New therapeutic strategies to treat human cancers expressing mutant p53 proteins

Targeting anti-apoptotic mechanisms in tumour cells: Strategies for enhancing Cancer therapy

Anti-cancer drug's cytotoxicity is determined by their ability to induce predetermined cell demise, commonly called apoptosis. The cancer-causing cells are able to evade cell death, which has been affiliated with both malignancy as well as resistance to cancer treatments. In order to avoid cell death, cancerous tumour cells often produce an abundance of anti-apoptotic proteins, becoming "dependent" on them. Consequently, protein inhibitors of cell death may prove to be beneficial as pharmacological targets for the future creation of cancer therapies. This article examines the molecular routes of apoptosis, its clinical manifestations, anti-cancer therapy options that target the intrinsic mechanism of apoptosis, proteins that prevent cell death, and members of the B-lymphoma-2 subset. In addition, novel approaches to cell death are highlighted, including how curcumin mitigates chemotherapy-induced apoptosis in healthy tissues and the various ways melatonin modifies apoptosis to improve cancer treatment efficacy, particularly through the TNF superfamily. Cancer treatment-induced increases in anti-apoptotic proteins lead to drug resistance; yet, ligands that trigger cell death by inhibiting these proteins are expected to improve chemotherapy's efficacy. The potential of frequency-modulated dietary phytochemicals as a cancer therapeutic pathway, including autophagy and apoptosis, is also explored. This approach may be more efficient than inhibition alone in overcoming drug resistance. Consequently, this method has the potential to allow for lower medication concentrations, reducing cytotoxicity and unwanted side effects.

Divergent regulation of long non-coding RNAs H19 and PURPL affects cell senescence in human dermal fibroblasts

Cellular senescence is a permanent cell growth arrest that occurs in response to various intrinsic and extrinsic stimuli and is associated with cellular and molecular changes. Long non-coding RNAs (lncRNAs) are key regulators of cellular senescence by affecting the expression of many important genes involved in senescence-associated pathways and processes. Here, we evaluated a panel of lncRNAs associated with senescence for their differential expression between young and senescent human dermal fibroblasts (NHDFs) and studied the effect of a known senomorphic compound, resveratrol, on the expression of lncRNAs in senescent NHDFs. As markers of senescence, we evaluated cell growth, senescence-associated (SA)-β-Gal staining, and the expression of p21, Lamin B1 and γH2AX. We found that H19 and PURPL were the most altered lncRNAs in replicative, in doxorubicin (DOXO) and ionising radiation (IR)-induced senescence models. We then investigated the function of H19 and PURPL in cell senescence by siRNA-mediated silencing in young and senescent fibroblasts, respectively. Our results showed that H19 knockdown reduced cell viability and induced cell senescence and autophagy of NHDFs through the regulation of the PI3K/AKT/mTOR pathway; conversely, PURPL silencing reversed senescence by reducing (SA)-β-Gal staining, recovering cell proliferation with an increase of S-phase cells, and reducing the p53-dependent DNA damage response. Overall, our data highlighted the role of H19 and PURPL in the senescent phenotype and suggested that these lncRNAs may have important implications in senescence-related diseases.

Unraveling the Guardian: p53's Multifaceted Role in the DNA Damage Response and Tumor Treatment Strategies

DNA damage can lead to mutations that can alter the function of oncogenes or tumor suppressor genes, thus promoting the development of cancer. p53 plays a multifaceted and complex role in the DNA damage response and cancer progression and is known as the 'guardian of the gene'. When DNA damage occurs, p53 is activated through a series of post-translational modifications, which stabilize the protein and enhance its function as a transcription factor. It regulates processes including cell cycle checkpoints, DNA repair and apoptosis, thereby preventing the spread of damaged DNA and maintaining genome integrity. On the one hand, p53 can initiate cell cycle arrest and induce cells to enter the G1/S and G2/M checkpoints, preventing cells with damaged DNA from continuing to proliferate and gaining time for DNA repair. At the same time, p53 can promote the activation of DNA repair pathways, including base excision repair, nucleotide excision repair and other repair pathways, to ensure the integrity of genetic material. If the damage is too severe to repair, p53 will trigger the apoptosis process to eliminate potential cancer risks in time. p53 also plays a pivotal role in cancer progression. Mutations in the p53 gene are frequently found in many cancers, and the mutated p53 not only loses its normal tumor suppressor function but may even acquire pro-cancer activity. Therefore, we also discuss therapeutic strategies targeting the p53 pathway, such as the use of small-molecule drugs to restore the function of wild-type p53, the inhibition of negative regulatory factors and synthetic lethality approaches for p53-deficient tumors. This review therefore highlights the important role of p53 in maintaining genomic stability and its potential in therapeutic strategies for cancer.

Polo-like kinase 2 targeting as novel strategy to sensitize mutant p53-expressing tumor cells to anticancer treatments

Polo-like kinase 2 (Plk2) belongs to a family of serine/threonine kinases, and it is involved in tumorigenesis of diverse kind of tissues. We previously reported that Plk2 gene was a transcriptional target of the mutant p53/NF-Y oncogenic complex. Plk2 protein can bind to and phosphorylate mutant p53 triggering an oncogenic autoregulatory feedback loop involved in cancer cell proliferation and chemoresistance. In this study, we aimed to assess whether the specific inhibition of Plk2 kinase activity by the selective TC-S 7005 inhibitor could decrease cell proliferation and migration inhibiting mutant p53 phosphorylation, thus disarming its oncogenic potential. We found that the Plk2 inhibitor treatment sensitized the cells to the irradiation and chemotherapy drugs, thereby overcoming the mutant p53-dependent chemoresistance. Taken together, we provided results that Plk2 could be considered a tractable pharmacological target for cancers expressing mutant p53 proteins. The combined treatment with conventional chemotherapeutic drugs and Plk2 inhibitors may represent a new candidate intervention approach, which may be considered for improving tumor cell sensitivity to DNA damaging drugs. KEY MESSAGES : Missense mutations are present in the TP53 gene in about half of all human cancers and correlate with poor patient outcome. Mutant p53 proteins exert gain of function (GOF) activities in tumor cells such as increased proliferation, genomic instability and resistance to therapies. Polo-like kinase 2 (PLK2) binds and phosphorylates mutant p53 protein strengthening its GOF activities. Pharmacologically targeting PLK2 weakens mutant p53 proteins and sensitizes tumor cells to therapeutic treatments.

Molecular Imaging of p53 in Mouse Models of Cancer Using a Radiolabeled Antibody TAT Conjugate with SPECT

Mutations of p53 protein occur in over half of all cancers, with profound effects on tumor biology. We present the first-to our knowledge-method for noninvasive visualization of p53 in tumor tissue in vivo, using SPECT, in 3 different models of cancer. Methods: Anti-p53 monoclonal antibodies were conjugated to the cell-penetrating transactivator of transcription (TAT) peptide and a metal ion chelator and then radiolabeled with 111In to allow SPECT imaging. 111In-anti-p53-TAT conjugates were retained longer in cells overexpressing p53-specific than non-p53-specific 111In-mIgG (mouse IgG from murine plasma)-TAT controls, but not in null p53 cells. Results: In vivo SPECT imaging showed enhanced uptake of 111In-anti-p53-TAT, versus 111In-mIgG-TAT, in high-expression p53R175H and medium-expression wild-type p53 but not in null p53 tumor xenografts. The results were confirmed in mice bearing genetically engineered KPC mouse-derived pancreatic ductal adenocarcinoma tumors. Imaging with 111In-anti-p53-TAT was possible in KPC mice bearing spontaneous p53R172H pancreatic ductal adenocarcinoma tumors. Conclusion: We demonstrate the feasibility of noninvasive in vivo molecular imaging of p53 in tumor tissue using a radiolabeled TAT-modified monoclonal antibody.

P53: A key player in diverse cellular processes including nuclear stress and ribosome biogenesis, highlighting potential therapeutic compounds

The tumor suppressor proteins are key transcription factors involved in the regulation of various cellular processes, such as apoptosis, DNA repair, cell cycle, senescence, and metabolism. The tumor suppressor protein p53 responds to different type of stress signaling, such as hypoxia, DNA damage, nutrient deprivation, oncogene activation, by activating or repressing the expression of different genes that target processes mentioned earlier. p53 has the ability to modulate the activity of many other proteins and signaling pathway through protein-protein interaction, post-translational modifications, or non-coding RNAs. In many cancers the p53 is found to be mutated or inactivated, resulting in the loss of its tumor suppressor function and acquisition of new oncogenic properties. The tumor suppressor protein p53 also plays a role in the development of other metabolic disorders such as diabetes, obesity, and fatty liver disease. In this review, we will summarize the current data and knowledge on the molecular mechanisms and the functions of p53 in different pathways and processes at the cellular level and discuss the its implications for human health and disease.

Comprehensive analysis of single-cell RNA and bulk RNA sequencing based on M2 tumor-associated macrophage and angiogenesis-related genes to assess prognosis and therapeutic response in lung adenocarcinoma

M2 tumor-associated macrophage (M2 TAM), a crucial component of the tumor microenvironment, has a significant impact on tumor invasion and metastasis in the form of angiogenesis for lung adenocarcinoma (LUAD). In this study, both single-cell RNA and bulk RNA sequencing data were analyzed to identify 12 M2 TAM and angiogenesis-related genes (OLR1, CTSL, HLA-DPB1, NUPR1, ALOX5, DOCK4, CSF2RB, PTPN6, TNFSF12, HNRNPA2B1, NCL, and BIRC2). These genes were used to construct a prognostic signature, which was subsequently validated using an external cohort. Moreover, the immune profile analysis indicated that the low-risk group exhibited a distinct immune cell infiltration and relatively active status. Importantly, the prognostic signature was closely associated with PD-1, CTLA4, tumor mutation burden, and anti-cancer drug sensitivity. In summary, this study proposes a new prognostic signature for patients with LUAD based on M2 TAM and angiogenesis-related genes. The signature forecasts the prognosis of LUAD by an independent manner, reveals the potential molecular mechanisms involved in tumor immune-related functions, and offers appropriate clinical strategies for the treatment of patients with LUAD.

Clinical calculator based on CT and clinicopathologic characteristics predicts short-term prognosis following resection of microsatellite-stabilized diffuse gastric cancer

PURPOSE

Although microsatellite stability/Epithelial-mesenchymal transition (MSS/EMT) subtypes have been reported in multiple cancer prognosis studies, strong confounding factors between MSS/EMT (usually with Lauren's diffuse phenotype) and diffuse gastric cancer (GC) may obscure the independent prognostic value of diffuse GC. Additionally, recent studies suggest a strong correlation between mural stratification based on CT and diffuse GC. This study aims to investigate potential prognostic factors of MSS diffuse GC using mural stratification and to develop a risk assessment model.

METHODS

This retrospective study included 131 patients with MSS diffuse GC who underwent radical surgery. Univariate and multivariate Cox proportional hazards regression analysis was used to identify model predictors and construct a nomogram for overall survival (OS) and recurrence-free survival (RFS) risks. The model's performance was evaluated using ROC, accuracy, and C-index. Internal validation of the model was conducted using the bootstrap resampling method.

RESULTS

Among 131 cases, 60 cases (45.8%) exhibited grade 2 mural stratification, which correlated with a poorer tumor prognosis and a more invasive phenotype. Furthermore, a nomogram for predicting OS and RFS prognosis was established based on multivariate results (age, extranodal invasion, mural stratification, and/or P53). The nomogram demonstrated excellent performance, with an AUC of 0.859 (95% CI 0.794-0.924) for OS and 0.859 (95% CI 0.789-0.929) for RFS. Internal validation using 1000 bootstrap samples yielded AUC values of 0.845 and 0.846 for OS and RFS, respectively.

CONCLUSION

Grade 2 mural stratification based on CT imaging revealed a more aggressive invasive phenotype, characterized by increased LN metastasis, higher rates of peritoneal metastasis, and a poorer short-term prognosis. Furthermore, the CT phenotype-based nomogram demonstrates favorable discrimination and calibration, enabling convenient individual short-term prognostic evaluation following resection of MSS diffuse GC.

Identification of Rare EIF3E::RSPO2 Fusion in Recurrent and Aggressive Urachal Adenocarcinoma

INTRODUCTION

Urachal cancer (UC) is a rare genitourinary malignancy arising from the urachus, an embryonic remnant of the placental allantois. Its diagnosis remains ambiguous with late-stage cancer detection and represents a highly aggressive disease. Due to its rarity, there is no clear consensus on molecular signatures and appropriate clinical management of UC.

CASE REPORT

We report a 45-year-old man with recurrent urachal adenocarcinoma (UA) treated with cystectomies, chemotherapy, and radiotherapy. The patient initially presented with hematuria and abdominal pain. Imaging revealed a nodular mass arising from the superior wall of the urinary bladder and extending to the urachus. Biopsy results suggested moderately differentiated UA with muscle layer involvement. The tumor recurred after 20 months, following which, another partial cystectomy was performed. Repeat progression was noted indicating highly aggressive disease. Targeted next-generation sequencing revealed the presence of EIF3E::RSPO2 fusion, along with BRAF and TP53 mutations, and EGFR gene amplification. This is the first case reporting the presence of this fusion in UA. Palliative medication and radiotherapy were administered to manage the disease.

CONCLUSION

Current treatment modality of surgery may be effective in the early stages of recurrent UA; however, a standard chemotherapy and radiotherapy regimen is yet to be determined for advanced stages. The detection of the rare EIF3E::RSPO2 fusion warrants further studies on the significance of this variant as a possible therapeutic target for improved clinical management.

Extracellular Vesicles in Breast Cancer: From Intercellular Communication to Therapeutic Opportunities

Breast cancer, a multifaceted and heterogeneous disease, poses significant challenges in terms of understanding its intricate resistance mechanisms and devising effective therapeutic strategies. This review provides a comprehensive overview of the intricate landscape of extracellular vesicles (EVs) in the context of breast cancer, highlighting their diverse subtypes, biogenesis, and roles in intercellular communication within the tumour microenvironment (TME). The discussion spans various aspects, from EVs and stromal cells in breast cancer to their influence on angiogenesis, immune response, and chemoresistance. The impact of EV production in different culture systems, including two dimensional (2D), three dimensional (3D), and organoid models, is explored. Furthermore, this review delves into the therapeutic potential of EVs in breast cancer, presenting emerging strategies such as engineered EVs for gene delivery, nanoplatforms for targeted chemotherapy, and disrupting tumour derived EVs as a treatment approach. Understanding these complex interactions of EV within the breast cancer milieu is crucial for identifying resistance mechanisms and developing new therapeutic targets.

An exploration of causal relationships between nine neurological diseases and the risk of breast cancer: a Mendelian randomization study

BACKGROUND

Some preceding researches have observed that certain neurological disorders, such as Alzheimer's disease and multiple sclerosis, may affect breast cancer risk. However, whether there are causal relationships between these neurological conditions and breast cancer is inconclusive. This study was designed to explore whether neurological disorders affected the risks of breast cancer overall and of the two subtypes (ER+ and ER-).

METHODS

In the course of this study, genome-wide association study (GWAS) data for nine neurological diseases (Alzheimer's disease, multiple sclerosis, Parkinson's disease, myasthenia gravis, generalized epilepsy, intracerebral haemorrhage, cerebral atherosclerosis, brain glioblastoma, and benign meningeal tumour) were collected from the Complex Trait Genetics lab and the MRC Integrative Epidemiology Unit, and single-nucleotide polymorphisms (SNPs) extensively associated with these neurological ailments had been recognized as instrumental variables (IVs). GWAS data on breast cancer were collected from the Breast Cancer Association Consortium (BCAC). Two-sample Mendelian randomization (MR) analyses as well as multivariable MR analyses were performed to determine whether these SNPs contributed to breast cancer risk. Additionally, the accuracy of the results was evaluated using the false discovery rate (FDR) multiple correction method. Both heterogeneity and pleiotropy were evaluated by analyzing sensitivities.

RESULTS

According to the results of two-sample MR analyses, Alzheimer's disease significantly reduced the risks of overall (OR 0.925, 95% CI [0.871-0.982], P = 0.011) and ER+ (OR 0.912, 95% CI [0.853-0.975], P = 0.007) breast cancer, but there was a negative result in ER- breast cancer. However, after multiple FDR corrections, the effect of Alzheimer's disease on overall breast cancer was not statistically significant. In contrast, multiple sclerosis significantly increased ER+ breast cancer risk (OR 1.007, 95% CI [1.003-1.011], P = 0.001). In addition, the multivariable MR analyses showed that Alzheimer's disease significantly reduced the risk of ER+ breast cancer (IVW: OR 0.929, 95% CI [0.864-0.999], P=0.047; MR-Egger: OR 0.916, 95% CI [0.846-0.992], P=0.031); however, multiple sclerosis significantly increased the risk of ER+ breast cancer (IVW: OR 1.008, 95% CI [1.003-1.012], P=4.35×10-4; MR-Egger: OR 1.008, 95% CI [1.003-1.012], P=5.96×10-4). There were no significant associations between the remainder of the neurological diseases and breast cancer.

CONCLUSIONS

This study found the trends towards a decreased risk of ER+ breast cancer in patients with Alzheimer's disease and an increased risk in patients with multiple sclerosis. However, due to the limitations of Mendelian randomization, we cannot determine whether there are definite causal relationships between neurological diseases and breast cancer risk. For conclusive evidences, more prospective randomized controlled trials will be needed in the future.

Mechanisms of drug resistance in HCC

HCC comprises ∼80% of primary liver cancer. HCC is the only major cancer for which death rates have not improved over the last 10 years. Most patients are diagnosed with advanced disease when surgical and locoregional treatments are not feasible or effective. Sorafenib, a multikinase inhibitor targeting cell growth and angiogenesis, was approved for advanced unresectable HCC in 2007. Since then, other multikinase inhibitors have been approved. Lenvatinib was found to be noninferior to sorafenib as a first-line agent. Regorafenib, cabozantinib, and ramucirumab were shown to prolong survival as second-line agents. Advances in immunotherapy for HCC have also added hope for patients, but their efficacy remains limited. A large proportion of patients with advanced HCC gain no long-term benefit from systemic therapy due to primary and acquired drug resistance, which, combined with its rising incidence, keeps HCC a highly fatal disease. This review summarizes mechanisms of primary and acquired resistance to therapy and includes methods for bypassing resistance. It addresses recent advancements in immunotherapy, provides new perspectives on the linkage between drug resistance and molecular etiology of HCC, and evaluates the role of the microbiome in drug resistance. It also discusses alterations in signaling pathways, dysregulation of apoptosis, modulations in the tumor microenvironment, involvement of cancer stem cells, changes in drug metabolism/transport, tumor hypoxia, DNA repair, and the role of microRNAs in drug resistance. Understanding the interplay among these factors will provide guidance on the development of new therapeutic strategies capable of improving patient outcomes.

A common molecular and cellular pathway in developing Alzheimer and cancer

Globally cancer and Alzheimer's disease (AD) are two major diseases and still, there is no clearly defined molecular mechanism. There is an opposite relation between cancer and AD which are the proportion of emerging cancer was importantly slower in AD patients, whereas slow emerging AD in patients with cancer. In cancer, regulation of cell mechanisms is interrupted by an increase in cell survival and proliferation, while on the contrary, AD is related to augmented neuronal death, that may be either produced by or associated with amyloid-β (Aβ) and tau deposition. Stated that the probability that disruption of mechanisms takes part in the regulation of cell survival/death and might be implicated in both diseases. The mechanism of actions such as DNA-methylation, genetic polymorphisms, or another mechanism of actions that induce alteration in the action of drugs with significant roles in resolving the finding to repair and live or die might take part in the pathogenesis of these two ailments. The functions of miRNA, p53, Pin1, the Wnt signaling pathway, PI3 KINASE/Akt/mTOR signaling pathway GRK2 signaling pathway, and the pathophysiological role of oxidative stress are presented in this review as potential candidates which hypothetically describe inverse relations between cancer and AD. Innovative materials almost mutual mechanisms in the aetiology of cancer and AD advocates novel treatment approaches. Among these treatment strategies, the most promising use treatment such as tyrosine kinase inhibitor, nilotinib, protein kinase C, and bexarotene.

Patient-derived tumor organoids with p53 mutations, and not wild-type p53, are sensitive to synergistic combination PARP inhibitor treatment

Poly (ADP-ribose) polymerase inhibitors (PARPi) are used for patients with BRCA1/2 mutations, but patients with other mutations may benefit from PARPi treatment. Another mutation that is present in more cancers than BRCA1/2 is mutation to the TP53 gene. In 2D breast cancer cell lines, mutant p53 (mtp53) proteins tightly associate with replicating DNA and Poly (ADP-ribose) polymerase (PARP) protein. Combination drug treatment with the alkylating agent temozolomide and the PARPi talazoparib kills mtp53 expressing 2D grown breast cancer cell lines. We evaluated the sensitivity to the combination of temozolomide plus PARPi talazoparib treatment to breast and lung cancer patient-derived tumor organoids (PDTOs). The combination of the two drugs was synergistic for a cytotoxic response in PDTOs with mtp53 but not for PDTOs with wtp53. The combination of talazoparib and temozolomide induced more DNA double-strand breaks in mtp53 expressing organoids than in wild-type p53 expressing organoids as shown by increased γ-H2AX protein expression. Moreover, breast cancer tissue microarrays (TMAs) showed a positive correlation between stable p53 and high PARP1 expression in sub-groups of breast cancers, which may indicate sub-classes of breast cancers sensitive to PARPi therapy. These results suggest that mtp53 could be a biomarker to predict response to the combination of PARPi talazoparib-temozolomide treatment.

Melatonin and ferroptosis: Mechanisms and therapeutic implications

Ferroptosis, a regulated form of cell death, is characterized by iron-dependent lipid peroxidation leading to oxidative damage to cell membranes. Cell sensitivity to ferroptosis is influenced by factors such as iron overload, lipid metabolism, and the regulation of the antioxidant system. Melatonin, with its demonstrated capacity to chelate iron, modulate iron metabolism proteins, regulate lipid peroxidation, and regulate antioxidant systems, has promise as a potential therapeutic agent in mediating ferroptosis. The availability of approved drugs targeting ferroptosis is limited; therefore, melatonin is a candidate for broad application due to its safety and efficacy in attenuating ferroptosis in noncancerous diseases. Melatonin has been demonstrated to attenuate ferroptosis in cellular and animal models of noncancerous diseases, showcasing effectiveness in organs such as the heart, brain, lung, liver, kidney, and bone. This review outlines the molecular mechanisms of ferroptosis, investigates melatonin's potential effects on ferroptosis, and discusses melatonin's therapeutic potential as a promising intervention against diseases associated with ferroptosis. Through this discourse, we aim to lay a strong foundation for developing melatonin as a therapeutic strategy to modulate ferroptosis in a variety of disease contexts.

Dynamic RNA profiles in the small intestinal epithelia of cats after Toxoplasma gondii infection

BACKGROUND

Felids are the only definitive hosts of Toxoplasma gondii. However, the biological features of the feline small intestine following T. gondii infection are poorly understood. We investigated the changes in the expression of RNAs (including mRNAs, long non-coding RNAs and circular RNAs) in the small intestinal epithelia of cats following T. gondii infection to improve our understanding of the life cycle of T. gondii and cat responses to T. gondii infection.

METHODS

Fifteen cats were randomly assigned to five groups, and the infection groups were inoculated with 600 tissue cysts of the T. gondii Pru strain by gavage. The small intestinal epithelia of cats were collected at 6, 10, 14, and 30 days post infection (DPI). Using high-throughput RNA sequencing (RNA-seq), we investigated the changes in RNA expression. The expression levels of differentially expressed (DE) genes and non-coding RNAs (ncRNAs) identified by RNA-seq were validated by quantitative reverse transcription PCR (qRT-PCR). Differential expression was determined using the DESeq R package.

RESULTS

In total, 207 annotated lncRNAs, 20,552 novel lncRNAs, 3342 novel circRNAs and 19,409 mRNAs were identified. Among these, 70 to 344 DE mRNAs, lncRNAs and circRNAs were detected, and the post-cleavage binding sites between 725 ncRNAs and 2082 miRNAs were predicted. Using the co-location method, we predicted that a total of 235 lncRNAs target 1044 protein-coding genes, while the results of co-expression analysis revealed that 174 lncRNAs target 2097 mRNAs. Pathway enrichment analyses of the genes targeted by ncRNAs suggested that most ncRNAs were significantly enriched in immune or diseases-related pathways. NcRNA regulatory networks revealed that a single ncRNA could be directly or indirectly regulated by multiple genes or ncRNAs that could influence the immune response of cats. Co-expression analysis showed that 242 circRNAs, mainly involved in immune responses, were significantly associated with T. gondii infection. In contrast, 1352 protein coding RNAs, mainly involved in nucleic acid process/repair pathways or oocyte development pathways, were negatively associated with T. gondii infection.

CONCLUSIONS

This study is the first to reveal the expression profiles of circRNAs, lncRNAs and mRNAs in the cat small intestine following T. gondii infection and will facilitate the elucidation of the role of ncRNAs in the pathogenesis of T. gondii infection in its definitive host, thereby facilitating the development of novel intervention strategies against T. gondii infection in humans and animals.

Patient-derived tumor organoids with p53 mutations, and not wild-type p53, are sensitive to synergistic combination PARP inhibitor treatment

Poly (ADP-ribose) polymerase inhibitors (PARPi) are used for patients with BRCA1/2 mutations, but patients with other mutations may benefit from PARPi treatment. Another mutation that is present in more cancers than BRCA1/2 is mutation to the TP53 gene. In 2D breast cancer cell lines, mutant p53 (mtp53) proteins tightly associate with replicating DNA and Poly (ADP-ribose) polymerase (PARP) protein. Combination drug treatment with the alkylating agent temozolomide and the PARPi talazoparib kills mtp53 expressing 2D grown breast cancer cell lines. We evaluated the sensitivity to the combination of temozolomide plus PARPi talazoparib treatment to breast and lung cancer patient-derived tumor organoids (PDTOs). The combination of the two drugs was synergistic for a cytotoxic response in PDTOs with mtp53 but not for PDTOs with wtp53. The combination of talazoparib and temozolomide induced more DNA double-strand breaks in mtp53 expressing organoids than in wild-type p53 expressing organoids as shown by increased γ-H2AX protein expression. Moreover, breast cancer tissue microarrays (TMAs) showed a positive correlation between stable p53 and high PARP1 expression in sub-groups of breast cancers, which may indicate sub-classes of breast cancers sensitive to PARPi therapy. These results suggest that mtp53 could be a biomarker to predict response to the combination of PARPi talazoparib-temozolomide treatment.

The Swedish childhood tumor biobank: systematic collection and molecular characterization of all pediatric CNS and other solid tumors in Sweden

The Swedish Childhood Tumor Biobank (BTB) is a nonprofit national infrastructure for collecting tissue samples and genomic data from pediatric patients diagnosed with central nervous system (CNS) and other solid tumors. The BTB is built on a multidisciplinary network established to provide the scientific community with standardized biospecimens and genomic data, thereby improving knowledge of the biology, treatment and outcome of childhood tumors. As of 2022, over 1100 fresh-frozen tumor samples are available for researchers. We present the workflow of the BTB from sample collection and processing to the generation of genomic data and services offered. To determine the research and clinical utility of the data, we performed bioinformatics analyses on next-generation sequencing (NGS) data obtained from a subset of 82 brain tumors and patient blood-derived DNA combined with methylation profiling to enhance the diagnostic accuracy and identified germline and somatic alterations with potential biological or clinical significance. The BTB procedures for collection, processing, sequencing, and bioinformatics deliver high-quality data. We observed that the findings could impact patient management by confirming or clarifying the diagnosis in 79 of the 82 tumors and detecting known or likely driver mutations in 68 of 79 patients. In addition to revealing known mutations in a broad spectrum of genes implicated in pediatric cancer, we discovered numerous alterations that may represent novel driver events and specific tumor entities. In summary, these examples reveal the power of NGS to identify a wide number of actionable gene alterations. Making the power of NGS available in healthcare is a challenging task requiring the integration of the work of clinical specialists and cancer biologists; this approach requires a dedicated infrastructure, as exemplified here by the BTB.

Recent advances in targeted therapy for pancreatic adenocarcinoma

Pancreatic adenocarcinoma (PDAC) is a fatal disease with a 5-year survival rate of 8% and a median survival of 6 mo. In PDAC, several mutations in the genes are involved, with Kirsten rat sarcoma oncogene (90%), cyclin-dependent kinase inhibitor 2A (90%), and tumor suppressor 53 (75%–90%) being the most common. Mothers against decapentaplegic homolog 4 represents 50%. In addition, the self-preserving cancer stem cells, dense tumor microenvironment (fibrous accounting for 90% of the tumor volume), and suppressive and relatively depleted immune niche of PDAC are also constitutive and relevant elements of PDAC. Molecular targeted therapy is widely utilized and effective in several solid tumors. In PDAC, targeted therapy has been extensively evaluated; however, survival improvement of this aggressive disease using a targeted strategy has been minimal. There is currently only one United States Food and Drug Administration-approved targeted therapy for PDAC – erlotinib, but the absolute benefit of erlotinib in combination with gemcitabine is also minimal (2 wk). In this review, we summarize current targeted therapies and clinical trials targeting dysregulated signaling pathways and components of the PDAC oncogenic process, analyze possible reasons for the lack of positive results in clinical trials, and suggest ways to improve them. We also discuss emerging trends in targeted therapies for PDAC: combining targeted inhibitors of multiple pathways. The PubMed database and National Center for Biotechnology Information clinical trial website (www.clinicaltrials.gov) were queried to identify completed and published (PubMed) and ongoing (clinicaltrials.gov) clinical trials (from 2003-2022) using the keywords pancreatic cancer and targeted therapy. The PubMed database was also queried to search for information about the pathogenesis and molecular pathways of pancreatic cancer using the keywords pancreatic cancer and molecular pathways.

The Role of Genetic Mutations in Mitochondrial-Driven Cancer Growth in Selected Tumors: Breast and Gynecological Malignancies

There is an increasing understanding of the molecular and cytogenetic background of various tumors that helps us better conceptualize the pathogenesis of specific diseases. Additionally, in many cases, these molecular and cytogenetic alterations have diagnostic, prognostic, and/or therapeutic applications that are heavily used in clinical practice. Given that there is always room for improvement in cancer treatments and in cancer patient management, it is important to discover new therapeutic targets for affected individuals. In this review, we discuss mitochondrial changes in breast and gynecological (endometrial and ovarian) cancers. In addition, we review how the frequently altered genes in these diseases (BRCA1/2, HER2, PTEN, PIK3CA, CTNNB1, RAS, CTNNB1, FGFR, TP53, ARID1A, and TERT) affect the mitochondria, highlighting the possible associated individual therapeutic targets. With this approach, drugs targeting mitochondrial glucose or fatty acid metabolism, reactive oxygen species production, mitochondrial biogenesis, mtDNA transcription, mitophagy, or cell death pathways could provide further tailored treatment.

2,2-Diphenethyl Isothiocyanate Enhances Topoisomerase Inhibitor-Induced Cell Death and Suppresses Multi-Drug Resistance 1 in Breast Cancer Cells

We previously reported that phenethyl isothiocyanate (PEITC), a dietary-related compound, can rescue mutant p53. A structure-activity relationships study showed that the synthetic analog 2,2-diphenylethyl isothiocyanate (DPEITC) is a more potent inducer of apoptosis than natural or synthetic ITCs. Here, we showed that DPEITC inhibited the growth of triple-negative breast cancer cells (MDA-MB-231, MDA-MB-468, and Hs578T) expressing "hotspot" p53 mutants, structural (p53^R280K, p53^R273H) or contact (p53^V157F), at IC₅₀ values significantly lower than PEITC. DPEITC inhibited the growth of HER2+ (p53^R175H SK-BR-3, p53^R175H AU565) and Luminal A (p53^L194F T47D) breast cancer (BC) cells harboring a p53 structural mutant. DPEITC induced apoptosis, irrespective of BC subtypes, by rescuing p53 mutants. Accordingly, the rescued p53 mutants induced apoptosis by activating canonical WT p53 targets and delaying the cell cycle. DPEITC acted synergistically with doxorubicin and camptothecin to inhibit proliferation and induce apoptosis. Under these conditions, DPEITC delayed BC cells in the G1 phase, activated p53 canonical targets, and enhanced pS1981-ATM. DPEITC reduced the expression of MDR1 and ETS1. These findings are the first report of synergism between a synthetic ITC and a chemotherapy drug via mutant p53 rescue. Furthermore, our data demonstrate that ITCs suppress the expression of cellular proteins that play a role in chemoresistance.

Novel Insights into the Role of the Antioxidants in Prostate Pathology

To date, it is known that antioxidants protect cells from damage caused by oxidative stress and associated with pathological conditions. Several studies have established that inflammation is a state that anticipates the neoplastic transformation of the prostate. Although many experimental and clinical data have indicated the efficacy of antioxidants in preventing this form of cancer, the discrepant results, especially from recent large-scale randomized clinical trials, make it difficult to establish a real role for antioxidants in prostate tumor. Despite these concerns, clinical efficacy and safety data show that some antioxidants still hold promise for prostate cancer chemoprevention. Although more studies are needed, in this review, we briefly describe the most common antioxidants that have shown benefits in preclinical and clinical settings, focusing our attention on synthesizing the advances made so far in prostate cancer chemoprevention using antioxidants as interesting molecules for the challenges of future therapies.

Targeting Y220C mutated p53 by Foeniculum vulgare-derived phytochemicals as cancer therapeutics

CONTEXT

The mutations in the TP53 gene are the most frequent (50-60% of human cancer) genetic alterations in cancer cells, indicating the critical role of wild-type p53 in the regulation of cell proliferation and apoptosis upon oncogenic stress. Most missense mutations are clustered in the DNA-binding core domain, disrupting DNA binding ability. However, some mutations like Y220C occur outside the DNA binding domain and are associated with p53 structure destabilization. Overall, the results of these mutations are single amino acid substitutions in p53 and the production of dysfunctional p53 protein in large amounts, consequently allowing the escape of apoptosis and rapid progression of tumor growth. Thus, therapeutic targeting of mutant p53 in tumors to restore its wild-type tumor suppression activity has immense potential for translational cancer research. Various molecules have been discovered with modern scientific techniques to reactivate mutant p53 by reverting structural changes and/or DNA binding ability. These compounds include small molecules, various peptides, and phytochemicals. TP53 protein is long thought of as a potential target; however, its translation for therapeutic purposes is still in its infancy. The study comprehensively analyzed the therapeutic potential of small phytochemicals from Foeniculum vulgare (Fennel) with drug-likeness and capability to reactivate mutant p53 (Y220C) through molecular docking simulation. The docking study and the stable molecular dynamic simulations revealed juglalin (- 8.6 kcal/mol), retinol (- 9.14 kcal/mol), and 3-nitrofluoranthene (- 8.43 kcal/mol) significantly bind to the mutated site suggesting the possibility of drug designing against the Y220C mutp53. The study supports these compounds for further animal based in vivo and in vitro research to validate their efficacy.

METHODS

For the purposes of drug repurposing, recently in-silico methods have presented with opportunity to rule out many compounds which have less probability to act as a drug based on their structural moiety and interaction with the target macromolecule. The study here utilizes molecular docking via Autodock 4.2.6 and molecular dynamics using Schrodinger 2021 to find potential therapeutic options which are capable to reactive the mutated TP53 protein.

In Vitro Anticancer Activity of Novel Ciprofloxacin Mannich Base in Lung Adenocarcinoma and High-Grade Serous Ovarian Cancer Cell Lines via Attenuating MAPK Signaling Pathway

Novel drugs are desperately needed in order to combat a significant challenge due to chemo-therapeutic resistance and bad prognosis. This research aimed to assess the anticancer activity of a newly synthesized ciprofloxacin Mannich base (CMB) on ovarian cancer (OVCAR-3) and lung cancer (A-549) cell lines and to investigate probable involved molecular mechanisms. The cytotoxic and pro-apoptotic impact of CMB on both cell lines was investigated using MTT assay, Annexin V assay, and cell cycle analysis, as well as caspase-3 activation. Western blotting was carried out to evaluate downstream targets of the MAPK pathway, while qRT PCR was used to evaluate the gene expression pattern of the p53/Bax/Bcl2 pathway. CMB treatment showed significantly reduced cell proliferation in both OVCAR-3 and A-549 cells with half maximum inhibitory concentration (IC₅₀) = 11.60 and 16.22 µg/mL, respectively. CMB also induced apoptosis, S phase cell cycle arrest, and up-regulated expression of p53, p21, and Bax while down-regulated Bcl2 expression. CMB also halted cell proliferation by deactivating the MAPK pathway. In conclusion, CMB may be regarded as a potential antiproliferative agent for lung and ovarian cancers due to anti-proliferative and pro-apoptotic actions via inhibition of the MAPK pathway and p53/Bax/Bcl2.

The Role of Deubiquitinating Enzyme in Head and Neck Squamous Cell Carcinoma

Ubiquitination and deubiquitination are two popular ways for the post-translational modification of proteins. These two modifications affect intracellular localization, stability, and function of target proteins. The process of deubiquitination is involved in histone modification, cell cycle regulation, cell differentiation, apoptosis, endocytosis, autophagy, and DNA repair after damage. Moreover, it is involved in the processes of carcinogenesis and cancer development. In this review, we discuss these issues in understanding deubiquitinating enzyme (DUB) function in head and neck squamous cell carcinoma (HNSCC), and their potential therapeutic strategies for HNSCC patients are also discussed.

Context-Dependent Function of Long Noncoding RNA PURPL in Transcriptome Regulation during p53 Activation

PURPL is a p53-induced lncRNA that suppresses basal p53 levels. Here, we investigated PURPL upon p53 activation in liver cancer cells, where it is expressed at significantly higher levels than other cell types. Using isoform sequencing, we discovered novel PURPL transcripts that have a retained intron and/or previously unannotated exons. To determine PURPL function upon p53 activation, we performed transcriptome sequencing (RNA-Seq) after depleting PURPL using CRISPR interference (CRISPRi), followed by Nutlin treatment to induce p53. Strikingly, although loss of PURPL in untreated cells altered the expression of only 7 genes, loss of PURPL resulted in altered expression of ~800 genes upon p53 activation, revealing a context-dependent function of PURPL. Pathway analysis suggested that PURPL is important for fine-tuning the expression of specific genes required for mitosis. Consistent with these results, we observed a significant decrease in the percentage of mitotic cells upon PURPL depletion. Collectively, these data identify novel transcripts from the PURPL locus and suggest that PURPL delicately moderates the expression of mitotic genes in the context of p53 activation to control cell cycle arrest.

Unraveling the Structural Changes in the DNA-Binding Region of Tumor Protein p53 (TP53) upon Hotspot Mutation p53 Arg248 by Comparative Computational Approach

The vital tissue homeostasis regulator p53 forms a tetramer when it binds to DNA and regulates the genes that mediate essential biological processes such as cell-cycle arrest, senescence, DNA repair, and apoptosis. Missense mutations in the core DNA-binding domain (109-292) simultaneously cause the loss of p53 tumor suppressor function and accumulation of the mutant p53 proteins that are carcinogenic. The most common p53 hotspot mutation at codon 248 in the DNA-binding region, where arginine (R) is substituted by tryptophan (W), glycine (G), leucine (L), proline (P), and glutamine (Q), is reported in various cancers. However, it is unclear how the p53 Arg248 mutation with distinct amino acid substitution affects the structure, function, and DNA binding affinity. Here, we characterized the pathogenicity and protein stability of p53 hotspot mutations at codon 248 using computational tools PredictSNP, Align GVGD, HOPE, ConSurf, and iStable. We found R248W, R248G, and R248P mutations highly deleterious and destabilizing. Further, we subjected all five R248 mutant-p53-DNA and wt-p53-DNA complexes to molecular dynamics simulation to investigate the structural stability and DNA binding affinity. From the MD simulation analysis, we observed increased RMSD, RMSF, and Rg values and decreased protein-DNA intermolecular hydrogen bonds in the R248-p53-DNA than the wt-p53-DNA complexes. Likewise, due to high SASA values, we observed the shrinkage of proteins in R248W, R248G, and R248P mutant-p53-DNA complexes. Compared to other mutant p53-DNA complexes, the R248W, R248G, and R248P mutant-p53-DNA complexes showed more structural alteration. MM-PBSA analysis showed decreased binding energies with DNA in all five R248-p53-DNA mutants than the wt-p53-DNA complexes. Henceforth, we conclude that the amino acid substitution of Arginine with the other five amino acids at codon 248 reduces the p53 protein's affinity for DNA and may disrupt cell division, resulting in a gain of p53 function. The proposed study influences the development of rationally designed molecular-targeted treatments that improve p53-based therapeutic outcomes in cancer.

To investigate the prognostic factors of stage Ⅰ-Ⅱ gastric cancer based on P53 mutation and tumor budding

BACKGROUND

P53 is a tumor suppressor and genome guardian factor, and tumor budding is a key link in tumor metastasis. The purpose of this study was to investigate P53 mutation and tumor budding in stage Ⅰ-Ⅱ gastric cancer, to explore the correlation with clinicopathological features, and to reveal the independent prognostic factors of gastric cancer.

METHODS

The data of 588 patients with stage Ⅰ-Ⅱ gastric cancer who underwent radical surgical resection from April 2015 to December 2016 in the Fourth Hospital of Hebei Medical University were retrospectively analyzed and followed up. Immunohistochemistry Envision method was used to conduct P53 staining for paraffin-embedded gastric cancer tissues, and ITBCC recommended tumor budding evaluation method was used to count tumor budding in gastric cancer tissues. The factors affecting the prognosis of gastric cancer were analyzed.

RESULTS

There were 209 cases (35.54%) of P53 wild-type and 379 cases (64.46 %) of P53 mutant in 588 patients with stage Ⅰ-Ⅱ gastric cancer. P53 mutation rate were closely correlated with Lauren classification (χ² =8.152, p = 0.017), degree of differentiation (χ² =10.495, p = 0.004), number of lymph node metastasis (χ² =25.550, p < 0.001), and clinical stage (χ² =7.617, p = 0.016). Tumor budding were closely correlated with Lauren classification (χ² =194.533, p < 0.001), degree of tissue differentiation (χ² =22.719, p < 0.001), depth of tumor invasion (χ² =19.204, p = 0.004), number of lymph node metastasis (χ² =22.555, p = 0.001), clinical stage (χ² =10.769, p = 0.005), and vascular tumors bolt (χ² =12.478, p = 0.002). The higher the tumor budding grade was, the higher the P53 mutation rate was (χ² =12.933, p = 0.002). Lauren classification (p < 0.001), degree of tissue differentiation (p = 0.005), vascular tumors bolt (p < 0.001) and P53 mutation (p = 0.006) were independent influencing factors for 5-year survival of patients with stage Ⅰ-Ⅱ gastric cancer.

CONCLUSION

P53 mutation status is an independent prognostic factor for gastric cancer patients and a promising cancer treatment target. Tumor budding is a very reliable independent prognostic parameter with important clinical value and should be routinely reported as a biomarker.

A comprehensive study of p53 protein

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

Mutant p53 in cancer: from molecular mechanism to therapeutic modulation

TP53, a crucial tumor suppressor gene, is the most commonly mutated gene in human cancers. Aside from losing its tumor suppressor function, mutant p53 (mutp53) often acquires inherent, novel oncogenic functions, which is termed "gain-of-function". Emerging evidence suggests that mutp53 is highly associated with advanced malignancies and poor prognosis, which makes it a target for development of novel cancer therapies. Herein, we provide a summary of our knowledge of the mutp53 types and mutp53 spectrum in cancers. The mechanisms of mutp53 accumulation and gain-of-function are also summarized. Furthermore, we discuss the gain-of-function of mutp53 in cancers: genetic instability, ferroptosis, microenvironment, and stemness. Importantly, the role of mutp53 in the clinic is also discussed, particularly with regard to chemotherapy and radiotherapy. Last, emphasis is given to emerging strategies on how to target mutp53 for tumor therapy. Thus, this review will contribute to better understanding of the significance of mutp53 as a target for therapeutic strategies.

Advancement of cell-penetrating peptides in combating triple-negative breast cancer

Extensive research efforts have been made and are still ongoing in the search for an ideal anti-cancer therapy. Almost all chemotherapeutics require a carrier or vehicle, a drug delivery system that can transport the drug specifically to the targeted cancer cells, sparing normal cells. Cell-penetrating peptides (CPPs) provide an effective and efficient pathway for the intra-cellular transportation of various bioactive molecules in several biomedical therapies. They are now well-recognized as facilitators of intracellular cargo delivery and have excellent potential for targeted anti-cancer therapy. In this review, we explain CPPs, recent progress in the development of new CPPs, and their utilization to transport cargoes such as imaging agents, chemotherapeutics, and short-interfering RNAs (siRNA) into tumor cells, contributing to the advancement of novel tumor-specific delivery systems.

The role of p53 in liver fibrosis

The tumor suppressor p53 is the central hub of a molecular network, which controls cell proliferation and death, and also plays an important role in the occurrence and development of liver fibrosis. The abundant post-translational processing and modification endow the functional diversity of p53. Considering the relationship between p53 and liver fibrosis, drug intervention targeting p53 or management of p53 regulation might be effective strategies to treat liver fibrosis. Here, we systematically discuss the regulation of p53 in different liver cells (hepatocytes, immune cells, HSCs, etc) and the role of p53 in the development of liver fibrosis, and propose possible interventions to prevent the pathogenic processes of liver fibrosis.

Conformational Heterogeneity and Frustration of the Tumor Suppressor p53 as Tuned by Punctual Mutations

The conformational heterogeneity of the p53 tumor suppressor, the wild-type (p53wt) and mutated forms, was investigated by a computational approach, including the modeling and all atoms of the molecular dynamics (MD) simulations. Four different punctual mutations (p53R175H, p53R248Q, p53R273H, and p53R282W) which are known to affect the DNA binding and belong to the most frequent hot-spot mutations in human cancers, were taken into consideration. The MD trajectories of the wild-type and mutated p53 forms were analyzed by essential dynamics to extract the relevant collective motions and by the frustration method to evaluate the degeneracy of the energy landscape. We found that p53 is characterized by wide collective motions and its energy landscape exhibits a rather high frustration level, especially in the regions involved in the binding to physiological ligands. Punctual mutations give rise to a modulation of both the collective motions and the frustration of p53, with different effects depending on the mutation. The regions of p53wt and of the mutated forms characterized by a high frustration level are also largely involved in the collective motions. Such a correlation is discussed also in connection with the intrinsic disordered character of p53 and with its central functional role.

In Vitro Cell Death Mechanisms Induced by Dicoma anomala Root Extract in Combination with ZnPcS4 Mediated-Photodynamic Therapy in A549 Lung Cancer Cells

Globally, lung cancer has remained the leading cause of morbidity and mortality in men and women. To enhance photodynamic therapeutic effects in vitro, the present study was designed to reduce dose-dependence in photodynamic therapy (PDT) and evaluate the anticancer effects of Dicoma anomala (D. anomala) root extracts (i.e., chloroform (Chl), ethyl acetate (EtOAc), and methanol (MeOH)) on A549 lung cancer cells. The most active extract of D. anomala (D.A) was used to establish the 50% inhibitory concentration (IC₅₀), which was further used to evaluate the anticancer efficacy of D.A in combination with ZnPcS₄-mediated PDT IC₅₀. The study further evaluated cell death mechanisms by cell viability/ cytotoxicity (LIVE/DEAD^TM assay), flow cytometry (Annexin V-fluorescein isothiocyanate (FITC)-propidium iodide (PI) staining), immunofluorescence (p38, p53, Bax, and caspase 3 expressions), and fluorometric multiplex assay (caspase 8 and 9) 24 h post-treatment with IC₅₀ concentrations of ZnPcS₄-mediated PDT and D.A MeOH root extract. Morphological changes were accompanied by a dose-dependent increase in cytotoxicity, decrease in viability, and proliferation in all experimental models. Apoptosis is the highly favored cell death mechanism observed in combination therapy groups. Apoptotic activities were supported by an increase in the number of dead cells in the LIVE/DEAD^TM assay, and the upregulation of p38, p53, Bax, caspase 3, 8, and 9 apoptotic proteins. In vitro experiments confirmed the cytotoxic and antiproliferative effects of D.A root extracts in monotherapy and in combination with ZnPcS₄-mediated PDT. Taken together, our findings demonstrated that D.A could be a promising therapeutic candidate worth exploring in different types of cancer.

Regulated cell death (RCD) in cancer: key pathways and targeted therapies

Regulated cell death (RCD), also well-known as programmed cell death (PCD), refers to the form of cell death that can be regulated by a variety of biomacromolecules, which is distinctive from accidental cell death (ACD). Accumulating evidence has revealed that RCD subroutines are the key features of tumorigenesis, which may ultimately lead to the establishment of different potential therapeutic strategies. Hitherto, targeting the subroutines of RCD with pharmacological small-molecule compounds has been emerging as a promising therapeutic avenue, which has rapidly progressed in many types of human cancers. Thus, in this review, we focus on summarizing not only the key apoptotic and autophagy-dependent cell death signaling pathways, but the crucial pathways of other RCD subroutines, including necroptosis, pyroptosis, ferroptosis, parthanatos, entosis, NETosis and lysosome-dependent cell death (LCD) in cancer. Moreover, we further discuss the current situation of several small-molecule compounds targeting the different RCD subroutines to improve cancer treatment, such as single-target, dual or multiple-target small-molecule compounds, drug combinations, and some new emerging therapeutic strategies that would together shed new light on future directions to attack cancer cell vulnerabilities with small-molecule drugs targeting RCD for therapeutic purposes.

Unraveling molecular mechanisms of Head and neck cancer

Malignancies that develop from mucosal epithelium of the upper aerodigestive tract are known as head and neck squamous cell carcinomas (HNSCC). Heterogeneity, late stage diagnosis and high recurrence rate are big hurdles in head and neck treatment regimen. Presently, the biomarkers available for diagnosis and prognosis of HNSCC are based on smoking as the major risk habit. This review shed light on the differential environment of HNSCC in smokeless tobacco consuming Indian patients. Frequent mutation in genes involved in DNA repair pathway (p53), cell proliferation (PIK3CA, HRAS) and cell death (CASP8, FADD) are common in western population. On the contrary, the genes involved in metastasis (MMPs, YAP1), lymphocyte proliferation (TNFRSF4, CD80), cell-cell adhesion (DCC, EDNRB), miRNA processing (DROSHA) and inflammatory responses (TLR9, IL-9) are mutated in Indian HNSCC patients. Gene ontology enrichment analysis highlighted that responses to chemical stimulus, immune pathways and stress pathways are highly enriched in Indian patients.

Li–Fraumeni Syndrome: Mutation of TP53 Is a Biomarker of Hereditary Predisposition to Tumor: New Insights and Advances in the Treatment

Simple Summary

Li–Fraumeni Syndrome (LFS) is a rare tumor predisposition syndrome in which the tumor suppressor TP53 gene is mutated in the germ cell population. LFS patients develop a broad spectrum of cancers in their lifetime. The risk to develop these tumors is not decreased by any type of treatment and if the analysis of the TP53 mutational status in the family members was not possible, tumors are often diagnosed in already advanced stages. This review aims to report the evidence for novel mechanisms of tumor onset related to germline TP53 mutations and possible treatments.

Abstract

Li–Fraumeni syndrome (LFS) is a rare familial tumor predisposition syndrome with autosomal dominant inheritance, involving germline mutations of the TP53 tumor suppressor gene. The most frequent tumors that arise in patients under the age of 45 are osteosarcomas, soft-tissue sarcomas, breast tumors in young women, leukemias/lymphomas, brain tumors, and tumors of the adrenal cortex. To date, no other gene mutations have been associated with LFS. The diagnosis is usually confirmed by genetic testing for the identification of TP53 mutations; therefore, these mutations are considered the biomarkers associated with the tumor spectrum of LFS. Here, we aim to review novel molecular mechanisms involved in the oncogenic functions of mutant p53 in LFS and to discuss recent new diagnostic and therapeutic approaches exploiting TP53 mutations as biomarkers and druggable targets.

Molecular testing of rhabdomyosarcoma in clinical trials to improve risk stratification and outcome: A consensus view from European paediatric Soft tissue sarcoma Study Group, Children's Oncology Group and Cooperative Weichteilsarkom-Studiengruppe

Rhabdomyosarcomas (RMSs) are the most common soft tissue sarcomas in children/adolescents less than 18 years of age with an annual incidence of 1-2/million. Inter/intra-tumour heterogeneity raise challenges in clinical, pathological and biological research studies. Risk stratification in European and North American clinical trials previously relied on clinico-pathological features, but now, incorporates PAX3/7-FOXO1-fusion gene status in the place of alveolar histology. International working groups propose a coordinated approach through the INternational Soft Tissue SaRcoma ConsorTium to evaluate the specific genetic abnormalities and generate and integrate molecular and clinical data related to patients with RMS across different trial settings. We review relevant data and present a consensus view on what molecular features should be assessed. In particular, we recommend the assessment of the MYOD1-LR122R mutation for risk escalation, as it has been associated with poor outcomes in spindle/sclerosing RMS and rare RMS with classic embryonal histopathology. The prospective analyses of rare fusion genes beyond PAX3/7-FOXO1 will generate new data linked to outcomes and assessment of TP53 mutations and CDK4 amplification may confirm their prognostic value. Pathogenic/likely pathogenic germline variants in TP53 and other cancer predisposition genes should also be assessed. DNA/RNA profiling of tumours at diagnosis/relapse and serial analyses of plasma samples is recommended where possible to validate potential molecular biomarkers, identify new biomarkers and assess how liquid biopsy analyses can have the greatest benefit. Together with the development of new molecularly-derived therapeutic strategies that we review, a synchronised international approach is expected to enhance progress towards improved treatment assignment, management and outcomes for patients with RMS.

CENP-A Regulation and Cancer

In mammals, CENP-A, a histone H3 variant found in the centromeric chromatin, is critical for faithful chromosome segregation and genome integrity maintenance through cell divisions. Specifically, it has dual functions, enabling to define epigenetically the centromere position and providing the foundation for building up the kinetochore. Regulation of its dynamics of synthesis and deposition ensures to propagate proper centromeres on each chromosome across mitosis and meiosis. However, CENP-A overexpression is a feature identified in many cancers. Importantly, high levels of CENP-A lead to its mislocalization outside the centromere. Recent studies in mammals have begun to uncover how CENP-A overexpression can affect genome integrity, reprogram cell fate and impact 3D nuclear organization in cancer. Here, we summarize the mechanisms that orchestrate CENP-A regulation. Then we review how, beyond its centromeric function, CENP-A overexpression is linked to cancer state in mammalian cells, with a focus on the perturbations that ensue at the level of chromatin organization. Finally, we review the clinical interest for CENP-A in cancer treatment.

Ataxia-telangiectasia mutated and ataxia telangiectasia and Rad3-related kinases as therapeutic targets and stratification indicators for prostate cancer

The DNA damage response is an integral part of a cells' ability to maintain genomic integrity by responding to and ameliorating DNA damage, or initiating cell death for irrepairably damaged cells. This response is often hijacked by cancer cells to evade cell death allowing mutant cells to persist, as well as in the development of treatment resistance to DNA damaging agents such as chemotherapy and radiation. Prostate cancer (PCa) cells often exhibit alterations in DNA damage response genes including ataxia telangiectasia mutated (ATM), correlating with aggressive disease phenotype. The recent success of Poly (ADP-ribose) polymerase (PARP) inhibition has led to several clinically approved PARP inhibitors for the treatment of men with metastatic PCa, however a key limitation is the development of drug resistance and relapse. An alternative approach is selectively targeting ATM and ataxia telangiectasia and Rad3-related (ATR) which, due to their position at the forefront of the DDR, represent attractive pharmacological targets. ATR inhibition has been shown to act synergistically with PARP inhibition and other cancer treatments to enhance anti-tumour activity. ATM-deficiency is a common characteristic of PCa and a synthetic lethal relationship exists between ATM and ATR, with ATR inhibition inducing selective cell death in ATM-deficient PCa cells. The current research highlights the feasibility of therapeutically targeting ATR in ATM-deficient prostate tumours and in combination with other treatments to enhance overall efficacy and reduce therapeutic resistance. ATM also represents an important molecular biomarker to stratify patients into targeted treatment groups and aid prognosis for personalised medicine.

Targeting Akt/NF-κB/p53 Pathway and Apoptosis Inducing Potential of 1,2-Benzenedicarboxylic Acid, Bis (2-Methyl Propyl) Ester Isolated from Onosma bracteata Wall. against Human Osteosarcoma (MG-63) Cells

Onosma bracteata Wall. is an important medicinal and immunity-enhancing herbs. This plant is commonly used in the preparation of traditional Ayurvedic drugs to treat numerous diseases. Inspired by the medicinal properties of this plant, the present study aimed to investigate the antiproliferative potential and the primary molecular mechanisms of the apoptotic induction against human osteosarcoma (MG-63) cells. Among all the fractions isolated from O. bracteata, ethyl acetate fraction (Obea) showed good antioxidant activity in superoxide radical scavenging assay and lipid peroxidation assay with an EC50 value of 95.12 and 80.67 µg/mL, respectively. Silica gel column chromatography of ethyl acetate (Obea) fraction of O. bracteata yielded a pure compound, which was characterized by NMR, FTIR, and HR-MS analysis and was identified as 1,2-benzene dicarboxylic acid, bis (2-methyl propyl) ester (BDCe fraction). BDCe fraction was evaluated for the antiproliferative potential against human osteosarcoma MG-63, human neuroblastoma IMR-32, and human lung carcinoma A549 cell lines by MTT assay and exhibited GI50 values of 37.53 μM, 56.05 μM, and 47.12 μM, respectively. In Mg-63 cells, the BDCe fraction increased the level of ROS and simultaneously decreased the mitochondria membrane potential (MMP) potential by arresting cells at the G0/G1 phase, suggesting the initiation of apoptosis. Western blotting analysis revealed the upregulation of p53, caspase3, and caspase9 while the expressions of p-NF-κB, p-Akt and Bcl-xl were decreased. RT-qPCR studies also showed upregulation in the expression of p53 and caspase3 and downregulation in the expression of CDK2, Bcl-2 and Cyclin E genes. Molecular docking analysis displayed the interaction between BDCe fraction with p53 (−151.13 kcal/mol) and CDK1 (−133.96 kcal/mol). The results of the present work suggest that the BDCe fraction has chemopreventive properties against osteosarcoma (MG-63) cells through the induction of cell cycle arrest and apoptosis via Akt/NF-κB/p53 pathways. This study contributes to the understanding of the utilization of BDCe fraction in osteosarcoma treatment.

Distinct Gene Mutations Are Associated With Clinicopathologic Features in Urachal Carcinoma

OBJECTIVES

To investigate the gene mutational profile of urachal carcinoma in correlation with its clinicopathologic features.

METHODS

We analyzed genetic mutations in 30 cases of urachal carcinoma by next-generation sequencing (NGS) test. Histologic slides and clinical data were reviewed.

RESULTS

The patients included 21 men and 9 women, with a mean age of 53 years (range, 24-75 years). The urachal carcinomas included mucinous (11), enteric (10), signet ring cell (8), and high-grade neuroendocrine (1) subtypes. Targeted NGS analysis demonstrated genetic mutations in all the urachal tumors (mean, 2; range, 1-4). TP53 was the most mutated gene (25), followed by KRAS (9) and GNAS (8) genes. TP53 mutations were more common in the signet ring cell subtype (7/8), and GNAS mutations were present only in the mucinous (5/11) and signet ring cell subtypes (3/8) but not in the enteric subtype (0/10). KRAS mutations were significantly associated with cancer stage IV (P = .02) and younger patient age (P = .046). Furthermore, the presence of KRAS mutations in urachal carcinoma portended a poorer overall survival (P = .006).

CONCLUSIONS

Urachal carcinoma demonstrates frequent gene mutations that are associated with distinct clinicopathologic features. Gene mutation may underlie the development and progression of this aggressive disease.

Advanced Strategies for Therapeutic Targeting of Wild-Type and Mutant p53 in Cancer

TP53 is a tumor suppressor gene that encodes a sequence-specific DNA-binding transcription factor activated by stressful stimuli; it upregulates target genes involved in growth suppression, cell death, DNA repair, metabolism, among others. TP53 is the most frequently mutated gene in tumors, with mutations not only leading to loss-of-function (LOF), but also gain-of-function (GOF) that promotes tumor progression, and metastasis. The tumor-specific status of mutant p53 protein has suggested it is a promising target for cancer therapy. We summarize the current progress of targeting wild-type and mutant p53 for cancer therapy through biotherapeutic and biopharmaceutical methods for (1) boosting p53 activity in cancer, (2) p53-dependent and p53-independent strategies for targeting p53 pathway functional restoration in p53-mutated cancer, (3) targeting p53 in immunotherapy, and (4) combination therapies targeting p53, p53 checkpoints, or mutant p53 for cancer therapy.

A Case of Li-Fraumeni Associated Thymoma

Thymomas are among the most common cancers of the anterior mediastinum. They rarely occur in patients with Li-Fraumeni syndrome (LFS), a hereditary syndrome that predisposes individuals to cancer and is characterized by mutations in the tumor suppressor encoding gene TP53. Here we describe a case of primary thymoma in a woman diagnosed with LFS. We cover the initial presentation and diagnosis, radiological findings, histopathological examination, and management of thymoma. In addition, we review p53 physiology and LFS pathophysiology to explore how TP53 expression might differ between the majority of thymomas and in thymomas associated with LFS. This altered pathophysiology may affect management and prognosis due to emerging evidence of increased resistance to conventional treatment, which suggests a need for close monitoring and consideration of novel treatment strategies such as programmed death-ligand 1 (PD-L1) inhibitors.

PRP4 Induces Epithelial–Mesenchymal Transition and Drug Resistance in Colon Cancer Cells via Activation of p53

Pre-mRNA processing factor 4B (PRP4) promotes pre-mRNA splicing and signal transduction. Recent studies have shown that PRP4 modulates the assembly of actin cytoskeleton in cancer cells and induces epithelial–mesenchymal transition (EMT) and drug resistance. PRP4 displays kinase domain-like cyclin-dependent kinases and mitogen-activated protein kinases, making it capable of phosphorylating p53 and other target proteins. In the current study, we report that PRP4 induces drug resistance and EMT via direct binding to the p53 protein, inducing its phosphorylation. Moreover, PRP4 overexpression activates the transcription of miR-210 in a hypoxia-inducible factor 1α (HIF-1α)-dependent manner, which activates p53. The involvement of miR-210 in the activation of p53 was confirmed by utilizing si-miR210. si-miR210 blocked the PRP4-activated cell survival pathways and reversed the PRP4-induced EMT phenotype. Moreover, we used deferoxamine as a hypoxia-mimetic agent, and si-HIF to silence HIF-1α. This procedure demonstrated that PRP4-induced EMT and drug resistance emerged in response to consecutive activation of HIF-1α, miR-210, and p53 by PRP4 overexpression. Collectively, our findings suggest that the PRP4 contributes to EMT and drug resistance induction via direct interactions with p53 and actions that promote upregulation of HIF-1α and miR-210. We conclude that PRP4 is an essential factor promoting cancer development and progression. Specific PRP4 inhibition could benefit patients with colon cancer.

Estrogen Receptor-Beta2 (ERβ2)-Mutant p53-FOXM1 Axis: A Novel Driver of Proliferation, Chemoresistance, and Disease Progression in High Grade Serous Ovarian Cancer (HGSOC)

Simple Summary

High grade serous ovarian cancer (HGSOC) is the most common and lethal subtype of ovarian cancer without effective therapeutic options. The high prevalence of mutations (~96%) in tumor suppressor p53 is a hallmark of HGSOC. Estrogen receptor-beta (ERβ) has been reported to be another important player in HGSOC, although the pro-versus anti-tumorigenic role of its different isoforms remains unclear. The aim of this study was to analyze the crosstalk between ERβ and mutant p53 and its impact on the pro-tumorigenic processes in HGSOC. Using the HGSOC cell line models and patient tumor tissue specimens, we demonstrated functional interaction between the ERβ2 isoform and mutant p53 and their ability to co-dependently increase FOXM1 gene transcription, decrease cell death, increase cell proliferation, and mediate resistance to carboplatin treatment. Furthermore, high levels of ERβ2 as well as FOXM1 correlated with worse patient survival. Collectively, our data suggest that the ERβ2-mutant p53-FOXM1 axis could be a novel therapeutic target for HGSOC.

Abstract

High grade serous ovarian cancer (HGSOC) is the most common and lethal subtype of epithelial ovarian cancer. Prevalence (~96%) of mutant p53 is a hallmark of HGSOC. Estrogen receptor-beta (ERβ) has been reported to be another important player in HGSOC, although the pro-versus anti-tumorigenic role of its different isoforms remains unsettled. However, whether there is functional interaction between ERβ and mutant p53 in HGSOC is unknown. ERβ1 and ERβ2 mRNA and protein analysis in HGSOC cell lines demonstrated that ERβ2 is the predominant isoform in HGSOC. Specificity of ERβ2 antibody was ascertained using cells depleted of ERβ2 and ERβ1 separately with isoform-specific siRNAs. ERβ2-mutant p53 interaction in cell lines was confirmed by co-immunoprecipitation and in situ proximity ligation assay (PLA). Expression levels of ERβ2, ERα, p53, and FOXM1 proteins and ERβ2-mutant p53 interaction in patient tumors were determined by immunohistochemistry (IHC) and PLA, respectively. ERβ2 levels correlate positively with FOXM1 levels and negatively with progression-free survival (PFS) and overall survival (OS). Quantitative chromatin immunoprecipitation (qChIP) and mRNA expression analysis revealed that ERβ2 and mutant p53 co-dependently regulated FOXM1 gene transcription. The combination of ERβ2-specific siRNA and PRIMA-1^MET that converts mutant p53 to wild type conformation increased apoptosis. Our work provides the first evidence for a novel ERβ2-mutant p53-FOXM1 axis that can be exploited for new therapeutic strategies against HGSOC.

Co-Delivery of p53 Restored and E7 Targeted Nucleic Acids by Poly (Beta-Amino Ester) Complex Nanoparticles for the Treatment of HPV Related Cervical Lesions

The p53 gene has the highest mutation frequency in tumors, and its inactivation can lead to malignant transformation, such as cell cycle arrest and apoptotic inhibition. Persistent high-risk human papillomavirus (HR-HPV) infection is the leading cause of cervical cancer. P53 was inactivated by HPV oncoprotein E6, promoting abnormal cell proliferation and carcinogenesis. To study the treatment of cervical intraepithelial neoplasia (CIN) and cervical cancer by restoring p53 expression and inactivating HPV oncoprotein, and to verify the effectiveness of nano drugs based on nucleic acid delivery in cancer treatment, we developed poly (beta-amino ester)537, to form biocompatible and degradable nanoparticles with plasmids (expressing p53 and targeting E7). In vitro and in vivo experiments show that nanoparticles have low toxicity and high transfection efficiency. Nanoparticles inhibited the growth of xenograft tumors and successfully reversed HPV transgenic mice’s cervical intraepithelial neoplasia. Our work suggests that the restoration of p53 expression and the inactivation of HPV16 E7 are essential for blocking the development of cervical cancer. This study provides new insights into the precise treatment of HPV-related cervical lesions.

Association Between Tumor Mutation Profile and Clinical Outcomes Among Hispanic-Latino Patients With Metastatic Colorectal Cancer

In the United States, CRC is the third most common type of cancer and the second leading cause of cancer-related death. Although the incidence of CRC among the Hispanic population has been declining, recently, a dramatic increase in CRC incidents among HL younger than 50 years of age has been reported. The incidence of early-onset CRC is more significant in HL population (45%) than in non-Hispanic Whites (27%) and African-Americans (15%). The reason for these racial disparities and the biology of CRC in the HL are not well understood. We performed this study to understand the biology of the disease in HL patients. We analyzed formalin-fixed paraffin-embedded tumor tissue samples from 52 HL patients with mCRC. We compared the results with individual patient clinical histories and outcomes. We identified commonly altered genes in HL patients (APC, TP53, KRAS, GNAS, and NOTCH). Importantly, mutation frequencies in the APC gene were significantly higher among HL patients. The combination of mutations in the APC, NOTCH, and KRAS genes in the same tumors was associated with a higher risk of progression after first-line of chemotherapy and overall survival. Our data support the notion that the molecular drivers of CRC might be different in HL patients.