Circulating Tumor Cell Clustering Shapes DNA Methylation to Enable Metastasis Seeding

An electrochemical biosensor based on mild reduction-activated CRISPR/Cas12a system for sensitive detection of circulating tumor cells

Circulating tumor cell (CTC) has been a valuable biomarker for the diagnosis of breast cancer, while folate receptor is a kind of cell surface receptor glycoprotein which is overexpressed in breast cancer. In this work, we have designed and fabricated an electrochemical biosensor for sensitive detection of folate receptor-positive CTCs based on mild reduction assisted CRISPR/Cas system. Specifically, folate functionalized magnetic beads are firstly prepared to capture CTCs owing to the strong affinity between folate and the folate receptors on the surface of cells. Then, the cell membranes are treated by mild reduction so as to expose a large number of free sulfhydryl groups, which can be coupled with maleimide-DNA to introduce the signal amplified CRISPR/Cas12a system. After the trans-cleavage activity of CRISPR/Cas12a is activated, the long chain DNA modified with electroactive molecules methylene blue can be randomly cleaved into short DNA fragments, which are then captured on the graphite electrode through the host-guest recognition with cucurbit [7]uril, generating highly amplified electrochemical signal corresponding to the number of CTCs. The electrochemical biosensor not only demonstrates the sensitivity with a low detection limit of 2 cells/mL, but also highlights its excellent selectivity and stability in complex environment. Therefore, our biosensor may provide an alternative tool for the analysis of CTCs.

Research progress of DNA methylation in colorectal cancer (Review)

DNA methylation is one of the earliest and most significant epigenetic mechanisms discovered. DNA methylation refers, in general, to the addition of a methyl group to a specific base in the DNA sequence under the catalysis of DNA methyltransferase, with S‑adenosine methionine as the methyl donor, via covalent bonding and chemical modifications. DNA methylation is an important factor in inducing cancer. There are different types of DNA methylation, and methylation at different sites plays different roles. It is well known that the progression of colorectal cancer (CRC) is affected by the methylation of key genes. The present review did not only discuss the potential relationship between DNA methylation and CRC but also discussed how DNA methylation affects the development of CRC by affecting key genes. Furthermore, the clinical significance of DNA methylation in CRC was highlighted, including that of the therapeutic targets and biomarkers of methylation; and the importance of DNA methylation inhibitors was discussed as a novel strategy for treatment of CRC. The present review did not only focus upon the latest research findings, but earlier reviews were also cited as references to older literature.

Cardiac glycosides with cytotoxic activity from the seeds of Thevetia peruviana

Phytochemical investigation on the extract of the seeds of Thevetia peruviana resulted in the isolation of six new cardiac glycosides, namely theveperosides A-F (1-6), including a rare 19-nor-cardenolide (1), together with seven known analogues (7-13). The chemical structures of these compounds were determined based on detailed spectroscopic analysis. The cytotoxic activities of 1-13 were evaluated against MCF-7, HCT-116, HeLa, and HepG2 cancer cell lines, and their structure-activity relationships (SARs) were investigated. Compound 3 exhibited the significant cytotoxic effects with IC50 values ranging from 0.032 to 0.055 μΜ, which could induce HepG2 cells apoptosis in a dose-dependent manner.

Survival mechanisms of circulating tumor cells and their implications for cancer treatment

Metastasis remains the principal trigger for relapse and mortality across diverse cancer types. Circulating tumor cells (CTCs), which originate from the primary tumor or its metastatic sites, traverse the vascular system, serving as precursors in cancer recurrence and metastasis. Nevertheless, before CTCs can establish themselves in the distant parenchyma, they must overcome significant challenges present within the circulatory system, including hydrodynamic shear stress (HSS), oxidative damage, anoikis, and immune surveillance. Recently, there has been a growing body of compelling evidence suggesting that a specific subset of CTCs can persist within the bloodstream, but the precise mechanisms of their survival remain largely elusive. This review aims to present an outline of the survival challenges encountered by CTCs and to summarize the recent advancements in understanding the underlying survival mechanisms, suggesting their implications for cancer treatment.

Capture of circulating metastatic cancer cell clusters from lung cancer patients can reveal unique genomic profiles and potential anti-metastatic molecular targets: A proof-of-concept study

Metastasis remains the leading cause of cancer deaths worldwide and lung cancer, known for its highly metastatic progression, remains among the most lethal of malignancies. Lung cancer metastasis can selectively spread to multiple different organs, however the genetic and molecular drivers for this process are still poorly understood. Understanding the heterogeneous genomic profile of lung cancer metastases is considered key in identifying therapeutic targets that prevent its spread. Research has identified the key source for metastasis being clusters of cells rather than individual cancer cells. These clusters, known as metastatic cancer cell clusters (MCCCs) have been shown to be 100-fold more tumorigenic than individual cancer cells. Unfortunately, access to these primary drivers of metastases remains difficult and has limited our understanding of their molecular and genomic profiles. Strong evidence in the literature suggests that differentially regulated biological pathways in MCCCs can provide new therapeutic drug targets to help combat cancer metastases. In order to expand research into MCCCs and their role in metastasis, we demonstrate a novel, proof of principle technology, to capture MCCCs directly from patients' whole blood. Our platform can be readily tuned for different solid tumor types by combining a biomimicry-based margination effect coupled with immunoaffinity to isolate MCCCs. Adopting a selective capture approach based on overexpressed CD44 in MCCCs provides a methodology that preferentially isolates them from whole blood. Furthermore, we demonstrate a high capture efficiency of more than 90% when spiking MCCC-like model cell clusters into whole blood. Characterization of the captured MCCCs from lung cancer patients by immunofluorescence staining and genomic analyses, suggests highly differential morphologies and genomic profiles. This study lays the foundation to identify potential drug targets thus unlocking a new area of anti-metastatic therapeutics.

Circulating Tumor Cells: Pathological, Molecular and Functional Characteristics

This Special Issue, 'Circulating Tumor Cells: Pathological, Molecular and Functional Characteristics 1 [...].

Recent progress in Surface-Enhanced Raman Spectroscopy detection of biomarkers in liquid biopsy for breast cancer

Breast cancer is the most commonly diagnosed cancer in women globally and a leading cause of cancer-related mortality. However, current detection methods, such as X-rays, ultrasound, CT scans, MRI, and mammography, have their limitations. Recently, with the advancements in precision medicine and technologies like artificial intelligence, liquid biopsy, specifically utilizing Surface-Enhanced Raman Spectroscopy (SERS), has emerged as a promising approach to detect breast cancer. Liquid biopsy, as a minimally invasive technique, can provide a temporal reflection of breast cancer occurrence and progression, along with a spatial representation of overall tumor information. SERS has been extensively employed for biomarker detection, owing to its numerous advantages such as high sensitivity, minimal sample requirements, strong multi-detection ability, and controllable background interference. This paper presents a comprehensive review of the latest research on the application of SERS in the detection of breast cancer biomarkers, including exosomes, circulating tumor cells (CTCs), miRNA, proteins and others. The aim of this review is to provide valuable insights into the potential of SERS technology for early breast cancer diagnosis.

E2F1-regulated USP5 contributes to the tumorigenic capacity of glioma stem cells through the maintenance of OCT4 stability

Mesenchymal glioma stem cells (MES GSCs) are a subpopulation of cells in glioblastoma (GBM) that contribute to a worse prognosis owing to their highly aggressive nature and resistance to radiation therapy. Here, OCT4 is characterized as a critical factor in sustaining the stemness phenotype of MES GSC. We find that OCT4 is expressed intensively in MES GSC and is intimately associated with poor prognosis, moreover, OCT4 depletion leads to diminished invasive capacity and impairment of the stem phenotype in MES GSC. Subsequently, we demonstrated that USP5 is a deubiquitinating enzyme which directly interacts with OCT4 and preserves OCT4 stability through its deubiquitination. USP5 was additionally proven to be aberrantly over-expressed in MES GSCs, and its depletion resulted in a noticeable diminution of OCT4 and consequently a reduced self-renewal and tumorigenic capacity of MES GSCs, which can be substantially restored by ectopic expression of OCT4. In addition, we detected the dominant molecule that regulates USP5 transcription, E2F1, with dual luciferase reporter gene analysis. In combination, targeting the E2F1-USP5-OCT4 axis is a potentially emerging strategy for the therapy of GBM.

Nanomaterial-Based Strategies for Preventing Tumor Metastasis by Interrupting the Metastatic Biological Processes

Tumor metastasis is the primary cause of cancer-related deaths. The prevention of tumor metastasis has garnered notable interest and interrupting metastatic biological processes is considered a potential strategy for preventing tumor metastasis. The tumor microenvironment (TME), circulating tumor cells (CTCs), and premetastatic niche (PMN) play crucial roles in metastatic biological processes. These processes can be interrupted using nanomaterials due to their excellent physicochemical properties. However, most studies have focused on only one aspect of tumor metastasis. Here, the hypothesis that nanomaterials can be used to target metastatic biological processes and explore strategies to prevent tumor metastasis is highlighted. First, the metastatic biological processes and strategies involving nanomaterials acting on the TME, CTCs, and PMN to prevent tumor metastasis are briefly summarized. Further, the current challenges and prospects of nanomaterials in preventing tumor metastasis by interrupting metastatic biological processes are discussed. Nanomaterial-and multifunctional nanomaterial-based strategies for preventing tumor metastasis are advantageous for the long-term fight against tumor metastasis and their continued exploration will facilitate rapid progress in the prevention, diagnosis, and treatment of tumor metastasis. Novel perspectives are outlined for developing more effective strategies to prevent tumor metastasis, thereby improving the outcomes of patients with cancer.

Perspectives in collective cell migration - moving forward

Collective cell migration, where cells move as a cohesive unit, is a vital process underlying morphogenesis and cancer metastasis. Thanks to recent advances in imaging and modelling, we are beginning to understand the intricate relationship between a cell and its microenvironment and how this shapes cell polarity, metabolism and modes of migration. The use of biophysical and mathematical models offers a fresh perspective on how cells migrate collectively, either flowing in a fluid-like state or transitioning to more static states. Continuing to unite researchers in biology, physics and mathematics will enable us to decode more complex biological behaviours that underly collective cell migration; only then can we understand how this coordinated movement of cells influences the formation and organisation of tissues and directs the spread of metastatic cancer. In this Perspective, we highlight exciting discoveries, emerging themes and common challenges that have arisen in recent years, and possible ways forward to bridge the gaps in our current understanding of collective cell migration.

Colorectal cancer and dormant metastases: Put to sleep or destroy?

After reading the review by An et al "Biological factors driving colorectal cancer metastasis", which covers the problem of the metastasis of colorectal cancer (CRC), I had a desire to discuss with readers one of the exciting problems associated with dormant metastases. Most deaths from CRCs are caused by metastases, which can be detected both at diagnosis of the primary tumor and several years or even decades after treatment. This is because tumor cells that enter the bloodstream can be destroyed by the immune system, cause metastatic growth, or remain dormant for a long time. Dormant tumor cells may not manifest themselves throughout a person's life or, after some time and under appropriate conditions, may give rise to the growth of metastases. In this editorial, we will discuss the most important features of dormant metastases and the mechanisms of premetastatic niche formation, as well as factors that contribute to the activation of dormant metastases in CRCs. We will pay special attention to the possible mechanisms involved in the formation of circulating tumor cell complexes and the choice of therapeutic strategies that promote the dormancy or destruction of tumor cells in CRCs.

Cuproptosis-related DNA methylation signature predict prognosis and immune microenvironment in cutaneous melanoma

The prognosis for Cutaneous Melanoma (CM), a skin malignant tumor that is extremely aggressive, is not good. A recently identified type of controlled cell death that is intimately related to immunotherapy and the development of cancer is called cuproptosis. Using The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) database, we developed and validated a DNA-methylation located in cuproptosis death-related gene prognostic signature (CRG-located DNA-methylation prognostic signature) to predict CM's prognosis. Kaplan-Meier analysis of our TCGA and GEO cohorts showed that high-risk patients had a shorter overall survival. The area under the curve (AUC) for the TCGA cohort was 0.742, while for the GEO cohort it was 0.733, according to the receiver operating characteristic (ROC) analysis. Furthermore, this signature was discovered as an independent prognostic indicator over CM patients based on Cox-regression analysis. Immunogenomic profiling indicated that majority immune-checkpoints got an opposite relationship with the signature, and patients in the group at low risk got higher immunophenoscore. Several immune pathways were enriched, according to functional enrichment analysis. In conclusion, a prognostic methylation signature for CM patients was established and confirmed. Because of its close relationship to the immune landscape, this signature may help clinicians make more accurate and individualized choices regarding therapy.

A Molecular Voyage: Multiomics Insights into Circulating Tumor Cells

Circulating tumor cells (CTCs) play a pivotal role in metastasis, the leading cause of cancer-associated death. Recent improvements of CTC isolation tools, coupled with a steady development of multiomics technologies at single-cell resolution, have enabled an extensive exploration of CTC biology, unlocking insights into their molecular profiles. A detailed molecular portrait requires CTC interrogation across various levels encompassing genomic, epigenetic, transcriptomic, proteomic and metabolic features. Here, we review how state-of-the-art multiomics applied to CTCs are shedding light on how cancer spreads. Further, we highlight the potential implications of CTC profiling for clinical applications aimed at enhancing cancer diagnosis and treatment.

SIGNIFICANCE

Exploring the complexity of cancer progression through cutting-edge multiomics studies holds the promise of uncovering novel aspects of cancer biology and identifying therapeutic vulnerabilities to suppress metastasis.

Liquid biopsy: An arsenal for tumour screening and early diagnosis

Cancer has become the second leading cause of death in the world, and more than 50% of cancer patients are diagnosed at an advanced stage. Early diagnosis of tumours is the key to improving patient quality of life and survival time and reducing the socioeconomic burden. However, there is still a lack of reliable early diagnosis methods in clinical practice. In recent years, liquid biopsy technology has developed rapidly. It has the advantages of noninvasiveness, easy access to sample sources, and reproducibility. It has become the main focus of research on the early diagnosis methods of tumours. This review summarises the research progress of existing liquid biopsy markers, such as circulating tumour DNA, circulating viral DNA, DNA methylation, circulating tumour cells, circulating RNA, exosomes, and tumour education platelets in early diagnosis of tumours, and analyses the current advantages and limitations of various markers, providing a direction for the application and transformation of liquid biopsy research in early diagnosis of clinical tumours.

Epigenetic regulation of breast cancer metastasis

Breast cancer is the most frequently diagnosed malignancy and the second leading cause of cancer-related mortality among women worldwide. Recurrent metastasis is associated with poor patient outcomes and poses a significant challenge in breast cancer therapies. Cancer cells adapting to a new tissue microenvironment is the key event in distant metastasis development, where the disseminating tumor cells are likely to acquire genetic and epigenetic alterations during the process of metastatic colonization. Despite several decades of research in this field, the exact mechanisms governing metastasis are not fully understood. However, emerging body of evidence indicates that in addition to genetic changes, epigenetic reprogramming of cancer cells and the metastatic niche are paramount toward successful metastasis. Here, we review and discuss the latest knowledge about the salient attributes of metastasis and epigenetic regulation in breast cancer and crucial research domains that need further investigation.

Exploiting the metabolic vulnerability of circulating tumour cells

Metastasis has a major part in the severity of disease and lethality of cancer. Circulating tumour cells (CTCs) represent a reservoir of metastatic precursors in circulation, most of which cannot survive due to hostile conditions in the bloodstream. Surviving cells colonise a secondary site based on a combination of physical, metabolic, and oxidative stress protection states required for that environment. Recent advances in CTC isolation methods and high-resolution 'omics technologies are revealing specific metabolic pathways that support this selection of CTCs. In this review, we discuss recent advances in our understanding of CTC biology and discoveries of adaptations in metabolic pathways during their selection. Understanding these traits and delineating mechanisms by which they confer acquired resistance or vulnerability in CTCs is crucial for developing successful prognostic and therapeutic strategies in cancer.

Emerging paradigms in cancer cell plasticity

Cancer cells metastasize to distant organs by altering their characteristics within the tumor microenvironment (TME) to effectively overcome challenges during the multistep tumorigenesis. Plasticity endows cancer cell with the capacity to shift between different morphological states to invade, disseminate, and seed metastasis. The epithelial-to-mesenchymal transition (EMT) is a theory derived from tissue biopsy, which explains the acquisition of EMT transcription factors (TFs) that convey mesenchymal features during cancer migration and invasion. On the other hand, adherent-to-suspension transition (AST) is an emerging theory derived from liquid biopsy, which describes the acquisition of hematopoietic features by AST-TFs that reprograms anchorage dependency during the dissemination of circulating tumor cells (CTCs). The induction and plasticity of EMT and AST dynamically reprogram cell-cell interaction and cell-matrix interaction during cancer dissemination and colonization. Here, we review the mechanisms governing cellular plasticity of AST and EMT during the metastatic cascade and discuss therapeutic challenges posed by these two morphological adaptations to provide insights for establishing new therapeutic interventions. [BMB Reports 2024; 57(6): 273-280].

Unravelling the Mysteries of the Sonic Hedgehog Pathway in Cancer Stem Cells: Activity, Crosstalk and Regulation

The Sonic Hedgehog (Shh) signalling pathway plays a critical role in normal development and tissue homeostasis, guiding cell differentiation, proliferation, and survival. Aberrant activation of this pathway, however, has been implicated in the pathogenesis of various cancers, largely due to its role in regulating cancer stem cells (CSCs). CSCs are a subpopulation of cancer cells with the ability to self-renew, differentiate, and initiate tumour growth, contributing significantly to tumorigenesis, recurrence, and resistance to therapy. This review focuses on the intricate activity of the Shh pathway within the context of CSCs, detailing the molecular mechanisms through which Shh signalling influences CSC properties, including self-renewal, differentiation, and survival. It further explores the regulatory crosstalk between the Shh pathway and other signalling pathways in CSCs, highlighting the complexity of this regulatory network. Here, we delve into the upstream regulators and downstream effectors that modulate Shh pathway activity in CSCs. This review aims to cast a specific focus on the role of the Shh pathway in CSCs, provide a detailed exploration of molecular mechanisms and regulatory crosstalk, and discuss current and developing inhibitors. By summarising key findings and insights gained, we wish to emphasise the importance of further elucidating the interplay between the Shh pathway and CSCs to develop more effective cancer therapies.

Clustered Circulating Tumor Cells as a Predictor of Adjuvant-chemotherapy Efficacy in Lung Cancer

BACKGROUND

Surrogate markers of minimal residual disease primarily include cell-free tumor DNA and circulating tumor cells. Cell-free tumor DNA might aid precise decision-making regarding who should receive adjuvant chemotherapy. However, there are no relevant reports on circulating tumor cells. Therefore, we aimed to verify whether perioperative clustered circulating tumour cells identification is a predictor of therapeutic efficacy in non-small cell lung cancer adjuvant chemotherapy.

METHODS

Circulating tumor cells were diagnosed under light microscopy using a size selection method in 128 patients with clinical stage I/II non-small cell lung cancer around surgery. The main endpoint was recurrence-free survival, and the effect of adjuvant chemotherapy was verified in both groups based on perioperative clustered circulating tumor cell identification.

RESULTS

In total, 49 and 79 patients were included in the clustered circulating tumor cell-positive and clustered circulating tumor cell-negative patient groups, respectively. In the clustered circulating tumor cell-positive patient group, adjuvant chemotherapy was performed in 18 patients (2-year recurrence-free survival rate, 71.8%). However, the 2-year recurrence-free survival rate was 36.3% in 31 patients who did not receive adjuvant chemotherapy (P < .01). In the clustered circulating tumor cell-negative patient group, adjuvant chemotherapy was provided in 11 patients (2-year recurrence-free survival rate, 90.9%). However, 68 patients did not receive adjuvant chemotherapy (2-year recurrence-free survival rate, 94.9%) (not significant).

CONCLUSIONS

In surgical cases of clinical stage I/II non-small cell lung cancer, patients with perioperative clustered circulating tumor cells had a poor prognosis, but adjuvant chemotherapy improved their prognosis.

KDM5 family as therapeutic targets in breast cancer: Pathogenesis and therapeutic opportunities and challenges

Breast cancer (BC) is the most frequent malignant cancer diagnosis and is a primary factor for cancer deaths in women. The clinical subtypes of BC include estrogen receptor (ER) positive, progesterone receptor (PR) positive, human epidermal growth factor receptor 2 (HER2) positive, and triple-negative BC (TNBC). Based on the stages and subtypes of BC, various treatment methods are available with variations in the rates of progression-free disease and overall survival of patients. However, the treatment of BC still faces challenges, particularly in terms of drug resistance and recurrence. The study of epigenetics has provided new ideas for treating BC. Targeting aberrant epigenetic factors with inhibitors represents a promising anticancer strategy. The KDM5 family includes four members, KDM5A, KDM5B, KDM5C, and KDMD, all of which are Jumonji C domain-containing histone H3K4me2/3 demethylases. KDM5 proteins have been extensively studied in BC, where they are involved in suppressing or promoting BC depending on their specific upstream and downstream pathways. Several KDM5 inhibitors have shown potent BC inhibitory activity in vitro and in vivo, but challenges still exist in developing KDM5 inhibitors. In this review, we introduce the subtypes of BC and their current therapeutic options, summarize KDM5 family context-specific functions in the pathobiology of BC, and discuss the outlook and pitfalls of KDM5 inhibitors in this disease.

Multiomics approach towards characterization of tumor cell plasticity and its significance in precision and personalized medicine

Cellular plasticity refers to the ability of cells to change their identity or behavior, which can be advantageous in some cases (e.g., tissue regeneration) but detrimental in others (e.g., cancer metastasis). With a better understanding of cellular plasticity, the complexity of cancer cells, their heterogeneity, and their role in metastasis is being unraveled. The plasticity of the cells could also prove as a nemesis to their characterization. In this review, we have attempted to highlight the possibilities and benefits of using multiomics approach in characterizing the plastic nature of cancer cells. There is a need to integrate fragmented evidence at different levels of cellular organization (DNA, RNA, protein, metabolite, epigenetics, etc.) to facilitate the characterization of different forms of plasticity and cell types. We have discussed the role of cellular plasticity in generating intra-tumor heterogeneity. Different omics level evidence is being provided to highlight the variety of molecular determinants discovered using different techniques. Attempts have been made to integrate some of this information to provide a quantitative assessment and scoring of the plastic nature of the cells. However, there is a huge gap in our understanding of mechanisms that lead to the observed heterogeneity. Understanding of these mechanism(s) is necessary for finding targets for early detection and effective therapeutic interventions in metastasis. Targeting cellular plasticity is akin to neutralizing a moving target. Along with the advancements in precision and personalized medicine, these efforts may translate into better clinical outcomes for cancer patients, especially in metastatic stages.

Platelets favor the outgrowth of established metastases

Despite abundant evidence demonstrating that platelets foster metastasis, anti-platelet agents have low therapeutic potential due to the risk of hemorrhages. In addition, whether platelets can regulate metastasis at the late stages of the disease remains unknown. In this study, we subject syngeneic models of metastasis to various thrombocytopenic regimes to show that platelets provide a biphasic contribution to metastasis. While potent intravascular binding of platelets to tumor cells efficiently promotes metastasis, platelets further support the outgrowth of established metastases via immune suppression. Genetic depletion and pharmacological targeting of the glycoprotein VI (GPVI) platelet-specific receptor in humanized mouse models efficiently reduce the growth of established metastases, independently of active platelet binding to tumor cells in the bloodstream. Our study demonstrates therapeutic efficacy when targeting animals bearing growing metastases. It further identifies GPVI as a molecular target whose inhibition can impair metastasis without inducing collateral hemostatic perturbations.

Distinct molecular profiles drive multifaceted characteristics of colorectal cancer metastatic seeds

Metastasis of primary tumors remains a challenge for early diagnosis and prevention. The cellular properties and molecular drivers of metastatically competent clones within primary tumors remain unclear. Here, we generated 10-16 single cell-derived lines from each of three colorectal cancer (CRC) tumors to identify and characterize metastatic seeds. We found that intrinsic factors conferred clones with distinct metastatic potential and cellular communication capabilities, determining organ-specific metastasis. Poorly differentiated or highly metastatic clones, rather than drug-resistant clones, exhibited poor clinical prognostic impact. Personalized genetic alterations, instead of mutation burden, determined the occurrence of metastatic potential during clonal evolution. Additionally, we developed a gene signature for capturing metastatic potential of primary CRC tumors and demonstrated a strategy for identifying metastatic drivers using isogenic clones with distinct metastatic potential in primary tumors. This study provides insight into the origin and mechanisms of metastasis and will help develop potential anti-metastatic therapeutic targets for CRC patients.

Lung endothelium exploits susceptible tumor cell states to instruct metastatic latency

In metastasis, cancer cells travel around the circulation to colonize distant sites. Due to the rarity of these events, the immediate fates of metastasizing tumor cells (mTCs) are poorly understood while the role of the endothelium as a dissemination interface remains elusive. Using a newly developed combinatorial mTC enrichment approach, we provide a transcriptional blueprint of the early colonization process. Following their arrest at the metastatic site, mTCs were found to either proliferate intravascularly or extravasate, thereby establishing metastatic latency. Endothelial-derived angiocrine Wnt factors drive this bifurcation, instructing mTCs to follow the extravasation-latency route. Surprisingly, mTC responsiveness towards niche-derived Wnt was established at the epigenetic level, which predetermined tumor cell behavior. Whereas hypomethylation enabled high Wnt activity leading to metastatic latency, methylated mTCs exhibited low activity and proliferated intravascularly. Collectively the data identify the predetermined methylation status of disseminated tumor cells as a key regulator of mTC behavior in the metastatic niche.

Decoding the interplay between genetic and non-genetic drivers of metastasis

Metastasis is a multistep process by which cancer cells break away from their original location and spread to distant organs, and is responsible for the vast majority of cancer-related deaths. Preventing early metastatic dissemination would revolutionize the ability to fight cancer. Unfortunately, the relatively poor understanding of the molecular underpinnings of metastasis has hampered the development of effective anti-metastatic drugs. Although it is now accepted that disseminating tumour cells need to acquire multiple competencies to face the many obstacles they encounter before reaching their metastatic site(s), whether these competencies are acquired through an accumulation of metastasis-specific genetic alterations and/or non-genetic events is often debated. Here we review a growing body of literature highlighting the importance of both genetic and non-genetic reprogramming events during the metastatic cascade, and discuss how genetic and non-genetic processes act in concert to confer metastatic competencies. We also describe how recent technological advances, and in particular the advent of single-cell multi-omics and barcoding approaches, will help to better elucidate the cross-talk between genetic and non-genetic mechanisms of metastasis and ultimately inform innovative paths for the early detection and interception of this lethal process.

Phenotypic Transitions the Processes Involved in Regulation of Growth and Proangiogenic Properties of Stem Cells, Cancer Stem Cells and Circulating Tumor Cells

Epithelial-mesenchymal transition (EMT) is a crucial process with significance in the metastasis of malignant tumors. It is through the acquisition of plasticity that cancer cells become more mobile and gain the ability to metastasize to other tissues. The mesenchymal-epithelial transition (MET) is the return to an epithelial state, which allows for the formation of secondary tumors. Both processes, EMT and MET, are regulated by different pathways and different mediators, which affects the sophistication of the overall tumorigenesis process. Not insignificant are also cancer stem cells and their participation in the angiogenesis, which occur very intensively within tumors. Difficulties in effectively treating cancer are primarily dependent on the potential of cancer cells to rapidly expand and occupy secondarily vital organs. Due to the ability of these cells to spread, the concept of the circulating tumor cell (CTC) has emerged. Interestingly, CTCs exhibit molecular diversity and stem-like and mesenchymal features, even when derived from primary tumor tissue from a single patient. While EMT is necessary for metastasis, MET is required for CTCs to establish a secondary site. A thorough understanding of the processes that govern the balance between EMT and MET in malignancy is crucial.

Exploring the Immunological Profile in Breast Cancer: Recent Advances in Diagnosis and Prognosis through Circulating Tumor Cells

This review offers a comprehensive exploration of the intricate immunological landscape of breast cancer (BC), focusing on recent advances in diagnosis and prognosis through the analysis of circulating tumor cells (CTCs). Positioned within the broader context of BC research, it underscores the pivotal role of the immune system in shaping the disease's progression. The primary objective of this investigation is to synthesize current knowledge on the immunological aspects of BC, with a particular emphasis on the diagnostic and prognostic potential offered by CTCs. This review adopts a thorough examination of the relevant literature, incorporating recent breakthroughs in the field. The methodology section succinctly outlines the approach, with a specific focus on CTC analysis and its implications for BC diagnosis and prognosis. Through this review, insights into the dynamic interplay between the immune system and BC are highlighted, with a specific emphasis on the role of CTCs in advancing diagnostic methodologies and refining prognostic assessments. Furthermore, this review presents objective and substantiated results, contributing to a deeper understanding of the immunological complexity in BC. In conclusion, this investigation underscores the significance of exploring the immunological profile of BC patients, providing valuable insights into novel advances in diagnosis and prognosis through the utilization of CTCs. The objective presentation of findings emphasizes the crucial role of the immune system in BC dynamics, thereby opening avenues for enhanced clinical management strategies.

Circulating tumor cell clustering modulates RNA splicing and polyadenylation to facilitate metastasis

Circulating tumor cell (CTC) clusters exhibit significantly higher metastatic potential compared to single CTCs. However, the underlying mechanism behind this phenomenon remains unclear, and the role of posttranscriptional RNA regulation in CTC clusters has not been explored. Here, we conducted a comparative analysis of alternative splicing (AS) and alternative polyadenylation (APA) profiles between single CTCs and CTC clusters. We identified 994 and 836 AS events in single CTCs and CTC clusters, respectively, with ∼20% of AS events showing differential regulation between the two cell types. A key event in this differential splicing was observed in SRSF6, which disrupted AS profiles and contributed to the increased malignancy of CTC clusters. Regarding APA, we found a global lengthening of 3' UTRs in CTC clusters compared to single CTCs. This alteration was primarily governed by 14 core APA factors, particularly PPP1CA. The modified APA profiles facilitated the cell cycle progression of CTC clusters and indicated their reduced susceptibility to oxidative stress. Further investigation revealed that the proportion of H2AFY mRNA with long 3' UTR instead of short 3' UTR was higher in CTC clusters than single CTCs. The AU-rich elements (AREs) within the long 3' UTR of H2AFY mRNA enhance mRNA stability and translation activity, resulting in promoting cell proliferation and invasion, which potentially facilitate the establishment and rapid formation of metastatic tumors mediated by CTC clusters. These findings provide new insights into the mechanisms driving CTC cluster metastasis.

Systematic optimization and evaluation of culture conditions for the construction of circulating tumor cell clusters using breast cancer cell lines

BACKGROUND

Circulating tumor cell (CTC) clusters play a critical role in carcinoma metastasis. However, the rarity of CTC clusters and the limitations of capture techniques have retarded the research progress. In vitro CTC clusters model can help to further understand the biological properties of CTC clusters and their clinical significance. Therefore, it is necessary to establish reliable in vitro methodological models to form CTC clusters whose biological characteristics are very similar to clinical CTC clusters.

METHODS

The assays of immunofluorescence, transmission electron microscopy, EdU incorporation, cell adhension and microfluidic chips were used. The experimental metastasis model in mice was used.

RESULTS

We systematically optimized the culture methods to form in vitro CTC clusters model, and more importantly, evaluated it with reference to the biological capabilities of reported clinical CTC clusters. In vitro CTC clusters exhibited a high degree of similarity to the reported pathological characteristics of CTC clusters isolated from patients at different stages of tumor metastasis, including the appearance morphology, size, adhesive and tight junctions-associated proteins, and other indicators of CTC clusters. Furthermore, in vivo experiments also demonstrated that the CTC clusters had an enhanced ability to grow and metastasize compared to single CTC.

CONCLUSIONS

The study provides a reliable model to help to obtain comparatively stable and qualified CTC clusters in vitro, propelling the studies on tumor metastasis.

CCDC58 is a potential biomarker for diagnosis, prognosis, immunity, and genomic heterogeneity in pan-cancer

Coiled-coil domain-containing 58 (CCDC58) is a member of the CCDC protein family. Similar to other members, CCDC58 exhibits potential tumorigenic roles in a variety of malignancies. However, there is no systematic and comprehensive pan-cancer analysis to investigate the diagnosis, prognosis, immune infiltration, and other related functions of CCDC58. We used several online websites and databases, such as TCGA, GTEx, UALCAN, HPA, CancerSEA, BioGRID, GEPIA 2.0, TIMER 2.0, and TISIDB, to extract CCDC58 expression data and clinical data of patients in pan-cancer. Then, the relationship between CCDC58 expression and diagnosis, prognosis, genetic alterations, DNA methylation, genomic heterogeneity, and immune infiltration level were determined. In addition, the biological function of CCDC58 in liver hepatocellular carcinoma (LIHC) was investigated. Pan-cancer analysis results showed that CCDC58 was differentially expressed in most tumors and showed excellent performance in diagnosis and prediction of prognosis. The expression of CCDC58 was highly correlated with genetic alterations, DNA methylation, and genomic heterogeneity in some tumors. In addition, the correlation analysis of CCDC58 with the level of immune infiltration and immune checkpoint marker genes indicated that CCDC58 might affect the composition of the tumor immune microenvironment. Enrichment analysis showed that CCDC58-related genes were mainly linked to mitosis, chromosome, and cell cycle. Finally, biological function experiments demonstrated that CCDC58 plays an important role in tumor cell proliferation and migration. CCDC58 was first identified as a pan-cancer biomarker. It may be used as a potential therapeutic target to improve the prognosis of patients in the future.

Beyond genetics: driving cancer with the tumour microenvironment behind the wheel

Cancer has long been viewed as a genetic disease of cumulative mutations. This notion is fuelled by studies showing that ageing tissues are often riddled with clones of complex oncogenic backgrounds coexisting in seeming harmony with their normal tissue counterparts. Equally puzzling, however, is how cancer cells harbouring high mutational burden contribute to normal, tumour-free mice when allowed to develop within the confines of healthy embryos. Conversely, recent evidence suggests that adult tissue cells expressing only one or a few oncogenes can, in some contexts, generate tumours exhibiting many of the features of a malignant, invasive cancer. These disparate observations are difficult to reconcile without invoking environmental cues triggering epigenetic changes that can either dampen or drive malignant transformation. In this Review, we focus on how certain oncogenes can launch a two-way dialogue of miscommunication between a stem cell and its environment that can rewire downstream events non-genetically and skew the morphogenetic course of the tissue. We review the cells and molecules of and the physical forces acting in the resulting tumour microenvironments that can profoundly affect the behaviours of transformed cells. Finally, we discuss possible explanations for the remarkable diversity in the relative importance of mutational burden versus tumour microenvironment and its clinical relevance.

Circulating tumor cells clusters and their role in Breast cancer metastasis; a review of literature

Breast cancer is a significant and deadly threat to women globally. Moreover, Breast cancer metastasis is a complicated process involving multiple biological stages, which is considered a substantial cause of death, where cancer cells spread from the original tumor to other organs in the body-representing the primary mortality factor. Circulating tumor cells (CTCs) are cancer cells detached from the primary or metastatic tumor and enter the bloodstream, allowing them to establish new metastatic sites. CTCs can travel alone or in groups called CTC clusters. Studies have shown that CTC clusters have more potential for metastasis and a poorer prognosis than individual CTCs in breast cancer patients. However, our understanding of CTC clusters' formation, structure, function, and detection is still limited. This review summarizes the current knowledge of CTC clusters' biological properties, isolation, and prognostic significance in breast cancer. It also highlights the challenges and future directions for research and clinical application of CTC clusters.

Is circulating tumor cell count-driven cost-effective for first-line therapy choice in HR+/HER2- metastatic breast cancer in the United States?

BACKGROUND

Circulating tumor cell (CTC) counting may be a useful non-invasive biomarker that helps patients choose first-line treatment options. Nevertheless, the cost of CTC inspection may impose an economic burden on patients, necessitating the simultaneous consideration of both its clinical effectiveness and cost. We evaluated the cost-effectiveness of CTC count-guided chemotherapy and endocrine therapy as first-line therapy for HR+/HER2-metastatic breast cancer (MBC) from the perspective of US payers.

METHODS

Based on the STIC CTC trial, a Markov model was constructed for three health states, and health outcomes were measured in quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER). One-way and probabilistic sensitivity analyses were performed to assess the robustness of the incremental cost per QALY.

RESULTS

The base-case analysis revealed that CTC count-driven treatment was associated with improved effectiveness by 0.07 QALYs and increased the overall cost by $9187.05 compared with clinician-driven first-line treatment choices, leading to an ICER of $138 354.15 per QALY. One-way sensitivity analysis indicated that the model was most sensitive to the cost of treatment for neutropenia and the utility for PFS; probability sensitivity analysis indicated that CTC count-driven treatment choices would be considered the cost-effective option at a willingness-to-pay threshold of $150 000 per QALY.

CONCLUSIONS

The findings of this cost-effectiveness analysis suggest that, at the current price of CTC enumeration, choosing first-line treatment options based on CTC count is a cost-effectiveness approach for treating patients with HR+/HER2- MBC in the US.

Sensational site: the sodium pump ouabain-binding site and its ligands

Cardiotonic steroids (CTS), used by certain insects, toads, and rats for protection from predators, became, thanks to Withering's trailblazing 1785 monograph, the mainstay of heart failure (HF) therapy. In the 1950s and 1960s, we learned that the CTS receptor was part of the sodium pump (NKA) and that the Na+/Ca2+ exchanger was critical for the acute cardiotonic effect of digoxin- and ouabain-related CTS. This "settled" view was upended by seven revolutionary observations. First, subnanomolar ouabain sometimes stimulates NKA while higher concentrations are invariably inhibitory. Second, endogenous ouabain (EO) was discovered in the human circulation. Third, in the DIG clinical trial, digoxin only marginally improved outcomes in patients with HF. Fourth, cloning of NKA in 1985 revealed multiple NKA α and β subunit isoforms that, in the rodent, differ in their sensitivities to CTS. Fifth, the NKA is a cation pump and a hormone receptor/signal transducer. EO binding to NKA activates, in a ligand- and cell-specific manner, several protein kinase and Ca2+-dependent signaling cascades that have widespread physiological effects and can contribute to hypertension and HF pathogenesis. Sixth, all CTS are not equivalent, e.g., ouabain induces hypertension in rodents while digoxin is antihypertensinogenic ("biased signaling"). Seventh, most common rodent hypertension models require a highly ouabain-sensitive α2 NKA and the elevated blood pressure is alleviated by EO immunoneutralization. These numerous phenomena are enabled by NKA's intricate structure. We have just begun to understand the endocrine role of the endogenous ligands and the broad impact of the ouabain-binding site on physiology and pathophysiology.

The Interplay between Glioblastoma Cells and Tumor Microenvironment: New Perspectives for Early Diagnosis and Targeted Cancer Therapy

Glioblastoma multiforme (GBM) stands out as the most tremendous brain tumor, constituting 60% of primary brain cancers, accompanied by dismal survival rates. Despite advancements in research, therapeutic options remain limited to chemotherapy and surgery. GBM molecular heterogeneity, the intricate interaction with the tumor microenvironment (TME), and non-selective treatments contribute to the neoplastic relapse. Diagnostic challenges arise from GBM advanced-stage detection, necessitating the exploration of novel biomarkers for early diagnosis. Using data from the literature and a bioinformatic tool, the current manuscript delineates the molecular interplay between human GBM, astrocytes, and myeloid cells, underscoring selected protein pathways belonging to astroglia and myeloid lineage, which can be considered for targeted therapies. Moreover, the pivotal role of extracellular vesicles (EVs) in orchestrating a favorable microenvironment for cancer progression is highlighted, suggesting their utility in identifying biomarkers for GBM early diagnosis.

Recent advances in photothermal nanomaterials-mediated detection of circulating tumor cells

Photothermal materials have shown great potential for cancer detection and treatment due to their excellent photothermal effects. Circulating tumor cells (CTCs) are tumor cells that are shed from the primary tumor into the blood and metastasize. In contrast to other tumor markers that are free in the blood, CTCs are a collective term for all types of tumor cells present in the peripheral blood, a source of tumor metastasis, and clear evidence of tumor presence. CTCs detection enables early detection, diagnosis and treatment of tumors, and plays an important role in cancer prevention and treatment. This review summarizes the application of various photothermal materials in CTC detection, including gold, carbon, molybdenum, phosphorus, etc. and describes the significance of CTC detection for early tumor diagnosis and tumor prognosis. Focus is also put on how various photothermal materials play their roles in CTCs detection, including CT, imaging and photoacoustic and therapeutic roles. The physicochemical properties, shapes, and photothermal properties of various photothermal materials are discussed to improve the detection sensitivity and efficiency and to reduce the damage to normal cells. These photothermal materials are capable of converting radiant light energy into thermal energy for highly-sensitive CTCs detection and improving their photothermal properties by various methods, and have achieved good results in various experiments. The use of photothermal materials for CTCs detection is becoming more and more widespread and can be of significant help in early cancer screening and later treatment.

CTC-Race: Single-Cell Motility Assay of Circulating Tumor Cells from Metastatic Lung Cancer Patients

Distinctive subpopulations of circulating tumor cells (CTCs) with increased motility are considered to possess enhanced tumor-initiating potential and contribute to metastasis. Single-cell analysis of the migratory CTCs may increase our understanding of the metastatic process, yet most studies are limited by technical challenges associated with the isolation and characterization of these cells due to their extreme scarcity and heterogeneity. We report a microfluidic method based on CTCs' chemotactic motility, termed as CTC-Race assay, that can analyze migrating CTCs from metastatic non-small-cell lung cancer (NSCLC) patients with advanced tumor stages and enable concurrent biophysical and biochemical characterization of them with single-cell resolution. Analyses of motile CTCs in the CTC-Race assay, in synergy with other single cell characterization techniques, could provide insights into cancer metastasis.

Peripheral arterial rather than venous blood is a better source of circulating tumor cells in early lung cancer

BACKGROUND

Circulating tumor cells (CTCs) play a crucial role in the early diagnosis and prognosis of lung cancer. Identification of a more suitable sample source could be a breakthrough towards enhancing CTC detectability in early-stage lung cancer. We investigated the differences in detectable CTCs between peripheral arterial and venous blood in early- and mid-stage lung cancer patients undergoing surgery and analyzed the association between clinicopathological factors and detectable CTCs in peripheral arterial and venous blood.

METHODS

Peripheral arterial and venous blood was collected in 5-mL samples from 56 patients with surgically resected and pathologically clear at early- or mid-stage lung cancer. Blood specimens were enriched for CTCs based on isolation by size of epithelial tumor cells. The CTCs were identified using Swiss Giemsa staining and immunohistochemistry for CD45/CD31.

RESULTS

In stage I lung cancer, CTC-positive rate was significantly higher in peripheral arterial than in venous blood (45.45% vs. 17.39%). There was no significant difference in the number of detectable CTCs between peripheral arterial and venous blood. A low degree of differentiation was associated with a high positive rate of CTCs in peripheral venous blood. The number of circulating tumor microemboli was significantly higher in patients with tumor size >3 cm compared with ≤3 cm.

CONCLUSION

CTC levels in peripheral arterial and venous blood differed little in lung cancer patients.Compared to peripheral venous blood, peripheral arterial blood had a higher CTC positivity rate in early-stage lung cancer.This study was favorable for early detection and monitoring of lung cancer.

Research progress on the multi-omics and survival status of circulating tumor cells

In the dynamic process of metastasis, circulating tumor cells (CTCs) emanate from the primary solid tumor and subsequently acquire the capacity to disengage from the basement membrane, facilitating their infiltration into the vascular system via the interstitial tissue. Given the pivotal role of CTCs in the intricate hematogenous metastasis, they have emerged as an essential resource for a deeper comprehension of cancer metastasis while also serving as a cornerstone for the development of new indicators for early cancer screening and new therapeutic targets. In the epoch of precision medicine, as CTC enrichment and separation technologies continually advance and reach full fruition, the domain of CTC research has transcended the mere straightforward detection and quantification. The rapid advancement of CTC analysis platforms has presented a compelling opportunity for in-depth exploration of CTCs within the bloodstream. Here, we provide an overview of the current status and research significance of multi-omics studies on CTCs, including genomics, transcriptomics, proteomics, and metabolomics. These studies have contributed to uncovering the unique heterogeneity of CTCs and identifying potential metastatic targets as well as specific recognition sites. We also review the impact of various states of CTCs in the bloodstream on their metastatic potential, such as clustered CTCs, interactions with other blood components, and the phenotypic states of CTCs after undergoing epithelial-mesenchymal transition (EMT). Within this context, we also discuss the therapeutic implications and potential of CTCs.

Stress in the metastatic journey - the role of cell communication and clustering in breast cancer progression and treatment resistance

Breast cancer stands as the most prevalent malignancy afflicting women. Despite significant advancements in its diagnosis and treatment, breast cancer metastasis continues to be a leading cause of mortality among women. To metastasize, cancer cells face numerous challenges: breaking away from the primary tumor, surviving in the circulation, establishing in a distant location, evading immune detection and, finally, thriving to initiate a new tumor. Each of these sequential steps requires cancer cells to adapt to a myriad of stressors and develop survival mechanisms. In addition, most patients with breast cancer undergo surgical removal of their primary tumor and have various therapeutic interventions designed to eradicate cancer cells. Despite this plethora of attacks and stresses, certain cancer cells not only manage to persist but also proliferate robustly, giving rise to substantial tumors that frequently culminate in the patient's demise. To enhance patient outcomes, there is an imperative need for a deeper understanding of the molecular and cellular mechanisms that empower cancer cells to not only survive but also expand. Herein, we delve into the intrinsic stresses that cancer cells encounter throughout the metastatic journey and the additional stresses induced by therapeutic interventions. We focus on elucidating the remarkable strategies adopted by cancer cells, such as cell-cell clustering and intricate cell-cell communication mechanisms, to ensure their survival.

In vivo photoacoustic flow cytometry-based study of the effect of melanin content on melanoma metastasis

A major cause of death in cancer patients is distant metastasis of tumors, in which circulating tumor cells (CTCs) are an important marker. Photoacoustic flow cytometry (PAFC) can monitor CTCs in real time, non-invasively, and label-free; we built a PAFC system and validated the feasibility of PAFC for monitoring CTCs using in vivo animal experiments. By cultivating heavily-pigmented and moderately-pigmented melanoma cells, more CTCs were detected in mice inoculated with moderately-pigmented tumor cells, resulting in more distant metastases and poorer survival status. Tumor cells with lower melanin content may produce more CTCs, increasing the risk of metastasis. CTC melanin content may be down-regulated during the metastatic which may be a potential indicator for assessing the risk of melanoma metastasis. In conclusion, PAFC can be used to assess the risk of melanoma metastasis by dynamically monitoring the number of CTCs and the CTC melanin content in future clinical diagnoses.

Dissemination of Circulating Tumor Cells in Breast and Prostate Cancer: Implications for Early Detection

Burgeoning evidence suggests that circulating tumor cells (CTCs) may disseminate into blood vessels at an early stage, seeding metastases in various cancers such as breast and prostate cancer. Simultaneously, the early-stage CTCs that settle in metastatic sites [termed disseminated tumor cells (DTCs)] can enter dormancy, marking a potential source of late recurrence and therapy resistance. Thus, the presence of these early CTCs poses risks to patients but also holds potential benefits for early detection and treatment and opportunities for possibly curative interventions. This review delves into the role of early DTCs in driving latent metastasis within breast and prostate cancer, emphasizing the importance of early CTC detection in these diseases. We further explore the correlation between early CTC detection and poor prognoses, which contribute significantly to increased cancer mortality. Consequently, the detection of CTCs at an early stage emerges as a critical imperative for enhancing clinical diagnostics and allowing for early interventions.

Circulating Tumor Cells: How Far Have We Come with Mining These Seeds of Metastasis?

Circulating tumor cells (CTCs) are cancer cells that slough off from the tumor and circulate in the peripheral blood and lymphatic system as micro metastases that eventually results in macro metastases. Through a simple blood draw, sensitive CTC detection from clinical samples has proven to be a useful tool for determining the prognosis of cancer. Recent technological developments now make it possible to detect CTCs reliably and repeatedly from a simple and straightforward blood test. Multicenter trials to assess the clinical value of CTCs have demonstrated the prognostic value of these cancer cells. Studies on CTCs have filled huge knowledge gap in understanding the process of metastasis since their identification in the late 19th century. However, these rare cancer cells have not been regularly used to tailor precision medicine and or identify novel druggable targets. In this review, we have attempted to summarize the milestones of CTC-based research from the time of identification to molecular characterization. Additionally, the need for a paradigm shift in dissecting these seeds of metastasis and the possible future avenues to improve CTC-based discoveries are also discussed.

Biological factors driving colorectal cancer metastasis

Approximately 20% of colorectal cancer (CRC) patients present with metastasis at diagnosis. Among Stage I-III CRC patients who undergo surgical resection, 18% typically suffer from distal metastasis within the first three years following initial treatment. The median survival duration after the diagnosis of metastatic CRC (mCRC) is only 9 mo. mCRC is traditionally considered to be an advanced stage malignancy or is thought to be caused by incomplete resection of tumor tissue, allowing cancer cells to spread from primary to distant organs; however, increasing evidence suggests that the mCRC process can begin early in tumor development. CRC patients present with high heterogeneity and diverse cancer phenotypes that are classified on the basis of molecular and morphological alterations. Different genomic and nongenomic events can induce subclone diversity, which leads to cancer and metastasis. Throughout the course of mCRC, metastatic cascades are associated with invasive cancer cell migration through the circulatory system, extravasation, distal seeding, dormancy, and reactivation, with each step requiring specific molecular functions. However, cancer cells presenting neoantigens can be recognized and eliminated by the immune system. In this review, we explain the biological factors that drive CRC metastasis, namely, genomic instability, epigenetic instability, the metastatic cascade, the cancer-immunity cycle, and external lifestyle factors. Despite remarkable progress in CRC research, the role of molecular classification in therapeutic intervention remains unclear. This review shows the driving factors of mCRC which may help in identifying potential candidate biomarkers that can improve the diagnosis and early detection of mCRC cases.

Epigenetic regulation in cancer

Epigenetic modifications are defined as heritable changes in gene activity that do not involve changes in the underlying DNA sequence. The oncogenic process is driven by the accumulation of alterations that impact genome's structure and function. Genetic mutations, which directly disrupt the DNA sequence, are complemented by epigenetic modifications that modulate gene expression, thereby facilitating the acquisition of malignant characteristics. Principals among these epigenetic changes are shifts in DNA methylation and histone mark patterns, which promote tumor development and metastasis. Notably, the reversible nature of epigenetic alterations, as opposed to the permanence of genetic changes, positions the epigenetic machinery as a prime target in the discovery of novel therapeutics. Our review delves into the complexities of epigenetic regulation, exploring its profound effects on tumor initiation, metastatic behavior, metabolic pathways, and the tumor microenvironment. We place a particular emphasis on the dysregulation at each level of epigenetic modulation, including but not limited to, the aberrations in enzymes responsible for DNA methylation and histone modification, subunit loss or fusions in chromatin remodeling complexes, and the disturbances in higher-order chromatin structure. Finally, we also evaluate therapeutic approaches that leverage the growing understanding of chromatin dysregulation, offering new avenues for cancer treatment.

Beyond genetics: Exploring the role of epigenetic alterations in breast cancer

Breast cancer remains a major global health challenge. Its rising incidence is attributed to factors such as delayed diagnosis, the complexity of its subtypes, and increasing drug resistance, all contributing to less-than-ideal patient outcomes. Central to the progression of breast cancer are epigenetic aberrations, which significantly contribute to drug resistance and the emergence of cancer stem cell traits. These include alterations in DNA methylation, histone modifications, and the expression of non-coding RNAs. Understanding these epigenetic changes is crucial for developing advanced breast cancer management strategies despite their complexity. Investigating these epigenetic modifications offers the potential for novel diagnostic markers, more accurate prognostic indicators, and the identification of reliable predictors of treatment response. This could lead to the development of new targeted therapies. However, this requires sustained, focused research efforts to navigate the challenges of understanding breast cancer carcinogenesis and its epigenetic underpinnings. A deeper understanding of epigenetic mechanisms in breast cancer can revolutionize personalized medicine. This could lead to significant improvements in patient care, including early detection, precise disease stratification, and more effective treatment options.

The expansion of liquid biopsies to vascular care: an overview of existing principles, techniques and potential applications to vascular malformation diagnostics

Vascular malformations are congenital lesions that occur due to mutations in major cellular signalling pathways which govern angiogenesis, cell proliferation, motility, and cell death. These pathways have been widely studied in oncology and are substrates for various small molecule inhibitors. Given their common molecular biology, there is now a potential to repurpose these cancer drugs for vascular malformation care; however, a molecular diagnosis is required in order to tailour specific drugs to the individual patient's mutational profile. Liquid biopsies (LBs), emerging as a transformative tool in the field of oncology, hold significant promise in this feat. This paper explores the principles and technologies underlying LBs and evaluates their potential to revolutionize the management of vascular malformations. The review begins by delineating the fundamental principles of LBs, focusing on the detection and analysis of circulating biomarkers such as cell-free DNA, circulating tumor cells, and extracellular vesicles. Subsequently, an in-depth analysis of the technological advancements driving LB platforms is presented. Lastly, the paper highlights the current state of research in applying LBs to various vascular malformations, and uses the aforementioned principles and techniques to conceptualize a liquid biopsy framework that is unique to vascular malformation research and clinical care.

The rare circulating tumor microemboli as a biomarker contributes to predicting early colorectal cancer recurrences after medical treatment

Early prognosis of cancer recurrence remains difficult partially due to insufficient and ineffective screening biomarkers or regimes. This study evaluated the rare circulating tumor microemboli (CTM) from liquid biopsy individually and together with circulating tumor cells (CTCs) and serum CEA/CA19-9 in a panel, on early prediction of colorectal cancer (CRC) recurrence. Stained CTCs/CTM were detected by a microfluidic chip-based automatic rare-cell imaging platform. ROC, AUC, Kaplan-Meier survival, and Cox proportional hazard models regarding 4 selected biomarkers were analyzed. The relative risk, odds ratio, predictive accuracy, and positive/negative predictive value of biomarkers individually and in combination, to predict CRC recurrence were assessed and preliminarily validated. The EpCAM+Hochest+CD45- CTCs/CTM could be found in all cancer stages, where more recurrences were observed in late-stage cases. Significant correlations between CTCs/CTM with metastatic stages and clinical treatment were illustrated. CA19-9 and CTM could be seen as independent risk factors in patient survivals, while stratified patients by grouped biomarkers on the Kaplan-Meier analyses presented more significant differences in predicting CRC recurrences. By monitoring the panel of selected biomarkers, disease progressions of 4 CRC patients during follow-up visits after first treatments within 3 years were predicted successfully. This study unveiled the value of rare CTM on clinical studies and a panel of selected biomarkers on predicting CRC recurrences in patients at the early time after medical treatment, in which the CTM and serum CA19-9 could be applied in clinical surveillance and CRC management to improve the accuracy.

Alone you go faster, together you go farther

The metastatic process is an extraordinarily complex step-by-step procedure, characterized by many analogies with migratory patterns of humans or animals across our planet. The ongoing interrogation of circulating tumor cells (CTCs), caught in the act of spreading from one location to another, is revealing distinct behaviors including biological, physical, and mechanical features that impact on their likelihood to form metastasis. In this viewpoint, I will discuss some of these findings and provide a perspective on the metastatic journey, open questions and opportunities to exploit some of the most recent discoveries for the development of antimetastasis medicines.

Pulmonary Tumor Thrombotic Microangiopathy in a Patient with Rapid Progressive Triple-Negative Breast Cancer

Introduction

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare complication of metastatic carcinoma, which occurs in patients with pulmonary arterial hypertension, and is mostly fatal. Circulating tumor cell clusters have been recognized as critical factors during breast cancer progression.

Case Presentation

An 80-year-old woman with triple-negative breast cancer was admitted to our hospital with progressive dyspnea and lower back pain. Breast cancer treatment included mastectomy, neoadjuvant and adjuvant chemotherapy as well as adjuvant radiotherapy, receiving her last cycle of radiotherapy 8 days before death. At admission, D-dimers were strongly elevated and platelets were low. NT-pro-BNP was moderately elevated. A CT scan of the chest did not show pulmonary embolism but revealed interlobular septal thickening, centrilobular consolidation, and distension of the pulmonary arteries. Moreover, new skeletal and most likely lymphatic metastasis was described. Treatment with oxygen and oral glucocorticoids was initiated, assuming radiotherapy-induced pneumonitis. Due to low expression of PD-L1 and her markedly bad performance status, tumor-specific therapy was not possible, and the treatment regimen was changed to best supportive care. The patient died 8 days after admission. Autopsy revealed numerous events consistent with tumor emboli in the pulmonary vessels, suggesting PTTM.

Conclusion

PTTM is a rare and mostly fatal complication in malignant breast cancer. As an early detection is difficult, further investigation is needed. Circulating tumor cluster cells may be one way to detect PTTM early and improve patients' survival.