IRAK4 mediates colitis-induced tumorigenesis and chemoresistance in colorectal cancer

Construction of IRAK4 inhibitor activity prediction model based on machine learning

Interleukin-1 receptor-associated kinase 4 (IRAK4) is a crucial serine/threonine protein kinase that belongs to the IRAK family and plays a pivotal role in Toll-like receptor (TLR) and Interleukin-1 receptor (IL-1R) signaling pathways. Due to IRAK4's significant role in immunity, inflammation, and malignancies, it has become an intriguing target for discovering and developing potent small-molecule inhibitors. Consequently, there is a pressing need for rapid and accurate prediction of IRAK4 inhibitor activity. Leveraging a comprehensive dataset encompassing activity data for 1628 IRAK4 inhibitors, we constructed a prediction model using the LightGBM algorithm and molecular fingerprints. This model achieved an R2 of 0.829, an MAE of 0.317, and an RMSE of 0.460 in independent testing. To further validate the model's generalization ability, we tested it on 90 IRAK4 inhibitors collected in 2023. Subsequently, we applied the model to predict the activity of 13,268 compounds with docking scores less than - 9.503 kcal/mol. These compounds were initially screened from a pool of 1.6 million molecules in the chemdiv database through high-throughput molecular docking. Among these, 259 compounds with predicted pIC50 values greater than or equal to 8.00 were identified. We then performed ADMET predictions on these selected compounds. Finally, through a rigorous screening process, we identified 34 compounds that adhere to the four complementary drug-likeness rules, making them promising candidates for further investigation. Additionally, molecular dynamics simulations confirmed the stable binding of the screened compounds to the IRAK4 protein. Overall, this work presents a machine learning model for accurate prediction of IRAK4 inhibitor activity and offers new insights for subsequent structure-guided design of novel IRAK4 inhibitors.

Inhibiting the IRAK4/NF-κB/NLRP3 signaling pathway can reduce pyroptosis in hippocampal neurons and seizure episodes in epilepsy

BACKGROUND

Interleukin-1 receptor-associated kinase 4 (IRAK4) plays an important role in immune modulation in various central nervous system disorders. However, IRAK4 has not been reported in epilepsy models in animal and clinical studies, nor has its involvement in regulating pyroptosis in epilepsy.

METHOD

First, we performed transcriptome sequencing, quantitative real-time polymerase chain reaction, and western blot analysis on the hippocampal tissues of refractory epilepsy patients to measure the mRNA and protein levels of IRAK4 and pyroptosis-related proteins. Second, we successfully established a pentylenetetrazol (PTZ)-induced seizure mouse model. We conducted behavioral tests, electroencephalography, virus injection, and molecular biology experiments to investigate the role of IRAK4 in seizure activity regulation.

RESULTS

IRAK4 is upregulated in the hippocampus of epilepsy patients and PTZ-induced seizure model mice. IRAK4 expression is observed in the hilar neurons of PTZ-induced mice. Knocking down IRAK4 in PTZ-induced mice downregulated pyroptosis-related protein expression and alleviated seizure activity. Overexpressing IRAK4 in naive mice upregulated pyroptosis-related protein expression and increased PTZ-induced abnormal neuronal discharges. IRAK4 and NF-κB were found to bind to each other in patient hippocampal tissue samples. Pyrrolidine dithiocarbamate reversed the pyroptosis-related protein expression increase caused by PTZ. PF-06650833 alleviated seizure activity and inhibited pyroptosis in PTZ-induced seizure mice.

CONCLUSION

IRAK4 plays a key role in the pathological process of epilepsy, and its potential mechanism may be related to pyroptosis mediated by the NF-κB/NLRP3 signaling pathway. PF-06650833 has potential as a therapeutic agent for alleviating epilepsy.

Toll-like receptor signalling via IRAK4 affects epithelial integrity and tightness through regulation of junctional tension

Toll-like receptors (TLRs) in mammalian systems are well known for their role in innate immunity. In addition, TLRs also fulfil crucial functions outside immunity, including the dorsoventral patterning function of the original Toll receptor in Drosophila and neurogenesis in mice. Recent discoveries in flies suggested key roles for TLRs in epithelial cells in patterning of junctional cytoskeletal activity. Here, we address the function of TLRs and the downstream key signal transduction component IRAK4 in human epithelial cells. Using differentiated human Caco-2 cells as a model for the intestinal epithelium, we show that these cells exhibit baseline TLR signalling, as revealed by p-IRAK4, and that blocking IRAK4 function leads to a loss of epithelial tightness involving key changes at tight and adherens junctions, such as a loss of epithelial tension and changes in junctional actomyosin. Changes upon IRAK-4 inhibition are conserved in human bronchial epithelial cells. Knockdown of IRAK4 and certain TLRs phenocopies the inhibitor treatment. These data suggest a model whereby TLR receptors near epithelial junctions might be involved in a continuous sensing of the epithelial state to promote epithelial tightness and integrity.

Colitis-associated carcinogenesis: crosstalk between tumors, immune cells and gut microbiota

Colorectal cancer (CRC) is the third most common cancer worldwide. One of the main causes of colorectal cancer is inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD). Intestinal epithelial cells (IECs), intestinal mesenchymal cells (IMCs), immune cells, and gut microbiota construct the main body of the colon and maintain colon homeostasis. In the development of colitis and colitis-associated carcinogenesis, the damage, disorder or excessive recruitment of different cells such as IECs, IMCs, immune cells and intestinal microbiota play different roles during these processes. This review aims to discuss the various roles of different cells and the crosstalk of these cells in transforming intestinal inflammation to cancer, which provides new therapeutic methods for chemotherapy, targeted therapy, immunotherapy and microbial therapy.

Synthesis and evaluation of dihydrofuro[2,3-b]pyridine derivatives as potent IRAK4 inhibitors

Interleukin-1 receptor-associated kinase 4 (IRAK4) is a key regulator to control downstream NF-κB and MAPK signals in the innate immune response and has been proposed as a therapeutic target for the treatment of inflammatory and autoimmune diseases. Herein, a series of IRAK4 inhibitors based on a dihydrofuro[2,3-b]pyridine scaffold was developed. Structural modifications of the screening hit 16 (IC₅₀ = 243 nM) led to IRAK4 inhibitors with improved potency but high clearance (Cl) and poor oral bioavailability, as exemplified by compound 21 (IC₅₀ = 6.2 nM, Cl = 43 ml/min/kg, F = 1.6%, LLE = 5.4). Structure modification aimed at improving LLE and reducing clearance identified compound 38. Compound 38 showed significantly improved clearance while maintained excellent biochemical potency against IRAK4 (IC₅₀ = 7.3 nM, Cl = 12 ml/min/kg, F = 21%, LLE = 6.0). Importantly, compound 38 had favorable in vitro safety and ADME profiles. Furthermore, compound 38 reduced the in vitro production of pro-inflammatory cytokines in both mouse iBMDMs and human PBMCs and was orally efficacious in the inhibition of serum TNF-α secretion in LPS-induced mouse model. These findings suggested that compound 38 has development potential as an IRAK4 inhibitor for the treatment of inflammatory and autoimmune disorders.

Design, synthesis, and pharmacological evaluation of N-(3-carbamoyl-1H-pyrazol-4-yl)-1,3-oxazole-4-carboxamide derivatives as interleukin-1 receptor-associated kinase 4 inhibitors with reduced potential for cytochrome P450 1A2 induction

Interleukin-1 receptor-associated kinase 4 (IRAK4) is a critical molecule in Toll-like receptor/interleukin-1 receptor signaling and an attractive therapeutic target for a wide range of inflammatory and autoimmune diseases as well as cancers. In our search for novel IRAK4 inhibitors, we conducted structural modification of a thiazolecarboxamide derivative 1, a lead compound derived from high-throughput screening hits, to elucidate structure-activity relationship and improve drug metabolism and pharmacokinetic (DMPK) properties. First, conversion of the thiazole ring of 1 to an oxazole ring along with introduction of a methyl group at the 2-position of the pyridine ring aimed at reducing cytochrome P450 (CYP) inhibition were conducted to afford 16. Next, modification of the alkyl substituent at the 1-position of the pyrazole ring of 16 aimed at improving CYP1A2 induction properties revealed that branched alkyl and analogous substituents such as isobutyl (18) and (oxolan-3-yl)methyl (21), as well as six-membered saturated heterocyclic groups such as oxan-4-yl (2), piperidin-4-yl (24, 25), and dioxothian-4-y (26), are effective for reducing induction potential. Representative compound AS2444697 (2) exhibited potent IRAK4 inhibitory activity with an IC50 value of 20 nM and favorable DMPK properties such as low risk of drug-drug interactions mediated by CYPs as well as excellent metabolic stability and oral bioavailability.

IRAK2, an Immune and Radiation-Response Gene, Correlates with Advanced Disease Features but Predicts Higher Post-Irradiation Local Control in Non-Metastatic and Resected Oral Cancer Patients

Gene Ontology (GO) analysis can provide a comprehensive function analysis for investigating genes, allowing us to identify the potential biological roles of genes. The present study conducted GO analysis to explore the biological function of IRAK2 and performed a case analysis to define its clinical role in disease progression and mediating tumor response to RT. Methods: We performed a GO enrichment analysis on the RNA-seq data to validate radiation-induced gene expression. A total of 172 I-IVB specimens from oral squamous cell carcinoma patients were collected for clinical analysis, from which IRAK2 expression was analyzed by immunohistochemistry. This was a retrospective study conducted between IRAK2 expression and the outcomes of oral squamous cell carcinoma patients after radiotherapy treatment. We conducted Gene Ontology (GO) analysis to explore the biological function of IRAK2 and performed a case analysis to define its clinical role in mediating tumor response to radiotherapy. GO enrichment analysis to validate radiation-induced gene expression was performed. Clinically, 172 stage I-IVB resected oral cancer patients were used to validate IRAK2 expression in predicting clinical outcomes. GO enrichment analysis showed that IRAK2 is involved in 10 of the 14 most enriched GO categories for post-irradiation biological processes, focusing on stress response and immune modulation. Clinically, high IRAK2 expression was correlated with adverse disease features, including pT3-4 status (p = 0.01), advanced overall stage (p = 0.02), and positive bone invasion (p = 0.01). In patients who underwent radiotherapy, the IRAK2-high group was associated with reduced post-irradiation local recurrence (p = 0.025) compared to the IRAK2-low group. IRAK2 plays a crucial role in the radiation-induced response. Patients with high IRAK2 expression demonstrated more advanced disease features but predicted higher post-irradiation local control in a clinical setting. These findings support IRAK2 as a potential predictive biomarker for radiotherapy response in non-metastatic and resected oral cancer patients.

Suppression of TLR signaling by IRAK-1 and -4 dual inhibitor decreases TPF-resistance-induced pro-oncogenic effects in HNSCC

Combination of docetaxel, cisplatin and 5-FU, known as TPF, is an FDA-approved treatment for head and neck squamous cell carcinoma (HNSCC). Acquired chemo-resistance to TPF, a primary reason for non-responsiveness to the treatment and relapse of tumor is a major concern for treatment failure, especially in elder patients. In this study, we investigated the role of Interleukin-1 receptor-associated kinases (IRAK) mediated Toll-like receptor (TLR)-signaling in chemo-resistance using a cell line-based in-vitro TPF-resistant HNSCC model of laryngeal origin. TPF chemo-resistant state showed over-expression and phosphorylation of the active downstream kinases IRAK-1 and IRAK-4 along with enhanced proliferative potential, survival, stemness and metastatic capability as compared to the parent cell line. Pharmacological inhibition of IRAK-1 and -4 had a cytostatic effect on chemo-resistant cells and re-sensitized them to chemotherapy. The treatment also decreased the pro-oncogenic effects of the chemo-resistant cells. Our study provides insights into the pro-oncogenic role of amplified IRAK-1 and-4 mediated TLR signaling in TPF-resistant HNSCC. Pharmacological inhibition of IRAK-1 and-4 signaling is a promising therapeutic strategy for TPF-resistant HNSCC. It can also be used as a combination therapy or a chemo-drug sparing regimen in HNSCC.

Pharmacologic characterization of TBP1901, a prodrug form of aglycone curcumin, and CRISPR-Cas9 screen for therapeutic targets of aglycone curcumin

Curcumin (aglycone curcumin) has antitumor properties in a variety of malignancies via the alteration of multiple cancer-related biological pathways; however, its clinical application has been hampered due to its poor bioavailability. To overcome this limitation, we have developed a synthesized curcumin β-D-glucuronide sodium salt (TBP1901), a prodrug form of aglycone curcumin. In this study, we aimed to clarify the pharmacologic characteristics of TBP1901. In β-glucuronidase (GUSB)-proficient mice, both curcumin β-D-glucuronide and its active metabolite, aglycone curcumin, were detected in the blood after TBP1901 injection, whereas only curcumin β-D-glucuronide was detected in GUSB-impaired mice, suggesting that GUSB plays a pivotal role in the conversion of TBP1901 into aglycone curcumin in vivo. TBP1901 itself had minimal antitumor effects in vitro, whereas it demonstrated significant antitumor effects in vivo. Genome-wide clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 screen disclosed the genes associated with NF-κB signaling pathway and mitochondria were among the highest hit. In vitro, aglycone curcumin inhibited NF-kappa B signaling pathways whereas it caused production of reactive oxygen species (ROS). ROS scavenger, N-acetyl-L-cysteine, partially reversed antitumor effects of aglycone curcumin. In summary, TBP1901 can exert antitumor effects as a prodrug of aglycone curcumin through GUSB-dependent activation.

Design of Novel IRAK4 Inhibitors Using Molecular Docking, Dynamics Simulation and 3D-QSAR Studies

Treatment of several autoimmune diseases and types of cancer has been an intense area of research over the past two decades. Many signaling pathways that regulate innate and/or adaptive immunity, as well as those that induce overexpression or mutation of protein kinases, have been targeted for drug discovery. One of the serine/threonine kinases, Interleukin-1 Receptor Associated Kinase 4 (IRAK4) regulates signaling through various Toll-like receptors (TLRs) and interleukin-1 receptor (IL1R). It controls diverse cellular processes including inflammation, apoptosis, and cellular differentiation. MyD88 gain-of-function mutations or overexpression of IRAK4 has been implicated in various types of malignancies such as Waldenström macroglobulinemia, B cell lymphoma, colorectal cancer, pancreatic ductal adenocarcinoma, breast cancer, etc. Moreover, over activation of IRAK4 is also associated with several autoimmune diseases. The significant role of IRAK4 makes it an interesting target for the discovery and development of potent small molecule inhibitors. A few potent IRAK4 inhibitors such as PF-06650833, RA9 and BAY1834845 have recently entered phase I/II clinical trial studies. Nevertheless, there is still a need of selective inhibitors for the treatment of cancer and various autoimmune diseases. A great need for the same intrigued us to perform molecular modeling studies on 4,6-diaminonicotinamide derivatives as IRAK4 inhibitors. We performed molecular docking and dynamics simulation of 50 ns for one of the most active compounds of the dataset. We also carried out MM-PBSA binding free energy calculation to identify the active site residues, interactions of which are contributing to the total binding energy. The final 50 ns conformation of the most active compound was selected to perform dataset alignment in a 3D-QSAR study. Generated RF-CoMFA (q² = 0.751, ONC = 4, r² = 0.911) model revealed reasonable statistical results. Overall results of molecular dynamics simulation, MM-PBSA binding free energy calculation and RF-CoMFA model revealed important active site residues of IRAK4 and necessary structural properties of ligand to design more potent IRAK4 inhibitors. We designed few IRAK4 inhibitors based on these results, which possessed higher activity (predicted pIC₅₀) than the most active compounds of the dataset selected for this study. Moreover, ADMET properties of these inhibitors revealed promising results and need to be validated using experimental studies.

Nano pom-poms prepared exosomes enable highly specific cancer biomarker detection

Extracellular vesicles (EVs), particularly nano-sized small EV exosomes, are emerging biomarker sources. However, due to heterogeneous populations secreted from diverse cell types, mapping exosome multi-omic molecular information specifically to their pathogenesis origin for cancer biomarker identification is still extraordinarily challenging. Herein, we introduced a novel 3D-structured nanographene immunomagnetic particles (NanoPoms) with unique flower pom-poms morphology and photo-click chemistry for specific marker-defined capture and release of intact exosome. This specific exosome isolation approach leads to the expanded identification of targetable cancer biomarkers with enhanced specificity and sensitivity, as demonstrated by multi-omic exosome analysis of bladder cancer patient tissue fluids using the next generation sequencing of somatic DNA mutations, miRNAs, and the global proteome (Data are available via ProteomeXchange with identifier PXD034454). The NanoPoms prepared exosomes also exhibit distinctive in vivo biodistribution patterns, highlighting the highly viable and integral quality. The developed method is simple and straightforward, which is applicable to nearly all types of biological fluids and amenable for enrichment, scale up, and high-throughput exosome isolation.

The clinical and prognostic significance of CMTM6/PD-L1 in oncology

The recent discovery of CMTM6 and to a lesser extent CMTM4, two members of the chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing family, as master positive regulators of PD-L1 expression, the primary ligand of programmed cell death 1 (PD-1), on tumor and immune cells has opened new horizons for investigating the role of CMTM6/CMTM4 in different aspects of oncology including their clinical and prognostic values in different cancer types. The absence of a specific review article addressing the available results about the clinical and prognostic roles of CMTM6 alone and/or in combination with PD-L1 in cancer has encouraged us to write this paper.

Comprehensive Pan-Cancer Analysis of IRAK Family Genes Identifies IRAK1 as a Novel Oncogene in Low-Grade Glioma

Background

The interleukin-1 receptor-associated kinases (IRAK) family genes, indispensable mediators of interleukin-1 receptor (IL1R) and Toll-like receptor (TLR)-inflammatory signaling, may be involved in the biological function of human cancers due to the crucial roles of inflammation in tumor development. Though a little research has demonstrated the function of individual IRAK family members in specific tumors, comprehensive analysis is still lacking in pan-cancer.

Methods

We analyzed the mRNA expression landscape, mutation, and prognosis value of IRAK genes based on The Cancer Genome Atlas (TCGA), cBioPortal, GlioVis, and Rembrandt databases. The correlation between the expression of IRAK genes and tumor microenvironment (TME), Stemness score, and immune subtypes was explored. Western blot, cell proliferation, apoptosis, migration assays, and xenograft models were utilized in this study.

Results

We found that the expression of IRAK genes extensively changed and was related to patient survival in pan-cancer. Besides, IRAK family genes were correlated with TME, Stemness score, and immune subtypes in most cases. Given that high expression of all IRAK family members predicted poor prognosis in low-grade glioma (LGG), the oncogenic function of the highest expressed IRAK1 in LGG has been confirmed in vitro and in vivo. IRAK1 was uncovered to inhibit cell apoptosis and augment malignancy of LGG in vitro and in vivo.

Conclusion

These findings revealed the potential targets of IRAK family genes in pan-cancer and provided insights for further investigation of IRAK1 as a novel oncogenic gene in LGG.

IRAK1 and IRAK4 as emerging therapeutic targets in hematologic malignancies

PURPOSE OF REVIEW

Cell intrinsic and extrinsic perturbations to inflammatory signaling pathways are a hallmark of development and progression of hematologic malignancies. The interleukin 1 receptor-associated kinases (IRAKs) are a family of related signaling intermediates (IRAK1, IRAK2, IRAK3, IRAK4) that operate at the nexus of multiple inflammatory pathways implicated in the hematologic malignancies. In this review, we explicate the oncogenic role of these kinases and review recent therapeutic advances in the dawning era of IRAK-targeted therapy.

RECENT FINDINGS

Emerging evidence places IRAK signaling at the confluence of adaptive resistance and oncogenesis in the hematologic malignancies and solid tissue tumors. Preclinical investigations nominate the IRAK kinases as targetable molecular dependencies in diverse cancers.

SUMMARY

IRAK-targeted therapies that have matriculated to early phase trials are yielding promising preliminary results. However, studies of IRAK kinase signaling continue to defy conventional signaling models and raise questions as to the design of optimal treatment strategies. Efforts to refine IRAK signaling mechanisms in the malignant context will inspire deliberate IRAK-targeted drug development and informed combination therapy.

Inhibition of Janus Kinase 1 synergizes docetaxel sensitivity in prostate cancer cells

Prostate cancer (PCa) is the second most common malignancy and is the fifth leading cause of cancer mortality among men globally. Docetaxel-based therapy remains the first-line treatment for metastatic castration-resistant prostate cancer. However, dose-limiting toxicity including neutropenia, myelosuppression and neurotoxicity is the major reason for docetaxel dose reductions and fewer cycles administered, despite a recent study showing a clear survival benefit with increased total number of docetaxel cycles in PCa patients. Although previous studies have attempted to improve the efficacy and reduce docetaxel toxicity through drug combination, no drug has yet demonstrated improved overall survival in clinical trial, highlighting the challenges of improving the activity of docetaxel monotherapy in PCa. Herein, we identified 15 lethality hits for which inhibition could enhance docetaxel sensitivity in PCa cells via a high-throughput kinome-wide loss-of-function screen. Further drug-gene interactions analyses identified Janus kinase 1 (JAK1) as a viable druggable target with existing experimental inhibitors and FDA-approved drugs. We demonstrated that depletion of endogenous JAK1 enhanced docetaxel-induced apoptosis in PCa cells. Furthermore, inhibition of JAK1/2 by baricitinib and ruxolitinib synergizes docetaxel sensitivity in both androgen receptor (AR)-negative DU145 and PC3 cells, but not in the AR-positive LNCaP cells. In contrast, no synergistic effects were observed in cells treated with JAK2-specific inhibitor, fedratinib, suggesting that the synergistic effects are mainly mediated through JAK1 inhibition. In conclusion, the combination therapy with JAK1 inhibitors and docetaxel could be a useful therapeutic strategy in the treatment of prostate cancers.

Establishing and Validating Cellular Functional Target Engagement Assay for Selective IRAK4 Inhibitor Discovery

One of the main reasons for the lack of drug efficacy in late-stage clinical trials is the lack of specific and selective target engagement. To increase the likelihood of success of new therapeutics, one approach is to conduct proximal target engagement testing during the early phases of preclinical drug discovery. To identify and optimize selective IRAK4 inhibitors, a kinase that has been implicated in multiple inflammatory and autoimmune diseases, we established an electrochemiluminescence (ECL)-based cellular endogenous IRAK1 activation assay as the most proximal functional evaluation of IRAK4 engagement to support structure-activity relationship (SAR) studies. Since IRAK1 activation is dependent on both the IRAK4 scaffolding function in Myddosome formation and IRAK4 kinase activity for signal transduction, this assay potentially captures inhibitors with different mechanisms of action. Data from this IRAK1 assay with compounds representing different structural classes showed statistically significant correlations when compared with results from both IRAK4 biochemical kinase activity and functional peripheral blood mononuclear cell (PBMC)-derived tumor necrosis factor α (TNFα) secretion assays, validating the biological relevancy of the IRAK1 target engagement as a biomarker of the IRAK4 activity. Plate uniformity and potency reproducibility evaluations demonstrated that this assay is amenable to high throughput. Using Bland-Altman assay agreement analysis, we demonstrated that incorporating such proximal pharmacological assessment of cellular target engagement to an in vitro screening funnel for SAR studies can prevent compound optimization toward off-target activity.

TPL2 enforces RAS-induced inflammatory signaling and is activated by point mutations

NF-κB transcription factors, driven by the IRAK/IKK cascade, confer treatment resistance in pancreatic ductal adenocarcinoma (PDAC), a cancer characterized by near-universal KRAS mutation. Through reverse-phase protein array and RNA sequencing we discovered that IRAK4 also contributes substantially to MAPK activation in KRAS-mutant PDAC. IRAK4 ablation completely blocked RAS-induced transformation of human and murine cells. Mechanistically, expression of mutant KRAS stimulated an inflammatory, autocrine IL-1β signaling loop that activated IRAK4 and the MAPK pathway. Downstream of IRAK4, we uncovered TPL2 (also known as MAP3K8 or COT) as the essential kinase that propels both MAPK and NF-κB cascades. Inhibition of TPL2 blocked both MAPK and NF-κB signaling, and suppressed KRAS-mutant cell growth. To counter chemotherapy-induced genotoxic stress, PDAC cells upregulated TLR9, which activated prosurvival IRAK4/TPL2 signaling. Accordingly, a TPL2 inhibitor synergized with chemotherapy to curb PDAC growth in vivo. Finally, from TCGA we characterized 2 MAP3K8 point mutations that hyperactivate MAPK and NF-κB cascades by impeding TPL2 protein degradation. Cancer cell lines naturally harboring these MAP3K8 mutations are strikingly sensitive to TPL2 inhibition, underscoring the need to identify these potentially targetable mutations in patients. Overall, our study establishes TPL2 as a promising therapeutic target in RAS- and MAP3K8-mutant cancers and strongly prompts development of TPL2 inhibitors for preclinical and clinical studies.

Interleukin-1 receptor-associated kinase 4 as a potential biomarker: Overexpression predicts poor prognosis in patients with glioma

The undetectable onset of glioma and the difficulty of surgery lead to a poor prognosis. Appropriate biomarkers for diagnosis and treatment need to be identified. Interleukin-1 receptor-associated kinase 4 (IRAK4) is involved in the initiation and progression of cancer. However, up until now, no report has revealed the relationship between IRAK4 and glioma. The present study aimed to examine the expression of IRAK4 in glioma, and to determine if there was a relationship between IRAK4 expression and clinical outcomes or survival prognosis. Thousands of glioma tissue samples and corresponding clinical information were obtained from various databases. Then a series of bioinformatics methods were used to reveal the role of IRAK4 in glioma. Finally, reverse transcription-quantitative PCR technology was used to verify the bioinformatics results. The study found that the expression of IRAK4 was significantly increased in glioma compared with the control brain tissue samples, and IRAK4, as an independent prognostic factor, shortened the overall survival time of patients with glioma. Gene Set Enrichment Analysis showed that IRAK4 promoted the activation of cell signalling pathways, such as NOD-like and Toll-like receptor signalling pathways. Co-expression analysis showed that the expression of IRAK4 was correlated with CMTM6, MOB1A and other genes. The present study demonstrated the role of IRAK4 as an oncogene in the pathological process of glioma for the first time, and highlights the potential of IRAK4 as a biomarker for prognostic evaluation and treatment of glioma.

Activity-Based Protein Profiling Reveals Potential Dasatinib Targets in Gastric Cancer

Dasatinib is a multi-target kinase inhibitor, whose targets include BCR-ABL, SRC family kinases, and various cancer kinases. The elevated SRC activity in gastric cancer (GC) has prompted the need for the therapeutic application of dasatinib in GC. We observed that the efficacy of dasatinib varied with the GC cell lines. The differential effect of dasatinib was not correlated with the basal SRC activity of each cell line. Moreover, the GC cell lines showing the strong antitumor effects of dasatinib were refractory to other SRC inhibitors, i.e., bosutinib and saracatinib, suggesting that unexpected dasatinib’s targets could exist. To profile the targets of dasatinib in GC, we performed activity-based protein profiling (ABPP) via mass spectrometry using a desthiobiotin-ATP probe. We identified 29 and 18 kinases as potential targets in dasatinib-sensitive (SNU-216, MKN-1) and -resistant (SNU-484, SNU-601) cell lines, respectively. The protein–protein interaction mapping of the differential drug targets in dasatinib-sensitive and -resistant GC using the STRING database suggested that dasatinib could target cellular energy homeostasis in the drug-sensitive GC. RNAi screening for identified targets indicated p90RSK could be a novel dasatinib target, which is important for maintaining the viability and motility of GC cells. Further functional validation of dasatinib off-target actions will provide more effective therapeutic options for GC.

HIF1α promotes tumor chemoresistance via recruiting GDF15-producing TAMs in colorectal cancer

Chemoresistance is a tremendous challenge to efficacy of systemic chemotherapy which is the preferred treatment for the advanced CRC patients. More tumor-associated macrophages (TAMs) are recruited into the CRC tumor under chemotherapy, which are highly implicated in the chemoresistance development, but the underlying molecular mechanism is unclear. Here, we present that activated HIF1α signaling in CRC cells under chemotherapy drives the expression of HMGB1to promotes macrophage infiltration and in turn chemoresistance development. Chemotherapeutic treatment with 5-FU leads to increased recruitment of macrophages into tumors, which display tumor-protective alternative activation. Mechanistically, tumor HIF1α signaling activated by chemo-induced ROS drives the transcription of HMGB1 to promote more macrophage infiltration into CRC tumor. Furthermore, high levels of GDF15 produced by TAMs impair the chemosensitity of tumor cells via enhancing fatty acids β-oxidation. Together, our current study reveals a new insight into the cross-talking between tumor cells and immune cells, and provides novel drug targets for clinic treatments for CRC.

Deciphering the Role of Innate Immune NF-ĸB Pathway in Pancreatic Cancer

Simple Summary

Chronic inflammation is a major mechanism that underlies the aggressive nature and treatment resistance of pancreatic cancer. In many ways, the molecular mechanisms that drive chronic inflammation in pancreatic cancer are very similar to our body’s normal innate immune response to injury or invading microorganisms. Therefore, during cancer development, pancreatic cancer cells hijack the innate immune pathway to foster a chronically inflamed tumor environment that helps shield them from immune attack and therapeutics. While blocking the innate immune pathway is theoretically reasonable, untoward side effects must also be addressed. In this review, we comprehensively summarize the literature that describe the role of innate immune signaling in pancreatic cancer, emphasizing the specific role of this pathway in different cell types. We review the interaction of the innate immune pathway and cancer-driving signaling in pancreatic cancer and provide an updated overview of novel therapeutic opportunities against this mechanism.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers with no effective treatment option. A predominant hallmark of PDAC is the intense fibro-inflammatory stroma which not only physically collapses vasculature but also functionally suppresses anti-tumor immunity. Constitutive and induced activation of the NF-κB transcription factors is a major mechanism that drives inflammation in PDAC. While targeting this pathway is widely supported as a promising therapeutic strategy, clinical success is elusive due to a lack of safe and effective anti-NF-κB pathway therapeutics. Furthermore, the cell type-specific contribution of this pathway, specifically in neoplastic cells, stromal fibroblasts, and immune cells, has not been critically appraised. In this article, we highlighted seminal and recent literature on molecular mechanisms that drive NF-κB activity in each of these major cell types in PDAC, focusing specifically on the innate immune Toll-like/IL-1 receptor pathway. We reviewed recent evidence on the signaling interplay between the NF-κB and oncogenic KRAS signaling pathways in PDAC cells and their collective contribution to cancer inflammation. Lastly, we reviewed clinical trials on agents that target the NF-κB pathway and novel therapeutic strategies that have been proposed in preclinical studies.