SAA1-dependent reprogramming of adipocytes by tumor cells is associated with triple negative breast cancer aggressiveness
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ABSTRACT: Cancer development and progression depend on tumor cell intrinsic factors, the tumor microenvironment and host characteristics. Despite the identification of the plasticity of adipocytes, the primary breast stromal cells, both in physiology and cancer, we lack a complete understanding of mechanisms that regulate adipocyte-tumor cell crosstalk. Here we dissected the breast cancer crosstalk with adipocytes and studied relevant molecules. We identified that the ability of breast cancer cells to dedifferentiate adipocytes is intrinsic subtype-dependent, with all breast cancer subtypes, except for HER2+ER+ subtype, capable of inducing this phenomenon. Crosstalk between breast cancer cells and adipocytes in vitro increased cancer stem-like features and recruitment of pro-tumorigenic immune cells, through chemokine production. Serum amyloid A1 (SAA1) was in vitro identified as a regulator of the adipocyte dedifferentiation program in triple-negative breast cancer (TNBC) through CD36 and P2XR7 signaling. In human TNBCs, SAA1 expression was associated with CAA infiltration, inflammation, stimulated lipolysis, stem-like properties and distinct tumor immune microenvironment. Our findings provide evidence that interaction between tumor cells and adipocytes through SAA1 release is relevant to the aggressiveness of TNBC, potentially supporting its targeting.
Project description:Adipocyte was found play a pivotal role in tumorgenesis, progression and metastasis in breast cancer. However, affection of adipocyte on gene expression profile in triple-negative breast cancer (TNBC) is still not clear. In the present study, firstly we reported the gene expression profiles of TNBC regulated by human adipocytes using NGS. TNBC cell MDA-MB-231 was used in this study. MDA-MB-231 cells were treated with medium derived from adipocytes culture supernatants. Using two different RNA libraries, we sequenced the complete transcriptome(including mRNA, lncRNA, circleRNA and small RNA) of MDA-MB-231 treated with medium derived from adipocytes culture supernatants.
Project description:Triple-negative breast cancer (TNBC) is defined by the absence of estrogen and progesterone receptors and human epidermal growth factor receptor 2, and is the most lethal and aggressive subtype of breast cancer. However, the genes which relate to promote tumor aggressiveness in TNBC remain unclear. In order to investigate specific genes and pathways involved in TNBC tumorigenesis, we compared genes differentially expressed between 3D cultures (3DC) or tumor xenograft models and control two-dimensional cultures (2DC). Total RNA was prepared from the TNBC cells under the condition of 2DC, 3DC and tumor xenograft models, and applied to Affymetrix Human Genome U133 Plus 2.0 Array.
Project description:Breast cancer is a heterogeneous disease for which prognosis and treatment strategies are largely governed by the receptor status (estrogen, progesterone and Her2-neu) of the tumor cells. Gene expression profiling of whole breast tumors further stratifies breast cancer into several molecular subtypes which also co-segregate with the receptor status of the tumor cells. We postulated that cancer associated fibroblasts (CAFs) within the tumor stroma may exhibit subtype specific gene expression profiles and thus contribute to the biology of the disease in a subtype specific manner. Several studies have reported gene expression profile differences between CAFs and normal breast fibroblasts but in none of these studies were the results stratified based on tumor subtypes. To address whether gene expression in breast cancer associated fibroblasts varies between breast cancer subtypes, we compared the gene expression profiles of early passage primary CAFs isolated from twenty human breast cancer samples representing three main subtypes; seven ER+, seven triple negative (TNBC) and six Her2+. We observed significant expression differences between CAFs derived from Her2+ breast cancer and CAFs from TNBC and ER+ cancers, particularly in pathways associated with cytoskeleton and integrin signaling. In the case of Her2+ breast cancer, the signaling pathways found to be selectively up regulated in CAFs may contribute to the more invasive properties and unfavorable prognosis of Her2+ breast cancer. These data demonstrate that in addition to the distinct molecular profiles that characterize the neoplastic cells, CAF gene expression is also differentially regulated in distinct subtypes of breast cancer. We isolated CAFs from twenty primary breast cancer samples representing three main subtypes (ER+ (n=7), TNBC (n=7), Her2+ (n=6)) and performed gene expression profile analyses on RNA isolated from these early passage CAFs. Those samples were done in two batches with 4 samples repeated in both batches. One TNBC sample was found to be an outlier and not used in the analysis.
Project description:Breast cancer is genetically and clinically heterogeneous. Triple negative cancer (TNBC) is a subtype of breast cancer usually associated with poor outcome and lack of benefit from target therapy. A pathway analysis in a microarray study was performed using TNBC compared with non-triple negative breast cancer (non-TNBC). Overexpression of several Wnt pathway genes, such as frizzled homolog 7 (FZD7), Low density lipoprotein receptor-related protein 6 (LRP6) and transcription factor 7 (TCF7) has been observed in TNBC. Focus was given to the Wnt pathway receptor, FZD7. To validate its function, inhibition of FZD7 using FZD7shRNA was carried out. Notably decreased cell proliferation, suppressed invasiveness and colony formation in triple negative MDA-MB-231 and BT-20 cells were observed. Mechanism study indicated that these effects occurred through silencing the canonical Wnt signaling pathway, as evidenced by loss of nuclear accumulation of ï?¢-catenin and decreased transcriptional activity of TCF7. In vivo study revealed that FZD7shRNA significantly suppressed the tumor formation in xenotransplation mice due to decrease cell proliferation. Our finding suggests that FZD7 involved canonical Wnt signaling pathway is essential for tumorigenesis of TNBC. Thus, FZD7 may be a biomarker and a potential therapeutic target for triple negative breast cancer. 14 pretreatment non-triple negative breast tumors compare with 5 triple negative breast tumor.
Project description:Goal: To define the digital transcriptome of three breast cancer subtypes (TNBC, Non-TNBC, and HER2-positive) using RNA-sequencing technology. To elucidate differentially expressed known and novel transcripts, alternatively spliced genes and differential isoforms and lastly expressed variants in our dataset. Method: Dr. Suzanne Fuqua (Baylor College of Medicine) provided the human breast cancer tissue RNA samples. All of the human samples were used in accordance with the IRB procedures of Baylor College of Medicine. The breast tumour types, TNBC, Non-TNBC and HER2-positive, were classified on the basis of immunohistochemical and RT-qPCR classification. Results: Comparative transcriptomic analyses elucidated differentially expressed transcripts between the three breast cancer groups, identifying several new modulators of breast cancer. We discovered subtype specific differentially spliced genes and splice isoforms not previously recognized in human transcriptome. Further, we showed that exon skip and intron retention are predominant splice events in breast cancer. In addition, we found that differential expression of primary transcripts and promoter switching are significantly deregulated in breast cancer compared to normal breast. We also report novel expressed variants, allelic prevalence and abundance, and coexpression with other variation, and splicing signatures. Additionally we describe novel SNPs and INDELs in cancer relevant genes with no prior reported association of point mutations with cancer mRNA profiles of 17 breast tumor samples of three different subtypes (TNBC, non-TNBC and HER2-positive) and normal human breast organoids (epithelium) samples (NBS) were sequenced using Illumina HiSeq.
Project description:Triple-negative breast cancer (TNBC) is defined by the absence of estrogen and progesterone receptors and human epidermal growth factor receptor 2, and is the most lethal and aggressive subtype of breast cancer. However, the genes which relate to promote tumor aggressiveness in TNBC remain unclear. In order to investigate specific genes and pathways involved in TNBC tumorigenesis, we compared genes differentially expressed between 3D cultures (3DC) or tumor xenograft models and control two-dimensional cultures (2DC).
Project description:Breast cancer is the most common malignancy that develops in women, responsible for the highest cancer-associated death rates. Triple negative breast cancers (TNBC) represent an important subtype that have an aggressive clinical phenotype, are associated with a higher likelihood of metastasis and are not responsive to current targeted therapies. miRNAs have emerged as an attractive candidate for molecular biomarkers and treatment targets in breast cancer, but their role in the progression of TNBC remains largely unexplored. This study has investigated miRNA expression profiles in 31 primary TNBC cases and in 13 lymph node metastases compared with 23 matched normal breast tissues to determine miRNAs associated with the initiation of this disease subtype and those associated with its metastasis. 71 miRNAs were differentially expressed in TNBC, the majority of which have previously been associated with breast cancer, including members of the miR-200 family and the miR-17-92 oncogenic cluster, suggesting that miRNAs involved in the initiation of TNBC are not subtype specific. However, the repertoire of miRNAs expressed in lymph node negative and lymph node positive TNBCs were largely distinct from one another. In particular, miRNA profiles associated with lymph node negative disease tended to be up-regulated, while those associated with lymph node positive disease were down-regulated and largely overlapped with the profiles of their matched lymph node metastases. miRNA expression profiles were examined in 31 primary TNBC cases and in 13 lymph node metastases compared with 23 matched normal breast tissues
Project description:It is widely recognized that cancer development and progression depend not only on tumor-cell intrinsic factors but also on its microenvironment and on the host characteristics. Adipocytes are the main stromal cells in the breast and an heterotypic interaction between breast epithelial cells and adipocytes has been demonstrated. To date, the alterations associated with adipocyte dedifferentiation has to be further studied. The aim of our work is to compare gene expression profile of mature adipocytes (MA), adipocytes dedifferentiated (DED) by breast cancer cells and mesenchymal stem cells (MSC) using the ASC52htert in vitro model.
Project description:Lacking effective targeted therapies, triple-negative breast cancer (TNBCs) is highly aggressive, metastatic, and clinically challenging breast cancer subtype with worst prognosis. Despite survival dependency on the proteasome pathway genes, the FDA-approved proteasome inhibitors induced minimal clinical response in TNBC patients due to weaker proteasome inhibition. Here, we show that a novel proteasome inhibitor Marizomib (Mzb), inhibited multiple proteasome catalytic activities and induced better anti-tumor response in TNBC cell line and patient-derived xenografts alone and in combination with a standard-of-care chemotherapy, doxorubicin. Mechanistically, Mzb inhibits oxidative phosphorylation (OXPHOS) via PGC-1α suppression in conjunction with proteasome inhibition in TNBC cells. Development of metastatic disease, especially brain metastasis, remains a reason for a greater mortality rate amongst TNBC patients. Mzb reduces lung and brain metastasis in vivo by reducing circulating tumor cells and the expression of multiple epithelial-to-mesenchymal genes. We also demonstrate that Mzb-induced OXPHOS inhibition upregulates glycolysis to fulfill the metabolic demand of TNBC cells and hence, combined inhibition of glycolysis with Mzb leads to a synergistic anti-cancer activity in vivo. Collectively, our data provide a strong rationale for the clinical evaluation of Mzb in primary and metastatic TNBC patients.
Project description:Breast cancer can classify molecular subtype, luminal A, B, and HER2-positive and triple-negative breast cancer. Especially TNBC, there is no therapeutic target compared to other molecular subtypes. To investigate dysregulated miRNAs in TNBC, we performed miRNA microarray using breast cancer tissue with matched normal tissue in each subtype.