Carcinoma Associated Mesenchymal Stem/Stromal Cells - Architects of the Pro-tumorigenic tumor microenvironment

Decoding the function of cancer-associated fibroblasts in osteosarcoma: Molecular pathways, therapeutic approaches and prognostic significance

Herein, we summarize the latest insights into osteosarcoma, the most prevalent primary malignant bone tumor, known for its aggressive nature, poor outcome, and especially poor prognosis when metastasis develops. Given recent research implicating the crucial role of the tumor microenvironment (TME) in osteosarcoma progression, cancer-associated fibroblasts (CAFs) emerged as key players. Through the secretion of cytokines, remodeling of the extracellular matrix (ECM), and cross-talk with osteosarcoma cells, CAFs collectively promote tumor growth, metastasis, and immune evasion. Exosomes derived from CAFs, which could also serve as important mediators of osteosarcoma progression, have been found to transport oncogenic lncRNAs like SNHG17 and linc00881. Moreover, some subtypes of CAFs, such as TOP2A + CAFs, have shown significant prognostic value for tumor aggressiveness. Thus, targeted CAFs was identified as a promising therapeutic modality, with strategies such as fibroblast activation protein (FAP) inhibition, TGF-β blockade, and CXCL12/CXCR4 axis inhibition demonstrating positive outcomes in preclinical models. The combination of CAF-targeted therapies with immunotherapies or chemotherapy has shown additional potential to reverse this CAF-induced resistance. Autophagy regulation in CAFs can be therapeutic opportunities for novel Interevent strategies.

Gastric cancer cells shuttle lactate to induce inflammatory CAF-like phenotype and function in bone marrow-derived mesenchymal stem cells

Metabolic reprogramming, exemplified by the "Warburg effect," is a hallmark of human cancers, leading to lactate buildup in tumors. Bone marrow-derived mesenchymal stem cells (BM-MSCs), key contributors to cancer-associated fibroblasts (CAFs), integrate into gastric cancer stroma through interactions with cancer cells. However, the role of lactate in activating BM-MSCs in this context remains unclear. Herein, exogenous lactate induced a pro-tumorigenic phenotype in BM-MSCs, which was blocked by AZD3965. Gastric cancer cells released more lactate under hypoxia than normoxia. While normoxic gastric cancer cells could educate BM-MSCs, hypoxic cells were more effective. However, the effects of the supernatant from gastric cancer cells in both conditions were significantly reduced by AZD3965. Similarly, prevention of lactate production by oxamic acid sodium significantly reduced the effects observed. Lactate-activated BM-MSCs showed NF-κB signaling activation, increased IL-8 secretion, and no change in TGF-β signaling. These activated BM-MSCs promoted gastric cancer cell migration and invasion through IL-8 secretion and enhanced resistance to CD8 + T cell cytotoxicity by upregulating PD-L1. Collectively, gastric cancer cells induce an iCAF-like phenotype and function in BM-MSCs through a lactate shuttle mechanism, emphasizing the role of metabolic reprogramming in cellular communication that fosters a supportive tumor microenvironment. Targeting lactate-related pathways may provide new therapeutic strategies to hinder BM-MSCs' supportive roles in gastric cancer.

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.

Construction of a stromal cell-related prognostic signature based on a 101-combination machine learning framework for predicting prognosis and immunotherapy response in triple-negative breast cancer

Background

Triple-negative breast cancer (TNBC) is a highly aggressive subtype with limited therapeutic targets and poor immunotherapy outcomes. The tumor microenvironment (TME) plays a key role in cancer progression. Advances in single-cell transcriptomics have highlighted the impact of stromal cells on tumor progression, immune suppression, and immunotherapy. This study aims to identify stromal cell marker genes and develop a prognostic signature for predicting TNBC survival outcomes and immunotherapy response.

Methods

Single-cell RNA sequencing (scRNA-seq) datasets were retrieved from the Gene Expression Omnibus (GEO) database and annotated using known marker genes. Cell types preferentially distributed in TNBC were identified using odds ratios (OR). Bulk transcriptome data were analyzed using Weighted correlation network analysis (WGCNA) to identify myCAF-, VSMC-, and Pericyte-related genes (MVPRGs). A consensus MVP cell-related signature (MVPRS) was developed using 10 machine learning algorithms and 101 model combinations and validated in training and validation cohorts. Immune infiltration and immunotherapy response were assessed using CIBERSORT, ssGSEA, TIDE, IPS scores, and an independent cohort (GSE91061). FN1, a key gene in the model, was validated through qRT-PCR, immunohistochemistry, RNA interference, CCK-8 assay, apoptosis assay and wound-healing assay.

Results

In TNBC, three stromal cell subpopulations-myofibroblastic cancer-associated fibroblasts (myCAF), vascular smooth muscle cells (VSMCs), and pericytes-were enriched, exhibiting high interaction frequencies and strong associations with poor prognosis. A nine-gene prognostic model (MVPRS), developed from 23 prognostically significant genes among the 259 MVPRGs, demonstrated excellent predictive performance and was validated as an independent prognostic factor. A nomogram integrating MVPRS, age, stage, and tumor grade offered clinical utility. High-risk group showed reduced immune infiltration and increased activity in tumor-related pathways like ANGIOGENESIS and HYPOXIA, while low-risk groups responded better to immunotherapy based on TIDE and IPS scores. FN1, identified as a key oncogene, was highly expressed in TNBC tissues and cell lines, promoting proliferation and migration while inhibiting apoptosis.

Conclusion

This study reveals TNBC microenvironment heterogeneity and introduces a prognostic signature based on myCAF, VSMC, and Pericyte marker genes. MVPRS effectively predicts TNBC prognosis and immunotherapy response, providing guidance for personalized treatment. FN1 was validated as a key oncogene impacting TNBC progression and malignant phenotype, with potential as a therapeutic target.

Fusion of glioma-associated mesenchymal stem/stromal cells with glioma cells promotes macrophage recruitment and M2 polarization via m6A modification of CSF1

Malignant glioma is the most common primary malignant tumor of the brain in adults, with glioblastoma (GBM) being the most aggressive subtype. Mesenchymal stem/stromal cells (MSCs) have been shown to fuse with tumor cells in various cancers including glioma, thereby regulating tumor progression. However, there has been no systematic research on the fusion of glioma-associated MSCs (GA-MSCs) with glioma cells. Here, it is shown that GA-MSCs are able to spontaneously fuse with glioma cells both in vitro and in vivo. The hybrid cells display significantly lower levels of N6-methyladenosine (m6A) modification and can modulate the glioma microenvironment by attracting and inducing M2-like polarization of macrophages. Mechanistically, the demethylase fat mass and obesity-associated protein (FTO) mediates demethylation in hybrids and promotes macrophage colony-stimulating factor (CSF1) secretion by increasing its RNA stability in an m6A-YTH domain family 2 (YTHDF2)-dependent manner. Our study reveals a novel crosstalk mechanism between glioma cells, GA-MSCs, and macrophages in glioma microenvironment, offering potential new approaches for glioma therapy.

Molecular biology of the deadliest cancer - glioblastoma: what do we know?

Glioblastomas are the most prevalent primary brain tumors and are associated with a dramatically poor prognosis. Despite an intensive treatment approach, including maximal surgical tumor removal followed by radio- and chemotherapy, the median survival for glioblastoma patients has remained around 18 months for decades. Glioblastoma is distinguished by its highly complex mechanisms of immune evasion and pronounced heterogeneity. This variability is apparent both within the tumor itself, which can exhibit multiple phenotypes simultaneously, and in its surrounding microenvironment. Another key feature of glioblastoma is its "cold" microenvironment, characterized by robust immunosuppression. Recent advances in single-cell RNA sequencing have uncovered new promising insights, revealing previously unrecognized aspects of this tumor. In this review, we consolidate current knowledge on glioblastoma cells and its microenvironment, with an emphasis on their biological properties and unique patterns of molecular communication through signaling pathways. The evidence underscores the critical need for personalized poly-immunotherapy and other approaches to overcome the plasticity of glioblastoma stem cells. Analyzing the tumor microenvironment of individual patients using single-cell transcriptomics and implementing a customized immunotherapeutic strategy could potentially improve survival outcomes for those facing this formidable disease.

Chemokines and their receptors in the esophageal carcinoma tumor microenvironment: key factors for metastasis and progression

Esophageal carcinoma (ESCA) is a highly malignant tumor with the highest incidence in Eastern Asia. Although treatment modalities for ESCA have advanced in recent years, the overall prognosis remains poor, as most patients are diagnosed at an advanced stage of the disease. There is an urgent need to promote early screening for ESCA to increase survival rates and improve patient outcomes. The development of ESCA is closely linked to the complex tumor microenvironment (TME), where chemokines and their receptors play pivotal roles. Chemokines are a class of small-molecule, secreted proteins and constitute the largest family of cytokines. They not only directly regulate tumor growth and proliferation but also influence cell migration and localization through specific receptor interactions. Consequently, chemokines and their receptors affect tumor invasion and metastatic spread. Furthermore, chemokines regulate immune cells, including macrophages and regulatory T cells, within the TME. The recruitment of these immune cells further leads to immunosuppression, creating favorable conditions for tumor growth and metastasis. This review examines the impact of ESCA-associated chemokines and their receptors on ESCA, emphasizing their critical involvement in the ESCA TME.

Mesenchymal stem cell-mediated adipogenic transformation: a key driver of oral squamous cell carcinoma progression

BACKGROUND

Interaction between mesenchymal stem cells (MSCs) and oral squamous cell carcinoma (OSCC) cells plays a major role in OSCC progression. However, little is known about adipogenic differentiation alteration in OSCC-derived MSCs (OSCC-MSCs) and how these alterations affect OSCC growth.

METHODS

MSCs were successfully isolated and cultured from normal gingival tissue, OSCC peritumoral tissue, and OSCC tissue. This included gingiva-derived MSCs (GMSCs), OSCC adjacent noncancerous tissues-derived MSCs (OSCCN-MSCs), and OSCC-MSCs. The adipogenic and osteogenic differentiation capabilities of these cells were evaluated using Oil Red O and Alizarin Red S staining, respectively. OSCC cells were then co-cultured with either OSCC-MSCs or GMSCs to assess the impact on OSCC cell proliferation and migration. Subcutaneous xenograft experiments were conducted in BALB/c-nu mice to further investigate the effects in vivo. Additionally, immunohistochemical staining was performed on clinical samples to determine the expression levels of fatty acid synthase (FASN) and the proliferation marker Ki67.

RESULTS

OSCC-MSCs exhibited enhanced adipogenic differentiation and reduced osteogenic differentiation compared to GMSCs. OSCC-MSCs significantly increased the proliferation and migration of OSCC cells relative to GMSCs and promoted tumor growth in mouse xenografts. Lipid droplet accumulation in the stroma was significantly more pronounced in OSCC + OSCC-MSCs xenografts compared to OSCC + GMSCs xenografts. Free fatty acids (FFAs) levels were elevated in OSCC tissues compared to normal gingival tissues. Moreover, OSCC-MSCs consistently secreted higher levels of FFAs in condition medium than GMSCs. Knockdown of FASN in OSCC-MSCs reduced their adipogenic potential and inhibited their ability to promote OSCC cell proliferation and migration. Clinical sample analysis confirmed higher FASN expression in OSCC stroma, correlating with larger tumor size and increased Ki67 expression in cancer tissues, and was associated with poorer overall survival.

CONCLUSIONS

OSCC-MSCs promoted OSCC proliferation and migration by upregulating FASN expression and facilitating FFAs secretion. Our results provide new insight into the mechanism of OSCC progression and suggest that the FASN of OSCC-MSCs may be potential targets of OSCC in the future.

Fusion of tumor cells and mesenchymal stem/stroma cells: a source of tumor heterogeneity, evolution and recurrence

The heterogeneity and evolution of tumors remain significant obstacles in cancer treatment, contributing to both therapy resistance and relapse. Mesenchymal stem/stromal cells (MSCs) are multipotent stromal cells within the tumor microenvironment that interact with tumor cells through various mechanisms, including cell fusion. While previous research has largely focused on the effects of MSC-tumor cell fusion on tumor proliferation, migration, and tumorigenicity, emerging evidence indicates that its role in tumor maintenance, evolution, and recurrence, particularly under stress conditions, may be even more pivotal. This review examines the connection between MSC-tumor cell fusion and several critical factors like tumor heterogeneity, cancer stem cells, and therapy resistance, highlighting the crucial role of cell fusion in tumor survival, evolution, and recurrence. Additionally, we explore potential therapeutic strategies aimed at targeting this process.

Exosome applications for the diagnosis and treatment of pancreatic ductal adenocarcinoma: An update (Review)

Pancreatic ductal adenocarcinoma (PDAC) is a malignant neoplasm that typically manifests with subtle clinical manifestations in its early stages and frequently eludes diagnosis until the advanced phases of the disease. The limited therapeutic options available for PDAC significantly contribute to its high mortality rate, highlighting the urgent need for novel biomarkers capable of effectively identifying early clinical manifestations and facilitating precise diagnosis. The pivotal role of cellular exosomes in both the pathogenesis and therapeutic interventions for PDAC has been underscored. Furthermore, researchers have acknowledged the potential of exosomes as targeted drug carriers against regulatory cells in treating PDAC. The present article aims to provide a comprehensive review encompassing recent advancements in utilizing exosomes for elucidating mechanisms underlying disease development, patterns of metastasis, diagnostic techniques and treatment strategies associated with PDAC.

Exploring the dichotomy of the mesenchymal stem cell secretome: Implications for tumor modulation via cell-signaling pathways

Current cancer therapeutic strategies for the treatment of cancer are often unsuccessful due to unwanted side effects and drug resistance. Therefore, the design and development of potent, new anticancer platforms, such as stem-cell treatments, have attracted much attention. Distinctive biological properties of stem cells include their capacity to secrete bioactive factors, their limited immunogenicity, and their capacity for renewing themselves. Mesenchymal stem cells (MSCs) are one of several kinds of stem cells that are conveniently extracted and are able to be cultivated in vitro utilizing various sources. The secretome of stem cells contains many trophic factors, including cytokines, chemokines, growth factors, and microRNA molecules that can either promote or inhibit the formation of tumors, based on the cell environment. In the current review, we focused on the secretome of mesenchymal stem cells. These stem cells act as a double-edged sword in the regulation of cell signal transduction pathways in that they can either suppress or promote tumors.

Mesenchymal Stem/Stromal cells in solid tumor Microenvironment: Orchestrating NK cell remodeling and therapeutic insights

Mesenchymal stem/stromal cells (MSCs), originating from normal tissues, possess the capacity to home to tumor sites and differentiate into tumor-associated MSCs (TA-MSCs), which are instrumental in shaping an immunosuppressive milieu within tumors. Natural killer (NK) cells, integral to the innate immune system, are endowed with the ability to eradicate target cells autonomously, serving as an immediate defense against neoplastic growths. Nonetheless, within the tumor microenvironment (TME), NK cells often exhibit a decline in both their numerical presence and functionality. TA-MSCs have been shown to exert profound inhibitory effects on the functions of tumor-infiltrating immune cells, notably NK cells. Understanding the mechanisms by which TA-MSCs contribute to NK cell dysfunction is critical for the advancement of immune surveillance and the enhancement of tumoricidal responses. This review summarizes existing literature on NK cell modulation by TA-MSCs within the TME and proposes innovative strategies to augment antitumor immunity.

Wound healing: insights into autoimmunity, ageing, and cancer ecosystems through inflammation and IL-6 modulation

Wound healing represents a complex and evolutionarily conserved process across vertebrates, encompassing a series of life-rescuing events. The healing process runs in three main phases: inflammation, proliferation, and maturation/remodelling. While acute inflammation is indispensable for cleansing the wound, removing infection, and eliminating dead tissue characterised by the prevalence of neutrophils, the proliferation phase is characterised by transition into the inflammatory cell profile, shifting towards the prevalence of macrophages. The proliferation phase involves development of granulation tissue, comprising fibroblasts, activated myofibroblasts, and inflammatory and endothelial cells. Communication among these cellular components occurs through intercellular contacts, extracellular matrix secretion, as well as paracrine production of bioactive factors and proteolytic enzymes. The proliferation phase of healing is intricately regulated by inflammation, particularly interleukin-6. Prolonged inflammation results in dysregulations during the granulation tissue formation and may lead to the development of chronic wounds or hypertrophic/keloid scars. Notably, pathological processes such as autoimmune chronic inflammation, organ fibrosis, the tumour microenvironment, and impaired repair following viral infections notably share morphological and functional similarities with granulation tissue. Consequently, wound healing emerges as a prototype for understanding these diverse pathological processes. The prospect of gaining a comprehensive understanding of wound healing holds the potential to furnish fundamental insights into modulation of the intricate dialogue between cancer cells and non-cancer cells within the cancer ecosystem. This knowledge may pave the way for innovative approaches to cancer diagnostics, disease monitoring, and anticancer therapy.

Decoding secret role of mesenchymal stem cells in regulating cancer stem cells and drug resistance

Drug resistance caused by the efflux of chemotherapeutic drugs is one of the most challenging obstacles to successful cancer therapy. Several efflux transporters have been identified since the discovery of the P-gp/ABCB1 transporter in 1976. Over the last four decades, researchers have focused on developing efflux transporter inhibitors to overcome drug resistance. However, even with the third-generation inhibitors available, we are still far from effectively inhibiting the efflux transporters. Additionally, Cancer stem cells (CSCs) pose another significant challenge, contributing to cancer recurrence even after successful treatment. The ability of CSCs to enter dormancy and evade detection makes them almost invulnerable to chemotherapeutic drug treatment. In this review, we discuss how Mesenchymal stem cells (MSCs), one of the key components of the Tumor Microenvironment (TME), regulate both the CSCs and efflux transporters. We propose a new approach focusing on MSCs, which can be crucial to successfully address CSCs and efflux transporters.

Mesenchymal Stem Cells Induce an Immunosuppressive Microenvironment in Pituitary Tumors

CONTEXT

The tumor microenvironment (TME) includes diverse cellular components such as mesenchymal stem cells (MSCs) and immune cells, among others. MSC have been isolated from different tumors and they favor tumor cell growth; however, their role in pituitary tumors (PTs) remains unknown.

OBJECTIVE

Herein we report the presence of MSCs in 2 adrenocorticotropin (ACTH)-secreting PTs causing Cushing disease (MCU), 2 nonfunctioning adenomas of gonadotrope differentiation (MNF), and 2 nontumoral pituitary glands (MS).

METHODS

We have analyzed the transcriptomic profiles by RNA sequencing and compared MSCs in terms of their immunosuppressive effects against lymphoid T-cell and macrophage populations by means of cocultures and flow cytometry.

RESULTS

Our transcriptomic analysis revealed molecular differences between MSCs derived from nontumoral pituitaries and MSCs derived from PTs. Two distinct subpopulations of MSC emerged: one displaying immunosuppressive properties and the other with increased proproliferative capabilities, regardless of their origin. MSCs derived from ACTH- and nonfunctioning PTs, but not those derived from nontumoral glands, significantly inhibited the proliferation of activated T cells, favored the generation of regulatory T cells, and promoted M2 macrophage polarization. Such immunosuppressive effects were correlated with an upregulation of programmed death ligand 1 and intracellular expression of macrophage colony-stimulating factor (M-CSF) and interleukin-10. Importantly, MSC derived from ACTH-PTs showed a higher immunosuppressive potential than MSC isolated from nonfunctioning tumors.

CONCLUSION

This study demonstrates the presence of at least 2 MSC subpopulations in the pituitary gland and suggests that immunosuppressive effects of MSCs may have important implications in PT growth.

Identification and validation of potential prognostic biomarkers in glioblastoma via the mesenchymal stem cell infiltration level

Aims

Mesenchymal stem cells (MSCs) are key components in promoting glioblastoma (GBM) progression. This study aimed to explore new therapeutic targets and related pathogenic mechanisms based on different MSCs infiltration levels in GBM patients.

Methods

We estimated the relationship between cell infiltration and prognosis of GBM. Subsequently, key risk genes were identified and prognostic models were constructed by LASSO-Cox analysis. The risk genes were validated by five independent external cohorts, single-cell RNA analysis, and immunohistochemistry of human GBM tissues. TIDE analysis predicted responsiveness to immune checkpoint inhibitors in different risk groups.

Results

The MSCs infiltration level was negatively associated with survival in GBM patients. LOXL1, LOXL4, and GUCA1A are key risk genes that promote GBM progression and may act through complex intercellular communication.

Conclusion

This research has provided a comprehensive study for exploring the MSCs infiltration environment on GBM progression, which could shed light on novel biomarkers and mechanisms involved in GBM progression.

Effect of the immune microenvironment on prognosis in oesophageal adenocarcinoma

Oesophageal adenocarcinoma (OAC) is amongst the most lethal cancers worldwide, with poor treatment response leading to low survival rates. Recent improvements have been achieved by including the tumour microenvironment (TME) and patients' immune profiles in treatment decisions. We already know that patients with immune-enriched/inflamed TME have better survival outcomes. However, OAC TME is largely immunosuppressed and appears to be treatment-resistant. Immunotherapeutic strategies are already part of the therapeutic plans in OAC; a greater understanding of the immune microenvironment underlying oesophageal adenocarcinoma is needed if we are to exploit the inherent cancer-fighting capabilities of each patient's immune system. Therefore, implementing the crosstalks between the tumour and its microenvironment (TME) might be the key to improving overall survival. In this review, we discuss accumulated evidence regarding TME and immune checkpoint inhibitors in OAC, as well as recent and ongoing therapeutic attempts to improve patient treatment and outcomes at an individual level.

Prognostic role of dynamic changes in inflammatory indicators in patients with non-small cell lung cancer treated with immune checkpoint inhibitors-a retrospective cohort study

Background

Immune checkpoint inhibitors (ICIs) have become one of the standard treatments for non-small cell lung cancer (NSCLC) patients without driver mutations. However, a considerable proportion of patients suffer from severe immune side effects and fail to respond to ICIs. As effective biomarkers, programmed cell death ligand 1 (PD-L1) expression, microsatellite instability (MSI), the tumor mutation burden (TMB) and tumor-infiltrating lymphocytes (TILs) require invasive procedures that place heavy physical and psychological burdens on patients. This study aims to identify simple and effective markers to optimize patient selection through therapeutic decisions and outcome prediction.

Methods

This retrospective study comprised 95 patients with metastatic NSCLC who were treated with ICIs either as the standard of care or in a clinical trial. The following data were extracted from the medical records. The baseline and dynamic neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were calculated in the present study. Responses were assessed by computed tomography (CT) imaging and classified according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 every 6-12 weeks during treatment.

Results

In total, 95 patients were included in the present study. The median age of patients was 61 years, 83.2% (79/95) patients were male, 62.1% (59/95) were former or current smokers, 66.3% (63/95) had adenocarcinoma, 93.7% (89/95) had stage IV disease, and 87.4% were without molecular alterations. A higher overall response rate (ORR) and prolonged median progression-free survival (PFS) was observed in patients with a lower cycle 3 (C3) NLR [7.7 vs. 5.5 months, hazard ratio (HR): 1.70, 95% confidence interval (CI): 0.90-3.22; P=0.12] and derived NLR (dNLR) (8.2 vs. 5.6 months, HR: 1.67, 95% CI: 0.94-2.97; P=0.08). After two cycles of ICI treatment, patients who had an increased NLR, dNLR, and PLR had a lower ORR and an inferior median PFS than those with a decreased NLR (5.5 vs. 8.5 months, HR: 1.87, 95% CI: 1.09-3.21; P=0.02), dNLR (5.6 vs. 8.4 months, HR: 1.49, 95% CI: 0.87-2.57; P=0.15), and PLR (11.8 vs. 5.5 months, HR: 2.28, 95% CI: 1.32-3.94; P=0.003). Moreover, patients with both an increased NLR and PLR had a worse ORR and median PFS than those with either an increased NLR or PLR, or both an increased NLR and PLR (11.8 vs. 5.5 vs. 5.6 months, P=0.003). In addition, the dynamic changes in the PLR could serve as an independent predictive factor of PFS in NSCLC patients treated with ICIs.

Conclusions

Elevated dynamic changes in the NLR and PLR were associated with lower response rates and shorter PFS in the patients with NSCLC treated with ICIs. Our results also highlight the role of dynamic changes in the PLR in identifying patients with NSCLC who could benefit from ICIs.

Molecular Alterations Associated with Histologically Overt Stromal Response in Patients with Prostate Cancer

Prostate cancer has substantial heterogeneity in clinical outcomes and therapeutic responses, posing challenges in predicting disease progression and tailoring treatment strategies. Recent studies have highlighted the potential prognostic value of evaluating the tumor microenvironment, including the presence of a histologically overt stromal response (HOST-response) characterized by peri-glandular stromal changes and architectural distortions. This retrospective study examined patient records from The Cancer Genome Atlas database to identify genomic alterations associated with the HOST-response in prostate cancer. Among 348 patients who underwent radical prostatectomy, 160 (45.98%) were identified as having a HOST-response. A gene expression analysis revealed 1263 genes with significantly higher expression in patients with a HOST-response. A protein-protein interaction network analysis identified seven hub genes (KIF2C, CENPA, CDC20, UBE2C, ESPL1, KIF23, and PLK1) highly interconnected in the network. A functional enrichment analysis revealed alterations in the cell division, cytoskeletal organization, cytokinesis, and interleukin-16 signaling pathways in patients with a HOST-response, suggesting dysregulated proliferation and inflammation. The distinct molecular signature associated with the HOST-response provides insights into the tumor-stroma interactions driving adverse outcomes and potential targets for tailored therapeutic interventions in this subset of patients with prostate cancer.

Patient-Derived Organoids as Therapy Screening Platforms in Cancer Patients

Patient-derived organoids (PDOs) developed ex vivo and in vitro are increasingly used for therapeutic screening. They provide a more physiologically relevant model for drug discovery and development compared to traditional cell lines. However, several challenges remain to be addressed to fully realize the potential of PDOs in therapeutic screening. This paper summarizes recent advancements in PDO development and the enhancement of PDO culture models. This is achieved by leveraging materials engineering and microfabrication technologies, including organs-on-a-chip and droplet microfluidics. Additionally, this work discusses the application of PDOs in therapy screening to meet diverse requirements and overcome bottlenecks in cancer treatment. Furthermore, this work introduces tools for data processing and analysis of organoids, along with their microenvironment. These tools aim to achieve enhanced readouts. Finally, this work explores the challenges and future perspectives of using PDOs in drug development and personalized screening for cancer patients.

The role of mesenchymal stem cells in cancer and prospects for their use in cancer therapeutics

Mesenchymal stem cells (MSCs) are recruited by malignant tumor cells to the tumor microenvironment (TME) and play a crucial role in the initiation and progression of malignant tumors. This role encompasses immune evasion, promotion of angiogenesis, stimulation of cancer cell proliferation, correlation with cancer stem cells, multilineage differentiation within the TME, and development of treatment resistance. Simultaneously, extensive research is exploring the homing effect of MSCs and MSC-derived extracellular vesicles (MSCs-EVs) in tumors, aiming to design them as carriers for antitumor substances. These substances are targeted to deliver antitumor drugs to enhance drug efficacy while reducing drug toxicity. This paper provides a review of the supportive role of MSCs in tumor progression and the associated molecular mechanisms. Additionally, we summarize the latest therapeutic strategies involving engineered MSCs and MSCs-EVs in cancer treatment, including their utilization as carriers for gene therapeutic agents, chemotherapeutics, and oncolytic viruses. We also discuss the distribution and clearance of MSCs and MSCs-EVs upon entry into the body to elucidate the potential of targeted therapies based on MSCs and MSCs-EVs in cancer treatment, along with the challenges they face.

Architectural organization and molecular profiling of 3D cancer heterospheroids and their application in drug testing

3D cancer cell cultures have enabled new opportunities for replacing compound testing in experimental animals. However, most solid tumors are composed of multiple cell types, including fibroblasts. In this study we developed multicellular tumor heterospheroids composed of cancer and fibroblasts cell lines. We developed heterospheroids by combining HT-29, MCF-7, PANC-1 or SW480 with 1BR.3.G fibroblasts, which we have previously reported support spheroid formation. We also tested fibroblast cell lines, MRC-5, GM00498 and HIF, but 1BR.3.G was found to best form heterospheroids with morphological similarity to in vivo tumor tissue. The architectural organization of heterospheroids was based on histological examination using immunohistochemistry. We found that HT-29 and MCF-7 cells developed spheroids with the cancer cells surrounding the fibroblasts, whereas PANC-1 cells interspersed with the fibroblasts and SW480 cells were surrounded by fibroblasts. The fibroblasts also expressed collagen-1 and FAP-α, and whole transcriptomic analysis (WTA) showed abundant ECM- and EMT-related expression in heterospheroids, thus reflecting a representative tumor-like microenvironment. The WTA showed that PANC-1 heterospheroids possess a strong EMT profile with abundant Vimentin and CDH2 expression. Drug testing was evaluated by measuring cytotoxicity of 5FU and cisplatin using cell viability and apoptosis assays. We found no major impact on the cytotoxicity when fibroblasts were added to the spheroids. We conclude that the cancer cell lines together with fibroblasts shape the architectural organization of heterospheroids to form tumor-like morphology, and we propose that the various 3D tumor structures can be used for drug testing directed against the cancer cells as well as the fibroblasts.

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.

Progenitor Cell Sources for 3D Bioprinting of Lymphatic Vessels and Potential Clinical Application

The lymphatic system maintains tissue fluid homeostasis and it is involved in the transport of nutrients and immunosurveillance. It also plays a pivotal role in both pathological and regenerative processes. Lymphatic development in the embryo occurs by polarization and proliferation of lymphatic endothelial cells from the lymph sacs, that is, lymphangiogenesis. Alternatively, lymphvasculogenesis further contributes to the formation of lymphatic vessels. In adult tissues, lymphatic formation rarely occurs under physiological conditions, being restricted to pathological processes. In lymphvasculogenesis, progenitor cells seem to be a source of lymphatic vessels. Indeed, mesenchymal stem cells, adipose stem cells, endothelial progenitor cells, and colony-forming endothelial cells are able to promote lymphatic regeneration by different mechanisms, such as direct differentiation and paracrine effects. In this review, we summarize what is known on the diverse stem/progenitor cell niches available for the lymphatic system, emphasizing the potential that these cells hold for lymphatic tissue engineering through 3D bioprinting and their translation to clinical application.

Bone Marrow Mesenchymal Stem Cells Promote Ovarian Cancer Cell Proliferation via Cytokine Interactions

Bone marrow mesenchymal stem cells (BMSCs) are key players in promoting ovarian cancer cell proliferation, orchestrated by the dynamic interplay between cytokines and their interactions with immune cells; however, the intricate crosstalk among BMSCs and cytokines has not yet been elucidated. Here, we aimed to investigate interactions between BMSCs and ovarian cancer cells. We established BMSCs with a characterized morphology, surface marker expression, and tri-lineage differentiation potential. Ovarian cancer cells (SKOV3) cultured with conditioned medium from BMSCs showed increased migration, invasion, and colony formation, indicating the role of the tumor microenvironment in influencing cancer cell behavior. BMSCs promoted SKOV3 tumorigenesis in nonobese diabetic/severe combined immunodeficiency mice, increasing tumor growth. The co-injection of BMSCs increased the phosphorylation of p38 MAPK and GSK-3β in SKOV3 tumors. Co-culturing SKOV3 cells with BMSCs led to an increase in the expression of cytokines, especially MCP-1 and IL-6. These findings highlight the influence of BMSCs on ovarian cancer cell behavior and the potential involvement of specific cytokines in mediating these effects. Understanding these mechanisms will highlight potential therapeutic avenues that may halt ovarian cancer progression.

A Review of CAR-T Combination Therapies for Treatment of Gynecological Cancers

CAR-T cell therapy offers a promising way for prolonged cancer remission, specifically in the case of blood cancers. However, its application in the treatment of solid tumors still faces many limitations. This review paper provides a comprehensive overview of the challenges and strategies associated with CAR-T cell therapy for solid tumors, with a focus on gynecological cancer. This study discusses the limitations of CAR-T therapy for solid tumor treatment, such as T cell exhaustion, stromal barrier, and antigen shedding. Additionally, it addresses possible approaches to increase CAR-T efficacy in solid tumors, including combination therapies with checkpoint inhibitors and chemotherapy, as well as the novel approach of combining CAR-T with oncolytic virotherapy. Given the lack of comprehensive research on CAR-T combination therapies for treating gynecological cancers, this review aims to provide insights into the current landscape of combination therapies for solid tumors and highlight the potential of such an approach in gynecology.

Identification of the Expression of TIE1 and Its Mediated Immunosuppression in Gastric Cancer

Background: Recently, various evidence has confirmed that Tyrosine Kinase with Immunoglobulin-like and EGF-like domains 1 (TIE1) promotes tumor growth in many cancers. However, the precise mechanism underlying TIE1's involvement in Gastric Cancer (GC) remains elusive. This research aimed to investigate the biological function of TIE1 in regulating GC progression. Methods: The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), GEPIA2.0, Sangerbox3.0 and TIMER databases were used to analyze the TIE1 expression. Immunohistochemistry (IHC) was used to demonstrate the expression of TIE1. TCGA, GEPIA2.0 and Kaplan-Meier were utilized for survival analysis and to explore the association of TIE1 with clinicopathological features. Protein-Protein Interaction (PPI) networks were constructed using Cytoscape. The potential molecular mechanism of TIE1 was investigated by Gene Ontology (GO), Kyoto Encyclopedia of Gene Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA). We studied the relationships between TIE1 and mutations, immune checkpoints (ICs), tumor mutational burden (TMB), as well as microsatellite instability (MSI) to explore the underlying mechanism of immunity in GC. Results: Compared with normal tissue, TIE1 was significantly overexpressed in GC tissues (p = 0.0072) and was associated with poor survival (P < 0.05). According to GO and KEGG enrichment analyses, TIE1 was enriched in signal pathways related to the occurrence, invasion, and migration of malignant tumors (i.e., PI3K-Akt signaling pathway, Calcium signaling pathway, etc.). Immune infiltration analysis suggested that TIE1 is positively correlated with macrophages M2 and negatively correlated with Mast cells, naive B cells and Follicular helper T cells (TFH), which may be a contributing factor to tumor progression. Furthermore, the research on the tumor microenvironment (TME) and tumor purity also proved that TIE1 may be an oncogene. Mutation analysis showed that the high expression group of TIE1 had a higher frequency of mutations in TP53 and ARID1, while the TMB score was lower. Conclusion: TIE1 might be an oncogene via regulating dysregulated immune infiltration to cause immunosuppression in GC and could be identified as a biomarker for prognosis and a therapeutic target for GC.

Osteosarcoma cells exhibit functional interactions with stromal cells, fostering a lung microenvironment conducive to the establishment of metastatic tumor cells

BACKGROUND

Osteosarcoma (OS) stands out as the most common bone tumor, with approximately 20% of the patients receiving a diagnosis of metastatic OS at their initial assessment. A significant challenge lies in the frequent existence of undetected metastases during the initial diagnosis. Mesenchymal stem cells (MSCs) possess unique abilities that facilitate tumor growth, and their interaction with OS cells is crucial for metastatic spread.

METHODS AND RESULTS

We demonstrated that, in vitro, MSCs exhibited a heightened migration response toward the secretome of non-metastatic OS cells. When challenged to a secretome derived from lungs preloaded with OS cells, MSCs exhibited greater migration toward lungs colonized with metastatic OS cells. Moreover, in vivo, MSCs displayed preferential migratory and homing behavior toward lungs colonized by metastatic OS cells. Metastatic OS cells, in turn, demonstrated an increased migratory response to the MSCs' secretome. This behavior was associated with heightened cathepsin D (CTSD) expression and the release of active metalloproteinase 2 (MMP2) by metastatic OS cells.

CONCLUSIONS

Our assessment focused on two complementary tumor capabilities crucial to metastatic spread, emphasizing the significance of inherent cell features. The findings underscore the pivotal role of signaling integration within the niche, with a complex interplay of migratory responses among established OS cells in the lungs, prometastatic OS cells in the primary tumor, and circulating MSCs. Pulmonary metastases continue to be a significant factor contributing to OS mortality. Understanding these mechanisms and identifying differentially expressed genes is essential for pinpointing markers and targets to manage metastatic spread and improve outcomes for patients with OS.

Glioblastoma-Associated Mesenchymal Stem/Stromal Cells and Cancer-Associated Fibroblasts: Partners in Crime?

Tumor-associated mesenchymal stem/stromal cells (TA-MSCs) have been recognized as attractive therapeutic targets in several cancer types, due to their ability to enhance tumor growth and angiogenesis and their contribution to an immunosuppressive tumor microenvironment (TME). In glioblastoma (GB), mesenchymal stem cells (MSCs) seem to be recruited to the tumor site, where they differentiate into glioblastoma-associated mesenchymal stem/stromal cells (GA-MSCs) under the influence of tumor cells and the TME. GA-MSCs are reported to exert important protumoral functions, such as promoting tumor growth and invasion, increasing angiogenesis, stimulating glioblastoma stem cell (GSC) proliferation and stemness, mediating resistance to therapy and contributing to an immunosuppressive TME. Moreover, they could act as precursor cells for cancer-associated fibroblasts (CAFs), which have recently been identified in GB. In this review, we provide an overview of the different functions exerted by GA-MSCs and CAFs and the current knowledge on the relationship between these cell types. Increasing our understanding of the interactions and signaling pathways in relevant models might contribute to future regimens targeting GA-MSCs and GB-associated CAFs to inhibit tumor growth and render the TME less immunosuppressive.

Forces at play: exploring factors affecting the cancer metastasis

Metastatic disease, a leading and lethal indication of deaths associated with tumors, results from the dissemination of metastatic tumor cells from the site of primary origin to a distant organ. Dispersion of metastatic cells during the development of tumors at distant organs leads to failure to comply with conventional treatments, ultimately instigating abrupt tissue homeostasis and organ failure. Increasing evidence indicates that the tumor microenvironment (TME) is a crucial factor in cancer progression and the process of metastatic tumor development at secondary sites. TME comprises several factors contributing to the initiation and progression of the metastatic cascade. Among these, various cell types in TME, such as mesenchymal stem cells (MSCs), lymphatic endothelial cells (LECs), cancer-associated fibroblasts (CAFs), myeloid-derived suppressor cells (MDSCs), T cells, and tumor-associated macrophages (TAMs), are significant players participating in cancer metastasis. Besides, various other factors, such as extracellular matrix (ECM), gut microbiota, circadian rhythm, and hypoxia, also shape the TME and impact the metastatic cascade. A thorough understanding of the functions of TME components in tumor progression and metastasis is necessary to discover new therapeutic strategies targeting the metastatic tumor cells and TME. Therefore, we reviewed these pivotal TME components and highlighted the background knowledge on how these cell types and disrupted components of TME influence the metastatic cascade and establish the premetastatic niche. This review will help researchers identify these altered components' molecular patterns and design an optimized, targeted therapy to treat solid tumors and restrict metastatic cascade.

Tumor-derived small extracellular vesicles facilitate omental metastasis of ovarian cancer by triggering activation of mesenchymal stem cells

BACKGROUND

Omental metastasis is the major cause of ovarian cancer recurrence and shortens patient survival, which can be largely attributed to the dynamic evolution of the fertile metastatic microenvironment driven by cancer cells. Previously, we found that adipose-derived mesenchymal stem cells (ADSCs) undergoing a phenotype shift toward cancer-associated fibroblasts (CAFs) participated in the orchestrated omental premetastatic niche for ovarian cancer. Here, we aim to elucidate the underlying mechanisms.

METHODS

Small extracellular vesicles were isolated from ovarian cancer cell lines (ES-2 and its highly metastatic subline, ES-2-HM) and patient ascites using ultracentrifugation. Functional experiments, including Transwell and EdU assays, and molecular detection, including Western blot, immunofluorescence, and RT-qPCR, were performed to investigate the activation of ADSCs in vitro. High-throughput transcriptional sequencing and functional assays were employed to identify the crucial functional molecules inducing CAF-like activation of ADSCs and the downstream effector of miR-320a. The impact of extracellular vesicles and miR-320a-activated ADSCs on tumor growth and metastasis was assessed in subcutaneous and orthotopic ovarian cancer xenograft mouse models. The expression of miR-320a in human samples was evaluated using in situ hybridization staining.

RESULTS

Primary human ADSCs cocultured with small extracellular vesicles, especially those derived from ES-2-HM, exhibited boosted migration, invasion, and proliferation capacities and elevated α-SMA and FAP levels. Tumor-derived small extracellular vesicles increased α-SMA-positive stromal cells, fostered omental metastasis, and shortened the survival of mice harboring orthotopic ovarian cancer xenografts. miR-320a was abundant in highly metastatic cell-derived extracellular vesicles, evoked dramatic CAF-like transition of ADSCs, targeted the 3'-untranslated region of integrin subunit alpha 7 and attenuated its expression. miR-320a overexpression in ovarian cancer was associated with omental metastasis and shorter survival. miR-320a-activated ADSCs facilitated tumor cell growth and omental metastasis. Depletion of integrin alpha 7 triggered CAF-like activation of ADSCs in vitro. Video Abstract CONCLUSIONS: miR-320a in small extracellular vesicles secreted by tumor cells targets integrin subunit alpha 7 in ADSCs and drives CAF-like activation, which in turn facilitates omental metastasis of ovarian cancer.

Mesenchymal Stem Cells: Their Role in the Tumor Microenvironment

Mesenchymal stem cells (MSCs) have been seen for years as great candidates for treating different diseases and an alternative to embryonic stem cells due to their differentiation capacity in vitro. More recent research has focused on their ability to modulate the immune response and regeneration at sites associated with inflammation, activities attributable to the release of trophic factors into the extracellular medium, a set of components known as the secretome. It has been possible to demonstrate the presence of these cells within the tumor microenvironment, which is associated with their tropism for sites of inflammation; however, their role here needs to be clarified. In different investigations, the feasibility of using MSCs or their secretome to treat cancer has been sought, with these results being ambiguous. It has been described that MSCs can be activated and present various phenotypes, which could explain the divergence in their action; however, these activation mechanisms and the different phenotypes still need to be well known. This review explores MSCs and their use in regenerative medicine with a targeted approach to cancer. Impact Statement This text addresses the diverging findings on the role of mesenchymal stem cells in the tumor microenvironment and discrepancies on the use of these cells as cancer treatment, separating the direct use of the cells from the use of the secretome. Multiple authors refer equally to the cells and their secretome to conclude on the positive or negative outcome, without taking into consideration how the cells are affected by their surroundings.

Curcumin Disrupts a Positive Feedback Loop between ADMSCs and Cancer Cells in the Breast Tumor Microenvironment via the CXCL12/CXCR4 Axis

Adipose tissue has a significant impact on breast cancer initiation and progression owing to its substantial proportion in the breast. Adipose-derived mesenchymal stem cells (ADMSCs) are major players in the breast tumor microenvironment (TME) as they interact with cancer cells. The intricate interaction between ADMSCs and cancer cells not only drives the differentiation of ADMSCs into cancer-associated fibroblasts (CAFs) but also the metastasis of cancer cells, which is attributed to the CXCL12/CXCR4 axis. We investigated the effects of curcumin, a flavonoid known for CXCL12/CXCR4 axis inhibition, on breast TME by analyzing whether it can disrupt the ADMSC-cancer positive loop. Using MCF7 breast cancer cell-derived conditioned medium (MCF7-CM), we induced ADMSC transformation and verified that curcumin diminished the phenotypic change, inhibiting CAF marker expression. Additionally, curcumin suppressed the CXCL12/CXCR4 axis and its downstream signaling both in ADMSCs and MCF7 cells. The CM from ADMSCs, whose ADMSC-to-CAF transformation was repressed by the curcumin treatment, inhibited the positive feedback loop between ADMSCs and MCF7 as well as epithelial-mesenchymal transition in MCF7. Our study showed that curcumin is a potent anti-cancer agent that can remodel the breast TME, thereby restricting the ADMSC-cancer positive feedback loop associated with the CXCL12/CXCR4 axis.

Stromal-Modulated Epithelial-to-Mesenchymal Transition in Cancer Cells

The ability of cancer cells to detach from the primary site and metastasize is the main cause of cancer- related death among all cancer types. Epithelial-to-mesenchymal transition (EMT) is the first event of the metastatic cascade, resulting in the loss of cell-cell adhesion and the acquisition of motile and stem-like phenotypes. A critical modulator of EMT in cancer cells is the stromal tumor microenvironment (TME), which can promote the acquisition of a mesenchymal phenotype through direct interaction with cancer cells or changes to the broader microenvironment. In this review, we will explore the role of stromal cells in modulating cancer cell EMT, with particular emphasis on the function of mesenchymal stromal/stem cells (MSCs) through the activation of EMT-inducing pathways, extra cellular matrix (ECM) remodeling, immune cell alteration, and metabolic rewiring.

RNA modification regulator DDC in endometrial cancer affects the tumor microenvironment and patient prognosis

Uterine corpus endometrial carcinoma (UCEC) is infiltrated by immune cells, which are involved in the growth and proliferation of malignant tumors and resistance to immunotherapy. This study suggested that RNA modification regulators played an important role in the development and prognosis of UCEC. Many studies confirmed that RNA modification played an essential role in tumor immune regulation, and abnormal RNA modification contributed to tumorigenesis and cancer progression. Based on the RNA modification regulatory factors, the UCEC samples from TCGA (The Cancer Genome Atlas) were classified into two clusters, namely Cluster A and Cluster B, using unsupervised consensus clustering. We obtained DEG (differentially expressed genes) between the two clusters, and constructed a risk model of RNA modification-related genes using DEGs. Cluster A had lower RNA modification regulatory factors, richer immune cell infiltration, and better prognosis. The differentially expressed genes between the two clusters were obtained, and these genes were used for modeling. This model divided patients with UCEC into two groups. The low-risk group had better immune infiltration, and the ROC (receiver operating characteristic) curve showed that this model had good predictive efficacy. The low-risk group had a better response to immunotherapy by immune checkpoint prediction. We obtained the key gene L-dopa decarboxylase (DDC) through the intersection of LASSO model genes and GEO dataset GSE17025. We evaluated the potential biological functions of DDC. The differences in the expression of DDC were verified by immunohistochemistry. We evaluated the relationship between DDC and immune cell infiltration and verified this difference using immunofluorescence. Cluster A with low expression of RNA modification regulators has better prognosis and richer immune cell infiltration, therefore, we believed that RNA modification regulators in UCEC were closely related to the tumor microenvironment. Also, the risk score could well predict the prognosis of patients and guide immunotherapy, which might benefit patients with UCEC.

IGF2BP2-meidated m6A modification of CSF2 reprograms MSC to promote gastric cancer progression

The interaction between tumor cells and stromal cells within the tumor microenvironment plays a critical role in cancer progression. Mesenchymal stem cells (MSCs) are important tumor stromal cells that exhibit pro-oncogenic activities when reprogrammed by the tumor. However, the precise mechanisms underlying MSC reprogramming in gastric cancer remain not well understood. QRT-PCR, western blot, and immunohistochemistry were used to examine gene and protein expression levels. In vitro and in vivo experiments were conducted to assess the biological functions of gastric cancer cells. RNA-sequencing, RNA immunoprecipitation (RIP), and meRIP assays were performed to investigate underlying molecular mechanisms. We found a significant increase in the expression and N6-methyladenosine (m6A) modification levels of colony-stimulating factor 2 (CSF2) in gastric cancer MSCs. CSF2 gene overexpression induced the reprogramming of normal MSCs into cancer-promoting MSCs, thereby enhancing the proliferation, migration, and drug resistance of gastric cancer cells through the secretion of various pro-inflammatory factors. Additionally, we demonstrated that the m6A reader IGF2BP2 bound to and stabilized CSF2 mRNA in gastric cancer MSCs. Notably, overexpression of IGF2BP2 mimicked the effect of CSF2 on MSCs, promoting gastric cancer progression. Finally, we unveiled that CSF2 induced the ubiquitination of Notch1 to reprogram MSCs. Our study highlights a critical role of IGF2BP2-mediated m6A modification of CSF2 in reprogramming MSCs, which presents a promising therapeutic target for gastric cancer.

Mesenchymal stem/stromal cells- a principal element for tumour microenvironment heterogeneity

The heterogeneity of the tumor microenvironment (TME) is a major obstacle in cancer treatment, making most therapeutic interventions palliative rather than curative. Previous studies have suggested that the reason for the low efficacy of immunotherapy and the relapse of the original responders over time may be due to the complex network of mesenchymal stem/stromal cells (MSCs), a population of multipotent progenitor cells existing in a variety of tissues. Cancer-associated MSCs (CA-MSCs) have already been isolated from various types of tumors and are characterized by their vigorous pro-tumorigenic functions. Although the roles of CA-MSCs from different sources vary widely, their origins are still poorly understood. Current evidence suggests that when local resident or distally recruited MSCs interact with tumor cells and other components in the TME, "naïve" MSCs undergo genetic and functional changes to form CA-MSCs. In this review, we mainly focus on the multiple roles of CA-MSCs derived from different sources, which may help in elucidating the formation and function of the entire TME, as well as discover innovative targets for anti-cancer therapies.

Mini-Review: Enteric glia of the tumor microenvironment: An affair of corruption

The tumor microenvironment corresponds to a complex mixture of bioactive products released by local and recruited cells whose normal functions have been "corrupted" by cues originating from the tumor, mostly to favor cancer growth, dissemination and resistance to therapies. While the immune and the mesenchymal cellular components of the tumor microenvironment in colon cancer have been under intense scrutiny over the last two decades, the influence of the resident neural cells of the gut on colon carcinogenesis has only very recently begun to draw attention. The vast majority of the resident neural cells of the gastrointestinal tract belong to the enteric nervous system and correspond to enteric neurons and enteric glial cells, both of which have been understudied in the context of colon cancer development and progression. In this review, we especially discuss available evidence on enteric glia impact on colon carcinogenesis. To highlight "corrupted" functioning in enteric glial cells of the tumor microenvironment and its repercussion on tumorigenesis, we first review the main regulatory effects of enteric glial cells on the intestinal epithelium in homeostatic conditions and we next present current knowledge on enteric glia influence on colon tumorigenesis. We particularly examine how enteric glial cell heterogeneity and plasticity require further appreciation to better understand the distinct regulatory interactions enteric glial cell subtypes engage with the various cell types of the tumor, and to identify novel biological targets to block enteric glia pro-carcinogenic signaling.

BM-MSCs display altered gene expression profiles in B-cell acute lymphoblastic leukemia niches and exert pro-proliferative effects via overexpression of IFI6

BACKGROUND

The tumor microenvironment (TME) is a supportive environment responsible for promoting the growth and proliferation of tumor cells. Current studies have revealed that the bone marrow mesenchymal stem cells (BM-MSCs), a type of crucial stromal cells in the TME, can promote the malignant progression of tumors. However, in the adult B-cell acute lymphoblastic leukemia (B-ALL) microenvironment, it is still uncertain what changes in BM-MSCs are induced by leukemia cells.

METHODS

In this study, we mimicked the leukemia microenvironment by constructing a BM-MSC-leukemia cell co-culture system. In vitro cell experiments, in vivo mouse model experiments, lentiviral transfection and transcriptome sequencing analysis were used to investigate the possible change of BM-MSCs in the leukemia niche and the potential factors in BM-MSCs that promote the progression of leukemia.

RESULTS

In the leukemia niche, the leukemia cells reduced the MSCs' capacity to differentiate towards adipogenic and osteogenic subtypes, which also promoted the senescence and cell cycle arrest of the MSCs. Meanwhile, compared to the mono-cultured MSCs, the gene expression profiles of MSCs in the leukemia niche changed significantly. These differential genes were enriched for cell cycle, cell differentiation, DNA replication, as well as some tumor-promoting biofunctions including protein phosphorylation, cell migration and angiogenesis. Further, interferon alpha-inducible protein 6 (IFI6), as a gene activated by interferon, was highly expressed in leukemia niche MSCs. The leukemia cell multiplication was facilitated evidently by IFI6 both in vitro and in vivo. Mechanistically, IFI6 might promote leukemia cell proliferation by stimulating SDF-1/CXCR4 axis, which leads to the initiation of downstream ERK signaling pathway. As suggested by further RNA sequencing analysis, the high IFI6 level in MSCs somewhat influenced the gene expression profile and biological functions of leukemia cells.

CONCLUSIONS

BM-MSCs in the leukemia niche have varying degrees of changes in biological characteristics and gene expression profiles. Overexpression of IFI6 in BM-MSCs could be a key factor in promoting the proliferation of B-ALL cells, and this effect might be exerted through the SDF-1/CXCR4/ERK signal stimulation. Targeting IFI6 or related signaling pathways might be an important measure to reduce the leukemia cell proliferation.

Stromal cells in the tumor microenvironment: accomplices of tumor progression?

The tumor microenvironment (TME) is made up of cells and extracellular matrix (non-cellular component), and cellular components include cancer cells and non-malignant cells such as immune cells and stromal cells. These three types of cells establish complex signals in the body and further influence tumor genesis, development, metastasis and participate in resistance to anti-tumor therapy. It has attracted scholars to study immune cells in TME due to the significant efficacy of immune checkpoint inhibitors (ICI) and chimeric antigen receptor T (CAR-T) in solid tumors and hematologic tumors. After more than 10 years of efforts, the role of immune cells in TME and the strategy of treating tumors based on immune cells have developed rapidly. Moreover, ICI have been recommended by guidelines as first- or second-line treatment strategies in a variety of tumors. At the same time, stromal cells is another major class of cellular components in TME, which also play a very important role in tumor metabolism, growth, metastasis, immune evasion and treatment resistance. Stromal cells can be recruited from neighboring non-cancerous host stromal cells and can also be formed by transdifferentiation from stromal cells to stromal cells or from tumor cells to stromal cells. Moreover, they participate in tumor genesis, development and drug resistance by secreting various factors and exosomes, participating in tumor angiogenesis and tumor metabolism, regulating the immune response in TME and extracellular matrix. However, with the deepening understanding of stromal cells, people found that stromal cells not only have the effect of promoting tumor but also can inhibit tumor in some cases. In this review, we will introduce the origin of stromal cells in TME as well as the role and specific mechanism of stromal cells in tumorigenesis and tumor development and strategies for treatment of tumors based on stromal cells. We will focus on tumor-associated fibroblasts (CAFs), mesenchymal stem cells (MSCs), tumor-associated adipocytes (CAAs), tumor endothelial cells (TECs) and pericytes (PCs) in stromal cells.

Insights into the tumor-stromal-immune cell metabolism cross talk in ovarian cancer

The ovarian cancer tumor microenvironment (TME) consists of a constellation of abundant cellular components, extracellular matrix, and soluble factors. Soluble factors, such as cytokines, chemokines, structural proteins, extracellular vesicles, and metabolites, are critical means of noncontact cellular communication acting as messengers to convey pro- or antitumorigenic signals. Vast advancements have been made in our understanding of how cancer cells adapt their metabolism to meet environmental demands and utilize these adaptations to promote survival, metastasis, and therapeutic resistance. The stromal TME contribution to this metabolic rewiring has been relatively underexplored, particularly in ovarian cancer. Thus, metabolic activity alterations in the TME hold promise for further study and potential therapeutic exploitation. In this review, we focus on the cellular components of the TME with emphasis on 1) metabolic signatures of ovarian cancer; 2) understanding the stromal cell network and their metabolic cross talk with tumor cells; and 3) how stromal and tumor cell metabolites alter intratumoral immune cell metabolism and function. Together, these elements provide insight into the metabolic influence of the TME and emphasize the importance of understanding how metabolic performance drives cancer progression.

Physiological and environmental factors affecting cancer risk and prognosis in obesity

Obesity results from a chronic excessive accumulation of adipose tissue due to a long-term imbalance between energy intake and expenditure. Available epidemiological and clinical data strongly support the links between obesity and certain cancers. Emerging clinical and experimental findings have improved our understanding of the roles of key players in obesity-associated carcinogenesis such as age, sex (menopause), genetic and epigenetic factors, gut microbiota and metabolic factors, body shape trajectory over life, dietary habits, and general lifestyle. It is now widely accepted that the cancer-obesity relationship depends on the site of cancer, the systemic inflammatory status, and micro environmental parameters such as levels of inflammation and oxidative stress in transforming tissues. We hereby review recent advances in our understanding of cancer risk and prognosis in obesity with respect to these players. We highlight how the lack of their consideration contributed to the controversy over the link between obesity and cancer in early epidemiological studies. Finally, the lessons and challenges of interventions for weight loss and better cancer prognosis, and the mechanisms of weight gain in survivors are also discussed.

The Dual Role of Mesenchymal Stem Cells in Cancer Pathophysiology: Pro-Tumorigenic Effects versus Therapeutic Potential

Mesenchymal stem/stromal cells (MSCs) are multipotent cells involved in numerous physiological events, including organogenesis, the maintenance of tissue homeostasis, regeneration, or tissue repair. MSCs are increasingly recognized as playing a major, dual, and complex role in cancer pathophysiology through their ability to limit or promote tumor progression. Indeed, these cells are known to interact with the tumor microenvironment, modulate the behavior of tumor cells, influence their functions, and promote distant metastasis formation through the secretion of mediators, the regulation of cell-cell interactions, and the modulation of the immune response. This dynamic network can lead to the establishment of immunoprivileged tissue niches or the formation of new tumors through the proliferation/differentiation of MSCs into cancer-associated fibroblasts as well as cancer stem cells. However, MSCs exhibit also therapeutic effects including anti-tumor, anti-proliferative, anti-inflammatory, or anti-oxidative effects. The therapeutic interest in MSCs is currently growing, mainly due to their ability to selectively migrate and penetrate tumor sites, which would make them relevant as vectors for advanced therapies. Therefore, this review aims to provide an overview of the double-edged sword implications of MSCs in tumor processes. The therapeutic potential of MSCs will be reviewed in melanoma and lung cancers.

The Secretome of Human Dental Pulp Stem Cells and Its Components GDF15 and HB-EGF Protect Amyotrophic Lateral Sclerosis Motoneurons against Death

Amyotrophic lateral sclerosis (ALS) is a fatal and incurable paralytic disorder caused by the progressive death of upper and lower motoneurons. Although numerous strategies have been developed to slow disease progression and improve life quality, to date only a few therapeutic treatments are available with still unsatisfactory therapeutic benefits. The secretome of dental pulp stem cells (DPSCs) contains numerous neurotrophic factors that could promote motoneuron survival. Accordingly, DPSCs confer neuroprotective benefits to the SOD1G93A mouse model of ALS. However, the mode of action of DPSC secretome on motoneurons remains largely unknown. Here, we used conditioned medium of human DPSCs (DPSCs-CM) and assessed its effect on survival, axonal length, and electrical activity of cultured wildtype and SOD1G93A motoneurons. To further understand the role of individual factors secreted by DPSCs and to circumvent the secretome variability bias, we focused on GDF15 and HB-EGF whose neuroprotective properties remain elusive in the ALS pathogenic context. DPSCs-CM rescues motoneurons from trophic factor deprivation-induced death, promotes axon outgrowth of wildtype but not SOD1G93A mutant motoneurons, and has no impact on the spontaneous electrical activity of wildtype or mutant motoneurons. Both GDF15 and HB-EGF protect SOD1G93A motoneurons against nitric oxide-induced death, but not against death induced by trophic factor deprivation. GDF15 and HB-EGF receptors were found to be expressed in the spinal cord, with a two-fold increase in expression for the GDF15 low-affinity receptor in SOD1G93A mice. Therefore, the secretome of DPSCs appears as a new potential therapeutic candidate for ALS.

Reassessing Breast Cancer-Associated Fibroblasts (CAFs) Interactions with Other Stromal Components and Clinico-Pathologic Parameters by Using Immunohistochemistry and Digital Image Analysis (DIA)

BACKGROUND

Breast cancer (BC) stroma has CD34- and αSMA-positive cancer-associated fibroblasts (CAFs) differently distributed. During malignant transformation, CD34-positive fibroblasts decrease while αSMA-positive CAFs increase. The prevalence of αSMA-positive CAFs in BC stroma makes microscopic examination difficult without digital image analysis processing (DIA). DIA was used to compare CD34- and αSMA-positive CAFs among breast cancer molecular subgroups. DIA-derived data were linked to age, survival, tumor stroma vessels, tertiary lymphoid structures (TLS), invasion, and recurrence.

METHODS

Double immunostaining for CD34 and αSMA showed different CAF distribution patterns in normal and BC tissues. Single CD34 immunohistochemistry on supplemental slides quantified tumor stroma CD34_CAFs. Digital image analysis (DIA) data on CAF density, intensity, stromal score, and H-score were correlated with clinico-pathologic factors.

RESULTS

CD34/αSMA CAF proportion was significantly related to age in Luminal A (LA), Luminal B (LB), and HER2 subtypes. CD34_CAF influence on survival, invasion, and recurrence of LA, LB-HER2, and TNBC subtypes was found to be significant. The CD34/αSMA-expressing CAFs exhibited a heterogeneous impact on stromal vasculature and TLS.

CONCLUSION

BC stromal CD34_CAFs/αSMA_CAFs have an impact on survival, invasion, and recurrence differently between BC molecular subtypes. The tumor stroma DIA assessment may have predictive potential to prognosis and long-term follow-up of patients with breast cancer.

Understanding human aging and the fundamental cell signaling link in age-related diseases: the middle-aging hypovascularity hypoxia hypothesis

Aging-related hypoxia, oxidative stress, and inflammation pathophysiology are closely associated with human age-related carcinogenesis and chronic diseases. However, the connection between hypoxia and hormonal cell signaling pathways is unclear, but such human age-related comorbid diseases do coincide with the middle-aging period of declining sex hormonal signaling. This scoping review evaluates the relevant interdisciplinary evidence to assess the systems biology of function, regulation, and homeostasis in order to discern and decipher the etiology of the connection between hypoxia and hormonal signaling in human age-related comorbid diseases. The hypothesis charts the accumulating evidence to support the development of a hypoxic milieu and oxidative stress-inflammation pathophysiology in middle-aged individuals, as well as the induction of amyloidosis, autophagy, and epithelial-to-mesenchymal transition in aging-related degeneration. Taken together, this new approach and strategy can provide the clarity of concepts and patterns to determine the causes of declining vascularity hemodynamics (blood flow) and physiological oxygenation perfusion (oxygen bioavailability) in relation to oxygen homeostasis and vascularity that cause hypoxia (hypovascularity hypoxia). The middle-aging hypovascularity hypoxia hypothesis could provide the mechanistic interface connecting the endocrine, nitric oxide, and oxygen homeostasis signaling that is closely linked to the progressive conditions of degenerative hypertrophy, atrophy, fibrosis, and neoplasm. An in-depth understanding of these intrinsic biological processes of the developing middle-aged hypoxia could provide potential new strategies for time-dependent therapies in maintaining healthspan for healthy lifestyle aging, medical cost savings, and health system sustainability.

The Role of Extracellular Vesicles in the Pathogenesis of Hematological Malignancies: Interaction with Tumor Microenvironment; a Potential Biomarker and Targeted Therapy

The tumor microenvironment (TME) plays an important role in the development and progression of hematological malignancies. In recent years, studies have focused on understanding how tumor cells communicate within the TME. In addition to several factors, such as growth factors, cytokines, extracellular matrix (ECM) molecules, etc., a growing body of evidence has indicated that extracellular vesicles (EVs) play a crucial role in the communication of tumor cells within the TME, thereby contributing to the pathogenesis of hematological malignancies. The present review focuses on how EVs derived from tumor cells interact with the cells in the TME, such as immune cells, stromal cells, endothelial cells, and ECM components, and vice versa, in the context of various hematological malignancies. EVs recovered from the body fluids of cancer patients often carry the bioactive molecules of the originating cells and hence can be considered new predictive biomarkers for specific types of cancer, thereby also acting as potential therapeutic targets. Here, we discuss how EVs influence hematological tumor progression via tumor-host crosstalk and their use as biomarkers for hematological malignancies, thereby benefiting the development of potential therapeutic targets.

Pancreatic Tumor-Targeting Stemsome Therapeutics

Owing to the intrinsic ability of stem cells to target the tumor environment, stem-cell-membrane-functionalized nanocarriers can target and load active anticancer drugs. In this work, a strategy that focuses on stem cells that self-target pancreatic cancer cells is developed. In particular, malignant deep tumors such as pancreatic cancer cells, one of the intractable tumors that currently have no successful clinical strategy, are available for targeting and destruction. By gaining the targeting ability of stem cells against pancreatic tumor cells, stem cell membranes can encapsulate nano-polylactide-co-glycolide loaded with doxorubicin to target and reduce deep pancreatic tumor tissues. Considering the lack of known target proteins on pancreatic tumor cells, the suggested platform technology can be utilized for targeting any malignant tumors in which surface target receptors are unavailable.

Novel strategies for cancer immunotherapy: counter-immunoediting therapy

The advent of immunotherapy has made an indelible mark on the field of cancer therapy, especially the application of immune checkpoint inhibitors in clinical practice. Although immunotherapy has proven its efficacy and safety in some tumors, many patients still have innate or acquired resistance to immunotherapy. The emergence of this phenomenon is closely related to the highly heterogeneous immune microenvironment formed by tumor cells after undergoing cancer immunoediting. The process of cancer immunoediting refers to the cooperative interaction between tumor cells and the immune system that involves three phases: elimination, equilibrium, and escape. During these phases, conflicting interactions between the immune system and tumor cells result in the formation of a complex immune microenvironment, which contributes to the acquisition of different levels of immunotherapy resistance in tumor cells. In this review, we summarize the characteristics of different phases of cancer immunoediting and the corresponding therapeutic tools, and we propose normalized therapeutic strategies based on immunophenotyping. The process of cancer immunoediting is retrograded through targeted interventions in different phases of cancer immunoediting, making immunotherapy in the context of precision therapy the most promising therapy to cure cancer.

Synthesis and Preclinical Evaluation of a Novel FAPI-04 Dimer for Cancer Theranostics

Overexpression of fibroblast activation protein (FAP) in cancer-associated fibroblasts in a wide variety of tumors enables a highly selective targeting strategy using FAP inhibitors (FAPIs). Quinoline-based FAPIs labeled with radionuclides have been widely developed for tumor-targeted nuclear medicine imaging. However, the short retention time of FAPIs at the tumor site limits their application in radionuclide therapy. In this study, a novel FAPI-04 dimer was synthesized and labeled with radionuclides to prolong the retention time in tumors for imaging and therapy. To prepare the FAPI-04 dimer complex, DOTA-Suc-Lys-(FAPI-04)₂, we used Fmoc-Lys(Boc)-OH as the linker to conjugate two FAPI-04 structures by an amide reaction. The resulting product was further modified by DOTA groups to allow for conjugation with radioactive metals. Both [⁶⁸Ga]Ga-(FAPI-04)₂ and [¹⁷⁷Lu]Lu-(FAPI-04)₂ showed a radiochemical purity of >99% and remained stable in vitro. In vivo, micro-PET images of SKOV3, A431, and H1299 xenografts revealed that the tumor uptake of [⁶⁸Ga]Ga-(FAPI-04)₂ was about twice that of [⁶⁸Ga]Ga-FAPI-04 and that the accumulation of [⁶⁸Ga]Ga-(FAPI-04)₂ at the tumor site did not significantly decrease even 3h after injection. The tumor-abdomen ratio of [⁶⁸Ga]Ga-(FAPI-04)₂ images was significantly higher than that of [¹⁸F]F-FDG images. For radionuclide therapy, [¹⁷⁷Lu]Lu-(FAPI-04)₂ effectively retarded tumor growth and displayed good tolerance. In conclusion, the DOTA-Suc-Lys-(FAPI-04)₂ design enhanced its uptake in FAP-expressing tumors, improved its retention time at the tumor site, and produced high-contrast imaging in xenografts after radionuclide labeling. Furthermore, it showed a noticeable antitumor effect. DOTA-Suc-Lys-(FAPI-04)₂ provides a new approach for applying FAPI derivatives in tumor theranostics.