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: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:Worldwide, breast cancer (BRCA) is the most common malignant tumor in women. Adriamycin (ADR) is considered one of the most effective agents for the treatment of BRCA, but its efficacy as a curative agent is compromised by intrinsic resistance and the acquisition of multidrug resistance characteristics during chemotherapy. The underlying mechanisms resulting in ADR resistance in BRCA remain poorly understood. Long non-coding RNA (lncRNA) are abnormally expressed in many cancers and are highly involved in its pathogenesis, including drug resistance. In order to systematically study the role of lncRNA in the resistance of BRCA cells to ADR, we used lncRNA expression microarray to establish gene expression profiles of ADR resistant cell lines and ADR sensitive cell lines.
Project description:Treatment of cancer cells with anti-cancer drugs often fails to achieve complete remission. Yet, such drug treatments may induce alteration in the tumor’s gene expression patterns, including those of Cancer/Testis Antigens (CTA). The degradation products of such antigens can be presented as HLA peptides on the surface of the tumor cells and be developed into anti-cancer immunotherapeutics. For example, the DNA methyl transferase inhibitor, 5-aza-2'-deoxycytidine (Decitabine) has limited anti-tumor efficacy, yet it induces the expression of many genes, including CTAs that are normally silenced in the healthy adult tissues. In this study, the presentation of many new HLA peptides derived from CTAs and induced by Decitabine was demonstrated in three human Glioblastoma cell lines. Such presentation of CTA-derived HLA peptides can be exploited for development of new treatment modalities, combining drug treatment with anti-CTA targeted immunotherapy. The Decitabine-induced HLA peptidomes include many CTAs that are not normally detected in healthy tissues or in cancer cells, unless treated with the drug. In addition, the study included large-scale analyses of the simultaneous effects of Decitabine on the transcriptomes, proteomes and HLA peptidomes of the human Glioblastoma cells. It demonstrates the poor correlations between these three levels of gene expression, both in their total levels and in their response to the drug.