Regulation Of P53 Research Articles

Deep learning untangles the resistance mechanism of p53 reactivator in lung cancer cells

Tumor suppressor p53 plays a pivotal role in suppressing cancer, so various drugs has been suggested to upregulate its function. However, drug resistance is still the biggest hurdle to be overcome. To address this, we developed a deep learning model called AnoDAN (anomalous gene detection using generative adversarial networks and graph neural networks for overcoming drug resistance) that unravels the hidden resistance mechanisms and identifies a combinatorial target to overcome the resistance. Our findings reveal that the TGF-β signaling pathway, alongside the p53 signaling pathway, mediates the resistance, with THBS1 serving as a core regulatory target in both pathways. Experimental validation in lung cancer cells confirms the effects of THBS1 on responsiveness to a p53 reactivator. We further discovered the positive feedback loop between THBS1 and the TGF-β pathway as the main source of resistance. This study enhances our understanding of p53 regulation and offers insights into overcoming drug resistance.

Deer antlers: the fastest growing tissue with least cancer occurrence.

Deer antlers are a bony organ solely able to acquired distinct unique attributes during evolution and all these attributes are against thus far known natural rules. One of them is as the fastest animal growing tissue (2 cm/day), they are remarkably cancer-free, despite high cell division rate. Although tumor-like nodules on the long-lived castrate antlers in some deer species do occur, but they are truly benign in nature. In this review, we tried to find the answer to this seemingly contradictory phenomenon based on the currently available information and give insights into possible clinic application. The antler growth center is located in its tip; the most intensive dividing cells are resident in the inner layer of reserve mesenchyme (RM), and these cells are more adopted to osteosarcoma rather than to normal bone tissues in gene expression profiles but acquire their energy mainly through aerobic oxidative phosphorylation pathway. To counteract propensity of neoplastic transformation, antlers evolved highly efficient apoptosis exactly in the RM, unparalleled by any known tissues; and annual wholesale cast to jettison the corps. Besides, some strong cancer suppressive genes including p53 cofactor genes and p53 regulator genes are highly positively selected by deer, which would have certainly contributed to curb tumorigenesis. Thus far, antler extracts and RM cells/exosomes have been tried on different cancer models either in vitro or in vivo, and all achieved positive results. These positive experimental results together with the anecdotal folklore that regular consumption of velvet antler is living with cancer-free would encourage us to test antlers in clinic settings.

PPM1D activity promotes the replication stress caused by cyclin E1 overexpression.

Oncogene-induced replication stress has been recognized as a major cause of genome instability in cancer cells. Increased expression of cyclin E1 caused by amplification of the CCNE1 gene is a common cause of replication stress in various cancers. Protein phosphatase magnesium-dependent 1 delta (PPM1D) is a negative regulator of p53 and has been implicated in termination of the cell cycle checkpoint. Amplification of the PPM1D gene or frameshift mutations in its final exon promote tumorigenesis. Here, we show that PPM1D activity further increases the replication stress caused by overexpression of cyclin E1. In particular, we demonstrate that cells expressing a truncated mutant of PPM1D progress faster from G1 to S phase and fail to complete licensing of the replication origins. In addition, we show that transcription-replication collisions and replication fork slowing caused by CCNE1 overexpression are exaggerated in cells expressing the truncated PPM1D. Finally, replication speed and accumulation of focal DNA copy number alterations caused by induction of CCNE1 expression was rescued by pharmacological inhibition of PPM1D. We propose that increased activity of PPM1D suppresses the checkpoint function of p53 and thus promotes genome instability in cells expressing the CCNE1 oncogene.

MDM2 amplification is rare in gastric cancer

The MDM2 proto-oncogene (MDM2) is a primary negative regulator of p53. The latter is frequently mutated in gastric cancer (GC). In the present study, we aimed to validate gene amplification, protein expression, and the putative tumor biological function of MDM2 in a well-characterized Western GC cohort. MDM2 amplification and protein expression were studied in a cohort of 327 GCs by fluorescence in situ hybridization (FISH) and immunohistochemistry. Gene amplification and protein expression were correlated with diverse clinicopathological patient characteristics including patient outcome. Immunohistochemically, 97 GCs (29.7%) were categorized as MDM2 positive and 230 GCs (70.3%) as negative. An amplification of MDM2 was found in 11 (3.4%) cases without evidence of intratumoral heterogeneity. Nine of these eleven (81.8%) cases showed MDM2 protein expression. MDM2 amplification correlated significantly with MDM2 protein expression (p < 0.001). On a case-by-case analysis, MDM2-amplified cases showed varied histological phenotypes and were most commonly microsatellite stable; EBV, HER2, and MET negative; and FGFR2 positive. A single case harbored both, MDM2 amplification and TP53 mutation. MDM2 amplification and MDM2 expression, respectively, did not correlate with overall or tumor-specific survival. Our targeted analysis of MDM2 in a well-characterized cohort of GC patients showed that MDM2 amplification is rare, of no specific histological phenotype, and may not be always mutually exclusive with TP53 mutations. Given the low number of cases, currently, no diagnostic or therapeutic recommendation related to MDM2 amplification can be given for GC of Western origin.

Integrated Network Pharmacology and Cellular Assay to Explore the Mechanisms of Selenized Tripterine Phytosomes (Se@Tri-PTs) Alleviating Podocyte Injury in Diabetic Nephropathy.

This work aimed to elucidate the mechanisms of Se@Tri-PTs in alleviating podocyte injury via network pharmacology and in vitro cellular assay. Selenized tripterine phytosomes (Se@Tri-PTs) have been confirmed to undertake synergistic and sensitized effects on inflammation, which may be curatively promising for diabetic nephropathy (DN). However, the mechanisms of Se@Tri-PTs in alleviating podocyte injury, a major contributor to DN, still remain unclear. The objective of the study was to find out the underlying mechanisms of Se@Tri-PTs in alleviating podocyte injury in diabetic nephropathy. The key components and targets of Tripterygium wilfordii (TW) significant for DN as well as the signaling pathways involved have been identified. A high glucose-induced podocyte injury model was established and verified by western blot. The protective concentration of Se@Tri-PTs was screened by CCK-8 assay. Podocytes cultured with high glucose were treated with Se@Tri-PTs under protective levels. The expression of key protective proteins, nephrin and desmin, in podocytes, was assayed by western blot. Further, autophagy- related proteins and factors, like NLRP3, Beclin-1, LC3II/LC3, P62, and SIRT1, were analyzed, which was followed by apoptosis detection. Network pharmacology revealed that several monomeric components of TW, especially Tri, act on DN through multiple targets and pathways, including the NLRP3-mediated inflammatory pathway. Se@Tri-PTs improved the viability of podocytes and alleviated their injury induced by high glucose at 5 μg/L or above. High-glucose induction promoted the expression of NLRP3 in podocytes, while a low concentration of Se@Tri-PTs suppressed the expression. A long-term exposure of high glucose significantly inhibited the autophagic activity of podocytes, as manifested by decreased Beclin-1 level, lower ratio of LC3 II/LC3 I, and up- regulation of P62. This abnormality was efficiently reversed by Se@Tri-PTs. Importantly, the expression of SIRT1 was up-regulated and podocyte apoptosis was reduced. Se@Tri-PTs can alleviate podocyte injury associated with DN by modulating NLRP3 expression through the pathway of SIRT1-mediated autophagy.

Cancer-specific association between Tau (MAPT) and cellular pathways, clinical outcome, and drug response

Tau (MAPT) is a microtubule-associated protein causing common neurodegenerative diseases or rare inherited frontotemporal lobar degenerations. Emerging evidence for non-canonical functions of Tau in DNA repair and P53 regulation suggests its involvement in cancer. To bring new evidence for a relevant role of Tau in cancer, we carried out an in-silico pan-cancer analysis of MAPT transcriptomic profile in over 10000 clinical samples from 32 cancer types and over 1300 pre-clinical samples from 28 cancer types provided by the TCGA and the DEPMAP datasets respectively. MAPT expression associated with key cancer hallmarks including inflammation, proliferation, and epithelial to mesenchymal transition, showing cancer-specific patterns. In some cancer types, MAPT functional networks were affected by P53 mutational status. We identified new associations of MAPT with clinical outcomes and drug response in a context-specific manner. Overall, our findings indicate that the MAPT gene is a potential major player in multiple types of cancer. Importantly, the impact of Tau on cancer seems to be heavily influenced by the specific cellular environment.

P21 Prevents the Exhaustion of CD4+ T Cells Within the Antitumor Immune Response Against Colorectal Cancer

Background and aimsT cells are crucial for the antitumor response against colorectal cancer (CRC). T cell reactivity to CRC is nevertheless limited by T cell exhaustion. However, molecular mechanisms regulating T cell exhaustion are only poorly understood. MethodsWe investigated the functional role of cyclin-dependent kinase 1a (Cdkn1a or p21) in CD4+ T cells using murine CRC models. Furthermore, we evaluated the expression of p21 in patients with stage I–IV CRC. In vitro co-culture models were used to understand the effector function of p21-deficient CD4+ T cells. ResultsWe observed that the activation of cell cycle regulator p21 is crucial for CD4+ T cell cytotoxic function and that p21-deficiency in Th1 cells leads to increased tumor growth in murine CRC. Similarly, low p21 expression in CD4+ T cells infiltrated into tumors of CRC patients is associated with reduced cancer-related survival. In mouse models of CRC, p21-deficient Th1 cells show signs of exhaustion, where an accumulation of effector/effector memory T cells and CD27/CD28 loss are predominant. Immune reconstitution of tumor-bearing Rag1-/- mice using ex vivo treated p21-deficient T cells with Palbociclib, an inhibitor of CDK4/6, restored cytotoxic function and prevented exhaustion of p21-deficient CD4+ T cells as a possible concept for future immunotherapy of human disease. ConclusionOur data reveal the importance of p21 in controlling cell cycle and preventing exhaustion of Th1 cells. Furthermore, we unveil the therapeutic potential of CDK inhibitors such as Palbociclib to reduce T cell exhaustion for future treatment of patients with colorectal cancer.

Targeting MDM2-p53 Axis through Drug Repurposing for Cancer Therapy: A Multidisciplinary Approach.

Cancer remains a major cause of morbidity and mortality worldwide, and while current therapies, such as chemotherapy, immunotherapy, and cell therapy, have been effective in many patients, the development of novel therapeutic options remains an urgent priority. Mouse double minute 2 (MDM2) is a key regulator of the tumor suppressor protein p53, which plays a critical role in regulating cellular growth, apoptosis, and DNA repair. Consequently, MDM2 has been the subject of extensive research aimed at developing novel cancer therapies. In this study, we employed a machine learning-based approach to establish a quantitative structure-activity relationship model capable of predicting the potential in vitro efficacy of small molecules as MDM2 inhibitors. Our model was used to screen 5883 FDA-approved drugs, resulting in the identification of promising hits that were subsequently evaluated using molecular docking and molecular dynamics simulations. Two antihistamine drugs, cetirizine (CZ) and rupatadine (RP), exhibited particularly favorable results in the initial in silico analyses. To further assess their potential use as the activators of the p53 pathway, we investigated the antiproliferative capability of the abovementioned drugs on human glioblastoma and neuroblastoma cell lines. Both the compounds exhibited significant antiproliferative effects on the abovementioned cell lines in a dose-dependent manner. The half-maximal inhibitory concentration (IC50) of CZ was found to be 697.87 and 941.37 μM on U87 and SH-SY5Y cell lines, respectively, while the IC50 of RP was found to be 524.28 and 617.07 μM on the same cell lines, respectively. Further investigation by quantitative reverse transcriptase polymerase chain reaction analysis revealed that the CZ-treated cell lines upregulate the expression of the p53-regulated genes involved in cell cycle arrest, apoptosis, and DNA damage response compared to their respective vehicle controls. These findings suggest that CZ activates the p53 pathway by inhibiting MDM2. Our results provide compelling preclinical evidence supporting the potential use of CZ as a modulator of the MDM2-p53 axis and its plausible repurposing for cancer treatment.

Ppm1d truncating mutations promote the development of genotoxic stress-induced AML.

Hematopoietic stem cells (HSCs) ensure blood cell production during the life-time of an organism, and to do so they need to balance self-renewal, proliferation, differentiation, and migration in a steady state as well as in response to stress or injury. Importantly, aberrant proliferation of HSCs leads to hematological malignancies, and thus, tight regulation by various tumor suppressor pathways, including p53, is essential. Protein phosphatase magnesium-dependent 1 delta (PPM1D) is a negative regulator of p53 and promotes cell survival upon induction of genotoxic stress. Truncating mutations in the last exon of PPM1D lead to the production of a stable, enzymatically active protein and are commonly associated with clonal hematopoiesis. Using a transgenic mouse model, we demonstrate that truncated PPM1D reduces self-renewal of HSCs in basal conditions but promotes the development of aggressive AML after exposure to ionizing radiation. Inhibition of PPM1D suppressed the colony growth of leukemic stem and progenitor cells carrying the truncated PPM1D, and remarkably, it provided protection against irradiation-induced cell growth. Altogether, we demonstrate that truncated PPM1D affects HSC maintenance, disrupts normal hematopoiesis, and that its inhibition could be beneficial in the context of therapy-induced AML.

P10.34.B ONCOGENIC ASPP2KAPPA(K), A DOMINANT-NEGATIVE ISOFORM OF THE APOPTOSIS STIMULATING PROTEIN OF P53-2 (ASPP2) PROMOTES CLASSICAL HALLMARKS OF CANCER IN GLIOBLASTOMA

Abstract BACKGROUND GB is the most common, most aggressive primary brain tumor with a deleterious prognosis. ASPP2 is a tumor suppressor, directly interacting with p53. We recently identified a dominant-negative isoform of ASPP2, named ASPP2κ, lacking the important p53 binding sites and show that ASPP2κ is highly expressed and functionally active in glioblastoma, affecting all classical hallmarks of cancer. MATERIAL AND METHODS Grade IV glioma (n=46) were assessed for ASPP2κ expression. Isogenic GB models, stably suppressing or overexpressing ASPP2κ, were established in A-172, U-251 and T98g cell lines and from resected GB tissue. The role of ASPP2κ in induction of apoptosis, cellular proliferation, migration and invasion was assessed in vitro and in vivo. Proteome arrays allowed to study pathways involved in ASPP2κ signaling. Two ASPP2κ knock-down (KD) NOD/SCID xenotransplant mouse models were established to study ASPP2κ in tumor engraftment and progression. RESULTS Frequent overexpression of ASPP2κ was confirmed in virtually all patients analyzed compared to tumor-free tissue. Expression thereby varied widely in between patients (2-40 fold). Functional analyses confirm that ASPP2κ directly affects multiple cancer hallmarks in GB, resulting in a more aggressive phenotype with impaired induction of apoptosis (avg. -25 %), higher proliferation (avg. +25%), migration (avg. +65%) and invasion (avg. +70%) rates. Silencing of ASPP2κ rescues the ASPP2 wt tumor suppressor phenotype, rendering cells more susceptible towards temozolomide (TMZ, avg. +25%), γ-irradiation (avg. +40%) or combinational approaches. Upregulation of p53 phosphorylation sites (S15: 2,5x/S46: 1,5x) and cell cycle regulators (p21: 2x, p27: 3x and pRAD: 2,5x) thereby confirms restoration of important p53-mediated pathways. GB mouse models confirm attenuated tumor engraftment and progression of ASPP2κ KD tumors in vivo. Mice carrying ASPP2κ-KD tumors presented with statistically significant increased overall survival in both models (p= 0.03 and p=0.005) and attenuated tumor growth (p=0.0001). Importantly, neo-angiogenesis was strongly regulated in relation to ASPP2κ expression, impairing tumor growth and metastasis in the ASPP2κ KD models. Downregulation of pro-angiogenic (VEGF 20x, angiogenin 4x) and upregulation of anti-angiogenic (endostatin 2x, LAP 2,5x) players in ASPP2κ KD models were confirmed. CONCLUSION ASPP2κ is highly expressed in GB, affecting all classical hallmarks of cancer, including regulation of apoptosis, cell cycle, invasion/metastasis and angiogenesis. ASPP2κ contributes to aggressiveness of disease and resistance to therapy and silencing of ASPP2κ re-activates crucial p53-mediated tumorsuppressor pathways. Studies evaluating ASPP2κ as a target for therapy are ongoing.

IL-17a-producing γδT cells and NKG2D signaling mediate bacterial endotoxin-induced neonatal lung injury: implications for bronchopulmonary dysplasia.

Bronchopulmonary dysplasia (BPD) is a chronic lung disease in preterm birth survivors characterized by inflammation, impaired alveolarization and dysmorphic vasculature. Activated IL-17A+ lymphocytes are key drivers of inflammation in preterm infants. We have shown that in immature mice chronic airway exposure to lipopolysaccharide (LPS) induces pulmonary inflammation, increased IL-17a expression, and hypoalveolarization, a BPD-like phenotype. The source of IL-17a and contribution to lung pathology is unknown. The natural-killer group 2, member D (NKG2D) receptor mediates activation and IL-17a production in γδ T cells by binding to stress molecules. LPS induces NKG2D ligand expression, including Rae-1 and MULT1. We hypothesized that IL-17a+ γδ T cells and NKG2D signaling mediate neonatal LPS-induced lung injury. Immature C57BL/6J (wild type), Nkg2d-/- or Tcrd-/- (lacking γδ T cells) mice were inoculated with 3ug/10ul of LPS from E. coli O26:B6 or 10ul of PBS intranasally on day of life 3, 5, 7, and 10. Selected mice were treated with neutralizing antibodies against IL-17a, or NKG2D intraperitoneally. Lung immune cells were assessed by flow cytometry and gene expression was analyzed by qPCR. Alveolar growth was assessed by lung morphometry. We established that anti-IL-17a antibody treatment attenuated LPS-induced hypoalveolarization. We found that LPS induced the fraction of IL-17a+NKG2D+ γδ T cells, a major source of IL-17a in the neonatal lung. LPS also induced lung mRNA expression of NKG2D, Rae-1, MULT1, and the DNA damage regulator p53. Anti-NKG2D treatment attenuated the effect of LPS on γδ T cell IL-17a expression, immune cell infiltration and hypoalveolarization. LPS-induced hypoalveolarization was also attenuated in Nkg2d-/- and Tcrd-/- mice. In tracheal aspirates of preterm infants IL-17A and its upstream regulator IL-23 were higher in infants who later developed BPD. Also, human ligands of NKG2D, MICA and MICB were present in the aspirates and MICA correlated with median FiO2. Our novel findings demonstrate a central role for activated IL-17a+ γδ T cells and NKG2D signaling in neonatal LPS-induced lung injury. Future studies will determine the role of NKG2D ligands and effectors, other NKG2D+ cells in early-life endotoxin-induced lung injury and inflammation with a long-term goal to understand how inflammation contributes to BPD pathogenesis.

Enhancing the invasive traits of breast cancers by CYP1B1 via regulation of p53 to promote uPAR expression

Human cytochrome P450 1B1 (CYP1B1) catalyzes estrogen metabolism to produce metabolites that promote the progression of breast cancer. Since the invasive properties of cancer cells cause cancer relapse, which dramatically reduces patient survival, we investigated the new pro-invasive mechanism involving CYP1B1 in breast cancer. Exploring clinical data from invasive breast cancer patients revealed that CYP1B1 exhibits a potential correlation with urokinase-type plasminogen activator receptor (uPAR). Interestingly, uPAR mRNA expression was elevated in invasive breast cancer patients carrying TP53 genes with driver mutations, and our results showed that CYP1B1 activates the uPAR pathway following regulation of p53 according to its mutant status. CYP1B1 suppressed wild-type (WT) p53 whereas it induced the oncogenic gain-of-function mutant p53R280K, not only via transcriptional regulation but also the protein stabilization and activation following phosphorylation on Ser15 residue of p53R280K. Intriguingly, results from CYP1B1 polymorphic gene study and 4-hydroxyestradiol (4-OHE2) treatment showed that CYP1B1 regulates p53s and uPAR through its enzymatic activity. Furthermore, effects of DMBA and TMS on uPAR expression disappeared in HCT116p53−/− cells, indicating that p53 is critical for uPAR induction by CYP1B1. Collectively, our results demonstrate that CYP1B1 may reduce the relapse-free survival rate of breast cancer patients by inducing invasive traits in cancer cells via p53 regulation based on the mutation status of TP53 genes and further activation of the uPAR pathway. The elucidation of the previously unknown molecular mechanism of CYP1B1 may provide evidence for the development of effective anti-cancer therapeutic strategies that target the progression of cancer invasion.

MiR-214 could promote myocardial fibrosis and cardiac mesenchymal transition in VMC mice through regulation of the p53 or PTEN-PI3K-Akt signali pathway, promoting CF proliferation and inhibiting its ng pathway

IntroductionThis study aimed to investigate the role of miR-214 in the bidirectional regulation of p53 and PTEN and its influence on myocardial fibrosis and cardiac mesenchymal transformation in mice with viral myocarditis (VMC). MethodsThe study established a VMC model in BALB/c mice by injecting them with the CVB3 virus intraperitoneally. Techniques such as ELISA, H&E staining, Masson staining, immunohistochemical staining, RT-qPCR, western blot, and dual-luciferase reporter gene assay were used to detect the expression levels of relevant factors in tissues and cells. Isolation and culture of cardiac fibroblasts (CFs) were also conducted. ResultsThe study found that miR-214 bidirectional regulation of p53 and PTEN promotes myocardial fibrosis and cardiac mesenchymal transformation in mice with VMC. The expression levels of collagen-related peptides, inflammatory-related factors, miR-214, mesenchymal transformation-related factors, and fibrosis-related factors were significantly increased, while the expression levels of p53, PTEN, and epithelial/endothelial cell phenotype marker factors were significantly decreased. Downregulation of miR-214 or upregulation of p53 and PTEN expression inhibited inflammatory cell and fibroblast infiltration in VMC mouse myocardial tissue. It reduced the proliferation ability while increasing the apoptosis of cardiac fibroblasts. ConclusionmiR-214 plays a significant role in the bidirectional inhibition of p53 and PTEN, which leads to myocardial fibrosis and cardiac mesenchymal transformation in mice with VMC. Downregulation of miR-214 or upregulation of p53 and PTEN expression may provide potential therapeutic targets for treating VMC-induced cardiac fibrosis and mesenchymal transformation.

Scribble promotes fibrosis-dependent mechanisms of hepatocarcinogenesis by p53/PUMA-mediated glycolysis

Backgrounds and aimsLiver cancer is the sixth most common type of cancer and the fifth leading cause of cancer mortality worldwide. Scribble has been shown to function as a neoplastic tumor suppressor gene in most tumors. Our previous studies reported that down-regulation or mislocalization of Scribble was sufficient to initiate mammary tumorigenesis and NSCLC. Recently, it was reported that Scribble was highly expressed in hepatocellular carcinoma (HCC). We aim to study how it was up-regulated and the contradictory role of Scribble in HCC. Methods and resultsUsing a mouse model of carbon tetrachloride (CCl4)-induced liver fibrosis system, we showed that Scribble was over-expressed and which may protect the mice against hepatic fibrosis. Unexpectedly, we found out the potential for Scribble to act as a tumor driver at the advanced stage of N-nitrosodiethylamine (DEN) plus CCl4 induced HCC mice model in vivo. In addition, we observed even higher expression of Scribble in HCC tumors harboring elevated levels of wild-type p53. Most importantly, nuclear translocated Scribble could interact with p53, which lead to enhanced stability and transcriptional activity of p53. Mechanistically, our data suggested that Scribble might drive HCC progression by promoting metabolic regulation of p53 through p53-upregulated modulator of apoptosis (PUMA)-mediated Warburg effect. ConclusionsOur data identified the molecular basis of hepatic fibrosis-specific gene expression of polarity gene, such as Scribble. Interestingly, with the progression from fibrosis to cirrhosis to HCC, its nuclear translocation promoted a wild-type p53-mediated cancer metabolic switch and tumor progression in HCC. Taken together, we demonstrated that Scribble was up-regulated and served a protective role in liver fibrosis, while also apparently acting as a tumor driver in fibrosis-dependent hepatocarcinogenesis.

Allyl-isothiocyanate against colorectal cancer via the mutual dependent regulation of p21 and Nrf2

Allyl-isothiocyanate (AITC) is a common Isothiocyanates (ITC) and its chemo-preventive and anti-tumor effects are believed to be related to the activation of NF-E2 p45-related Factor 2 (Nrf2). However, its anti-tumor effects on colorectal cancer (CRC) are not well elucidated. Here, we investigated the therapeutic in vitro and/or in vivo effects and mechanisms of action (MOA) for AITC on CRC cell line HCT116 (human) and MC38 (mouse). AITC treatment in a low concentration range (1 mg/kg in vivo) significantly inhibited the tumor cell growth and increased the expression of p21 and Nrf2. The AITC-mediated induction of p21 was dependent on Nrf2 but independent on p53 in vitro and in vivo at low dose. In contrast, the high dose of AITC (5 mg/kg in vivo) failed to increase substantial levels of p21/MdmX, and impaired the total antioxidant capacity of tumors and subsequent anti-tumor effect in vivo. These results suggest that an optimal dose of AITC is important and required for the proper Nrf2 activation and its anti-CRC effects and thus, providing insights into the potential applications of AITC for the prevention and treatment of CRC.

HypoxamiR-210-3p regulates mesenchymal stem cells proliferation via P53 & Akt.

Transplanted stem cells (˃95%) into ischemic myocardium die because of unfavourable conditions. Moreover, hypoxia role in the cell cycle regulation has been studied in transformed/immortalized cell lines which may have altered cell cycle regulators and/or mutated and, can't be transplanted in patients. We quest to find out the mechanism of cell cycle regulation in mesenchymal stem cells (MSC) to regulate its survival and proliferation in repair processes. Additionally, critically analysed role of hypoxamiR-210-3p, and cell cycle regulators that can regulate cell proliferation under hypoxic conditions. Bone marrow-derived MSC (BM-MSC) isolated from young male Fischer-344 rats by flushing the cavity of femur and propagated in vitro under 1% hypoxia for 72h showed an increased in cell proliferation ( 30%, p < 0.05) compared to normoxia. miR-210-3p, role in cell proliferation under hypoxic condition was confirmed by knockdown. Loss of function studies with transfection of anti-mir-210-3p, we observed decrease in proliferation of BM-MSC under hypoxia. Furthermore, BM-MSC proliferation due to miR-210-3p was confirmed using CFSE assay and flow cytometry, in which more cells were observed in S-phase. Mechanistically, western blot analysis showed miR-210-3p inhibition upregulates p53 and p21 expression and subsequent decrease in pAkt under hypoxia. On contrary, CFSE and Western blot under normoxic conditions showed downregulation of p53 and p21 whilst upregulation of pAkt indicated the key role of miR-210-3p in BM-MSC proliferation. Our results demonstrate the role of miR-210-3p in BM-MSC proliferation under both hypoxic and normoxic conditions and illustrate the potential mechanism via the regulation of pAkt, p53 and p21.

The APC/C E3 ligase subunit ANAPC11 mediates FOXO3 protein degradation to promote cell proliferation and lymph node metastasis in urothelial bladder cancer

Urothelial bladder cancer (UBC) is one of the most prevalent malignancies worldwide, with striking tumor heterogeneity. Elucidating the molecular mechanisms that can be exploited for the treatment of aggressive UBC is a particularly relevant goal. Protein ubiquitination is a critical post-translational modification (PTM) that mediates the degradation of target protein via the proteasome. However, the roles of aberrant protein ubiquitination in UBC development and the underlying mechanisms by which it drives tumor progression remain unclear. In this study, taking advantage of clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein (Cas) 9 technology, we identified the ubiquitin E3 ligase ANAPC11, a critical subunit of the anaphase-promoting complex/cyclosome (APC/C), as a potential oncogenic molecule in UBC cells. Our clinical analysis showed that elevated expression of ANAPC11 was significantly correlated with high T stage, positive lymph node (LN) metastasis, and poor outcomes in UBC patients. By employing a series of in vitro experiments, we demonstrated that ANAPC11 enhanced the proliferation and invasiveness of UBC cells, while knockout of ANAPC11 inhibited the growth and LN metastasis of UBC cells in vivo. By conducting immunoprecipitation coupled with mass spectrometry, we confirmed that ANAPC11 increased the ubiquitination level of the Forkhead transcription factor FOXO3. The resulting decrease in FOXO3 protein stability led to the downregulation of the cell cycle regulator p21 and decreased expression of GULP1, a downstream effector of androgen receptor signaling. Taken together, these findings indicated that ANAPC11 plays an oncogenic role in UBC by modulating FOXO3 protein degradation. The ANAPC11–FOXO3 regulatory axis might serve as a novel therapeutic target for UBC.

Cellular senescence in liver diseases: From mechanisms to therapies.

Cellular senescence is an irreversible state of cell cycle arrest, characterized by a gradual decline in cell proliferation, differentiation, and biological functions. Cellular senescence is double-edged for that it can provoke organ repair and regeneration in physiological conditions but contribute to organ and tissue dysfunction and prime multiple chronic diseases in pathological conditions. The liver has a strong regenerative capacity, where cellular senescence and regeneration are closely involved. Herein, this review firstly introduces the morphological manifestations of senescent cells, the major regulators (p53, p21, and p16), and the core pathophysiologic mechanisms underlying senescence process, and then specifically generalizes the role and interventions of cellular senescence in multiple liver diseases, including alcoholic liver disease, nonalcoholic fatty liver disease, liver fibrosis, and hepatocellular carcinoma. In conclusion, this review focuses on interpreting the importance of cellular senescence in liver diseases and summarizes potential senescence-related regulatory targets, aiming to provide new insights for further researches on cellular senescence regulation and therapeutic developments for liver diseases.

SELENOF Controls Proliferation and Cell Death in Breast-Derived Immortalized and Cancer Cells.

SELENOF expression is significantly lower in aggressive breast tumors compared to normal tissue, indicating that its reduction or loss may drive breast tumorigenesis. Deletion of SELENOF in non-tumorigenic immortalized breast epithelial MCF-10A cells resulted in enhanced proliferation, both in adherent culture and matrix-assisted three-dimmensional (3D) growth. Modulation of SELENOF in vitro through deletion or overexpression corresponded to changes in the cell-cycle regulators p21 and p27, which is consistent with breast tumor expression data from the METABRIC patient database. Together, these findings indicate that SELENOF affects both proliferation and cell death in normal epithelial and breast cancer cells, largely through the regulation of p21 and p27. In glandular cancers like breast cancer, the filling of luminal space is one of the hallmarks of early tumorigenesis. Loss of SELENOF abrogated apoptosis and autophagy, which are required for the formation of hollow acini in MCF-10A cells in matrix-assisted 3D growth, resulting in luminal filling. Conversely, overexpression of SELENOF induced cell death via apoptosis and autophagy. In conclusion, these findings are consistent with the notion that SELENOF is a breast tumor suppressor, and its loss contributes to breast cancer etiology.

Evaluation of the p53 pathway in polycystic ovarian syndrome pathogenesis and apoptosis enhancement in human granulosa cells through transcriptome data analysis

The polycystic ovarian syndrome (PCOS) is closely associated with enhanced apoptosis of granulosa cells, which have a vital role in maturation of oocytes. p53 plays a critical role in the regulation of apoptosis and cell cycle arrest, metabolism and insulin resistance. The aim of this study was to investigate the impact of p53 pathway in enhancing apoptosis and abnormal function of granulosa cells. In this study, microarray analysis and RNA sequencing were downloaded from the GEO and used as datasets. Principal Component Analysis (PCA) and online SSizer tool were applied to evaluate the experiment quality control and sample sufficiency, respectively. Bioinformatics’ analyses were performed on the selected datasets, and validated by qRT-PCR and western blot analyses. Three datasets out of five ones were chosen for re-analyzing based on the PCA outcomes. 21 deregulated genes were identified via filters including p < 0.05 and |log2FC|≥ 1. Functional enrichment analysis confirmed the relevance of cell cycle regulation and apoptosis as common biological hallmarks in PCOS. Results have shown differentially expressed p53 target genes involved in apoptosis (BAX, FAS, PMAIP1, and CASP8), cell cycle (Cyclins, Cyclin dependent kinases), glucose metabolism and insulin resistance (THBS1), and p53 regulation (MDM2). Subsequently, the relative mRNA expression of FAS, PMAIP1 and MDM2 genes, and protein levels of p53 and MDM2 were confirmed using granulosa cells collected from 20 PCOS women and 18 control individuals by qRT-PCR and western blot, respectively. Results of this study represent the possible role of p53 pathway in pathogenesis of PCOS particularly, through the enhancement of apoptosis in granulosa cells.