Similar Datasets
Project description:The promyelocytic leukemia (PML) protein organizes nuclear aggregates known as PML nuclear bodies (PML-NBs), where many transcription factors localize to be regulated. In addition, associations of PML and PML-NBs with chromatin are described in various cell types, further implicating PML in transcriptional regulation. However, a complete understanding of the functional consequences of PML association to DNA in cellular contexts where it promotes relevant phenotypes is still lacking. We examined PML chromatin association in triple-negative breast cancer (TNBC) cell lines, where it exerts important oncogenic functions. We find that PML associates discontinuously with large heterochromatic PML-associated domains (PADs) that contain discrete gene-rich euchromatic sub-domains locally depleted of PML. PML promotes heterochromatic organization in PADs and expression of pro-metastatic genes embedded in these sub-domains. Importantly, this occurs outside PML-NBs, suggesting that nucleoplasmic PML exerts a relevant gene regulatory function. We also find that PML plays indirect regulatory roles in TNBC cells by promoting the expression of pro-metastatic genes outside PADs. Our findings suggest that PML is an important transcriptional regulator of pro-oncogenic metagenes in TNBC cells, via transcriptional regulation and epigenetic organization of heterochromatin domains that embed regions of local transcriptional activity.
| S-EPMC10639071 | biostudies-literature
Project description:The promyelocytic leukemia (PML) protein organizes nuclear aggregates known as PML nuclear bodies (PML-NBs), where many transcription factors and transcriptional regulators converge to be regulated. Specific associations of PML and PML-NBs with chromatin are described in different cell types, further implicating PML in transcriptional regulation. However, a complete understanding of the functional consequences of PML association to DNA in a cellular context where it regulates relevant phenotypes is still lacking.We examined the role of PML in chromatin association and transcription in triple-negative breast cancer (TNBC), a pathological condition where PML exerts important oncogenic functions. We find that PML associates discontinuously with large heterochromatic PML-associated domains (PADs) that contain gene-rich euchromatic sub-domains locally depleted of PML. PML promotes heterochromatic organization in PADs and expression of pro-metastatic genes embedded in these sub-domains. Importantly, this occurs outside PML-NBs, suggesting that nucleoplasmic PML exerts a cell type-relevant function of transcriptional regulation. PML also plays an indirect regulatory function in TBNC cells by promoting the expression of pro-metastatic genes outside PADs.Our findings demonstrate that PML is an important transcriptional regulator of metastasis and pro-oncogenic metagenes in TNBC cells, via distinct molecular activities that include indirect transcriptional regulation and direct epigenetic organization of heterochromatin domains that embed regions of localized transcriptional activity.
2023-09-11 | GSE226111 | GEO
Project description:The promyelocytic leukemia (PML) protein organizes nuclear aggregates known as PML nuclear bodies (PML-NBs), where many transcription factors and transcriptional regulators converge to be regulated. Specific associations of PML and PML-NBs with chromatin are described in different cell types, further implicating PML in transcriptional regulation. However, a complete understanding of the functional consequences of PML association to DNA in a cellular context where it regulates relevant phenotypes is still lacking.We examined the role of PML in chromatin association and transcription in triple-negative breast cancer (TNBC), a pathological condition where PML exerts important oncogenic functions. We find that PML associates discontinuously with large heterochromatic PML-associated domains (PADs) that contain gene-rich euchromatic sub-domains locally depleted of PML. PML promotes heterochromatic organization in PADs and expression of pro-metastatic genes embedded in these sub-domains. Importantly, this occurs outside PML-NBs, suggesting that nucleoplasmic PML exerts a cell type-relevant function of transcriptional regulation. PML also plays an indirect regulatory function in TBNC cells by promoting the expression of pro-metastatic genes outside PADs.Our findings demonstrate that PML is an important transcriptional regulator of metastasis and pro-oncogenic metagenes in TNBC cells, via distinct molecular activities that include indirect transcriptional regulation and direct epigenetic organization of heterochromatin domains that embed regions of localized transcriptional activity.
2023-09-11 | GSE226060 | GEO
Project description:The promyelocytic leukemia (PML) protein organizes nuclear aggregates known as PML nuclear bodies (PML-NBs), where many transcription factors and transcriptional regulators converge to be regulated. Specific associations of PML and PML-NBs with chromatin are described in different cell types, further implicating PML in transcriptional regulation. However, a complete understanding of the functional consequences of PML association to DNA in a cellular context where it regulates relevant phenotypes is still lacking.We examined the role of PML in chromatin association and transcription in triple-negative breast cancer (TNBC), a pathological condition where PML exerts important oncogenic functions. We find that PML associates discontinuously with large heterochromatic PML-associated domains (PADs) that contain gene-rich euchromatic sub-domains locally depleted of PML. PML promotes heterochromatic organization in PADs and expression of pro-metastatic genes embedded in these sub-domains. Importantly, this occurs outside PML-NBs, suggesting that nucleoplasmic PML exerts a cell type-relevant function of transcriptional regulation. PML also plays an indirect regulatory function in TBNC cells by promoting the expression of pro-metastatic genes outside PADs.Our findings demonstrate that PML is an important transcriptional regulator of metastasis and pro-oncogenic metagenes in TNBC cells, via distinct molecular activities that include indirect transcriptional regulation and direct epigenetic organization of heterochromatin domains that embed regions of localized transcriptional activity.
2023-09-11 | GSE240309 | GEO
Project description:PML modulates epigenetic composition of chromatin to regulate expression of pro-metastatic genes in triple-negative breast cancer
| PRJNA939167 | ENA
Project description:PML modulates epigenetic composition of chromatin to regulate expression of pro-metastatic genes in triple-negative breast cancer [ATAC-seq]
| PRJNA1003122 | ENA
Project description:PML modulates epigenetic composition of chromatin to regulate expression of pro-metastatic genes in triple-negative breast cancer [RNA-seq]
| PRJNA938748 | ENA
Project description:PML modulates epigenetic composition of chromatin to regulate expression of pro-metastatic genes in triple-negative breast cancer [ChIP-seq]
| PRJNA938442 | ENA
Project description:Oncogene addiction postulates that the survival and growth of certain tumor cells is dependent upon the activity of one oncogene, despite their multiple genetic and epigenetic abnormalities. This phenomenon provides a foundation for molecular targeted therapy and a rationale for oncogene-based stratification. We have previously reported that the Promyelocytic Leukemia protein (PML) is upregulated in triple negative breast cancer (TNBC) and it regulates cancer-initiating cell function, thus suggesting that this protein can be therapeutically targeted in combination with PML-based stratification. However, the effects of PML perturbation on the bulk of tumor cells remained poorly understood. Here we demonstrate that TNBC cells are addicted to the expression of this nuclear protein. PML inhibition led to a remarkable growth arrest combined with features of senescence in vitro and in vivo. Mechanistically, the growth arrest and senescence were associated to a decrease in MYC and PIM1 kinase levels, with the subsequent accumulation of CDKN1B (p27), a trigger of senescence. In line with this notion, we found that PML is associated to the promoter regions of MYC and PIM1, consistent with their direct correlation in breast cancer specimens. Altogether, our results provide a feasible explanation for the functional similarities of MYC, PIM1, and PML in TNBC and encourage further study of PML targeting strategies for the treatment of this breast cancer subtype.
| S-EPMC7104349 | biostudies-literature
Project description:The tumor microenvironment (TME) plays key roles in promoting disease progression in the aggressive triple-negative subtype of breast cancer (TNBC; Basal/Basal-like). Here, we took an integrative approach and determined the impact of tumor-stroma-inflammation networks on pro-metastatic phenotypes in TNBC. With the TCGA dataset we found that the pro-inflammatory cytokines tumor necrosis factor α (TNFα) and interleukin 1β (IL-1β), as well as their target pro-metastatic chemokines CXCL8 (IL-8), CCL2 (MCP-1), and CCL5 (RANTES) were expressed at significantly higher levels in basal patients than luminal-A patients. Then, we found that TNFα- or IL-1β-stimulated co-cultures of TNBC cells (MDA-MB-231, MDA-MB-468, BT-549) with mesenchymal stem cells (MSCs) expressed significantly higher levels of CXCL8 compared to non-stimulated co-cultures or each cell type alone, with or without cytokine stimulation. CXCL8 was also up-regulated in TNBC co-cultures with breast cancer-associated fibroblasts (CAFs) derived from patients. CCL2 and CCL5 also reached the highest expression levels in TNFα/IL-1β-stimulated TNBC:MSC/CAF co-cultures. The elevations in CXCL8 and CCL2 expression partly depended on direct physical contacts between the tumor cells and the MSCs/CAFs, whereas CCL5 up-regulation was entirely dependent on cell-to-cell contacts. Supernatants of TNFα-stimulated TNBC:MSC "Contact" co-cultures induced robust endothelial cell migration and sprouting. TNBC cells co-cultured with MSCs and TNFα gained migration-related morphology and potent migratory properties; they also became more invasive when co-cultured with MSCs/CAFs in the presence of TNFα. Using siRNA to CXCL8, we found that CXCL8 was significantly involved in mediating the pro-metastatic activities gained by TNFα-stimulated TNBC:MSC "Contact" co-cultures: angiogenesis, migration-related morphology of the tumor cells, as well as cancer cell migration and invasion. Importantly, TNFα stimulation of TNBC:MSC "Contact" co-cultures in vitro has increased the aggressiveness of the tumor cells in vivo, leading to higher incidence of mice with lung metastases than non-stimulated TNBC:MSC co-cultures. Similar tumor-stromal-inflammation networks established in-culture with luminal-A cells demonstrated less effective or differently-active pro-metastatic functions than those of TNBC cells. Overall, our studies identify novel tumor-stroma-inflammation networks that may promote TNBC aggressiveness by increasing the pro-malignancy potential of the TME and of the tumor cells themselves, and reveal key roles for CXCL8 in mediating these metastasis-promoting activities.
| S-EPMC6473166 | biostudies-literature