Discovery of Non-peptide Small Molecule Allosteric Modulators of the Src-family Kinase, Hck

Recent advances in hematopoietic cell kinase in cancer progression: Mechanisms and inhibitors

Hematopoietic cell kinase (Hck), a non-receptor tyrosine kinase belonging to the Src kinase family, is intricately linked to the pathogenesis of numerous human diseases, with a particularly pronounced association with cancer. Hck not only directly impacts the proliferation, migration, and apoptosis of cancer cells but also interacts with JAK/STAT, MEK/ERK, PI3K/AKT, CXCL12/CXCR4, and other pathways. Hck also influences the tumor microenvironment to facilitate the onset and progression of cancer. This paper delves into the functional role and regulatory mechanisms of Hck in various solid tumors. Additionally, it explores the implications of Hck in hematological malignancies. The review culminates with a summary of the current research status of Hck inhibitors, the majority of which are in the pre-clinical phase of investigation. Notably, these inhibitors are predominantly utilized in the therapeutic management of leukemia, with their combinatorial potential indicating promising avenues for future research. In conclusion, this review underscores the significance of the mechanism of Hck in solid tumors. This insight is crucial for comprehending the current research trends regarding Hck: targeted therapy against Hck shows great promise in both diagnosis and treatment of malignant tumors. Further investigation into the role of Hck in cancer, coupled with the development of specific inhibitors, has the potential to revolutionize approaches to cancer treatment.

Early-onset pulmonary and cutaneous vasculitis driven by constitutively active SRC-family kinase HCK

BACKGROUND

Inborn errors of immunity (IEI) are genetic disorders characterized by various degrees of immune dysregulation that can manifest as immune deficiency, autoimmunity or autoinflammation. The routine use of next-generation sequencing in the clinic has facilitated the identification of an ever-increasing number of IEI, revealing the roles of immunologically important genes in human pathologies. However, despite this progress, treatment is still extremely challenging.

OBJECTIVE

We report a new monogenic autoinflammatory disorder caused by a de novo activating mutation, p.Tyr515*, in hematopoietic cell kinase (HCK). The disease is characterized by cutaneous vasculitis and chronic pulmonary inflammation that progresses to fibrosis.

METHODS

Whole-exome sequencing, Sanger sequencing, mass spectrometry and western blotting were performed to identify and characterize the pathogenic HCK mutation. Dysregulation of mutant HCK was confirmed ex vivo in primary cells and in vitro in transduced cell lines.

RESULTS

Mutant HCK lacking the C-terminal inhibitory tyrosine Tyr522 exhibited increased kinase activity and enhanced myeloid cell priming, migration and effector functions, such as production of the inflammatory cytokines IL-1β, IL-6, IL-8 and TNFα and production of reactive oxygen species. These aberrant functions were reflected by inflammatory leukocyte infiltration of the lungs and skin. Moreover, an overview of the clinical course of the disease, including therapies, provides evidence for the therapeutic efficacy of the Janus kinase (JAK) 1/2 inhibitor ruxolitinib in inflammatory lung disease.

CONCLUSION

We propose HCK-driven pulmonary and cutaneous vasculitis as a novel autoinflammatory disorder of IEI.

Identification of key genes in the tumor microenvironment of lung adenocarcinoma

The tumor microenvironment plays an important role in tumor development and progression, but the role of immune and stromal cells in this environment has not been sufficiently studied. In this study, we aimed to identify key genes associated with the microenvironment of lung adenocarcinoma (LUAD). Raw data for stromal and immune cells in malignant tumors were downloaded from The Cancer Genome Atlas (TCGA). These expression data were used to identify the differentially expressed genes (DEGs) in tissue samples of LUAD with high and low immune scores. A protein-protein interaction (PPI) network based on genes with significant differential expression was constructed. Additionally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to functionally annotate putative hub genes. These genes were assessed via Kaplan Meier analysis to determine their correlation with overall survival. In total, we identified 216 DEGs which were correlated with immune and stromal scores, including 30 hub genes which were identified based on the PPI network. Further analysis suggested that the expression levels of 10 of these genes were significantly correlated with overall survival of LUAD patients. These key hub genes included CCR2, CCR5, CD53, CYBB, HCK, IRF8, LCP2, PLEK, PTPRC, and TLR7. Moreover, the expression level of CCR2 was found to have strong prognostic value for LUAD patients. Additionally, high expression of CYBB was also correlated with better survival of patients with LUAD. The results of this study open several new avenues to explore in the treatment of LUAD.

Emerging Kinase Therapeutic Targets in Pancreatic Ductal Adenocarcinoma and Pancreatic Cancer Desmoplasia

Kinase drug discovery represents an active area of therapeutic research, with previous pharmaceutical success improving patient outcomes across a wide variety of human diseases. In pancreatic ductal adenocarcinoma (PDAC), innovative pharmaceutical strategies such as kinase targeting have been unable to appreciably increase patient survival. This may be due, in part, to unchecked desmoplastic reactions to pancreatic tumors. Desmoplastic stroma enhances tumor development and progression while simultaneously restricting drug delivery to the tumor cells it protects. Emerging evidence indicates that many of the pathologic fibrotic processes directly or indirectly supporting desmoplasia may be driven by targetable protein tyrosine kinases such as Fyn-related kinase (FRK); B lymphoid kinase (BLK); hemopoietic cell kinase (HCK); ABL proto-oncogene 2 kinase (ABL2); discoidin domain receptor 1 kinase (DDR1); Lck/Yes-related novel kinase (LYN); ephrin receptor A8 kinase (EPHA8); FYN proto-oncogene kinase (FYN); lymphocyte cell-specific kinase (LCK); tec protein kinase (TEC). Herein, we review literature related to these kinases and posit signaling networks, mechanisms, and biochemical relationships by which this group may contribute to PDAC tumor growth and desmoplasia.

Structure, function, and inhibitor targeting of HIV-1 Nef-effector kinase complexes

Antiretroviral therapy has revolutionized the treatment of AIDS, turning a deadly disease into a manageable chronic condition. Life-long treatment is required because existing drugs do not eradicate HIV-infected cells. The emergence of drug-resistant viral strains and uncertain vaccine prospects highlight the pressing need for new therapeutic approaches with the potential to clear the virus. The HIV-1 accessory protein Nef is essential for viral pathogenesis, making it a promising target for antiretroviral drug discovery. Nef enhances viral replication and promotes immune escape of HIV-infected cells but lacks intrinsic enzymatic activity. Instead, Nef works through diverse interactions with host cell proteins primarily related to kinase signaling pathways and endosomal trafficking. This review emphasizes the structure, function, and biological relevance of Nef interactions with host cell protein-tyrosine kinases in the broader context of Nef functions related to enhancement of the viral life cycle and immune escape. Drug discovery targeting Nef-mediated kinase activation has allowed identification of promising inhibitors of multiple Nef functions. Pharmacological inhibitors of Nef-induced MHC-I down-regulation restore the adaptive immune response to HIV-infected cells in vitro and have the potential to enhance immune recognition of latent viral reservoirs as part of a strategy for HIV clearance.