The cellular response to p53: the decision between life and death

Olive leaf extract-derived chitosan-metal nanocomposite: Green synthesis and dual antimicrobial-anticancer action

In this study, we developed a novel nanocomposite by synthesizing zinc (ZnNPs), copper (CuNPs), and silver (AgNPs) nanoparticles using olive leaf extract and incorporating them into a chitosan polymer. This approach combines the biocompatibility of chitosan with the antimicrobial and anticancer properties of metal nanoparticles, enhanced by the phytochemical richness of olive leaf extract. The significance of our research lies in its potential to offer a biodegradable and stable alternative to conventional antibiotics and cancer treatments, particularly in combating multidrug-resistant bacteria and various cancer types. Comprehensive characterization through Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and Transmission Electron Microscopy (TEM) confirmed the successful synthesis of the nanocomposites, with an average size of ~22.6 nm. Phytochemical analysis highlighted the antioxidant-rich composition of both the olive leaf extract and the nanoparticles themselves. Functionally, the synthesized nanoparticles exhibited potent antimicrobial activity against multidrug-resistant bacterial strains, outperforming traditional antibiotics by inhibiting key resistance genes (ermC, tetX3-q, blaZ, and Ery-msrA). In anticancer assessments, the nanoparticles showed selective cytotoxicity towards cancer cells in a concentration-dependent manner, with CuNPs and AgNPs showing particularly strong anticancer effects, while demonstrating minimal toxicity towards normal cells. ZnNPs were noted for their low cytotoxicity, highlighting the safety profile of these nanoparticles. Further, the nanoparticles induced apoptosis in cancer cells, as evidenced by the modulation of oncogenes (P21, P53, and BCL2), suggesting their therapeutic potential. The findings of our study underscore the versatile applications of these biogenic nanoparticles in developing safer and more effective antimicrobial and anticancer therapies.

Apoptosis Due to After-effects of Acute Ethanol Exposure in Brain Cortex: Intrinsic and Extrinsic Signaling Pathways

Alcohol hangover is the combination of negative mental and physical symptoms which can be experienced after a single episode of alcohol consumption, starting when blood alcohol concentration approaches zero. We previously demonstrated that hangover provokes mitochondrial dysfunction, oxidative stress, imbalance in antioxidant defenses, and impairment in cellular bioenergetics. Chronic and acute ethanol intake induces neuroapoptosis but there are no studies which evaluated apoptosis at alcohol hangover. The aim of the present work was to study alcohol residual effects on intrinsic and extrinsic apoptotic signaling pathways in mice brain cortex. Male Swiss mice received i.p. injection of ethanol (3.8 g/kg) or saline. Six hours after injection, at alcohol hangover onset, mitochondria and tissue lysates were obtained from brain cortex. Results indicated that during alcohol hangover a loss of granularity of mitochondria and a strong increment in mitochondrial permeability were observed, indicating the occurrence of swelling. Alcohol-treated mice showed a significant 35% increase in Bax/Bcl-2 ratio and a 5-fold increase in the ratio level of cytochrome c between mitochondria and cytosol. Caspase 3, 8 and 9 protein expressions were 32%, 33% and 20% respectively enhanced and the activity of caspase 3 and 6 was 30% and 20% increased also due to the hangover condition. Moreover, 38% and 32% increments were found in PARP1 and p53 protein expression respectively and on the contrary, SIRT-1 was almost 50% lower than controls due to the hangover condition. The present work demonstrates that alcohol after-effects could result in the activation of mitochondrial and non-mitochondrial apoptosis pathways.

A novel EGFR inhibitor, HNPMI, regulates apoptosis and oncogenesis by modulating BCL-2/BAX and p53 in colon cancer

BACKGROUND AND PURPOSE

Colorectal cancer (CRC) is the second most lethal disease, with high mortality due to its heterogeneity and chemo-resistance. Here, we have focused on the epidermal growth factor receptor (EGFR) as an effective therapeutic target in CRC and studied the effects of polyphenols known to modulate several key signalling mechanisms including EGFR signalling, associated with anti-proliferative and anti-metastatic properties.

EXPERIMENTAL APPROACH

Using ligand- and structure-based cheminformatics, we developed three potent, selective alkylaminophenols, 2-[(3,4-dihydroquinolin-1(2H)-yl)(p-tolyl)methyl]phenol (THTMP), 2-[(1,2,3,4-tetrahydroquinolin-1-yl)(4-methoxyphenyl)methyl]phenol (THMPP) and N-[2-hydroxy-5-nitrophenyl(4'-methylphenyl)methyl]indoline (HNPMI). These alkylaminophenols were assessed for EGFR interaction, EGFR-pathway modulation, cytotoxic and apoptosis induction, caspase activation and transcriptional and translational regulation. The lead compound HNPMI was evaluated in mice bearing xenografts of CRC cells.

KEY RESULTS

Of the three alkylaminophenols tested, HNPMI exhibited the lowest IC50 in CRC cells and potential cytotoxic effects on other tumour cells. Modulation of EGFR pathway down-regulated protein levels of osteopontin, survivin and cathepsin S, leading to apoptosis. Cell cycle analysis revealed that HNPMI induced G0/G1 phase arrest in CRC cells. HNPMI altered the mRNA for and protein levels of several apoptosis-related proteins including caspase 3, BCL-2 and p53. HNPMI down-regulated the proteins crucial to oncogenesis in CRC cells. Assays in mice bearing CRC xenografts showed that HNPMI reduced the relative tumour volume.

CONCLUSIONS AND IMPLICATIONS

HNPMI is a promising EGFR inhibitor for clinical translation. HNPMI regulated apoptosis and oncogenesis by modulating BCL-2/BAX and p53 in CRC cell lines, showing potential as a therapeutic agent in the treatment of CRC.

Induction of G0/G1 phase cell cycle arrest and apoptosis by thymol through ROS generation and caspase-9/-3 activation in breast and colorectal cancer cell lines

BACKGROUND

Cancer is a major malignancy and one of the leading causes of death; it calls for a proactive strategy for the cure. Herbs are reservoirs of novel chemical entities and their phytochemical exploration has contributed considerably to the discovery of new anticancer drugs. Thymol, a natural phenolic monoterpenoid, has been implicated with many medicinal properties, including anticancer ones. However, the anti-proliferative and apoptosis-inducing ability of thymol on MDA-MB-231 and HCT-8 cell lines has not been studied yet in detail, and hence this study was conceived.

MATERIALS AND METHODS

We studied the cytotoxicity, morphological alterations of the cell, oxidative stress, cell cycle modulation, apoptosis and expression of apoptosis-related proteins that ensued due to thymol treatment in these cancer cells.

RESULTS

Thymol inhibited the cell proliferation, altered the morphology of the cells, increased the intracellular ROS level, arrested the cells in G0/G1 phase, induced apoptosis, upregulated pro-apoptotic protein p53 expression, downregulated anti-apoptotic protein Bcl-xL expression, and activated caspase-9 and -3.

CONCLUSION

These findings elucidate that thymol induces apoptosis through the intrinsic pathway, in MDA-MB-231 breast and HCT-8 colorectal cancer cells through ROS generation and G0/G1 phase cell cycle arrest. This reiterates the broad-spectrum anti-tumor potential of thymol and provides an insight to study further to be developed into an anticancer drug.

USP19 Negatively Regulates p53 and Promotes Cervical Cancer Progression

p53 is a tumor suppressor gene activated in response to cellular stressors that inhibits cell cycle progression and induces pro-apoptotic signaling. The protein level of p53 is well balanced by the action of several E3 ligases and deubiquitinating enzymes (DUBs). Several DUBs have been reported to negatively regulate and promote p53 degradation in tumors. In this study, we identified USP19 as a negative regulator of p53 protein level. We demonstrate a direct interaction between USP19 and p53 by pull down assay. The overexpression of USP19 promoted ubiquitination of p53 and reduced its protein half-life. We also demonstrate that CRISPR/Cas9-mediated knockout of USP19 in cervical cancer cells elevates p53 protein levels, resulting in reduced colony formation, cell migration, and cell invasion. Overall, our results indicate that USP19 negatively regulates p53 protein levels in cervical cancer progression.

Hdac1 and Hdac2 regulate the quiescent state and survival of hair-follicle mesenchymal niche

While cell division is essential for self-renewal and differentiation of stem cells and progenitors, dormancy is required to maintain the structure and function of the stem-cell niche. Here we use the hair follicle to show that during growth, the mesenchymal niche of the hair follicle, the dermal papilla (DP), is maintained quiescent by the activity of Hdac1 and Hdac2 in the DP that suppresses the expression of cell-cycle genes. Furthermore, Hdac1 and Hdac2 in the DP promote the survival of DP cells throughout the hair cycle. While during growth and regression this includes downregulation of p53 activity and the control of p53-independent programs, during quiescence, this predominantly involves p53-independent mechanisms. Remarkably, Hdac1 and Hdac2 in the DP during the growth phase also participate in orchestrating the hair cycle clock by maintaining physiological levels of Wnt signaling in the vicinity of the DP. Our findings not only provide insight into the molecular mechanism that sustains the function of the stem-cell niche in a persistently changing microenvironment, but also unveil that the same mechanism provides a molecular toolbox allowing the DP to affect and fine tune the microenvironment.

Changes in the Mitochondria in the Aging Process-Can α-Tocopherol Affect Them?

Aerobic organisms use molecular oxygen in several reactions, including those in which the oxidation of substrate molecules is coupled to oxygen reduction to produce large amounts of metabolic energy. The utilization of oxygen is associated with the production of ROS, which can damage biological macromolecules but also act as signaling molecules, regulating numerous cellular processes. Mitochondria are the cellular sites where most of the metabolic energy is produced and perform numerous physiological functions by acting as regulatory hubs of cellular metabolism. They retain the remnants of their bacterial ancestors, including an independent genome that encodes part of their protein equipment; they have an accurate quality control system; and control of cellular functions also depends on communication with the nucleus. During aging, mitochondria can undergo dysfunctions, some of which are mediated by ROS. In this review, after a description of how aging affects the mitochondrial quality and quality control system and the involvement of mitochondria in inflammation, we report information on how vitamin E, the main fat-soluble antioxidant, can protect mitochondria from age-related changes. The information in this regard is scarce and limited to some tissues and some aspects of mitochondrial alterations in aging. Improving knowledge of the effects of vitamin E on aging is essential to defining an optimal strategy for healthy aging.

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

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

Fyn Phosphorylates Transglutaminase 2 (Tgm2) and Modulates Autophagy and p53 Expression in the Development of Diabetic Kidney Disease

Autophagy is involved in the development of diabetic kidney disease (DKD), the leading cause of end-stage renal disease. The Fyn tyrosine kinase (Fyn) suppresses autophagy in the muscle. However, its role in kidney autophagic processes is unclear. Here, we examined the role of Fyn kinase in autophagy in proximal renal tubules both in vivo and in vitro. Phospho-proteomic analysis revealed that transglutaminase 2 (Tgm2), a protein involved in the degradation of p53 in the autophagosome, is phosphorylated on tyrosine 369 (Y369) by Fyn. Interestingly, we found that Fyn-dependent phosphorylation of Tgm2 regulates autophagy in proximal renal tubules in vitro, and that p53 expression is decreased upon autophagy in Tgm2-knockdown proximal renal tubule cell models. Using streptozocin (STZ)-induced hyperglycemic mice, we confirmed that Fyn regulated autophagy and mediated p53 expression via Tgm2. Taken together, these data provide a molecular basis for the role of the Fyn-Tgm2-p53 axis in the development of DKD.

To not love thy neighbor: mechanisms of cell competition in stem cells and beyond

Cell competition describes the process in which cells of greater fitness are capable of sensing and instructing elimination of lesser fit mutant cells. Since its discovery in Drosophila, cell competition has been established as a critical regulator of organismal development, homeostasis, and disease progression. It is therefore unsurprising that stem cells (SCs), which are central to these processes, harness cell competition to remove aberrant cells and preserve tissue integrity. Here, we describe pioneering studies of cell competition across a variety of cellular contexts and organisms, with the ultimate goal of better understanding competition in mammalian SCs. Furthermore, we explore the modes through which SC competition takes place and how this facilitates normal cellular function or contributes to pathological states. Finally, we discuss how understanding of this critical phenomenon will enable targeting of SC-driven processes, including regeneration and tumor progression.

NFκB-Mediated Expression of Phosphoinositide 3-Kinase δ Is Critical for Mesenchymal Transition in Retinal Pigment Epithelial Cells

Epithelial mesenchymal transition (EMT) plays a vital role in a variety of human diseases including proliferative vitreoretinopathy (PVR), in which retinal pigment epithelial (RPE) cells play a key part. Transcriptomic analysis showed that the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway was up-regulated in human RPE cells upon treatment with transforming growth factor (TGF)-β2, a multifunctional cytokine associated with clinical PVR. Stimulation of human RPE cells with TGF-β2 induced expression of p110δ (the catalytic subunit of PI3Kδ) and activation of NFκB/p65. CRISPR-Cas9-mediated depletion of p110δ or NFκB/p65 suppressed TGF-β2-induced fibronectin expression and activation of Akt as well as migration of these cells. Intriguingly, abrogating expression of NFκB/p65 also blocked TGF-β2-induced expression of p110δ, and luciferase reporter assay indicated that TGF-β2 induced NFκB/p65 binding to the promoter of the PIK3CD that encodes p110δ. These data reveal that NFκB/p65-mediated expression of PI3Kδ is essential in human RPE cells for TGF-β2-induced EMT, uncovering hindrance of TGF-β2-induced expression of p110δ as a novel approach to inhibit PVR.

Modulation of oral cancer and periodontitis using chemotherapeutic agents - A narrative review

Periodontitis, an inflammatory condition, is linked to a higher risk of developing oral cancer. Periodontitis may be a precipitating factor for tumorigenesis and the aggressiveness of specific cancer variants. Although genetics is considered the primary etiologic factor for the development of most cancers, many factors have come to be recognized in the initiation and progression of oral cancer. Consecutively, it is suggestive that periodontitis and oral cancer are distinct disease entities but share common pathogenic mechanisms. Oxidative stress and epigenetic mechanisms are among the most researched mechanisms responsible for initiating apoptotic mechanisms implicated in periodontitis and oral cancer. Current research aims to formulate therapeutic agents to intercede in these mechanisms via host modulation therapy and epigenetic therapy. These advances can revolutionize the treatment of periodontitis and oral cancer. This review aims to shed light on the common pathogenic mechanisms of these diseases and the various host modulation agents that could be beneficial in their treatment.

Prediction of protein stability changes upon single-point variant using 3D structure profile

Identifying protein thermodynamic stability changes upon single-point variants is crucial for studying mutation-induced alterations in protein biophysics, genomic variants, and mutation-related diseases. In the last decade, various computational methods have been developed to predict the effects of single-point variants, but the prediction accuracy is still far from satisfactory for practical applications. Herein, we review approaches and tools for predicting stability changes upon the single-point variant. Most of these methods require tertiary protein structure as input to achieve reliable predictions. However, the availability of protein structures limits the immediate application of these tools. To improve the performance of a computational prediction from a protein sequence without experimental structural information, we introduce a new computational framework: MU3DSP. This method assesses the effects of single-point variants on protein thermodynamic stability based on point mutated protein 3D structure profile. Given a protein sequence with a single variant as input, MU3DSP integrates both sequence-level features and averaged features of 3D structures obtained from sequence alignment to PDB to assess the change of thermodynamic stability induced by the substitution. MU3DSP outperforms existing methods on various benchmarks, making it a reliable tool to assess both somatic and germline substitution variants and assist in protein design. MU3DSP is available as an open-source tool at https://github.com/hurraygong/MU3DSP.

Signaling pathways and targeted therapies in lung squamous cell carcinoma: mechanisms and clinical trials

Lung cancer is the leading cause of cancer-related death across the world. Unlike lung adenocarcinoma, patients with lung squamous cell carcinoma (LSCC) have not benefitted from targeted therapies. Although immunotherapy has significantly improved cancer patients' outcomes, the relatively low response rate and severe adverse events hinder the clinical application of this promising treatment in LSCC. Therefore, it is of vital importance to have a better understanding of the mechanisms underlying the pathogenesis of LSCC as well as the inner connection among different signaling pathways, which will surely provide opportunities for more effective therapeutic interventions for LSCC. In this review, new insights were given about classical signaling pathways which have been proved in other cancer types but not in LSCC, including PI3K signaling pathway, VEGF/VEGFR signaling, and CDK4/6 pathway. Other signaling pathways which may have therapeutic potentials in LSCC were also discussed, including the FGFR1 pathway, EGFR pathway, and KEAP1/NRF2 pathway. Next, chromosome 3q, which harbors two key squamous differentiation markers SOX2 and TP63 is discussed as well as its related potential therapeutic targets. We also provided some progress of LSCC in epigenetic therapies and immune checkpoints blockade (ICB) therapies. Subsequently, we outlined some combination strategies of ICB therapies and other targeted therapies. Finally, prospects and challenges were given related to the exploration and application of novel therapeutic strategies for LSCC.

Cimetidine-Based Cationic Amphiphiles for In Vitro Gene Delivery Targetable to Colon Cancer

Cimetidine, a histamine-2 (H2) receptor antagonist, has been found to have anticancer properties against a number of cancer-type cells. In this report, we have demonstrated that cimetidine can acts as a hydrophilic domain in cationic lipids and targetable to the gastric system by carrying reporter genes and therapeutic genes through in vitro transfection. Two lipids, namely, Toc-Cim and Chol-Cim consisting cimetidine as the main head group and hydrophobic moieties as alpha-tocopherol or cholesterol, respectively, were designed and synthesized. 1,2-Dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) is a well-known co-lipid employed to produce liposomes as uniform vesicles. The liposomes and lipoplexes were structurally and functionally evaluated for global surface charges and hydrodynamic diameters, and results found that both liposome and lipoplex size and surface charges are optimal to screen the transfection potentials. DNA-binding studies were analyzed as complete binding at all formulated N/P ratios. The liposomes and lipoplexes of both the lipids Toc-Cim and Chol-Cim show minimal cytotoxicity even though at higher concentrations. The results of the transfection experiments revealed that tocopherol-based cationic lipids (Toc-Cim) show finer transfection efficacy with optimized N/P ratios (2:1 and 4:1) in the colon cancer cell line. Toc-Cim lipoplexes show higher cellular uptake compare to Chol-Cim in the colon cancer cell line at 2:1 and 4:1 N/P ratios. Toc-Cim and Chol-Cim lipids showed highly compatible serum, examined up to 50% of the serum concentration. To evaluate the apoptotic cell death in CT-26 cells, exposed to Toc-Cim:p53 and Chol-Cim:p53 lipoplexes at 2:1 N/P ratios, superior results showed with Toc-Cim:p53. An effect of TP53 protein expression in CT-26 cell lines assayed by western blot, transfected with Toc-Cim:p53 and Chol-Cim:p53 lipoplexes, demonstrated the superior efficacy of Toc-Cim. All of the findings suggest that Toc-Cim lipid is relatively secure and is an effective transfection agent to colon cancer gene delivery.

p53: From Fundamental Biology to Clinical Applications in Cancer

Simple Summary

p53 tumour suppressor gene is the most altered in cancer. Several decades of research have established that it is of pivotal importance in prompting neoplastic phenomena, including cancer initiation and progression. However, it has crucial functions for cellular life. Knowledge and awareness about these multifaceted properties should be part of the cultural background of all scientists. In this review, we describe and discuss the multifaceted roles of p53, from its discovery to clinical applications in cancer therapy.

Abstract

p53 tumour suppressor gene is our major barrier against neoplastic transformation. It is involved in many cellular functions, including cell cycle arrest, senescence, DNA repair, apoptosis, autophagy, cell metabolism, ferroptosis, immune system regulation, generation of reactive oxygen species, mitochondrial function, global regulation of gene expression, miRNAs, etc. Its crucial importance is denounced by the high percentage of amino acid sequence identity between very different species (Homo sapiens, Drosophila melanogaster, Rattus norvegicus, Danio rerio, Canis lupus familiaris, Gekko japonicus). Many of its activities allowed life on Earth (e.g., repair from radiation-induced DNA damage) and directly contribute to its tumour suppressor function. In this review, we provide paramount information on p53, from its discovery, which is an interesting paradigm of science evolution, to potential clinical applications in anti-cancer treatment. The description of the fundamental biology of p53 is enriched by specific information on the structure and function of the protein as well by tumour/host evolutionistic perspectives of its role.

Activation of p53 in anoxic freshwater crayfish, Faxonius virilis

Tumor suppressing transcription factor p53 regulates multiple pathways including DNA repair, cell survival, apoptosis, and autophagy. The current work studies stress-induced activation of p53 in anoxic crayfish (Faxonius virilis). Relative levels of target proteins and mRNAs involved in the DNA damage response was measured in normoxic control and anoxic hepatopancreas and tail muscle. Phosphorylation levels of p53 was assessed using immunoblotting at sites known to be phosphorylated (Serine 15 and 37) in response to DNA damage or reduced oxygen signaling. The capacity for DNA binding by phospho-p53 was also measured, followed by transcript analysis of a potentially pro-apoptotic downstream target, the etoposide induced (ei24) gene. Following this, both inhibitor (MDM2) and activator (p19-ARF) protein levels in response to low oxygen stress were studied. The results showed an increase in p53 levels during anoxia in both hepatopancreases and tail muscle. Increased transcript levels of ei24, a downstream target of p53, support the activation of p53 under anoxic stress. Cytoplasmic accumulation of Ser-15 p-p53 was observed during anoxia when proteins from cytoplasmic and nuclear fractions were measured. Increased cytoplasmic concentration is known to initiate an apoptotic response, which can be assumed as a preparatory step to prevent autophagy. The results suggest that p53 might play a protective role in crayfish defense against low oxygen stress. Understanding how anoxia-tolerant organisms are able to protect against DNA damage could provide important clues towards survival under metabolic rate depression and preparation for recovery to minimize damage.

microRNA-Mediated Encoding and Decoding of Time-Dependent Signals in Tumorigenesis

microRNAs, pivotal post-transcriptional regulators of gene expression, in the past decades have caught the attention of researchers for their involvement in different biological processes, ranging from cell development to cancer. Although lots of effort has been devoted to elucidate the topological features and the equilibrium properties of microRNA-mediated motifs, little is known about how the information encoded in frequency, amplitude, duration, and other features of their regulatory signals can affect the resulting gene expression patterns. Here, we review the current knowledge about microRNA-mediated gene regulatory networks characterized by time-dependent input signals, such as pulses, transient inputs, and oscillations. First, we identify the general characteristic of the main motifs underlying temporal patterns. Then, we analyze their impact on two commonly studied oncogenic networks, showing how their dysfunction can lead to tumorigenesis.

Morin mitigates ifosfamide induced nephrotoxicity by regulation of NF-kappaB/p53 and Bcl-2 expression

Ifosfamide (IFO) is used for treating childhood solid tumors, but its use is limited by its adverse effects on kidneys. Morin may be used to prevent nephrotoxic and other side effects. We investigated the underlying mechanisms of the protective effects of morin on IFO induced nephrotoxicity. We used 35 male rats divided into five groups of seven: control group, morin group, IFO group, 100 mg/kg morin + IFO group and 200 mg/kg morin + IFO group. We measured kidney tissue oxidant, antioxidant and inflammatory parameters using ELISA, and apoptosis was evaluated using immunohistochemistry and real time PCR. Serum urea, creatinine and kidney injury molecule-1 (KIM-1) levels were increased by IFO treatment; elevated levels were decreased significantly by treatment with both 100 and 200 mg/kg morin. Morin treatment also decreased oxidative stress and lipid oxidation in IFO treated rats. The ameliorative effect of morin on inflammatory response was due to reduced levels of NF-κB and TNF-α. Morin also reduced NF-κB/p53 levels by increasing Bcl-2 expression in IFO treated kidneys. Morin may prevent IFO induced nephrotoxicity via the NF-κB/p53 and Bcl-2 signaling pathways.

Puf-A promotes cancer progression by interacting with nucleophosmin in nucleolus

Previously, we identified Puf-A as a novel member of Puf-family RNA-binding proteins; however, its biological functions remain obscure. Analysis of tumor samples of non-small cell lung cancer (NSCLC) showed that high Puf-A expression correlated with high histology grade and abnormal p53 status. Kaplan-Meier curve for overall survival revealed high expression of Puf-A to predict poor prognosis in stage I NSCLC. Among patients with colorectal cancer, high Puf-A expression also showed an adverse impact on overall survival. In lung cancer cell lines, downregulation of p53 increased Puf-A expression, and upregulation of p53 dampened its expression. However, luciferase reporter assays indicated that PUF-A locus harbored the p53-response element, but regulated Puf-A transcription indirectly. In vivo suppression of p53 in CCSP-rtTA/TetO-Cre/LSL-Kras^G12D/p53^flox/flox conditional mutant mice accelerated the progression of the Kras^G12D-driven lung cancer, along with enhanced expression of Puf-A. Importantly, intranasal delivery of shPuf-A to the inducible Kras^G12D/p53^flox/flox mice suppressed tumor progression. Puf-A silencing led to marked decreases in the 80S ribosomes, along with decrease in S6 and L5 in the cytoplasm and accumulation in the nucleolus. Based on immunofluorescence staining and immunoprecipitation studies, Puf-A interacted with NPM1 in nucleolus. Puf-A silencing resulted in NPM1 translocation from nucleolus to nucleoplasm and this disruption of NPM1 localization was reversed by a rescue experiment. Mechanistically, Puf-A silencing altered NPM1 localization, leading to the retention of ribosomal proteins in nucleolus and diminished ribosome biogenesis, followed by cell-cycle arrest/cell death. Puf-A is a potential theranostic target for cancer therapy and an important player in cancer progression.

Arsenic sulfide reverses cisplatin resistance in non-small cell lung cancer in vitro and in vivo through targeting PD-L1

BACKGROUND

Recent studies have found that programmed death ligand 1 (PD-L1) might be involved in chemotherapy resistance in non-small cell lung cancer (NSCLC). Arsenic sulfide (As₄ S₄ ) has been recognized to have antitumor activities and enhance the cytotoxic effect of chemotherapy drugs. In this study, we aimed to verify the relationship between PD-L1 and cisplatin (DDP) resistance and identify whether As₄ S₄ could reverse DDP resistance through targeting PD-L1 in NSCLC.

METHODS

The effect of As₄ S₄ and DDP on cell proliferation and apoptosis was investigated in NSCLC cell lines. The expression of p53 and PD-L1 proteins was measured by western blotting analysis. The levels of miR-34a-5p, miR-34a-3p and PD-L1 in cells were measured by real-time qPCR analysis. Mouse xenograft models were established by inoculation with A549/DDP (DDP-resistant) cells.

RESULTS

Depletion of PD-L1 inhibited DDP resistance in A549/DDP and H1299/DDP cells. As₄ S₄ was capable of sensitizing A549/DDP cells to DDP by enhancing apoptosis. As₄ S₄ upregulated p53 expression and downregulated PD-L1 expression in A549/DDP cells. As₄ S₄ increased miR-34a-5p level in A549/DDP cells. Inhibition of p53 by PFT-α partially restored the levels of PD-L1 and miR-34a-5p. Pretreatment with PFT-α suppressed the apoptosis rate induced by cotreatment of As₄ S₄ and DDP in A549/DDP cells. Cotreatment of DDP and As₄ S₄ notably reduced the tumor size when compared with DDP treatment alone in vivo.

CONCLUSIONS

Upregulation of PD-L1 was correlated with DDP resistance in NSCLC cells. Mechanistic analyses indicated that As₄ S₄ might sensitize NSCLC cells to DDP through targeting p53/miR-34a-5p/PD-L1 axis.

Chemopreventive effects of pterostilbene through p53 and cell cycle in mouse lung of squamous cell carcinoma model

Cell proliferation and cell death abnormalities are strongly linked to the development of cancer, including lung cancer. The purpose of this study was to investigate the effect of pterostilbene on cell proliferation and cell death via cell cycle arrest during the transition from G1 to S phase and the p53 pathway. A total of 24 female Balb/C mice were randomly categorized into four groups (n = 6): N-nitroso-tris-chloroethyl urea (NTCU) induced SCC of the lungs, vehicle control, low dose of 10 mg/kg PS + NTCU (PS10), and high dose of 50 mg/kg PS + NTCU (PS50). At week 26, all lungs were harvested for immunohistochemistry and Western blotting analysis. Ki-67 expression is significantly lower, while caspase-3 expression is significantly higher in PS10 and PS50 as compared to the NTCU (p < 0.05). There was a significant decrease in cyclin D1 and cyclin E2 protein expression in PS10 and PS50 when compared to the NTCU (p < 0.05). PS50 significantly increased p53, p21, and p27 protein expression when compared to NTCU (p < 0.05). Pterostilbene is a potential chemoprevention agent for lung SCC as it has the ability to upregulate the p53/p21 pathway, causing cell cycle arrest.

In vivo anticancer effects of Momordica charantia seed fat on hepatocellular carcinoma in a rat model

Background

Momordica charantia or bitter melon is a well-known vegetable with a number of therapeutic actions in Ayurvedic medicine. Alpha-eleostearic acid, a conjugated trienoic fatty acid present in bitter melon is proven to have anticancer properties. Crude seed oil from local bitter melon varieties could be an effective and economical anticancer therapy.

Objective(s)

The study was conducted to evaluate the anticancer effect of the crude oil from the seeds of Matale green variety of bitter melon on a hepatocellular carcinoma-induced rat model.

Materials and methods

Hepatocellular carcinoma (HCC) was experimentally induced in Wistar rats. Crude seed oil of Matale green bitter melon (MGBM) was supplemented to one treatment group in concurrence with carcinoma induction and to another treatment group after the development of carcinoma. After 168 days, gross morphological, histopathological, biochemical, hematological and gene-expression analysis of treated and control groups were performed.

Results

Oral supplementation of MGBM seed oil showed a statistically significant reduction (p < 0.05) in the average number, diameter and area of hepatic dysplastic nodules and a reduction in the size of histopathological neoplastic lesions in both treatment groups compared to the non-treated control group. The expression of tumor suppressor gene p53 and anti-apoptotic gene Bcl-2 were significantly increased while the expression of apoptotic gene caspase 3 was significantly reduced in the treatment group when MGBM supplementation was in concurrence with carcinogenesis (p < 0.05).

Conclusion

Crude seed oil from the MGBM has anticancer effects against experimentally induced HCC in Wistar rats, specially when supplemented in concurrence with carcinoma induction.

Long noncoding RNAs in the regulation of p53-mediated apoptosis in human cancers

Long noncoding RNAs (lncRNAs) are widely known for their regulatory function in transcriptional and posttranscriptional processes. The involvement of such non-protein-coding RNAs in nuclear organization and chromatin remodeling is often associated with an increased risk of human malignancies. In cancer, lncRNAs either promote cell survival or may act as a growth suppressor, thus conferring a key regulatory function other than their established role in fundamental cellular processes. Interestingly, lncRNAs interfere with the stages of apoptosis and related pathways involving p53. Many of these molecules either regulate or are regulated by p53 while mounting oncogenic events. Consequently, they may confer both prosurvival or proapoptotic functions depending upon the tissue type. Since the mechanism of cell death is bypassed in many human cancers, it has emerged that the lncRNAs are either overexpressed or knocked down to sensitize cells to apoptotic stimuli. Nonetheless, the abundant expression of lncRNAs in tumor cells renders them suitable targets for anticancer therapies. Although the role of lncRNAs in the p53 network and apoptosis has been independently defined, their interplay in activating p53-target genes during cell cycle arrest remains unexplored. Thus, we have specifically reviewed the possible involvement of lncRNAs in the p53-mediated apoptosis of human cancer cells. In particular, we summarize the growing evidence from individual studies and analyze whether lncRNAs are essential to facilitate apoptosis in a p53-dependent manner. This may lead to the identification of p53-associated lncRNAs that are suitable therapeutic targets or diagnostic/prognostic markers.

Simple rapid in vitro screening method for SARS-CoV-2 anti-virals that identifies potential cytomorbidity-associated false positives

Background

The international SARS-CoV-2 pandemic has resulted in an urgent need to identify new anti-viral drugs for treatment of COVID-19. The initial step to identifying potential candidates usually involves in vitro screening that includes standard cytotoxicity controls. Under-appreciated is that viable, but stressed or otherwise compromised cells, can also have a reduced capacity to replicate virus. A refinement proposed herein for in vitro drug screening thus includes a simple growth assay to identify drug concentrations that cause cellular stress or “cytomorbidity”, as distinct from cytotoxicity or loss of viability.

Methods

A simple rapid bioassay is presented for antiviral drug screening using Vero E6 cells and inhibition of SARS-CoV-2 induced cytopathic effects (CPE) measured using crystal violet staining. We use high cell density for cytotoxicity assays, and low cell density for cytomorbidity assays.

Results

The assay clearly illustrated the anti-viral activity of remdesivir, a drug known to inhibit SARS-CoV-2 replication. In contrast, nitazoxanide, oleuropein, cyclosporine A and ribavirin all showed no ability to inhibit SARS-CoV-2 CPE. Hydroxychloroquine, cyclohexamide, didemnin B, γ-mangostin and linoleic acid were all able to inhibit viral CPE at concentrations that did not induce cytotoxicity. However, these drugs inhibited CPE at concentrations that induced cytomorbidity, indicating non-specific anti-viral activity.

Conclusions

We describe the methodology for a simple in vitro drug screening assay that identifies potential anti-viral drugs via their ability to inhibit SARS-CoV-2-induced CPE. The additional growth assay illustrated how several drugs display anti-viral activity at concentrations that induce cytomorbidity. For instance, hydroxychloroquine showed anti-viral activity at concentrations that slow cell growth, arguing that its purported in vitro anti-viral activity arises from non-specific impairment of cellular activities. The cytomorbidity assay can therefore rapidly exclude potential false positives.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-021-01587-z.

Enhanced G1 arrest and apoptosis via MDM4/MDM2 double knockdown and MEK inhibition in wild-type TP53 colon and gastric cancer cells with aberrant KRAS signaling

Murine double minute homolog 2 (MDM2) is an oncoprotein that induces p53 degradation via ubiquitin-ligase activity. MDM4 cooperates with MDM2-mediated p53 degradation, directly inhibiting p53 transcription by binding to its transactivation domain. Our previous study reported that the simultaneous inhibition of MDM2 and MDM4 using nutlin-3 (an inhibitor of the MDM2-p53 interaction) and chimeric small interfering RNA with DNA-substituted seed arms (named chiMDM2 and chiMDM4) more potently activated p53 than the MDM2 or MDM4 inhibitor alone and synergistically augmented antitumor effects in various types of cancer cells with the wild-type (wt) TP53. Recently, the synergism of MDM2 and mitogen-activated protein kinase kinase (MEK) inhibitors has been demonstrated in wt TP53 colorectal and non-small cell lung cancer cells harboring mutant-type (mt) KRAS. The current study examined whether chiMDM4 augmented the synergistic antitumor effects of MDM2 and MEK inhibition using chiMDM2 or nutlin-3 and trametinib, respectively. ChiMDM2 and trametinib used in combination demonstrated a synergistic antitumor activity in HCT116 and LoVo colon cancer cells, and SNU-1 gastric cancer cells harboring wt TP53 and mt KRAS. Furthermore, chiMDM4 synergistically enhanced this combinational effect. Similar results were observed when nutlin-3 was used instead of chiMDM2. MDM4/MDM2 double knockdown combined with trametinib treatment enhanced G1 arrest and apoptosis induction. This was associated with the accumulation of p53, suppression of phosphorylated-extracellular signal-regulated kinase 2, inhibition of retinoblastoma phosphorylation, suppression of E2F1-activated proteins, and potent activation of pro-apoptotic proteins, such as Fas and p53 upregulated modulator of apoptosis. The results inidcated that the triple inhibition of MDM4, MDM2 and MEK exerted a potent antitumor effect in wt TP53 colon and gastric cancer cells with mt KRAS. Simultaneous activation of p53 and inhibition of aberrant KRAS signaling may be a rational treatment strategy for gastrointestinal tumors.

Exploring the differentially expressed genes in human lymphocytes upon response to ionizing radiation: a network biology approach

Purpose

The integration of large-scale gene data and their functional analysis needs the effective application of various computational tools. Here we attempted to unravel the biological processes and cellular pathways in response to ionizing radiation using a systems biology approach.

Materials and Methods

Analysis of gene ontology shows that 80, 42, 25, and 35 genes have roles in the biological process, molecular function, the cellular process, and immune system pathways, respectively. Therefore, our study emphasizes gene/protein network analysis on various differentially expressed genes (DEGs) to reveal the interactions between those proteins and their functional contribution upon radiation exposure.

Results

A gene/protein interaction network was constructed, which comprises 79 interactors with 718 interactions and TP53, MAPK8, MAPK1, CASP3, MAPK14, ATM, NOTCH1, VEGFA, SIRT1, and PRKDC are the top 10 proteins in the network with high betweenness centrality values. Further, molecular complex detection was used to cluster these associated partners in the network, which produced three effective clusters based on the Molecular Complex Detection (MCODE) score. Interestingly, we found a high functional similarity from the associated genes/proteins in the network with known radiation response genes.

Conclusion

This network-based approach on DEGs of human lymphocytes upon response to ionizing radiation provides clues for an opportunity to improve therapeutic efficacy.

Metformin Inhibits the Urea Cycle and Reduces Putrescine Generation in Colorectal Cancer Cell Lines

The urea cycle (UC) removes the excess nitrogen and ammonia generated by nitrogen-containing compound composites or protein breakdown in the human body. Research has shown that changes in UC enzymes are not only related to tumorigenesis and tumor development but also associated with poor survival in hepatocellular, breast, and colorectal cancers (CRC), etc. Cytoplasmic ornithine, the intermediate product of the urea cycle, is a specific substrate for ornithine decarboxylase (ODC, also known as ODC1) for the production of putrescine and is required for tumor growth. Polyamines (spermidine, spermine, and their precursor putrescine) play central roles in more than half of the steps of colorectal tumorigenesis. Given the close connection between polyamines and cancer, the regulation of polyamine metabolic pathways has attracted attention regarding the mechanisms of action of chemical drugs used to prevent CRC, as the drug most widely used for treating type 2 diabetes (T2D), metformin (Met) exhibits antitumor activity against a variety of cancer cells, with a vaguely defined mechanism. In addition, the influence of metformin on the UC and putrescine generation in colorectal cancer has remained unclear. In our study, we investigated the effect of metformin on the UC and putrescine generation of CRC in vivo and in vitro and elucidated the underlying mechanisms. In nude mice bearing HCT116 tumor xenografts, the administration of metformin inhibited tumor growth without affecting body weight. In addition, metformin treatment increased the expression of monophosphate (AMP)-activated protein kinase (AMPK) and p53 in both HCT116 xenografts and colorectal cancer cell lines and decreased the expression of the urea cycle enzymes, including carbamoyl phosphate synthase 1 (CPS1), arginase 1 (ARG1), ornithine trans-carbamylase (OTC), and ODC. The putrescine levels in both HCT116 xenografts and HCT116 cells decreased after metformin treatment. These results demonstrate that metformin inhibited CRC cell proliferation via activating AMPK/p53 and that there was an association between metformin, urea cycle inhibition and a reduction in putrescine generation.

To Breathe or Not to Breathe: The Role of Oxygen in Bone Marrow-Derived Mesenchymal Stromal Cell Senescence

Stem cell-based cellular therapy is a promising tool for the treatment of pathological conditions with underlying severe tissue damage or malfunction like in chronic cardiovascular, musculoskeletal, or inflammatory conditions. One of the biggest technical challenges of the use of natural stem cells, however, is the prevention of their premature senescence during therapeutical manipulations. Culturing stem cells under hypoxic conditions is believed to be a possible route to fulfill this goal. Here, we review current literature data on the effects of hypoxia on bone marrow-derived mesenchymal stromal cells, one of the most popular tools of practical cellular therapy, in the context of their senescence.

miR-10a as a therapeutic target and predictive biomarker for MDM2 inhibition in acute myeloid leukemia

Pharmacological inhibition of MDM2/4, which activates the critical tumor suppressor p53, has been gaining increasing interest as a strategy for the treatment of acute myeloid leukemia (AML). While clinical trials of MDM2 inhibitors have shown promise, responses have been confined to largely molecularly undefined patients, indicating that new biomarkers and optimized treatment strategies are needed. We previously reported that the microRNA miR-10a is strongly overexpressed in some AML, and demonstrate here that it modulates several key members of the p53/Rb network, including p53 regulator MDM4, Rb regulator RB1CC1, p21 regulator TFAP2C, and p53 itself. The expression of both miR-10a and its downstream targets were strongly predictive of MDM2 inhibitor sensitivity in cell lines, primary AML specimens, and correlated to response in patients treated with both MDM2 inhibitors and cytarabine. Furthermore, miR-10a inhibition induced synergy between MDM2 inhibitor Nutlin-3a and cytarabine in both in vitro and in vivo AML models. Mechanistically this synergism primarily occurs via the p53-mediated activation of cytotoxic apoptosis at the expense of cytoprotective autophagy. Together these findings demonstrate that miR-10a may be useful as both a biomarker to identify patients most likely to respond to cytarabine+MDM2 inhibition and also a druggable target to increase their efficacy.

Role of Bcl-2 Family Proteins in Photodynamic Therapy Mediated Cell Survival and Regulation

Photodynamic therapy (PDT) is a treatment modality that involves three components: combination of a photosensitizer, light and molecular oxygen that leads to localized formation of reactive oxygen species (ROS). The ROS generated from this promising therapeutic modality can be lethal to the cell and leads to consequential destruction of tumor cells. However, sometimes the ROS trigger a stress response survival mechanism that helps the cells to cope with PDT-induced damage, resulting in resistance to the treatment. One preferred mechanism of cell death induced by PDT is apoptosis, and B-cell lymphoma 2 (Bcl-2) family proteins have been described as a major determinant of life or death decision of the death pathways. Apoptosis is a cellular self-destruction mechanism to remove old cells through the biological event of tissue homeostasis. The Bcl-2 family proteins act as a critical mediator of a life–death decision of cells in maintaining tissue homeostasis. There are several reports that show cancer cells developing resistance due to the increased interaction of the pro-survival Bcl-2 family proteins. However, the key mechanisms leading to apoptosis evasion and drug resistance have not been adequately understood. Therefore, it is critical to understand the mechanisms of PDT resistance, as well as the Bcl-2 family proteins, to give more insight into the treatment outcomes. In this review, we describe the role of Bcl-2 gene family proteins’ interaction in response to disease progression and PDT-induced resistance mechanisms.

Deletion of NKX3.1 via CRISPR/Cas9 Induces Prostatic Intraepithelial Neoplasia in C57BL/6 Mice

Several techniques have been employed for deletion of the NKX3.1 gene, resulting in developmental defects of the prostate, including alterations in ductal branching morphogenesis and prostatic secretions as well as epithelial hyperplasia and dysplasia. To investigate whether the CRISPR/Cas9-mediated technique can be applied to study prostate carcinogenesis through exon I deletion of NKX3.1 gene, alterations in the prostatic intraepithelial neoplasia (PIN) and their regulatory mechanism were observed in the prostate of NKX3.1 knockout (KO) mice produced by the CRISPR/Cas9-mediated NKX3.1 mutant gene, at the ages of 16 and 24 weeks. The weight of dorsal-lateral prostate (DLP) and anterior prostate (AP) were observed to be increased in only the 24 weeks KO mice, although morphogenesis was constant in all groups. Obvious PIN 1 and 2 lesions were frequently detected in prostate of the 24 weeks KO mice, as compared with the same age wild type (WT) mice. Ki67, a key indicator for PIN, was densely stained in the epithelium of prostate in the 24 weeks KO mice, while the expression of p53 protein was suppressed in the same group. Also, both the 16 and 24 weeks KO mice reveal inhibition of the PI3K/AKT/mTOR pathway in the prostate. However, prostate specific antigen (PSA) levels and Bax/Bcl-2 expressions were decreased in the prostate of 16 weeks KO mice, and were increased in only the 24 weeks KO mice. Taken together, the results of the present study provide additional evidence that CRISPR/Cas9-mediated exon 1 deletion of the NKX3.1 gene successfully induces PIN lesions, along with significant alterations of Ki67 expression, EGFR signaling pathway, and cancer-regulated proteins.

Deferasirox-Dependent Iron Chelation Enhances Mitochondrial Dysfunction and Restores p53 Signaling by Stabilization of p53 Family Members in Leukemic Cells

Iron is crucial to satisfy several mitochondrial functions including energy metabolism and oxidative phosphorylation. Patients affected by Myelodysplastic Syndromes (MDS) and acute myeloid leukemia (AML) are frequently characterized by iron overload (IOL), due to continuous red blood cell (RBC) transfusions. This event impacts the overall survival (OS) and it is associated with increased mortality in lower-risk MDS patients. Accordingly, the oral iron chelator Deferasirox (DFX) has been reported to improve the OS and delay leukemic transformation. However, the molecular players and the biological mechanisms laying behind remain currently mostly undefined. The aim of this study has been to investigate the potential anti-leukemic effect of DFX, by functionally and molecularly analyzing its effects in three different leukemia cell lines, harboring or not p53 mutations, and in human primary cells derived from 15 MDS/AML patients. Our findings indicated that DFX can lead to apoptosis, impairment of cell growth only in a context of IOL, and can induce a significant alteration of mitochondria network, with a sharp reduction in mitochondrial activity. Moreover, through a remarkable reduction of Murine Double Minute 2 (MDM2), known to regulate the stability of p53 and p73 proteins, we observed an enhancement of p53 transcriptional activity after DFX. Interestingly, this iron depletion-triggered signaling is enabled by p73, in the absence of p53, or in the presence of a p53 mutant form. In conclusion, we propose a mechanism by which the increased p53 family transcriptional activity and protein stability could explain the potential benefits of iron chelation therapy in terms of improving OS and delaying leukemic transformation.

Pinning Control for the p53-Mdm2 Network Dynamics Regulated by p14ARF

p53 regulates the cellular response to genotoxic damage and prevents carcinogenic events. Theoretical and experimental studies state that the p53-Mdm2 network constitutes the core module of regulatory interactions activated by cellular stress induced by a variety of signaling pathways. In this paper, a strategy to control the p53-Mdm2 network regulated by p14ARF is developed, based on the pinning control technique, which consists into applying local feedback controllers to a small number of nodes (pinned ones) in the network. Pinned nodes are selected on the basis of their importance level in a topological hierarchy, their degree of connectivity within the network, and the biological role they perform. In this paper, two cases are considered. For the first case, the oscillatory pattern under gamma-radiation is recovered; afterward, as the second case, increased expression of p53 level is taken into account. For both cases, the control law is applied to p14ARF (pinned node based on a virtual leader methodology), and overexpressed Mdm2-mediated p53 degradation condition is considered as carcinogenic initial behavior. The approach in this paper uses a computational algorithm, which opens an alternative path to understand the cellular responses to stress, doing it possible to model and control the gene regulatory network dynamics in two different biological contexts. As the main result of the proposed control technique, the two mentioned desired behaviors are obtained.

Transcription Factors in Cancer Development and Therapy

Cancer is a multi-step process and requires constitutive expression/activation of transcription factors (TFs) for growth and survival. Many of the TFs reported so far are critical for carcinogenesis. These include pro-inflammatory TFs, hypoxia-inducible factors (HIFs), cell proliferation and epithelial-mesenchymal transition (EMT)-controlling TFs, pluripotency TFs upregulated in cancer stem-like cells, and the nuclear receptors (NRs). Some of those, including HIFs, Myc, ETS-1, and β-catenin, are multifunctional and may regulate multiple other TFs involved in various pro-oncogenic events, including proliferation, survival, metabolism, invasion, and metastasis. High expression of some TFs is also correlated with poor prognosis and chemoresistance, constituting a significant challenge in cancer treatment. Considering the pivotal role of TFs in cancer, there is an urgent need to develop strategies targeting them. Targeting TFs, in combination with other chemotherapeutics, could emerge as a better strategy to target cancer. So far, targeting NRs have shown promising results in improving survival. In this review, we provide a comprehensive overview of the TFs that play a central role in cancer progression, which could be potential therapeutic candidates for developing specific inhibitors. Here, we also discuss the efforts made to target some of those TFs, including NRs.

Transcription Factors in Cancer Development and Therapy

Cancer is a multi-step process and requires constitutive expression/activation of transcription factors (TFs) for growth and survival. Many of the TFs reported so far are critical for carcinogenesis. These include pro-inflammatory TFs, hypoxia-inducible factors (HIFs), cell proliferation and epithelial-mesenchymal transition (EMT)-controlling TFs, pluripotency TFs upregulated in cancer stem-like cells, and the nuclear receptors (NRs). Some of those, including HIFs, Myc, ETS-1, and β-catenin, are multifunctional and may regulate multiple other TFs involved in various pro-oncogenic events, including proliferation, survival, metabolism, invasion, and metastasis. High expression of some TFs is also correlated with poor prognosis and chemoresistance, constituting a significant challenge in cancer treatment. Considering the pivotal role of TFs in cancer, there is an urgent need to develop strategies targeting them. Targeting TFs, in combination with other chemotherapeutics, could emerge as a better strategy to target cancer. So far, targeting NRs have shown promising results in improving survival. In this review, we provide a comprehensive overview of the TFs that play a central role in cancer progression, which could be potential therapeutic candidates for developing specific inhibitors. Here, we also discuss the efforts made to target some of those TFs, including NRs.

Molecular cloning, characterization and expression analysis of p53 from turbot Scophthalmus maximus and its response to thermal stress

The tumor suppressor protein, p53 plays a crucial role in protecting genetic integrity. Once activated by diverse cell stresses, p53 reversibly activates downstream target genes to regulate cell cycle and apoptosis. However, few studies have investigated the effects of thermal stress in turbot, specifically the p53 signaling pathway. In this study, the rapid amplification of cDNA ends was used to obtain a full-length cDNA of the turbot p53 gene (Sm-p53) and perform bioinformatics analysis. The results showed that the cDNA of the Sm-p53 gene was 2928 bp in length, encoded a 381 amino acid protein, with a theoretical isoelectric point of 6.73. It was composed of a DNA binding and a tetramerization domain. Expression of Sm-p53 in different tissues was detected and quantified by qRT-PCR, and was highest in the liver. We also investigated the expression profiles of Sm-p53 in different tissue and TK cells after thermal stress. These result suggested that Sm-p53 plays a key role, and provides a theoretical basis for Sm-p53 changes in environmental stress responses in the turbot.

Methionine sulfoxide reductase A (MsrA) modulates cells and protects against Mycoplasma genitalium induced cytotoxicity

Methionine sulfoxide reductase A (MsrA) is a ubiquitous antioxidant repair enzyme which specifically reduces the oxidized methionine (Met-O) in proteins to methionine (Met). Previous studies have shown that lack of or overexpression of MsrA in cells affects the function of proteins and can lead to altered cellular processes. Interestingly, some pathogenic bacteria secrete and/or carry MsrA on their surface, suggesting some key roles for this enzyme in the modulation of host cellular processes. Therefore, we investigated how exogenously added MsrA affects the ability of the host cells in combating infection by using an in vitroMycoplasma genitalium cytotoxicity model. HeLa cells pretreated with MsrA and infected with M. genitalium showed significantly lower necrosis (cytotoxicity) than untreated cells infected with M. genitalium. Intriguingly, necrotic cell death pathway specific real time RT-PCR revealed that M. genitalium infection upregulates the expression of the TNF gene in HeLa cells and that MsrA pretreatment of the cells downregulates its expression significantly. Consistent with this, enzyme linked immunosorbent assay (ELISA) results showed that HeLa cells pretreated with MsrA secreted reduced levels of TNF-α following M. genitalium infection. Also, our study demonstrates that MsrA treatment of cells affects the phosphorylation status of transcriptional regulators such as NF-кB, JNK and p53 that regulate different cytokines. Further, fluorescent microscopy showed the cellular uptake of exogenously added MsrA fused with red fluorescent protein (MsrA-RFP). Altogether, our results suggest that secreted MsrA may help pathogens to modulate host cellular processes.

Two Birds with One Stone: NFAT1-MDM2 Dual Inhibitors for Cancer Therapy

The tumor suppressor p53 is believed to be the mostly studied molecule in modern biomedical research. Although p53 interacts with hundreds of molecules to exert its biological functions, there are only a few modulators regulating its expression and function, with murine double minute 2 (MDM2) playing a key role in this regard. MDM2 also contributes to malignant transformation and cancer development through p53-dependent and -independent mechanisms. There is an increasing interest in developing MDM2 inhibitors for cancer prevention and therapy. We recently demonstrated that the nuclear factor of activated T cells 1 (NFAT1) activates MDM2 expression. NFAT1 regulates several cellular functions in cancer cells, such as cell proliferation, migration, invasion, angiogenesis, and drug resistance. Both NFAT isoforms and MDM2 are activated and overexpressed in several cancer subtypes. In addition, a positive correlation exists between NFAT1 and MDM2 in tumor tissues. Our recent clinical study has demonstrated that high expression levels of NFAT1 and MDM2 are independent predictors of a poor prognosis in patients with hepatocellular carcinoma. Thus, inhibition of the NFAT1-MDM2 pathway appears to be a novel potential therapeutic strategy for cancer. In this review, we summarize the potential oncogenic roles of MDM2 and NFAT1 in cancer cells and discuss the efforts of discovery and the development of several newly identified MDM2 and NFAT1 inhibitors, focusing on their potent in vitro and in vivo anticancer activities. This review also highlights strategies and future directions, including the need to focus on the development of more specific and effective NFAT1-MDM2 dual inhibitors for cancer therapy.

Elevated Expression of RIOK1 Is Correlated with Breast Cancer Hormone Receptor Status and Promotes Cancer Progression

Purpose

RIOK1 has been proved to play an important role in cancer cell proliferation and migration in various types of cancers—such as colorectal and gastric cancers. However, the expression of RIOK1 in breast cancer (BC) and the relationship between RIOK1 expression and the development of BC are not well characterized. In this study, we assessed the expression of RIOK1 in BC and evaluated the mechanisms underlying its biological function in this disease context.

Materials and Methods

We used immunohistochemistry, western blot and quantitative real-time polymerase chain reaction to evaluate the expression of RIOK1 in BC patients. Then, knockdown or overexpression of RIOK1 were used to evaluate the effect on BC cells in vitro and in vivo. Finally, we predicted miR-204-5p could be a potential regulator of RIOK1.

Results

We found that the expression levels of RIOK1 were significantly higher in hormone receptor (HR)–negative BC patients and was associated with tumor grades (p=0.010) and p53 expression (p=0.008) and survival duration (p=0.011). Kaplan-Meier analysis suggested a tendency for the poor prognosis. In vitro, knockdown of RIOK1 could inhibit proliferation, invasion, and induced apoptosis in HR-negative BC cells and inhibited tumorigenesis in vivo, while overexpression of RIOK1 promoted HR-positive tumor progression. MiR-204-5p could regulate RIOK1 expression and be involved in BC progression.

Conclusion

These findings indicate that RIOK1 expression could be a biomarker of HR-negative BC, and it may serve as an effective prognostic indicator and promote BC progression.

Role of limonin in anticancer effects of Evodia rutaecarpa on ovarian cancer cells

Background

Ovarian cancer therapy generally involves systemic chemotherapy with anticancer drugs; however, chemotherapy with a platinum-based drug has often been shown to cause adverse reactions and drug resistance in ovarian cancer patients. Evodia rutaecarpa (ER) reportedly shows anticancer activity against various types of cancer cells. However, the effects of ER have not yet been fully uncovered in ovarian cancer.

Methods

In the present study, we investigated the anticancer effects of an ER extract and its components against the ovarian cancer cell lines SKOV-33, A2780, RMUG-S and a cisplatin-resistant SKOV-3 cell line (Cis^R SKOV-3). Cell viability and colony formation assays along with subcellular fractionation analysis, immunoblotting, and immunofluorescence staining were performed.

Results

ER treatment led to a significant reduction in the viability of SKOV-3 cells. Moreover, limonin, a compound found in ER, reduced the viability of both serous-type (SKOV-3 and A2780) and mucinous-type (RMUG-S) ovarian cancer cells by inducing apoptosis via activation of the p53 signaling pathway. Furthermore, limonin reversed the drug resistance through activation of apoptosis in Cis^R SKOV-3.

Conclusion

Taken together, our findings suggest that limonin contributes to the anti-ovarian cancer effects of ER by inducing apoptosis via activation of the p53 signaling pathway.

The Inhibitory Mechanisms of Tumor PD-L1 Expression by Natural Bioactive Gallic Acid in Non-Small-Cell Lung Cancer (NSCLC) Cells

Non-small-cell lung cancer (NSCLC) is the most common lung cancer subtype and accounts for more than 80% of all lung cancer cases. Epidermal growth factor receptor (EGFR) phosphorylation by binding growth factors such as EGF activates downstream prooncogenic signaling pathways including KRAS-ERK, JAK-STAT, and PI3K-AKT. These pathways promote the tumor progression of NSCLC by inducing uncontrolled cell cycle, proliferation, migration, and programmed death-ligand 1 (PD-L1) expression. New cytotoxic drugs have facilitated considerable progress in NSCLC treatment, but side effects are still a significant cause of mortality. Gallic acid (3,4,5-trihydroxybenzoic acid; GA) is a phenolic natural compound, isolated from plant derivatives, that has been reported to show anticancer effects. We demonstrated the tumor-suppressive effect of GA, which induced the decrease of PD-L1 expression through binding to EGFR in NSCLC. This binding inhibited the phosphorylation of EGFR, subsequently inducing the inhibition of PI3K and AKT phosphorylation, which triggered the activation of p53. The p53-dependent upregulation of miR-34a induced PD-L1 downregulation. Further, we revealed the combination effect of GA and anti-PD-1 monoclonal antibody in an NSCLC-cell and peripheral blood mononuclear-cell coculture system. We propose a novel therapeutic application of GA for immunotherapy and chemotherapy in NSCLC.

Synthesis and Reactivity of 6,8-Dibromo-2-ethyl-4H-benzo[d][1,3]oxazin-4-one Towards Nucleophiles and Electrophiles and Their Anticancer Activity

BACKGROUND

The genetic heterogeneity of tumor cells and the development of therapy-resistant cancer cells in addition to the high cost necessitate the continuous development of novel targeted therapies.

METHODS

In this regard, 14 novel benzoxazinone derivatives were synthesized and examined for anticancer activity against two human epithelial cancer cell lines; breast MCF-7 and liver HepG2 cells. 6,8-Dibromo-2- ethyl-4H-benzo[d][1,3]oxazin-4-one was subjected to react with nitrogen nucleophiles to afford quinazolinone derivatives and other related moieties (3-12). Benzoxazinone 2 responds to attack with oxygen nucleophile such as ethanol to give ethyl benzoate derivative 13. The reaction of benzoxazinone 2 with carbon electrophile such as benzaldehyde derivatives afforded benzoxazinone derivatives 14a and 14b.The structure of the prepared compounds was confirmed with spectroscopic tools including IR, 1H-NMR, and 13C-NMR.

RESULTS

Derivatives 3, 9, 12, 13, and 14b exhibited high antiproliferative activity and were selective against cancer cells showing no toxicity in normal fibroblasts. Derivative 3 with NH-CO group in quinazolinone ring was effective only against breast cells, while derivative 12 with NH-CO group in imidazole moiety was only effective against liver cells probably through arresting cell cycle and enabling repair mechanisms. The other derivatives (9, 13, and 14b) had broader antiproliferative activity against both cell lines. These derivatives enhance the expression of the p53 and caspases 9 and 3 to varying degrees in both cell lines. Derivative 14b caused the highest induction in the investigated genes and was the only derivative to inhibit the EGFR activity.

CONCLUSIONS

The unique features about derivative 14b could be attributed to its high lipophilicity, high carbon content, or its extended conjugation through planar aromatic system. More investigations are required to identify the lead compound(s) in animal models.

IL-20 promotes hypoxia/reoxygenation-induced mitochondrial dysfunction and apoptosis in cardiomyocytes by upregulating oxidative stress by activating the PKC/NADPH oxidase pathway

Acute myocardial infarction (AMI) is the maximum critical cardiovascular event and causes high morbidity and mortality worldwide. The ischemia and reperfusion that occur in AMI cause apoptosis and cellular dysfunction in cardiomyocytes. IL-20, an IL-10 family member, is involved in various inflammatory diseases. Therefore, we sought to elucidate the role of IL-20 in the infarcted heart following ischemia/reperfusion (I/R) injury. We found that IL-20 and its receptors, IL-20R1 and IL-20R2, were increased in H2C2 cardiomyoblast cells and ventricular tissues subjected to hypoxia/reoxygenation (H/R) stimulation. The presence of IL-20 further inhibited the cell viability of H9C2 cells and primary cardiomyocytes. Our results suggested that IL-20 elicited an increase in Ca²⁺ and activation of the PKC/NADPH oxidase pathway, leading to the elevation of oxidase stress and downregulation of AKT. Furthermore, we demonstrated that IL-20 was able to mediate H/R-induced apoptosis via PKC/NADPH oxidase/AKT signaling. Our findings implied that IL-20 was responsive to H/R stress in vitro and in rat hearts undergoing I/R injury, and this upregulation of IL-20 may contribute to the apoptosis of cardiomyocytes.

Sesamin inhibits cervical cancer cell proliferation by promoting p53/PTEN-mediated apoptosis

Background: Sesamin is a major bioactive compound in sesame seeds and has various biological properties, including anti-inflammatory and anticancer activities. Here, we explored whether sesamin activates p53, which is widely inhibited in cervical cancer cells, thereby inducing p53-mediated apoptosis. Methods: Human HeLa and SiHa cervical cancer cells and normal Hs68 dermal cells were used as cell models. Cell proliferation, cell cycle distribution, and apoptosis were evaluated by the CCK-8 assay and flow cytometry using PI/Annexin V staining, respectively. Protein expression and phosphorylation were determined using western blotting. The involvement of p53 in the apoptotic cascade was assessed by a specific inhibitor. Results: Sesamin (75 and 150 μM) clearly inhibited SiHa and HeLa cell proliferation in a dose-dependent fashion, but did not affect the proliferation of Hs68 cells. Meanwhile, sesamin increased the sub-G1 phase ratio and apoptosis, up to approximately 38.5% and 37.8%, respectively. Furthermore, sesamin induced p53 phosphorylation at serine-46 and serine-15 and upregulated the levels of PUMA, Bax, and PTEN, while inhibiting AKT phosphorylation at serine-473. Inhibition of p53 by pifithrin-α significantly reduced the levels of PUMA, Bax, and PTEN but restored AKT phosphorylation in SiHa cells exposed to sesamin. Pifithrin-α also reduced apoptosis and restored the proliferation of HeLa and SiHa cells exposed to sesamin. Conclusions: These findings indicate that sesamin inhibits cervical cancer cell proliferation, and its mechanism may be attributed to the induction of p53/PTEN-mediated apoptosis. This suggests that sesamin might be useful as an adjuvant in promoting anti-cervical cancer treatments.

Molecular Biology of Basal and Squamous Cell Carcinomas

The prevalent keratinocyte-derived neoplasms of the skin are basal cell carcinoma and squamous cell carcinoma. Both so-called non-melanoma skin cancers comprise the most common cancers in humans by far. Common risk factors for both tumor entities include sun exposure, DNA repair deficiencies leading to chromosomal instability, or immunosuppression. Yet, fundamental differences in the development of the two different entities have been and are currently unveiled. The constitutive activation of the sonic hedgehog signaling pathway by acquired mutations in the PTCH and SMO genes appears to represent the early basal cell carcinoma developmental determinant. Although other signaling pathways are also affected, small hedgehog inhibitory molecules evolve as the most promising basal cell carcinoma treatment options systemically as well as topically in current clinical trials. For squamous cell carcinoma development, mutations in the p53 gene, especially UV-induced mutations, have been identified as early events. Yet, other signaling pathways including epidermal growth factor receptor, RAS, Fyn, or p16INK4a signaling may play significant roles in squamous cell carcinoma development. The improved understanding of the molecular events leading to different tumor entities by de-differentiation of the same cell type has begun to pave the way for modulating new molecular targets therapeutically with small molecules.

Autologous tumor‑derived microvesicles influence gene expression profiles and enhance protumorigenic chemotactic potential, signal transduction and cellular respiration in gastric cancer cells

Tumor‑derived microvesicles (TMVs) interact with a variety of different cell types within the immune system, including lymphocytes, monocytes, dendritic cells and tumor cells that they have originated from. In the present study, the effects of autologous‑TMVs (auto‑TMVs) on gene expression, chemotaxis, intercellular signaling and cellular metabolism were examined in cells of the gastric cancer (GC) cell line 1415 (GC1415). The effects of auto‑TMVs on mRNA gene expression in GC1415 cells were assessed using pathway‑focused PCR arrays. A chemotaxis assay was performed using the HoloMonitor M4 System. Signaling pathways were evaluated using western blot analysis, and cellular respiration was measured using the Seahorse XF Cell Mito Stress Test. Exposure of the GC1415 cells to auto‑TMVs led to the overexpression (75 genes) and underexpression (96 genes) of genes that are associated with signal transduction, metabolism, chemotaxis, angiogenesis and metastasis. The auto‑TMVs were indicated to induce chemotaxis and activate the PI3K/AKT signaling pathway in GC1415 cells. However, the MAPK/ERK signaling pathway was not indicated to be activated. Furthermore, studies on cellular respiration in GC1415 cells exposed to auto‑TMVs demonstrated a metabolic shift to glycolysis. The results of the current study thus indicate that auto‑TMVs may exert an effect on tumor cell function.

Radiation effects on early phase of NT2/D1 neural differentiation in vitro

Purpose: Widespread medical use of radiation in diagnosis, imaging and treatment of different central nervous system malignancies lead to various consequences. Aim of this study was to further elucidate mechanism of cell response to radiation and possible consequence on neural differentiation.Materials and methods: NT2/D1 cells that resemble neural progenitors were used as a model system. Undifferentiated NT2/D1 cells and NT2/D1 cells in the early phase of neural differentiation were irradiated with low (0.2 Gy) and moderate (2 Gy) doses of γ radiation. The effect was analyzed on apoptosis, cell cycle, senescence, spheroid formation and the expression of genes and miRNAs involved in the regulation of pluripotency or neural differentiation.Results: Two grays of irradiation induced apoptosis, senescence and cell cycle arrest of NT2/D1 cells, accompanied with altered expression of several genes (SOX2, OCT4, SOX3, PAX6) and miRNAs (miR-219, miR-21, miR124-a). Presented results show that 2 Gy of radiation significantly affected early phase of neural differentiation in vitro.Conclusions: These results suggest that 2 Gy of radiation significantly affected early phase of neural differentiation and affect the population of neural progenitors. These findings might help in better understanding of side effects of radiotherapy in treatments of central nervous system malignancies.