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

Interleukin-6 Is a Crucial Factor in Shaping the Inflammatory Tumor Microenvironment in Ovarian Cancer and Determining Its Hot or Cold Nature with Diagnostic and Prognostic Utilities

Ovarian cancer (OC) remains the leading cause of cancer-related deaths among women, often diagnosed at advanced stages due to the lack of effective early diagnostic procedures. To reduce the high mortality rates in OC, reliable biomarkers are urgently needed, especially to detect OC at its earliest stage, predict specific drug responses, and monitor patients. The cytokine interleukin-6 (IL6) is associated with low survival rates, treatment resistance, and recurrence. In this review, we summarize the role of IL6 in inflammation and how IL6 contributes to ovarian tumorigenesis within the tumor microenvironment, influencing whether the tumor is subsequently classified as "hot" or "cold". We further dissect the molecular and cellular mechanisms through which IL6 production and downstream signaling are regulated, to enhance our understanding of its involvement in OC development, as well as OC resistance to treatment. We highlight the potential of IL6 to be used as a reliable diagnostic biomarker to help detect OC at its earliest stage, and as a part of predictive and prognostic signatures to improve OC management. We further discuss ways to leverage artificial intelligence and machine learning to integrate IL6 into diverse biomarker-based strategies.

Global modulation of gene expression and transcriptome size in aneuploid combinations of maize

Genomic imbalance refers to the more severe phenotypic consequences of changing a single chromosome compared to changing the whole genomic set. Previous genomic imbalance studies in maize have identified gene expression modulation in aneuploids of single chromosome arms. Here, the modulation of gene expression in more complex aneuploids, e.g., monosomy of one chromosome arm and trisomy of another was examined to determine the extent that combination aneuploids were additive, multiplicative, or rebalanced in terms of their effect on gene expression. A series of genetic crosses was performed to produce one, two, and three copies of one arm with independent one, two, and three copies of the other arm in each of the three genotypes for the opposite arm. In total, 31 combinations were analyzed. By examining RNA modulation, we found that cis genes on varied chromosome arms are generally more dosage-compensated in aneuploid combinations than in single aneuploidy even though some showed a clear dosage effect. For genes on the unvaried chromosomes (trans), there is greater modulation in most of the aneuploidy combinations. Finally, 22 of the 31 combinations were found to have an altered transcriptome size, suggesting that extensive stoichiometric changes of genomic regions upset global messenger RNA (mRNA) transcription. Overall, these results have important implications for understanding the role of genomic stoichiometry for mechanisms of gene expression, the evolution of dosage-sensitive duplicated genes, the evolution of sex chromosomes, the rapid growth adaptation of aneuploid cancer cells, and the control of quantitative traits.

Epithelial-mesenchymal transition orchestrates tumor microenvironment: current perceptions and challenges

The epithelial-mesenchymal transition (EMT) is a critical process in cancer progression, facilitating tumor cells to develop invasive traits and augmenting their migratory capabilities. EMT is primed by tumor microenvironment (TME)-derived signals, whereupon cancer cells undergoing EMT in turn remodel the TME, thereby modulating tumor progression and therapeutic response. This review discusses the mechanisms by which EMT coordinates TME dynamics, including secretion of soluble factors, direct cell contact, release of exosomes and enzymes, as well as metabolic reprogramming. Recent evidence also indicates that cells undergoing EMT may differentiate into cancer-associated fibroblasts, thereby establishing themselves as functional constituents of the TME. Elucidating the relationship between EMT and the TME offers novel perspectives for therapeutic strategies to enhance cancer treatment efficacy. Although EMT-directed therapies present significant therapeutic potential, the current lack of effective targeting approaches-attributable to EMT complexity and its microenvironmental context dependency-underscores the necessity for mechanistic investigations and translational clinical validation.

Oncogenic signaling in the Drosophila prostate-like accessory gland activates a pro-tumorigenic program in the absence of proliferation

Drosophila models for tumorigenesis have revealed conserved mechanisms of signaling involved in mammalian cancer. Many of these models use highly mitotically active Drosophila tissues. Few Drosophila tumorigenesis models use adult tissues, when most cells are terminally differentiated and postmitotic. The Drosophila accessory glands are prostate-like tissues, and a model for prostate tumorigenesis using this tissue has been explored. In this prior model, oncogenic signaling was induced during the proliferative stages of accessory gland development, raising the question of how oncogenic activity impacts the terminally differentiated, postmitotic adult tissue. Here, we show that oncogenic signaling in the adult Drosophila accessory gland leads to activation of a conserved pro-tumorigenic program, similar to that of mitotic tissues, but in the absence of proliferation. In our experiments, oncogenic signaling in the adult gland led to tissue hypertrophy with nuclear anaplasia, in part through endoreduplication. Oncogene-induced gene expression changes in the adult Drosophila prostate-like model overlapped with those in polyploid prostate cancer cells after chemotherapy, which potentially mediate tumor recurrence. Thus, the adult accessory glands provide a useful model for aspects of prostate cancer progression that lack cellular proliferation.

Cells in the Polyaneuploid Cancer Cell State Are Prometastatic

Our research aims to understand the adaptive-ergo potentially metastatic-responses of prostate cancer to changing microenvironments. Emerging evidence implicates a role of the polyaneuploid cancer cell (PACC) state in metastasis, positing the PACC state as capable of conferring metastatic competency. Mounting in vitro evidence supports increased metastatic potential of cells in the PACC state. Additionally, our recent retrospective study revealed that PACC presence in patient prostate tumors at the time of radical prostatectomy was predictive of future metastasis. To test for a causative relationship between PACC state biology and metastasis in prostate cancer, we leveraged a novel method designed for flow cytometric detection of circulating tumor cells (CTC) and disseminated tumor cells (DTC) from animal models. This approach provides both quantitative and qualitative information about the number and PACC status of recovered CTCs and DTCs. Specifically, we applied this approach to the analysis of subcutaneous, caudal artery, and intracardiac murine models. Collating data from all models, we found that 74% of recovered CTCs and DTCs were in the PACC state. Furthermore, in vivo colonization assays proved that PACC populations can regain proliferative capacity at metastatic sites. Additional in vitro analyses revealed a PACC-specific partial epithelial-to-mesenchymal transition phenotype and a prometastatic secretory profile, together providing preliminary evidence of prometastatic mechanisms specific to the PACC state. Implications: Considering that many anticancer agents induce the PACC state, our data position the increased metastatic competency of PACC state cells as an important unforeseen ramification of neoadjuvant regimens, which may help explain clinical correlations between chemotherapy and metastatic progression.

Cancer nuclear envelope rupture and repair in taxane resistance

Taxanes, including paclitaxel, docetaxel, and cabazitaxel, are key agents in cancer treatment, often used as front-line chemotherapy drugs in combination with other agent(s) (commonly carboplatin) and as second-line treatments alone. Generally, taxanes are highly effective, but drug resistance unavoidably develops following repeated treatment. Taxanes work by binding to and stabilizing microtubules, leading to mitotic arrest, mitotic catastrophe, and micronucleation. The long-recognized mechanisms of drug resistance generally can be classified into three categories: drug efflux, microtubule polymerization, and apoptotic pathway. A recent new addition to this list is a mechanism related to the nuclear envelope, as cancer cells undergo micronucleation and nuclear membrane rupture when treated with taxanes. All these mechanisms may operate simultaneously as taxane resistance is multi-factorial. Here, we review the cell biology understanding of nuclear envelope breaking in production of micronucleation, and nuclear membrane rupture and repair, and propose that these processes are involved in taxane resistance.

Multicompartmentalized Microvascularized Tumor-on-a-Chip to Study Tumor-Stroma Interactions and Drug Resistance in Ovarian Cancer

Introduction

The majority of ovarian cancer (OC) patients receiving standard of care chemotherapy develop chemoresistance within 5 years. The tumor microenvironment (TME) is a dynamic and influential player in disease progression and therapeutic response. However, there is a lack of models that allow us to elucidate the compartmentalized nature of TME in a controllable, yet physiologically relevant manner and its critical role in modulating drug resistance.

Methods

We developed a 3D microvascularized multiniche tumor-on-a-chip formed by five chambers (central cancer chamber, flanked by two lateral stromal chambers and two external circulation chambers) to recapitulate OC-TME compartmentalization and study its influence on drug resistance. Stromal chambers included endothelial cells alone or cocultured with normal fibroblasts or cancer-associated fibroblasts (CAF).

Results

The tumor-on-a-chip recapitulated spatial TME compartmentalization including vessel-like structure, stromal-mediated extracellular matrix (ECM) remodeling, generation of oxygen gradients, and delayed drug diffusion/penetration from the circulation chamber towards the cancer chamber. The cancer chamber mimicked metastasis-like migration and increased drug resistance to carboplatin/paclitaxel treatment in the presence of CAF when compared to normal fibroblasts. CAF-mediated drug resistance was rescued by ECM targeted therapy. Critically, these results demonstrate that cellular crosstalk recreation and spatial organization through compartmentalization are essential to determining the effect of the compartmentalized OC-TME on drug resistance.

Conclusions

Our results present a functionally characterized microvascularized multiniche tumor-on-a-chip able to recapitulate TME compartmentalization influencing drug resistance. This technology holds the potential to guide the design of more effective and targeted therapeutic strategies to overcome chemoresistance in OC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-024-00817-y.

Senescence-associated secretory phenotype regulation by dual drug delivery biomimetic nanoplatform for enhanced tumor chemotherapy

Many chemotherapies, which are still the main clinical treatment for primary tumors, will induce persistent DNA damage in non-tumor stromal cells, especially cancer-associated fibroblasts (CAFs), and activate them to secrete senescence-associated secretory phenotype (SASP). The transition could further result in the formation of tumor immunosuppressive microenvironment and cause drug resistance of neighboring tumor cells. To solve this dilemma, a multi-functional biomimetic drug delivery system (named mPtP@Lipo) was rationally developed by combining CAFs reshaper ginsenoside 20(S)-protopanaxadiol (PPD) and cisplatin prodrug (PtLA) to inhibit tumor progression and the formation of SASP. To achieve effective delivery of these molecules deep into the desmoplastic tumor, fibroblast membrane was fused with liposomes as a targeting carrier. In vitro and in vivo results showed that mPtP@Lipo could penetrate deep into the tumor, reverse CAFs phenotype and inhibit SASP formation, which then blocked the immunosuppressive progress and thus reinforced anti-tumor immune response. The combination of chemotherapeutics and CAFs regulator could achieve both tumor inhibition and tumor immune microenvironment remodeling. In conclusion, mPtP@Lipo provides a promising strategy for the comprehensive stromal-desmoplastic tumor treatment.

An unscheduled switch to endocycles induces a reversible senescent arrest that impairs growth of the Drosophila wing disc

A programmed developmental switch to G / S endocycles results in tissue growth through an increase in cell size. Unscheduled, induced endocycling cells (iECs) promote wound healing but also contribute to cancer. Much remains unknown, however, about how these iECs affect tissue growth. Using the D. melanogaster wing disc as model, we find that populations of iECs initially increase in size but then subsequently undergo a heterogenous arrest that causes severe tissue undergrowth. iECs acquired DNA damage and activated a Jun N-terminal kinase (JNK) pathway, but, unlike other stressed cells, were apoptosis-resistant and not eliminated from the epithelium. Instead, iECs entered a JNK-dependent and reversible senescent-like arrest. Senescent iECs promoted division of diploid neighbors, but this compensatory proliferation did not rescue tissue growth. Our study has uncovered unique attributes of iECs and their effects on tissue growth that have important implications for understanding their roles in wound healing and cancer.

Efficient separation of large particles and giant cancer cells using an isosceles trapezoidal spiral microchannel

Polyploid giant cancer cells (PGCCs) contribute to the genetic heterogeneity and evolutionary dynamics of tumors. Their size, however, complicates their isolation from mainstream tumor cell populations. Standard techniques like fluorescence-activated cell sorting (FACS) rely on fluorescent labeling, introducing potential challenges in subsequent PGCC analyses. In response, we developed the Isosceles Trapezoidal Spiral Microchannel (ITSμC), a microfluidic device optimizing the Dean drag force (FD) and exploiting uniform vortices for enhanced separation. Numerical simulations highlighted ITSμC's advantage in producing robust FD compared to rectangular and standard trapezoidal channels. Empirical results confirmed its ability to segregate larger polystyrene (PS) particles (avg. diameter: 50 μm) toward the inner wall, while directing smaller ones (avg. diameter: 23 μm) outward. Utilizing ITSμC, we efficiently isolated PGCCs from doxorubicin-resistant triple-negative breast cancer (DOXR-TNBC) and patient-derived cancer (PDC) cells, achieving outstanding purity, yield, and viability rates (all greater than 90%). This precision was accomplished without fluorescent markers, and the versatility of ITSμC suggests its potential in differentiating a wide range of heterogeneous cell populations.

Cells in the Polyaneuploid Cancer Cell State are Pro-Metastatic

There remains a large need for a greater understanding of the metastatic process within the prostate cancer field. Our research aims to understand the adaptive - ergo potentially metastatic - responses of cancer to changing microenvironments. Emerging evidence has implicated a role of the Polyaneuploid Cancer Cell (PACC) state in metastasis, positing the PACC state as capable of conferring metastatic competency. Mounting in vitro evidence supports increased metastatic potential of cells in the PACC state. Additionally, our recent retrospective study of prostate cancer patients revealed that PACC presence in the prostate at the time of radical prostatectomy was predictive of future metastatic progression. To test for a causative relationship between PACC state biology and metastasis, we leveraged a novel method designed for flow-cytometric detection of circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) in subcutaneous, caudal artery, and intracardiac mouse models of metastasis. This approach provides both quantitative and qualitative information about the number and PACC-status of recovered CTCs and DTCs. Collating data from all models, we found that 74% of recovered CTCs and DTCs were in the PACC state. In vivo colonization assays proved PACC populations can regain proliferative capacity at metastatic sites following dormancy. Additional direct and indirect mechanistic in vitro analyses revealed a PACC-specific partial Epithelial-to-Mesenchymal-Transition phenotype and a pro-metastatic secretory profile, together providing preliminary evidence that PACCs are mechanistically linked to metastasis.

Polyploid giant cancer cells induced by Docetaxel exhibit a senescence phenotype with the expression of stem cell markers in ovarian cancer cells

Docetaxel (Doc) plays a crucial role in clinical antineoplastic practice. However, it is continuously documented that tumors frequently develop chemoresistance and relapse, which may be related to polyploid giant cancer cells (PGCCs). The aim of this study was investigate the formation mechanism and biological behavior of PGCCs induced by Doc. Ovarian cancer cells were treated with Doc, and then the effect of Doc on cellular viability was evaluated by MTT assay and microscopic imaging analysis. The biological properties of PGCCs were further evaluated by Hoechst 33342 staining, cell cycle and DNA content assay, DNA damage response (DDR) signaling detection, β-galactosidase staining, mitochondrial membrane potential detection, and reverse transcription-quantitative polymerase chain reaction. The results indicated that Doc reduced cellular viability; however, many cells were still alive, and were giant and polyploid. Doc increased the proportion of cells stayed in the G2/M phase and reduced the number of cells. In addition, the expression of γ-H2A.X was constantly increased after Doc treatment. PGCCs showed senescence-associated β-galactosidase activity and an increase in the monomeric form of JC-1. The mRNA level of octamer-binding transcription factor 4 (OCT4) and krüppel-like factor 4 (KLF4) was significantly increased in PGCCs. Taken together, our results suggest that Doc induces G2/M cell cycle arrest, inhibits the proliferation and activates persistent DDR signaling to promote the formation of PGCCs. Importantly, PGCCs exhibit a senescence phenotype and express stem cell markers.

Oncogenic signaling in the adult Drosophila prostate-like accessory gland leads to activation of a conserved pro-tumorigenic program, in the absence of proliferation

Drosophila models for tumorigenesis and metastasis have revealed conserved mechanisms of signaling that are also involved in mammalian cancer. Many of these models use the proliferating tissues of the larval stages of Drosophila development, when tissues are highly mitotically active, or stem cells are abundant. Fewer Drosophila tumorigenesis models use adult animals to initiate tumor formation when many tissues are largely terminally differentiated and postmitotic. The Drosophila accessory glands are prostate-like tissues and a model for some aspects of prostate tumorigenesis using this tissue has been explored. In this model, oncogenic signaling was induced during the proliferative stage of accessory gland development, raising the question of how oncogenic activity would impact the terminally differentiated and postmitotic adult tissue. Here, we show that oncogenic signaling in the adult Drosophila accessory gland leads to activation of a conserved pro-tumorigenic program, similar to that observed in mitotic larval tissues, but in the absence of proliferation. Oncogenic signaling in the adult postmitotic gland leads to tissue hyperplasia with nuclear anaplasia and aneuploidy through endoreduplication, which increases polyploidy and occasionally results in non-mitotic neoplastic-like extrusions. We compare gene expression changes in our Drosophila model with that of endocycling prostate cancer cells induced by chemotherapy, which potentially mediate tumor recurrence after treatment. Similar signaling pathways are activated in the Drosophila gland and endocycling cancer cells, suggesting the adult accessory glands provide a useful model for aspects of prostate cancer progression that do not involve cellular proliferation.

Multicompartmentalized microvascularized tumor-on-a-chip to study tumor-stroma interactions and drug resistance in ovarian cancer

Introduction

The majority of ovarian cancer (OC) patients receiving standard of care chemotherapy develop chemoresistance within 5 years. The tumor microenvironment (TME) is a dynamic and influential player in disease progression and therapeutic response. However, there is a lack of models that allow us to elucidate the compartmentalized nature of TME in a controllable, yet physiologically relevant manner and its critical role in modulating drug resistance.

Methods

We developed a 3D microvascularized multiniche tumor-on-a-chip formed by five chambers (central cancer chamber, flanked by two lateral stromal chambers and two external circulation chambers) to recapitulate OC-TME compartmentalization and study its influence on drug resistance. Stromal chambers included endothelial cells alone or cocultured with normal fibroblasts or cancer-associated fibroblasts (CAF).

Results

The tumor-on-a-chip recapitulated spatial TME compartmentalization including vessel-like structure, stromal-mediated extracellular matrix (ECM) remodeling, generation of oxygen gradients, and delayed drug diffusion/penetration from the circulation chamber towards the cancer chamber. The cancer chamber mimicked metastasis-like migration and increased drug resistance to carboplatin/paclitaxel treatment in the presence of CAF when compared to normal fibroblasts. CAF-mediated drug resistance was rescued by ECM targeted therapy. Critically, these results demonstrate that cellular crosstalk recreation and spatial organization through compartmentalization are essential to determining the effect of the compartmentalized OC-TME on drug resistance.

Conclusions

Our results present a functionally characterized microvascularized multiniche tumor-on-a-chip able to recapitulate TME compartmentalization influencing drug resistance. This technology holds the potential to guide the design of more effective and targeted therapeutic strategies to overcome chemoresistance in OC.

Cellular Transformation by Human Cytomegalovirus

Epstein-Barr virus (EBV), Kaposi sarcoma human virus (KSHV), human papillomavirus (HPV), hepatitis B and C viruses (HBV, HCV), human T-lymphotropic virus-1 (HTLV-1), and Merkel cell polyomavirus (MCPyV) are the seven human oncoviruses reported so far. While traditionally viewed as a benign virus causing mild symptoms in healthy individuals, human cytomegalovirus (HCMV) has been recently implicated in the pathogenesis of various cancers, spanning a wide range of tissue types and malignancies. This perspective article defines the biological criteria that characterize the oncogenic role of HCMV and based on new findings underlines a critical role for HCMV in cellular transformation and modeling the tumor microenvironment as already reported for the other human oncoviruses.

Deciphering the Molecular Mechanisms behind Drug Resistance in Ovarian Cancer to Unlock Efficient Treatment Options

Ovarian cancer is a highly lethal form of gynecological cancer. This disease often goes undetected until advanced stages, resulting in high morbidity and mortality rates. Unfortunately, many patients experience relapse and succumb to the disease due to the emergence of drug resistance that significantly limits the effectiveness of currently available oncological treatments. Here, we discuss the molecular mechanisms responsible for resistance to carboplatin, paclitaxel, polyadenosine diphosphate ribose polymerase inhibitors, and bevacizumab in ovarian cancer. We present a detailed analysis of the most extensively investigated resistance mechanisms, including drug inactivation, drug target alterations, enhanced drug efflux pumps, increased DNA damage repair capacity, and reduced drug absorption/accumulation. The in-depth understanding of the molecular mechanisms associated with drug resistance is crucial to unveil new biomarkers capable of predicting and monitoring the kinetics during disease progression and discovering new therapeutic targets.

Polyploidy in Cancer: Causal Mechanisms, Cancer-Specific Consequences, and Emerging Treatments

Drug resistance is the major determinant for metastatic disease and fatalities, across all cancers. Depending on the tissue of origin and the therapeutic course, a variety of biological mechanisms can support and sustain drug resistance. Although genetic mutations and gene silencing through epigenetic mechanisms are major culprits in targeted therapy, drug efflux and polyploidization are more global mechanisms that prevail in a broad range of pathologies, in response to a variety of treatments. There is an unmet need to identify patients at risk for polyploidy, understand the mechanisms underlying polyploidization, and to develop strategies to predict, limit, and reverse polyploidy thus enhancing efficacy of standard-of-care therapy that improve better outcomes. This literature review provides an overview of polyploidy in cancer and offers perspective on patient monitoring and actionable therapy.

Transcriptome analysis of polyploid giant cancer cells and their progeny reveals a functional role for p21 in polyploidization and depolyploidization

Polyploid giant cancer cells (PGCC) are frequently detected in tumors and are increasingly recognized for their roles in chromosomal instability and associated genome evolution that leads to cancer recurrence. We previously reported that therapy stress promotes polyploidy, and that acid ceramidase plays a role in depolyploidization. In this study, we used an RNA-seq approach to gain a better understanding of the underlying transcriptomic changes that occur as cancer cells progress through polyploidization and depolyploidization. Our results revealed gene signatures that are associated with disease-free and/or overall survival in several cancers and identified the cell cycle inhibitor CDKN1A/p21 as the major hub in PGCC and early progeny. Increased expression of p21 in PGCC was limited to the cytoplasm. We previously demonstrated that the sphingolipid enzyme acid ceramidase is dispensable for polyploidization upon therapy stress but plays a crucial role in depolyploidization. The current study demonstrates that treatment of cells with ceramide is not sufficient for p53-independent induction of p21 and that knockdown of acid ceramidase, which hydrolyzes ceramide, does not interfere with upregulation of p21. In contrast, blocking the expression of p21 with UC2288 prevented the induction of acid ceramidase and inhibited both the formation of PGCC from parental cells as well as the generation of progeny from PGCC. Taken together, our data suggest that p21 functions upstream of acid ceramidase and plays an important role in polyploidization and depolyploidization.

Clonal differences underlie variable responses to sequential and prolonged treatment

Cancer cells exhibit dramatic differences in gene expression at the single-cell level, which can predict whether they become resistant to treatment. Treatment perpetuates this heterogeneity, resulting in a diversity of cell states among resistant clones. However, it remains unclear whether these differences lead to distinct responses when another treatment is applied or the same treatment is continued. In this study, we combined single-cell RNA sequencing with barcoding to track resistant clones through prolonged and sequential treatments. We found that cells within the same clone have similar gene expression states after multiple rounds of treatment. Moreover, we demonstrated that individual clones have distinct and differing fates, including growth, survival, or death, when subjected to a second treatment or when the first treatment is continued. By identifying gene expression states that predict clone survival, this work provides a foundation for selecting optimal therapies that target the most aggressive resistant clones within a tumor. A record of this paper's transparent peer review process is included in the supplemental information.

An unscheduled switch to endocycles induces a reversible senescent arrest that impairs growth of the Drosophila wing disc

A programmed developmental switch to G / S endocycles results in tissue growth through an increase in cell size. Unscheduled, induced endocycling cells (iECs) promote wound healing but also contribute to cancer. Much remains unknown, however, about how these iECs affect tissue growth. Using the D. melanogasterwing disc as model, we find that populations of iECs initially increase in size but then subsequently undergo a heterogenous arrest that causes severe tissue undergrowth. iECs acquired DNA damage and activated a Jun N-terminal kinase (JNK) pathway, but, unlike other stressed cells, were apoptosis-resistant and not eliminated from the epithelium. Instead, iECs entered a JNK-dependent and reversible senescent-like arrest. Senescent iECs promoted division of diploid neighbors, but this compensatory proliferation did not rescue tissue growth. Our study has uncovered unique attributes of iECs and their effects on tissue growth that have important implications for understanding their roles in wound healing and cancer.

Dormant cancer cells and polyploid giant cancer cells: The roots of cancer recurrence and metastasis

Tumour cell dormancy is critical for metastasis and resistance to chemoradiotherapy. Polyploid giant cancer cells (PGCCs) with giant or multiple nuclei and high DNA content have the properties of cancer stem cell and single PGCCs can individually generate tumours in immunodeficient mice. PGCCs represent a dormant form of cancer cells that survive harsh tumour conditions and contribute to tumour recurrence. Hypoxic mimics, chemotherapeutics, radiation and cytotoxic traditional Chinese medicines can induce PGCCs formation through endoreduplication and/or cell fusion. After incubation, dormant PGCCs can recover from the treatment and produce daughter cells with strong proliferative, migratory and invasive abilities via asymmetric cell division. Additionally, PGCCs can resist hypoxia or chemical stress and have a distinct protein signature that involves chromatin remodelling and cell cycle regulation. Dormant PGCCs form the cellular basis for therapeutic resistance, metastatic cascade and disease recurrence. This review summarises regulatory mechanisms governing dormant cancer cells entry and exit of dormancy, which may be used by PGCCs, and potential therapeutic strategies for targeting PGCCs.

Generation of Polyploid Giant Cancer Cells (PGCCs) from Hey Ovarian Cancer Cells and Analysis of Embryonic Properties

Polyploid giant cancer cells (PGCCs) play a fundamental role in tumor initiation, dormancy, drug resistance, and metastasis, although the detailed biology of PGCCs remains poorly understood. The lack of literature on establishing a reproducible in vitro system for generating PGCCs is the leading technological obstacle to studying the biology of PGCCs. Here we provide a detailed protocol for generating stable PGCCs from Hey cancer cells and studying the PGCCs' embryonic stemness. This protocol includes (1) generating PGCCs of high purity in 2D culture by exposing Hey cells to paclitaxel, monitoring the cell cycle and amitotic budding of daughter cells from PGCCs, and collecting and studying the daughter cells; (2) inducing PGCCs to form spheroids expressing embryonic stemness markers and observing the spheroids' cleavage and blastocyst-like structure; and (3) inducing redifferentiation of PGCCs into different lineages of differentiated cells.

Stabilizing vimentin phosphorylation inhibits stem-like cell properties and metastasis of hybrid epithelial/mesenchymal carcinomas

Epithelial-mesenchymal transition (EMT) empowers epithelial cells with mesenchymal and stem-like attributes, facilitating metastasis, a leading cause of cancer-related mortality. Hybrid epithelial-mesenchymal (E/M) cells, retaining both epithelial and mesenchymal traits, exhibit heightened metastatic potential and stemness. The mesenchymal intermediate filament, vimentin, is upregulated during EMT, enhancing the resilience and invasiveness of carcinoma cells. The phosphorylation of vimentin is critical to its structure and function. Here, we identify that stabilizing vimentin phosphorylation at serine 56 induces multinucleation, specifically in hybrid E/M cells with stemness properties but not epithelial or mesenchymal cells. Cancer stem-like cells are especially susceptible to vimentin-induced multinucleation relative to differentiated cells, leading to a reduction in self-renewal and stemness. As a result, vimentin-induced multinucleation leads to sustained inhibition of stemness properties, tumor initiation, and metastasis. These observations indicate that a single, targetable phosphorylation event in vimentin is critical for stemness and metastasis in carcinomas with hybrid E/M properties.

The potential role of interleukins and interferons in ovarian cancer

Ovarian cancer poses significant challenges and remains a highly lethal disease with limited treatment options. In the context of ovarian cancer, interleukins (ILs) and interferons (IFNs), important cytokines that play crucial roles in regulating the immune system, have emerged as significant factors influencing its development. This article provides a comprehensive review of the involvement of various ILs, including those from the IL-1 family, IL-2 family, IL-6 family, IL-8 family, IL-10 family, and IL-17 family, in ovarian cancer. The focus is on their impact on tumor growth, metastasis, and their role in evading immune responses within the tumor microenvironment. Additionally, the article conducts an in-depth examination of the oncogenic or antitumor roles of each IL in the context of ovarian cancer pathogenesis and progression. Besides, we elucidated the enhancements in the treatment of ovarian cancer through the utilization of type-I IFN and type-II IFN. Recent research has shed light on the intricate mechanisms through which specific ILs and IFNs contribute to the advancement of the disease. By incorporating recent findings, this review also seeks to inspire further investigations into unexplored mechanisms, fostering ongoing research to develop more effective therapeutic strategies for ovarian cancer. Moreover, through an in-depth analysis of IL- and IFN-associated clinical trials, we have highlighted their promising potential of in the treatment of ovarian cancer. These clinical trials serve to reinforce the significant outlook for utilizing ILs and IFNs as therapeutic agents in combating this disease.

NANOG Dominates Interleukin-6-Induced Sphere Formation in Prostate Cancer

OBJECTIVE

Identifying the dynamics of prostate tumor aggressiveness is essential to find new therapeutics for the treatment. Cancer stem cells contribute to cancer progression by promoting tumor growth and metastasis, resisting treatment, and evading the immune system. Interleukin 6 (IL-6) is a pleiotropic cytokine that functions in inflammation, immune response, etc. However, dysregulated expression of IL-6 plays a pathological role in such conditions as cancer. In this study, we aimed to elucidate the effect of IL-6 on cancer stemness genes in prostate cancer cells.

METHODS

Enrichment of stem-like cells was achieved through the formation of tumor spheres using the DU-145 cell line. Sphere formation was conducted in a medium supplemented with IL-6 and compared to a control group. The number of spheres was quantified, and the resulting pellet was collected for quantitative reverse transcription polymerase chain reaction analysis to assess the impact of IL-6 induction on the expression of stemness-related genes.

RESULTS

Tumor sphere numbers and sizes increased in IL-6-induced environment. NANOG expression elevated in an IL-6-enriched environment compared to the nontreated spheres. Our results demonstrated that IL-6 induction in prostate tumor spheres upregulates NANOG gene expression.

CONCLUSION

Inducing IL-6 in prostate tumor spheres stimulates stemness biomarker NANOG genes. NANOG may be suggested as a therapeutic target for metastatic prostate cancer.

Molecular mechanism of vimentin nuclear localization associated with the migration and invasion of daughter cells derived from polyploid giant cancer cells

BACKGROUND

Polyploid giant cancer cells (PGCCs), a specific type of cancer stem cells (CSCs), can be induced by hypoxic microenvironments, chemical reagents, radiotherapy, and Chinese herbal medicine. Moreover, PGCCs can produce daughter cells that undergo epithelial-mesenchymal transition, which leads to cancer recurrence and disseminated metastasis. Vimentin, a mesenchymal cell marker, is highly expressed in PGCCs and their daughter cells (PDCs) and drives migratory persistence. This study explored the molecular mechanisms by which vimentin synergistically regulates PGCCs to generate daughter cells with enhanced invasive and metastatic properties.

METHODS

Arsenic trioxide (ATO) was used to induce the formation of PGCCs in Hct116 and LoVo cells. Immunocytochemical and immunohistochemical assays were performed to determine the subcellular localization of vimentin. Cell function assays were performed to compare the invasive metastatic abilities of the PDCs and control cells. The molecular mechanisms underlying vimentin expression and nuclear translocation were investigated by real-time polymerase chain reaction, western blotting, cell function assays, cell transfection, co-immunoprecipitation, and chromatin immunoprecipitation, followed by sequencing. Finally, animal xenograft experiments and clinical colorectal cancer samples were used to study vimentin expression in tumor tissues.

RESULTS

Daughter cells derived from PGCCs showed strong proliferative, migratory, and invasive abilities, in which vimentin was highly expressed and located in both the cytoplasm and nucleus. Vimentin undergoes small ubiquitin-like modification (SUMOylation) by interacting with SUMO1 and SUMO2/3, which are associated with nuclear translocation. P62 regulates nuclear translocation of vimentin by controlling SUMO1 and SUMO2/3 expression. In the nucleus, vimentin acts as a transcription factor that regulates CDC42, cathepsin B, and cathepsin D to promote PDC invasion and migration. Furthermore, animal experiments and human colorectal cancer specimens have confirmed the nuclear translocation of vimentin.

CONCLUSION

P62-dependent SUMOylation of vimentin plays an important role in PDC migration and invasion. Vimentin nuclear translocation and overexpressed P62 of cancer cells may be used to predict patient prognosis, and targeting vimentin nuclear translocation may be a promising therapeutic strategy for metastatic cancers.

Pushing the boundaries of innovation: the potential of ex vivo organ perfusion from an interdisciplinary point of view

Ex vivo machine perfusion (EVMP) is an emerging technique for preserving explanted solid organs with primary application in allogeneic organ transplantation. EVMP has been established as an alternative to the standard of care static-cold preservation, allowing for prolonged preservation and real-time monitoring of organ quality while reducing/preventing ischemia-reperfusion injury. Moreover, it has paved the way to involve expanded criteria donors, e.g., after circulatory death, thus expanding the donor organ pool. Ongoing improvements in EVMP protocols, especially expanding the duration of preservation, paved the way for its broader application, in particular for reconditioning and modification of diseased organs and tumor and infection therapies and regenerative approaches. Moreover, implementing EVMP for in vivo-like preclinical studies improving disease modeling raises significant interest, while providing an ideal interface for bioengineering and genetic manipulation. These approaches can be applied not only in an allogeneic and xenogeneic transplant setting but also in an autologous setting, where patients can be on temporary organ support while the diseased organs are treated ex vivo, followed by reimplantation of the cured organ. This review provides a comprehensive overview of the differences and similarities in abdominal (kidney and liver) and thoracic (lung and heart) EVMP, focusing on the organ-specific components and preservation techniques, specifically on the composition of perfusion solutions and their supplements and perfusion temperatures and flow conditions. Novel treatment opportunities beyond organ transplantation and limitations of abdominal and thoracic EVMP are delineated to identify complementary interdisciplinary approaches for the application and development of this technique.

Perspectives and mechanisms for targeting mitotic catastrophe in cancer treatment

Mitotic catastrophe is distinct from other cell death modes due to unique nuclear alterations characterized as multi and/or micronucleation. Mitotic catastrophe is a common and virtually unavoidable consequence during cancer therapy. However, a comprehensive understanding of mitotic catastrophe remains lacking. Herein, we summarize the anticancer drugs that induce mitotic catastrophe, including microtubule-targeting agents, spindle assembly checkpoint kinase inhibitors, DNA damage agents and DNA damage response inhibitors. Based on the relationships between mitotic catastrophe and other cell death modes, we thoroughly evaluated the roles played by mitotic catastrophe in cancer treatment as well as its advantages and disadvantages. Some strategies for overcoming its shortcomings while fully utilizing its advantages are summarized and proposed in this review. We also review how mitotic catastrophe regulates cancer immunotherapy. These summarized findings suggest that the induction of mitotic catastrophe can serve as a promising new therapeutic approach for overcoming apoptosis resistance and strengthening cancer immunotherapy.

IL-1β is involved in docetaxel chemoresistance by regulating the formation of polyploid giant cancer cells in non-small cell lung cancer

Docetaxel (Doc) is a cornerstone of chemotherapy; however, treatment with Doc often and inevitably leads to drug resistance and the formation of polyploid giant cancer cells (PGCCs). In this study, we investigated the effect of Doc on non-small cell lung cancer to explore the role of PGCCs in drug resistance and the molecular mechanisms that regulate this resistance. We found that Doc induced G2/M cell cycle arrest and cell death in A549 and NCI-H1299 cells. However, many cells remained alive and became PGCCs by decreasing the expression of key regulatory proteins related to the cell cycle and proliferation. Notably, the PGCCs showed typical features of senescence, especially upregulation of p21 and p-histone H2A.X expression. Moreover, the mRNA level of IL-1β in the senescence-associated secretory phenotype was increased significantly with the development of PGCCs. Inhibition of IL-1β reduced the expression of p-histone H2A.X and promoted polyploidy to enhance the proapoptotic effect of Doc. Taken together, our results suggested that IL-1β was involved in the formation of PGCCs and regulated the senescence of PGCCs, which contributed to drug resistance to Doc. Therefore, targeting IL-1β in PGCCs may be a novel approach to overcome drug resistance.

Targeting polyploid giant cancer cells potentiates a therapeutic response and overcomes resistance to PARP inhibitors in ovarian cancer

To understand the mechanism of acquired resistance to poly(ADP-ribose) polymerase inhibitors (PARPi) olaparib, we induced the formation of polyploid giant cancer cells (PGCCs) in ovarian and breast cancer cell lines, high-grade serous cancer (HGSC)-derived organoids, and patient-derived xenografts (PDXs). Time-lapse tracking of ovarian cancer cells revealed that PGCCs primarily developed from endoreplication after exposure to sublethal concentrations of olaparib. PGCCs exhibited features of senescent cells but, after olaparib withdrawal, can escape senescence via restitutional multipolar endomitosis and other noncanonical modes of cell division to generate mitotically competent resistant daughter cells. The contraceptive drug mifepristone blocked PGCC formation and daughter cell formation. Mifepristone/olaparib combination therapy substantially reduced tumor growth in PDX models without previous olaparib exposure, while mifepristone alone decreased tumor growth in PDX models with acquired olaparib resistance. Thus, targeting PGCCs may represent a promising approach to potentiate the therapeutic response to PARPi and overcome PARPi-induced resistance.

Using a Dual CRISPR/Cas9 Approach to Gain Insight into the Role of LRP1B in Glioblastoma

LRP1B remains one of the most altered genes in cancer, although its relevance in cancer biology is still unclear. Recent advances in gene editing techniques, particularly CRISPR/Cas9 systems, offer new opportunities to evaluate the function of large genes, such as LRP1B. Using a dual sgRNA CRISPR/Cas9 gene editing approach, this study aimed to assess the impact of disrupting LRP1B in glioblastoma cell biology. Four sgRNAs were designed for the dual targeting of two LRP1B exons (1 and 85). The U87 glioblastoma (GB) cell line was transfected with CRISPR/Cas9 PX459 vectors. To assess LRP1B-gene-induced alterations and expression, PCR, Sanger DNA sequencing, and qRT-PCR were carried out. Three clones (clones B9, E6, and H7) were further evaluated. All clones presented altered cellular morphology, increased cellular and nuclear size, and changes in ploidy. Two clones (E6 and H7) showed a significant decrease in cell growth, both in vitro and in the in vivo CAM assay. Proteomic analysis of the clones' secretome identified differentially expressed proteins that had not been previously associated with LRP1B alterations. This study demonstrates that the dual sgRNA CRISPR/Cas9 strategy can effectively edit LRP1B in GB cells, providing new insights into the impact of LRP1B deletions in GBM biology.

Biomarkers in Breast Cancer: An Old Story with a New End

Breast cancer is the second most frequent cancer in the world. It is a heterogeneous disease and the leading cause of cancer mortality in women. Advances in molecular technologies allowed for the identification of new and more specifics biomarkers for breast cancer diagnosis, prognosis, and risk prediction, enabling personalized treatments, improving therapy, and preventing overtreatment, undertreatment, and incorrect treatment. Several breast cancer biomarkers have been identified and, along with traditional biomarkers, they can assist physicians throughout treatment plan and increase therapy success. Despite the need of more data to improve specificity and determine the real clinical utility of some biomarkers, others are already established and can be used as a guide to make treatment decisions. In this review, we summarize the available traditional, novel, and potential biomarkers while also including gene expression profiles, breast cancer single-cell and polyploid giant cancer cells. We hope to help physicians understand tumor specific characteristics and support decision-making in patient-personalized clinical management, consequently improving treatment outcome.

Cells in the polyaneuploid cancer cell (PACC) state have increased metastatic potential

Although metastasis is the leading cause of cancer deaths, it is quite rare at the cellular level. Only a rare subset of cancer cells (~ 1 in 1.5 billion) can complete the entire metastatic cascade: invasion, intravasation, survival in the circulation, extravasation, and colonization (i.e. are metastasis competent). We propose that cells engaging a Polyaneuploid Cancer Cell (PACC) phenotype are metastasis competent. Cells in the PACC state are enlarged, endocycling (i.e. non-dividing) cells with increased genomic content that form in response to stress. Single-cell tracking using time lapse microscopy reveals that PACC state cells have increased motility. Additionally, cells in the PACC state exhibit increased capacity for environment-sensing and directional migration in chemotactic environments, predicting successful invasion. Magnetic Twisting Cytometry and Atomic Force Microscopy reveal that cells in the PACC state display hyper-elastic properties like increased peripheral deformability and maintained peri-nuclear cortical integrity that predict successful intravasation and extravasation. Furthermore, four orthogonal methods reveal that cells in the PACC state have increased expression of vimentin, a hyper-elastic biomolecule known to modulate biomechanical properties and induce mesenchymal-like motility. Taken together, these data indicate that cells in the PACC state have increased metastatic potential and are worthy of further in vivo analysis.

Clonal differences underlie variable responses to sequential and prolonged treatment

Cancer cells exhibit dramatic differences in gene expression at the single-cell level which can predict whether they become resistant to treatment. Treatment perpetuates this heterogeneity, resulting in a diversity of cell states among resistant clones. However, it remains unclear whether these differences lead to distinct responses when another treatment is applied or the same treatment is continued. In this study, we combined single-cell RNA-sequencing with barcoding to track resistant clones through prolonged and sequential treatments. We found that cells within the same clone have similar gene expression states after multiple rounds of treatment. Moreover, we demonstrated that individual clones have distinct and differing fates, including growth, survival, or death, when subjected to a second treatment or when the first treatment is continued. By identifying gene expression states that predict clone survival, this work provides a foundation for selecting optimal therapies that target the most aggressive resistant clones within a tumor.

Cancer-associated fibroblasts in gynecological malignancies: are they really allies of the enemy?

Molecular and cellular components of the tumor microenvironment are essential for cancer progression. The cellular element comprises cancer cells and heterogeneous populations of non-cancer cells that satisfy tumor needs. Immune, vascular, and mesenchymal cells provide the necessary factors to feed the tumor mass, promote its development, and favor the spread of cancer cells from the primary site to adjacent and distant anatomical sites. Cancer-associated fibroblasts (CAFs) are mesenchymal cells that promote carcinogenesis and progression of various malignant neoplasms. CAFs act through the secretion of metalloproteinases, growth factors, cytokines, mitochondrial DNA, and non-coding RNAs, among other molecules. Over the last few years, the evidence on the leading role of CAFs in gynecological cancers has notably increased, placing them as the cornerstone of neoplastic processes. In this review, the recently reported findings regarding the promoting role that CAFs play in gynecological cancers, their potential use as therapeutic targets, and the new evidence suggesting that they could act as tumor suppressors are analyzed and discussed.

CCL18 signaling from tumor-associated macrophages activates fibroblasts to adopt a chemoresistance-inducing phenotype

The heterogeneity of cancer-associated fibroblasts (CAFs) might be ascribed to differences in origin. CD10 and GPR77 have been reported to identify a chemoresistance-inducing CAF subset in breast cancer. However, the precise mechanism for the formation of the CD10⁺GPR77⁺ CAFs remains unknown. In this study, we found that CCL18 expression was positively correlated with the density of CD10⁺GPR77⁺ CAFs in breast cancer and associated with a poor response to chemotherapy. Moreover, CCL18 secreted by tumor-associated macrophages (TAMs) activated a CD10⁺GPR77⁺ CAF phenotype in normal breast-resident fibroblasts (NBFs), which could then enrich cancer stem cells (CSCs) and induce chemoresistance in breast cancer cells. Mechanistically, CCL18 activated NF-κB signaling via PITPNM3 and thus enhanced the production of IL-6 and IL-8. Furthermore, intratumoral CCL18 injection significantly induced the activation of NBFs and the chemoresistance of xenografts in vivo. In addition, targeting CCL18 by anti-CCL18 antibody could inhibit the formation of CD10⁺GPR77⁺ CAFs and recover the chemosensitivity in vivo, leading to effective tumor control. Collectively, these findings reveal that inflammatory signaling crosstalk between TAMs and fibroblasts is responsible for the formation of the CD10⁺GPR77⁺ CAFs, suggesting CCL18-PITPNM3 signaling is a potential therapeutic target to block the activation of this specific CAF subtype and tumor chemoresistance.

High-Risk Oncogenic Human Cytomegalovirus

Human cytomegalovirus (HCMV) is a herpesvirus that infects between 40% and 95% of the population worldwide, usually without symptoms. The host immune response keeps the virus in a latent stage, although HCMV can reactivate in an inflammatory context, which could result in sequential lytic/latent viral cycles during the lifetime and thereby participate in HCMV genomic diversity in humans. The high level of HCMV intra-host genomic variability could participate in the oncomodulatory role of HCMV where the virus will favor the development and spread of cancerous cells. Recently, an oncogenic role of HCMV has been highlighted in which the virus will directly transform primary cells; such HCMV strains are named high-risk (HR) HCMV strains. In light of these new findings, this review defines the criteria that characterize HR-HCMV strains and their molecular as well as the phenotypic impact on the infected cell and its tumor microenvironment.

Role of STAT3 in the pathogenesis of nasopharyngeal carcinoma and its significance in anticancer therapy

Nasopharyngeal carcinoma (NPC) is a type of head and neck tumor with noticeable regional and ethnic differences. It is associated with Epstein-Barr virus infection and has a tendency for local and distant metastasis. NPC is also highly sensitive to radiotherapy and chemotherapy. Over 70% of patients present with locoregionally advanced disease, and distant metastasis is the primary reason for treatment failure. A signal transducer and activator of transcription 3 (STAT3) promotes NPC oncogenesis through mechanisms within cancerous cells and their interactions with the tumor microenvironment, which is critical in the initiation, progression, and metastasis of NPC. Further, p-STAT3 is strongly associated with advanced NPC. Recent research on STAT3 has focused on its expression at the center of various oncogenic pathways. Here, we discuss the role of STAT3 in NPC and its potential therapeutic inhibitors and analogs for the treatment and control of NPC.

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.

Isoliquiritigenin Inhibits Gastric Cancer Stemness, Modulates Tumor Microenvironment, and Suppresses Tumor Growth through Glucose-Regulated Protein 78 Downregulation

Chemotherapy is the treatment of choice for gastric cancer; however, the currently available therapeutic drugs for treatment have limited efficacy. Cancer stemness and the tumor microenvironment may play crucial roles in tumor growth and chemoresistance. Glucose-regulated protein 78 (GRP78) is an endoplasmic reticulum chaperone facilitating protein folding and cell homeostasis during stress and may participate in chemoresistance. Isoliquiritigenin (ISL) is a bioactive flavonoid found in licorice. In this study, we demonstrated the role of GRP78 in gastric cancer stemness and evaluated GRP78-mediated stemness inhibition, tumor microenvironment regulation, and chemosensitivity promotion by ISL. ISL not only suppressed GRP78-mediated gastric cancer stem cell–like characteristics, stemness-related protein expression, and cancer-associated fibroblast activation but also gastric tumor growth in xenograft animal studies. The findings indicated that ISL is a promising candidate for clinical use in combination chemotherapy.

Polyploid giant cancer cells are dependent on cholesterol for progeny formation through amitotic division

Polyploid Giant Cancer Cells (PGCC) are increasingly being recognized as drivers of cancer recurrence. Therapy stress promotes the formation of these cells, which upon stress cessation often successfully generate more aggressive progeny that repopulate the tumor. Therefore, identification of potential PGCC vulnerabilities is key to preventing therapy failure. We have previously demonstrated that PGCC progeny formation depends on the lysosomal enzyme acid ceramidase (ASAH1). In this study, we compared transcriptomes of parental cancer cells and PGCC in the absence or presence of the ASAH1 inhibitor LCL521. Results show that PGCC express less INSIG1, which downregulates cholesterol metabolism and that inhibition of ASAH1 increased HMGCR which is the rate limiting enzyme in cholesterol synthesis. Confocal microscopy revealed that ceramide and cholesterol do not colocalize. Treatment with LCL521 or simvastatin to inhibit ASAH1 or HMGCR, respectively, resulted in accumulation of ceramide at the cell surface of PGCC and prevented PGCC progeny formation. Our results suggest that similarly to inhibition of ASAH1, disruption of cholesterol signaling is a potential strategy to interfere with PGCC progeny formation.

Low Intensity Ultrasound as an Antidote to Taxane/Paclitaxel-induced Cytotoxicity

The taxane family of compounds, including Taxol/paclitaxel and Taxotere/docetaxel, are surprisingly successful drugs used in combination or alone for the treatment of most major solid tumors, especially metastatic cancer. The drugs are commonly used in regimen with other agents (often platinum drugs) as frontline treatment, or used as a single agent in a dose dense regimen for recurrent cancer. The major side effects of taxanes are peripheral neuropathy, alopecia, and neutropenia, which are grave burden for patients and limit the full potential of the taxane drugs. Especially in the current treatment protocol for peripheral neuropathy, taxane dosage is reduced once the symptoms present, resulting in the loss of full or optimal cancer killing activity.

Substantial efforts have been made to address the problem of cytotoxic side effects of taxanes, though strategies remain very limited. Following administration of the taxane compound by infusion, taxane binds to cellular microtubules and is sequestered within the cells for several days. Taxane stabilizes and interferes with microtubule function, leading to ultimate death of cancer cells, but also damages hair follicles, peripheral neurons, and hemopoietic stem cells. Currently, cryo-treatment is practiced to limit exposure and side effects of the drug during infusion, though the effectiveness is uncertain or limited.

A recent laboratory finding may provide a new strategy to counter taxane cytotoxicity, that a brief exposure to low density ultrasound waves was sufficient to eliminate paclitaxel cytotoxicity cells in culture by transiently breaking microtubule filaments, which were then relocated to lysosomes for disposal. Thus, ultrasonic force to break rigid microtubules is an effective solution to counter taxane cytotoxicity. The discovery and concept of low intensity ultrasound as an antidote may have the potential to provide a practical strategy to counter paclitaxel-induced peripheral neuropathy and alopecia that resulted from chemotherapy.

Taxanes are a class of important drugs used in chemotherapy to treat several major cancers. This article reviews a new laboratory discovery that ultrasound can be used as an antidote for the peripheral cytotoxicity of taxane drugs and discusses the potential development and application of low intensity ultrasound to prevent side effects in chemotherapeutic treatment of cancer patients.

Tumors and Cytomegalovirus: An Intimate Interplay

Human cytomegalovirus (HCMV) is a herpesvirus that alternates lytic and latent infection, infecting between 40 and 95% of the population worldwide, usually without symptoms. During its lytic cycle, HCMV can result in fever, asthenia, and, in some cases, can lead to severe symptoms such as hepatitis, pneumonitis, meningitis, retinitis, and severe cytomegalovirus disease, especially in immunocompromised individuals. Usually, the host immune response keeps the virus in a latent stage, although HCMV can reactivate in an inflammatory context, which could result in sequential lytic/latent viral cycles during the lifetime and thereby participate in the HCMV genomic diversity in humans and the high level of HCMV intrahost genomic variability. The oncomodulatory role of HCMV has been reported, where the virus will favor the development and spread of cancerous cells. Recently, an oncogenic role of HCMV has been highlighted in which the virus will directly transform primary cells and might therefore be defined as the eighth human oncovirus. In light of these new findings, it is critical to understand the role of the immune landscape, including the tumor microenvironment present in HCMV-harboring tumors. Finally, the oncomodulatory/oncogenic potential of HCMV could lead to the development of novel adapted therapeutic approaches against HCMV, especially since immunotherapy has revolutionized cancer therapeutic strategies and new therapeutic approaches are actively needed, particularly to fight tumors of poor prognosis.

Role of Complement System in Kidney Transplantation: Stepping From Animal Models to Clinical Application

Kidney transplantation is a life-saving strategy for patients with end-stage renal diseases. Despite the advances in surgical techniques and immunosuppressive agents, the long-term graft survival remains a challenge. Growing evidence has shown that the complement system, part of the innate immune response, is involved in kidney transplantation. Novel insights highlighted the role of the locally produced and intracellular complement components in the development of inflammation and the alloreactive response in the kidney allograft. In the current review, we provide the updated understanding of the complement system in kidney transplantation. We will discuss the involvement of the different complement components in kidney ischemia-reperfusion injury, delayed graft function, allograft rejection, and chronic allograft injury. We will also introduce the existing and upcoming attempts to improve allograft outcomes in animal models and in the clinical setting by targeting the complement system.

The life cycle of polyploid giant cancer cells and dormancy in cancer: Opportunities for novel therapeutic interventions

Recent data suggest that most genotoxic agents in cancer therapy can lead to shock of genome and increase in cell size, which leads whole genome duplication or multiplication, formation of polyploid giant cancer cells, activation of an early embryonic program, and dedifferentiation of somatic cells. This process is achieved via the giant cell life cycle, a recently proposed mechanism for malignant transformation of somatic cells. Increase in both cell size and ploidy allows cells to completely or partially restructures the genome and develop into a blastocyst-like structure, similar to that observed in blastomere-stage embryogenesis. Although blastocyst-like structures with reprogrammed genome can generate resistant or metastatic daughter cells or benign cells of different lineages, they also acquired ability to undergo embryonic diapause, a reversible state of suspended embryonic development in which cells enter dormancy for survival in response to environmental stress. Therapeutic agents can activate this evolutionarily conserved developmental program, and when cells awaken from embryonic diapause, this leads to recurrence or metastasis. Understanding of the key mechanisms that regulate the different stages of the giant cell life cycle offers new opportunities for therapeutic intervention.