NF-κB is involved in the regulation of autophagy in mutant p53 cells in response to ionizing radiation

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.

Multilevel Regulation of NF-κB Signaling by NSD2 Suppresses Kras-Driven Pancreatic Tumorigenesis

Pancreatic ductal adenocarcinoma (PDAC) is a clinically challenging cancer with a dismal overall prognosis. NSD2 is an H3K36-specific di-methyltransferase that has been reported to play a crucial role in promoting tumorigenesis. Here, the study demonstrates that NSD2 acts as a putative tumor suppressor in Kras-driven pancreatic tumorigenesis. NSD2 restrains the mice from inflammation and Kras-induced ductal metaplasia, while NSD2 loss facilitates pancreatic tumorigenesis. Mechanistically, NSD2-mediated H3K36me2 promotes the expression of IκBα, which inhibits the phosphorylation of p65 and NF-κB nuclear translocation. More importantly, NSD2 interacts with the DNA binding domain of p65, attenuating NF-κB transcriptional activity. Furthermore, inhibition of NF-κB signaling relieves the symptoms of Nsd2-deficient mice and sensitizes Nsd2-null PDAC to gemcitabine. Clinically, NSD2 expression decreased in PDAC patients and negatively correlated to nuclear p65 expression. Together, the study reveals the important tumor suppressor role of NSD2 and multiple mechanisms by which NSD2 suppresses both p65 phosphorylation and downstream transcriptional activity during pancreatic tumorigenesis. This study opens therapeutic opportunities for PDAC patients with NSD2 low/loss by combined treatment with gemcitabine and NF-κBi.

Boron-Containing MOF Nanoparticles with Stable Metabolism in U87-MG Cells Combining Microdosimetry To Evaluate Relative Biological Effectiveness of Boron Neutron Capture Therapy

Accurate prediction of the relative biological effectiveness (RBE) of boron neutron capture therapy (BNCT) is challenging. The therapy is different from other radiotherapy; the dynamic distribution of boron-containing compounds in tumor cells affects the therapeutic outcome considerably and hampers accurate measurement of the neutron-absorbed dose. Herein, we used boron-containing metal-organic framework nanoparticles (BMOFs) with high boron content to target U87-MG cells and maintain the concentration of the 10B isotope in cells. The content of boron in the cells could maintain 90% (60 ppm) within 20 min compared with that at the beginning; therefore, the accurate RBE of BNCT can be acquired. The effects of BNCT upon cells after neutron irradiation were observed, and the neutron-absorbed dose was obtained by Monte Carlo simulations. The RBE of BMOFs was 6.78, which was 4.1-fold higher than that of a small-molecule boron-containing agent (boric acid). The energy spectrum of various particles was analyzed by Monte Carlo simulations, and the RBE was verified theoretically. Our results suggested that the use of nanoparticle-based boron carriers in BNCT may have many advantages and that maintaining a stable boron distribution within cells may significantly improve the efficiency of BNCT.

The protective activity of natural flavonoids against osteoarthritis by targeting NF-κB signaling pathway

Osteoarthritis (OA) is a typical joint disease associated with chronic inflammation. The nuclear factor-kappaB (NF-κB) pathway plays an important role in inflammatory activity and inhibiting NF-κB-mediated inflammation can be a potential strategy for treating OA. Flavonoids are a class of naturally occurring polyphenols with anti-inflammatory properties. Structurally, natural flavonoids can be divided into several sub-groups, including flavonols, flavones, flavanols/catechins, flavanones, anthocyanins, and isoflavones. Increasing evidence demonstrates that natural flavonoids exhibit protective activity against the pathological changes of OA by inhibiting the NF-κB signaling pathway. Potentially, natural flavonoids may suppress NF-κB signaling-mediated inflammatory responses, ECM degradation, and chondrocyte apoptosis. The different biological actions of natural flavonoids against the NF-κB signaling pathway in OA chondrocytes might be associated with the differentially substituted groups on the structures. In this review, the efficacy and action mechanism of natural flavonoids against the development of OA are discussed by targeting the NF-κB signaling pathway. Potentially, flavonoids could become useful inhibitors of the NF-κB signaling pathway for the therapeutic management of OA.

Interference with pathways activated by topoisomerase inhibition alters the surface expression of PD-L1 and MHC I in colon cancer cells

Topoisomerase inhibitors are clinically used to treat various cancer types, including colorectal cancer. These drugs also activate signaling pathways that modulate cell survival and immune cell functions. Immunotherapy is promising for certain tumors, including microsatellite instable colorectal cancer, but not for microsatellite stable colorectal cancer. The reasons for this lack of responsiveness are largely unknown. Understanding how colorectal cancer cell-surface proteins interact with tumor-resident immune cells may offer an opportunity to identify molecules that, if targeted, may render tumor cells visible to immune cells. The present study used flow cytometry, fluorescent staining and immunoblotting to examine if inhibition of pathways activated by topoisomerase-targeting drugs may modulate the outcomes of treatment through effects on cell cycle arrest and apoptosis, and by altering surface expression levels of programmed death-ligand 1 (PD-L1) or major histocompatibility complex protein I (MHC I). Inhibition of either NF-κB or DNA-damage response (DDR) potently enhanced cell death in combination with topoisomerase inhibition, while only NF-κB inhibition increased MHC I. PD-L1 upregulation was moderately affected by NF-κB or DDR inhibitors, while both topoisomerase inhibitors and DNA damaging agents may enhance the surface expression of MHC I molecules on colon cancer cells. Such enhanced expression of MHC I may be suppressed by inhibitors of ataxia-telangiectasia mutated or checkpoint kinase kinases. Additionally, adaptive tolerance to topoisomerase inhibition caused altered cell cycle response, and reduced the expression levels of both PD-L1 and MHC I on both microsatellite instable and stable colon cancer cell lines. Therefore, targeted modulation of DDR pathways, PD-L1, MHC I or other immune regulators in colon cancer cells may make them more visible to immune cells and enable rational combination of conventional therapy with immunotherapy.

Role of p53 in Regulating Radiation Responses

p53 is known as the guardian of the genome and plays various roles in DNA damage and cancer suppression. The p53 gene was found to express multiple p53 splice variants (isoforms) in a physiological, tissue-dependent manner. The various genes that up- and down-regulated p53 are involved in cell viability, senescence, inflammation, and carcinogenesis. Moreover, p53 affects the radioadaptive response. Given that several studies have already been published on p53, this review presents its role in the response to gamma irradiation by interacting with MDM2, NF-κB, and miRNA, as well as in the inflammation processes, senescence, carcinogenesis, and radiation adaptive responses. Finally, the potential of p53 as a biomarker is discussed.

Crosslink between p53 and metastasis: focus on epithelial-mesenchymal transition, cancer stem cell, angiogenesis, autophagy, and anoikis

INTRODUCTION

P53, as a tumor suppressor gene, is believed to be one of the most mutated genes in cancer cells. The mutant forms of this protein often play a tumorigenic role in cancer cells. Recent evidence shows that p53 plays a critical role in the migration, metastasis, and invasion of cancer cells. The present article aims to investigate the molecular mechanism that induces metastasis in cancer cells generated by the mutant P53, and to highlight the compounds targeting mutant-p53 together with their clinical applications.

METHODS

A detailed literature search was conducted to find information about the role of the mutant-p53 in the processes involved in metastasis in various databases.

RESULTS

A growing body of evidence suggests that Mutant-p53 enhances tumor metastasis affecting the Epithelial-mesenchymal transition (EMT) process, cancer stem cells, angiogenesis, autophagy, anoikis, and any other mechanisms regarding metastasis.

CONCLUSIONS

Taken together, targeting mutant-p53 by altering the processes involved in metastasis could be a potential therapeutic strategy in the treatment of metastatic cancer.