Deciphering p53 signaling in tumor suppression

Better neuroprotective profile of caffeic acid phenyl ester over resveratrol in non-traumatic ischemia-reperfusion injury of the spinal cord

BACKGROUND

Spinal cord ischemia has serious sequelae. The aim of this study is to investigate the effects of resveratrol and caffeic acid phenyl ester (CAPE), a propolis derivative, on spinal cord injury induced by ischemia-reperfusion (IR).

METHODS

In our research, 30 male Wistar albino rats, 200-250 gr, were used. Before the experiment, during a week of the process, the rats were fed with these two agents, and the experimental group rats were exposed to spinal cord IR injury. At the end of the experiment, spinal cord samples were taken from the sacrificed rats. Bax, p53, nNOS, and Beclin-1 immunoreactivity moreover TUNEL (+) cells were evaluated with immunohistochemically in the IR-induced damaged rats.

RESULTS

It has been clearly determined that the TUNEL (+) apoptotic cell number and immunopositive cells of nNOS, Beclin-1, p53, Bax were raised in the IR group. However, these increments partially were restored in the resveratrol and CAPE-fed rats with IR-induced injury.

CONCLUSION

In light of our data, resveratrol, and CAPE could be beneficial in spinal cord IR injury. Although both agents provide beneficial effects, it can be said that CAPE is partially more effective in spinal cord injury caused by IR.

Research Progress on Ferroptosis and Nanotechnology-Based Treatment in Triple-Negative Breast Cancer

In recent years, more and more researches on cell death mode in breast cancer, including apoptosis, ferroptosis, etc. Ferroptosisis a regulated form of cell death characterized by iron-dependent accumulation of lipid peroxidation to lethal levels, and numerous studies have shown that ferroptosis is closely associated with tumor cells. Breast cancer is one of the malignant tumors with the highest incidence in women, and TNBC accounts for about 15-20% of all types of breast cancer. Due to the poor prognosis, strong aggressiveness, high drug resistance and lack of molecular targeting characteristics of TNBC, the treatment of TNBC faces many difficulties and great challenges. A large number of studies have shown that ferroptosis plays an important role in the occurrence and development of TNBC, tumor diagnosis, treatment and prognosis, among which the main mechanisms inducing ferroptosis include oxidative stress pathway, iron metabolism pathway and lipid metabolism pathway. Since TNBC is highly sensitive to oxidative stress pathways, intracellular GSH reduces reactive oxygen species under the action of GSH peroxidase (GPX), and when intracellular lipid peroxidase (LPO) accumulates to a certain level, ferroptosis will be induced, thus achieving the purpose of killing TNBC cells. In addition, lipid metabolism is highly consistent with the high lipid level of TNBC tumor cells. As a new therapeutic method, nanotechnology has added security to the treatment of cancer with its high safety and excellent biocompatibility. Therefore, the combination of nanotechnology with iron-based radiotherapy, chemotherapy, targeting and immunization has great research value for the treatment of TNBC In addition, the novel idea of treating TNBC with ethnopharmacology combined with ferroptosis is also involved. This article reviews the mechanism of ferroptosis and the recent research on the treatment prospects of TNBC based on ferroptosis and nanotechnology, hoping to provide references for the treatment of diseases based on ferroptosis.

Understanding the complexity of p53 in a new era of tumor suppression

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.

Systematic Characterization of p53-Regulated Long Noncoding RNAs across Human Cancers Reveals Remarkable Heterogeneity among Different Tumor Types

The p53 tumor suppressor protein, a sequence-specific DNA binding transcription factor, regulates the expression of a large number of genes, in response to various forms of cellular stress. Although the protein coding target genes of p53 have been well studied, less is known about its role in regulating long noncoding genes and their functional relevance to cancer. Here we report the genome-wide identification of a large set (>1,000) of long noncoding RNAs (lncRNA), which are putative p53 targets in a colon cancer cell line and in human patient datasets from five different common types of cancer. These lncRNAs have not been annotated by other studies of normal unstressed systems. In the colon cancer cell line, a high proportion of these lncRNAs are uniquely induced by different chemotherapeutic agents that activate p53, whereas others are induced by more than one agent tested. Further, subsets of these lncRNAs independently predict overall and disease-free survival of patients across the five different common cancer types. Interestingly, both genetic alterations and patient survival associated with different lncRNAs are unique to each cancer tested, indicating extraordinary tissue-specific variability in the p53 noncoding response. The newly identified noncoding p53 target genes have allowed us to construct a classifier for tumor diagnosis and prognosis.

IMPLICATIONS

Our results not only identify myriad p53-regulated long noncoding (lncRNA), they also reveal marked drug-induced, as well as tissue- and tumor-specific heterogeneity in these putative p53 targets and our findings have enabled the construction of robust classifiers for diagnosis and prognosis.

Platelet microparticles influence gene expression and modulate biological activities of chronic myeloid leukemia cells (K562)

BACKGROUND

The current understanding emphasizes the intricate interplay between the Leukemic cell and its environment. Platelet-derived microparticles play a crucial role in facilitating intercellular communication and contribute to the complex landscape of cancer pathology. This study aimed to investigate the influence of platelet-derived microparticles on cell proliferation, apoptosis, and the expression of key genes, including P53, P21, Cyclin D1, Bax, and Bcl-2, within the context of a chronic myeloid leukemia cell line (K562).

METHODS AND RESULTS

Platelet-derived microparticles were obtained through centrifugation at various speeds, and their concentration was quantified using the BCA assay. To determine the size and immunophenotypic characteristics of the PMPs, both the DLS technique and flow cytometry were employed. Cell proliferation was assessed using the MTT assay and hemocytometer, and cell cycle analysis was conducted through DNA content evaluation. Real-time PCR was utilized for gene expression analysis of Bax, Bcl-2, Cyclin D1, P53, and P21. Flow cytometry was employed to examine cell apoptosis. The findings revealed that platelet-derived microparticles have the ability to decrease proliferation of the K562 cell line, while not exerting an impact on apoptosis and cell cycle progression. Analysis through real-time PCR indicated an upregulation in the gene expression of P53, P21, and Bcl-2, accompanied by a downregulation in Bax and Cyclin D1.

CONCLUSION

This investigation sheds light on the intricate relationship between chronic myeloid leukemia and its microenvironment, particularly the involvement of platelet-derived microparticles. The study underscores the potential of platelet-derived microparticles to influence cell behavior and gene expression, providing a deeper understanding of their role in CML and its therapeutic implications.

Capturing Protein-Protein Interactions with Acidic Amino Acids Reactive Cross-Linkers

Acidic residues (Asp and Glu) have a high prevalence on protein surfaces, but cross-linking reactions targeting these residues are limited. Existing methods either require high-concentration coupling reagents or have low structural compatibility. Here a previously reported "plant-and-cast" strategy is extended to develop heterobifunctional cross-linkers. These cross-linkers first react rapidly with Lys sidechains and then react with Asp and Glu sidechains, in a proximity-enhanced fashion. The cross-linking reaction proceeds at neutral pH and room temperature without coupling reagents. The efficiency and robustness of cross-linking using model proteins, ranging from small monomeric proteins to large protein complexes are demonstrated. Importantly, it is shown that this type of cross-linkers are efficient at identifying protein-protein interactions involving acidic domains. The Cross-linking mass spectrometry (XL-MS) study with p53 identified 87 putative binders of the C-terminal domain of p53. Among them, SARNP, ZRAB2, and WBP11 are shown to regulate the expression and alternative splicing of p53 target genes. Thus, these carboxylate-reactive cross-linkers will further expand the power of XL-MS in the analysis of protein structures and protein-protein interactions.

Combined absence of TRP53 target genes ZMAT3, PUMA and p21 cause a high incidence of cancer in mice

Transcriptional activation of target genes is essential for TP53-mediated tumour suppression, though the roles of the diverse TP53-activated target genes in tumour suppression remains poorly understood. Knockdown of ZMAT3, an RNA-binding zinc-finger protein involved in regulating alternative splicing, in haematopoietic cells by shRNA caused leukaemia only with the concomitant absence of the PUMA and p21, the critical effectors of TRP53-mediated apoptosis and cell cycle arrest respectively. We were interested to further investigate the role of ZMAT3 in tumour suppression beyond the haematopoietic system. Therefore, we generated Zmat3 knockout and compound gene knockout mice, lacking Zmat3 and p21, Zmat3 and Puma or all three genes. Puma-/-p21-/-Zmat3-/- triple knockout mice developed tumours at a significantly higher frequency compared to wild-type, Puma-/-Zmat3-/- or p21-/-Zmat3-/-deficient mice. Interestingly, we observed that the triple knockout and Puma-/-Zmat3-/- double deficient animals succumbed to lymphoma, while p21-/-Zmat3-/- animals developed mainly solid cancers. This analysis suggests that in addition to ZMAT3 loss, additional TRP53-regulated processes must be disabled simultaneously for TRP53-mediated tumour suppression to fail. Our findings reveal that the absence of different TRP53 regulated tumour suppressive processes changes the tumour spectrum, indicating that different TRP53 tumour suppressive pathways are more critical in different tissues.

P53 together with ferroptosis: a promising strategy leaving cancer cells without escape

TP53, functioning as the keeper of the genome, assumes a pivotal function in the inhibition of tumorigenesis. Recent studies have revealed that p53 regulates ferroptosis pathways within tumor cells and is closely related to tumorigenesis. Therefore, we summarize the pathways and mechanisms by which p53 regulates ferroptosis and identify a series of upstream and downstream molecules involved in this process. Furthermore, we construct a p53-ferroptosis network centered on p53. Finally, we present the progress of drugs to prevent wild-type p53 (wtp53) degeneration and restore wtp53, highlighting the deficiencies of drug development and the prospects for p53 in cancer treatment. These findings provide novel strategies and directions for future cancer therapy.

Transcription Silencing and CpGs Hypermethylation as Therapeutic Gene Editing in Clinical Colorectal Adenocarcinoma Repression

Background/Aims

Colorectal cancer is the most common cancer in oncopathology, with an increasing incidence among the elderly during the last decade. Various genetic and environmental factors play important roles in the emergence of colorectal adenocarcinoma. Non-coding RNAs, approximately 20-22 nucleotides, are transcribed irregularly in many cancer cells and play a critical role in many metabolic pathways in clinical cancer cases. DNA methylation is a critical epigenetic alteration that controls gene expression. In the current study, transcriptional silencing and CpG hypermethylation were developed as a therapeutic gene editing strategy for the clinical repression of colorectal adenocarcinoma.

Methods

A human colorectal adenocarcinoma cell line (Caco2) and a normal lung fibroblast cell line (Wi38) were utilized as the paradigms in this research to examine the effect of mir155 molecule transfection and CpGs-island (CGI) methylation. Cell counting was achieved using six-well and 24-well plates before transfection using a hemocytometer. The two cell lines were transfected with the mir155 agomir and antagomir molecules. The transfection efficiency, cell viability, cell IC50, and target gene expression were measured, and CGIs-methylation was achieved by bisulfate conversion.

Results

The outcomes revealed the downregulation of oncogenes (AKT1 and VCAM1 genes as cancer-associated genes) and the upregulation of tumor suppressor genes (TSGs, Tp53 and KEAP1). In addition, CpG-islands methylation showed significant blocking of the oncogene promoter regions, and the switch on of TSG promoter regions was continuous.

Conclusions

miRNA-CGI-methylation led to the regression of Caco2 cell proliferation, suggesting the potential use of RNA silencing and DNA methylation in targeted gene therapy for colorectal cancer.

Evaluation of immuno-histochemical markers in oral squamous cell carcinoma

Evaluation of immuno-histochemical (IHC) markers like p53, p63, PDPN, C-erb-B2, CK19, and VEGF in oral squamous cell carcinoma (OSCCs) is of interest to dentists. Sixty formalin-fixed paraffin embedded tissue blocks from the Department of Oral Pathology, New Horizon Dental College and Research, Institute, Sakri, Bilaspur, Chhattisgarh, India. The conventional IHC method was used to assess the expression of p53, p63, PDPN, C- erb-B2, CK19 and VEGF using the different antibodies. Data shows that P53, p63 had high values of labeling index (LI) of staining while PDPN, C-erb-B2 had low values of LI of staining. The values of LI of staining for CK19, and VEGF were in between the two types of IHCs. Combining the analysis of multiple IHC markers for OSCC can yield precise cancer diagnosis results.

Neoadjuvant pyrotinib plus trastuzumab and chemotherapy for HER2-positive breast cancer: a prospective cohort study

BACKGROUND

This prospective study aims to investigate the efficacy and safety of pyrotinib (P) combined with 4 cycles of epirubicin and cyclophosphamide followed by 4 cycles of taxane and trastuzumab (P + EC-TH) regimen as neoadjuvant therapy for human epidermal growth factor receptor 2 (HER2) positive breast cancer and to investigate the predictive value of p53, p63, and epidermal growth factor receptor (EGFR) status for neoadjuvant efficacy.

METHODS

A total of 138 HER2-positive breast cancer patients who received neoadjuvant therapy and underwent surgery were included. Case group: 55 patients received P + EC-TH regimen.

CONTROL GROUP

83 patients received EC-TH regimen. The chi-square test, Fisher's exact test, and logistic regression analysis were applied. The primary endpoint was total pathologic complete response (tpCR), and the secondary endpoints were breast pathologic complete response (bpCR), overall response rate (ORR), and adverse events (AEs).

RESULTS

In the case group, the tpCR rate was 63.64% (35/55), the bpCR rate was 69.09% (38/55), and the ORR was 100.00% (55/55). In the control group, the tpCR rate was 39.76% (33/83), the bpCR rate was 44.58% (37/83), and the ORR was 95.18% (79/83). The case group had significantly higher tpCR and bpCR rates than those of the control group (P < 0.05), but there was no significant difference in ORR (P > 0.05). The tpCR was associated with the status of estrogen receptor (ER), progesterone receptor (PR), and androgen receptor (AR), and the patients with any negative ER, PR, AR, or combined, were more likely to achieve tpCR than those with positive results (P < 0.05). The p53-positive patients were more likely to achieve tpCR and bpCR than p53-negative patients (P < 0.05). The incidence of hypokalemia and diarrhea in the case group was higher than that in the control group (P < 0.05). The AEs developed were all manageable, and no treatment-related death occurred.

CONCLUSION

The efficacy and safety of the P + EC-TH regimen were verified by this study. The HER2-positive breast cancer patients treated with the EC-TH neoadjuvant regimen were more likely to achieve tpCR or bpCR if pyrotinib was administered simultaneously.

Effect of Oroxylum indicum on hepatocellular carcinoma via the P53 and VEGF pathways based on microfluidic chips

BACKGROUND

Hepatocellular carcinoma (HCC), abbreviated as liver cancer, is one of the most common cancers in clinics. HCC has a wider spread and higher incidence due to its high malignancy and metastasis. In HCC, effective strategies to block cancer cell migration, invasion, and neovascularization need to be further studied. Consumption of flavonoid-rich Oroxylum indicum (OI) has been associated with multiple beneficial effects, including anti-inflammatory and anticancer properties, but the potential effects on HCC have not been thoroughly investigated.

OBJECTIVE

In this study, we aimed to reveal the effect of OI on HCC and its potential mechanism through microfluidic technology.

METHODS

We designed microfluidic chips for cell migration, invasion, and neovascularization to evaluate the effect of OI on HepG2 cells. To further explore the mechanism of its anti-liver cancer action, the relevant signaling pathways were studied by microfluidic chips, RT‒qPCR and immunofluorescence techniques. Compared to the control group, cell migration, invasion, and angiogenesis were significantly reduced in each administration group. According to the P53 and VEGF pathways predicted by network pharmacology, RT‒qPCR and immunofluorescence staining experiments were conducted.

RESULTS

The results showed that OI upregulated the expression of Bax, P53 and Caspase-3 and downregulated the expression of Bcl-2 and MDM2. It has been speculated that OI may directly or indirectly induce apoptosis of HepG2 cells by regulating apoptosis-related genes. OI blocks the VEGF signaling pathway by downregulating the expression levels of VEGF, HIF-1α and EGFR and inhibits the migration and invasion of HepG2 cells and the formation of new blood vessels.

CONCLUSION

Our findings suggest that OI may inhibit the migration, invasion, and neovascularization of HepG2 cells, and its regulatory mechanism may be related to the regulation of the P53 and VEGF pathways.

Proteasome Inhibitors against Glioblastoma-Overview of Molecular Mechanisms of Cytotoxicity, Progress in Clinical Trials, and Perspective for Use in Personalized Medicine

Proteasome inhibitors are moieties targeting the proteolytic activity of a proteasome, with demonstrated efficacy in certain hematological malignancies and candidate drugs in other types of cancer, including glioblastoma (GBM). They disturb the levels of proteasome-regulated proteins and lead to the cell cycle inhibition and apoptosis of GBM cells. The accumulation of cell cycle inhibitors p21 and p27, and decreased levels of prosurvival molecules NFKB, survivin, and MGMT, underlie proteasome inhibitors' cytotoxicity when used alone or in combination with the anti-GBM cytostatic drug temozolomide (TMZ). The evidence gathered in preclinical studies substantiated the design of clinical trials that employed the two most promising proteasome inhibitors, bortezomib and marizomib. The drug safety profile, maximum tolerated dose, and interaction with other drugs were initially evaluated, mainly in recurrent GBM patients. A phase III study on newly diagnosed GBM patients who received marizomib as an adjuvant to the Stupp protocol was designed and completed in 2021, with the Stupp protocol receiving patients as a parallel control arm. The data from this phase III study indicate that marizomib does not improve the PFS and OS of GBM patients; however, further analysis of the genetic and epigenetic background of each patient tumor may shed some light on the sensitivity of individual patients to proteasome inhibition. The mutational and epigenetic makeup of GBM cells, like genetic alterations to TP53 and PTEN, or MGMT promoter methylation levels may actually determine the response to proteasome inhibition.

Meningioma animal models: a systematic review and meta-analysis

BACKGROUND

Animal models are widely used to study pathological processes and drug (side) effects in a controlled environment. There is a wide variety of methods available for establishing animal models depending on the research question. Commonly used methods in tumor research include xenografting cells (established/commercially available or primary patient-derived) or whole tumor pieces either orthotopically or heterotopically and the more recent genetically engineered models-each type with their own advantages and disadvantages. The current systematic review aimed to investigate the meningioma model types used, perform a meta-analysis on tumor take rate (TTR), and perform critical appraisal of the included studies. The study also aimed to assess reproducibility, reliability, means of validation and verification of models, alongside pros and cons and uses of the model types.

METHODS

We searched Medline, Embase, and Web of Science for all in vivo meningioma models. The primary outcome was tumor take rate. Meta-analysis was performed on tumor take rate followed by subgroup analyses on the number of cells and duration of incubation. The validity of the tumor models was assessed qualitatively. We performed critical appraisal of the methodological quality and quality of reporting for all included studies.

RESULTS

We included 114 unique records (78 using established cell line models (ECLM), 21 using primary patient-derived tumor models (PTM), 10 using genetically engineered models (GEM), and 11 using uncategorized models). TTRs for ECLM were 94% (95% CI 92-96) for orthotopic and 95% (93-96) for heterotopic. PTM showed lower TTRs [orthotopic 53% (33-72) and heterotopic 82% (73-89)] and finally GEM revealed a TTR of 34% (26-43).

CONCLUSION

This systematic review shows high consistent TTRs in established cell line models and varying TTRs in primary patient-derived models and genetically engineered models. However, we identified several issues regarding the quality of reporting and the methodological approach that reduce the validity, transparency, and reproducibility of studies and suggest a high risk of publication bias. Finally, each tumor model type has specific roles in research based on their advantages (and disadvantages).

SYSTEMATIC REVIEW REGISTRATION

PROSPERO-ID CRD42022308833.

Chromosome-level Asian elephant genome assembly and comparative genomics of long-lived mammals reveal the common substitutions for cancer resistance

The naked mole rat (Heterocephalus glaber), bats (e.g., genus Myotis), and elephants (family Elephantidae) are known as long-lived mammals and are assumed to be excellent cancer antagonists. However, whether there are common genetic changes underpinning cancer resistance in these long-lived species is yet to be fully established. Here, we newly generated a high-quality chromosome-level Asian elephant (Elephas maximus) genome and identified that the expanded gene families in elephants are involved in Ras-associated and base excision repair pathways. Moreover, we performed comparative genomic analyses of 12 mammals and examined genes with signatures of positive selection in elephants, naked mole rat, and greater horseshoe bat. Residues at positively selected sites of CDR2L and ALDH6A1 in these long-lived mammals enhanced the inhibition of tumor cell migration compared to those in short-lived relatives. Overall, our study provides a new genome resource and a preliminary survey of common genetic changes in long-lived mammals.

p53 amyloid pathology is correlated with higher cancer grade irrespective of the mutant or wild-type form

p53 (also known as TP53) mutation and amyloid formation are long associated with cancer pathogenesis; however, the direct demonstration of the link between p53 amyloid load and cancer progression is lacking. Using multi-disciplinary techniques and 59 tissues (53 oral and stomach cancer tumor tissue samples from Indian individuals with cancer and six non-cancer oral and stomach tissue samples), we showed that p53 amyloid load and cancer grades are highly correlated. Furthermore, next-generation sequencing (NGS) data suggest that not only mutant p53 (e.g. single-nucleotide variants, deletions, and insertions) but wild-type p53 also formed amyloids either in the nucleus (50%) and/or in the cytoplasm in most cancer tissues. Interestingly, in all these cancer tissues, p53 displays a loss of DNA-binding and transcriptional activities, suggesting that the level of amyloid load correlates with the degree of loss and an increase in cancer grades. The p53 amyloids also sequester higher amounts of the related p63 and p73 (also known as TP63 and TP73, respectively) protein in higher-grade tumor tissues. The data suggest p53 misfolding and/or aggregation, and subsequent amyloid formation, lead to loss of the tumor-suppressive function and the gain of oncogenic function, aggravation of which might determine the cancer grade.

Active Ingredients from Chinese Medicine for Combination Cancer Therapy

Combination therapy against cancer has gained increasing attention because it can help to target multiple pathways to tackle oncologic progression and improve the limited antitumor effect of single-agent therapy. Chinese medicine has been studied extensively in cancer therapy and proven to be efficacious in many cases due to its wide spectrum of anticancer activities. In this review, we aim to summarize the recent progress of active ingredients from Chinese medicine (AIFCM) in combination with various cancer therapeutic modalities, including chemotherapy, gene therapy, radiotherapy, phototherapy and immunotherapy. In addition to highlighting the potential contribution of AIFCM in combination cancer therapy, we also elucidate the underlying mechanisms behind their synergistic effect and improved anticancer efficacy, thereby encouraging the inclusion of these AIFCM as part of effective armamentarium in fighting intractable cancers. Finally, we present the challenges and future perspectives of AIFCM combination therapy as a feasible and promising strategy for the optimization of cancer treatment and better clinical outcomes.

KLF12 promotes the proliferation of breast cancer cells by reducing the transcription of p21 in a p53-dependent and p53-independent manner

Breast cancer is the most common cancer affecting women worldwide. Many genes are involved in the development of breast cancer, including the Kruppel Like Factor 12 (KLF12) gene, which has been implicated in the development and progression of several cancers. However, the comprehensive regulatory network of KLF12 in breast cancer has not yet been fully elucidated. This study examined the role of KLF12 in breast cancer and its associated molecular mechanisms. KLF12 was found to promote the proliferation of breast cancer and inhibit apoptosis in response to genotoxic stress. Subsequent mechanistic studies showed that KLF12 inhibits the activity of the p53/p21 axis, specifically by interacting with p53 and affecting its protein stability via influencing the acetylation and ubiquitination of lysine370/372/373 at the C-terminus of p53. Furthermore, KLF12 disrupted the interaction between p53 and p300, thereby reducing the acetylation of p53 and stability. Meanwhile, KLF12 also inhibited the transcription of p21 independently of p53. These results suggest that KLF12 might have an important role in breast cancer and serve as a potential prognostic marker and therapeutic target.

JMJD5 inhibits lung cancer progression by regulating glucose metabolism through the p53/TIGAR pathway

Metabolic reprogramming is considered one of the main driving forces for tumor progression, providing energy and substrates of biosynthesis to support rapid neoplastic proliferation. Particularly, the tumor suppressor protein p53 was shown to revert the Warburg effect and play complex roles in regulating glucose metabolism. Jumonji C domain-containing protein 5 (JMJD5) has previously been reported as a negative regulator of p53. However, the role of JMJD5 in p53-mediated metabolic reprogramming remains elusive. Here, we discovered that knockdown of JMJD5 significantly enhances TIGAR expression in p53 wild-type non-small cell lung cancer (NSCLC) cells, which could further suppress glycolysis and promote the pentose phosphate pathway. Besides, JMJD5 knockdown promotes the NSCLC cell proliferation in vitro and xenograft tumor growth in vivo, while silencing TIGAR can abolish this effect. Low JMJD5 expression levels are associated with elevated TIGAR levels and correlates with poor prognosis in lung cancer patients. Taken together, our findings suggest that JMJD5 is a key regulator of tumor glucose metabolism by targeting the p53/TIGAR metabolic pathway.

Decoding the Role of MDM2 as a Potential Ubiquitin E3 Ligase and Identifying the Therapeutic Efficiency of Alkaloids against MDM2 in Combating Glioblastoma

Glioblastomas (GBMs) represent the most aggressive form of brain tumor arising from the malignant transformation of astrocytes. Despite various advancements, treatment options remain limited to chemotherapy and radiotherapy followed by surgery giving an overall survival of 14-15 months. These therapies are somewhere restricted in giving a better survival and cure. There is a need for new therapeutics that could potentially target GBM based on molecular pathways and pathology. Here, ubiquitin E3 ligases can be used as targets as they bind a wide array of substrates and therefore can be attractive targets for new inhibitors. Through this study, we have tried to sort various ubiquitin E3 ligases based on their expression, pathways to which these ligases are associated, and mutational frequencies, and then we tried to screen potent inhibitors against the most favorable E3 ligase as very few studies are available concerning inhibition of E3 ligase in GBM. Our study found MDM2 to be the most ideal E3 ligase and further we tried to target MDM2 against various compounds under the alkaloid class. Molecular Docking and MD simulations combined with ADMET properties and BBB scores revealed that only evodiamine and sanguinarine were effective in inhibiting MDM2. We also tried to give a proposed mechanism of how these inhibitors mediate the p53 signaling in GBM. Therefore, the new scaffolds predicted by the computational approach could help in designing promising therapeutic agents targeting MDM2 in glioblastoma.

Development and validation of an inflammatory response-related prognostic model and immune infiltration analysis in glioblastoma

Background

Despite receiving standard treatment, the prognosis of glioblastoma (GBM) patients is still poor. Considering the heterogeneity of each patient, it is imperative to identify reliable risk model that can effectively predict the prognosis of each GBM patient to guide the personalized treatment.

Methods

Transcriptomic gene expression profiles and corresponding clinical data of GBM patients were downloaded from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) databases. Inflammatory response-related genes were extracted from Gene Set Enrichment Analysis (GSEA) website. Univariate Cox regression analysis was used for prognosis-related inflammatory genes (P<0.05). A polygenic prognostic risk model was constructed using least absolute shrinkage and selection operator (LASSO) Cox regression analysis. Validation was performed through CGGA cohort. Overall survival (OS) was compared by Kaplan-Meier analysis. A nomogram was plotted to accurately predict the prognosis for each patient. GSEA was used for the pathway enrichment analysis. The single sample GSEA (ssGSEA) algorithm was implemented to conduct the immune infiltration analysis. The potential role of oncostatin M receptor (OSMR) in GBM was investigated through the in vitro experiment.

Results

A prognostic risk model consisting of 4 genes (PTPRN, OSMR, MYD88, and EFEMP2) was developed. GBM patients in the high-risk group had worse OS. The time-dependent ROC curves showed an area under the curve (AUC) of 0.782, 0.765, and 0.784 for 1-, 2-, and 3-year survival in TCGA cohort, while the AUC in the CGGA cohort was 0.589, 0.684, and 0.785 at 1, 2, and 3 years, respectively. The risk score, primary-recurrent-secondary (PRS) type, and isocitrate dehydrogenase (IDH) mutation could predict the prognosis of GBM patients well. The nomogram accurately predicted the 1-, 2-, and 3-year OS for each patient. Immune cell infiltration was associated with the risk score and the model could predict immunotherapy responsiveness. The expression of the prognostic gene was correlated with the sensitivity to antitumor drugs. Interference of OSMR inhibited proliferation and migration and promoted apoptosis of GBM cells.

Conclusions

The prognostic model based on 4 inflammatory response-related genes had reliable predictive power to effectively predict clinical outcome in GBM patients and provided the guide for the personalized treatment.

Short-term carcinogenicity study of N-methyl-N-nitrosourea in FVB-Trp53 heterozygous mice

Carcinogenicity tests predict the tumorigenic potential of various substances in the human body by studying tumor induction in experimental animals. There is a need for studies that explore the use of FVB/N-Trp53em2Hwl/Korl (FVB-Trp53+/-) mice, created by TALEN-mediated gene targeting in Korea, in carcinogenicity tests. This study was performed to determine whether FVB-Trp53+/- mice are a suitable model for short-term carcinogenicity studies. To compare the carcinogenicity at different concentrations, 25, 50, and 75 mg/kg of N-methyl-N-nitrosourea (MNU), a known carcinogen, were administered intraperitoneally to FVB-Trp53+/- and wild-type male mice. After 26 weeks, the survival rate was significantly reduced in FVB-Trp53+/- mice compared to the wild-type mice in the 50 and 75 mg/kg groups. The incidence of thymic malignant lymphoma (TML) in the 50 and 75 mg/kg groups was 54.2 and 59.1% in FVB-Trp53+/- male mice, respectively. TML metastasized to the lungs, spleen, lymph nodes, liver, kidney, and heart in FVB-Trp53+/- male mice. Furthermore, the incidence of primary lung tumors, such as adenomas and adenocarcinomas, was 65.4, 62.5, and 45.4% in the FVB-Trp53+/- mice of the 25, 50, and 75 mg/kg groups, respectively. The main tumor types in FVB-Trp53+/- mice were TML and primary lung tumors, regardless of the dose of MNU administered. These results suggest that systemic tumors may result from malfunctions in the p53 gene and pathway, which is an important factor in the pathogenesis of human cancers. Therefore, FVB-Trp53 heterozygous mice are suitable for short-term carcinogenicity tests using positive carcinogens, and that the best result using MNU, a positive carcinogen, might have a single dose of 50 mg/kg.

Novel compounds that synergize with aminoglycoside G418 or eRF3 degraders for translational readthrough of nonsense mutant TP53 and PTEN

The TP53 and PTEN tumour suppressor genes are inactivated by nonsense mutations in a significant fraction of human tumours. TP53 nonsense mutatant tumours account for approximately one million new cancer cases per year worldwide. We have screened chemical libraries with the aim of identifying compounds that induce translational readthrough and expression of full-length p53 protein in cells with nonsense mutation in this gene. Here we describe two novel compounds with readthrough activity, either alone or in combination with other known readthrough-promoting substances. Both compounds induced levels of full-length p53 in cells carrying R213X nonsense mutant TP53. Compound C47 showed synergy with the aminoglycoside antibiotic and known readthrough inducer G418, whereas compound C61 synergized with eukaryotic release factor 3 (eRF3) degraders CC-885 and CC-90009. C47 alone showed potent induction of full-length PTEN protein in cells with different PTEN nonsense mutations. These results may facilitate further development of novel targeted cancer therapy by pharmacological induction of translational readthrough.

p53/p21 pathway activation contributes to the ependymal fate decision downstream of GemC1

Multiciliated ependymal cells and adult neural stem cells are components of the adult neurogenic niche, essential for brain homeostasis. These cells share a common glial cell lineage regulated by the Geminin family members Geminin and GemC1/Mcidas. Ependymal precursors require GemC1/Mcidas expression to massively amplify centrioles and become multiciliated cells. Here, we show that GemC1-dependent differentiation is initiated in actively cycling radial glial cells, in which a DNA damage response, including DNA replication-associated damage and dysfunctional telomeres, is induced, without affecting cell survival. Genotoxic stress is not sufficient by itself to induce ependymal cell differentiation, although the absence of p53 or p21 in progenitors hinders differentiation by maintaining cell division. Activation of the p53-p21 pathway downstream of GemC1 leads to cell-cycle slowdown/arrest, which permits timely onset of ependymal cell differentiation in progenitor cells.

Translational readthrough of nonsense mutant TP53 by mRNA incorporation of 5-Fluorouridine

TP53 nonsense mutations in cancer produce truncated inactive p53 protein. We show that 5-FU metabolite 5-Fluorouridine (FUr) induces full-length p53 in human tumor cells carrying R213X nonsense mutant TP53. Ribosome profiling visualized translational readthrough at the R213X premature stop codon and demonstrated that FUr-induced readthrough is less permissive for canonical stop codon readthrough compared to aminoglycoside G418. FUr is incorporated into mRNA and can potentially base-pair with guanine, allowing insertion of Arg tRNA at the TP53 R213X UGA premature stop codon and translation of full-length wild-type p53. We confirmed that full-length p53 rescued by FUr triggers tumor cell death by apoptosis. FUr also restored full-length p53 in TP53 R213X mutant human tumor xenografts in vivo. Thus, we demonstrate a novel strategy for therapeutic rescue of nonsense mutant TP53 and suggest that FUr should be explored for treatment of patients with TP53 nonsense mutant tumors.

Molecular subtypes of cuproptosis regulators and their correlation with clinical prognosis and immune response in glioma

Cuproptosis is a newly described form of cell death. However, nothing is known about the roles of cuproptosis regulators in glioma. First, we explored the characteristics of cuproptosis molecular subtypes and relevant tumor microenvironment (TME) immune cell infiltration patterns in glioma. Using unsupervised clustering analysis, we identified two cuproptosis subtypes and three gene clusters that exhibited different clinical characteristics and TME cell infiltration patterns. Then, we developed and validated a cuproptosis-related prognostic model for predicting the overall survival of glioma patients. We established a risk score tool based on a nomogram to assess the clinical applicability of the cuproptosis model. A high cuproptosis risk score with high immune cell infiltration level, tumor mutation burden, gene alterations, and immunity activation had an unfavorable overall survival. Next, we identified possible competing endogenous ribonucleic acid regulatory networks based on significantly differentially expressed genes between high-risk and low-risk groups and screened several candidate small molecular compounds that may improve chemotherapy. Data from IMvigor and GSE78200 showed that the cuproptosis score affected the prognosis of patients who received immunotherapy. Our study indicated that cuproptosis regulators are involved in TME immune infiltration and impact the clinical prognosis in glioma. It is necessary for clinical practice to develop different therapeutic strategies according to the different phenotypes associated with immune response. The present findings provide new insight for improving immunotherapy strategies and individualized treatment in glioma.

TP53 Mutation Mapping in Advanced Non-Small Cell Lung Cancer: A Real-World Retrospective Cohort Study

BACKGROUND

TP53 is frequently mutated in solid tumors, but its basic mutation mapping is mixed, particularly in aggressive-stage lung cancer.

EXPERIMENTAL DESIGN

We curated a total of 139 advanced non-small cell lung cancer (NSCLC) patients who harbored wild-type TP53 (TP53wt) or mutated TP53 (TP53mut) based on next-generation sequencing (NGS) to analyze multiple-dimensional data types, including tumor mutation burden (TMB), programmed death receptor ligand 1 (PD-L1) expression, co-mutant alterations, hotspot mutations distribution, and therapy response.

RESULTS

TP53 was evident in 125 mutations and significantly associated with male sex, adenocarcinoma differentiation, smoking history, PD-L1 tumor proportion score, and TMB level. The most frequent mutations were distributed on exon 8, but there were no distinct hotspot mutations. After outlining the co-mutation genes, it is interesting to note that DNA damage repair (DDR) genes were frequent alterations in the mutated TP53 cohort. Even though there was no significant difference between the TP53wt and TP53mut cohorts on therapy response, patients with nucleotide variation in G>T achieved a relatively higher durable clinical benefit (DCB) rate.

CONCLUSIONS

This real-world retrospective study suggests that molecular stratification on the basis of TP53 mutations should be deeply explored for NSCLC to optimize and modify clinical therapy choices.

The propofol-induced mitochondrial damage in fetal rat hippocampal neurons via the AMPK/P53 signaling pathway

BACKGROUND

Propofol is a commonly used general anesthetic that may cause neuronal damage, especially in infants and young children. Mitochondria play an essential role in cellular metabolism and signal transduction. Propofol may cause neurotoxicity by inhibiting mitochondrial function, but the mechanism by this which occurs remains unclear.

METHODS

First, the primary rat hippocampal neurons were cultured for 7 days in vitro. The neurons were incubated with propofol at different times or different concentrations, and then the adenosine triphosphate (ATP), reactive oxygen species (ROS), mitochondrial membrane potential, and apoptosis-related proteins were analyzed. Based on the results of the 1st phase, the neurons were then incubated with propofol (100 µM) or corresponding reagents, including 5-aminoimidazole-4-carboxamide ribonucleotide, tenovin-1, and pifithrin-α. Subsequently, the ATP, ROS, mitochondrial membrane potential, phospho-adenosine 5'-monophosphate-activated protein kinase (p-AMPK), protein 53 (p53), and related apoptosis proteins were analyzed.

RESULTS

Higher propofol concentrations or longer incubation times were associated with more pronounced decreases in ATP, B-cell lymphoma 2 (Bcl-2), and mitochondrial membrane potential, and more pronounced increases in ROS, BCL2-associated X (Bax), Cytochrome C (CytC), and cleaved caspase-9. Additionally, after incubation with propofol (100 µM), neuronal Bcl-2, p-AMPK, ATP, and mitochondrial membrane potential were downregulated, and ROS, p53, CytC, Bax, cleaved caspase-3, and cleaved caspase-9 were upregulated. AMPK activators or p53 inhibitors reversed the above-mentioned changes.

CONCLUSIONS

Propofol (100 µM)-induced mitochondrial damage in fetal rat hippocampal neurons may be mediated by the AMPK/p53 signaling pathway. Propofol (100 µM) was shown to inhibit the activity of AMPK in neurons, upregulate the expression of p53, and then activate the mitochondrial-dependent apoptosis pathway, which may lead to neuronal apoptosis.

Long noncoding RNA ST8SIA6-AS1 promotes cell proliferation and metastasis in triple-negative breast cancer by targeting miR-145-5p/CDCA3 to inactivate the p53/p21 signaling pathway

BACKGROUND

Triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer, always exhibits a poor prognosis due to high risk of early recurrence and distant metastasis. Long noncoding RNAs (lncRNAs) have been reported as crucial regulators in breast cancer. However, the functions and action mechanisms of lncRNA ST8SIA6-AS1 in TNBC are largely unknown.

METHODS

Quantitative real-time PCR and western blot assays were used to measure the expression levels of different genes and proteins. Cell proliferation ability was monitored by CCK-8, colony forming and flow cytometry assays. Wound healing and transwell assays were performed to evaluate cell migration and invasion. The regulatory mechanisms of ST8SIA6-AS1 in TNBC were confirmed by dual luciferase reporter and RIP assays. A mouse xenograft model was established to investigate the role of ST8SIA6-AS1 in TNBC tumor growth.

RESULTS

ST8SIA6-AS1 displayed a higher expression in TNBC cells. Silencing ST8SIA6-AS1 impaired cell proliferation, cell cycle progression, migration, and invasion in vitro, and slowed tumor growth in vivo. Mechanistically, ST8SIA6-AS1 could facilitate the expression of its target CDCA3 (cell division cycle associated protein 3) and inactivate the p53/p21 signaling by inhibiting miR-145-5p. Moreover, miR-145-5p exerted a tumor-suppressive activity by targeting CDCA3. The tumor-suppressive effects induced by ST8SIA6-AS1 knockdown were abated by the down-regulation of miR-145-5p or the up-regulation of CDCA3.

CONCLUSION

ST8SIA6-AS1 exerts an oncogenic role in TNBC by interacting with miR-145-5p to up-regulate CDCA3 expression and inactivate the p53/p21 signaling, highlighting ST8SIA6-AS1 as a promising molecular target to combat TNBC.

Distinct p53 isoforms code for opposing transcriptional outcomes

p53 genes are conserved transcriptional activators that respond to stress. These proteins can also downregulate genes, but the mechanisms are not understood and are generally assumed to be indirect. Here, we investigate synthetic and native cis-regulatory elements in Drosophila to examine opposing features of p53-mediated transcriptional control in vivo. We show that transcriptional repression by p53 operates continuously through canonical DNA binding sites that confer p53-dependent transactivation at earlier developmental stages. p53 transrepression is correlated with local H3K9me3 chromatin marks and occurs without the need for stress or Chk2. In sufficiency tests, two p53 isoforms qualify as transrepressors and a third qualifies as a transcriptional activator. Targeted isoform-specific knockouts dissociate these opposing transcriptional activities, highlighting features that are dispensable for transactivation but critical for repression and for proper germ cell formation. Together, these results demonstrate that certain p53 isoforms function as constitutive tissue-specific repressors, raising important implications for tumor suppression by the human counterpart.

CLP36 promotes p53 deficient sarcoma progression through suppression of atrophin-1 interacting protein-4 (AIP-4)-dependent degradation of YAP1

Background: p53 deficiency is a key causal factor for tumor development and progression. p53 acts in this process through, at least in part, cooperation with YAP1 but the underlying molecular mechanism is incompletely understood. In this paper, we show that CLP36, an actinin-binding cytoskeletal protein, links p53 deficiency to up-regulation of YAP1 expression and sarcoma progression.

Methods: Immunohistochemical staining and Western blotting were used to investigate the effect of p53 deficiency on CLP36 expression in sarcoma tissues and cells. Furthermore, molecular, cellular, and genetic knockout and knockdown approaches were employed to investigate the functions of CLP36 in regulation of sarcoma cell behavior in culture and tumor growth in mice. Finally, biochemical approaches were used to investigate the molecular mechanism by which CLP36 regulates the malignant behavior of p53 deficient sarcoma cells.

Results: We have found that the expression of CLP36 is up-regulated in response to loss of p53 in sarcoma tissues and cells. Depletion of CLP36 inhibited malignant behavior of p53 deficient sarcoma cells. Furthermore, knockout of CLP36 in mice markedly inhibited p53 deficiency-induced tumorigenesis and improved the survival of the p53 deficient mice. Mechanistically, CLP36 promoted p53 deficiency-induced tumorigenesis through inhibition of E3 ligase atrophin-1 interacting protein-4 (AIP-4)-dependent proteasomal degradation of YAP1 and consequently increase of YAP1 expression.

Conclusions: Our results reveal a crucial role of CLP36 in linking p53 deficiency to up-regulation of YAP1 expression and sarcoma progression. Our findings suggest that therapeutic targeting the CLP36/YAP1 signaling axis may provide an effective strategy for alleviation of p53 deficient sarcoma progression.

19q13.12 KRAB zinc-finger protein ZNF383 represses p53 signaling pathway by interacting with p53

As one of the most important tumor suppressors, the activity of p53 is precisely regulated. However, the mechanism of p53 regulation is still being elucidated and new regulatory molecules for p53 have also been frequently identified. Our previous works revealed that two members of the KRAB zinc-finger protein (KZFP) family Apak and PISA, which are located on human 19q13.12, participated in the regulation of p53 signaling pathway. KZFPs genes are mainly amplified via tandem in situ duplication during evolution, which indicates that similar sequences and functions may be conserved in evolutionarily and physically close KZFPs. Here, we revealed that ZNF383, another member of the KZFPs mapped at 19q13.12, could inhibit p53-mediated apoptosis and the activation of IFN-β pathway by decreasing the H3K36me2 level at p53's binding sites and the attenuating the binding of p53 to its target genes. We further explored the effect of other KZFPs clustered on 19q13.12 on p53, and found that 85% of these KZFPs exerted p53-repressive activity. Intriguingly, an acidic amino acid-enriched sequence, the SAcL motif in the zinc-finger domains of these KZFPs, was found to be critical for p53 binding. Taken together, our findings revealed the KZFPs cluster located at 19q13.12 not only was involved in p53 regulation but also exhibited different features in the selective regulation of p53 and functional mechanisms, and for the first time, confirmed a motif in KZFPs that mediates the interaction of KZFPs and p53. These results would enrich the knowledge on the role, sequence features, and functional mechanisms of the KZFP family in p53 regulation.

miR-887-3p Inhibits the Progression of Colorectal Cancer via Downregulating DNMT1 Expression and Regulating P53 Expression

Colorectal cancer (CRC) is the third most diagnosed cancer worldwide and the second leading cause of cancer-related deaths. Many researchers have reported that abnormal microRNAs (miRs) were expressed in CRC and participated in the occurrence and progression of CRC. However, there are few reports of miR-887-3p regulating CRC development. In the current study, we investigated the abnormal expression of miR-887-3p and also demonstrated its regulatory role and detailed molecular mechanism in CRC. Initially, miRNA expression data were obtained from TCGA-COAD that consisted of 453 CRC samples and 8 normal tissue samples. These were downloaded and analyzed to compare the expression level of miR-887-3p in CRC tissues to that in normal tissues. Moreover, 32 pairs of surgically resected CRC tumors and para-cancer tissues from our hospital were collected. Quantitative real-time PCR (qRT-PCR) was performed to detect miR-887-3p expression levels in CRC tissues, para-cancer tissues, several CRC cell lines, and an intestinal epithelial cell line. Following miR-887-3p mimic transfection in colon cancer SW480 cell line, the regulatory roles of miR-887-3p on cell proliferation, apoptosis, invasion, migration, and epithelial-mesenchymal transition (EMT) were detected through CCK-8, flow cytometry, transwell assay, and Western blot. After potential targeting protein was predicted by bioinformatic websites, the luciferase reporter assay and Western blot were used to confirm the target of miR-887-3p. The targeting protein expressions were detected by Western blot and qRT-PCR. The relationship between miR-887-3p level and the effect of miR-887-3p on P53 expression was evaluated by Western blot and qRT-PCR. The effects of miR-887-3p on CRC cell growth in vivo by xenograft tumor experiments were investigated, and Ki-67 in tumor tissue was determined by immunohistochemistry. Results. The COAD data demonstrated that the expression levels of miR-887-3p in CRC clinical sample tissues and cell line cultures were remarkably lower than para-cancer normal tissues and NCM460 cells (normal colonic epithelial cell line). Functional experiments demonstrated that overexpression of miR-887-3p in SW480 cells significantly reduced proliferation, migration, invasion, and EMT, and promoted cancer cell apoptosis. Additionally, Western blot, qRT-PCR, and luciferase reporter assays confirmed that DNMT1 was a downstream target of miR-887-3p. Moreover, the blocking of DNMT1 by miR-887-3p mimics also promoted P53 expression. Finally, overexpression of DNMT1 in SW480 cells could partially reverse the regulatory effect of miR-887-3p mimics on CRC cell development. From in vivo experiments, overexpression of miR-887-3p could inhibit tumor growth in CRC xenograft mice and reduce the Ki-67 level. Conclusion. The microRNA miR-887-3p is a potential biomarker of CRC. It inhibited CRC cell proliferation, invasion, and EMT, and promoted cell apoptosis through targeting and downregulating DNMT1 and promoting P53 expression. Therefore, miR-887-3p may be a good biomarker and therapeutic target for CRC treatment.

Metabolomics and integrated network pharmacology analysis reveal SNKAF decoction suppresses cell proliferation and induced cell apoptisis in hepatocellular carcinoma via PI3K/Akt/P53/FoxO signaling axis

BACKGROUND

There is no comprehensive treatment method for hepatocellular carcinoma (HCC); hence, research and development are still focused on systemic therapies, including drugs. Sinikangai fang (SNKAF) decoction, a classic Chinese herbal prescription, has been widely used to treat liver cancer. However, there is no research on its core active component and target.

METHODS

Mouse models were established to measure the anticancer effect of SNKAF decoction on HCC. Further, we investigated the effect of SNKAF decoction on inhibition of hepatoma cells proliferation using cell viability, cloning and invasion assays in vitro. The components of SNKAF were collected from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database and TCM@Taiwan database. Metabolomic analysis was used to identify the potential genes and pathways in HCC treated with SNKAF decoction. Then, the expression of phosphoinositide 3-kinase (PI3K), Akt, P53, FoxO proteins of the potential signal pathways were detected using Western blot.

RESULTS

The animal experiments showed that SNKAF decoction inhibited tumor growth (P < 0.05) and induced no weight loss in the mice. In vitro data showed that HCCLM3 and MHCC97H cell proliferation was inhibited by SNKAF serum in a time- and concentration dependent manner. Further combined analysis network pharmacology with metabonomics showed that 217 target genes overlapped. The core target genes included BCL2, MCL1, Myc, PTEN, gsk3b, CASP9, CREB1, MDM2, pt53 and CCND1. Cancer-associated pathways were largely involved in SNKAF mechanisms, including P53, FoxO, and PI3K/Akt signaling pathways, which are closely related to induced-tumor cell apoptosis. In addition, Western bolt verified that 10% SNKAF serum significantly affected the main proteins of PI3K/Akt/P53/FoxO signaling pathway in both cell lines.

CONCLUSION

SNKAF decoction-containing serum inhibited HCCLM3 and MHCC97H cell proliferation, migration, invasion, and induced-tumor cell apoptosis in-vivo. We confirmed that SNKAF decoction is a promising alternative treatments for HCC patients.

The genotypes and phenotypes of missense mutations in the proline domain of the p53 protein

The p53 protein is structurally and functionally divided into five domains. The proline-rich domain is localized at amino acids 55-100. 319 missense mutations were identified solely in the proline domain from human cancers. Six hotspot mutations were identified at amino acids 72, 73, 82, 84, 89, and 98. Codon 72 contains a polymorphism that changes from proline (and African descent) to arginine (with Caucasian descent) with increasing latitudes northward and is under natural selection for pigmentation and protection from UV light exposure. Cancers associated with mutations in the proline domain were considerably enriched for melanomas and skin cancers compared to mutations in other p53 domains. These hotspot mutations are enriched at UV mutational signatures disrupting amino acid signals for binding SH-3-containing proteins important for p53 function. Among the protein-protein interaction sites identified by hotspot mutations were MDM-2, a negative regulator of p53, XAF-1, promoting p53 mediated apoptosis, and PIN-1, a proline isomerase essential for structural folding of this domain.

Deciphering the acetylation code of p53 in transcription regulation and tumor suppression

Although it is well established that p53-mediated tumor suppression mainly acts through its ability in transcriptional regulation, the molecular mechanisms of this regulation are not completely understood. Among a number of regulatory modes, acetylation of p53 attracts great interests. p53 was one of the first non-histone proteins found to be functionally regulated by acetylation and deacetylation, and subsequent work has established that reversible acetylation is a general mechanism for regulation of non-histone proteins. Unlike other types of post-translational modifications occurred during stress responses, the role of p53 acetylation has been recently validated in vivo by using the knockin mice with both acetylation-defective and acetylation-mimicking p53 mutants. Here, we review the role of acetylation in p53-mediated activities, with a focus on which specific acetylation sites are critical for p53-dependent transcription regulation during tumor suppression and how acetylation of p53 recruits specific “readers” to execute its promoter-specific regulation of different targets. We also discuss the role of p53 acetylation in differentially regulating its classic activities in cell cycle arrest, senescence and apoptosis as well as newly identified unconventional functions such as cell metabolism and ferroptosis.

Correlation of Ferroptosis and Other Types of Cell Death in Neurodegenerative Diseases

Ferroptosis is defined as an iron-dependent, non-apoptotic cell death pathway, with specific morphological phenotypes and biochemical changes. There is a growing realization that ferroptosis has significant implications for several neurodegenerative diseases. Even though ferroptosis is different from other forms of programmed death such as apoptosis and autophagic death, they involve a number of common protein molecules. This review focuses on current research on ferroptosis and summarizes the cross-talk among ferroptosis, apoptosis, and autophagy that are implicated in neurodegenerative diseases. We hope that this information provides new ideas for understanding the mechanisms and searching for potential therapeutic approaches and prevention of neurodegenerative diseases.

ZNF498 promotes hepatocellular carcinogenesis by suppressing p53-mediated apoptosis and ferroptosis via the attenuation of p53 Ser46 phosphorylation

Background

Dysfunctional p53 signaling is one of the major causes of hepatocellular carcinoma (HCC) tumorigenesis and development, but the mechanisms underlying p53 inactivation in HCC have not been fully clarified. The role of Krüppel-associated box (KRAB)-type zinc-finger protein ZNF498 in tumorigenesis and the underlying mechanisms are poorly understood.

Methods

Clinical HCC samples were used to assess the association of ZNF498 expression with clinicopathological characteristics and patient outcomes. A mouse model in which HCC was induced by diethylnitrosamine (DEN) was used to explore the role of ZNF498 in HCC initiation and progression. ZNF498 overexpression and knockdown HCC cell lines were employed to examine the effects of ZNF498 on cellular proliferation, apoptosis, ferroptosis and tumor growth. Western blotting, immunoprecipitation, qPCR, luciferase assays and flow cytometry were also conducted to determine the underlying mechanisms related to ZNF498 function.

Results

ZNF498 was found to be highly expressed in HCC, and increased ZNF498 expression was positively correlated with advanced pathological grade and poor survival in HCC patients. Furthermore, ZNF498 promoted DEN-induced hepatocarcinogenesis and progression in mice. Mechanistically, ZNF498 directly interacted with p53 and suppressed p53 transcriptional activation by inhibiting p53 Ser46 phosphorylation. ZNF498 competed with p53INP1 for p53 binding and suppressed PKCδ- and p53INP1-mediated p53 Ser46 phosphorylation. In addition, functional assays revealed that ZNF498 promoted liver cancer cell growth in vivo and in vitro in a p53-dependent manner. Moreover, ZNF498 inhibited p53-mediated apoptosis and ferroptosis by attenuating p53 Ser46 phosphorylation.

Conclusions

Our results strongly suggest that ZNF498 suppresses apoptosis and ferroptosis by attenuating p53 Ser46 phosphorylation in hepatocellular carcinogenesis, revealing a novel ZNF498-PKCδ-p53INP1-p53 axis in HCC cells that would enrich the non-mutation p53-inactivating mechanisms in HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02288-3.

Ferroptosis in Cancer Immunotherapy—Implications for Hepatocellular Carcinoma

Ferroptosis is a recently recognized iron-dependent form of non-apoptotic regulated cell death (RCD) characterized by lipid peroxide accumulation to lethal levels. Cancer cells, which show an increased iron dependency to enable rapid growth, seem vulnerable to ferroptosis. There is also increasing evidence that ferroptosis might be immunogenic and therefore could synergize with immunotherapies. Hepatocellular carcinoma (HCC) is the most common primary liver tumor with a low survival rate due to frequent recurrence and limited efficacy of conventional chemotherapies, illustrating the urgent need for novel drug approaches or combinatorial strategies. Immunotherapy is a new treatment approach for advanced HCC patients. In this setting, ferroptosis inducers may have substantial clinical potential. However, there are still many questions to answer before the mystery of ferroptosis is fully unveiled. This review discusses the existing studies and our current understanding regarding the molecular mechanisms of ferroptosis with the goal of enhancing response to immunotherapy of liver cancer. In addition, challenges and opportunities in clinical applications of potential candidates for ferroptosis-driven therapeutic strategies will be summarized. Unraveling the role of ferroptosis in the immune response could benefit the development of promising anti-cancer therapies that overcome drug resistance and prevent tumor metastasis.

Hypoxia-related gene signature for predicting LUAD patients' prognosis and immune microenvironment

Lung adenocarcinoma (LUAD) is a prevalent lung cancer histology with high morbidity and mortality. Moreover, assessment approaches for patients' prognoses are still not effective. Based on mRNA expression and clinical data from the Cancer Genome Atlas (TCGA)-LUAD data set, we utilized hypoxia-related gene set in MsigDB database to identify hypoxia-related differentially expressed genes (DEGs). On the basis of levels of hypoxia-related DEGs, K-means consensus clustering was introduced to divide LUAD patients into subgroups. After hypoxia-related DEGs were analyzed through univariate, Lasso and multivariate Cox regression analyses, 6 of them were determined to be used for evaluating LUAD patients' prognostic signature. With median risk score obtained from hypoxia-related gene signature as threshold, LUAD patients were divided into high- and low-risk groups. Besides, Kaplan-Meier curves, receiver operator characteristic (ROC) curves, univariate and multivariate Cox regression analyses verified that hypoxia-related gene signature was an important prognostic factor independent of clinical features. Gene set enrichment analysis (GSEA) displayed that pathways which showed differences between high- and low-risk groups in activation of pentose-phosphate pathway and p53 signaling pathway. CIBERSORT was utilized to assess infiltration level of each immune cell from two groups, indicating the differences in infiltration abundance of Plasma cells, T cells CD4⁺ memory activated and Macrophages M1 cells between high- and low-risk groups. We drew a nomogram for predicting one-, three- and five-year survival of LUAD patients following risk scores of hypoxia-related gene signature and six clinical factors. Calibration curves showed a high fit between survival predicted by nomogram and actual survival. In conclusion, hypoxia-related gene signature can be introduced for predicting LUAD patients' prognosis and assessment of the patients' immune microenvironment, guiding clinicians to make appropriate decisions during diagnosis and treatment of LUAD patients.

p53 partial loss-of-function mutations sensitize to chemotherapy

The tumor suppressive transcription factor p53 is frequently inactivated in cancer cells by missense mutations that cluster in the DNA binding domain. 30% hit mutational hotspot residues, resulting in a complete loss of transcriptional activity and mutant p53-driven chemotherapy resistance. Of the remaining 70% of non-hotspot mutants, many are partial loss-of-function (partial-LOF) mutants with residual transcriptional activity. The therapeutic consequences of a partial-LOF have remained largely elusive. Using a p53 mutation engineered to reduce DNA binding, we demonstrate that partial-LOF is sufficient to enhance oncogene-driven tumorigenesis in mouse models of lung and pancreatic ductal adenocarcinoma and acute myeloid leukemia. Interestingly, mouse and human tumors with partial-LOF mutations showed mutant p53 protein accumulation similar as known for hotspot mutants. Different from the chemotherapy resistance caused by p53-loss, the partial-LOF mutant sensitized to an apoptotic chemotherapy response and led to a survival benefit. Mechanistically, the pro-apoptotic transcriptional activity of mouse and human partial-LOF mutants was rescued at high mutant protein levels, suggesting that accumulation of partial-LOF mutants enables the observed apoptotic chemotherapy response. p53 non-hotspot mutants with partial-LOF, therefore, represent tumorigenic p53 mutations that need to be distinguished from other mutations because of their beneficial impact on survival in a therapy context.

Research progress on the mechanism of ferroptosis and its clinical application

Ferroptosis is a mode of cell death dependent on iron ions, which is mainly induced by the decrease of the biological activity of glutathione peroxidase or the accumulation of lipid peroxidation and reactive oxygen species (ROS). It is significantly different from autophagy and other forms of cell death in terms of cell morphology and biochemistry. The exact mechanisms of ferroptosis are not clear. More and more studies have shown that various tumor diseases and nervous system diseases are closely related to ferroptosis. The occurrence and development of related diseases can be tolerated by stimulating or inhibiting the occurrence of ferroptosis. Therefore, ferroptosis has occupied a very important position in recent years. This article reviews the discovery process, characteristics, mechanisms, inducers, inhibitors of ferroptosis and its related clinical applications to lay a foundation for follow-up researchers to study ferroptosis and provide some reference value.

A functional PVA aerogel-based membrane obtaining sutureability through modified electrospinning technology and achieving promising anti-adhesion effect after cardiac surgery

Pericardial barrier destruction, inflammatory cell infiltration, and fibrous tissue hyperplasia, trigger adhesions after cardiac surgery. There are few anti-adhesion materials that are both functional and sutureable for pericardial reconstruction. Besides, a few studies have reported on the mechanism of preventing pericardial adhesion. Herein, a functional barrier membrane with sutureability was developed via a modified electrospinning method. It was composed of poly(l-lactide-co-caprolactone) (PLCL) nanofibers, poly(vinyl alcohol) (PVA) aerogel, and melatonin, named PPMT. The PPMT had a special microstructure manifested as a staggered arrangement of nanofibers on the surface and a layered macroporous aerogel structure in a cross-section. Besides providing the porosity and hydrophilicity obtained from PVA, the structure also had suitable mechanical properties for stitching due to the addition of PLCL nanofibers. Furthermore, it inhibited the proliferation of fibroblasts by suppressing the activation of Fas and P53, and achieved anti-inflammatory effects by affecting the activity of inflammatory cells and reducing the release of pro-inflammatory factors, such as interleukin 8 (IL-8) and tumor necrosis factor α (TNF-α). Finally, in vivo transplantation showed that it up-regulated the expression of matrix metalloproteinase-1 (MMP1) and tissue inhibitor of metalloproteinase-1 (TIMP1), and down-regulated the expression of Vinculin and transforming growth factor β (TGF-β) in the myocardium, thereby reducing the formation of adhesions. Collectively, these results demonstrate a great potential of PPMT membrane for practical application to anti-adhesion.

•

A functional PVA aerogel-based membrane (PPMT) obtained sutureability through modified electrospinning technology.

•

The primary mechanism to anti-adhesion of PPMT membrane was explored.

•

Promising anti-adhesion effect of PPMT membrane was accomplished in pericardium reconstruction in rabbit.

DNA methylation in genes associated with the evolution of ageing and disease: A critical review

Ageing is characterised by a physical decline in biological functioning which results in a progressive risk of mortality with time. As a biological phenomenon, it is underpinned by the dysregulation of a myriad of complex processes. Recently, however, ever-increasing evidence has associated epigenetic mechanisms, such as DNA methylation (DNAm) with age-onset pathologies, including cancer, cardiovascular disease, and Alzheimer's disease. These diseases compromise healthspan. Consequently, there is a medical imperative to understand the link between epigenetic ageing, and healthspan. Evolutionary theory provides a unique way to gain new insights into epigenetic ageing and health. This review will: (1) provide a brief overview of the main evolutionary theories of ageing; (2) discuss recent genetic evidence which has revealed alleles that have pleiotropic effects on fitness at different ages in humans; (3) consider the effects of DNAm on pleiotropic alleles, which are associated with age related disease; (4) discuss how age related DNAm changes resonate with the mutation accumulation, disposable soma and programmed theories of ageing; (5) discuss how DNAm changes associated with caloric restriction intersect with the evolution of ageing; and (6) conclude by discussing how evolutionary theory can be used to inform investigations which quantify age-related DNAm changes which are linked to age onset pathology.

Focal Point of Fanconi Anemia Signaling

Among human genetic diseases, Fanconi Anemia (FA) tops all with its largest number of health complications in nearly all human organ systems, suggesting the significant roles played by FA genes in the maintenance of human health. With the accumulated research on FA, the encoded protein products by FA genes have been building up to the biggest cell defense signaling network, composed of not only 22+ FA proteins but also ATM, ATR, and many other non-FA proteins. The FA D2 group protein (FANCD2) and its paralog form the focal point of FA signaling to converge the effects of its upstream players in response to a variety of cellular insults and simultaneously with downstream players to protect humans from contracting diseases, including aging and cancer. In this review, we update and discuss how the FA signaling crucially eases cellular stresses through understanding its focal point.

Expert consensus on the clinical application of recombinant adenovirus human p53 for head and neck cancers

The first gene therapy product, recombinant adenovirus human p53 (rAd-p53 ), has been approved by CFDA since 2013. During these years, most of the clinical trials and the relevant basic research were carried out by Chinese oncologists. Gendicine was proved to be a safe and promising gene therapy drug for patients who suffered from head and neck squamous cell carcinoma (HNSCC). The basic therapeutic theories of gene therapy were totally different from the traditional ones, such as surgeries or radio- and chemotherapy, and the evaluation of treatment outcomes should also be changed simultaneously. However, there still existed a lot of misunderstandings about gene therapy, which resulted in improper administration, insufficient dosage calculation, and treatment cycles, and the treatment outcomes were unsatisfactory, especially for inexperienced oncologists or hospitals. Therefore, we will provide some practical guidance here on the gene therapy of rAd-p53 based on our previous research and experience, which focused on the basic theories and clinical issues, to answer the questions arising during the clinical of gene therapy and to accelerate the development of gene therapy for the benefit of patients bearing malignant tumors.

Targeting ferroptosis for cancer therapy: iron metabolism and anticancer immunity

Ferroptosis is a new form of programmed cell death characterized by iron-dependent accumulation of lipid peroxidation, which plays an important role in cancer biology. Ferroptosis is involved in many biological processes, such as amino acid metabolism, glutathione metabolism, iron metabolism, and lipid metabolism. Iron is an essential trace element in a variety of normal cell processes, such as DNA synthesis and repair, cell respiration, metabolism and signal transduction, etc., and iron metabolism disorder has been considered as one of the metabolic markers of malignant cancer cells. In addition, iron is involved in the regulation of innate and adaptive immune responses, suggesting that targeted regulation of iron metabolism may contribute to anti-tumor immunity and cancer therapy. In this review, the regulatory mechanism of ferroptosis, the interaction between ferroptosis on tumor cell metabolism, and anti-tumor immunity were systematically reviewed. Immunotherapy combined with targeted regulation of iron and iron-dependent regulation of ferroptosis should be the focus of future ferroptosis research.

The transcription factor PBX3 promotes tumor cell growth through transcriptional suppression of the tumor suppressor p53

Pre-B-cell leukemia transcription factor 3 (PBX3) is a member of the PBX family and contains a highly conserved homologous domain. PBX3 is involved in the progression of gastric cancer, colorectal cancer, and prostate cancer; however, the detailed mechanism by which it promotes tumor growth remains to be elucidated. Here, we found that PBX3 silencing induces the expression of the cell cycle regulator p21, leading to an increase in colorectal cancer (CRC) cell apoptosis as well as suppression of proliferation and colony formation. Furthermore, we found that PBX3 is highly expressed in clinical CRC patients, in whom p21 expression is aberrantly low. We found that the regulation of p21 transcription by PBX3 occurs through the upstream regulator of p21, the tumor suppressor p53, as PBX3 binds to the p53 promoter and suppresses its transcriptional activity. Finally, we revealed that PBX3 regulates tumor growth through regulation of the p53/p21 axis. Taken together, our results not only describe a novel mechanism regarding PBX3-mediated regulation of tumor growth but also provide new insights into the regulatory mechanism of the tumor suppressor p53.