P53 and The Immune Response: 40 Years of Exploration-A Plan for the Future

Targeted therapies for myelodysplastic syndromes/neoplasms (MDS): current landscape and future directions

INTRODUCTION

Myelodysplastic syndromes/neoplasms (MDS) are a heterogeneous group of hematologic malignancies that are stratified into high-risk (HR-MDS) and low-risk (LR-MDS) categories. Until recently, LR-MDS has been typically managed by supportive measures and erythropoiesis-stimulating agents (ESAs); whereas management of HR-MDS typically included hypomethylating agents and allogeneic hematopoietic stem cell transplant. However, the limited rates and durations of response observed with these interventions prompted the search for targeted therapies to improve the outcomes among patients with MDS.

AREAS COVERED

Here, we review the current landscape of targeted therapies in MDS. These include pyruvate kinase and hypoxia-inducible factor (HIF) activators; TGF-beta, telomerase, BCL2 and isocitrate dehydrogenase (IDH) inhibitors; as well as novel approaches targeting inflammation, pyroptosis, immune evasion, and RNA splicing machinery.

EXPERT OPINION

This review highlights the progress and challenges in MDS treatment. Despite some promising results, many therapies remain in early development or have faced setbacks, emphasizing the need for a more comprehensive understanding of the disease's pathobiology. Continued research into targeted therapies, homogenous clinical trial designs, as well as increased incorporation of molecular prognostic tools and artificial intelligence into trial design are essential for developing effective treatments for MDS and improving patient outcomes.

Long-term PS micro/nano-plastic exposure: Particle size effects on hepatopancreas injury in Parasesarma pictum

With the widespread use of plastic products, microplastics and nanoplastics have emerged as prevalent pollutants in coastal aquatic ecosystems. Parasesarma pictum, a common estuarine crab species, was selected as a model organism. P. pictum was exposed to polystyrene (PS) particles of sizes 80 nm (80PS), 500 nm (500PS), and 1000 nm (1000PS), as well as to clean seawater (CK) for 21 days. Histological and fluorescent staining results showed that PS particles of all three sizes induced hepatopancreatic nuclear pyknosis, cell junction damage, and necrosis. The degree of damage was observed as 1000PS > 80PS > 500PS. Transcriptomic analysis revealed that major differentially expressed genes (DEGs) were associated with cellular processes, membrane components, and catalytic activity. The respiratory chain disruptions and immune exhaustion induced by 1000PS were notably stronger than those by 80PS and 500PS. Additionally, necrosis caused hepatopancreas injury in P. pictum rather than apoptosis or autophagy after long-term PS particle exposure. Furthermore, PS particles of all three sizes inhibited innate immunity, while the complement pathway was not significantly affected in the 80PS group. This study elucidated potential distinctions in how plastic particles of varying sizes (nanoplastics, microplastics, and micro/nanoplastics) impact P. pictum, providing a reference for toxicological mechanism research on microplastics and nanoplastics in aquatic organisms. Future research should focus on exploring long-term effects and potential mitigation strategies for microplastics and nanoplastics of more types and a wider range of particle size pollution in aquatic environments.

Evaluating targeted therapies in older patients with TP53-mutated AML

Mutation of thetumor suppressor gene, TP53 (tumor protein 53), occurs in up to 15% of all patients with acute myeloid leukemia (AML) and is enriched within specific clinical subsets, most notably in older adults, and including secondary AML cases arising from preceding myeloproliferative neoplasm (MPN), myelodysplastic syndrome (MDS), patients exposed to prior DNA-damaging, cytotoxic therapies. In all cases, these tumors have remained difficult to effectively treat with conventional therapeutic regimens. Newer approaches fortreatmentofTP53-mutated AML have shifted to interventions that maymodulateTP53 function, target downstream molecular vulnerabilities, target non-p53 dependent molecular pathways, and/or elicit immunogenic responses. This review will describe the basic biology of TP53, the clinical and biological patterns of TP53 within myeloid neoplasms with a focus on elderly AML patients and will summarize newer therapeutic strategies and current clinical trials.

[18F]FDG PET-CT radiomics signature to predict pathological complete response to neoadjuvant chemoimmunotherapy in non-small cell lung cancer: a multicenter study

OBJECTIVES

This study aims to develop and validate a radiomics model based on 18F-fluorodeoxyglucose positron emission tomography-computed tomography ([18F]FDG PET-CT) images to predict pathological complete response (pCR) to neoadjuvant chemoimmunotherapy in non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

One hundred eighty-five patients receiving neoadjuvant chemoimmunotherapy for NSCLC at 5 centers from January 2019 to December 2022 were included and divided into a training cohort and a validation cohort. Radiomics models were constructed via the least absolute shrinkage and selection operator (LASSO) method. The performances of models were evaluated by the area under the receiver operating characteristic curve (AUC). In addition, genetic analyses were conducted to reveal the underlying biological basis of the radiomics score.

RESULTS

After the LASSO process, 9 PET-CT radiomics features were selected for pCR prediction. In the validation cohort, the ability of PET-CT radiomics model to predict pCR was shown to have an AUC of 0.818 (95% confidence interval [CI], 0.711, 0.925), which was better than the PET radiomics model (0.728 [95% CI, 0.610, 0.846]), CT radiomics model (0.732 [95% CI, 0.607, 0.857]), and maximum standard uptake value (0.603 [95% CI, 0.473, 0.733]) (p < 0.05). Moreover, a high radiomics score was related to the upregulation of pathways suppressing tumor proliferation and the infiltration of antitumor immune cell.

CONCLUSION

The proposed PET-CT radiomics model was capable of predicting pCR to neoadjuvant chemoimmunotherapy in NSCLC patients.

CLINICAL RELEVANCE STATEMENT

This study indicated that the generated 18F-fluorodeoxyglucose positron emission tomography-computed tomography radiomics model could predict pathological complete response to neoadjuvant chemoimmunotherapy, implying the potential of our radiomics model to personalize the neoadjuvant chemoimmunotherapy in lung cancer patients.

KEY POINTS

• Recognizing patients potentially benefiting neoadjuvant chemoimmunotherapy is critical for individualized therapy of lung cancer. • [18F]FDG PET-CT radiomics could predict pathological complete response to neoadjuvant immunotherapy in non-small cell lung cancer. • [18F]FDG PET-CT radiomics model could personalize neoadjuvant chemoimmunotherapy in lung cancer patients.

PUMA/RIP3 Mediates Chemotherapy Response via Necroptosis and Local Immune Activation in Colorectal Cancer

Induction of programmed cell death (PCD) is a key cytotoxic effect of anticancer therapies. PCD is not confined to caspase-dependent apoptosis, but includes necroptosis, a regulated form of necrotic cell death controlled by receptor-interacting protein (RIP) kinases 1 and 3, and mixed lineage kinase domain-like (MLKL) pseudokinase. Necroptosis functions as a defense mechanism against oncogenic mutations and pathogens and can be induced by a variety of anticancer agents. However, the functional role and regulatory mechanisms of necroptosis in anticancer therapy are poorly understood. In this study, we found that RIP3-dependent but RIP1-independent necroptosis is engaged by 5-fluorouracil (5-FU) and other widely used antimetabolite drugs, and functions as a major mode of cell death in a subset of colorectal cancer cells that express RIP3. We identified a novel 5-FU-induced necroptosis pathway involving p53-mediated induction of the BH3-only Bcl-2 family protein, p53 upregulated modulator of apoptosis (PUMA), which promotes cytosolic release of mitochondrial DNA and stimulates its sensor z-DNA-binding protein 1 (ZBP1) to activate RIP3. PUMA/RIP3-dependent necroptosis mediates the in vitro and in vivo antitumor effects of 5-FU and promotes a robust antitumor immune response. Our findings provide a rationale for stimulating necroptosis to enhance tumor cell killing and antitumor immune response leading to improved colorectal cancer treatments.

Cell fate regulation governed by p53: Friends or reversible foes in cancer therapy

Cancer is a leading cause of death worldwide. Targeted therapies aimed at key oncogenic driver mutations in combination with chemotherapy and radiotherapy as well as immunotherapy have benefited cancer patients considerably. Tumor protein p53 (TP53), a crucial tumor suppressor gene encoding p53, regulates numerous downstream genes and cellular phenotypes in response to various stressors. The affected genes are involved in diverse processes, including cell cycle arrest, DNA repair, cellular senescence, metabolic homeostasis, apoptosis, and autophagy. However, accumulating recent studies have continued to reveal novel and unexpected functions of p53 in governing the fate of tumors, for example, functions in ferroptosis, immunity, the tumor microenvironment and microbiome metabolism. Among the possibilities, the evolutionary plasticity of p53 is the most controversial, partially due to the dizzying array of biological functions that have been attributed to different regulatory mechanisms of p53 signaling. Nearly 40 years after its discovery, this key tumor suppressor remains somewhat enigmatic. The intricate and diverse functions of p53 in regulating cell fate during cancer treatment are only the tip of the iceberg with respect to its equally complicated structural biology, which has been painstakingly revealed. Additionally, TP53 mutation is one of the most significant genetic alterations in cancer, contributing to rapid cancer cell growth and tumor progression. Here, we summarized recent advances that implicate altered p53 in modulating the response to various cancer therapies, including chemotherapy, radiotherapy, and immunotherapy. Furthermore, we also discussed potential strategies for targeting p53 as a therapeutic option for cancer.

p53 suppresses MHC class II presentation by intestinal epithelium to protect against radiation-induced gastrointestinal syndrome

Radiation-induced gastrointestinal syndrome is a major complication and limiting factor for radiotherapy. Tumor suppressor p53 has a protective role in radiation-induced gastrointestinal toxicity. However, its underlying mechanism remains unclear. Here we report that regulating the IL12-p40/MHC class II signaling pathway is a critical mechanism by which p53 protects against radiation-induced gastrointestinal syndrome. p53 inhibits the expression of inflammatory cytokine IL12-p40, which in turn suppresses the expression of MHC class II on intestinal epithelial cells to suppress T cell activation and inflammation post-irradiation that causes intestinal stem cell damage. Anti-IL12-p40 neutralizing antibody inhibits inflammation and rescues the defects in intestinal epithelial regeneration post-irradiation in p53-deficient mice and prolongs mouse survival. These results uncover that the IL12-p40/MHC class II signaling mediates the essential role of p53 in ensuring intestinal stem cell function and proper immune reaction in response to radiation to protect mucosal epithelium, and suggest a potential therapeutic strategy to protect against radiation-induced gastrointestinal syndrome.

Immunologic Signatures of Peripheral Blood T Cells Reveal the Outcome of p53MVA Vaccine and Pembrolizumab Treatment in Patients with Advanced Ovarian Cancer

PURPOSE

Our previous studies indicated that p53-reactive T cells were associated with clinical benefit in patients with advanced ovarian cancer who were treated with p53-expressing modified vaccinia Ankara (p53MVA) vaccine and gemcitabine chemotherapy. To replace chemotherapy with an approach that will enhance vaccine efficacy and antitumor immunity, we treated patients with p53MVA in combination with PD-1 checkpoint blocker, pembrolizumab. We also attempted to further characterize the activation status of T cells prior to vaccination and during treatment.

EXPERIMENTAL DESIGN

Patients received up to three triweekly vaccinations concurrent with pembrolizumab, followed by pembrolizumab monotherapy at 3-week intervals. Correlative studies analyzed peripheral blood T-cell phenotypes and profiles of immune function gene expression.

RESULTS

We observed 6/28 (21%) patients with a clinical benefit to therapy, including 3 partial responses (PR) and 3 patients with stable disease (SD) for 6+ months. The median progression-free survival was 1.8 months (95% confidence interval: 1.7-3.8) and median overall survival was 15.1 months (9.4-30.4). Two patients remain progression-free at 28 and 33 months. Of the 18 patients evaluable in correlative studies, 6 were immunologic responders of whom 5 had clinical benefit (3 PR, 2 SD). Immunologic non-responders expressed in pretreatment peripheral blood mononuclear cell samples high levels of mRNA for multiple molecules associated with terminally differentiated T cells.

CONCLUSIONS

p53MVA/pembrolizumab immunotherapy showed promising antitumor activity in patients who demonstrated functionally competent peripheral blood T cells. Detection of markers of terminally differentiated T cells before treatment may identify patients unlikely to respond to p53MVA/pembrolizumab.

SIGNIFICANCE

The activity of a combination immunotherapy of p53 vaccine and PD-1 checkpoint blockade in patients with platinum-resistant ovarian cancer was evaluated in a phase II trial. Clinical benefit was correlated with the responsive immune status of patients before and during the treatment, defining potential predictive markers for immune therapy.

A Second Career for p53 as A Broad-Spectrum Antiviral?

As the world exits the global pandemic caused by the previously unknown SARS-CoV-2, we also mark the 30th anniversary of p53 being named "molecule of the year" by Science based on its role as a tumor suppressor. Although p53 was originally discovered in association with a viral protein, studies on its role in preventing carcinogenesis have far overshadowed research related to p53's role in viral infections. Nonetheless, there is an extensive body of scientific literature demonstrating that p53 is a critical component of host immune responses to viral infections. It is striking that diverse viruses have independently developed an impressive repertoire of varied mechanisms to counter the host defenses that are mediated by and through p53. The variety of ways developed by viruses to disrupt p53 in their hosts attests to the protein's importance in combatting viral pathogens. The present perspective aims to make the case that p53 ought to be considered a virus suppressor in addition to a tumor suppressor. It is hoped that additional research aimed at more fully understanding the role of p53 in antiviral immunity will result in the world being better positioned for the next pandemic than it was when SARS-CoV-2 emerged to produce COVID-19.

APOBEC3G Is a p53-Dependent Restriction Factor in Respiratory Syncytial Virus Infection of Human Cells Included in the p53/Immune Axis

Identifying and understanding genetic factors that influence the propagation of the human respiratory syncytial virus (RSV) can lead to health benefits and possibly augment recent vaccine approaches. We previously identified a p53/immune axis in which the tumor suppressor p53 directly regulates the expression of immune system genes, including the seven members of the APOBEC3 family of DNA cytidine deaminases (A3), which are innate immune sentinels against viral infections. Here, we examined the potential p53 and A3 influence in RSV infection, as well as the overall p53-dependent cellular and p53/immune axis responses to infection. Using a paired p53 model system of p53+ and p53- human lung tumor cells, we found that RSV infection activates p53, leading to the altered p53-dependent expression of A3D, A3F, and A3G, along with p53 site-specific binding. Focusing on A3G because of its 10-fold-greater p53 responsiveness to RSV, the overexpression of A3G can reduce RSV viral replication and syncytial formation. We also observed that RSV-infected cells undergo p53-dependent apoptosis. The study was expanded to globally address at the transcriptional level the p53/immune axis response to RSV. Nearly 100 genes can be directly targeted by the p53/immune axis during RSV infection based on our p53BAER analysis (Binding And Expression Resource). Overall, we identify A3G as a potential p53-responsive restriction factor in RSV infection. These findings have significant implications for RSV clinical and therapeutic studies and other p53-influenced viral infections, including using p53 adjuvants to boost the response of A3 genes.

Network Pharmacology, Molecular Docking, and Molecular Dynamics Simulation to Elucidate the Molecular Targets and Potential Mechanism of Phoenix dactylifera (Ajwa Dates) against Candidiasis

Candidiasis, caused by opportunistic fungal pathogens of the Candida genus, poses a significant threat to immunocompromised individuals. Natural compounds derived from medicinal plants have gained attention as potential sources of anti-fungal agents. Ajwa dates (Phoenix dactylifera L.) have been recognized for their diverse phytochemical composition and therapeutic potential. In this study, we employed a multi-faceted approach to explore the anti-candidiasis potential of Ajwa dates' phytochemicals. Utilizing network pharmacology, we constructed an interaction network to elucidate the intricate relationships between Ajwa dates phytoconstituents and the Candida-associated molecular targets of humans. Our analysis revealed key nodes in the network (STAT3, IL-2, PTPRC, STAT1, CASP1, ALB, TP53, TLR4, TNF and PPARG), suggesting the potential modulation of several crucial processes (the regulation of the response to a cytokine stimulus, regulation of the inflammatory response, positive regulation of cytokine production, cellular response to external stimulus, etc.) and fungal pathways (Th17 cell differentiation, the Toll-like receptor signaling pathway, the C-type lectin receptor signaling pathway and necroptosis). To validate these findings, molecular docking studies were conducted, revealing the binding affinities of the phytochemicals towards selected Candida protein targets of humans (ALB-rutin (-9.7 kJ/mol), STAT1-rutin (-9.2 kJ/mol), STAT3-isoquercetin (-8.7 kJ/mol), IL2-β-carotene (-8.5 kJ/mol), CASP1-β-carotene (-8.2 kJ/mol), TP53-isoquercetin (-8.8 kJ/mol), PPARG-luteolin (-8.3 kJ/mol), TNF-βcarotene (-7.7 kJ/mol), TLR4-rutin (-7.4 kJ/mol) and PTPRC-rutin (-7.0 kJ/mol)). Furthermore, molecular dynamics simulations of rutin-ALB and rutin-STAT1 complex were performed to gain insights into the stability and dynamics of the identified ligand-target complexes over time. Overall, the results not only contribute to the understanding of the molecular interactions underlying the anti-fungal potential of specific phytochemicals of Ajwa dates in humans but also provide a rational basis for the development of novel therapeutic strategies against candidiasis in humans. This study underscores the significance of network pharmacology, molecular docking and dynamics simulations in accelerating the discovery of natural products as effective anti-fungal agents. However, further experimental validation of the identified compounds is warranted to translate these findings into practical therapeutic applications.

Intrinsic p53 Activation Restricts Gammaherpesvirus-Driven Germinal Center B Cell Expansion during Latency Establishment

Gammaherpesviruses (GHV) are DNA tumor viruses that establish lifelong latent infections in lymphocytes. For viruses such as Epstein-Barr virus (EBV) and murine gammaherpesvirus 68 (MHV68), this is accomplished through a viral gene-expression program that promotes cellular proliferation and differentiation, especially of germinal center (GC) B cells. Intrinsic host mechanisms that control virus-driven cellular expansion are incompletely defined. Using a small-animal model of GHV pathogenesis, we demonstrate in vivo that tumor suppressor p53 is activated specifically in B cells that are latently infected by MHV68. In the absence of p53, the early expansion of MHV68 latency was greatly increased, especially in GC B cells, a cell-type whose proliferation was conversely restricted by p53. We identify the B cell-specific latency gene M2, a viral promoter of GC B cell differentiation, as a viral protein sufficient to elicit a p53-dependent anti-proliferative response caused by Src-family kinase activation. We further demonstrate that EBV-encoded latent membrane protein 1 (LMP1) similarly triggers a p53 response in primary B cells. Our data highlight a model in which GHV latency gene-expression programs that promote B cell proliferation and differentiation to facilitate viral colonization of the host trigger aberrant cellular proliferation that is controlled by p53.

IMPORTANCE

Gammaherpesviruses cause lifelong infections of their hosts, commonly referred to as latency, that can lead to cancer. Latency establishment benefits from the functions of viral proteins that augment and amplify B cell activation, proliferation, and differentiation signals. In uninfected cells, off-schedule cellular differentiation would typically trigger anti-proliferative responses by effector proteins known as tumor suppressors. However, tumor suppressor responses to gammaherpesvirus manipulation of cellular processes remain understudied, especially those that occur during latency establishment in a living organism. Here we identify p53, a tumor suppressor commonly mutated in cancer, as a host factor that limits virus-driven B cell proliferation and differentiation, and thus, viral colonization of a host. We demonstrate that p53 activation occurs in response to viral latency proteins that induce B cell activation. This work informs a gap in our understanding of intrinsic cellular defense mechanisms that restrict lifelong GHV infection.

RYBP contributes to improved prognosis in colorectal cancer via regulation of cell cycle, apoptosis and oxaliplatin sensitivity

Ring1 and YY‑1 binding protein (RYBP) is a member of the polycomb repressive complex 1 and serves as a transcriptional suppressor via epigenetic modification. RYBP has a tumour‑suppressive role in solid tumours, but its function in colorectal cancer (CRC) remains unknown. The present study evaluated the expression of RYBP using immunohistochemistry in 140 cases of primary CRC and 11 patient‑matched cases of liver metastases. Using CRC cell lines with different TP53 gene status such as HCT116 (TP53wt/wt), HCT116 (TP53‑/‑), SW48 and DLD‑1 cells, proliferation, cell cycle progression and apoptosis, as well as the effect of RYBP on oxaliplatin sensitivity, were assessed. Clinical data showed that low RYBP expression was significantly associated with risk of distant metastasis and recurrence, and patients with high RYBP expression demonstrated significantly better cancer‑specific and disease‑free survival. In vitro experiments revealed that RYBP suppressed cell proliferation by inducing cell cycle arrest and apoptosis in TP53 wild‑type cells. In addition, endogenous RYBP overexpression enhanced sensitivity to oxaliplatin. Therefore, RYBP may contribute to improved prognosis in CRC by regulating the cell cycle, apoptosis and oxaliplatin sensitivity via the p53‑mediated pathway.

A bioinformatic analysis of the role of TP53 status on the infiltration of CD8+ T cells into the tumor microenvironment

CD8+ T cells play basic roles in the immune system in a tumor microenvironment (TME) to fight cancer. Several reports have suggested signs of the involvement of tumor protein p53 (TP53) in a complex immune system network. Moreover, our previous research indicated that TP53 orchestrates the polarization and infiltration of macrophages into the TME. In the present study, the clinical function of TP53 status (wild/mutant) in CD8+ T cell infiltration was assessed using more than 10,000 The Cancer Genome Atlas (TCGA) samples from 30 cancer types through Tumor Immune Estimation (TIMER). Our investigation revealed that CD8+ T cell infiltration was higher in head and neck squamous cell carcinoma (HNSC) and uterine corpus endometrial carcinoma (UCEC) patients with wild-type TP53 than in those with mutant TP53. Wild-type TP53 conferred a good prognosis for HNSC and UCEC (P<0.05). In contrast, CD8+ T cell infiltration in lung adenocarcinoma (LUAD) patients with wild-type TP53 was much lower than in those with mutant TP53. Notably, clinical outcomes for LUAD with wild-type TP53 were poor (P<0.05). This study was the first to provide insights into the novel association of TP53 with CD8+ T cells infiltration in the TME in patients with HNSC, LUAD, and UCEC. Therefore, TP53 status acts as a prognostic marker, and this can be used as a basis to further study the effect of targeting TP53 in these patients. Furthermore, our study found that TP53 status was a reliable predictive factor and therapeutic target in patients with HNSC and UCEC.

Recent advances in targeting the "undruggable" proteins: from drug discovery to clinical trials

Undruggable proteins are a class of proteins that are often characterized by large, complex structures or functions that are difficult to interfere with using conventional drug design strategies. Targeting such undruggable targets has been considered also a great opportunity for treatment of human diseases and has attracted substantial efforts in the field of medicine. Therefore, in this review, we focus on the recent development of drug discovery targeting "undruggable" proteins and their application in clinic. To make this review well organized, we discuss the design strategies targeting the undruggable proteins, including covalent regulation, allosteric inhibition, protein-protein/DNA interaction inhibition, targeted proteins regulation, nucleic acid-based approach, immunotherapy and others.

Biomolecular Condensation of the Human Papillomavirus E2 Master Regulator with p53: Implications in Viral Replication

p53 exerts its tumour suppressor activity by modulating hundreds of genes and it can also repress viral replication. Such is the case of human papillomavirus (HPV) through targeting the E2 master regulator, but the biochemical mechanism is not known. We show that the C-terminal DNA binding domain of HPV16 E2 protein (E2C) triggers heterotypic condensation with p53 at a precise 2/1 E2C/p53 stoichiometry at the onset for demixing, yielding large regular spherical droplets that increase in size with E2C concentration. Interestingly, transfection experiments show that E2 co-localizes with p53 in the nucleus with a grainy pattern, and recruits p53 to chromatin-associated foci, a function independent of the DNA binding capacity of p53 as judged by a DNA binding impaired mutant. Depending on the length, DNA can either completely dissolve or reshape heterotypic droplets into irregular condensates containing p53, E2C, and DNA, and reminiscent of that observed linked to chromatin. We propose that p53 is a scaffold for condensation in line with its structural and functional features, in particular as a promiscuous hub that binds multiple cellular proteins. E2 appears as both client and modulator, likely based on its homodimeric DNA binding nature. Our results, in line with the known role of condensation in eukaryotic gene enhancement and silencing, point at biomolecular condensation of E2 with p53 as a means to modulate HPV gene function, strictly dependent on host cell replication and transcription machinery.

Diepoxybutane induces the p53-dependent transactivation of the CCL4 gene that mediates apoptosis in exposed human lymphoblasts

Diepoxybutane (DEB) is the most toxic metabolite of the environmental chemical 1,3-butadiene. We previously demonstrated the occurrence of DEB-induced p53-mediated apoptosis in human lymphoblasts. The p53 protein functions as a master transcriptional regulator in orchestrating the genomic response to a variety of stress signals. Transcriptomic analysis indicated that C-C chemokine ligand 4 (CCL4) gene expression was elevated in a p53-dependent manner in DEB-exposed p53-proficient TK6 cells, but not in DEB-exposed p53-deficient NH32 cells. Thus, the objective of this study was to determine whether the CCL4 gene is a transcriptional target of p53 and deduce its role in DEB-induced apoptosis in human lymphoblasts. Endogenous and exogenous wild-type p53 transactivated the activity of the CCL4 promoter in DEB-exposed lymphoblasts, but mutant p53 activity on this promoter was reduced by ∼80% under the same experimental conditions. Knockdown of the upregulated CCL4 mRNA levels in p53-proficient TK6 cells inhibited DEB-induced apoptosis by ∼45%-50%. Collectively, these observations demonstrate for the first time that the CCL4 gene is upregulated by wild-type p53 at the transcriptional level, and this upregulation mediates apoptosis in DEB-exposed human lymphoblasts.

The Wheel of p53 Helps to Drive the Immune System

The p53 tumor suppressor protein is best known as an inhibitor of the cell cycle and an inducer of apoptosis. Unexpectedly, these functions of p53 are not required for its tumor suppressive activity in animal models. High-throughput transcriptomic investigations as well as individual studies have demonstrated that p53 stimulates expression of many genes involved in immunity. Probably to interfere with its immunostimulatory role, many viruses code for proteins that inactivate p53. Judging by the activities of immunity-related p53-regulated genes it can be concluded that p53 is involved in detection of danger signals, inflammasome formation and activation, antigen presentation, activation of natural killer cells and other effectors of immunity, stimulation of interferon production, direct inhibition of virus replication, secretion of extracellular signaling molecules, production of antibacterial proteins, negative feedback loops in immunity-related signaling pathways, and immunologic tolerance. Many of these p53 functions have barely been studied and require further, more detailed investigations. Some of them appear to be cell-type specific. The results of transcriptomic studies have generated many new hypotheses on the mechanisms utilized by p53 to impact on the immune system. In the future, these mechanisms may be harnessed to fight cancer and infectious diseases.

Targeting p53 pathways: mechanisms, structures, and advances in therapy

The TP53 tumor suppressor is the most frequently altered gene in human cancers, and has been a major focus of oncology research. The p53 protein is a transcription factor that can activate the expression of multiple target genes and plays critical roles in regulating cell cycle, apoptosis, and genomic stability, and is widely regarded as the "guardian of the genome". Accumulating evidence has shown that p53 also regulates cell metabolism, ferroptosis, tumor microenvironment, autophagy and so on, all of which contribute to tumor suppression. Mutations in TP53 not only impair its tumor suppressor function, but also confer oncogenic properties to p53 mutants. Since p53 is mutated and inactivated in most malignant tumors, it has been a very attractive target for developing new anti-cancer drugs. However, until recently, p53 was considered an "undruggable" target and little progress has been made with p53-targeted therapies. Here, we provide a systematic review of the diverse molecular mechanisms of the p53 signaling pathway and how TP53 mutations impact tumor progression. We also discuss key structural features of the p53 protein and its inactivation by oncogenic mutations. In addition, we review the efforts that have been made in p53-targeted therapies, and discuss the challenges that have been encountered in clinical development.

Mutant P53 in the formation and progression of the tumor microenvironment: Friend or foe

TP53 is the most frequently mutated gene in human cancer. It encodes the tumor suppressor protein p53, which suppresses tumorigenesis by acting as a critical transcription factor that can induce the expression of many genes controlling a plethora of fundamental cellular processes, including cell cycle progression, survival, apoptosis, and DNA repair. Missense mutations are the most frequent type of mutations in the TP53 gene. While these can have variable effects, they typically impair p53 function in a dominant-negative manner, thereby altering intra-cellular signaling pathways and promoting cancer development. Additionally, it is becoming increasingly apparent that p53 mutations also have non-cell autonomous effects that influence the tumor microenvironment (TME). The TME is a complex and heterogeneous milieu composed of both malignant and non-malignant cells, including cancer-associated fibroblasts (CAFs), adipocytes, pericytes, different immune cell types, such as tumor-associated macrophages (TAMs) and T and B lymphocytes, as well as lymphatic and blood vessels and extracellular matrix (ECM). Recently, a large body of evidence has demonstrated that various types of p53 mutations directly affect TME. They fine-tune the inflammatory TME and cell fate reprogramming, which affect cancer progression. Notably, re-educating the p53 signaling pathway in the TME may be an effective therapeutic strategy in combating cancer. Therefore, it is timely to here review the recent advances in our understanding of how TP53 mutations impact the fate of cancer cells by reshaping the TME.

Utility of atherosclerosis-associated serum antibodies against colony-stimulating factor 2 in predicting the onset of acute ischemic stroke and prognosis of colorectal cancer

Introduction

Autoantibodies against inflammatory cytokines may be used for the prevention of atherosclerosis. Preclinical studies consider colony-stimulating factor 2 (CSF2) as an essential cytokine with a causal relationship to atherosclerosis and cancer. We examined the serum anti-CSF2 antibody levels in patients with atherosclerosis or solid cancer.

Methods

We measured the serum anti-CSF2 antibody levels via amplified luminescent proximity homogeneous assay-linked immunosorbent assay based on the recognition of recombinant glutathione S-transferase-fused CSF2 protein or a CSF2-derived peptide as the antigen.

Results

The serum anti-CSF2 antibody (s-CSF2-Ab) levels were significantly higher in patients with acute ischemic stroke (AIS), acute myocardial infarction (AMI), diabetes mellitus (DM), and chronic kidney disease (CKD) compared with healthy donors (HDs). In addition, the s-CSF2-Ab levels were associated with intima-media thickness and hypertension. The analyzes of samples obtained from a Japan Public Health Center-based prospective study suggested the utility of s-CSF2-Ab as a risk factor for AIS. Furthermore, the s-CSF2-Ab levels were higher in patients with esophageal, colorectal, gastric, and lung cancer than in HDs but not in those with mammary cancer. In addition, the s-CSF2-Ab levels were associated with unfavorable postoperative prognosis in colorectal cancer (CRC). In CRC, the s-CSF2-Ab levels were more closely associated with poor prognosis in patients with p53-Ab-negative CRC despite the lack of significant association of the anti-p53 antibody (p53-Ab) levels with the overall survival.

Conclusion

S-CSF2-Ab was useful for the diagnosis of atherosclerosis-related AIS, AMI, DM, and CKD and could discriminate poor prognosis, especially in p53-Ab-negative CRC.

5-Hydroxymethylfurfural induces mice frailty through cell senescence-associated sarcopenia caused by chronic inflammation

Objective

5-Hydroxymethylfurfural (5-HMF) is an important component of air pollution, confirmed to be a risk factor for pulmonary inflammation. However, its association with general health is unknown. This article aimed to clarify the effect and mechanism of 5-HMF in the occurrence and aggravation of frailty in mice by investigating whether exposure to 5-HMF was linked to the occurrence and aggravation of mice frailty.

Methods

Twelve male C57BL/6 mice (12-month-old, 38 ± 1 g) were randomly divided into the control group and the 5-HMF group. The 5-HMF group was treated with 5-HMF (1 mg/kg/day, respiratory exposure) for 12 months, whereas the control group was treated with equal amounts of sterile water. After the intervention, the ELISA method was used to detect the serum inflammation level of the mice, and the physical performance and frail status were evaluated using a Fried physical phenotype-based assessment tool. The differences in the body compositions were calculated from their MRI images, and the pathological changes in their gastrocnemius muscle were revealed using the H&E staining. Furthermore, the senescence of skeletal muscle cells was evaluated by measuring the expression levels of senescence-related proteins by the western blotting.

Results

In the 5-HMF group, serum inflammatory factors IL-6, TNF-α, and CRP levels were significantly raised (p < 0.01). Mice in this group had higher frailty scores and significantly reduced grip strength (p < 0.001), slower weight gains, less WVgastrocnemius muscle masses, and lower sarcopenia indices (SI). In addition, the cross-sectional areas of their skeletal muscles were reduced, and the levels of their cell senescence-related proteins (p53, p21, p16, SOD1, SOD2, SIRT1, SIRT3) were considerably altered (p < 0.01).

Conclusion

5-HMF may induce chronic and systemic inflammation, which in turn accelerates the progression of the frailty of mice through cell senescence.

Liaisons dangereuses: Intrinsic Disorder in Cellular Proteins Recruited to Viral Infection-Related Biocondensates

Liquid-liquid phase separation (LLPS) is responsible for the formation of so-called membrane-less organelles (MLOs) that are essential for the spatio-temporal organization of the cell. Intrinsically disordered proteins (IDPs) or regions (IDRs), either alone or in conjunction with nucleic acids, are involved in the formation of these intracellular condensates. Notably, viruses exploit LLPS at their own benefit to form viral replication compartments. Beyond giving rise to biomolecular condensates, viral proteins are also known to partition into cellular MLOs, thus raising the question as to whether these cellular phase-separating proteins are drivers of LLPS or behave as clients/regulators. Here, we focus on a set of eukaryotic proteins that are either sequestered in viral factories or colocalize with viral proteins within cellular MLOs, with the primary goal of gathering organized, predicted, and experimental information on these proteins, which constitute promising targets for innovative antiviral strategies. Using various computational approaches, we thoroughly investigated their disorder content and inherent propensity to undergo LLPS, along with their biological functions and interactivity networks. Results show that these proteins are on average, though to varying degrees, enriched in disorder, with their propensity for phase separation being correlated, as expected, with their disorder content. A trend, which awaits further validation, tends to emerge whereby the most disordered proteins serve as drivers, while more ordered cellular proteins tend instead to be clients of viral factories. In light of their high disorder content and their annotated LLPS behavior, most proteins in our data set are drivers or co-drivers of molecular condensation, foreshadowing a key role of these cellular proteins in the scaffolding of viral infection-related MLOs.

p53 engages the cGAS/STING cytosolic DNA sensing pathway for tumor suppression

Tumor suppression by TP53 involves cell-autonomous and non-cell-autonomous mechanisms. TP53 can suppress tumor growth by modulating immune system functions; however, the mechanistic basis for this activity is not well understood. We report that p53 promotes the degradation of the DNA exonuclease TREX1, resulting in cytosolic dsDNA accumulation. We demonstrate that p53 requires the ubiquitin ligase TRIM24 to induce TREX1 degradation. The cytosolic DNA accumulation resulting from TREX1 degradation activates the cytosolic DNA-sensing cGAS/STING pathway, resulting in induction of type I interferons. TREX1 overexpression sufficed to block p53 activation of the cGAS/STING pathway. p53-mediated induction of type I interferon (IFNB1) is suppressed by cGAS/STING knockout, and p53's tumor suppressor activities are compromised by the loss of signaling through the cGAS/STING pathway. Thus, our study reveals that p53 utilizes the cGAS/STING innate immune system pathway for both cell-intrinsic and cell-extrinsic tumor suppressor activities.

Drugging p53 in cancer: one protein, many targets

Mutations in the TP53 tumour suppressor gene are very frequent in cancer, and attempts to restore the functionality of p53 in tumours as a therapeutic strategy began decades ago. However, very few of these drug development programmes have reached late-stage clinical trials, and no p53-based therapeutics have been approved in the USA or Europe so far. This is probably because, as a nuclear transcription factor, p53 does not possess typical drug target features and has therefore long been considered undruggable. Nevertheless, several promising approaches towards p53-based therapy have emerged in recent years, including improved versions of earlier strategies and novel approaches to make undruggable targets druggable. Small molecules that can either protect p53 from its negative regulators or restore the functionality of mutant p53 proteins are gaining interest, and drugs tailored to specific types of p53 mutants are emerging. In parallel, there is renewed interest in gene therapy strategies and p53-based immunotherapy approaches. However, major concerns still remain to be addressed. This Review re-evaluates the efforts made towards targeting p53-dysfunctional cancers, and discusses the challenges encountered during clinical development.

Epitope identification for p53R273C mutant

BACKGROUND

With the rise of immunotherapy based on cancer neoantigen, identification of neoepitopes has become an urgent problem to be solved. The TP53 R273C mutation is one of the hotspot mutations of TP53, however, the immunogenicity of this mutation is not yet clear. The aim of this study is to identify potential epitopes for p53R273C mutant.

METHODS

In this study, bioinformatic methods, peptide exchange assay, and peptide-immunized human leukocyte antigen (HLA) transgenic mouse model were used to explore the immunogenicity of this mutation.

RESULTS

Peptides with higher affinity to common HLA-A alleles (A*11:01, A*02:01) were discovered by computational prediction. All the 8-11 mer peptides contain the mutation site were synthesized and soluble peptides were used in the peptide exchange assay. However, the exchange efficiencies of these predicted peptides to HLAs were lower. Fortunately, other peptides with higher exchange efficiency were discovered. Then, the immunogenicity of these peptides was validated with the HLA-A2 transgenic mice model.

CONCLUSION

We identified three potential neoepitopes of p53R273C for HLA-A*02:01, one potential neoepitope for HLA-A*11:01 and no neoepitope for HLA-A*24:02.

A comprehensive study of p53 protein

The protein p53 has been extensively investigated since it was found 43 years ago and has become a "guardian of the genome" that regulates the division of cells by preventing the growth of cells and dividing them, that is, inhibits the development of tumors. Initial proof of protein existence by researchers in the mid-1970s was found by altering and regulating the SV40 big T antigen termed the A protein. Researchers demonstrated how viruses play a role in cancer by employing viruses' ability to create T-antigens complex with viral tumors, which was discovered in 1979 following a viral analysis and cancer analog research. Researchers later in the year 1989 explained that in Murine Friend, a virus-caused erythroleukemia, commonly found that p53 was inactivated to suggest that p53 could be a "tumor suppressor gene." The TP53 gene, encoding p53, is one of human cancer's most frequently altered genes. The protein-regulated biological functions of all p53s include cell cycles, apoptosis, senescence, metabolism of the DNA, angiogenesis, cell differentiation, and immunological response. We tried to unfold the history of the p53 protein, which was discovered long back in 1979, that is, 43 years of research on p53, and how p53's function has been developed through time in this article.

p53 Mutation as Plausible Predictor for Endocrine Resistance Therapy in Luminal Breast Cancer

Endocrine therapy resistance in Luminal Breast Cancer is a significant issue to be tackled, but currently, no specific biomarker could be used to anticipate this event. p53 mutation is widely known as one of Breast Cancer's most prominent genetic alterations. Its mutation could generate various effects in Estrogen Receptor and Progesterone Receptor molecular works, tangled in events leading to the aggravation of endocrine therapy resistance. Hence the possibility of p53 mutation utilization as an endocrine therapy resistance predictive biomarker is plausible. The purpose of this review is to explore the latest knowledge of p53 role in Estrogen Receptor and Progesterone Receptor molecular actions, thus aggravating the Endocrine Therapy resistance in Luminal Breast Cancer, from which we could define possibilities and limitations to utilize p53 as the predictive biomarker of endocrine therapy resistance in Luminal Breast Cancer.

TP53-Mutated Myelodysplastic Syndrome and Acute Myeloid Leukemia: Biology, Current Therapy, and Future Directions

TP53-mutated myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) form a distinct group of myeloid disorders with dismal outcomes. TP53-mutated MDS and AML have lower response rates to either induction chemotherapy, hypomethylating agent-based regimens, or venetoclax-based therapies compared with non-TP53-mutated counterparts and a poor median overall survival of 5 to 10 months. Recent advances have identified novel pathogenic mechanisms in TP53-mutated myeloid malignancies, which have the potential to improve treatment strategies in this distinct clinical subgroup. In this review, we discuss recent insights into the biology of TP53-mutated MDS/AML, current treatments, and emerging therapies, including immunotherapeutic and nonimmune-based approaches for this entity.

SIGNIFICANCE

Emerging data on the impact of cytogenetic aberrations, TP53 allelic burden, immunobiology, and tumor microenvironment of TP53-mutated MDS and AML are further unraveling the complexity of this disease. An improved understanding of the functional consequences of TP53 mutations and immune dysregulation in TP53-mutated AML/MDS coupled with dismal outcomes has resulted in a shift from the use of cytotoxic and hypomethylating agent-based therapies to novel immune and nonimmune strategies for the treatment of this entity. It is hoped that these novel, rationally designed combinations will improve outcomes in this area of significant unmet need.

The complexity of p53-mediated metabolic regulation in tumor suppression

Although the classic activities of p53 including induction of cell-cycle arrest, senescence, and apoptosis are well accepted as critical barriers to cancer development, accumulating evidence suggests that loss of these classic activities is not sufficient to abrogate the tumor suppression activity of p53. Numerous studies suggest that metabolic regulation contributes to tumor suppression, but the mechanisms by which it does so are not completely understood. Cancer cells rewire cellular metabolism to meet the energetic and substrate demands of tumor development. It is well established that p53 suppresses glycolysis and promotes mitochondrial oxidative phosphorylation through a number of downstream targets against the Warburg effect. The role of p53-mediated metabolic regulation in tumor suppression is complexed by its function to promote both cell survival and cell death under different physiological settings. Indeed, p53 can regulate both pro-oxidant and antioxidant target genes for complete opposite effects. In this review, we will summarize the roles of p53 in the regulation of glucose, lipid, amino acid, nucleotide, iron metabolism, and ROS production. We will highlight the mechanisms underlying p53-mediated ferroptosis, AKT/mTOR signaling as well as autophagy and discuss the complexity of p53-metabolic regulation in tumor development.

CDCA3 Predicts Poor Prognosis and Affects CD8+ T Cell Infiltration in Renal Cell Carcinoma

Background

Cell division cycle associated 3 (CDCA3) mediates the ubiquitination WEE1 kinase at G2/M phase. However, its contribution to cancer immunity remains uncertain.

Methods

We first evaluated the effect of CDCA3 on the prognosis of patients with renal cell carcinoma (RCC). The results of bioinformatics analysis were verified by the tissue microarray, immunofluorescence (IF) staining, CCK-8 assay, colony formation, cell cycle, and Western blot.

Results

Bioinformatics analysis predicated CDCA3 was an independent predictor of poor prognosis in RCC and was associated with poor TNM stage and grade. CDCA3 was related to the infiltration of CD8⁺ T cells and Tregs. Tissue microarray demonstrated that CDCA3 was strongly associated with poor prognosis and positively relevant to CD8⁺ T infiltration. In vitro experiments showed that exgenomic interference of CDCA3 could attenuate cellular proliferation, arrest cell cycle, and blockade accumulation of CDK4, Bub3, and Cdc20 in mitosis process.

Conclusion

CDCA3 presents as a good biomarker candidate to predict the prognosis of RCC patients and potentiates the immune tumor microenvironment (TME) of RCC.

Targeting Mutant p53 for Cancer Treatment: Moving Closer to Clinical Use?

Simple Summary

Cancer is largely caused by genetic alterations such as mutations in a group of genes known as cancer driver genes. Many of the key advances in cancer treatment in recent years have involved blocking these driver genes using a new generation of anti-cancer drugs. Although p53 is the most frequently mutated gene in human cancers, historically, it has proved difficult to develop drugs against it. However, recently, several new drugs have become available for neutralizing the cancer-promoting effects of mutant p53. The aim of this article is to discuss the most promising of these drugs, especially those that are being investigated in clinical trials.

Abstract

Mutant p53 is one of the most attractive targets for new anti-cancer drugs. Although traditionally regarded as difficult to drug, several new strategies have recently become available for targeting the mutant protein. One of the most promising of these involves the use of low molecular weight compounds that promote refolding and reactivation of mutant p53 to its wild-type form. Several such reactivating drugs are currently undergoing evaluation in clinical trials, including eprenetapopt (APR-246), COTI-2, arsenic trioxide and PC14586. Of these, the most clinically advanced for targeting mutant p53 is eprenetapopt which has completed phase I, II and III clinical trials, the latter in patients with mutant TP53 myelodysplastic syndrome. Although no data on clinical efficacy are currently available for eprenetapopt, preliminary results suggest that the drug is relatively well tolerated. Other strategies for targeting mutant p53 that have progressed to clinical trials involve the use of drugs promoting degradation of the mutant protein and exploiting the mutant protein for the development of anti-cancer vaccines. With all of these ongoing trials, we should soon know if targeting mutant p53 can be used for cancer treatment. If any of these trials show clinical efficacy, it may be a transformative development for the treatment of patients with cancer since mutant p53 is so prevalent in this disease.

Identification of molecular mechanism and key biomarkers in membranous nephropathy by bioinformatics analysis

OBJECTIVES

Membranous nephropathy (MN) is an autoimmune nephropathy. The incidence of MN is increasing gradually in recent years. Previous studies focused on antibody production, complement activation and podocyte injury in MN. However, the etiology and underlying mechanism of MN remain to be further studied.

METHODS

GSE104948 and GSE108109 of glomerular expression profile were downloaded from Gene Expression Omnibus (GEO) database, GSE47184, GSE99325, GSE104954, GSE108112, GSE133288 of renal tubule expression profile, and GSE73953 of peripheral blood mononuclear cells (PBMCs) expression profile. After data integration by Networkanalyst, differentially expressed genes (DEGs) between MN and healthy samples were obtained. DEGs were enriched in gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG), and protein-protein interaction (PPI) networks of these genes were constructed through Metascape, etc. We further understood the function of hub genes through gene set enrichment analysis (GSEA). The diagnostic value of DEGs in MN was evaluated by receiver operating characteristic (ROC) analysis.

RESULTS

A total of 3 genes (TP53, HDAC5, and SLC2A3) were screened out. Among them, the up-regulated TP53 expression may be closely related to MN renal pathological changes. However, the expression of MN podocyte target antigen was not significantly different from that of healthy controls. In addition, the changes of Wnt signaling pathway in PBMCs and the effects of SLC2A3 on the differentiation of M2 monocyte need further study.

CONCLUSION

It is difficult to unify a specific mechanism for the changes of glomerulus, renal tubules and PBMCs in MN patients. This may be related to the pathogenesis, pathology and immune characteristics of MN. MN podocyte target antigen may not be the root cause of the disease, but a stage result in the pathogenesis process.

New Drug Development and Clinical Trial Design by Applying Genomic Information Management

Depending on the patients’ genotype, the same drug may have different efficacies or side effects. With the cost of genomic analysis decreasing and reliability of analysis methods improving, vast amount of genomic information has been made available. Several studies in pharmacology have been based on genomic information to select the optimal drug, determine the dose, predict efficacy, and prevent side effects. This paper reviews the tissue specificity and genomic information of cancer. If the tissue specificity of cancer is low, cancer is induced in various organs based on a single gene mutation. Basket trials can be performed for carcinomas with low tissue specificity, confirming the efficacy of one drug for a single gene mutation in various carcinomas. Conversely, if the tissue specificity of cancer is high, cancer is induced in only one organ based on a single gene mutation. An umbrella trial can be performed for carcinomas with a high tissue specificity. Some drugs are effective for patients with a specific genotype. A companion diagnostic strategy that prescribes a specific drug for patients selected with a specific genotype is also reviewed. Genomic information is used in pharmacometrics to identify the relationship among pharmacokinetics, pharmacodynamics, and biomarkers of disease treatment effects. Utilizing genomic information, sophisticated clinical trials can be designed that will be better suited to the patients of specific genotypes. Genomic information also provides prospects for innovative drug development. Through proper genomic information management, factors relating to drug response and effects can be determined by selecting the appropriate data for analysis and by understanding the structure of the data. Selecting pre-processing and appropriate machine-learning libraries for use as machine-learning input features is also necessary. Professional curation of the output result is also required. Personalized medicine can be realized using a genome-based customized clinical trial design.

Crocodile Oil Modulates Inflammation and Immune Responses in LPS-Stimulated RAW 264.7 Macrophages

Crocodile oil (CO) is generated from the fatty tissues of crocodiles as a by-product of commercial aquaculture. CO is extensively applied in the treatment of illnesses including asthma, emphysema, skin ulcers, and cancer, as well as wound healing. Whether CO has anti-inflammatory properties and encourages an immune response remains uncertain. The impact of CO on inflammatory conditions in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and the mechanisms behind it were examined in this work. Cells were treated with 0.125–2% CO dissolved in 0.5% propylene glycol with or without LPS. The production and expression of inflammatory cytokines and mediators were also examined in this research. CO reduced the synthesis and gene expression of interleukin-6 (IL-6). Consistently, CO inhibited the expression and synthesis of inflammatory markers including cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), nitric oxide (NO), and nuclear factor kappa B (NF-κB). Furthermore, CO reduced the effects of DNA damage. CO also increased the cell-cycle regulators, cyclins D2 and E2, which improved the immunological response. CO might thus be produced as a nutraceutical supplement to help avoid inflammatory diseases.

Complementary omics strategies to dissect p53 signaling networks under nutrient stress

Signaling trough p53is a major cellular stress response mechanism and increases upon nutrient stresses such as starvation. Here, we show in a human hepatoma cell line that starvation leads to robust nuclear p53 stabilization. Using BioID, we determine the cytoplasmic p53 interaction network within the immediate-early starvation response and show that p53 is dissociated from several metabolic enzymes and the kinase PAK2 for which direct binding with the p53 DNA-binding domain was confirmed with NMR studies. Furthermore, proteomics after p53 immunoprecipitation (RIME) uncovered the nuclear interactome under prolonged starvation, where we confirmed the novel p53 interactors SORBS1 (insulin receptor signaling) and UGP2 (glycogen synthesis). Finally, transcriptomics after p53 re-expression revealed a distinct starvation-specific transcriptome response and suggested previously unknown nutrient-dependent p53 target genes. Together, our complementary approaches delineate several nodes of the p53 signaling cascade upon starvation, shedding new light on the mechanisms of p53 as nutrient stress sensor. Given the central role of p53 in cancer biology and the beneficial effects of fasting in cancer treatment, the identified interaction partners and networks could pinpoint novel pharmacologic targets to fine-tune p53 activity.

p53/NF-kB Balance in SARS-CoV-2 Infection: From OMICs, Genomics and Pharmacogenomics Insights to Tailored Therapeutic Perspectives (COVIDomics)

SARS-CoV-2 infection affects different organs and tissues, including the upper and lower airways, the lung, the gut, the olfactory system and the eye, which may represent one of the gates to the central nervous system. Key transcriptional factors, such as p53 and NF-kB and their reciprocal balance, are altered upon SARS-CoV-2 infection, as well as other key molecules such as the virus host cell entry mediator ACE2, member of the RAS-pathway. These changes are thought to play a central role in the impaired immune response, as well as in the massive cytokine release, the so-called cytokine storm that represents a hallmark of the most severe form of SARS-CoV-2 infection. Host genetics susceptibility is an additional key side to consider in a complex disease as COVID-19 characterized by such a wide range of clinical phenotypes. In this review, we underline some molecular mechanisms by which SARS-CoV-2 modulates p53 and NF-kB expression and activity in order to maximize viral replication into the host cells. We also face the RAS-pathway unbalance triggered by virus-ACE2 interaction to discuss potential pharmacological and pharmacogenomics approaches aimed at restoring p53/NF-kB and ACE1/ACE2 balance to counteract the most severe forms of SARS-CoV-2 infection.

TP53 R273C Mutation Is Associated With Poor Prognosis in LGG Patients

Purpose: With the progress of cancer immunotherapy, hotspot mutations of common oncogenes and tumor suppressors are becoming new potential therapeutic targets. TP53 R273C mutation is one of the hotspot mutations of TP53, and it has a higher frequency in low-grade glioma (LGG). However, the function of this mutation and its prognostic significance in LGG are not still clear.

Methods: To address this question, RNA sequencing, clinical, and SNP data of LGG patients from the TCGA database were downloaded. The Kaplan–Meier (KM) method was used for survival analysis. Immune cell populations in this cohort were assessed via the MCP counter and CIBERSORT. DNA damage/repair scores were calculated by GSVA analysis. WGCNA was conducted to identify genes related to TMB.

Results: In the context of IDH1/2 mutation, LGG patients with TP53 R273C mutation had worse prognosis than other mutation types and wild types. This conclusion is still valid in LGG patients who had received chemotherapy or radiotherapy. Considering the 1p19q codeletion status, it was found that patients with both R273C mutation and 1p19q non-codeletion had the worst prognosis. Further analysis showed that LGG patients with TP53 R273C mutation had higher M2 macrophage infiltration and tumor mutation burden (TMB) than that of TP53 wild-type LGG patients, and higher TMB indicates poor prognosis in LGG patients. Furthermore, we identified genes which could be associated with higher M2 macrophage infiltration and TMB in LGG patients with TP53 R273C mutation.

Conclusion: The study indicates that TP53 R273C mutation is very likely oncogenic and may be used as an indicator of the prognosis of LGG.

TP53 Gene Therapy as a Potential Treatment for Patients with COVID-19

SGT-53 is a novel investigational agent that comprises an immunoliposome carrying a plasmid vector driving expression of the human TP53 gene that encodes wild-type human p53. SGT-53 is currently in phase II human trials for advanced pancreatic cancer. Although p53 is best known as a tumor suppressor, its participation in both innate and adaptive immune responses is well documented. It is now clear that p53 is an important component of the host response to various viral infections. To facilitate their viral life cycles, viruses have developed a diverse repertoire of strategies for counteracting the antiviral activities of host immune system by manipulating p53-dependent pathways in host cells. Coronaviruses reduce endogenous p53 levels in the cells they infect by enhancing the degradation of p53 in proteasomes. Thus, interference with p53 function is an important component in viral pathogenesis. Transfection of cells by SGT-53 has been shown to transiently produce exogenous p53 that is active as a pleiotropic transcription factor. We herein summarize the rationale for repurposing SGT-53 as a therapy for infection by SARS-CoV-2, the pathogen responsible for the COVID-19 pandemic. Because p53 regulation was found to play a crucial role in different infection stages of a wide variety of viruses, it is rational to believe that restoring p53 function based on SGT-53 treatment may lead to beneficial therapeutic outcomes for infectious disease at large including heretofore unknown viral pathogens that may emerge in the future.

Targeting the P53 Protein for Cancer Therapies: The Translational Impact of P53 Research

It is only recently that drugs targeting K-RAS and Tp53 missense mutations have been developed, and along with the allele specific nature of some of these drugs comes the possibility of combining them with the immunologic therapies for cancers. It has taken about 40 years since their discoveries to understand the pathways they command, how they function, and how they interact with the environment of the cells they control. This communication focuses on the transfer of some of the hard won information about the p53 protein, its mutations, structures, and activities learned in the basic science laboratory and translated to the clinic.

DNA Damage Response (DDR) proteins in canine cancer as potential research targets in comparative oncology

The DNA damage response (DDR) is a complex signal transduction network that is activated when endogenous or exogenous genotoxins damage or interfere with the replication of genomic DNA. Under such conditions, the DDR promotes DNA repair and ensures accurate replication and division of the genome. High levels of genomic instability are frequently observed in cancers and can stem from germline loss‐of‐function mutations in certain DDR genes, such as BRCA1, BRCA2, and p53, that form the basis of human cancer predisposition syndromes. In addition, mutation and/or aberrant expression of multiple DDR genes are frequently observed in sporadic human cancers. As a result, the DDR is considered to represent a viable target for cancer therapy in humans and a variety of strategies are under investigation. Cancer is also a significant cause of mortality in dogs, a species that offers certain advantages for experimental oncology. Domestic dogs present numerous inbred lines, many of which display predisposition to specific forms of cancer and the study of which may provide insight into the biological basis of this susceptibility. In addition, clinical trials are possible in dogs and may lead to therapeutic insights that could ultimately be extended to humans. Here we review what is known specifically about the DDR in dogs and discuss how this knowledge could be extended and exploited to advance experimental oncology in this species.

A Bioactive Extract Rich in Triterpenic Acid and Polyphenols from Olea europaea Promotes Systemic Immunity and Protects Atlantic Salmon Smolts Against Furunculosis

In the present study, the modulation of the transcriptional immune response (microarray analysis) in the head kidney (HK) of the anadromous fish Atlantic salmon (Salmo salar) fed a diet supplemented with an olive fruit extract (AQUOLIVE^®) was evaluated. At the end of the trial (133 days), in order to investigate the immunomodulatory properties of the phytogenic tested against a bacterial infection, an in vivo challenge with Aeromonas salmonicida was performed. A total number of 1,027 differentially expressed genes (DEGs) (805 up- and 222 downregulated) were found when comparing the transcriptomic profiling of the HK from fish fed the control and AQUOLIVE^® diets. The HK transcripteractome revealed an expression profile that mainly favored biological processes related to immunity. Particularly, the signaling of i-kappa B kinase/NF-kappa and the activation of leukocytes, such as granulocytes and neutrophils degranulation, were suggested to be the primary actors of the innate immune response promoted by the tested functional feed additive in the HK. Moreover, the bacterial challenge with A. salmonicida that lasted 12 days showed that the cumulative survival was higher in fish fed the AQUOLIVE^® diet (96.9 ± 6.4%) than the control group (60.7 ± 13.5%). These results indicate that the dietary supplementation of AQUOLIVE^® at the level of 0.15% enhanced the systemic immune response and reduced the A. salmonicida cumulative mortality in Atlantic salmon smolts.

Investigation on the Potential Correlation Between TP53 and Esophageal Cancer

Background:TP53 family members play an indispensable role in various human cancers, while the gene expression profiles, prognostic value, and potential mechanism in esophageal cancer (ESCA) are yet unclear.

Methods: The expression and roles of TP53 family members in ESCA were investigated using the Cancer Genome Atlas (TCGA), Tumor Immune Estimation Resource (TIMER), Kaplan–Meier plotter, gene set enrichment analysis (GSEA), and UALCAN databases. The expression of TP53 between ESCA and the corresponding adjacent tissues was validated using qRT-PCR. Furthermore, the effects of TP53 on esophageal squamous cell carcinoma (ESCC) cell migration and proliferation were examined using the Transwell assay, scratch test, and crystal violet assay. The correlation between TP53 and mTOR pathways was evaluated by Western blotting.

Results: This study showed a correlation between high mRNA expression of TP53 members (TP53, TP63, and TP73) and clinical cancer stages and nodal metastasis status in ESCA patients. Moreover, the expression of TP53 was significantly associated with the overall survival (OS) of ESCA patients. Additional experiments verified that the mRNA of TP53 was upregulated in ESCC patients. Moreover, the downregulated expression of TP53 significantly retarded ESCC cell migration and proliferation and might activate the mTOR signaling pathway and inhibit TP53-dependent autophagy.

Conclusion:TP53 has a prognostic value in ESCA and may be a leading factor in promoting ESCA pathogenesis.

The Enhancing Immune Response and Anti-Inflammatory Effects of Caulerpa lentillifera Extract in RAW 264.7 Cells

Background: Caulerpa lentillifera (CL) is a green seaweed, and its edible part represents added value as a functional ingredient. CL was dried and extracted for the determination of its active compounds and the evaluation of its biological activities. The major constituents of CL extract (CLE), including tannic acid, catechin, rutin, and isoquercetin, exhibited beneficial effects, such as antioxidant activity, anti-diabetic activity, immunomodulatory effects, and anti-cancer activities in in vitro and in vivo models. Whether CLE has an anti-inflammatory effect and immune response remains unclear. Methods: This study examined the effect of CLE on the inflammatory status and immune response of lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and the mechanisms involved therein. RAW264.7 cells were treated with different concentrations of CLE (0.1–1000 µg/mL) with or without LPS (1 µg/mL) for 24 h. Expression and production of the inflammatory cytokines, enzymes, and mediators were evaluated. Results: CLE suppressed expression and production of the pro-inflammatory cytokines IL-6 and TNF-α. Moreover, CLE inhibited expression and secretion of the inflammatory enzyme COX-2 and the mediators PGE2 and NO. CLE also reduced DNA damage. Furthermore, CLE stimulated the immune response by modulating the cell cycle regulators p27, p53, cyclin D2, and cyclin E2. Conclusions: CLE inhibits inflammatory responses in LPS-activated macrophages by downregulating inflammatory cytokines and mediators. Furthermore, CLE has an immunomodulatory effect by modulating cell cycle regulators.

Zebrafish BID Exerts an Antibacterial Role by Negatively Regulating p53, but in a Caspase-8-Independent Manner

Bid (BH3-interacting domain death agonist), a member of the Bcl-2 family, plays a crucial role in the initiation of apoptosis. Independent of its apoptotic function, Bid is also involved in the regulation of inflammation and innate immunity. However, the role of Bid during bacterial pathogen infection remains unclear. In the present study, Bid of zebrafish (Dario rerio) was cloned and its functions during Edwardsiella ictaluri infection were investigated. Zebrafish Bid enhances the apoptosis rate of Epithelioma papulosum cyprini (EPC) cells following E. ictaluri infection. Importantly, in vitro and in vivo bacterial invasion assays showed that overexpressed Bid could significantly inhibit the invasion and proliferation of E. ictaluri. Real-time qPCR analysis revealed that p53 gene expression was downregulated in embryos microinjected with Bid-FLAG. Further, in vitro and in vivo bacterial invasion assays showed that overexpressed p53 increased the invasion and proliferation of E. ictaluri. Moreover, the invasion and proliferation of E. ictaluri were inhibited when co-overexpressing Bid and p53 in vivo and in vitro. Further, the numbers of E. ictaluri in larvae treated with Z-IETD-FMK (caspase-8 inhibitor) were higher than those of larvae without Z-IETD-FMK treatment, while the number of E. ictaluri in larvae microinjected with bid-Flag decreased significantly, even if the larvae were treated in advance with Z-IETD-FMK. Collectively, our study demonstrated a novel antibacterial activity of fish Bid, providing evidence for understanding the function of apoptosis associated gene in pathogen infection.

Peptide-Based Vaccines for Hepatocellular Carcinoma: A Review of Recent Advances

Primary liver cancer is the sixth most commonly diagnosed cancer and the third leading cause of cancer-related deaths worldwide. After surgery, up to 70% of patients experience relapses. The current first-line therapy for advanced cases of hepatocellular carcinoma (HCC) comprises sorafenib and lenvatinib administered as single-drug therapies. Regorafenib, cabozantinib, and ramucirumab are administered as second-line therapies. Recently, it has been reported that using the immune checkpoint inhibitors atezolizumab (anti-PDL1 antibody) and bevacizumab (anti-VEGF antibody) leads to longer overall survival of unresectable cases, when compared with the use of sorafenib. The role of cancer immunity against HCC has attracted the attention of clinicians. In this review, we describe our phase I/II clinical trials of peptide vaccines targeting GPC3 in HCC and discuss the potential of peptide vaccines targeting common cancer antigens that are highly expressed in HCC, such as WT-I, AFP, ROBO1, and FOXM1. Further, we introduce recent cancer vaccines targeting neoantigens, which have attracted attention in recent times, as well as present our preclinical studies, the results of which might aid to initiate a neoantigen vaccine clinical trial, which would be the first of its kind in Japan.

Promising New Tools for Targeting p53 Mutant Cancers: Humoral and Cell-Based Immunotherapies

Transcription factor and oncosuppressor protein p53 is considered as one of the most promising molecular targets that remains a high-hanging fruit in cancer therapy. TP53 gene encoding the p53 protein is known to be the most frequently mutated gene in human cancers. The loss of transcriptional functions caused by mutations in p53 protein leads to deactivation of intrinsic tumor suppressive responses associated with wild-type (WT) p53 and acquisition of new pro-oncogenic properties such as enhanced cell proliferation, metastasis and chemoresistance. Hotspot mutations of p53 are often immunogenic and elicit intratumoral T cell responses to mutant p53 neoantigens, thus suggesting this protein as an attractive candidate for targeted anti-cancer immunotherapies. In this review we discuss the possible use of p53 antigens as molecular targets in immunotherapy, including the application of T cell receptor mimic (TCRm) monoclonal antibodies (mAbs) as a novel powerful approach.