Lyn mediates FIP1L1-PDGFRA signal pathway facilitating IL-5RA intracellular signal through FIP1L1-PDGFRA/JAK2/Lyn/Akt network complex in CEL

Molecular Signature of Neuroinflammation Induced in Cytokine-Stimulated Human Cortical Spheroids

Crucial in the pathogenesis of neurodegenerative diseases is the process of neuroinflammation that is often linked to the pro-inflammatory cytokines Tumor necrosis factor alpha (TNFα) and Interleukin-1beta (IL-1β). Human cortical spheroids (hCSs) constitute a valuable tool to study the molecular mechanisms underlying neurological diseases in a complex three-dimensional context. We recently designed a protocol to generate hCSs comprising all major brain cell types. Here we stimulate these hCSs for three time periods with TNFα and with IL-1β. Transcriptomic analysis reveals that the main process induced in the TNFα- as well as in the IL-1β-stimulated hCSs is neuroinflammation. Central in the neuroinflammatory response are endothelial cells, microglia and astrocytes, and dysregulated genes encoding cytokines, chemokines and their receptors, and downstream NFκB- and STAT-pathway components. Furthermore, we observe sets of neuroinflammation-related genes that are specifically modulated in the TNFα-stimulated and in the IL-1β-stimulated hCSs. Together, our results help to molecularly understand human neuroinflammation and thus a key mechanism of neurodegeneration.

Clinical Significance and Immunologic Landscape of a Five-IL(R)-Based Signature in Lung Adenocarcinoma

Interleukins (ILs) and interleukin receptors (ILRs) play important role in the antitumor immune response. However, the expression signature and clinical characteristics of the IL(R) family in lung adenocarcinoma (LUAD) remains unclear. The main purpose of this study was to explore the expression profile of IL(R) family genes and construct an IL(R)-based prognostic signature in LUAD. Five public datasets of 1,312 patients with LUAD were enrolled in this study. Samples from The Cancer Genome Atlas (TCGA) were used as the training set, and samples from the other four cohorts extracted from Gene Expression Omnibus (GEO) database were used as the validation set. Additionally, the profile of IL(R) family signature was explored, and the association between this signature and immunotherapy response was also analyzed. Meanwhile, the prognostic value was compared between this IL(R)-based signature and different immunotherapy markers. A signature based on five identified IL(R)s (IL7R, IL5RA, IL20RB, IL11, IL22RA1) was constructed using the TCGA dataset through univariate/multivariable Cox proportional hazards regression and least absolute shrinkage and selection operator (LASSO) Cox analysis. These cases with LUAD were stratified into high- and low-risk group according to the risk score. This signature showed a strong prognostic ability, which was verified by the five independent cohorts and clinical subtypes. The IL(R)-based models presented unique characteristics in terms of immune cell infiltration and immune inflammation profile in tumor microenvironment (TME). Biological pathway analysis confirmed that high-risk patients showed significant T- and B-cell immunosuppression and rapid tumor cell proliferation. More importantly, we researched the relationship between this IL(R)-based signature and immune checkpoints, tumor mutation burden (TMB), tumor purity and ploidy, and tumor immune dysfunction and exclusion (TIDE) score, which confirmed that this signature gave the best prognostic value. We first provided a robust prognostic IL(R)-based signature, which had the potential as a predictor for immunotherapy response to realize individualized treatment of LUAD.

S100A8 and S100A9 Promote Apoptosis of Chronic Eosinophilic Leukemia Cells

S100A8 and S100A9 function as essential factors in inflammation and also exert antitumor or tumorigenic activity depending on the type of cancer. Chronic eosinophilic leukemia (CEL) is a rare hematological malignancy having elevated levels of eosinophils and characterized by the presence of the FIP1L1-PDGFRA fusion gene. In this study, we examined the pro-apoptotic mechanisms of S100A8 and S100A9 in FIP1L1-PDGFRα+ eosinophilic cells and hypereosinophilic patient cells. S100A8 and S100A9 induce apoptosis of the FIP1L1-PDGFRα+ EoL-1 cells via TLR4. The surface TLR4 expression increased after exposure to S100A8 and S100A9 although total TLR4 expression decreased. S100A8 and S100A9 suppressed the FIP1L1-PDGFRα-mediated signaling pathway by downregulating FIP1L1-PDGFRα mRNA and protein expression and triggered cell apoptosis by regulating caspase 9/3 pathway and Bcl family proteins. S100A8 and S100A9 also induced apoptosis of imatinib-resistant EoL-1 cells (EoL-1-IR). S100A8 and S100A9 blocked tumor progression of xenografted EoL-1 and EoL-1-IR cells in NOD-SCID mice and evoked apoptosis of eosinophils derived from hypereosinophilic syndrome as well as chronic eosinophilic leukemia. These findings may contribute to a progressive understanding of S100A8 and S100A9 in the pathogenic and therapeutic mechanism of hematological malignancy.

Mechanisms of glucocorticoid resistance in hypereosinophilic syndromes

BACKGROUND

Glucocorticoids (GC) are considered first-line therapy for most patients with hypereosinophilic syndrome (HES). Although response rates are generally high, many patients require moderate to high doses for control of eosinophilia and symptoms, and up to 15% of patients do not respond at all. Despite this, little is known about the mechanisms of GC resistance in patients with HES.

OBJECTIVE

To explore the aetiology of GC resistance in HES.

METHODS

Clinical data and samples from 26 patients with HES enrolled on a prospective study of GC responsiveness and 23 patients with HES enrolled on a natural history study of eosinophilia for whom response to GC was known were analysed retrospectively. Expression of GC receptor isoforms was assessed by quantitative RT-PCR in purified eosinophils. Serum cytokine levels were quantified by suspension array assay in multiplex.

RESULTS

Despite an impaired eosinophil response to GC after 7 days of treatment, the expected rise in absolute neutrophil count was seen in 7/7 GC-resistant patients, suggesting that GC resistance in HES is not a global phenomenon. Eosinophil mRNA expression of glucocorticoid receptor (GR) isoforms (α, β, and P) was similar between GC-sensitive (n = 20) and GC-resistant (n = 9) patients with HES. Whereas geometric mean serum levels were also comparable between GC-r (n = 11) and GC-s (n = 19) for all cytokines tested, serum IL-5 levels were >100 pg/mL only in GC-r patients.

CONCLUSIONS AND CLINICAL RELEVANCE

These data suggest that the mechanism of GC resistance in HES is not due to a global phenomenon affecting all lineages, but may be due, at least in some patients, to impairment of eosinophil apoptosis by increased levels of IL-5.

Lyn Kinase Promotes the Proliferation of Malignant Melanoma Cells through Inhibition of Apoptosis and Autophagy via the PI3K/Akt Signaling Pathway

Melanoma is a malignant tumor of cutaneous melanocytes that is characterized by high grade malignancy, rapid progression and high mortality. Thus far, its specific etiological mechanism has been unclear. In this study, we discovered that Lyn kinase expression was up-regulated in melanoma tissues and cells. The function of Lyn was determined by knocking down its expression with a lentivirus containing Lyn shRNA and upregulating its expression with pcDNA3.1-Lyn in the melanoma cell lines M14 and A375. The results showed that Lyn knockdown could significantly inhibit the proliferation, migration and invasiveness through its inhibition of apoptosis and autophagy via the PI3K/Akt pathway in melanoma cell lines. This was further confirmed by treatment with PI3K inhibitor BEZ235. Up-regulation of Lyn promoted the expression of p-Akt and Cyclin D1. Additionally, we investigated the effects of Lyn inhibitor Bafetinib on melanoma cells and the results were consistent with Lyn knockdown. Collectively, our results indicated that Lyn plays a carcinogenic role in multiple cellular functions during melanoma development through regulating apoptosis and autophagy via the PI3K/Akt pathway and may be a valuable potential target for the clinical treatment of melanoma.