P53 Pathway Research Articles

Arsenic-induced downregulation of BRWD3 suppresses proliferation and induces apoptosis in lung adenocarcinoma cells through the p53 and p65 pathways.

Bromodomain and WD-repeat domain-containing protein 3 (BRWD3) exhibits high expression in lung adenocarcinoma (LUAD) tissues and cells; however, its function in arsenic-induced toxicological responses remains unclear. This study aimed to investigate BRWD3 expression in response to arsenic-induced conditions and its impact on the proliferation and apoptosis of LUAD cell line SPC-A1 upon BRWD3 knockdown. The results revealed a decrease in BRWD3 expression in SPC-A1 cells treated with sodium arsenite (NaAsO2), but not sodium arsenite's metabolites. BRWD3 knockdown suppressed cell proliferation and induced apoptosis in SPC-A1 cells. Western blot analysis revealed that BRWD3 knockdown resulted in the upregulation of p53, phospho-p53-Ser392, and its downstream factors including MDM2, Bak, and Bax. Additionally, we observed the downregulation of p65, phospho-p65-Ser276, phospho-p65-Ser536, and its downstream factors, including IκBα, BIRC3, XIAP and CIAP1. Moreover, polymerase chain reaction analysis showed that BRWD3 knockdown also resulted in the downregulation of proliferation-related genes and upregulation of apoptosis-related genes. In conclusion, BRWD3 mediated proliferation and apoptosis via the p53 and p65 pathways in response to arsenic exposure, suggesting potential implications for LUAD treatment through BRWD3 downregulation by arsenic.

Investigation on the signaling pathways in the mechanism of hyperoxia-induced acute lung injury based on transcriptomics sequencing

To observe and verify the changes of transcriptome in hyperoxia-induced acute lung injury (HALI), and to further clarify the changes of pathways in HALI. Twelve healthy male C57BL/6J mice were randomly divided into normoxia group and HALI group according to the random number table, with 6 mice in each group. The mice in the normoxia group were fed normally in the room, and the mice in the HALI group was exposed to 95% oxygen to reproduce the HALI animal model. After 72 hours of hyperoxia exposure, the lung tissues were taken for transcriptome sequencing, and then Kyoto Encyclopedia of Genes and Genomes database (KEGG) pathway enrichment analysis was performed. The pathological changes of lung tissue were observed under light microscope after hematoxylin-eosin (HE) staining. Real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to verify the key molecules in the signal pathways closely related to HALI identified by transcriptomics analysis. Transcriptomic analysis showed that hyperoxia induced 537 differentially expressed genes in lung tissue of mice as compared with the normoxia group including 239 up-regulated genes and 298 down-regulated genes. Further KEGG pathway enrichment analysis identified 20 most significantly enriched pathway entries, and the top three pathways were ferroptosis signaling pathway, p53 signaling pathway and glutathione (GSH) metabolism signaling pathway. The related genes in the ferroptosis signaling pathway included the up-regulated gene heme oxygenase-1 (HO-1) and the down-regulated gene solute carrier family 7 member 11 (SLC7A11). The related genes in the p53 signaling pathway included the up-regulated gene tumor suppressor gene p53 and the down-regulated gene murine double minute 2 (MDM2). The related gene in the GSH metabolic signaling pathway was up-regulated gene glutaredoxin 1 (Grx1). The light microscope showed that the pulmonary alveolar structure of the normoxia group was normal. In the HALI group, the pulmonary alveolar septum widened and thickened, and the alveolar cavity shrank or disappeared. RT-RCR and Western blotting confirmed that compared with the normoxia group, the mRNA and protein expressions of HO-1 and p53 in lung tissue of the HALI group were significantly increased [HO-1 mRNA (2-ΔΔCt): 2.16±0.17 vs. 1.00±0.00, HO-1 protein (HO-1/β-actin): 1.05±0.01 vs. 0.79±0.01, p53 mRNA (2-ΔΔCt): 2.52±0.13 vs. 1.00±0.00, p53 protein (p53/β-actin): 1.12±0.02 vs. 0.58±0.03, all P < 0.05], and the mRNA and protein expressions of Grx1, MDM2, SLC7A11 were significantly decreased [Grx1 mRNA (2-ΔΔCt): 0.53±0.05 vs. 1.00±0.00, Grx1 protein (Grx1/β-actin): 0.54±0.03 vs. 0.93±0.01, MDM2 mRNA (2-ΔΔCt): 0.48±0.03 vs. 1.00±0.00, MDM2 protein (MDM2/β-actin): 0.57±0.02 vs. 1.05±0.01, SLC7A11 mRNA (2-ΔΔCt): 0.50±0.06 vs. 1.00±0.00, SLC7A11 protein (SLC7A11/β-actin): 0.72±0.03 vs. 0.98±0.01, all P < 0.05]. HALI is closely related to ferroptosis, p53 and GSH metabolism signaling pathways. Targeting the key targets in ferroptosis, p53 and GSH metabolism signaling pathways may be an important strategy for the prevention and treatment of HALI.

Identification of Copper Homeostasis-Related Gene Signature for Predicting Prognosis in Patients with Epithelial Ovarian Cancer.

This research aims to establish a copper homeostasis-related gene signature for predicting the prognosis of epithelial ovarian cancer and to investigate its underlying mechanisms. We mainly constructed the copper homeostasis-related gene signature by LASSO regression analysis. Then multiple methods were used to evaluate the independent predictive ability of the model and explored the mechanisms. The 15-copper homeostasis-related gene (15-CHRG) signature was successfully established. Utilizing an optimal cut-off value of 0.35, we divided the training dataset into high-risk and low-risk subgroups. Kaplan-Meier analysis revealed that survival times for the high-risk subgroup were significantly shorter than those in the low-risk group (P < .05). Additionally, the Area Under the Curve (AUC) of the 15-CHRG signature achieved 0.822 at 1 year, 0.762 at 3 years, and 0.696 at 5 years in the training set. COX regression analysis confirmed the 15-CHRG signature as both accurate and independent. Gene set enrichment (GSEA), Kyoto Encyclopedia of Gene and Genome (KEGG) and Gene Ontology (GO) analysis showed that there were significant differences in apoptosis, p53 pathway, protein synthesis, hydrolase and transport-related pathways between high-risk group and low-risk group. In tumor immune cell (TIC) analysis, the increased expression of resting mast cells was positively correlated with the risk score. Consequently, the 15-CHRG signature shows significant potential as a method for accurately predicting clinical outcomes and treatment responses in patients with epithelial ovarian cancer.

MYBL2 is a Novel Independent Prognostic Biomarker and Correlated with TMB in pancreatic cancer.

Background: Pancreatic cancer continues to pose a significant threat due to its high mortality rate. While MYB family genes have been identified as oncogenes in certain cancer types, their role in pancreatic cancer remains largely unexplored. Methods: The mRNA and protein expression of MYB family genes in pancreatic cancer samples was analyzed using TNMplot, HPA, and TISBID online bioinformatics tools, sourced from the TCGA and GETx databases. The relationship between MYB family gene expression and survival time was assessed through Kaplan-Meier analysis, while the prognostic impact of MYB family gene expression was evaluated using the Cox proportional hazards model. Additionally, Spearman's correlation analysis was employed to investigate the correlation between MYB family genes and TMB/MSI. Results: The integration of data from various databases demonstrated that all MYB family genes exhibited dysregulated expression in pancreatic cancer. However, only the expression of the MYBL2 gene displayed a notable association with the grade and stage of pancreatic cancer. Furthermore, the MYBL2 gene exhibited significant variations in both univariate and multivariate factor analyses.Subsequent functional analyses revealed a significant correlation between MYBL2 expression in pancreatic cancers and various biological processes, such as DNA replication, tumor proliferation, G2M checkpoint regulation, pyrimidine metabolism, and the P53 pathway. Additionally, a notable positive association was observed between MYBL2 expression and tumor mutational burden (TMB), a predictive indicator for response to PD1 antibody treatment. Conclusion: MYBL2 may be a double marker for independent diagnosis and PD1 antibody response prediction of pancreatic cancer patients.

Metochalcone induces senescence-associated secretory phenotype via JAK2/STAT3 pathway in breast cancer.

Breast and lung cancers are the leading causes of mortality and most frequently diagnosed cancers in women and men, respectively, worldwide. Although the antitumor activity of chalcones has been extensively studied, the molecular mechanisms of isoliquiritigenin analog 2', 4', 4-trihydroxychalcone (metochalcone; TEC) against carcinomas remain less well understood. In this study, we found that TEC inhibited cell proliferation of breast cancer BT549 cells and lung cancer A549 cells in a concentration-dependent manner. TEC induced cell cycle arrest in the S-phase, cell migration inhibition in vitro, and reduced tumor growth in vivo. Moreover, transcriptomic analysis revealed that TEC modulated the activity of the JAK2/STAT3 and P53 pathways. TEC triggered the senescence-associated secretory phenotype (SASP) by repressing the JAK2/STAT3 axis. The mechanism of metochalcone against breast cancer depended on the induction of SASP via deactivation of the JAK2/STAT3 pathway, highlighting the potential of chalcone in senescence-inducing therapy against carcinomas.

METTL14-Mediated m6a Modification of CDKN2A Promotes the Development of Retinoblastoma by Inhibiting the p53 Pathway.

The methyltransferase 14, N6-adenosine-methyltransferase subunit (METTL14) and Cyclin-dependent kinase inhibitor 2A (CDKN2A) have been identified as involved in the regulation of various cancer progression, while their mechanism and regulatory effect in retinoblastoma (RB) is still unclear. Cell colony formation, CCK-8 as well as Western blotting were used to evaluate the proliferation, apoptosis as well as p53 protein level of RB cell line. The METTL14 and CDKN2A levels were detected by qRT-PCR or Western blotting when METTL14 was up-regulated or CDKN2A was down-regulated. MeRIP and Pearson analysis were performed to confirm the regulatory relationship between METTL14 among CDKN2A. We found that the levels of CDKN2A and METTL14 were abundant in RB samples, as well as RB cells. METTL14 enhances N6-methyladenosine (m6A) modification of CDKN2A to upregulate its mRNA and protein levels. The proliferation of RB cells can be inhibited by silencing CDKN2A, which promotes apoptosis and p53 protein level. Furthermore, high-expression of METTL14 eliminated the anti-tumor effect of CDKN2A silencing in RB progression in vitro. CDKN2A is mediated by METTL14-m6A modified and restrains p53 pathway activation to accelerate the malignancy of RB. This points to the METTL14-m6A-CDKN2A-p53 pathway axis as a possible prospective target for the future RB treatment.

Apolipoprotein L3 inhibits breast cancer proliferation and modulates cell cycle via the P53 pathway.

Background: Breast cancer is the second most common cause of cancer-related mortality globally. Apolipoprotein L3 (APOL3), a member of the apolipoprotein family, has been implicated in the pathogenesis of cardiovascular diseases. Nevertheless, the functions and underlying mechanisms of APOL3 in breast cancer have yet to be elucidated. Methods: The patient data were sourced from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. Quantitative real-time PCR (qRT-PCR), western blotting, and immunohistochemistry (IHC) assays were used to assess expression of APOL3. Cell proliferation rates were determined by Cell Counting Kit-8 (CCK-8) and colony formation assays. Flow cytometry was used to examine cell cycle distribution. Western blotting was conducted to investigate the expression of cell cycle related proteins. A xenograft model was used to evaluate the effect of APOL3 in vivo. APOL3-binding proteins were identified through mass spectrometry, co-immunoprecipitation (CO-IP) assay and immunofluorescence assay. Results: APOL3 expression was significantly downregulated in breast cancer, and its low expression was correlated with poor prognostic outcomes. Overexpression of APOL3 suppressed breast cancer cell proliferation, induced cell cycle disruption. Conversely, knockdown of APOL3 promoted cell proliferation. In vivo animal experiments demonstrated that APOL3 overexpression can inhibit tumor proliferation. Mass spectrometry, CO-IP and immunofluorescence assay confirmed the interaction between APOL3 and Y-box binding protein 1 (YBX1). Furthermore, YBX1 knockdown following APOL3 knockdown mitigated the enhanced proliferation. These results provide new ideas for clinically targeting APOL3 to inhibit proliferation in breast cancer. Conclusions: Our findings indicate that APOL3 inhibits breast cancer cell proliferation and cell cycle modulating P53 pathway through the interaction of YBX1.

Bioassay-guided isolation of two antiproliferative metabolites from Pterocarpus indicus Willd. against TGF-β-induced prostate stromal cells (WPMY-1) proliferation via PI3K/AKT signaling pathway.

Benign prostatic hyperplasia (BPH) is the enlargement of the prostate gland, primarily occurring in aging men, in which transforming growth factor-beta (TGF-β) plays a critical role in prostate cell hyperproliferation and leads to uncomfortable urinary symptoms in BPH patients. Pterocarpus indicus Willd. is well known for its ethnopharmacological applications for treating ailments such as diuresis and bladder stones. This study aimed to examine the effect of P. indicus extract (PI extract) on TGF-β-induced WPMY-1 cell proliferation, followed by bioassay-guided fractionation to isolate the active metabolites. Angolensin (Ang) and maackiain (Mac) were isolated from bioassay-guided fractionation. Network analysis was performed to investigate the potential mechanisms. Furthermore, network analysis of the Ang-Mac combination in BPH highlighted the potential top ten pathways, including PI3K/AKT signaling pathway. Accordingly, subsequent investigation focused on evaluating the effect of PI extract, Ang, Mac, and Ang-Mac combination on the expression of PCNA, p53, and PI3K/AKT protein localization and expression. Results revealed inhibition of cell proliferation in TGF-β-induced WPMY-1 cells, correlating with downregulated PCNA expression. While PI extract and Mac induced apoptosis via p53 upregulation, Ang and Ang-Mac combination did not significantly affect apoptosis through the p53 pathway. Additionally, both metabolites exhibited potent inhibition of p-PI3K and p-AKT protein localization and expression in the nucleus of TGF-β-induced WPMY-1 cells. This study suggests that PI extract, Ang, and Mac are promising compounds for treating BPH, as evidenced by in silico and in vitro studies. Additionally, Ang and Mac could be used to standardize PI extract in future investigations.

TGF-β Mediates the Role of P53 and microRNA-Related Signaling Pathways in the Pathogenesis of Diabetic Nephropathy in Rats

TGF-β Mediates the Role of P53 and microRNA-Related Signaling Pathways in the Pathogenesis of Diabetic Nephropathy in Rats

Bladder Cancer Patients with Elevated SPRR1B Expression Experiencing a Poor Prognosis.

SPRR1B, a member of the small proline-rich protein family, is implicated in various epithelial cancers as a potential oncogene linked to tumour growth and poor survival outcomes. However, its role in urothelial bladder carcinoma (UBC) remains to be fully elucidated. Transcriptional profiling data from The Cancer Genome Atlas grouped UBC samples in accordance with SPRR1B expression. Bioinformatic analysis was conducted to evaluate whether SPRR1B is a prognostic factor and a survival factor in UBC. Gene set enrichment analysis (GSEA) was performed to study immune cells and pathways. Reverse transcription quantitative real-time polymerase chain reaction detected gene expression. Immunohistochemistry assessed protein expression. Spearman correlation test analysed the correlation between SPRR1B and the protein p53. The bioinformatics results indicated that the expression level of SPRR1B in UBC tissues was significantly increased compared with that in normal bladder tissues, correlating with clinical characteristics. A high expression predicted poor prognosis and survival. Univariate Cox statistics showed that a high expression level of SPRR1B was correlated with UBC patients having poor overall survival (OS) (p < 0.05). In addition, on the basis of the multivariate Cox analysis, SPRR1B expression was independently correlated with OS (p = 0.005). GSEA analysis revealed enrichment in the p53, apoptosis, and cell cycle signalling pathways, and an association with B cells, lymphocytes, and natural killer cells. In addition, SPRR1B was found to be associated with immune infiltration based on the analysis of immune cell infiltration. Performing corresponding verification on a small number of tissues collected from bladder cancer patients revealed that the expression of this protein was negatively correlated with the expression of p53. SPRR1B overexpression predicts poor UBC outcomes, suggesting its role as a prognostic marker and therapeutic target. Further research is necessary to elucidate its role in UBC progression.

Inhibiting H2AX Can Ameliorate Myocardial Ischemia/Reperfusion Injury by Regulating P53/JNK Signaling Pathway.

Myocardial ischemia-reperfusion (I/R) injury is a significant area of focus in cardiovascular disease research. I/R injury can increase intracellular oxidative stress, leading to DNA damage. H2AX plays a crucial role in DNA repair. This study utilized mouse and cell models of myocardial I/R to investigate the impact of H2AX on cardiomyocytes during I/R. This study initially assessed the expression of H2AX in MI/R mice compared to a sham surgery group. Subsequently, cardiac function, infarct area, and mitochondrial damage were evaluated after inhibiting H2AX in MI/R mice and a negative control group. Furthermore, the study delved into the molecular mechanisms by analyzing the expression of H2AX, P53, p-JNK, SHP2, p-SHP2, p-RAS, parkin, Drp1, Cyt-C, Caspase-3, and Caspase-8 in cardiomyocytes following the addition of JNK or P53 agonists. The results from western blotting in vivo indicated significantly higher H2AX expression in the MI/R group compared to the sham group. Inhibiting H2AX improved cardiac function, reduced myocardial infarct area, and mitigated mitochondrial damage in the MI/R group. In vitro experiments demonstrated that inhibiting H2AX could attenuate mitochondrial damage and apoptosis in myocardial cells by modulating the P53 and JNK signaling pathways. These findings suggested that inhibiting H2AX may alleviate myocardial I/R injury through the regulation of the P53/JNK pathway, highlighting H2AX as a potential target for the treatment of myocardial ischemia/reperfusion injury.

Evaluation of GATA3 and p53 Expression in Urothelial Carcinoma and their Association with Clinicopathological Parameters: A Cross-sectional Study

Introduction: Bladder cancer is the tenth most common cancer worldwide, with 90% of bladder cancers are Urothelial Carcinoma (UC). In India, its incidence is 1.6 per lakh population annually. GATA3 is a recently used immunohistochemical marker which is highly sensitive for UC. Alterations in the p53 pathway play an important role in tumour progression and the assessment of prognosis. Aim: To study the expression of GATA3 and p53 in UC and their association with clinicopathological parameters. Materials and Methods: An ambispective cross-sectional study was conducted in the Department of Pathology, Kalinga Institute of Medical Sciences, Bhubaneswar, Odisha, India, from September 2020 to August 2022. A total of 50 cases of histologically proven UC were subjected to immunohistochemistry with GATA3 and p53. The expression of GATA3 and p53 was evaluated in UC, and their association with clinicopathological parameters like age, gender, personal habits, tumour site, symptoms and signs, histological grade, and invasion into lamina propria and muscle was studied. The Chi-square test was used to determine the relationship between all parameters, with a p-value &lt;0.05 considered statistically significant. Results were analysed by standard software (Stata version 23.1). Results: GATA3 expression was observed in 94% (47/50) of cases of UC. GATA3 expression was associated with histological grade and muscle invasion, with 66.7% (4/6) expression in high-grade muscle-invasive UC, compared to 91.30% (21/23) in non muscle invasive UC, and 100% (21/21) in low-grade UC. Additionally, 66.7% (14/21) of low-grade UC showed p53 expression, whereas 80% (24/30) of high-grade UC demonstrated p53 expression. Conclusion: GATA3 is a sensitive and specific marker for UC. Its expression is highly variable among different histological types of UC and decreases with increasing grade of tumour in the study. p53 expression was associated with the histological grade of the tumour and was statistically significant in this study. GATA3 can be utilised to predict the probable grade of the tumour and its behaviour by correlating it with p53.

A Machine Learning Method for a Blood Diagnostic Model of Pancreatic Cancer Based on microRNA Signatures.

This study aimed to construct a blood diagnostic model for pancreatic cancer (PC) using miRNA signatures by a combination of machine learning and biological experimental verification. Gene expression profiles of patients with PC and transcriptome normalization data were obtained from the Gene Expression Omnibus (GEO) database. Using random forest algorithm, lasso regression algorithm, and multivariate cox regression analyses, the classifier of differentially expressed miRNAs was identified based on algorithms and functional properties. Next, the ROC curve analysis was used to evaluate the predictive performance of the diagnostic model. Finally, we analyzed the expression of two specific miRNAs in Capan-1, PANC-1, and MIA PaCa-2 pancreatic cells using qRT-PCR. Integrated microarray analysis revealed that 33 common miRNAs exhibited significant differences in expression profiles between tumor and normal groups (P value < 0.05 and |logFC| > 0.3). Pathway analysis showed that differentially expressed miRNAs were related to P00059 p53 pathway, hsa04062 chemokine signaling pathway, and cancer-related pathways including PC. In ENCORI database, the hsa-miR-4486 and hsa-miR-6075 were identified by random forest algorithm and lasso regression algorithm and introduced as major miRNA markers in PC diagnosis. Further, the receiver operating characteristic curve analysis achieved the area under curve score > 80%, showing good sensitivity and specificity of the two-miRNA signature model in PC diagnosis. Additionally, hsa-miR-4486 and hsa-miR-6075 genes expressions in three pancreatic cells were all up-regulated by qRT-PCR. In summary, these findings suggest that the two miRNAs, hsa-miR-4486 and hsa-miR-6075, could serve as valuable prognostic markers for PC.

Selenium deficiency exacerbated Bisphenol A-induced intestinal toxicity in chickens: Apoptosis and cell cycle arrest mediated by ROS/P53

Bisphenol A (BPA) is a phenolic organic synthetic compound that is used as the raw material of polycarbonate plastics, and its safety issues have recently attracted wide attention. Selenium (Se) deficiency has gradually developed into a global disease affecting intestinal function via oxidative stress and apoptosis. However, the toxic effects and potential mechanisms of BPA exposure and Se deficiency in the chicken intestines have not been studied. In this study, BPA exposure and/or Se deficiency models were established in vivo and in vitro to investigate the effects of Se deficiency and BPA on chicken jejunum. The results showed that BPA exposure and/or Se deficiency increased jejunum oxidative stress and DNA damage, activated P53 pathway, led to mitochondrial dysfunction, and induced apoptosis and cell cycle arrest. Using protein-protein molecular docking, we found a strong binding ability between P53 and peroxisome proliferator-activated receptor γ coactivator-1, thereby regulating mitochondrial dysfunctional apoptosis. In addition, we used N-acetyl-L-cysteine and pifithrin-α for in vitro intervention and found that N-acetyl-L-cysteine and pifithrin-α intervention reversed the aforementioned adverse effects. This study clarified the potential mechanism by which Se deficiency exacerbates BPA induced intestinal injury in chickens through reactive oxygen species/P53, which provides a new idea for the study of environmental combined toxicity of Se deficiency, and insights into animal intestinal health from a new perspective.

Tubuloside A Induces DNA Damage and Apoptosis in Human Ovarian Cancer A2780 Cells

Objective: Ovarian carcinoma is one of the most lethal gynecological cancers, as it responds later to diagnostic methods and therapeutic responses in advanced stages. Many phytochemical compounds have been shown to be protective against cancer. Tubuloside A (TbA) is the main compound extracted from the plant Cistanche tubulosa, and its pharmacological effects have been studied broadly. Until now, the role of TbA in human ovarian carcinoma is unknown. The goal of this study was to evaluate the effects of TbA on DNA damage and apoptosis in A2780 cell lines. Methods: Different concentrations of TbA (1, 5, 25, 50, and 100 µM) and 5- Fluorouracil (1, 5, 25, 50, and 100 µM) treated to the human ovarian cancer cell (A2780) line for 24 h. After incubation, cell viability (MTT), genotoxicity (Comet analyses), and mRNA expression analyses of apoptotic markers (Caspase-3, Bax, Bcl-2, and p53) were determined. Results: Applied doses of 50 and 100 µM of TbA and 5- Fluorouracil significantly reduced cell viability. Also, TbA increased DNA damage in A2780 cells. Additionally, TbA up-regulated the mRNA expressions of caspase-3, Bax, and p53, which are apoptosis-inducing factors, and down-regulated the expression of Bcl-2. Conclusion: These results show that the p53 and caspase-3 signaling pathways may exhibit a key role in TbA-associated effects on A2780 cells and TbA may be a potential drug aspirant for ovarian cancer therapy.

CEP-1347 Dually Targets MDM4 and PKC to Activate p53 and Inhibit the Growth of Uveal Melanoma Cells.

Uveal melanoma (UM) is among the most common primary intraocular neoplasms in adults, with limited therapeutic options for advanced/metastatic disease. Since UM is characterized by infrequent p53 mutation coupled with the overexpression of MDM4, a major negative regulator of p53, we aimed to investigate in this study the effects on UM cells of CEP-1347, a novel MDM4 inhibitor with a known safety profile in humans. We also examined the impact of CEP-1347 on the protein kinase C (PKC) pathway, known to play a pivotal role in UM cell growth. High-grade UM cell lines were used to analyze the effects of genetic and pharmacological inhibition of MDM4 and PKC, respectively, as well as those of CEP-1347 treatment, on p53 expression and cell viability. The results showed that, at its clinically relevant concentrations, CEP-1347 reduced not only MDM4 expression but also PKC activity, activated the p53 pathway, and effectively inhibited the growth of UM cells. Importantly, whereas inhibition of either MDM4 expression or PKC activity alone failed to efficiently activate p53 and inhibit cell growth, inhibition of both resulted in effective activation of p53 and inhibition of cell growth. These data suggest that there exists a hitherto unrecognized interaction between MDM4 and PKC to inactivate the p53-dependent growth control in UM cells. CEP-1347, which dually targets MDM4 and PKC, could therefore be a promising therapeutic candidate in the treatment of UM.

Selenium promotes immunogenic radiotherapy against cervical cancer metastasis through evoking P53 activation

Radiotherapy is still the recommended treatment for cervical cancer. However, radioresistance and radiation-induced side effects remain one of the biggest clinical problems. Selenium (Se) has been confirmed to exhibit radiation-enhancing effects for cancer treatment. However, Se species dominate the biological activities and which form of Se possesses better radiosensitizing properties and radiation safety remains elusive. Here, different Se species (the valence state of Se ranged from - 2, 0, +4 to + 6) synergy screen was carried out to identify the potential radiosensitizing effects and radiation safety of Se against cervical cancer. We found that the therapeutic effects varied with the changes in the Se valence state. Sodium selenite (+4) displayed strong cancer-killing effects but also possessed severe cytotoxicity. Sodium selenate (+6) neither enhanced the killing effects of X-ray nor possessed anticancer activity by its alone treatment. Although nano-selenium (0), especially Let-SeNPs, has better radiosensitizing activity, the - 2 organic Se, such as selenadiazole derivative SeD (-2) exhibited more potent anticancer effects and possessed a higher safe index. Overall, the selected Se drugs were able to synergize with X-ray to inhibit cell growth, clone formation, and cell migration by triggering G2/M phase arrest and apoptosis, and SeD (-2) was found to exhibit more potent enhancing capacity. Further mechanism studies showed that SeD mediated p53 pathway activation by inducing DNA damage through promoting ROS production. Additionally, SeD combined with X-ray therapy can induce an anti-tumor immune response in vivo. More importantly, SeD combined with X-ray significantly inhibited the liver metastasis of tumor cells and alleviated the side effects caused by radiation therapy in tumor-bearing mice. Taken together, this study demonstrates the radiosensitization and radiation safety effects of different Se species, which may shed light on the application of such Se-containing drugs serving as side effects-reducing agents for cervical cancer radiation treatment.

Exposure to fluoride exacerbates the cognitive deficit of diabetic patients living in areas with endemic fluorosis, as well as of rats with type 2 diabetes induced by streptozotocin via a mechanism that may involve excessive activation of the poly(ADP ribose) polymerase-1/P53 pathway

Epidemiology has shown that fluoride exposure is associated with the occurrence of diabetes. However, whether fluoride affects diabetic encephalopathy is unclear. Elderly diabetic patients in areas with endemic (n = 169) or no fluorosis (108) and controls (85) underwent Montreal Cognitive Assessment. Sprague-Dawley rats receiving streptozotocin and/or different fluoride doses were examined for spatial learning and memory, brain morphology, blood-brain barrier, fasting blood glucose and insulin. Cultured SH-SY5Y cells were treated with 50 mM glucose and/or low- or high-dose fluoride, and P53-knockdown or poly-ADP-ribose polymerase-1 (PARP-1) inhibition. The levels of PARP-1, P53, poly-ADP-ribose (PAR), apoptosis-inducing factor (AIF), and phosphorylated-histone H2A.X (ser139) were measured by Western blotting. Reactive oxygen species (ROS), 8-hydroxydeguanosine (8-OHdG), PARP-1 activity, acetyl-P53, nicotinamide adenine dinucleotide (NAD+), activities of mitochondrial hexokinase1 (HK1) and citrate synthase (CS), mitochondrial membrane potential and apoptosis were assessed biochemically. Cognition of diabetic patients in endemic fluorosis areas was poorer than in other regions. In diabetic rats, fasting blood glucose, insulin resistance and blood-brain barrier permeability were elevated, while spatial learning and memory and Nissl body numbers in neurons declined. In these animals, expression and activity of P53 and PARP-1 and levels of NAD+, PAR, ROS, 8-OHdG, p-histone H2A.X (ser139), AIF and apoptosis content increased; whereas mitochondrial HK1 and CS activities and membrane potential decreased. SH-SY5Y cells exposed to glucose exhibited changes identical to diabetic rats. The changes in diabetic rats and cells treated with glucose were aggravated by fluoride. P53-knockout or PARP-1 inhibition mitigated the effects of glucose with/without low-dose fluoride. Elevation of diabetic encephalopathy was induced by exposure to fluoride and the underlying mechanism may involve overactivation of the PARP-1/P53 pathway.

Denticleless E3 ubiquitin protein ligase (DTL) maintains the proliferation and differentiation of epidermis and hair follicles during skin development.

A precise balance between the proliferation and differentiation of epidermal progenitors is required to achieve the barrier function during the development of epidermis. During the entire process of skin development, the newly formed basal layer cells divide, differentiate, and migrate outward to the surface of the skin, which is tightly regulated by a series of events related to cell cycle progression. The CRL4DTL complex (Cullin 4 RING ligase, in association with the substrate receptor DTL) has long emerged as a master regulator in various cellular processes, which mediates the degradation of key cell cycle proteins. However, the roles of DTL in regulating epidermal morphogenesis during skin development remain unclear. We showed that DTL deficiency in epidermal progenitor cells leads to defects in epidermal stratification and loss of hair follicles accompanied by reduced epidermal progenitor cells and disturbed cell cycle progression during skin development. Transcriptome analysis revealed that p53 pathway is activated in DTL-depleted epidermal progenitor cells. The apoptosis of epidermal cells showed in DTL deficiency mice is rescued by the absence of p53, but the proliferation and differentiation defects were p53-independent. Our findings indicate that DTL plays a vital role in epidermal malformation during skin development.

Aspirin boosts the synergistic effect of EGFR/p53 inhibitors on lung cancer cells by regulating AKT/mTOR and p53 pathways.

The regimen of afatinib and vinorelbine has been used to treat breast or lung cancer cells with some limitations. Aspirin alone or in combination with other agents has shown unique efficacy in the treatment of cancer. We designed a preclinical study to investigate whether the triple therapy of aspirin, afatinib, and vinorelbine could synergistically inhibit the growth of p53 wild-type nonsmall cell lung cancer (NSCLC) cells. Three NSCLC cells A549, H460, and H1975 were selected to study the effect of triple therapy on cell proliferation and apoptosis. Compared to single agents, triple therapy synergistically inhibited the proliferation of lung cancer cells with combination index <1. Meanwhile, the therapeutic indexof triple therapy was superior to that of single agents, indicating a balance between efficacy and safety in the combination of three agents. Mechanistic studies showed that triple therapy significantly induced apoptosis by decreasing mitochondrial membrane potential, increasing reactive oxygen species, and regulating mitochondria-related proteins. Moreover, epidermal growth factor receptor(EGFR) downstream signaling proteins including JNK, AKT, and mTOR were dramatically suppressed and p53 was substantially increased after NSCLC cells were exposed to the triple therapy. We provided evidence that the triple therapy of aspirin, afatinib and vinorelbine synergistically inhibited lung cancer cell growth through inactivation of the EGFR/AKT/mTOR pathway and accumulation of p53, providing a new treatment strategy for patients with p53 wild-type NSCLC.