Protein Profiling Identify Distinct Tumor-Tissue Protein Expression Pattern Specific for Relapsing Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease. Several genetic drivers have been suggested based on gene-expression and RNA sequencing. However, clinical trials based on these molecular subclassifications have failed to improve treatment results and standard of care in DLBCL is still R-CHOP (rituximab, cyclophosphamide, doxorubicin, prednisone) based therapy, which results in approximately an 70% 5-year overall survival rate. Nordic Lymphoma Group (NLG) has conducted two large phase II trials (NLG-LBC-04; NCT 01502982 and NLG-LBC-05; NCT 01325194) during the last decade with the aim of improving the treatment outcome for young (<65 years) high-risk patients with primary DLBCL. Both protocols were based on biweekly administered R-CHOP-14 with etoposide (R-CHOEP) and systemic central nervous system (CNS) prophylaxis. Various factors acting at different biological levels may influence pathology of the disease, and discrepancies between gene expression and the final combination of the functional proteins may be present due to, e.g., translational inhibition/activation and posttranslational modifications. Mass spectrometry-based protein profiling is a high throughput methodology that enables identification of the proteins in a given cell or tissue and the global protein expression can be compared between patients. The aim of our study was to search for prognostic markers and possible therapeutic targets at the protein level in a uniformly treated patient cohort from the two Nordic trials (n=64) with available tumor-tissue. Thus, in this study, we investigated the protein expression pattern in the pre-therapeutic formalin-fixed paraffin embedded tumor samples by nano liquid-chromatography coupled to a mass spectrometer (Orbitrap Fusion) through an EASY-Spray nano-electrospray ion source (nLC-MS/MS). We identified 4,622 proteins with at least two unique peptides across all samples. In the combined cohort, we were able to, based on differential protein expression of 190 proteins between patients (p<0.05) with treatment sensitive (n=53) and relapsing (n=11) lymphoma, identify three clusters with one of the clusters containing only patients with experienced relapsing disease. Interestingly, among other identified differentially expressed proteins, we emphasize the identification of voltage dependent anion channel 3 (VDAC3) and the GTPase RAC1. This pattern of protein expression suggests disturbance in reactive oxidative species (ROS) signaling and regulation of tumor cell proliferation between relapsing and therapy-responding patients. Assessment of these specific protein expression patterns in the three clusters may provide a useful parameter for prediction of relapsing disease in DLBCL patients but still awaits further validation in a separate patient cohort. Disclosures Holte: Gilead: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Nordic: Membership on an entity's Board of Directors or advisory committees; Nanovector: Membership on an entity's Board of Directors or advisory committees, Other: lectures honorarias; Novartis: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Jørgensen: Gilead/Kite: Consultancy; Novartis: Consultancy; Celgene/BMS: Consultancy; Roche: Consultancy.

Anti-CD20 Therapy Alters the Protein Signature in Experimental Murine AIH, but Not Exclusively Towards Regeneration

Background: Autoimmune hepatitis (AIH) is a chronic autoimmune inflammatory disease that usually requires lifelong immunosuppression. Frequent recurrences after the discontinuation of therapy indicate that intrahepatic immune regulation is not restored by current treatments. Studies of other autoimmune diseases suggest that temporary depletion of B cells can improve disease progression in the long term. Methods: We tested a single administration of anti-CD20 antibodies to reduce B cells and the amount of IgG to induce intrahepatic immune tolerance. We used our experimental murine AIH (emAIH) model and treated the mice with anti-CD20 during the late stage of the disease. Results: After treatment, the mice showed the expected reductions in B cells and serum IgGs, but no improvements in pathology. However, all treated animals showed a highly altered serum protein expression pattern, which was a balance between inflammation and regeneration. Conclusions: In conclusion, anti-CD20 therapy did not produce clinically measurable results because it triggered inflammation, as well as regeneration, at the proteomic level. This finding suggests that anti-CD20 is ineffective as a sole treatment for AIH or emAIH.

In Silico Identification of Small Molecules as New Cdc25 Inhibitors through the Correlation between Chemosensitivity and Protein Expression Pattern

The cell division cycle 25 (Cdc25) protein family plays a crucial role in controlling cell proliferation, making it an excellent target for cancer therapy. In this work, a set of small molecules were identified as Cdc25 modulators by applying a mixed ligand-structure-based approach and taking advantage of the correlation between the chemosensitivity of selected structures and the protein expression pattern of the proposed target. In the first step of the in silico protocol, a set of molecules acting as Cdc25 inhibitors were identified through a new ligand-based protocol and the evaluation of a large database of molecular structures. Subsequently, induced-fit docking (IFD) studies allowed us to further reduce the number of compounds biologically screened. In vitro antiproliferative and enzymatic inhibition assays on the selected compounds led to the identification of new structurally heterogeneous inhibitors of Cdc25 proteins. Among them, J3955, the most active inhibitor, showed concentration-dependent antiproliferative activity against HepG2 cells, with GI50 in the low micromolar range. When J3955 was tested in cell-cycle perturbation experiments, it caused mitotic failure by G2/M-phase cell-cycle arrest. Finally, Western blotting analysis showed an increment of phosphorylated Cdk1 levels in cells exposed to J3955, indicating its specific influence in cellular pathways involving Cdc25 proteins.

Doublesex Mediates the Development of Sex-Specific Pheromone Organs in Bicyclus Butterflies via Multiple Mechanisms

The Bicyclus lineage of satyrid butterflies exhibits male-specific traits, the scent organs, used for chemical communication during courtship. These organs consist of tightly packed brush-like scales (hair-pencils) that rub against scent patches to disperse pheromones, but the evolution and molecular basis of these organ’s male-limited development remains unknown. Here, we examine the evolution of the number and location of the scent patches and hair-pencils within 53 species of Bicyclus butterflies, and the involvement of the sex determinant gene doublesex (dsx) in scent organ development in Bicyclus anynana using CRISPR/Cas9. We show that scent patches and hair-pencils arose via multiple, independent gains, in a correlated manner. Further, an initially nonsex-specific Dsx protein expression pattern in developing wing discs becomes male-specific and spatially refined to areas that develop the scent patches. Functional perturbations of dsx show that this gene activates patch development in males whereas hair-pencils develop in both sexes without Dsx input. Dsx in females is, instead, required to repress hair-pencils whereas Dsx in males regulates minor aspects of its development. These findings suggest that the patches and hair-pencils evolve as correlated composite organs presumably due to their functional integration. Divergence in the function of dsx isoforms occurred across the sexes, where the male isoform promotes patch development in males and the female isoform represses hair-pencil development in females, both leading to the development of male-limited traits. Furthermore, evolution in number of patches in males is due to the evolution of spatial regulation of dsx.

Doublesexmediates the development of sex-specific pheromone organs inBicyclusbutterflies via multiple mechanisms

TheBicycluslineage of satyrid butterflies exhibits male-specific traits, the scent organ complex, used for chemical communication during courtship. This complex consists of tightly packed brush-like scales (hair-pencils) that rub against scent patches to disperse pheromones, but the evolution and molecular basis of the organ’s male-limited development remains unknown. Here, we examine the evolution of the number and location of the scent patches and hair-pencils within 53 species ofBicyclusbutterflies, and the involvement of the sex determinant genedoublesex (dsx)in scent organ development inBicyclus anynanausing CRISPR/Cas9. We show that scent patches and hair-pencils arose via multiple, independent gains, in a correlated manner. Further, an initially non-sex-specific Dsx protein expression pattern in developing wing discs becomes male-specific and spatially refined to areas that develop the scent organ complex over the course of development. Functional perturbations ofdsxshow that this gene is required for male patch development whereas hair-pencils can develop in both sexes without Dsx input. Dsx in females is, instead, required to repress hair-pencils. These findings suggest that the patches and hair-pencils evolve as correlated composite organs that are sex-limited via the spatial regulation ofdsx. Divergence in the function ofdsxisoforms occurs in both sexes, where the male isoform promotes patch development in males and the female isoform represses hair-pencil development in females, both leading to the development of male-limited traits. Furthermore, evolution in number and location of patches, but not of hair-pencils, appears to be regulated by spatial regulation ofdsx.