The oncogenicity of tumor-derived mutant p53 is enhanced by the recruitment of PLK3

Myrtenol ameliorates inflammatory, oxidative, apoptotic, and hyperplasic effects of urethane-induced atypical adenomatous hyperplasia in the rat lung

Lung atypical adenomatous hyperplasia (AAH) is a forerunner of pulmonary adenocarcinoma. The drugs being utilized in the remediation of this type of hyperplasia have some adverse impacts. The present research focused on the potential anti-hyperplasia effect of myrtenol, an herbal terpenoid, on urethane-induced lung AAH in rats. Rats were injected with urethane (1.5 g/kg) thrice at 48 h intervals, and 20 weeks later, the animals were treated with 50 mg/kg myrtenol intraperitoneally once a day for 1 week. The ELISA method was used to measure inflammatory cytokines and oxidative parameters in the lung tissue and bronchoalveolar lavage fluid (BALF). The expression of NFκB and apoptotic/antiapoptotic factors (P53/Bcl-2) was evaluated by western blot and immunohistochemistry, respectively. H&E staining was performed for histopathological investigation. Histopathology confirmed the anti-hyperplasia effect of myrtenol, which was evidenced by the reduction of bronchoalveolar wall thickness and inflammation score. It also decreased hyperplasia progression by reducing Bcl-2, IL-10, p53, and Ki67. Compared with the urethane group, myrtenol normalized the activity of the oxidative stress markers malondialdehyde (MDA), total antioxidant capacity (TAC), glutathione peroxidase (GPX), and superoxide dismutase (SOD). Moreover, it showed an anti-inflammatory effect by decreasing lung and BALF IL-1β levels and NFκB expression. Myrtenol may have a promising effect on lung cancer treatment by counteracting lung hyperplasia via modulation of inflammation, oxidative stress, and apoptosis.

p53 Genetics and Biology in Lung Carcinomas: Insights, Implications and Clinical Applications

The TP53 gene is renowned as a tumor suppressor, playing a pivotal role in overseeing the cell cycle, apoptosis, and maintaining genomic stability. Dysregulation of p53 often contributes to the initiation and progression of various cancers, including lung cancer (LC) subtypes. The review explores the intricate relationship between p53 and its role in the development and progression of LC. p53, a crucial tumor suppressor protein, exists in various isoforms, and understanding their distinct functions in LC is essential for advancing our knowledge of this deadly disease. This review aims to provide a comprehensive literature overview of p53, its relevance to LC, and potential clinical applications.

High PLK3 levels are linked with less tumor invasion, lower FIGO stage and better prognosis of endometrial cancer

Aim: To evaluate correlations of tumor PLK3 with clinical features and prognosis of resectable endometrial cancer (EC) patients.Methods: Tumor tissues from 200 EC patients receiving surgical resections and adjacent tissues from 50 of them were collected for PLK3 determination using immunohistochemistry.Results: Tumor PLK3 negatively linked with myometrial invasion ≥50%, lymphovascular invasion, stromal cervical invasion, and International Federation of Gynecology and Obstetrics stage (all p < 0.050). High tumor PLK3 independently related to longer disease-free survival (DFS) (p = 0.044) and overall survival (OS) (p = 0.049). Its prognostic value was also validated by time-dependent receiver operating characteristic analyses (area under curve at most timepoints was >0.700).Conclusion: Tumor PLK3 potentially reflects prolonged DFS and OS in EC patients undergoing surgical resections.

PLK3 is linked with higher tumor stage and unfavorable prognosis in patients with colorectal cancer

Objective: This study intended to explore the relationship of PLK3 with prognosis in patients with colorectal cancer (CRC). Methods: PLK3 positivity was detected by immunohistochemistry in 160 patients with CRC receiving surgical resection. Results: The median tumor PLK3-positive rate was 26.5%. Tumor PLK3-positive rate was related to increased lymph node stage (p = 0.002) and tumor-node-metastasis stage (p < 0.001) of CRC. Tumor PLK3-positive rate ≥30% was related to shortened disease-free survival (p = 0.009) and overall survival (p = 0.003); tumor PLK3-positive rate ≥50% showed a stronger correlation with them (both p = 0.001), which was validated by multivariate Cox regression analyses (both p < 0.05). Conclusion: Tumor PLK3-positive rate ≥50% relates to increased tumor stage and unfavorable survival in patients with CRC.

Identification of PLK1-PBD Inhibitors from the Library of Marine Natural Products: 3D QSAR Pharmacophore, ADMET, Scaffold Hopping, Molecular Docking, and Molecular Dynamics Study

PLK1 is found to be highly expressed in various types of cancers, but the development of inhibitors for it has been slow. Most inhibitors are still in clinical stages, and many lack the necessary selectivity and anti-tumor effects. This study aimed to create new inhibitors for the PLK1-PBD by focusing on the PBD binding domain, which has the potential for greater selectivity. A 3D QSAR model was developed using a dataset of 112 compounds to evaluate 500 molecules. ADMET prediction was then used to select three molecules with strong drug-like characteristics. Scaffold hopping was employed to reconstruct 98 new compounds with improved drug-like properties and increased activity. Molecular docking was used to compare the efficient compound abbapolin, confirming the high-activity status of [(14S)-14-hydroxy-14-(pyridin-2-yl)tetradecyl]ammonium,[(14S)-15-(2-furyl)-14-hydroxypentadecyl]ammonium and [(14S)-14-hydroxy-14-phenyltetradecyl]ammonium. Molecular dynamics simulations and MMPBSA were conducted to evaluate the stability of the compounds in the presence of proteins. An in-depth analysis of [(14S)-15-(2-furyl)-14-hydroxypentadecyl]ammonium and [(14S)-14-hydroxy-14-phenyltetradecyl]ammonium identified them as potential candidates for PLK1 inhibitors.

TUBA1A licenses APC/C-mediated mitotic progression to drive glioblastoma growth by inhibiting PLK3

Glioblastoma (GBM) is the most common, aggressive, and chemorefractory primary brain tumor in adults. Identifying novel drug targets is crucial for GBM treatment. Here, we demonstrate that tubulin alpha 1a (TUBA1A) is significantly upregulated in GBM compared to low-grade gliomas (LGG) and normal tissues. High TUBA1A expression is associated with poor survival in GBM patients. TUBA1A knockdown results in mitotic arrest and reduces tumor growth in mice. TUBA1A interacts with the polo-like kinase 3 (PLK3) in the cytoplasm to inhibit its activation. This interaction licenses activation of the anaphase-promoting complex or cyclosome (APC/C) to ensure proper Foxm1-mediated metaphase-to-anaphase transition and mitotic exit. Overall, our findings demonstrate that targeting TUBA1A attenuates GBM cell growth by suppressing mitotic progression in a PLK3-dependent manner.

PLK3 promotes the proneural-mesenchymal transition in glioblastoma via transcriptional regulation of C5AR1

BACKGROUND

Accumulating evidence suggests that polo-like kinase 3 (PLK3) plays an essential role in tumor cells and induces cell proliferation and may have implications for the prognosis of various cancers. We sought to define the role of PLK3-dependent proneural-mesenchymal transition (PMT) in the glioblastoma (GBM) therapy.

METHODS AND RESULTS

We analyzed the expression data for PLK3 by using the TCGA database. PLK3 expression in GBM cell lines was determined by qRT-PCR and Western blotting. PLK3 levels were modulated using Lentivirus infection, and the effects on symptoms, tumor volume, and survival in mice intracranial xenograft models were determined. Irradiation (IR) was performed to induce PMT. PLK3 expression was significantly elevated in mesenchymal subtype GBM and promoted tumor proliferation in GBM. Additionally enriched PLK3 expression could be associated with poor prognosis in GBM patients compared with those who have lower PLK3 expression. Mechanically, PLK3-dependent PMT induced radioresistance in GBM cells via transcriptional regulation of complement C5a receptor 1 (C5AR1). In therapeutic experiments conducted in vitro, targeting PLK3 by using small molecule inhibitor decreased tumor growth and radioresistance of GBM cells both in vitro and in vivo.

CONCLUSIONS

PLK3-C5AR1 axis induced PMT thus enhanced radioresistance in GBM and could become a novel potential therapeutic target for GBM.

Targeting the p53 signaling pathway in cancers: Molecular mechanisms and clinical studies

Tumor suppressor p53 can transcriptionally activate downstream genes in response to stress, and then regulate the cell cycle, DNA repair, metabolism, angiogenesis, apoptosis, and other biological responses. p53 has seven functional domains and 12 splice isoforms, and different domains and subtypes play different roles. The activation and inactivation of p53 are finely regulated and are associated with phosphorylation/acetylation modification and ubiquitination modification, respectively. Abnormal activation of p53 is closely related to the occurrence and development of cancer. While targeted therapy of the p53 signaling pathway is still in its early stages and only a few drugs or treatments have entered clinical trials, the development of new drugs and ongoing clinical trials are expected to lead to the widespread use of p53 signaling-targeted therapy in cancer treatment in the future. TRIAP1 is a novel p53 downstream inhibitor of apoptosis. TRIAP1 is the homolog of yeast mitochondrial intermembrane protein MDM35, which can play a tumor-promoting role by blocking the mitochondria-dependent apoptosis pathway. This work provides a systematic overview of recent basic research and clinical progress in the p53 signaling pathway and proposes that TRIAP1 is an important therapeutic target downstream of p53 signaling.

The ubiquitin ligase TRIM21 regulates mutant p53 accumulation and gain of function in cancer

The tumor suppressor TP53 is the most frequently mutated gene in human cancers. Mutant p53 (mutp53) proteins often accumulate to very high levels in human cancers to promote cancer progression through the gain-of-function (GOF) mechanism. Currently, the mechanism underlying mutp53 accumulation and GOF is incompletely understood. Here, we identified TRIM21 as a critical E3 ubiquitin ligase of mutp53 by screening for specific mutp53-interacting proteins. TRIM21 directly interacted with mutp53 but not WT p53, resulting in ubiquitination and degradation of mutp53 to suppress mutp53 GOF in tumorigenesis. TRIM21 deficiency in cancer cells promoted mutp53 accumulation and GOF in tumorigenesis. Compared with p53R172H knockin mice, which displayed mutp53 accumulation specifically in tumors but not normal tissues, TRIM21 deletion in p53R172H knockin mice resulted in mutp53 accumulation in normal tissues, an earlier tumor onset, and a shortened life span of mice. Furthermore, TRIM21 was frequently downregulated in some human cancers, including colorectal and breast cancers, and low TRIM21 expression was associated with poor prognosis in patients with cancers carrying mutp53. Our results revealed a critical mechanism underlying mutp53 accumulation in cancers and also uncovered an important tumor-suppressive function of TRIM21 and its mechanism in cancers carrying mutp53.

Inhibitors of the PLK1 polo-box domain: drug design strategies and therapeutic opportunities in cancer

INTRODUCTION

Polo Like Kinase 1 (PLK1) is a key regulator of mitosis and its overexpression is frequently observed in a wide variety of human cancers, while often being associated with poor survival rates. Therefore, it is considered a potential and attractive target for cancer therapeutic development. The Polo like kinase family is characterized by the presence of a unique C terminal polobox domain (PBD) involved in regulating kinase activity and subcellular localization. Among the two functionally essential, druggable sites with distinct properties that PLK1 offers, targeting the PBD presents an alternative approach for therapeutic development.

AREAS COVERED

Significant progress has been made in progressing from the peptidic PBD inhibitors first identified, to peptidomimetic and recently drug-like small molecules. In this review, the rationale for targeting the PBD over the ATP binding site is discussed, along with recent progress, challenges, and outlook.

EXPERT OPINION

The PBD has emerged as a viable alternative target for the inhibition of PLK1, and progress has been made in using compounds to elucidate mechanistic aspects of activity regulation and in determining roles of the PBD. Studies have resulted in proof of concept of in vivo efficacy suggesting promise for PBD binders in clinical development.

Toward Accurate Coarse-Grained Simulations of Disordered Proteins and Their Dynamic Interactions

Intrinsically disordered proteins (IDPs) play crucial roles in cellular regulatory networks and are now recognized to often remain highly dynamic even in specific interactions and assemblies. Accurate description of these dynamic interactions is extremely challenging using atomistic simulations because of the prohibitive computational cost. Efficient coarse-grained approaches could offer an effective solution to overcome this bottleneck if they could provide an accurate description of key local and global properties of IDPs in both unbound and bound states. The recently developed hybrid-resolution (HyRes) protein model has been shown to be capable of providing a semiquantitative description of the secondary structure propensities of IDPs. Here, we show that greatly improved description of global structures and transient interactions can be achieved by introducing a solvent-accessible surface area-based implicit solvent term followed by reoptimization of effective interaction strengths. The new model, termed HyRes II, can semiquantitatively reproduce a wide range of local and global structural properties of a set of IDPs of various lengths and complexities. It can also distinguish the level of compaction between folded proteins and IDPs. In particular, applied to the disordered N-terminal transactivation domain (TAD) of tumor suppressor p53, HyRes II is able to recapitulate various nontrivial structural properties compared to experimental results, some of them to a level of accuracy that is almost comparable to results from atomistic explicit solvent simulations. Furthermore, we demonstrate that HyRes II can be used to simulate the dynamic interactions of TAD with the DNA-binding domain of p53, generating structural ensembles that are highly consistent with existing NMR data. We anticipate that HyRes II will provide an efficient and relatively reliable tool toward accurate coarse-grained simulations of dynamic protein interactions.

Mutant p53 Depletion by Novel Inhibitors for HSP40/J-Domain Proteins Derived from the Natural Compound Plumbagin

Simple Summary

The tumor suppressor p53 is frequently mutated in human cancer. Accumulation of missense mutant p53 (mutp53) in tumors is crucial for malignant progression, and cancers are often addicted to oncogenic mutp53. However, strategies to deplete mutp53 have not yet been established. Recent studies have shown that misfolded or conformational mutp53 is stabilized by DNAJA1, a member of HSP40, also known as J-domain proteins (JDPs). However, no selective DNAJA1 inhibitor is clinically available. Through a molecular docking study, we identified a potential DNAJA1 inhibitor, called PLTFBH, derived from the natural compound plumbagin, as a compound that bound to and reduced protein levels of DNAJA1 and several other HSP40/JDPs. PLTFBH reduced the levels of conformational mutp53 and inhibited cancer cell migration in a manner dependent on DNAJA1 and mutp53.

Abstract

Accumulation of missense mutant p53 (mutp53) in cancers promotes malignant progression. DNAJA1, a member of HSP40 (also known as J-domain proteins: JDPs), is shown to prevent misfolded or conformational mutp53 from proteasomal degradation. Given frequent addiction of cancers to oncogenic mutp53, depleting mutp53 by DNAJA1 inhibition is a promising approach for cancer therapy. However, there is no clinically available inhibitor for DNAJA1. Our in silico molecular docking study with a natural compound-derived small molecule library identified a plumbagin derivative, PLIHZ (plumbagin–isoniazid analog), as a potential compound binding to the J domain of DNAJA1. PLIHZ efficiently reduced the levels of DNAJA1 and several conformational mutp53 with minimal impact on DNA contact mutp53 and wild-type p53 (wtp53). An analog, called PLTFBH, which showed a similar activity to PLIHZ in reducing DNAJA1 and mutp53 levels, inhibited migration of cancer cells specifically carrying conformational mutp53, but not DNA contact mutp53, p53 null, and wtp53, which was attenuated by depletion of DNAJA1 or mutp53. Moreover, PLTFBH reduced levels of multiple other HSP40/JDPs with tyrosine 7 (Y7) and/or tyrosine 8 (Y8) but failed to deplete DNAJA1 mutants with alanine substitution of these amino acids. Our study suggests PLTFBH as a potential inhibitor for multiple HSP40/JDPs.

Comprehensive Analysis of Genomic Alterations in Hepatoid Adenocarcinoma of the Stomach and Identification of Clinically Actionable Alterations

Simple Summary

Hepatoid adenocarcinoma of the stomach (HAS) is a subset of gastric cancer (GC) histologically characterized by hepatocellular carcinoma-like foci with or without alpha-fetoprotein secretion, which is easily misdiagnosed. Genomic alterations and potential targets for this population are still largely unknown. Additionally, treatment regimens of HAS are mainly based on GC guidelines, which is not reasonable for diseases with great heterogeneity. The present study comprehensively depicts the genomic features of HAS, and they are significantly different from GC, AFP-producing GC (AFPGC), and liver hepatocellular carcinoma (LIHC). Multiple aggressive behavior-related amplificated or deleted regions in HAS are firstly reported. Moreover, reliable and practicable clinically actionable alterations for HAS are identified, providing evidence for making personalized therapy based on the genomic characteristics of HAS instead of GC.

Abstract

Hepatoid adenocarcinoma of the stomach (HAS) is a rare malignancy with aggressive biological behavior. This study aimed to compare the genetic landscape of HAS with liver hepatocellular carcinoma (LIHC), gastric cancer (GC), and AFP-producing GC (AFPGC) and identify clinically actionable alterations. Thirty-eight cases of HAS were collected for whole-exome sequencing. Significantly mutated genes were identified. TP53 was the most frequently mutated gene (66%). Hypoxia, TNF-α/NFκB, mitotic spindle assembly, DNA repair, and p53 signaling pathways mutated frequently. Mutagenesis mechanisms in HAS were associated with spontaneous or enzymatic deamination of 5-methylcytosine to thymine and defective homologous recombination-related DNA damage repair. However, LIHC was characteristic of exposure to aflatoxin and aristolochic acid. The copy number variants (CNVs) in HAS was significantly different compared to LIHC, GC, and AFPGC. Aggressive behavior-related CNVs were identified, including local vascular invasion, advanced stages, and adverse prognosis. In 55.26% of HAS patients there existed at least one clinically actionable alteration, including ERBB2, FGFR1, CDK4, EGFR, MET, and MDM2 amplifications and BRCA1/2 mutations. MDM2 amplification with functional TP53 was detected in 5% of HAS patients, which was proved sensitive to MDM2 inhibitors. A total of 10.53% of HAS patients harbored TMB > 10 muts/Mb. These findings improve our understanding of the genomic features of HAS and provide potential therapeutic targets.

PLK3 amplification and tumor immune microenvironment of metastatic tumors are linked to adjuvant treatment outcomes in uterine serous cancer

Uterine serous carcinoma (USC), an aggressive variant of endometrial cancer representing approximately 10% of endometrial cancer diagnoses, accounts for ∼39% of endometrial cancer-related deaths. We examined the role of genomic alterations in advanced-stage USC associated with outcome using paired primary-metastatic tumors (n = 29) treated with adjuvant platinum and taxane chemotherapy. Comparative genomic analysis of paired primary-metastatic patient tumors included whole exome sequencing and targeted gene expression. Both PLK3 amplification and the tumor immune microenvironment (TIME) in metastatic tumors were linked to time-to-recurrence (TTR) risk without any such association observed with primary tumors. TP53 loss was significantly more frequent in metastatic tumors of platinum-resistant versus platinum-sensitive patients and was also associated with increased recurrence and mortality risk. Increased levels of chr1 breakpoints in USC metastatic versus primary tumors co-occur with PLK3 amplification. PLK3 and the TIME are potential targets for improving outcomes in USC adjuvant therapy.

System analysis of FHIT in LUAD and LUSC: The expression, prognosis, gene regulation network, and regulation targets

BACKGROUND

Fragile histidine triad (FHIT) is a strong tumor suppressor gene, and cells deficient in FHIT are prone to acquiring cancer-promoting mutations. Due to its location, deletions within FHIT are common in cancer. Over 50% of cancers show loss of FHIT expression. However, to date, expression levels, gene regulatory networks, prognostic value, and target prediction of FHIT in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) have not been fully reported. Therefore, systematic analysis of FHIT expression, gene regulatory network, prognostic value, and targeted prediction in patients with LUAD and LUSC has important guiding significance, providing new therapeutic targets and strategies for clinical treatment of lung cancer to further improve the therapeutic effect of lung cancer.

METHODS

Multiple free online databases were used for the abovementioned analysis in this study, including cBioPortal, TRRUST, Human Protein Atlas, GeneMANIA, GEPIA, Metascape, UALCAN, LinkedOmics, and TIMER.

RESULTS

FHIT was upregulated in patients with LUAD, and downregulated in patients with LUSC. Genetic alterations of FHIT were found in patients with LUAD (7%), and LUSC (10%). The promoter methylation of FHIT was lower in patients with LUAD and LUSC. FHIT expression significantly correlated with LUSC pathological stages. Furthermore, patients with LUAD and LUSC having low FHIT expression levels had a longer survival than those having high FHIT expression levels. FHIT and its neighboring genes (the 50 most frequently altered neighboring genes of FHIT) functioned in the regulation of protein kinase and DNA binding in patients with LUAD, as well as cell channels and membrane potential in patients with LUSC. Gene ontology enrichment analysis revealed that the functions of FHIT and its neighboring genes are mainly related to disordered domain-specific binding, protein kinase binding, and ion gated channel activity in patients with LUAD, as well as calcium ion binding and intracellular ligand-gated ion channel activity in patients with LUSC. Transcription factor targets of FHIT and its neighboring genes in patients with lung cancer were found: USF1, SOX6, USF2, SIRT1, VHL, LEF1, EZH2, TP53, HDAC1, ESR1, EGR1, YY1, MYC, RELA, NFKB1, and E2F1 in LUAD; and HDAC1, DNMT1, and E2F1 in LUSC. We further explored the FHIT-associated kinase (PRKCQ, AURKB and ATM in LUAD as well as PLK3 in LUSC) and FHIT-associated miRNA targets (MIR-188, MIR-323, and MIR-518A-2 in LUAD). Furthermore, the following genes had the strongest correlation with FHIT expression in patients with lung cancer: NICN1, HEMK1, and BDH2 in LUAD, and ZMAT1, TTC21A, and NICN1 in LUSC. FHIT expression was positively associated with immune cell infiltration (B cell) in patients with LUAD, as well as B cell, CD8 + T, CD4 + T cells, macrophages, and dendritic cells in patients with LUSC. Nevertheless, FHIT expression was negatively associated with CD8 + T cells and neutrophils in patients with LUAD.

CONCLUSIONS

The expression, gene regulatory network, prognostic value and targeted prediction of FHIT in patients with LUAD and LUSC were systematically analyzed and revealed in this study, thereby laying a foundation for further research on the role of FHIT in LUAD and LUSC occurrence. This study provides new LUAD and LUSC therapeutic targets and prognostic biomarkers as a reference for fundamental and clinical research.