Project description:Epithelioid Sarcoma (ES) is a rare neoplasm uniquely comprised of cells exhibiting both mesenchymal and epithelial features. Having propensity for local and distant recurrence, it can pose a diagnostic dilemma secondary to pathologic complexity. Patients have dismal prognosis due to lack of effective therapy. HDAC inhibitors exhibit marked anti-tumor effects in various malignancies. Our studies demonstrate that pan-HDAC inhibitors constitute potentially novel therapeutics versus ES. Human ES cells (VAESBJ, HS-ES, Epi544) were studied in vitro to evaluate the effects of HDACi. Gene array analysis was used to identify the impact of HDACi on ES gene expression in three cell lines.
Project description:Acquired drug resistance prevents targeted cancer therapy from achieving stable and complete responses. Emerging evidence implicates a key role for nonmutational mechanisms including changes in cell state during early stages of acquired drug resistance. Targeting nonmutational resistance may therefore present a therapeutic opportunity to eliminate residual surviving tumor cells and impede relapse. A variety of cancer cell lines harbor quiescent, reversibly drug-tolerant “persister” cells which survive cytotoxic drugs including targeted therapies and chemotherapies. These persister cells survive drug through nonmutational mechanisms which are poorly understood. Specifically targeting persister cells is a promising strategy to prevent tumor relapse. We sought to identify therapeutically exploitable vulnerabilities in persister cells using the HER2-amplified breast cancer line BT474 as an experimental model. Similar to other persister cell models, upon treatment with the HER2 inhibitor lapatinib (2uM concentration) for nine or more days, the majority of BT474 cells die, revealing a small population of quiescent surviving persister cells. Removal of lapatinib allows the persister cells to regrow and to re-acquire sensitivity to lapatinib. Subsequent lapatinib treatment re-derives persister cells. The reversibility of persister cell drug resistance indicates a nonmutational resistance mechanism. Here we provide RNAseq gene expression profiling data generated from parental BT474 cells compared to BT474 persister cells generated from nine days of treatment with 2 uM lapatinib. These data can be used to identify genes and pathways which are upregulated in persister cells, revealing potential therapeutic targets. 3 biological replicates of BT474 persister cells, two biological replicates of BT474 parental cells
Project description:We compared the mRNAs expression profile of HeLa cells between two phases of the mitotic cell cycle: S and G2/M phases. Results provide insight into the regulation of transcript levels during mitotic cell cycle progression. HeLa cells were synchronized with double thymidine blockade (12 hours with 2 mM thymidine, 12 hours release, and 12 hours with 2 mM thymidine), and cells were taken after 2 hours release (S phase) and 8 hours release (G2/M phase). Keywords: time course Comparison of mRNAs measured at S phase (2 hours release after double thymidine blockade) and at G2/M phase (8 hours release after double thymidine blockade); 3 biological replicates at each of the two time points; two technical replicates with dye swapping per comparison; additional comparison between G2/M (8h) and S (2h).
Project description:The intention was to detect genes that are determining trastuzumab efficiency in HER2-positive breast cancer cell lines with different resistance phenotypes. While BT474 should be sensitive to the drug treatment, HCC1954 is expected to be resistant due to a PI3K mutation. The cell line BTR50 has been derived from BT474 and was cultured to be resistant as well. Based on RNA-Seq data, we performed differential expression analyses on these breast cancer cell lines with and without trastuzumab treatment. In detail, five separate tests were performed, namely resistant cells vs. wild type, i.e. HCC1954 and BTR50 vs. BT474, respectively, and untreated vs. drug treated cells. The significant genes of the first two tests should contribute to resistance. The significant genes of the test BT474 vs. its drug treated version should contribute to the trastuzumab effect. To exclude false positives from the combined gene set (#64), we removed ten genes that were also significant in the test BTR50 vs. its drug treated version. This way we ended up with 54 genes that are very likely to determine trastuzumab efficiency in HER2-positive breast cancer cell lines. mRNA profiles of human breast cancer cell lines were generated by deep sequencing using Illumina HiSeq 2000. The cell lines BT474 and HCC1954 were analyzed with and without trastuzumab treatment. HCC1954 is known to be trastuzumab resistant. Additionally, the cell line BTR50 was generated as resistant version of BT474, and was analyzed with and without trastuzumab as well.
Project description:We compared the poly(A) tail length status of mRNAs of HeLa cells between two phases of the mitotic cell cycle: S and G2/M phases. Hundreds of mRNAs were found to be regulated by changes in their poly(A) tail length during mitotic cell cycle in a phase specific manner. Many of these differentially polyadenylated mRNAs encode proteins related to cell death, cell cycle and cellular growth and proliferation. HeLa cells were synchronized with double thymidine blockade (12 hours with 2 mM thymidine, 12 hours release, and 12 hours with 2 mM thymidine), and samples were taken after 2 hours release (S phase) and 8 hours release (G2/M phase). For each condition total RNA was purified by two different procedures: poly(U) chromatography and oligo(dT)-chromatography. Poly(U)-chromatography (Jacobson, 1987): 100 μg of total RNA were bound to poly(U)-sepharose (Sigma) and eluted at 35ºC to isolate mRNAs with short poly(A) tail (<30As, SHORT fraction). Oligo(dT) chromatography: mRNAs were purified independently of their poly(A) tail length with Ambion Poly(A)Purist kit from 20 μg total RNA (ALL fraction). Jacobson, A. Purification and fractionation of poly(A)+ RNA. Methods in Enzymology (1987) 152: 254-261. Keywords: time course Comparison of ALL fraction mRNAs and SHORT fraction mRNAs measured after 2 hours (S phase) and 8 hours release (G2/M) from double thymidine blockade; 3 biological replicates at each of the two time points; two technical replicates with dye swapping per comparison.
Project description:ATP synthase is crucial for ATP synthesis in living cells. Recently, ATP synthase was found not only in mitochondria but also on the extracellular surface, named as ectopic ATP synthase (ecto-ATP synthase). ATP synthase inhibitor is a potential drug candidate to fight cancer by blocking the ecto-ATP synthase of cancer cells. In this study, we applied dynamic phosphoproteomics to elucidate the molecular responses to ecto-ATP synthase blockade.
Project description:Rev-Erba and Rev-Erbb are nuclear receptors that regulate the expression of genes involved in the control of circadian rhythm, metabolism, and inflammatory responses. Rev-Erbs function as transcriptional repressors by recruiting NCoR/HDAC3 co-repressor complexes to Rev-Erb response elements in enhancers and promoters of target genes, but the molecular basis for cell-specific programs of repression is not known. Here, we present evidence that in macrophages, Rev-Erbs regulate target gene expression by inhibiting the functions of distal enhancers that are selected by macrophage lineage-determining factors, thereby establishing a macrophage-specific program of repression. Remarkably, the repressive functions of Rev-Erbs are associated with their ability to inhibit the transcription of enhancer-derived RNAs (eRNAs). Furthermore, targeted degradation of eRNAs at two enhancers subject to negative regulation by Rev-Erbs resulted in reduced expression of nearby mRNAs, implying a direct role of these eRNAs in enhancer function. By precisely defining eRNA start sites using a method that quantifies nascent 5' ends (5'-GRO-Seq), we show that transfer of full enhancer activity to a target promoter requires both the sequences mediating transcription factor binding and the specific sequences encoding the eRNA transcript. These studies provide evidence for direct roles of eRNAs in contributing to enhancer functions and suggest that Rev-Erbs act to suppress gene expression at a distance by repressing eRNA transcription. Using ChIPseq, GRO-seq, and 5'GRO-seq to determine mechanism of RevErb in transcriptional regulation in macrophages