Project description:DNA binding anticancer agents cause alteration in chromatin structure and dynamics. Here, we report the dynamic interaction of the DNA intercalator and potential anticancer, plant alkaloid, Sanguinarine (SGR) with chromatin. Association of SGR with different levels of chromatin structure was found to be enthalpydriven. Apart from DNA it binds with comparable affinity to histones and induces chromatin aggregation. The dual binding property of SGR leads to inhibition of core histone modifications. Although, it potently inhibits H3K9 methylation by G9a in vitro, H3K4 and H3R17 methylation are more profoundly inhibited in cells. SGR inhibits histone acetylation both in vitro and in vivo. It does not affect the in vitro transcription from DNA template but significantly represses acetylation dependent chromatin transcription. SGR mediated repression of epigenetic marks and the alteration of chromatin geography, also result in modulation of global gene expression. These data conclusively, show the anticancer DNA binding intercalator as a modulator of chromatin modifications and transcription in the chromatin context.
Project description:DNA-binding anticancer agents cause alteration in chromatin structure and dynamics. Here, we report the dynamic interaction of the DNA intercalator and potential anticancer, plant alkaloid, sanguinarine (SGR) with chromatin. Association of SGR with different levels of chromatin structure was found to be enthalpy driven. Apart from DNA, it binds with comparable affinity to histones and induces chromatin aggregation. The dual binding property of SGR leads to inhibition of core histone modifications. Although it potently inhibits H3K9 methylation by G9a in vitro, H3K4 and H3R17 methylation are more profoundly inhibited in cells. SGR inhibits histone acetylation both in vitro and in vivo. It does not affect the in vitro transcription from DNA template but significantly represses acetylation-dependent chromatin transcription. SGR mediated repression of epigenetic marks and the alteration of chromatin geography also result in modulation of global gene expression. These data conclusively show that the anticancer DNA-binding intercalator as a modulator of chromatin modifications and transcription in the chromatin context.
Project description:DNA binding anticancer agents cause alteration in chromatin structure and dynamics. Here, we report the dynamic interaction of the DNA intercalator and potential anticancer, plant alkaloid, Sanguinarine (SGR) with chromatin. Association of SGR with different levels of chromatin structure was found to be enthalpydriven. Apart from DNA it binds with comparable affinity to histones and induces chromatin aggregation. The dual binding property of SGR leads to inhibition of core histone modifications. Although, it potently inhibits H3K9 methylation by G9a in vitro, H3K4 and H3R17 methylation are more profoundly inhibited in cells. SGR inhibits histone acetylation both in vitro and in vivo. It does not affect the in vitro transcription from DNA template but significantly represses acetylation dependent chromatin transcription. SGR mediated repression of epigenetic marks and the alteration of chromatin geography, also result in modulation of global gene expression. These data conclusively, show the anticancer DNA binding intercalator as a modulator of chromatin modifications and transcription in the chromatin context. The total RNA was isolated from control and treated cells using TRIZOL (Invitrogen) method. The Micromax direct labeling kit, MPS502 (PerkinElmer) was used to synthesize the labeled cDNA from 70 ug of total RNA and further process the hybridized cDNA on the array. All the steps were carried out according to manufacturerâs instructions (www.perkinelmer.com/lifesciences). The array slides were scanned immediately by PerkinElmer Scan array Gx Microarray scanner. The Scan array software (PerkinElmer) was used for grid wise normalization of array images. Two arrays were used with at least one biological treatment of cells and dye swap experiment were included in the final analysis. . The data was analysed by GeneSpring GX and Biointerpreter software from Genotypic Technology, Bangalore. The differential expression was considered if the Log 2 mean of at least -1 for the down regulated genes and +1 for the upregulated genes. We considered only the genes that were reproducible from both replicates.
Project description:DNA-binding anticancer agents cause alteration in chromatin structure and dynamics. Here, we report the dynamic interaction of the DNA intercalator and potential anticancer, plant alkaloid, sanguinarine (SGR) with chromatin. Association of SGR with different levels of chromatin structure was found to be enthalpy driven. Apart from DNA, it binds with comparable affinity to histones and induces chromatin aggregation. The dual binding property of SGR leads to inhibition of core histone modifications. Although it potently inhibits H3K9 methylation by G9a in vitro, H3K4 and H3R17 methylation are more profoundly inhibited in cells. SGR inhibits histone acetylation both in vitro and in vivo. It does not affect the in vitro transcription from DNA template but significantly represses acetylation-dependent chromatin transcription. SGR mediated repression of epigenetic marks and the alteration of chromatin geography also result in modulation of global gene expression. These data conclusively show that the anticancer DNA-binding intercalator as a modulator of chromatin modifications and transcription in the chromatin context. The total RNA was isolated from control and treated cells using the TRIzol (Invitrogen) method. The Micromax direct labeling kit, MPS502 (PerkinElmer), was used to synthesize the labeled cDNA from 70 ug of total RNA and further process the hybridized cDNA on the array. All the steps were carried out according to manufacturer’s instructions (www.perkinelmer.com/lifesciences). The array slides were scanned immediately by the PerkinElmer Scan array Gx Microarray scanner. The Scan array software (PerkinElmer) was used for grid wise normalization of array images. Five arrays were used with at least two biological treatments of cells, and dye-swap experiments were included in the final analysis. The data was analysed by GeneSpring GX and Biointerpreter software from Genotypic Technology, Bangalore. The differential expression was considered if the Log 2 mean of at least -1 for the downregulated genes and +1 for the upregulated genes. We considered only the genes that were reproducible from all five replicates.
Project description:EPR is a long non-coding RNA (lncRNA) that controls cell proliferation in mammary gland cells by regulating gene transcription. Here, we report on Mettl7a1 as a direct target of EPR. We show that EPR induces Mettl7a1 transcription by rewiring three-dimensional chromatin interactions at the Mettl7a1 locus. Our data indicate that METTL7A1 contributes to EPR-dependent inhibition of TGF-β signaling. METTL7A1 is absent in tumorigenic murine mammary gland cells and its human ortholog (METTL7A) is downregulated in breast cancers. Importantly, re-expression of METTL7A1 in 4T1 tumorigenic cells attenuates their transformation potential, with the putative methyltransferase activity of METTL7A1 being dispensable for its biological functions. We found that METTL7A1 localizes in the cytoplasm whereby it interacts with factors implicated in the early steps of mRNA translation, associates with ribosomes, and affects the levels of target proteins without altering mRNA abundance. Overall, our data indicates that METTL7A1 —a transcriptional target of EPR— modulates translation of select transcripts.
Project description:Fusion-positive rhabdomyosarcoma is an aggressive pediatric cancer molecularly characterized by arrested myogenesis. The defining genetic driver, PAX3::FOXO1, encodes a chimeric gain-of-function transcription factor. An incomplete understanding of PAX3::FOXO1’s in vivo chromatin regulatory mechanisms has hindered therapeutic development. Here, we establish a PAX3::FOXO1 zebrafish injection model and a semi-automated ChIP-seq normalization strategy to evaluate how PAX3::FOXO1 initially interfaces with and modulates chromatin in a developmental context. We find that PAX3::FOXO1 interacts with inaccessible chromatin through partial/homeobox motif recognition consistent with pioneering activity. However, PAX3::FOXO1-genome binding through a composite paired box/homeobox motif alters chromatin accessibility and redistributes H3K27ac to activate neural transcriptional programs. We uncover neural signatures that are highly representative of clinical rhabdomyosarcoma gene expression programs that are enriched following chemotherapy. Overall, we identify partial/homeobox motif recognition as a key mode for PAX3::FOXO1 pioneer function and identify neural signatures as a potentially critical PAX3::FOXO1 tumor initiation event.
Project description:Fusion-positive rhabdomyosarcoma is an aggressive pediatric cancer molecularly characterized by arrested myogenesis. The defining genetic driver, PAX3::FOXO1, encodes a chimeric gain-of-function transcription factor. An incomplete understanding of PAX3::FOXO1’s in vivo chromatin regulatory mechanisms has hindered therapeutic development. Here, we establish a PAX3::FOXO1 zebrafish injection model and a semi-automated ChIP-seq normalization strategy to evaluate how PAX3::FOXO1 initially interfaces with and modulates chromatin in a developmental context. We find that PAX3::FOXO1 interacts with inaccessible chromatin through partial/homeobox motif recognition consistent with pioneering activity. However, PAX3::FOXO1-genome binding through a composite paired box/homeobox motif alters chromatin accessibility and redistributes H3K27ac to activate neural transcriptional programs. We uncover neural signatures that are highly representative of clinical rhabdomyosarcoma gene expression programs that are enriched following chemotherapy. Overall, we identify partial/homeobox motif recognition as a key mode for PAX3::FOXO1 pioneer function and identify neural signatures as a potentially critical PAX3::FOXO1 tumor initiation event.
Project description:Fusion-positive rhabdomyosarcoma is an aggressive pediatric cancer molecularly characterized by arrested myogenesis. The defining genetic driver, PAX3::FOXO1, encodes a chimeric gain-of-function transcription factor. An incomplete understanding of PAX3::FOXO1’s in vivo chromatin regulatory mechanisms has hindered therapeutic development. Here, we establish a PAX3::FOXO1 zebrafish injection model and a semi-automated ChIP-seq normalization strategy to evaluate how PAX3::FOXO1 initially interfaces with and modulates chromatin in a developmental context. We find that PAX3::FOXO1 interacts with inaccessible chromatin through partial/homeobox motif recognition consistent with pioneering activity. However, PAX3::FOXO1-genome binding through a composite paired box/homeobox motif alters chromatin accessibility and redistributes H3K27ac to activate neural transcriptional programs. We uncover neural signatures that are highly representative of clinical rhabdomyosarcoma gene expression programs that are enriched following chemotherapy. Overall, we identify partial/homeobox motif recognition as a key mode for PAX3::FOXO1 pioneer function and identify neural signatures as a potentially critical PAX3::FOXO1 tumor initiation event.