Gain-of-Function Mutant p53: All the Roads Lead to Tumorigenesis

Identification of a novel prognostic marker ADGRG6 in pancreatic adenocarcinoma: multi-omics analysis and experimental validation

Background

Pancreatic adenocarcinoma (PAAD) ranks among the most lethal malignancies worldwide. Current treatment options have limited efficacy, underscoring the need for new therapeutic targets.

Methods

This study employed a multi-omics analytical framework to delve into the expression profiles and prognostic implications of ADGRG6 within the pan-cancer dataset of The Cancer Genome Atlas (TCGA) database, highlighting the prognostic value and potential carcinogenic role of ADGRG6 in PAAD, which was further validated using data from multiple PAAD cohorts in the Gene Expression Omnibus (GEO) database. To assess the role of ADGRG6 in the tumor microenvironment of PAAD, we evaluated immune infiltration using CIBERSORT, ssGSEA, xCell and Tracking Tumor Immunophenotype (TIP), and utilized single-cell sequencing data to explore cell-cell interactions. Further cellular and animal experiments, such as colony formation assay, transwell assay, western blot, real-time PCR, and tumor xenograft experiments, were used to investigate the effect of ADGRG6 on the proliferation, metastatic potential and immune marker expression of PAAD and the underlying mechanisms.

Results

ADGRG6 emerged as a potential prognostic biomarker and a therapeutic target for PAAD, which was further corroborated by data extracted from multiple PAAD cohorts archived in the GEO database. Single-cell sequencing and immune infiltration analyses predicted the positive correlation of ADGRG6 with the infiltration of immune cells and with the interaction between malignant cells and fibroblasts/macrophages within the PAAD microenvironment. In vitro cell assays demonstrated that ADGRG6 promoted the proliferation, metastatic potential and immune marker expression of PAAD cells by increasing protein level of mutated p53 (mutp53), which activated a spectrum of gain-of-functions to promote cancer progression via the EGFR, AMPK and NF-κB signaling cascades. Furthermore, subcutaneous xenograft experiments in mice demonstrated that ADGRG6 knockdown substantially suppressed the growth of engrafted PAAD tumors.

Conclusions

ADGRG6 may serve as a novel prognostic marker and a therapeutic targets for PAAD, playing a crucial role in the proliferation, metastasis, and immune marker regulation of PAAD through elevating protein level of mutated p53.

Translational Advances in Oncogene and Tumor-Suppressor Gene Research

Cancer, characterized by the uncontrolled proliferation of cells, is one of the leading causes of death globally, with approximately one in five people developing the disease in their lifetime. While many driver genes were identified decades ago, and most cancers can be classified based on morphology and progression, there is still a significant gap in knowledge about genetic aberrations and nuclear DNA damage. The study of two critical groups of genes-tumor suppressors, which inhibit proliferation and promote apoptosis, and oncogenes, which regulate proliferation and survival-can help to understand the genomic causes behind tumorigenesis, leading to more personalized approaches to diagnosis and treatment. Aberration of tumor suppressors, which undergo two-hit and loss-of-function mutations, and oncogenes, activated forms of proto-oncogenes that experience one-hit and gain-of-function mutations, are responsible for the dysregulation of key signaling pathways that regulate cell division, such as p53, Rb, Ras/Raf/ERK/MAPK, PI3K/AKT, and Wnt/β-catenin. Modern breakthroughs in genomics research, like next-generation sequencing, have provided efficient strategies for mapping unique genomic changes that contribute to tumor heterogeneity. Novel therapeutic approaches have enabled personalized medicine, helping address genetic variability in tumor suppressors and oncogenes. This comprehensive review examines the molecular mechanisms behind tumor-suppressor genes and oncogenes, the key signaling pathways they regulate, epigenetic modifications, tumor heterogeneity, and the drug resistance mechanisms that drive carcinogenesis. Moreover, the review explores the clinical application of sequencing techniques, multiomics, diagnostic procedures, pharmacogenomics, and personalized treatment and prevention options, discussing future directions for emerging technologies.

The key vulnerabilities and therapeutic opportunities in the USP7-p53/MDM2 axis in cancer

The MDM2/MDMX-p53 circuitry is essential for controlling the development, apoptosis, immune response, angiogenesis, senescence, cell cycle progression, and proliferation of cancer cells. Research has demonstrated that USP7 exerts strong control over p53, MDM2, and MDMX stability, with multiple mediator proteins influencing the USP7-p53-MDM2/MDMX axis to modify p53 expression level and function. In cases where p53 is of the wild type (Wt-p53) in tumors, inhibiting USP7 promotes the degradation of MDM2/MDMX, leading to the activation of p53 signaling. This, in turn, results in cell cycle arrest and apoptosis. Hence, targeting USP7 presents a promising avenue for cancer therapy. Targeting USP7 in tumors that harbor mutant p53 (Mut-p53) is unlikely and remains largely unexplored due to the existence of numerous USP7 targets that function independently of p53. Considering that Mut-p53 exhibits resistance to degradation by MDM2 and other E3 ligases and also shares the same signaling pathways as Wt-p53, it is reasonable to suggest that USP7 may play a role in stabilizing Mut-p53. However, there is still much to be done in this area. If the hypothesis is correct, USP7 may be a potent target in cancers containing both Wt-p53 and Mut-p53.

CNPY2 in Solid Tumors: Mechanisms, Biomarker Potential, and Therapeutic Implications

Canopy FGF signaling regulator 2 (CNPY2) has emerged as a crucial player in cancer development by promoting cell proliferation, tissue repair, and angiogenesis. This review synthesizes the current understanding of CNPY2's role in solid tumors, particularly renal cell carcinoma, prostate cancer, hepatocellular carcinoma, and non-small-cell lung cancer. CNPY2 modulates key pathways such as p53, MYLIP, NF-κB, and AKT/GSK3β, thereby driving tumor growth and progression. In renal cell carcinoma, CNPY2 paradoxically promotes tumor growth through p53 upregulation, while in hepatocellular carcinoma, CNPY2 drives cell cycle progression via p53 destabilization. In prostate cancer, it enhances tumor progression by stabilizing androgen receptors through MYLIP interaction, and in non-small-cell lung cancer, it contributes to chemoresistance and metastasis through NF-κB and AKT/GSK3β signaling. Additionally, CNPY2 influences the tumor microenvironment, impacting immune function and metastatic potential. As a potential biomarker, CNPY2 shows promise for cancer detection and prognosis, particularly when used in combination with other markers. Early therapeutic strategies, including siRNA and miRNA approaches, are under exploration, though challenges remain due to CNPY2's expression in normal tissues and potential off-target effects. This review underscores the need for further research to fully elucidate CNPY2's oncogenic mechanisms and develop targeted therapies. Improved understanding of CNPY2's diverse roles may lead to novel diagnostic and therapeutic approaches in solid tumors.

The Role of p53 Mutations in Early and Late Response to Mitotic Aberrations

Mutations in the TP53 gene and chromosomal instability (CIN) are two of the most common alterations in cancer. CIN, marked by changes in chromosome numbers and structure, drives tumor development, but is poorly tolerated in healthy cells, where developmental and tissue homeostasis mechanisms typically eliminate cells with chromosomal abnormalities. Mechanisms that allow cancer cells to acquire and adapt to CIN remain largely unknown. Tumor suppressor protein p53, often referred to as the "guardian of the genome", plays a critical role in maintaining genomic stability. In cancer, CIN strongly correlates with TP53 mutations, and recent studies suggest that p53 prevents the propagation of cells with abnormal karyotypes arising from mitotic errors. Furthermore, p53 dysfunction is frequent in cells that underwent whole-genome doubling (WGD), a process that facilitates CIN onset, promotes aneuploidy tolerance, and is associated with poor patient prognosis across multiple cancer types. This review summarizes current insights into p53's role in protecting cells from chromosome copy number alterations and discusses the implications of its dysfunction for the adaption and propagation of cancer cells.

Cabozantinib selectively induces proteasomal degradation of p53 somatic mutant Y220C and impedes tumor growth

Inactivation of p53 by mutations commonly occurs in human cancer. The mutated p53 proteins may escape proteolytic degradation and exhibit high expression in tumors and acquire gain-of-function activity that promotes tumor progression and chemo-resistance. Therefore, selectively targeting of the gain-of-function p53 mutants may serve as a promising therapeutic strategy for cancer prevention and treatment. In this study, we identified cabozantinib, a multikinase inhibitor currently used in the clinical treatment of several types of cancer, as a selective inducer of proteasomal degradation of the p53-Y220C mutant. We demonstrate that cabozantinib disrupts the interaction between p53Y220C and USP7, a deubiquitylating enzyme, resulting in the dissociation of p53Y220C protein from its binding with USP7 and subsequent ubiquitination and degradation mediated by CHIP (the carboxyl terminal of Hsp70-interacting protein). We also show that cabozantinib displays preferential cytotoxicity to p53Y220C-harboring cancer cells both in vitro and in vivo. This study demonstrates a novel, p53-Y220C mutant-targeted anticancer action and mechanism for cabozantinib and provides the rationale for use of this drug in the treatment of cancers that carry the p53-Y220C mutation.

Small molecules that targeting p53 Y220C protein: mechanisms, structures, and clinical advances in anti-tumor therapy

The p53 protein is regarded as the "Guardian of the Genome," but its mutation is tumor progression and present in more than half of malignant tumors. The pro-metastatic property of mutant p53 makes a strong argument for targeting mutant p53 with new therapeutic strategies. However, mutant p53 was considered as a challenging target for drug discovery due to the lack of small molecular binding pockets. Among them, mutant p53 Y220C creates a narrow crevice since the side chains dynamics on protein surface, which is suitable for designing small molecules to occupy the cavity and recovery the tumor suppressing function. Here, we describe the mechanism of p53 related signal pathway and how p53 Y220C regulate the tumorigenesis. We review the two types of p53 Y220C modulators including restoring the conformation of mutant p53 Y220C protein to wild-type p53 protein and recruiting histone acetyltransferase p300/CBP to acetylate p53 Y220C thus enables p53 Y220C dependent upregulation of apoptotic genes and downregulation of DNA damage response pathways. We also report clinical advances and challenges of these molecules in p53 Y220C medicated tumor therapy.

Proteasomal Dysfunction in Cancer: Mechanistic Pathways and Targeted Therapies

Proteasomes are the catalytic complexes in eukaryotic cells that decide the fate of proteins involved in various cellular processes in an energy-dependent manner. The proteasomal system performs its function by selectively destroying the proteins labelled with the small protein ubiquitin. Dysfunctional proteasomal activity is allegedly involved in various clinical disorders such as cancer, neurodegenerative disorders, ageing, and so forth, making it an important therapeutic target. Notably, compared to healthy cells, cancer cells have a higher protein homeostasis requirement and a faster protein turnover rate. The ubiquitin-proteasome system (UPS) helps cancer cells increase rapidly and experience less apoptotic cell death. Therefore, understanding UPS is essential to design and discover some effective inhibitors for cancer therapy. Hereby, we have focused on the role of the 26S proteasome complex, mainly the UPS, in carcinogenesis and seeking potential therapeutic targets in treating numerous cancers.

Intraoperative blood auto-transfusion restrained the malignancy of Liver Cancer via regulating functions of tumor cells and Kuffer cells

The role of IBA in regulating the recovery of liver cancer was investigated using a rat model of liver cancer and an intraoperative blood return model (IBA). SD rats were used to construct the IBA model. Kupffer cells were isolated from liver cancer tissues, and their biological characteristics were analyzed by flow cytometry. Comet assay was used to detect DNA damage in tumor cells; clone formation assay and transwell assay were used to detect tumor cell proliferation and migration ability. Western blot analysis was used to determine the changes in related signaling pathways. After the IBA treatment, the production of KCs was significantly promoted in rat liver cancer tissues, and the expression levels of cell cycle arrest proteins P53, AEN and CDKN1A were also significantly increased. In tumor cells, IBA induced cell cycle arrest and cellular DNA damage in a p53-mediated manner. In addition, the proliferation and migration of cancer cells were also significantly inhibited. Similar to the in vivo data, the expression of TP53, AEN and CDKN1A was also up-regulated. Our study showed that IBA can inhibit the malignant transformation of hepatocellular carcinoma by modulating the function-dependent p53-mediated pathway of tumor cells and KCs.

From regulation to deregulation of p53 in hematologic malignancies: implications for diagnosis, prognosis and therapy

The p53 protein, encoded by the TP53 gene, serves as a critical tumor suppressor, playing a vital role in maintaining genomic stability and regulating cellular responses to stress. Dysregulation of p53 is frequently observed in hematological malignancies, significantly impacting disease progression and patient outcomes. This review aims to examine the regulatory mechanisms of p53, the implications of TP53 mutations in various hematological cancers, and emerging therapeutic strategies targeting p53. We conducted a comprehensive literature review to synthesize recent findings related to p53's multifaceted role in hematologic cancers, focusing on its regulatory pathways and therapeutic potential. TP53 mutations in hematological malignancies often lead to treatment resistance and poor prognosis. Current therapeutic strategies, including p53 reactivation and gene therapy, show promise in improving treatment outcomes. Understanding the intricacies of p53 regulation and the consequences of its mutations is essential for developing effective diagnostic and therapeutic strategies in hematological malignancies, ultimately enhancing patient care and survival.

Current insights and future directions of Li-Fraumeni syndrome

Li-Fraumeni syndrome is a rare yet serious hereditary cancer predisposition syndrome, marked by a significant early-life increased risk of developing cancer. Primarily caused by germline mutations in the TP53 tumor suppressor gene, Li-Fraumeni syndrome is associated with a wide range of malignancies. Clinical management of Li-Fraumeni syndrome could be challenging, especially the lifelong surveillance and follow-up of patients which requires a multidisciplinary approach. Emerging insights into the molecular and clinical basis of Li-Fraumeni syndrome, coupled with advances in genomic technologies and targeted therapies, offer promise in optimizing risk assessment, early detection, and treatment strategies tailored to the unique clinical and molecular profiles of affected individuals. This review discusses Li-Fraumeni syndrome in more depth, reviewing molecular, genomic, epidemiological, clinical, and therapeutic aspects of this disease.

Differential effect of plakoglobin in restoring the tumor suppressor activities of p53-R273H vs. p53-R175H mutants

The six most common missense mutations in the DNA binding domain of p53 are known as "hot spots" and include two of the most frequently occurring p53 mutations (p53-R175H and p53-R273H). p53 stability and function are regulated by various post-translational modifications such as phosphorylation, acetylation, sumoylation, methylation, and interactions with other proteins including plakoglobin. Previously, using various carcinoma cell lines we showed that plakoglobin interacted with wild-type and several endogenous p53 mutants (e.g., R280K, R273H, S241F, S215R, R175H) and restored their tumor suppressor activities in vitro. Since mutant p53 function is both mutant-specific and cell context-dependent, we sought herein, to determine if plakoglobin tumor suppressive effects on exogenously expressed p53-R273H and p53-R175H mutants are similarly maintained under the same genetic background using the p53-null and plakoglobin-deficient H1299 cell line. Functional assays were performed to assess colony formation, migration, and invasion while immunoblotting and qPCR were used to examine the subcellular distribution and expression of specific proteins and genes that are typically regulated by or regulate p53 function and are altered in mutant p53-expressing cell lines and tumors. We show that though, plakoglobin interacted with both p53-R273H and p53-R175H mutants, it had a differential effect on the transcription and subcellular distribution of their gene targets and their overall oncogenic properties in vitro. Notably, we found that plakoglobin's tumor suppressive effects were significantly stronger in p53-R175H expressing cells compared to p53-R273H cells. Together, our results indicate that exploring plakoglobin interactions with p53-R175H may be useful for the development of cancer therapeutics focused on the restoration of p53 function.

MIR193BHG inhibits the proliferation, migration and invasion of trophoblasts by upregulating p53

Aberrant expression of long non-coding RNAs (lncRNAs) serves a crucial role in the biological function of trophoblasts and contributes to preeclampsia (PE). lncRNA MIR193BHG expression is increased in PE placental tissues. In the present study, the effects of MIR193BHG on the function of trophoblasts were assessed to elucidate its underlying molecular mechanisms. The subcellular localization of MIR193BHG in HTR-8/SVneo human first-trimester extravillous trophoblast cells was determined using a fluorescent in situ hybridization assay and by conducting nucleocytoplasmic separation. The effect of MIR193BHG knockdown or overexpression on proliferation, migration, invasion and apoptosis was evaluated in vitro using Cell Counting Kit-8, wound healing, Transwell and flow cytometry assays. RNA-sequencing, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis and protein-protein interaction network construction were subsequently performed to screen the downstream molecules regulated by MIR193BHG. Finally, rescue experiments were conducted to ascertain whether MIR193BHG influenced the biological function of trophoblasts via p53. MIR193BHG was predominantly localized in the nucleus of HTR-8/SVneo cells and overexpression of MIR193BHG significantly inhibited proliferation, migration and invasion, while increasing the rate of apoptosis of HTR-8/SVneo cells. Knockdown of MIR193BHG had the opposite effect. Furthermore, overexpression of MIR193BHG led to increases in both mRNA and protein levels of p53 compared with the control group, and knockdown of p53 rescued the effects induced by overexpression of MIR193BHG on cell proliferation, migration and invasion, while partially counteracting its effects on apoptosis of HTR-8/SVneo cells. In conclusion, the findings of the present study suggested that MIR193BHG served a critical role in progression of PE by regulating the expression of p53, and may be a novel therapeutic target for PE.

Disrupting the interaction between a p53 gain-of-function mutant and the transcriptional co-activator PC4 reverses drug resistance in cancer cells

PC4 is a chromatin-associated protein and transcriptional coactivator whose role in gene regulation by wild-type p53 is now well known. Little is known about the roles of PC4 in tumor cells bearing mutant p53 genes. We show that PC4 associates with one of the tumor-associated gain-of-function p53 mutants, R273H. This association drives its recruitment to two promoters, UBE2C and MDR1, known to be responsible for imparting aggressive growth and resistance to many drugs. Here, we introduced a peptide that disrupts the PC4-R273Hp53 interaction to tumor cells bearing the R273HTP53 gene, which led to a lowering of MDR1 expression and abrogation of drug resistance in a mutant-specific manner. The results suggest that the PC4-R273Hp53 interaction may be a promising target for reducing proliferation and drug resistance in tumors.

The influence of a modified p53 C-terminal peptide by using a tumor-targeting sequence on cellular apoptosis and tumor treatment

The restoration of the function of p53 in tumors is a therapeutic strategy for the highly frequent mutation of the TP53 tumor suppressor gene. P460 is a wild-type peptide derived from the p53 C-terminus and has been proven to be capable of restoring the tumor suppressor function of p53. The poor accumulation of drugs in tumors is a serious hindrance to tumor treatment. For enhancing the activity of P460, the tumor-targeting sequence Arg-Gly-Asp-Arg (RGDR, C-end rule peptide) was introduced into the C-terminus of P460 to generate the new peptide P462. P462 presented better activity than P460 in inhibiting the proliferation of cancer cells and increasing the number of tumor cells undergoing apoptosis. Cell adhesion analysis and tumor imaging results revealed that P462 showed more specific and extensive binding with tumor cells and greater accumulation in tumors than the wild-type peptide. Importantly, treatment with P462 was more efficacious than that with P460 in vivo and was associated with considerably improved tumor-homing activity. This study highlights the importance of the roles of the tumor-homing sequence RGDR in the enhancement in cell attachment and tumor accumulation. The results of this work indicate that P462 could be a novel drug candidate for tumor treatment.

Ferulic acid interventions ameliorate NDEA-CCl4-induced hepatocellular carcinoma via Nrf2 and p53 upregulation and Akt/PKB-NF-κB-TNF-α pathway downregulation in male Wistar rats

Hepatocellular carcinoma is a prevalent form of liver cancer that is life threatening. Many chemically synthesized anti-cancer drugs have various degrees of side effects. Hence, this study investigated the effect of FEAC interventions on NDEA-CCl4-induced HCAR in male Wistar rats. HCAR was induced by intraperitoneal administration of 200 mg/kg of NDEA and 0.5 mL/kg CCl4 (as a promoter of HCAR). Following the induction of HCAR, rats were treated differently with two different doses (25 and 50 mg/kg) of FEAC. HCAR induction was confirmed by the significant elevation of serum levels of ALT, AST, and α-FP. Also elevated significantly were liver levels of Akt/PKB, NF-κB, TNF-α, MDA, GSH, and activities of GST, SOD, and CAT, while levels of liver p53 and Nrf2 were significantly lowered compared with normal rats. Treatment interventions with both 25 and 50 mg/kg of FEAC against the DEN-CCl4-induced HCAR gave comparable effects, marked by a significant reduction in the levels of serum ALT, AST and α-FP, as well as liver levels of MDA, GSH, Akt/PKB, NF-κB, TNF-α, GST, SOD, and CAT, while levels of liver p53 and Nrf2 were significantly elevated compared with normal rats. Put together and judging by the outcomes of this study, FEAC being a potent antioxidant may also be potent against chemical-induced HCAR via upregulation of p53 and Nrf2, as well as downregulation of the Akt/PKB-NF-κB pathway in rats.

Driver Mutations in Pancreatic Cancer and Opportunities for Targeted Therapy

Pancreatic cancer is the sixth leading cause of cancer-related mortality globally. As the most common form of pancreatic cancer, pancreatic ductal adenocarcinoma (PDAC) represents up to 95% of all pancreatic cancer cases, accounting for more than 300,000 deaths annually. Due to the lack of early diagnoses and the high refractory response to the currently available treatments, PDAC has a very poor prognosis, with a 5-year overall survival rate of less than 10%. Targeted therapy and immunotherapy are highly effective and have been used for the treatment of many types of cancer; however, they offer limited benefits in pancreatic cancer patients due to tumor-intrinsic and extrinsic factors that culminate in drug resistance. The identification of key factors responsible for PDAC growth and resistance to different treatments is highly valuable in developing new effective therapeutic strategies. In this review, we discuss some molecules which promote PDAC initiation and progression, and their potential as targets for PDAC treatment. We also evaluate the challenges associated with patient outcomes in clinical trials and implications for future research.

LRP8 promotes tumorigenesis in ovarian cancer through inhibiting p53 signaling

Ovarian cancer (OC) is the most lethal gynecological malignancy with a high mortality rate. Low-density lipoprotein (LDL) receptor-related protein 8 (LRP8) is a cell membrane receptor belonging LDL receptor family and is involved in several tumor progressions. However, there is limited understanding of how LRP8 mediates OC development. LRP8 expression level was identified in human OC tissues and cells using immunohistochemical staining and quantitative polymerase chain reaction assays, respectively. Functions of LRP8 in OC progression were evaluated by Celigo cell counting, wound healing, transwell and flow cytometry assays, and the xenograft models. The human phospho-kinase array analysis was used for screening potential signaling involved in OC development. We observed that LRP8 was overexpressed in OC tissues, and high expression of LRP8 was associated with poor prognosis of OC patients. Functionally, LRP8 knockdown remarkably reduced proliferation and migration of OC cells, and induced apoptosis and S phase cycle arrest. LRP8 deficiency attenuated in vivo tumor growth of OC cells. Moreover, the addition of p53 inhibitor partially reversed the effects of LRP8 knockdown on OC cell proliferation and apoptosis, indicating the involvement of p53 signaling in LRP8-mediated OC progression. This study confirmed that LRP8/p53 axis contributed to OC progression, which might serve as a novel potential therapeutic target for OC patients.

A unique chaperoning mechanism in class A JDPs recognizes and stabilizes mutant p53

J-domain proteins (JDPs) constitute a large family of molecular chaperones that bind a broad spectrum of substrates, targeting them to Hsp70, thus determining the specificity of and activating the entire chaperone functional cycle. The malfunction of JDPs is therefore inextricably linked to myriad human disorders. Here, we uncover a unique mechanism by which chaperones recognize misfolded clients, present in human class A JDPs. Through a newly identified β-hairpin site, these chaperones detect changes in protein dynamics at the initial stages of misfolding, prior to exposure of hydrophobic regions or large structural rearrangements. The JDPs then sequester misfolding-prone proteins into large oligomeric assemblies, protecting them from aggregation. Through this mechanism, class A JDPs bind destabilized p53 mutants, preventing clearance of these oncoproteins by Hsp70-mediated degradation, thus promoting cancer progression. Removal of the β-hairpin abrogates this protective activity while minimally affecting other chaperoning functions. This suggests the class A JDP β-hairpin as a highly specific target for cancer therapeutics.

G-4 inhibits triple negative breast cancer by inducing cell apoptosis and promoting LCN2-dependent ferroptosis

Compound G-4 is a derivate of cyclin-dependent kinase inhibitor Rocovitine and showed strong sensitivity to triple negative breast cancer (TNBC) cells. In this study, the antitumor activity, mechanism and possible targets of G-4 in TNBC were investigated. Flow cytometry and immunoblotting showed that G-4 not only arrested the S phase of the cell cycle, but also induced apoptosis in TNBC cells via the mitochondrial pathway through inhibiting epidermal growth factor receptor (EGFR), AKT and MAPK pathways. In addition, G-4 induced the iron-mutagenesis process in TNBC cells and down-regulated differentially expressed gene lipid carrier protein 2 (LCN2) by RNA-seq. Moreover, G-4 elevated levels of cytosolic reactive oxygen species (ROS), lipid ROS, Fe and malondialdehyde (MDA), but decreased levels of superoxide dismutase (SOD) and glutathione (GSH), consistent with the effects of iron-mutagenic agonists Erastin and RSL3, which were inhibited by the iron inhibitor ferrostatin-1 (Fer-1). Furthermore, a LCN2 knockdown cell model was established by siRNA transfection, the IC50 of G-4 was increased nearly 100-fold, accompanied by a trend of no ferroptosis characteristic index. The results indicated that G-4 suppressed the malignant phenotype of TNBC, induced apoptosis by inhibiting EGFR pathway and promoted LCN2-dependent ferroptosis.

Molecular mechanisms underlying the regulation of tumour suppressor genes in lung cancer

Tumour suppressor genes play a cardinal role in the development of a large array of human cancers, including lung cancer, which is one of the most frequently diagnosed cancers worldwide. Therefore, extensive studies have been committed to deciphering the underlying mechanisms of alterations of tumour suppressor genes in governing tumourigenesis, as well as resistance to cancer therapies. In spite of the encouraging clinical outcomes demonstrated by lung cancer patients on initial treatment, the subsequent unresponsiveness to first-line treatments manifested by virtually all the patients is inherently a contentious issue. In light of the aforementioned concerns, this review compiles the current knowledge on the molecular mechanisms of some of the tumour suppressor genes implicated in lung cancer that are either frequently mutated and/or are located on the chromosomal arms having high LOH rates (1p, 3p, 9p, 10q, 13q, and 17p). Our study identifies specific genomic loci prone to LOH, revealing a recurrent pattern in lung cancer cases. These loci, including 3p14.2 (FHIT), 9p21.3 (p16INK4a), 10q23 (PTEN), 17p13 (TP53), exhibit a higher susceptibility to LOH due to environmental factors such as exposure to DNA-damaging agents (carcinogens in cigarette smoke) and genetic factors such as chromosomal instability, genetic mutations, DNA replication errors, and genetic predisposition. Furthermore, this review summarizes the current treatment landscape and advancements for lung cancers, including the challenges and endeavours to overcome it. This review envisages inspired researchers to embark on a journey of discovery to add to the list of what was known in hopes of prompting the development of effective therapeutic strategies for lung cancer.

Multidimensional pan-cancer analysis of HSPA5 and its validation in the prognostic value of bladder cancer

Endoplasmic reticulum (ER) stress-related genes are closely related to the occurrence, development, and immunotherapy response of tumors. This study provides a comprehensive assessment of HSPA5 from a pan-cancer perspective using multi-omics data. We analyzed the function of HSPA5 in multiple tumor types using multiple databases. Finally, immunohistochemistry was used to examine the relationship between HSPA5 expression in tissue microarrays from 100 patients with bladder cancer and the prognosis of patients with bladder cancer. Using the TCGA database, we were able to determine that HSPA5 is significantly elevated in a number of common malignancies and is linked with a bad prognosis. Cox regression analysis showed that the high expression of HSPA5 was correlated with OS, progression free survival (PFS), disease free survival (DFS), and disease special survival (DSS) of adrenocortical carcinoma (ACC). In addition, we discovered significant disparities in HSPA5 methylation and phosphorylation levels between various malignancies and normal tissues. HSPA5 expression was significantly correlated with the levels of infiltrating cells and immune checkpoint genes. HSPA5 is highly expressed in bladder cancer and patients with high HSPA5 expression have a poor prognosis. Our study provides a basis for further understanding of the role of ER stress-related gene HSPA5 in different tumor genesis and development. HSPA5 has also been shown to be a prognostic biomarker for bladder cancer patients.

Elevated PDE4C level serves as a candidate diagnostic biomarker and correlates with poor survival in thyroid carcinoma

Thyroid carcinoma (THCA) is the most common endocrine cancer. Phosphodiesterase (PDE) 4 enzyme family, as specific regulator of cyclic adenosine monophosphate, may play a important role in THCA. However, few studies on PDE4 enzyme family in THCA have been reported yet. Therefore, this study aimed to systematically analyze the changes of PDE4 enzyme family in THCA, and look for potential target for THCA therapy. We systematically analyzed the expression differences, prognostic value, genetic alteration, methylation modification, and the correlation with tumor immune microenvironment of PDE4 family in THCA using several public databases, including TCGA, GEO, GSCA, TNMplot, cBioPortal, DiseaseMeth and TIMER. Besides, functional enrichment analysis and protein-protein interaction (PPI) network of PDE4 family was investigated using Metascape and STRING databases. The expression levels of PDE4A, PDE4B and PDE4D were down-regulated in THCA patients at different cancer stages, while the expression level of PDE4C was significantly up-regulated. Moreover, THCA patients with higher PDE4C expression had shorter progress free survival compared with those with lower PDE4C expression. The low genomic alteration frequencies and mildly increased methylation levels of PDE4 family were found in THCA patients. Except for PDE4A, the expression levels of PDE4B, PDE4C and PDE4D could affect many immune cells infiltration during THCA progression. Four PDE4 subtypes were all enriched in cAMP catabolic process. Nevertheless, PDE4C was not enriched in the cAMP binding signal pathway, and PDE4B was not enriched in the G alphas signaling events. Notably, PDE4C participated in cAMP metabolic process by regulating adenylate cyclases (ADCYs), which involved ADCY1, ADCY5, ADCY6, ADCY8 and ADCY9. The findings of this study provide a partial basis for the role of PDE4 family in the occurrence and development of THCA. In addition, this study also suggested that PDE4C might be a potential prognostic marker of THCA, which could serve as a reference for future basic and clinical research.

TP53 gain-of-function mutations promote osimertinib resistance via TNF-α-NF-κB signaling in EGFR-mutated lung cancer

EGFR tyrosine kinase inhibitors (TKIs) are effective against EGFR-mutated lung cancer, but tumors eventually develop resistance to these drugs. Although TP53 gain-of-function (GOF) mutations promote carcinogenesis, their effect on EGFR-TKI efficacy has remained unclear. We here established EGFR-mutated lung cancer cell lines that express wild-type (WT) or various mutant p53 proteins with CRISPR-Cas9 technology and found that TP53-GOF mutations promote early development of resistance to the EGFR-TKI osimertinib associated with sustained activation of ERK and expression of c-Myc. Gene expression analysis revealed that osimertinib activates TNF-α-NF-κB signaling specifically in TP53-GOF mutant cells. In such cells, osimertinib promoted interaction of p53 with the NF-κB subunit p65, translocation of the resulting complex to the nucleus and its binding to the TNF promoter, and TNF-α production. Concurrent treatment of TP53-GOF mutant cells with the TNF-α inhibitor infliximab suppressed acquisition of osimertinib resistance as well as restored osimertinib sensitivity in resistant cells in association with attenuation of ERK activation and c-Myc expression. Our findings indicate that induction of TNF-α expression by osimertinib in TP53-GOF mutant cells contributes to the early development of osimertinib resistance, and that TNF-α inhibition may therefore be an effective strategy to overcome such resistance in EGFR-mutant lung cancer with TP53-GOF mutations.

Comprehensive analysis of the potential pathogenesis of COVID-19 infection and liver cancer

BACKGROUND

A growing number of clinical examples suggest that coronavirus disease 2019 (COVID-19) appears to have an impact on the treatment of patients with liver cancer compared to the normal population, and the prevalence of COVID-19 is significantly higher in patients with liver cancer. However, this mechanism of action has not been clarified.

AIM

To investigate the disease relevance of COVID-19 in liver cancer.

METHODS

Gene sets for COVID-19 (GSE180226) and liver cancer (GSE87630) were obtained from the Gene Expression Omnibus database. After identifying the common differentially expressed genes (DEGs) of COVID-19 and liver cancer, functional enrichment analysis, protein-protein interaction network construction and screening and analysis of hub genes were performed. Subsequently, the validation of the differential expression of hub genes in the disease was performed and the regulatory network of transcription factors and hub genes was constructed.

RESULTS

Of 518 common DEGs were obtained by screening for functional analysis. Fifteen hub genes including aurora kinase B, cyclin B2, cell division cycle 20, cell division cycle associated 8, nucleolar and spindle associated protein 1, etc., were further identified from DEGs using the "cytoHubba" plugin. Functional enrichment analysis of hub genes showed that these hub genes are associated with P53 signalling pathway regulation, cell cycle and other functions, and they may serve as potential molecular markers for COVID-19 and liver cancer. Finally, we selected 10 of the hub genes for in vitro expression validation in liver cancer cells.

CONCLUSION

Our study reveals a common pathogenesis of liver cancer and COVID-19. These common pathways and key genes may provide new ideas for further mechanistic studies.

A CANCER PERSISTENT DNA REPAIR CIRCUIT DRIVEN BY MDM2, MDM4 (MDMX), AND MUTANT P53 FOR RECRUITMENT OF MDC1 AND 53BP1 TO CHROMATIN

The influence of the metastasis promoting proteins mutant p53 (mtp53) and MDM2 on Cancer Persistent Repair (CPR) to promote cancer cell survival is understudied. Interactions between the DNA repair choice protein 53BP1 and wild type tumor suppressor protein p53 (wtp53) regulates cell cycle control. Cancer cells often express elevated levels of transcriptionally inactive missense mutant p53 (mtp53) that interacts with MDM2 and MDM4/MDMX (herein called MDMX). The ability of mtp53 to maintain a 53BP1 interaction while in the context of interactions with MDM2 and MDMX has not been described. We asked if MDM2 regulates chromatin-based phosphorylation events in the context of mtp53 by comparing the chromatin of T47D breast cancer cells with and without MDM2 in a phospho-peptide stable isotope labeling in cell culture (SILAC) screen. We found reduced phospho-53BP1 chromatin association, which we confirmed by chromatin fractionation and immunofluorescence in multiple breast cancer cell lines. We used the Proximity Ligation Assay (PLA) in breast cancer cell lines and detected 53BP1 in close proximity to mtp53, MDM2, and the DNA repair protein MDC1. Through disruption of the mtp53-MDM2 interaction, by either Nutlin 3a or a mtp53 R273H C-terminal deletion, we uncovered that mtp53 was required for MDM2-53BP1 interaction foci. Our data suggests that mtp53 works with MDM2 and 53BP1 to promote CPR and cell survival.

miR-460b-5p promotes proliferation and differentiation of chicken myoblasts and targets RBM19 gene

The meat production of broilers is crucial to economic benefits of broiler industries, while the slaughter performance of broilers is directly determined by skeletal muscle development. Hence, the broiler breeding for growth traits shows a great importance. As a kind of small noncoding RNA, microRNA (miRNA) can regulate the expression of multiple genes and perform a wide range of regulation in organisms. Currently, more and more studies have confirmed that miRNAs are closely associated with skeletal muscle development of chickens. Based on our previous miR-seq analysis (accession number: PRJNA668199), miR-460b-5p was screened as one of the key miRNAs probably involved in the growth regulation of chickens. However, the regulatory effect of miR-460b-5p on the development of chicken skeletal muscles is still unclear. Therefore, miR-460b-5p was further used for functional validation at the cellular level in this study. The expression pattern of miR-460b-5p was investigated in proliferation and differentiation stages of chicken primary myoblasts. It was showed that the expression level of miR-460b-5p gradually decreased from the proliferation stage (GM 50%) to the lowest at 24 h of differentiation. As differentiation proceeded, miR-460b-5p expression increased significantly, reaching the highest and stabilizing at 72 h and 96 h of differentiation. Through mRNA quantitative analysis of proliferation marker genes, CCK-8 and Edu assays, miR-460b-5p was found to significantly facilitate the transition of myoblasts from G1 to S phase and promote chicken myoblast proliferation. mRNA and protein quantitative analysis of differentiation marker genes, as well as the indirect immunofluorescence results of myotubes, revealed that miR-460b-5p significantly stimulated myotube development and promote chicken myoblast differentiation. In addition, the target relationship was validated for miR-460b-5p according to the dual-luciferase reporter assay and mRNA quantitative analysis, which indicates that miR-460b-5p was able to regulate RBM19 expression by specifically binding to the 3' UTR of RBM19. In summary, miR-460b-5p has positive regulatory effects on the proliferation and differentiation of chicken myoblasts, and RBM19 is a target gene of miR-460b-5p.

p53 Gain-of-Function Mutation Induces Metastasis via BRD4-Dependent CSF-1 Expression

TP53 mutations are frequent in esophageal squamous cell carcinoma (ESCC) and other SCCs and are associated with a proclivity for metastasis. Here, we report that colony-stimulating factor-1 (CSF-1) expression is upregulated significantly in a p53-R172H-dependent manner in metastatic lung lesions of ESCC. The p53-R172H-dependent CSF-1 signaling, through its cognate receptor CSF-1R, increases tumor cell invasion and lung metastasis, which in turn is mediated in part through Stat3 phosphorylation and epithelial-to-mesenchymal transition (EMT). In Trp53R172H tumor cells, p53 occupies the Csf-1 promoter. The Csf-1 locus is enriched with histone 3 lysine 27 acetylation (H3K27ac), which is likely permissive for fostering an interaction between bromodomain-containing domain 4 (BRD4) and p53-R172H to regulate Csf-1 transcription. Inhibition of BRD4 not only reduces tumor invasion and lung metastasis but also reduces circulating CSF-1 levels. Overall, our results establish a novel p53-R172H-dependent BRD4-CSF-1 axis that promotes ESCC lung metastasis and suggest avenues for therapeutic strategies for this difficult-to-treat disease.

SIGNIFICANCE

The invasion-metastasis cascade is a recalcitrant barrier to effective cancer therapy. We establish that the p53-R172H-dependent BRD4-CSF-1 axis is a mediator of prometastatic properties, correlates with patient survival and tumor stages, and its inhibition significantly reduces tumor cell invasion and lung metastasis. This axis can be exploited for therapeutic advantage. This article is featured in Selected Articles from This Issue, p. 2489.

Mutant p53 gain-of-function stimulates canonical Wnt signaling via PI3K/AKT pathway in colon cancer

Aberrant canonical Wnt signaling is a hallmark of colon cancer. The TP53 tumor suppressor gene is altered in many solid tumors, including colorectal cancer, resulting in mutant versions of p53 (mut-p53) that lose their tumor suppressor capacities and acquire new-oncogenic functions (GOFs) critical for disease progression. Although the mechanisms related to mut-p53 GOF have been explored extensively, the relevance of mut-p53 in the canonical Wnt pathway is not well defined. This work investigated the influence of mut-p53 compared to wt-p53 in β-catenin-dependent Wnt signaling. Using the TCGA public data from Pan-Cancer and the GEPIA2 platform, an in silico analysis of wt-p53 versus mut-p53 genotyped colorectal cancer patients showed that TP53 (p53) and CTNNB1 (β-catenin) are significantly overexpressed in colorectal cancer, compared with normal tissue. Using p53 overexpression or p53 knockdown assays of wt-p53 or mut-p53, we found that while wt-p53 antagonizes canonical Wnt signaling, mut-p53 induces the opposite effect, improving the β-catenin-dependent transcriptional activity and colony formation ability of colon cancer cells, which were both decreased by mut-p53 knockdown expression. The mechanism involved in mut-p53-induced activation of canonical Wnt appears to be via AKT-mediated phosphorylation of Ser 552 of β-catenin, which is known to stabilize and enhance its transcriptional activity. We also found that while wt-p53 expression contributes to 5-FU sensitivity in colon cancer cells, the RITA p53 reactivating molecule counteracted the resistance against 5-FU in cells expressing mut-p53. Our results indicate that mut-p53 GOF acts as a positive regulator of canonical Wnt signaling and participates in the induction of resistance to 5-FU in colon cancer cells.

Integrative Analysis of the Role of TP53 in Human Pan-Cancer

Tumor protein P53 (TP53) is an important tumor suppressor gene in humans. Under normal circumstances, TP53 can help repair mutated genes, or promote the death of cells with severe gene mutations (specifically, TP53 prevents cells from arrest in the G1/S phase when deoxyribonucleic acid (DNA) is damaged and promotes apoptosis if not repaired), and prevents normal cells from becoming malignant cells. TP53 mutations affect its tumor suppressor function, leading to the development of malignant tumors. In this study, using a public database, we explored the pan-cancer expression of TP53, its impact on patient survival and prognosis, the types of gene mutations, its correlation with immunity, and its regulation of other transcription factors and micro RNA (miRNA). The docking sites of therapeutic drugs and key amino acid sites of action provide a basis for future targeted therapies. TP53 has important biological functions in the human body. This study provides a theoretical basis for clinical TP53 gene therapy.

Mutant p53 Gain-of-Function Induces Migration and Invasion through Overexpression of miR-182-5p in Cancer Cells

The master-key TP53 gene is a tumor suppressor that is mutated in more than 50% of human cancers. Some p53 mutants lose their tumor suppressor activity and acquire new oncogenic functions, known as a gain of function (GOF). Recent studies have shown that p53 mutants can exert oncogenic effects through specific miRNAs. We identified the differentially expressed miRNA profiles of the three most frequent p53 mutants (p53R273C, p53R248Q, and p53R175H) after their transfection into the Saos-2 cell line (null p53) as compared with p53WT transfected cells. The associations between these miRNAs and the signaling pathways in which they might participate were identified with miRPath Software V3.0. QRT-PCR was employed to validate the miRNA profiles. We observed that p53 mutants have an overall negative effect on miRNA expression. In the global expression profile of the human miRNome regulated by the p53R273C mutant, 72 miRNAs were underexpressed and 35 overexpressed; in the p53R175H miRNAs profile, our results showed the downregulation of 93 and upregulation of 10 miRNAs; and in the miRNAs expression profile regulated by the p53R248Q mutant, we found 167 decreased and 6 increased miRNAs compared with p53WT. However, we found overexpression of some miRNAs, like miR-182-5p, in association with processes such as cell migration and invasion. In addition, we explored whether the induction of cell migration and invasion by the p53R48Q mutant was dependent on miR-182-5p because we found overexpression of miR-182-5p, which is associated with processes such as cell migration and invasion. Inhibition of mutant p53R248Q and miR-182-5p increased FOXF2-MTSS1 levels and decreased cell migration and invasion. In summary, our results suggest that p53 mutants increase the expression of miR-182-5p, and this miRNA is necessary for the p53R248Q mutant to induce cell migration and invasion in a cancer cell model.

It is not all about the alpha: elevated expression of p53β variants is associated with lower probability of survival in a retrospective melanoma cohort

BACKGROUND

Melanoma is the deadliest type of skin cancer and despite improvements in treatment outcomes, melanoma claimed 57,043 lives in 2020. In most malignancies, p53 mutation rates are above 50% and provide prognostic indications. However, in melanoma where less than a quarter of cases harbour a p53 mutation, the significance of the tumour suppressor may be questioned. Instead, p53 isoforms, which modulate p53's canonical function, may be of greater clinical importance.

METHODS

The expression of p53 isoforms was evaluated in 123 melanoma specimens by immunohistochemistry using p53 isoform-specific antibodies (DO-1, KJC8, KJC40, and KJC133). To determine whether TP53 mutations may be driving p53 isoform expression, TP53 was sequenced in 30 FFPE melanoma samples.

RESULTS

The C-terminally truncated p53β isoforms (KJC8) were found to be the most highly expressed p53 isoforms compared to all other isoforms. Further, elevated KJC8 staining was found to correlate with reduced probability of melanoma-specific survival, while KJC40 staining (Δ40p53) positively correlated with reduced melanoma thickness. TAp53 isoforms (p53 retaining both transactivation domains, DO-1), were the second highest p53 isoforms expressed across all samples. Elevated DO-1 staining was also associated with worse survival outcomes and more advanced stages of cancer. Given that the isoforms are likely to work in concert, composite isoform profiles were generated. Composite biomarker profiles revealed that elevated TAp53 (DO-1) and p53β (KJC8) expression, accompanied by low Δ40p53 (KJC40) and Δ133p53 (KJC133) expression was associated with the worst survival outcomes. Supporting the lack of predictive biomarker potential of TP53 in melanoma, no clinicopathological or p53 isoform expression associations could be linked to TP53 status.

CONCLUSIONS

Given the lack of prognostic biomarker potential derived from TP53 status, this study highlights how p53 isoform expression might progress this field and, pending further validation, may provide additional information to treating oncologists that might be factored into treatment decisions.

Prognostic value of amino acid metabolism-related gene expression in invasive breast carcinoma

BACKGROUND

An increasing number of studies indicated that metabolic reprogramming of amino acid metabolism may either promote or inhibit tumor progression. The purpose of this study was to investigate the ability of a gene risk signature associated with amino acid metabolism to predict the prognosis and immune characteristics of invasive breast carcinoma.

METHODS

LASSO Cox regression analysis was performed to construct and validate the prognostic risk signature based on the expression of 9 amino acid metabolism-related genes. The predictive value of the signature, immune characteristics, and chemotherapeutic drugs was also predicted. Finally, 9 significant genes were examined in MDA-MB-231 and MCF-7 cells, and the predicted chemotherapeutic drugs were also verified.

RESULTS

The prognosis of the low-risk group was better than that of the high-risk group. The areas under the curve (AUCs) at 1, 2, and 3 years were 0.852, 0.790, and 0.736, respectively. In addition, the GSEA results for KEGG and GO revealed that samples with a high-risk score exhibited a variety of highly malignant manifestations. The high-risk group was characterized by an increased number of M2 macrophages, a high level of tumor purity, low levels of APC co-stimulation, cytolytic activity, HLA, para-inflammation, and type I IFN response. Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) confirmed that MDA-MB-231 and MCF-7 cells express 9 amino acid metabolism-related genes differently. In addition, cell experiments were conducted to examine the effect of cephaeline-induced on cell viability, migration ability, and protein expression of the PI3K/AKT signaling pathway and HIF-1α.

CONCLUSION

We established a risk signature based on 9 amino acid metabolism-related genes for invasive breast carcinoma. Further analyses revealed that this risk signature is superior to other clinical indexes in survival prediction and that the subgroups identified by the risk signature exhibit distinct immune characteristics. Cephaeline was determined to be a superior option for patients in high-risk groups.

Increased demand for FAD synthesis in differentiated and stem pancreatic cancer cells is accomplished by modulating FLAD1 gene expression: the inhibitory effect of Chicago Sky Blue

FLAD1, along with its FAD synthase (FADS, EC 2.7.7.2) product, is crucial for flavin homeostasis and, due to its role in the mitochondrial respiratory chain and nuclear epigenetics, is closely related to cellular metabolism. Therefore, it is not surprising that it could be correlated with cancer. To our knowledge, no previous study has investigated FLAD1 prognostic significance in pancreatic ductal adenocarcinoma (PDAC). Thus, in the present work, the FAD synthesis process was evaluated in two PDAC cell lines: (a) PANC-1- and PANC-1-derived cancer stem cells (CSCs), presenting the R273H mutation in the oncosuppressor p53, and (b) MiaPaca2 and MiaPaca2-derived CSCs, presenting the R248W mutation in p53. As a control, HPDE cells expressing wt-p53 were used. FADS expression/activity increase was found with malignancy and even more with stemness. An increased FAD synthesis rate in cancer cell lines is presumably demanded by the increase in the FAD-dependent lysine demethylase 1 protein amount as well as by the increased expression levels of the flavoprotein subunit of complex II of the mitochondrial respiratory chain, namely succinate dehydrogenase. With the aim of proposing FADS as a novel target for cancer therapy, the inhibitory effect of Chicago Sky Blue on FADS enzymatic activity was tested on the recombinant 6His-hFADS2 (IC50  = 1.2 μm) and PANC-1-derived CSCs' lysate (IC50  = 2-10 μm). This molecule was found effective in inhibiting the growth of PANC-1 and even more of its derived CSC line, thus assessing its role as a potential chemotherapeutic drug.

SET-mediated epigenetic dysregulation of p53 impairs trichloroethylene-induced DNA damage response

Trichloroethylene (TCE) was a widely used industrial solvent, and now has become a major environmental pollutant. Exposure to TCE has been found to result in significant damage to the liver, leading to hepatic toxicity. In our previous study, we discovered that a histone chaperon called SET plays a crucial role in mediating the DNA damage and apoptosis caused by TCE in hepatic cells. However, the precise function of SET in the response to DNA damage is still not fully understood. In this study, we evaluated TCE-induced DNA damage of hepatic L-02 cells with SET-knockdown, then analyzed alterations of H3K79me3 and p53 in hepatic cells and carcinogenic mice livers. Results suggested that SET interferes with DNA response via mediating down-regulation of p53 and partially suppressing H3K79me3 under treatment of TCE. To further verify the regulatory cascade, H3K79me3 was reduced and p53 was knocked down in L-02 cells respectively, and extent of DNA damage was evaluated. Reduced H3K79me3 was found leading to down-regulation of p53 which further exacerbated TCE-induced DNA injury. These findings demonstrated that SET-H3K79me3-p53 served as an epigenetic regulatory axis involved in TCE-induced DNA damage response.

LINC01605 Is a Novel Target of Mutant p53 in Breast and Ovarian Cancer Cell Lines

TP53 is the most frequently mutated gene in human cancers. Most TP53 genomic alterations are missense mutations, which cause a loss of its tumour suppressor functions while providing mutant p53 (mut_p53) with oncogenic features (gain-of-function). Loss of p53 tumour suppressor functions alters the transcription of both protein-coding and non-protein-coding genes. Gain-of-function of mut_p53 triggers modification in gene expression as well; however, the impact of mut_p53 on the transcription of the non-protein-coding genes and whether these non-protein-coding genes affect oncogenic properties of cancer cell lines are not fully explored. In this study, we suggested that LINC01605 (also known as lincDUSP) is a long non-coding RNA regulated by mut_p53 and proved that mut_p53 directly regulates LINC01605 by binding to an enhancer region downstream of the LINC01605 locus. We also showed that the loss or downregulation of LINC01605 impairs cell migration in a breast cancer cell line. Eventually, by performing a combined analysis of RNA-seq data generated in mut_TP53-silenced and LINC01605 knockout cells, we showed that LINC01605 and mut_p53 share common gene pathways. Overall, our findings underline the importance of ncRNAs in the mut_p53 network in breast and ovarian cancer cell lines and in particular the importance of LINC01605 in mut_p53 pro-migratory pathways.

Crosstalk between long non-coding RNAs and p53 signaling pathway in colorectal cancer: A review study

Colorectal cancer (CRC) is one of the most prevalent malignancies worldwide and the third leading cause of cancer-related fatalities. Long non-coding RNAs (lncRNAs) are key regulators of diverse physiological processes and are dysregulated in a wide range of pathophysiological circumstances such as CRC. Studies revealed that aberrant expressions of lncRNAs clearly modulate the expression level of p53 gene in CRC, thereby transactivating multiple downstream pathways. P53 is regarded as a crucial tumor suppressor gene which promotes cell-cycle arrest, DNA repair, senescence or apoptosis in response to cellular stresses. P53 is also mutated in CRC as well as various types of human malignancies. Therefore, lncRNAs interact with the p53 signaling pathway in numerus ways and significantly influence CRC-related processes. The current findings in the investigation of the crosstalk between lncRNAs and the P53 pathway in controlling CRC carcinogenesis, tumor progression, and therapeutic resistance are summarized in the this review. A deeper knowledge of CRC carcinogenesis may also have implications in CRC prevention and treatment through more research.

Targeting mutant p53 stabilization for cancer therapy

Over 50% cancer bears TP53 mutation, the highly stabilized mutant p53 protein drives the tumorigenesis and progression. Mutation of p53 not only cause loss-of-function and dominant-negative effects (DNE), but also results in the abnormal stability by the regulation of the ubiquitin-proteasome system and molecular chaperones that promote tumorigenesis through gain-of-function effects. The accumulation of mutant p53 is mainly regulated by molecular chaperones, including Hsp40, Hsp70, Hsp90 and other biomolecules such as TRIM21, BAG2 and Stat3. In addition, mutant p53 forms prion-like aggregates or complexes with other protein molecules and result in the accumulation of mutant p53 in tumor cells. Depleting mutant p53 has become one of the strategies to target mutant p53. This review will focus on the mechanism of mutant p53 stabilization and discuss how the strategies to manipulate these interconnected processes for cancer therapy.

Selective nuclear export inhibitor KPT‑330 enhances the radiosensitivity of esophageal carcinoma cells

Although the concurrent application of definitive chemoradiation has improved the prognosis of patients with esophageal cancer, resistance to therapy poses a major threat to treatment. The present study aimed to investigate whether the use of KPT-330, a selective inhibitor of nuclear export (SINE), enhances the radiosensitivity of esophageal cancer cells. Immunohistochemical staining assays were employed to evaluate the expression and prognostic significance of chromosome maintenance protein-1 (CRM1) in 111 esophageal carcinoma (ESCA) tissues collected from patients with esophageal squamous cell carcinoma. The data showed that the expression of CRM1 in the ESCA tissues was significantly upregulated compared with that in the normal adjacent tissues. Furthermore, patients with higher CRM1 expression had significantly decreased overall survival compared with those with lower CRM1 expression. The effects of KPT-330 and/or radiation on ECA109 human ESCA cells were also evaluated. KPT-330 suppressed the viability of the ECA109 cells. A colony formation assay demonstrated that a combination of KPT-330 and radiation significantly decreased ECA109 cell proliferation. Flow cytometric analysis showed that KPT-330 increased the arrest of the ECA109 cells at the G₂/M phase and induced apoptosis. In addition, western blotting revealed that the inhibitory effect of KPT-330 on cell viability was associated with the increased expression of p53 and promotion of the nuclear accumulation of the p53 protein. In conclusion, the present study demonstrated that CRM1 expression is associated with the prognosis of patients with ESCA following radiotherapy. The inhibition of CRM1 expression by the SINE inhibitor KPT-330 increases radiosensitivity and is potentially useful in a combination treatment strategy for esophageal cancers.

STAMBPL1 promotes the progression of lung adenocarcinoma by inhibiting DHRS2 expression

BACKGROUND

Lung cancer is responsible for the majority of cancer deaths in the world. We found a significant increase of STAMBPL1 expression in lung adenocarcinoma (LUAD) tissues and cells. However, its mechanism has not been clarified.

METHODS

LUAD tissues and adjacent normal tissues were collected from 62 patients treated in the First Affiliated Hospital of Wenzhou Medical University from August 2018 to August 2021. In vivo, the clinical data and STAMBPL1 expression of 62 patients with LUAD were analyzed by qPCR. In vitro, cell experiments were carried out after STAMBPL1 knockdown in A549 and H1299 cells to determine cell growth, migration rate, evasiveness, colony-forming ability, and apoptosis. Gene sequencing was used to explore the expression of various genes in A549 and H1299 cells to verify that DHRS2 was up-regulated after STAMBPL1 knockdown; cell experiments further detected the role of the DHRS2 gene after DHRS2 overexpression in A549 and H1299 cells. A rescue experiment was conducted to certify that STAMBPL1 promotes NSCLC progression by regulating DHRS2 expression.

RESULTS

After STAMBPL1 knockdown by siRNA. Migration, invasion, colony formation, and proliferation of siRNA groups were suppressed than those of NC groups in A549 and H1299 cells, while the cell apoptosis rate of siRNA groups increased significantly. By using gene-sequence analysis, we found that the expression level of the DHRS2 gene was up-regulated in STAMBPL1 siRNA groups, compared with STAMBPL1 NC (negative control) groups in A549 and H1299, which was verified by qPCR and WB. Further experiments showed that the DHRS2 OE group was suppressed in cell proliferation, migration, and invasion in the A549 and H1299 cell lines compared to the DHRS2 NC group, while DHRS2 OE group was significantly enhanced in the cell apoptosis in the A549 and H1299 cell lines. According to the rescue experiment, cell proliferation, migration, and invasion of the STAMBPL1 SI+DHRS2 SI group were enhanced compared with the STAMBPL1 SI+DHRS2 NC group in A549 and H1299 cells, while the STAMBPL1 SI+DHRS2 OE group were further decreased.

CONCLUSIONS

The expression of STAMBPL1 mRNA is significantly up-regulated in LUAD, promoting the progression of LUAD by down-regulating the expression of DHRS2 and acting as a potential biomarker of LUAD.

Understanding human aging and the fundamental cell signaling link in age-related diseases: the middle-aging hypovascularity hypoxia hypothesis

Aging-related hypoxia, oxidative stress, and inflammation pathophysiology are closely associated with human age-related carcinogenesis and chronic diseases. However, the connection between hypoxia and hormonal cell signaling pathways is unclear, but such human age-related comorbid diseases do coincide with the middle-aging period of declining sex hormonal signaling. This scoping review evaluates the relevant interdisciplinary evidence to assess the systems biology of function, regulation, and homeostasis in order to discern and decipher the etiology of the connection between hypoxia and hormonal signaling in human age-related comorbid diseases. The hypothesis charts the accumulating evidence to support the development of a hypoxic milieu and oxidative stress-inflammation pathophysiology in middle-aged individuals, as well as the induction of amyloidosis, autophagy, and epithelial-to-mesenchymal transition in aging-related degeneration. Taken together, this new approach and strategy can provide the clarity of concepts and patterns to determine the causes of declining vascularity hemodynamics (blood flow) and physiological oxygenation perfusion (oxygen bioavailability) in relation to oxygen homeostasis and vascularity that cause hypoxia (hypovascularity hypoxia). The middle-aging hypovascularity hypoxia hypothesis could provide the mechanistic interface connecting the endocrine, nitric oxide, and oxygen homeostasis signaling that is closely linked to the progressive conditions of degenerative hypertrophy, atrophy, fibrosis, and neoplasm. An in-depth understanding of these intrinsic biological processes of the developing middle-aged hypoxia could provide potential new strategies for time-dependent therapies in maintaining healthspan for healthy lifestyle aging, medical cost savings, and health system sustainability.

Pharmacological properties and derivatives of saikosaponins-a review of recent studies

OBJECTIVES

Saikosaponins (SSs) constitute a class of medicinal monomers characterised by a triterpene tricyclic structure. Despite their potential therapeutic effects for various pathological conditions, the underlying mechanisms of their actions have not been systematically analysed. Here, we mainly review the important anti-inflammatory, anticancer, and antiviral mechanisms underlying SS actions.

METHODS

Information from multiple scientific databases, such as PubMed, the Web of Science, and Google Scholar, was collected between 2018 and 2023. The search term used was saikosaponin.

KEY FINDINGS

Numerous studies have shown that Saikosaponin A exerts anti-inflammatory effects by modulating cytokine and reactive oxygen species (ROS) production and lipid metabolism. Moreover, saikosaponin D exerts antitumor effects by inhibiting cell proliferation and inducing apoptosis and autophagy, and the antiviral mechanisms of SSs, especially against SARS-CoV-2, have been partially revealed. Interestingly, an increasing body of experimental evidence suggests that SSs show the potential for use as anti-addiction, anxiolytic, and antidepressant treatments, and therefore, the related molecular mechanisms warrant further study.

CONCLUSIONS

An increasing amount of data have indicated diverse SS pharmacological properties, indicating crucial clues for future studies and the production of novel saikosaponin-based anti-inflammatory, efficacious anticancer, and anti-novel-coronavirus agents with improved efficacy and reduced toxicity.

Gentian Violet Inhibits Cell Proliferation through Induction of Apoptosis in Ovarian Cancer Cells

Gentian violet (GV) is known to have antibacterial and antifungal effects, but recent studies have demonstrated its inhibitory effects on the growth of several types of cancer cells. Here, we investigated the anticancer efficacy of GV in ovarian cancer cells. GV significantly reduced the proliferation of OVCAR8, SKOV3, and A2780 cells. Results of transferase dUTP nick and labeling (TUNEL) assay and Western blot assay indicated that the inhibitory effect of GV on ovarian cancer cells was due to the induction of apoptosis. Moreover, GV significantly increased reactive oxygen species (ROS) and upregulated the expression of p53, PUMA, BAX, and p21, critical components for apoptosis induction, in ovarian cancer cells. Our results suggest that GV is a novel antiproliferative agent and is worthy of exploration as a potential therapeutic agent for ovarian cancer.

ATF2 loss promotes 5-FU resistance in colon cancer cells via activation of the ATR-Chk1 damage response pathway

BACKGROUND

The role of ATF2 in colon cancer (CC) is controversial. Recently, we reported that low ATF2 expression is characteristic of highly invasive tumors, suggesting that ATF2 might also be involved in therapy resistance. 5-Fluorouracil (5-FU) is the best-known chemotherapeutic drug for CC, but drug resistance affects its curative effect. To date, the role of ATF2 in the 5-FU response remains elusive.

METHODS/RESULTS

For our study, we had available HCT116 cells (wild-type p53) and HT29 colon tumor cells (mutant p53) and their corresponding CRISPR‒Cas9-generated ATF2-KO clones. We observed that loss of ATF2 triggered dose- and time-dependent 5-FU resistance in HCT116 cells by activating the DNA damage response (DDR) pathway with high p-ATR^Thr1989 and p-Chk1^Ser317 levels accompanied by an increase in the DNA damage marker γ-H2AX in vitro and in vivo using the chicken chorioallantoic membrane (CAM) model. Chk1 inhibitor studies causally displayed the link between DDR and drug resistance. There were contradictory findings in HT29 ATF2-KO cells upon 5-FU exposure with low p-Chk1^Ser317 levels, strong apoptosis induction, but no effects on DNA damage. In ATF2-silenced HCT116 p53^-/- cells, 5-FU did not activate the DDR pathway. Co-immunoprecipitation and proximity ligation assays revealed that upon 5-FU treatment, ATF2 binds to ATR to prevent Chk1 phosphorylation. Indeed, in silico modelling showed reduced ATR-Chk1 binding when ATF2 was docked into the complex.

CONCLUSIONS

We demonstrated a novel ATF2 scaffold function involved in the DDR pathway. ATF2-negative cells are highly resistant due to effective ATR/Chk1 DNA damage repair. Mutant p53 seems to overwrite the tumor suppressor function of ATF2.

circDYRK1A tethers biological behaviors of gastric carcinoma using novel bioinformatics analysis and experimental validations

Gastric cancer has been one of the wide public health burdens with its high morbidity and mortality over several decades. As the unconventional modules among RNA families, circular RNAs present their blazing biological effects during gastric carcinogenesis. Though diverse hypothetical mechanisms were reported, further tests were necessitated for authentication. Herein, this study pinpointed a representative circDYRK1A which screened from vast amounts of public data sets using surprisingly novel bioinformatics approaches together with validations from the in vitro findings and then concluded that circDYRK1A tethered the biological behavior and swayed the clinicopathological features with gastric cancer patients thus providing an in-depth awareness for gastric carcinoma.

Ferulic Acid: A Review of Pharmacology, Toxicology, and Therapeutic Effects on Pulmonary Diseases

Ferulic acid (FA), a prevalent dietary phytochemical, has many pharmacological effects, including anti-oxidation and anti-inflammation effects, and has been widely used in the pharmaceutical, food, and cosmetics industries. Many studies have shown that FA can significantly downregulate the expression of reactive oxygen species and activate nuclear factor erythroid-2-related factor-2/heme oxygenase-1 signaling, exerting anti-oxidative effects. The anti-inflammatory effect of FA is mainly related to the p38 mitogen-activated protein kinase and nuclear factor-kappaB signaling pathways. FA has demonstrated potential clinical applications in the treatment of pulmonary diseases. The transforming growth factor-β1/small mothers against decapentaplegic 3 signaling pathway can be blocked by FA, thereby alleviating pulmonary fibrosis. Moreover, in the context of asthma, the T helper cell 1/2 imbalance is restored by FA. Furthermore, FA ameliorates acute lung injury by inhibiting nuclear factor-kappaB and mitogen-activated protein kinase pathways via toll-like receptor 4, consequently decreasing the expression of downstream inflammatory mediators. Additionally, there is a moderate neuraminidase inhibitory activity showing a tendency to reduce the interleukin-8 level in response to influenza virus infections. Although the application of FA has broad prospects, more preclinical mechanism-based research should be carried out to test these applications in clinical settings. This review not only covers the literature on the pharmacological effects and mechanisms of FA, but also discusses the therapeutic role and toxicology of FA in several pulmonary diseases.

The targeted next-generation sequence revealed SMAD4, AKT1, and TP53 mutations from circulating cell-free DNA of breast cancer and its effect on protein structure - A computational approach

Breast cancer biomarkers that detect marginally advanced stages are still challenging. The detection of specific abnormalities, targeted therapy selection, prognosis, and monitoring of treatment effectiveness over time are all made possible by circulating free DNA (cfDNA) analysis. The proposed study will detect specific genetic abnormalities from the plasma cfDNA of a female breast cancer patient by sequencing a cancer-related gene panel (MGM455 - Oncotrack Ultima), including 56 theranostic genes (SNVs and small INDELs). Initially, we determined the pathogenicity of the observed mutations using PredictSNP, iStable, Align-GVGD, and ConSurf servers. As a next step, molecular dynamics (MD) was implemented to determine the functional significance of SMAD4 mutation (V465M). Lastly, the mutant gene relationships were examined using the Cytoscape plug-in GeneMANIA. Using ClueGO, we determined the gene's functional enrichment and integrative analysis. The structural characteristics of SMAD4 V465M protein by MD simulation analysis further demonstrated that the mutation was deleterious. The simulation showed that the native structure was more significantly altered by the SMAD4 (V465M) mutation. Our findings suggest that SMAD4 V465M mutation might be significantly associated with breast cancer, and other patient-found mutations (AKT1-E17K and TP53-R175H) are synergistically involved in the process of SMAD4 translocate to nuclease, which affects the target gene translation. Therefore, this combination of gene mutations could alter the TGF-β signaling pathway in BC. We further proposed that the SMAD4 protein loss may contribute to an aggressive phenotype by inhibiting the TGF-β signaling pathway. Thus, breast cancer's SMAD4 (V465M) mutation might increase their invasive and metastatic capabilities.Communicated by Ramaswamy H. Sarma.

SCF-FBXL8 contributes to liver metastasis and stem-cell-like features in colorectal cancer cells by mediating ubiquitination and degradation of TP53

BACKGROUND

FBXL8 is a conserved F-box protein, belonging to the ubiquitin ligase complex, which promotes the development and progression of tumours. However, the regulation function and mechanism of FBXL8's involvement in colorectal cancer (CRC) remain unclear.

METHODS

RT-PCR is used to detect gene expression levels. Protein levels were determined by western blotting and flow cytometry. The bindings of FBXL8 and p53 and ubiquitination levels were detected by cell transfection and immunoprecipitation. The transwell assay was used to measure the ability of cells to migrate and invade. Animal studies were used to verify the function of FBXL8 in vivo.

RESULTS

The expression of FBXL8 was up-regulated in CRC tissues, and its overexpression was associated with poor prognosis in CRC patients. The up-regulation of FBXL8 promoted the proliferation, invasion and migration of CRC tumour cells and maintained the stem-cell characteristics of colorectal tumour cells. Further analysis demonstrated that FBXL8 targeted p53 and reduced its stability through ubiquitination. Knockout of FBXL8 down-regulated the proliferation, migration and stem-like properties of tumour cells. CRC mouse xenograft tumour model confirmed that FBXL8 gene knockout inhibited tumour formation and liver metastasis.

CONCLUSION

FBXL8 was highly expressed in CRC. Mechanism studies have shown that FBXL8 degraded tumour suppressor gene p53 by ubiquitination. FBXL8 knockout inhibited the proliferation and stem characteristics of CRC cells, so SCF-FBXL8-TP53 has potential to be used as a therapeutic target for CRC in subsequent studies.

Mendelian inheritance revisited: dominance and recessiveness in medical genetics

Understanding the consequences of genotype for phenotype (which ranges from molecule-level effects to whole-organism traits) is at the core of genetic diagnostics in medicine. Many measures of the deleteriousness of individual alleles exist, but these have limitations for predicting the clinical consequences. Various mechanisms can protect the organism from the adverse effects of functional variants, especially when the variant is paired with a wild type allele. Understanding why some alleles are harmful in the heterozygous state - representing dominant inheritance - but others only with the biallelic presence of pathogenic variants - representing recessive inheritance - is particularly important when faced with the deluge of rare genetic alterations identified by high throughput DNA sequencing. Both awareness of the specific quantitative and/or qualitative effects of individual variants and the elucidation of allelic and non-allelic interactions are essential to optimize genetic diagnosis and counselling.

The complex network of transcription factors, immune checkpoint inhibitors and stemness features in colorectal cancer: A recent update

Cancer immunity is regulated by several mechanisms that include co-stimulatory and/or co-inhibitory molecules known as immune checkpoints expressed by the immune cells. In colorectal cancer (CRC), CTLA-4, LAG3, TIM-3 and PD-1 are the major co-inhibitory checkpoints involved in tumor development and progression. On the other hand, the deregulation of transcription factors and cancer stem cells activity plays a major role in the development of drug resistance and in the spread of metastatic disease in CRC. In this review, we describe how the modulation of such transcription factors affects the response of CRC to therapies. We also focus on the role of cancer stem cells in tumor metastasis and chemoresistance and discuss both preclinical and clinical approaches for targeting stem cells to prevent their tumorigenic effect. Finally, we provide an update on the clinical applications of immune checkpoint inhibitors in CRC and discuss the regulatory effects of transcription factors on the expression of the immune inhibitory checkpoints with specific focus on the PD-1 and PD-L1 molecules.