Interleukin-1 receptor-associated kinase 4 (IRAK4) is a pivotal enzyme in the Toll-like receptor (TLR)/MYD88 dependent signaling pathway, which is highly activated in rheumatoid arthritis tissues and activated B cell-like diffuse large B-cell lymphoma (ABC-DLBCL). Inflammatory responses followed by IRAK4 activation promote B-cell proliferation and aggressiveness of lymphoma. Moreover, proviral integration site for Moloney murine leukemia virus 1 (PIM1) functions as an anti-apoptotic kinase in propagation of ABC-DLBCL with ibrutinib resistance. We developed a dual IRAK4/PIM1 inhibitor KIC-0101 that potently suppresses the NF-κB pathway and proinflammatory cytokine induction in vitro and in vivo. In rheumatoid arthritis mouse models, treatment with KIC-0101 significantly ameliorated cartilage damage and inflammation. KIC-0101 inhibited the nuclear translocation of NF-κB and activation of JAK/STAT pathway in ABC-DLBCLs. In addition, KIC-0101 exhibited an anti-tumor effect on ibrutinib-resistant cells by synergistic dual suppression of TLR/MYD88-mediated NF-κB pathway and PIM1 kinase. Our results suggest that KIC-0101 is a promising drug candidate for autoimmune diseases and ibrutinib-resistant B-cell lymphomas.
Transcriptional regulator YAP is activated in multiple human cancers and plays critical roles in tumor initiation, progression, metastasis, and drug resistance. However, therapeutic targeting of the Hippo–YAP pathway has been challenging due to its low druggability and limited knowledge of YAP regulation in cancer. Here we present a functional screen and identify a novel therapeutic target for YAP-driven tumorigenesis. RNAi screening using an oncogenic YAP activation model identified the serine/threonine kinase MK5 as a positive regulator of YAP. MK5 physically interacted with YAP and counteracted CK1δ/ϵ-mediated YAP ubiquitination and degradation independent of LATS1/2. MK5 kinase activity was essential for protecting YAP from ubiquitin-mediated degradation and cytoplasmic retention. Downregulating MK5 expression inhibited the survival of YAP-activated cancer cell lines and mouse xenograft models. MK5 upregulation was associated with high levels of YAP expression and poor prognosis in clinical tumor samples, confirming its important role for YAP activity in human cancer. These results uncover MK5 as a novel factor that regulates YAP stability, and targeting the YAP degradation pathway controlled by MK5 is a potential strategy for suppressing YAP activity in cancer. Significance: These findings reveal MK5 is a novel kinase that regulates YAP in a LATS-independent manner and can be targeted for cancer therapy.
Direct inhibitors of glycogen synthase kinase 3β (GSK3β) have been investigated and reported for the past 20 years. In the search for novel scaffold inhibitors, 3000 compounds were selected through structure-based virtual screening (SBVS), and then high-throughput enzyme screening was performed. Among the active hit compounds, pyrazolo [1,5-a]pyrimidin-7-amine derivatives showed strong inhibitory potencies on the GSK3β enzyme and markedly activated Wnt signaling. The result of the molecular dynamics (MD) simulation, enhanced by the upper-wall restraint, was used as an advanced structural query for the SBVS. In this study, strong inhibitors designed to inhibit the GSK3β enzyme were discovered through SBVS. Our study provides structural insights into the binding mode of the inhibitors for further lead optimization.
Human cerebral organoids are promising tools for investigating brain development and the pathogenesis underlying neurological disorders. To use organoids for drug effectiveness and safety screening, the organoids dispensed into each well must be prepared under precisely the same conditions as the cells. Despite decades of extensive research on approaches to improve organoid generation, various challenges remain, such as low yields and heterogeneity in size and differentiation both within and between batches. Here, we newly established uniform cerebral organoids (UCOs) derived from induced pluripotent stem cells by optimizing organoid size and performing real-time monitoring of telencephalic differentiation marker expression. These organoids exhibited morphological uniformity and consistent expression of FOXG1 during telencephalic differentiation, with high productivity. Moreover, UCOs faithfully recapitulated early corticogenesis, concomitant with the establishment of neuroepithelial populations, cortical plate neurons, and glial cells. Furthermore, UCOs systematically developed neural networks and exhibited both excitatory and inhibitory electrophysiological signals when exposed to neurotransmission blockers. Neurodevelopmental disease models derived from UCOs manifested neurite outgrowth defects, which could be ameliorated with targeted drug treatment. We propose UCOs as an advanced platform with low organoid variations and high reproducibility for modeling both brain development and neurological diseases.
Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and remains a leading cause of cancer-related mortality worldwide. Lung adenocarcinoma (AD) and lung squamous cell carcinoma (SCC) represent the two major histological subtypes with distinct molecular characteristics. POU domain class 6 transcription factor 1 (POU6F1) is involved in gene regulation and cellular differentiation, but its clinical significance in NSCLC remains unclear. This study investigated the clinicopathologic and prognostic significance of POU6F1 expression in NSCLC. POU6F1 mRNA expression was analyzed in tumor tissues obtained from 153 patients with NSCLC using quantitative real-time polymerase chain reaction. The associations between POU6F1 expression and clinicopathological characteristics were evaluated, and survival analysis was performed to determine its prognostic value. In addition, publicly available datasets from The Cancer Genome Atlas (TCGA) were analyzed to validate the clinical significance of POU6F1 expression. High POU6F1 expression was observed in 48 patients (31.4%), whereas 105 patients (68.6%) showed low expression. High POU6F1 expression was significantly associated with younger age (p = 0.027), female sex (p = 0.041), non-smoking status (p = 0.002), adenocarcinoma histology (p = 0.021), and the presence of EGFR mutations (p = 0.038). Survival analysis demonstrated that high POU6F1 expression was associated with improved overall survival in patients with NSCLC (p = 0.015). When stratified by histological subtype, higher POU6F1 expression was associated with better survival outcomes in AD but not in SCC. Analysis of TCGA datasets confirmed that elevated POU6F1 expression was significantly associated with favorable survival in AD, whereas no significant prognostic value was observed in SCC. POU6F1 expression is significantly associated with clinicopathological characteristics and improved survival in patients with lung AD. Multivariate Cox regression analysis further confirmed that POU6F1 expression was an independent prognostic factor for overall survival. These findings suggest that POU6F1 may serve as a potential prognostic biomarker based on mRNA expression in NSCLC, particularly in AD. Further studies are warranted to validate these findings at the protein level and to elucidate the underlying biological mechanisms.
Radiotherapy is the central component in non-small cell lung cancer (NSCLC) treatment. Nonetheless, its therapeutic effectiveness is frequently compromised by adaptive engagement of prosurvival signaling pathways that foster radioresistance. STAT3 functions as the central signaling node that orchestrates cellular survival responses following radiation exposure. This study investigated whether nitroxoline, a clinically approved antimicrobial agent with STAT3-inhibitory activity, enhances radiosensitivity of NSCLC cells and how these effects are mechanistically regulated. We examined the combined effects of nitroxoline and radiation on cell viability and associated signaling pathways in NSCLC cells. Nitroxoline significantly enhanced radiation-induced cytotoxicity and suppressed clonogenic survival compared with radiation alone. Irradiation increased STAT3, AKT, and mTOR phosphorylation, whereas nitroxoline effectively suppressed the basal and radiation-induced activation of these pathways. The combination treatment markedly augmented radiation-induced apoptosis, as demonstrated by increased p53 expression and enhanced PARP and caspase-3 cleavage. Additionally, nitroxoline amplified radiation-induced DNA damage signaling, resulting in pronounced γ-H2AX and DNA-PKcs accumulation. Nitroxoline enhanced NSCLC cell radiosensitivity by suppressing STAT3–AKT–mTOR survival signaling, promoting apoptosis, and amplifying radiation-induced DNA damage, indicating the potential of repurposing nitroxoline as a radiosensitizer to improve radiotherapy outcomes in patients with NSCLC.