p53 amyloid aggregation in cancer: function, mechanism, and therapy

Oncogenic R248W mutation induced conformational perturbation of the p53 core domain and the structural protection by proteomimetic amyloid inhibitor ADH-6

The involvement of p53 aggregation in cancer pathogenesis emphasizes the importance of unraveling the mechanisms underlying mutation-induced p53 destabilization. And understanding how small molecule inhibitors prevent the conversion of p53 into aggregation-primed conformations is pivotal for the development of therapeutics targeting p53-aggregation-associated cancers. A recent experimental study highlights the efficacy of the proteomimetic amyloid inhibitor ADH-6 in stabilizing R248W p53 and inhibiting its aggregation in cancer cells by interacting with the p53 core domain (p53C). However, it remains mostly unclear how R248W mutation induces destabilization of p53C and how ADH-6 stabilizes this p53C mutant and inhibits its aggregation. Herein, we conducted all-atom molecular dynamics simulations of R248W p53C in the absence and presence of ADH-6, as well as that of wild-type (WT) p53C. Our simulations reveal that the R248W mutation results in a shift of helix H2 and β-hairpin S2-S2' towards the mutation site, leading to the destruction of their neighboring β-sheet structure. This further facilitates the formation of a cavity in the hydrophobic core, and reduces the stability of the β-sandwich. Importantly, two crucial aggregation-prone regions (APRs) S9 and S10 are disturbed and more exposed to solvent in R248W p53C, which is conducive to p53C aggregation. Intriguingly, ADH-6 dynamically binds to the mutation site and multiple destabilized regions in R248W p53C, partially inhibiting the shift of helix H2 and β-hairpin S2-S2', thus preventing the disruption of the β-sheets and the formation of the cavity. ADH-6 also reduces the solvent exposure of APRs S9 and S10, which disfavors the aggregation of R248W p53C. Moreover, ADH-6 can preserve the WT-like dynamical network of R248W p53C. Our study elucidates the mechanisms underlying the oncogenic R248W mutation induced p53C destabilization and the structural protection of p53C by ADH-6.

Understanding the complexity of p53 in a new era of tumor suppression

p53 was discovered 45 years ago as an SV40 large T antigen binding protein, coded by the most frequently mutated TP53 gene in human cancers. As a transcription factor, p53 is tightly regulated by a rich network of post-translational modifications to execute its diverse functions in tumor suppression. Although early studies established p53-mediated cell-cycle arrest, apoptosis, and senescence as the classic barriers in cancer development, a growing number of new functions of p53 have been discovered and the scope of p53-mediated anti-tumor activity is largely expanded. Here, we review the complexity of different layers of p53 regulation, and the recent advance of the p53 pathway in metabolism, ferroptosis, immunity, and others that contribute to tumor suppression. We also discuss the challenge regarding how to activate p53 function specifically effective in inhibiting tumor growth without harming normal homeostasis for cancer therapy.

Developing theragnostics for Alzheimer's disease: Insights from cancer treatment

The prevalence of Alzheimer's disease (AD) and its associated economic and societal burdens are on the rise, but there are no curative treatments for AD. Interestingly, this neurodegenerative disease shares several biological and pathophysiological features with cancer, including cell-cycle dysregulation, angiogenesis, mitochondrial dysfunction, protein misfolding, and DNA damage. However, the genetic factors contributing to the overlap in biological processes between cancer and AD have not been actively studied. In this review, we discuss the shared biological features of cancer and AD, the molecular targets of anticancer drugs, and therapeutic approaches. First, we outline the common biological features of cancer and AD. Second, we describe several anticancer drugs, their molecular targets, and their effects on AD pathology. Finally, we discuss how protein-protein interactions (PPIs), receptor inhibition, immunotherapy, and gene therapy can be exploited for the cure and management of both cancer and AD. Collectively, this review provides insights for the development of AD theragnostics based on cancer drugs and molecular targets.

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

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

Amyloid, Crohn's disease, and Alzheimer's disease - are they linked?

Crohn's disease (CD) is a chronic inflammatory disease that most frequently affects part of the distal ileum, but it may affect any part of the gastrointestinal tract. CD may also be related to systemic inflammation and extraintestinal manifestations. Alzheimer's disease (AD) is the most common neurodegenerative disease, gradually worsening behavioral and cognitive functions. Despite the meaningful progress, both diseases are still incurable and have a not fully explained, heterogeneous pathomechanism that includes immunological, microbiological, genetic, and environmental factors. Recently, emerging evidence indicates that chronic inflammatory condition corresponds to an increased risk of neurodegenerative diseases, and intestinal inflammation, including CD, increases the risk of AD. Even though it is now known that CD increases the risk of AD, the exact pathways connecting these two seemingly unrelated diseases remain still unclear. One of the key postulates is the gut-brain axis. There is increasing evidence that the gut microbiota with its proteins, DNA, and metabolites influence several processes related to the etiology of AD, including β-amyloid abnormality, Tau phosphorylation, and neuroinflammation. Considering the role of microbiota in both CD and AD pathology, in this review, we want to shed light on bacterial amyloids and their potential to influence cerebral amyloid aggregation and neuroinflammation and provide an overview of the current literature on amyloids as a potential linker between AD and CD.

Building an Understanding of Proteostasis in Reproductive Cells: The Impact of Reactive Carbonyl Species on Protein Fate

Significance: Stringent regulation of protein homeostasis pathways, under both physiological and pathological conditions, is necessary for the maintenance of proteome fidelity and optimal cell functioning. However, when challenged by endogenous or exogenous stressors, these proteostasis pathways can become dysregulated with detrimental consequences for protein fate, cell survival, and overall organism health. Most notably, there are numerous somatic pathologies associated with a loss of proteostatic regulation, including neurodegenerative disorders, type 2 diabetes, and some cancers. Recent Advances: Lipid oxidation-derived reactive carbonyl species (RCS), such as 4-hydroxynonenal (4HNE) and malondialdehyde, are relatively underappreciated purveyors of proteostatic dysregulation, which elicit their effects via the nonenzymatic post-translational modification of proteins. Emerging evidence suggests that a subset of germline proteins can serve as substrates for 4HNE modification. Among these, prevalent targets include succinate dehydrogenase, heat shock protein A2 and A-kinase anchor protein 4, all of which are intrinsically associated with fertility. Critical Issues: Despite growing knowledge in this field, the RCS adductomes of spermatozoa and oocytes are yet to be comprehensively investigated. Furthermore, the manner by which RCS-mediated adduction impacts protein fate and drives cellular responses, such as protein aggregation, requires further examination in the germline. Given that RCS-protein adduction has been attributed a role in infertility, there has been sparked research investment into strategies to prevent lipid peroxidation in germ cells. Future Directions: An increased depth of knowledge regarding the mechanisms and substrates of RCS-mediated protein modification in reproductive cells may reveal important targets for the development of novel therapies to improve fertility and pregnancy outcomes for future generations.

The ISG15-Protease USP18 Is a Pleiotropic Enhancer of HIV-1 Replication

The innate immune response to viruses is formed in part by interferon (IFN)-induced restriction factors, including ISG15, p21, and SAMHD1. IFN production can be blocked by the ISG15-specific protease USP18. HIV-1 has evolved to circumvent host immune surveillance. This mechanism might involve USP18. In our recent studies, we demonstrate that HIV-1 infection induces USP18, which dramatically enhances HIV-1 replication by abrogating the antiviral function of p21. USP18 downregulates p21 by accumulating misfolded dominant negative p53, which inactivates wild-type p53 transactivation, leading to the upregulation of key enzymes involved in de novo dNTP biosynthesis pathways and inactivated SAMHD1. Despite the USP18-mediated increase in HIV-1 DNA in infected cells, it is intriguing to note that the cGAS-STING-mediated sensing of the viral DNA is abrogated. Indeed, the expression of USP18 or knockout of ISG15 inhibits the sensing of HIV-1. We demonstrate that STING is ISGylated at residues K224, K236, K289, K347, K338, and K370. The inhibition of STING K289-linked ISGylation suppresses its oligomerization and IFN induction. We propose that human USP18 is a novel factor that potentially contributes in multiple ways to HIV-1 replication.

Aggresome formation promotes ASK1/JNK signaling activation and stemness maintenance in ovarian cancer

Aggresomes are the product of misfolded protein aggregation, and the presence of aggresomes has been correlated with poor prognosis in cancer patients. However, the exact role of aggresomes in tumorigenesis and cancer progression remains largely unknown. Herein, the multiomics screening reveal that OTUD1 protein plays an important role in retaining ovarian cancer stem cell (OCSC) properties. Mechanistically, the elevated OTUD1 protein levels lead to the formation of OTUD1-based cytoplasmic aggresomes, which is mediated by a short peptide located in the intrinsically disordered OTUD1 N-terminal region. Furthermore, OTUD1-based aggresomes recruit ASK1 via protein-protein interactions, which in turn stabilize ASK1 in a deubiquitinase-independent manner and activate the downstream JNK signaling pathway for OCSC maintenance. Notably, the disruption of OTUD1-based aggresomes or treatment with ASK1/JNK inhibitors, including ibrutinib, an FDA-approved drug that was recently identified as an MKK7 inhibitor, effectively reduced OCSC stemness (OSCS) of OTUD1high ovarian cancer cells. In summary, our work suggests that aggresome formation in tumor cells could function as a signaling hub and that aggresome-based therapy has translational potential for patients with OTUD1high ovarian cancer.

Unveiling the mechanistic link between extracellular amyloid fibrils, mechano-signaling and YAP activation in cancer

The tumor microenvironment is a complex ecosystem that plays a critical role in cancer progression and treatment response. Recently, extracellular amyloid fibrils have emerged as novel components of the tumor microenvironment; however, their function remains elusive. In this study, we establish a direct connection between the presence of amyloid fibrils in the secretome and the activation of YAP, a transcriptional co-activator involved in cancer proliferation and drug resistance. Furthermore, we uncover a shared mechano-signaling mechanism triggered by amyloid fibrils in both melanoma and pancreatic ductal adenocarcinoma cells. Our findings highlight the crucial role of the glycocalyx protein Agrin which binds to extracellular amyloid fibrils and acts as a necessary factor in driving amyloid-dependent YAP activation. Additionally, we reveal the involvement of the HIPPO pathway core kinase LATS1 in this signaling cascade. Finally, we demonstrate that extracellular amyloid fibrils enhance cancer cell migration and invasion. In conclusion, our research expands our knowledge of the tumor microenvironment by uncovering the role of extracellular amyloid fibrils in driving mechano-signaling and YAP activation. This knowledge opens up new avenues for developing innovative strategies to modulate YAP activation and mitigate its detrimental effects during cancer progression.

Amyloid aggregates induced by the p53-R280T mutation lead to loss of p53 function in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant tumor that is highly prevalent in Southeast Asia, especially in South China. The pathogenesis of NPC is complex, and genetic alterations of tumor suppressors and proto-oncogenes play important roles in NPC carcinogenesis. p53 is unexpectedly highly expressed in NPC and possesses an uncommon mutation of R280T, which is different from a high frequency of hotspot mutations or low expression in other tumors. However, the mechanism of p53 loss of function and its correlation with R280T in NPC are still unclear. In this study, p53 amyloid aggregates were found to be widespread in NPC and can be mainly induced by the R280T mutation. Aggregated p53-R280T impeded its entry into the nucleus and was unable to initiate the transcription of downstream target genes, resulting in decreased NPC cell cycle arrest and apoptosis. In addition, NPC cells with p53-R280T amyloid aggregates also contributed aggressively to tumor growth in vivo. Transcriptome analysis suggested that p53 amyloid aggregation dysregulated major signaling pathways associated with the cell cycle, proliferation, apoptosis, and unfolded protein response (UPR). Further studies revealed that Hsp90, as a key molecular chaperone in p53 folding, was upregulated in NPC cells with p53-R280T aggregation, and the upregulated Hsp90 facilitated p53 aggregation in turn, forming positive feedback. Therefore, Hsp90 inhibitors could dissociate p53-R280T aggregation and restore the suppressor function of p53 in vitro and in vivo. In conclusion, our study demonstrated that p53-R280T may misfold to form aggregates with the help of Hsp90, resulting in the inability of sequestered p53 to initiate the transcription of downstream target genes. These results revealed a new mechanism for the loss of p53 function in NPC and provided novel mechanistic insight into NPC pathogenesis.

The von Hippel-Lindau protein forms fibrillar amyloid assemblies that are mitigated by the anti-amyloid molecule Purpurin

The von Hippel-Lindau protein (pVHL) is a tumor suppressor involved in oxygen regulation via dynamic nucleocytoplasmic shuttling. It plays a crucial role in cell survival by degrading hypoxia-inducible factors (HIFs). Mutations in the VHL gene cause angiogenic tumors, characterized as VHL syndrome. However, aggressive tumors involving wild-type pVHL have also been described but the underlying mechanism remains to be revealed. We have previously shown that pVHL possesses several short amyloid-forming motifs, making it aggregation-prone. In this study, using a series of biophysical assays, we demonstrated that a pVHL-derived fragment (pVHL104-140) that harbors the nuclear export motif and HIF binding site, forms amyloid-like fibrillar structures in vitro by following secondary-nucleation-based kinetics. The peptide also formed amyloids at acidic pH that mimics the tumor microenvironment. We, subsequently, validated the amyloid formation by pVHL in vitro. Using the Curli-dependent amyloid generator (C-DAG) expression system, we confirmed the amyloidogenesis of pVHL in bacterial cells. The pVHL amyloids are an attractive target for therapeutics of the VHL syndrome. Accordingly, we demonstrated in vitro that Purpurin is a potent inhibitor of pVHL fibrillation. The amyloidogenic behavior of wild-type pVHL and its inhibition provide novel insights into the molecular underpinning of the VHL syndrome and its possible treatment.

Elucidating the Mechanisms of R248Q Mutation-Enhanced p53 Aggregation and Its Inhibition by Resveratrol

Aggregation of p53 mutants can result in loss-of-function, gain-of-function, and dominant-negative effects that contribute to tumor growth. Revealing the mechanisms underlying mutation-enhanced p53 aggregation and dissecting how small molecule inhibitors prevent the conversion of p53 into aggregation-primed conformations are fundamentally important for the development of novel therapeutics for p53 aggregation-associated cancers. A recent experimental study shows that resveratrol (RSV) has an inhibitory effect on the aggregation of hot-spot R248Q mutant of the p53 core domain (p53C), while pterostilbene (PT) exhibits a relatively poor inhibitory efficacy. However, the conformational properties of the R248Q mutant leading to its enhanced aggregation propensity and the inhibitory mechanism of RSV against p53C aggregation are not well understood. Herein, we performed extensive all-atom molecular dynamics simulations on R248Q p53C in the absence and presence of RSV/PT, as well as wild-type (WT) p53C. Our simulations reveal that loop L3, where the mutation resides, remains compact in WT p53C, while it becomes extended in the R248Q mutant. The extension of loop L3 weakens the interactions between loop L3 and two crucial aggregation-prone regions (APRs) of p53C, leading to impaired interactions within the APRs and their structural destabilization as well as p53C. The destabilized APRs in the R248Q mutant are more exposed than in WT p53C, which is conducive to p53C aggregation. RSV has a higher preference to bind to R248Q p53C than PT. This binding not only stabilizes loop L3 of R248Q mutant to its WT-like conformation, preventing L3-extension-caused APRs' destabilization but also reduces APRs' solvent exposure, thereby inhibiting R248Q p53C aggregation. However, PT exhibits a lower hydrogen-bonding capability and a higher self-association propensity, which would lead to a reduced p53C binding and a weakened inhibitory effect on R248Q mutant aggregation. Our study provides mechanistic insights into the R248Q mutation-enhanced aggregation propensity and RSV's potent inhibition against R248Q p53C aggregation.

Realization of Amyloid-like Aggregation as a Common Cause for Pathogenesis in Diseases

Amyloids were conventionally referred to as extracellular and intracellular accumulation of Aβ42 peptide, which causes the formation of plaques and neurofibrillary tangles inside the brain leading to the pathogenesis in Alzheimer's disease. Subsequently, amyloid-like deposition was found in the etiology of prion diseases, Parkinson's disease, type II diabetes, and cancer, which was attributed to the aggregation of prion protein, α-Synuclein, islet amyloid polypeptide protein, and p53 protein, respectively. Hence, traditionally amyloids were considered aggregates formed exclusively by proteins or peptides. However, since the last decade, it has been discovered that other metabolites, like single amino acids, nucleobases, lipids, glucose derivatives, etc., have a propensity to form amyloid-like toxic assemblies. Several studies suggest direct implications of these metabolite assemblies in the patho-physiology of various inborn errors of metabolisms like phenylketonuria, tyrosinemia, cystinuria, and Gaucher's disease, to name a few. In this review, we present a comprehensive literature overview that suggests amyloid-like structure formation as a common phenomenon for disease progression and pathogenesis in multiple syndromes. The review is devoted to providing readers with a broad knowledge of the structure, mode of formation, propagation, and transmission of different extracellular amyloids and their implications in the pathogenesis of diseases. We strongly believe a review on this topic is urgently required to create awareness about the understanding of the fundamental molecular mechanism behind the origin of diseases from an amyloid perspective and possibly look for a common therapeutic strategy for the treatment of these maladies by designing generic amyloid inhibitors.

Targeting the p53 signaling pathway in cancers: Molecular mechanisms and clinical studies

Tumor suppressor p53 can transcriptionally activate downstream genes in response to stress, and then regulate the cell cycle, DNA repair, metabolism, angiogenesis, apoptosis, and other biological responses. p53 has seven functional domains and 12 splice isoforms, and different domains and subtypes play different roles. The activation and inactivation of p53 are finely regulated and are associated with phosphorylation/acetylation modification and ubiquitination modification, respectively. Abnormal activation of p53 is closely related to the occurrence and development of cancer. While targeted therapy of the p53 signaling pathway is still in its early stages and only a few drugs or treatments have entered clinical trials, the development of new drugs and ongoing clinical trials are expected to lead to the widespread use of p53 signaling-targeted therapy in cancer treatment in the future. TRIAP1 is a novel p53 downstream inhibitor of apoptosis. TRIAP1 is the homolog of yeast mitochondrial intermembrane protein MDM35, which can play a tumor-promoting role by blocking the mitochondria-dependent apoptosis pathway. This work provides a systematic overview of recent basic research and clinical progress in the p53 signaling pathway and proposes that TRIAP1 is an important therapeutic target downstream of p53 signaling.

Anticancer efficacy of hirsuteine against colorectal cancer by opposite modulation of wild-type and mutant p53

PURPOSE

The present study aimed to explore the anticancer activity of hirsuteine (HST), an indole alkaloid from the traditional Chinese herbal medicine Uncaria rhynchophylla, against colorectal cancer (CRC) and the underlining mechanism.

METHODS

MTT, colony formation, flow cytometry and MDC staining were conducted to confirm the antiproliferative effect of HST on human CRC cells harboring different p53 status. Protein expressions were evaluated by the Western blot analysis. p53 protein half-life and the interaction between p53 and MDM2 were investigated using cycloheximide (CHX)-chase assay and Co-immunoprecipitation (Co-IP), respectively. Transcriptional activity of p53 was examined by qRT-PCR and Chromatin immunoprecipitation (ChIP). Xenograft tumor in nude mice was created to evaluate in vivo anticancer effect of HST against CRC.

RESULTS

HST inhibited cell growth, arrested cell cycle and induced autophagy, showing efficient anticancer effects on CRC cells independent of p53 status. In HCT-8 cells, HST prolonged wtp53 half-life, and upregulated mRNA level of p21, suggesting that HST activated the p53 pathway through enhancement of wtp53 stability and transcriptional activity. Meanwhile in SW620 cells, HST induced MDM2-mediated proteasomal degradation of mutp53^R273H, increased the DNA-binding ability of mutp53^R273H at the p21 promoter, and upregulated mRNA levels of p21 and MDM2, demonstrating the depletion of mutp53^R273H and restoration of its wild-type-like properties by HST. p53 knockdown by siRNA significantly impaired the growth inhibition of HST on HCT-8 and SW620 cells. Moreover, HST showed anticancer effects in xenograft tumors, accompanied with an opposite regulation of wtp53 and mutp53 ^R273H in mechanism.

CONCLUSION

This study revealed the anticancer efficacy of HST against CRC via opposite modulation of wtp53 and mutp53 ^R273H, indicating the potential of HST to be a CRC drug candidate targeting p53 signaling.

Retinal determination gene networks: from biological functions to therapeutic strategies

The retinal determinant gene network (RDGN), originally discovered as a critical determinator in Drosophila eye specification, has become an important regulatory network in tumorigenesis and progression, as well as organogenesis. This network is not only associated with malignant biological behaviors of tumors, such as proliferation, and invasion, but also regulates the development of multiple mammalian organs. Three members of this conservative network have been extensively investigated, including DACH, SIX, and EYA. Dysregulated RDGN signaling is associated with the initiation and progression of tumors. In recent years, it has been found that the members of this network can be used as prognostic markers for cancer patients. Moreover, they are considered to be potential therapeutic targets for cancer. Here, we summarize the research progress of RDGN members from biological functions to signaling transduction, especially emphasizing their effects on tumors. Additionally, we discuss the roles of RDGN members in the development of organs and tissue as well as their correlations with the pathogenesis of chronic kidney disease and coronary heart disease. By summarizing the roles of RDGN members in human diseases, we hope to promote future investigations into RDGN and provide potential therapeutic strategies for patients.

PRIMA-1 inhibits Y220C p53 amyloid aggregation and synergizes with cisplatin in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. Although many therapeutic options are available, several factors, including the presence of p53 mutations, impact tumor development and therapeutic resistance. TP53 is the second most frequently mutated gene in HCC, comprising more than 30% of cases. Mutations in p53 result in the formation of amyloid aggregates that promote tumor progression. The use of PRIMA-1, a small molecule capable of restoring p53, is a therapeutic strategy to pharmacologically target the amyloid state mutant p53. In this study, we characterize an HCC mutant p53 model for the study of p53 amyloid aggregation in HCC cell lines, from in silico analysis of p53 mutants to a 3D-cell culture model and demonstrate the unprecedented inhibition of Y220C mutant p53 aggregation by PRIMA-1. In addition, our data show beneficial effects of PRIMA-1 in several "gain of function" properties of mutant-p53 cancer cells, including migration, adhesion, proliferation, and drug resistance. We also demonstrate that the combination of PRIMA-1 and cisplatin is a promising approach for HCC therapy. Taken together, our data support the premise that targeting the amyloid-state of mutant p53 may be an attractive therapeutic approach for HCC, and highlight PRIMA-1 as a new candidate for combination therapy with cisplatin.

Novel compounds that synergize with aminoglycoside G418 or eRF3 degraders for translational readthrough of nonsense mutant TP53 and PTEN

The TP53 and PTEN tumour suppressor genes are inactivated by nonsense mutations in a significant fraction of human tumours. TP53 nonsense mutatant tumours account for approximately one million new cancer cases per year worldwide. We have screened chemical libraries with the aim of identifying compounds that induce translational readthrough and expression of full-length p53 protein in cells with nonsense mutation in this gene. Here we describe two novel compounds with readthrough activity, either alone or in combination with other known readthrough-promoting substances. Both compounds induced levels of full-length p53 in cells carrying R213X nonsense mutant TP53. Compound C47 showed synergy with the aminoglycoside antibiotic and known readthrough inducer G418, whereas compound C61 synergized with eukaryotic release factor 3 (eRF3) degraders CC-885 and CC-90009. C47 alone showed potent induction of full-length PTEN protein in cells with different PTEN nonsense mutations. These results may facilitate further development of novel targeted cancer therapy by pharmacological induction of translational readthrough.

Transition of amyloid/mutant p53 from tumor suppressor to an oncogene and therapeutic approaches to ameliorate metastasis and cancer stemness

The tumor suppressor p53 when undergoes amyloid formation confers several gain-of-function (GOF) activities that affect molecular pathways crucial for tumorigenesis and progression like some of the p53 mutants. Even after successful cancer treatment, metastasis and recurrence can result in poor survival rates. The major cause of recurrence is mainly the remnant cancer cells with stem cell-like properties, which are resistant to any chemotherapy treatment. Several studies have demonstrated the role of p53 mutants in exacerbating cancer stemness properties and epithelial-mesenchymal transition in these remnant cancer cells. Analyzing the amyloid/mutant p53-mediated signaling pathways that trigger metastasis, relapse or chemoresistance may be helpful for the development of novel or improved individualized treatment plans. In this review, we discuss the changes in the metabolic pathways such as mevalonate pathway and different signaling pathways such as TGF-β, PI3K/AKT/mTOR, NF-κB and Wnt due to p53 amyloid formation, or mutation. In addition to this, we have discussed the role of the regulatory microRNAs and lncRNAs linked with the mutant or amyloid p53 in human malignancies. Such changes promote tumor spread, potential recurrence, and stemness. Importantly, this review discusses the cancer therapies that target either mutant or amyloid p53, restore wild-type functions, and exploit the synthetic lethal interactions with mutant p53.