Effects of differentiated hMADS adipocytes on BT474 and SKBR3 breast cancer cells
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ABSTRACT: Analysis of gene expression levels of HER2-positive breast cancer cells exposed to the conditioned medium from adipocytes. The hypothesis tested in the present study was that adipocytes secrete factors that induce the resistance of cancer cells to antibody-dependent cellular cytotoxicity mediated by trastuzumab. The results provide insight into the genes that may be involved in the adipocyte-induced cancer resistance to trastuzumab treatment. BT474 cells or SKBR3 cells were exposed to the conditioned medium (CM) from differentiated hMADS (#hMADS) or to the control medium for 2 h. Total RNA was extracted and analyzed. The experiment was performed in triplicate.
Project description:Analysis of gene expression levels of HER2-positive breast cancer cells exposed to the conditioned medium from adipocytes. The hypothesis tested in the present study was that adipocytes secrete factors that induce the resistance of cancer cells to antibody-dependent cellular cytotoxicity mediated by trastuzumab. The results provide insight into the genes that may be involved in the adipocyte-induced cancer resistance to trastuzumab treatment.
Project description:Analysis of gene expression levels of HER2-positive breast cancer cells exposed to the conditioned medium from adipocytes. The hypothesis tested in the present study was that adipocytes secrete factors that induce the resistance of cancer cells to antibody-dependent cellular cytotoxicity mediated by trastuzumab. The results provide insight into the genes that may be involved in the adipocyte-induced cancer resistance to trastuzumab treatment. BT474 cells or SKBR3 cells were exposed to the conditioned medium (CM) from differentiated hMADS (#hMADS) or to the control medium for 2 h. Total RNA was extracted and analyzed. The experiment was performed in triplicate.
Project description:HER2-positive breast cancer is one of the most prevalent forms of cancer among women worldwide. Generally, the molecular characteristics of this breast cancer include activation of human epidermal growth factor receptor-2 (HER2) and hormone receptor activation. HER2-positive is associated with a higher death rate, which led to the development of a monoclonal antibody called trastuzumab, specifically targeting HER2. The success rate of HER2-positive breast cancer treatment has been increased; however, drug resistance remains a challenge. This fact motivated us to explore the underlying molecular mechanisms of trastuzumab resistance. For this purpose, a two-fold approach was taken by considering well-known breast cancer cell lines SKBR3 and BT474. In the first fold, trastuzumab treatment doses were optimized separately for both cell lines. This was done based on the proliferation rate of cells in response to a wide variety of medication dosages. Thereafter, each cell line was cultivated with a steady dosage of herceptin for several months. During this period, six time points were selected for further in vitro analysis, ranging from the untreated cell line at the beginning to a fully resistant cell line at the end of the experiment. In the second fold, nucleic acids were extracted for further high throughput-based microarray experiments of gene and microRNA expression. Such expression data were further analyzed in order to infer the molecular mechanisms involved in the underlying development of trastuzumab resistance. In the list of differentially expressed genes and miRNAs, multiple genes (e.g., BIRC5, E2F1, TFRC, and USP1) and miRNAs (e.g., hsa miR 574 3p, hsa miR 4530, and hsa miR 197 3p) responsible for trastuzumab resistance were found. Downstream analysis showed that TFRC, E2F1, and USP1 were also targeted by hsa-miR-8485. Moreover, it indicated that miR-4701-5p was highly expressed as compared to TFRC in the SKBR3 cell line. These results unveil key genes and miRNAs as molecular regulators for trastuzumab resistance.
Project description:Tolfenamic acid (TA) is a nonsteroidal anti-inflammatory drug that inhibits pancreatic cancer cell and tumor growth through decreasing expression of specificity protein (Sp) transcription factors. TA also inhibits growth of erbB2-overexpressing BT474 and SKBR3 breast cancer cells; however, in contrast to pancreatic cancer cells, TA induced down-regulation of erbB2 but not Sp proteins. TA-induced erbB2 down-regulation was accompanied by decreased erbB2-dependent kinase activities, induction of p27, and decreased expression of cyclin D1. TA also decreased erbB2 mRNA expression and promoter activity, and this was due to decreased mRNA stability in BT474 cells and, in both cell lines, TA decreased expression of the YY1 and AP-2 transcription factors required for basal erbB2 expression. In addition, TA also inhibited tumor growth in athymic nude mice in which BT474 cells were injected into the mammary fat pad. TA represents a novel and promising new anticancer drug that targets erbB2 by decreasing transcription of this oncogene.
Project description:We found that trastuzumab (herceptin) treatment significantly decreased five miRNAs and increased three others in SKBr3 cells, whereas in BT474 cells it significantly decreased two miRNAs and increased nine. The only miRNA that shared the same change in both cell lines was miRNA-194 (miR-194), which was upregulated following trastuzumab treatment.
Project description:To develop gene-miRNA and pathway-miRNA networks in trastuzumab treatment, we performed a recent miRNA microarray profiling in trastuzumab treated/untreated SKBR3 and BT474 cell lines. The cells were plated at a starting density of 2 millions in 100 mm cell culture dishes and then, they were treated with 6 ug/mL trastuzumab and PBS in two replicates. Total RNA was isolated with the TRIzol reagent (Invitrogen) according to the manufacturer's instructions.
Project description:SKBR3 cells, which bear both an HER2 and a RARA gene amplification, were treated for 12 or 48 hours with 100 nM retinoic acid, 100 nM lapatinib or the combination.The two drugs synergize and induce massive apoptosis. The aim is to find the molecular mechanism(s) of this synergism. Gene expression profiling was performed using Agilent two-color 4X44K arrays. Original processed data are available in the archive: http://www.ebi.ac.uk/arrayexpress/files/E-MEXP-3192/E-MEXP-3192.additional.zip
Project description:Alterations in HOXB genes expression in breast cancer have been described and related to therapy response and disease progression. However, due to breast cancer complexity and heterogeneity, added to the use of different technical approaches, the observed expression profiles are sometimes contradictory. Here, we provided the analyses of HOXB7, HOXB8 and HOXB9 expression profiles in cell lines extensively used in the literature addressing the putative role of HOXB genes in breast cancer (MCF7, BT474, SKBR3, MDA231 and MDA468) and representative of the clinical breast cancer molecular subtypes (Luminal A, Luminal B, HER2+ and Triple-negatives Claudin-low/Basal), compared to a normal breast model (MCF10A), using quantitative-PCR (qPCR). This technique allows a very sensitive quantification of gene expression and was performed using the fluorophore SYBR Green in order to obtain the expression levels relative to a reference gene, GAPDH in this case. We showed that HOXB7 is upregulated in all breast cancer cells analyzed, while HOXB8 and HOXB9 are significantly upregulated in MCF7 (Luminal A), BT474 (Luminal B) and MDA231 cells (Triple-negative Claudin-low). In addition, we found that the magnitude of the upregulation is highly subtype-specific, being the HER2+ cells the model with lowest HOXB7 upregulation, presenting very low or even null expression for HOXB8 and HOXB9, respectively. These results are analyzed in more detail in "HOX genes function in Breast Cancer development" [1] and are potentially relevant for a better understanding of the molecular heterogeneity of breast cancer, in addition to be a valuable tool assisting researchers in the choice of the most suitable cell models to perform functional assays concerning HOXB7, HOXB8 and HOXB9 genes.
Project description:Adipocytes in the breast tumour microenvironment promotes acquired treatment resistance. We used an in vitro adipocyte-conditioned media approach to investigate the direct paracrine effects of adipocyte secretory factors on MDA-MB-231 breast cancer cells treated with doxorubicin to clarify the underlying treatment resistance mechanisms. Cell-viability assays, and Western blots were performed to determine alterations in apoptotic, proliferation and lipid metabolism protein markers. Free fatty acids (FFA) and inflammatory markers in the collected treatment-conditioned media were also quantified. Adipocyte secretory factors increased the cell-viability of doxorubicin-treated cells (p < 0.0001), which did not correspond to apoptosis or proliferation pathways. Adipocyte secretory factors increased the protein expression of hormone-sensitive lipase (p < 0.05) in doxorubicin-treated cells. Adipocyte secretory factors increased the utilization of leptin (p < 0.05) and MCP-1 (p < 0.01) proteins and possibly inhibited release of linoleic acid by doxorubicin-treated cells (treatment-conditioned media FFA profiles). Adipocyte secretory factors induced doxorubicin treatment resistance, by increasing the utilization of inflammatory mediators and inhibiting the release of FFA by doxorubicin-treated cells. This further promotes inflammation and lipid metabolic reprogramming (lipid storage) in the tumour microenvironment, which breast cancer cells use to evade the toxic effects induced by doxorubicin and confers to acquired treatment resistance.
Project description:BackgroundCurrently, most of the research on breast cancer has been carried out in conventional two-dimensional (2D) cell cultures due to its practical benefits, however, the three-dimensional (3D) cell culture is becoming the model of choice in cancer research because it allows cell-cell and cell-extracellular matrix (ECM) interactions, mimicking the native microenvironment of tumors in vivo.MethodsIn this work, we evaluated the effect of 3D cell organization on the expression pattern of miRNAs (by Small-RNAseq) and mRNAs (by microarrays) in the breast cancer SKBR3 cell line and analyzed the biological processes and signaling pathways regulated by the differentially expressed protein-coding genes (DE-mRNAs) and miRNAs (DE-microRNAs) found in the organoids.ResultsWe obtained well-defined cell-aggregated organoids with a grape cluster-like morphology with a size up to 9.2 × 105 μm3. The transcriptomic assays showed that cell growth in organoids significantly affected (all p < 0.01) the gene expression patterns of both miRNAs, and mRNAs, finding 20 upregulated and 19 downregulated DE-microRNAs, as well as 49 upregulated and 123 downregulated DE-mRNAs. In silico analysis showed that a subset of 11 upregulated DE-microRNAs target 70 downregulated DE-mRNAs. These genes are involved in 150 gene ontology (GO) biological processes such as regulation of cell morphogenesis, regulation of cell shape, regulation of canonical Wnt signaling pathway, morphogenesis of epithelium, regulation of cytoskeleton organization, as well as in the MAPK and AGE-RAGE signaling KEGG-pathways. Interestingly, hsa-mir-122-5p (Fold Change (FC) = 15.4), hsa-mir-369-3p (FC = 11.4), and hsa-mir-10b-5p (FC = 20.1) regulated up to 81% of the 70 downregulated DE-mRNAs.ConclusionThe organotypic 3D cell-organization architecture of breast cancer SKBR3 cells impacts the expression pattern of the miRNAs-mRNAs network mainly through overexpression of hsa-mir-122-5p, hsa-mir-369-3p, and hsa-mir-10b-5p. All these findings suggest that the interaction between cell-cell and cell-ECM as well as the change in the culture architecture impacts gene expression, and, therefore, support the pertinence of migrating breast cancer research from conventional cultures to 3D models.