Factors involved in cancer metastasis: a better understanding to "seed and soil" hypothesis

GC-MSCs transcriptionally upregulate SALL4 in gastric cancer through miR-4669/TIMP3/β-catenin signaling

BACKGROUNDS

Gastric cancer-associated mesenchymal stem cells (GC-MSCs) as integral components of the tumor microenvironment potentiate gastric cancer growth and metastasis. SALL4 is aberrantly upregulated in gastric cancer and pivotal for malignant progression. Whether GC-MSCs is responsible for SALL4 upregulation and the underlying mechanisms remains elusive.

METHODS

Cancer growth and metastasis capacities were assessed by cell colony formation assay, transwell assay, and epithelial-mesenchymal transition protein detection in vitro as well as subcutaneous xenograft and peritoneal metastasis models in vivo. SALL4 was measured by qPCR, western blot and immunohistochemistry staining. Gain- and loss-functional analysis were performed for miRNA and target gene. β-catenin signaling was assessed by immunofluorescence staining and Top/FopFlash luciferase assay. Transcriptional regulation was conducted using chemicals, luciferase reporter and ChIP assay. Clinical tissues and TCGA-STAD database were included for expression profile, correlation and clinical relevance analysis.

RESULTS

GC-MSCs promoted gastric cancer growth and metastasis along with elevation of SALL4 and miR-4669 in cancer cells and tissues. Overexpression of miR-4669 mimicked GC-MSC effects, while miR-4669 knockdown eliminated their oncogenic roles. TIMP3 was identified as a target of miR-4669 and mediated its functions. TIMP3 overexpression counteracted GC-MSC-induced cancer progression and SALL4 expression. GC-MSCs activated SALL4 transcription through the miR-4669/TIMP3/β-catenin pathway. The regulatory axis was aberrantly expressed in gastric cancer tissues, correlated with each other in certain cancer tissues and associated with lymph node metastasis.

CONCLUSIONS

GC-MSCs transcriptionally upregulate SALL4 to facilitate gastric cancer cell growth and metastasis via miR-4669/TIMP3/β-catenin pathway, highlighting the crucial role of GC-MSCs in the aberrant upregulation of SALL4.

Single-Cell and Bulk RNA Sequencing Reveal Tumor Cell Characteristics and Communication Features of Primary and Lymphatic Metastatic Hypopharyngeal Squamous Cell Carcinoma

BACKGROUND

Lymph node metastasis (LNM) is strongly associated with poor prognosis in hypopharyngeal squamous carcinoma (HPSCC). Identifying key drivers of LNM and potential therapeutic targets in HPSCC is therefore essential for the early detection of high-risk patients and for informing personalized treatment strategies.

METHODS

Single-cell RNA sequencing data were used to characterize malignant epithelial cells (maECs) in HPSCC primary tumors (PT) and LNM, as well as differences in cell-to-cell communication. Concurrently, combined with bulk RNA sequencing data, a ligand receptor pairs (LRs) model was developed to predict the prognosis of HPSCC patients.

RESULTS

PT and LNM maECs have different gene expression characteristics, with genes involved in interferon signaling and TGF-β response pathways enriched in LNM maECs, suggesting potential immunosuppressive reprogramming. Cell communication analysis revealed distinct interactions and signaling features in PT and LNM microenvironments. Subsequently, a 4-LRs model was constructed to stratify HPSCC patients into low-or high-risk groups, with the high-risk group demonstrating significantly worse overall survival (OS) outcomes compared with the low-risk group in the training (p < 0.0001), testing (p = 0.0021), and entire (p < 0.0001) cohorts. Receiver operating characteristic curves showed that this risk model can effectively predict the 1-, 3-, and 5-year OS of HPSCC patients. Notably, the risk score effectively discriminated LNM status (area under the curve [AUC] = 0.927) among HPSCC patients, highlighting its potential as a HPSCC metastasis prediction tool.

CONCLUSIONS

These results provide biomarkers of LNM maECs as well as potential mechanisms of HPSCC metastasis, which may help with the precision treatment, diagnosis, and prognosis of HPSCC.

Emerging therapeutic strategies and opportunities in targeting protein pathways for breast cancer treatment: a critical review

Understanding breast cancer at a molecular level is essential for developing effective treatments due to its significant impact on women's mortality rates globally. Targeted medicines focus on specific proteins crucial to breast cancer progression, offering a promising treatment avenue. These proteins, often overexpressed or mutated in cancer cells, are vital for cell proliferation, division, and survival. Targeted drugs aim to inhibit these proteins, halting disease progression and sparing non-cancerous cells, which reduces side effects and improves patient quality of life. Key proteins in breast cancer treatment include HER2 (human epidermal growth factor receptor 2), ER (estrogen receptor), and PR (progesterone receptor). Drugs like Trastuzumab target HER2 to impede tumor growth in HER2-positive cancers, while hormone therapies targeting ER and PR improve outcomes for hormone receptor-positive cancers. Examining proteins such as EGFR, HER2/Neu, and ER reveals their roles in cancer pathways, with pathways like PI3K/Akt/mTOR (phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin) and MAPK (mitogen-activated protein kinase) being crucial targets for therapies, potentially revolutionizing breast cancer treatment.

The regulatory role of m6A in cancer metastasis

Metastasis remains a primary cause of cancer-related mortality, with its intricate mechanisms continuing to be uncovered through advancing research. Among the various regulatory processes involved, RNA modification has emerged as a critical epitranscriptomic mechanism influencing cancer metastasis. N6-methyladenosine (m6A), recognized as one of the most prevalent and functionally significant RNA modifications, plays a central role in the regulation of RNA metabolism. In this review, we explore the multifaceted role of m6A in the different stages of cancer metastasis, including epithelial-mesenchymal transition, invasion, migration, and colonization. In addition to summarizing the current state of our understanding, we offer insights into how m6A modifications modulate key oncogenic pathways, highlighting the implications of recent discoveries for therapeutic interventions. Furthermore, we critically assess the limitations of previous studies and propose areas for future research, including the potential for targeting m6A as a novel approach in anti-metastatic therapies. Our analysis provides a comprehensive understanding of the regulatory landscape of m6A in metastasis, offering directions for continued exploration in this rapidly evolving field.

Cancer metastasis: molecular mechanisms and therapeutic interventions

The metastatic cascade is a complicated process where cancer cells travel across multiple organs distant from their primary site of onset. Despite the wide acceptance of the 'seed and soil' theory, mechanisms driving metastasis organotropism remain mystery. Using breast cancer of different subtypes as the disease model, we characterized the 'metastatic profile of cancer cells' and the 'redox status of the organ microenvironment' as the primary determinants of cancer metastasis organotropism. Mechanically, we identified a positive correlation between cancer metabolic plasticity and stemness, and proposed oxidative stress as the selection power of cancer cells succeeding the metastasis cascade. Therapeutically, we proposed the use of pro-oxidative therapeutics in ablating cancer cells taking advantages of this fragile moment during metastasis. We comprehensively reviewed current pro-oxidative strategies for treating cancers that cover the first line chemo- and radio-therapies, approaches relying on naturally existing power including magnetic field, electric field, light and sound, nanoparticle-based anti-cancer composites obtained through artificial design, as well as cold atmospheric plasma as an innovative pro-oxidative multi-modal modality. We discussed possible combinations of pro-oxidative approaches with existing therapeutics in oncology prior to the forecast of future research directions. This paper identified the fundamental mechanics driving metastasis organotropism and proposed intervention strategies accordingly. Insights provided here may offer clues for the design of innovative solutions that may open a new paradigm for cancer treatment.

Oxidative stress as a catalyst in prostate cancer progression: unraveling molecular mechanisms and exploring therapeutic interventions

Prostate cancer is the second most common malignancy among men worldwide, with its incidence and mortality rates steadily increasing. Although androgen deprivation therapy (ADT) combined with androgen receptor inhibitors has shown significant efficacy in treating prostate cancer, resistance to treatment remains a major challenge, particularly in patients with metastatic prostate cancer. Reactive oxygen species (ROS), a class of highly reactive molecules, can induce oxidative stress within cells, thereby affecting cellular survival and function. In cancer cells, elevated ROS levels not only promote proliferation and invasion but also contribute to the malignancy of tumors by modulating the tumor microenvironment, enhancing angiogenesis, and facilitating extracellular matrix remodeling. This review systematically explores the pathways of ROS generation in prostate cancer, their interaction with the androgen receptor signaling pathway, and the role of external factors such as obesity and aging in promoting ROS production. The findings highlight that ROS drive prostate cancer progression through multiple mechanisms, including altering the tumor microenvironment, activating the unfolded protein response (UPR), and regulating miRNA expression. By providing a comprehensive analysis of ROS-mediated mechanisms in prostate cancer, this review offers new insights into the development of targeted antioxidant therapeutic strategies.

The concomitant tumor suspension cells derived from SKBR-3 exhibit circulating tumor cell features

Metastatic diseases are the major causes of cancer related deaths. Circulating tumor cells are important mediators for distant metastases. However, knowledge about circulating tumor cells is still limited due to their small quantity, lack of explicit markers, interferences from blood cells and immune cells, and so on. In this study, we discovered the concomitant tumor suspension cells in a human epidermal growth factor receptor 2 enriched type breast cancer cell line, SKBR-3. In vitro cultured SKBR-3 shed suspension cells in a spontaneous and continuous manner, which can survive and proliferate infinitely under suspension state. We therefore established the "progeny" suspension cell line of its adherent counterpart, or so-called the concomitant tumor suspension cell line. The concomitant tumor suspension cells were in an intermediate partial-epithelial-mesenchymal transition state and were highly adapted to survival in the blood circulation system. The tendency to form microtumors suggests that they are closely related to the metastases of cancers. This study provides a new direction for investigating metastases. By screening more cancer cell lines and establishing more concomitant tumor suspension cell lines, we can acquire much more knowledge implying the evolution of circulating tumor cells, and achieve a better understanding of cancer metastases.

Tumor-nerve interactions in cancer regulation and progression

Tumor-nerve interactions play a critical role in tumor progression, metastasis, and treatment resistance, redefining our understanding of the tumor microenvironment. This review provides a comprehensive analysis of how the peripheral and central nervous systems contribute to cancer biology, focusing on mechanisms of neural invasion, immune evasion, and tumor adaptation. It has highlighted the emerging potential of repurposing nervous system-targeted drugs originally developed for neurodegenerative and autoimmune diseases as innovative cancer therapies. The review also addresses key challenges, including the limitations of current experimental models and the complexity of translating preclinical findings to clinical applications. By bridging the gap between neuroscience and oncology, this interdisciplinary study aims to discover novel therapeutic strategies to improve outcomes for cancer patients.

Platelet-mediated circulating tumor cell evasion from natural killer cell killing through immune checkpoint CD155-TIGIT

BACKGROUND AND AIMS

Circulating tumor cells (CTCs) are precursors of cancer metastasis. However, how CTCs evade immunosurveillance during hematogenous dissemination remains unclear.

APPROACH AND RESULTS

We identified CTC-platelet adhesions by single-cell RNA sequencing and multiplex immunofluorescence of blood samples from multiple cancer types. Clinically, CTC-platelet aggregates were associated with significantly shorter progression-free survival and overall survival in patients with HCC. In vitro, ex vivo, and in vivo assays demonstrated direct platelet adhesions gifted cancer cells with an evasive ability from NK cell killing by upregulating inhibitory checkpoint CD155 (PVR cell adhesion molecule), therefore facilitating distant metastasis. Mechanistically, CD155 was transcriptionally regulated by the FAK/JNK/c-Jun cascade in a platelet contact-dependent manner. Further competition assays and cytotoxicity experiments revealed that CD155 on CTCs inhibited NK-cell cytotoxicity only by engaging with immune receptor TIGIT, but not CD96 and DNAM1, another 2 receptors for CD155. Interrupting the CD155-TIGIT interactions with a TIGIT antibody restored NK-cell immunosurveillance on CTCs and markedly attenuated tumor metastasis.

CONCLUSIONS

Our results demonstrated CTC evasion from NK-cell-mediated innate immunosurveillance mainly through immune checkpoint CD155-TIGIT, potentially offering an immunotherapeutic strategy for eradicating CTCs.

SATB1 in cancer progression and metastasis: mechanisms and therapeutic potential

Cancer remains a major global health challenge, with prostate cancer, lung cancer, colorectal cancer, and breast cancer accounting for nearly half of all diagnoses. Despite advancements in cancer treatment, metastasis to distant organs continues to be the leading cause of cancer-related mortality. The progression of cancer involves the alteration of numerous genes, with dynamic changes in chromatin organization and histone modifications playing a critical role in regulating cancer-associated genes. Special AT-rich sequence-binding protein 1 (SATB1), a critical chromatin organizer, plays a pivotal role in cancer progression by regulating gene expression, chromatin remodeling, and cell signaling pathways. SATB1 binds to AT-rich DNA sequences, acting as a scaffold for chromatin-modifying enzymes and transcription factors, thus coordinating the regulation of extensive gene networks. Its overexpression has been implicated in a wide range of cancers and is associated with poor prognosis, aggressive tumor phenotypes, and enhanced epithelial-mesenchymal transition (EMT). Moreover, SATB1's activity is modulated by microRNAs (miRNAs) and post-translational modifications, further contributing to its complex regulatory functions. Given its crucial involvement in cancer progression and metastasis, SATB1 has emerged as a promising target for novel therapeutic strategies. This review delves into the molecular mechanisms of SATB1 in cancer and explores potential therapeutic approaches for targeting this key regulator in cancer treatment.

Genome-wide transcriptome analysis and drug target discovery reveal key genes and pathways in thyroid cancer metastasis

Introduction

Metastasis is the major cause of thyroid cancer morbidity and mortality. However, the mechanisms are still poorly understood.

Methods

We performed genome-wide transcriptome analysis comparing gene expression profile of metastatic thyroid cancer cells (Met) with primary tumor cells established from transgenic mouse models of papillary thyroid cancer (PTC), follicular thyroid cancer (FTC), poorly differentiated thyroid cancer (PDTC), and anaplastic thyroid cancer (ATC).

Results

Genes involved in tumor microenvironment (TME), inflammation, and immune escape were significantly overexpressed in Met cells. Notably, IL-6-mediated inflammatory and PD-L1 pathways were highly active in Met cells with increased secretion of pro-inflammatory and pro-metastatic cytokines such as CCL2, CCL11, IL5, IL6, and CXCL5. Furthermore, Met cells showed robust overexpression of Tbxas1, a thromboxane A synthase 1 gene that catalyzes the conversion of prostaglandin H2 to thromboxane A2 (TXA2), a potent inducer of platelet aggregation. Application of aspirin, a TXA2 inhibitor, significantly reduced lung metastases. Mertk, a member of the TAM (Tyro, Axl, Mertk) family of RTKs, was also overexpressed in Met cells, which led to increased MAPK activation, epithelial-mesenchymal transition (EMT), and enrichment of cancer stem cells. Braf-mutant Met cells developed resistance to BRAFV600E inhibitor PLX4720, but remained sensitive to β-catenin inhibitor PKF118-310.

Conclusion

We have identified several overexpressed genes/pathways in thyroid cancer metastasis, making them attractive therapeutic targets. Given the complexity of metastasis involving multiple pathways (PD-L1, Mertk, IL6, COX-1/Tbxas1-TXA2), simultaneously targeting more than one of these pathways may be warranted to achieve better therapeutic effect for metastatic thyroid cancer.

Cell fusion as a driver of metastasis: re-evaluating an old hypothesis in the age of cancer heterogeneity

Numerous studies have investigated the molecular mechanisms and signalling pathways underlying cancer metastasis, as there is still no effective treatment for this terminal stage of the disease. However, the exact processes that enable primary cancer cells to acquire a metastatic phenotype remain unclear. Increasing attention has been focused on the fusion of cancer cells with myeloid cells, a phenomenon that may result in hybrid cells, so-called Tumour Hybrid Cells (THCs), with enhanced migratory, angiogenic, immune evasion, colonisation, and metastatic properties. This process has been shown to potentially drive tumour progression, drug resistance, and cancer recurrence. In this review, we explore the potential mechanisms that govern cancer cell fusion, the molecular mediators involved, the metastatic characteristics acquired by fusion-derived hybrids, and their clinical significance in human cancer. Additionally, we discuss emerging pharmacological strategies aimed at targeting fusogenic molecules as a means to prevent metastatic dissemination.

Breaking boundaries: role of the brain barriers in metastatic process

Brain metastases (BMs) are the most common intracranial tumors in adults and occur 3-10 times more frequently than primary brain tumors. Despite intensive multimodal therapies, including resection, radiotherapy, and chemotherapy, BMs are associated with poor prognosis and remain challenging to treat. BMs predominantly originate from primary lung (20-56%), breast (5-20%), and melanoma (7-16%) tumors, although they can arise from other cancer types less frequently. The metastatic cascade is a multistep process involving local invasion, intravasation into the bloodstream or lymphatic system, extravasation into normal tissue, and colonization of the distal site. After reaching the brain, circulating tumor cells (CTCs) breach the blood-brain barrier (BBB).The selective permeability of the BBB poses a significant challenge for therapeutic compounds, limiting the treatment efficacy of BMs. Understanding the mechanisms of tumor cell interactions with the BBB is crucial for the development of effective treatments. This review provides an in-depth analysis of the brain barriers, including the BBB, blood-spinal cord barrier, blood-meningeal barrier, blood-arachnoid barrier, and blood-cerebrospinal fluid barrier. It explores the molecular and cellular components of these barriers and their roles in brain metastasis, highlighting the importance of this knowledge for identifying druggable targets to prevent or limit BM formation.

Facilitation of Tumor Stroma-Targeted Therapy: Model Difficulty and Co-Culture Organoid Method

Background: Tumors, as intricate ecosystems, comprise oncocytes and the highly dynamic tumor stroma. Tumor stroma, representing the non-cancerous and non-cellular composition of the tumor microenvironment (TME), plays a crucial role in oncogenesis and progression, through its interactions with biological, chemical, and mechanical signals. This review aims to analyze the challenges of stroma mimicry models, and highlight advanced personalized co-culture approaches for recapitulating tumor stroma using patient-derived tumor organoids (PDTOs). Methods: This review synthesizes findings from recent studies on tumor stroma composition, stromal remodeling, and the spatiotemporal heterogeneities of the TME. It explores popular stroma-related models, co-culture systems integrating PDTOs with stromal elements, and advanced techniques to improve stroma mimicry. Results: Stroma remodeling, driven by stromal cells, highlights the dynamism and heterogeneity of the TME. PDTOs, derived from tumor tissues or cancer-specific stem cells, accurately mimic the tissue-specific and genetic features of primary tumors, making them valuable for drug screening. Co-culture models combining PDTOs with stromal elements effectively recreate the dynamic TME, showing promise in personalized anti-cancer therapy. Advanced co-culture techniques and flexible combinations enhance the precision of tumor-stroma recapitulation. Conclusions: PDTO-based co-culture systems offer a promising platform for stroma mimicry and personalized anti-cancer therapy development. This review underscores the importance of refining these models to advance precision medicine and improve therapeutic outcomes.

Microenvironmental Regulation of Dormancy in Breast Cancer Metastasis: "An Ally that Changes Allegiances"

Breast cancer remission after treatment is sometimes long-lasting, but in about 30% of cases, there is a relapse after a so-called dormant state. Cellular cancer dormancy, the propensity of disseminated tumor cells (DTCs) to remain in a nonproliferative state for an extended period, presents an opportunity for therapeutic intervention that may prevent reawakening and the lethal consequences of metastatic outgrowth. Therefore, identification of dormant DTCs and detailed characterization of cancer cell-intrinsic and niche-specific [i.e., tumor microenvironment (TME) mediated] mechanisms influencing dormancy in different metastatic organs are of great importance in breast cancer. Several microenvironmental drivers of DTC dormancy in metastatic organs, such as the lung, bone, liver, and brain, have been identified using in vivo models and/or in vitro three-dimensional culture systems. TME induction and persistence of dormancy in these organs are mainly mediated by signals from immune cells, stromal cells, and extracellular matrix components of the TME. Alterations of the TME have been shown to reawaken dormant DTCs. Efforts to capitalize on these findings often face translational challenges due to limited availability of representative patient samples and difficulty in designing dormancy-targeting clinical trials. In this chapter, we discuss current approaches to identify dormant DTCs and provide insights into cell-extrinsic (i.e., TME) mechanisms driving breast cancer cell dormancy in distant organs.

Metabolic Reprogramming and Adaption in Breast Cancer Progression and Metastasis

Recent evidence has revealed that cancer is not solely driven by genetic abnormalities but also by significant metabolic dysregulation. Cancer cells exhibit altered metabolic demands and rewiring of cellular metabolism to sustain their malignant characteristics. Metabolic reprogramming has emerged as a hallmark of cancer, playing a complex role in breast cancer initiation, progression, and metastasis. The different molecular subtypes of breast cancer exhibit distinct metabolic genotypes and phenotypes, offering opportunities for subtype-specific therapeutic approaches. Cancer-associated metabolic phenotypes encompass dysregulated nutrient uptake, opportunistic nutrient acquisition strategies, altered utilization of glycolysis and TCA cycle intermediates, increased nitrogen demand, metabolite-driven gene regulation, and metabolic interactions with the microenvironment. The tumor microenvironment, consisting of stromal cells, immune cells, blood vessels, and extracellular matrix components, influences metabolic adaptations through modulating nutrient availability, oxygen levels, and signaling pathways. Metastasis, the process of cancer spread, involves intricate steps that present unique metabolic challenges at each stage. Successful metastasis requires cancer cells to navigate varying nutrient and oxygen availability, endure oxidative stress, and adapt their metabolic processes accordingly. The metabolic reprogramming observed in breast cancer is regulated by oncogenes, tumor suppressor genes, and signaling pathways that integrate cellular signaling with metabolic processes. Understanding the metabolic adaptations associated with metastasis holds promise for identifying therapeutic targets to disrupt the metastatic process and improve patient outcomes. This chapter explores the metabolic alterations linked to breast cancer metastasis and highlights the potential for targeted interventions in this context.

miRNA signatures affecting the survival outcome in distant metastasis of triple-negative breast cancer

Triple-negative breast cancer (TNBC) constitutes for 10-15% of all breast cancer cases. Tumor heterogeneity, high invasiveness, distant metastasis, lack of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2 expression contribute to TNBC associated with poor overall survival outcomes amongst diseased individuals. The disparity in clinico-pathological and metastatic patterns to distant sites has substantially enhanced the incidences of tumor recurrence. Survival outcomes amongst metastatic TNBC patients are worse in comparison to non-metastatic TNBC counterparts. MicroRNAs (miRNAs) have emerged as significant drivers to function either as oncogene or tumor suppressors by exerting modulating effects on the expression of target genes in the TNBC tumor microenvironment. The pleiotropic nature of miRNAs expands their preclinical and clinical utility in combating both metastatic and non-metastatic TNBC cases and thereby improves their survival outcomes. The present review article aims to highlight the varying survival outcomes in metastatic and non-metastatic TNBC cases. The present review article emphasizes the therapeutic and prognostic potential of miRNAs in TNBC to improve survival outcomes by retarding distant metastasis to lung, bone, brain, and lymph nodes.

Current landscape of exosomal non-coding RNAs in prostate cancer: Modulators and biomarkers

Prostate cancer (PCa) has the highest frequency of diagnosis among solid tumors and ranks second as the primary cause of cancer-related deaths. Non-coding RNAs (ncRNAs), such as microRNAs, long non-coding RNAs and circular RNAs, frequently exhibit dysregulation and substantially impact the biological behavior of PCa. Compared with circulating ncRNAs, ncRNAs loaded into exosomes are more stable because of protection by the lipid bilayer. Furthermore, exosomal ncRNAs facilitate the intercellular transfer of molecules and information. Increasing evidence suggests that exosomal ncRNAs hold promising potential in the progression, diagnosis and prognosis of PCa. This review aims to discuss the functions of exosomal ncRNAs in PCa, evaluate their possible applications as clinical biomarkers and therapeutic targets, and provide a comprehensive overview of the ncRNAs regulatory network in PCa. We also identified ncRNAs that can be utilized as biomarkers for diagnosis, staging, grading and prognosis assessment in PCa. This review offers researchers a fresh perspective on the functions of exosomal ncRNAs in PCa and provides additional options for its diagnosis, progression monitoring, and prognostic prediction.

Metabolic reprogramming and therapeutic resistance in primary and metastatic breast cancer

Metabolic alterations, a hallmark of cancer, enable tumor cells to adapt to their environment by modulating glucose, lipid, and amino acid metabolism, which fuels rapid growth and contributes to treatment resistance. In primary breast cancer, metabolic shifts such as the Warburg effect and enhanced lipid synthesis are closely linked to chemotherapy failure. Similarly, metastatic lesions often display distinct metabolic profiles that not only sustain tumor growth but also confer resistance to targeted therapies and immunotherapies. The review emphasizes two major aspects: the mechanisms driving metabolic resistance in both primary and metastatic breast cancer, and how the unique metabolic environments in metastatic sites further complicate treatment. By targeting distinct metabolic vulnerabilities at both the primary and metastatic stages, new strategies could improve the efficacy of existing therapies and provide better outcomes for breast cancer patients.

Solitary Renal Metastases From Stage IA Primary Lung Adenocarcinoma With Co-Alteration of EGFR, RB1, and MAP3K1: A Case Report

We report a case of 59-year-old female with solitary bilateral renal metastases after surgery of stage IA primary lung adenocarcinoma who underwent next-generation sequencing (NGS) of both lesions. The patient received right upper lobectomy and lymph node dissection, which revealed primary invasive lung adenocarcinoma (pT1cN0M0, stage IA3). Two years following this, positron emission tomography-computed tomography (PET/CT) revealed multiple masses in both kidneys without other distant metastases, and ultrasonography-guided puncture biopsy indicated the presence of metastatic lung adenocarcinoma. The NGS of both the primary and metastatic lesions revealed the co-alteration of epidermal growth factor receptor (EGFR), RB transcriptional corepressor 1 (RB1), and mitogen-activated protein kinase kinase 1 (MAP3K1), which is potentially associated with the risk of renal metastasis in early postoperative non-small cell lung cancer.

Nerve growth factor inducible (VGF) is a secreted mediator for metastatic breast cancer tropism to the brain

Brain metastases are one of the most serious clinical problems in breast cancer (BC) progression, associated with lower survival rates and a lack of effective therapies. Thus, to dissect the early stages of the brain metastatic process, we studied the impact of brain organotropic BC cells' secretomes on the establishment of the brain pre-metastatic niche (PMN). We found that BC cells with specific tropism to the brain caused significant blood-brain barrier (BBB) disruption, as well as microglial activation, in both in vitro and in vivo models. Further, we searched for a brain-organotropic metastatic signature, as a promising source for the discovery of new biomarkers involved in brain metastatic progression. Of relevance, we identified VGF (nerve growth factor inducible) as a key mediator in this process, also impacting the BBB and microglial functions both in vitro and in vivo. In a series of human breast tumors, VGF was found to be expressed in both cancer cells and the adjacent stroma. Importantly, VGF-positive tumors showed a significantly worse prognosis and were associated with HER2 (human epidermal growth factor receptor 2) overexpression and triple-negative molecular signatures. Further clinical validation in primary tumors from metastatic BC cases showed a significant association between VGF and the brain metastatic location, clearly and significantly impacting on the prognosis of BC patients with brain metastasis. In conclusion, our study reveals a unique secretome signature for BC with a tropism for the brain, highlighting VGF as a crucial mediator in this process. Furthermore, its specific impact as a poor prognostic predictor for BC patients with brain metastasis opens new avenues to target VGF to control the progression of brain metastatic disease. © 2024 The Pathological Society of Great Britain and Ireland.

Multifunctional Biomimetic Liposomes with Improved Tumor-Targeting for TNBC Treatment by Combination of Chemotherapy, Antiangiogenesis and Immunotherapy

Triple negative breast cancer (TNBC) featuring high relapses and metastasis shows limited clinical therapeutic efficiency with chemotherapy for the extremely complex tumor microenvironment, especially angiogenesis and immunosuppression. Combination of antiangiogenesis and immunotherapy holds promise for effective inhibition of tumor proliferation and invasion, while it remains challenging for specific targeting drug delivery to tumors and metastatic lesions. Here, a multifunctional biomimetic liposome loading Gambogic acid (G/R-MLP) is developed using Ginsenoside Rg3 (Rg3) to substitute cholesterol and cancer cell membrane coating, which is designed to increase long-circulating action by a low immunogenicity and specifically deliver gambogic acid (GA) to tumor site and metastatic lesions by homologous targeting and glucose transporter targeting. After G/R-MLP accumulates in the primary tumors and metastatic nodules, it synergistically enhances the antitumor efficacy of GA, effectively suppressing the tumor growth and lung metastasis by killing tumor cells, inhibiting tumor cell migration and invasion, achieving antiangiogenesis and improving the antitumor immunity. All in all, the strategy combining chemotherapy, antiangiogenesis, and immunotherapy improves therapeutic efficiency and prolonged survival, providing a new perspective for the clinical treatment of TNBC.

Effect of micropillar density on morphology and migration of low and high metastatic potential breast cancer cells

Study of cell migration in cancer is crucial to the comprehension of the processes and factors that govern tumor spread. Cancer cells migrate invading tissues, causing alterations in cell adhesion, cytoskeleton, and signaling pathways. Little is known about the physical attributes of cancer cells that change when interacting with microenvironments. In this work, the local topography of the ECM has been mimicked through micropillar array substrates. MDA-MB-231 and MCF-7 breast cancer cells, exhibiting high and low metastatic potential, respectively, were analyzed. Differences in morphology and migration of the cells were investigated by examining the cell spreading area, circularity, aspect ratio, migration speed, and migration path. This work encountered that none of the studied cell lines have preferential orientation migrating on uniform patterns. In contrast, cell migration on graded patterns shows preferential orientation along the longitudinal direction from sparser to denser zones which is significantly influenced by substrate stiffness and indicates that both cell lines can sense the spacing gradient and respond to this topographical cue. The migration speed of the breast cancer cell lines significantly decreases from the sparse to medium to dense zones, registering higher values for the MDA-MB-231.

Regulation of KLRC and Ceacam gene expression by miR-141 supports cell proliferation and metastasis in cervical cancer cells

INTRODUCTION

MicroRNAs (miRNAs) are single RNA molecules that act as global regulators of gene expression in mammalian cells and thus constitute attractive targets in treating cancer. Here we aimed to investigate the possible involvement of miRNA-141 (miR-141) in cervical cancer and to identify its potential targets in cervical cancer cell lines.

METHODS

The level of miR-141 in HeLa and C-33A cells has been assessed using the quantitative real-time PCR (qRT-PCR). A new miR-141 construct has been performed in a CMV promoter vector tagged with GFP. Using microarray analysis, we identified the potentially regulated genes by miR-141 in transfected HeLa cells. The protein profile of killer-like receptor C1 (KLRC1), KLRC3, carcinoembryonic antigen-related cell adhesion molecule 3 (CAM3), and CAM6 was investigated in HeLa cells transfected with either an inhibitor, antagonist miR-141, or miR-141 overexpression vector using immunoblotting and flow cytometry assay. Finally, ELISA assay has been used to monitor the produced cytokines from transfected HeLa cells.

RESULTS

The expression of miR-141 significantly increased in HeLa and C-33A cells compared to the normal cervical HCK1T cell line. Transfection of HeLa cells with an inhibitor, antagonist miR-141, showed a potent effect on cancer cell viability, unlike the transfection of miR-141 overexpression vector. The microarray data of HeLa cells overexpressed miR-141 provided a hundred of downregulated genes, including KLRC1, KLRC3, CAM3, and CAM6. KLRC1 and KLRC3 expression profiles markedly depleted in HeLa cells transfected with miR-141 overexpression accompanied by decreasing interleukin 8 (IL-8), indicating the role of miR-141 in avoiding programmed cells death in HeLa cells. Likewise, CAM3 and CAM6 expression reduced markedly in miR-141 transduced cells accompanied by an increasing level of transforming growth factor beta (TGF-β), indicating the impact of miR-141 in cancer cell migration. The IntaRNA program and miRWalk were used to check the direct interaction and potential binding sites between miR-141 and identified genes. Based on this, the seeding regions of each potential target was cloned upstream of the luciferase reporter gene in the pGL3 control vector. Interestingly, the luciferase activities of constructed vectors were significantly decreased in HeLa cells pre-transfected with miR-141 overexpression vector, while increasing enormously in cells pre-transfected with miR-141 specific inhibitor.

CONCLUSION

Together, these data uncover an efficient miR-141-based mechanism that supports cervical cancer progression and identifies miR-141 as a credible therapeutic target.

The role of circular RNA during the urological cancer metastasis: exploring regulatory mechanisms and potential therapeutic targets

Metastasis is a major contributor to treatment failure and death in urological cancers, representing an important biomedical challenge at present. Metastases form as a result of cancer cells leaving the primary site, entering the vasculature and lymphatic vessels, and colonizing clones elsewhere in the body. However, the specific regulatory mechanisms of action underlying the metastatic process of urological cancers remain incompletely elucidated. With the deepening of research, circular RNAs (circRNAs) have been found to not only play a significant role in tumor progression and prognosis but also show aberrant expression in various tumor metastases, consequently impacting tumor metastasis through multiple pathways. Therefore, circRNAs are emerging as potential tumor markers and treatment targets. This review summarizes the research progress on elucidating how circRNAs regulate the urological cancer invasion-metastasis cascade response and related processes, as well as their role in immune microenvironment remodeling and circRNA vaccines. This body of work highlights circRNA regulation as an emerging therapeutic target for urological cancers, which should motivate further specific research in this regard.

Comprehensive transcriptomic analysis of prostate cancer lung metastases

Metastatic prostate cancer (mPCa) is a widespread disease with high mortality. Unraveling molecular mechanisms of disease progression is of utmost importance. The microenvironment in visceral organs and the skeletal system is of particular interest as a harbinger of metastatic spread. Therefore, we performed a comprehensive transcriptomic analysis of prostate cancer lung metastases with a special focus on differentially expressed genes attributable to the microenvironment. Digital gene expression analysis using the NanoString nCounter analysis system was performed on formalin-fixed, paraffin-embedded (FFPE) tissue from prostate cancer (PCa) lung metastases (n = 24). Data were compared to gene expression data from primary PCa and PCa bone metastases. Bioinformatic analysis was performed using several publicly available tools. In comparison to prostate cancer bone metastases, 209 genes were significantly upregulated, and 100 genes were significantly downregulated in prostate cancer lung metastases. Among the up-regulated genes, the top 10 genes with the most significant P-value were HLA-DPB1, PTPRC, ITGB7, C3, CCL21, CCL5, ITGAM, SERPINA1, MFAP4, ARAP2 and among the down-regulated genes, the top 10 genes with the most significant P-value were FOXC2, TWIST1, CDK14, CHAD, IBSP, EPN3, VIT, HAPLN1, SLC44A4, TBX1. In PCa lung metastases genes associated with immunogenic responses were upregulated while genes associated with epithelial-mesenchymal transition were down-regulated. We also showed that CXCR3/CXCL10 axis plays a significant role in prostate cancer lung metastases in comparison to bone metastases. In this study, we comprehensively explored transcriptomic alterations in PCa lung metastases in comparison to primary PCa and PCa bone metastases. In PCa lung metastases genes associated with immunogenic responses are upregulated while genes associated with epithelial-mesenchymal transition are down-regulated. This points to a more immunogenic phenotype of PCa lung metastases thus potentially making patients more susceptible to immunotherapeutic approaches.

Lipocalin-2 promotes breast cancer brain metastasis by enhancing tumor invasion and modulating brain microenvironment

Breast cancer is the leading cancer diagnosed in women globally, with brain metastasis emerging as a major cause of death, particularly in human epidermal growth factor receptor 2 positive and triple-negative breast cancer subtypes. Comprehensive understanding of the molecular foundations of central nervous system metastases is imperative for the evolution of efficacious treatment strategies. Lipocalin-2 (LCN2), a secreted iron transport protein with multiple functions, has been linked to the progression of breast cancer brain metastasis (BCBM). In primary tumors, LCN2 promotes the proliferation and angiogenesis of breast cancer cells, triggers the epithelial-mesenchymal transition, interacts with matrix metalloproteinase-9, thereby facilitating the reorganization of the extracellular matrix and enhancing cancer cell invasion and migration. In brain microenvironment, LCN2 undermines the blood-brain barrier and facilitates tumor seeding in the brain by modulating the behavior of key cellular components. In summary, this review meticulously examines the fuel role of LCN2 in BCBM cascade, and investigates the potential mechanisms involved. It highlights the potential of LCN2 as both a therapeutic target and biomarker, indicating that interventions targeting LCN2 may offer improved outcomes for patients afflicted with BCBM.

Recent advances in breast cancer metastasis with special emphasis on metastasis to the brain

Understanding the underlying mechanisms of breast cancer metastasis is of vital importance for developing treatment approaches. This review emphasizes contemporary breakthrough studies with special focus on breast cancer brain metastasis. Acquired mutational changes in metastatic lesions are often distinct from the primary tumor, suggesting altered mutagenesis pathways. The concept of micrometastases and heterogeneity within the tumors unravels novel therapeutic targets at genomic and molecular levels through epigenetic and proteomic profiling. Several pre-clinical studies have identified mechanisms involving the immune system, where tumor associated macrophages are key players. Expression of cell proteins like Syndecan1, fatty acid-binding protein 7 and tropomyosin kinase receptor B have been implicated in aiding the transmigration of breast cancer cells to the brain. Changes in the proteomic landscape of the blood-brain-barrier show altered permeability characteristics, supporting entry of cancer cells. Findings from laboratory studies pave the path for the emergence of new biomarkers, especially blood-based miRNA and circulating tumor cell markers for prognostic staging. The constantly evolving therapeutics call for clinical trials backing supportive evidence of efficacies of both novel and existing approaches. The challenge lying ahead is discovering innovative techniques to replace use of human samples and optimize small-scale patient recruitment in trials.

Advancements in precision nanomedicine design targeting the anoikis-platelet interface of circulating tumor cells

Tumor metastasis, the apex of cancer progression, poses a formidable challenge in therapeutic endeavors. Circulating tumor cells (CTCs), resilient entities originating from primary tumors or their metastases, significantly contribute to this process by demonstrating remarkable adaptability. They survive shear stress, resist anoikis, evade immune surveillance, and thwart chemotherapy. This comprehensive review aims to elucidate the intricate landscape of CTC formation, metastatic mechanisms, and the myriad factors influencing their behavior. Integral signaling pathways, such as integrin-related signaling, cellular autophagy, epithelial-mesenchymal transition, and interactions with platelets, are examined in detail. Furthermore, we explore the realm of precision nanomedicine design, with a specific emphasis on the anoikis‒platelet interface. This innovative approach strategically targets CTC survival mechanisms, offering promising avenues for combatting metastatic cancer with unprecedented precision and efficacy. The review underscores the indispensable role of the rational design of platelet-based nanomedicine in the pursuit of restraining CTC-driven metastasis.

The role of host response to chemotherapy: resistance, metastasis and clinical implications

Chemotherapy remains the primary treatment for most metastatic cancers. However, the response to chemotherapy and targeted agents is often transient, and concurrent development of resistance is the primary impediment to effective cancer therapy. Strategies to overcome resistance to treatment have focused on cancer cell intrinsic factors and the tumor microenvironment (TME). Recent evidence indicates that systemic chemotherapy has a significant impact on the host that either facilitates tumor growth, allowing metastatic spread, or renders treatment ineffective. These host responses include the release of bone marrow-derived cells, activation of stromal cells in the TME, and induction of different molecular effectors. Here, we provide an overview of chemotherapy-induced systemic host responses that support tumor aggressiveness and metastasis, and which contribute to therapy resistance. Studying host responses to chemotherapy provides a solid basis for the development of adjuvant strategies to improve treatment outcomes and delay resistance to chemotherapy. This review discusses the emerging field of host response to cancer therapy, and its preclinical and potential clinical implications, explaining how under certain circumstances, these host effects contribute to metastasis and resistance to chemotherapy.

Solitary liver metastasis from adenoid cystic carcinoma of the submandibular gland

Adenoid cystic carcinoma (ACC) is a rare tumour of the salivary glands characterised by distant metastases, mainly to lungs and bone. Isolated metastasis to the liver is unusual. We present the case of a woman with an ACC of the submandibular gland (pT1N0) who underwent radical submandibular gland excision and selective neck dissection. Preoperative imaging identified a liver lesion with features suggestive of a haemangioma. Two-year postoperatively, a surveillance CT neck/trunk showed an increase in size of the left liver lobe lesion. Subsequent MR liver and US-guided biopsy confirmed the lesion to be metastatic ACC. The patient underwent a successful left lateral liver sectionectomy. She remains disease-free 2.5 years after her liver resection. A literature search revealed only four other similar cases. This report highlights that even early-stage ACCs of the salivary gland may present with synchronous solitary liver metastasis which can be effectively treated with curative surgery.

CEACAM6 Promotes Lung Metastasis via Enhancing Proliferation, Migration and Suppressing Apoptosis of Prostate Cancer Cells

BACKGROUND/AIM

Metastatic prostate cancer (mPCa) results in high morbidity and mortality. Visceral metastases in particular are associated with a shortened survival. Our aim was to unravel the molecular mechanisms that underly pulmonary spread in mPCa.

MATERIALS AND METHODS

We performed a comprehensive transcriptomic analysis of PCa lung metastases, followed by functional validation of candidate genes. Digital gene expression analysis utilizing the NanoString technology was performed on mRNA extracted from formalin-fixed, paraffin-embedded (FFPE) tissue from PCa lung metastases. The gene expression data from primary PCa and PCa lung metastases were compared, and several publicly available bioinformatic analysis tools were used to annotate and validate the data.

RESULTS

In PCa lung metastases, 234 genes were considerably up-regulated, and 78 genes were significantly down-regulated when compared to primary PCa. Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) was identified as suitable candidate gene for further functional validation. CEACAM6 as a cell adhesion molecule has been implicated in promoting metastatic disease in several solid tumors, such as colorectal or gastric cancer. We showed that siRNA knockdown of CEACAM6 in PC-3 and LNCaP cells resulted in decreased cell viability and migration as well as enhanced apoptosis. Comprehensive transcriptomic analyses identified several genes of interest that might promote metastatic spread to the lung.

CONCLUSION

Functional validation revealed that CEACAM6 might play an important role in fostering metastatic spread to the lung of PCa patients via enhancing proliferation, migration and suppressing apoptosis in PC-3 and LNCaP cells. CEACAM6 might pose an attractive therapeutic target to prevent metastatic disease.

Revisiting the role of mesenchymal stromal cells in cancer initiation, metastasis and immunosuppression

Immune checkpoint blockade (ICB) necessitates a thorough understanding of intricate cellular interactions within the tumor microenvironment (TME). Mesenchymal stromal cells (MSCs) play a pivotal role in cancer generation, progression, and immunosuppressive tumor microenvironment. Within the TME, MSCs encompass both resident and circulating counterparts that dynamically communicate and actively participate in TME immunosurveillance and response to ICB. This review aims to reevaluate various facets of MSCs, including their potential self-transformation to function as cancer-initiating cells and contributions to the creation of a conducive environment for tumor proliferation and metastasis. Additionally, we explore the immune regulatory functions of tumor-associated MSCs (TA-MSCs) and MSC-derived extracellular vesicles (MSC-EVs) with analysis of potential connections between circulating and tissue-resident MSCs. A comprehensive understanding of the dynamics of MSC-immune cell communication and the heterogeneous cargo of tumor-educated versus naïve MSCs may unveil a new MSC-mediated immunosuppressive pathway that can be targeted to enhance cancer control by ICB.

Tumor cell-released autophagosomes (TRAPs) induce PD-L1-decorated NETs that suppress T-cell function to promote breast cancer pulmonary metastasis

BACKGROUND

Lung metastasis is the primary cause of breast cancer-related mortality. Neutrophil extracellular traps (NETs) are involved in the progression of breast cancer. However, the mechanism of NET formation is not fully understood. This study posits that tumor cell-released autophagosomes (TRAPs) play a crucial role in this process.

METHODS

TRAPs were isolated from breast cancer cell lines to analyze their impact on NET formation in both human and mouse neutrophils. The study used both in vitro and in vivo models, including Toll-like receptor 4 (TLR4-/-) mice and engineered breast cancer cell lines. Immunofluorescence, ELISA, Western blotting, RNA sequencing, and flow cytometry were employed to dissect the signaling pathways leading to NET production and to explore their immunosuppressive effects, particularly focusing on the impact of NETs on T-cell function. The therapeutic potential of targeting TRAP-induced NETs and their immunosuppressive functions was evaluated using DNase I and αPD-L1 antibodies. Clinical relevance was assessed by correlating circulating levels of TRAPs and NETs with lung metastasis in patients with breast cancer.

RESULTS

This study showed that TRAPs induced the formation of NETs in both human and mouse neutrophils by using the high mobility group box 1 and activating the TLR4-Myd88-ERK/p38 signaling axis. More importantly, PD-L1 carried by TRAP-induced NETs inhibited T-cell function in vitro and in vivo, thereby contributing to the formation of lung premetastatic niche (PMN) immunosuppression. In contrast, Becn1 KD-4T1 breast tumors with decreased circulating TRAPs in vivo reduced the formation of NETs, which in turn attenuated the immunosuppressive effects in PMN and resulted in a reduction of breast cancer pulmonary metastasis in murine models. Moreover, treatment with αPD-L1 in combination with DNase I that degraded NETs restored T-cell function and significantly reduced tumor metastasis. TRAP levels in the peripheral blood positively correlated with NET levels and lung metastasis in patients with breast cancer.

CONCLUSIONS

Our results demonstrate a novel role of TRAPs in the formation of PD-L1-decorated NETs, which may provide a new strategy for early detection and treatment of pulmonary metastasis in patients with breast cancer.

The Different Gene Expression Profile in the Eutopic and Ectopic Endometrium Sheds New Light on the Endometrial Seed in Endometriosis

The changes in endometrial cells, both in the eutopic endometrium of patients with and without endometriosis and in lesions at ectopic sites, are frequently described and often compared to tumorigenesis. In tumorigenesis, the concept of "seed and soil" is well established. The seed refers to tumor cells with metastatic potential, and the soil is any organ or tissue that provides a suitable environment for the seed to grow. In this systematic review (PRISMA-S), we specifically compared the development of endometriosis with the "seed and soil" hypothesis. To determine changes in the endometrial seed, we re-analyzed the mRNA expression data of the eutopic and ectopic endometrium, paying special attention to the epithelial-mesenchymal transition (EMT). We found that the similarity between eutopic endometrium without and with endometriosis is extremely high (~99.1%). In contrast, the eutopic endometrium of patients with endometriosis has a similarity of only 95.3% with the ectopic endometrium. An analysis of EMT-associated genes revealed only minor differences in the mRNA expression levels of claudin family members without the loss of other cell-cell junctions that are critical for the epithelial phenotype. The array data suggest that the changes in the eutopic endometrium (=seed) are quite subtle at the beginning of the disease and that most of the differences occur after implantation into ectopic locations (=soil).

Gut microbiome-mediated monocytes promote liver metastasis

The gut microbiome plays an important role in tumor growth by regulating immune cell function. However, the role of the gut microbiome-mediated monocytes in liver metastasis remains unclear. In this study, we found that fecal microbiome transplantation (FMT) from the stool of patients with liver metastasis (LM) significantly promoted liver metastasis compared with healthy donors (HD). Monocytes were upregulated in liver tissues by the CCL2/CCR2 axis in LM patients' stool transplanted mouse model. CCL2/CCR2 inhibition and monocyte depletion significantly suppress liver metastasis. FMT using LM patients' stool enhanced the plasma lipopolysaccharides (LPS) concentration. The LPS/TLR4 signaling pathway is crucial for gut microbiome-mediated liver metastasis. These results indicated that monocytes contribute to liver metastasis via the CCL2/CCR2 axis.

Anoikis-related gene signatures in colorectal cancer: implications for cell differentiation, immune infiltration, and prognostic prediction

Colorectal cancer (CRC) is a malignant tumor originating from epithelial cells of the colon or rectum, and its invasion and metastasis could be regulated by anoikis. However, the key genes and pathways regulating anoikis in CRC are still unclear and require further research. The single cell transcriptome dataset GSE221575 of GEO database was downloaded and applied to cell subpopulation type identification, intercellular communication, pseudo time cell trajectory analysis, and receptor ligand expression analysis of CRC. Meanwhile, the RNA transcriptome dataset of TCGA, the GSE39582, GSE17536, and GSE17537 datasets of GEO were downloaded and merged into one bulk transcriptome dataset. The differentially expressed genes (DEGs) related to anoikis were extracted from these data sets, and key marker genes were obtained after feature selection. A clinical prognosis prediction model was constructed based on the marker genes and the predictive effect was analyzed. Subsequently, gene pathway analysis, immune infiltration analysis, immunosuppressive point analysis, drug sensitivity analysis, and immunotherapy efficacy based on the key marker genes were conducted for the model. In this study, we used single cell datasets to determine the anoikis activity of cells and analyzed the DEGs of cells based on the score to identify the genes involved in anoikis and extracted DEGs related to the disease from the transcriptome dataset. After dimensionality reduction selection, 7 marker genes were obtained, including TIMP1, VEGFA, MYC, MSLN, EPHA2, ABHD2, and CD24. The prognostic risk model scoring system built by these 7 genes, along with patient clinical data (age, tumor stage, grade), were incorporated to create a nomogram, which predicted the 1-, 3-, and 5-years survival of CRC with accuracy of 0.818, 0.821, and 0.824. By using the scoring system, the CRC samples were divided into high/low anoikis-related prognosis risk groups, there are significant differences in immune infiltration, distribution of immune checkpoints, sensitivity to chemotherapy drugs, and efficacy of immunotherapy between these two risk groups. Anoikis genes participate in the differentiation of colorectal cancer tumor cells, promote tumor development, and could predict the prognosis of colorectal cancer.

Tumor biomarkers for diagnosis, prognosis and targeted therapy

Tumor biomarkers, the substances which are produced by tumors or the body's responses to tumors during tumorigenesis and progression, have been demonstrated to possess critical and encouraging value in screening and early diagnosis, prognosis prediction, recurrence detection, and therapeutic efficacy monitoring of cancers. Over the past decades, continuous progress has been made in exploring and discovering novel, sensitive, specific, and accurate tumor biomarkers, which has significantly promoted personalized medicine and improved the outcomes of cancer patients, especially advances in molecular biology technologies developed for the detection of tumor biomarkers. Herein, we summarize the discovery and development of tumor biomarkers, including the history of tumor biomarkers, the conventional and innovative technologies used for biomarker discovery and detection, the classification of tumor biomarkers based on tissue origins, and the application of tumor biomarkers in clinical cancer management. In particular, we highlight the recent advancements in biomarker-based anticancer-targeted therapies which are emerging as breakthroughs and promising cancer therapeutic strategies. We also discuss limitations and challenges that need to be addressed and provide insights and perspectives to turn challenges into opportunities in this field. Collectively, the discovery and application of multiple tumor biomarkers emphasized in this review may provide guidance on improved precision medicine, broaden horizons in future research directions, and expedite the clinical classification of cancer patients according to their molecular biomarkers rather than organs of origin.

Pro: "Is Spread Through Air Spaces an In Vivo Phenomenon or an Inducible Artifact?"

In this PRO-CON debate, you will read very different perspectives about a simple question regarding an observation under the microscope: What is the significance of tumor cells in the air spaces of the lung parenchyma beyond the tumor edge of a resected lung cancer? An important underlying question is whether this entire PRO-CON debate is a mere academic exercise or whether spread through air spaces (STAS), as currently defined, describes a clinically useful phenomenon. The journey of STAS began with a complete paradigm shift to reverse the thinking that all air space tumor cells beyond the edge of lung cancers are an artifact. This led to a new concept where STAS could be separated from artifacts with a definition that has proven to be clinically useful. As with any major change in thinking, it is understandable that there would be some disagreement with this paradigm shift. Nevertheless, after a decade since it was described, many pathologists and clinicians around the world have found STAS to provide important information about the behavior of lung cancer. Numerous PRO-STAS articles supporting the usefulness of STAS have been published with clinical data on many thousands of patients from numerous institutions all over the world. In contrast, for the CON-STAS articles, widespread international representation and data are limited. It is now difficult to ignore the numerous reports and is reasonable to consider how to use the presence of STAS in clinical decisions. Hopefully, this PRO-CON debate will further stimulate clinical and scientific investigations aimed at a better understanding of STAS.

Adipose-derived stem cells promote glycolysis and peritoneal metastasis via TGF-β1/SMAD3/ANGPTL4 axis in colorectal cancer

Peritoneal metastasis, the third most common metastasis in colorectal cancer (CRC), has a poor prognosis for the rapid progression and limited therapeutic strategy. However, the molecular characteristics and pathogenesis of CRC peritoneal metastasis are poorly understood. Here, we aimed to elucidate the action and mechanism of adipose-derived stem cells (ADSCs), a prominent component of the peritoneal microenvironment, in CRC peritoneal metastasis formation. Database analysis indicated that ADSCs infiltration was increased in CRC peritoneal metastases, and high expression levels of ADSCs marker genes predicted a poor prognosis. Then we investigated the effect of ADSCs on CRC cells in vitro and in vivo. The results revealed that CRC cells co-cultured with ADSCs exhibited stronger metastatic property and anoikis resistance, and ADSCs boosted the intraperitoneal seeding of CRC cells. Furthermore, RNA sequencing was carried out to identify the key target gene, angiopoietin like 4 (ANGPTL4), which was upregulated in CRC specimens, especially in peritoneal metastases. Mechanistically, TGF-β1 secreted by ADSCs activated SMAD3 in CRC cells, and chromatin immunoprecipitation assay showed that SMAD3 facilitated ANGPTL4 transcription by directly binding to ANGPTL4 promoter. The ANGPTL4 upregulation was essential for ADSCs to promote glycolysis and anoikis resistance in CRC. Importantly, simultaneously targeting TGF-β signaling and ANGPTL4 efficiently reduced intraperitoneal seeding in vivo. In conclusion, this study indicates that tumor-infiltrating ADSCs promote glycolysis and anoikis resistance in CRC cells and ultimately facilitate peritoneal metastasis via the TGF-β1/SMAD3/ANGPTL4 axis. The dual-targeting of TGF-β signaling and ANGPTL4 may be a feasible therapeutic strategy for CRC peritoneal metastasis.

Role of imbalanced gut microbiota in promoting CRC metastasis: from theory to clinical application

Metastasis poses a major challenge in colorectal cancer (CRC) treatment and remains a primary cause of mortality among patients with CRC. Recent investigations have elucidated the involvement of disrupted gut microbiota homeostasis in various facets of CRC metastasis, exerting a pivotal influence in shaping the metastatic microenvironment, triggering epithelial-mesenchymal transition (EMT), and so on. Moreover, therapeutic interventions targeting the gut microbiota demonstrate promise in enhancing the efficacy of conventional treatments for metastatic CRC (mCRC), presenting novel avenues for mCRC clinical management. Grounded in the "seed and soil" hypothesis, this review consolidates insights into the mechanisms by which imbalanced gut microbiota promotes mCRC and highlights recent strides in leveraging gut microbiota modulation for the clinical prevention and treatment of mCRC. Emphasis is placed on the considerable potential of manipulating gut microbiota within clinical settings for managing mCRC.

The Role of Ion Channels and Chemokines in Cancer Growth and Metastasis: A Proposed Mode of Action Using Peptides in Cancer Therapy

Metastasis (Met) largely contributes to the major cause of cancer deaths throughout the world, rather than the growth of the tumor mass itself. The present report brings together several of the pertinent contributors to cancer growth and metastatic processes from an activity standpoint. Such biological activities include the following: (1) cell adherence and detachment; (2) cell-to-cell contact; (3) contact inhibition; (4) the cell interfacing with the extracellular matrix (ECM); (5) tumor cell-to-stroma communication networks; (6) chemotaxis; and (7) cell membrane potential. Moreover, additional biochemical factors that contribute to cancer growth and metastasis have been shown to comprise the following: (a) calcium levels in the extracellular matrix and in intracellular compartments; (b) cation voltage and ATP-regulated potassium channels; (c) selective and non-selective cation channels; and (d) chemokines (cytokines) and their receptors, such as CXCL12 (SDF-1) and its receptor/binding partner, CXCR4. These latter molecular components represent a promising group of an interacting and synchronized set of candidates ideal for peptide therapeutic targeting for cancer growth and metastasis. Such peptides can be obtained from naturally occurring proteins such as alpha-fetoprotein (AFP), an onco-fetal protein and clinical biomarker.

The burgeoning importance of PIWI-interacting RNAs in cancer progression

PIWI-interacting RNAs (piRNAs) are a class of small noncoding RNA molecules that specifically bind to piwi protein family members to exert regulatory functions in germ cells. Recent studies have found that piRNAs, as tissue-specific molecules, both play oncogenic and tumor suppressive roles in cancer progression, including cancer cell proliferation, metastasis, chemoresistance and stemness. Additionally, the atypical manifestation of piRNAs and PIWI proteins in various malignancies presents a promising strategy for the identification of novel biomarkers and therapeutic targets in the diagnosis and management of tumors. Nonetheless, the precise functions of piRNAs in cancer progression and their underlying mechanisms have yet to be fully comprehended. This review aims to examine current research on the biogenesis and functions of piRNA and its burgeoning importance in cancer progression, thereby offering novel perspectives on the potential utilization of piRNAs and piwi proteins in the management and treatment of advanced cancer.

Clinical variables associated with immune checkpoint inhibitor outcomes in patients with metastatic urothelial carcinoma: a multicentre retrospective cohort study

OBJECTIVES

Immune checkpoint inhibitors (ICIs) are indicated for metastatic urothelial cancer (mUC), but predictive and prognostic factors are lacking. We investigated clinical variables associated with ICI outcomes.

METHODS

We performed a multicentre retrospective cohort study of 135 patients who received ICI for mUC, 2016-2021, at three Canadian centres. Clinical characteristics, body mass index (BMI), metastatic sites, neutrophil-to-lymphocyte ratio (NLR), response and survival were abstracted from chart review.

RESULTS

We identified 135 patients and 62% had received ICI as a second-line or later treatment for mUC. A BMI ≥25 was significantly correlated to a higher overall response rate (ORR) (45.4% vs 16.3%, p value=0.020). Patients with BMI ≥30 experienced longer median overall survival (OS) of 24.8 vs 14.4 for 25≤BMI<30 and 8.5 months for BMI <25 (p value=0.012). The ORR was lower in the presence of bone metastases (16% vs 41%, p value=0.006) and liver metastases (16% vs 39%, p value=0.013). Metastatic lymph nodes were correlated with higher ORR (40% vs 20%, p value=0.032). The median OS for bone metastases was 7.3 versus 18 months (p value <0.001). Patients with liver metastases had a median OS of 8.6 versus 15 months (p value=0.006). No difference for lymph nodes metastases (13.5 vs 12.7 months, p value=0.175) was found. NLR ≥4 had worse OS (8.2 vs 17.7 months, p value=0.0001). In multivariate analysis, BMI ≥30, bone metastases, NLR ≥4, performance status ≥2 and line of ICI ≥2 were independent factors for OS.

CONCLUSIONS

Our data identified BMI and bone metastases as novel clinical biomarkers that were independently associated with ICI outcomes in mUC. External and prospective validation are warranted.

Biochemical outcome in metastatic prostate cancer patients following prostate-directed radiotherapy

Background

The role of cytoreductive local radiotherapy (RT) in metastatic prostate cancer (mPCa) has recently been established. This study aimed to evaluate the biochemical outcome of local RT in mPCa.

Methods

This randomised controlled phase III study was conducted at the Clinical Oncology Department, Suez Canal University Hospital. Eligible participants were de-novo or metachronous mPCa patients with Eastern Cooperative Oncology Group performance status of 0-2. Participants were randomised to receive either cytoreductive prostate-directed RT in addition to standard care or standard care alone. The conventional radiation schedule of 70 Gy/35 fractions or the hypofractionated schedule of 55 Gy/20 fractions were delivered. The primary endpoint was biochemical progression-free survival (BPFS), and the secondary endpoint was overall survival (OS). Survival and post-hoc analyses were performed using Cox regression and the Kaplan-Meier method with the log-rank test.

Results

Between 23 November 2020 and 21 2022, 70 patients were enrolled in this study. Of them, 34 patients were assigned to the prostate RT group, and 29 patients were assigned to the control group. At a median follow-up of 12 months, the median BPFS has not been reached for the prostate RT group compared to 4.067 months for the control group (HR: 0.147, p < 0.001). Subgroup analysis showed that the median BPFS was statistically significantly correlated with low-volume (95% CI, 0.004 to 0.262, p = 0·001) and hormonal-sensitive metastatic disease (95% CI, 0.010 to 0.192, p < 0·001). The median OS was 16.33 months for the prostate-RT group compared to 11.33 months for the control group (HR: 0.313, p = 0.003).

Conclusion

Prostate-directed RT improved BPFS and OS in mPCa patients, particularly in those with low volume and hormonal-sensitive disease.

Trial Registration

This trial is registered on (27/4/2023), retrospectively registered with pactr.samrc.ac.za, PACTR202305854600529, URL: https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=25510.

Seed and Soil: Consensus Molecular Subgroups (CMS) and Tumor Microenvironment Features Between Primary Lesions and Metastases of Different Organ Sites in Colorectal Cancer

Purpose

Consensus molecular subtypes (CMS) are mainly used for biological interpretability and clinical stratification of colorectal cancer (CRC) in primary tumors (PT) but few in metastases. The heterogeneity of CMS distribution in metastases and the concordance of CMS between PT and metastases still lack sufficient study. We used CMS to classify CRC metastases and combine it with histopathological analysis to explore differences between PT and distant metastases.

Patients and Methods

We obtained gene expression profiles for 942 PT samples from TCGA database (n=376) and GEO database (n=566), as well as 442 metastasis samples from GEO database. Among these, 765 PT samples and 442 metastasis samples were confidently identified with CMS using the "CMS classifier" and enrolled for analysis. Clinicopathological manifestation and CMS classification of CRC metastases were assessed with data from GEO, TCGA, and cBioPortal. Overall, 105 PT-metastasis pairs were extracted from 10 GEO datasets to assess CMS concordance. Tumor microenvironment (TME) features between PT and metastases were analyzed by immune-stromal infiltration with ESTIMATE and xCell algorithms. Finally, TME features were validated with multiplex immunohistochemistry in 27 PT-metastasis pairs we retrospectively collected.

Results

Up to 64% of CRC metastases exhibited concordant CMS groups with matched PT, and the TME of metastases was similar to that of PT. For most common distant metastases, liver metastases were predominantly CMS2 and lung and peritoneal metastases were mainly CMS4, highlighting "seed" of tumor cells of different CMS groups had a preference for metastasis to "soil" of specific organs. Compared with PT, cancer-associated fibroblasts (CAF) reduced in liver metastases, CD4+T cells and M2-like macrophages increased in lung metastases, and M2-like macrophages and CAF increased in peritoneal metastases.

Conclusion

Our findings underscore the importance of CMS-guided specific organ monitoring and treatment post-primary tumor surgery for patients. Differences in immune-stromal infiltration among different metastases provide targeted therapeutic opportunities for metastatic CRC.

Molecular perspectives on systemic priming and concomitant immunity in colorectal carcinoma

The progression of metastasis, a complex systemic disease, is facilitated by interactions between tumor cells and their isolated microenvironments. Over the past few decades, researchers have investigated the metastatic spread of cancer extensively, identifying multiple stages in the process, such as intravasation, extravasation, tumor latency, and the development of micrometastasis and macrometastasis. The premetastatic niche is established in target organs by the accumulation of aberrant immune cells and extracellular matrix proteins. The "seed and soil" idea, which has become widely known and accepted, is being used to this day to guide cancer studies. Changes in the local and systemic immune systems have a major impact on whether an infection spreads or not. The belief that the immune response may play a role in slowing tumor growth and may be beneficial against the metastatic disease underpins the responsiveness shown in the immunological landscape of metastasis. Various hypotheses on the phylogenesis of metastases have been proposed in the past. The primary tumor's secreting factors shape the intratumoral microenvironment and the immune landscape, allowing this progress to be made. Therefore, it is evident that among disseminated tumor cells, there are distinct phenotypes that either carry budding for metastasis or have the ability to obtain this potential or in systemic priming through contact with substantial metastatic niches that have implications for medicinal chemistry. Concurrent immunity signals that the main tumor induces an immune response that may not be strong enough to eradicate the tumor. Immunotherapy's success with some cancer patients shows that it is possible to effectively destroy even advanced-stage tumors by modifying the microenvironment and tumor-immune cell interactions. This review focuses on the metastasome in colorectal carcinoma and the therapeutic implications of site-specific metastasis, systemic priming, tumor spread, and the relationship between the immune system and metastasis.

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.

Radiotherapy in the management of synchronous metastatic lung cancer

Metastatic lung cancer classically portends a poor prognosis. The management of metastatic lung cancer has dramatically changed with the emergence of immune checkpoint inhibitors, targeted therapy and due to a better understanding of the oligometastatic process. In metastatic lung cancers, radiation therapy which was only used with palliative intent for decades, represents today a promising way to treat primary and oligometastatic sites with a curative intent. Herein we present through a literature review the role of radiotherapy in the management of synchronous metastatic lung cancers.

Adhesion, metastasis, and inhibition of cancer cells: a comprehensive review

This comprehensive review delves into cancer's complexity, focusing on adhesion, metastasis, and inhibition. It explores the pivotal role of these factors in disease progression and therapeutic strategies. This review covers cancer cell migration, invasion, and colonization of distant organs, emphasizing the significance of cell adhesion and the intricate metastasis process. Inhibition approaches targeting adhesion molecules, such as integrins and cadherins, are discussed. Overall, this review contributes significantly to advancing cancer research and developing targeted therapies, holding promise for improving patient outcomes worldwide. Exploring different inhibition strategies revealed promising therapeutic targets to alleviate adhesion and metastasis of cancer cells. The effectiveness of integrin-blocking antibodies, small molecule inhibitors targeting Focal adhesion kinase (FAK) and the Transforming Growth Factor β (TGF-β) pathway, and combination therapies underscores their potential to disrupt focal adhesions and control epithelial-mesenchymal transition processes. The identification of as FAK, Src, β-catenin and SMAD4 offers valuable starting points for further research and the development of targeted therapies. The complex interrelationships between adhesion and metastatic signaling networks will be relevant to the development of new treatment approaches.