Project description:Invasive Lobular Carcinoma (ILC) is the second most frequent breast cancer (BCa) type and encompasses 10-15% of BCa cases. FOXA1 specific mutations are enriched in this subtype of BCa, however their role in breast cancer pathogenesis is still ill-defined. FOXA1, together with estrogen receptor (ER), is a key transcription factor for the correct activation of estrogen-dependent gene expression and, consequently, for mammary gland development and BCa identity. FOXA1 has the capability to bind to and de-compact heterochromatin to render it accessible for other nuclear proteins, such as ER, and allow activation of their transcriptional programs upon estrogen stimulation. In this project, we aim to elucidate the role of FOXA1 missense mutations in altering its binding to DNA, chromatin accessibility, ER-dependent transcription and their implication in limiting the sensitivity to standard-of-care anti-hormonal therapy, commonly used in ER-positive BCa patients. To this end, we have generated BCa cell lines expressing these FOXA1 mutations and we will employ ATAC-Seq, RIME assays, ChIP-Seq and RNA-Seq to ascertain their effect on DNA accessibility, DNA binding capability, as well as binding of transcriptional coregulators, such as ER, to chromatin. We will extend our analyses to our internal BCa patient datasets with detailed clinical annotation to study the correlation between presence of FOXA1 mutations and response to anti-hormonal therapy of ER-positive BCa patients. The results of this project will allow to understand how the different mutations in the Forkhead domain can alter FOXA1 and ER function, transcriptional regulation and response to anti-hormonal therapy in ER-positive BCa patients.
Project description:Invasive Lobular Carcinoma (ILC) is the second most frequent breast cancer (BCa) type and encompasses 10-15% of BCa cases. FOXA1 specific mutations are enriched in this subtype of BCa, however their role in breast cancer pathogenesis is still ill-defined. FOXA1, together with estrogen receptor (ER), is a key transcription factor for the correct activation of estrogen-dependent gene expression and, consequently, for mammary gland development and BCa identity. FOXA1 has the capability to bind to and de-compact heterochromatin to render it accessible for other nuclear proteins, such as ER, and allow activation of their transcriptional programs upon estrogen stimulation. In this project, we aim to elucidate the role of FOXA1 missense mutations in altering its binding to DNA, chromatin accessibility, ER-dependent transcription and their implication in limiting the sensitivity to standard-of-care anti-hormonal therapy, commonly used in ER-positive BCa patients. To this end, we have generated BCa cell lines expressing these FOXA1 mutations and we will employ ATAC-Seq, RIME assays, ChIP-Seq and RNA-Seq to ascertain their effect on DNA accessibility, DNA binding capability, as well as binding of transcriptional coregulators, such as ER, to chromatin. We will extend our analyses to our internal BCa patient datasets with detailed clinical annotation to study the correlation between presence of FOXA1 mutations and response to anti-hormonal therapy of ER-positive BCa patients. The results of this project will allow to understand how the different mutations in the Forkhead domain can alter FOXA1 and ER function, transcriptional regulation and response to anti-hormonal therapy in ER-positive BCa patients.
Project description:Invasive Lobular Carcinoma (ILC) is the second most frequent breast cancer (BCa) type and encompasses 10-15% of BCa cases. FOXA1 specific mutations are enriched in this subtype of BCa, however their role in breast cancer pathogenesis is still ill-defined. FOXA1, together with estrogen receptor (ER), is a key transcription factor for the correct activation of estrogen-dependent gene expression and, consequently, for mammary gland development and BCa identity. FOXA1 has the capability to bind to and de-compact heterochromatin to render it accessible for other nuclear proteins, such as ER, and allow activation of their transcriptional programs upon estrogen stimulation. In this project, we aim to elucidate the role of FOXA1 missense mutations in altering its binding to DNA, chromatin accessibility, ER-dependent transcription and their implication in limiting the sensitivity to standard-of-care anti-hormonal therapy, commonly used in ER-positive BCa patients. To this end, we have generated BCa cell lines expressing these FOXA1 mutations and we will employ ATAC-Seq, RIME assays, ChIP-Seq and RNA-Seq to ascertain their effect on DNA accessibility, DNA binding capability, as well as binding of transcriptional coregulators, such as ER, to chromatin. We will extend our analyses to our internal BCa patient datasets with detailed clinical annotation to study the correlation between presence of FOXA1 mutations and response to anti-hormonal therapy of ER-positive BCa patients. The results of this project will allow to understand how the different mutations in the Forkhead domain can alter FOXA1 and ER function, transcriptional regulation and response to anti-hormonal therapy in ER-positive BCa patients.
Project description:Invasive Lobular Carcinoma (ILC) is the second most frequent breast cancer (BCa) type and encompasses 10-15% of BCa cases. FOXA1 specific mutations are enriched in this subtype of BCa, however their role in breast cancer pathogenesis is still ill-defined. FOXA1, together with estrogen receptor (ER), is a key transcription factor for the correct activation of estrogen-dependent gene expression and, consequently, for mammary gland development and BCa identity. FOXA1 has the capability to bind to and de-compact heterochromatin to render it accessible for other nuclear proteins, such as ER, and allow activation of their transcriptional programs upon estrogen stimulation. In this project, we aim to elucidate the role of FOXA1 missense mutations in altering its binding to DNA, chromatin accessibility, ER-dependent transcription and their implication in limiting the sensitivity to standard-of-care anti-hormonal therapy, commonly used in ER-positive BCa patients. To this end, we have generated BCa cell lines expressing these FOXA1 mutations and we will employ ATAC-Seq, RIME assays, ChIP-Seq and RNA-Seq to ascertain their effect on DNA accessibility, DNA binding capability, as well as binding of transcriptional coregulators, such as ER, to chromatin. We will extend our analyses to our internal BCa patient datasets with detailed clinical annotation to study the correlation between presence of FOXA1 mutations and response to anti-hormonal therapy of ER-positive BCa patients. The results of this project will allow to understand how the different mutations in the Forkhead domain can alter FOXA1 and ER function, transcriptional regulation and response to anti-hormonal therapy in ER-positive BCa patients.
Project description:Invasive Lobular Carcinoma (ILC) is the second most frequent breast cancer (BCa) type and encompasses 10-15% of BCa cases. FOXA1 specific mutations are enriched in this subtype of BCa, however their role in breast cancer pathogenesis is still ill-defined. FOXA1, together with estrogen receptor (ER), is a key transcription factor for the correct activation of estrogen-dependent gene expression and, consequently, for mammary gland development and BCa identity. FOXA1 has the capability to bind to and de-compact heterochromatin to render it accessible for other nuclear proteins, such as ER, and allow activation of their transcriptional programs upon estrogen stimulation. In this project, we aim to elucidate the role of FOXA1 missense mutations in altering its binding to DNA, chromatin accessibility, ER-dependent transcription and their implication in limiting the sensitivity to standard-of-care anti-hormonal therapy, commonly used in ER-positive BCa patients. To this end, we have generated BCa cell lines expressing these FOXA1 mutations and we will employ ATAC-Seq, RIME assays, ChIP-Seq and RNA-Seq to ascertain their effect on DNA accessibility, DNA binding capability, as well as binding of transcriptional coregulators, such as ER, to chromatin. We will extend our analyses to our internal BCa patient datasets with detailed clinical annotation to study the correlation between presence of FOXA1 mutations and response to anti-hormonal therapy of ER-positive BCa patients. The results of this project will allow to understand how the different mutations in the Forkhead domain can alter FOXA1 and ER function, transcriptional regulation and response to anti-hormonal therapy in ER-positive BCa patients.
Project description:Exclusion of lymphocytes from tumors is a major barrier for effective immuno- and chemo-therapy of cancer. We found that FOXA1 overexpression inversely correlates with expression of antigen processing and presentation and interferon signaling genes in different cancer types. FOXA1 binds to STAT proteins and inhibits expression of antigen presentation and interferon response genes and tumor immunity independent of the forkhead domain - DNA binding function. Increased FOXA1 also correlates with immunotherapy resistance in murine triple negative breast tumor and bladder cancer in patients and chemo-resistance in breast cancer patients. Our results reveal that FOXA1 is a key immune suppressor, suggesting that FOXA1 overexpression may predict tumor resistance to immuno- and chemo-therapies and that depletion of FOXA1 may therapeutically convert cancers from ‘immune-cold’ to ‘immune-hot’ diseases.
Project description:The forkhead transcription factor, Foxp3, is pivotal to the development and function of CD4+CD25+ T regulatory (Treg) cells that limit autoimmunity and maintain immune homeostasis. Previous data indicated that many of the functions of Foxp3 are controlled by the acetylation of several lysines within the forkhead domain. We now show that mutation of each of two lysines within the forkhead domain of Foxp3, lysine at position 382 (K17) and lysine at position 393 (K18), impaired Treg suppressive function in vivo and in vitro. Lysine mutations also decreased Treg expression of multiple functionally important Foxp3-regulated genes, and inhibited the promoter remodeling of target genes (CTLA-4 and IL-2) without affecting Foxp3 expression level. These data point to the need for a further understanding of the effects of various post-translational modifications on Foxp3 function. Our studies also provide a rationale for developing small molecule inhibitors of such post-translational modifications so as to regulate Foxp3+ Treg function clinically. RNA from three independent samples from magnetically separated CD4+CD25- T-effector cells transduced with EV, WT-Fopx3, Foxp3-K17R or Foxp3-K18R
Project description:We determine by genome-wide location analysis (ChIP-Seq) that Foxa1 occupies 5,682 binding sites in the adult murine liver. Although Foxa1 and its closest paralog Foxa2 (GEO accessions: GSE25836 and GSE26729) share a large fraction of binding sites in the liver, each protein also occupies distinct regulatory elements in vivo. Foxa1-only sites have a weaker forkhead motif are enriched for p53 binding sites and are frequently found near genes important to cell cycle regulation, while Foxa2-restricted sites show only a stronger match to the forkhead consensus and are found in genes involved in steroid and lipid metabolism. Thus, Foxa1 and Foxa2, while redundant during development, have evolved divergent roles in the adult liver, ensuring the maintenance of both genes during evolution. 5 biological replicates examined
Project description:The forkhead protein FOXA1 has been found to play a critical role in orchestrating hormonal-signaling network and to function as a pioneer factor to regulate breast-specific gene expression,However, whether interplay between O-GlcNAcylation and FOXA1 affects the genome-wide transcriptional activity of this TF and subsequently orchestrates downstream gene expression networks in breast cancer progression needs further elucidation.