The expression of IL-6 and its related genes in acute leukemia

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.

The cytokine network in acute myeloid leukemia

Acute myeloid leukemia (AML) is a highly heterogeneous malignancy of the blood and bone marrow, characterized by clonal expansion of myeloid stem and progenitor cells and rapid disease progression. Chemotherapy has been the first-line treatment for AML for more than 30 years. Application of recent high-throughput next-generation sequencing technologies has revealed significant molecular heterogeneity to AML, which in turn has motivated efforts to develop new, targeted therapies. However, due to the high complexity of this disease, including multiple driver mutations and the coexistence of multiple competing tumorigenic clones, the successful incorporation of these new agents into clinical practice remains challenging. These continuing difficulties call for the identification of innovative therapeutic approaches that are effective for a larger cohort of AML patients. Recent studies suggest that chronic immune stimulation and aberrant cytokine signaling act as triggers for AML initiation and progression, facets of the disease which might be exploited as promising targets in AML treatment. However, despite the greater appreciation of cytokine profiles in AML, the exact functions of cytokines in AML pathogenesis are not fully understood. Therefore, unravelling the molecular basis of the complex cytokine networks in AML is a prerequisite to develop new therapeutic alternatives based on targeting cytokines and their receptors.

Serum levels of selected cytokines and soluble adhesion molecules in acute myeloid leukemia: Soluble receptor for interleukin-2 predicts overall survival

BACKGROUND

Acute myeloid leukemia (AML) cells are highly resistant to chemotherapeutic drugs. Cytokines and adhesion molecules may contribute to this resistance and affect treatment outcome. The aim of this study was to evaluate the independence and additional prognostic information of baseline serum levels of selected cytokines and soluble adhesion molecules, included in analyses with standard prognostic indicators.

METHODS

We used biochip array technology to measure levels of selected cytokines and soluble adhesion molecules in serum samples of 80 newly diagnosed AML patients. The markers of tumour microenvironment were analysed against high risk karyotype, hyperleucocytosis, higher age, lactic dehydrogenase levels and presence of FLT3-ITD and NPM-1 mutation.

RESULTS

All evaluated analytes were independent of standard prognostic indicators. Fifteen were associated with overall and eight with progression-free survival in univariate analysis. After correction for multiple testing, we identified soluble interleukin-2 receptor-α as an independent indicator of overall survival. Further, the soluble type I TNF-α receptor was close to statistical significance for both overall and progression-free survival.

CONCLUSIONS

Baseline levels of soluble interleukin-2 receptor-α predict overall survival in newly diagnosed AML. The TNF-α type I soluble receptor is a candidate prognostic marker in AML and is worth of further investigation.

Bone marrow - mesenchymal stem cells impact on the U937 cells in the presence of staphylococcal enterotoxin B (SEB)

The growing resistance against conventional chemotherapy in acute myeloid leukemia (AML) is a noticeable clinical concern. Therefore, many researchers are looking for novel substances to overcome drug resistance in cancer. Staphylococcal enterotoxin B (SEB) is a superantigen (SAg) and a promising compound which has lethal effects on malignant cells. In this unprecedented study, SEB was used against U937 cells in a co-culture system in the presence of human bone marrow-mesenchymal stem cells (hBM-MSCs). The effects of hBM-MSCs on the proliferation and survival of U937 cell line with SEB was assessed using MTT assay and AnnexinV/PI flowcytometry, respectively. Moreover, the expression of IL-6, IL-10, TGF-β, and inhibitor of nuclear factor kappa-B kinase (IKKb) was evaluated by real-time PCR technique. The same experiments were also carried out using hBM-MSCs-conditioned medium (hBM-MSCs-CM). The results showed that SEB reduced the proliferation and survival of U937 cell line, but hBM-MSCs or hBM-MSCs-CM suppressed the effects of SEB. Furthermore, real-timePCR demonstrated that SEB could decrease the expression of IL-6, IL-10, and TGF-β in hBM-MSCs (P < .05), while the production of IKKb was increased in comparison with the control group. These findings help us to have a broader understanding ofthe usage of SEB in the treatment of haematological malignancies, especially if it is targeted against hBM-MSCs to disrupt their supportive effects on malignant cells.

Differential regulation of hepcidin in cancer and non-cancer tissues and its clinical implications

Hepcidin is a crucial peptide for regulating cellular iron efflux. Because iron is essential for cell survival, especially for highly active cells, such as tumor cells, it is imperative to understand how tumor cells manipulate hepcidin expression for their own metabolic needs. Studies suggest that hepcidin expression and regulation in tumor cells show important differences in comparison with those in non-tumorous cells. These differences should be investigated to develop new strategies to fight cancer cells. Manipulating hepcidin expression to starve cancer cells for iron may prove to be a new therapy in the anticancer arsenal.

Acute Myelogenous Leukemia Cells Secrete Factors that Stimulate Cellular LDL Uptake via Autocrine and Paracrine Mechanisms

Leukemic cells isolated from most patients with acute myelogenous leukemia (AML) have higher low density lipoprotein (LDL) uptake than normal mononuclear blood cells. Little is known, however, about the mechanism behind the elevated LDL uptake. We investigated if AML cells secrete factors that stimulate cellular LDL uptake. Mononuclear blood cells were isolated from peripheral blood from 42 patients with AML at diagnosis. Cellular LDL uptake was determined from the degradation rate of ¹²⁵I-labelled LDL. Conditioned media from AML cells stimulated the LDL degradation in the leukemic cell lines KG1 and HL60, and in isolated AML cells. The stimulatory effect correlated with the LDL degradation in the AML cells directly after isolation from blood. Conditioned media also autostimulated LDL degradation in the AML cells themselves. Concentrations of IL-6 and IL-8 in AML cell conditioned media correlated with the LDL degradation in AML cells directly after isolation from blood. Addition of R-TNF-α, but not IL-6 or IL-8, stimulated LDL degradation in HL60, KG1, and AML cells. The LDL degradation in AML cells could be inhibited by a LDL receptor blocking antibody. AML cells secrete factors that stimulate LDL uptake in a paracrine and autocrine pattern which open up therapeutic possibilities to inhibit the uptake of LDL by administration of antibodies to these factors.

Salivary and Serum Interleukin-6 Levels in Oral Premalignant Disorders and Squamous Cell Carcinoma: Diagnostic Value and Clinicopathologic Correlations

Aim: To assess the diagnostic utility of serum and salivary interleukin 6 (IL-6) levels in the differential diagnosis of potentially malignant lesions and conditions (PMLs/PMCs) and oral squamous cell carcinoma (OSCC) in a high oral cancer prevalence region. Methods: After appropriate ethical clearance and informed consent, salivary and blood samples were collected from 100 participants in each group (OSCC, PMLs, and healthy controls). Serum and salivary IL-6 levels were measured by enzyme-linked immunosorbent assay and data were subjected to appropriate statistical analysis. Results: Significant differences in IL-6 concentration were noted between OSCC and PML/C patients in both serum and saliva, with salivary levels being 2 to 3 fold higher than serum values in all the groups. Receiver operating characteristic curve analysis demonstrated 96% specificity and 99% sensitivity for salivary IL-6 in differentiating PML from OSCC. Conclusions: The results of the present study suggest that the pro-inflammatory cytokine, IL-6, is elevated in the saliva of patients with OSSC compared to PMD and controls, and thus may prove to have diagnostic and/or prognostic significance.

TNF-α, a good or bad factor in hematological diseases?

Tumor necrosis factor-alpha (TNF-α) is a highly pleiotropic cytokine involved in a spectrum of physiological processes that control inflammation, anti-tumor responses and homeostasis through two receptors, TNF-R1 and TNF-R2. In general, TNF-R1 mediates cytotoxicity, resistance to infection and stimulation of NF-κB. By contrast, TNF-R2 has been implicated in proliferation of T-cell line, thymocytes and human mononuclear cells. Hematological malignancies are the types of cancer that affect normal hematopoiesis, have a speedy development, high lethal rate and until now still have no effective treatment. Several studies have shown that inflammatory cytokines play an important role in the onset and progress of these diseases. In this review, we summarize the recent studies and evaluate the positive or negative role of TNF-α in some hematological malignancies or diseases with a malignant tendency.

Impact of interleukin-6 in hematological malignancies

Almost 3 decades have passed since the discovery and cloning of IL-6, and a tremendous amount of work has contributed to the current knowledge of the biological functions of this cytokine, its receptor, and the signaling pathways that are activated. The understanding of the role of IL-6 in human disease has led to the development of novel therapeutic strategies that block the biological functions of IL-6. In clinical studies, IL-6 and IL-6 receptor antibodies have proven efficacy in rheumatoid arthritis, systemic juvenile idiopathic arthritis, and Castleman's disease, conditions that are known to be driven by IL-6. The focus of this overview is the role of IL-6 in the pathophysiology of hematological malignancies.

JTE-607, a multiple cytokine production inhibitor, induces apoptosis accompanied by an increase in p21waf1/cip1 in acute myelogenous leukemia cells

Proinflammatory cytokines and growth factors have been thought to play crucial roles in the pathology of acute myelogenous leukemia (AML) by supporting the proliferation and survival of AML cells in an autocrine and paracrine manner, although further elucidation is required. JTE-607 was originally identified as a multiple cytokine inhibitor that suppresses production of proinflammatory cytokines from lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells. Herein, we report that JTE-607 exhibits inhibitory activity on the growth of AML cell lines accompanying reduction of the proinflammatory cytokine and growth factor production. In in vitro studies, JTE-607 suppressed expression and production of cytokines, which are spontaneously up-regulated in AML cell lines. JTE-607 also abrogated proliferation of AML cells in a concentration range in which colony formation of normal bone marrow cells was not affected. The growth inhibition by JTE-607 was characterized by induction of cell-cycle arrest at the S-phase and apoptosis, accompanied by a decrease in c-Myc and increase in p21(waf1/cip1). In a leukemia model engrafted with U-937 cells, JTE-607 significantly prolonged survival in mice and reduced human cytokine mRNA levels in the bone marrow. These results suggest the usefulness of JTE-607 in therapeutic applications for patients with hypercytokinemia and aggressive AML cell proliferation.

Physical activity and hematologic cancer prevention

This chapter presents the epidemiologic evidence on the association between physical activity and hematologic cancers and related hypothesized biologic mechanisms. Some preliminary indications of a protective role for physical activity for non-Hodgkin's lymphoma, leukemia, multiple myeloma, and Hodgkin's lymphoma exist, but the level of epidemiologic evidence is still insufficient to make any definitive conclusions regarding the nature of these associations. Several plausible biologic mechanisms underlying the possible associations between physical activity and hematologic cancers have been proposed, including enhancement of immune function, reduction in obesity, improvement of antioxidant defense systems, impact on metabolic hormones, and anti-inflammatory effects. Future studies should improve the estimation of physical activity by using more reliable, valid, and comprehensive measurement tools, assessing all components of physical activity (type, intensity, and time period), and conducting intervention studies to evaluate the effect of physical activity on various biomarkers of cancer in order to provide further insight into plausible biologic mechanisms underlying the possible association between physical activity and hematologic cancers.

IL-3 and oncogenic Abl regulate the myeloblast transcriptome by altering mRNA stability

The growth factor interleukin-3 (IL-3) promotes the survival and growth of multipotent hematopoietic progenitors and stimulates myelopoiesis. It has also been reported to oppose terminal granulopoiesis and to support leukemic cell growth through autocrine or paracrine mechanisms. The degree to which IL-3 acts at the posttranscriptional level is largely unknown. We have conducted global mRNA decay profiling and bioinformatic analyses in 32Dcl3 myeloblasts indicating that IL-3 caused immediate early stabilization of hundreds of transcripts in pathways relevant to myeloblast function. Stabilized transcripts were enriched for AU-Response elements (AREs), and an ARE-containing domain from the interleukin-6 (IL-6) 3′-UTR rendered a heterologous gene responsive to IL-3-mediated transcript stabilization. Many IL-3-stabilized transcripts had been associated with leukemic transformation. Deregulated Abl kinase shared with IL-3 the ability to delay turnover of transcripts involved in proliferation or differentiation blockade, relying, in part, on signaling through the Mek/Erk pathway. These findings support a model of IL-3 action through mRNA stability control and suggest that aberrant stabilization of an mRNA network linked to IL-3 contributes to leukemic cell growth.

Clinical significance of plasmacytosis in the day+14 bone marrow of patients with acute myeloid leukaemia undergoing induction chemotherapy

BACKGROUND

The design of chemotherapy-induction regimens for acute myeloid leukaemia (AML) is directed towards the early elimination of bone marrow (BM) leukaemic blast cells (LBCs). Patients with AML after induction show LBC reduction in a hypoplastic BM and also demonstrate a varying number of residual BM plasma cells (PCs).

AIM

To relate PC number to several blood and BM parameters as well as clinical features such as infection and survival.

METHODS

On the 14th day after the start of chemotherapy (D+14) BM samples were examined for residual PCs in 60 adult (>or=15 years) patients undergoing AML-induction chemotherapy, and the proportion of PCs was related to blood and BM parameters including French-American-British (FAB) subtype, other inflammatory cells, antecedent infection, attainment of complete remission and 36-month survival.

RESULTS

Median PC proportion of 11.3% (range 0.1-48.7%) in D+14 BM aspirates and 10.7% (0.6-41%) in trephine biopsies was observed. Their number showed a direct relationship with residual BM lymphocytes (r=0.368; p=0.025). Higher numbers of residual PCs also reflected the presence of infection before diagnosis and coincident with treatment (p=0.039). Although we could not demonstrate an association between PC numbers and 36-month survival, PC numbers were significantly higher in patients with residual leukaemia at D>14 (p=0.007).

CONCLUSION

D+14 BM PC number reflects the effectiveness of induction chemotherapy and the presence of antecedent inflammation or infection.

JTE-607, a multiple cytokine production inhibitor, ameliorates disease in a SCID mouse xenograft acute myeloid leukemia model

OBJECTIVE

Accumulating findings suggest that in acute myeloid leukemia (AML) patients, proinflammatory cytokines and growth factors play important roles in the proliferation and survival of AML cells in an autocrine and paracrine manner, leading to deterioration of AML. JTE-607 is a multiple cytokine inhibitor that potently suppresses production of proinflammatory cytokines. In the present study, we investigated the potency of JTE-607 as an antileukemic agent by exploiting a SCID mouse acute leukemia model.

METHODS

SCID mice injected with anti-asialo-GM1 antibody were exposed to sublethal total-body irradiation at a dose of 3 Gy and then inoculated intravenously with AML cells. JTE-607 was administered using osmotic minipumps. The effects of JTE-607 on mouse survival time, human interleukin (IL)-8 levels in mouse plasma, and proportion of human CD45(+) cells in the bone marrow were studied.

RESULTS

The survival time of the mice was strictly dependent on the number of U-937 cells proliferating in vivo. Administration of JTE-607 during the initial 7 days significantly prolonged survival of the mice, suggesting killing activity of JTE-607 against AML cells in vivo. Delayed administration of JTE-607 also prolonged the survival of mice bearing established leukemia with an effect comparable to the maximum tolerable dose of cytarabine. Flow cytometer analysis of bone marrow cells revealed decreased number of human CD45(+) cells. Human IL-8 level was also reduced by JTE-607.

CONCLUSION

Our results indicate that JTE-607 has potential to be a new class of antileukemic drug that exerts inhibitory activities against both the proliferation and proinflammatory cytokine production of AML cells.

Cognitive impairment, fatigue, and cytokine levels in patients with acute myelogenous leukemia or myelodysplastic syndrome

BACKGROUND

The objective of the current study was to assess the correlations between cognitive function, fatigue, quality of life, and circulating cytokine levels in patients with acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS).

METHODS

Fifty-four patients with AML/MDS were seen for pretreatment evaluation of their cognitive function and symptoms. Fifty percent of the sample was reevaluated 1 month later, when response to protocol chemotherapy was assessed.

RESULTS

A significant proportion of patients had impaired cognitive function prior to the institution of chemotherapy. Sixty-five percent of patients also experienced significant fatigue. Levels of the circulating cytokines interleukin 1 (IL-1), IL-1 receptor antagonist (IL-1RA), IL-6, IL-8, and tumor necrosis factor-alpha (TNF-alpha) were elevated highly compared with normal controls. Higher IL-6 levels were associated with poorer executive function, whereas higher IL-8 levels were associated with better memory performance. IL-6, IL-1RA, and TNF-alpha levels were related to ratings of fatigue. Fatigue and cognitive dysfunction were unrelated. Hemoglobin levels were not associated significantly with either cognitive dysfunction or fatigue. Patients who obtained a complete response tended to have better fine motor control at baseline and lower circulating IL-1 levels. Treatment did not have a significant impact on cognition, although fatigue levels tended to increase.

CONCLUSIONS

Patients with AML/MDS are highly symptomatic and experience cognitive impairment and fatigue before the initiation of their treatment. The current results indicated a correlation between these symptoms and levels of circulating cytokines, providing some support to the hypothesis that cancer-related symptoms are related at least in part to cytokine-immunologic activation. Elucidation of immunologic correlates of symptoms will allow for targeted interventions.

Leukemic cells and the cytokine patchwork

BACKGROUND

In leukemia, the clonal population is characterized by a hierarchical organization. Although the majority of the leukemic population is generated after post-determinic divisions, a subset of cells retain undifferentiated "blast" morphology. In addition, leukemic cells often have numerical or structural chromosomal abnormalities, aberrant gene expression patterns, and abnormal cell surface marker profiles. Despite these differences when compared to normal bone marrow and blood cells, leukemic cell survival and proliferation, just like that of normal progenitor cells, is influenced by hematopoietic growth factors. A major issue is whether differential regulation of normal and leukemic hematopoietic cells by cytokines can be exploited in antileukemic treatment or, in contrast, whether in vivo cytokine therapy may even be harmful to the patients.

PROCEDURE

Here we review the results of recent experimental and clinical observations that investigated the influence of cytokines on leukemic cell growth and differentiation in vitro and in vivo.

RESULTS

The majority of studies indicate that hematopoietic growth factors are involved in the regulation of proliferation and terminal differentiation of leukemic blast cells. Genetic aberrations involving cytokines or their receptors may contribute to leukemogenesis. Abundant interactions, cross-lineage stimulation, and aberrant response patterns seem to transform the complex cytokine network regulation of normal hematopoiesis into an even more interlaced "patchwork" that controls leukemic hematopoiesis.

CONCLUSIONS

Since hematopoietic growth factors are present in high serum concentrations in patients with acute leukemia and myelodysplastic syndromes, consequences of possible interactions should be kept in mind even when well-defined human recombinant factors in single application are to be involved in antileukemic protocols.

Association of acute parvovirus B19 infection with new onset of acute lymphoblastic and myeloblastic leukaemia

AIMS

To investigate the association of acute parvovirus B19 infection with new onset of acute lymphoblastic and myeloblastic leukaemia.

METHODS

Cerebrospinal fluid (CSF) samples from patients with acute myelogenous leukaemia (AML) at diagnosis (n = 2) and acute lymphoblastic leukaemia (ALL) at diagnosis (n = 14) were analysed for parvovirus B19 DNA by means of nested polymerase chain reaction. In addition, samples from patients with benign intracranial hypertension (BIH) (n = 10) and hydrocephalus (n = 13) were tested as controls.

RESULTS

Four leukaemia cases were positive-common ALL (n = 2), null cell ALL (n =1), and M7 AML (n = 1)-whereas all controls were negative (Yates corrected chi(2) value, 3.97; p = 0.046; odds ratio, 16.92; confidence interval, 1.03 to 77.18). All four patients were significantly anaemic, but none was encephalitic or had evidence of central nervous system leukaemia. In three of these patients, serum tumour necrosis alpha, interferon gamma, interleukin 6, granulocyte-macrophage colony stimulating factor (range, 34.93-3800.06 pg/ml), and macrophage chemoattractant protein 1 were detectable. All of these four patients carried at least one of the HLA-DRB1 alleles, which have been associated with symptomatic parvovirus B19 infection.

CONCLUSION

Erythroid suppression and immune cell proliferation are both associated with B19 infection and may also be important in the pathogenesis of acute leukaemia.