The complementary roles of STAT3 and STAT1 in cancer biology: insights into tumor pathogenesis and therapeutic strategies

Sigma1 inhibitor suppression of adaptive immune resistance mechanisms mediated by cancer cell derived extracellular vesicles

Adaptive immune resistance in cancer describes the various mechanisms by which tumors adapt to evade anti-tumor immune responses. IFN-γ induction of programmed death-ligand 1 (PD-L1) was the first defined and validated adaptive immune resistance mechanism. The endoplasmic reticulum (ER) is central to adaptive immune resistance as immune modulatory secreted and integral membrane proteins are dependent on ER. Sigma1 is a unique ligand-regulated integral membrane scaffolding protein enriched in the ER of cancer cells. PD-L1 is an integral membrane glycoprotein that is translated into the ER and processed through the cellular secretory pathway. At the cell surface, PD-L1 is an immune checkpoint molecule that binds PD-1 on activated T-cells and blocks anti-tumor immunity. PD-L1 can also be incorporated into cancer cell-derived extracellular vesicles (EVs), and EV-associated PD-L1 can inactivate T-cells within the tumor microenvironment. Here, we demonstrate that a selective small molecule inhibitor of Sigma1 can block IFN-γ mediated adaptive immune resistance in part by altering the incorporation of PD-L1 into cancer cell-derived EVs. Sigma1 inhibition blocked post-translational maturation of PD-L1 downstream of IFN-γ/STAT1 signaling. Subsequently, EVs released in response to IFN-γ stimulation were significantly less potent suppressors of T-cell activation. These results suggest that by reducing tumor derived immune suppressive EVs, Sigma1 inhibition may promote antitumor immunity. Sigma1 modulation presents a novel approach to regulating the tumor immune microenvironment by altering the content and production of EVs. Altogether, these data support the notion that Sigma1 may play a role in adaptive immune resistance in the tumor microenvironment.

N-terminal truncation of STAT1 transcription factor causes CD3- and CD20-negative non-Hodgkin lymphoma through upregulation of STAT3-mediated oncogenic functions

The cytokine-driven transcription factor STAT1 (signal transducer and activator of transcription 1) executes anti-microbial and pro-apoptotic functions, and loss-of-function mutations are associated with increased susceptibility to various infections and the development of tumors. A targeted mutation in mice expressing an N-terminally truncated STAT1 protein (STAT1-ΔN) typically develops splenomegaly in animals older than 6 months due to the formation of splenic non-Hodgkin lymphomas. The expression of the STAT1-ΔN variant resulted in the disruption of normal spleen architecture by malignant CD3- and CD20-negative tumor cells, which stained positively for both tyrosine-phosphorylated STAT1 and STAT3. Immunoblotting of lysates from isolated tumor cells revealed the cytokine-independent hyperphosphorylation of both STAT proteins, whereas the expression level of NF-κB was significantly reduced. Gel-shift assays showed that the DNA-binding activity of STAT1-ΔN was increased compared to the wild-type protein. This elevated level of tyrosine-phosphorylated STAT1-ΔN did not further increase upon stimulation of isolated tumor cells with either interferon-γ (IFNγ), lipopolysaccharide (LPS), or the combination of both. Since the truncation mutant was unable to accumulate in the nucleus upon cytokine stimulation, real-time PCR data from tumor tissue as well as from isolated, IFNγ/LPS-treated lymphoma cells demonstrated significantly reduced STAT1-regulated target gene expression despite its observed hyperphosphorylation. The nuclear import defect of tyrosine-phosphorylated STAT1-ΔN was associated with an elevated tyrosine-phosphorylation level of its antagonistic homolog STAT3, which is a known oncogene. These data demonstrate that the lack of STAT1 nuclear accumulation interferes with the functional balance between the two STAT proteins and, thereby, promotes the formation of phospho-STAT3-expressing CD3-/- CD20-/- non-Hodgkin lymphomas in the spleens of the diseased animals.

Modulating the JAK/STAT pathway with natural products: potential and challenges in cancer therapy

The Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) pathway is a critical signaling network governing cellular functions such as immune responses, proliferation, and apoptosis. Dysregulation of this pathway is strongly implicated in cancer progression. This review explores the therapeutic potential of natural products, including Curcumin, Resveratrol, Apigenin, and Epigallocatechin Gallate (EGCG), as modulators of the JAK/STAT pathway. These phytochemicals exhibit anticancer activity by inhibiting JAK/STAT phosphorylation, blocking STAT dimerization, and interfering with STAT-DNA binding. A systematic evaluation of included peer-reviewed studies highlights their promise as complementary agents to conventional cancer therapies. However, challenges such as poor bioavailability and the need for robust clinical validation remain significant hurdles. Addressing these limitations through advanced drug delivery systems and rigorous trials could unlock their full potential in cancer treatment.

Studying the efficacy of JBOL volatile components in idiopathic pulmonary fibrosis (IPF) using GC-MS and network pharmacology

Jin Bei oral liquid (JBOL) is a Chinese medicinal preparation for the treatment of idiopathic pulmonary fibrosis (IPF), Clinical trials have shown that IPF patients using JBOL have improved their lung function indicators FVC% and DLCO% by approximately 2.10% and 7.74%, suggesting that the agent has a positive effect in slowing disease progression. In this study, the active volatile components of JBOL were systematically identified and analyzed using gas chromatography-mass spectrometry (GC-MS), network pharmacology and molecular docking techniques. It was found that JBOL contains a variety of compounds with antifibrotic potential, which act through multi-target and multi-pathway mechanisms. Network pharmacological analyses revealed multiple targets of JBOL associated with key pathological processes in IPF, and key active ingredients were screened based on degree values (including Sedanolide, Ligustilide, Senkyunolide H, Senkyunolide I, α-Terpineol, and 4-Terpineol). Molecular docking results showed that these compounds have high affinity for target proteins. Finally, suitable quantitative methods were established and methodologically validated for these six compounds, and these methods were used to determine the content of 8 batches of JBOL and analyze the differences in content between batches.The present study provides a scientific basis for the quality control and standardization of its JBOL by identifying and analyzing its active volatile components.

Chalcone-9: a novel inhibitor of the JAK-STAT pathway with potent anti-cancer effects in triple-negative breast cancer cells

BACKGROUND

Breast cancer remains the leading cause of cancer incidence and mortality among women worldwide, with triple-negative breast cancer (TNBC) posing significant treatment challenges. The dysregulation of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway contributes to tumor progression, making it a potential therapeutic target. Chalcones, known for their diverse biological activities, including anti-cancer effects, hold promise for drug development. This study explores the anti-cancer activity of (E)-4-(3-(2-(benzyloxy)-6-hydroxyphenyl)-3-oxoprop-1-en-1-yl)benzoic acid (chalcone-9), a novel chalcone derivative.

METHODS

The cytotoxic effects of chalcone-9 were evaluated in breast cancer cell lines, including TNBC lines MDA-MB-231 and MDA-MB-468. Western blotting and qRT-PCR were used to analyze the impact on JAK1, JAK2, STAT1, and STAT3 activation and their downstream gene expression. In silico molecular docking analysis was conducted to determine whether chalcone-9 can interact with JAK1 and JAK2. A wound healing assay was used to observe the effect of chalcone-9 on tumor cell migration, and flow cytometry was employed to analyze whether chalcone-9 inhibits tumor cell cycle progression and induces apoptosis. The expression of apoptosis markers was also assessed.

RESULTS

Chalcone-9 exhibited dose-dependent cytotoxicity in breast cancer cell lines, with TNBC cells showing higher sensitivity. Chalcone-9 effectively inhibited the activation of JAK1, JAK2, STAT1, and STAT3, outperforming conventional JAK/STAT inhibitors. The structure of chalcone-9 was confirmed to stably interact with JAK1 and JAK2 proteins. It also suppressed STAT1 and STAT3 target gene expression, reduced tumor cell migration, and induced apoptosis, as evidenced by PARP and caspase cleavage and decreased survivin levels.

CONCLUSIONS

Chalcone-9 demonstrates significant anti-cancer activity, particularly against TNBC. By targeting the JAK/STAT pathway and promoting apoptosis, chalcone-9 emerges as a promising therapeutic candidate for aggressive breast cancers.

STAT3 Signaling Pathway in Health and Disease

Signal transducer and activator of transcription 3 (STAT3) is a critical transcription factor involved in multiple physiological and pathological processes. While STAT3 plays an essential role in homeostasis, its persistent activation has been implicated in the pathogenesis of various diseases, particularly cancer, bone-related diseases, autoimmune disorders, inflammatory diseases, cardiovascular diseases, and neurodegenerative conditions. The interleukin-6/Janus kinase (JAK)/STAT3 signaling axis is central to STAT3 activation, influencing tumor microenvironment remodeling, angiogenesis, immune evasion, and therapy resistance. Despite extensive research, the precise mechanisms underlying dysregulated STAT3 signaling in disease progression remain incompletely understood, and no United States Food and Drug Administration (USFDA)-approved direct STAT3 inhibitors currently exist. This review provides a comprehensive evaluation of STAT3's role in health and disease, emphasizing its involvement in cancer stem cell maintenance, metastasis, inflammation, and drug resistance. We systematically discuss therapeutic strategies, including JAK inhibitors (tofacitinib, ruxolitinib), Src Homology 2 domain inhibitors (S3I-201, STATTIC), antisense oligonucleotides (AZD9150), and nanomedicine-based drug delivery systems, which enhance specificity and bioavailability while reducing toxicity. By integrating molecular mechanisms, disease pathology, and emerging therapeutic interventions, this review fills a critical knowledge gap in STAT3-targeted therapy. Our insights into STAT3 signaling crosstalk, epigenetic regulation, and resistance mechanisms offer a foundation for developing next-generation STAT3 inhibitors with greater clinical efficacy and translational potential.

A high-resolution view of the immune and stromal cell response to Haemophilus ducreyi infection in human volunteers

Haemophilus ducreyi causes the genital ulcer disease chancroid and cutaneous ulcers in children. To study its pathogenesis, we developed a human challenge model in which we infect the skin on the upper arm of human volunteers with H. ducreyi to the pustular stage of disease. The model has been used to define lesional architecture, describe the immune infiltrate into the infected sites using flow cytometry, and explore the molecular basis of the immune response using bulk RNA-seq. Here, we used single cell RNA-seq (scRNA-seq) and spatial transcriptomics to simultaneously characterize multiple cell types within infected human skin and determine the cellular origin of differentially expressed transcripts that we had previously identified by bulk RNA-seq. We obtained paired biopsies of pustules and wounded (mock infected) sites from five volunteers for scRNA-seq. We identified 13 major cell types, including T- and NK-like cells, macrophages, dendritic cells, as well as other cell types typically found in the skin. Immune cell types were enriched in pustules, and some subtypes within the major cell types were exclusive to pustules. Sufficient tissue specimens for spatial transcriptomics were available from four of the volunteers. T- and NK-like cells were highly associated with multiple antigen presentation cell types. In pustules, type I interferon stimulation was high in areas that were high in antigen presentation-especially in macrophages near the abscess-compared to wounds. Together, our data provide a high-resolution view of the cellular immune response to the infection of the skin with a human pathogen.IMPORTANCEA high-resolution view of the immune infiltrate due to infection with an extracellular bacterial pathogen in human skin has not yet been defined. Here, we used the human skin pathogen Haemophilus ducreyi in a human challenge model to identify on a single cell level the types of cells that are present in volunteers who fail to spontaneously clear infection and form pustules. We identified 13 major cell types. Immune cells and immune-activated stromal cells were enriched in pustules compared to wounded (mock infected) sites. Pustules formed despite the expression of multiple pro-inflammatory cytokines, such as IL-1β and type I interferon. Interferon stimulation was most evident in macrophages, which were proximal to the abscess. The pro-inflammatory response within the pustule may be tempered by regulatory T cells and cells that express indoleamine 2,3-dioxygenase, leading to failure of the immune system to clear H. ducreyi.

Role of cancer stem cell heterogeneity in intrahepatic cholangiocarcinoma

Background

Intrahepatic cholangiocarcinoma (ICC) is a highly invasive bile duct cancer with poor prognosis due to frequent recurrence and limited effective treatments. Cancer stem cells (CSCs) contribute to ICC's therapeutic resistance and recurrence, driven by distinct cellular subpopulations with variable tumorigenic properties. Recent advances in single-cell RNA sequencing (scRNA-seq) have enabled a deeper exploration of cellular heterogeneity in tumors, offering insights into unique CSC subgroups that impact ICC progression and patient outcomes. This study aimed to investigate the effect of CSC heterogeneity on the prognosis of ICC.

Methods

The scRNA-seq dataset GSE142784 was retrieved from the Gene Expression Omnibus (GEO) database, and Bulk RNA-seq data were obtained from The Cancer Genome Atlas (TCGA) databases. Hallmarks and AUCell R package were adopted for analyzing the signaling pathway activity, CellChat for observing cell communication between subgroups, and SCENIC for analyzing transcription factors expression. The immune cell infiltration and drug sensitivity of the model were analyzed using the CIBERSORT algorithm and the "pRRophetic" R packages, respectively. And immunohistochemistry (IHC) tests were used to evaluate expression of transcription factors in ICC patients.

Results

Based on scRNA-seq data, five clusters (DLK+, CD13+, CD90+, CD133+, and other cholangiocarcinoma cells) were observed in ICC, which presented different signaling pathway activities, such as HSF1 and STAT1 were highly expressed in the CD133 cluster, and consistent with the results of IHC tests. Pathways like Notch and Wnt/β-catenin signaling transferred among above subgroups. Further, subgroups favored varied immune response and drug sensitivity, and CD133+ subgroup patients showed significantly shortened recurrence-free survival (RFS).

Conclusions

Configuring the subgroup of ICC is helpful for predicting the prognosis and drug resistance in ICC and can provide new strategies for cancer treatment.

Predicting TF-Target Gene Association Using a Heterogeneous Network and Enhanced Negative Sampling

Identifying interactions between transcription factors (TFs) and target genes is crucial for understanding the molecular mechanisms involved in biological processes and diseases. Traditional biological experiments used to determine these interactions are often time-consuming, costly, and limited in scale. Current computational methods mainly predict binding sites rather than direct interactions. Although recent studies have achieved high performance in predicting TF-target gene associations, they still face a significant challenge related to constructing a robust dataset of positive and negative samples. Currently, methods do not adequately focus on selecting negative samples, resulting in incomplete coverage of potential TF-target gene relationships. This article proposes a method to select enhanced negative samples to improve the prediction performance of TF-target gene interactions. Experimental results show that the proposed method achieves an average area under the curve (AUC) value of 0.9024 ± 0.0008 through 5-fold cross-validation. These results demonstrate the model's high efficiency and accuracy, confirming its potential application in predicting TF-target gene interactions across various datasets and paving the way for large-scale biomedical research.

STAT3-related lncRNAs in colorectal cancer progression; Special focus on immune cell's evasion

Colorectal cancer (CRC) is globally ranked as the third leading cause of cancer-related deaths in both men and women. There is an urgent need for novel biomarkers to facilitate early diagnosis and enhance patient care, thereby improving treatment response and reducing mortality rates. Signal transducer and activator of transcription 3 (STAT3) is essential for controlling the anti-tumor immune response since it is a hub for several oncogenic signaling pathways. In the tumor environment, STAT3 is widely overactivated in both malignant and non-cancerous cells. It is involved in suppressing the expression of critical immune activation regulators and encouraging the synthesis of immunosuppressive substances. Long noncoding RNAs (lncRNAs), a kind of non-coding RNA, are critical for CRC development, apoptosis, and metastasis because they influence important signaling pathways such as STAT3 signaling and contribute to gene regulation at the epigenetic, transcriptional, and post-transcriptional levels. Moreover, lncRNAs have a significant role in modifying the TME and control the expression of important immunological checkpoints, such as PD-L1. Therefore, a comprehensive understanding of the regulatory roles of lncRNAs is crucial for identifying diagnostic, prognostic, and predictive biomarkers for CRC. Thus, the objective of the present review study is to provide a comprehensive overview of the interaction between the STAT3 signaling pathway and various lncRNAs, as well as their implications for apoptosis, metastasis, and immune evasion in CRC.

Roles of Post-Translational Modifications of Transcription Factors Involved in Breast Cancer Hypoxia

BC is the most commonly diagnosed cancer and the second leading cause of cancer death among women worldwide. Cellular stress is a condition that leads to disrupted homeostasis by extrinsic and intrinsic factors. Among other stressors, hypoxia is a driving force for breast cancer (BC) progression and a general hallmark of solid tumors. Thus, intratumoral hypoxia is an important determinant of invasion, metastasis, treatment failure, prognosis, and patient mortality. Acquisition of the epithelial-mesenchymal transition (EMT) phenotype is also a consequence of tumor hypoxia. The cellular response to hypoxia is mainly regulated by the hypoxia signaling pathway, governed by hypoxia-inducible factors (HIFs), mainly HIF1α. HIFs are a family of transcription factors (TFs), which induce the expression of target genes involved in cell survival and proliferation, metabolic reprogramming, angiogenesis, resisting apoptosis, invasion, and metastasis. HIF1α cooperates with a large number of other TFs. In this review, we focused on the crosstalk and cooperation between HIF1α and other TFs involved in the cellular response to hypoxia in BC. We identified a cluster of TFs, proposed as the HIF1α-TF interactome, that orchestrates the transcription of target genes involved in hypoxia, due to their post-translational modifications (PTMs), including phosphorylation/dephosphorylation, ubiquitination/deubiquitination, SUMOylation, hydroxylation, acetylation, S-nitrosylation, and palmitoylation. PTMs of these HIF1α-related TFs drive their stability and activity, degradation and turnover, and the bidirectional translocation between the cytoplasm or plasma membrane and nucleus of BC cells, as well as the transcription/activation of proteins encoded by oncogenes or inactivation of tumor suppressor target genes. Consequently, PTMs of TFs in the HIF1α interactome are crucial regulatory mechanisms that drive the cellular response to oxygen deprivation in BC cells.

The IL-1β/STAT1 Axis inhibits STAT3 function via Sequestration of the transcriptional activator GLIS2, leading to postoperative vascular dysfunction

Surgery-induced endothelial dysfunction is crucial in thrombus formation, driven by the release of inflammatory mediators due to surgical trauma. The STAT family, known for amplifying inflammatory responses via cytokine activation, plays an unclear role in the signaling mechanisms from surgery to molecular activation, and their regulatory effects on inflammation vary. This study aimed to identify key signaling pathways responsible for vascular dysfunction post-surgery and to discover potential targets for predicting or preventing thrombosis. To explore this, endothelial cells were co-cultured with post-surgical trauma serum and analyzed using various assays. Bioinformatics analysis linked surgical trauma with pathways involving thrombosis, interleukins, cytokines, and STAT signaling. Elevated inflammatory mediators were observed in mouse serum post-surgical trauma, with IL-6 activating STAT3 to enhance endothelial proliferation, while IL-1β activated STAT1, inhibiting STAT3's effects. Gli-similar 2 (GLIS2), a novel coactivator of STAT3, was found to regulate STAT transcription. STAT1, however, inhibited GLIS2's interaction with STAT3, suppressing STAT3's role in endothelial proliferation. The study concludes that IL-1β-triggered STAT1 activation impedes GLIS2-STAT3 interaction, reducing STAT3's transcriptional activity and leading to endothelial dysfunction, presenting new targets for preventing post-surgical trauma endothelial dysfunction and thrombosis.

Functional Involvement of Signal Transducers and Activators of Transcription in the Pathogenesis of Influenza A Virus

Signal transducers and activators of transcription (STATs) function both as signal transducers and transcription regulators. STAT proteins are involved in the signaling pathways of cytokines and growth factors; thus, they participate in various life activities and play especially critical roles in antiviral immunity. Convincing evidence suggests that STATs can establish innate immune status through multiple mechanisms, efficiently eliminating pathogens. STAT1 and STAT2 can activate the antiviral status by regulating the interferon (IFN) signal. In turn, suppressor of cytokine signaling-1 (SOCS1) and SOCS3 can modulate the activation of STATs and suppress the excessive antiviral immune response. STAT3 not only regulates the IFN signal, but also transduces Interleukin-6 (IL-6) to stimulate the host antiviral response. The function of STAT4 and STAT5 is related to CD4+ T helper (Th) cells, and the specific mechanism of STAT5 remains to be studied. STAT6 mainly exerts antiviral effects by mediating IL-4 and IL-13 signaling. Here, we reviewed the recent findings regarding the critical roles of STATs in the interactions between the host and viral infection, especially influenza A virus (IAV) infection. We also discuss the molecular mechanisms underlying their functions in antiviral responses.

miR-181a: regulatory roles, cancer-associated signaling pathway disruptions, and therapeutic potential

INTRODUCTION

microRNA-181a (miR-181a) is a crucial post-transcriptional regulator of many mRNA transcripts and noncoding-RNAs, influencing cell proliferation, cancer cell stemness, apoptosis, and immune responses. Its abnormal expression is well-characterized in numerous cancers, establishing it as a significant genomic vulnerability and biomarker in cancer research.

AREAS COVERED

Here, we summarize miR-181a's correlation with poor patient outcomes across numerous cancers and the mechanisms governing miR-181a's activity and processing. We comprehensively describe miR-181a's involvement in multiple regulatory cancer signaling pathways, cellular processes, and the tumor microenvironment. We also discuss current therapeutic approaches to targeting miR-181a, highlighting their limitations and future potential.

EXPERT OPINION

miR-181a is a clinically relevant pan-cancer biomarker with potential as a therapeutic target. Its regulatory control of tumorigenic signaling pathways and immune responses positions it as a promising candidate for personalized treatments. The success of miR-181a as a target relies on the development of specific therapeutics platforms. Future research on miR-181a's role in the tumor microenvironment and the RNA binding proteins that regulate its stability will help uncover new techniques to targeting miR-181a. Further research into miR-181a serum levels in patients undergoing therapy will help to better stratify patients and enhance therapeutic success.

Structure, function, signaling pathways and clinical therapeutics: The translational potential of STAT3 as a target for cancer therapy

Cancer remains one of the most difficult human diseases to overcome because of its complexity and diversity. Signal transducers and transcriptional activators 3 (STAT3) protein has been found to be overexpressed in a wide range of cancer types. Hyperactivation of STAT3 is particularly associated with low survival in cancer patients. This review summarizes the specific molecular mechanisms of STAT3 in cancer development. STAT3 is activated by extracellular signals in the cytoplasm, interacts with different enzymes in the nucleus, mitochondria or endoplasmic reticulum, and subsequently participates in cancer development. The phosphorylated STAT3 at tyrosine 705 site (YP-STAT3) enters the nucleus and regulates a number of tumor-related biological processes such as angiogenesis, migration invasion, cell proliferation and cancer cell stemness. In contrast, the phosphorylated STAT3 at serine 727 site (SP-STAT3) is found on the mitochondria, affects electron respiration transport chain activity and thereby prevents tumor cell apoptosis. SP-STAT3 also appears on the mitochondria-associated endoplasmic reticulum membrane, influences the flow of Ca2+, and affects tumor progression. In addition, we summarize the direct and indirect inhibitors of STAT3 which are currently undergoing clinical studies. Some of them such as TTI101 and BBI608 have been approved by the FDA for the treatment of certain cancers. All in all, STAT3 plays an important role in cancer progression and becomes a potential target for cancer treatment.

STAT1 as a potential therapeutic target to treat bladder cancer

BACKGROUND

Previous studies have reported that STAT1 (Signal Transducer and Activator of Transcription 1) is associated with multiple tumor progression. This study aimed to investigate the role and related mechanisms of STAT1 in bladder cancer.

METHODS

STAT1 expression in bladder cancer tissues and human bladder cancer cell lines was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The bladder cancer cell line T24 was transfected with overexpressing lentivirus targeting STAT1. Cell proliferation, invasion, and apoptosis were measured by Cell Counting Kit-8, Transwell assays, and flow cytometric analysis. Furthermore, RNA-Seq was performed to identify the downstream signaling pathways. Finally, the signaling pathway-related molecules were determined by RT-qPCR and western blot assays.

RESULTS

The overexpression of STAT1 inhibited bladder cancer cell proliferation and invasion while enhancing apoptosis. Moreover, the overexpression of STAT1 in bladder cancer cells delayed tumor tumorigenesis in vitro. Mechanistically, RNA-Seq analysis revealed that the JAK-STAT signaling pathway was up-regulated, especially SOCS1 (suppressor of cytokine signaling 1) and SOCS3 (suppressor of cytokine signaling 3) in STAT1-sufficient cells.

CONCLUSIONS

These results indicate the potential of STAT1 as a therapeutic target in bladder cancer.

Wee1 inhibitor PD0166285 sensitized TP53 mutant lung squamous cell carcinoma to cisplatin via STAT1

BACKGROUND

Lung squamous cell carcinoma (LUSCs) is associated with high mortality (20-30%) and lacks of effective treatments. Almost all LUSC exhibit somatic mutations in TP53. Wee1, a tyrosine kinase, regulates the cell cycle at the G2/M checkpoint. In TP53-deficient cells, the dependence on G2/M checkpoints increases. PD0166285 is the first reported drug with inhibitory activity against both Wee1 and PKMYT1.

METHODS

Protein expression was determined by Western blot analysis. Cell proliferation was assessed using cell colony formation and CCK-8 assays. Cell cycle was performed by PI staining with flow cytometry. Apoptosis was evaluated using Annexin V-Phycoerythrin double staining and flow cytometry. DNA damage was detected through comet assay and immunofluorescence assay. In vivo, apoptosis and anti-tumor effects were assessed using the TUNEL assay, a nude mouse model, and immunohistochemistry (IHC). Co-immunoprecipitation assay was used to detect protein-protein interactions. We analyzed Wee1, PKMYT1, and Stat1 expression in pan-cancer studies using the Ualcan public database and assessed their prognostic implications with Kaplan-Meier curves.

RESULT

PD0166285, a Wee1 inhibitor, effectively inhibits Wee1 activity, promoting cell entry into a mitotic crisis. Moreover, PD0166285 sensitizes cells to cisplatin, enhancing clinical outcomes. Our study demonstrated that PD016628 regulates the cell cycle through Rad51 and results in cell cycle arrest at the G2/M phase. We observed increased apoptosis in tumor cells treated with PD0166285, particularly when combined with cisplatin, indicating an enhanced apoptotic response. The upregulation of γ-H2AX serves as an indicator of mitotic catastrophe. Co-immunoprecipitation and data analysis revealed that apoptosis in LUSC is mediated through the Stat1 pathway, accompanied by decreased levels of Socs3. Furthermore, IHC staining confirmed significant differences in the expression of Phospho-CDK1 and γ-H2AX in LUSCs, suggesting involvement in DNA damage.

CONCLUSIONS

In summary, our study suggests that PD0166285, an inhibitor of Wee1, sensitizes LUSC cells to cisplatin and modulates DNA damage and apoptosis pathways through Rad51 and Stat1, respectively. These findings highlight the combination of PD0166285 and cisplatin as a promising therapeutic approach for treating LUSC.

Immunological signatures from irradiated cancer-associated fibroblasts

Introduction

Cancer-associated fibroblasts (CAFs) are abundant and influential elements of the tumor microenvironment (TME), giving support to tumor development in multiple ways. Among other mechanisms, CAFs are important regulators of immunological processes occurring in tumors. However, CAF-mediated tumor immunomodulation in the context of radiotherapy remains poorly understood. In this study, we explore effects of radiation on CAF-derived immunoregulatory signals to the TME.

Methods

Primary CAF cultures were established from freshly collected human NSCLC lung tumors. CAFs were exposed to single-high or fractionated radiation regimens (1x18Gy or 3x6Gy), and the expression of different immunoregulatory cell-associated and secreted signaling molecules was analyzed 48h and 6 days after initiation of treatment. Analyses included quantitative measurements of released damage-associated molecular patterns (DAMPs), interferon (IFN) type I responses, expression of immune regulatory receptors, and secretion of soluble cytokines, chemokines, and growth factors. CAFs are able to survive ablative radiation regimens, however they enter into a stage of premature cell senescence.

Results

Our data show that CAFs avoid apoptosis and do not contribute by release of DAMPs or IFN-I secretion to radiation-mediated tumor immunoregulation. Furthermore, the secretion of relevant immunoregulatory cytokines and growth factors including TGF-β, IL-6, IL-10, TNFα, IL-1β, VEGF, CXCL12, and CXCL10 remain comparable between non-irradiated and radiation-induced senescent CAFs. Importantly, radiation exposure modifies the cell surface expression of some key immunoregulatory receptors, including upregulation of CD73 and CD276.

Discussion

Our data suggest that CAFs do not participate in the release of danger signals or IFN-I secretion following radiotherapy. The immune phenotype of CAFs and radiation-induced senescent CAFs is similar, however, the observed elevation of some cell surface immunological receptors on irradiated CAFs could contribute to the establishment of an enhanced immunosuppressive TME after radiotherapy.

Clinical Significance of SIRPα Expression on Tumor-Associated Macrophages in Patients with Lung Squamous Cell Carcinoma

BACKGROUND

Signal-regulatory protein alpha (SIRPα) is an immune checkpoint molecule expressed on macrophages that functions to inhibit phagocytosis by binding to CD47 expressed on tumor cells. SIRPα has attracted increasing attention as a novel target for cancer immunotherapy; however, the expression and immune function of SIRPα in lung squamous cell carcinoma (LUSC) remain unclear. Therefore, this study aimed to identify the clinical importance of SIRPα expression in LUSC and to explore the factors that elevate SIRPα expression.

PATIENTS AND METHODS

Primary LUSC specimens surgically resected from 172 patients underwent immunohistochemical evaluation of the association of SIRPα expression on tumor-associated macrophages with clinicopathological features and clinical outcomes. Furthermore, we analyzed the association of SIRPα expression with tumor-infiltrating lymphocytes and the expression of programmed cell death ligand 1 (PD-L1). In vitro, monocytes were treated with cytokines, and SIRPα protein expression was assessed by flow cytometry.

RESULTS

There were no differences in SIRPα expression and clinicopathological factors. High SIRPα expression was significantly associated with PD-L1-positive expression, and high CD8, PD-1, and CD163 expression. The high SIRPα expression group showed significantly shorter recurrence-free survival (RFS) and overall survival (OS). On multivariate analysis, high SIRPα expression was an independent poor prognostic factor for RFS and OS. The expression of SIRPα protein in monocytes was upregulated by treatment with IFNγ.

CONCLUSION

Our analysis revealed that high SIRPα expression significantly predicts poor prognosis in patients with surgically resected LUSC.

The co-location of CD14+APOE+ cells and MMP7+ tumour cells contributed to worse immunotherapy response in non-small cell lung cancer

Intra-tumour immune infiltration is a crucial determinant affecting immunotherapy response in non-small cell lung cancer (NSCLC). However, its phenotype and related spatial structure have remained elusive. To overcome these restrictions, we undertook a comprehensive study comprising spatial transcriptomic (ST) data (28 712 spots from six samples). We identified two distinct intra-tumour infiltration patterns: immune exclusion (characterised by myeloid cells) and immune activation (characterised by plasma cells). The immune exclusion and immune activation signatures showed adverse and favourable roles in NSCLC patients' survival, respectively. Notably, CD14+APOE+ cells were recognised as the main cell type in immune exclusion samples, with increased epithelial‒mesenchymal transition and decreased immune activities. The co-location of CD14+APOE+ cells and MMP7+ tumour cells was observed in both ST and bulk transcriptomics data, validated by multiplex immunofluorescence performed on 20 NSCLC samples. The co-location area exhibited the upregulation of proliferation-related pathways and hypoxia activities. This co-localisation inhibited T-cell infiltration and the formation of tertiary lymphoid structures. Both CD14+APOE+ cells and MMP7+ tumour cells were associated with worse survival. In an immunotherapy cohort from the ORIENT-3 clinical trial, NSCLC patients who responded unfavourably exhibited higher infiltration of CD14+APOE+ cells and MMP7+ tumour cells. Within the co-location area, the MK, SEMA3 and Macrophage migration inhibitory factor (MIF) signalling pathway was most active in cell‒cell communication. This study identified immune exclusion and activation patterns in NSCLC and the co-location of CD14+APOE+ cells and MMP7+ tumour cells as contributors to immune resistance.

Single-cell analysis of chemotherapy-resistant microenvironment identifies a chemo-response biomarker for pancreatic cancer

Background

Pancreatic ductal adenocarcinoma (PDAC) is a highly fatal, aggressive cancer due to limited response chemotherapy. The tumor microenvironment (TME) has emerged as a key player in the development of chemoresistance and in malignant progression. In this study, we hypothesized that chemotherapy response is predictable by chemotherapy-related cell types and their differentially expressed genes (DEGs).

Methods

DEGs of chemoresistance cell types were identified via single cell analysis and Wilcoxon test. A chemotherapy response signature was established using a random forest model and validated with public datasets. Bulk cell fraction was analyzed using BayesPrism algorithms. Log-rank test was used to analyze survival of PDAC patients.

Results

We found that natural killer (NK) cells, myeloid cells, and erythroid cells were highly infiltrated in chemo-resistant TME. A total of 36 chemoresistance-related DEGs of chemo-resistant cells were identified in chemo-resistant PDAC. Functional enrichment analysis showed that chemoresistance upregulated various inflammation-related pathways, including TGF-β signaling. Based on these features, we constructed a random forest model to predict the response and survival for PDAC patients, which accurately distinguished high-risk and chemoresistant patients with significantly poorer prognosis in both the training and independent validation datasets. Cox regression analysis indicated that predicted labels were an independent prognostic factor in PDAC. Moreover, deconvolution of TME confirmed higher infiltration levels of M2 macrophage and NK cells in predicted chemoresistance. When combined with chemotherapy response related tumor mutations, the model showed excellent ability in predicting chemotherapy response and survival.

Conclusions

The TME was closely associated with the chemotherapy response and prognosis of PDAC. Our TME-based random forest model predicted chemotherapy response with complementary knowledge to the response-related genetic mutations.

Photosensitive and dual-targeted chromium nanoparticle delivering small interfering RNA YTHDF1 for molecular-targeted immunotherapy in liver cancer

Tumor-associated macrophages (TAMs) are a promising target for cancer immunotherapy, but delivering therapeutic agents to TAMs within the tumor microenvironment (TME) is challenging. In this study, a photosensitive, dual-targeting nanoparticle system (M.RGD@Cr-CTS-siYTHDF1 NPs) was developed. The structure includes a shell of DSPE-modified RGD peptides targeting integrin receptors on tumor cells and carboxymethyl mannose targeting CD206 receptors on macrophages, with a core of chitosan adsorbing m6A reading protein YTHDF1 siRNA and chromium nanoparticles (Cr NPs). The approach is specifically designed to target TAM and cancer cells, utilizing the photothermal effect of Cr NPs to disrupt the TME and deliver siYTHDF1 to TAM. In experiments with tumor-bearing mice, M.RGD@Cr-CTS-siYTHDF1 NPs, when exposed to laser irradiation, effectively killed tumor cells, disrupted the TME, delivered siYTHDF1 to TAMs, silenced the YTHDF1 gene, and shifted the STAT3-STAT1 equilibrium by reducing STAT3 and enhancing STAT1 expression. This reprogramming of TAMs towards an anti-tumor phenotype led to a pro-immunogenic TME state. The strategy also suppressed immunosuppressive IL-10 production, increased expression of immunostimulatory factors (IL-12 and IFN-γ), boosted CD8 + T cell infiltration and M1-type TAMs, and reduced Tregs and M2-type TAMs within the TME. In conclusion, the dual-targeting M.RGD@Cr-CTS-siYTHDF1 NPs, integrating dual-targeting capabilities with photothermal therapy (PTT) and RNA interference, offer a promising approach for molecular targeted cancer immunotherapy with potential for clinical application.

Immunological landscape of solid cancer: Interplay between tumor and autoimmunity

The immune system, a central player in maintaining homeostasis, emerges as a pivotal factor in the pathogenesis and progression of two seemingly disparate yet interconnected categories of diseases: autoimmunity and cancer. This chapter delves into the intricate and multifaceted role of the immune system, particularly T cells, in orchestrating responses that govern the delicate balance between immune surveillance and self-tolerance. T cells, pivotal immune system components, play a central role in both diseases. In autoimmunity, aberrant T cell activation drives damaging immune responses against normal tissues, while in cancer, T cells exhibit suppressed responses, allowing the growth of malignant tumors. Immune checkpoint receptors, example, initially explored in autoimmunity, now revolutionize cancer treatment via immune checkpoint blockade (ICB). Though effective in various tumors, ICB poses risks of immune-related adverse events (irAEs) akin to autoimmunity. This chapter underscores the importance of understanding tumor-associated antigens and their role in autoimmunity, immune checkpoint regulation, and their implications for both diseases. It also explores autoimmunity resulting from cancer immunotherapy and shared molecular pathways in solid tumors and autoimmune diseases, highlighting their interconnectedness at the molecular level. Additionally, it sheds light on common pathways and epigenetic features shared by autoimmunity and cancer, and the potential of repurposing drugs for therapeutic interventions. Delving deeper into these insights could unlock therapeutic strategies for both autoimmunity and cancer.

The role of IGFBP-3 in tumor development and progression: enlightenment for diagnosis and treatment

IGFBP-3 is aberrantly expressed in many tumor types, and its serum and tumor tissue levels provide auxiliary information for assessing the degree of tumor malignancy and patient prognosis, making it a potential therapeutic target for human malignancies and conferring it remarkable clinical value for determining patient prognosis. In this review, we provide a comprehensive overview of the aberrant expression, diverse biological effects, and clinical implications of IGFBP-3 in tumors and its role as a potential prognostic marker and therapeutic target for tumors. In addition, we summarize the signaling pathways through which IGFBP-3 exerts its effects. IGFBP-3 comprises an N-terminal, an intermediate region, and a C-terminal structural domain, each exerting different biological effects in several tumor cell types in an IGF-dependent/non-independent manner. IGFBP-3 shares an intricate relationship with the tumor microenvironment, thereby affecting tumor growth. Overall, IGFBP-3 is an essential regulatory factor that mediates tumor occurrence and progression. Gaining deeper insights into the fundamental characteristics of IGFBP-3 and its role in various tumor types will provide new perspectives and allow for the development of novel strategies for cancer diagnosis, treatment, and prognostic evaluation.

Oncogenic STAT Transcription Factors as Targets for Cancer Therapy: Innovative Strategies and Clinical Translation

Despite advances in our understanding of molecular aspects of oncogenesis, cancer remains a leading cause of death. The malignant behavior of a cancer cell is driven by the inappropriate activation of transcription factors. In particular, signal transducers and activators of transcription (STATs), which regulate many critical cellular processes such as proliferation, apoptosis, and differentiation, are frequently activated inappropriately in a wide spectrum of human cancers. Multiple signaling pathways converge on the STATs, highlighting their importance in the development and progression of oncogenic diseases. STAT3 and STAT5 are two members of the STAT protein family that are the most frequently activated in cancers and can drive cancer pathogenesis directly. The development of inhibitors targeting STAT3 and STAT5 has been the subject of intense investigations in the last decade, although effective treatment options remain limited. In this review, we investigate the specific roles of STAT3 and STAT5 in normal physiology and cancer biology, discuss the opportunities and challenges in pharmacologically targeting STAT proteins and their upstream activators, and offer insights into novel therapeutic strategies to identify STAT inhibitors as cancer therapeutics.