Novel drug targets for personalized precision medicine in relapsed/refractory diffuse large B-cell lymphoma: a comprehensive review

Precision Medicine in Hematology 2021: Definitions, Tools, Perspectives, and Open Questions

During the past few years, our understanding of molecular mechanisms and cellular interactions relevant to malignant blood cell disorders has improved substantially. New insights include a detailed knowledge about disease-initiating exogenous factors, endogenous (genetic, somatic, epigenetic) elicitors or facilitators of disease evolution, and drug actions and interactions that underlie efficacy and adverse event profiles in defined cohorts of patients. As a result, precision medicine and personalized medicine are rapidly growing new disciplines that support the clinician in making the correct diagnosis, in predicting outcomes, and in optimally selecting patients for interventional therapies. In addition, precision medicine tools are greatly facilitating the development of new drugs, therapeutic approaches, and new multiparametric prognostic scoring models. However, although the emerging roles of precision medicine and personalized medicine in hematology and oncology are clearly visible, several questions remain. For example, it remains unknown how precision medicine tools can be implemented in healthcare systems and whether all possible approaches are also affordable. In addition, there is a need to define terminologies and to relate these to specific and context-related tools and strategies in basic and applied science. To discuss these issues, a working conference was organized in September 2019. The outcomes of this conference are summarized herein and include a proposal for definitions, terminologies, and applications of precision and personalized medicine concepts and tools in hematologic neoplasms. We also provide proposals aimed at reducing costs, thereby making these applications affordable in daily practice.

Beclin1‑armed oncolytic Vaccinia virus enhances the therapeutic efficacy of R‑CHOP against lymphoma in vitro and in vivo

Non-Hodgkin lymphoma (NHL) is a form of lymphoid malignancy, with diffuse large B cell lymphoma (DLBCL) being the most common NHL isoform. Approximately half of patients with DLBCL are successfully cured via first-line Rituximab, Cyclophosphamide, Epirubicin, Vindesine, Prednisolone (R-CHOP) treatment. However, 30–40% of patients with DLBCL ultimately suffer from treatment-refractory or relapsed disease. These patients often suffer from high mortality rates owing to a lack of suitable therapeutic options, and all patients are at a high risk of serious treatment-associated dose-dependent toxicity. As such, it is essential to develop novel treatments for NHL that are less toxic and more efficacious. Oncolytic Vaccinia virus (OVV) has shown promise as a means of treating numerous types of cancer. Gene therapy strategies further enhance OVV-based therapy by improving tumor cell recognition and immune evasion. Beclin1 is an autophagy-associated gene that, when upregulated, induces excess autophagy and cell death. The present study aimed to develop an OVV-Beclin1 therapy capable of inducing autophagic tumor cell death. OVV-Beclin1 was able to efficiently kill NHL cells and to increase the sensitivity of these cells to R-CHOP, thereby decreasing the dose-dependent toxic side effects associated with this chemotherapeutic regimen. The combination of OVV-Beclin1 and R-CHOP also significantly improved tumor growth inhibition and survival in a BALB/c murine model system owing to the synergistic induction of autophagic cell death. Together, these findings suggest that OVV-Beclin1 infection can induce significant autophagic cell death in NHL, highlighting this as a novel means of inducing tumor cell death via a mechanism that is distinct from apoptosis and necrosis.

CREBBP/EP300 mutations promoted tumor progression in diffuse large B-cell lymphoma through altering tumor-associated macrophage polarization via FBXW7-NOTCH-CCL2/CSF1 axis

Epigenetic alterations play an important role in tumor progression of diffuse large B-cell lymphoma (DLBCL). However, the biological relevance of epigenetic gene mutations on tumor microenvironment remains to be determined. The core set of genes relating to histone methylation (KMT2D, KMT2C, EZH2), histone acetylation (CREBBP, EP300), DNA methylation (TET2), and chromatin remodeling (ARID1A) were detected in the training cohort of 316 patients by whole-genome/exome sequencing (WGS/WES) and in the validation cohort of 303 patients with newly diagnosed DLBCL by targeted sequencing. Their correlation with peripheral blood immune cells and clinical outcomes were assessed. Underlying mechanisms on tumor microenvironment were investigated both in vitro and in vivo. Among all 619 DLBCL patients, somatic mutations in KMT2D (19.5%) were most frequently observed, followed by mutations in ARID1A (8.7%), CREBBP (8.4%), KMT2C (8.2%), TET2 (7.8%), EP300 (6.8%), and EZH2 (2.9%). Among them, CREBBP/EP300 mutations were significantly associated with decreased peripheral blood absolute lymphocyte-to-monocyte ratios, as well as inferior progression-free and overall survival. In B-lymphoma cells, the mutation or knockdown of CREBBP or EP300 inhibited H3K27 acetylation, downregulated FBXW7 expression, activated the NOTCH pathway, and downstream CCL2/CSF1 expression, resulting in tumor-associated macrophage polarization to M2 phenotype and tumor cell proliferation. In B-lymphoma murine models, xenografted tumors bearing CREBBP/EP300 mutation presented lower H3K27 acetylation, higher M2 macrophage recruitment, and more rapid tumor growth than those with CREBBP/EP300 wild-type control via FBXW7-NOTCH-CCL2/CSF1 axis. Our work thus contributed to the understanding of aberrant histone acetylation regulation on tumor microenvironment as an alternative mechanism of tumor progression in DLBCL.

Genetic and epigenetic determinants of diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma and is notorious for its heterogeneity, aggressive nature, and the frequent development of resistance and/or relapse after treatment with standard chemotherapy. To address these problems, a strong emphasis has been placed on researching the molecular origins and mechanisms of DLBCL to develop effective treatments. One of the major insights produced by such research is that DLBCL almost always stems from genetic damage that occurs during the germinal center (GC) reaction, which is required for the production of high-affinity antibodies. Indeed, there is significant overlap between the mechanisms that govern the GC reaction and those that drive the progression of DLBCL. A second important insight is that some of the most frequent genetic mutations that occur in DLBCL are those related to chromatin and epigenetics, especially those related to proteins that “write” histone post-translational modifications (PTMs). Mutation or deletion of these epigenetic writers often renders cells unable to epigenetically “switch on” critical gene sets that are required to exit the GC reaction, differentiate, repair DNA, and other essential cellular functions. Failure to activate these genes locks cells into a genotoxic state that is conducive to oncogenesis and/or relapse.

A three-gene signature based on tumour microenvironment predicts overall survival of osteosarcoma in adolescents and young adults

Evidences shows that immune and stroma related genes in the tumour microenvironment (TME) play a key regulator in the prognosis of Osteosarcomas (OSs). The purpose of this study was to develop a TME-related risk model for assessing the prognosis of OSs. 82 OSs cases aged ≤25 years from TARGET were divided into two groups according to the immune/stromal scores that were analyzed by the Estimate algorithm. The differentially expressed genes (DEGs) between the two groups were analyzed and 122 DEGs were revealed. Finally, three genes (COCH, MYOM2 and PDE1B) with the minimum AIC value were derived from 122 DEGs by multivariate cox analysis. The three-gene risk model (3-GRM) could distinguish patients with high risk from the training (TARGET) and validation (GSE21257) cohort. Furthermore, a nomogram model included 3-GRM score and clinical features were developed, with the AUC values in predicting 1, 3 and 5-year survival were 0.971, 0.853 and 0.818, respectively. In addition, in the high 3-GRM score group, the enrichment degrees of infiltrating immune cells were significantly lower and immune-related pathways were markedly suppressed. In summary, this model may be used as a marker to predict survival for OSs patients in adolescent and young adults.

Biomarkers and novel therapeutic approaches for diffuse large B-cell lymphoma in the era of precision medicine

Despite the great efforts for better treatment options for diffuse large B-cell lymphoma (DLBCL) (most common form of non-Hodgkin lymphoma, NHL) to treat and prevent relapse, it continues to be a challenge. Here, we present an overview of DLBCL and address the diagnostic assays and molecular techniques used in its diagnosis, role of biomarkers in detection, treatment of early and advanced stage DLBCL, and novel drug regimens. We discuss the significant biomarkers that have emerged as essential tools for stratifying patients according to risk factors and for providing insights into the use of more targeted and individualized therapeutics. We discuss techniques such as gene expression studies, including next-generation sequencing, which have enabled a more understanding of the complex pathogenesis of DLBCL and have helped determine molecular targets for novel therapeutic agents. We examine current treatment approaches, outline the findings of completed clinical trials, and provide updates for ongoing clinical trials. We highlight clinical trials relevant to the significant fraction of DLBCL patients who present with complex cases marked by high relapse rates. Supported by an increased understanding of targetable pathways in DLBCL, clinical trials involving specialized combination therapies are bringing us within reach the promise of an effective cure to DLBCL using precision medicine. Optimization of therapy remains a crucial objective, with the end goal being a balance between high survival rates through targeted and personalized treatment while reducing adverse effects in DLBCL patients of all subsets.

Sirt6 promotes tumorigenesis and drug resistance of diffuse large B-cell lymphoma by mediating PI3K/Akt signaling

Background

Sirtuin 6 (Sirt6) is a highly conserved ADP-ribosylase and NAD+ dependent deacylase, involved in broad cellular processes. This molecule possesses contradictory roles in carcinogenesis, as it has been documented to both suppressing and augmenting tumor growth. This project aimed to explore the expression and functions of Sirt6 in diffuse large B-cell lymphoma (DLBCL), especially with regards to the regulatory role of OSS_128167, a novel small molecular inhibitor targeting Sirt6.

Methods

Immunohistochemistry (IHC) was conducted to assess the expression of Sirt6 on paraffin-embedded tissues. Microarray dataset GSE32918 and GSE83632 were obtained from Gene Expression Omnibus and survival analysis was performed. Lentivirus vectors either encoding shSirt6, lvSirt6 or empty lentiviral vector were stably transfected into DLBCL cells. LY1 cell transfected with shSirt6 were performed RNA-sequencing (RNA-seq) analysis, functional enrichment analyses of gene ontology (GO) and gene set enrichment analysis (GSEA). DLBCL cells were subcutaneously injected to SCID beige mice to establish xenograft models.

Results

Sirt6 is found to be overexpressed in DLBCL, and is related to poor prognosis. Sirt6-deprived DLBCL cells displayed augmented sensitivity towards chemotherapy, higher rates of apoptosis, dysfunctional cell proliferation, and arrested cell cycle progression between the G2 and M phases. Selective OSS_128167-mediated Sirt6 blockage resulted in similar anti-lymphoma effects when compared to Sirt6 knocked-down DLBCL cells. PI3K signaling along with phosphorylation of its downstream targets was reduced upon Sirt6 downregulation. Xenograft models subjected to either OSS_128167 treatment or Sirt6-knockdown showed suppressed tumor growth and lower Ki-67 level.

Conclusions

These findings provide mechanistic insights into the oncogenic activity of Sirt6 in DLBCL for the first time and highlighted the potency of OSS_128167 for novel therapeutic strategies in DLBCL.

Risk Factors for Cancer-specific Mortality and Cardiovascular Mortality in Patients With Diffuse Large B-cell Lymphoma

BACKGROUND

The purpose of this study was to assess the risk factors for cancer-specific mortality and cardiovascular mortality in patients with diffuse large B-cell lymphoma (DLBCL).

PATIENTS AND METHODS

A retrospective cohort study involving patients with DLBCL who were registered in the Surveillance, Epidemiology, and End Results (SEER) database was performed. The risk factors for cancer-specific mortality and cardiovascular mortality were analyzed using the competing risk regression model.

RESULTS

A total of 62,950 patients with DLBCL were enrolled, of which 23,302 (37.50%) died of cancer and 2940 (4.70%) died of cardiovascular disease. The competing risk multivariate analysis displayed that age at diagnosis (hazard ratio [HR], 1.033; 95% confidence interval [CI], 1.032-1.034), marriedstatus (HR, 1.293; 95% CI, 1.241-1.347), black race (HR, 1.079; 95% CI, 1.021-1.139), and tumor stage (II: HR, 1.143; 95%CI, 1.095-1.192; III: HR, 1.459; 95% CI, 1.395-1.526; IV: HR, 1.961; 95% CI. 1.889-2.035) were the risk factors for cancer-specific mortality, but not female gender (HR, 0.938; 95% CI, 0.913,0.965) or treatment modalities (chemotherapy: HR, 0.522; 95% CI, 0.505-0.540; radiotherapy: HR, 0.782; 95% CI, 0.728-0.839; chemotherapy + radiotherapy: HR, 0.422; 95% CI, 0.403-0.441). Age at diagnosis (HR, 1.059; 95% CI, 1.055-1.062) and black race (HR, 1.246; 95% CI, 1.067-1.456) were the risk factors for cardiovascular mortality rather than female gender (HR, 0.803; 95% CI, 0.743-0.867) and married status (HR, 0.841; 95% CI, 0.745-0.950).

CONCLUSIONS

Age at diagnosis, married status, black race, and higher tumor stage are associated with an increased risk of cancer-specific mortality in patients with DLBCL, whereas age at diagnosis and black race are associated with a higher risk of cardiovascular mortality.

ENGINE: a Phase III randomized placebo controlled study of enzastaurin/R-CHOP as frontline therapy in high-risk diffuse large B-cell lymphoma patients with the genomic biomarker DGM1

While combination of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) cures most patients with diffuse large B-cell lymphoma (DLBCL), those with high-risk international prognostic index disease have inferior survival. Enzastaurin as a potent inhibitor of PKC-β and PI3K/AKT pathway suppressor has been tested in many clinical trials including two key studies in DLBCL: Phase III maintenance study (Preventing Relapse in Lymphoma Using Daily Enzastaurin [PRELUDE]) and a first-line Phase II study (S028). DNA extracted from PRELUDE patients' blood samples was retrospectively genotyped identifying a novel genetic biomarker, DGM1 that showed high correlation with response to enzastaurin. A similar finding observed in the S028 study suggested that addition of enzastaurin to R-CHOP may significantly improve outcomes as frontline therapy for high-risk DGM1 positive DLBCL patients. ENGINE is a global, multicenter, placebo-controlled and randomized study to compare the effect of R-CHOP/enzastaurin as frontline treatment in high-risk DLBCL patients. The primary end point for this study is overall survival in patients who are DGM1 positive. Clinical Trial Registration Identifier: NCT03263026.

Novel cyclophosphamide of natural products osalmide and pterostilbene induces cytotoxicity and cell cycle arrest in diffuse large B-cell lymphoma cells

Diffuse large B-cell lymphoma (DLBCL) is the most common category and disease entity of non-Hodgkin lymphoma. Osalmide and pterostilbene are natural products with anticancer activities via different mechanism. In this study, using a new synthetic strategy for the two natural products, we obtained the compound DCZ0801, which was previously found to have anti-multiple myeloma activity. We performed both in vitro and in vivo assays to investigate its bioactivity and explore its underlying mechanism against DLBCL cells. The results showed that DCZ0801 treatment gave rise to a dose- and time-dependent inhibition of cell viability as determined by CCK-8 assay and flow cytometry assay. Western blot analysis results showed that the expression of caspase-3, caspase-8, caspase-9 and Bax was increased, while BCL-2 and BCL-XL levels were decreased, which suggested that DCZ0801 inhibited cell proliferation and promoted intrinsic apoptosis. In addition, DCZ0801 induced G0/G1 phase arrest by downregulating the protein expression levels of CDK4, CDK6 and cyclin D1. Furthermore, DCZ0801 exerted an anti-tumor effect by down-regulating the expressions of p-PI3K and p-AKT. There also existed a trend that the expression of p-JNK and p-P38 was restrained. Intraperitoneal injection of DCZ0801 suppressed tumor development in xenograft mouse models. The preliminary metabolic study showed that DCZ0801 displayed a rapid metabolism within 30 min. These results demonstrated that DCZ0801 may be a new potential anti-DLBCL agent in DLBCL therapy.

CRISPR/Cas9-Mediated Foxp1 Silencing Restores Immune Surveillance in an Immunocompetent A20 Lymphoma Model

The interaction of lymphoma cells with their microenvironment has an important role in disease pathogenesis and is being actively pursued therapeutically using immunomodulatory drugs, including immune checkpoint inhibitors. Diffuse large B-cell lymphoma (DLBCL) is an aggressive high-grade disease that remains incurable in ~40% of patients treated with R-CHOP immunochemotherapy. The FOXP1 transcription factor is abundantly expressed in such high-risk DLBCL and we recently identified its regulation of immune response signatures, in particular, its suppression of the cell surface expression of major histocompatibility class II (MHC-II), which has a critical role in antigen presentation to T cells. Using CRISPR/Cas9 genome editing we have depleted Foxp1 expression in the aggressive murine A20 lymphoma cell line. When grown in BALB/c mice, this cell line provides a high-fidelity immunocompetent disseminated lymphoma model that displays many characteristics of human DLBCL. Transient Foxp1-depletion using siRNA, and stable depletion using CRISPR (generated by independently targeting Foxp1 exon six or seven) upregulated cell surface I-Ab (MHC-II) expression without impairing cell viability in vitro. RNA sequencing of Foxp1-depleted A20 clones identified commonly deregulated genes, such as the B-cell marker Cd19, and hallmark DLBCL signatures such as MYC-targets and oxidative phosphorylation. Immunocompetent animals bearing Foxp1-depleted A20 lymphomas showed significantly-improved survival, and 20% did not develop tumors; consistent with modulating immune surveillance, this was not observed in immunodeficient NOD SCIDγ mice. The A20 Foxp1 CRISPR model will help to further characterize the contribution of Foxp1 to lymphoma immune evasion and the potential for Foxp1 targeting to synergize with other immunotherapies.

New Insights on the Emerging Genomic Landscape of CXCR4 in Cancer: A Lesson from WHIM

Deciphering the molecular alterations leading to disease initiation and progression is currently crucial to identify the most relevant targets for precision therapy in cancer patients. Cancers express a complex chemokine network influencing leucocyte infiltration and angiogenesis. Moreover, malignant cells also express a selective repertoire of chemokine receptors that sustain their growth and spread. At present, different cancer types have been shown to overexpress C-X-C chemokine receptor type 4 (CXCR4) and to respond to its ligand C-X-C motif chemokine 12 (CXCL12). The CXCL12/CXCR4 axis influences cancer biology, promoting survival, proliferation, and angiogenesis, and plays a pivotal role in directing migration of cancer cells to sites of metastases, making it a prognostic marker and a therapeutic target. More recently, mutations in the C-terminus of CXCR4 have been identified in the genomic landscape of patients affected by Waldenstrom's macroglobulinemia, a rare B cell neoplasm. These mutations closely resemble those occurring in Warts, Hypogammaglobulinemia, Immunodeficiency, and Myelokathexis (WHIM) syndrome, an immunodeficiency associated with CXCR4 aberrant expression and activity and with chemotherapy resistance in clinical trials. In this review, we summarize the current knowledge on the relevance of CXCR4 mutations in cancer biology, focusing on its importance as predictors of clinical presentation and response to therapy.

Avadomide monotherapy in relapsed/refractory DLBCL: safety, efficacy, and a predictive gene classifier

Treatment options for relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) are limited, with no standard of care; prognosis is poor, with 4- to 6-month median survival. Avadomide (CC-122) is a cereblon-modulating agent with immunomodulatory and direct antitumor activities. This phase 1 dose-expansion study assessed safety and clinical activity of avadomide monotherapy in patients with de novo R/R DLBCL and transformed lymphoma. Additionally, a novel gene expression classifier, which identifies tumors with a high immune cell infiltration, was shown to enrich for response to avadomide in R/R DLBCL. Ninety-seven patients with R/R DLBCL, including 12 patients with transformed lymphoma, received 3 to 5 mg avadomide administered on continuous or intermittent schedules until unacceptable toxicity, disease progression, or withdrawal. Eighty-two patients (85%) experienced ≥1 grade 3/4 treatment-emergent adverse events (AEs), most commonly neutropenia (51%), infections (24%), anemia (12%), and febrile neutropenia (10%). Discontinuations because of AEs occurred in 10% of patients. Introduction of an intermittent 5/7-day schedule improved tolerability and reduced frequency and severity of neutropenia, febrile neutropenia, and infections. Among 84 patients with de novo R/R DLBCL, overall response rate (ORR) was 29%, including 11% complete response (CR). Responses were cell-of-origin independent. Classifier-positive DLBCL patients (de novo) had an ORR of 44%, median progression-free survival (mPFS) of 6 months, and 16% CR vs an ORR of 19%, mPFS of 1.5 months, and 5% CR in classifier-negative patients (P = .0096). Avadomide is being evaluated in combination with other antilymphoma agents. This trial was registered at www.clinicaltrials.gov as #NCT01421524.

PDGFD induces ibrutinib resistance of diffuse large B‑cell lymphoma through activation of EGFR

Ibrutinib, an FDA approved, orally administered BTK inhibitor, has demonstrated high response rates to diffuse large B-cell lymphoma (DLBCL), however, complete responses are infrequent and acquired resistance to BTK inhibition can emerge. The present study investigated the role of the platelet-derived growth factor D (PDGFD) gene and the ibrutinib resistance of DLBCL in relation to epidermal growth factor receptor (EGFR). Bioinformatics was used to screen and analyze differentially expressed genes (DEGs) in complete response (CR), partial response (PR) and stable disease (SD) in DLBCL treatment with ibrutinib, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to analyze enriched the signaling pathways increasing DEGs. The Search Tool for Interactions of Chemicals database was used to analyze the target genes of ibrutinib. An interaction network of DEGs, disease-related genes and ibrutinib was constructed. The expression of PDGFD in tissues that were resistant or susceptible to DLBCL/ibrutinib was detected via immunohistochemistry (IHC), and the expression of PDGFD in DLBCL/ibrutinib-resistant strains and their parental counterparts were examined via reverse transcription-quantitative PCR and western blot analyses. Subsequently, a drug-resistant cell model of DLBCL/ibrutinib in which PDGFD was silenced was constructed. The apoptosis of the DLBCL/ibrutinib-resistant strains was examined using MTT and flow cytometry assays. EGFR gene expression was then assessed. At the same time, a PDGFD-interfering plasmid and an EGFR overexpression plasmid were transfected into the DLBCL drug-resistant cells (TMD8-ibrutinib, HBL1-ibrutinib) separately or together. MTT was used to measure cell proliferation and changes in the IC₅₀ of ibrutinib. A total of 86 DEGs that increased in the CR, PR and SD tissues were screened, and then evaluated with GO and KEGG. The interaction network diagram showed that there was a regulatory relationship between PDGFD and disease-related genes, and that PDGFD could indirectly target the ibrutinib target gene EGFR, indicating that PDGFD could regulate DLBCL via EGFR. IHC results showed high expression of PDGFD in diffuse large B-cell lymphoma tissues with ibrutinib tolerance. PDGFD expression in ibrutinib-resistant DLBCL cells was higher compared with in parental cells. Following interference with PDGFD expression in ibrutinib-resistant DLBCL cells, the IC₅₀ value of ibrutinib decreased, the rate of apoptosis increased and EGFR expression decreased. In brief, EGFR overexpression can reverse the resistance of DLBCL to ibrutinib via PDGFD interference, and PDGFD induces the resistance of DLBCL to ibrutinib via EGFR.

Artificial Intelligence-Driven Structurization of Diagnostic Information in Free-Text Pathology Reports

BACKGROUND

Free-text sections of pathology reports contain the most important information from a diagnostic standpoint. However, this information is largely underutilized for computer-based analytics. The vast majority of NLP-based methods lack a capacity to accurately extract complex diagnostic entities and relationships among them as well as to provide an adequate knowledge representation for downstream data-mining applications.

METHODS

In this paper, we introduce a novel informatics pipeline that extends open information extraction (openIE) techniques with artificial intelligence (AI) based modeling to extract and transform complex diagnostic entities and relationships among them into Knowledge Graphs (KGs) of relational triples (RTs).

RESULTS

Evaluation studies have demonstrated that the pipeline's output significantly differs from a random process. The semantic similarity with original reports is high (Mean Weighted Overlap of 0.83). The precision and recall of extracted RTs based on experts' assessment were 0.925 and 0.841 respectively (P <0.0001). Inter-rater agreement was significant at 93.6% and inter-rated reliability was 81.8%.

CONCLUSION

The results demonstrated important properties of the pipeline such as high accuracy, minimality and adequate knowledge representation. Therefore, we conclude that the pipeline can be used in various downstream data-mining applications to assist diagnostic medicine.

Single-Dose Pharmacokinetics, Safety, and Tolerability of Avadomide (CC-122) in Subjects With Mild, Moderate, or Severe Renal Impairment

CC-122 (Avadomide) is a nonphthalimide analogue of thalidomide that has multiple pharmacological activities including immune modulation of several immune cell subsets, antigrowth activity, antiproliferative activity, and antiangiogenic activity. CC-122 as monotherapy and in combination with other agents is being evaluated for multiple indications including hematologic malignancies and advanced solid tumors. Given that renal clearance is one of the major routes of elimination for CC-122 and its clearance/exposure could be affected by renal impairment, a total of 50 subjects with various degrees of renal function were enrolled in an open-label, single-dose study to evaluate the impact of renal impairment on CC-122 pharmacokinetic disposition. The study showed that following administration of a single oral dose of 3 mg CC-122, renal impairment reduced both the apparent total plasma clearance and renal clearance of CC-122, but it had less impact on CC-122 absorption, as demonstrated by similar T_max and C_max among groups with various degrees of renal function. Compared with exposure in subjects with normal renal function, total plasma exposure to CC-122 increased by ∼20%, ∼50%, and ∼120% in subjects with mild, moderate, and severe renal insufficiency, respectively. Results from this study combined with modeling/simulation suggest that dose adjustments are necessary in patients with moderate or severe but not with mild renal impairment. Finally, a single dose of 3 mg CC-122 was safe and well tolerated by healthy subjects and subjects with mild, moderate, and severe renal impairment.

Proteasomal cysteine deubiquitinase inhibitor b-AP15 suppresses migration and induces apoptosis in diffuse large B cell lymphoma

BACKGROUND

The first line therapy for patients with diffuse large B cell (DLBCL) is R-CHOP. About half of DLBCL patients are either refractory to, or will relapse, after the treatment. Therefore, identifying novel drug targets and effective therapeutic agents is urgently needed for improving DLBCL patient survival. b-AP15, a selective small molecule inhibitor of proteasomal USP14 and UCHL5 deubiquitinases (DUBs), has shown selectivity and efficacy in several other types of cancer cells. This is the first study to report the effect of b-AP15 in DLBCL.

METHODS

Cell lines of two DLBCL subtypes, Germinal Center B Cell/ GCB (SU-DHL-4, OCI-LY-1, OCI-LY-19) and Activated B Cell/ABC (SU-DHL-2), were used in the current study. Cell viability was measured by MTS assay, proliferation by trypan blue exclusion staining assay, cellular apoptosis by Annexin V-FITC/PI staining and mitochondrial outer membrane permeability assays, the activities of 20S proteasome peptidases by cleavage of specific fluorogenic substrates, and cell migration was detected by transwell assay in these GCB- and ABC-DLBCL cell lines. Mouse xenograft models of SU-DHL-4 and SU-DHL-2 cells were used to determine in vivo effects of b-AP15 in DLBCL tumors.

RESULTS

b-AP15 inhibited proteasome DUB activities and activated cell death pathway, as evident by caspase activation and mitochondria apoptosis in GCB- and ABC- DLBCL cell lines. b-AP15 treatment suppressed migration of GCB- and ABC-DLBCL cells via inhibiting Wnt/β-catenin and TGFβ/Smad pathways. Additionally, b-AP15 significantly inhibited the growth of GCB- and ABC DLBCL in xenograft models.

CONCLUSIONS

These results indicate that b-AP15 inhibits cell migration and induces apoptosis in GCB- and ABC-DLBCL cells, and suggest that inhibition of 19S proteasomal DUB should be a novel strategy for DLBCL treatment.

An Engineered Fusion Protein Anti-CD19(Fab)-LDM Effectively Inhibits ADR-Resistant B Cell Lymphoma

The 5-year survival rate of patients with B cell lymphoma is about 50% after initial diagnosis, mainly because of resistance to chemotherapy. Hence, it is necessary to understand the mechanism of chemo-resistance and to explore novel methods to circumvent multidrug resistance. Previously, we showed that an engineered cytotoxic fusion protein anti-CD19(Fab)-LDM (lidamycin), can induce apoptosis of B-lymphoma cells. Herein, we successfully established an adriamycin (ADR)-resistant B cell lymphoma cell line BJAB/ADR. The mRNA and protein level of ATP-binding cassette subfamily B member 1 (ABCB1) were significantly overexpressed in BJAB/ADR cells. Increased efflux function of ABCB1 was observed by analyzing intracellular accumulation and efflux of Rhodamine 123. The efflux of Rhodamine 123 could be significantly ameliorated by verapamil. Treatment with anti-CD19(Fab)-LDM at different concentrations induced cytotoxic response of BJAB/ADR cells similar to that of the sensitive cells. In vivo studies showed that anti-CD19(Fab)-LDM had better antitumor effect in BJAB and BJAB/ADR cell lymphoma xenografts compared with ADR or LDM treatment alone. Taken together, anti-CD19(Fab)-LDM can effectively inhibit the growth of BJAB/ADR cells both in vitro and in vivo. Anti-CD19(Fab)-LDM could be a promising molecule for the treatment of drug resistant cancers.

Application of NanoString technologies in companion diagnostic development

Introduction: NanoString nCounter technology, a novel molecular assay, is gaining prevalent use in clinical settings as it can overcome some common constraints that are associated with the use of polymerase chain reaction (PCR). Compared to PCR, NanoString technology does not involve any amplification steps, which significantly minimizes the chance of contamination. NanoString measures the number of mRNA transcripts directly by 'molecular counting', as up to 800 colored probes can be run simultaneously in a single reaction. Areas covered: This manuscript reviews the principle of NanoString and covers the main applications of NanoString in companion diagnostics with a focus on cancer immunotherapy and disease prognosis estimation. This review has also taken a step in the direction of personalized medicine, with the application of NanoString on the realm of companion diagnostics. Expert opinion: NanoString is going to take a vital role in companion diagnostics and personalized medicine, owing to its simple and easy to use characteristics. Yet, the use of NanoString requires normalization of expression level, which is represented by the copy number of respective mRNA, with a reference gene. Furthermore, difficulty in probe design, which demands prior knowledge of known sequence, has also been a limitation of NanoString.

Identification and characterization of a murine model of BCR‑ABL1+ acute B‑lymphoblastic leukemia with central nervous system metastasis

Breakpoint cluster region (BCR)-Abelson murine leukemia (ABL)1⁺ acute B-lymphoblastic leukemia (B-ALL) is a disease associated with a dismal prognosis and a high incidence of central nervous system (CNS) metastasis. However, BCR-ABL1⁺ B-ALL with CNS infiltration has not been previously characterized, at least to the best of our knowledge. In the present study, a murine model of BCR-ABL1⁺ B-ALL with CNS metastasis was established using retroviral transduction. The vast majority of BCR-ABL1⁺ leukemic cells were found to be immature B cells with a variable proportion of pro-B and pre-B populations. The present results indicated that the BCR-ABL1⁺ B-leukemic cells expressed high levels integrin subunit alpha 6 (Itga6) and L-selectin adhesion molecules, and have an intrinsic ability to disseminate and accumulate in CNS tissues, predominantly in meninges. On the whole, these results provide an approach for addressing the mechanisms of BCR-ABL1⁺ B-ALL with CNS metastasis and may guide the development of novel therapeutic strategies.

C-X-C Chemokine Receptor 4 in Diffuse Large B Cell Lymphoma: Achievements and Challenges

Diffuse large B cell lymphoma (DLBCL), an aggressive cancer of the B cells, is the most common subtype of non-Hodgkin lymphoma (NHL) worldwide. In China, the cases of DLBCL increase yearly. C-X-C chemokine receptor 4 (CXCR4) has been implicated in the migration and trafficking of malignant B cells in several hematological malignancies, and only a few reports have been published on the role of CXCR4 in the metastasis of DLBCL. This review summarizes the relevant perspectives on the functional mechanism, prognostic significance, and therapeutic applications of the CXCL12/CXCR4 axis in DLBCL, in particular DLBCL with bone marrow involvement.

Anti-CD19 CAR T-Cell Therapy for Adult Patients With Refractory Large B-Cell Lymphoma

Chimeric antigen receptor (CAR) T-cell therapies represent a new paradigm in targeted cancer therapy. T cells play a key role in immune surveillance, but tumors have developed multiple mechanisms for evading that surveillance. CAR T-cell technology aims to enhance the innate ability of the body to fight foreign invaders, and in this way, effectively fight cancer and potentially reduce the number of treatments required. In fact, many patients have had long-lasting clinical responses to therapy with a single treatment. The journey to receiving CAR T-cell therapy involves a number of steps prior to infusion, including an initial consultation and workup, apheresis, bridging therapy, and lymphodepletion. Patients are then closely monitored after infusion. Successful treatment requires collaboration between the patient, caregivers, and the multidisciplinary team. Here we discuss the biology of CAR T-cell technology, clinical trial data, and the path to accessing this revolutionary and potentially curative treatment.

Valproate in combination with rituximab and CHOP as first-line therapy in diffuse large B-cell lymphoma (VALFRID)

The aims of the present study were to establish the maximally tolerated dose (MTD) of the histone deacetylase inhibitor valproate together with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) in patients with diffuse large B-cell lymphoma (DLBCL). A phase 1 dose escalation study of valproate together with R-CHOP followed by a dose expansion study using the established MTD of valproate was performed. MTD of valproate together with R-CHOP was established at 60 mg/kg per day, as higher doses resulted in auditory adverse events (AEs). In the study population, 2-year progression-free survival was 84.7% (95% confidence interval [CI], 73.2%-98%). The 2-year overall survival (OS) was 96.8% (n = 31; 95% CI, 90.8%-100%). These data were compared with 2 risk-factor matched populations of R-CHOP-treated patients from the Swedish Lymphoma Registry (cohort A, n = 330 and B, n = 165). As compared with the matched cohorts, we observed a statistically significant (P = .034 and 0.028, respectively) beneficial effect of the addition of valproate to R-CHOP on the OS in the studied population. In conclusion, addition of valproate to R-CHOP is a feasible strategy in first-line treatment of DLBCL. The proposed phase 2 dose is 60 mg/kg per day together with prednisone. Auditory AEs were unexpected and warrant close monitoring. Our findings suggest that drugs that target histone deacetylation may add benefit and are tolerable when combined with standard R-CHOP in DLBCL. The phase 1 trial was registered at www.clinicaltrials.gov as #NCT01622439.

L-Type Cav 1.2 Calcium Channel-α-1C Regulates Response to Rituximab in Diffuse Large B-Cell Lymphoma

PURPOSE

One third of patients with diffuse large B-cell lymphoma (DLBCL) succumb to the disease partly due to rituximab resistance. Rituximab-induced calcium flux is an important inducer of apoptotic cell death, and we investigated the potential role of calcium channels in rituximab resistance.

EXPERIMENTAL DESIGN

The distinctive expression of calcium channel members was compared between patients sensitive and resistant to rituximab, cyclophosphamide, vincristine, doxorubicin, prednisone (RCHOP) regimen. The observation was further validated through mechanistic in vitro and in vivo studies using cell lines and patient-derived xenograft mouse models.

RESULTS

A significant inverse correlation was observed between CACNA1C expression and RCHOP resistance in two independent DLBCL cohorts, and CACNA1C expression was an independent prognostic factor for RCHOP resistance after adjusting for International Prognostic Index, cell-of-origin classification, and MYC/BCL2 double expression. Loss of CACNA1C expression reduced rituximab-induced apoptosis and tumor shrinkage. We further demonstrated direct interaction of CACNA1C with CD20 and its role in CD20 stabilization. Functional modulators of L-type calcium channel showed expected alteration in rituximab-induced apoptosis and tumor suppression. Furthermore, we demonstrated that CACNA1C expression was directly regulated by miR-363 whose high expression is associated with worse prognosis in DLBCL.

CONCLUSIONS

We identified the role of CACNA1C in rituximab resistance, and modulating its expression or activity may alter rituximab sensitivity in DLBCL.

Inhibition of the PI3K/AKT signaling pathway sensitizes diffuse large B-cell lymphoma cells to treatment with proteasome inhibitors via suppression of BAG3

Proteasome inhibitors represent a novel class of drugs that have clinical efficacy against hematological and solid cancer types, including acute myeloid leukaemia, myelodysplastic syndrome an non-small cell lung cancer. It has been demonstrated that the anti-apoptotic protein B-cell lymphoma-2-associated athanogene 3 (BAG3) is induced by proteasome inhibitors in various cancer cells and serves an important role in chemotherapy resistance. The phosphatidylinositol 3-kinase (PI3K)/RAC-α serine/threonine-protein kinase (AKT) pathway is constitutively activated in a number of lymphoid malignancy types, including diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma. In the present study, the aim was to elucidate the role of the PI3K/AKT signaling pathway in the induction of BAG3, following exposure to a proteasome inhibitor in DLBCL cell lines. Bortezomib and MG132 were used as proteasome inhibitors. Western blotting was used to evaluate the roles of proteasome inhibitors and the PI3K/AKT pathway in BAG3 induction in DLBCL cells (LY1 and LY8), and LY294002 was used to block the PI3K/AKT pathway. Cell viability was detected using a Cell Counting Kit-8 assay. Apoptosis of LY1 and LY8 cells was quantified by Annexin V/7-amino-actinomycin D flow cytometry. The BAG3 protein was markedly induced upon exposure to bortezomib and MG132 in a dose-dependent manner. The PI3K/AKT inhibitor LY294002 significantly suppressed the induction of BAG3 by proteasome inhibitors. Inhibition of the PI3K/AKT pathway decreased the proliferation and increased the apoptosis induced by proteasome inhibitors. The present results indicated that the PI3K/AKT pathway is associated with the activation of BAG3 expression in DLBCL cells, and is involved in the protective response against proteasome inhibition.

Sleeping Beauty Screen Identifies RREB1 and Other Genetic Drivers in Human B-cell Lymphoma

Follicular lymphoma and diffuse large B-cell lymphoma (DLBCL) are the most common non-Hodgkin lymphomas distinguishable by unique mutations, chromosomal rearrangements, and gene expression patterns. Here, it is demonstrated that early B-cell progenitors express 2',3'-cyclic-nucleotide 3' phosphodiesterase (CNP) and that when targeted with Sleeping Beauty (SB) mutagenesis, Trp53R270H mutation or Pten loss gave rise to highly penetrant lymphoid diseases, predominantly follicular lymphoma and DLBCL. In efforts to identify the genetic drivers and signaling pathways that are functionally important in lymphomagenesis, SB transposon insertions were analyzed from splenomegaly specimens of SB-mutagenized mice (n = 23) and SB-mutagenized mice on a Trp53R270H background (n = 7) and identified 48 and 12 sites with statistically recurrent transposon insertion events, respectively. Comparison with human data sets revealed novel and known driver genes for B-cell development, disease, and signaling pathways: PI3K-AKT-mTOR, MAPK, NFκB, and B-cell receptor (BCR). Finally, functional data indicate that modulating Ras-responsive element-binding protein 1 (RREB1) expression in human DLBCL cell lines in vitro alters KRAS expression, signaling, and proliferation; thus, suggesting that this proto-oncogene is a common mechanism of RAS/MAPK hyperactivation in human DLBCL. IMPLICATIONS: A forward genetic screen identified new genetic drivers of human B-cell lymphoma and uncovered a RAS/MAPK-activating mechanism not previously appreciated in human lymphoid disease. Overall, these data support targeting the RAS/MAPK pathway as a viable therapeutic target in a subset of human patients with DLBCL.

CXCR4 and CCR7 Expression in Primary Nodal Diffuse Large B-Cell Lymphoma-A Clinical and Immunohistochemical Study

BACKGROUND

A few studies have evaluated the expression of chemokine receptors CXCR4 and CCR7 in diffuse large B-cell lymphoma (DLBCL); however, the association between CXCR4 and CCR7 with bone marrow (BM) involvement and their synergistic effect on prognosis is still unclear. Our study investigated this aspect.

METHODS

Specimens were obtained from 61 primary nodal DLBCL patients and 100 reactive proliferative lymphadenitis patients. CXCR4 and CCR7 expression levels were examined by immunohistochemical staining; the relationship between these levels and clinical parameters and the differences in overall survival were analyzed.

RESULTS

CXCR4 and CCR7 overexpression was observed in the malignant lymph node tissues from most DLBCL patients. CCR7 expression was significantly higher in the non-GCB than the GCB subtype; CXCR4 positivity rates showed no significant difference between the 2 subtypes. In DLBCL patients with BM involvement, CXCR4 was overexpressed in almost all BM samples, but CCR7 expression was low in BM. CXCR4 overexpression was associated with advanced Ann Arbor stages, MYC overexpression, and increased extranodal infiltration; CCR7 was associated with advanced Ann Arbor stages and elevated LDH. Like the case for CCR7, the survival rate of CXCR4-positive DLBCL patients was significantly lower than that of the CXCR4-negative patients. CXCR4⁺CCR7⁺ patients had the lowest survival rate.

CONCLUSIONS

There is a positive correlation between CXCR4 overexpression and BM involvement. CXCR4 and CCR7 overexpression is associated with poorer overall survival, especially in CXCR4 and CCR7 copositive patients. CXCR4, CCR7, Ki-67 index, and MYC were independent prognostic factors for DLBCL. Blocking CXCR4 and/or CCR7 can be a novel therapeutic strategy for DLBCL.

Dissecting diffuse large B-cell lymphomas of the "not otherwise specified" type: the impact of molecular techniques

The updated edition of the Classification of Tumours of Haematopoietic and Lymphoid Tissues, published in September 2017 by the World Health Organization (WHO), presents many important changes to the document published in 2008. Most of these novelties are linked to the exceptional development of biomolecular techniques during the last 10 years. To illustrate how much new technologies have contributed to the better classification of single entities, as well as the discovery of new ones, would go beyond the objectives of this work. For this reason, we will take diffuse large B-cell lymphoma as an example of the cognitive improvement produced by high-yield technologies (such as the gene expression profile, the study of copy number variation, and the definition of the mutational spectrum). The acquisition of this knowledge not only has a speculative value but also represents the elements for effective application in daily practice. On the one hand, it would allow the development of personalised therapy programs, and on the other it would promote the transition from the bench of the researcher's laboratory to the patient's bedside.

Phase 2 Study of Daratumumab in Relapsed/Refractory Mantle-Cell Lymphoma, Diffuse Large B-Cell Lymphoma, and Follicular Lymphoma

BACKGROUND

Daratumumab is a CD38 monoclonal antibody approved for treating relapsed/refractory and newly diagnosed multiple myeloma. Preclinical daratumumab studies demonstrated cytotoxic activity and reduced tumor growth in B-cell non-Hodgkin lymphoma (NHL) subtypes, including diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), and mantle-cell lymphoma (MCL).

PATIENTS AND METHODS

This was a phase 2, open-label, multicenter, 2-stage trial. Patients with relapsed/refractory DLBCL, FL, or MCL with ≥ 50% CD38 expression were eligible for stage 1. Daratumumab (16 mg/kg; 28-day cycles) was administered intravenously weekly for 2 cycles, every 2 weeks for 4 cycles, and every 4 weeks thereafter. Overall response rate was the primary end point. Pharmacokinetic and safety were also evaluated. Stage 2 was planned to further assess daratumumab in larger populations of NHL subtypes if futility criteria were not met. The study was registered with ClinicalTrials.gov (NCT02413489).

RESULTS

The trial screened 138 patients resulting in accrual of 15 patients with DLBCL, 16 with FL, and 5 with MCL. Median CD38 expression across treated patients was 70%. Overall response rate was 6.7%, 12.5%, and not evaluable in DLBCL, FL, and MCL cohorts, respectively. The most common grade 3/4 treatment-emergent adverse event was thrombocytopenia (11.1%), and 4 (11.1%) patients discontinued treatment because of treatment-emergent adverse events. Infusion-related reactions occurred in 72.2% of patients (3 patients with grade 3; no grade 4).

CONCLUSION

In NHL, the safety and pharmacokinetics of daratumumab were consistent with myeloma studies. Screen-fail rates were high, prespecified futility thresholds were met in 2 cohorts, and the study was terminated. Studies in other hematologic malignancies and amyloidosis are ongoing.

Identification of a novel PDGFRA point mutation at p.P6L as a potential molecular target of imatinib in an eosinophilia patient showing genetic heterogeneity

Eosinophilia is a severe disease with increased eosinophil count. The transcript of FIP1L1-PDGFRA fusion gene is a genetic biomarker of clonal eosinophilia screened routinely by reverse transcript PCR (RT-PCR) during diagnosis. Another significant genetic biomarker is the PDGFRA gene alone as some of its mutations are targets of imatinib. In this study, we identified a patient who had typical symptoms of Eosinophilia but had no response to the first-line treatment of hormonotherapy. This patient also showed bone rupture and eosinophil bone infiltration, which are extremely rare among all known eosinophilia patients. We identified the FIP1L1-PDGFRA fusion gene via RT-PCR and Sanger sequencing. Using next generation sequencing (NGS), we detected point mutations in PDGFRA, MYOM2, and ASXL3. The patient then received imatinib therapy, leading to the complete disappearance of FIP1L1-PDGFRA fusion gene and mutated MYOM2. The level of PDGFRA point mutation was also decreased from pre-treatment: 57.86% down to 42.99% at 6 months and to 38.80% at one-year after treatment. The level of ASXL3 mutations did not change significantly. To the best of our knowledge, this is the first case in which the point mutation of PDGFRA has been identified at p.P6L in exon 2, likely making it sensitive to imatinib and thus should be further studied as a potential new molecular target of imatinib therapy.

Effect of mechanistic target of rapamycin inhibitors on postrenal transplantation malignancy: A nationwide cohort study

BACKGROUND

Post-transplantation malignancy influenced graft survival and overall survival in the patients receiving renal transplantation. Immunosuppressants influenced the immune surveillance, but whether immunosuppressive agents have impact for incidence of post-transplantation malignancy is still elusive in Taiwan.

METHOD

We conducted a nationwide population-based study. Patients who did not have malignancy history and received kidney transplantation between 2000 and 2010 were enrolled. Specific immunosuppressive users are defined as sustained use (more than 12 months) after renal transplantation. The primary outcome is the development of cancer after kidney transplantation. A Cox proportional hazards model was used to determine the risk of cancer development.

RESULT

Among 4438 recipients, 559 of them were diagnosed with malignancy after 1 year of transplantation. A total of 742 of recipients were as user of mechanistic target of rapamycin (mTOR) inhibitors. The mTOR users had higher rate of receiving pulse therapy. The hazard ratios (HR) for mTOR inhibitor users with exposure more than 5 years for overall malignancy and urothelial malignancy were 0.68 (95% CI: 0.48-0.95, P = 0.02) and 0.60 (95% CI: 0.36-0.99, P = 0.02), respectively. For the overall mortality and reentry of dialysis, the probability of both groups was similar (overall mortality: P = 0.53; reentry of dialysis: P = 0.77).

CONCLUSION

Among the recipients of renal transplantation in Taiwan, mTOR inhibitors with exposure more than 5 years provided a protective role in reducing the risk of overall neoplasm and urothelial malignancy. The probability of reentry of dialysis and overall mortality was similar between the mTORi users and nonusers.

Chemical modulation of transcription factors

Transcription factors (TFs) constitute a diverse class of sequence-specific DNA-binding proteins, which are key to the modulation of gene expression. TFs have been associated with human diseases, including cancer, Alzheimer's and other neurodegenerative diseases, which makes this class of proteins attractive targets for chemical biology and medicinal chemistry research. Since TFs lack a common binding site or structural similarity, the development of small molecules to efficiently modulate TF biology in cells and in vivo is a challenging task. This review highlights various strategies that are currently being explored for the identification and development of modulators of Myc, p53, Stat, Nrf2, CREB, ER, AR, HIF, NF-κB, and BET proteins.

"Triple hit" lymphomas: A retrospective cytology case series of an uncommon high grade B-cell malignancy with C-MYC, BCL-2 and BCL-6 rearrangements

The Revised fourth Edition World Health Organization (WHO) Classification of Tumors of Hematopoietic and Lymphoid Tissues suggests novel categories, including "high grade B-cell lymphoma with MYC and BCL2 and BCL6 gene rearrangements." These diseases are known colloquially as "double hit" and "triple hit" lymphomas. The "first-hit" in these cases is the harboring of a MYC rearrangement. Concurrent derangements of BCL2 and BCL6 can be the "second-hit" or "third-hit." To our knowledge, this is the first report of "triple-hit" lymphomas in cytology specimens. The files of the Cleveland Clinic (January 2007 through December 2017) were searched for all "triple hit" lymphomas. Four cases met inclusion criteria (cytology slides in files and histologically confirmed "triple hit" lymphoma). All slides were reviewed. The mean age was 65 years, with a male predominance. All patients presented at advanced stage and showed progressive disease despite therapy. FISH studies (histologic sections) confirmed translocations of MYC (8q24), BCL2 (18q21) and BCL6 (3q27) in all patients. All cases were characterized by high cellularity, dispersed cells, presence of stripped nuclei, lymphoglandular bodies, apoptotic bodies, cytomegaly, nucleomegaly, nuclear envelope irregularities, macronucleoli (most often single), recognizable mitoses and presence of cytoplasmic vacuoles (variable). The WHO recommends that all large B-cell lymphomas be investigated using cytogenetic or molecular techniques. Concurrent inhibition of MYC and BCL2 is a potentially effective treatment strategy for triple hit lymphomas, and an expanding literature exists regarding predictive biomarkers and therapeutic regimens. It is our intention to raise awareness of this uncommon mature B-cell neoplasm within the cytodiagnostic community.

Expression of ribosomal and actin network proteins and immunochemotherapy resistance in diffuse large B cell lymphoma patients

Diffuse large B cell lymphoma (DLBCL) patients with early relapse or refractory disease have a very poor outcome. Immunochemotherapy resistance will probably, also in the era of targeted drugs, remain the major cause of treatment failure. We used proteomic mass spectrometry to analyse the global protein expression of micro-dissected formalin-fixed paraffin-embedded tumour tissues from 97 DLBCL patients: 44 with primary refractory disease or relapse within 1 year from diagnosis (REF/REL), and 53 who were progression-free more than 5 years after diagnosis (CURED). We identified 2127 proteins: 442 were found in all patients and 102 were differentially expressed. Sixty-five proteins were overexpressed in REF/REL patients, of which 46 were ribosomal proteins (RPs) compared with 2 of the 37 overexpressed proteins in CURED patients (P = 7·6 × 10^-10 ). Twenty of 37 overexpressed proteins in CURED patients were associated with actin regulation, compared with 1 of 65 in REF/REL patients (P = 1·4 × 10^-9 ). Immunohistochemical staining showed higher expression of RPS5 and RPL17 in REF/REL patients while MARCKS-like protein, belonging to the actin network, was more highly expressed in CURED patients. Even though functional studies aimed at individual proteins and protein interactions to evaluate potential clinical effect are needed, our findings suggest new mechanisms behind immunochemotherapy resistance in DLBCL.

CD20-TCB with Obinutuzumab Pretreatment as Next-Generation Treatment of Hematologic Malignancies

Purpose: Despite promising clinical activity, T-cell-engaging therapies including T-cell bispecific antibodies (TCB) are associated with severe side effects requiring the use of step-up-dosing (SUD) regimens to mitigate safety. Here, we present a next-generation CD20-targeting TCB (CD20-TCB) with significantly higher potency and a novel approach enabling safer administration of such potent drug.Experimental Design: We developed CD20-TCB based on the 2:1 TCB molecular format and characterized its activity preclinically. We also applied a single administration of obinutuzumab (Gazyva pretreatment, Gpt; Genentech/Roche) prior to the first infusion of CD20-TCB as a way to safely administer such a potent drug.Results: CD20-TCB is associated with a long half-life and high potency enabled by high-avidity bivalent binding to CD20 and head-to-tail orientation of B- and T-cell-binding domains in a 2:1 molecular format. CD20-TCB displays considerably higher potency than other CD20-TCB antibodies in clinical development and is efficacious on tumor cells expressing low levels of CD20. CD20-TCB also displays potent activity in primary tumor samples with low effector:target ratios. In vivo, CD20-TCB regresses established tumors of aggressive lymphoma models. Gpt enables profound B-cell depletion in peripheral blood and secondary lymphoid organs and reduces T-cell activation and cytokine release in the peripheral blood, thus increasing the safety of CD20-TCB administration. Gpt is more efficacious and safer than SUD.Conclusions: CD20-TCB and Gpt represent a potent and safer approach for treatment of lymphoma patients and are currently being evaluated in phase I, multicenter study in patients with relapsed/refractory non-Hodgkin lymphoma (NCT03075696). Clin Cancer Res; 24(19); 4785-97. ©2018 AACR See related commentary by Prakash and Diefenbach, p. 4631.

The tumor suppressive TGF-β/SMAD1/S1PR2 signaling axis is recurrently inactivated in diffuse large B-cell lymphoma

The sphingosine-1-phosphate receptor S1PR2 and its downstream signaling pathway are commonly silenced in diffuse large B-cell lymphoma (DLBCL), either by mutational inactivation or through negative regulation by the oncogenic transcription factor FOXP1. In this study, we examined the upstream regulators of S1PR2 expression and have newly identified the transforming growth factor-β (TGF-β)/TGF-βR2/SMAD1 axis as critically involved in S1PR2 transcriptional activation. Phosphorylated SMAD1 directly binds to regulatory elements in the S1PR2 locus as assessed by chromatin immunoprecipitation, and the CRISPR-mediated genomic editing of S1PR2, SMAD1, or TGFBR2 in DLBCL cell lines renders cells unresponsive to TGF-β-induced apoptosis. DLBCL clones lacking any 1 of the 3 factors have a clear growth advantage in vitro, as well as in subcutaneous xenotransplantation models, and in a novel model of orthotopic growth of DLBCL cells in the spleens and bone marrow of MISTRG mice expressing various human cytokines. The loss of S1pr2 induces hyperproliferation of the germinal center (GC) B-cell compartment of immunized mice and accelerates MYC-driven lymphomagenesis in spontaneous and serial transplantation models. The specific loss of Tgfbr2 in murine GC B-cell phenocopies the effects of S1pr2 loss on GC B-cell hyperproliferation. Finally, we show that SMAD1 expression is aberrantly downregulated in >85% of analyzed DLBCL patients. The combined results uncover an important novel tumor suppressive function of the TGF-β/TGF-βR2/SMAD1/S1PR2 axis in DLBCL, and show that DLBCL cells have evolved to inactivate the pathway at the level of SMAD1 expression.

Expression of programmed death ligand 1 is associated with poor prognosis in myeloid sarcoma patients

Myeloid sarcoma (MS) is a rare condition and is an extramedullary tumour of immature myeloid cells. It is now known that the programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway suppresses the host antitumor responses and that these products are expressed on both tumour cells and tumour-infiltrating cells in various malignancies. However, little is known about the significance of PD-1/PD-L1 expression on tumour cells and tumour microenvironmental cells in MS. To investigate the clinicopathological significance of PD-1/PD-L1 expression in MS, we analyzed 98 patients by immunohistochemistry. Of these, 10.2% of cases had neoplastic tumour cells positive for PD-L1 (nPD-L1⁺ ). However, the rate of nPD-L1⁺ was <5% (range: 0.27 to 2.97%). On the other hand, PD-L1 expression on 1 or more of stromal cells in the tumour microenvironment (miPD-L1⁺ ) was observed in 37.8% of cases. Because all nPD-L1⁺ cases expressed PD-1 on less than 5% of tumour cells, we compared the miPD-L1⁺ and miPD-L1^- groups. There was a correlation between miPD-L1⁺ status and the number of PD-1-expressing tumour -infiltrating lymphocytes (PD-1⁺ TILs; P = .0229). miPD-L1⁺ was found to be associated with poorer overall survival and progression-free survival (P = .00392, P = .00261, respectively). Multivariate analysis also confirmed miPD-L1⁺ to be an independent poor prognostic factor. In conclusion, our study indicated that the immunotherapy blocking the PD-1/PD-L1 pathway may improve the clinical outcome of MS.

Bruton tyrosine kinase inhibitor ONO/GS-4059: from bench to bedside

The Bruton tyrosine kinase (BTK) inhibitor, ibrutinib, has been approved for the treatment of chronic lymphocytic leukemia, mantle cell lymphoma, and Waldenstroms macroglobulinemia. Acquired resistance to ibrutinib due to BTK C481S mutation has been reported. Mutations in PLC?2 can also mediate resistance to ibrutinib. Untoward effects due to off-target effects are also disadvantages of ibrutinib. More selective and potent BTK inhibitors (ACP-196, ONO/GS-4059, BGB-3111, CC-292) are being investigated. This review summarized the preclinical research and clinical data of ONO/GS-4059.

How to Hit Mesenchymal Stromal Cells and Make the Tumor Microenvironment Immunostimulant Rather Than Immunosuppressive

Experimental evidence indicates that mesenchymal stromal cells (MSCs) may regulate tumor microenvironment (TME). It is conceivable that the interaction with MSC can influence neoplastic cell functional behavior, remodeling TME and generating a tumor cell niche that supports tissue neovascularization, tumor invasion and metastasization. In addition, MSC can release transforming growth factor-beta that is involved in the epithelial-mesenchymal transition of carcinoma cells; this transition is essential to give rise to aggressive tumor cells and favor cancer progression. Also, MSC can both affect the anti-tumor immune response and limit drug availability surrounding tumor cells, thus creating a sort of barrier. This mechanism, in principle, should limit tumor expansion but, on the contrary, often leads to the impairment of the immune system-mediated recognition of tumor cells. Furthermore, the cross-talk between MSC and anti-tumor lymphocytes of the innate and adaptive arms of the immune system strongly drives TME to become immunosuppressive. Indeed, MSC can trigger the generation of several types of regulatory cells which block immune response and eventually impair the elimination of tumor cells. Based on these considerations, it should be possible to favor the anti-tumor immune response acting on TME. First, we will review the molecular mechanisms involved in MSC-mediated regulation of immune response. Second, we will focus on the experimental data supporting that it is possible to convert TME from immunosuppressive to immunostimulant, specifically targeting MSC.

Retrospective screening of microarray data to identify candidate IFN-inducible genes in a HTLV-1 transformed model

HuT-102 cells are considered one of the most representable human T-lymphotropic virus 1 (HTLV-1)-infected cell lines for studying adult T-cell lymphoma (ATL). In our previous studies, genome-wide screening was performed using the GeneChip system with Human Genome Array U133 Plus 2.0 for transforming growth factor-β-activated kinase 1 (TAK1)-, interferon regulatory factor 3 (IRF3)- and IRF4-regulated genes to demonstrate the effects of interferon-inducible genes in HuT-102 cells. Our previous findings demonstrated that TAK1 induced interferon inducible genes via an IRF3-dependent pathway and that IRF4 has a counteracting effect. As our previous data was performed by manual selection of common interferon-related genes mentioned in the literature, there has been some obscure genes that have not been considered. In an attempt to maximize the outcome of those microarrays, the present study reanalyzed the data collected in previous studies through a set of computational rules implemented using ‘R’ software, to identify important candidate genes that have been missed in the previous two studies. The final list obtained consisted of ten genes that are highly recommend as potential candidate for therapies targeting the HTLV-1 infected cancer cells. Those genes are ATM, CFTR, MUC4, PARP14, QK1, UBR2, CLEC7A (Dectin-1), L3MBTL, SEC24D and TMEM140. Notably, PARP14 has gained increased attention as a promising target in cancer cells.

FOXO1 promotes resistance of non-Hodgkin lymphomas to anti-CD20-based therapy

Diminished overall survival rate of non-Hodgkin lymphoma (NHL) patients treated with a combination regimen of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) has been recently linked to recurrent somatic mutations activating FOXO1. Despite of the clinical relevance of this finding, the molecular mechanism driving resistance to R-CHOP therapy remains largely unknown. Herein, we investigated the potential role of FOXO1 in the therapeutic efficacy of rituximab, the only targeted therapy included in the R-CHOP regimen. We found CD20 transcription is negatively regulated by FOXO1 in NHL cell lines and in human lymphoma specimens carrying activating mutations of FOXO1. Furthermore, both the expression of exogenous mutants of FOXO1 and the inhibition of AKT led to FOXO1 activation in lymphoma cells, increased binding to MS4A1 promoter and diminished CD20 expression levels. In contrast, a disruption of FOXO1 with CRISPR/Cas9 genome-editing (sgFOXO1) resulted in CD20 upregulation, improved the cytotoxicity induced by rituximab and the survival of mice with sgFOXO1 tumors. Accordingly, pharmacological inhibition of FOXO1 activity in primary samples upregulated surface CD20 levels. Importantly, FOXO1 was required for the downregulation of CD20 levels by the clinically tested inhibitors of BTK, SYK, PI3K and AKT. Taken together, these results indicate for the first time that the AKT-unresponsive mutants of FOXO1 are important determinant of cell response to rituximab-induced cytotoxicity, and suggest that the genetic status of FOXO1 together with its transcriptional activity need further attention while designing anti-CD20 antibodies based regimens for the therapy of pre-selected lymphomas.

B Cell Lymphoma Immunotherapy Using TLR9-Targeted Oligonucleotide STAT3 Inhibitors

Growing evidence links the aggressiveness of non-Hodgkin’s lymphoma, especially the activated B cell-like type diffuse large B cell lymphomas (ABC-DLBCLs) to Toll-like receptor 9 (TLR9)/MyD88 and STAT3 transcription factor signaling. Here, we describe a dual-function molecule consisting of a clinically relevant TLR9 agonist (CpG7909) and a STAT3 inhibitor in the form of a high-affinity decoy oligodeoxynucleotide (dODN). The CpG-STAT3dODN blocked STAT3 DNA binding and activity, thus reducing expression of downstream target genes, such as MYC and BCL2L1, in human and mouse lymphoma cells. We further demonstrated that injections (i.v.) of CpG-STAT3dODN inhibited growth of human OCI-Ly3 lymphoma in immunodeficient mice. Moreover, systemic CpG-STAT3dODN administration induced complete regression of the syngeneic A20 lymphoma, resulting in long-term survival of immunocompetent mice. Both TLR9 stimulation and concurrent STAT3 inhibition were critical for immune-mediated therapeutic effects, since neither CpG7909 alone nor CpG7909 co-injected with unconjugated STAT3dODN extended mouse survival. The CpG-STAT3dODN induced expression of genes critical to antigen-processing/presentation and Th1 cell activation while suppressing survival signaling. These effects resulted in the generation of lymphoma cell-specific CD8/CD4-dependent T cell immunity protecting mice from tumor rechallenge. Our results suggest that CpG-STAT3dODN as a systemic/local monotherapy or in combination with PD1 blockade can provide an opportunity for treating patients with B cell NHL.

Identification of Poly(ADP-Ribose) Polymerase Macrodomain Inhibitors Using an AlphaScreen Protocol

Macrodomains recognize intracellular adenosine diphosphate (ADP)-ribosylation resulting in either removal of the modification or a protein interaction event. Research into compounds that modulate macrodomain functions could make important contributions. We investigated the interactions of all seven individual macrodomains of the human poly(ADP-ribose) polymerase (PARP) family members PARP9, PARP14, and PARP15 with five mono-ADP-ribosylated (automodified) ADP-ribosyltransferase domains using an AlphaScreen assay. Several mono-ADP-ribosylation-dependent interactions were identified, and they were found to be in the micromolar affinity range using surface plasmon resonance (SPR). We then focused on the interaction between PARP14 macrodomain-2 and the mono-ADP-ribosylated PARP10 catalytic domain, and probed a ~1500-compound diverse library for inhibitors of this interaction using AlphaScreen. Initial hit compounds were verified by concentration-response experiments using AlphaScreen and SPR, and they were tested against PARP14 macrodomain-2 and -3. Two initial hit compounds and one chemical analog each were further characterized using SPR and microscale thermophoresis. In conclusion, our results reveal novel macrodomain interactions and establish protocols for identification of inhibitors of such interactions.