | biostudies-arrayexpress