Cellular Oncology最新文献

Purpose: Malignant melanoma is the deadliest skin cancer, with a poor prognosis in advanced stages. We reported that both Hedgehog-GLI (HH/GLI) and Mitogen-activated protein Kinase (MAPK) extracellular signal-regulated kinase 5 (ERK5) pathways promote melanoma growth, and that ERK5 activation is required for HH/GLI-dependent melanoma cell proliferation. Here, we explored whether ERK5 regulates HH/GLI signaling.

Methods: Both genetic (using ERK5-specific shRNA) and pharmacologic (using the ERK5 inhibitors JWG-071 and AX15836, and the MAPK/ERK kinase 5, MEK5 inhibitors GW284543 and BIX02189) targeting approaches were used. Luciferase assay using the GLI-binding site luciferase reporter was performed to evaluate GLI transcriptional activity. A constitutively active form of MEK5 (MEK5DD) was used to induce ERK5 activation. 3D spheroid assays were performed in melanoma cells.

Results: Genetic and pharmacologic ERK5 inhibition reduces GLI1 and GLI2 protein levels and transcriptional activity of endogenous HH/GLI pathway induced by the agonist SAG in NIH/3T3 cells. In these cells, MEK5DD overexpression potentiates transcriptional activity of endogenous HH/GLI pathway induced by SAG, whereas ERK5 silencing prevents this effect. Consistently, MEK5DD overexpression increases GLI1 and GLI2 protein levels. In melanoma cells, ERK5 silencing reduces GLI1 and GLI2 mRNA and protein levels and inhibits GLI transcriptional activity. MEK5DD further increases the transcriptional activity of the HH/GLI pathway and GLI1 protein levels. Combination of GLI and MEK5 inhibitors is more effective than single treatments in reducing melanoma spheroid growth.

Conclusions: MEK5-ERK5 is an activator of GLI transcription factors, and combined targeting of these pathways warrants further preclinical investigation as a potential innovative therapeutic approach for melanoma.

Hypoxia is a critical microenvironmental condition that plays a major role in driving tumorigenesis and cancer progression. Increasing evidence has revealed novel functions of hypoxia in intercellular communication. The hypoxia induced tumor derived exosomes (hiTDExs) released in high quantities by tumor cells under hypoxia are packed with unique cargoes that are essential for cancer cells' interactions within their microenvironment. These hiTDExs facilitate not only immune evasion but also promote cancer cell growth, survival, angiogenesis, EMT, resistance to therapy, and the metastatic spread of the disease. Nevertheless, direct interventions targeting hypoxia signaling in cancer therapy face challenges related to tumor progression and resistance, limiting their clinical effectiveness. Therefore, deepening our understanding of the molecular processes through which hiTDExs remodels tumors and their microenvironment, as well as how tumor cells adjust to hypoxic conditions, remains essential. This knowledge will pave the way for novel approaches in treating hypoxic tumors. In this review, we discuss recent work revealing the hiTDExs mediated interactions between tumor and its microenvironment. We have described key hiTDExs cargos (lncRNA, circRNAs, cytokines, etc.) and their targets in the receipt cells, responsible for various biological effects. Moreover, we emphasized the importance of hiTDExs as versatile elements of cell communication in the tumor microenvironment. Finally, we highlighted the effects of hiTDExs on the molecular changes in target cells by executing molecular cargo transfer between cells and altering signaling pathways. Currently, hiTDExs show promise in the treatment of diseases. Understanding the molecular processes through which hiTDExs influence tumor behavior and their microenvironment, along with how tumor cells adapt to and survive in low-oxygen conditions, remains a central focus in cancer research, paving the way for innovative strategies in treating hypoxic tumors and enhancing immunotherapy.

Purpose: Central nervous system (CNS) involvement and/or relapse remains one of the most important causes of morbidity/mortality in paediatric B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) patients. To identify novel therapeutic targets and develop less aggressive therapies, a better understanding of the cellular and molecular microenvironment in leptomeningeal metastases is key. Here, we aimed to investigate the formation of metastatic leptomeningeal aggregates and their relevance to the expansion, survival and chemoresistance acquisition of leukaemia cells.

Methods: We used BCP-ALL xenograft mouse models, combined with immunohistofluorescence and flow cytometry, to study the development of CNS metastasis and the contribution of leptomeningeal cells to the organisation of leukaemic aggregates. To in vitro mimic the CNS metastasis, we established co-cultures of three-dimensional (3D) ALL cell spheroids and human leptomeningeal cells (hLMCs) and studied the effects on gene expression, proliferation, cytokine production, and chemoresistance.

Results: In xenografted mice, ALL cells infiltrated the CNS at an early stage and, after crossing an ER-TR7⁺ fibroblast-like meningeal cell layer, they proliferated extensively and formed large vascularised leukaemic aggregates supported by a network of podoplanin⁺ leptomeningeal cells. In leukaemia spheroid-hLMC co-cultures, unlike conventional 2D co-cultures, meningeal cells strongly promoted the proliferation of leukaemic cells and generated a pro-inflammatory microenvironment. Furthermore, in 3D cell aggregates, leukaemic cells also developed chemoresistance, at least in part due to ABC transporter up-regulation.

Conclusion: Our results provide evidence for the formation of metastatic ALL-leptomeningeal cell aggregates, their pro-inflammatory profile and their contribution to leukaemic cell expansion, survival and chemoresistance in the CNS.

Introduction: Germline CDKN2A variant predisposes to childhood acute lymphoblastic leukemia (ALL) through allelic expression imbalance (AEI). It is unknown, therefore, how these germline variations work and whether they all confer B-ALL susceptibility through AEI.

Methods and results: Using allele-specific Taqman PCR assays, we demonstrated that preferentially expressed of those functional inherited coding variants in leukemic cells compared to hematopoietic cells. In an inherent p 16^Ink4a-defective Ba/F3 cell model overexpressing functional p16^INK4A variants showed enhanced susceptibility to transformation by BCR-ABL1-, NRAS^G12D-, and JAK2^R683G + CRLF2-. Notably, the variant p16^INK4A exhibited higher transcription level than wild-type allele in co-expression studies. While CDK4/6 inhibitor partially suppressed NRAS^G12D-, and JAK2^R683G + CRLF2-induced transformation, it proved ineffective against BCR-ABL1-induced leukemic transformation. Differential gene expression analysis revealed upregulation of m6A-related gene PRRC2A, whose knockout partially restored wild-type p16^INK4A expression.

Conclusion: These findings illuminate how inherited CDKN2A genetic variations of coding region influence ALL development through AEI mechanisms.

Tumor-infiltrating myeloid cells (TIMs), which encompass tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), myeloid-derived suppressor cells (MDSCs), and tumor-associated dendritic cells (TADCs), are of great importance in tumor microenvironment (TME) and are integral to both pro- and anti-tumor immunity. Nevertheless, the phenotypic heterogeneity and functional plasticity of TIMs have posed challenges in fully understanding their complexity roles within the TME. Emerging evidence suggested that the presence of TIMs is frequently linked to prevention of cancer treatment and improvement of patient outcomes and survival. Given their pivotal function in the TME, TIMs have recently been recognized as critical targets for therapeutic approaches aimed at augmenting immunostimulatory myeloid cell populations while depleting or modifying those that are immunosuppressive. This review will explore the important properties of TIMs related to immunity, angiogenesis, and metastasis. We will also document the latest therapeutic strategies targeting TIMs in preclinical and clinical settings. Our objective is to illustrate the potential of TIMs as immunological targets that may improve the outcomes of existing cancer treatments.

Background: Adoptive cell therapy (ACT) mediates durable and complete regression of various cancers. However, its efficacy is limited by the long-term persistence of cytotoxic T lymphocytes, given their irreversible dysfunction within the tumor microenvironment. Herein, we aimed to establish an artificial lung metastasis model to examine T-lymphocyte subsets, in order to identify potential effective cell subsets for ACT.

Methods: A metastatic lung melanoma mouse model was established using OVA-expressing melanoma B16 cells. Flow cytometry analysis was conducted to examine the surface markers, transcription factors, and secreted cytokines of tumor-specific CD8⁺ T cells within metastatic tissues. The infiltrated cells were sorted by flow cytometry for in vitro tumor cell killing assays or in vivo cell infusion therapy combined with chemotherapeutic drugs and immune checkpoint blockade antibodies.

Results: Exhausted CD8⁺ T cells (Tex) exhibited high heterogeneity in metastatic tissues. Among Tex cells, the CXCR6^- precursor cell showed certain memory characteristics, including phenotype, transcription factors, and maintenance, whereas the CXCR6⁺ subpopulation partially lost these traits. Moreover, CXCR6⁺ precursor cells effectively replenished effector-like Tex cells in metastatic tissues and exerted direct cytotoxicity against tumor cells. Notably, transferring these tumor-specific CXCR6⁺ precursor-exhausted T (Texp) cells into recipients induced a substantial regression of metastasis. In addition, these cells could respond to immune checkpoint blockade, which could better control tumor metastasis.

Conclusions: In our study, a subset of antigen-specific CXCR6-expressing Texp cells was observed within the metastatic tissue. The cells served as a crucial source of effector-like Tex cells and exerted direct cytotoxic effects on tumor cells. Adoptive transfer of CXCR6⁺ Texp cells effectively mitigated lung metastasis in mice. This study helps elucidate the role of Texp cells in metastasis, thereby offering novel insights into enhancing the efficacy and durability of immunotherapy.

Cell senescence is a natural response within our organisms. Initially, it was considered an effective anti-tumor mechanism. However, it is now believed that while cell senescence initially acts as a robust barrier against tumor initiation, the subsequent accumulation of senescent cells can paradoxically promote cancer recurrence and cause damage to neighboring tissues. This intricate balance between cell proliferation and senescence plays a pivotal role in maintaining tissue homeostasis. Moreover, senescence cells secrete many bioactive molecules collectively termed the senescence-associated secretory phenotype (SASP), which can induce chronic inflammation, alter tissue architecture, and promote tumorigenesis through paracrine signaling. Among the myriads of compounds, senotherapeutic drugs have emerged as exceptionally promising candidates in anticancer treatment. Their ability to selectively target senescent cells while sparing healthy tissues represents a paradigm shift in therapeutic intervention, offering new avenues for personalized oncology medicine. Senolytics have introduced new therapeutic possibilities by enabling the targeted removal of senescent cells. As standalone agents, they can clear tumor cells in a senescent state and, when combined with chemo- or radiotherapy, eliminate residual senescent cancer cells after treatment. This dual approach allows for the intentional use of lower-dose therapies or the removal of unintended senescent cells post-treatment. Additionally, by targeting non-cancerous senescent cells, senolytics may help reduce tumor formation risk, limit recurrence, and slow disease progression. This article examines the mechanisms of cellular senescence, its role in cancer treatment, and the importance of senotherapy, with particular attention to the therapeutic potential of senolytic drugs.

Background: Sorafenib is a commonly used first-line kinase-targeted drug for advanced hepatocellular carcinoma (HCC) patients suffering from limited efficacy. Emerging evidence indicates that sorafenib exerts anti-cancer activity through the induction of ferroptosis in HCC cells, but the underlying mechanism is still unclear.

Methods: The whole transcriptome sequencing and bioinformatics analysis were used to screen for target genes. The expression and subcellular localization of regulatory factor X1 (RFX1) were determined through immunohistochemistry, immunofluorescence, PCR and western blot analyses. The impact of RFX1 on HCC cell growth was assessed using CCK8, colony formation assays, cell death assays, and animal experiments. Glutathione measurement, iron assay and lipid peroxidation detection assays were performed to investigate ferroptosis of HCC cells. The regulatory mechanism of RFX1 in HCC was investigated by sgRFX1, co-IP, ChIP and luciferase experiments. Immunohistochemical and survival analyses were performed to examine the prognostic significance of RFX1 in HCC.

Results: In this study, we found that RFX1 promote ferroptosis in HCC cells. Further, we showed that sorafenib induces cell death through RFX1-mediated ferroptosis in HCC cells. The enhancing effect of RFX1 on HCC cell ferroptosis is largely dependent on inhibition of cystine/glutamate antiporter (system Xc-) activity through the BECN-SLC7A11 axis, where RFX1 directly binds to the promoter region of BECN1 and upregulates BECN1 expression. In addition, a STAT3-RFX1-BECN1 signalling loop was found to promote RFX1 expression in HCC cells.

Conclusions: Our study reveals a novel mechanism underlying sorafenib-induced HCC cell death.

T helper (Th) cell subsets play pivotal roles in regulating immune responses within the tumor microenvironment, influencing both tumor progression and anti-tumor immunity. Among these subsets, Th1 cells promote cytotoxic responses through the production of IFN-γ, while Th2 cells and regulatory T cells (Tregs) exert immunosuppressive effects that support tumor growth. Th9 and Th17 cells have context-dependent roles, contributing to both pro-inflammatory and regulatory processes in tumor immunity. Tumor antigen-specific T cells within the tumor microenvironment often exhibit a dysfunctional phenotype due to increased expression of inhibitory receptors such as CTLA-4 and PD-1, leading to reduced antitumor activity. Monoclonal antibodies that block these inhibitory signals-collectively known as immune checkpoint inhibitors (ICIs)-can reactivate these T cells, enhancing their ability to target and destroy cancer cells. Recent advancements have highlighted the critical role of T helper subsets in modulating responses to ICIs, with their interactions remaining a focus of ongoing research. Both positive and negative effects of ICIs have been reported in relation to Th cell subsets, with some effects depending on the type of tumor microenvironment. This review summarizes the crucial roles of different T helper cell subsets in tumor immunity and their complex relationship with immune checkpoint inhibitor therapy.

Background: Lenvatinib is a potent first-line therapy for patients with hepatocellular carcinoma (HCC), but it also increased the number of neutrophils in HCC tumor microenvironment.

Methods: CitH3, MPO-DNA, elastase and MPO activity were measured for assessing neutrophil extracellular traps (NETs) in vivo and in vitro. Cell cuproptosis was assessed by measurement of copper content, FDX1, and pyruvate. The functions of lenvatinib, DNase I, interleukin 33 (IL33) neutralizing antibody and GPX4 in tumor growth were explored in mice.

Results: Lenvatinib induced NETs in the HCC tumor microenvironment via HCC cells, but not through the direct stimulation of neutrophils. In addition, NET clearance by DNase I improves the efficacy of lenvatinib therapy in HCC mouse models. Mechanistically, lenvatinib promoted the expression and secretion of IL33 by HCC cells that triggered NET formation. Moreover, IL33 knockdown in Hepa1-6 cells improved lenvatinib efficacy in Hepa1-6-bearing HCC model mice and reduced NET formation in the tumor microenvironment. Subsequently, lenvatinib increased IL33 production by increasing the NDUFA4L2 expression in HCC cells. Furthermore, we found that IL33 triggered NET formation in neutrophils by increasing the protein expression of PADI4 via the Akt/mTOR signaling pathway. Rapamycin inhibition of mTOR reduced PADI4 expression and NET formation. Consistently, PADI4 inhibition by the selective PAD4 inhibitor GSK484 hydrochloride (GSK484) improved lenvatinib response to HCC therapy. Importantly, NETs contribute to lenvatinib resistance by inhibiting cuproptosis, but not apoptosis, pyroptosis, or ferroptosis in HCC cells. Treatment with GSK484 reversed the inhibitory effects of NETs on cuproptosis and sensitized the HCC cells to lenvatinib.

Conclusions: Our study revealed that lenvatinib-induced NETs inhibited the cuproptosis of HCC cells, suggesting that targeting the IL33/PADI4/NET axis represents a promising therapeutic strategy for ameliorating lenvatinib resistance in HCC.