Prognosis and therapy of chronic lymphocytic leukemia and small lymphocytic lymphoma

Lipid uptake in chronic lymphocytic leukemia

Many cancers rely on glucose as an energy source, but it is becoming increasingly apparent that some cancers use alternate substrates to fuel their proliferation. Chronic lymphocytic leukaemia (CLL) is one such cancer. Through the use of flow cytometry and confocal microscopy, low levels of glucose uptake were observed in the OSU-CLL and HG3 CLL cell lines relative to highly glucose-avid Raji cells (Burkitt's lymphoma). Glucose uptake in CLL cells correlated with low expression of the GLUT1 and GLUT3 receptors. In contrast, both CLL cell lines and primary CLL cells, but not healthy B cells, were found to rapidly internalise medium- and long-chain, but not short-chain, fatty acids (FAs). Differential FA uptake was also observed in primary cells taken from patients with unmutated immunoglobulin heavy variable chain usage (IGHV) compared with patients with mutated IGHV. Delipidation of serum in the culture medium slowed the proliferation and significantly reduced the viability of OSU-CLL and HG3 cells, effects that were partially reversed by supplementation with a chemically defined lipid concentrate. These observations highlight the potential importance of FAs in the pathogenesis of CLL and raise the possibility that targeting FA utilisation may represent a novel therapeutic and prognostic approach in this disease.

Acalabrutinib: Nursing Considerations for Use in Patients With Chronic Lymphocytic Leukemia and Small Lymphocytic Lymphoma

BACKGROUND

Acalabrutinib is a next-generation Bruton tyrosine kinase inhibitor (BTKi) that has moved to the forefront of treatment options for patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). Patients with CLL/SLL can experience adverse events and toxicities unique to BTKi therapy.

OBJECTIVES

This article provides an overview of nursing considerations for the treatment of patients with CLL/SLL with acalabrutinib, focusing on safety, toxicity management, and adherence.

METHODS

A review of information identified through structured searches of key publications and websites and data from pivotal clinical trials was performed.

FINDINGS

Increased awareness of the unique disease characteristics of patients with CLL/SLL and of the efficacy and safety profile of acalabrutinib allows nurses to play a vital role in improving patient outcomes. With this knowledge, nurses can support patients through education on potential side effects, drug-drug interactions, and treatment adherence, as well as monitor for clinical symptoms and laboratory findings requiring intervention.

Primary Epicardial Malt Lymphoma: A New Physiopathologic Entity Mimicking a Pericardial Compressive Syndrome

MALT lymphoma is a non-Hodgkin lymphoma developing from B cells and is a type of marginal zone lymphoma. It can develop in any organs, but no case of primary cardiac location has yet been reported. We report the first observation of a primary epicardial MALT lymphoma mimicking a compressive pericardial syndrome. (Level of Difficulty: Advanced.)

TLR Signaling Is Activated in Lymph Node-Resident CLL Cells and Is Only Partially Inhibited by Ibrutinib

Chronic lymphocytic leukemia (CLL) is a malignancy of mature B cells driven by B-cell receptor (BCR) signaling and activated primarily in the lymph node. The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib effectively inhibits BCR-dependent proliferation and survival signals and has emerged as a breakthrough therapy for CLL. However, complete remissions are uncommon and are achieved only after years of continuous therapy. We hypothesized that other signaling pathways that sustain CLL cell survival are only partially inhibited by ibrutinib. In normal B cells, Toll-like receptor (TLR) signaling cooperates with BCR signaling to activate prosurvival NF-κB. Here, we show that an experimentally validated gene signature of TLR activation is overexpressed in lymph node-resident CLL cells compared with cells in the blood. Consistent with TLR activation, we detected phosphorylation of NF-κB, STAT1, and STAT3 in lymph node-resident CLL cells and in cells stimulated with CpG oligonucleotides in vitro. CpG promoted IRAK1 degradation, secretion of IL10, and extended survival of CLL cells in culture. CpG-induced TLR signaling was significantly inhibited by both an IRAK1/4 inhibitor and ibrutinib. Although inhibition of TLR signaling was incomplete with either drug, the combination achieved superior results, including more effective inhibition of TLR-mediated survival signaling. Our data suggest an important role for TLR signaling in CLL pathogenesis and in sustaining the viability of CLL cells during ibrutinib therapy. The combination of ibrutinib with a TLR pathway inhibitor could provide superior antitumor activity and should be investigated in clinical studies. SIGNIFICANCE: CLL relies on the concomitant cooperation of B-cell receptor and Toll-like receptor signaling; inhibition of both pathways is superior to inhibition of either pathway alone. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/2/360/F1.large.jpg.

Immunological changes with kinase inhibitor therapy for chronic lymphocytic leukemia

Ibrutinib and idelalisib are kinase inhibitors that have revolutionized the treatment of chronic lymphocytic leukemia (CLL). Capable of inducing durable remissions, these agents also modulate the immune system. Both ibrutinib and idelalisib abrogate the tumor-supporting microenvironment by disrupting cell-cell interactions, modulating the T-cell compartment, and altering the cytokine milieu. Ibrutinib also partially restores T-cell and myeloid defects associated with CLL. In contrast, immune-related adverse effects, including pneumonitis, colitis, hepatotoxicity, and infections are of particular concern with idelalisib. While opportunistic infections and viral reactivations occur with both ibrutinib and idelalisib, these complications are less common and less severe with ibrutinib, especially when used as monotherapy without additional immunosuppressive agents. This review discusses the impact of ibrutinib and idelalisib on the immune system, including infectious and auto-immune complications as well as their specific effects on the B-cell, T-cell, and myeloid compartment.

Discovery and development of differentially methylated regions in human papillomavirus-related oropharyngeal squamous cell carcinoma

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) exhibits a different composition of epigenetic alterations. In this study, we identified differentially methylated regions (DMRs) with potential utility in screening for HPV-positive OPSCC. Genome wide DNA methylation was measured using methyl-CpG binding domain protein-enriched genome sequencing (MBD-seq) in 50 HPV-positive OPSCC tissues and 25 normal tissues. Fifty-one DMRs were defined with maximal methylation specificity to cancer samples. The Cancer Genome Atlas (TCGA) methylation array data was used to evaluate the performance of the proposed candidates. Supervised hierarchical clustering of 51 DMRs found that HPV-positive OPSCC had significantly higher DNA methylation levels compared to normal samples, and non-HPV-related head and neck squamous cell carcinoma (HNSCC). The methylation levels of all top 20 DNA methylation biomarkers in HPV-positive OPSCC were significantly higher than those in normal samples. Further confirmation using quantitative methylation specific PCR (QMSP) in an independent set of 24 HPV-related OPSCCs and 22 controls showed that 16 of the 20 candidates had significant higher methylation levels in HPV-positive OPSCC samples compared with controls. One candidate, OR6S1, had a sensitivity of 100%, while 17 candidates (KCNA3, EMBP1, CCDC181, DPP4, ITGA4, BEND4, ELMO1, SFMBT2, C1QL3, MIR129-2, NID2, HOXB4, ZNF439, ZNF93, VSTM2B, ZNF137P and ZNF773) had specificities of 100%. The prediction accuracy of the 20 candidates rang from 56.2% to 99.8% by receiver operating characteristic analysis. We have defined 20 highly specific DMRs in HPV-related OPSCC, which can potentially be applied to molecular-based detection tests and improve disease management.

Upregulation of long noncoding RNA MIAT in aggressive form of chronic lymphocytic leukemias

Long noncoding RNAs (lncRNAs) are non-proten-coding transcripts of more than 200 nucleotides generated by RNA polymerase II and their expressions are tightly regulated in cell type specific- and/or cellular differential stage specific- manner. MIAT, originally isolated as a candidate gene for myocardial infarction, encodes lncRNA (termed MIAT). Here, we determined the expression level of MIAT in established leukemia/lymphoma cell lines and found its upregulation in lymphoid but not in myeloid cell lineage with mature B cell phenotype. MIAT expression level was further determined in chronic lymphocytic leukemias (CLL), characterized by expansion of leukemic cells with mature B phenotype, to demonstrate relatively high occurrence of MIAT upregulation in aggressive form of CLL carrying either 17p-deletion, 11q-deletion, or Trisomy 12 over indolent form carrying 13p-deletion. Furthermore, we show that MIAT constitutes a regulatory loop with OCT4 in malignant mature B cell, as was previously reported in mouse pulripotent stem cell, and that both molecules are essential for cell survival.

IFI16 reduced expression is correlated with unfavorable outcome in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. Its clinical course is typically indolent; however, based on a series of pathobiological, clinical, genetic, and phenotypic parameters, patient survival varies from less than 5 to more than 20 years. In this paper, we show for the first time that the expression of the interferon-inducible DNA sensor IFI16, a member of the PYHIN protein family involved in proliferation inhibition and apoptosis regulation, is associated with the clinical outcome in CLL. We studied 99 CLLs cases by immunohistochemistry and 10 CLLs cases by gene expression profiling. We found quite variable degrees of IFI16 expression among CLLs cases. Noteworthy, we observed that a reduced IFI16 expression was associated with a very poor survival, but only in cases with ZAP70/CD38 expression. Furthermore, we found that IFI16 expression was associated with a specific gene expression signature. As IFI16 can be easily detected by immunohistochemistry or flow cytometry, it may become a part of phenotypic screening in CLL patients if its prognostic role is confirmed in independent series.

Direct in vivo evidence for increased proliferation of CLL cells in lymph nodes compared to bone marrow and peripheral blood

Chronic Lymphocytic Leukemia (CLL) is a progressive malignancy of mature B-cells that involves the peripheral blood (PB), lymph nodes (LNs) and bone marrow (BM). While the majority of CLL cells are in a resting state, small populations of proliferating cells exist; however, the anatomical site of active cell proliferation remains to be definitively determined. Based on findings that CLL cells in LNs have increased expression of B-cell activation genes, we tested the hypothesis that the fraction of “newly born” cells would be highest in the LNs. Using a deuterium oxide (²H) in vivo labeling method in which patients consumed deuterated (heavy) water (²H₂O), we determined CLL cell kinetics in concurrently obtained samples from LN, PB, and BM. The LN was identified as the anatomical site harboring the largest fraction of newly born cells, compared to PB and BM. In fact, the calculated birth rate in the LN reached as high a 3.3% of the clone per day. Subdivision of the bulk CLL population by flow cytometry identified the subpopulation with the CXCR4^dimCD5^bright phenotype as containing the highest proportion of newly born cells within each compartment, including the LN, identifying this subclonal population as an important target for novel treatment approaches.

The role of B-cell receptor inhibitors in the treatment of patients with chronic lymphocytic leukemia

Chronic lymphocytic leukemia is a malignancy of mature auto-reactive B cells. Genetic and functional studies implicate B-cell receptor signaling as a pivotal pathway in its pathogenesis. Full B-cell receptor activation requires tumor-microenvironment interactions in lymphoid tissues. Spleen tyrosine kinase, Bruton's tyrosine kinase, and the phosphatidylinositol 3-kinase (PI3K) δ isoform are essential for B-cell receptor signal transduction but also mediate the effect of other pathways engaged in chronic lymphocytic leukemia cells in the tissue-microenvironment. Orally bioavailable inhibitors of spleen tyrosine kinase, Bruton's tyrosine kinase, or PI3Kδ, induce high rates of durable responses. Ibrutinib, a covalent inhibitor of Bruton's tyrosine kinase, and idelalisib, a selective inhibitor of PI3Kδ, have obtained regulatory approval in chronic lymphocytic leukemia. Ibrutinib and idelalisib are active in patients with high-risk features, achieving superior disease control in difficult-to-treat patients than prior best therapy, making them the preferred agents for chronic lymphocytic leukemia with TP53 aberrations and for patients resistant to chemoimmunotherapy. In randomized trials, both ibrutinib, versus ofatumumab, and idelalisib in combination with rituximab, versus placebo with rituximab improved survival in relapsed/refractory chronic lymphocytic leukemia. Responses to B-cell receptor inhibitors are mostly partial, and within clinical trials treatment is continued until progression or occurrence of intolerable side effects. Ibrutinib and idelalisib are, overall, well tolerated; notable adverse events include increased bruising and incidence of atrial fibrillation on ibrutinib and colitis, pneumonitis and transaminase elevations on idelalisib. Randomized trials investigate the role of B-cell receptor inhibitors in first-line therapy and the benefit of combinations. This review discusses the biological basis for targeted therapy of chronic lymphocytic leukemia with B-cell receptor inhibitors, and summarizes the clinical experience with these agents.

The prognostic significance of surface dipeptidylpeptidase IV (CD26) expression in B-cell chronic lymphocytic leukemia

A number of factors related to B-cell chronic lymphocytic leukemia (B-CLL) patients' prognosis have been identified. However, still some factors better reflecting disease activity in individual cases are explored. The study aimed to evaluate prognostic significance of dipeptidylpeptidase IV/CD26 expression on B-CLL cells and its relationship with other well established prognostic factors. The study included 94 patients with newly diagnosed B-CLL and involved analysis of clinical, laboratory, flow-cytometry and cytogenetic data. Detailed analysis showed that CD26 expression on B-CLL cells correlates with Rai's clinical stage of the disease at diagnosis (p=0.034), β2-microglobulin concentration (p=0.012), lactic acid dehydrogenase activity (p=0.045) and absolute lymphocytes' count (p=0.027) in the blood. The multivariate analysis revealed that time to treatment (TTT) was significantly influenced by Rai clinical stage, LDH activity in blood and CD26 expression on B-CLL cell's. Moreover, in the multivariate analysis restricted to the group of patients with documented cytogenetic risk (n=36) CD26 expression, Rai clinical stage and cytogenetic profile remained their independent impact on TTT. The results of our study indicate that the CD26 expression should be incorporated in B-CLL patients risk assessment along with well known prognostic factors, since it seems to have a relationship with the tumor mass and influences TTT.