Project description:By using a unique functional protein microarray platform, we found that the FDA approved drug ibrutinib can inhibits ERBB4 activity in the same nM range as its canonical target, BTK. Cell-based assays revealed that ibrutinib treatment inhibited cell growth in some ERBB4 expressing cancer cells whereas no response was observed in other cells. Therefore, to identify global gene expression differences between ibrutinib responsive and non-responsive cancer cells, we performed RNA-Seq, and identified a signature featuring the WNT pathway that predicts growth responsiveness to ibrutinib in ERBB4 expressing cancers.
Project description:<p>The purpose of the study was to compare gene expression profiles from a cohort of crizotinib-resistant ALK-rearranged lung tumors and a cohort of treatment-naive ALK-rearranged lung tumors. Expression profiles were generated by RNA-seq. In parallel, gene expression profiles were obtained from ALK-rearranged lung cancer cell lines in the presence or absence of the ALK inhibitor TAE684. Gene expression profiles were also obtained from ALK-rearranged cells ectopically expressing genes associated with ALK inhibitor resistance that were identified from a functional genetic study.</p>
Project description:The four members of the epidermal growth factor receptor (EGFR/ERBB) family form homo- and heterodimers which mediate ligand-specific regulation of many key cellular processes in normal and cancer tissues. While signaling through the EGFR has been extensively studied on the molecular level, signal transduction through ERBB3/ERBB4 heterodimers is less well understood. Here, we generated isogenic mouse Ba/F3 cells that express full-length and functional membrane-integrated ERBB3 and ERBB4 or ERBB4 alone, to serve as a defined cellular model for biological and phosphoproteomics analysis of ERBB3/ERBB4 signaling. ERBB3 co-expression significantly enhanced Ba/F3 cell proliferation upon neuregulin-1 (NRG1) treatment. For comprehensive signaling studies we performed quantitative mass spectrometry (MS) experiments to compare the basal ERBB3/ERBB4 cell phosphoproteome to NRG1 treatment of ERBB3/ERBB4 and ERBB4 cells. We employed a workflow comprising differential isotope labeling with mTRAQ reagents followed by chromatographic peptide separation and final phosphopeptide enrichment prior to MS analysis. Overall, we identified 9686 phosphorylation sites which could be confidently localized to specific residues. Statistical analysis of three replicate experiments revealed 492 phosphorylation sites which were significantly changed in NRG1-treated ERBB3/ERBB4 cells. Bioinformatics data analysis recapitulated regulation of mitogen-activated protein kinase and Akt pathways, but also indicated signaling links to cytoskeletal functions and nuclear biology. Comparative assessment of NRG1-stimulated ERBB4 Ba/F3 cells indicated that ERBB3 did not trigger defined signaling pathways but more broadly enhanced phosphoproteome regulation in cells expressing both receptors. In conclusion, our data provide the first global picture of ERBB3/ERBB4 signaling and provide numerous potential starting points for further mechanistic studies
Project description:This phase I trial studies the side effects and best dose of ibrutinib in treating B-cell non-Hodgkin lymphoma that has returned or does not respond to treatment in patients with human immunodeficiency virus (HIV) infection. Ibrutinib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. It is not yet known whether it is safe for patients with HIV infection to receive ibrutinib while also taking anti-HIV drugs.
Project description:Like all receptor tyrosine kinases (RTKs), ErbB4 signals through a canonical signaling involving phosphorylation cascades. However, ErbB4 can also signal through a non-canonical mechanism whereby the intracellular domain is released into the cytoplasm by regulated intermembrane proteolysis (RIP) and translocates to the nucleus where it regulates transcription. These different signaling mechanisms depend on the generation of alternative spliced isoforms, a RIP cleavable ErbB4-JMa and an uncleavable ErbB4-JMb. Non-canonical signaling by ErbB4-JMa has been implicated in the regulation of brain, heart, mammary gland, lung, and immune cell development. However, most studies on non-canonical ErbB4 signaling have been performed in vitro due to the lack of an adequate mouse model. We created an ErbB4-JMa specific knock out mouse and demonstrate that RIP-dependent, non-canonical signaling by ErbB4-JMa is required for the regulation of GFAP expression during cortical development. We also show that ErbB4-JMa signaling is not required for the development of the heart, mammary glands, sensory ganglia. Furthermore, we identify genes whose expression during cortical development is regulated by ErbB4, and show that the expression of two of them, CRYM and DBi, depend on ErbB4-JMa. Thus, we provide the first animal model to study the roles of non-canonical RTK in vivo.
Project description:ERBB4 is a member of the epidermal growth factor receptor (EGFR)/ERBB subfamily of receptor tyrosine kinases that regulates cellular processes including proliferation, migration and survival. ERBB4 signaling is involved in embryogenesis and homeostasis of adult tissues, but also in human pathologies such as cancer, neurological disorders and cardiovascular diseases. A mass spectrometry screen revealed guanine nucleotide exchange factor (GEF) VAV3, an activator of Rho family GTPases, as a novel ERBB4-interacting protein in breast cancer cells. The ERBB4-VAV3-interaction was confirmed by targeted mass-spectrometry, coimmunoprecipitation experiments, and further defined by demonstrating that kinase activity and tyrosine residues 1022 and 1162 of ERBB4, as well as the intact phosphotyrosine-interacting SH2 domain of VAV3 were necessary for the interaction. ERBB4 was also shown to stimulate tyrosine phosphorylation of the VAV3 activation domain, which is required for GEF activity of VAV proteins. In addition to VAV3, also the other members of the VAV family, VAV1 and VAV2 were shown to coprecipitate with ERBB4. Analyses of the effects of overexpression of dominant-negative VAV3 constructs or downregulation of VAV3 expression by shRNAs in breast cancer cells demonstrated that active VAV3 was involved in ERBB4-stimulated migration. These findings define the VAV GTPases as novel effectors of ERBB4 activity in a signaling pathway relevant for cancer cell migration.
Project description:Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) are the most prevalent B-lymphocyte neoplasms in which abnormal activation of the Bruton’s tyrosine kinase (BTK)–mediated B-cell receptor (BCR) signaling pathway contributes to pathogenesis. Ibrutinib is an oral covalent BTK inhibitor that has shown some efficacy in both indications. To improve ibrutinib efficacy through combination therapy, we first investigated differential gene expression in parental and ibrutinib-resistant cell lines to better understand the mechanisms of resistance. Ibrutinib-resistant TMD8 cells had higher BCL2 gene expression and increased sensitivity to ABT-199, a BCL-2 inhibitor. Consistently, clinical samples from ABC-DLBCL patients who experienced poorer response to ibrutinib had higher BCL2 gene expression. We further demonstrated synergistic growth suppression by ibrutinib and ABT-199 in multiple ABC-DLBCL, GCB-DLBCL, and FL lymphoma cell lines. The combination of both drugs also reduced colony formation, increased apoptosis, and inhibited tumor growth in a TMD8 xenograft model. A synergistic combination effect was also found in ibrutinib-resistant cells generated by either genetic mutation or drug treatment. Together, these findings suggest a potential clinical benefit from ibrutinib and ABT-199 combination therapy.
Project description:Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) are the most prevalent B-lymphocyte neoplasms in which abnormal activation of the Bruton’s tyrosine kinase (BTK)–mediated B-cell receptor (BCR) signaling pathway contributes to pathogenesis. Ibrutinib is an oral covalent BTK inhibitor that has shown some efficacy in both indications. To improve ibrutinib efficacy through combination therapy, we first investigated differential gene expression in parental and ibrutinib-resistant cell lines to better understand the mechanisms of resistance. Ibrutinib-resistant TMD8 cells had higher BCL2 gene expression and increased sensitivity to ABT-199, a BCL-2 inhibitor. Consistently, clinical samples from ABC-DLBCL patients who experienced poorer response to ibrutinib had higher BCL2 gene expression. We further demonstrated synergistic growth suppression by ibrutinib and ABT-199 in multiple ABC-DLBCL, GCB-DLBCL, and FL lymphoma cell lines. The combination of both drugs also reduced colony formation, increased apoptosis, and inhibited tumor growth in a TMD8 xenograft model. A synergistic combination effect was also found in ibrutinib-resistant cells generated by either genetic mutation or drug treatment. Together, these findings suggest a potential clinical benefit from ibrutinib and ABT-199 combination therapy.
Project description:We established two representative ABC DLBCL cell lines (TMD8 and OCI-Ly10) with ibrutinib resistance by gradually increasing the concentration of ibrutinib during passage in culture. RNA-seq analysis demonstrated that the BCR pathway gene signature is enriched in resistant cell lines when compared to parental cells. The most upregulated gene is EGR1, a transcription factor that activates multiple oncogenic pathways including MYC and E2F. Elevated EGR1 expression is also observed in ibrutinib-resistant primary mantle cell lymphoma cells when treated with ibrutinib. Using multiple metabolic and genetic approaches, we discovered that overexpression of EGR1 causes metabolic reprogramming to oxidative phosphorylation (OXPHOS) and ibrutinib resistance. Mechanistically, EGR1 mediates metabolic reprogramming through transcriptional activation of PDP1, a phosphatase that dephosphorylates and activates the E1 component of the large pyruvate dehydrogenase complex. Therefore, EGR1-mediated PDP1 activation accelerates intracellular ATP production via the mitochondrial tricarboxylic acid (TCA) cycle, leading to sufficient energy to enhance the proliferation and survival of ibrutinib-resistant lymphoma cells. Finally, we demonstrate that targeting OXPHOS with IM156, a newly developed OXPHOS inhibitor, inhibits the growth of ibrutinib-resistant lymphoma cells both in vitro and in patient-derived xenograft mouse models.