Project description:High expression of the FOXP1 transcription factor distinguishes the highly aggressive Activated B Cell (ABC) type of Diffuse Large B Cell Lymphoma (DLBCL) from the more indolent Germinal Center (GCB) DLBCL subtype and is correlated with poor prognosis. A genetic or functional role for FOXP1 in lymphomagenesis and/or tumor maintenance, however, remains unknown. Here, we report that sustained expression of FOXP1 is necessary for ABC DLBCL cell line survival. Genome-wide transcript profiling reveals that FOXP1 acts directly and indirectly by enforcing expression of known ABC DLBCL hallmarks, including the classical NF-kappaB survival pathway. Our data further suggest that FOXP1 maintains the ABC subtype distinction by repressing gene expression programs dominant in GCB DLBCL and supports a model in which the target of ABC DLBCL transformation is a transitory cell type en route from the germinal center B cell to the terminally differentiated plasma cell.
Project description:Trial Design:
This is a feasibility randomised controlled trial.
Aim:
The study aims to test the Healthy Eating and Active Lifestyle After Bowel Cancer - HEAL ABC intervention and HEAL ABC resources for feasibility and will inform a future definitive randomised controlled trial (RCT).
Objectives:
1. Is it practical to run HEAL ABC study as a definitive randomised controlled trial?
2. Adherence to intervention, motivations, barriers and facilitators of CRC survivors to follow HEAL ABC.
Study Population:
Colorectal cancer survivors who completed surgery and/or active treatment.
Intervention:
The intervention group will use HEAL ABC resource with supportive telephone calls every two weeks during the intervention period and once a month during the follow up period.
Control:
Participants follow standard care recommendations.
Timing and duration:
3 months intervention with 6 months follow up period
Project description:ATP-binding cassette (ABC) transporters can translocate a broad spectrum of molecules across the cell membrane including physiological cargo and toxins. ABC transporters are known for the role they play in resistance towards anticancer agents in chemotherapy of cancer patients. There are 68 ABC transporters annotated in the genome of the social amoeba Dictyostelium discoideum. We have characterized more than half of these ABC transporters through a systematic study of mutations in their genes. We have analyzed morphological and transcriptional phenotypes for these mutants during growth and development and found that most of the mutants exhibited rather subtle phenotypes. A few of the genes may share physiological functions, as reflected in their transcriptional phenotypes. Since most of the abc-transporter mutants showed subtle morphological phenotypes, we utilized these transcriptional phenotypes to identify genes that are important for development by looking for transcripts whose abundance was unperturbed in most of the mutants. We found a set of 668 genes that includes many validated D. discoideum developmental genes. We have also found that abcG6 and abcG18 may have potential roles in intercellular signaling during terminal differentiation of spores and stalks. Transcriptional phenotyping during development of abc transporter mutants in Dictyostelium discoideum
Project description:ATP-binding cassette (ABC) transporters can translocate a broad spectrum of molecules across the cell membrane including physiological cargo and toxins. ABC transporters are known for the role they play in resistance towards anticancer agents in chemotherapy of cancer patients. There are 68 ABC transporters annotated in the genome of the social amoeba Dictyostelium discoideum. We have characterized more than half of these ABC transporters through a systematic study of mutations in their genes. We have analyzed morphological and transcriptional phenotypes for these mutants during growth and development and found that most of the mutants exhibited rather subtle phenotypes. A few of the genes may share physiological functions, as reflected in their transcriptional phenotypes. Since most of the abc-transporter mutants showed subtle morphological phenotypes, we utilized these transcriptional phenotypes to identify genes that are important for development by looking for transcripts whose abundance was unperturbed in most of the mutants. We found a set of 668 genes that includes many validated D. discoideum developmental genes. We have also found that abcG6 and abcG18 may have potential roles in intercellular signaling during terminal differentiation of spores and stalks.
Project description:RNA interference screens identified the transcription factor IRF4 as essential for the survival of the activated B-cell-like subtype of diffuse large B-cell lymphoma (ABC-DLBCL). Analysis of IRF4 genomic targets in ABC-DLBCL and Multiple Myeloma (MM) revealed that IRF4 regulates distinct networks in these cancers. IRF4 peaks in ABC-DLBCL, but not MM, were enriched for a composite ETS-IRF DNA motif that can be bound by heterodimers of IRF4 and the ETS-family transcription factor SPIB, whose expression is also essential for ABC-DLBCL survival. Gene expression and ChIP-Seq analysis identified essential genes co-regulated by IRF4 and SPIB. Together, these factors regulate a critical oncogenic loop by activating CARD11, which controls ABC-DLBCL survival via the NF-kB pathway. The interaction between IRF4 and SPIB presents an attractive therapeutic target in this aggressive lymphoma.
Project description:Interferon regulatory factor 4 (IRF4) is a transcriptional regulator with critical roles in the normal development and malignant transformation of lymphocytes. Recently we have shown that plasma cell cancers (multiple myeloma, MM) are addicted to an aberrant gene expression program ochestrated by wild-type IRF4 for their survival. Here we show that an aggressive malignancy of mature B cells, the activated B cell for of Diffuse Large B Cell lymphoma (ABC-DLBC), also depends on IRF4 for survival. With genome-wide expression profiling and localization (ChIP-Seq) assays, we identified IRF4 target genes in ABC-DLBCL as members of diverse pathways related to B cell biology and malignant behavior, distinct from IRF4 targets in MM. For example, we find the gene encoding the NFkB signal transduction adapter protein CARD11 is a target of IRF4 activation, driving the critical NFkB pathway in ABC-DLBCL. Further, we find enrichment of DNA binding motifs for ETS-IRF factors in regions of IRF4 binding in ABC-DLBCL suggesting cooperative activity between IRF4 and an ETS family transcription factor. Through complementation assays we show that IRF4 and the critical ABC-DLBCL ETS factor SPIB interact with one another and are key to ABC-DLBCL survival. Together our data show that ABC-DLBCL is addicted to the interaction between IRF4 and SPIB, in part through a positive feedback loop invovling CARD11 and the activation of the NFkB pathway. These data suggest theraepeutic potential in targeting the IRF4:SPIB interface in ABC-DLBCL.
Project description:B-cell receptor (BCR) signaling is essential for the diffuse large B-cell lymphoma (DLBCL) subtype that originates from activated B-cells (ABC). ABC-DLBCL cells are sensitive to Bruton tyrosine kinase intervention. However, ABC-DLBCL patients had overall response rates of 33-37% for Bruton tyrosine kinase inhibitors, suggesting the evaluation of combination-based treatment for improved efficacy. We investigated the efficacy and mechanism of AZD5153 combined with the Bruton tyrosine kinase inhibitor acalabrutinib in ABC-DLBCL preclinical models. AZD5153 is a bivalent BET inhibitor that simultaneously engages the two bromodomains of BRD4. Adding AZD5153 to acalabrutinib demonstrated a combination benefit in ABC-DLBCL cell lines and PDX models. Differential expression analyses in treated tumors identified significant alterations of BCR, PAX5, RELB/alternative NFκB, and toll-like receptor/interferon signaling. PAX5 is a transcription factor for BCR signaling genes and may be critical to the perpetually active BCR signaling in ABC-DLBCL. We demonstrate that AZD5153 decreases PAX5 expression, while acalabrutinib disruption to BCR signaling inhibits PAX5 activation. Furthermore, several interferons were decreased by AZD5153 and acalabrutinib in tumors. Adding IFNß1 to cells in vitro restored PAX5 activation. Our results demonstrate AZD5153 enhances the efficacy of acalabrutinib through PAX5 and BCR mechanisms that are critical for ABC-DLBCL.
Project description:We have developed a novel immunocompetent multi-lesion mouse model of activated B cell diffuse large B-cell lymphoma (ABC-DLBCL; the pBIC mice) that recapitulates relatively fast the molecular, cellular and tumor microenvironment of aggressive human ABC-DLBCL. We demonstrate that perturbed p53 signaling cooperates with constitutive NF-kB activation in GC-experienced plasmablasts with blocked terminal differentiation to promote lymphomagenesis and tumor progression through triggering downstream intracellular molecular addictions (e.g. deregulating Foxp1 and AID pathways) and intercellular immunosuppressive signals for evading anti-tumoral responses (e.g. MHC-II antigen presentation and deregulating PD-L1/PD-1 immune checkpoint). Our immunocompetent ABC-DLBCL murine model provides in vivo evidence that PD-1 blockade cooperates with anti-CD20-based current standard-of-care therapy to reshape the immunosuppressive TME and facilitate long-term anti-tumoral responses. Therefore, our results support that immune checkpoints may hold promising therapeutic potential in ABC-DLBCL.