PLK1, A Potential Target for Cancer Therapy

Time-Lapse Imaging to Analyze Cell Fate in Response to Antimitotics

Time-lapse imaging is a powerful technique widely used in Cellular and Molecular Biology to capture and analyze the dynamic processes of living cells over specific time periods. Particularly, in the study of cell division, under normal conditions or after drug treatments, this methodology can provide essential data that is impossible to obtain from conventional cell-fixed-based assays. In the context of evaluating cell fate after antimitotic drug treatment, time-lapse imaging provides valuable insights into the mechanisms of action of these compounds. Antimitotic drugs belong to a class of anticancer compounds that interfere with mitosis by targeting microtubules or specific kinases and molecular motors involved in the mitotic apparatus. This chapter aims to highlight the significant advantage of using time-lapse microscopy to assess the effects of antimitotic drugs on cell behavior and fates. We describe the full protocol for time-lapse imaging, using the human lung adenocarcinoma A549 cell line as a model, after exposure to the antimitotic BI2536, a potent inhibitor of polo-like kinase 1 (PLK1). This description includes software for imaging acquisition and data analysis.

Only Infant MLL-Rearranged Leukemia Is Susceptible to an Inhibition of Polo-like Kinase 1 (PLK-1) by Volasertib

MLL-rearranged (MLLr) leukemia is characterized by a poor prognosis. Depending on the cell of origin, it differs in the aggressiveness and therapy response. For instance, in adults, volasertib blocking Polo-like kinase 1 (PLK-1) exhibited limited success. Otherwise, PLK-1 characterizes an infant MLLr signature, indicating potential sensitivity. By using our CRISPR/Cas9 MLLr model in CD34+ cells from human cord blood (huCB) and bone marrow (huBM) mimicking the infant and adult patient diseases, we were able to shed light on this phenomenon. The PLK-1 mRNA level was significantly increased in our huCB compared to the huBM model, which was underpinned by analyzing infant and adult MLLr leukemia patients. Importantly, the expression levels correlated with a functional response. Volasertib induced a significant dose-dependent decrease in proliferation and cell cycle arrest, most pronounced in the infant model. Mechanistically, upon volasertib treatment, we uncovered negative feedback only in the huBM model by compensatory upregulation of PLK-1 and related genes like AURKA involved in mitosis. Importantly, the poor response could be overcome by a combinatorial strategy with alisertib, an Aurora kinase A inhibitor. Our study emphasizes the importance of considering the cell of origin in therapeutic decision-making and provides the rationale for evaluating volasertib and alisertib in MLLr leukemia.

Integration of Machine Learning and Experimental Validation to Identify Anoikis-Related Prognostic Signature for Predicting the Breast Cancer Tumor Microenvironment and Treatment Response

Background/Objectives: Anoikis-related genes (ANRGs) are crucial in the invasion and metastasis of breast cancer (BC). The underlying role of ANRGs in the prognosis of breast cancer patients warrants further study. Methods: The anoikis-related prognostic signature (ANRS) was generated using a variety of machine learning methods, and the correlation between the ANRS and the tumor microenvironment (TME), drug sensitivity, and immunotherapy was investigated. Moreover, single-cell analysis and spatial transcriptome studies were conducted to investigate the expression of prognostic ANRGs across various cell types. Finally, the expression of ANRGs was verified by RT-PCR and Western blot analysis (WB), and the expression level of PLK1 in the blood was measured by the enzyme-linked immunosorbent assay (ELISA). Results: The ANRS, consisting of five ANRGs, was established. BC patients within the high-ANRS group exhibited poorer prognoses, characterized by elevated levels of immune suppression and stromal scores. The low-ANRS group had a better response to chemotherapy and immunotherapy. Single-cell analysis and spatial transcriptomics revealed variations in ANRGs across cells. The results of RT-PCR and WB were consistent with the differential expression analyses from databases. NU.1025 and imatinib were identified as potential inhibitors for SPIB and PLK1, respectively. Additionally, findings from ELISA demonstrated increased expression levels of PLK1 in the blood of BC patients. Conclusions: The ANRS can act as an independent prognostic indicator for BC patients, providing significant guidance for the implementation of chemotherapy and immunotherapy in these patients. Additionally, PLK1 has emerged as a potential blood-based diagnostic marker for breast cancer patients.

PSF-lncRNA interaction as a target for novel targeted anticancer therapies

The Polypyrimidine Tract-Binding Protein-Associated Splicing Factor (PSF), a component of the Drosophila Behavior/Human Splicing (DBHS) complex, plays a pivotal role in cancer pathogenesis. The epigenetic regulation mediated by PSF and long noncoding RNA (lncRNA), along with PSF's alternative splicing activity, has been implicated in promoting cancer cell proliferation, migration, invasion, metastasis, and drug resistance in various human cancers. Recent research highlights the therapeutic promise of targeting the PSF-lncRNA interaction to combat aggressive malignancies, making it a compelling target for cancer therapy. This review offers a detailed synthesis of the current understanding of PSF's role in oncogenic pathways and recent progress in identifying inhibitors of PSF-lncRNA interactions. Furthermore, it discusses the potential of using these inhibitors in cancer treatment strategies, especially as adjuncts to immune checkpoint blockade therapies to improve the efficacy of anti-PD-(L)1 treatments in Glioblastoma Multiforme (GBM). By outlining the interaction patterns of existing PSF-lncRNA inhibitors, this article aims to guide the development and refinement of future pharmacological interventions.

Uncovering Cell Cycle Dysregulations and Associated Mechanisms in Cancer and Neurodegenerative Disorders: A Glimpse of Hope for Repurposed Drugs

The cell cycle is the sequence of events orchestrated by a complex network of cell cycle proteins. Unlike normal cells, mature neurons subsist in a quiescent state of the cell cycle, and aberrant cell cycle activation triggers neuronal death accompanied by neurodegeneration. The periodicity of cell cycle events is choreographed by various mechanisms, including DNA damage repair, oxidative stress, neurotrophin activity, and ubiquitin-mediated degradation. Given the relevance of cell cycle processes in cancer and neurodegeneration, this review delineates the overlapping cell cycle events, signaling pathways, and mechanisms associated with cell cycle aberrations in cancer and the major neurodegenerative disorders. We suggest that dysregulation of some common fundamental signaling processes triggers anomalous cell cycle activation in cancer cells and neurons. We discussed the possible use of cell cycle inhibitors for neurodegenerative disorders and described the associated challenges. We propose that a greater understanding of the common mechanisms driving cell cycle aberrations in cancer and neurodegenerative disorders will open a new avenue for the development of repurposed drugs.

Nanoparticles Bounded to Interfering RNAs as a Therapy for Pancreatic Cancer: A Systematic Review

Pancreatic cancer is one of the tumors with poor prognosis and low survival due to late diagnosis, high resistance, and very limited effective therapeutic options. Thus, new pharmacological treatments are necessary to improve the prognosis of patients. In this context, nanoparticles represent an efficient system for transporting and administering therapeutic molecules. Furthermore, siRNA can be used in cancer treatment to selectively inhibit the expression of any target gene. Therefore, nanoparticles associated with siRNA have been tested as a new therapeutic strategy to solve the pancreatic cancer treatment failure in the clinical setting. The current article presents a systematic revision of the literature of the last 10 years in which nanoparticles loading siRNA are used in pancreatic cancer. This research was carried out in three databases (PubMed, Scopus, and Web of Science) obtaining 164 articles from which 37 were selected. Our results show an overall view of the high effectiveness of this new therapy that combines nanoparticles with genetic therapy in pancreatic cancer suggesting that siRNA-based medicines will likely open up a new therapeutic era in the treatment of this type of tumors.

Polo-like Kinase 1 Predicts Lymph Node Metastasis in Middle Eastern Colorectal Cancer Patients; Its Inhibition Reverses 5-Fu Resistance in Colorectal Cancer Cells

Polo-like kinase 1 (PLK1) is a serine/threonine-protein kinase essential for regulating multiple stages of cell cycle progression in mammals. Aberrant regulation of PLK1 has been observed in numerous human cancers and is linked to poor prognoses. However, its role in the pathogenesis of colorectal cancer (CRC) in the Middle East remains unexplored. PLK1 overexpression was noted in 60.3% (693/1149) of CRC cases and was significantly associated with aggressive clinico-pathological parameters and p-ERK1/2 overexpression. Intriguingly, multivariate logistic regression analysis identified PLK1 as an independent predictor of lymph node metastasis. Our in vitro experiments demonstrated that CRC cells with high PLK1 levels were resistant to 5-Fu treatment, while those with low PLK1 expression were sensitive. To investigate PLK1's role in chemoresistance, we used the specific inhibitor volasertib, which effectively reversed 5-Fu resistance. Interestingly, forced PLK1 expression activated the CRAF-MEK-ERK signaling cascade, while its inhibition suppressed this cascade. PLK1 knockdown reduced epithelial-to-mesenchymal transition (EMT) progression and stem cell-like traits in 5-Fu-resistant cells, implicating PLK1 in EMT induction and stemness in CRC. Moreover, silencing ERK1/2 significantly mitigated chemoresistance, EMT, and stemness properties in CRC cell lines that express PLK1. Furthermore, the knockdown of Zeb1 attenuated EMT and stemness, suggesting a possible link between EMT activation and the maintenance of stemness in CRC. Our findings underscore the pivotal role of PLK1 in mediating chemoresistance and suggest that PLK1 inhibition may represent a potential therapeutic strategy for the management of aggressive colorectal cancer subtypes.

Molecular Landscape of Bladder Cancer: Key Genes, Transcription Factors, and Drug Interactions

Bladder cancer is among the most prevalent tumors in the urinary system and is known for its high malignancy. Although traditional diagnostic and treatment methods are established, recent research has focused on understanding the molecular mechanisms underlying bladder cancer. The primary objective of this study is to identify novel diagnostic markers and discover more effective targeted therapies for bladder cancer. This study identified differentially expressed genes (DEGs) between bladder cancer tissues and adjacent normal tissues using data from The Cancer Genome Atlas (TCGA). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted to explore the functional roles of these genes. A protein-protein interaction (PPI) network was also constructed to identify and analyze hub genes within this network. Gene set variation analysis (GSVA) was conducted to investigate the involvement of these genes in various biological processes and pathways. Ten key genes were found to be significantly associated with bladder cancer: IL6, CCNA2, CCNB1, CDK1, PLK1, TOP2A, AURKA, AURKB, FOXM1, and CALML5. GSVA analyses revealed that these genes are involved in a variety of biological processes and signaling pathways, including coagulation, UV-response-down, apoptosis, Notch signaling, and Wnt/beta-catenin signaling. The diagnostic relevance of these genes was validated through ROC curve analysis. Additionally, potential therapeutic drug interactions with these key genes were identified. This study provides valuable insights into key genes and their roles in bladder cancer. The identified genes and their interactions with therapeutic drugs could serve as potential biomarkers, presenting new opportunities for enhancing the diagnosis and prognosis of bladder cancer.

Targeting focal adhesion kinase (FAK) in cancer therapy: A recent update on inhibitors and PROTAC degraders

Focal adhesion kinase (FAK) is considered as a pivotal intracellular non-receptor tyrosine kinase, and has garnered significant attention as a promising target for anticancer drug development. As of early 2024, a total of 12 drugs targeting FAK have been approved for clinical or preclinical studies worldwide, including three PROTAC degraders. In recent three years (2021-2023), significant progress has been made in designing targeted FAK anticancer agents, including the development of a novel benzenesulfofurazan type NO-releasing FAK inhibitor and the first-in-class dual-target inhibitors simultaneously targeting FAK and HDACs. Given the pivotal role of FAK in the discovery of anticancer drugs, as well as the notable advancements achieved in FAK inhibitors and PROTAC degraders in recent years, this review is underbaked to present a comprehensive overview of the function and structure of FAK. Additionally, the latest findings on the inhibitors and PROTAC degraders of FAK from the past three years, along with their optimization strategies and anticancer activities, were summarized, which might help to provide novel insights for the development of novel targeted FAK agents with promising anticancer potential and favorable pharmacological profiles.

Proteomic basis for pancreatic acinar cell carcinoma and pancreatoblastoma as similar yet distinct entities

Acinar cell carcinoma (ACC) and pancreatoblastoma (PBL) are rare pancreatic malignancies with acinar differentiation. Proteogenomic profiling of ACC and PBL revealed distinct protein expression patterns compared to pancreatic ductal adenocarcinoma (PDAC) and benign pancreas. ACC and PBL exhibited similarities, with enrichment in proteins related to RNA processing, chromosome organization, and the mitoribosome, while PDACs overexpressed proteins associated with actin-based processes, extracellular matrix, and immune-active stroma. Pathway activity differences in metabolic adaptation, epithelial-to-mesenchymal transition, and DNA repair were characterized between these diseases. PBL showed upregulation of Wnt-CTNNB1 and IGF2 pathways. Seventeen ACC-specific proteins suggested connections to metabolic diseases with mitochondrial dysfunction, while 34 PBL-specific proteins marked this pediatric cancer with an embryonic stem cell phenotype and alterations in chromosomal proteins and the cell cycle. This study provides novel insights into the proteomic landscapes of ACC and PBL, offering potential targets for diagnostic and therapeutic development.

Rational Design of HER2-Targeted Combination Therapies to Reverse Drug Resistance in Fibroblast-Protected HER2+ Breast Cancer Cells

Introduction

Fibroblasts, an abundant cell type in the breast tumor microenvironment, interact with cancer cells and orchestrate tumor progression and drug resistance. However, the mechanisms by which fibroblast-derived factors impact drug sensitivity remain poorly understood. Here, we develop rational combination therapies that are informed by proteomic profiling to overcome fibroblast-mediated therapeutic resistance in HER2+ breast cancer cells.

Methods

Drug sensitivity to the HER2 kinase inhibitor lapatinib was characterized under conditions of monoculture and exposure to breast fibroblast-conditioned medium. Protein expression was measured using reverse phase protein arrays. Candidate targets for combination therapy were identified using differential expression and multivariate regression modeling. Follow-up experiments were performed to evaluate the effects of HER2 kinase combination therapies in fibroblast-protected cancer cell lines and fibroblasts.

Results

Compared to monoculture, fibroblast-conditioned medium increased the expression of plasminogen activator inhibitor-1 (PAI1) and cell cycle regulator polo like kinase 1 (PLK1) in lapatinib-treated breast cancer cells. Combination therapy of lapatinib with inhibitors targeting either PAI1 or PLK1, eliminated fibroblast-protected cancer cells, under both conditions of direct coculture with fibroblasts and protection by fibroblast-conditioned medium. Analysis of publicly available, clinical transcriptomic datasets revealed that HER2-targeted therapy fails to suppress PLK1 expression in stroma-rich HER2+ breast tumors and that high PAI1 gene expression associates with high stroma density. Furthermore, we showed that an epigenetics-directed approach using a bromodomain and extraterminal inhibitor to globally target fibroblast-induced proteomic adaptions in cancer cells, also restored lapatinib sensitivity.

Conclusions

Our data-driven framework of proteomic profiling in breast cancer cells identified the proteolytic degradation regulator PAI1 and the cell cycle regulator PLK1 as predictors of fibroblast-mediated treatment resistance. Combination therapies targeting HER2 kinase and these fibroblast-induced signaling adaptations eliminates fibroblast-protected HER2+ breast cancer cells.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-024-00823-0.

Synthesis and Antitumour Evaluation of Tricyclic Indole-2-Carboxamides against Paediatric Brain Cancer Cells

Antitumour properties of some cannabinoids (CB) have been reported in the literature as early as 1970s, however there is no clear consensus to date on the exact mechanisms leading to cancer cell death. The indole-based WIN 55,212-2 and SDB-001 are both known as potent agonists at both CB1 and CB2 receptors, yet we demonstrate herein that only the former can exert in vitro antitumour effects when tested against a paediatric brain cancer cell line KNS42. In this report, we describe the synthesis of novel 3,4-fused tricyclic indoles and evaluate their functional potencies at both cannabinoid receptors, as well as their abilities to inhibit the growth or proliferation of KNS42 cells. Compared to our previously reported indole-2-carboxamides, these 3,4-fused tricyclic indoles had either completely lost activities, or, showed moderate-to-weak antagonism at both CB1 and CB2 receptors. Compound 23 displayed the most potent antitumour properties among the series. Our results further support the involvement of non-CB pathways for the observed antitumour activities of amidoalkylindole-based cannabinoids, in line with our previous findings. Transcriptomic analysis comparing cells treated or non-treated with compound 23 suggested the observed antitumour effects of 23 are likely to result mainly from disruption of the FOXM1-regulated cell cycle pathways.

AKT Inhibition Sensitizes to Polo-Like Kinase 1 Inhibitor Onvansertib in Prostate Cancer

Polo-like kinase 1 (PLK1) inhibitors have had limited antitumor efficacy as single agents, and focus of current efforts is on combination therapies. We initially confirmed that the PLK1-specific inhibitor onvansertib (ONV) could enhance responses to a PARP inhibitor (olaparib) in prostate cancer xenografts. To identify more effective combinations, we screened a library of bioactive compounds for efficacy in combination with ONV in LNCaP prostate cancer cells, which identified a series of compounds including multiple AKT inhibitors. We confirmed in vitro synergy between ONV and the AKT inhibitor ipatasertib (IPA) and found that the combination increased apoptosis. Mechanistic studies showed that ONV increased expression of the antiapoptotic protein SURVIVIN and that this was mitigated by IPA. Studies in three PTEN-deficient prostate cancer xenograft models showed that cotreatment with IPA and ONV led to significant tumor growth inhibition compared with monotherapies. Together, these in vitro and in vivo studies demonstrate that the efficacy of PLK1 antagonists can be enhanced by PARP or AKT inhibition and support further development of these combination therapies.

Polo-like kinase 1 (PLK1) is a novel CARD14-binding protein in keratinocytes

Caspase recruitment domain (CARD)-containing protein 14 (CARD14) is an intracellular protein that mediates nuclear factor-kappa B (NF-ĸB) signaling and proinflammatory gene expression in skin keratinocytes. Several hyperactivating CARD14 mutations have been associated with psoriasis and other inflammatory skin diseases. CARD14-induced NF-ĸB signaling is dependent on the formation of a CARD14-BCL10-MALT1 (CBM) signaling complex, but upstream receptors and molecular mechanisms that activate and regulate CARD14 signaling are still largely unclear. Using unbiased affinity purification and mass spectrometry (AP-MS) screening, we discover polo-like kinase 1 (PLK1) as a novel CARD14-binding protein. CARD14-PLK1 binding is independent of the CARD14 CARD domain but involves a consensus phospho-dependent PLK1-binding motif in the CARD14 linker region (LR). Expression of the psoriasis-associated CARD14(E138A) variant in human keratinocytes induces the recruitment of PLK1 to CARD14-containing signalosomes in interphase cells, but does not affect the specific location of PLK1 in mitotic cells. Finally, disruption of the PLK1-binding motif in CARD14(E138A) increases CARD14-induced proinflammatory signaling and gene expression. Together, our data identify PLK1 as a novel CARD14-binding protein and indicate a negative regulatory role for PLK1 in CARD14 signaling.

Identification and validation of an immune-derived multiple programmed cell death index for predicting clinical outcomes, molecular subtyping, and drug sensitivity in lung adenocarcinoma

OBJECTIVES

Comprehensive cross-interaction of multiple programmed cell death (PCD) patterns in the patients with lung adenocarcinoma (LUAD) have not yet been thoroughly investigated.

METHODS

Here, we collected 19 different PCD patterns, including 1911 PCD-related genes, and developed an immune-derived multiple programmed cell death index (MPCDI) based on machine learning methods.

RESULTS

Using the median MPCDI scores, we categorized the LUAD patients into two groups: low-MPCDI and high-MPCDI. Our analysis of the TCGA-LUAD training cohort and three external GEO cohorts (GSE37745, GSE30219, and GSE68465) revealed that patients with high-MPCDI experienced a more unfavorable prognosis, whereas those with low-MPCDI had a better prognosis. Furthermore, the results of both univariate and multivariate Cox regression analyses further confirmed that MPCDI serves as a novel independent risk factor. By combining clinical characteristics with the MPCDI, we constructed a nomogram that provides an accurate and reliable quantitative tool for personalized clinical management of LUAD patients. The findings obtained from the analysis of C-index and the decision curve revealed that the nomogram outperformed various clinical variables in terms of net clinical benefit. Encouragingly, the low-MPCDI patients are more sensitive to commonly used chemotherapy drugs, which suggests that MPCDI scores have a guiding role in chemotherapy for LUAD patients.

CONCLUSION

Therefore, MPCDI can be used as a novel clinical diagnostic classifier, providing valuable insights into the clinical management and clinical decision-making for LUAD patients.

Oncogenic SLC2A11-MIF fusion protein interacts with polypyrimidine tract binding protein 1 to facilitate bladder cancer proliferation and metastasis by regulating mRNA stability

Chimeric RNAs, distinct from DNA gene fusions, have emerged as promising therapeutic targets with diverse functions in cancer treatment. However, the functional significance and therapeutic potential of most chimeric RNAs remain unclear. Here we identify a novel fusion transcript of solute carrier family 2-member 11 (SLC2A11) and macrophage migration inhibitory factor (MIF). In this study, we investigated the upregulation of SLC2A11-MIF in The Cancer Genome Atlas cohort and a cohort of patients from Sun Yat-Sen Memorial Hospital. Subsequently, functional investigations demonstrated that SLC2A11-MIF enhanced the proliferation, antiapoptotic effects, and metastasis of bladder cancer cells in vitro and in vivo. Mechanistically, the fusion protein encoded by SLC2A11-MIF interacted with polypyrimidine tract binding protein 1 (PTBP1) and regulated the mRNA half-lives of Polo Like Kinase 1, Roundabout guidance receptor 1, and phosphoinositide-3-kinase regulatory subunit 3 in BCa cells. Moreover, PTBP1 knockdown abolished the enhanced impact of SLC2A11-MIF on biological function and mRNA stability. Furthermore, the expression of SLC2A11-MIF mRNA is regulated by CCCTC-binding factor and stabilized through RNA N4-acetylcytidine modification facilitated by N-acetyltransferase 10. Overall, our findings revealed a significant fusion protein orchestrated by the SLC2A11-MIF-PTBP1 axis that governs mRNA stability during the multistep progression of bladder cancer.

From Crypts to Cancer: A Holistic Perspective on Colorectal Carcinogenesis and Therapeutic Strategies

Colorectal cancer (CRC) represents a significant global health burden, with high incidence and mortality rates worldwide. Recent progress in research highlights the distinct clinical and molecular characteristics of colon versus rectal cancers, underscoring tumor location's importance in treatment approaches. This article provides a comprehensive review of our current understanding of CRC epidemiology, risk factors, molecular pathogenesis, and management strategies. We also present the intricate cellular architecture of colonic crypts and their roles in intestinal homeostasis. Colorectal carcinogenesis multistep processes are also described, covering the conventional adenoma-carcinoma sequence, alternative serrated pathways, and the influential Vogelstein model, which proposes sequential APC, KRAS, and TP53 alterations as drivers. The consensus molecular CRC subtypes (CMS1-CMS4) are examined, shedding light on disease heterogeneity and personalized therapy implications.

Therapeutic Potential of PLK1, KIF4A, CDCA5, UBE2C, CDT1, SKA3, AURKB, and PTTG1 Genes in Triple-Negative Breast Cancer: Correlating Their Expression with Sensitivity to GSK 461364 and IKK 16 Drugs

The treatment of triple-negative breast cancer (TNBC) has been associated with challenges due to the lack of expression of ER, PR, and HER2 receptors in tumor cells. This study aimed to identify genes with potential therapeutic targets in TNBC. Data from the cancer genome atlas regarding breast cancer (BC) were downloaded. After initial preprocessing, cancer samples were categorized into four groups: TNBC, HER2-positive, luminal A, and luminal B. Gene expression differences between these groups were calculated, focusing on genes that showed differential expression in TNBC. A protein-protein interaction network was conducted to identify hub genes among the candidate genes related to TNBC. The protein expression of candidate genes was assessed using immunohistochemistry data from the human protein atlas. Drug resistance and sensitivity associated with hub genes were identified using data from PharmacoDB. TNBC samples and the RT-qPCR method were used to confirm the results. Our findings revealed that eight genes, namely PLK1, KIF4A, CDCA5, UBE2C, CDT1, SKA3, AURKB, and PTTG1, had significant upregulation at the RNA level in TNBC subgroup compared to other subgroups and could be considered hub genes in TNBC. Compared to other subgroups, their expression level in TNBC samples had high sensitivity and specificity. RT-qPCR results also demonstrated a significant increase in levels of SKA3 and PTTG1 in the TNBC compared to healthy tissue and other subgroups. The protein expression of these genes was notably high in some BC samples. PharmacoDB data showed that some candidate genes were closely linked to drug sensitivity of GSK 461364 and IKK 16. The results of this study showed a significant increase in the expression level of PLK1, KIF4A, CDCA5, UBE2C, CDT1, SKA3, AURKB, and PTTG1 in TNBC compared to other BC subgroups. These genes show considerable promise as therapeutic targets for the TNBC subgroup.

Proteomic analysis reveals a PLK1-dependent G2/M degradation program and a role for AKAP2 in coordinating the mitotic cytoskeleton

Ubiquitination is an essential regulator of cell division. The kinase Polo-like kinase 1 (PLK1) promotes protein degradation at G2/M phase through the E3 ubiquitin ligase Skp1-Cul1-F box (SCF)βTrCP. However, the magnitude to which PLK1 shapes the mitotic proteome is uncharacterized. Combining quantitative proteomics with pharmacologic PLK1 inhibition revealed a widespread, PLK1-dependent program of protein breakdown at G2/M. We validated many PLK1-regulated proteins, including substrates of the cell-cycle E3 SCFCyclin F, demonstrating that PLK1 promotes proteolysis through at least two distinct E3 ligases. We show that the protein-kinase-A-anchoring protein A-kinase anchor protein 2 (AKAP2) is cell-cycle regulated and that its mitotic degradation is dependent on the PLK1/βTrCP signaling axis. Expression of a non-degradable AKAP2 mutant resulted in actin defects and aberrant mitotic spindles, suggesting that AKAP2 degradation coordinates cytoskeletal organization during mitosis. These findings uncover PLK1's far-reaching role in shaping the mitotic proteome post-translationally and have potential implications in malignancies where PLK1 is upregulated.

Molecular Alterations Associated with Histologically Overt Stromal Response in Patients with Prostate Cancer

Prostate cancer has substantial heterogeneity in clinical outcomes and therapeutic responses, posing challenges in predicting disease progression and tailoring treatment strategies. Recent studies have highlighted the potential prognostic value of evaluating the tumor microenvironment, including the presence of a histologically overt stromal response (HOST-response) characterized by peri-glandular stromal changes and architectural distortions. This retrospective study examined patient records from The Cancer Genome Atlas database to identify genomic alterations associated with the HOST-response in prostate cancer. Among 348 patients who underwent radical prostatectomy, 160 (45.98%) were identified as having a HOST-response. A gene expression analysis revealed 1263 genes with significantly higher expression in patients with a HOST-response. A protein-protein interaction network analysis identified seven hub genes (KIF2C, CENPA, CDC20, UBE2C, ESPL1, KIF23, and PLK1) highly interconnected in the network. A functional enrichment analysis revealed alterations in the cell division, cytoskeletal organization, cytokinesis, and interleukin-16 signaling pathways in patients with a HOST-response, suggesting dysregulated proliferation and inflammation. The distinct molecular signature associated with the HOST-response provides insights into the tumor-stroma interactions driving adverse outcomes and potential targets for tailored therapeutic interventions in this subset of patients with prostate cancer.

Dual TTK/PLK1 inhibition has potent anticancer activity in TNBC as monotherapy and in combination

Background

Threonine tyrosine kinase (TTK) and polo-like kinase 1 (PLK1) are common essential kinases that collaborate in activating the spindle assembly checkpoint (SAC) at the kinetochore, ensuring appropriate chromosome alignment and segregation prior to mitotic exit. Targeting of either TTK or PLK1 has been clinically evaluated in cancer patients; however, dual inhibitors have not yet been pursued. Here we present the in vitro and in vivo characterization of a first in class, dual TTK/PLK1 inhibitor (BAL0891).

Methods

Mechanism of action studies utilized biochemical kinase and proteomics-based target-engagement assays. Cellular end-point assays included immunoblot- and flow cytometry-based cell cycle analyses and SAC integrity evaluation using immunoprecipitation and immunofluorescence approaches. Anticancer activity was assessed in vitro using cell growth assays and efficacy was evaluated, alone and in combination with paclitaxel and carboplatin, using mouse models of triple negative breast cancer (TNBC).

Results

BAL0891 elicits a prolonged effect on TTK, with a transient activity on PLK1. This unique profile potentiates SAC disruption, forcing tumor cells to aberrantly exit mitosis with faster kinetics than observed with a TTK-specific inhibitor. Broad anti-proliferative activity was demonstrated across solid tumor cell lines in vitro. Moreover, intermittent intravenous single-agent BAL0891 treatment of the MDA-MB-231 mouse model of TNBC induced profound tumor regressions associated with prolonged TTK and transient PLK1 in-tumor target occupancy. Furthermore, differential tumor responses across a panel of thirteen TNBC patient-derived xenograft models indicated profound anticancer activity in a subset (~40%). Using a flexible dosing approach, pathologically confirmed cures were observed in combination with paclitaxel, whereas synergy with carboplatin was schedule dependent.

Conclusions

Dual TTK/PLK1 inhibition represents a novel approach for the treatment of human cancer, including TNBC patients, with a potential for potent anticancer activity and a favorable therapeutic index. Moreover, combination approaches may provide an avenue to expand responsive patient populations.

Reversal of the tamoxifen‑resistant breast cancer malignant phenotype by proliferation inhibition with bromosulfonamidine amino‑podophyllotoxin

One of the lignans isolated from plants within the genus Podophyllum is podophyllotoxin (PPT). PPT and its derivatives are pharmacologically active compounds with potential antiproliferative properties in several kinds of tumors. Although these compounds have been used to treat other malignancies, no PPT derivative-based chemotherapeutic agent has been used to cure tamoxifen (TAM)-resistant breast cancer in clinical trials, to the best of our knowledge. Thus, using TAM-resistant breast cancer as a disease model, the present study assessed the effects of a recently synthesized PPT derivative, bromosulfonamidine amino-PPT (BSAPPT), on TAM-resistant breast cancer. Using the tamoxifen-resistant breast cancer cell model (MCF-7/TAMR) in vitro, Cell Counting Kit-8 and colony formation assays were adopted to evaluate the effect of BSAPPT on cell proliferation. Cell apoptosis and cell cycle assays were used to assess the influence of BSAPPT on cell apoptosis and the cell cycle in MCF-7/TAMR. The targets of the potential mechanism of action were analyzed by RT-qPCR and western blotting. The present study demonstrated that BSAPPT suppressed MCF-7/TAMR cell proliferation in a dose-dependent manner. By modulating the level of expression of genes linked to both apoptosis and the cell cycle, BSAPPT triggered MCF-7/TAMR cells to undergo apoptosis and prevented them from entering the cell cycle. Consequently, BSAPPT blocked these cells from proliferating, thereby halting the malignant advancement of TAM-resistant breast cancer. Therefore, these findings indicate that new therapeutic agents involving BSAPPT may be developed to facilitate the treatment of TAM-resistant breast cancer.

A polo-like kinase 1 inhibitor enhances erastin sensitivity in head and neck squamous cell carcinoma cells in vitro

BACKGROUND

Polo-like kinase 1 (PLK1) is a critical therapeutic target in the treatment of head and neck squamous cell carcinoma (HNSCC). The objective of this study was to investigate the therapeutic effect of the combination of BI 2536, a PLK1 inhibitor, and erastin, a ferroptosis inducer, in HNSCC.

METHODS

The proliferation, invasion, and migration abilities of Tu177 and FaDu cells upon exposure to BI 2536 and erastin, used in combination or alone, were tested. Fe2+, glutathione (GSH), and malondialdehyde (MDA) detection kits were used to determine whether the addition of BI 2536 enhanced the accumulation of Fe2+ and MDA, along with the depletion of GSH. Quantitative real-time PCR, western blot analyses were performed to investigate whether BI 2536 further altered the mRNA and expression level of ferroptosis genes. Furthermore, si PLK1 was used to investigate whether targeting PLK1 gene promoted erastin-induced ferroptosis.

RESULTS

The combination of BI 2536 and erastin exerted a stronger cytotoxicity than treatment with a single agent. Compared with erastin treatment alone, the combination of BI 2536 and erastin lowered the ability of tumor cells to self-clone, invade, and migrate. BI 2536 enhanced the accumulation of Fe2+ and MDA, and the depletion of GSH. BI 2536 increased erastin-induced changes in ferroptosis-related gene mRNA and expression. Importantly, targeting PKL1 enhanced the anti-cancer effect of erastin.

CONCLUSION

BI 2536 enhanced the sensitivity of HNSCC cells to erastin, which provides a new perspective for cancer treatment.

Affinity enhancement of polo-like kinase 1 polo box domain-binding ligands by a bivalent approach using a covalent kinase-binding component

The polo-like kinase 1 (Plk1) is an important cell cycle regulator that is recognized as a target molecule for development of anti-cancer agents. Plk1 consists of a catalytic kinase domain (KD) and a polo-box domain (PBD), which engages in protein-protein interactions (PPIs) essential to proper Plk1 function. Recently, we developed extremely high-affinity PBD-binding inhibitors based on a bivalent approach using the Plk1 KD-binding inhibitor, BI2536, and a PBD-binding peptide. Certain of the resulting bivalent constructs exhibited more than 100-fold Plk1 affinity enhancement relative to the best monovalent PBD-binding ligands. Herein, we report an extensive investigation of bivalent ligands that utilize the non-selective kinase inhibitor Wortmannin as a Plk1 KD-binding component. We found that bivalent ligands incorporating Wortmannin demonstrated affinity enhancements that could be similar to what we had obtained with BI2536 and that they could tightly bind to the protein. This suggests that these tight binding ligands might be useful for structural analysis of full-length Plk1.

Secondary Analysis of Human Bulk RNA-Seq Dataset Suggests Potential Mechanisms for Letrozole Resistance in Estrogen-Positive (ER+) Breast Cancer

Estrogen receptor-positive (ER+) breast cancer is common among postmenopausal women and is frequently treated with Letrozole, which inhibits aromatase from synthesizing estrogen from androgens. Decreased estrogen slows the growth of tumors and can be an effective treatment. The increase in Letrozole resistance poses a unique problem for patients. To better understand the underlying molecular mechanism(s) of Letrozole resistance, we reanalyzed transcriptomic data by comparing individuals who responded to Letrozole therapy (responders) to those who were resistant to treatment (non-responders). We identified SOX11 and S100A9 as two significant differentially expressed genes (DEGs) between these patient cohorts, with "PLK1 signaling events" being the most significant signaling pathway. We also identified PRDX4 and E2F8 gene products as being the top mechanistic transcriptional markers for ER+ treatment resistance. Many of the significant DEGs that we identified play a known role in ER+ breast cancer or other types of cancer, which partially validate our results. Several of the gene products we identified are novel in the context of ER+ breast cancer. Many of the genes that we identified warrant further research to elucidate the more specific molecular mechanisms of Letrozole resistance in this patient population and could potentially be used as prognostic markers with further wet lab validation. We anticipate that these findings could contribute to improved detection and therapeutic outcomes in aromatase-resistant ER+ breast cancer patients.

Specific and efficient knockdown of intracellular miRNA using partially neutralized phosphate-methylated DNA oligonucleic acid-loaded mesoporous silica nanoparticles

Antisense oligonucleotides (ASOs) are molecules used to regulate RNA expression by targeting specific RNA sequences. One specific type of ASO, known as neutralized DNA (nDNA), contains site-specific methyl phosphotriester (MPTE) linkages on the phosphate backbone, changing the negatively charged DNA phosphodiester into a neutralized MPTE with designed locations. While nDNA has previously been employed as a sensitive nucleotide sequencing probe for the PCR, the potential of nDNA in intracellular RNA regulation and gene therapy remains underexplored. Our study aims to evaluate the regulatory capacity of nDNA as an ASO probe in cellular gene expression. We demonstrated that by tuning MPTE locations, partially and intermediately methylated nDNA loaded onto mesoporous silica nanoparticles (MSNs) can effectively knock down the intracellular miRNA, subsequently resulting in downstream mRNA regulation in colorectal cancer cell HCT116. Additionally, the nDNA ASO-loaded MSNs exhibit superior efficacy in reducing miR-21 levels over 72 hours compared to the efficacy of canonical DNA ASO-loaded MSNs. The reduction in the miR-21 level subsequently resulted in the enhanced mRNA levels of tumour-suppressing genes PTEN and PDCD4. Our findings underscore the potential of nDNA in gene therapies, especially in cancer treatment via a fine-tuned methylation location.

Diosgenin potentiates the anticancer effect of doxorubicin and volasertib via regulating polo-like kinase 1 and triggering apoptosis in hepatocellular carcinoma cells

A common approach to cancer therapy is the combination of a natural product with chemotherapy to overcome sustained cell proliferation and chemotherapy resistance obstacles. Diosgenin (DG) is a phytosteroidal saponin that is naturally present in a vast number of plants and has been shown to exert anti-cancer activities against several tumor cells. Herein, we assessed the chemo-modulatory effects of DG on volasertib (Vola) as a polo-like kinase 1 (PLK1) inhibitor and doxorubicin (DOX) in hepatocellular carcinoma (HCC) cell lines. DOX and Vola were applied to two human HCC cell lines (HepG2 and Huh-7) alone or in combination with DG. The cell viability was determined, and gene expressions of PLK1, PCNA, P53, caspase-3, and PARP1 were evaluated by RT-qPCR. Moreover, apoptosis induction was determined by measuring active caspase-3 level using ELISA method. DG enhanced the anticancer effects of Vola and DOX. Moreover, DG enhanced Vola- and DOX-induced cell death by downregulating the expressions of PLK1 and PCNA, elevating the expressions of P53 and active caspase-3. DG showed promising chemo-modulatory effects to Vola and DOX against HCC that may be attributed partly to the downregulation of PLK1 and PCNA, upregulation of tumor suppressor protein P53, and apoptosis induction. Thus, DG combination with chemotherapy may be a promising treatment approach for HCC.

Therapeutic implications of signaling pathways and tumor microenvironment interactions in esophageal cancer

Esophageal cancer (EC) is significantly influenced by the tumor microenvironment (TME) and altered signaling pathways. Downregulating these pathways in EC is essential for suppressing tumor development, preventing metastasis, and enhancing therapeutic outcomes. This approach can increase tumor sensitivity to treatments, enhance patient outcomes, and inhibit cancer cell proliferation and spread. The TME, comprising cellular and non-cellular elements surrounding the tumor, significantly influences EC's development, course, and treatment responsiveness. Understanding the complex relationships within the TME is crucial for developing successful EC treatments. Immunotherapy is a vital TME treatment for EC. However, the heterogeneity within the TME limits the application of anticancer drugs outside clinical settings. Therefore, identifying reliable microenvironmental biomarkers that can detect therapeutic responses before initiating therapy is crucial. Combining approaches focusing on EC signaling pathways with TME can enhance treatment outcomes. This integrated strategy aims to interfere with essential signaling pathways promoting cancer spread while disrupting factors encouraging tumor development. Unraveling aberrant signaling pathways and TME components can lead to more focused and efficient treatment approaches, identifying specific cellular targets for treatments. Targeting the TME and signaling pathways may reduce metastasis risk by interfering with mechanisms facilitating cancer cell invasion and dissemination. In conclusion, this integrative strategy has significant potential for improving patient outcomes and advancing EC research and therapy. This review discusses the altered signaling pathways and TME in EC, focusing on potential future therapeutics.

Iron-Confined CRISPR/Cas9-Ribonucleoprotein Delivery System for Redox-Responsive Gene Editing

Clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) is a promising gene editing tool to treat diseases at the genetic level. Nonetheless, the challenge of the safe and efficient delivery of CRISPR/Cas9 to host cells constrains its clinical applicability. In the current study, a facile, redox-responsive CRISPR/Cas9-Ribonucleoprotein (RNP) delivery system by combining iron-coordinated aggregation with liposomes (Fe-RNP@L) is reported. The Fe-RNP is formed by the coordination of Fe3+ with amino and carboxyl groups of Cas9, which modifies the lipophilicity and surface charge of RNP and alters cellular uptake from primary endocytosis to endocytosis and cholesterol-dependent membrane fusion. RNP can be rapidly and reversibly released from Fe-RNP in response to glutathione without loss of structural integrity and enzymatic activity. In addition, iron coordination also improves the stability of RNP and substantially mitigates cytotoxicity. This construct enabled highly efficient cytoplasmic/nuclear delivery (≈90%) and gene-editing efficiency (≈70%) even at low concentrations. The high payload content, high editing efficiency, good stability, low immunogenicity, and ease of production and storage, highlight its potential for diverse genome editing and clinical applications.

Research on drug treatment and the novel signaling pathway of chronic atrophic gastritis

BACKGROUND

Chronic atrophic gastritis (CAG) is a global digestive system disease and one of the important causes of gastric cancer. The incidence of CAG has been increasing yearly worldwide.

PURPOSE

This article reviews the latest research on the common causes and future therapeutic targets of CAG as well as the pharmacological effects of corresponding clinical drugs. We provide a detailed theoretical basis for further research on possible methods for the treatment of CAG and reversal of the CAG process.

RESULTS

CAG often develops from chronic gastritis, and its main pathological manifestation is atrophy of the gastric mucosa, which can develop into gastric cancer. The drug treatment of CAG can be divided into agents that regulate gastric acid secretion, eradicate Helicobacter. pylori (H. pylori), protect gastric mucous membrane, or inhibit inflammatory factors according to their mechanism of action. Although there are limited specific drugs for the treatment of CAG, progress is being made in defining the pathogenesis and therapeutic targets of the disease. Growing evidence shows that NF-κB, PI3K/AKT, Wnt/ β-catenin, MAPK, Toll-like receptors (TLRs), Hedgehog, and VEGF signaling pathways play an important role in the development of CAG.

Targeting polo-like kinase 1 to treat kidney diseases

Globally, ∼850 million individuals suffer from some form of kidney disease. This staggering figure underscores the importance of continued research and innovation in the field of nephrology to develop effective treatments and improve overall global kidney health. In current research, the polo-like kinase (Plk) family has emerged as a group of highly conserved enzyme kinases vital for proper cell cycle regulation. Plks are defined by their N-terminal kinase domain and C-terminal polo-box domain, which regulate their catalytic activity, subcellular localization, and substrate recognition. Among the Plk family members, Plk1 has garnered significant attention due to its pivotal role in regulating multiple mitotic processes, particularly in the kidneys. It is a crucial serine-threonine (Ser-Thr) kinase involved in cell division and genomic stability. In this review, we delve into the types and functions of Plks, focusing on Plk1's significance in processes such as cell proliferation, spindle assembly, and DNA damage repair. The review also underscores Plk1's vital contributions to maintaining kidney homeostasis, elucidating its involvement in nuclear envelope breakdown, anaphase-promoting complex/cyclosome activation, and the regulation of mRNA translation machinery. Furthermore, the review discusses how Plk1 contributes to the development and progression of kidney diseases, emphasizing its overexpression in conditions such as acute kidney injury, chronic kidney disease, and so forth. It also highlights the importance of exploring Plk1 modulators as targeted therapies for kidney diseases in future. This review will help in understanding the role of Plk1 in kidney disease development, paving the way for the discovery and development of novel therapeutic approaches to manage kidney diseases effectively.

AVERON notebook to discover actionable cancer vulnerabilities enabled by neomorph protein-protein interactions

Genomic alterations, such as missense mutations, often lead to the activation of oncogenic pathways and cell transformation by rewiring protein-protein interaction (PPI) networks. Understanding how mutant-directed neomorph PPIs (neoPPIs) drive cancer is vital to developing new personalized clinical strategies. However, the experimental interrogation of neoPPI functions in patients with cancer is highly challenging. To address this challenge, we developed a computational platform, termed AVERON for discovering actionable vulnerabilities enabled by rewired oncogenic networks. AVERON enables rapid systematic profiling of the clinical significance of neomorph PPIs across different cancer types, informing molecular mechanisms of neoPPI-driven tumorigenesis, and revealing therapeutically actionable neoPPI-regulated genes. We demonstrated the application of the AVERON platform by evaluating the biological functions and clinical significance of 130 neomorph interactions, experimentally determined for oncogenic BRAFV600E. The AVERON application to broad sets of mutant-directed PPIs may inform new testable biological models and clinical strategies in cancer.

Mitotic kinases are emerging therapeutic targets against metastatic breast cancer

This review aims to outline mitotic kinase inhibitors' roles as potential therapeutic targets and assess their suitability as a stand-alone clinical therapy or in combination with standard treatments for advanced-stage solid tumors, including triple-negative breast cancer (TNBC). Breast cancer poses a significant global health risk, with TNBC standing out as the most aggressive subtype. Comprehending the role of mitosis is crucial for understanding how TNBC advances from a solid tumor to metastasis. Chemotherapy is the primary treatment used to treat TNBC. Some types of chemotherapeutic agents target cells in mitosis, thus highlighting the need to comprehend the molecular mechanisms governing mitosis in cancer. This understanding is essential for devising targeted therapies to disrupt these mitotic processes, prevent or treat metastasis, and improve patient outcomes. Mitotic kinases like Aurora kinase A, Aurora Kinase B, never in mitosis gene A-related kinase 2, Threonine-Tyrosine kinase, and Polo-kinase 1 significantly impact cell cycle progression by contributing to chromosome separation and centrosome homeostasis. When these kinases go awry, they can trigger chromosome instability, increase cell proliferation, and activate different molecular pathways that culminate in a transition from epithelial to mesenchymal cells. Ongoing clinical trials investigate various mitotic kinase inhibitors as potential biological treatments against advanced solid tumors. While clinical trials against mitotic kinases have shown some promise in the clinic, more investigation is necessary, since they induce severe adverse effects, particularly affecting the hematopoietic system.

Anoikis resistance regulates immune infiltration and drug sensitivity in clear-cell renal cell carcinoma: insights from multi omics, single cell analysis and in vitro experiment

Background

Anoikis is a form of programmed cell death essential for preventing cancer metastasis. In some solid cancer, anoikis resistance can facilitate tumor progression. However, this phenomenon is underexplored in clear-cell renal cell carcinoma (ccRCC).

Methods

Using SVM machine learning, we identified core anoikis-related genes (ARGs) from ccRCC patient transcriptomic data. A LASSO Cox regression model stratified patients into risk groups, informing a prognostic model. GSVA and ssGSEA assessed immune infiltration, and single-cell analysis examined ARG expression across immune cells. Quantitative PCR and immunohistochemistry validated ARG expression differences between immune therapy responders and non-responders in ccRCC.

Results

ARGs such as CCND1, CDKN3, PLK1, and BID were key in predicting ccRCC outcomes, linking higher risk with increased Treg infiltration and reduced M1 macrophage presence, indicating an immunosuppressive environment facilitated by anoikis resistance. Single-cell insights showed ARG enrichment in Tregs and dendritic cells, affecting immune checkpoints. Immunohistochemical analysis reveals that ARGs protein expression is markedly elevated in ccRCC tissues responsive to immunotherapy.

Conclusion

This study establishes a novel anoikis resistance gene signature that predicts survival and immunotherapy response in ccRCC, suggesting that manipulating the immune environment through these ARGs could improve therapeutic strategies and prognostication in ccRCC.

MYC and HSF1 Cooperate to Drive PLK1 inhibitor Sensitivity in High Grade Serous Ovarian Cancer

Ovarian cancer is a deadly female cancer with high rates of recurrence. The primary treatment strategy for patients is platinum-based therapy regimens that almost universally develop resistance. Consequently, new therapeutic avenues are needed to overcome the plateau that current therapies have on patient outcomes. We describe a gene amplification involving both HSF1 and MYC, wherein these two genes on chromosome 8q are co-amplified in over 7% of human tumors that is enriched to over 30% of patients with ovarian cancer. We further found that HSF1 and MYC transcriptional activity is correlated in human tumors and ovarian cancer cell lines, suggesting they may cooperate in ovarian cancer cells. CUT&RUN for HSF1 and MYC in co-amplified ovarian cancer cells revealed that HSF1 and MYC have overlapping binding at a substantial number of locations throughout the genome where their binding peaks are near identical. Consistent with these data, a protein-protein interaction between HSF1 and MYC was detected in ovarian cancer cells, implying these two transcription factors have a molecular cooperation. Further supporting their cooperation, growth of HSF1-MYC co-amplified ovarian cancer cells were found to be dependent on both HSF1 and MYC. In an attempt to identify a therapeutic target that could take advantage of this dependency on both HSF1 and MYC, PLK1 was identified as being correlated with HSF1 and MYC in primary human tumor specimens, consistent with a previously established effect of PLK1 on HSF1 and MYC protein levels. Targeting PLK1 with the compound volasertib (BI-6727) revealed a greater than 200-fold increased potency of volasertib in HSF1-MYC co-amplified ovarian cancer cells compared to ovarian cancer cells wild-type HSF1 and MYC copy number, which extended to several growth assays, including spheroid growth. Volasertib, and other PLK1 inhibitors, have not shown great success in clinical trials and this study suggests that targeting PLK1 may be viable in a precision medicine approach using HSF1-MYC co-amplification as a biomarker for response.

Proteasome activation is critical for cell death induced by inhibitors of polo-like kinase 1 (PLK1) in multiple cancers

Inhibitors of polo-like kinase (PLK) are currently being evaluated as anticancer drugs. However, the molecular mechanism of PLK inhibitor-induced cell death is not fully understood. In this study, we found that GW843682X and BI2536, two inhibitors of PLK1, significantly induced cell death in multiple type cells. The induction of cell death was related to the preferring expression of PLK1. However, in human umbilical vascular endothelial cells (HUVEC) and human colorectal carcinoma cells, which expressed higher levels of both PLK1 and PLK2, PLK1 inhibitors induced very low levels of cell death. Clinical analysis reveals PLK1 presence in 26 of 30 NPC tumor tissues. In in vivo NPC lung metastasis nude mouse models, PLK1 inhibitors decreased NPC progress. Mechanistically, the PLK1 inhibitor did not activate p53, and the cell death was not reversed by p53 inhibition. Moreover, PLK1 inhibitor-induced cell death was PARP- and caspase-independent. Although PLK1 inhibitors induced down-regulation of calpain inhibitor calpastatin and calpain was activated by PLK1 inhibition, calpain blocking did not reverse cell death induced by PLK1 inhibitors, suggesting the non-involvement of calpain. Surprisingly, we found that PLK1 inhibitors induced the activation of proteasome, and the treatment of cells with PLK1 inhibitors reduced the levels of ubiquitinated proteins. And proteasome inhibitors reversed cell death induced by PLK1 inhibitors in various cell types in which PLK1 was preferentially expressed. Moreover, PLK1 inhibition reversed the degradation of proteins including p53, caspase 8, PARP and calpastatin. These results suggest that the activation of proteasome is critical for cell death induced by PLK1 inhibition.

Biological role and expression of translationally controlled tumor protein (TCTP) in tumorigenesis and development and its potential for targeted tumor therapy

Translationally controlled tumor protein (TCTP), also known as histamine-releasing factor (HRF) or fortilin, is a highly conserved protein found in various species. To date, multiple studies have demonstrated the crucial role of TCTP in a wide range of cellular pathophysiological processes, including cell proliferation and survival, cell cycle regulation, cell death, as well as cell migration and movement, all of which are major pathogenic mechanisms of tumorigenesis and development. This review aims to provide an in-depth analysis of the functional role of TCTP in tumor initiation and progression, with a particular focus on cell proliferation, cell death, and cell migration. It will highlight the expression and pathological implications of TCTP in various tumor types, summarizing the current prevailing therapeutic strategies that target TCTP.

FBXO45 levels regulated ferroptosis renal tubular epithelial cells in a model of diabetic nephropathy by PLK1

Objective

This research aims to investigate the role and underlying biological mechanism of FBXO45 in regulating ferroptosis of renal fibrocytes in a diabetic nephropathy (DN) model.

Methods

C57BL/6 mice were fed with a high-fat diet and injected with streptozotocin to induce diabetes. Human renal glomerular endothelial cells stimulated with d-glucose.

Results

Serum FBXO45 mRNA expression was found to be down-regulated in patients with DN. There was a negative correlation between the expression of serum FBXO45 mRNA and serum α-SMA, Collagen I, and E-cadherin mRNA in patients with DN. Additionally, the expression of serum FBXO45 mRNA showed a negative correlation with blood sugar levels. Based on a 3D model prediction, it was observed that FBXO45 interacts with polo-like kinase 1 (PLK1) at GLY-271, ILE-226, GLY-166, LEU-165, ARG-245, and ASN-220, while PLK1 interacts with FBXO45 at TYR-417, ARG-516, HIS-489, TYR-485, GLN-536, and ARG-557. This interaction was confirmed through immunoprecipitation assay, which showed the interlinking of FBXO45 protein with PLK1 protein.

Conclusions

These findings indicate that FBXO45 plays a role in mitigating ferroptosis in DN through the regulation of the PLK1/GPX4/SOX2 pathway. This highlights the potential of targeting FBXO45 as a therapeutic approach to ameliorate ferroptosis in DN.

Overexpression of PLK1 Molecule Following Incomplete Thermal Ablation Promotes the Proliferation and Invasion of Residual Hepatocellular Carcinoma

TAT, a widely used treatment for HCC, can exacerbate the progression of residual HCC. The present study investigated the mechanism of action of PLK1 following ITA of HCC. The PLK1 levels in HCC were determined using qRT-PCR from clinical patient samples, IHC from tissue microarray, and data from globally high-throughput data and microarrays. The PLK1 levels and their effect on the biological phenotype of heat-stress HCC cells were evaluated through in vitro experiments. We detected PLK1 abnormal expression in HCC models of nude mice subjected to ITA. We detected the effects of different PLK1 expression levels on EMT pathway proteins. PLK1 exhibited an overexpression in HCC tissues with an SMD of 1.19 (3414 HCC and 3036 non-HCC tissues were included), distinguishing HCC from non-HCC effectively (AUC = 0.9). The qRT-PCR data from clinical HCC patient samples and IHC from HCC tissue microarray results also indicated an overexpressed level. In the incomplete ablation models, an increased PLK1 expression was found in both heat-stress cells and subcutaneous tumors. The upregulation of PLK1 following ITA was found to enhance the malignancy of HCC and exacerbate the proliferation, migration, and invasion of residual HCC cells, whereas PLK1 knockdown suppressed the biological malignancy of HCC cells. Meanwhile, PLK1 has different regulatory effects on various EMT pathway proteins. PLK1 promotes the progression of residual HCC by activating EMT pathway after ITA, which might provide a novel idea for the treatment and prognosis of residual HCC.

Genetic Microcephaly in a Saudi Population: Unique Spectrum of Affected Genes Including a Novel One

Background: Genetic microcephaly is linked to an increased risk of developmental disabilities, epilepsy, and motor impairment. The aim of this study is to describe the spectrum of identifiable genetic etiologies, clinical characteristics, and radiologic features of genetic microcephaly in patients referred to a tertiary center in Saudi Arabia. Method: This is a retrospective chart review study of all patients with identifiable genetic microcephaly presenting to a tertiary center in Saudi Arabia. The patients' demographics, clinical, laboratory, radiologic, and molecular findings were collected. Results: Of the total 128 cases referred, 52 cases (40%) had identifiable genetic causes. Monogenic disorders were found in 48 cases (92%), whereas chromosomal disorders were found in only 4 cases (8%). Developmental disability was observed in 40 cases (84%), whereas only 8 cases (16%) had borderline IQ or mild developmental delay. Epilepsy was seen in 29 cases (56%), and motor impairment was seen in 26 cases (50%). Brain magnetic resonance imaging (MRI) revealed abnormalities in 26 (50%) of the cohort. Hereditary neurometabolic disorders were seen in 7 (15%) of the 48 cases with monogenic disorders. The most common gene defect was ASPM, which is responsible for primary microcephaly type 5 and was seen in 10 cases (19%). A novel PLK1 gene pathogenic mutation was seen in 3 cases (6%). Conclusion: Single gene defect is common in this Saudi population, with the ASPM gene being the most common. Hereditary neurometabolic disorders are a common cause of genetic microcephaly. Furthermore, we propose the PKL1 gene mutation as a possible novel cause of genetic microcephaly.

Targeted PLK1 suppression through RNA interference mediated by high-fidelity Cas13d mitigates osteosarcoma progression via TGF-β/Smad3 signalling

Osteosarcoma is the most common primary bone malignancy in children and adolescents. Overexpression of polo-like kinase 1 (PLK1) is frequent in osteosarcoma and drives disease progression and metastasis, making it a promising therapeutic target. In this study, we explored PLK1 knockdown in osteosarcoma cells using RNA interference mediated by high-fidelity Cas13d (hfCas13d). PLK1 was found to be significantly upregulated in osteosarcoma tumour tissues compared to normal bone. sgRNA-mediated PLK1 suppression via hfCas13d transfection inhibited osteosarcoma cell proliferation, induced G2/M cell cycle arrest, promoted apoptosis, reduced cell invasion and increased expression of the epithelial marker E-cadherin. Proximity labelling by TurboID coupled with co-immunoprecipitation identified novel PLK1 interactions with Smad3, a key intracellular transducer of TGF-β signalling. PLK1 knockdown impaired Smad2/3 phosphorylation and modulated TGF-β/Smad3 pathway inactivation. Finally, in vivo delivery of hfCas13d vectors targeting PLK1 substantially attenuated osteosarcoma xenograft growth in nude mice. Taken together, this study highlights PLK1 as a potential therapeutic target and driver of disease progression in osteosarcoma. It also demonstrates the utility of hfCas13d-mediated gene knockdown as a strategy for targeted therapy. Further optimization of PLK1 suppression approaches may ultimately improve clinical outcomes for osteosarcoma patients.

The role of the master cancer regulator Pin1 in the development and treatment of cancer

This review examines the complex role of Pin1 in the development and treatment of cancer. Pin1 is the only peptidyl-prolyl isomerase (PPIase) that can recognize and isomerize phosphorylated Ser/Thr-Pro peptide bonds. Pin1 catalyzes a structural change in phosphorylated Ser/Thr-Pro motifs that can modulate protein function and thereby impact cell cycle regulation and tumorigenesis. The molecular mechanisms by which Pin1 contributes to oncogenesis are reviewed, including Pin1 overexpression and its correlation with poor cancer prognosis, and the contribution of Pin1 to aggressive tumor phenotypes involved in therapeutic resistance is discussed, with an emphasis on cancer stem cells, the epithelial-to-mesenchymal transition (EMT), and immunosuppression. The therapeutic potential of Pin1 inhibition in cancer is discussed, along with the promise and the difficulties in identifying potent, drug-like, small-molecule Pin1 inhibitors. The available evidence supports the efficacy of targeting Pin1 as a novel cancer therapeutic by analyzing the role of Pin1 in a complex network of cancer-driving pathways and illustrating the potential of synergistic drug combinations with Pin1 inhibitors for treating aggressive and drug-resistant tumors.

Transcriptomic analysis and experiments revealed that remimazolam promotes proliferation and G1/S transition in HCT8 cells

Background

Remimazolam is a new ultrashort-acting benzodiazepine for sedation and anesthesia. The effects of remimazolam and the mechanism by which it functions in cancer cells have not been determined. This research aimed to explore the mechanism of remimazolam action in colon cancer treatment, using bioinformatics analysis and in vitro experiments.

Methods

Cell cycle progression, colony formation, self-renewal capacity, and apoptosis detection were performed in HCT8 cells treated with or without remimazolam. Transcriptome sequencing, Gene Ontology, Kyoto Encyclopedia of Genes and Genome, Protein-Protein Interaction, Gene Set Enrichment Analysis, Western blotting, and qPCR were performed to investigate the mechanism of action of remimazolam in HCT8 colon cancer cells.

Results

Remimazolam promoted proliferation and cell-cycle progression of HCT8 cells. After remimazolam treatment, a total of 1,096 differentially expressed genes (DEGs) were identified: 673 genes were downregulated, and 423 genes were upregulated. The DEGs were enriched mainly in "DNA replication", "cell cycle", and "G1/S transition" related pathways. There were 15 DEGs verified by qPCR, and representative biomarkers were detected by Western Bloting. The remimazolam-mediated promotion of cell proliferation and cell cycle was reversed by G1T28, a CDK4/6 inhibitor.

Conclusion

Remimazolam promoted cell-cycle progression and proliferation in HCT8 colon cancer cells, indicating that the long-term use of remimazolam has potential adverse effects in the anesthesia of patients with colon cancer.

KinPred-RNA-kinase activity inference and cancer type classification using machine learning on RNA-seq data

Kinases as important enzymes can transfer phosphate groups from high-energy and phosphate-donating molecules to specific substrates and play essential roles in various cellular processes. Existing algorithms for kinase activity from phosphorylated proteomics data are often costly, requiring valuable samples. Moreover, methods to extract kinase activities from bulk RNA sequencing data remain undeveloped. In this study, we propose a computational framework KinPred-RNA to derive kinase activities from bulk RNA-sequencing data in cancer samples. KinPred-RNA framework, using the extreme gradient boosting (XGBoost) regression model, outperforms random forest regression, multiple linear regression, and support vector machine regression models in predicting kinase activities from cancer-related RNA sequencing data. Efficient gene signatures from the LINCS-L1000 dataset were used as inputs for KinPred-RNA. The results highlight its potential to be related to biological function. In conclusion, KinPred RNA constitutes a significant advance in cancer research by potentially facilitating the identification of cancer.

Antiproliferative Activity of N-Acylhydrazone Derivative on Hepatocellular Carcinoma Cells Involves Transcriptional Regulation of Genes Required for G2/M Transition

Liver cancer is the second leading cause of cancer-related death in males. It is estimated that approximately one million deaths will occur by 2030 due to hepatic cancer. Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer subtype and is commonly diagnosed at an advanced stage. The drug arsenal used in systemic therapy for HCC is very limited. Multikinase inhibitors sorafenib (Nexavar®) and lenvatinib (Lenvima®) have been used as first-line drugs with modest therapeutic effects. In this scenario, it is imperative to search for new therapeutic strategies for HCC. Herein, the antiproliferative activity of N-acylhydrazone derivatives was evaluated on HCC cells (HepG2 and Hep3B), which were chemically planned on the ALL-993 scaffold, a potent inhibitor of vascular endothelial growth factor 2 (VEGFR2). The substances efficiently reduced the viability of HCC cells, and the LASSBio-2052 derivative was the most effective. Further, we demonstrated that LASSBio-2052 treatment induced FOXM1 downregulation, which compromises the transcriptional activation of genes required for G2/M transition, such as AURKA and AURKB, PLK1, and CDK1. In addition, LASSBio-2052 significantly reduced CCNB1 and CCND1 expression in HCC cells. Our findings indicate that LASSBio-2052 is a promising prototype for further in vivo studies.

Centrosomes and associated proteins in pathogenesis and treatment of breast cancer

Breast cancer is the most prevalent malignancy among women worldwide. Despite significant advances in treatment, it remains one of the leading causes of female mortality. The inability to effectively treat advanced and/or treatment-resistant breast cancer demonstrates the need to develop novel treatment strategies and targeted therapies. Centrosomes and their associated proteins have been shown to play key roles in the pathogenesis of breast cancer and thus represent promising targets for drug and biomarker development. Centrosomes are fundamental cellular structures in the mammalian cell that are responsible for error-free execution of cell division. Centrosome amplification and aberrant expression of its associated proteins such as Polo-like kinases (PLKs), Aurora kinases (AURKs) and Cyclin-dependent kinases (CDKs) have been observed in various cancers, including breast cancer. These aberrations in breast cancer are thought to cause improper chromosomal segregation during mitosis, leading to chromosomal instability and uncontrolled cell division, allowing cancer cells to acquire new genetic changes that result in evasion of cell death and the promotion of tumor formation. Various chemical compounds developed against PLKs and AURKs have shown meaningful antitumorigenic effects in breast cancer cells in vitro and in vivo. The mechanism of action of these inhibitors is likely related to exacerbation of numerical genomic instability, such as aneuploidy or polyploidy. Furthermore, growing evidence demonstrates enhanced antitumorigenic effects when inhibitors specific to centrosome-associated proteins are used in combination with either radiation or chemotherapy drugs in breast cancer. This review focuses on the current knowledge regarding the roles of centrosome and centrosome-associated proteins in breast cancer pathogenesis and their utility as novel targets for breast cancer treatment.

MSI-DTI: predicting drug-target interaction based on multi-source information and multi-head self-attention

Identifying drug-target interactions (DTIs) holds significant importance in drug discovery and development, playing a crucial role in various areas such as virtual screening, drug repurposing and identification of potential drug side effects. However, existing methods commonly exploit only a single type of feature from drugs and targets, suffering from miscellaneous challenges such as high sparsity and cold-start problems. We propose a novel framework called MSI-DTI (Multi-Source Information-based Drug-Target Interaction Prediction) to enhance prediction performance, which obtains feature representations from different views by integrating biometric features and knowledge graph representations from multi-source information. Our approach involves constructing a Drug-Target Knowledge Graph (DTKG), obtaining multiple feature representations from diverse information sources for SMILES sequences and amino acid sequences, incorporating network features from DTKG and performing an effective multi-source information fusion. Subsequently, we employ a multi-head self-attention mechanism coupled with residual connections to capture higher-order interaction information between sparse features while preserving lower-order information. Experimental results on DTKG and two benchmark datasets demonstrate that our MSI-DTI outperforms several state-of-the-art DTIs prediction methods, yielding more accurate and robust predictions. The source codes and datasets are publicly accessible at https://github.com/KEAML-JLU/MSI-DTI.

Degradation of Polo-like Kinase 1 by the Novel Poly-Arginine N-Degron Pathway PROTAC Regulates Tumor Growth in Nonsmall Cell Lung Cancer

Polo-like kinase 1 (PLK1), which is crucial in cell cycle regulation, is considered a promising anticancer drug target. Herein, we present the N-degron pathway-based proteolysis targeting chimera (PROTAC) for PLK1 degradation, targeting the Polo-box domain (PBD). We identified DD-2 as the most potent PROTAC that selectively induces PLK1 degradation in cancer cells, including HeLa and nonsmall cell lung cancer (NSCLC), through the N-degron pathway. DD-2 exhibited significant in vitro anticancer effects, inducing G2/M arrest and apoptosis in HeLa and NSCLC cell lines. DD-2 showed significant tumor growth inhibition in a xenograft mouse model using HeLa and NSCLC cell lines, highlighting its potential in cancer treatment. Furthermore, the combination of DD-2 with tyrosine kinase inhibitor (TKI), osimertinib, effectively suppressed tumor growth in double-mutated H1975 cell lines, emphasizing DD-2's potential in combination cancer therapies. Collectively, this study demonstrates the potential of the N-degron pathway, especially using DD-2, for targeted cancer therapies.

Phytochemical constituents, in-vitro anticancer activity and computational studies of Cymbopogon schoenanthus

The cytotoxic effects of Cymbopogon schoenanthus L. aerial part ethanol extract were examined against some cancer cell lines, and HUVEC normal cell lines using MTT assay. The ethanolic extract was prepared by ultrasonic-assisted extraction and analyzed by GC-MS and HPLC. The extract was found to be rich in terpene compounds. The extract proved to be highly selective and effective against breast and prostate cancer cell lines (MDA-MB-435, MCF-7, and DU 145) with IC50 as low as 0.7913 ± 0.14, 12.841 ± 0.21, and 30.51 ± 0.18 µg/ml, respectively. In silico modeling was performed to investigate the binding orientation and affinity of the major identified compounds against Polo-like kinase (PLK1 protein) a cancer molecular target using molecular docking and molecular dynamic whereas eudesm-5-en-11-ol, piperitone, and 2,3-dihydrobenzofuran displayed better binding affinity and stability against PLK1 compared to the reference drug. These findings encourage further in vivo studies to assess the anti-cancer effects of C. schoenanthus extract and its components.