Targeting Death-Associated Protein Kinases for Treatment of Human Diseases: Recent Advances and Future Directions

Comprehensive exploration of programmed cell death landscape in lung adenocarcinoma combining multi-omic analysis and experimental verification

The mortality and therapeutic failure in lung adenocarcinoma (LUAD) are mainly resulted from the wide metastasis and chemotherapy resistance. Up to now, accurate and stable predictive prognostic indicator for revealing the progress and novel therapeutic strategies of LUAD is infrequent, nonetheless. Diversified programmed cell death (PCD) has been widely confirmed that participated in the occurrence and development of various malignant tumors, respectively. In this research, we integrated fourteen types of PCD, bulk multi-omic data from TCGA-LUAD and other cohorts in gene expression omnibus (GEO) and clinical LUAD patients to develop our analysis. Consequently, pivotal fourteen PCD genes, especially CAMP, CDK5R1, CTSW, DAPK2, GAB2, GAPDH, GATA2, HGF, MAPT, NAPSA, NUPR1, PIK3CG, PLA2G3, and SLC7A11, were utilized to establish the prognostic signature, namely cell death index (CDI). The validation in several external cohorts indicated that CDI can be regarded as a potential risk factor of LUAD patients. Combined with other common clinical information, a nomogram with potential predictive ability was constructed. Besides, according to the CDI signature, the tumor microenvironment (TME) and sensitivity to some potential chemotherapeutic drugs were further and deeply explored. Notably, verification and functional experiments further demonstrated the remarkable correlation between CDI and unfold protein response. Given all the above, a novel CDI gene signature was indicated to predict the prognosis and exploit precision therapeutic strategies of LUAD patients.

Discovery and optimization of isoliquiritigenin as a death-associated protein kinase 1 inhibitor

Death-associated protein kinase 1 (DAPK1) is a phosphotransferase in the serine/threonine kinase family. Inhibiting DAPK1 is expected to be beneficial in treating Alzheimer's disease and protecting neuronal cells during cerebral ischemia. In this study, we demonstrated that the natural chalcone isoliquiritigenin inhibits DAPK1 in an ATP-competitive manner, and we synthesized halogen derivatives to amplify the inhibitory effect. Among the compounds tested, the chlorine, bromine, and iodine derivatives exhibited high DAPK1 inhibitory activity and binding affinity. Crystal structure analysis revealed that this improvement is attributable to the halogen atoms fitting well into the hydrophobic pocket formed by I77, L93, and I160. In particular, the chlorine derivative showed a significant enthalpic contribution to the interaction with DAPK1, suggesting its potential as a primary compound for new DAPK1 inhibitors.

N6-Methyladenosine Methyltransferase Component KIAA1429 Is a Potential Target of Cancer Therapy

N6-methyladenosine (m6A), the most abundant RNA modification in eukaryotes, has a crucial impact on tumorigenesis. KIAA1429 is the key component of the m6A methyltransferase complex, in which KIAA1429 functions as a scaffold to bridge the catalytic core proteins. KIAA1429 is often overexpressed in malignances, associated with patient prognosis, and required for tumorigenesis. KIAA1429 regulates the expression of a number of tumor-associated genes in an m6A -dependent manner, and thus, contributes to cell proliferation, migration, drug resistance, tumor formation and metastasis. This review focuses on recent progress in the understanding of roles and mechanisms of KIAA1429 in cancers, and offers ideas for potential anti-cancer therapeutic methods by targeting KIAA1429.

Targeting cis-p-tau and neuro-related gene expression in traumatic brain injury: therapeutic insights from TC-DAPK6 treatment in mice

BACKGROUND

Traumatic brain injury (TBI) is a significant global health concern and is characterized by brain dysfunction resulting from external physical forces, leading to brain pathology and neuropsychiatric disorders such as anxiety. This study investigates the effects of TC-DAPK6 on tau hyper-phosphorylation, gene expression, anxiety, and behavior impairment in the TBI mice model.

METHODS AND RESULTS

A weight drop model induced the TBI and the anxiety levels were evaluated using an elevated plus maze (EPM) test. TC-DAPK6 was intraperitoneally administered one-month post-TBI and continued for two months. The total cis-p-tau ratio in the brain was assessed using western blot and immunofluorescence staining. Molecular analysis was conducted on Aff2, Zkscan16, Kcna1, Pcdhac2, and Pcdhga8 to investigate the function and pathogenic role of TC-DAPK6 in neurological diseases in the cerebral cortex tissues of TBI-model mice, and the results were compared with TC-DAPK6 TBI-treatment group. The anxiety level and phosphorylation of tau protein in the TBI group were significantly increased compared to the sham groups and decreased substantially in the TBI-treatment group after TC-DAPK6 administration; the TBI group mostly spent their time with open arms. TC-DAPK6 decreased the expression level of genes as much as the sham group. Meanwhile, KCNA1 showed the highest fold of changes in the TBI and TBI-treatment groups.

CONCLUSIONS

The study demonstrates a clear association between cis-p-tau and neuro-related gene expression levels in TBI-induced mice. Targeting these pathways with DAPK1 inhibitors, shows promise for therapeutic interventions in TBI and related neurodegenerative disorders.

Protection of blood-brain barrier by endothelial DAPK1 deletion after stroke

Death-associated protein kinase (DAPK) 1 is a critical mediator for neuronal cell death in cerebral ischemia, but its role in blood-brain barrier (BBB) disruption is incompletely understood. Here, we found that endothelial-specific deletion of Dapk1 using Tie2 Cre protected the brain of Dapk1fl/fl mice against middle cerebral artery occlusion (MCAO), characterized by mitigated Evans blue dye (EBD) extravasation, reduced infarct size and improved behavior. In vitro experiments also indicated that DAPK1 deletion inhibited oxygen-glucose deprivation (OGD)-induced tight junction alteration between cerebral endothelial cells (CECs). Mechanistically, we revealed that DAPK1-DAPK3 interaction activated cytosolic phospholipase A2 (cPLA2) in OGD-stimulated CECs. Our results thus suggest that inhibition of endothelial DAPK1 specifically prevents BBB damage after stroke.

DNA methylation variations of DNA damage response correlate survival and local immune status in melanomas

AIM

We aimed to explore the impact of DNA methylation alterations on the DNA damage response (DDR) in melanoma prognosis and immunity. MATERIAL & METHODS: Different melanoma cohorts with molecular and clinical data were included.

RESULTS

Hierarchical clustering utilizing different combinations of DDR-relevant CpGs yielded distinct melanoma subtypes, which were characteristic of different prognoses, transcriptional function profiles of DDR, and immunity and immunotherapy responses but were associated with similar tumor mutation burdens. We then constructed and validated a clinically applicable 4-CpG risk-score signature for predicting survival and immunotherapy response.

CONCLUSION

Our study describes the close interrelationship among DNA methylation, DDR machinery, local tumor immune status, melanoma prognosis, and immunotherapy response.

ZIPK collaborates with STAT5A in p53-mediated ROS accumulation in hyperglycemia-induced vascular injury

In this study we investigate the role of Zipper-interacting protein kinase (ZIPK) in high glucose-induced vascular injury, focusing on its interaction with STAT5A and its effects on p53 and inducible nitric oxide synthase (NOS2) expression. Human umbilical vein endothelial cells (HUVECs) are cultured under normal (5 mM) and high (25 mM) glucose conditions. Protein and gene expression levels are assessed by western blot analysis and qPCR respectively, while ROS levels are measured via flow cytometry. ZIPK expression is manipulated using overexpression plasmids, siRNAs, and shRNAs. The effects of the ZIPK inhibitor TC-DAPK6 are evaluated in a diabetic rat model. Our results show that high glucose significantly upregulates ZIPK, STAT5A, p53, and NOS2 expressions in HUVECs, thus increasing oxidative stress. Silencing of STAT5A reduces p53 and NOS2 expressions and reactive oxygen species (ROS) accumulation. ZIPK is essential for high glucose-induced p53 expression and ROS accumulation, while silencing of ZIPK reverses these effects. Overexpression of ZIPK combined with STAT5A silencing attenuates glucose-induced alterations in p53 and NOS2 expression, thereby preventing cell damage. Coimmunoprecipitation reveals a direct interaction between ZIPK and STAT5A in the nucleus under high-glucose condition. In diabetic rats, TC-DAPK6 treatment significantly decreases ZIPK, p53, and NOS2 expressions. Our findings suggest that ZIPK plays a critical role in high glucose-induced vascular injury via STAT5A-mediated pathways, proposing that ZIPK is a potential therapeutic target for diabetic vascular complications.

Potent, Selective, and Orally Bioavailable Quinazoline-Based STK17A/B Dual Inhibitors

STK17A is a novel uncharacterized member of the death-associated protein family of serine and threonine kinases. Overexpression of STK17A is observed in many cancers. We identified a lead compound that is based on a quinazoline core. Optimizations of the lead compound led to the discovery of potent and selective STK17A/B inhibitors with drug-like properties and oral bioavailability. Compound 9 had an STK17A inhibitory IC50 of 23 nM. Based on profiling studies against two wild-type kinase panels (375 and 398 kinases, respectively), compound 9 had strong inhibition of both STK17A and STK17B but moderate off-target inhibition only for AAK1, MYLK4, and NEK3/5. In addition, compound 9 had good oral bioavailability, paving the way for in vivo studies against various cancers.

Development of 5-hydroxybenzothiophene derivatives as multi-kinase inhibitors with potential anti-cancer activity

Aim: Chemoresistance in cancer challenges the classical therapeutic strategy of 'one molecule-one target'. To combat this, multi-target therapies that inhibit various cancer-relevant targets simultaneously are proposed. Methods & results: We introduce 5-hydroxybenzothiophene derivatives as effective multi-target kinase inhibitors, showing notable growth inhibitory activity across different cancer cell lines. Specifically, compound 16b, featuring a 5-hydroxybenzothiophene hydrazide scaffold, emerged as a potent inhibitor, displaying low IC50 values against key kinases and demonstrating significant anti-cancer effects, particularly against U87MG glioblastoma cells. It induced G2/M cell cycle arrest, apoptosis and inhibited cell migration by modulating apoptotic markers. Conclusion: 16b represents a promising lead for developing new anti-cancer agents targeting multiple kinases with affinity to the hydroxybenzothiophene core.

Clinical value assessment for serum hsa_tsr013526 in the diagnosis of gastric carcinoma

Gastric carcinoma (GC) is a malignant tumor that is detrimental to human health. Transfer RNA-derived small RNAs are a newly identified class of noncoding small RNAs with specific biological functions that are aberrantly expressed in cancer. The aim of this study was to investigate the potential of hsa_tsr013526 as a biomarker for GC. Quantitative real-time fluorescence polymerase chain reaction was used to detect the expression level of hsa_tsr013526. The molecular characteristics of hsa_tsr013526 were verified by agarose gel electrophoresis, Sanger sequencing, and separation of nuclear and cytoplasmic RNA fractions. By testing the receiver operating characteristic (ROC) curves, the diagnostic efficiency of GC using hsa_tsr013526 was determined. Finally, we predicted the downstream of hsa_tsr013526 using functional assays and bioinformatics analysis. Serum expression of hsa_tsr013526 was higher in GC patients than in healthy donors. Serum expression showed differential changes in GC patients, gastritis patients, and healthy donors. Chi-squared tests showed that high expression of hsa_tsr013526 was significantly correlated with T stage, lymphatic metastasis, and tumor node metastasis stage. ROC curve analysis indicated that GC patients could be discriminated from healthy donors or gastritis patients based on their serum levels of hsa_tsr013526. Furthermore, hsa_tsr013526 expression was significantly reduced in postoperative GC patients (p = .0016). High expression of hsa_tsr013526 promotes gastric cancer cell proliferation, invasion, and migration. Serum hsa_tsr013526 was stable and specific, and could be used for dynamic monitoring of GC patients. Therefore, hsa_tsr013526 may be a new biomarker for the diagnosis and postoperative monitoring of GC patients.

Illuminating function of the understudied druggable kinome

The human kinome, with more than 500 proteins, is crucial for cell signaling and disease. Yet, about one-third of kinases lack in-depth study. The Data and Resource Generating Center for Understudied Kinases has developed multiple resources to address this challenge including creation of a heavy amino acid peptide library for parallel reaction monitoring and quantitation of protein kinase expression, use of understudied kinases tagged with a miniTurbo-biotin ligase to determine interaction networks by proximity-dependent protein biotinylation, NanoBRET probe development for screening chemical tool target specificity in live cells, characterization of small molecule chemical tools inhibiting understudied kinases, and computational tools for defining kinome architecture. These resources are available through the Dark Kinase Knowledgebase, supporting further research into these understudied protein kinases.

Death-associated protein kinase 1 as a therapeutic target for Alzheimer's disease

Alzheimer's disease (AD) is the most prevalent form of dementia in the elderly and represents a major clinical challenge in the ageing society. Neuropathological hallmarks of AD include neurofibrillary tangles composed of hyperphosphorylated tau, senile plaques derived from the deposition of amyloid-β (Aβ) peptides, brain atrophy induced by neuronal loss, and synaptic dysfunctions. Death-associated protein kinase 1 (DAPK1) is ubiquitously expressed in the central nervous system. Dysregulation of DAPK1 has been shown to contribute to various neurological diseases including AD, ischemic stroke and Parkinson's disease (PD). We have established an upstream effect of DAPK1 on Aβ and tau pathologies and neuronal apoptosis through kinase-mediated protein phosphorylation, supporting a causal role of DAPK1 in the pathophysiology of AD. In this review, we summarize current knowledge about how DAPK1 is involved in various AD pathological changes including tau hyperphosphorylation, Aβ deposition, neuronal cell death and synaptic degeneration. The underlying molecular mechanisms of DAPK1 dysregulation in AD are discussed. We also review the recent progress regarding the development of novel DAPK1 modulators and their potential applications in AD intervention. These findings substantiate DAPK1 as a novel therapeutic target for the development of multifunctional disease-modifying treatments for AD and other neurological disorders.

Characterization of the molecular interactions between resveratrol derivatives and death-associated protein kinase 1

Death-associated protein kinase 1 (DAPK1), a Ca2+/calmodulin-regulated serine/threonine kinase, regulates cell apoptosis and autophagy and has been implicated in the pathogenesis of Alzheimer's disease (AD). Targeting DAPK1 may be a promising approach for treating AD. In our previous study, we found that a natural polyphenol, resveratrol (1), is a moderate DAPK1 inhibitor. In the present study, we investigated the interactions between natural and synthetic derivatives of 1 and DAPK1. Binding assays including intrinsic fluorescence quenching, protein thermal shift and isothermal titration calorimetry indicated that oxyresveratrol (3), a hydroxylated derivative, and pinostilbene (5), a methoxylated derivative, bind to DAPK1 with comparable affinity to 1. The enzymatic assay showed that 3 more effectively inhibits the intrinsic ATPase activity of DAPK1 compared with 1. Crystallographic analysis revealed that the binding modes of the methoxylated derivatives were different from those of 1 and 3, resulting in a unique interaction. Our results suggest that 3 may be helpful in treating AD and provide a clue for the development of promising DAPK1 inhibitors.