PBK/TOPK: An Effective Drug Target with Diverse Therapeutic Potential

The role of Rhizoma Paridis saponins on anti-cancer: The potential mechanism and molecular targets

Cancer is a disease characterized by uncontrolled cell proliferation, leading to excessive growth and invasion that can spread to other parts of the body. Traditional Chinese medicine has made new advancements in the treatment of cancer, providing new perspectives and directions for cancer treatment. Rhizoma Paridis is a widely used Chinese herbal medicine with documented anti-cancer effects dating back to ancient times. Modern research has shown that Rhizoma Paridis saponins (RPS) have various pharmacological activities. RPS can inhibit cancer in multiple ways, such as suppressing tumor growth, inducing cell cycle arrest, promoting cell apoptosis, enhancing cell autophagy, inducing ferroptosis, reducing inflammation, inhibiting angiogenesis, as well as inhibiting metastasis and invasion, and these findings demonstrate the potent anti-cancer activity of RPS. Polyphyllin I, polyphyllin II, polyphyllin VI, and polyphyllin VII have been widely reported as the main active ingredients with anti-cancer properties. Polyphyllin D, polyphyllin E, and polyphyllin G have also been confirmed to possess strong anti-cancer activity in recent years. Therefore, this review dives deep into the molecular mechanisms underlying the anti-cancer effects of RPS to serve as a valuable reference for future scientific research and their potential applications in cancer treatment.

Crosstalk of different cell-death patterns predicts prognosis and drug sensitivity in glioma

BACKGROUND

Glioma is a malignant brain tumor originating from glial cells, and there still a challenge to accurately predict the prognosis. Programmed cell death (PCD) plays a key role in tumorigenesis and immune response. However, the crosstalk and potential role of various PCDs in prognosis and tumor microenvironment remains unknown. Therefore, we comprehensively discussed the relationship between different models of PCD and the prognosis of glioma and provided new ideas for the optimal targeted therapy of glioma.

MATERIALS AND METHODS

We compared and analyzed the role of 14 PCD patterns on the prognosis from different levels. We constructed the cell death risk score (CDRS) index and conducted a comprehensive analysis of CDRS and TME characteristics, clinical characteristics, and drug response.

RESULTS

Effects of different PCDs at the genomic, functional, and immune microenvironment levels were discussed. CDRS index containing 6 gene signatures and a nomogram were established. High CDRS is associated with a worse prognosis. Through transcriptome and single-cell data, we found that patients with high CDRS showed stronger immunosuppressive characteristics. Moreover, the high-CDRS group was resistant to the traditional glioma chemotherapy drug Vincristine, but more sensitive to the Temozolomide and the clinical experimental drug Bortezomib. In addition, we identified 19 key potential therapeutic targets during malignant differentiation of tumor cells.

CONCLUSION

Overall, we provide the first systematic description of the role of 14 PCDs in glioma. A new CDRS model was built to predict the prognosis and to provide a new idea for the targeted therapy of glioma.

Cancer testis antigens: Emerging therapeutic targets leveraging genomic instability in cancer

Cancer care has witnessed remarkable progress in recent decades, with a wide array of targeted therapies and immune-based interventions being added to the traditional treatment options such as surgery, chemotherapy, and radiotherapy. However, despite these advancements, the challenge of achieving high tumor specificity while minimizing adverse side effects continues to dictate the benefit-risk balance of cancer therapy, guiding clinical decision making. As such, the targeting of cancer testis antigens (CTAs) offers exciting new opportunities for therapeutic intervention of cancer since they display highly tumor specific expression patterns, natural immunogenicity and play pivotal roles in various biological processes that are critical for tumor cellular fitness. In this review, we delve deeper into how CTAs contribute to the regulation and maintenance of genomic integrity in cancer, and how these mechanisms can be exploited to specifically target and eradicate tumor cells. We review the current clinical trials targeting aforementioned CTAs, highlight promising pre-clinical data and discuss current challenges and future perspectives for future development of CTA-based strategies that exploit tumor genomic instability.

PDZ-binding kinase inhibitor OTS514 suppresses the proliferation of oral squamous carcinoma cells

OBJECTIVE

PDZ-binding kinase (PBK) has been reported as a poor prognostic factor and is a promising molecular target for anticancer therapeutics. Here, we aimed to investigate the effect of specific PBK inhibitor OTS514 on the survival of OSCC cells.

METHODS

Four OSCC cell lines (HSC-2, HSC-3, SAS, and OSC-19) were used to examine the effect of OTS514 on cell survival and apoptosis. DNA microarray analysis was conducted to investigate the effect of OTS514 on gene expression in OSCC cells. Gene set enrichment analysis was performed to identify molecular signatures related to the antiproliferative effect of OTS514.

RESULTS

OTS514 decreased the cell survival of OSCC cells dose-dependently, and administration of OTS514 readily suppressed the HSC-2-derived tumor growth in immunodeficient mice. Treatment with OTS514 significantly increased the number of apoptotic cells and caspase-3/7 activity. Importantly, OTS514 suppressed the expression of E2F target genes with a marked decrease in protein levels of E2F1, a transcriptional factor. Moreover, TP53 knockdown attenuated OTS514-induced apoptosis.

CONCLUSION

OTS514 suppressed the proliferation of OSCC cells by downregulating the expression of E2F target genes and induced apoptosis by mediating the p53 signaling pathway. These results highlight the clinical application of PBK inhibitors in the development of molecular-targeted therapeutics against OSCC.

Bruceine D and Narclasine inhibit the proliferation of breast cancer cells and the prediction of potential drug targets

BACKGROUND

Breast cancer is one of the most common female malignancies. This study explored the underlying mechanism through which the two plant compounds (Brucaine D and Narclasine) inhibited the proliferation of breast cancer cells.

OBJECTIVE

The purpose of this study was to explore the effect of Brucaine D and Narclasine on breast cancer development and their potential drug targets.

METHODS

GSE85871 dataset containing 212 samples and the hallmark gene set "h.all.v2023.1.Hs.symbols.gmt" were downloaded from the Gene Expression Omnibus (GEO) database and the Molecular Signatures Database (MSigDB) database, respectively. Principal component analysis (PCA) was applied to classify clusters showing similar gene expression pattern. Single sample gene set enrichment analysis (ssGSEA) was used to calculate the hallmark score for different drug treatment groups. The expressions of genes related to angiogenesis, glycolysis and cell cycle were detected. Protein-protein interaction (PPI) network analysis was performed to study the interaction of the hub genes. Then, HERB database was employed to identify potential target genes for Narclasine and Bruceine D. Finally, in vitro experiments were conducted to validate partial drug-target pair.

RESULTS

PCA analysis showed that the significant changes in gene expression patterns took place in 6 drugs treatment groups (Narciclasine, Bruceine D, Japonicone A, 1beta-hydroxyalatolactone, Britanin, and four mixture drugs) in comparison to the remaining drug treatment groups. The ssGSEA pathway enrichment analysis demonstrated that Narciclasine and Bruceine treatments had similar enriched pathways, for instance, suppressed pathways related to angiogenesis, Glycolysis, and cell cycle, etc.. Further gene expression analysis confirmed that Narciclasine and Bruceine had a strong ability to inhibit these cell cycle genes, and that MYC, CHEK2, MELK, CDK4 and EZH2 were closely interacted with each other in the PPI analysis. Drug target prediction revealed that Androgen Receptor (AR) and Estrogen Receptor 1 (ESR1) were the targets for Bruceine D, and Cytochrome P450 3A4 enzyme (CYP3A4) was the target for Narciclasine. Cell experiments also confirmed the connections between Narciclasine and CYP3A4.

CONCLUSION

The present study uncovered that Narciclasine and Bruceine D could inhibit the growth of breast cancer and also predicted the potential targets for these two drugs, providing a new therapeutic direction for breast cancer patients.

Exploring the role of PRDX4 in the development of uterine corpus endometrial carcinoma

Peroxicedoxin 4 (PRDX4), a member of the peroxicedoxins (PRDXs), has been reported in many cancer-related studies, but its role in uterine corpus endometrial carcinoma (UCEC) is not fully understood. In the present study, we found that PRDX4 was highly expressed in UCEC tissues and cell lines through the combination of bioinformatics analysis and experiments, and elevated PRDX4 levels were associated with poor prognosis. Knockdown of PRDX4 significantly blocked the proliferation and migration of the UCEC cell line Ishikawa and reduced degree of cell confluence. These findings highlight the oncogenic role of PRDX4 in UCEC. In addition, genes that interact with PRDX4 in UCEC were MT-ATP8, PBK, and PDIA6, and we speculated that these genes interacted with each other to promote disease progression in UCEC. Thus, PRDX4 is a potential diagnostic biomarker for UCEC, and targeting PRDX4 may be a potential therapeutic strategy for patients with UCEC.

TMT-based quantitative proteomics reveals the targets of andrographolide on LPS-induced liver injury

BACKGROUND

Andrographolide (Andro) is a diterpenoid derived from Andrographis paniculate, which has anti-inflammatory, antibacterial, antiviral and hepatoprotective activities. Gram-negative bacterial infections can cause varying degrees of liver injury in chickens, although Andro has been shown to have a protective effect on the liver, its underlying mechanism of action and effects on liver proteins are not known.

METHODS

The toxicity of Andro on the viability of leghorn male hepatoma (LMH) cells at different concentrations and times was analyzed by CCK-8 assays. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in the culture supernatants were measured using an automatic biochemical analyzer to evaluate the protective effect of androscopolide on LPS-induced injury of LMH cells. Subsequently, TMT proteomics analysis were performed on the negative control group (NC group), LPS, and LPS-Andro groups, and bioinformatics analysis was performed on the differentially expressed proteins (DEPs).

RESULTS

It was found that Andro reduced ALT and AST levels in the cell supernatant and alleviated LPS-induced injury in LMH cells. Proteomic analysis identified 50 and 166 differentially expressed proteins in the LPS vs. NC group and LPS-Andro vs. LPS group, respectively. Andro may be involved in steroid metabolic processes, negative regulation of MAPK cascade, oxidative stress, and other processes to protect against LPS-induced liver injury.

CONCLUSIONS

Andro protects against LPS-induced liver injury, HMGCS1, HMGCR, FDPS, PBK, CAV1, PRDX1, PRDX4, and PRDX6, which were identified by differential proteomics, may be the targets of Andro. Our study may provide new theoretical support for Andro protection against liver injury.

TOPK mediates immune evasion of renal cell carcinoma via upregulating the expression of PD-L1

Although anti-PD-L1 therapy has been used in the clinical treatment of renal cell carcinoma (RCC), a proportion of patients are not sensitive to it, which may be attributed to the heterogeneity of PD-L1 expression. Here, we demonstrated that high TOPK (T-LAK cell-originated Protein Kinase) expression in RCC promoted PD-L1 expression by activating ERK2 and TGF-β/Smad pathways. TOPK was positively correlated with PD-L1 expression levels in RCC. Meanwhile, TOPK significantly inhibited the infiltration and function of CD8⁺ T cells and promoted the immune escape of RCC. Moreover, inhibition of TOPK significantly enhanced CD8⁺ T cell infiltration, promoted CD8⁺ T cell activation, enhanced anti-PD-L1 therapeutic efficacy, and synergistically enhanced anti-RCC immune response. In conclusion, this study proposes a new PD-L1 regulatory mechanism that is expected to improve the effectiveness of immunotherapy for RCC.

TOPK promotes the growth of esophageal cancer in vitro and in vivo by enhancing YB1/eEF1A1 signal pathway

T-LAK-originated protein kinase (TOPK), a dual specificity serine/threonine kinase, is up-regulated and related to poor prognosis in many types of cancers. Y-box binding protein 1 (YB1) is a DNA/RNA binding protein and serves important roles in multiple cellular processes. Here, we reported that TOPK and YB1 were both highly expressed in esophageal cancer (EC) and correlated with poor prognosis. TOPK knockout effectively suppressed EC cell proliferation and these effects were reversible by rescuing YB1 expression. Notably, TOPK phosphorylated YB1 at Thr 89 (T89) and Ser 209 (S209) amino acid residues, then the phosphorylated YB1 bound with the promoter of the eukaryotic translation elongation factor 1 alpha 1 (eEF1A1) to activate its transcription. Consequently, the AKT/mTOR signal pathway was activated by up-regulated eEF1A1 protein. Importantly, TOPK inhibitor HI-TOPK-032 suppressed the EC cell proliferation and tumor growth by TOPK/YB1/eEF1A1 signal pathway in vitro and in vivo. Taken together, our study reveals that TOPK and YB1 are essential for the growth of EC, and TOPK inhibitors may be applied to retard cell proliferation in EC. This study highlights the promising therapeutic potential of TOPK as a target for treatment of EC.

The role of the SGK3/TOPK signaling pathway in the transition from acute kidney injury to chronic kidney disease

Introduction: Profibrotic phenotype of renal tubular epithelial cells (TECs) featured with epithelial to mesenchymal transition (EMT) and profibrotic factors secretion, and aberrant accumulation of CD206⁺ M2 macrophages are the key points in the transition from acute kidney injury (AKI) to chronic kidney disease (CKD). Nevertheless, the underlying mechanisms involved remain incompletely understood. Serum and glucocorticoid-inducible kinase (SGK) is a serine/threonine protein kinase, required for intestinal nutrient transport and ion channels modulation. T-LAK-cell-originated protein kinase (TOPK) is a member of the mitogen activated protein kinase family, linked to cell cycle regulation. However, little is known about their roles in AKI-CKD transition. Methods: In this study, three models were constructed in C57BL/6 mice: low dose and multiple intraperitoneal injection of cisplatin, 5/6 nephrectomy and unilateral ureteral obstruction model. Rat renal tubular epithelial cells (NRK-52E) were dealt with cisplatin to induce profibrotic phenotype, while a mouse monocytic cell line (RAW264.7) were cultured with cisplatin or TGF-β1 to induce M1 or M2 macrophage polarization respectively. And co-cultured NRK-52E and RAW264.7 through transwell plate to explore the interaction between them. The expression of SGK3 and TOPK phosphorylation were detected by immunohistochemistry, immunofluorescence and western blot analysis. Results: In vivo, the expression of SGK3 and p-TOPK were gradually inhibited in TECs, but enhanced in CD206⁺ M2 macrophages. In vitro, SGK3 inhibition aggravated epithelial to mesenchymal transition through reducing the phosphorylation state of TOPK, and controlling TGF-β1 synthesis and secretion in TECs. However, SGK3/TOPK axis activation promoted CD206⁺ M2 macrophage polarization, which caused kidney fibrosis by mediating macrophage to myofibroblast transition (MMT). When co-cultured, the TGF-β1 from profibrotic TECs evoked CD206⁺ M2 macrophage polarization and MMT, which could be attenuated by SGK3/TOPK axis inhibition in macrophages. Conversely, SGK3/TOPK signaling pathway activation in TECs could reverse CD206⁺ M2 macrophages aggravated EMT. Discussion: We revealed for the first time that SGK3 regulated TOPK phosphorylation to mediate TECs profibrotic phenotype, macrophage plasticity and the crosstalk between TECs and macrophages during AKI-CKD transition. Our results demonstrated the inverse effect of SGK3/TOPK signaling pathway in profibrotic TECs and CD206⁺ M2 macrophages polarization during the AKI-CKD transition.

Identifying TOPK and Hypoxia Hallmarks in Esophageal Tumors for Photodynamic/Chemo/Immunotherapy and Liver Metastasis Inhibition with Nanocarriers

Although esophageal squamous cell carcinoma (ESCC) is one of the most lethal cancers, there are major bottlenecks in its therapeutic approaches, primarily the identification of clinically relevant targets and the lack of effective targeted therapeutics. Herein, we identified the hallmarks of ESCC, namely, high T-lymphokine-activated killer cell-originated protein kinase (TOPK) expression in human ESCC tumors and its correlation with poor patient prognosis and hypoxia in the tumor microenvironment. We developed hypoxia-sensitive nanoparticles encapsulating TOPK inhibitor OTS964 and photosensitizer chlorin e6 for the imaging-directed precision therapy of ESCC tumors. The sub-100 nm monodisperse nanoparticles efficiently delivered drugs into the human ESCC KYSE 150 cancer cells to kill the cells. The nanoparticles were selectively accumulated in the ESCC tumors after intravenous (i.v.) injection, thereby enabling the diagnosis and photoacoustic imaging-guided local laser irradiation of tumors. The combination of chemotherapy and photodynamic therapy effectively eradicated human ESCC KYSE 150 tumors and inhibited liver metastasis and recurrence by suppressing TOPK and inducing ESCC cell apoptosis. The nanoparticle-based therapies further stimulated high rates of natural killer cells in ESCC tumors, thereby exhibiting the potential of immunotherapy. This study identified important therapeutic targets of ESCC tumors and delineated an effective nanocarrier-based approach for tumor microenvironment and molecular targeted therapy.

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.

PDZ-binding kinase aggravates pancreatic neuroendocrine neoplasm progression by activating the AKT/mTOR pathway

The therapeutic effects of existing drug regimens against pancreatic neuroendocrine neoplasms (pNENs) remain limited, and identifying ideal therapeutic targets is warranted. PDZ binding kinase (PBK) may play an oncogenic role in most solid tumors. However, its function in pNEN remains unclear. In this study, pNEN samples and International Cancer Genome Consortium data were used to determine the clinical significance of PBK. Cell counting and CCK8 assays were used to assess cell proliferation. Flow cytometry was used to assess drug-induced apoptosis and cell cycle arrest. An in vivo PBK-targeting experiment was performed in mice bearing pNENs. Western blotting, quantitative PCR, and immunohistochemistry were performed to assess the molecular mechanisms. PBK was significantly upregulated in pNEN tissues compared with paracancerous tissues. Additionally, PBK was a poor prognostic factor for pNEN patients. PBK was found to promote the proliferation of pNEN cells by activating the AKT/mTOR pathway. Furthermore, PBK inhibition combined with everolimus treatment had enhanced antitumour effects on pNEN via inhibiting AKT/mTOR pathway and inducing G0/G1 phase cell cycle arrest. This study highlights that PBK plays an oncogenic role in and is a promising therapeutic target for pNEN.

Identification of Novel Hub Genes Associated with Psoriasis Using Integrated Bioinformatics Analysis

Psoriasis is a chronic, prolonged, and recurrent inflammatory skin disease and the current therapeutics can only alleviate the symptoms rather than cure it completely. Therefore, we aimed to identify the molecular signatures and specific biomarkers of psoriasis to provide novel clues for psoriasis and targeted therapy. In the present study, the Gene Expression Omnibus (GEO) database was used to retrieve three microarray datasets (GSE166388, GSE50790 and GSE42632) and to explore the differentially expressed genes (DEGs) in psoriasis using the Affy package in R software. The gene ontology (GO) and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway enrichment were utilized to determine the common DEGs and their capabilities. The STRING database was used to develop DEG-encoded proteins and a protein-protein interaction network (PPI) and the Cytohubba plugin to classify hub genes. Using the NetworkAnalyst platform, we detected transcription factors (TFs), microRNAs and drug candidates interacting with hub genes. In addition, the expression levels of hub genes in HaCaT cells were detected by western blot. We screened the up- and downregulated DEGs from the transcriptome microarrays of corresponding psoriasis patients. Functional enrichment of DEGs in psoriasis was mainly associated with positive regulation of leukocyte cell-cell adhesion and T cell activation, cytokine binding, cytokine activity and the Wnt signaling pathway. Through further data processing, we obtained 57 intersecting genes in the three datasets and probed them in STRING to determine the interaction of their expressed proteins and we obtained the critical 10 hub genes in the Cytohubba plugin, including TOP2A, CDKN3, MCM10, PBK, HMMR, CEP55, ASPM, KIAA0101, ESC02, and IL-1β. Using these hub genes as targets, we obtained 35 TFs and 213 miRNAs that may regulate these genes and 33 potential therapeutic agents for psoriasis. Furthermore, the expression levels of TOP2A, MCM10, PBK, ASPM, KIAA0101 and IL-1β were observably increased in HaCaT cells. In conclusion, we identified potential biomarkers, risk factors and drugs for psoriasis.

Identification of PBK as a hub gene and potential therapeutic target for medulloblastoma

Medulloblastoma (MB) is the most frequent malignant brain tumor in pediatrics. Since the current standard of care for MB consisting of surgery, cranio-spinal irradiation and chemotherapy often leads to a high morbidity rate, a number of patients suffer from long-term sequelae following treatment. Targeted therapies hold the promise of being more effective and less toxic. Therefore, the present study aimed to identify hub genes with an upregulated expression in MB and to search for potential therapeutic targets from these genes. For this purpose, gene expression profile datasets were obtained from the Gene Expression Omnibus database and processed using R 3.6.0 software to screen differentially expressed genes (DEGs) between MB samples and normal brain tissues. A total of 282 upregulated and 436 downregulated DEGs were identified. Functional enrichment analysis revealed that the upregulated DEGs were predominantly enriched in the cell cycle, DNA replication and cell division. The top 10 hub genes were identified from the protein-protein interaction network of upregulated genes, and one identified hub gene [PDZ binding kinase (PBK)] was selected for further investigation due to its possible role in the pathogenesis of MB. The aberrant expression of PBK in MB was verified in additional independent gene expression datasets. Survival analysis demonstrated that a higher expression level of PBK was significantly associated with poorer clinical outcomes in non-Wingless MBs. Furthermore, targeting PBK with its inhibitor, HI-TOPK-032, impaired the proliferation and induced the apoptosis of two MB cell lines, with the diminished phosphorylation of downstream effectors of PBK, including ERK1/2 and Akt, and the activation of caspase-3. Hence, these results suggest that PBK may be a potential prognostic biomarker and a novel candidate of targeted therapy for MB.

PBK/TOPK Is a Favorable Prognostic Biomarker Correlated with Antitumor Immunity in Colon Cancers

Immune checkpoint inhibitor therapy has proven efficacy in a subset of colon cancer patients featuring a deficient DNA mismatch repair system or a high microsatellite instability profile. However, there is high demand for more effective biomarkers to expand the colon cancer population responding to ICI therapy. PBK/TOPK, a serine/threonine kinase, plays a role in cell cycle regulation and mitotic progression. Here, we investigated the correlation between PBK/TOPK expression and tumor immunity and its prognostic value in colon cancer. Based on large-scale bioinformatics analysis, we discovered that elevated PBK/TOPK expression predicted a favorable outcome in patients with colon cancer and was positively associated with immune infiltration levels of CD8+ T cells, CD4+ T cells, natural killer cells, and M1 macrophages. In contrast, a negative correlation was found between PBK/TOPK expression and immune suppressor cells, including regulatory T cells and M2 macrophages. Furthermore, the expression of PBK/TOPK was correlated with the expression of T-cell cytotoxicity genes in colon cancer. Additionally, high PBK/TOPK expression was associated with mutations in DNA damage repair genes, and thus with increased tumor mutation and neoantigen burden. These findings suggest that PBK/TOPK may serve as a prognostic and predictive biomarker for immunotherapy in colon cancer.

High expression of PDZ-binding kinase is correlated with poor prognosis and immune infiltrates in hepatocellular carcinoma

Background

PDZ-binding kinase (PBK) encodes a serine/threonine protein kinase related to the dual specific mitogen-activated protein kinase kinase (MAPKK) family. There is evidence that overexpression of this gene is associated with tumorigenesis. However, the role of PBK in hepatocellular carcinoma (HCC) remains unclear. Therefore, we evaluated the prognostic role of PBK and its correlation with immune infiltrates in hepatocellular carcinoma.

Methods

The expression of PBK in pan-cancers was studied by Onconmine and TIMER. The expression of PBK in HCC patients and its relationship with clinicopathological characteristics were analyzed using The Gene Expression Profiling Interactive Analysis (GEPIA), The human protein atlas database (HPA), The Cancer Genome Atlas (TCGA), and Gene Expression Omnibus (GEO) databases. Receiver operating characteristic (ROC) curve was used to determine the diagnostic value of PBK in HCC patients. The relationship between PBK and prognosis of HCC was performed by GEPIA and Kaplan Meier plotter web tool. The correlations between the clinical characteristics and overall survival were analyzed by Univariate Cox regression and Multivariate Cox hazards regression to identify possible prognostic factors for HCC patients. LinkedOmics was applied to investigate co-expression associated with PBK and to analyze Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The network map of PBK and related genes is constructed by GeneMANIA. Finally, TIMER and TISIDB were used to analyze the correlations between PBK and tumor-infiltrating immune cells.

Results

Multiple database analysis shows that PBK was highly expressed in many types of tumors, including hepatocellular carcinoma, and was significantly related to tumor stage (P=0.0089), age (P=0.0131), and race (P=0.0024) of HCC patients. The receiver operating characteristic (ROC) curve analysis showed that PBK had high diagnostic potential to HCC in GSE76427 (AUC=0.8799), GSE121248 (AUC=0.9224), GSE62232 (AUC=0.9975), and GSE84402 (AUC=0.9541). Multivariate Cox hazards regression showed that high expression of PBK may be an independent risk factor for overall survival in HCC patients (HR = 1.566, 95% CI=1.062–2.311, P= 0.024). The Protein–protein interaction network showed that PBK significantly interacted with LRRC47, ARAF, LGALS9B, TTK, DLG1, and other essential genes. Furthermore, enrichment analysis showed that PBK and co-expressed genes participated in many biological processes, cell composition, molecular functions, and pathways in HCC. Finally, the immune infiltration analysis by TIMER and TISIDB indicated that a significant tightly correlation between PBK and macrophages, neutrophils, as well as chemokines and receptors.

Conclusions

High expression of PBK is significantly correlated with poor survival and immune infiltrates in hepatocellular carcinoma. Our study suggests that PBK can be used as a biomarker of poor prognosis and potential immune therapy target in hepatocellular carcinoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02479-w.

Alterations of Chromatin Regulators in the Pathogenesis of Urinary Bladder Urothelial Carcinoma

Simple Summary

Urinary bladder cancer is one of the ten major cancers worldwide, with higher incidences in males, in smokers, and in highly industrialized countries. New therapies beyond cytotoxic chemotherapy are urgently needed to improve treatment of these tumors. A better understanding of the mechanisms underlying their development may help in this regard. Recently, it was discovered that a group of proteins regulating the state of chromatin and thus gene expression is exceptionally and frequently affected by gene mutations in bladder cancers. Altered function of these mutated chromatin regulators must therefore be fundamental in their development, but how and why is poorly understood. Here we review the current knowledge on changes in chromatin regulators and discuss their possible consequences for bladder cancer development and options for new therapies.

Abstract

Urothelial carcinoma (UC) is the most frequent histological type of cancer in the urinary bladder. Genomic changes in UC activate MAPK and PI3K/AKT signal transduction pathways, which increase cell proliferation and survival, interfere with cell cycle and checkpoint control, and prevent senescence. A more recently discovered additional category of genetic changes in UC affects chromatin regulators, including histone-modifying enzymes (KMT2C, KMT2D, KDM6A, EZH2), transcription cofactors (CREBBP, EP300), and components of the chromatin remodeling complex SWI/SNF (ARID1A, SMARCA4). It is not yet well understood how these changes contribute to the development and progression of UC. Therefore, we review here the emerging knowledge on genomic and gene expression alterations of chromatin regulators and their consequences for cell differentiation, cellular plasticity, and clonal expansion during UC pathogenesis. Our analysis identifies additional relevant chromatin regulators and suggests a model for urothelial carcinogenesis as a basis for further mechanistic studies and targeted therapy development.

Application of comprehensive bioinformatics approaches to reconnoiter crucial genes and pathways underpinning hepatocellular carcinoma: a drug repurposing endeavor

Hepatocellular carcinoma (HCC) is the fifth most common neoplasm in the world. Chronic inflammation of liver and associated wound healing processes collectively contribute to the development of cirrhosis which further progresses to dysplastic nodule and then to HCC. Etiological mediators and ongoing manipulations at cellular level in HCC are well established; however, key protein interactions and genetic alterations involved in stepwise hepatocarcinogenic pathways are seldom explored. This study aims to unravel novel targets of HCC and repurpose the FDA-approved drugs against the same. Genetic data pertinent to different stages of HCC were retrieved from GSE6764 dataset and analyzed via GEO2R. Subsequently, protein-protein interaction network analysis of differentially expressed genes was performed to identify the hub genes with significant interaction. Hub genes displaying higher interactions were considered as potential HCC targets and were validated thorough UALCAN and GEPIA databases. These targets were screened against FDA-approved drugs through molecular docking and dynamics simulation studies to capture the drugs with potential activity against HCC. Finally, cytotoxicity of the shortlisted drug was confirmed in vitro by MTT assay. CDC20 was identified as potential druggable target. Docking, binding energy calculations, and dynamic studies revealed significant interaction exhibited by Labetalol with CDC20. Further, in MTT assay, Labetalol demonstrated an IC₅₀ of 200.29 µg/ml in inhibiting the cell growth of HepG2 cell line. In conclusion, this study discloses a series of key genetic underpinnings of HCC and recommends the pertinence of labetalol as a potential repurposable drug against HCC.

PBK/TOPK Inhibitor Suppresses the Progression of Prolactinomas

BACKGROUND

Prolactinoma is the most common type of pituitary tumors, and its resultant tumor occupying and hormone disturbance greatly damage the health of patients. In this study, we investigated a protein kinase-PDZ Binding Kinase (PBK)/T-LAK Cell-Originated Protein Kinase (TOPK) as a candidate protein regulating prolactin (PRL) secretion and tumor growth of prolactinomas.

METHODS

Downloaded prolactinoma transcriptome dataset from Gene Expression Omnibus (GEO) database, and screened differentially expressed genes (DEGs) between normal pituitary tissues and prolactinoma tissues. Then, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of DEGs were performed, a protein-protein interaction (PPI) network was constructed and the hub genes were identified. After a literature search, TOPK was presumed as an candidate target regulating the prolactinoma. We found a specific inhibitor of TOPK to investigate its effects on the proliferation, migration, apoptosis and PRL secretion of pituitary tumor cells. Finally, the regulation of TOPK inhibitor on its downstream target-p38 Mitogen Activated Protein Kinase (p38 MAPK) was detected to explore the potential mechanism.

RESULTS

A total of 361 DEGs were identified, and 20 hub genes were screened out. TOPK inhibitor HI-TOPK-032 could suppress the proliferation & migration and induce apoptosis of pituitary tumor cells in vitro, and reduce PRL secretion and tumor growth in vivo. HI-TOPK-032 also inhibited the phosphorylation level of the downstream target p38 MAPK, suggesting that TOPK inhibitors regulate the development of prolactinoma by mediating p38 MAPK.

CONCLUSION

Our study of identification and functional validation of TOPK suggests that this candidate can be a promising molecular target for prolactinoma treatment.