Final Report Summary - LYMFOXP1 (ROLE OF THE TRANSCRIPTION FACTOR FOXP1 IN B CELL FUNCTION AND LYMPHOMAGENESIS)
Germinal center (GC) B cells are particularly prone to neoplastic transformation, which accounts for the high incidence of GC-derived lymphomas diagnosed in the western world. Diffuse large B-cell lymphoma (DLBCL) is the most common GC-derived lymphoma in adults, and is characterized by its clinical heterogeneity in terms of patient survival and response to therapy. Frequently, these lymphoma B cells show symptoms of aberrant FOXP1 expression, find ways to inactivate tumor suppression, and further accumulate great levels of heterogeneity that contribute to tumoral evolution and resistance to treatment. Thus, we hypothesized that NF-kB hyperactivation and yet not completely understood mechanisms of ongoing genomic instability in FOXP1-positive lymphoma B cells, are primary drivers in the genetic and epigenetic pathogenesis of DLBCL. In the LYMFOXP1 MSCA-project, we proposed to explore the role of FOXP1 as a transcriptional regulator of mature B-cell function and lymphomagenesis, with the overall goal to identify novel transcriptional targets of FOXP1 deregulation in B cells, exploring their potential mechanisms of regulation and designing novel potential therapeutic strategies to target them.
Thanks to the funding from an International Incoming Fellowship from the Marie Sklodowska-Curie Program, we were able to generate new conditional mice that incorporate several selected genetic alterations that are recurrently found in human DLBCL, which were targeted to GC B cells by the use of the Cg1-CRE strategy. Survival analysis, histopathology, flow-cytometry and molecular characterization of tumors demonstrate aggressive DLBCL-like features in these mice, as well as FOXP1 expression. We have further performed comprehensive integrative studies comparing results from these mice with genome-wide genetic and epigenetic data obtained from human DLBCL cell lines and from primary human samples (fresh biopsies, FFPE samples and normal tonsillar tissues). Novel biomarkers and deregulated molecular pathways have been identified by these approaches, for which we have designed and proposed to explore novel therapeutic strategies utilizing investigational regimens with aptamers, miRNA mimics and/or monoclonal antibodies. We are convinced that our FOXP1-positive DLBCL mouse model represents an exciting novel pre-clinical model to better understand the pathogenic mechanisms that deregulate the GC response and lead to aberrant humoral immunity and lymphomagenesis.
The LYMFOXP1 proposal aimed at tackling the crosstalk between FOXP1 transcriptional deregulation and genomic instability mechanisms leading to GC-derived DLBCL lymphomagenesis, a highly prevalent disease in Europe. In the context of the specific objectives and experimental approaches contemplated in the project, we expect that the study of a very attractive research topic combined with novel, comprehensive and in vivo strategies will make the scientific and technical impact of the obtained results very high. Indeed, two manuscripts characterizing the novel DLBCL mouse model and describing a novel mechanism of FOXP1 contribution to genomic instability are at late stages of preparation. In addition, the genome-wide approaches and cellular samples have fueled other related scientific collaborations, which have already produced two publications in high impact journals (JACI, 2014 and Nature Communications, 2016) and have generated results to contribute in other 5 manuscripts in preparation. The LYMFOXP1 research topic, both from a basic and translational perspective, holds a great international interest in the scientific community. This is reflected in the prestigious meetings dealing with B cell biology, GC function and lymphomagenesis, and in the large number of highly renowned scientists devoted to these topics (e.g. the first European Keystone Symposia about immunobiology of B cells has been recently held in Stockholm). In the European context, Dr. Roa belongs to a network of B-cell groups (DeamiNET) that gathers on a regular basis and that is currently working cooperatively to promote the international impact of this type of research proposal. Although LYMFOXP1 addresses basic molecular and cellular mechanisms, it also includes the access to human lymphoma samples to confirm the translational value of the results. Furthermore, the proposal aims to testing pre-clinically in animal models a list of novel and combinatorial therapeutic strategies that may show significant impact in the progression of DLBLC, and therefore could grow in the future into the design of novel clinical trials. Finally, LYMFOXP1 goals have been concerned with better understanding the pathogenesis of a prevalent disease, and we expect that the results may ultimately have recognizable social impact in the Horizon2020 context of health and well-being.
Thanks to the funding from an International Incoming Fellowship from the Marie Sklodowska-Curie Program, we were able to generate new conditional mice that incorporate several selected genetic alterations that are recurrently found in human DLBCL, which were targeted to GC B cells by the use of the Cg1-CRE strategy. Survival analysis, histopathology, flow-cytometry and molecular characterization of tumors demonstrate aggressive DLBCL-like features in these mice, as well as FOXP1 expression. We have further performed comprehensive integrative studies comparing results from these mice with genome-wide genetic and epigenetic data obtained from human DLBCL cell lines and from primary human samples (fresh biopsies, FFPE samples and normal tonsillar tissues). Novel biomarkers and deregulated molecular pathways have been identified by these approaches, for which we have designed and proposed to explore novel therapeutic strategies utilizing investigational regimens with aptamers, miRNA mimics and/or monoclonal antibodies. We are convinced that our FOXP1-positive DLBCL mouse model represents an exciting novel pre-clinical model to better understand the pathogenic mechanisms that deregulate the GC response and lead to aberrant humoral immunity and lymphomagenesis.
The LYMFOXP1 proposal aimed at tackling the crosstalk between FOXP1 transcriptional deregulation and genomic instability mechanisms leading to GC-derived DLBCL lymphomagenesis, a highly prevalent disease in Europe. In the context of the specific objectives and experimental approaches contemplated in the project, we expect that the study of a very attractive research topic combined with novel, comprehensive and in vivo strategies will make the scientific and technical impact of the obtained results very high. Indeed, two manuscripts characterizing the novel DLBCL mouse model and describing a novel mechanism of FOXP1 contribution to genomic instability are at late stages of preparation. In addition, the genome-wide approaches and cellular samples have fueled other related scientific collaborations, which have already produced two publications in high impact journals (JACI, 2014 and Nature Communications, 2016) and have generated results to contribute in other 5 manuscripts in preparation. The LYMFOXP1 research topic, both from a basic and translational perspective, holds a great international interest in the scientific community. This is reflected in the prestigious meetings dealing with B cell biology, GC function and lymphomagenesis, and in the large number of highly renowned scientists devoted to these topics (e.g. the first European Keystone Symposia about immunobiology of B cells has been recently held in Stockholm). In the European context, Dr. Roa belongs to a network of B-cell groups (DeamiNET) that gathers on a regular basis and that is currently working cooperatively to promote the international impact of this type of research proposal. Although LYMFOXP1 addresses basic molecular and cellular mechanisms, it also includes the access to human lymphoma samples to confirm the translational value of the results. Furthermore, the proposal aims to testing pre-clinically in animal models a list of novel and combinatorial therapeutic strategies that may show significant impact in the progression of DLBLC, and therefore could grow in the future into the design of novel clinical trials. Finally, LYMFOXP1 goals have been concerned with better understanding the pathogenesis of a prevalent disease, and we expect that the results may ultimately have recognizable social impact in the Horizon2020 context of health and well-being.
