Iron metabolism is a critical factor in tumorigenesis and development. Although TP53 mutations are prevalent in glioblastoma (GBM), the mechanisms by which TP53 regulates iron metabolism remain elusive. We reveal an imbalance iron homeostasis in GBM via TCGA database analysis. TP53 mutations disrupted iron homeostasis in GBM, characterized by elevated total iron levels and reduced ferritin (FTH). The gain-of-function effect triggered by TP53 mutations upregulates itchy E3 ubiquitin-protein ligase (ITCH) protein expression in astrocytes, leading to FTH degradation and an increase in free iron levels. TP53-mut astrocytes were more tolerant to the high iron environment induced by exogenous ferric ammonium citrate (FAC), but the increase in intracellular free iron made them more sensitive to Erastin-induced ferroptosis. Interestingly, we found that Erastin combined with FAC treatment significantly increased ferroptosis. These findings provide new insights for drug development and therapeutic modalities for GBM patients with TP53 mutations from iron metabolism perspectives.
Ferroptosis/drug effects* ; Humans ; Iron/metabolism* ; Glioblastoma/metabolism* ; Tumor Suppressor Protein p53/metabolism* ; Homeostasis/physiology* ; Ferritins/metabolism* ; Brain Neoplasms/genetics* ; Mutation ; Astrocytes/drug effects* ; Cell Line, Tumor ; Piperazines/pharmacology* ; Quaternary Ammonium Compounds/pharmacology* ; Ferric Compounds

This paper aimed to investigate the role and potential mechanism of p53 on primordial follicle activation. Firstly, the p53 mRNA expression in the ovary of neonatal mice at 3, 5, 7 and 9 days post-partum (dpp) and the subcellular localization of p53 were detected to confirm the expression pattern of p53. Secondly, 2 dpp and 3 dpp ovaries were cultured with p53 inhibitor Pifithrin-μ (PFT-μ, 5 μmol/L) or equal volume of dimethyl sulfoxide for 3 days. The function of p53 in primordial follicle activation was determined by hematoxylin staining and whole ovary follicle counting. The proliferation of cell was detected by immunohistochemistry. The relative mRNA levels and protein levels of the key molecules involved in the classical pathways associated with the growing follicles were examined by immunofluorescence staining, Western blot and real-time PCR, respectively. Finally, rapamycin (RAP) was used to intervene the mTOR signaling pathway, and ovaries were divided into four groups: Control, RAP (1 μmol/L), PFT-μ (5 μmol/L), PFT-μ (5 μmol/L) + RAP (1 μmol/L) groups. The number of follicles in each group was determined by hematoxylin staining and whole ovary follicle counting. The results showed that the expression of p53 mRNA was decreased with the activation of primordial follicles in physiological condition. p53 was expressed in granulosa cells and oocyte cytoplasm of the primordial follicles and growing follicles, and the expression of p53 in the primordial follicles was higher than that in the growing follicles. Inhibition of p53 promoted follicle activation and reduced the primordial follicle reserve. Inhibition of p53 promoted the proliferation of the granulosa cells and oocytes. The mRNA and protein expression levels of key molecules in the PI3K/AKT signaling pathway including AKT, PTEN, and FOXO3a were not significantly changed after PFT-μ treatment, while the expression of RPS6/p-RPS6, the downstream effectors of the mTOR signaling pathway, was upregulated. Inhibition of both p53 and mTOR blocked p53 inhibition-induced primordial follicle activation. Collectively, these findings suggest that p53 may inhibit primordial follicle activation through the mTOR signaling pathway to maintain the primordial follicle reserve.
Female ; Animals ; Mice ; Tumor Suppressor Protein p53/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Hematoxylin ; Signal Transduction/physiology* ; TOR Serine-Threonine Kinases ; Sirolimus ; RNA, Messenger

BACKGROUND: Serum antinuclear antibodies (ANAs) are positive in some patients with chronic lymphocytic leukemia (CLL), but the prognostic value of ANAs remains unknown. The aim of this study was to evaluate the role of ANAs as a prognostic factor in CLL. METHODS: This study retrospectively analyzed clinical data from 216 newly diagnosed CLL subjects with ANAs test from 2007 to 2017. Multivariate Cox regression analyses were used to screen the independent prognostic factors related to time to first treatment (TTFT), progression free survival (PFS) and overall survival (OS). Receiver operator characteristic curves and area under the curve (AUC) were utilized to assess the predictive accuracy of ANAs together with other independent factors for OS. RESULTS: The incidence of ANAs abnormality at diagnosis was 13.9%. ANAs positivity and TP53 disruption were independent prognostic indicators for OS. The AUC of positive ANAs together with TP53 disruption was 0.766 (95% confidence interval [CI]: 0.697-0.826), which was significantly larger than that of either TP53 disruption (AUC: 0.706, 95% CI: 0.634-0.772, P = 0.034) or positive ANAs (AUC: 0.595, 95% CI: 0.520-0.668, P < 0.001) in OS prediction. Besides, serum positive ANAs as one additional parameter to CLL-international prognostic index (IPI) obtained superior AUCs in predicting CLL OS than CLL-IPI alone. CONCLUSION This study identified ANAs as an independent prognostic factor for CLL, and further investigations are needed to validate this finding.
ADP-ribosyl Cyclase 1 ; blood ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antibodies, Antinuclear ; blood ; Autoimmunity ; physiology ; Female ; Humans ; Kaplan-Meier Estimate ; Leukemia, Lymphocytic, Chronic, B-Cell ; blood ; mortality ; Male ; Middle Aged ; Multivariate Analysis ; Mutation ; genetics ; Proportional Hazards Models ; Retrospective Studies ; Survival Analysis ; Tumor Suppressor Protein p53 ; blood ; Young Adult ; ZAP-70 Protein-Tyrosine Kinase ; blood

OBJECTIVE: To explore the protective effect and apoptosis-related mechanism of electroacupuncture (EA) preconditioning in the rats with cerebral ischemia-reperfusion injury. METHODS: Sixty male SD rats, 3 months old, at SPF grade were randomized into a sham-operation group, an ischemia-reperfusion group and an EA preconditioning group, 20 rats in each one. In the ischemia-reperfusion group and EA preconditioning group, the modified MCAO suture-occlusion method was adopted to exert ischemia for 2 h and reperfusion for 3 h, and thus, the models of focal cerebral ischemia-reperfusion injury were prepared on the right side. In the sham-operation group, the right common carotid artery was separated and no more management was given. In the EA preconditioning group, EA at "Baihui" (GV 20), "Shenshu" (BL 23) and "Sanyinjiao" (SP 6) was provided before modeling, with disperse-dense wave, at 2 Hz/100 Hz, 1 mA in intensity. The stimulation for 15 min was taken as one unit (meaning electric stimulation for 10 min and needle retaining for 5 min without electric stimulation). Such preconditioning was repeated continuously for 4 times, totally for 1 h. The neuroethologic condition was assessed in 3 h of reperfusion in each group. TTC staining method was used to determine the percentage of cerebral infarction zone, TUNEL method was to determine the apoptosis index (AI) in hippocampal neuron and the immunohistochemical method (IHC) was to determine the protein expression of p53 and caspase-3. RESULTS: Compared with the sham-operation group, the neuroethologic score, the percentage of cerebral infarction zone and neuronal AI were all increased obviously in the ischemia-reperfusion group (all <0.01). Compared with the ischemia-reperfusion group, the neuroethologic score, the percentage of cerebral infarction zone and neuronal AI were all reduced obviously in the EA preconditioning group (all <0.01). p53's nuclei and caspase-3's cytoplasms were stained. The positive cells of both of them were brown-yellow in color. In the sham-operation group, the structure of the right hippocampal CA3 neurons of rats was clear, with few positive cells. In the ischemia-perfusion group, the positive expressions of p53 and caspase-3 in the right hippocampal CA3 were increased obviously (<0.01). Compared with the ischemia-reperfusion group, the positive expressions of caspase-3 and p53 in the right hippocampal CA3 were significantly reduced in the EA preconditioning group (<0.01). CONCLUSION Electroacupuncture preconditioning relieves ischemic injury in brain tissue of rats probably through inhibiting the expressions of p53 and caspase-3 to resisting neuronal apoptosis.
Acupuncture Points ; Animals ; Brain Ischemia ; Caspase 3 ; physiology ; Electroacupuncture ; Hippocampus ; Humans ; Male ; Neurons ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; Tumor Suppressor Protein p53 ; physiology

DNA double-stranded break (DSB) is one of the most catastrophic damages of genotoxic insult. Inappropriate repair of DNA DSBs results in the loss of genetic information, mutation, and the generation of harmful genomic rearrangements, which predisposes an organism to immunodeficiency, neurological damage, and cancer. The tumor repressor p53 plays a key role in DNA damage response, and has been found to be mutated in 50% of human cancer. p53, p63, and p73 are three members of the p53 gene family. Recent discoveries have shown that human p53 gene encodes at least 12 isoforms. Different p53 members and isoforms play various roles in orchestrating DNA damage response to maintain genomic integrity. This review briefly explores the functions of p53 and its isoforms in DNA DSB repair.
Animals ; DNA Breaks, Double-Stranded ; DNA Repair ; Humans ; Mice ; Protein Isoforms ; physiology ; Tumor Protein p73 ; physiology ; Tumor Suppressor Protein p53 ; genetics ; physiology

OBJECTIVETo investigate the effect of oridonin on the human acute lymphocytic leukemia cell line Jurkat and its mechanism.

METHODSJurkat cells were cultured in vitro and treated with various concentrations (0, 1.25, 2.5, 5, and 10 μmol/L) of oridonin for different lengths of time (24, 48, and 72 hours). The proliferation of Jurkat cells was analyzed by MTT assay. The changes in nuclear morphology were evaluated by fluorescence microscopy at 12 hours after treatment with various concentrations of oridonin. The expression levels of Brg1, P53, and C-myc were determined by semi-quantitative Western blot in Jurkat cells treated with various concentrations of oridonin for 24 hours or 5 μmol/L oridonin for various lengths of time (0, 2, 6, 12, and 24 hours). The expression levels of P53 and C-myc and proliferation of Jurkat cells were evaluated after Brg1 expression was knocked down by Brg1-specific siRNA.

RESULTSCompared with the control group, the proliferation of oridonin-treated Jurkat cells was significantly inhibited in a concentration- and time-dependent manner (P<0.05). According to the florescence microscopic analysis, oridonin treatment led to nuclear pyknosis in Jurkat cells. Compared with the control group, Jurkat cells treated with 5 μmol/L oridonin had reduced expression of Brg1 and C-myc but elevated expression of P53. Brg1 knock-down led to a significant reduction in proliferation of Jurkat cells (P<0.05), up-regulated expression of P53, and down-regulated expression of C-myc.

CONCLUSIONSOridonin can inhibit the proliferation of Jurkat cells, probably via the Brg1 signaling pathway.

Antineoplastic Agents, Phytogenic ; pharmacology ; Cell Proliferation ; drug effects ; DNA Helicases ; analysis ; physiology ; Diterpenes, Kaurane ; pharmacology ; Dose-Response Relationship, Drug ; Down-Regulation ; Humans ; Jurkat Cells ; Nuclear Proteins ; analysis ; physiology ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; Proto-Oncogene Proteins c-myc ; analysis ; Signal Transduction ; physiology ; Transcription Factors ; analysis ; physiology ; Tumor Suppressor Protein p53 ; analysis

OBJECTIVETo explore the inhibition mechanism and safety of pyrazolo[1,5-a]pyrazin-4(5H)-one derivatives against proliferation of human lung cancer A549 cells, H322 cells, and human umbilical vein endothelial cell (HUVEC).

METHODSCells were treated with 40 Μmol/L of the ppo3a, ppo3b, ppo3i, and 0.1% DMSO (control) for 48 hours, respectively. Apoptosis was determined by Hoechst 33258 staining assay in H322 and A549 cells. Cell cycle distribution was determined by flow cytometry analysis in A549 cell. LC3-II, p53, and heat shock protein (HSP) 70 protein levels were detected by Western blotting in A549 cells treated with ppo3b for 48 hours. The morphology and viability of HUVEC were observed by inverted microscope and sulforhodamine B (SRB) assay.

RESULTSPpo3a, ppo3b, and ppo3i significantly induced apoptosis in H322 and A549 cells. A strong G1-phase arrest was concomitant with the growth inhibitory effect on A549 cells. Ppo3b effectively elevated the p53 protein level, but significantly reduced the HSP70 protein level. There were no significantly inhibitory effect on the morphology and viability of HUVEC when treated with ppo3a, ppo3b, and ppo3i.

CONCLUSIONSppo3a, ppo3b, and ppo3i could inhibit H322 proliferation through apoptosis and inhibit A549 through apoptosis and G1-phase arrest. The protein p53 and HSP70 might involve in the inhibition effects. These derivatives might be a clue to find effective and safe drug for lung cancers.

Apoptosis ; drug effects ; Cell Cycle Checkpoints ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; HSP70 Heat-Shock Proteins ; analysis ; physiology ; Humans ; Pyrazoles ; pharmacology ; Tumor Suppressor Protein p53 ; analysis ; physiology

To study the effect of total matrines and extracts from Periplaneta americana on negative endometrial cancer cell JEC of progesterone receptors. After detecting the effect of total matrine, extracts from P. americana and their combination on JEC cells' growth inhibition, cell cycle, P53 and c-erbB-2 gene protein expressions through MTT, flow cytometry instrument and Western blot method, the author found that, (1) MTT: total matrines and extracts from P. americana could inhibit the growth of JEC cell, with significant increase in the inhibitory effect in the combination group. (2) Flow cytometry instrument: the cell cycle at G0/G1 increased after the treatment with total matrines, the cell cycle at G2/M increased after the treatment with extracts from periplaneta americana, and the ratio of G0/G1 cell cycle in the combination group was significantly higher than the other groups, with inhibition in cell growth and statistical difference in inter-group comparison (P < 0.05). (3) Western blot: the expression level of P53 increased and c-erbB-2 decreased after the treatment with total matrines, extracts from P. americana and their combination on JEC cell, with statistical difference in inter-group comparison (P < 0.05). The above results suggested that total matrines, extracts from P. americana and their combination could induce cell cycle arrest and inhibit the growth of JEC cell by up-regulating P53 and down-regulating the c-erbB-2 level.
Alkaloids ; therapeutic use ; Animals ; Cell Line, Tumor ; Endometrial Neoplasms ; chemistry ; drug therapy ; pathology ; Female ; Flow Cytometry ; Humans ; Periplaneta ; Phytotherapy ; Plant Extracts ; therapeutic use ; Quinolizines ; therapeutic use ; Receptors, Progesterone ; analysis ; Tumor Suppressor Protein p53 ; analysis ; physiology

As a critical tumor suppressor, p53 is inactivated in human cancer cells by somatic gene mutation or disruption of pathways required for its activation. Therefore, it is critical to elucidate the mechanism underlying p53 activation after genotoxic and cellular stresses. Accumulating evidence has indicated the importance of posttranslational modifications such as acetylation in regulating p53 stability and activity. However, the physiological roles of the eight identified acetylation events in regulating p53 responses remain to be fully understood. By employing homologous recombination, we introduced various combinations of missense mutations (lysine to arginine) into eight acetylation sites of the endogenous p53 gene in human embryonic stem cells (hESCs). By determining the p53 responses to DNA damage in the p53 knock-in mutant hESCs and their derivatives, we demonstrate physiological importance of the acetylation events within the core domain (K120 and K164) and at the C-terminus (K370/372/373/381/382/386) in regulating human p53 responses to DNA damage.
Acetylation ; Cells, Cultured ; DNA Damage ; Embryonic Stem Cells ; physiology ; Fibroblasts ; physiology ; Gene Expression Regulation ; Gene Knock-In Techniques ; Humans ; Protein Processing, Post-Translational ; Protein Stability ; Transcription, Genetic ; Tumor Suppressor Protein p53 ; physiology

BACKGROUNDIron is a biocorrodible metal that might be used in bioabsorbable stents. This study investigated the effects at the cellular and protein levels of soluble divalent iron (ferrous gluconate) and soluble trivalent iron (ferric chloride) on the proliferation of human aortic smooth muscle cell (HASMC) in vitro.

METHODSThe water-soluble tetrazolium (WST-1) test was used to evaluate the effect of iron on proliferation of HASMC and Western blotting was used to measure the levels of signaling proteins involved in proliferative and apoptosis pathways.

RESULTSHASMC proliferation was inhibited in a concentration dependent manner after treatment with soluble divalent and trivalent iron at concentrations of 100-500 µmol/L. Western blotting analysis showed that the proliferating cell nuclear antigen (PCNA) expression following treatment with soluble divalent iron and trivalent iron at 100, 300 and 500 µmol/L was reduced compared to the control. The PCNA expression decreased with increasing iron concentration and to a greater extent with the trivalent iron than with the divalent iron treatment group. The p53 expression was markedly increased in a concentration dependent manner in both iron treatment groups.

CONCLUSIONThe soluble divalent iron and, to a greater degree trivalent iron, inhibited HASMC proliferation in a dosedependent manner, which may be attributed to reduction of PCNA expression and increase of p53 expression.

Cell Proliferation ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Humans ; Iron ; pharmacology ; Myocytes, Smooth Muscle ; chemistry ; drug effects ; physiology ; Proliferating Cell Nuclear Antigen ; analysis ; Tumor Suppressor Protein p53 ; analysis