Project description:Mammalian target of rapamycin (mTOR) is a serine/threonine kinase involved in multiple intracellular signaling pathways promoting tumor growth. mTOR is aberrantly activated in a significant portion of breast cancers and is a promising target for treatment. Rapamycin and its analogues are in clinical trials for breast cancer treatment. Patterns of gene expression (metagenes) may also be used to simulate a biologic process of effects of a drug treatment. In this study, we tested the hypothesis that the gene-expression signature regulated by rapamycin could predict disease outcome for patients with breast cancer. Results: Colony formation and sulforhodamine B (IC50 < 1nM) assays, and xenograft animals showed that MDA-MB-468 cells were sensitive to treatment with rapamycin. The comparison of in vitro and in vivo gene expression data identified a signature, termed rapamycin metagene index (RMI), of 31 genes upregulated by rapamycin treatment in vitro as well as in vivo (false discovery rate of 10%). In the Miller dataset, RMI was significantly associated with tumor size or lymph node status. High (>75) percentile) RMI was significantly associated with longer survival (P = 0.015). On multivariate analysis, RMI (P = 0.029), tumor size (P = 0.015) and lymph node status (P = 0.01) were prognostic. In van 't Veer study, RMI was not associated with the time to develop distant metastasis (P = 0.41). In Wang dataset, RMI predicted time to disease relapse (P = 0.09). Conclusions: Rapamycin-regulated gene expression signature predicts clinical outcome in breast cancer. This supports the central role of mTOR signaling in breast cancer biology and provides further impetus to pursue mTOR-targeted therapies for breast cancer treatment. Mol Cancer. 2009 Sep 24;8(1):75. Experiment Overall Design: Rapamycin treatment of MDA-MB-468 breast cancer cell line: Experiment Overall Design: MDA-MB-468 cell line was treated by DMSO (vehicle) and 100 nM rapamycin for 24 hours. We sought to identify differentially expressed genes. Experiment Overall Design: Rapamycin treatment of breast tumor xenografts: Experiment Overall Design: MDA-MB-468 cells were inoculated in the mammary fat pad of female nude mice. When resulting tumor volumes had reached 75-150 mm3, the mice were divided in four groups. Groups 1 and 2 received a single injection of DMSO (vehicle) or rapamycin (15 mg/kg) intraperitoneally and sacrificied 24 h later (1-day groups). Groups 3 and 4 received weekly injections of DMSO or rapamycin for 3 weeks and sacrificied 24 h after the last injection (22-day groups).
Project description:The goal of this work was to identify all estrogen receptor beta target genes using RNA sequencing in MDA-MB-468 triple negative breast cancer cells engineered with inducible expression of full length estrogen receptor beta. MDA-MB-468 breast cancer cells with inducible ERb expression (MDA-468-ERb cells) were treated in triplicate with vehicle (control, no ERb) or doxycycline (plus ERb) for 48 hr prior to treatment with 0.1% DMSO vehicle or 10 nM 17b-estradiol for 4 hr.
Project description:The impact of three different chemodrugs (Adriamycin, Taxotere, Cytoxan) on the breast cancer cell line (MDA-MB-468) was analyzed compared to the parental cell by RNA-sequencing.
Project description:We analysed aquired chemotherapeutic resistance of two different triple negative breast cancer cell lines BT-549 (Doxorubicin resistance) and MDA-MB-468 (5-Fluorouracil) by comparing the proteome of the parental cell line with the resistant cell line.
Project description:This study was designed to investigate the Metformin mode of action in different subtypes of breast cancer using cell and molecular, and systems biology techniques. To that end, several concentrations of Metformin have been used. Besides, five different breast cancer cell lines representing the five breast cancer phenotypes have been employed in this study. These cell lines were BT-474, MCF-7, MDA-MB-231, MDA-MB-468, and SkBr3 as representative for (Luminal B, Luminal A, Claudin-low, Basal-like, and HER2) subtypes respectively. Interestingly, Metformin treatment significantly reduced cancer cell viability and proliferation while inducing cell apoptosis and enhanced cell necrosis of the Basal-like (MDA-MB-468), although, the less sensitive subtype is HER2 (SkBr3).
Project description:Gene expression profiling by microarray analysis of tumors formed from inoculation of the established human breast cancer cell line MDA-MB-468 in two groups of mice: lean control and DIO mice.
Project description:The thyroid hormone receptor beta (TRβ) is a tumor suppressor in multiple types of solid tumors, most prominently in breast and thyroid cancer. An increased understanding of the molecular mechanisms by which TRβ abrogates tumorigenesis could aid in understanding the core tumor suppressive program that TRβ facilitates. Here, we introduce TRβ into the MDA-MB-468 basal-like breast cancer cell line and perform RNA-sequencing to determine changes in transcriptomic signaling. The TRβ expressing MDA-MB-468 cells exhibit a more epithelial character as determined by PCA-PAM50 score and through repression of mesenchymal cytokeratins. The epithelial to mesenchymal transition pathway is also significantly reduced. The MDA-MB-468 dataset was also compared to RNA sequencing results from the thyroid cancer line SW1736 to determine which genes are TRβ regulated across both tissue types. Stearate biosynthesis was revealed as upregulated from the shared gene set, a lipid which is known to repress breast tumorigenesis, as were chromatin remodeling pathways. These data provide novel insights into the molecular mechanisms by which TRβ suppresses breast tumorigenesis and suggests a common metabolic role in breast and thyroid cancer as well a role for TRβ in the maintenance of epithelial cellular identity.
Project description:To investigate FOXC1 chromatin binding, and the effect of FOXC1 CRISPR knockout in triple negative breast cancer cell lines MDA-MB-231, MDA-MB-468, Hs578t, and Bt-549.
Project description:To investigate FOXC1 chromatin binding, and the effect of FOXC1 CRISPR knockout in triple negative breast cancer cell lines MDA-MB-231, MDA-MB-468, Hs578t, and Bt-549.