Decreased IL-10 accelerates B-cell leukemia/lymphoma in a mouse model of pediatric lymphoid leukemia

Causal pathways in lymphoid leukemia: the gut microbiota, immune cells, and serum metabolites

Background

We employed Mendelian randomization (MR) to investigate the causal relationship between the gut microbiota and lymphoid leukemia, further exploring the causal relationships among immune cells, lymphoid leukemia, and potential metabolic mediators.

Methods

We utilized data from the largest genome-wide association studies to date, encompassing 418 species of gut microbiota, 713 types of immune cells, and 1,400 serum metabolites as exposures. Summary statistics for lymphoid leukemia, acute lymphocytic leukemia (ALL), and chronic lymphocytic leukemia (CLL) were obtained from the FinnGen database. We performed bidirectional Mendelian analyses to explore the causal relationships among the gut microbiota, immune cells, serum metabolites, and lymphoid leukemia. Additionally, we conducted a two-step mediation analysis to identify potential intermediary metabolites between immune cells and lymphoid leukemia.

Results

Several gut microbiota were found to have causal relationships with lymphoid leukemia, ALL, and CLL, particularly within the Firmicutes and Bacteroidetes phyla. In the two-step MR analysis, various steroid hormone metabolites (such as DHEAS, pregnenolone sulfateprogestogen derivatives, and androstenediol-related compounds) were identified as potential intermediary metabolites between lymphoid leukemia and immune cells. In ALL, the causal relationship between 1-palmitoyl-2-docosahexaenoyl-GPE (16:0/22:6) and ALL was mediated by CD62L-plasmacytoid DC%DC (mediated proportion=-2.84%, P=0.020). In CLL, the causal relationship between N6,n6,n6-trimethyllysine and CLL was mediated by HLA DR+ CD8br AC (mediated proportion=4.07%, P=0.021).

Conclusion

This MR study provides evidence supporting specific causal relationships between the gut microbiota and lymphoid leukemia, as well as between certain immune cells and lymphoid leukemia with potential intermediary metabolites.

Immune Microenvironment in Childhood Cancers: Characteristics and Therapeutic Challenges

The tumor immune microenvironment is pivotal in cancer initiation, advancement, and regulation. Its molecular and cellular composition is critical throughout the disease, as it can influence the balance between suppressive and cytotoxic immune responses within the tumor's vicinity. Studies on the tumor immune microenvironment have enriched our understanding of the intricate interplay between tumors and their immunological surroundings in various human cancers. These studies illuminate the role of significant components of the immune microenvironment, which have not been extensively explored in pediatric tumors before and may influence the responsiveness or resistance to therapeutic agents. Our deepening understanding of the pediatric tumor immune microenvironment is helping to overcome challenges related to the effectiveness of existing therapeutic strategies, including immunotherapies. Although in the early stages, targeted therapies that modulate the tumor immune microenvironment of pediatric solid tumors hold promise for improved outcomes. Focusing on various aspects of tumor immune biology in pediatric patients presents a therapeutic opportunity that could improve treatment outcomes. This review offers a comprehensive examination of recent literature concerning profiling the immune microenvironment in various pediatric tumors. It seeks to condense research findings on characterizing the immune microenvironment in pediatric tumors and its impact on tumor development, metastasis, and response to therapeutic modalities. It covers the immune microenvironment's role in tumor development, interactions with tumor cells, and its impact on the tumor's response to immunotherapy. The review also discusses challenges targeting the immune microenvironment for pediatric cancer therapies.

Nlp-dependent ER-to-Golgi transport

The mechanism that maintains ER-to-Golgi vesicles formation and transport is complicated. As one of the adapters, Ninein-like protein (Nlp) participated in assembly and transporting of partial ER-to-Golgi vesicles that contained specific proteins, such as β-Catenin and STING. Nlp acted as a platform to sustain the specificity and continuity of cargoes during COPII and COPI-coated vesicle transition and transportation through binding directly with SEC31A as well as Rab1B. Thus, we proposed an integrated transport model that particular adapter participated in specific cargo selection or transportation through cooperating with different membrane associated proteins to ensure the continuity of cargo trafficking. Deficiency of Nlp led to vesicle budding failure and accumulation of unprocessed proteins in ER, which further caused ER stress as well as Golgi fragmentation, and PERK-eIF2α pathway of UPR was activated to reduce the synthesis of universal proteins. In contrast, upregulation of Nlp resulted in Golgi fragmentation, which enhanced the cargo transport efficiency between ER and Golgi. Moreover, Nlp deficient mice were prone to spontaneous B cell lymphoma, since the developments and functions of lymphocytes significantly depended on secretory proteins through ER-to-Golgi vesicle trafficking, including IL-13, IL-17 and IL-21. Thus, perturbations of Nlp altered ER-to-Golgi communication and cellular homeostasis, and might contribute to the pathogenesis of B cell lymphoma.

Single nucleotide polymorphisms conferring susceptibility to leukemia and oral mucositis: a multi-center pilot study of patients prior to conditioning therapy for hematopoietic cell transplant

PURPOSE

Leukemias have been associated with oral manifestations, reflecting susceptibility to cancer therapy-induced oral mucositis. We sought to identify SNPs associated with both leukemia and oral mucositis (OM).

METHODS

Whole exome sequencing was performed on leukemia and non-cancer blood disorder (ncBD) patients' saliva samples (N = 50) prior to conditioning therapy. WHO OM grading scores were determined: moderate to severe (OM2-4) vs. none to mild (OM0-1). Reads were processed using Trim Galorev0.6.7, Bowtie2v2.4.1, Samtoolsv1.10, Genome Analysis Toolkit (GATK)v4.2.6.1, and DeepVariantv1.4.0. We utilized the following pipelines: P1 analysis with PLINK2v3.7, SNP2GENEv1.4.1 and MAGMAv1.07b, and P2 [leukemia (N = 42) vs. ncBDs (N = 8)] and P3 [leukemia + OM2-4 (N = 18) vs. leukemia + OM0-1 (N = 24)] with Z-tests of genotypes and protein-protein interaction determination. GeneCardsSuitev5.14 was used to identify phenotypes (P1 and P2, leukemia; P3, oral mucositis) and average disease-causing likelihood and DGIdb for drug interactions. P1 and P2 genes were analyzed with CytoScape plugin BiNGOv3.0.3 to retrieve overrepresented Gene Ontology (GO) terms and Ensembl's VEP for SNP outcomes.

RESULTS

In P1, 457 candidate SNPs (28 genes) were identified and 21,604 SNPs (1016 genes) by MAGMAv1.07b. Eighteen genes were associated with "leukemia" per VarElectv5.14 analysis and predicted to be deleterious. In P2 and P3, 353 and 174 SNPs were significant, respectively. STRINGv12.0 returned 77 and 32 genes (C.L. = 0.7) for P2 and P3, respectively. VarElectv5.14 determined 60 genes from P2 associated with "leukemia" and 11 with "oral mucositis" from P3. Overrepresented GO terms included "cellular process," "signaling," "hemopoiesis," and "regulation of immune response."

CONCLUSIONS

We identified candidate SNPs possibly conferring susceptibility to develop leukemia and oral mucositis.

Vitamin C Inhibits Lipopolysaccharide-Induced Hyperinflammatory State of Chronic Myeloid Leukemia Cells through Purinergic Signaling and Autophagy

Background: Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by the overproduction of white blood cells, leading to symptoms such as fatigue, infections, and other complications. CML patients must take measures to prevent infections to mitigate the exacerbation of cancer cell proliferation and comorbidities. Methods: This study investigated whether vitamin C can suppress the hyperinflammatory activation of K-562 cells induced by lipopolysaccharide (LPS) and whether purinergic signaling (ATP and P2X7 receptor) and autophagy play a role in it. Two different doses of vitamin C (5 µg/mL and 10 µg/mL) were employed, along with the lysosome inhibitor chloroquine (CQ; 100 µM), administered 2 h prior to LPS stimulation (10 ng/mL) for a duration of 22 h in K-562 cells (3 × 105 cells/mL/well). Results: Both doses of vitamin C reduced the release of interleukin-6 (IL-6) (5 µg/mL, p < 0.01 and 10 µg/mL, p < 0.01) and tumor necrosis factor (TNF) (5 µg/mL, p < 0.01 and 10 µg/mL, p < 0.01) induced by LPS. Furthermore, in LPS + CQ-stimulated cells, vitamin C at a concentration of 10 µg/mL inhibited the expression of LC3-II (p < 0.05). Conversely, both doses of vitamin C led to the release of the anti-inflammatory cytokine interleukin-10 (IL-10) (5 µg/mL, p < 0.01 and 10 µg/mL, p < 0.01), while only the 10 µg/mL dose of vitamin C induced the release of Klotho (10 µg/mL, p < 0.01). In addition, both doses of vitamin C reduced the accumulation of ATP (5 µg/mL, p < 0.01 and 10 µg/mL, p < 0.01) and decreased the expression of the P2X7 receptor at the mRNA level. Conclusions: Vitamin C inhibits the hyperinflammatory state induced by LPS in K-562 cells, primarily by inhibiting the ATP accumulation, P2X7 receptor expression, and autophagy signaling.

Age and ligand specificity influence the outcome of pathogen engagement on preleukemic and leukemic B-cell precursor populations

Common infections have long been proposed to play a role in the development of pediatric B-cell acute lymphoblastic leukemia (B-ALL). However, epidemiologic studies report contradictory effects of infection exposure on subsequent B-ALL risk, and no specific pathogen has been definitively linked to the disease. A unifying mechanism to explain the divergent outcomes could inform disease prevention strategies. We previously reported that the pattern recognition receptor (PRR) ligand Poly(I:C) exerted effects on B-ALL cells that were distinct from those observed with other nucleic acid-based PRR ligands. Here, using multiple double-stranded RNA (dsRNA) moieties, we show that the overall outcome of exposure to Poly(I:C) reflects the balance of opposing responses induced by its ligation to endosomal and cytoplasmic receptors. This PRR response biology is shared between mouse and human B-ALL and can increase leukemia-initiating cell burden in vivo during the preleukemia phase of B-ALL, primarily through tumor necrosis factor α signaling. The age of the responding immune system further influences the impact of dsRNA exposure on B-ALL cells in both mouse and human settings. Overall, our study demonstrates that potentially proleukemic and antileukemic effects can each be generated by the stimulation of pathogen recognition pathways and indicates a mechanistic explanation for the contrasting epidemiologic associations reported for infection exposure and B-ALL.

A dual-role for IL-10: From leukemogenesis to the tumor progression in acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer in the world, and accounts for 25% of all childhood cancers among children under 15 years of age. Longitudinal studies have shown that children with ALL are born with a deregulated immune response that, together with postnatal environmental exposures, favor the onset of the disease. In this context, IL-10, a key cytokine in the regulation of the immune response, presents itself as a paradoxical mediator, initially influencing the development of ALL through the regulation of inflammatory processes and later on the progression of malignancy, with the increase of this molecule in the leukemia microenvironment. According to the literature, this cytokine plays a critical role in the natural history of the disease and plays an important role in two different though complex scenarios. Thus, in this review, we explore the dual role of IL-10 in ALL, and describe its biological characteristics, immunological mechanisms and genetics, as well as its impact on the leukemia microenvironment and its clinical implications.

Defining the Basal and Immunomodulatory Mediator-Induced Phosphoprotein Signature in Pediatric B Cell Acute Lymphoblastic Leukemia (B-ALL) Diagnostic Samples

It is theorized that dysregulated immune responses to infectious insults contribute to the development of pediatric B-ALL. In this context, our understanding of the immunomodulatory-mediator-induced signaling responses of leukemic blasts in pediatric B-ALL diagnostic samples is rather limited. Hence, in this study, we defined the signaling landscape of leukemic blasts, as well as normal mature B cells and T cells residing in diagnostic samples from 63 pediatric B-ALL patients. These samples were interrogated with a range of immunomodulatory-mediators within 24 h of collection, and phosflow analyses of downstream proximal signaling nodes were performed. Our data reveal evidence of basal hyperphosphorylation across a broad swath of these signaling nodes in leukemic blasts in contrast to normal mature B cells and T cells in the same sample. We also detected similarities in the phosphoprotein signature between blasts and mature B cells in response to IFNγ and IL-2 treatment, but significant divergence in the phosphoprotein signature was observed between blasts and mature B cells in response to IL-4, IL-7, IL-10, IL-21 and CD40 ligand treatment. Our results demonstrate the existence of both symmetry and asymmetry in the phosphoprotein signature between leukemic and non-leukemic cells in pediatric B-ALL diagnostic samples.

Gut microbiome immaturity and childhood acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia (ALL) is the most common cancer of childhood. Here, we map emerging evidence suggesting that children with ALL at the time of diagnosis may have a delayed maturation of the gut microbiome compared with healthy children. This finding may be associated with early-life epidemiological factors previously identified as risk indicators for childhood ALL, including caesarean section birth, diminished breast feeding and paucity of social contacts. The consistently observed deficiency in short-chain fatty-acid-producing bacterial taxa in children with ALL has the potential to promote dysregulated immune responses and to, ultimately, increase the risk of transformation of preleukaemic clones in response to common infectious triggers. These data endorse the concept that a microbiome deficit in early life may contribute to the development of the major subtypes of childhood ALL and encourage the notion of risk-reducing microbiome-targeted intervention in the future.

The RUNX Family of Proteins, DNA Repair, and Cancer

The RUNX family of transcription factors, including RUNX1, RUNX2, and RUNX3, are key regulators of development and can function as either tumor suppressors or oncogenes in cancer. Emerging evidence suggests that the dysregulation of RUNX genes can promote genomic instability in both leukemia and solid cancers by impairing DNA repair mechanisms. RUNX proteins control the cellular response to DNA damage by regulating the p53, Fanconi anemia, and oxidative stress repair pathways through transcriptional or non-transcriptional mechanisms. This review highlights the importance of RUNX-dependent DNA repair regulation in human cancers.

Overexpression of interleukin-20 correlates with favourable prognosis in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma worldwide, accounting for about 40% of cases. The role of cytokines in the pathogenesis of lymphomas has been rarely addressed, although cytokines have a close immunological relationship with lymphocytes. We observed overexpression of interleukin (IL)-20 in reactive germinal centres (GCs) leading us to hypothesise that IL-20 may play a role in lymphomagenesis. In this study, we surveyed for IL-20 expression in various types of lymphoma and found that IL-20 was expressed most frequently in follicular lymphoma (94%), but also in Burkitt lymphoma (81%), mantle cell lymphoma (57%), nodal marginal zone lymphoma (56%), Hodgkin lymphomas (50%), small lymphocytic lymphoma (50%) and diffuse large B-cell lymphoma (DLBCL, 48%). IL-20 was not expressed in extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), lymphoplasmacytic lymphoma, and plasmacytoma. T-cell lymphomas were largely negative for IL-20 expression, except for anaplastic large cell lymphoma (ALCL, 61%), which frequently expressed IL-20, especially in cutaneous ALCL, and showed an inverse association with ALK expression (p=0.024). We further tested IL-20 expression in another large cohort of DLBCL and found IL-20 expression more frequently in germinal centre B-cell (GCB) than in non-GCB subtype [16/26 (62%) versus 24/64 (38%), p=0.038]. In this cohort, IL-20 was associated with a lower rate of extranodal involvement (p=0.009), bone marrow involvement (p=0.040), and better overall survival (p=0.020). Mechanistically, IL-20 overexpression promoted G1 cell cycle arrest and subsequent apoptosis of DLBCL cells and vice versa in vitro. We conclude that IL-20 may be involved in lymphomagenesis and may be useful as a prognostic marker in patients with DLBCL. In addition, IL-20 plays an inhibitory role in DLBCL growth, probably through cell cycle regulation.

Germline ETV6 mutation promotes inflammation and disrupts lymphoid development of early hematopoietic progenitors

Germline mutations in ETV6 are associated with a syndrome of thrombocytopenia and leukemia predisposition, and ETV6 is among the most commonly mutated genes in leukemias, especially childhood B-cell acute lymphoblastic leukemia. However, the mechanisms underlying disease caused by ETV6 dysfunction are poorly understood. To address these gaps in knowledge, using CRISPR/Cas9, we developed a mouse model of the most common recurrent, disease-causing germline mutation in ETV6. We found defects in hematopoiesis related primarily to abnormalities of the multipotent progenitor population 4 (MPP4) subset of hematopoietic progenitor cells and evidence of sterile inflammation. Expression of ETV6 in Ba/F3 cells altered the expression of several cytokines, some of which were also detected at higher levels in the bone marrow of the mice with Etv6 mutation. Among these, interleukin-18 and interleukin-13 abrogated B-cell development of sorted MPP4 cells, but not common lymphoid progenitors, suggesting that inflammation contributes to abnormal hematopoiesis by impairing lymphoid development. These data, along with those from humans, support a model in which ETV6 dysfunction promotes inflammation, which adversely affects thrombopoiesis and promotes leukemogenesis.