ABSTRACT
The development of drug resistance reduces the efficacy of cancer therapy. Tumor cells can acquire resistance to MDM2 inhibitors, which are currently under clinical evaluation. We generated RG7388-resistant neuroblastoma cells, which became more proliferative and metabolically active and were less sensitive to DNA-damaging agents in vitro and in vivo, compared with wild-type cells. The resistance was associated with a mutation of the p53 protein (His193Arg). This mutation abated its transcriptional activity via destabilization of the tetrameric p53-DNA complex and was observed in many cancer types. Finally, we found that Cisplatin and various BH3-mimetics could enhance RG7388-mediated apoptosis in RG7388-resistant neuroblastoma cells, thereby partially overcoming resistance to MDM2 inhibition.
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The aim of this study is to explore the effects and specific mechanisms of heparanase on angiogenesis and iron deficiency anemia in TP53 mutant cancer. For this purpose, we conducted in vitro cell experiments and in vivo animal experiments respectively. In this study, we first analyzed the differential expression of heparanase in TP53 wild-type and mutant cells, and analyzed its effects on iron removal and angiogenesis in two types of CALU-1 and NCI-H358 cells. Secondly, we validated whether the mechanism of action of heparanase on TP53 mutant cells for iron removal and angiogenesis is related to VEGF. We applied the iron removal agonist erastin and VEGF inhibitor bevacizumab in both in vitro and in vivo experiments to validate the relationship between heparanase and VEGF in the mechanisms of iron removal and angiogenesis. The experimental results show that heparanase is highly expressed in TP53 mutated cancer cells, and has anti-ferroptosis and pro-angiogenic effects. Our experiment also confirmed that the effect of heparanase on TP53 mutant cancer's iron removal and angiogenesis is related to VEGF. In short, heparanase is highly expressed in p53 mutated lung cancer, and the mechanism of ferroptosis tolerance to TP53 mutated cancer is related to VEGF.
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The tumor suppressor proteins are key transcription factors involved in the regulation of various cellular processes, such as apoptosis, DNA repair, cell cycle, senescence, and metabolism. The tumor suppressor protein p53 responds to different type of stress signaling, such as hypoxia, DNA damage, nutrient deprivation, oncogene activation, by activating or repressing the expression of different genes that target processes mentioned earlier. p53 has the ability to modulate the activity of many other proteins and signaling pathway through protein-protein interaction, post-translational modifications, or non-coding RNAs. In many cancers the p53 is found to be mutated or inactivated, resulting in the loss of its tumor suppressor function and acquisition of new oncogenic properties. The tumor suppressor protein p53 also plays a role in the development of other metabolic disorders such as diabetes, obesity, and fatty liver disease. In this review, we will summarize the current data and knowledge on the molecular mechanisms and the functions of p53 in different pathways and processes at the cellular level and discuss the its implications for human health and disease.
Subject(s)
Ribosomes , Tumor Suppressor Protein p53 , Humans , Tumor Suppressor Protein p53/metabolism , Tumor Suppressor Protein p53/genetics , Animals , Ribosomes/metabolism , Neoplasms/metabolism , Neoplasms/drug therapy , Neoplasms/pathology , Neoplasms/genetics , Cell Nucleus/metabolism , Stress, Physiological/physiology , Signal Transduction/physiologyABSTRACT
OBJECTIVES: To analyze the immunohistochemical staining pattern of mismatch repair (MMR) proteins and p53 in endometrial carcinoma cases, including different subtypes and stages, to gain insights into their role in the pathogenesis and clinical behaviour of this malignancy. METHODS: In this study, we investigate the association between MMR deficiency, p53 mutational status, and clinical outcomes in various subtypes of endometrial carcinoma. The immunohistochemical staining pattern of MMR proteins in 96 cases of endometrial carcinoma have been analyzed, including 72 endometrioid, 14 papillary serous, 5 clear cell, and 5 mixed Müllerian tumor. RESULTS: The results showed that 36 cases were MMR deficient, with the majority being of endometrioid subtype. The p53 immunostain showed a mutational pattern in a subset of cases, with a documented dismal prognosis. However, aforementioned stains failed to predict synchronous or metachronous cancers in 5 patients. CONCLUSION: These findings highlight the importance of MMR and p53 immunohistochemical staining in the classification, and prognosis of endometrial carcinoma.
Subject(s)
DNA Mismatch Repair , Endometrial Neoplasms , Immunohistochemistry , Tumor Suppressor Protein p53 , Humans , Female , Endometrial Neoplasms/pathology , Endometrial Neoplasms/metabolism , Endometrial Neoplasms/genetics , Tumor Suppressor Protein p53/metabolism , Middle Aged , Aged , Adult , Prognosis , Carcinoma, Endometrioid/pathology , Carcinoma, Endometrioid/metabolism , Mutation , Aged, 80 and overABSTRACT
p53 was discovered 45 years ago as an SV40 large T antigen binding protein, coded by the most frequently mutated TP53 gene in human cancers. As a transcription factor, p53 is tightly regulated by a rich network of post-translational modifications to execute its diverse functions in tumor suppression. Although early studies established p53-mediated cell-cycle arrest, apoptosis, and senescence as the classic barriers in cancer development, a growing number of new functions of p53 have been discovered and the scope of p53-mediated anti-tumor activity is largely expanded. Here, we review the complexity of different layers of p53 regulation, and the recent advance of the p53 pathway in metabolism, ferroptosis, immunity, and others that contribute to tumor suppression. We also discuss the challenge regarding how to activate p53 function specifically effective in inhibiting tumor growth without harming normal homeostasis for cancer therapy.
Subject(s)
Neoplasms , Tumor Suppressor Protein p53 , Humans , Tumor Suppressor Protein p53/metabolism , Tumor Suppressor Protein p53/genetics , Neoplasms/genetics , Neoplasms/metabolism , Neoplasms/pathology , Animals , Ferroptosis/genetics , Signal Transduction , Apoptosis , Protein Processing, Post-TranslationalABSTRACT
Genetic mutations in TP53 contribute to human malignancies through various means. To date, there have been a variety of therapeutic strategies targeting p53, including gene therapy to restore normal p53 function, mutant p53 rescue, inhibiting the MDM2-p53 interaction, p53-based vaccines, and a number of other approaches. This review focuses on the functions of TP53 and discusses the aberrant roles of mutant p53 in various types of cancer. Recombinant human p53 adenovirus, trademarked as Gendicine, which is the first anti-tumor gene therapy drug, has made tremendous progress in cancer gene therapy. We herein discuss the biological mechanisms by which Gendicine exerts its effects and describe the clinical responses reported in clinical trials. Notably, the clinical studies suggest that the combination of Gendicine with chemotherapy and/or radiotherapy may produce more pronounced efficacy in slowing tumor growth and progression than gene therapy/chemotherapy alone. Finally, we summarize the methods of administration of recombinant human p53 adenovirus for different cancer types to provide a reference for future clinical trials.
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Head and neck malignancies are the seventeenth most common malignancies, worldwide and second most common malignancy in India. So current study aims to compare between molecular marker p53 analysis and HPE for tumour positivity in primary resected margins in head and neck SCC. 61 patients with head and neck SCC were included in this prospective observational cross-sectional study performed in tertiary care hospital. A detailed history general physical examination blood investigation was done before the surgery. After the surgery, primary lesion from the resected tumour was sent for HPE analysis. From the same specimen, the margins at distance of 0.5-1 cm from primary tumour were sent for p53 mutation analysis. Report of p-53 mutation was noted and entered to the Performa. In our study we found out that in PDSCC HPE negative margins were found positive for p53 mutation in 81% cases. Which suggest that evaluation for p53 mutation should be done in PDSCC cases for HPE negative margins with in 1 cm. In patients of head and neck squamous cell carcinoma with free margins on HPE p-53 mutation is significantly associated to the PDSCC and margin upto 0.7 mm so recommended for p-53 profile can be beneficial in cases of the PDSCC and margins up to 0.7 mm for further management or for possibility of recurrence and its management to improve patients survival and decrease morbidity and mortality.
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BACKGROUND: The tumor burden before chimeric antigen receptor T (CAR-T) cell therapy was one of the critical factors affecting the prognosis of lymphoma. It was a challenge to effectively reduce the tumor burden of relapsed/refractory large B-cell lymphoma with p53 mutation. OBJECTIVE: Here, we have presented a case of relapsed/refractory large B-cell lymphoma with p53 mutation being controlled by the treatment with daratumumab and venetoclax, followed by CAR-T cell therapy. CASE PRESENTATION: The patient was a 56-year-old female who was diagnosed with relapsed/ refractory diffuse large B cell lymphoma (DLBCL) transformed from follicular lymphoma. The patient was treated with daratumumab, venetoclax, and GEMOX (gemcitabine and oxaliplatin) under the guidance of high-throughput drug sensitivity analysis. We used a CD38 positive lymphoma cell line with p53 mutation to construct tumor models for validating the anti- lymphoma effect of the combination therapy of daratumumab and venetoclax. RESULTS: The patient achieved a complete metabolic response after treatment with daratumumab, venetoclax, and GEMOX. Then, she further achieved a complete molecular response after she subsequently received CAR-T cell therapy, and she has been living without a lymphoma recurrence. The results from the animal study showed that the combination of daratumumab and venetoclax could significantly enhance the antitumor effect on CD38-positive lymphoma with p53 mutation. CONCLUSION: The results from our successful case and animal experiments provide new avenues for the treatment of relapsed/refractory large B-cell lymphoma with p53 mutation. Further clinical trials are reuqired to treat CD38-positive lymphoma with the combination of daratumumab and venetoclax.
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p53 is mutated in half of cancer cases. However, no p53-targeting drugs have been approved. Here, we reposition decitabine for triple-negative breast cancer (TNBC), a subtype with frequent p53 mutations and extremely poor prognosis. In a retrospective study on tissue microarrays with 132 TNBC cases, DNMT1 overexpression was associated with p53 mutations (P = 0.037) and poor overall survival (OS) (P = 0.010). In a prospective DEciTabinE and Carboplatin in TNBC (DETECT) trial (NCT03295552), decitabine with carboplatin produced an objective response rate (ORR) of 42% in 12 patients with stage IV TNBC. Among the 9 trialed patients with available TP53 sequencing results, the 6 patients with p53 mutations had higher ORR (3/6 vs. 0/3) and better OS (16.0 vs. 4.0 months) than the patients with wild-type p53. In a mechanistic study, isogenic TNBC cell lines harboring DETECT-derived p53 mutations exhibited higher DNMT1 expression and decitabine sensitivity than the cell line with wild-type p53. In the DETECT trial, decitabine induced strong immune responses featuring the striking upregulation of the innate immune player IRF7 in the p53-mutated TNBC cell line (upregulation by 16-fold) and the most responsive patient with TNBC. Our integrative studies reveal the potential of repurposing decitabine for the treatment of p53-mutated TNBC and suggest IRF7 as a potential biomarker for decitabine-based treatments.
Subject(s)
Decitabine , Interferon Regulatory Factor-7 , Mutation , Triple Negative Breast Neoplasms , Tumor Suppressor Protein p53 , Humans , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/genetics , Triple Negative Breast Neoplasms/immunology , Female , Decitabine/therapeutic use , Decitabine/pharmacology , Tumor Suppressor Protein p53/genetics , Middle Aged , Retrospective Studies , Interferon Regulatory Factor-7/genetics , Carboplatin/therapeutic use , Carboplatin/pharmacology , Cell Line, Tumor , Adult , DNA (Cytosine-5-)-Methyltransferase 1/genetics , Prospective Studies , Aged , Antimetabolites, Antineoplastic/therapeutic use , Antimetabolites, Antineoplastic/pharmacology , Antineoplastic Combined Chemotherapy Protocols/therapeutic useABSTRACT
The G-rich DNA, such as telomere, tends to form G-quadruplex (G4) structure, which slows down the replication fork progression, induces replication stress, and becomes the chromosome fragile sites. Here we described a molecular strategy that cells developed to overcome the DNA replication stress via DNA helicase regulation. The p53N236S (p53S) mutation has been found in the Werner syndrome mouse embryo fibroblast (MEFs) escaped from senescence, could be the driving force for cell escaping senescence. We revealed that the p53S could transcriptionally up-regulate DNA helicases expression, including Wrn, Blm, Timeless, Ddx, Mcm, Gins, Fanc, as well as telomere specific proteins Terf1, Pot1, through which p53S promoted the unwinding of G4 structures, and protected the cells from DNA replication stress induced by G4 stabilizer. By modified iPOND (isolation of proteins on nascent DNA) assay and telomere assay, we demonstrated that the p53S could promote the recruitment of those helicases to the DNA replication forks, facilitated the maintenance of telomere, and prevent the telomere dysfunction induced by G4 stabilizer. Interestingly, we did not observe the function of promoting G4 resolving and facilitating telomere lengthening in the cells with Li-Fraumeni Syndrome mutation-p53R172H (p53H), which suggests that this is the specific gain of function for p53S. Together our data suggest that the p53S could gain the new function of releasing the replication stress via regulating the helicase function and G4 structure, which benefits telomere lengthening. This strategy could be applied to the treatment of diseases caused by telomere replication stress.
Subject(s)
DNA Replication , Werner Syndrome , Animals , Mice , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Werner Syndrome Helicase/genetics , DNA Helicases/genetics , DNA Helicases/metabolism , DNA/genetics , Telomere/genetics , Telomere/metabolism , RecQ Helicases/genetics , RecQ Helicases/metabolismABSTRACT
BACKGROUND: This prospective cohort study evaluated the feasibility of using endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) samples for comprehensive mutational analysis of cancer-related genes using microtissues. METHODS: Fifty patients with suspected pancreatic cancer presenting consecutively at the Kindai University Hospital between January 2018 and January 2019 were enrolled. Cancerous tissues from EUS-FNB were obtained from each tumor and subjected to histological examination and mutational analysis. The primary endpoint was the collection rate of EUS-FNB specimens suitable for comprehensive cancer panels using deep sequencing. Clinical history and genetic variations between the disease control and progressive disease groups of patients on chemotherapy were evaluated as secondary endpoints. RESULTS: The collection rate of EUS-FNB specimens suitable for comprehensive cancer panels using deep sequencing was 93.6%. The cancer panel was sequenced for 25 patients with pancreatic cancer treated initially with systemic chemotherapy. Mutation in p53 and Smad4 were positively and negatively associated, respectively, with disease control at the initial evaluation. The median time to progression in 15 patients with p53 and without Smad4 mutations was 182.0 days; whereas, it was 92.5 days in other 10 patients; this difference was significant (p = 0.020). CONCLUSIONS: Tissue samples from EUS-FNB were suitable for mutational analysis. Pancreatic cancers with p53 and without Smad4 mutations responded better to chemotherapy and had a better prognosis than those others.
Subject(s)
Adenocarcinoma , Pancreatic Neoplasms , Humans , Adenocarcinoma/pathology , Endoscopic Ultrasound-Guided Fine Needle Aspiration , Mutation , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/genetics , Prognosis , Prospective Studies , Tumor Suppressor Protein p53/genetics , Pancreatic NeoplasmsABSTRACT
p53 plays a critical role in tumor suppression and is the most frequently mutated gene in human cancers. Most p53 mutants (mutp53) are missense mutations and are thus expressed in human cancers. In human cancers that retain wtp53, the wtp53 activities are downregulated through multiple mechanisms. For example, the overexpression of the negative regulators of p53, MDM2/MDMX, can also efficiently destabilize and inactivate wtp53. Therefore, both wtp53 and mutp53 have become promising and intensively explored therapeutic targets for cancer treatment. Current efforts include the development of small molecule compounds to disrupt the interaction between wtp53 and MDM2/MDMX in human cancers expressing wtp53 and to restore wtp53-like activity to p53 mutants in human cancers expressing mutp53. In addition, a synthetic lethality approach has been applied to identify signaling pathways affected by p53 dysfunction, which, when targeted, can lead to cell death. While an intensive search for p53-targeted cancer therapy has produced potential candidates with encouraging preclinical efficacy data, it remains challenging to develop such drugs with good efficacy and safety profiles. A more in-depth understanding of the mechanisms of action of these p53-targeting drugs will help to overcome these challenges.
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PURPOSE: Serine metabolism is frequently dysregulated in many types of cancers and the tumor suppressor p53 is recently emerging as a key regulator of serine metabolism. However, the detailed mechanism remains unknown. Here, we investigate the role and underlying mechanisms of how p53 regulates the serine synthesis pathway (SSP) in bladder cancer (BLCA). METHODS: Two BLCA cell lines RT-4 (WT p53) and RT-112 (p53 R248Q) were manipulated by applying CRISPR/Cas9 to examine metabolic differences under WT and mutant p53 status. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and non-targeted metabolomics analysis were adopted to identify metabolomes changes between WT and p53 mutant BLCA cells. Bioinformatics analysis using the cancer genome atlas and Gene Expression Omnibus datasets and immunohistochemistry (IHC) staining was used to investigate PHGDH expression. Loss-of-function of PHGDH and subcutaneous xenograft model was adopted to investigate the function of PHGDH in mice BLCA. Chromatin immunoprecipitation (Ch-IP) assay was performed to analyze the relationships between YY1, p53, SIRT1 and PHGDH expression. RESULTS: SSP is one of the most prominent dysregulated metabolic pathways by comparing the metabolomes changes between wild-type (WT) p53 and mutant p53 of BLCA cells. TP53 gene mutation shows a positive correlation with PHGDH expression in TCGA-BLCA database. PHGDH depletion disturbs the reactive oxygen species homeostasis and attenuates the xenograft growth in the mouse model. Further, we demonstrate WT p53 inhibits PHGDH expression by recruiting SIRT1 to the PHGDH promoter. Interestingly, the DNA binding motifs of YY1 and p53 in the PHGDH promoter are partially overlapped which causes competition between the two transcription factors. This competitive regulation of PHGDH is functionally linked to the xenograft growth in mice. CONCLUSION: YY1 drives PHGDH expression in the context of mutant p53 and promotes bladder tumorigenesis, which preliminarily explains the relationship between high-frequency mutations of p53 and dysfunctional serine metabolism in bladder cancer.
Subject(s)
Tumor Suppressor Protein p53 , Urinary Bladder Neoplasms , Humans , Animals , Mice , Tumor Suppressor Protein p53/genetics , Sirtuin 1/genetics , Sirtuin 1/metabolism , Genes, p53 , Chromatography, Liquid , Tandem Mass Spectrometry , Urinary Bladder Neoplasms/genetics , Serine/metabolism , Cell Line, Tumor , YY1 Transcription Factor/genetics , YY1 Transcription Factor/metabolismABSTRACT
The transcription factor p53, a widely accepted tumor suppressor, regulates the expression of many oncogenes and their downstream signaling pathways, resulting in a series of biological outcomes. Mutations and deletions of the p53 gene often occur in tumor tissues and are involved in their development. In addition to its role in tumors, p53 has a widespread expression in the brain and participates in most cell processes, such as dendrite formation, oxidative stress, apoptosis, autophagy, DNA repair, and cell cycle arrest. Therefore, abnormalities in p53 and its related signaling pathways play an important role in the diagnosis and treatment of central nervous system diseases. This review mainly discusses the latest findings regarding the role of p53 in some central nervous system diseases, such as brain tumors, Alzheimer disease, Parkinson disease, autism, epilepsy, spinocerebellar ataxia, and so on, to provide a comprehensive interpretation of the treatment of neurological diseases from a new perspective.
Subject(s)
Central Nervous System Diseases , Neoplasms , Humans , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Neoplasms/genetics , Apoptosis , Gene Expression Regulation , Mutation , Central Nervous System Diseases/geneticsABSTRACT
Low-grade and high-grade serous carcinomas have unique clinical, morphological, underlying molecular alterations, and vastly different biologic behavior (Prat et al., 2018, Vang et al., 2009). The differentiation into high and low-grade serous carcinoma is important for clinical management and prognosis and is easily recognized by practicing pathologists. High-grade serous carcinoma is characterized by marked nuclear atypia and pleomorphism, frequent, often atypical mitosis with papillary or three-dimensional clusters, p53 mutation, and block-like p16 staining. In contrast, low-grade serous carcinomas have a different morphologic appearance with micropapillary formation, small nests of tumor cells having low to intermediate grade nuclei, and absence of significant mitosis. Low-grade serous carcinoma is often associated with micropapillary variant of ovarian serous borderline tumor. The low-grade serous carcinoma shows wild type p53 expression, patchy p16 staining, and often K-RAS, N-RAS, and/or B-RAF mutation. Here we report a case of mullerian high grade serous with a deceptive morphology resembling low-grade serous carcinoma with micropapillary features and moderate nuclear atypia. However, the tumor is simultaneously p53 and K-RAS mutated. This case illustrates three critical issues; a) potential to be mistaken as a low-grade serous carcinoma because of morphologic appearance and relative uniform cytologic feature. b). raise the question of true progression of low-grade to high-grade serous carcinoma, a rare phenomenon as described in the literature, and c). whether the biologic behavior and/or response to therapy would differ from the classic forms.
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Genetic predisposition, environmental factors, and infectious agents interact in the development of gastric diseases. Helicobacter pylori (Hp) and Epstein-Barr virus (EBV) infection has recently been shown to be correlated with these diseases. A cross-sectional study was performed on 100 hospitalized Italian patients with and without gastric diseases. The patients were stratified into four groups. Significant methylation status differences among CDH1, DAPK, COX2, hMLH1 and CDKN2A were observed for coinfected (Hp-EBV group) patients; particularly, a significant presence of COX2 (p = 0.0179) was observed. For microsatellite instability, minor stability was described in the Hp-HBV group (69.23%, p = 0.0456). Finally, for p53 mutation in the EBV group, exon 6 was, significantly, most frequent in comparison to others (p = 0.0124), and in the Hp-EBV group exon 8 was, significantly, most frequent in comparison to others (p < 0.0001). A significant positive relationship was found between patients with infection (Hp, EBV or both) and p53 mutation (rho = 0.383, p = 0.0001), methylation status (rho = 0.432, p < 0.0001) and microsatellite instability (rho = 0.285, p = 0.004). Finally, we observed among infection and methylation status, microsatellite instability, and p53 mutation a significant positive relationship only between infection and methylation status (OR = 3.78, p = 0.0075) and infection and p53 mutation (OR = 6.21, p = 0.0082). According to our analysis, gastric disease in the Sicilian population has different pathways depending on the presence of various factors, including infectious agents such as Hp and EBV and genetic factors of the subject.
Subject(s)
DNA Methylation , Epstein-Barr Virus Infections , Genes, p53 , Helicobacter Infections , Microsatellite Instability , Stomach Diseases , Helicobacter pylori , Helicobacter Infections/complications , Epstein-Barr Virus Infections/complications , Herpesvirus 4, Human , Coinfection , Stomach Diseases/genetics , Stomach Diseases/microbiology , Stomach Diseases/virology , Genes, p53/genetics , Mutation , Sicily , Humans , Male , Female , Young Adult , Adult , Middle Aged , Aged , Aged, 80 and over , Logistic ModelsABSTRACT
Introduction: Liquid biopsy based on the analysis of circulating cell-free DNA (cfDNA), as well as on detection of point mutations by digital droplet PCR (ddPCR), has revolutionized the research in oncology. In recent years, this technique has been pioneering in veterinary medicine since it is a minimally invasive approach with very promising results for characterization of tumors. Methods: The aim of this study was, firstly, to analyze the concentration and the fragmentation pattern of cfDNA of dogs with mammary tumors (n = 36) and healthy dogs (n = 5) and its correlation with clinicopathological data. Secondly, analysis of TP53 gene expression and the point mutation in the codon 245 were performed in cfDNA and in tumor tissues to assess their potential as plasma biomarkers. Results and discussion: Our results highlighted that those dogs with worse clinicopathological characteristics (simple or undifferentiated carcinomas, higher histological grade and presence of peritumoral inflammation) shown higher cfDNA concentration and higher concentrations of short-fragments (<190 bp) than healthy dogs. In addition, although no detection of the point mutation in codon 245 of TP53 gene could be detected neither in plasma nor tumor tissue, an increased TP53 expression was detected in animals with tumors bearing malignant characteristics. Finally, a high concordance with TP53 gene expression in plasma and tumor tissue and cfDNA concentration was also found. The results derived from this work confirm the valuable potential of cfDNA and its fragments, as well as the analysis of TP53 expression in plasma as useful liquid biomarkers for clinical application in veterinary oncology.
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TP53 (or p53) is widely accepted to be a tumor suppressor. Upon various cellular stresses, p53 mediates cell cycle arrest and apoptosis to maintain genomic stability. p53 is also discovered to suppress tumor growth through regulating metabolism and ferroptosis. However, p53 is always lost or mutated in human and the loss or mutation of p53 is related to a high risk of tumors. Although the link between p53 and cancer has been well established, how the different p53 status of tumor cells help themselves evade immune response remains largely elusive. Understanding the molecular mechanisms of different status of p53 and tumor immune evasion can help optimize the currently used therapies. In this context, we discussed the how the antigen presentation and tumor antigen expression mode altered and described how the tumor cells shape a suppressive tumor immune microenvironment to facilitate its proliferation and metastasis.
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Asperolides A (AA), one of the new tetranorlabdane diterpenoids, is proved to inhibit the proliferation of lung cancer cells and bone metastasis of breast cancer cells. Herein, we report that AA induces apoptosis and cell cycle arrest of hepatoma cells. It intensely inhibits proliferation of Huh-7 cell, compared with HepG-2 and L02 cells. AA elevates the activity of mitogen-activated protein kinases (MAPKs), in which the activation of ERK and JNK improves cell survival. However, phosphorylation of p53 at S33 by p38 activation could be a principal factor in the AA-induced apoptosis and G2/M cell cycle arrest of Huh-7 cells. The S33 site of p53-Y220C mutant, as the specific activation site of p38, reactivates the wild-type function of mutant p53 protein, which leads to a higher sensitivity of Huh-7 cells to AA. These results provide new insights into the molecular mechanisms of AA as a developing mutant p53 rescue drug.
ABSTRACT
Mutations in the p53 gene are common and occur in over 50% of all cancers, as it is involved in DNA damage repair, cell cycle regulation and apoptosis. Moreover, the p53 gene is mutated in 70% of colon cancers. Therefore, the development of drugs to combat this mutation requires urgent attention. With this in mind, in silico drug design approaches were applied on quinoline derivatives with anticancer activity. In 3D-QSAR study, steric, electrostatic, hydrophobic and H-bond acceptor fields (SEHA) play an important role in prediction and design of new colon cancer compounds. Indeed, the two best CoMSIA/SEHA models with (Q2 = 0.737, R2 = 0.914, Rpred2 = 0.720) and (Q2 = 0.738, R2 = 0.919, Rpred2= 0.739) show good prediction of human colon carcinoma HCT 116 (p53+/+) and (p53-/-) activities, respectively. Furthermore, the predictive ability and robustness of these models were tested by several validation methods. Molecular docking analyses reveal crucial interactions with the active sites of the p53 protein in both wild type and mutant. Based on these theoretical studies, we designed 10 new compounds with good anticancer activity potential, which were evaluated using ADMET properties. Molecular dynamics simulations were performed to confirm the detailed binding mode of the docking results. Finally, the MM-GBSA based on molecular dynamics simulation confirmed that the designed compounds were able to form stable hydrogen bonding interactions with the crucial residues, which are essential to overcome the p53 mutation in colon cancer.Communicated by Ramaswamy H. Sarma.