Resveratrol and aspirin eliminate tetraploid cells for anticancer chemoprevention

Tetraploidy in normal tissues and diseases: mechanisms and consequences

Tetraploidisation plays a crucial role in evolution, development, stress adaptation, and disease, but its beneficial or pathological effects in different tissues remain unclear. This study aims to compare physiological and unphysiological tetraploidy in eight steps: 1) mechanisms of diploidy-to-tetraploidy transition, 2) induction and elimination of unphysiological tetraploidy, 3) tetraploid cell characteristics, 4) stress-induced unphysiological tetraploidy, 5) comparison of physiological vs. unphysiological tetraploidy, 6) consequences of unphysiological stress-induced tetraploidy, 7) nutritional or pharmacological prevention strategies of tetraploidisation, and 8) knowledge gaps and future perspectives. Unphysiological tetraploidy is an adaptive stress response at a given threshold, often involving mitotic slippage. If tetraploid cells evade elimination through apoptosis or immune surveillance, they may re-enter the cell cycle, causing genetic instability, micronuclei formation, aneuploidy, modification of the epigenome and the development of diseases. The potential contributions of unphysiological tetraploidy to neurodegenerative, cardiovascular and diabetes related diseases are summarized in schematic figures and contrasted with its role in cancer development. The mechanisms responsible for the transition from physiological to unphysiological tetraploidy and the tolerance to tetraploidisation in unphysiological tetraploidy are not fully understood. Understanding these mechanisms is of critical importance to allow the development of targeted nutritional and pharmacological prevention strategies and therapies.

High-Throughput Empirical and Virtual Screening To Discover Novel Inhibitors of Polyploid Giant Cancer Cells in Breast Cancer

Therapy resistance in breast cancer is increasingly attributed to polyploid giant cancer cells (PGCCs), which arise through whole genome doubling and exhibit heightened resilience to standard treatments. Characterized by enlarged nuclei and increased DNA content, these cells tend to be dormant under therapeutic stress, driving disease relapse. Despite their critical role in resistance, strategies to effectively target PGCCs are limited, largely due to the lack of high-throughput methods for assessing their viability. Traditional assays lack the sensitivity needed to detect PGCC-specific elimination, prompting the development of novel approaches. To address this challenge, we developed a high-throughput single-cell morphological analysis workflow designed to differentiate compounds that selectively inhibit non-PGCCs, PGCCs, or both. Using this method, we screened a library of 2726 FDA Phase 1-approved drugs, identifying promising anti-PGCC candidates, including proteasome inhibitors, FOXM1, CHK, and macrocyclic lactones. Notably, RNA-Seq analysis of cells treated with the macrocyclic lactone Pyronaridine revealed AXL inhibition as a potential strategy for targeting PGCCs. Although our single-cell morphological analysis pipeline is powerful, empirical testing of all existing compounds is impractical and inefficient. To overcome this limitation, we trained a machine learning model to predict anti-PGCC efficacy in silico, integrating chemical fingerprints and compound descriptions from prior publications and databases. The model demonstrated a high correlation with experimental outcomes and predicted efficacious compounds in an expanded library of over 6,000 drugs. Among the top-ranked predictions, we experimentally validated five compounds as potent PGCC inhibitors using cell lines and patient-derived models. These findings underscore the synergistic potential of integrating high-throughput empirical screening with machine learning-based virtual screening to accelerate the discovery of novel therapies, particularly for targeting therapy-resistant PGCCs in breast cancer.

High-Throughput Empirical and Virtual Screening to Discover Novel Inhibitors of Polyploid Giant Cancer Cells in Breast Cancer

Therapy resistance in breast cancer is increasingly attributed to polyploid giant cancer cells (PGCCs), which arise through whole-genome doubling and exhibit heightened resilience to standard treatments. Characterized by enlarged nuclei and increased DNA content, these cells tend to be dormant under therapeutic stress, driving disease relapse. Despite their critical role in resistance, strategies to effectively target PGCCs are limited, largely due to the lack of high-throughput methods for assessing their viability. Traditional assays lack the sensitivity needed to detect PGCC-specific elimination, prompting the development of novel approaches. To address this challenge, we developed a high-throughput single-cell morphological analysis workflow designed to differentiate compounds that selectively inhibit non-PGCCs, PGCCs, or both. Using this method, we screened a library of 2,726 FDA Phase 1-approved drugs, identifying promising anti-PGCC candidates, including proteasome inhibitors, FOXM1, CHK, and macrocyclic lactones. Notably, RNA-Seq analysis of cells treated with the macrocyclic lactone Pyronaridine revealed AXL inhibition as a potential strategy for targeting PGCCs. Although our single-cell morphological analysis pipeline is powerful, empirically testing all existing compounds is impractical and inefficient. To overcome this limitation, we trained a machine learning model to predict anti-PGCC efficacy in silico, integrating chemical fingerprints and compound descriptions from prior publications and databases. The model demonstrated a high correlation with experimental outcomes and predicted efficacious compounds in an expanded library of over 6,000 drugs. Among the top-ranked predictions, we experimentally validated two compounds as potent PGCC inhibitors. These findings underscore the synergistic potential of integrating high-throughput empirical screening with machine learning-based virtual screening to accelerate the discovery of novel therapies, particularly for targeting therapy-resistant PGCCs in breast cancer.

Polyploid giant cancer cells: origin, possible pathways of formation, characteristics, and mechanisms of regulation

Polyploid giant cancer cells (PGCCs) are characterized by the presence of either a single enlarged nucleus or multiple nuclei and are closely associated with tumor progression and treatment resistance. These cells contribute significantly to cellular heterogeneity and can arise from various stressors, including radiation, chemotherapy, hypoxia, and environmental factors. The formation of PGCCs can occur through mechanisms such as endoreplication, cell fusion, cytokinesis failure, mitotic slippage, or cell cannibalism. Notably, PGCCs exhibit traits similar to cancer stem cells (CSCs) and generate highly invasive progeny through asymmetric division. The presence of PGCCs and their progeny is pivotal in conferring resistance to chemotherapy and radiation, as well as facilitating tumor recurrence and metastasis. This review provides a comprehensive analysis of the origins, potential formation mechanisms, stressors, unique characteristics, and regulatory pathways of PGCCs, alongside therapeutic strategies targeting these cells. The objective is to enhance the understanding of PGCC initiation and progression, offering novel insights into tumor biology.

Tetraploidy as a metastable state towards malignant cell transformation within a systemic approach of cancer development

Tetraploidy, a condition in which a cell has four homologous sets of chromosomes, may be a natural physiological condition or pathophysiological such as in cancer cells or stress induced tetraploidisation. Its contribution to cancer development is well known. However, among the many models proposed to explain the causes, mechanisms and steps of malignant cell transformation, only few integrate tetraploidization into a systemic multistep approach of carcinogenesis. Therefore, we will i) describe the molecular and cellular characteristics of tetraploidy; ii) assess the contribution of stress-induced tetraploidy in cancer development; iii) situate tetraploidy as a metastable state leading to cancer development in a systemic cell-centered approach; iiii) consider knowledge gaps and future perspectives. The available data shows that stress-induced tetraploidisation/polyploidisation leads to p53 stabilisation, cell cycle arrest, followed by cellular senescence or apoptosis, suppressing the proliferation of tetraploid cells. However, if tetraploid cells escape the G1-tetraploidy checkpoint, it may lead to uncontrolled proliferation of tetraploid cells, micronuclei induction, aneuploidy and deploidisation. In addition, tetraploidization favors 3D-chromatin changes and epigenetic effects. The combined effects of genetic and epigenetic changes allow the expression of oncogenic gene expression and cancer progression. Moreover, since micronuclei are inducing inflammation, which in turn may induce additional tetraploidization, tetraploidy-derived genetic instability leads to a carcinogenic vicious cycle. The concept that polyploid cells are metastable intermediates between diploidy and aneuploidy is not new. Metastability denotes an intermediate energetic state within a dynamic system other than the system's state at least energy. Considering in parallel the genetic/epigenetic changes and the probable entropy levels induced by stress-induced tetraploidisation provides a new systemic approach to describe cancer development.

Characterization of polyploidy in cancer: Current status and future perspectives

Various cancers frequently exhibit polyploidy, observed in a condition where a cell possesses more than two sets of chromosomes, which is considered a hallmark of the disease. The state of polyploidy often leads to aneuploidy, where cells possess an abnormal number or structure of chromosomes. Recent studies suggest that oncogenes contribute to aneuploidy. This finding significantly underscores its impact on cancer. Cancer cells exposed to certain chemotherapeutic drugs tend to exhibit an increased incidence of polyploidy. This occurrence is strongly associated with several challenges in cancer treatment, including metastasis, resistance to chemotherapy and the recurrence of malignant tumors. Indeed, it poses a significant hurdle to achieve complete tumor eradication and effective cancer therapy. Recently, there has been a growing interest in the field of polyploidy related to cancer for developing effective anti-cancer therapies. Polyploid cancer cells confer both advantages and disadvantages to tumor pathogenicity. This review delineates the diverse characteristics of polyploid cells, elucidates the pivotal role of polyploidy in cancer, and explores the advantages and disadvantages it imparts to cancer cells, along with the current approaches tried in lab settings to target polyploid cells. Additionally, it considers experimental strategies aimed at addressing the outstanding questions within the realm of polyploidy in relation to cancer.

Single-cell morphological and transcriptome analysis unveil inhibitors of polyploid giant breast cancer cells in vitro

Considerable evidence suggests that breast cancer therapeutic resistance and relapse can be driven by polyploid giant cancer cells (PGCCs). The number of PGCCs increases with the stages of disease and therapeutic stress. Given the importance of PGCCs, it remains challenging to eradicate them. To discover effective anti-PGCC compounds, there is an unmet need to rapidly distinguish compounds that kill non-PGCCs, PGCCs, or both. Here, we establish a single-cell morphological analysis pipeline with a high throughput and great precision to characterize dynamics of individual cells. In this manner, we screen a library to identify promising compounds that inhibit all cancer cells or only PGCCs (e.g., regulators of HDAC, proteasome, and ferroptosis). Additionally, we perform scRNA-Seq to reveal altered cell cycle, metabolism, and ferroptosis sensitivity in breast PGCCs. The combination of single-cell morphological and molecular investigation reveals promising anti-PGCC strategies for breast cancer treatment and other malignancies.

Tetraploidization Increases the Motility and Invasiveness of Cancer Cells

Polyploidy and metastasis are associated with a low probability of disease-free survival in cancer patients. Polyploid cells are known to facilitate tumorigenesis. However, few data associate polyploidization with metastasis. Here, by generating and using diploid (2n) and tetraploid (4n) clones from malignant fibrous histiocytoma (MFH) and colon carcinoma (RKO), we demonstrate the migration and invasion advantage of tetraploid cells in vitro using several assays, including the wound healing, the OrisTM two-dimensional cell migration, single-cell migration tracking by video microscopy, the Boyden chamber, and the xCELLigence RTCA real-time cell migration. Motility advantage was observed despite tetraploid cell proliferation weakness. We could also demonstrate preferential metastatic potential in vivo for the tetraploid clone using the tail vein injection in mice and tracking metastatic tumors in the lung. Using the Mitelman Database of Chromosome Aberrations in Cancer, we found an accumulation of polyploid karyotypes in metastatic tumors compared to primary ones. This work reveals the clinical relevance of the polyploid subpopulation and the strategic need to highlight polyploidy in preclinical studies as a therapeutic target for metastasis.

Towards prevention of aneuploidy-associated cellular senescence and aging: more questions than answers?

The aim of this review is to discuss how aneuploidy contributes to the aging process, and to identify plausible strategies for its prevention. After an overview of mechanisms leading to aneuploidy and the major features of cellular senescence, we discuss the link between (i) aneuploidy and cellular senescence; (ii) aneuploidy and aging; and (iii) cellular senescence and aging. We also consider (i) interactions between aneuploidy, micronuclei, cellular senescence and aging, (ii) the potential of nutritional treatments to prevent aneuploidy-associated senescence and aging, and (iii) knowledge and technological gaps. Evidence for a causal link between aneuploidy, senescence and aging is emerging. In vitro, aneuploidy accompanies the entry into cellular senescence and can itself induce senescence. How aneuploidy contributes in vivo to cellular senescence is less clear. Several routes depending on aneuploidy and/or senescence converge towards chronic inflammation, the major driver of unhealthy aging. Aneuploidy can induce the pro-inflammatory Senescence Associated Secretory Phenotype (SASP), either directly or as a result of micronucleus (MN) induction leading to leakage of DNA into the cytoplasm and triggering of the cGAS-STING pathway of innate immune response. A major difficulty in understanding the impact of aneuploidy on senescence and aging in vivo, results from the heterogeneity of cellular senescence in different tissues at the cytological and molecular level. Due to this complexity, there is at the present time no biomarker or biomarker combination characteristic for all types of senescent cells. In conclusion, a deeper understanding of the critical role aneuploidy plays in cellular senescence and aging is essential to devise practical strategies to protect human populations from aneuploidy-associated pathologies. We discuss emerging evidence, based on in vitro and in vivo studies, that adequate amounts of specific micronutrients are essential for prevention of aneuploidy in humans and that precise nutritional intervention may be essential to help avoid the scourge of aneuploidy-driven diseases.

Resveratrol downregulates ENaCs through the activation of AMPK in human colon cancer cells

Epithelial sodium channels (ENaCs) are critically engaged in a number of hallmarks of cancer progression, including proliferation, migration, invasion and apoptosis. Thus, the inhibition of ENaCs possesses therapeutic potential in cancer. Resveratrol, a natural polyphenol with anti-carcinogenic activity, is a potent activator of 5' AMP-activated protein kinase (AMPK) which reduces the abundance of ENaCs in the cell membrane by causing the internalization of the β subunit. However, the effect of resveratrol on ENaCs in cancer cells is unknown. Therefore, in this study, we aimed to investigate the effects of resveratrol on ENaCs in human colon cancer cells HCT116 and HT29. The influences of resveratrol either alone or together with AMPK inhibitor compound C (CC), and ENaC inhibitor amiloride on cell viability were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The expression levels of phospho-AMPK Thr¹⁷² and βENaC in cells were determined by immunofluorescence staining, and the expression of apoptotic markers Caspase-3 and Caspase-9 were analyzed by qRT-PCR. Resveratrol was found to activate AMPK in a dose-dependent manner. Both AMPK activation by resveratrol and ENaC inhibition by amiloride decreased cell viability and increased apoptosis significantly. AMPK activation also reduced βENaC expression in cells. Our results suggest that ENaC inhibition through AMPK activation might be a potential mechanism underlying the anti-cancer effects of resveratrol.

The role of AMPK in cancer metabolism and its impact on the immunomodulation of the tumor microenvironment

Adenosine monophosphate-activated protein kinase (AMPK) is a key metabolic sensor that is pivotal for the maintenance of cellular energy homeostasis. AMPK contributes to diverse metabolic and physiological effects besides its fundamental role in glucose and lipid metabolism. Aberrancy in AMPK signaling is one of the determining factors which lead to the development of chronic diseases such as obesity, inflammation, diabetes, and cancer. The activation of AMPK and its downstream signaling cascades orchestrate dynamic changes in the tumor cellular bioenergetics. It is well documented that AMPK possesses a suppressor role in the context of tumor development and progression by modulating the inflammatory and metabolic pathways. In addition, AMPK plays a central role in potentiating the phenotypic and functional reprogramming of various classes of immune cells which reside in the tumor microenvironment (TME). Furthermore, AMPK-mediated inflammatory responses facilitate the recruitment of certain types of immune cells to the TME, which impedes the development, progression, and metastasis of cancer. Thus, AMPK appears to play an important role in the regulation of anti-tumor immune response by regulating the metabolic plasticity of various immune cells. AMPK effectuates the metabolic modulation of anti-tumor immunity via nutrient regulation in the TME and by virtue of its molecular crosstalk with major immune checkpoints. Several studies including that from our lab emphasize on the role of AMPK in regulating the anticancer effects of several phytochemicals, which are potential anticancer drug candidates. The scope of this review encompasses the significance of the AMPK signaling in cancer metabolism and its influence on the key drivers of immune responses within the TME, with a special emphasis on the potential use of phytochemicals to target AMPK and combat cancer by modulating the tumor metabolism.

Nondiploid cancer cells: Stress, tolerance and therapeutic inspirations

Aberrant ploidy status is a prominent characteristic in malignant neoplasms. Approximately 90% of solid tumors and 75% of haematopoietic malignancies contain aneuploidy cells, and 30%-60% of tumors undergo whole-genome doubling, indicating that nondiploidy might be a prevalent genomic aberration in cancer. Although the role of aneuploid and polyploid cells in cancer remains to be elucidated, recent studies have suggested that nondiploid cells might be a dangerous minority that severely challenges cancer management. Ploidy shifts cause multiple fitness coasts for cancer cells, mainly including genomic, proteotoxic, metabolic and immune stresses. However, nondiploid comprises a well-adopted subpopulation, with many tolerance mechanisms evident in cells along with ploidy shifts. Aneuploid and polyploid cells elegantly maintain an autonomous balance between the stress and tolerance during adaptive evolution in cancer. Breaking the balance might provide some inspiration for ploidy-selective cancer therapy and alleviation of ploidy-related chemoresistance. To understand of the complex role and therapeutic potential of nondiploid cells better, we reviewed the survival stresses and adaptive tolerances within nondiploid cancer cells and summarized therapeutic ploidy-selective alterations for potential use in developing future cancer therapy.

Applications of resveratrol in the treatment of gastrointestinal cancer

Natural product compounds have lately attracted interest in the scientific community as a possible treatment for gastrointestinal (GI) cancer, due to their anti-inflammatory and anticancer properties. There are many preclinical, clinical, and epidemiological studies, suggesting that the consumption of polyphenol compounds, which are abundant in vegetables, grains, fruits, and pulses, may help to prevent various illnesses and disorders from developing, including several GI cancers. The development of GI malignancies follows a well-known path, in which normal gastrointestinal cells acquire abnormalities in their genetic composition, causing the cells to continuously proliferate, and metastasize to other sites, especially the brain and liver. Natural compounds with the ability to affect oncogenic pathways might be possible treatments for GI malignancies, and could easily be tested in clinical trials. Resveratrol is a non-flavonoid polyphenol and a natural stilbene, acting as a phytoestrogen with anti-cancer, cardioprotective, anti-oxidant, and anti-inflammatory properties. Resveratrol has been shown to overcome resistance mechanisms in cancer cells, and when combined with conventional anticancer drugs, could sensitize cancer cells to chemotherapy. Several new resveratrol analogs and nanostructured delivery vehicles with improved anti-GI cancer efficacy, absorption, and pharmacokinetic profiles have already been developed. This present review focuses on the in vitro and in vivo effects of resveratrol on GI cancers, as well as the underlying molecular mechanisms of action.

Polyploid giant cancer cell characterization: New frontiers in predicting response to chemotherapy in breast cancer

Although polyploid cells were first described nearly two centuries ago, their ability to proliferate has only recently been demonstrated. It also becomes increasingly evident that a subset of tumor cells, polyploid giant cancer cells (PGCCs), play a critical role in the pathophysiology of breast cancer (BC), among other cancer types. In BC, PGCCs can arise in response to therapy-induced stress. Their progeny possess cancer stem cell (CSC) properties and can repopulate the tumor. By modulating the tumor microenvironment (TME), PGCCs promote BC progression, chemoresistance, metastasis, and relapse and ultimately impact the survival of BC patients. Given their pro- tumorigenic roles, PGCCs have been proposed to possess the ability to predict treatment response and patient prognosis in BC. Traditionally, DNA cytometry has been used to detect PGCCs.. The field will further derive benefit from the development of approaches to accurately detect PGCCs and their progeny using robust PGCC biomarkers. In this review, we present the current state of knowledge about the clinical relevance of PGCCs in BC. We also propose to use an artificial intelligence-assisted image analysis pipeline to identify PGCC and map their interactions with other TME components, thereby facilitating the clinical implementation of PGCCs as biomarkers to predict treatment response and survival outcomes in BC patients. Finally, we summarize efforts to therapeutically target PGCCs to prevent chemoresistance and improve clinical outcomes in patients with BC.

Targeting tumor cell senescence and polyploidy as potential therapeutic strategies

Senescence is a unique state of growth arrest that develops in response to a plethora of cellular stresses, including replicative exhaustion, oxidative injury, and genotoxic insults. Senescence has been implicated in the pathogenesis of multiple aging-related pathologies, including cancer. In cancer, senescence plays a dual role, initially acting as a barrier against tumor progression by enforcing a durable growth arrest in premalignant cells, but potentially promoting malignant transformation in neighboring cells through the secretion of pro-tumorigenic drivers. Moreover, senescence is induced in tumor cells upon exposure to a wide variety of conventional and targeted anticancer drugs (termed Therapy-Induced Senescence-TIS), representing a critical contributing factor to therapeutic outcomes. As with replicative or oxidative senescence, TIS manifests as a complex phenotype of macromolecular damage, energetic dysregulation, and altered gene expression. Senescent cells are also frequently polyploid. In vitro studies have suggested that polyploidy may confer upon senescent tumor cells the ability to escape from growth arrest, thereby providing an additional avenue whereby tumor cells escape the lethality of anticancer treatment. Polyploidy in tumor cells is also associated with persistent energy production, chromatin remodeling, self-renewal, stemness and drug resistance - features that are also associated with escape from senescence and conversion to a more malignant phenotype. However, senescent cells are highly heterogenous and can present with variable phenotypes, where polyploidy is one component of a complex reversion process. Lastly, emerging efforts to pharmacologically target polyploid tumor cells might pave the way towards the identification of novel targets for the elimination of senescent tumor cells by the incorporation of senolytic agents into cancer therapeutic strategies.

A Selective β-Catenin-Metadherin/CEACAM1-CCL3 Axis Mediates Metastatic Heterogeneity upon Tumor-Macrophage Interaction

Tumor heterogeneity plays a key role in cancer relapse and metastasis, however, the distinct cellular behaviors and kinetics of interactions among different cancer cell subclones and the tumor microenvironment are poorly understood. By profiling an isogenic model that resembles spontaneous human ovarian cancer metastasis with an highly metastatic (HM) and non-metastatic (NM) tumor cell pair, one finds an upregulation of Wnt/β-catenin signaling uniquely in HM. Using humanized immunocompetent mice, one shows for the first time that activated β-catenin acts nonautonomously to modulate the immune microenvironment by enhancing infiltrating tumor-associated macrophages (TAM) at the metastatic site. Single-cell time-lapse microscopy further reveals that upon contact with macrophages, a significant subset of HM, but not NM, becomes polyploid, a phenotype pivotal for tumor aggressiveness and therapy resistance. Moreover, HM, but not NM, polarizes macrophages to a TAM phenotype. Mechanistically, β-catenin upregulates cancer cell surface metadherin, which communicates through CEACAM1 expressed on macrophages to produce CCL3. Tumor xenografts in humanized mice and clinical patient samples both corroborate the relevance of enhanced metastasis, TAM activation, and polyploidy in vivo. The results thus suggest that targeting the β-catenin-metadherin/CEACAM1-CCL3 positive feedback cascade holds great therapeutic potential to disrupt polyploidization of the cancer subclones that drive metastasis.

Autophagy modulating therapeutics inhibit ovarian cancer colony generation by polyploid giant cancer cells (PGCCs)

BACKGROUND

Genomic instability and chemoresistance can arise in cancer due to a unique form of plasticity: that of polyploid giant cancer cells (PGCCs). These cells form under the stress of chemotherapy and have higher than diploid chromosome content. PGCCs are able to then repopulate tumors through an asymmetric daughter cell budding process. PGCCs have been observed in ovarian cancer histology, including the deadly and common form high-grade serous ovarian carcinoma (HGSC). We previously discovered that drugs which disrupt the cellular recycling process of autophagy are uniquely efficacious in pre-clinical HGSC models. While autophagy induction has been associated with PGCCs, it has never been previously investigated if autophagy modulation interacts with the PGCC life cycle and this form of tumor cell plasticity.

METHODS

CAOV3 and OVCAR3 ovarian cancer cell lines were treated with carboplatin or docetaxel to induce PGCC formation. Microscopy was used to characterize and quantify PGCCs formed by chemotherapy. Two clinically available drugs that inhibit autophagy, hydroxychloroquine and nelfinavir, and a clinically available activator of autophagy, rapamycin, were employed to test the effect of these autophagy modulators on PGCC induction and subsequent colony formation from PGCCs. Crystal violet-stained colony formation assays were used to quantify the tumor-repopulating stage of the PGCC life cycle.

RESULTS

Autophagy inhibitors did not prevent PGCC formation in OVCAR3 or CAOV3 cells. Rapamycin did not induce PGCC formation on its own nor did it exacerbate PGCC formation by chemotherapy. However, hydroxychloroquine prevented efficient colony formation in CAOV3 PGCCs induced by carboplatin (27% inhibition) or docetaxel (41% inhibition), as well as in OVCAR3 cells (95% and 77%, respectively). Nelfinavir similarly prevented colony formation in CAOV3 PGCCs induced by carboplatin (64% inhibition) or docetaxel (94% inhibition) as well as in OVCAR3 cells (89% and 80%, respectively). Rapamycin surprisingly also prevented PGCC colony outgrowth (52-84% inhibition).

CONCLUSIONS

While the autophagy previously observed to correlate with PGCC formation is unlikely necessary for PGCCs to form, autophagy modulating drugs severely impair the ability of HGSC PGCCs to form colonies. Clinical trials which utilize hydroxychloroquine, nelfinavir, and/or rapamycin after chemotherapy may be of future interest.

IL-6 promotes drug resistance through formation of polyploid giant cancer cells and stromal fibroblast reprogramming

To understand the role of polyploid giant cancer cells (PGCCs) in drug resistance and disease relapse, we examined the mRNA expression profile of PGCCs following treatment with paclitaxel in ovarian cancer cells. An acute activation of IL-6 dominated senescence-associated secretory phenotype lasted 2–3 weeks and declined during the termination phase of polyploidy. IL-6 activates embryonic stemness during the initiation of PGCCs and can reprogram normal fibroblasts into cancer-associated fibroblasts (CAFs) via increased collagen synthesis, activation of VEGF expression, and enrichment of CAFs and the GPR77 + /CD10 + fibroblast subpopulation. Blocking the IL-6 feedback loop with tocilizumab or apigenin prevented PGCC formation, attenuated embryonic stemness and the CAF phenotype, and inhibited tumor growth in a patient-derived xenograft high-grade serous ovarian carcinoma model. Thus, IL-6 derived by PGCCs is capable of reprogramming both cancer and stromal cells and contributes to the evolution and remodeling of cancer. Targeting IL-6 in PGCCs may represent a novel approach to combating drug resistance.

Mechanisms involved in selecting and maintaining neuroblastoma cancer stem cell populations, and perspectives for therapeutic targeting

Pediatric neuroblastomas (NBs) are heterogeneous, aggressive, therapy-resistant embryonal tumours that originate from cells of neural crest (NC) origin and in particular neuroblasts committed to the sympathoadrenal progenitor cell lineage. Therapeutic resistance, post-therapeutic relapse and subsequent metastatic NB progression are driven primarily by cancer stem cell (CSC)-like subpopulations, which through their self-renewing capacity, intermittent and slow cell cycles, drug-resistant and reversibly adaptive plastic phenotypes, represent the most important obstacle to improving therapeutic outcomes in unfavourable NBs. In this review, dedicated to NB CSCs and the prospects for their therapeutic eradication, we initiate with brief descriptions of the unique transient vertebrate embryonic NC structure and salient molecular protagonists involved NC induction, specification, epithelial to mesenchymal transition and migratory behaviour, in order to familiarise the reader with the embryonic cellular and molecular origins and background to NB. We follow this by introducing NB and the potential NC-derived stem/progenitor cell origins of NBs, before providing a comprehensive review of the salient molecules, signalling pathways, mechanisms, tumour microenvironmental and therapeutic conditions involved in promoting, selecting and maintaining NB CSC subpopulations, and that underpin their therapy-resistant, self-renewing metastatic behaviour. Finally, we review potential therapeutic strategies and future prospects for targeting and eradication of these bastions of NB therapeutic resistance, post-therapeutic relapse and metastatic progression.

Polyploidy formation in cancer cells: How a Trojan horse is born

Ploidy increase has been shown to occur in different type of tumors and participate in tumor initiation and resistance to the treatment. Polyploid giant cancer cells (PGCCs) are cells with multiple nuclei or a single giant nucleus containing multiple complete sets of chromosomes. The mechanism leading to formation of PGCCs may depend on: endoreplication, mitotic slippage, cytokinesis failure, cell fusion or cell cannibalism. Polyploidy formation might be triggered in response to various genotoxic stresses including: chemotherapeutics, radiation, hypoxia, oxidative stress or environmental factors like: air pollution, UV light or hyperthermia. A fundamental feature of polyploid cancer cells is the generation of progeny during the reversal of the polyploid state (depolyploidization) that may show high aggressiveness resulting in the formation of resistant disease and tumor recurrence. Therefore, we propose that modern anti-cancer therapies should be designed taking under consideration polyploidization/ depolyploidization processes, which confer the polyploidization a hidden potential similar to a Trojan horse delayed aggressiveness. Various mechanisms and stress factors leading to polyploidy formation in cancer cells are discussed in this review.

Metabolic Reprogramming by Reduced Calorie Intake or Pharmacological Caloric Restriction Mimetics for Improved Cancer Immunotherapy

Caloric restriction and fasting have been known for a long time for their health- and life-span promoting effects, with coherent observations in multiple model organisms as well as epidemiological and clinical studies. This holds particularly true for cancer. The health-promoting effects of caloric restriction and fasting are mediated at least partly through their cellular effects-chiefly autophagy induction-rather than reduced calorie intake per se. Interestingly, caloric restriction has a differential impact on cancer and healthy cells, due to the atypical metabolic profile of malignant tumors. Caloric restriction mimetics are non-toxic compounds able to mimic the biochemical and physiological effects of caloric restriction including autophagy induction. Caloric restriction and its mimetics induce autophagy to improve the efficacy of some cancer treatments that induce immunogenic cell death (ICD), a type of cellular demise that eventually elicits adaptive antitumor immunity. Caloric restriction and its mimetics also enhance the therapeutic efficacy of chemo-immunotherapies combining ICD-inducing agents with immune checkpoint inhibitors targeting PD-1. Collectively, preclinical data encourage the application of caloric restriction and its mimetics as an adjuvant to immunotherapies. This recommendation is subject to confirmation in additional experimental settings and in clinical trials. In this work, we review the preclinical and clinical evidence in favor of such therapeutic interventions before listing ongoing clinical trials that will shed some light on this subject.

Cancer regeneration: Polyploid cells are the key drivers of tumor progression

In spite of significant advancements of therapies for initial eradication of cancers, tumor relapse remains a major challenge. It is for a long time known that polyploid malignant cells are a main source of resistance against chemotherapy and irradiation. However, therapeutic approaches targeting these cells have not been appropriately pursued which could partly be due to the shortage of knowledge on the molecular biology of cell polyploidy. On the other hand, there is a rising trend to appreciate polyploid/ multinucleated cells as key players in tissue regeneration. In this review, we suggest an analogy between the functions of polyploid cells in normal and malignant tissues and discuss the idea that cell polyploidy is an evolutionary conserved source of tissue regeneration also exploited by cancers as a survival factor. In addition, polyploid cells are highlighted as a promising therapeutic target to overcome drug resistance and relapse.

In S. cerevisiae hydroxycitric acid antagonizes chronological aging and apoptosis regardless of citrate lyase

Caloric restriction mimetics (CRMs) are promising molecules to prevent age-related diseases as they activate pathways driven by a true caloric restriction. Hydroxycitric acid (HCA) is considered a bona fide CRM since it depletes acetyl-CoA pools by acting as a competitive inhibitor of ATP citrate lyase (ACLY), ultimately repressing protein acetylation and promoting autophagy. Importantly, it can reduce inflammation and tumour development. In order to identify phenotypically relevant new HCA targets we have investigated HCA effects in Saccharomyces cerevisiae, where ACLY is lacking. Strikingly, the drug revealed a powerful anti-aging effect, another property proposed to mark bona fide CRMs. Chronological life span (CLS) extension but also resistance to acetic acid of HCA treated cells were associated to repression of cell apoptosis and necrosis. HCA also largely prevented cell deaths caused by a severe oxidative stress. The molecule could act widely by negatively modulating cell metabolism, similarly to citrate. Indeed, it inhibited both growth reactivation and the oxygen consumption rate of yeast cells in stationary phase. Genetic analyses on yeast CLS mutants indicated that part of the HCA effects can be sensed by Sch9 and Ras2, two conserved key regulators of nutritional and stress signal pathways of primary importance. Our data together with published biochemical analyses indicate that HCA may act with multiple mechanisms together with ACLY repression and allowed us to propose an integrated mechanistic model as a basis for future investigations.

Modulation of the tumor microenvironment by natural agents: implications for cancer prevention and therapy

The development of cancer is not just the growth and proliferation of a single transformed cell, but its surrounding environment also coevolves with it. Indeed, successful cancer progression depends on the ability of the tumor cells to develop a supportive tumor microenvironment consisting of various types of stromal cells. The interactions between the tumor and stromal cells are bidirectional and mediated through a variety of growth factors, cytokines, metabolites, and other biomolecules secreted by these cells. Tumor-stromal crosstalk creates optimal conditions for the tumor growth, metastasis, evasion of immune surveillance, and therapy resistance, and its targeting is being explored for clinical management of cancer. Natural agents from plants and marine life have been at the forefront of traditional medicine. Numerous epidemiological studies have reported the health benefits imparted on the consumption of certain fruits, vegetables, and their derived products. Indeed, a significant majority of anti-cancer drugs in clinical use are either naturally occurring compounds or their derivatives. In this review, we describe fundamental cellular and non-cellular components of the tumor microenvironment and discuss the significance of natural compounds in their targeting. Existing literature provides hope that novel prevention and therapeutic approaches will emerge from ongoing scientific efforts leading to the reduced tumor burden and improve clinical outcomes in cancer patients.

Acquired resistance to combined BET and CDK4/6 inhibition in triple-negative breast cancer

BET inhibitors are promising therapeutic agents for the treatment of triple-negative breast cancer (TNBC), but the rapid emergence of resistance necessitates investigation of combination therapies and their effects on tumor evolution. Here, we show that palbociclib, a CDK4/6 inhibitor, and paclitaxel, a microtubule inhibitor, synergize with the BET inhibitor JQ1 in TNBC lines. High-complexity DNA barcoding and mathematical modeling indicate a high rate of de novo acquired resistance to these drugs relative to pre-existing resistance. We demonstrate that the combination of JQ1 and palbociclib induces cell division errors, which can increase the chance of developing aneuploidy. Characterizing acquired resistance to combination treatment at a single cell level shows heterogeneous mechanisms including activation of G1-S and senescence pathways. Our results establish a rationale for further investigation of combined BET and CDK4/6 inhibition in TNBC and suggest novel mechanisms of action for these drugs and new vulnerabilities in cells after emergence of resistance.

Breast Cancer With Brain Metastases: Perspective From a Long-Term Survivor

The purpose of this essay is to inform others that it is possible to survive breast cancer with brain metastases. The second author is the subject patient and a long-term survivor of systemic metastatic breast cancer with numerous brain metastases (corresponding to 8% survivor group). We credit her survival to a combination of (1) medicine as practiced by an excellent oncologist with whom we developed a partnership to manage the patient’s health, (2) our informed exploration of the available scientific knowledge including a review of scientific research articles that go beyond conventional care, and (3) the patient’s supplementation with numerous repurposed drugs and other substances reported to have antitumor properties. Alongside her conventional treatment (the medical standard of care), it seems likely that this supplementation has been a key factor in the patient’s long-term survival. We also point out that the lack of follow-up magnetic resonance imaging brain scans for early detection of brain metastases poses substantial risks for patients with HER2+ metastatic breast cancer in non–central nervous system locations. Thus, we suggest that research be conducted on such early detection for possible inclusion in the recommendations for the medical standard of care. Finally, medical doctors and also patients with backgrounds in biological science may wish to consider potential options and advantages of repurposed drugs and other substances reported in scientific publications when the medical standard of care has limited options for advanced cancer and other severe chronic health conditions. However, any efforts along this line by patients should be in collaboration with their medical doctors.

The "life code": A theory that unifies the human life cycle and the origin of human tumors

Tumors arise from the transformation of normal stem cells or mature somatic cells. Intriguingly, two types of tumors have been observed by pathologists for centuries: well-differentiated tumors and undifferentiated tumors. Well-differentiated tumors are architecturally similar to the tissues from which they originate, whereas undifferentiated tumors exhibit high nuclear atypia and do not resemble their tissue of origin. The relationship between these two tumor types and the human life cycle has not been clear. Here I propose a unifying theory that explains the processes of transformation of both tumor types with our life cycle. Human life starts with fertilization of an egg by a sperm to form a zygote. The zygote undergoes successive rounds of cleavage division to form blastomeres within the zona pellucida, with progressive decreases in cell size, and the cleaved blastomeres then compact to form a 32-cell or a "64n" morula [n = 1 full set of chromosomes]. Thus early embryogenesis can be interpreted as a progressive increase in ploidy, and if the zona pellucida is considered a cell membrane and cleavage is interpreted as endomitosis, then the 32-cell morula can be considered a multinucleated giant cell (or 64n syncytium). The decrease in cell size is accompanied by an increase in the nuclear-to-cytoplasmic (N/C) ratio, which then selectively activates a combined set of embryonic transcription factors that dedifferentiate the parental genome to a zygotic genome. This process is associated with a morphologic transition from a morula to a blastocyst and formation of an inner cell mass that gives rise to a new embryonic life. If the subsequent differentiation proceeds to complete maturation, then a normal life results. However, if differentiation is blocked at any point along the continuum of primordial germ cell to embryonic maturation to fetal organ maturation, a well-differentiated tumor will develop. Depending on the level of developmental hierarchy at which the stem cell differentiation is blocked, the resulting tumor can range from highly malignant to benign. Undifferentiated tumors are derived from mature somatic cells through dedifferentiation via a recently described reprogramming mechanism named the giant cell life cycle or the giant cell cycle. This mechanism can initiate "somatic embryogenesis" via an increase in ploidy ranging from 4n to 64n or more, similar to that in normal embryogenesis. This dedifferentiation mechanism is initiated through an endocycle and is followed by endomitosis, which leads to the formation of mononucleated or multinucleated polyploid giant cancer cells (PGCCs), that is, cancer stem-like cells that mimic the blastomere-stage embryo. The giant cell life cycle leads to progressive increases in the N/C ratio and awakens the suppressed embryonic reprogram, resulting in mature somatic transformation into undifferentiated tumors. Thus, the increase in ploidy explains not only normal embryogenesis for well-differentiated tumors but also "somatic embryogenesis" for undifferentiated tumors. I refer to this ploidy increase as the 'life code". The concept of the "life code" may provide a simple theoretical framework to guide our immense efforts to understand cancer and fight this disease.

The Mithralog EC-7072 Induces Chronic Lymphocytic Leukemia Cell Death by Targeting Tonic B-Cell Receptor Signaling

B-cell receptor (BCR)-dependent signaling is central for leukemia B-cell homeostasis, as underscored by the promising clinical results obtained in patients with chronic lymphocytic leukemia (CLL) treated with novel agents targeting components of this pathway. Herein, we demonstrate that the mithralog EC-7072 displays high ex vivo cytotoxic activity against leukemia cells from CLL patients independently from high-risk prognostic markers and IGHV mutational status. EC-7072 was significantly less toxic against T cells and NK cells and did not alter the production of the immune effector molecules IFN-γ and perforin. EC-7072 directly triggered caspase-3-dependent CLL cell apoptosis, which was not abrogated by microenvironment-derived factors that sustain leukemia cell survival. RNA-sequencing analyses revealed a dramatic EC-7072-driven reprograming of the transcriptome of CLL cells, including a wide downregulation of multiple components and targets of the BCR signaling pathway. Accordingly, we found decreased levels of phosphorylated signaling nodes downstream of the BCR. Crosslinking-mediated BCR activation antagonized CLL cell death triggered by EC-7072, increased the phosphorylation levels of the abovementioned signaling nodes and upregulated BCL2 expression, suggesting that the mithralog disrupts CLL cell viability by targeting the BCR signaling axis at multiple levels. EC-7072 exerted similar or higher antileukemic activity than that of several available CLL therapies and displayed additive or synergistic interaction with these drugs in killing CLL cells. Overall, our findings provide rationale for future investigation to test whether EC-7072 may be a potential therapeutic option for patients with CLL and other B-cell malignancies.

Tumor Microenvironment and Cell Fusion

Cell fusion is a highly regulated biological process that occurs under both physiological and pathological conditions. The cellular and extracellular environment is critical for the induction of the cell-cell fusion. Aberrant cell fusion is initiated during tumor progression. Tumor microenvironment is a complex dynamic system formed by the interaction between tumor cells and their surrounding cells. Cell-cell fusion mediates direct interaction between tumor cells and their surrounding cells and is associated with tumor initiation and progression. Various microenvironmental factors affect cell fusion in tumor microenvironment and generate hybrids that acquire genomes of both parental cells and exhibit novel characteristics, such as tumor stem cell-like properties, radioresistance, drug resistance, immune evasion, and enhanced migration and invasion abilities, which are closely related to the initiation, invasion, and metastasis of tumor. The phenotypic characteristics of hybrids are based on the phenotypes of parental cells, and the fusion of tumor cells with diverse types of microenvironmental fusogenic cells is concomitant with phenotypic heterogeneity. This review highlights the types of fusogenic cells in tumor microenvironment that can fuse with tumor cells and their specific significance and summarizes the various microenvironmental factors affecting tumor cell fusion. This review may be used as a reference to develop strategies for future research on tumor cell fusion and the exploration of cell fusion-based antitumor therapies.

The dualistic origin of human tumors

Life starts with a zygote, which is formed by the fusion of a haploid sperm and egg. The formation of a blastomere by cleavage division (nuclear division without an increase in cell size) is the first step in embryogenesis, after the formation of the zygote. Blastomeres are responsible for reprogramming the parental genome as a new embryonic genome for generation of the pluripotent stem cells which then differentiate by Waddington's epigenetic landscape to create a new life. Multiple authors over the past 150 years have proposed that tumors arises from development gone awry at a point within Waddington's landscape. Recent discoveries showing that differentiated somatic cells can be reprogrammed into induced pluripotent stem cells, and that somatic cell nuclear transfer can be used to successfully clone animals, have fundamentally reshaped our understanding of tumor development and origin. Differentiated somatic cells are plastic and can be induced to dedifferentiate into pluripotent stem cells. Here, I review the evidence that suggests somatic cells may have a previously overlooked endogenous embryonic program that can be activated to dedifferentiate somatic cells into stem cells of various potencies for tumor initiation. Polyploid giant cancer cells (PGCCs) have long been observed in cancer and were thought originally to be nondividing. Contrary to this belief, recent findings show that stress-induced PGCCs divide by endoreplication, which may recapitulate the pattern of cleavage-like division in blastomeres and lead to dedifferentiation of somatic cells by a programmed process known as "the giant cell cycle", which comprise four distinct but overlapping phases: initiation, self-renewal, termination and stability. Depending on the intensity and type of stress, different levels of dedifferentiation result in the formation of tumors of different grades of malignancy. Based on these results, I propose a unified dualistic model to demonstrate the origin of human tumors. The tenet of this model includes four points, as follows. 1. Tumors originate from a stem cell at a specific developmental hierarchy, which can be achieved by dualistic origin: dedifferentiation of the zygote formed by two haploid gametes (sexual reproduction) via the blastomere during normal development, or transformation from damaged or aged mature somatic cells via a blastomere-like embryonic program (asexual reproduction). 2. Initiation of the tumor begins with a stem cell that has uncoupled the differentiation from the proliferation program which results in stem cell maturation arrest. 3. The developmental hierarchy at which stem cells arrest determines the degree of malignancy: the more primitive the level at which stem cells arrest, the greater the likelihood of the tumor being malignant. 4. Environmental factors and intrinsic genetic or epigenetic alterations represent the risk factors or stressors that facilitate stem cell arrest and somatic cell dedifferentiation. However, they, per se, are not the driving force of tumorigenesis. Thus, the birth of a tumor can be viewed as a triad that originates from a stem cell via dedifferentiation through a blastomere or blastomere-like program, which then differentiates along Waddington's landscape, and arrests at a developmental hierarchy. Blocking the PGCC-mediated dedifferentiation process and inducing their differentiation may represent a novel alternative approach to eliminate the tumor occurrence and therapeutic resistance.

Why AMPK agonists not known to be stressors may surprisingly contribute to miscarriage or hinder IVF/ART

Here we examine recent evidence suggesting that many drugs and diet supplements (DS), experimental AMP-activated protein kinase (AMPK) agonists as well as energy-depleting stress, lead to decreases in anabolism, growth or proliferation, and potency of cultured oocytes, embryos, and stem cells in an AMPK-dependent manner. Surprising data for DS and drugs that have some activity as AMPK agonists in in vitro experiments show possible toxicity. This needs to be balanced against a preponderance of evidence in vivo that these drugs and DS are beneficial for reproduction. We here discuss and analyze data that leads to two possible conclusions: First, although DS and drugs that have some of their therapeutic mechanisms mediated by AMPK activity associated with low ATP levels, some of the associated health problems in vivo and in vitro fertilization/assisted reproductive technologies (IVF/ART) may be better-treated by increasing ATP production using CoQ10 (Ben-Meir et al., Aging Cell 14:887-895, 2015). This enables high developmental trajectories simultaneous with solving stress by energy-requiring responses. In IVF/ART, it is ultimately best to maintain handling and culture of gametes and embryos in the quietest state with low metabolic activity (Leese et al., Mol Hum Reprod 14:667-672, 2008; Leese, Bioessays 24 (9):845-849, 2002) using back-to-nature or simplex algorithms to identify optima (Biggers, Reprod Biomed Online 4 Suppl 1:30-38, 2002). Stress markers, such as checkpoint proteins like TRP53 (aka p53) (Ganeshan et al., Exp Cell Res 358:227-233, 2017); Ganeshan et al., Biol Reprod 83:958-964, 2010) and a small set of kinases from the protein kinome that mediate enzymatic stress responses, can also be used to define optima. But, some gametes or embryos may have been stressed in vivo prior to IVF/ART or IVF/ART optimized for one outcome may be suboptimal for another. Increasing nutrition or adding CoQ10 to increase ATP production (Yang et al., Stem Cell Rev 13:454-464, 2017), managing stress enzyme levels with inhibitors (Xie et al., Mol Hum Reprod 12:217-224, 2006), or adding growth factors such as GM-CSF (Robertson et al., J Reprod Immunol 125:80-88, 2018); Chin et al., Hum Reprod 24:2997-3009, 2009) may increase survival and health of cultured embryos during different stress exposure contexts (Puscheck et al., Adv Exp Med Biol 843:77-128, 2015). We define "stress" as negative stimuli which decrease normal magnitude and speed of development, and these can be stress hormones, reactive oxygen species, inflammatory cytokines, or physical stimuli such as hypoxia. AMPK is normally activated by high AMP, commensurate with low ATP, but it was recently shown that if glucose is present inside the cell, AMPK activation by low ATP/high AMP is suppressed (Zhang et al., Nature 548:112-116, 2017). As we discuss in more detail below, this may also lead to greater AMPK agonist toxicity observed in two-cell embryos that do not import glucose. Stress in embryos and stem cells increases AMPK in large stimulation indexes but also direness indexes; the fastest AMPK activation occurs when stem cells are shifted from optimal oxygen to lower or high levels (Yang et al., J Reprod Dev 63:87-94, 2017). CoQ10 use may be better than risking AMPK-dependent metabolic and developmental toxicity when ATP is depleted and AMPK activated. Second, the use of AMPK agonists, DS, and drugs may best be rationalized when insulin resistance or obesity leads to aberrant hyperglycemia and hypertriglyceridemia, and obesity that negatively affect fertility. Under these conditions, beneficial effects of AMPK on increasing triglyceride and fatty acid and glucose uptake are important, as long as AMPK agonist exposures are not too high or do not occur during developmental windows of sensitivity. During these windows of sensitivity suppression of anabolism, proliferation, and stemness/potency due to AMPK activity, or overexposure may stunt or kill embryos or cause deleterious epigenetic changes.

NSAID use and somatic exomic mutations in Barrett's esophagus

Background

Use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) has been shown to protect against tetraploidy, aneuploidy, and chromosomal alterations in the metaplastic condition Barrett’s esophagus (BE) and to lower the incidence and mortality of esophageal adenocarcinoma (EA). The esophagus is exposed to both intrinsic and extrinsic mutagens resulting from gastric reflux, chronic inflammation, and exposure to environmental carcinogens such as those found in cigarettes. Here we test the hypothesis that NSAID use inhibits accumulation of point mutations/indels during somatic genomic evolution in BE.

Methods

Whole exome sequences were generated from 82 purified epithelial biopsies and paired blood samples from a cross-sectional study of 41 NSAID users and 41 non-users matched by sex, age, smoking, and continuous time using or not using NSAIDs.

Results

NSAID use reduced overall frequency of point mutations across the spectrum of mutation types, lowered the frequency of mutations even when adjusted for both TP53 mutation and smoking status, and decreased the prevalence of clones with high variant allele frequency. Never smokers who consistently used NSAIDs had fewer point mutations in signature 17, which is commonly found in EA. NSAID users had, on average, a 50% reduction in functional gene mutations in nine cancer-associated pathways and also had less diversity in pathway mutational burden compared to non-users.

Conclusions

These results indicate NSAID use functions to limit overall mutations on which selection can act and supports a model in which specific mutant cell populations survive or expand better in the absence of NSAIDs.

Electronic supplementary material

The online version of this article (10.1186/s13073-018-0520-y) contains supplementary material, which is available to authorized users.

Somatic polyploidy is associated with the upregulation of c-MYC interacting genes and EMT-like signature

The dependence of cancer on overexpressed c-MYC and its predisposition for polyploidy represents a double puzzle. We address this conundrum by cross-species transcription analysis of c-MYC interacting genes in polyploid vs. diploid tissues and cells, including human vs. mouse heart, mouse vs. human liver and purified 4n vs. 2n mouse decidua cells. Gene-by-gene transcriptome comparison and principal component analysis indicated that c-MYC interactants are significantly overrepresented among ploidy-associated genes. Protein interaction networks and gene module analysis revealed that the most upregulated genes relate to growth, stress response, proliferation, stemness and unicellularity, as well as to the pathways of cancer supported by MAPK and RAS coordinated pathways. A surprising feature was the up-regulation of epithelial-mesenchymal transition (EMT) modules embodied by the N-cadherin pathway and EMT regulators from SNAIL and TWIST families. Metabolic pathway analysis also revealed the EMT-linked features, such as global proteome remodeling, oxidative stress, DNA repair and Warburg-like energy metabolism. Genes associated with apoptosis, immunity, energy demand and tumour suppression were mostly down-regulated. Noteworthy, despite the association between polyploidy and ample features of cancer, polyploidy does not trigger it. Possibly it occurs because normal polyploidy does not go that far in embryonalisation and linked genome destabilisation. In general, the analysis of polyploid transcriptome explained the evolutionary relation of c-MYC and polyploidy to cancer.

Activation of activator protein 2 alpha by aspirin alleviates atherosclerotic plaque growth and instability in vivo

AIMS

Aspirin has been used for the secondary prevention and treatment of cardiovascular disease for several decades. We investigated the roles of transcriptional factor activator protein 2α (AP-2α) in the beneficial effects of aspirin in the growth and vulnerability of atherosclerotic plaque.

METHODS AND RESULTS

In mice deficient of apolipoprotein E (Apoe-/-), aspirin (20, 50 mg/kg/day) suppressed the progression of atherosclerosis in aortic roots and increased the plaque stability in carotid atherosclerotic plaques induced by collar-placement. In vivo lentivirus-mediated RNA interference of AP-2α reversed the inhibitory effects of aspirin on atherosclerosis in Apoe-/- mice. Mechanically, aspirin increased AP-2α phosphorylation and its activity, upregulated IkBα mRNA and protein levels, and reduced oxidative stress in cultured vascular smooth muscle cells. Furthermore, deficiency of AP-2α completely abolished aspirin-induced upregulation of IkBα levels and inhibition of oxidative stress in Apoe-/- mice. Clinically, conventional doses of aspirin increased AP-2α phosphorylation and IkBα protein expression in humans subjects.

CONCLUSION

Aspirin activates AP-2α to upregulate IkBα gene expression, resulting in attenuations of plaque development and instability in atherosclerosis.

Identification of Resveratrol, an Herbal Compound, as an Activator of the Calcium-Activated Chloride Channel, TMEM16A

Calcium-activated chloride channels (CaCCs) play vital roles in a variety of physiological processes. Dysfunction of the CaCCs is implicated in many diseases. Drug discovery targeting at CaCCs has recently become possible with the determination that TMEM16A is the molecular identity of CaCCs. In this study, we demonstrated that resveratrol (RES), a Chinese traditional medicine compound, is a novel activator of TMEM16A. The yellow fluorescence protein quenching assay and measurement of intracellular calcium fluorescence intensity show that RES activates TMEM16A channels in an intracellular Ca²⁺-independent way. The data of inside-out patch clamp revealed that RES dose-dependently activates TMEM16A (EC₅₀ = 47.92 ± 9.35 μM). Furthermore, RES enhanced the contractions of the ileum of guinea pigs by activating the TMEM16A channel, which indicated that RES might be a promising drug for the treatment of gastrointestinal hypomotility. As RES was able to induce TMEM16A channel activation, TMEM16A can be added to the list of RES drug targets.

Synergism of co-delivered nanosized antioxidants displayed enhanced anticancer efficacy in human colon cancer cell lines

Combination of chemopreventive and/or therapeutic agents is the imminent smart approach to cope up with cancer because it may act on multiple targets through different pathways. In the present study, we have synthesized multiple chemopreventive and/or therapeutic agents (Curcumin, Quercetin and Aspirin) loaded nanoparticles by simple cation-anion interaction among the amine groups of chitosan (CS) and phosphate groups of sodium hexametaphosphate (SHMP). These nanosized bioactive materials (CS-SHMP-CQA-NPs) were well characterized and found most effective in colon cancer cell line (HCT-116) compared to other cancer cell lines. Triplex chemopreventive and/or therapeutic agents-loaded NPs were synergistically inducing apoptosis in HCT-116 cells compared to two-chemopreventive agents-loaded NPs as evident by an increase in sub-G₁ cells (percent), and chromatin condensation along with the decrease in mitochondrial membrane potential (MMP). Interestingly, Chou–Talalay analysis revealed that CS-SHMP-CQA-NPs showed strong synergistic effect in its all doses. Thus, our study demonstrates that nanoparticles based bioactive materials significantly inhibit the growth of HCT-116 cells and thus could be a promising approach for colon cancer chemoprevention.

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Multiple antioxidants loaded nanoparticle base bioactive materials have been synthesized.

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This nanoparticular bioactive materials (CS-SHMP-CQA-NPs) were well characterized and found most effective in colon cancer cell line (HCT-116) compared to other cancer cell lines.

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Nanosized bioactivematerial inhibited HCT-116 cells synergistically, could be a promising approach for colon cancer chemotherapy.

Whole-genome duplication increases tumor cell sensitivity to MPS1 inhibition

Several lines of evidence indicate that whole-genome duplication resulting in tetraploidy facilitates carcinogenesis by providing an intermediate and metastable state more prone to generate oncogenic aneuploidy. Here, we report a novel strategy to preferentially kill tetraploid cells based on the abrogation of the spindle assembly checkpoint (SAC) via the targeting of TTK protein kinase (better known as monopolar spindle 1, MPS1). The pharmacological inhibition as well as the knockdown of MPS1 kills more efficiently tetraploid cells than their diploid counterparts. By using time-lapse videomicroscopy, we show that tetraploid cells do not survive the aborted mitosis due to SAC abrogation upon MPS1 depletion. On the contrary diploid cells are able to survive up to at least two more cell cycles upon the same treatment. This effect might reflect the enhanced difficulty of cells with whole-genome doubling to tolerate a further increase in ploidy and/or an elevated level of chromosome instability in the absence of SAC functions. We further show that MPS1-inhibited tetraploid cells promote mitotic catastrophe executed by the intrinsic pathway of apoptosis, as indicated by the loss of mitochondrial potential, the release of the pro-apoptotic cytochrome c from mitochondria, and the activation of caspases. Altogether, our results suggest that MPS1 inhibition could be used as a therapeutic strategy for targeting tetraploid cancer cells.

Centrosome amplification, chromosomal instability and cancer: mechanistic, clinical and therapeutic issues

Centrosomes, the main microtubule-organizing centers in most animal cells, are of crucial importance for the assembly of a bipolar mitotic spindle and subsequent faithful segregation of chromosomes into two daughter cells. Centrosome abnormalities can be found in virtually all cancer types and have been linked to chromosomal instability (CIN) and tumorigenesis. Although our knowledge on centrosome structure, replication, and amplification has greatly increased within recent years, still only very little is known on nature, causes, and consequences of centrosome aberrations in primary tumor tissues. In this review, we summarize our current insights into the mechanistic link between centrosome aberrations, aneuploidy, CIN and tumorigenesis. Mechanisms of induction and cellular consequences of aneuploidy, tetraploidization and CIN, as well as origin and effects of supernumerary centrosomes will be discussed. In addition, animal models for both CIN and centrosome amplification will be outlined. Finally, we describe approaches to exploit centrosome amplification, aneuploidy and CIN for novel and specific anticancer treatment strategies based on the modulation of chromosome missegregation rates.

Morphometric analysis of immunoselection against hyperploid cancer cells

An at least transient increase of ploidy, usually by whole genome duplication, is a frequent event in oncogenesis, explaining the cytogenetic features of at least 40% of solid cancers. Here, we show that fibrosarcomas induced by the carcinogen methylcholanthrene (MCA) are distinct with respect to their ploidy status when they arise in immunocompetent wild type versus severely immunodeficient Rag2^−/−γc^−/− mice. MCA-induced fibrosarcomas are particularly hyperploid if they develop in an immunodeficient setting, correlating with higher DNA content, increased nuclear surface, as well as hyperphosphorylation of eukaryotic initiation factor 2` (eIF2`), a biomarker indicating endoplasmic reticulum (ER) stress. Upon transfer of such cells into wild type mice, such hyperploid, ER-stressed cells (that originated in Rag2^−/−γc^−/− mice) fail to proliferate and actually induce a protective anticancer immune response. In contrast, such cells do form tumors in Rag2^−/−γc^−/− recipients (which lack T, B and NK cells) as well as in Rag2^−/− recipients (which only lack T and B lymphocytes) and conserve their hyperploidy as well as eIF2` hyperphosphorylation. To measure these parameters, we developed a morphometric analysis tool that is applicable to immunohistochemistry of formaldehyde-fixed, paraffin-embedded tissues. This software automatically identifies and quantifies the surface of nuclei and determines the intensity of eIF2` phosphorylation within a perinuclear region of interest. Comparative analyses performed on cultured cells and tissue sections validated the accuracy of this method, which can be used to investigate ploidy and ER stress in cancers in situ.

Emerging links among Chromosome Instability (CIN), cancer, and aging

Aneuploidy was predicted to cause cancer. To test the prediction, various Chromosome Instability (CIN) mice models that carry transgenic mutations in mitotic regulators have been created. The availability of these mice has aided researchers in discovering connections between CIN, cancer, and aging. This review will focus on recent interdisciplinary findings regarding how CIN and aneuploidy affect carcinogenesis, immune dysfunction, and aging. High CIN can be generated in vivo by various intrinsic alterations (e.g., gene mutation, epigenetic modification) and extrinsic/environmental challenges (e.g., biological, chemical, biophysical), while immune surveillance, cell death, and natural turnover can remove cells with CIN. CIN itself is mutagenic and may cause further cellular mutations, which can be carcinogenic. Mitotically damaged cells can activate senescence-related tumor suppressors (e.g., p21^WAF1 , p27^KIP1 , p16^INK4A ), which may lead to tissue-level senescence/aging through inflammatory paracrine mechanisms called Senescence-Associated Secretory Phenotype (SASP) and Senescence Inflammatory Response (SIR). Organs with high CIN show altered gene expressions in both organ-specific and non-specific manners. Organ-specific gene expression signatures include activation of oncogenic pathways. Non-organ-specific gene expression signatures include metabolic changes and downregulations in immune functions. Immune surveillance normally targets senescent cells and tetraploid cells, a form of aneuploidy, for elimination. However, with partial immune dysfunction, immune surveillance is weakened with systemic CIN. In this case, more senescent cells and aneuploid cells survive, which further leads to an inflammatory, pro-tumorigenic, and senescent/aging microenvironment. We also discuss how we may intervene in this sequence of events to prevent CIN- or age-related carcinogenesis and/or some aspects of tissue aging. © 2016 Wiley Periodicals, Inc.

Aspirin in pancreatic cancer: chemopreventive effects and therapeutic potentials

Pancreatic cancer is one of the most aggressive malignancies with dismal prognosis. Recently, aspirin has been found to be an effective chemopreventive agent for many solid tumors. However, the function of aspirin use in pancreatic cancer largely remains unknown. We herein argued that aspirin could also lower the risk of pancreatic cancer. Importantly, aspirin assumes pleiotropic effects by targeting multiple molecules. It could further target the unique tumor biology of pancreatic cancer and modify the cancer microenvironment, thus showing remarkable therapeutic potentials. Besides, aspirin could reverse the chemoradiation resistance by repressing tumor repopulation and exert synergistic potentials with metformin on pancreatic cancer chemoprevention. Moreover, aspirin secondarily benefits pancreatic cancer patients through modestly reducing cancer pain and the risk of venous thromboembolism. Furthermore, new aspirin derivatives and delivery systems might help to improve risk-to-benefit ratio. In brief, aspirin is a promising chemopreventive agent and exerts significant therapeutic potentials in pancreatic cancer.

Cell Fusion in the War on Cancer: A Perspective on the Inception of Malignancy

Cell fusion occurs in development and in physiology and rarely in those settings is it associated with malignancy. However, deliberate fusion of cells and possibly untoward fusion of cells not suitably poised can eventuate in aneuploidy, DNA damage and malignant transformation. How often cell fusion may initiate malignancy is unknown. However, cell fusion could explain the high frequency of cancers in tissues with low underlying rates of cell proliferation and mutation. On the other hand, cell fusion might also engage innate and adaptive immune surveillance, thus helping to eliminate or retard malignancies. Here we consider whether and how cell fusion might weigh on the overall burden of cancer in modern societies.

Surrogate Markers: Lessons from the Next Gen?

The article by Banerjee and colleagues published in this issue of the journal involving a randomized control prevention trial of ursodeoxycholic acid (UDCA) in Barrett esophagus reported a null outcome despite being well designed and executed. Possible reasons for this null outcome are discussed focusing on use of surrogate endpoints in the trial. The trial is especially topical because it comes at a time when there are calls for a Pre-Cancer Genome Atlas (PCGA) for "understanding the earliest molecular and cellular events associated with cancer initiation…" This commentary discusses current concepts in prevention research including branched evolution that leads to therapeutic resistance. Length bias sampling postulates underdiagnosis is due to rapidly progressing disease that is difficult to detect by screening because it progresses to cancer too rapidly and that overdiagnosis is the result of very slowly or nonprogressing disease that is easy to detect by screening because it persists for a lifetime and the patient dies of unrelated causes. Finally, it also explores study designs, including surrogate endpoints in Barrett esophagus trials, and opportunities and pitfalls for a PCGA in the context of high levels of over and underdiagnosis of Barrett esophagus as well as many other cancers and their precursors. Cancer Prev Res; 9(7); 512-7. ©2016 AACRSee related article by Banerjee, et al., p. 528.

Antiproliferative Fate of the Tetraploid Formed after Mitotic Slippage and Its Promotion; A Novel Target for Cancer Therapy Based on Microtubule Poisons

Microtubule poisons inhibit spindle function, leading to activation of spindle assembly checkpoint (SAC) and mitotic arrest. Cell death occurring in prolonged mitosis is the first target of microtubule poisons in cancer therapies. However, even in the presence of microtubule poisons, SAC and mitotic arrest are not permanent, and the surviving cells exit the mitosis without cytokinesis (mitotic slippage), becoming tetraploid. Another target of microtubule poisons-based cancer therapy is antiproliferative fate after mitotic slippage. The ultimate goal of both the microtubule poisons-based cancer therapies involves the induction of a mechanism defined as mitotic catastrophe, which is a bona fide intrinsic oncosuppressive mechanism that senses mitotic failure and responds by driving a cell to an irreversible antiproliferative fate of death or senescence. This mechanism of antiproliferative fate after mitotic slippage is not as well understood. We provide an overview of mitotic catastrophe, and explain new insights underscoring a causal association between basal autophagy levels and antiproliferative fate after mitotic slippage, and propose possible improved strategies. Additionally, we discuss nuclear alterations characterizing the mitotic catastrophe (micronuclei, multinuclei) after mitotic slippage, and a possible new type of nuclear alteration (clustered micronuclei).

Genome management and mismanagement--cell-level opportunities and challenges of whole-genome duplication

Whole-genome duplication (WGD) doubles the DNA content in the nucleus and leads to polyploidy. In whole-organism polyploids, WGD has been implicated in adaptability and the evolution of increased genome complexity, but polyploidy can also arise in somatic cells of otherwise diploid plants and animals, where it plays important roles in development and likely environmental responses. As with whole organisms, WGD can also promote adaptability and diversity in proliferating cell lineages, although whether WGD is beneficial is clearly context-dependent. WGD is also sometimes associated with aging and disease and may be a facilitator of dangerous genetic and karyotypic diversity in tumorigenesis. Scaling changes can affect cell physiology, but problems associated with WGD in large part seem to arise from problems with chromosome segregation in polyploid cells. Here we discuss both the adaptive potential and problems associated with WGD, focusing primarily on cellular effects. We see value in recognizing polyploidy as a key player in generating diversity in development and cell lineage evolution, with intriguing parallels across kingdoms.

Sustained proliferation in cancer: Mechanisms and novel therapeutic targets

Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth. Early steps in tumor development are associated with a fibrogenic response and the development of a hypoxic environment which favors the survival and proliferation of cancer stem cells. Part of the survival strategy of cancer stem cells may manifested by alterations in cell metabolism. Once tumors appear, growth and metastasis may be supported by overproduction of appropriate hormones (in hormonally dependent cancers), by promoting angiogenesis, by undergoing epithelial to mesenchymal transition, by triggering autophagy, and by taking cues from surrounding stromal cells. A number of natural compounds (e.g., curcumin, resveratrol, indole-3-carbinol, brassinin, sulforaphane, epigallocatechin-3-gallate, genistein, ellagitannins, lycopene and quercetin) have been found to inhibit one or more pathways that contribute to proliferation (e.g., hypoxia inducible factor 1, nuclear factor kappa B, phosphoinositide 3 kinase/Akt, insulin-like growth factor receptor 1, Wnt, cell cycle associated proteins, as well as androgen and estrogen receptor signaling). These data, in combination with bioinformatics analyses, will be very important for identifying signaling pathways and molecular targets that may provide early diagnostic markers and/or critical targets for the development of new drugs or drug combinations that block tumor formation and progression.

Identification of Selective Lead Compounds for Treatment of High-Ploidy Breast Cancer

Increased ploidy is common in tumors but treatments for tumors with excess chromosome sets are not available. Here, we characterize high-ploidy breast cancers and identify potential anticancer compounds selective for the high-ploidy state. Among 354 human breast cancers, 10% have mean chromosome copy number exceeding 3, and this is most common in triple-negative and HER2-positive types. Women with high-ploidy breast cancers have higher risk of recurrence and death in two patient cohorts, demonstrating that it represents an important group for improved treatment. Because high-ploidy cancers are aneuploid, rather than triploid or tetraploid, we devised a two-step screen to identify selective compounds. The screen was designed to assure both external validity on diverse karyotypic backgrounds and specificity for high-ploidy cell types. This screen identified novel therapies specific to high-ploidy cells. First, we discovered 8-azaguanine, an antimetabolite that is activated by hypoxanthine phosphoribosyltransferase 1 (HPRT1), suggesting an elevated gene-dosage of HPRT1 in high-ploidy tumors can control sensitivity to this drug. Second, we discovered a novel compound, 2,3-diphenylbenzo[g]quinoxaline-5,10-dione (DPBQ). DPBQ activates p53 and triggers apoptosis in a polyploid-specific manner, but does not inhibit topoisomerase or bind DNA. Mechanistic analysis demonstrates that DPBQ elicits a hypoxia gene signature and its effect is replicated, in part, by enhancing oxidative stress. Structure-function analysis defines the core benzo[g]quinoxaline-5,10 dione as being necessary for the polyploid-specific effects of DPBQ. We conclude that polyploid breast cancers represent a high-risk subgroup and that DPBQ provides a functional core to develop polyploid-selective therapy. Mol Cancer Ther; 15(1); 48-59. ©2015 AACR.

Aspirin Targets SIRT1 and AMPK to Induce Senescence of Colorectal Carcinoma Cells

Cancer therapies attempt to destroy the entire tumor, but this tends to require toxic compounds and high doses of radiation. Recently, considerable attention has focused on therapy-induced senescence (TIS), which can be induced in cancer cells by low doses of therapeutic drugs or radiation and provides a barrier to tumor development. However, the molecular mechanisms governing TIS remain elusive. Special attention has been paid to the potential chemopreventive effect of aspirin against human colorectal cancer. In this study, we investigated the effects of aspirin on TIS of human colorectal carcinoma (CRC) cells and show that it occurs via sirtuin 1 (SIRT1) and AMP-activated protein kinase (AMPK), two key regulators of cellular metabolism. Aspirin increased the senescence of CRC cells, increased the protein levels of SIRT1, phospho-AMPK (T172), and phospho-acetyl CoA carboxylase (S79), and reduced the cellular level of ATP. Small-interfering RNA-mediated downregulation or pharmacological inhibition of SIRT1 or AMPK significantly attenuated the aspirin-induced cellular senescence in CRC cells. In contrast, treatment with a SIRT1 agonist or an AMP analog induced cellular senescence. Remarkably, SIRT1 knockdown abrogated the aspirin-induced activation of AMPK, and vice versa. During the progression of aspirin-induced cellular senescence in CRC cells, SIRT1 showed increased deacetylase activity at a relatively early time point but was characterized by decreased activity with increased cytoplasmic localization at a later time point. Collectively, these novel findings suggest that aspirin could provide anticancer effects by inducing senescence in human CRC cells through the reciprocal regulation of SIRT1-AMPK pathways.