Project description:Dysregulation of DNA methylation is an established feature of breast cancers. DNA demethylating therapies like decitabine are proposed for the treatment of triple-negative breast cancers (TNBCs) and indicators of response need to be identified. For this purpose, we characterized the effects of decitabine in a panel of 10 breast cancer cell lines and observed a range of sensitivity to decitabine that was not subtype-specific. Knockdown of potential key effectors demonstrated the requirement of deoxycytidine kinase (DCK) for decitabine response in breast cancer cells. In treatment-naive breast tumors, DCK was higher in TNBCs, and DCK levels were sustained or increased post chemotherapy treatment. This suggests that limited DCK levels will not be a barrier to response in TNBC patients treated with decitabine as a second line treatment or in a clinical trial. Methylome analysis revealed that genome-wide, region-specific, tumor suppressor gene-specific methylation, and decitabine-induced demethylation did not predict response to decitabine. Gene set enrichment analysis (GSEA) of transcriptome data demonstrated that decitabine induced genes within apoptosis, cell cycle, stress, and immune pathways in decitabine treated cells. Induced genes included those characterized by the viral mimicry response; however knockdown of key effectors of the pathway did not affect decitabine sensitivity suggesting that breast cancer growth suppression by decitabine is independent of viral mimicry. Finally, taxol-resistant breast cancer cells expressing high levels of multidrug resistance transporter ABCB1 remained sensitive to decitabine, suggesting that the drug could be used as second-line treatment for chemoresistant patients. We used microarrays to determine genome-wide expression changes induced by DNA de-methylating agent decitabine in breast cancer cell lines
Project description:To investigate the role of iNOS in tumor cell morphology and gene expression, we utilized CRISPR-Cas9 gene editing (NOS2 Double Nickase Plasmid, Santa Cruz) to knockout NOS2 in SUM159 cells. After puromycin selection, resistant clones were selected by immunoblotting for iNOS expression and nitrite/nitrate colorimetric assay. We then performed gene expression profiling analysis using data obtained from RNA-seq of parental SUM159 cells compared to NOS2KO SUM159 cells.
Project description:We used a transmitochondrial cybrid (cybrids)-based discovery approach to identify mitochondria-regulated cancer pathways in TN BCa. Cybrids were generated under a moderately metastatic TN BCa cell line SUM159 as the common nuclear background with mitochondria from benign breast epithelium (A1N4) and moderately metastatic (SUM159) TN BCa cells. In vitro and in vivo studies suggested that even under the common moderately cancerous nuclear background, mitochondria from benign cells inhibit and metastatic cell induce cancer properties of a moderately aggressive TN BCa cell. Gene expression studies identified c-Src onco-pathway as one of the major cancer pathways altered according to the mitochondria status of the cybrids. SUM159 Ï0 cells were used as nuclear donor and A1N4 and SUM 159 cells were used as mitochondrial donor cells. The two groups were profiled for gene expression using microarrays. two group comparison (159/SUM159 vs A1/SUM159)
Project description:The objective of this experiment was to determine global gene expression change in triple negative cell line upon knockdown of TGFBR3. Genotype specific differences in expression profiles have been evaluated using human HuGene1.0-ST affymetrix array. RNA was extracted from SUM159 controls and SUM159 TGFBR3KD cells cultured in 3-dimensional in vitro system.
Project description:Acute myeloid leukemia (AML), and other myeloid malignancies, are frequently treated with hypomethylating agents like decitabine. Alterations in the epigenome, induced by decitabine, are likely to result in gene expression changes. The effects of decitabine have not been systemically studied using primary AML samples. We cultured 18 different primary AML samples for 7 days, the last 3 days of which included 100 nM decitabine (DAC) or 100 nm cytarabine (AraC). We hypothesized that decitabine treatment would result in detectable and consistent gene expression changes. For comparison, we also analyzed mRNA from cells treated with DMSO control (mock) and mRNA from uncultured cells taken at the time of diagnosis.
Project description:Acute myeloid leukemia (AML), and other myeloid malignancies, are frequently treated with hypomethylating agents like decitabine. Alterations in the epigenome, induced by decitabine, are likely to result in gene expression changes. The effects of decitabine have not been systemically studied using primary AML samples.
Project description:Purpose:Triple negative breast cancer (TNBC) commonly metastasizes to the brain and predicts poor prognosis with limited therapeutic options. TNBC frequently harbors BRCA mutations translating to platinum sensitivity; platinum response may be augmented by additional suppression of DNA repair mechanisms through poly(ADP-ribose)polymerase (PARP) inhibition. We evaluated brain penetrance and efficacy of Carboplatin +/- the PARP inhibitor ABT888, and investigated gene expression changes in murine intracranial (IC) TNBC models stratified by BRCA and molecular subtype status. Experimental design:Athymic mice were inoculated intra-cerebrally with BRCA-mutant: SUM149 (basal), MDA-MB-436 (claudin-low), or BRCA-wild-type: MDA-MB-468 (basal), MDA-MB-231BR (claudin-low) TNBC cells and treated with PBS control (IP, weekly), Carboplatin (50mg/kg/week, IP), ABT888 (25mg/kg/day, OG), or their combination. DNA-damage (?-H2AX) and apoptosis (cleaved-Caspase-3(cC3)) were assessed via IHC of IC tumors. Gene expression of BRCA-mutant IC tumors was measured. Results: Carboplatin+/-ABT888 significantly improved survival in BRCA-mutant IC models compared to control, but did not improve survival in BRCA-wild-type IC models. Carboplatin+ABT888 revealed a modest survival advantage versus Carboplatin in BRCA-mutant models. ABT888 yielded a marginal survival benefit in the MDA-MB-436 but not in the SUM149 model. BRCA-mutant SUM149 expression of ?-H2AX and cC3 proteins was elevated in all treatment groups compared to Control, while BRCA-wild-type MDA-MB-468 cC3 expression did not increase with treatment. Carboplatin treatment induced common gene expression changes in BRCA-mutant models.Conclusions: Carboplatin+/-ABT888 improves survival in BRCA-mutant IC TNBC models with corresponding DNA damage and gene expression changes. Combination therapy represents a promising treatment strategy for patients with TNBC brain metastases warranting further clinical investigation. reference x sample
Project description:Purpose:Triple negative breast cancer (TNBC) commonly metastasizes to the brain and predicts poor prognosis with limited therapeutic options. TNBC frequently harbors BRCA mutations translating to platinum sensitivity; platinum response may be augmented by additional suppression of DNA repair mechanisms through poly(ADP-ribose)polymerase (PARP) inhibition. We evaluated brain penetrance and efficacy of Carboplatin +/- the PARP inhibitor ABT888, and investigated gene expression changes in murine intracranial (IC) TNBC models stratified by BRCA and molecular subtype status. Experimental design:Athymic mice were inoculated intra-cerebrally with BRCA-mutant: SUM149 (basal), MDA-MB-436 (claudin-low), or BRCA-wild-type: MDA-MB-468 (basal), MDA-MB-231BR (claudin-low) TNBC cells and treated with PBS control (IP, weekly), Carboplatin (50mg/kg/week, IP), ABT888 (25mg/kg/day, OG), or their combination. DNA-damage (?-H2AX) and apoptosis (cleaved-Caspase-3(cC3)) were assessed via IHC of IC tumors. Gene expression of BRCA-mutant IC tumors was measured. Results: Carboplatin+/-ABT888 significantly improved survival in BRCA-mutant IC models compared to control, but did not improve survival in BRCA-wild-type IC models. Carboplatin+ABT888 revealed a modest survival advantage versus Carboplatin in BRCA-mutant models. ABT888 yielded a marginal survival benefit in the MDA-MB-436 but not in the SUM149 model. BRCA-mutant SUM149 expression of ?-H2AX and cC3 proteins was elevated in all treatment groups compared to Control, while BRCA-wild-type MDA-MB-468 cC3 expression did not increase with treatment. Carboplatin treatment induced common gene expression changes in BRCA-mutant models.Conclusions: Carboplatin+/-ABT888 improves survival in BRCA-mutant IC TNBC models with corresponding DNA damage and gene expression changes. Combination therapy represents a promising treatment strategy for patients with TNBC brain metastases warranting further clinical investigation.
Project description:We used a transmitochondrial cybrid (cybrids)-based discovery approach to identify mitochondria-regulated cancer pathways in TN BCa. Cybrids were generated under a moderately metastatic TN BCa cell line SUM159 as the common nuclear background with mitochondria from benign breast epithelium (A1N4) and moderately metastatic (SUM159) TN BCa cells. In vitro and in vivo studies suggested that even under the common moderately cancerous nuclear background, mitochondria from benign cells inhibit and metastatic cell induce cancer properties of a moderately aggressive TN BCa cell. Gene expression studies identified c-Src onco-pathway as one of the major cancer pathways altered according to the mitochondria status of the cybrids.
Project description:We conducted RNA sequencing of SUM159 DAPK3 KO and control cells followed by Gene Set Enrichment Analysis (GSEA) to identify altered gene expression pathways by DAPK3 knockout. Epithelial-mesenchymal transition (EMT) pathway was the top significantly down-regulated pathway in SUM159 DAPK3 KO cells as compared to control cells.