Suppression of CXCL-1 Could Restore Necroptotic Pathway in Chronic Lymphocytic Leukemia

Deregulation of New Cell Death Mechanisms in Leukemia

Hematological malignancies are among the top five most frequent forms of cancer in developed countries worldwide. Although the new therapeutic approaches have improved the quality and the life expectancy of patients, the high rate of recurrence and drug resistance are the main issues for counteracting blood disorders. Chemotherapy-resistant leukemic clones activate molecular processes for biological survival, preventing the activation of regulated cell death pathways, leading to cancer progression. In the past decade, leukemia research has predominantly centered around modulating the well-established processes of apoptosis (type I cell death) and autophagy (type II cell death). However, the development of therapy resistance and the adaptive nature of leukemic clones have rendered targeting these cell death pathways ineffective. The identification of novel cell death mechanisms, as categorized by the Nomenclature Committee on Cell Death (NCCD), has provided researchers with new tools to overcome survival mechanisms and activate alternative molecular pathways. This review aims to synthesize information on these recently discovered RCD mechanisms in the major types of leukemia, providing researchers with a comprehensive overview of cell death and its modulation.

Strategies for modifying the chimeric antigen receptor (CAR) to improve safety and reduce toxicity in CAR T cell therapy for cancer

Immune cell therapy with chimeric antigen receptor (CAR) T cells, which has shown promising efficacy in patients with some hematologic malignancies, has introduced several successfully approved CAR T cell therapy products. Nevertheless, despite significant advances, treatment with these products has major challenges regarding potential toxicity and sometimes fatal adverse effects for patients. These toxicities can result from cytokine release or on-target off-tumor toxicity that targets healthy host tissue following CAR T cell therapy. The present study focuses on the unexpected side effects of targeting normal host tissues with off-target toxicity. Also, recent safety strategies such as replacing or adding different components to CARs and redesigning CAR structures to eliminate the toxic impact of CAR T cells, including T cell antigen coupler (TAC), switch molecules, suicide genes, and humanized monoclonal antibodies in the design of CARs, are discussed in this review.

Bioinformatics Analysis of Prognostic Significance and Immune Characteristics of CXC Chemokine Family in Patients with Lung Adenocarcinoma

Objective

To screen CXC chemokines related to the risk of lung adenocarcinoma (LUAD) using bioinformatics and construct a CXC-based prognostic risk model to improve the diagnosis and treatment of LUAD patients.

Methods

The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) database were searched to obtain mRNA expression data and clinicopathological information of LUAD patients. CXC genes differentially expressed in LUAD were screened using the R packages. Further, risk factors significantly associated with the survival of LUAD patients were obtained by the univariate Cox proportional hazard regression, LASSO regression, and multivariate Cox proportional hazard regression analysis, following which a risk prediction model was constructed. The performance of the CXCL13-based model in predicting the prognosis of low-risk and high-risk effect LUAD patients was verified, and the association between the model and the degree of tumor immune cell infiltration was investigated.

Results

CXCL13 was significantly highly expressed in the cancer tissues of LUAD patients. The risk of death in patients with highly expressed CXCL13 was about 1.5 times higher than in those with lowly expressed CXCL13 (HR = 1.5153357). CXCL13-based risk scoring showed that the high-risk score of LUAD patients was significantly correlated with poor prognosis, but no relation between the two was found in the GEO validation sets, suggesting that this risk model may not be accurate enough. In addition, activated B cells, CD4+ T cells, CD8+ T cells, and dendritic cells were significantly positively correlated with the high risk of LUAD.

Conclusions

Although we found that a high expression of CXCL13 was associated with a high risk of death and immune cell infiltration and activation in LUAD patients, the CXCL13-based risk model was not accurate enough for predicting the prognosis of LUAD patients.

Increased TOX expression concurrent with PD-1, Tim-3, and CD244 expression in T cells from patients with acute myeloid leukemia

BACKGROUND

T cell dysregulation is a common event in leukemia. Recent findings have indicated that aberrant expression of immune checkpoint proteins may be associated with disease relapse and progression in acute myeloid leukemia (AML). TOX, a transcription factor in the HMG-box protein superfamily, was found to be a potential target for immunotherapy not only in solid tumors but also in hematological malignancies. However, little is known about TOX expression and co-expression with immune checkpoint proteins or the exhausted phenotype in the T cell subsets in AML. Thus, in this study, we analyzed TOX expression and co-expression with PD-1, Tim-3, and CD244 in T cells.

METHODS

TOX expression and co-expression with PD-1, Tim-3, and CD244 in CD3+, CD4+, regulatory T (Treg), and CD8+ T cells were analyzed by multi-color fluorescent flow cytometry in peripheral blood (PB) and bone marrow (BM) samples from patients with de novo AML and AML in complete remission (CR) and healthy individuals (HIs).

RESULTS

A significantly increased percentage of TOX+CD3+, CD4+, and CD8+ T cells was found in PB from patients with de novo AML in comparison with HIs. Double-positive TOX+CD244+, TOX+PD-1+, and TOX+Tim-3+ T cells markedly increased in the CD3+, CD4+, and CD8+ T cell populations in de novo AML patients compared with HIs, and similar trends were demonstrated for TOX+Tim-3+CD3+/CD4+/CD8+ T cells in de novo AML compared with AML-CR patients. In addition, the number of TOX+, TOX+PD-1+, and TOX+Tim-3+Treg cells significantly increased in de novo AML patients compared with HIs, and TOX+PD-1+Treg cells were higher in de novo AML compared with AML-CR patients. Moreover, TOX positively correlated with Tim-3 expression in CD8+ and Treg cells, and a positive correlation between the expression of TOX+ CD4+ and CD244+CD4+ T cells was found. Furthermore, an increased percentage of TOX+Tim-3+ T cells in BM was also found in de novo AML patients compared with HIs.

CONCLUSIONS

Increased TOX concurrent with PD-1, Tim-3, and CD244 in T cells may contribute to T cell exhaustion and impair their function in AML. Such exhausted T cells may be partially revised when AML patients achieve CR after chemotherapy. TOX may be considered a potential target for reversing T cell exhaustion and improving T cell function in AML.

Arhgap21 Deficiency Results in Increase of Osteoblastic Lineage Cells in the Murine Bone Marrow Microenvironment

ARHGAP21 is a member of the RhoGAP family of proteins involved in cell growth, differentiation, and adhesion. We have previously shown that the heterozygous Arhgap21 knockout mouse model (Arhgap21^+/-) presents several alterations in the hematopoietic compartment, including increased frequency of hematopoietic stem and progenitor cells (HSPC) with impaired adhesion in vitro, increased mobilization to peripheral blood, and decreased engraftment after bone marrow transplantation. Although these HSPC functions strongly depend on their interactions with the components of the bone marrow (BM) niche, the role of ARHGAP21 in the marrow microenvironment has not yet been explored. In this study, we investigated the composition and function of the BM microenvironment in Arhgap21^+/- mice. The BM of Arhgap21^+/- mice presented a significant increase in the frequency of phenotypic osteoblastic lineage cells, with no differences in the frequencies of multipotent stromal cells or endothelial cells when compared to the BM of wild type mice. Arhgap21^+/- BM cells had increased capacity of generating osteogenic colony-forming units (CFU-OB) in vitro and higher levels of osteocalcin were detected in the Arhgap21^+/- BM supernatant. Increased expression of Col1a1, Ocn and decreased expression of Trap1 were observed after osteogenic differentiation of Arhgap21^+/- BM cells. In addition, Arhgap21^+/- mice recipients of normal BM cells showed decreased leucocyte numbers during transplantation recovery. Our data suggest participation of ARHGAP21 in the balanced composition of the BM microenvironment through the regulation of osteogenic differentiation.

Therapeutic targeting of PIM KINASE signaling in cancer therapy: Structural and clinical prospects

BACKGROUND

PIM kinases are well-studied drug targets for cancer, belonging to Serine/Threonine kinases family. They are the downstream target of various signaling pathways, and their up/down-regulation affects various physiological processes. PIM family comprises three isoforms, namely, PIM-1, PIM-2, and PIM-3, on alternative initiation of translation and they have different levels of expression in different types of cancers. Its structure shows a unique ATP-binding site in the hinge region which makes it unique among other kinases.

SCOPE OF REVIEW

PIM kinases are widely reported in hematological malignancies along with prostate and breast cancers. Currently, many drugs are used as inhibitors of PIM kinases. In this review, we highlighted the physiological significance of PIM kinases in the context of disease progression and therapeutic targeting. We comprehensively reviewed the PIM kinases in terms of their expression and regulation of different physiological roles. We further predicted functional partners of PIM kinases to elucidate their role in the cellular physiology of different cancer and mapped their interaction network.

MAJOR CONCLUSIONS

A deeper mechanistic insight into the PIM signaling involved in regulating different cellular processes, including transcription, apoptosis, cell cycle regulation, cell proliferation, cell migration and senescence, is provided. Furthermore, structural features of PIM have been dissected to understand the mechanism of inhibition and subsequent implication of designed inhibitors towards therapeutic management of prostate, breast and other cancers.

GENERAL SIGNIFICANCE

Being a potential drug target for cancer therapy, available drugs and PIM inhibitors at different stages of clinical trials are discussed in detail.

Anticoagulants Used in Cardiac Catheterization of Patients With Chronic Lymphocytic Leukemia: A Case Report and Overview

Percutaneous coronary intervention (PCI) is one of the most frequently performed invasive therapeutic procedures and plays a key role in the long-term survival of patients with ischemic heart disease. Over 965,000 angioplasties are performed annually in the United States alone. While the technique and equipment have undergone significant revisions and improvement, the medical community will still benefit from more data and guidance on the optimal selection of mandatory peri-operation anticoagulation in specific, high-risk populations. Many of these procedures are performed on high-risk individuals who have an inherently higher risk of hemorrhage or thrombosis. Unfractionated heparin is the most popular choice in the general population, however, its use carries certain limitations. Here we will describe the use of an uncommonly used anticoagulant in a patient being actively treated for leukemia. We will also discuss the unique properties and benefits of the four most frequently used anticoagulants during a cardiac angioplasty. Our team describes the successful use of bivalirudin during an urgent PCI in a 71-year-old female with eight previous stents that was followed by an uncomplicated recovery period. Our experience contributes to a small, but growing, body of evidence that bivalirudin may be a safe choice to use in lieu of unfractionated heparin in patients with underlying oncological disease. Our patient had several comorbidities that significantly increased their risk of bleeding. We will also review the clinical trials that compared the four most commonly used anticoagulants during cardiac catheterization.

NFAT5 Regulated by STUB1, Facilitates Malignant Cell Survival and p38 MAPK Activation by Upregulating AQP5 in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is a clonal proliferative disease of mature B lymphocytes. To further improve the prognosis of patients, it is necessary to further elucidate the pathogenesis of CLL and find more effective therapeutic targets. Nuclear Factor of Activated T cells 5 (NFAT5) is the major activated transcription factor (TF) upon osmotic pressure increase in mammalian cells, and it also regulates many target genes to affect various cellular functions. The effects of NFAT5 on tumor growth and metastasis have also been widely revealed. However, the effects of NFAT5 on the progression of CLL are still unclear. In this study, we found abnormally high expression of NFAT5 in human CLL patients. Additionally, NFAT5 depletion suppressed proliferation and stimulated apoptosis of CLL cells. Our data further confirmed NFAT5 regulated AQP5 expression and the phosphorylation of p38 MAPK. We also found that AQP5 overexpression reversed the inhibitory effect of NFAT5 depletion on cell proliferation in CLL cells. Furthermore, we revealed STUB1 directly bound to NFAT5 and promoted its degradation. Taken together, our results indicate the involvement of NFAT5 in CLL progression and suggest that NFAT5 could serve as a promising therapeutic target for CLL treatment.