Sea buckthorn extract mitigates chronic obstructive pulmonary disease by suppression of ferroptosis via scavenging ROS and blocking p53/MAPK pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Sea buckthorn (Hippophae rhamnoides), a traditional Tibetan medicinal herb, exhibits protective effects against cardiovascular and respiratory diseases. Although Sea buckthorn extract (SBE) has been confirmed to alleviate airway inflammation in mice, its therapeutic effect and underlying mechanism on chronic obstructive pulmonary disease (COPD) requires further clarification. AIM OF THE STUDY: To elucidate the alleviative effect and molecular mechanism of SBE on lipopolysaccharides (LPS)/porcine pancreatic elastase (PPE)-induced COPD by blocking ferroptosis. METHODS: The anti-ferroptotic effects of SBE were evaluated in human BEAS-2B bronchial epithelial cells using CCK8, RT-qPCR, western blotting, and transmission electron microscopy. Transwell was employed to detect chemotaxis of neutrophils. COPD model was induced by intranasally administration of LPS/PPE in mice and measured by alterations of histopathology, inflammation, and ferroptosis. RNA-sequencing, western blotting, antioxidant examination, flow cytometry, DARTS, CETSA, and molecular docking were then used to investigate its anti-ferroptotic mechanisms. RESULTS: In vitro, SBE not only suppressed erastin- or RSL3-induced ferroptosis by suppressing lipid peroxides (LPOs) production and glutathione (GSH) depletion, but also suppressed ferroptosis-induced chemotactic migration of neutrophils via reducing mRNA expression of chemokines. In vivo, SBE ameliorated LPS/PPE-induced COPD phenotypes, and inhibited the generation of LPOs, cytokines, and chemokines. RNA-sequencing showed that p53 pathway and mitogen-activated protein kinases (MAPK) pathway were implicated in SBE-mediated anti-ferroptotic action. SBE repressed erastin- or LPS/PPE-induced overactivation of p53 and MAPK pathway, thereby decreasing expression of diamine acetyltransferase 1 (SAT1) and arachidonate 15-lipoxygenase (ALOX15), and increasing expression of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11). Mechanistically, erastin-induced elevation of reactive oxygen species (ROS) was reduced by SBE through directly scavenging free radicals, thereby contributing to its inhibition of p53 and MAPK pathways. CETSA, DARTS, and molecular docking further showed that ROS-generating enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) may be the target of SBE. Overexpression of NOX4 partially impaired the anti-ferroptotic activity of SBE. CONCLUSION: Our results demonstrated that SBE mitigated COPD by suppressing p53 and MAPK pro-ferroptosis pathways via directly scavenging ROS and blocking NOX4. These findings also supported the clinical application of Sea buckthorn in COPD therapy.

Unlocking the potential of LHPP: Inhibiting glioma growth and cell cycle via the MDM2/p53 pathway.

The recurrence of glioma after treatment has remained an intractable problem for many years. Recently, numerous studies have explored the pivotal role of the mouse double minute 2 (MDM2)/p53 pathway in cancer treatment. Lysine phosphate phosphohistidine inorganic pyrophosphate phosphatase (LHPP), a newly discovered tumor suppressor, has been confirmed in numerous studies on tumors, but its role in glioma remains poorly understood. Expression matrices in The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) databases were analyzed using gene set enrichment analysis (GSEA), revealing significant alterations in the p53 pathway among glioma patients with high LHPP expression. The overexpression of LHPP in glioma cells resulted in a reduction in cell proliferation, migration, and invasive ability, as well as an increase in apoptosis and alterations to the cell cycle. The present study has identified a novel inhibitory mechanism of LHPP against glioma, both in vivo and in vitro. The results demonstrate that LHPP exerts anti-glioma effects via the MDM2/p53 pathway. These findings may offer a new perspective for the treatment of glioma in the clinic.

Integrated stress response (ISR) activation and apoptosis through HRI kinase by PG3 and other p53 pathway-restoring cancer therapeutics.

Restoration of the p53 pathway has been a long-term goal in the field of cancer research to treat tumors with mutated p53 and aggressive clinical behavior. p53 pathway restoration in p53-deficient cancers can be achieved by small molecules via p53-dependent or p53-independent processes. Hereafter p53-independent restoration of p53-pathway-signaling in p53-deficient/mutated tumors is referred to as 'restoration of the p53 pathway'. We compare activation of p53 target genes by novel compounds PG3 and PG3-Oc, that activate p53-target genes in a p53-independent manner, and four mutant p53-activating compounds while Nutlin-3a is used as negative control. PG3 and PG3-Oc upregulate p21, PUMA, and DR5 in five cancer cell lines with various p53 mutational statuses through ATF4 (Activating Transcriptional Factor 4) and integrated stress response (ISR) independent of p53. Mutant p53-targeting compounds induce expression of the 3 major downstream p53 target genes and ATF4 in a highly variable and cell-type-dependent manner. PG3 treatment activates ATF4 through ISR via kinase HRI (Heme-Regulated Inhibitor). ATF4 mediates upregulation of PUMA, p21, and NAG-1/GDF15 (Nonsteroidal anti-inflammatory drug-activated gene 1). We note that PUMA mediates apoptosis through activation of caspase-8 in HT29 cells and potentially caspase-10 in SW480 cells. We provide a novel mechanism engaged by PG3 to induce cell death via the HRI/ATF4/PUMA axis. Our results provide unique insights into the mechanism of action of PG3 as a novel cancer therapeutic targeting p53 pathway-like tumor suppression.

Long non-coding RNA MAGEA4-AS1 binding to p53 enhances MK2 signaling pathway and promotes the proliferation and metastasis of oral squamous cell carcinoma.

Long non-coding RNAs (lncRNAs) regulate the occurrence, development and progression of oral squamous cell carcinoma (OSCC). We elucidated the expression features of MAGEA4-AS1 in patients with OSCC and its activity as an OSCC biomarker. Furthermore, the impact of up-regulation of MAGEA4-AS1 on the cellular behaviors (proliferation, migration and invasion) of OSCC cells and intrinsic signal mechanisms were evaluated. Firstly, we analyzed MAGEA4-AS1 expression data in The Cancer Genome Atlas (TCGA) OSCC using a bioinformatics approach and in 45 pairs of OSCC tissues using qPCR. Then CCK-8, ethynyl deoxyuridine, colony formation, transwell and wound healing assays were conducted to assess changes in the cell proliferation, migration and invasion protential of shMAGEA4-AS1 HSC3 and CAL27 cells. The RNA sequence of MAGEA4-AS1 was identified using the rapid amplification of cDNA ends (RACE) assay. And whole-transcriptome sequencing was used to identify MAGEA4-AS1 affected genes. Additionally, dual-luciferase reporter system, RNA-binding protein immunoprecipitation (RIP), and rescue experiments were performed to clarify the role of the MAGEA4-AS1-p53-MK2 signaling pathway. As results, we found MAGEA4-AS1 was up-regulated in OSCC tissues. We identified a 418 nucleotides length of the MAGEA4-AS1 transcript and it primarily located in the cell nucleus. MAGEA4-AS1 stable knockdown weakened the proliferation, migration and invasion abilities of OSCC cells. Mechanistically, p53 protein was capable to activate MK2 gene transcription. RIP assay revealed an interaction between p53 and MAGEA4-AS1. MK2 up-regulation in MAGEA4-AS1 down-regulated OSCC cells restored MK2 and epithelial-to-mesenchymal transition related proteins' expression levels. In conclusion, MAGEA4-AS1-p53 complexes bind to MK2 promoter, enhancing the transcription of MK2 and activating the downstream signaling pathways, consequently promoting the proliferation and metastasis of OSCC cells. MAGEA4-AS1 may serve as a diagnostic marker and therapeutic target for OSCC patients.

Pervasive expostulation of p53 gene promoting the precipitation of neurogenic convulsions: A journey in therapeutic advancements.

Epilepsy, a neurological disorder characterized by prolonged and excessive seizures, has been linked to elevated levels of the tumor suppressor gene p53, which contributes to neuronal dysfunction. This review explores the molecular mechanisms of p53 in epilepsy and discusses potential future therapeutic strategies. Research indicates that changes in p53 expression during neuronal apoptosis, neuroinflammation, and oxidative stress play a significant role in the pathogenesis of epilepsy. Elevated p53 disrupts glutamatergic neurotransmission and hyperactivates NMDA and AMPA receptors, leading to increased neuronal calcium influx, mitochondrial oxidative stress, and activation of apoptotic pathways mediated neuronal dysfunction, exacerbating epileptogenesis. The involvement of p53 in epilepsy suggests that targeting this protein could be beneficial in mitigating neuronal damage and preventing seizure recurrence. Pharmacological agents like pifithrin-α have shown promise in reducing p53-mediated apoptosis and seizure severity. Gene therapy approaches, such as viral vector-mediated delivery of wild-type p53 or RNA interference targeting mutant p53, have also been effective in restoring normal p53 function and reducing seizure susceptibility. Despite these advances, the heterogeneous nature of epilepsy and potential long-term side effects of p53 modulation present challenges. Future research should focus on elucidating the precise molecular mechanisms of p53 and developing personalized therapeutic strategies. Modulating p53 activity holds promise for reducing seizure susceptibility and improving the quality of life for individuals with epilepsy. The current review provides the understanding the intricate role of p53 in neuroinflammatory pathways, including JAK-STAT, JNK, NF-κB, Sonic Hedgehog, and Wnt, is crucial for developing targeted therapies.

Mechanisms of action of Sappan lignum for prostate cancer treatment: network pharmacology, molecular docking and experimental validation.

Background: Prostate cancer (PCa) is the most common non-cutaneous malignancy in men globally. Sappan lignum, which exists in the heartwood of Caesalpinia sappan L., has antitumor effects; however, its exact mechanism of action remains unclear. This study elucidated the underlying mechanisms of Sappan lignum in PCa through network pharmacology approaches and molecular docking techniques. Moreover, the therapeutic effects of Sappan lignum on PCa were verified through in vitro experiments. Methods: The constituent ingredients of Sappan lignum were retrieved from the HERB database. Active plant-derived compounds of Sappan lignum were screened based on gastrointestinal absorption and gastric drug properties. Disease targets for PCa were screened using unpaired and paired case datasets from the Gene Expression Omnibus. Intersection targets were used for gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis. Core targets were identified through topological analysis parameters and their clinical relevance was validated through The Cancer Genome Atlas database. The affinity between the phytochemicals of Sappan lignum and core proteins was verified using the molecular docking technique. Validation experiments confirmed the significant potential of Sappan lignum in treating PCa. Results: Twenty-one plant-derived compounds of Sappan lignum and 821 differentially expressed genes associated with PCa were collected. Among 32 intersection targets, 8 were screened according to topological parameters. KEGG analysis indicated that the antitumor effects of Sappan lignum on PCa were primarily associated with the p53 pathway. The molecular docking technique demonstrated a strong affinity between 3-deoxysappanchalcone (3-DSC) and core proteins, particularly cyclin B1 (CCNB1). CCNB1 expression correlated with clinicopathological features in patients with PCa. Experimental results revealed that 3-DSC exhibited anti-proliferative, anti-migratory, and pro-apoptotic effects on 22RV1 and DU145 cells while also causing G2/M phase cell cycle arrest, potentially through modulating the p53/p21/CDC2/CCNB1 pathway. Conclusion: This research highlights the promising therapeutic potential of Sappan lignum in treating PCa, with a particular focus on targeting the p53 pathway.

SNPs Give LACTB Oncogene-Like Functions and Prompt Tumor Progression via Dual-Regulating p53.

LACTB is identified as a tumor suppressor in several tumors. However, preliminary study reveals that LACTB is overexpressed in osteosarcoma and indicates poor prognosis. Two missense mutations (rs34317102 and rs2729835) exist simultaneously in 92.31% of osteosarcoma patients and cause M5L and R469K double mutations in LACTB, suggesting the biologic function of LACTB protein may be altered in osteosarcoma. Moreover, LACTBM5L+R469K overexpression can promote malignant progression in different tumors, which suggests that the M5L and R469K mutations confer oncogene-like functions to LACTB. Mechanistically, LACTBM5L+R469K not only reduces the wild type p53 via enhancing PSMB7 catalytic activity, but also protects p53R156P protein from lysosomal degradation, which suggesting LACTBM5L+R469K is a dual-regulator for wt-p53 and mutant p53, and derive oncogene-like functions. More importantly, clavulanate potassium, a bacterial ß-lactamase inhibitor, can inhibit osteosarcoma proliferation and sensitize osteosarcoma to cisplatin by binding and blocking LACTBM5L+R469K. These findings revealed that the M5L and R469K double mutations can diminish the tumor suppressive ability of wild type LACTB and provide oncogene-like functions to LACTB. Inhibiting LACTBM5L+R469K can suppress the progression of osteosarcoma harbouring wild-type or mutant p53. Clavulanate potassium is a promising drug by targeting LACTBM5L+R469K-p53 pathway for the treatment of osteosarcoma patients.

Wnt/B-catenin activation and TP53 mutations associate with distinct immune profiles in advanced thyroid cancer.

CONTEXT: Anaplastic thyroid carcinomas (ATCs) and poorly differentiated thyroid carcinomas (PDTCs) exhibit distinct immune-related gene expression profiles. Most ATCs are characterized by active immune interactions (hot or altered immunosuppressed immunophenotypes), while PDTCs are largely immunologically inert (cold immunophenotypes). OBJECTIVE: This study aimed to elucidate the mechanisms driving these divergent immunological fates, focusing on the Wnt/ß-catenin pathway and TP53 mutations. RESULTS: Our data reveal that ATCs frequently harbor TP53 mutations (83.3%), which correlate with a hot immunophenotype, characterized by high expression of ß-catenin-regulated cytokine CCL4 and recruitment of CD103+ dendritic cells. Conversely, PDTCs, with a lower incidence of TP53 mutations (12.5%), often exhibit a cold immunophenotype. In cold cancers and PDTCs, ß-catenin is overexpressed suggesting that Wnt/ß-catenin pathway activation drives immune exclusion through CCL4 downregulation.Further analysis indicated that loss of p53 function is inversely correlated with ß-catenin expression. P53-mutated cancers showed significantly higher expression of CCL4 and densities of CD103+ dendritic cells compared to their p53-wild-type counterparts. Additionally, p53-mutated ATCs expressed a higher number of immune-related genes, supporting the role of p53 loss in activating immune responses in cancer. CONCLUSION: Our study indicates a potential correlation between the activation of the Wnt/ß-catenin pathway and the development of cold thyroid cancers, which may be mediated by the suppression of CCL4 expression. Concurrently, mutations in the p53 gene appear to be linked with the occurrence of hot thyroid cancers. While these associations are compelling, they are based on observational data. Experimental research is necessary to determine the causal relationships underlying these findings.

Anti-Mullerian Hormone Induces Foxo1 and Sirt1 Genes Expression in Mouse Ovary.

BACKGROUND: Anti-Mullerian hormone (AMH) plays a pivotal role in follicular growth and atresia. Recent studies highlighted the role of AMH in attenuating granulosa cell apoptosis and subsequent follicular atresia. Despite the raising understanding of the role of AMH in folliculogenesis, and its contribution to the pathophysiology of certain diseases such as polycystic ovary syndrome, the effect of AMH on the expression of genes regulating folliculogenesis is stills limited. OBJECTIVE: This study aims to gain insights into the effect of AMH on atresia regulating genes. METHOD: In vivo study was performed on C57BL/6J mice injected with AMH for one month. Thereafter, relative gene expression quantification of Foxo1, Sirt1, p53, Bim, and Bax genes were performed using RT-PCR. RESULTS: In this study, AMH significantly enhanced the expression of Foxo1 and Sirt1 gene compared to the control group. On the contrary, AMH did not modulate the expression of p53, Bim, or Bax genes. AMH was also found to increase serum FSH and LH levels in a dosedependent manner. CONCLUSION: This study demonstrated the capability of AMH to induce Foxo1 and Sirt1 genes. Moreover, our study revealed the role of AMH in elevating LH serum level which is a main contributor to the pathophysiology of polycystic ovary syndrome, opening new avenues for the study of AMH as a main contributor to the stalled follicular atresia and growth associated with the disease.

Immunohistochemistry Markers in Ovarian and Fallopian Tube Neoplasms: a Comprehensive Review.

Immunohistochemistry (IHC) has emerged as a crucial tool in diagnosing and managing ovarian cancer, offering invaluable insights into tumor biology and guiding therapeutic decisions. The intricate histopathological landscape of ovarian cancer presents challenges in accurate diagnosis and classification. IHC offers a complementary approach, aiding in the characterization of tumor subtypes, prognostication, and prediction of treatment response. By targeting specific biomarkers, IHC enables the identification of diverse histological features and molecular alterations associated with ovarian malignancies. The integration of IHC into routine diagnostic workflows enhances diagnostic accuracy, aids in the subclassification of ovarian tumors, and facilitates personalized treatment strategies. Emphasis is placed on the judicious selection of antibody panels tailored to specific clinical scenarios, ensuring optimal utilization of resources and minimizing diagnostic pitfalls. Overall, this review underscores the pivotal role of IHC in refining the diagnosis, prognostication, and management of ovarian cancer, highlighting its significance in the era of precision medicine. By leveraging the molecular insights provided by IHC, clinicians and pathologists can optimize patient care and improve outcomes in ovarian cancer management.

LncRNA-HMG incites colorectal cancer cells to chemoresistance via repressing p53-mediated ferroptosis.

Upon chemotherapy, excessive reactive oxygen species (ROS) often lead to the production of massive lipid peroxides in cancer cells and induce cell death, namely ferroptosis. The elimination of ROS is pivotal for tumor cells to escape from ferroptosis and acquire drug resistance. Nevertheless, the precise functions of long non-coding RNAs (lncRNAs) in ROS metabolism and tumor drug-resistance remain elusive. In this study, we identify LncRNA-HMG as a chemoresistance-related lncRNA in colorectal cancer (CRC) by high-throughput screening. Abnormally high expression of LncRNA-HMG predicts poorer prognosis in CRC patients. Concurrently, we found that LncRNA-HMG protects CRC cells from ferroptosis upon chemotherapy, thus enhancing drug resistance of CRC cells. LncRNA-HMG binds to p53 and facilitates MDM2-mediated degradation of p53. Decreased p53 induces upregulation of SLC7A11 and VKORC1L1, which contribute to increase the supply of reducing agents and eliminate excessive ROS. Consequently, CRC cells escape from ferroptosis and acquire chemoresistance. Importantly, inhibition of LncRNA-HMG by anti-sense oligo (ASO) dramatically sensitizes CRC cells to chemotherapy in patient-derived xenograft (PDX) model. LncRNA-HMG is also a transcriptional target of ß-catenin/TCF and activated Wnt signals trigger the marked upregulation of LncRNA-HMG. Collectively, these findings demonstrate that LncRNA-HMG promotes CRC chemoresistance and might be a prognostic or therapeutic target for CRC.

Interleukin-34-orchestrated tumor-associated macrophage reprogramming is required for tumor immune escape driven by p53 inactivation.

As the most frequent genetic alteration in cancer, more than half of human cancers have p53 mutations that cause transcriptional inactivation. However, how p53 modulates the immune landscape to create a niche for immune escape remains elusive. We found that cancer stem cells (CSCs) established an interleukin-34 (IL-34)-orchestrated niche to promote tumorigenesis in p53-inactivated liver cancer. Mechanistically, we discovered that Il34 is a gene transcriptionally repressed by p53, and p53 loss resulted in IL-34 secretion by CSCs. IL-34 induced CD36-mediated elevations in fatty acid oxidative metabolism to drive M2-like polarization of foam-like tumor-associated macrophages (TAMs). These IL-34-orchestrated TAMs suppressed CD8+ T cell-mediated antitumor immunity to promote immune escape. Blockade of the IL-34-CD36 axis elicited antitumor immunity and synergized with anti-PD-1 immunotherapy, leading to a complete response. Our findings reveal the underlying mechanism of p53 modulation of the tumor immune microenvironment and provide a potential target for immunotherapy of cancer with p53 inactivation.

Mitochondrial genome-derived circRNAs: Orphan epigenetic regulators in molecular biology.

Mitochondria are vital for cellular activities, influencing ATP production, Ca2+ signaling, and reactive oxygen species generation. It has been proposed that nuclear genome-derived circular RNAs (circRNAs) play a role in biological processes. For the first time, this study aims to comprehensively explore experimentally confirmed human mitochondrial genome-derived circRNAs (mt-circRNAs) via in-silico analysis. We utilized wide-ranging bioinformatics tools to anticipate their roles in molecular biology, involving miRNA sponging, protein antagonism, and peptide translation. Among five well-characterized mt-circRNAs, SCAR/mc-COX2 stands out as particularly significant with the potential to sponge around 41 different miRNAs, which target several genes mostly involved in endocytosis, MAP kinase, and PI3K-Akt pathways. Interestingly, circMNTND5 and mecciND1 specifically interact with miRNAs through their unique back-splice junction sequence. These exclusively targeted miRNAs (has-miR-5186, 6888-5p, 8081, 924, 672-5p) are predominantly associated with insulin secretion, proteoglycans in cancer, and MAPK signaling pathways. Moreover, all mt-circRNAs intricately affect the P53 pathway through miRNA sequestration. Remarkably, mc-COX2 and circMNTND5 appear to be involved in the RNA's biogenesis by antagonizing AGO1/2, EIF4A3, and DGCR8. All mt-circRNAs engaged with IGF2BP proteins crucial in redox signaling, and except mecciND1, they all potentially generate at least one protein resembling the immunoglobulin heavy chain protein. Given P53's function as a redox-sensitive transcription factor, and insulin's role as a crucial regulator of energy metabolism, their indirect interplay with mt-circRNAs could influence cellular outcomes. However, due to limited attention and infrequent data availability, it is advisable to conduct more thorough investigations to gain a deeper understanding of the functions of mt-circRNA.

FABP4 deficiency ameliorates alcoholic steatohepatitis in mice via inhibition of p53 signaling pathway.

Fatty acid-binding protein 4 (FABP4) plays an essential role in metabolism and inflammation. However, the role of FABP4 in alcoholic steatohepatitis (ASH) remains unclear. This study aimed to investigate the function and underlying mechanisms of FABP4 in the progression of ASH. We first obtained alcoholic hepatitis (AH) datasets from the National Center for Biotechnology Information-Gene Expression Omnibus database and conducted bioinformatics analysis to identify critical genes in the FABP family. We then established ASH models of the wild-type (WT) and Fabp4-deficient (Fabp4-/-) mice to investigate the role of FABP4 in ASH. Additionally, we performed transcriptional profiling of mouse liver tissue and analyzed the results using integrative bioinformatics. The FABP4-associated signaling pathway was further verified. FABP4 was upregulated in two AH datasets and was thus identified as a critical biomarker for AH. FABP4 expression was higher in the liver tissues of patients with alcoholic liver disease and ASH mice than in the corresponding control samples. Furthermore, the Fabp4-/- ASH mice showed reduced hepatic lipid deposition and inflammation compared with the WT ASH mice. Mechanistically, Fabp4 may be involved in regulating the p53 and sirtuin-1 signaling pathways, subsequently affecting lipid metabolism and macrophage polarization in the liver of ASH mice. Our results demonstrate that Fabp4 is involved in the progression of ASH and that Fabp4 deficiency may ameliorate ASH. Therefore, FABP4 may be a potential therapeutic target for ASH treatment.

Periplaneta americana extract CII-3 triggers cell senescence through activating ROS-p38 MAPK-p53 signaling pathway in SKOV3 cells.

This study aimed to investigate effect of Periplaneta americana extract CII-3 (CII-3) in senescence of SKOV3 cells. Proliferation, colony forming and cell senescence of SKOV3 cells were determined. ROS production was evaluated by flow cytometry. Transcription of telomerase (TERT), p38 MAPK and p53 gene and protein expression of p-p38 MAPK and p-p53, were identified. CII-3 at different concentrations significantly inhibited SKOV3 proliferation, and 80 µg/ml demonstrated the highest inhibitory effect. CII-3 significantly blocked cell cycle in G0/G1 phase (P<0.01) and reduced colony forming efficiency (P<0.001) of SKOV3 cells compared to those in Control group. CII-3 significantly increased SA-ß-Gal positive staining SKOV3 cells (P<0.001) and reduced mitochondrial membrane potential (P<0.01) compared to those in Control group. CII-3 markedly decreased TERT gene transcription of SKOV3 cells compared to that in Control group (P<0.001). CII-3 also triggered significantly higher ROS levels in SKOV3 cells compared to that in Control group (P<0.001). CII-3 significantly increased p-p38 MAPK (P<0.001), p-p53 (P<0.001) and p21 (P<0.001) expressions of SKOV3 cells compared to those in Control group. In conclusion, CII-3 triggered cell senescence of SKOV3 cells through activating ROS-p38 MAPK-p53 signaling pathway. This study would provide a promising strategy for inhibiting cancer cell proliferation by including cell senescence.

Cucurbitacin B Inhibits the Proliferation of WPMY-1 Cells and HPRF Cells via the p53/MDM2 Axis.

Modern research has shown that Cucurbitacin B (Cu B) possesses various biological activities such as liver protection, anti-inflammatory, and anti-tumor effects. However, the majority of research has primarily concentrated on its hepatoprotective effects, with limited attention devoted to exploring its potential impact on the prostate. Our research indicates that Cu B effectively inhibits the proliferation of human prostate stromal cells (WPMY-1) and fibroblasts (HPRF), while triggering apoptosis in prostate cells. When treated with 100 nM Cu B, the apoptosis rates of WPMY-1 and HPRF cells reached 51.73 ± 5.38% and 26.83 ± 0.40%, respectively. In addition, the cell cycle assay showed that Cu B had a G2/M phase cycle arrest effect on WPMY-1 cells. Based on RNA-sequencing analysis, Cu B might inhibit prostate cell proliferation via the p53 signaling pathway. Subsequently, the related gene and protein expression levels were measured using quantitative real-time PCR (RT-qPCR), immunocytochemistry (ICC), and enzyme-linked immunosorbent assays (ELISA). Our results mirrored the regulation of tumor protein p53 (TP53), mouse double minute-2 (MDM2), cyclin D1 (CCND1), and thrombospondin 1 (THBS1) in Cu B-induced prostate cell apoptosis. Altogether, Cu B may inhibit prostate cell proliferation and correlate to the modulation of the p53/MDM2 signaling cascade.

Significance of P53-Binding Protein 1 as a Novel Molecular Histological Marker for Hypopharyngeal Squamous Neoplasms.

The DNA damage response protein p53-binding protein 1 (53BP1) accumulates and forms foci at double-strand DNA breaks, indicating the extent of DNA instability. However, the potential role of 53BP1 as a molecular biomarker for hypopharyngeal squamous cell carcinoma (HPSCC) diagnosis remains unknown. Here, we evaluated the potential of immunofluorescence-based analysis of 53BP1 expression to differentiate the histology of hypopharyngeal neoplasms. A total of 125 lesions from 39 surgically or endoscopically resected specimens from patients with HPSCC was histologically evaluated. 53BP1 expression in the nucleus was examined using immunofluorescence. The number of 53BP1 nuclear foci increased with the progression from non-tumorous to low-grade dysplasia, high-grade dysplasia, and squamous cell carcinoma. Unstable 53BP1 expression served as an independent factor for distinguishing lesions that required intervention. Colocalization of 53BP1 foci in proliferating cells, as assessed by Ki67, was increased in tumors ≥ 1000 µm in depth compared to those <1000 µm in depth at the tumor surface. Hence, the expression patterns of nuclear 53BP1 foci were associated with the progression of hypopharyngeal neoplasms. These findings suggest that 53BP1 could serve as an ancillary marker to support histological diagnosis and predict the factors that influence prognosis in patients with HPSCC.

TP53 Mutation-Mediated Immune Evasion in Cancer: Mechanisms and Therapeutic Implications.

Mutation in p53 is the most frequent event in cancer development and a leading cause of cancer therapy resistance due to evasion of the apoptosis cascade. Beyond chemotherapies and radiation therapies, growing evidence indicates that p53-mutant tumors are resistant to a broad range of immune-based therapies, such as immune checkpoint inhibitors, chimeric antigen receptor (CAR) T, and hematopoietic stem cell transplantation (HSCT). This highlights the role of p53 mutations in driving immune evasion of tumor cells. In this review, we first summarize recent studies revealing mechanisms by which p53-mutant tumors evade immune surveillance from T cells, natural killer (NK) cells, and macrophages. We then review how these mutant tumor cells reshape the tumor microenvironment (TME), modulating bystander cells such as macrophages, neutrophils, and regulatory T (Treg) cells to foster immunosuppression. Additionally, we review clinical observations indicative of immune evasion associated with p53 loss or mutations. Finally, we discuss therapeutic strategies to enhance immune response in p53 wild-type (WT) or mutant tumors.

Palmitic Acid Induces Oxidative Stress and Senescence in Human Brainstem Astrocytes, Downregulating Glutamate Reuptake Transporters-Implications for Obesity-Related Sympathoexcitation.

Obesity has been associated with a chronic increase in sympathetic nerve activity, which can lead to hypertension and other cardiovascular diseases. Preliminary studies from our lab found that oxidative stress and neuroinflammation in the brainstem contribute to sympathetic overactivity in high-fat-diet-induced obese mice. However, with glial cells emerging as significant contributors to various physiological processes, their role in causing these changes in obesity remains unknown. In this study, we wanted to determine the role of palmitic acid, a major form of saturated fatty acid in the high-fat diet, in regulating sympathetic outflow. Human brainstem astrocytes (HBAs) were used as a cell culture model since astrocytes are the most abundant glial cells and are more closely associated with the regulation of neurons and, hence, sympathetic nerve activity. In the current study, we hypothesized that palmitic acid-mediated oxidative stress induces senescence and downregulates glutamate reuptake transporters in HBAs. HBAs were treated with palmitic acid (25 µM for 24 h) in three separate experiments. After the treatment period, the cells were collected for gene expression and protein analysis. Our results showed that palmitic acid treatment led to a significant increase in the mRNA expression of oxidative stress markers (NQO1, SOD2, and CAT), cellular senescence markers (p21 and p53), SASP factors (TNFα, IL-6, MCP-1, and CXCL10), and a downregulation in the expression of glutamate reuptake transporters (EAAT1 and EAAT2) in the HBAs. Protein levels of Gamma H2AX, p16, and p21 were also significantly upregulated in the treatment group compared to the control. Our results showed that palmitic acid increased oxidative stress, DNA damage, cellular senescence, and SASP factors, and downregulated the expression of glutamate reuptake transporters in HBAs. These findings suggest the possibility of excitotoxicity in the neurons of the brainstem, sympathoexcitation, and increased risk for cardiovascular diseases in obesity.

Direct DNA binding by BRCA1 on ß-hCG promoter and its clinical implications.

Objective: The role of ß-hCG in breast cancer is largely unknown, this study aims to analyse the gene expression and clinical implications of ß-hCG and its isoforms in various cancers focussing particularly in Breast Invasive Carcinoma (BRCA). A mechanistic approach deciphering the transcriptional regulation of ß-hCG by BRCA1 was also explored. Methods: Data from various comprehensive gene expression platforms like UALCAN, GEPIA2, GENT2, TIMER2, LinkedOmics, and STRING were used to analyse the expression of ß-hCG and its clinical implications; Immunohistochemistry and ELISA for ß-hCG expression analysis from human breast cancer patients; Electrophoretic mobility shift assay (EMSA) to analyse the direct binding of BRCA1 on ß-hCG; Immunoblotting and Luciferase assay to understand the regulation of ß-hCG by p53 were performed. Results: Results from UALCAN and GENT2 gene expression cancer database revealed that TNBC subtypes and high-grade metaplastic carcinoma shows elevated expression of ß-hCG and infiltration of various immune cells were also identified in BRCA by TIMER2. It was observed that most of the isoforms of ß-hCG (CGB) are upregulated in breast cancers irrespective of hormonal status when BRCA1 gene is mutated according to TIMER2. Similar results were observed with Lymphoid neoplasm diffuse large B-cell lymphoma (LGG) and DLBC (Brain lower grade glioma) when BRCA1 is mutated. These results correlate with our earlier reports indicating expression of ß-hCG in BRCA1 defective condition. We have also identified direct binding of BRCA1 on ß-hCG promoter. Conclusion: All these findings demonstrate the importance of ß-hCG as a potential target in BRCA1-deficient carcinomas.