Phosphorylation of PBK/TOPK Tyr74 by JAK2 promotes Burkitt lymphoma tumor growth

PTPN23[Thr] variant reduces susceptibility and tumorigenesis in esophageal squamous cell carcinoma through dephosphorylation of EGFR

Post-translational modifications (PTMs) have emerged as pivotal regulators of the development of cancers, including esophageal squamous cell carcinoma (ESCC). Here, we conducted a comprehensive analysis of PTM-related genetic variants associated with ESCC risk using large-scale genome-wide and exome-wide association datasets. We observed significant enrichment of PTM-related variants in the ESCC risk loci and identified five variants that were significantly associated with ESCC risk. Among them, rs6780013 in PTPN23 exhibited the highest level of significance in ESCC susceptibility in 9,728 ESCC cases and 10,977 controls (odds ratio [OR] = 0.85, 95 % confidence interval [CI] = 0.81- 0.89, P = 9.77 × 10-14). Further functional investigations revealed that PTPN23[Thr] variant binds to EGFR and modulates its phosphorylation at Thr699. PTPN23[Thr] variant substantially inhibited ESCC cell proliferation both in vitro and in vivo. Our findings underscore the critical role of PTPN23[Thr]-EGFR interaction in ESCC development, providing more insights into the pathogenesis of this cancer.

TOPK promotes the development of psoriasis and worenine alleviates psoriasiform dermatitis by inhibiting TOPK activity

BACKGROUND

Psoriasis is an inflammatory skin disease. The pathogenesis of psoriasis has not been fully elucidated. T-lymphokine-activated killer cell-originated protein kinase (TOPK) activity increases in a proinflammatory environment, and inhibiting TOPK blocks inflammation. However, whether TOPK is involved in the pathogenesis of psoriasis remains to be identified.

OBJECTIVES

We aimed to study the role of TOPK in psoriasis and attempted to find a drug targeting TOPK for the prevention and treatment of psoriasis.

METHOD

Firstly, the expressions of TOPK in psoriatic patients, psoriatic cell and animal model were analysed by Gene Expression Omnibus database, immunohistochemistry (IHC) staining and western blot (WB). After inhibiting TOPK by chemical or gene knockout, the effect of TOPK on the development of psoriasis was verified in cell and animal model by WB, qRT-PCR, ELISA, haematoxylin-eosin (H&E) and IHC staining. Moreover, phosphoproteomic analysis was performed to explore the signalling pathways regulated by TOPK in the occurrence and development of psoriasis. Then, an in vitro kinase assay was performed to prove TOPK kinase activity was inhibited by worenine. Ultimately, WB, qRT-PCR, ELISA, H&E and IHC staining were used to verify the anti-psoriasis effect of worenine by inhibiting TOPK was in cell and animal model.

RESULTS

In this study, we found that TOPK was highly expressed in psoriasis patients, psoriatic cell and animal model, which suggests that TOPK might be associated with psoriasis pathogenesis. Interestingly, chemical or genetic inhibition of TOPK alleviated M5- and imiquimod (IMQ)-induced psoriasis-like dermatitis, which further confirmed the role of TOPK in promoting the development of psoriasis. Moreover, we determined that worenine inhibited TOPK kinase activity. In addition, worenine relieved M5- and IMQ-induced psoriasiform dermatitis by inhibiting TOPK activity.

CONCLUSIONS

T-lymphokine-activated killer cell-originated protein kinase promotes the development of psoriasis. Therefore, TOPK might be a promising drug target for the prevention and treatment of psoriasis. Worenine alleviates psoriasiform dermatitis by inhibiting TOPK activity, providing new strategies for clinical intervention.

FYN/TOPK/HSPB1 axis facilitates the proliferation and metastasis of gastric cancer

BACKGROUND

FYN is a nonreceptor tyrosine kinase that regulates diverse pathological processes. The pro-cancer role of FYN in multiple malignancies has been elucidated. However, the mechanisms that FYN promotes gastric cancer (GC) progression remain largely unknown.

METHODS

In vitro and in vivo assays were used to investigate the function of FYN. FYN, TOPK, p-TOPK expression in GC specimens were detected by immunohistochemistry. Phosphoproteomics assays identify TOPK downstream substrate molecules. The molecular mechanism was determined using COIP assays, pull-down assays, immunofluorescence co-localization assays, western blotting, ³²p-labeled isotope radioautography assays, vitro kinase assays, and TOPK knockout mice.

RESULTS

FYN was found to be significantly upregulated in GC tissues as well as in GC cells. Knockdown of FYN expression markedly attenuated the malignant phenotype of GC cells in vitro and in vivo. Mechanistically, we identified TOPK/PBK as a novel downstream substrate of FYN, FYN directly phosphorylates TOPK at Y272. One phosphospecific antibodies against Y272 was developed to validate the phosphorylation of TOPK by FYN. Moreover, the TOPK-272F mutation impaired the interaction between TOPK and FYN, leading to disappeared TOPK phosphorylation. Consistently, human GC tissues displayed increased p-TOPK(Y272), which correlated with poor survival. Phosphoproteomics results showed a significant downregulation of both HSPB1 and p-HSPB1(ser15) in TOPK-knockdown cells, which was confirmed by TOPK-konckout mice.

CONCLUSIONS

FYN directly binds to TOPK in GC cells and phosphorylates TOPK at the Y272, which leads to proliferation and metastasis of GC. FYN-TOPK axis facilitates GC progression by phosphorylating HSPB1. Collectively, our study elucidates the pivotal role of the FYN-TOPK-HSPB1 cascade in GC.

Identification of oncogenes and tumor-suppressor genes with hepatocellular carcinoma: A comprehensive analysis based on TCGA and GEO datasets

Aim: Existing targeted therapies for hepatocellular carcinoma (HCC) are resistant and have limitations. It is crucial to find new HCC-related target genes. Methods: RNA-sequencing data of HCC were gathered from The Cancer Genome Atlas and Gene Expression Omnibus datasets. Initially, differentially expressed genes between normal and tumor tissues were identified from four Gene Expression Omnibus datasets, GSE36376, GSE102079, GSE54236, and GSE45267. GO terms and KEGG pathway enrichment analyses were performed to explore the potential biological functions of differentially expressed genes. A PPI network was constructed by using the STRING database, and up-regulated and down-regulated hub genes were defined through 12 topological approaches. Subsequently, the correlation bounded by up-regulated genes and down-regulated genes in the diagnosis, prognosis, and clinicopathological features of HCC was analyzed. Beyond a shadow of doubt, the key oncogene PBK and tumor suppressor gene F9 were screened out, and the specific mechanism was investigated through GSEA enrichment analysis and immune correlation analysis. The role of PBK in HCC was further verified by western blot, CCK8, transwell, and tube formation experiments. Results: CDCA5, CDC20, PBK, PRC1, TOP2A, and NCAPG are good indicators of HCC diagnosis and prognosis. The low expressions of F9, AFM, and C8B indicate malignant progression and poor prognosis of HCC. PBK was found to be closely related to VEGF, VEGFR, and PDGFR pathways. Experiments showed that PBK promotes HCC cell proliferation, migration, invasion, and tube formation in HUVEC cells. F9 was negatively correlated with the degree of immune infiltration, and low expression of F9 suggested a poor response to immunotherapy. Conclusion: The role of HCC-related oncogenes and tumor-suppressor genes in diagnosis and prognosis was identified. In addition, we have found that PBK may promote tumor proliferation through angiogenesis and F9 may be a predictor of tumor immunotherapy response.