Targeting p53 for Novel Anticancer Therapy

The activity of pyrazolo[4,3-e][1,2,4]triazine and pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulphonamide derivatives in monolayer and spheroid breast cancer cell cultures

In the last decade, an increasing interest in compounds containing pyrazolo[4,3-e][1,2,4]triazine moiety is observed. Therefore, the aim of the research was to synthesise a novel sulphonyl pyrazolo[4,3-e][1,2,4]triazines (2a, 2b) and pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulphonamide derivatives (3a, 3b) to assess their anticancer activity. The MTT assay showed that 2a, 2b, 3a, 3b have stronger cytotoxic activity than cisplatin in both breast cancer cells (MCF-7 and MDA-MB-231) and exhibited weaker effect on normal breast cells (MCF-10A). The obtained results showed that the most active compound 3b increased apoptosis via caspase 9, caspase 8, and caspase 3/7. It is worth to note that compound 3b suppressed NF-κB expression and promoted p53, Bax, and ROS which play important role in activation of apoptosis. Moreover, our results confirmed that compound 3b triggers autophagy through increased formation of autophagosomes, expression of beclin-1 and mTOR inhibition. Thus, our study defines a possible mechanism underlying 3b-induced anti-cancer activity against breast cancer cell lines.

Targeting the p53-p21 axis in liver cancer: Linking cellular senescence to tumor suppression and progression

Liver cancer is a major health epidemic worldwide, mainly due to its high mortality rates and limited treatment options. The association of cellular senescence to tumorigenesis and the cancer hallmarks remains a subject of interest in cancer biology. The p53-p21 signalling axis is an important regulator in restoring the cell's balance by supporting tumor suppression and tumorigenesis in liver cancer. We review the novel molecular mechanisms that p53 and its downstream effector, p21, employ to induce cellular senescence, making it last longer, and halt the proliferation of damaged hepatocytes to become tumorous cells. We also examine how dysregulation of this pathway contributes to HCC pathogenesis, proliferation, survival, acquired resistance to apoptosis, and increased invasiveness. Furthermore, we comprehensively describe the molecular cross-talk between the p53-p21 signalling axis and major cell cycle signalling pathways, including Wnt/β-catenin, PI3K/Akt, and TGF-β in liver cancer and provide an overview of promising candidates for chemoprevention and future therapeutic strategies. This review article explores the roles of the p53-p21 pathway in liver cancer, examining its function in promoting cellular senescence under normal conditions and its potential role in cancer progression. It also highlights novel therapeutic drugs and drug targets within the pathway and discusses the implications for treatment strategies and prognosis in liver cancer.

Abemaciclib-induced epithelial-mesenchymal transition mediated by cyclin-dependent kinase 4/6 independent of cell cycle arrest pathway

Abemaciclib (ABM), a cyclin-dependent kinase 4/6 inhibitor, shows pharmacological effects in cell cycle arrest. Epithelial-mesenchymal transition is an important cellular event associated with pathophysiological states such as organ fibrosis and cancer progression. In the present study, we evaluated the contribution of factors associated with cell cycle arrest to ABM-induced epithelial-mesenchymal transition. Treatment with 0.6 µM ABM induced both cell cycle arrest and epithelial-mesenchymal transition-related phenotypic changes. Interestingly, the knockdown of cyclin-dependent kinase 4/6, pharmacological targets of ABM or cyclin D1, which forms complexes with cyclin-dependent kinase 4/6, resulted in cell cycle arrest at the G1-phase and induction of epithelial-mesenchymal transition, indicating that downregulation of cyclin-dependent kinase 4/6-cyclin D1 complexes would mimic ABM. In contrast, knockdown of the Rb protein, which is phosphorylated by cyclin-dependent kinase 4/6, had no effect on the expression level of α-smooth muscle actin, an epithelial-mesenchymal transition marker. Furthermore, ABM-induced epithelial-mesenchymal transition was not affected by Rb knockdown, suggesting that Rb is not involved in the transition process. Our study is the first to suggest that cyclin-dependent kinase 4/6-cyclin D1 complexes, as pharmacological targets of ABM, may contribute to ABM-induced epithelial-mesenchymal transition, followed by clinical disorders such as organ fibrosis and cancer progression. This study suggests that blocking epithelial-mesenchymal transition might be a promising way to prevent negative side effects caused by a medication (ABM) without affecting its ability to treat the disease.

Pesticide-induced alterations in zebrafish (Danio rerio) behavior, histology, DNA damage and mRNA expression: An integrated approach

To assess the impact of glyphosate and 2,4-D herbicides, as well as the insecticide imidacloprid, both individually and in combination, the gills of adult zebrafish were used due to their intimate interaction with chemicals diluted in water. Bioassays were performed exposing the animals to the different pesticides and their mixture for 96 h. The behavior of the fish was analyzed, a histological examination of the gills was carried out, and the genotoxic effects were also analyzed by means of the comet assay (CA) and the change in the expression profiles of genes involved in the pathways of the oxidative stress and cellular apoptosis. The length traveled and the average speed of the control fish, compared to those exposed to the pesticides and mainly those exposed to the mixture, were significantly greater. All the groups exposed individually exhibited a decrease in thigmotaxis time, indicating a reduction in the behavior of protecting themselves from predators. Histological analysis revealed significant differences in the structures of the gill tissues. The quantification of the histological lesions showed mild lesions in the fish exposed to imidacloprid, moderate to severe lesions for glyphosate, and severe lesions in the case of 2,4-D and the mixture of pesticides. The CA revealed the sensitivity of gill cells to DNA damage following exposure to glyphosate, 2,4-D, imidacloprid and the mixture. Finally, both genes involved in the oxidative stress pathway and those related to the cell apoptosis pathway were overexpressed, while the ogg1 gene, involved in DNA repair, was downregulated.

Inhibition of PRL2 Upregulates PTEN and Attenuates Tumor Growth in Tp53-deficient Sarcoma and Lymphoma Mouse Models

The phosphatases of regenerating liver (PRL) are oncogenic when overexpressed. We previously found that PRL2 deletion increases PTEN, decreases Akt activity, and suppresses tumor development in a partial Pten-deficient mouse model. The current study aims to further establish the mechanism of PTEN regulation by PRL2 and expand the therapeutic potential for PTEN augmentation mediated by PRL2 inhibition in cancers initiated without PTEN alteration. The TP53 gene is the most mutated tumor suppressor in human cancers, and heterozygous or complete deletion of Tp53 in mice leads to the development of sarcomas and thymic lymphomas, respectively. There remains a lack of adequate therapies for the treatment of cancers driven by Tp53 deficiency or mutations. We show that Prl2 deletion leads to PTEN elevation and attenuation of Akt signaling in sarcomas and lymphomas developed in Tp53 deficiency mouse models. This results in increased survival and reduced tumor incidence because of impaired tumor cell proliferation. In addition, inhibition of PRL2 with a small-molecule inhibitor phenocopies the effect of genetic deletion of Prl2 and reduces Tp53 deficiency-induced tumor growth. Taken together, the results further establish PRL2 as a negative regulator of PTEN and highlight the potential of PRL2 inhibition for PTEN augmentation therapy in cancers with wild-type PTEN expression.

SIGNIFICANCE

Prl2 deletion attenuates Tp53 deficiency-induced tumor growth by increasing PTEN and reducing Akt activity. Targeting Tp53-null lymphoma with PRL inhibitors lead to reduced tumor burden, providing a therapeutic approach via PTEN augmentation.

Aloe-Emodin Isolated from Rheum Undulatum L. Regulates Cell Cycle Distribution and Cellular Senescence in Human Prostate Cancer LNCaP Cells

Senescence can promote hyperplastic pathologies, such as cancer. Prostate cancer is the second most common type of cancer in men. The p21-mediate cellular senescence, facilitated through the tumor suppressor p53-dependent pathway, is considered the primary mechanism for cancer treatment. Aloe-emodin, has been reported to exert anticancer effects in various types of cancers. This study aimed to investigate the bioactivity of aloe-emodin in LNCaP cells via the activation of p21-mediated cellular senescence. Aloe-emodin treatment increased the percentage of cells in the G1 phase while decreasing the percentage in the S phase. This effect was reflected in the expression levels of proteins associated with cell cycle progression, such as p21CIP, retinoblastoma protein, and cyclin-dependent kinase2/4 in LNCaP cells. However, aloe-emodin-treated LNCaP cells did not induce cell cycle arrest at G2/M checkpoint. Moreover, increased senescence-associated-galactosidase activity was observed in a dose-dependent manner following treatment with aloe-emodin. Aloe-emodin also induced DNA damage by modulating the expression of histone H2AX and lamin B1. Furthermore, aloe-emodin inhibited the proliferation of LNCaP cells, contrasting with the exponential growth observed in the nontreated cells. Importantly, this inhibition did not impact the immune system, as evidenced by the increased proliferation of splenocytes isolated from mice. These findings provide preliminary evidence of the anticancer effect of aloe-emodin in LNCaP cells, necessitating further investigations into the underlying mechanisms in vivo and human subjects.

Contaminated sediment in the Detroit River provokes acclimated responses in wild brown bullhead (Ameiurus nebulosus) populations

In a previous study, adaptive responses to a single polycyclic aromatic hydrocarbon (PAH), benzo[a]pyrene (BaP), were identified in brown bullhead (Ameiurus nebulosus) captured from contaminated sites across the Great Lakes. The tumor suppressor p53 and phase I toxin metabolizing CYP1A genes showed a elevated and refractory response, respectively, up to the F1 generation (Williams and Hubberstey, 2014). As an extension to the first study, bullhead were exposed to sediment collected from sites along the Detroit River to see if these adaptive responses are attainable when fish from a contaminated site are exposed to a mixture of contaminants, instead of a single compound. p53 and CYP1A proteins were measured again with the addition of phase II glutathione-s-transferase (GST) activity in the present study. Three treatment groups were measured: acute (treated immediately), cleared (depurated for three months and subsequent treatment), and farm raised F1 offspring. All three treatment groups were exposed to clean and contaminated sediment for 24 and 96 h. Acute fish from contaminated sites exposed to contaminated sediment revealed an initial elevated p53 response that did not persist in fish after long-term contaminated sediment exposure. Acute fish from contaminated sites exposed to contaminated sediment revealed refractory CYP1A expression, which disappeared in cleared fish and whose F1 response overlapped with clean site F1 offspring. Decreasing GST activity was evident in both clean and contaminated fish over time, and only clean site fish responded to long-term contaminated sediment deliberately with increasing GST activity. Because p53 and CYP1A gene expression and GST activity responses did not overlap between contaminated fish treatment groups, our study suggests that contaminated fish have acclimated to the contaminants present in their environments and no evidence of adaptation could be detected within these biomarkers.

Caspase-8 and Tyrosine Kinases: A Dangerous Liaison in Cancer

Caspase-8 is a cysteine-aspartic acid protease that has been identified as an initiator caspase that plays an essential role in the extrinsic apoptotic pathway. Evasion of apoptosis is a hallmark of cancer and Caspase-8 expression is silenced in some tumors, consistent with its central role in apoptosis. However, in the past years, several studies reported an increased expression of Caspase-8 levels in many tumors and consistently identified novel "non-canonical" non-apoptotic functions of Caspase-8 that overall promote cancer progression and sustain therapy resistance. These reports point to the ability of cancer cells to rewire Caspase-8 function in cancer and raise the question of which are the signaling pathways aberrantly activated in cancer that may contribute to the hijack of Caspase-8 activity. In this regard, tyrosine kinases are among the first oncogenes ever identified and genomic, transcriptomic and proteomic studies indeed show that they represent a class of signaling molecules constitutively activated in most of the tumors. Here, we aim to review and discuss the role of Caspase-8 in cancer and its interplay with Src and other tyrosine kinases.

PROTACs: A novel strategy for cancer drug discovery and development

Proteolysis targeting chimera (PROTAC) technology has become a powerful strategy in drug discovery, especially for undruggable targets/proteins. A typical PROTAC degrader consists of three components: a small molecule that binds to a target protein, an E3 ligase ligand (consisting of an E3 ligase and its small molecule recruiter), and a chemical linker that hooks first two components together. In the past 20 years, we have witnessed advancement of multiple PROTAC degraders into the clinical trials for anticancer therapies. However, one of the major challenges of PROTAC technology is that only very limited number of E3 ligase recruiters are currently available as E3 ligand for targeted protein degradation (TPD), although human genome encodes more than 600 E3 ligases. Thus, there is an urgent need to identify additional effective E3 ligase recruiters for TPD applications. In this review, we summarized the existing RING-type E3 ubiquitin ligase and their small molecule recruiters that act as effective E3 ligands of PROTAC degraders and their application in anticancer drug discovery. We believe that this review could serve as a reference in future development of efficient E3 ligands of PROTAC technology for cancer drug discovery and development.

Butein inhibits cancer cell growth by rescuing the wild-type thermal stability of mutant p53

p53 is a transcription factor that activates the expression of various genes involved in the maintenance of genomic stability, and more than 50% of cancers harbor inactivating p53 mutations, which are indicative of highly aggressive cancer and poor prognosis. Pharmacological targeting of mutant p53 to restore the wild-type p53 tumor-suppressing function is a promising strategy for cancer therapy. In this study, we identified a small molecule, Butein, that reactivates mutant p53 activity in tumor cells harboring the R175H or R273H mutation. Butein restored wild-type-like conformation and DNA-binding ability in HT29 and SK-BR-3 cells harboring mutant p53-R175H and mutant p53-R273H, respectively. Moreover, Butein enabled the transactivation of p53 target genes and decreased the interactions of Hsp90 with mutant p53-R175H and mutant p53-R273H proteins, while Hsp90 overexpression reversed targeted p53 gene activation. In addition, Butein induced thermal stabilization of wild-type p53, mutant p53-R273H and mutant p53-R175H, as determined via CETSA. From docking study, we further proved that Butein binding to p53 stabilized the DNA-binding loop-sheet-helix motif of mutant p53-R175H and regulated its DNA-binding activity via an allosteric mechanism, conferring wild-type-like the DNA-binding activity of mutant p53. Collectively, the data suggest that Butein is a potential antitumor agent that restores p53 function in cancers harboring mutant p53-R273H or mutant p53-R175H. SIGNIFICANCE: Butein restores the ability of mutant p53 to bind DNA by reversing its transition to the Loop3 (L3) state, endows p53 mutants with thermal stability and re-establishes their transcriptional activity to induce cancer cell death.

Molecular Spectroscopy Evidence of 1,3,5-Tris(4-carboxyphenyl)benzene Binding to DNA: Anticancer Potential along with the Comparative Binding Profile of Intercalation via Modeling Studies

One of medicinal chemistry's top priorities is the discovery of new molecules with anticancer potential. Compounds that interact with DNA are an intriguing family of chemotherapeutic medications used to treat cancer. Studies in this area have uncovered a plethora of potential anticancer medicines, such as groove binding, alkylating, and intercalator compounds. The anticancer activity of DNA intercalators (molecules that intercalate between DNA base pairs) has drawn special interest. The current study investigated the promising anticancer drug 1,3,5-Tris(4-carboxyphenyl)benzene (H3BTB) against breast and cervical cancer cell lines. In addition, 1,3,5-Tris(4-carboxyphenyl)benzene binds to DNA by groove binding. The binding of H3BTB to DNA was found to be significant which unwinds the DNA helix. Considerable electrostatic and non-electrostatic contributions were present in the binding's free energy. The cytotoxic potential of H3BTB is effectively demonstrated by the computational study outcomes, which include molecular docking and molecular dynamics (MD) simulations. The minor groove binding for the H3BTB-DNA complex is supported by molecular docking research. This study will promote empirical investigation into the synthesis of metallic and non-metallic H3BTB derivatives and their potential use as bioactive molecules for the treatment of cancer.

The synergistic function of long and short forms of β4GalT1 in p53-mediated drug resistance in bladder cancer cells

β1,4-galactosyltransferase-1 (β4GalT1) is a type II membrane protein that catalyzes the transfer of galactose (Gal) from UDP-Gal to N-acetylglucosamine (GlcNAc) and forms a LacNAc structure. β4GalT1 has a long form (termed β4GalT1-L) and a short form (termed β4GalT1-S) in mammalian cells. Although β4GalT1 has been proven to play an important role in many biological and pathological processes, such as differentiation, immune responses and cancer development, the different functions of the two β4GalT1 forms remain ambiguous. In this study, we demonstrated that total β4GalT1 was upregulated in bladder cancer. Overexpression of β4GalT1-S, but not β4GalT1-L, increased drug resistance in bladder epithelial cells by upregulating p53 expression. Glycoproteomic analysis revealed that the substrate specificities of the two β4GalT1 forms were different. Among the LacNAcylated proteins, the E3 ligase MDM2 could be preferentially modified by β4GalT1-L compared to β4GalT1-S, and this modification could increase the binding of MDM2 and p53 and further facilitate the degradation of p53. Our data proved that the two forms of β4GalT1 could synergistically regulate p53-mediated cell survival under chemotherapy treatment. These results provide insights into the role of β4GalT1-L and β4GalT1-S and suggest their differentially important implications in the development of bladder cancer.

Targeting the "hallmarks of aging" to slow aging and treat age-related disease: fact or fiction?

Aging is a major risk factor for a number of chronic diseases, including neurodegenerative and cerebrovascular disorders. Aging processes have therefore been discussed as potential targets for the development of novel and broadly effective preventatives or therapeutics for age-related diseases, including those affecting the brain. Mechanisms thought to contribute to aging have been summarized under the term the "hallmarks of aging" and include a loss of proteostasis, mitochondrial dysfunction, altered nutrient sensing, telomere attrition, genomic instability, cellular senescence, stem cell exhaustion, epigenetic alterations and altered intercellular communication. We here examine key claims about the "hallmarks of aging". Our analysis reveals important weaknesses that preclude strong and definitive conclusions concerning a possible role of these processes in shaping organismal aging rate. Significant ambiguity arises from the overreliance on lifespan as a proxy marker for aging, the use of models with unclear relevance for organismal aging, and the use of study designs that do not allow to properly estimate intervention effects on aging rate. We also discuss future research directions that should be taken to clarify if and to what extent putative aging regulators do in fact interact with aging. These include multidimensional analytical frameworks as well as designs that facilitate the proper assessment of intervention effects on aging rate.

2,4-Dichlorophenoxyacetic acid (2,4-D) affects DNA integrity and retina structure in zebrafish larvae

Monitoring the potential risk of herbicides in non-target organisms is a crucial issue for environmental safety. 2,4-D is an herbicide of high environmental relevance that has been shown to exert toxic effects to soil and aquatic biota. In the present study, we investigated the possible genotoxic and retinal development effects of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide in early life stages zebrafish (Danio rerio). Genotoxicity was evaluated by measuring DNA damage using the comet assay and also by the mRNA expression of genes implicated in apoptosis and/or DNA repair. Retinal development toxicity was evaluated with histological approach. The results obtained revealed that 2,4-D alters DNA integrity of zebrafish larvae. Moreover, transcriptomic data showed a significant induction of p-53 and casp-3 genes and a significant decrease of lig-4 in larvae exposed to the highest tested concentration of 2,4-D (0.8 mg/L). This suggested that p-53 gene regulates the process of DNA repair and apoptosis with increased levels of 2,4-D. The histopathological analysis revealed that early exposure to 2,4-D damaged the structure of larvae retina. Overall, this study is the first to report the DNA damage, casp-3, lig-4 and p-53 regulation, as well as the ocular developmental toxicity in zebrafish larvae at environmentally relevant concentrations of 2,4-D herbicide.

Recent advances in the pharmacological targeting of ubiquitin-regulating enzymes in cancer

As a post-translational modification that has pivotal roles in protein degradation, ubiquitination ensures that intracellular proteins act in a precise spatial and temporal manner to regulate diversified cellular processes. Perturbation of the ubiquitin system contributes directly to the onset and progression of a wide variety of diseases, including various subtypes of cancer. This highly regulated system has been for years an active research area for drug discovery that is exemplified by several approved drugs. In this review, we will provide an update of the main breakthrough scientific discoveries that have been leading the clinical development of ubiquitin-targeting therapies in the last decade, with a special focus on E1 and E3 modulators. We will further discuss the unique challenges of identifying new potential therapeutic targets within this ubiquitous and highly complex machinery, based on available crystallographic structures, and explore chemical approaches by which these challenges might be met.

Recent findings on the role of wild-type and mutant p53 in cancer development and therapy

The p53 protein is a tumor suppressor encoded by the TP53 gene and consists of 393 amino acids with four main functional domains. This protein responds to various cellular stresses to regulate the expression of target genes, thereby causing DNA repair, cell cycle arrest, apoptosis, metabolic changes, and aging. Mutations in the TP53 gene and the functions of the wild-type p53 protein (wtp53) have been linked to various human cancers. Eight TP53 gene mutations are located in codons, constituting 28% of all p53 mutations. The p53 can be used as a biomarker for tumor progression and an excellent target for designing cancer treatment strategies. In wild-type p53-carrying cancers, abnormal signaling of the p53 pathway usually occurs due to other unusual settings, such as high MDM2 expression. These differences between cancer cell p53 and normal cells have made p53 one of the most important targets for cancer treatment. In this review, we have dealt with various issues, such as the relative contribution of wild-type p53 loss of function, including transactivation-dependent and transactivation-independent activities in oncogenic processes and their role in cancer development. We also discuss the role of p53 in the process of ferroptosis and its targeting in cancer treatment. Finally, we focus on p53-related drug delivery systems and investigate the challenges and solutions.

Genome Editing Approaches with CRISPR/Cas9 for Cancer Treatment: Critical Appraisal of Preclinical and Clinical Utility, Challenges, and Future Research

The increasing burden on human malignant diseases became a major concern for healthcare practitioners, that must deal with tumor relapse and the inability to efficiently treat metastasis, in addition to side effects. Throughout the decades, many therapeutic strategies have been employed to improve the clinical outcomes of cancer patients and great efforts have been made to develop more efficient and targeted medicines. The malignant cell is characterized by genetic and epigenetic modifications, therefore targeting those specific drivers of carcinogenesis is highly desirable. Among the genome editing technologies, CRISPR/Cas9 stood as a promising candidate for cancer treatment alternatives, due to its low complexity design. First described as a defense mechanism of bacteria against invading foreign DNA, later it was shown that CRISPR components can be engineered to target specific DNA sequences in a test tube, a discovery that was awarded later with the Nobel Prize in chemistry for its rapid expansion as a reliable genome editing tool in many fields of research, including medicine. The present paper aims of describing CRISPR/Cas9 potential targets for malignant disorders, and the approaches used for achieving this goal. Aside from preclinical studies, we also present the clinical trials that use CRISPR-based technology for therapeutic purposes of cancer. Finally, a summary of the presented studies adds a more focused view of the therapeutic value CRISPR/Cas9 holds and the associated shortcomings.

PIK3R3, a regulatory subunit of PI3K, modulates ovarian cancer stem cells and ovarian cancer development and progression by integrative analysis

Background

Ovarian cancer is the most lethal gynecologic disease and is one of the most commonly diagnosed cancers among women worldwide. The phosphatidylinositol 3-kinase (PI3K) family plays an important regulatory role in various cancer signaling pathways, including those involved in ovarian cancer development; however, its exact function remains to be fully understood. We conducted this study to understand the role of P13K in the molecular mechanisms underlying ovarian cancer development.

Methods

To determine the differential gene expression of phosphoinositide-3-kinase regulatory subunit 3 (PIK3R3), a regulatory subunit of PI3K, in normal, tumor, and metastatic ovary tissues, TNM plotter analysis was performed. The microarray dataset GSE53759 was downloaded from Gene Expression Omnibus. ROC plotter analysis was conducted to understand the potential of PIK3R3 as a predictive marker for effectiveness of therapy in ovarian cancer. muTarget was used to identify mutations that alter PIK3R3 expression in ovarian cancer. To determine the interacting partners for PIK3R3 in ovarian tissues, the interactome-atlas tool was used. The Kyoto encyclopedia of genes and genomes (KEGG) analysis was conducted to identify the pathways in which these interacting partners were primarily enriched.

Results

PIK3R3 was overexpressed in ovarian and metastatic tumors. Elevated PIK3R3 levels were observed in ovarian cancer stem cells, wherein inhibiting PIK3R3 expression significantly reduced the size of ovarian cancer spheroids. Treatment of ovarian cancer stem cells with PF-04691502 (10 μM), an inhibitor of both PI3K and mTOR kinases, also reduced the size of spheroids and the level of OCT4. PIK3R3 was highly expressed in ovarian cancer with several somatic mutations and was predicted better outcomes in patients undergoing Avastin® chemotherapy using bioinformatic tool. Protein interaction analysis showed that PIK3R3 interacts with 157 genes, including GRB2, EGFR, ERBB3, PTK2, HCK, IGF1R, YES1, and PIK3CA, in the ovary. KEGG enrichment analysis revealed that the interacting partners of PIK3R3 are involved in the ErbB signaling pathway, proteoglycans in cancer, FoxO, prolactin, chemokine, and insulin signaling pathways.

Conclusions

PIK3R3 plays a pivotal role in ovarian cancer development and is therefore a potential candidate for developing novel therapeutic approaches.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09807-7.

Potential clinical utility of liquid biopsies in ovarian cancer

BACKGROUND

Ovarian cancer (OC) is the most lethal gynecologic malignancy worldwide. One of the main challenges in the management of OC is the late clinical presentation of disease that results in poor survival. Conventional tissue biopsy methods and serological biomarkers such as CA-125 have limited clinical applications. Liquid biopsy is a novel sampling method that analyzes distinctive tumour components released into the peripheral circulation, including circulating tumour DNA (ctDNA), circulating tumour cells (CTCs), cell-free RNA (cfRNA), tumour-educated platelets (TEPs) and exosomes. Increasing evidence suggests that liquid biopsy could enhance the clinical management of OC by improving early diagnosis, predicting prognosis, detecting recurrence, and monitoring response to treatment. Capturing the unique tumour genetic landscape can also guide treatment decisions and the selection of appropriate targeted therapies. Key advantages of liquid biopsy include its non-invasive nature and feasibility, which allow for serial sampling and longitudinal monitoring of dynamic tumour changes over time. In this review, we outline the evidence for the clinical utility of each liquid biopsy component and review the advantages and current limitations of applying liquid biopsy in managing ovarian cancer. We also highlight future directions considering the current challenges and explore areas where more studies are warranted to elucidate its emerging clinical potential.

Bisdemethoxycurcumin sensitizes the response of cisplatin resistant non-small cell lung carcinoma cell lines by activating apoptosis and autophagy

Lung cancer belongs to the most frequent and deadliest cancer types worldwide, non-small cell lung carcinoma (NSCLC) being the most frequent type. Development of chemoresistance in NSCLC patients is common and responsible for bad outcome. Curcuminoids are naturally occurring substances with prominent cytotoxic effects in different cancer cells. Here we analyzed influence of bisdemethoxycurcumin (BDMC) on phenotype and molecular mechanisms in cisplatin-sensitive NSCLC cell lines (A549 and H460) and their cisplatin-resistant counterparts. NSCLC cell lines were exposed to BDMC and analyzed by cell viability, proliferation, and motility assays, as well as fluorescence-activated cell sorting. Immunoblotting was assessed to detect apoptosis and autophagy. Colony-formation assay and multicellular tumor spheroid model were used to investigate the effects of BDMC. Expression levels of different Hedgehog-pathway genes were determined by RT-qPCR analysis. We identified substantial cytotoxic effects of BDMC on NSCLC cells in general and on cisplatin-resistant NSCLC cells in special. BDMC markedly decreased the cell viability by inducing apoptosis and autophagy in a cell-type specific manner. BDMC emphasized cisplatin-induced cell death and inhibited cell cycle progression of cisplatin-resistant NSCLC cells. Scratch-closure, colony formation, and multicellular spheroid growth in cisplatin-resistant NSCLC cell lines were inhibited by BDMC. Expression profile analyses of different Hedgehog-pathway regulatory genes showed that Gli1, the mean transcriptional regulator of this pathway, was markedly decreased upon the BDMC treatment, this decrement being most prominent in cisplatin-resistant cells. Our data identified BDMC as a potent substance that may be suitable for combined cisplatin-based therapy in cisplatin-resistant subpopulation of NSCLC patients.

Results from a First-in-Human Phase I Study of Siremadlin (HDM201) in Patients with Advanced Wild-Type TP53 Solid Tumors and Acute Leukemia

PURPOSE

This phase I, dose-escalation study investigated the recommended dose for expansion (RDE) of siremadlin, a p53-MDM2 inhibitor, in patients with wild-type TP53 advanced solid or hematologic cancers.

PATIENTS AND METHODS

Initial dosing regimens were: 1A (day 1; 21-day cycle; dose 12.5-350 mg) and 2A (days 1-14; 28-day cycle; dose 1-20 mg). Alternative regimens included 1B (days 1 and 8; 28-day cycle) and 2C (days 1-7; 28-day cycle). The primary endpoint was incidence of dose-limiting toxicities (DLT) during cycle 1.

RESULTS

Overall, 115 patients with solid tumors and 93 with hematologic malignancies received treatment. DLTs occurred in 8/92 patients with solid tumors and 10/53 patients with hematologic malignancies. In solid tumors, an RDE of 120 mg was defined in 1B. In hematologic tumors, RDEs were defined in 1A: 250 mg, 1B: 120 mg, and 2C: 45 mg. More patients with hematologic malignancies compared with solid tumors experienced grade 3/4 treatment-related adverse events (71% vs. 45%), most commonly resulting from myelosuppression. These were more frequent and severe in patients with hematologic malignancies; 22 patients exhibited tumor lysis syndrome. Overall response rates at the RDEs were 10.3% [95% confidence interval (CI), 2.2-27.4] in solid tumors and 4.2% (95% CI, 0.1-21.1), 20% (95% CI, 4.3-48.1), and 22.2% (95% CI, 8.6-42.3) in acute myeloid leukemia (AML) in 1B, 1A, and 2C, respectively.

CONCLUSIONS

A common safety profile was identified and preliminary activity was noted, particularly in AML. Comprehensive investigation of dosing regimens yielded recommended doses/regimens for future combination studies.

Cytotoxicity, genotoxicity, and gene expression changes induced by methanolic extract of Moringa stenopetala leaf with LC-qTOF-MS metabolic profile

Moringa stenopetala (Baker f.) Cuf.and other Moringa species have traditionally been used to treat various diseases. The purpose of this study was to determine the cytotoxic and genotoxic effects of the methanolic extract of M. stenopetala leaf and its fractions on selected tumor cells. Cytotoxicity was determined by MTT assay. The comet assay was used toassess DNA damage, and gel electrophoresis was used to determine DNA fragmentation. Gene expression was analyzed by qPCR using two specific genes for each cancer cell line. Fractionation of the methanolic extract (E-1) on Diaion HP-20 yielded five fractions (Fr-2 to Fr-6); only Fr-4 and Fr-6 were cytotoxic to breast cancer cells (MCF-7; IC₅₀ = 58.3 ± 0.93 and 35.8 ± 2.44 μg/mL, respectively), human hepatocellular carcinoma cells (HepG2; IC₅₀ = 57.8 ± 1.57 and 39.3 ± 1.90 μg/mL, respectively), and Fr-4 was cytotoxic to human colon cancer cells (HCT-116; IC₅₀ = 94.2 ± 4.9 μg/mL). In addition, exposure of the cancer cells to Fr-4 and Fr-6 resulted in a high level of DNA damage. Moreover, relative expression of MTAP and CDKN2A in MCF-7 were increased, whereas expression of p21 and p53 in HCT-116, and APC and TERT in HepG2 were decreased, similar to that of doxorubicin. LC-qTOF-MS was used to identify metabolites in E-1, the majority of which were enriched in Fr-4. Two terpenes (loliolide and dihydroactinidiolide), the majority of the flavonoids, and niazirin were about two fold enriched in Fr-4, whereas the majority of the lipids were 4-10 fold enriched. However, Fr-6 hardly showed compounds other than the two terpenes that were enriched 1.5 and 7 fold. The findings suggest that Fr-4 and Fr-6 are promising sources of compounds possessing cytotoxic and genotoxic properties.

α-Mangostin Nanoparticles Cytotoxicity and Cell Death Modalities in Breast Cancer Cell Lines

α-Mangostin (AMG) is a potent anticancer xanthone that was discovered in mangosteen (Garcinia mangostana Linn.). AMG possesses the highest opportunity for chemopreventive and chemotherapeutic therapy. AMG inhibits every step in the process of carcinogenesis. AMG suppressed multiple breast cancer (BC) cell proliferation and apoptosis by decreasing the creation of cancerous compounds. Accumulating BC abnormalities and their associated molecular signaling pathways promotes novel treatment strategies. Chemotherapy is a commonly used treatment; due to the possibility of unpleasant side effects and multidrug resistance, there has been substantial progress in searching for alternative solutions, including the use of plant-derived natural chemicals. Due to the limitations of conventional cancer therapy, nanotechnology provides hope for effective and efficient cancer diagnosis and treatment. Nanotechnology enables the delivery of nanoparticles and increased solubility of drugs and drug targeting, resulting in increased cytotoxicity and cell death during BC treatment. This review summarizes the progress and development of AMG’s cytotoxicity and the mechanism of death BC cells. The combination of natural medicine and nanotechnology into a synergistic capital will provide various benefits. This information will aid in the development of AMG nanoparticle preparations and may open up new avenues for discovering an effective BC treatment.

A Novel Peptide Derived from Ginger Induces Apoptosis through the Modulation of p53, BAX, and BCL2 Expression in Leukemic Cell Lines

Despite the efficacy of chemotherapy, the adverse effects of chemotherapeutic drugs are considered a limitation of leukemia treatment. Therefore, a chemotherapy drug with minimal side effects is currently needed. One interesting molecule for this purpose is a bioactive peptide isolated from plants since it has less toxicity to normal cells. In this study, we extracted protein from the Zingiber officinale rhizome and performed purification to acquire the peptide fraction with the highest cytotoxicity using ultrafiltration, reverse-phase chromatography, and off-gel fractionation to get the peptide fraction that contained the highest cytotoxicity. Finally, a novel antileukemic peptide, P2 (sequence: RALGWSCL), was identified from the highest cytotoxicity fraction. The P2 peptide reduced the cell viability of NB4, MOLT4, and Raji cell lines without an effect on the normal peripheral blood mononuclear cells. The combination of P2 and daunorubicin significantly decreased leukemic cell viability when compared to treatment with either P2 or daunorubicin alone. In addition, leukemic cells treated with P2 demonstrated increased apoptosis and upregulation of caspase 3, 8, and 9 gene expression. Moreover, we also examined the effects of P2 on p53, which is the key regulator of apoptosis. Our results showed that treatment of leukemic cells with P2 led to the upregulation of p53 and Bcl-2-associated X protein, and the downregulation of B-cell lymphoma 2, indicating that p53 is involved in apoptosis induction by P2. The results of this study are anticipated to be useful for the development of P2 as an alternative drug for the treatment of leukemia.

The Role of p53 Expression in Patients with RAS/BRAF Wild-Type Metastatic Colorectal Cancer Receiving Irinotecan and Cetuximab as Later Line Treatment

Background

Preclinical and clinical data indicate that p53 expression might modulate the activity of the epidermal growth factor receptor (EGFR), influencing response/resistance to anti-EGFR monoclonal antibodies. However, the association between p53 status and clinical outcome has not been clarified yet.

Objective

In our study, we evaluated the role of p53 expression in patients with RAS/BRAF wild-type metastatic colorectal cancer (mCRC) receiving irinotecan/cetuximab in an exploratory and a validation cohort.

Patients and Methods

p53 expression was analysed in patients with RAS/BRAF wild-type mCRC receiving second-line or third-line irinotecan/cetuximab. Survival distribution was assessed by the Kaplan–Meier method, while the log-rank test was used for survival comparison.

Results

Among 120 patients with RAS/BRAF wild-type mCRC included in our analysis, 52 (59%) and 19 (59%) patients showed p53 overexpression in the exploratory and validation cohort, respectively. In the exploratory cohort, low p53 expression was correlated with better median progression-free survival (hazard ratio 0.39; p < 0.0001), median overall survival (hazard ratio: 0.23; p < 0.0001) and response rate (p < 0.0001). These results were confirmed by data of the validation cohort where we observed better median progression-free survival (hazard ratio: 0.48; p = 0.0399), median overall survival (hazard ratio: 0.26; p = 0.0027) and response rate (p =0.0007) in patients with p53 normal expression mCRC.

Conclusions

In our study, p53 overexpression was associated with anti-EGFR treatment resistance in patients with RAS/BRAF WT mCRC, as confirmed in a validation cohort. Larger studies are needed to validate the role of p53 and investigate EGFR cross-talk in these patients.

Inhibition mechanism of naphthylphenylamine derivatives acting on the CDC25B dual phosphatase and analysis of the molecular processes involved in the high cytotoxicity exerted by one selected derivative in melanoma cells

The dual phosphatases CDC25 are involved in cell cycle regulation and overexpressed in many tumours, including melanoma. CDC25 is a promising target for discovering anticancer drugs, and several studies focussed on characterisation of quinonoid CDC25 inhibitors, frequently causing undesired side toxic effects. Previous work described an optimisation of the inhibition properties by naphthylphenylamine (NPA) derivatives of NSC28620, a nonquinonoid CDC25 inhibitor. Now, the CDC25B•inhibitor interaction was investigated through fluorescence studies, shedding light on the different inhibition mechanism exerted by NPA derivatives. Among the molecular processes, mediating the specific and high cytotoxicity of one NPA derivative in melanoma cells, we observed decrease of phosphoAkt, increase of p53, reduction of CDC25 forms, cytochrome c cytosolic translocation and increase of caspase activity, that lead to the activation of an apoptotic programme. A basic knowledge on CDC25 inhibitors is relevant for discovering potent bioactive molecules, to be used as anticancer agents against the highly aggressive melanoma.

Synthesis and Preclinical Evaluation of Indole Triazole Conjugates as Microtubule Targeting Agents that are Effective against MCF-7 Breast Cancer Cell Lines

CDATA[Background: Microtubules are considered to be an important therapeutic target for most of the anticancer drugs. These are highly dynamic structures comprising of α-tubulin and β-tubulin which are usually heterodimers and found to be involved in cell movement, intracellular trafficking, and mitosis inhibition of which might kill the tumour cells or inhibit the abnormal proliferation of cells. Most of the tubulin polymerization inhibitors, such as Vinca alkaloids, consist of Indole as the main scaffold. The literature also suggests using triazole moiety in the chemical entities, potentiating the inhibitory activity against cell proliferation. So, in our study, we used indole triazole scaffolds to synthesize the derivatives against tubulin polymerization.

OBJECTIVE

The main objective of this study to synthesize indole triazole conjugates by using environmentally friendly solvents (green chemistry) and click chemistry. To carry out the MTT assay and tubulin polymerization assay for the synthesized indole triazole conjugates.

METHODS

All the synthesized molecules were subjected to molecular docking studies using Schrodinger suite and the structural confirmation was performed by Mass, proton-NMR and carbon-NMR, documented in DMSO and CDCL3. Biological studies were performed using DU145 (prostate cancer), A-549 (lung cancer) and, MCF-7 (breast cancer), cell lines obtained from ATCC were maintained as a continuous culture. MTT assay was performed for the analogues using standard protocol. Cell cycle analysis was carried out using flow cytometry.

RESULTS

The Indole triazole scaffolds were synthesized using the principles of Green chemistry. The triazole formation is mainly achieved by using the Click chemistry approach. Structural elucidation of synthesized compounds was performed using Mass spectroscopy (HR-MS), Proton-Nuclear Magnetic Spectroscopy (¹H-NMR) and Carbon-Nuclear Magnetic Spectroscopy (¹³C-NMR). The XP-docked poses and free energy binding calculations revealed that 2c and 2g molecules exhibited the highest docking affinity against the tubulin-colchicine domain (PDB:1SA0). In vitro cytotoxic assessment revealed that 2c and 2g displayed promising cytotoxicity in MTT assay (with CTC50 values 3.52μM and 2.37μM) which are in good agreement with the computational results. 2c and 2g also arrested 63 and 66% of cells in the G₂/M phase, respectively, in comparison to control cells (10%) and tubulin polymerization inhibition assay revealed that 2c and 2g exhibited significant inhibition of tubulin polymerization with IC₅₀ values of 2.31μM, and 2.62μM, respectively in comparison to Nocodazole, a positive control, resulted in an IC₅₀ value of 2.51μM.

CONCLUSION

Indole triazole hybrids were synthesized using click chemistry, and docking studies were carried out using Schrodinger for the designed molecules. Process Optimization has been done for both the schemes. Twelve compounds (2a-2l) have been successfully synthesized and analytical evaluation was performed using NMR and HR-MS. In vitro evaluation was for the synthesized molecules to check tubulin polymerization inhibition for antiproliferative action. Among the synthesized compounds, 2c and 2g have potent anticancer activities by inhibiting tubulin polymerization.

Cellular Mechanism of Gene Mutations and Potential Therapeutic Targets in Ovarian Cancer

Ovarian cancer is a common and complex malignancy with poor prognostic outcome. Most women with ovarian cancer are diagnosed with advanced stage disease due to a lack of effective detection strategies in the early stage. Traditional treatment with cytoreductive surgery and platinum-based combination chemotherapy has not significantly improved prognosis and 5-year survival rates are still extremely poor. Therefore, novel treatment strategies are needed to improve the treatment of ovarian cancer patients. Recent advances of next generation sequencing technologies have both confirmed previous known mutated genes and discovered novel candidate genes in ovarian cancer. In this review, we illustrate recent advances in identifying ovarian cancer gene mutations, including those of TP53, BRCA1/2, PIK3CA, and KRAS genes. In addition, we discuss advances in targeting therapies for ovarian cancer based on these mutated genes in ovarian cancer. Further, we associate between detection of mutation genes by liquid biopsy and the potential early diagnostic value in ovarian cancer.

Distinct Classes of Flavonoids and Epigallocatechin Gallate, Polyphenol Affects an Oncogenic Mutant p53 Protein, Cell Growth and Invasion in a TNBC Breast Cancer Cell Line

Mutant p53(s) are widely considered as oncogenes and promote several gain-of-function oncogenic activities. p53 mutations correlate with higher rates of metastasis and poor survival; therefore, it is paramount to inhibit mutant p53 protein either directly or indirectly. Although some compounds have been developed, none of them have achieved a desirable level of specificity. Some of these compounds only targeted specific mutations. In search of less-toxic compounds, we tested plant-derived compounds on mutant p53 triple-negative breast cancer cell lines. Here, we show that the compounds tested reduced the protein levels of one of the more frequent oncogenic p53 mutants (R249S; hot spot mutation), and its important targets that promote invasion and metastasis, including GMPS and IMPDH1. All compounds tested perturbed the invasion potential of the breast cancer cell line. These compounds downregulated several nucleotide metabolism genes (NMGs) which are essential for cell cycle progression. We observed S-phase arrest correlating to reduced cell proliferation and increased replication stress. Moreover, we also show a reduction of key ETS transcription family members including ETS2, ETS1, ETV1, and ETV4, which are involved in invasion and metastasis. We propose that these compounds may inhibit invasion by interfering with multiple pathways. Our findings exemplify that these tested compounds could inhibit invasion and cell growth in TNBC in a nucleotide-dependent manner.

Protopine/Gemcitabine Combination Induces Cytotoxic or Cytoprotective Effects in Cell Type-Specific and Dose-Dependent Manner on Human Cancer and Normal Cells

The natural alkaloid protopine (PRO) exhibits pharmacological properties including anticancer activity. We investigated the effects of PRO, alone and in combination with the chemotherapeutic gemcitabine (GEM), on human tumor cell lines and non-tumor human dermal fibroblasts (HDFs). We found that treatments with different PRO/GEM combinations were cytotoxic or cytoprotective, depending on concentration and cell type. PRO/GEM decreased viability in pancreatic cancer MIA PaCa-2 and PANC-1 cells, while it rescued the GEM-induced viability decline in HDFs and in tumor MCF-7 cells. Moreover, PRO/GEM decreased G1, S and G2/M phases, concomitantly with an increase of subG1 phase in MIA PaCa-2 and PANC-1 cells. Differently, PRO/GEM restored the normal progression of the cell cycle, altered by GEM, and decreased cell death in HDFs. PRO alone increased mitochondrial reactive oxygen species (ROS) in MIA PaCa-2, PANC-1 cells and HDFs, while PRO/GEM increased both intracellular and mitochondrial ROS in the three cell lines. These results indicate that specific combinations of PRO/GEM may be used to induce cytotoxic effects in pancreatic tumor MIA PaCa-2 and PANC-1 cells, but have cytoprotective or no effects in HDFs.

p21WAF1/CIP1 promotes p53 protein degradation by facilitating p53-Wip1 and p53-Mdm2 interaction

Downregulation of the p53 tumor suppressor in cancers is frequently accompanied by the upregulation of Wip1 (a phosphatase) and Mdm2 (an E3 ubiquitin ligase). Mdm2 binds and ubiquitinates p53, promoting its degradation by the proteasome. As the p53/Mdm2 interaction is alleviated by the phosphorylation of the serine-15 (S15) residue of p53, Wip1, which can directly dephosphorylate phospho-S15, facilitates the Mdm2-mediated degradation of p53. Here, we found that p21^WAF1/CIP1, previously shown to bind p53 and Mdm2, reduces the cellular levels of p53 protein by decreasing its stability. This is accompanied by a decrease in p53-S15 phosphorylation levels. In agreement, p21 promotes the p53/Wip1 interaction. Additionally, p21 interacts with Wip1, forming a trimeric complex of p53, p21, and Wip1. Studies using a p21 deletion mutant that cannot bind p53 revealed that the p53/p21 complex is more efficient than p53 alone in facilitating the binding of p53 to Wip1 and Mdm2. These findings indicate that p21 is a novel negative regulator of p53 stability and therefore, may be used as a target to restore p53 activity by preventing the action of Wip1 and Mdm2 on p53.

BRD7 inhibits tumor progression by positively regulating the p53 pathway in hepatocellular carcinoma

Background: Bromodomain-containing protein 7 (BRD7) is identified as a transcriptional regulator and plays an important role in the development and progression of various tumors. Our previous study demonstrated that BRD7 acts as a potential tumor suppressor in hepatocellular carcinoma (HCC). However, the specific molecular mechanism underlying the BRD7-mediated inhibition of HCC progression remains poorly understood.

Methods: We performed ChIP-seq analysis to investigate the gene network mediated by BRD7. Immunohistochemical analysis was performed to analyze potential associations between the p53 and BRD7 expression and the effect of their overexpression on disease pathogenesis and outcome. In addition, we performed biological function experiments to determine the effect of BRD7 and p53 on these functions that are central to tumorigenesis. Finally, we employed a BALB/c model for execution of xenograft transplants to examine the effect of either overexpressing or under-expressing BRD7 and p53 on tumor growth in mice injected with cells.

Results: Our results suggested that BRD7 regulates the p53 pathway. Specifically, BRD7 was demonstrated to upregulate the transcription level of p53 by directly binding to the upstream regulatory region of the p53 transcriptional initiation site, thereby enhancing its promoter activity. Moreover, immunohistochemical analysis showed that wild-type p53 (WTp53) expression is positively associated with BRD7 expression and survival of patients with HCC. Additionally,changes of p53 expression could affect the tumor suppressive role of BRD7 on HCC cell proliferation, migration/invasion, cell-cycle, and tumor growth in vitro and in vivo. Furthermore, changes of BRD7 expression in HCC cells significantly altered the expression of p53 signal-related molecules such as p21, Bax, Bcl2, and cyclin D1, indicating that BRD7 may positively regulate activation of the p53 pathway.

Conclusions: Collectively, our results indicated that BRD7 exerts anti-tumor effects in HCC through transcriptionally activating p53 pathway. These critical roles of BRD7may provide some promising diagnostic and therapeutic targets for HCC.

The Intricate Role of p53 in Adipocyte Differentiation and Function

For more than three decades, numerous studies have demonstrated the function of p53 in cell cycle, cellular senescence, autophagy, apoptosis, and metabolism. Among diverse functions, the essential role of p53 is to maintain cellular homeostatic response to stress by regulating proliferation and apoptosis. Recently, adipocytes have been studied with increasing intensity owing to the increased prevalence of metabolic diseases posing a serious public health concern and because metabolic dysfunction can directly induce tumorigenesis. The prevalence of metabolic diseases has steadily increased worldwide, and a growing interest in these diseases has led to the focus on the role of p53 in metabolism and adipocyte differentiation with or without metabolic stress. However, our collective understanding of the direct role of p53 in adipocyte differentiation and function remains insufficient. Therefore, this review focuses on the newly discovered roles of p53 in adipocyte differentiation and function.

Induction of Redox-Mediated Cell Death in ER-Positive and ER-Negative Breast Cancer Cells by a Copper(II)-Phenolate Complex: An In Vitro and In Silico Study

This research was aimed at finding the cytotoxic potential of the mixed ligand copper(II) complex [Cu(tdp)(phen)](ClO₄)—where H(tdp) is the tetradentate ligand 2-[(2-(2-hydroxyethylamino)-ethylimino)methyl]phenol, and phen is 1,10-phenanthroline—to two genotypically different breast cancer cells, MCF-7 (p53⁺ and ER⁺) and MDA-MB-231 (p53^- and ER^-). The complex has been already shown to be cytotoxic to ME180 cervical carcinoma cells. The special focus in this study was the induction of cell death by apoptosis and necrosis, and its link with ROS. The treatment brought about nuclear fragmentation, phosphatidylserine externalization, disruption of mitochondrial trans-membrane potential, DNA damage, cell cycle arrest at sub-G1 phase, and increase of ROS generation, followed by apoptotic death of cells during early hours and a late onset of necrosis in the cells surviving the apoptosis. The efficacy of the complex against genotypically different breast cancer cells is attributed to a strong association through p53-mitochondrial redox—cell cycle junction. The ADMET properties and docking of the complex at the active site of Top1 are desirable attributes of a lead molecule for development into a therapeutic. Thus, it is shown that the copper(II)–phenolate complex[Cu(tdp)(phen)]⁺ offers potential to be developed into a therapeutic for breast cancers in general and ER-negative ones in particular.

RBM10, a New Regulator of p53

The tumor suppressor p53 acts as a transcription factor that regulates the expression of a number of genes responsible for DNA repair, cell cycle arrest, metabolism, cell migration, angiogenesis, ferroptosis, senescence, and apoptosis. It is the most commonly silenced or mutated gene in cancer, as approximately 50% of all types of human cancers harbor TP53 mutations. Activation of p53 is detrimental to normal cells, thus it is tightly regulated via multiple mechanisms. One of the recently identified regulators of p53 is RNA-binding motif protein 10 (RBM10). RBM10 is an RNA-binding protein frequently deleted or mutated in cancer cells. Its loss of function results in various deformities, such as cleft palate and malformation of the heart, and diseases such as lung adenocarcinoma. In addition, RBM10 mutations are frequently observed in lung adenocarcinomas, colorectal carcinomas, and pancreatic ductal adenocarcinomas. RBM10 plays a regulatory role in alternative splicing. Several recent studies not only linked this splicing regulation of RBM10 to cancer development, but also bridged RBM10's anticancer function to the p53 pathway. This review will focus on the current progress in our understanding of RBM10 regulation of p53, and its role in p53-dependent cancer prevention.

Anti-tyrosinase, anti-cholinesterase and cytotoxic activities of extracts and phytochemicals from the Tunisian Citharexylum spinosum L.: Molecular docking and SAR analysis

Previously phytochemical investigations carried out on the flowers and trunk bark extracts of Citharexylum spinosum L. tree, allowed the isolation of twenty molecules belonging to several families of natural substances [triterpene acids, iridoid glycosides, phenylethanoid glycosides, 8,3'-neolignan glycosides, together with other phenolic compounds]. In the present work, a biological evaluation (anti-tyrosinase, anticholinesterase and cytotoxic activities) was performed on the prepared extracts and the isolated secondary metabolites. The results showed that the EtOAc extract of the trunk bark displayed the highest anti-tyrosinase effect with a percent inhibition of 55.0 ± 1.8% at a concentration of 100 µg/mL. The highest anticholinesterase activity was presented by the same extract with an IC₅₀ value of 99.97 ± 3.01 µg/mL. The EtOAc extract of flowers and that of the trunk bark displayed the best cytotoxic property with IC₅₀ values of 96.00 ± 2.85 and 88.75 ± 2.00 µg/mL, respectively, against the human cervical cancer cell line (HeLa), and IC₅₀ values of 188.23 ± 3.88 and 197.00 ± 4.25 µg/mL, respectively, against the human lung cancer (A549) cell lines. Biological investigation of the pure compounds showed that the two 8,3'-neolignan glycosides, plucheosides D₁-D₂, generate the highest anti-tyrosinase potency with a percent inhibition of 61.4 ± 2.0 and 79.5 ± 2.3%, respectively, at a concentration of 100 µM. The iridoid glycosides exhibited a significant anticholinesterase activity with IC₅₀ values ranging from 17.19 ± 1.02 to 52.24 ± 2.50 µM. Triterpene pentacyclic acids and iridoid glycosides exerted encouraging cytotoxic effects against HeLa with IC₅₀ values ranging from 9.00 ± 1.10 to 25.00 ± 1.00 µM. The study of the structure-activity relationship (SAR) has been sufficiently and widely discussed. The natural compounds that exhibited the significant bioactivities were docked.

Synthesis, Antiproliferative and Cytotoxic Activities, DNA Binding Features and Molecular Docking Study of Novel Enamine Derivatives

Novel enamine derivatives were synthesized from the reaction of lactone and chalcones and their antiproliferative and cytotoxic activities against six cancer cell lines (e. g., HeLa, HT29, A549, MCF7, PC3 and Hep3B) and one normal cell lines (e. g., FL) were investigated along with their mode of interactions with CT-DNA. Most of the enamine derivatives with IC₅₀ values of 86-168 μM demonstrated much stronger antiproliferative activity than the starting molecules against the cancer cells. While, among the enamine derivatives, four compounds displayed higher cytotoxic potency than the control drugs (5-fluorouracil and cisplatin) against the Hep3B cell lines, these compounds did not exhibit any significant toxicity against normal cells, FL. The UV/VIS spectral data suggest that eight compounds cause hypochromism with a slight bathochromic shift (∼6 nm), indicating that they bind to the DNA by way of an intercalative or minor groove binding mode. The binding constants of the compounds are in the range of 0.1×103 M^-1 -2.3×104 M^-1 . The antiproliferative activity of studied enamine derivatives could possibly be due to their DNA binding as well as their cytotoxic properties. In addition to these assays, the chalcones and enamine derivatives were investigated by molecular docking to calculate the synergistic effect of antiproliferative activities against six human cancer cell lines.

The novel camptothecin derivative, CPT211, induces cell cycle arrest and apoptosis in models of human breast cancer

OBJECTIVE

Breast cancer is the second leading cause of cancer deaths in women worldwide and represents a highly aggressive nature with limited therapeutic options; thus, investigating novel therapeutic agents for breast cancer is much needed. In this study, we investigated the anticancer effects of a novel camptothecin derivative, CPT211, against human breast cancer.

METHODS

We used hormone receptor-positive MCF-7, triple-negative (TNBC) MDA-MB-231, and HER2-positive BT-474 human breast cancer cells to examine cytotoxicity of CPT211. We measured cell viability with dose dependence of CPT211 treatments by an MTT assay and investigated the potential underlying mechanism through flow cytometric and Western blot methods. Furthermore, we evaluated the efficacy of the treatment combination of CPT211 and doxorubicin in a mouse model bearing MDA-MB-231 xenografts.

RESULTS

CPT211 treatment led to dose-dependent decreases in cell viability of both MCF-7 and MDA-MB-231 cells, but not BT-474 cells. Analysis of the underlying molecular mechanism revealed that CPT211 activated p53-mediated apoptosis, by triggering intrinsic and extrinsic apoptotic pathways in MCF-7 cells. Additionally, CPT211 induced apoptosis and cell cycle arrest of MDA-MB-231 cells by activating Fas/FADD/caspase-8 signaling, suggesting that CPT211-mediated MDA-MB-231 cell apoptosis may occur through an extrinsic apoptosis pathway. CPT211 treatment with doxorubicin in mice bearing MDA-MB-231 xenografts was shown to enhance caspase-8 and caspase-7 activation, resulting in significant inhibition of tumor growth.

CONCLUSIONS

These results indicate that Fas/FADD/caspase-8 activation plays an important role in CPT211-mediated tumor growth suppression in TNBC, and the novel camptothecin derivative, CPT211, can be exploited for specific targeted therapies and potentially improve approaches to combination treatments for human breast cancer.

Effect of COL4A1 Expression on the Survival of Neoadjuvant Chemotherapy Breast Cancer Patients

Optimal therapy for each patient depends on their subtype, anatomic cancer stage, gene status, and preferences. Neoadjuvant chemotherapy-treated tumors have shown attenuated tumor growth, but the therapy cannot completely reduce tumor cell dissemination to blood stream and distant metastasis. Though it has been indicated that the protein of the collagen type IV alpha 1 (COL4A1) gene is induced by p53 to inhibit angiogenesis and tumorigenic activity in cancer cells, its prognostic significance in breast cancer (BC) patients has not yet been fully elucidated. We analysed 206 BC and fresh paired-match adjacent normal breast tissue from tissue microarrays (TMAs) and COL4A1-stained TMAs using immunohistochemistry. These were used to evaluate COL4A1 expression in BC and to analyse the relationship between this expression and clinicopathological factors and prognosis. The expression of the COL4A1 protein was significantly higher in normal adjacent tissue than in the tumor tissues of BC (P < 0.0001). The low COL4A1 expression of the BC patients had decreased metastasis incidence ratio than those exhibiting high COL4A1 expression (P=0.034). Low COL4A1 expression in the tumor cells of BC patients was found to significantly reduce the overall survival (OS) and relapse-free survival (RFS) rates of neoadjuvant chemotherapy patients (P=0.047 and P=0.025, respectively). We also validated the results to ensure their consistency with a web server program for survival analysis from the Cancer Genome Atlas (TCGA) database (P=0.057). Additionally, COL4A1 expression was positively correlated with p53 expression (P=0.00076). Thus, we present clinical evidence that COL4A1 expression can be used as a biomarker of better prognosis of BC patients receiving neoadjuvant chemotherapy.

Recent Small-Molecule Inhibitors of the p53-MDM2 Protein-Protein Interaction

This review presents the last decade of studies on the synthesis of various types of small-molecule inhibitors of the p53- Mouse double minute 2 homolog (MDM2) protein-protein interaction. The main focus is placed on synthetic approaches to such molecules, their cytotoxicity, and MDM2 binding characteristics.

Cancer Cells Employ Nuclear Caspase-8 to Overcome the p53-Dependent G2/M Checkpoint through Cleavage of USP28

Cytosolic caspase-8 is a mediator of death receptor signaling. While caspase-8 expression is lost in some tumors, it is increased in others, indicating a conditional pro-survival function of caspase-8 in cancer. Here, we show that tumor cells employ DNA-damage-induced nuclear caspase-8 to override the p53-dependent G2/M cell-cycle checkpoint. Caspase-8 is upregulated and localized to the nucleus in multiple human cancers, correlating with treatment resistance and poor clinical outcome. Depletion of caspase-8 causes G2/M arrest, stabilization of p53, and induction of p53-dependent intrinsic apoptosis in tumor cells. In the nucleus, caspase-8 cleaves and inactivates the ubiquitin-specific peptidase 28 (USP28), preventing USP28 from de-ubiquitinating and stabilizing wild-type p53. This results in de facto p53 protein loss, switching cell fate from apoptosis toward mitosis. In summary, our work identifies a non-canonical role of caspase-8 exploited by cancer cells to override the p53-dependent G2/M cell-cycle checkpoint.

Assessment of acyl-CoA cholesterol acyltransferase (ACAT-1) role in ovarian cancer progression-An in vitro study

Abnormal accumulation of acyl-CoA cholesterol acyltransferase-1 (ACAT-1) mediated cholesterol ester has been shown to contribute to cancer progression in various cancers including leukemia, glioma, breast, pancreatic and prostate cancers. However, the significance of ACAT-1 and cholesterol esters (CE) is relatively understudied in ovarian cancer. In this in vitro study, we assessed the expression and contribution of ACAT-1 in ovarian cancer progression. We observed a significant increase in the expression of ACAT-1 and CE levels in a panel of ovarian cancer cell lines (OC-314, SKOV-3 and IGROV-1) compared to primary ovarian epithelial cells (normal controls). To confirm the tumor promoting capacity of ACAT-1, we inhibited ACAT-1 expression and activity by treating our cell lines with an ACAT inhibitor, avasimibe, or by stable transfection with ACAT-1 specific short hairpin RNA (shRNA). We observed significant suppression of cell proliferation, migration and invasion in ACAT-1 knockdown ovarian cancer cell lines compared to their respective controls (cell lines transfected with scrambled shRNA). ACAT-1 inhibition enhanced apoptosis with a concurrent increase in caspases 3/7 activity and decreased mitochondrial membrane potential. Increased generation of reactive oxygen species (ROS) coupled with increased expression of p53 may be the mechanism(s) underlying pro-apoptotic action of ACAT-1 inhibition. Additionally, ACAT-1 inhibited ovarian cancer cell lines displayed enhanced chemosensitivity to cisplatin treatment. These results suggest ACAT-1 may be a potential new target for the treatment of ovarian cancer.

Effect of new olivacine derivatives on p53 protein level

BACKGROUND

The p53 protein is a transcription factor for many genes, including genes involved in inhibiting cell proliferation and inducing apoptosis in genotoxically damaged and tumor-transformed cells. In more than 55% of cases of human cancers, loss of the essential function of p53 protein is found. In numerous reports, it has been shown that small molecules (chemical compounds) can restore the suppressor function of the mutant p53 protein in tumor cells. The aim of this study was to evaluate the potential anticancer activity of three newly synthesized olivacine derivatives.

METHODS

The study was performed using two cell lines-CCRF/CEM (containing the mutant p53 protein) and A549 (containing a non-mutant, wild-type p53 protein). The cells were incubated with olivacine derivatives for 18 h and then assays were carried out: measurement of the amount of p53 and p21 proteins, detection of apoptosis, cell cycle analysis, and rhodamine 123 accumulation assay (evaluation of P-glycoprotein inhibition). Multiple-criteria decision analysis was used to compare the anticancer activity of the tested compounds.

RESULTS

Each tested compound caused the reconstitution of suppressor activity of the p53 protein in cells with the mutant protein. In addition, one of the compounds showed significant antitumor activity in both wild-type and mutant cells. For all compounds, a stronger effect on the level of the p53 protein was observed than for the reference compound-ellipticine.

CONCLUSIONS

The observed effects of the tested new olivacine derivatives (pyridocarbazoles) suggest that they are good candidates for new anticancer drugs.

Identification of miRNA-Based Signature as a Novel Potential Prognostic Biomarker in Patients with Breast Cancer

To identify the novel, noninvasive biomarkers to assess the outcome and prognosis of breast cancer (BC), patients with high sensitivity and specificity are greatly desired. Herein, the miRNA expression profile and matched clinical features of BC patients were extracted from The Cancer Genome Atlas (TCGA) database. The preliminary candidates were screened out by the univariate Cox regression test. Then, with the help of LASSO Cox regression analysis, the hsa-let-7b, hsa-mir-101-2, hsa-mir-135a-2, hsa-mir-22, hsa-mir-30a, hsa-mir-31, hsa-mir-3130-1, hsa-mir-320b-1, hsa-mir-3678, hsa-mir-4662a, hsa-mir-4772, hsa-mir-493, hsa-mir-556, hsa-mir-652, hsa-mir-6733, hsa-mir-874, and hsa-mir-9-3 were selected to construct the overall survival (OS) predicting signature, while the hsa-mir-130a, hsa-mir-204, hsa-mir-217, hsa-mir-223, hsa-mir-24-2, hsa-mir-29b-1, hsa-mir-363, hsa-mir-5001, hsa-mir-514a-1, hsa-mir-624, hsa-mir-639, hsa-mir-659, and hsa-mir-6892 were adopted to establish the recurrence-free survival (RFS) predicting signature. Referring to the median risk scores generated by the OS and RFS formulas, respectively, subgroup patients with high risk were strongly related to a poor OS and RFS revealed by Kaplan-Meier (K-M) plots. Meanwhile, receiver operating curve (ROC) analysis validated the accuracy and stability of these two signatures. When stratified by clinical features, such as tumor stage, age, and molecular subtypes, we found that the miRNA-based OS and RFS classifiers were still significant in predicting OS/RFS and showed the best predictive values than any other features. Besides, functional prediction analyses showed that these targeted genes of the enrolled miRNAs were enriched in cancer-associated pathways, such as MAPK/RTK, Ras, and PI3K-Akt signaling pathways. In summary, our observations demonstrate that the novel miRNA-based OS and RFS signatures are independent prognostic indicators for BC patients and worthy to be validated by further prospective studies.

Synthesis, structural characterisation, and cytotoxicity studies of Bi, W, and Mo containing homo- and hetero-bimetallic polyoxometalates

Three new and different homo- and hetero-bimetallic polyoxometalate (POM) species have been synthesised by simple one-pot synthetic methods utilising naturally occurring bismite (Bi₂O₃) (or Bi(NO₃)₃·5H₂O) and aryl sulfonic acids. The POM species isolated are (NH₄)₁₄[Bi₂W₂₂O₇₆]·14H₂O (1·14H₂O), (NH₄)[Bi(DMSO)₇][Mo₈O₂₆]·H₂O (2·H₂O) and [(NH₄)₄(Mo₃₆O₁₀₈(OH)₄·16H₂O)]·45H₂O (3·45H₂O). The compounds have been characterised by X-ray crystallography, energy dispersive X-ray spectroscopy (EDX), powdered X-ray diffraction (PXRD), mass spectrometry (ESI-MS), Raman spectroscopy, thermogravimetric (TGA) and ICP analyis. In vitro cytoxicity and proliferation studies conducted on 1 and 3, highlight the low toxicity of these species.

Major obstacles to doxorubicin therapy: Cardiotoxicity and drug resistance

Background

Doxorubicin is one of the most commonly prescribed and time-tested anticancer drugs. Although being considered as a first line drug in different types of cancers, the two main obstacles to doxorubicin therapy are drug-induced cardiotoxicity and drug resistance.

Method

The study utilizes systemic reviews on publications of previous studies obtained from scholarly journal databases including PubMed, Medline, Ebsco Host, Google Scholar, and Cochrane. The study utilizes secondary information obtained from health organizations using filters and keywords to sustain information relevancy. The study utilizes information retrieved from studies captured in the peer-reviewed journals on “doxorubicin-induced cardiotoxicity” and “doxorubicin resistance.”

Discussion and results

The exact mechanisms of cardiotoxicity are not known; various hypotheses are studied. Doxorubicin can lead to free radical generation in various ways. The commonly proposed underlying mechanisms promoting doxorubicin resistance are the expression of multidrug resistance proteins as well as other causes.

Conclusion

In this review, we have described the major obstacles to doxorubicin therapy, doxorubicin-induced cardiotoxicity as well as the mechanisms of cancer drug resistance and in following the treatment failures.

TP53 in bone and soft tissue sarcomas

Genomic and functional study of existing and emerging sarcoma targets, such as fusion proteins, chromosomal aberrations, reduced tumor suppressor activity, and oncogenic drivers, is broadening our understanding of sarcomagenesis. Among these mechanisms, the tumor suppressor p53 (TP53) plays significant roles in the suppression of bone and soft tissue sarcoma progression. Although mutations in TP53 were thought to be relatively low in sarcomas, modern techniques including whole-genome sequencing have recently illuminated unappreciated alterations in TP53 in osteosarcoma. In addition, oncogenic gain-of-function activities of missense mutant p53 (mutp53) have been reported in sarcomas. Moreover, new targeting strategies for TP53 have been discovered: restoration of wild-type p53 (wtp53) activity through inhibition of TP53 negative regulators, reactivation of the wtp53 activity from mutp53, depletion of mutp53, and targeting of vulnerabilities in cells with TP53 deletions or mutations. These discoveries enable development of novel therapeutic strategies for therapy-resistant sarcomas. We have outlined nine bone and soft tissue sarcomas for which TP53 plays a crucial tumor suppressive role. These include osteosarcoma, Ewing sarcoma, chondrosarcoma, rhabdomyosarcoma (RMS), leiomyosarcoma (LMS), synovial sarcoma, liposarcoma (LPS), angiosarcoma, and undifferentiated pleomorphic sarcoma (UPS).