Cancer-Associated Fibroblast-Induced Remodeling of Tumor Microenvironment in Recurrent Bladder Cancer

Multifaceted roles of OCT4 in tumor microenvironment: biology and therapeutic implications

OCT4 (Octamer-binding transcription factor 4, encoded by the POU5F1 gene) is a master transcription factor for maintaining the self-renewal and pluripotency of pluripotent stem cells, as well as a pioneer factor regulating epigenetics-driven cell reprogramming and cell fate conversion. It is also detected in a variety of cancer tissues and particularly in a small subpopulation of cancer cells known as cancer stem cells (CSCs). Accumulating evidence has revealed that CSCs are a dynamic population, exhibiting shift between multipotency and differentiation states, or quiescence and proliferation states. Such cellular plasticity of CSCs is profoundly influenced by dynamic interplay between CSCs and the tumor microenvironment (TME). Here, we review recent evidence showing that OCT4 expressed in CSCs plays a multifaceted role in shaping the TME by interacting with the cellular TME components, including cancer-associated fibroblasts, tumor endothelial cells, tumor-infiltrating immune cells, as well as the non-cellular TME components, such as extracellular matrix (ECM), metabolites, soluble factors (e.g., growth factors, cytokines and chemokines), and intra-tumoral microbiota. Together, OCT4 regulates crucial processes encompassing ECM remodeling, epithelial-mesenchymal transition, metabolic reprogramming, angiogenesis, and immune responses. The complex and bidirectional interactions between OCT4-expressing CSCs and the TME create a supportive niche for tumor growth, invasion, and resistance to therapy. Better understanding OCT4's roles in such interactions can provide deeper insights into potential therapeutic strategies and targets for disrupting the supportive environment of tumors. The emerging therapies targeting OCT4 in CSCs might hold promise to resensitize therapeutic-resistant cancer cells, and to eradicate all cancer cells when combined with other therapies targeting the bulk of differentiated cancer cells as well as the TME.

The role of cancer-associated fibroblasts in the tumour microenvironment of urinary system

Urological tumours are a type of neoplasms that significantly jeopardise human life and wellbeing. Cancer-associated fibroblasts (CAFs), serving as the primary component of the stromal cellular milieu, form a diverse cellular cohort that exerts substantial influence on tumourigenesis and tumour progression. In this review, we summarised the literatures regarding the functions of CAFs in the urinary tumour microenvironment (TME). We primarily examined the multifaceted activities of CAFs in the TME of urological system tumours, including inhibiting tumour immunity, remodelling the extracellular matrix, promoting tumour growth, metastasis, drug resistance and their clinical applications. We also discussed potential future directions for leveraging artificial intelligence in CAFs research. KEY POINTS: The interaction of CAFs with various cell secretory factors in the TME of urological tumors. The application of CAFs in diagnosis, treatment and prognosis of urological tumors.

LOX+ iCAFs in HNSCC have the potential to predict prognosis and immunotherapy responses revealed by single cell RNA sequencing analysis

Carcinoma-associated fibroblasts (CAFs) exhibit significant heterogeneity and are closely associated with progression, resistance to anticancer therapies, and poor prognosis in head and neck squamous cell carcinoma (HNSCC). However, the specific functional role of CAFs in HNSCC has been inadequately explored. In this study, we utilized a single-cell RNA sequencing dataset from HNSCC (GSE103322) to recluster CAFs via the Seurat pipeline. On the basis of the reported markers, we identified two CAF subtypes, LOX-myCAFs and LOX + iCAFs, and generated signature markers for each. Through unsupervised consensus clustering, we identified and characterized two molecular subtypes of HNSCC-TCGA, each exhibiting distinct dysregulated cancer hallmarks, immunological tumor microenvironments, and stemness characteristics. The robustness of the LOX + iCAF-related signature clustering, particularly in terms of prognosis and prediction of immunotherapeutic response, was validated in an ANOVA cohort via a GEO dataset (GSE159067) consisting of 102 HNSCC patients. A positive correlation was validated between the expression of LOX and that of CD86, a marker of M1 macrophage polarization. Further experiments involving the coculture of conditioned medium derived from LOX-silenced CAFs with CAL-27 and UM-SCC-1 cell lines revealed that LOX silencing led to decreased proliferation and migration of these cancer cells, which was mediated by epithelial-mesenchymal transition (EMT) through IL-34- induced CSF1R/Akt signaling. In summary, our single-cell and bulk RNA sequencing analyses revealed a LOX + iCAF-related signature that can predict the prognosis and response to immunotherapy in HNSCC patients. Additionally, the LOX gene was identified as a promising therapeutic target for HNSCC treatment.

The TMBIM1-YBX1 axis orchestrates MDSC recruitment and immunosuppressive microenvironment in pancreatic cancer

Background: Pancreatic ductal adenocarcinoma (PDAC) is notorious for its profoundly immunosuppressive nature. The complex crosstalk between diverse immune cell types and heterogeneous tumor cell populations shapes this challenging tumor immune microenvironment (TIME). In this study, the role of transmembrane BAX inhibitor motif-containing 1 (TMBIM1) in modulating the TIME and its potential as a therapeutic target in PDAC were investigated. Methods: RNA sequencing was used to assess differential gene expression between PANC-1 cells with TMBIM1 knockdown and control cells. Single-cell RNA sequencing further validated the role of TMBIM1 in modulating the expression of CCL2 and PD-L1. Mechanistic insights were gained through chromatin immunoprecipitation, ELISA, real-time quantitative PCR, and flow cytometry experiments. To evaluate the impact of TMBIM1 on immune cell dynamics, we employed an in vitro chemotaxis assay and an in vivo C57BL/6J mouse xenograft model to examine CD8+ T-cell activation and myeloid-derived suppressor cell (MDSC) infiltration. Additionally, the therapeutic potential of TMBIM1 knockdown combined with anti-PD-1 antibody treatment was investigated in PDAC animal models. Results: TMBIM1 was significantly upregulated in pancreatic cancer tissues and cell lines, driving pancreatic cancer cell proliferation, growth, and migration both in vitro and in vivo. Elevated TMBIM1 expression induced high infiltration of MDSCs and fostered an immunosuppressive tumor microenvironment. Mechanistically, TMBIM1 binds to the transcription factor Y box binding protein 1 (YBX1), which in turn increases the affinity of YBX1 for the PD-L1 and CCL2 gene promoters. This interaction results in their upregulation, leading to increased MDSC infiltration, thereby facilitating the immunosuppressive TIME in PDAC. Notably, the combination of TMBIM1 knockdown with anti-PD-1 therapy had a more potent antitumor effect than anti-PD-1 therapy alone. Conclusions: Our study reveals that the TMBIM1/YBX1 axis is a key driver of immune evasion in PDAC and shapes the immunosuppressive TIME through the upregulation of CCL2 and PD-L1 expression. These findings highlight TMBIM1 as a potential therapeutic target to sensitize PDAC to immunotherapy.

Prognostic value and immune landscapes of disulfidptosis‑related lncRNAs in bladder cancer

Disulfidptosis, which was recently identified, has shown promise as a potential cancer treatment. Nonetheless, the precise role of long non-coding RNAs (lncRNAs) in this phenomenon is currently unclear. To elucidate their significance in bladder cancer (BLCA), a signature of disulfidptosis-related lncRNAs (DRlncRNAs) was developed and their potential prognostic significance was explored. BLCA sample data were sourced from The Cancer Genome Atlas. A predictive signature comprising DRlncRNAs was formulated and subsequently validated. The combination of this signature with clinical characteristics facilitated the development of a nomogram with practical clinical utility. Additionally, enrichment analysis was conducted, the tumor microenvironment (TME) was assessed, the tumor mutational burden (TMB) was analyzed, and drug sensitivity was explored. Reverse transcription-quantitative PCR (RT-qPCR) was utilized to quantify lncRNA expression. The results revealed an eight-gene signature based on DRlncRNAs was established, and the predictive accuracy of the nomogram that incorporated the risk score [area under the curve (AUC)=0.733] outperformed the nomogram without it (AUC=0.703). High-risk groups were associated with pathways such as WNT signaling, focal adhesion and cell cycle pathways. The TME study revealed that high-risk patients had increased immune infiltration, whereas the TMB and tumor immune dysfunction and exclusion scores in low-risk patients indicated a potentially robust immune response. Drug sensitivity analysis identified appropriate antitumor drugs for each group. RT-qPCR experiments validated significant differences in DRlncRNAs expression between normal and BLCA cell lines. In conclusion, the prognostic risk signature, which includes the eight identified DRlncRNAs, demonstrates promise for predicting prognosis of patients with BLCA and guiding the selection of suitable immunotherapy and chemotherapy strategies.

Construction and validation of prognosis and treatment outcome models based on plasma membrane tension characteristics in bladder cancer

Background

Plasma membrane tension-related genes (MTRGs) are known to play a crucial role in tumor progression by influencing cell migration and adhesion. However, their specific mechanisms in bladder cancer (BLCA) remain unclear.

Methods

Transcriptomic, clinical and mutation data from BLCA patients were collected from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Clusters associated with MTRGs were identified by consensus unsupervised cluster analysis. The genes of different clusters were analyzed by GO and KEGG gene enrichment analysis. Differentially expressed genes (DEGs) were screened from different clusters. Consensus cluster analysis of prognostic DEGs was performed to identify gene subtypes. Patients were then randomly divided into training and validation groups, and MTRG scores were constructed by logistic minimum absolute contraction and selection operator (LASSO) and Cox regression analysis. We assessed changes in clinical outcomes and immune-related factors between different patient groups. The single-cell RNA sequencing (scRNA-seq) dataset for BLCA was collected and analyzed from the Tumor Immune Single-cell Hub (TISCH) database. Biological functions were investigated using a series of experiments including quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), wound healing, transwell, etc.

Results

Our MTRG score is based on eight genes (HTRA1, GOLT1A, DCBLD2, UGT1A1, FOSL1, DSC2, IGFBP3 and TAC3). Higher scores were characterized by lower cancer stem cell (CSC) indices, as well as higher tumor microenvironment (TME) stromal and immune scores, suggesting that high scores were associated with poorer prognosis. In addition, some drugs such as cisplatin, paclitaxel, doxorubicin, and docetaxel exhibited lower IC50 values in the high MTRG score group. Functional experiments have demonstrated that downregulation of DCBLD2 affects tumor cell migration, but not proliferation.

Conclusions

Our study sheds light on the prognostic significance of MTRGs within the TME and their correlation with immune infiltration patterns, ultimately impacting patient survival in BLCA. Notably, our findings highlight DCBLD2 as a promising candidate for targeted therapeutic interventions in the clinical management of BLCA.

Single-cell dissection of multifocal bladder cancer reveals malignant and immune cells variation between primary and recurrent tumor lesions

Bladder carcinoma (BLCA) is characterized by a high rate of post-surgery recurrence and multifocality. Multifocal tumors have a higher risk of recurrence compared to single tumors, significantly impacting bladder cancer-specific mortality. However, the interregional or intraregional heterogeneity within both primary and recurrent tumors remains poorly understood. Here, we employed single-cell RNA sequencing to analyze tumor lesions from five multifocal bladder cancer patients comprising three primary tumors and two recurrent tumors. Our findings revealed that malignant cells derived from recurrent multifocal bladder cancer exhibited higher interregional transcriptional similarity and consistent cellular communication. Furthermore, our analysis uncovered that malignant cells from recurrent tumors may evade immune destruction by suppressing cytokine responses and natural killer cell activity. Notably, we identified a preference for the expression of the tryptophan metabolic enzyme IL4I1 on SPP1+ macrophages in recurrent tumors. Functional analyses have revealed that IL4I1 may promotes tumor progression in recurrent tumors by activating the aryl hydrocarbon receptor (AHR) and recruiting regulatory T cells to suppress adaptive immunity. Taken together, our study provides a comprehensive understanding of primary and recurrent multifocal bladder tumors, offering valuable resources for analyzing the multifocality and recurrence of bladder cancer.

Targeting cancer-associated fibroblasts with pirfenidone: A novel approach for cancer therapy

Cancer-associated fibroblasts (CAFs) are a heterogeneous cell population within the tumor that have recently come into the spotlight. By extracellular matrix (ECM) remodeling and robust cross-talk with cancer cells via different secretions such as cytokines, chemokines, and growth factors, CAFs contribute to cancer progression and poorer prognoses in patients. Novel candidates have been developed to inhibit CAFs; however, due to safety and efficacy issues, none have successfully passed clinical trials. Despite these shortcomings, one concept embraced by many researchers is to repurpose non-oncology drugs with potential anti-cancer properties for cancer treatment. One such example is pirfenidone (PFD), an oral anti-fibrotic medication, primarily administered for idiopathic pulmonary fibrosis. Emerging evidence suggests that PFD has promising anti-cancer effects, mainly manifesting through targeting CAFs. With inhibitory effects on CAFs, PFD restricts cancer proliferation, metastasis, immunosuppression, drug resistance, and tumor stiffness. To improve efficacy and minimize adverse effects, several innovative approaches have been proposed for targeting CAFs via PFD. Interestingly, combination therapy comprising PFD and chemotherapeutics e.g. doxorubicin has shown synergistic anti-cancer effects while protecting normal tissue. Furthermore, novel drug delivery systems, e.g. biomimetic liposomes and multilayer core-shell nanoparticles, have enhanced the pharmacokinetic properties of PFD and further increased its intratumoral delivery. Single-cell RNA sequencing (scRNA-seq) has also been suggested to characterize different subpopulations of CAFs and design precise PFD-based therapeutic strategies. Herein, we discuss the promising anti-cancer effects of PFD via inhibition of CAFs. We then provide findings on novel PFD-based approaches to target CAFs using combination therapy, nanocarrier-based drug delivery, and scRNA-seq.

The axis of tumor-associated macrophages, extracellular matrix proteins, and cancer-associated fibroblasts in oncogenesis

The extracellular matrix (ECM) is a complex, dynamic network of multiple macromolecules that serve as a crucial structural and physical scaffold for neighboring cells. In the tumor microenvironment (TME), ECM proteins play a significant role in mediating cellular communication between cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs). Revealing the ECM modification of the TME necessitates the intricate signaling cascades that transpire among diverse cell populations and ECM proteins. The advent of single-cell sequencing has enabled the identification and refinement of specific cellular subpopulations, which has substantially enhanced our comprehension of the intricate milieu and given us a high-resolution perspective on the diversity of ECM proteins. However, it is essential to integrate single-cell data and establish a coherent framework. In this regard, we present a comprehensive review of the relationships among ECM, TAMs, and CAFs. This encompasses insights into the ECM proteins released by TAMs and CAFs, signaling integration in the TAM-ECM-CAF axis, and the potential applications and limitations of targeted therapies for CAFs. This review serves as a reliable resource for focused therapeutic strategies while highlighting the crucial role of ECM proteins as intermediates in the TME.

Tumor‑associated macrophages activated in the tumor environment of hepatocellular carcinoma: Characterization and treatment (Review)

Hepatocellular carcinoma (HCC) tissue is rich in dendritic cells, T cells, B cells, macrophages, natural killer cells and cellular stroma. Together they form the tumor microenvironment (TME), which is also rich in numerous cytokines. Tumor‑associated macrophages (TAMs) are involved in the regulation of tumor development. TAMs in HCC receive stimuli in different directions, polarize in different directions and release different cytokines to regulate the development of HCC. TAMs are mostly divided into two cell phenotypes: M1 and M2. M1 TAMs secrete pro‑inflammatory mediators, and M2 TAMs secrete a variety of anti‑inflammatory and pro‑tumorigenic substances. The TAM polarization in HCC tumors is M2. Both direct and indirect methods for TAMs to regulate the development of HCC are discussed. TAMs indirectly support HCC development by promoting peripheral angiogenesis and regulating the immune microenvironment of the TME. In terms of the direct regulation between TAMs and HCC cells, the present review mainly focuses on the molecular mechanism. TAMs are involved in both the proliferation and apoptosis of HCC cells to regulate the quantitative changes of HCC, and stimulate the related invasive migratory ability and cell stemness of HCC cells. The present review aims to identify immunotherapeutic options based on the mechanisms of TAMs in the TME of HCC.

Cancer associated fibroblasts and metabolic reprogramming: unraveling the intricate crosstalk in tumor evolution

Metabolic reprogramming provides tumors with an energy source and biofuel to support their survival in the malignant microenvironment. Extensive research into the intrinsic oncogenic mechanisms of the tumor microenvironment (TME) has established that cancer-associated fibroblast (CAFs) and metabolic reprogramming regulates tumor progression through numerous biological activities, including tumor immunosuppression, chronic inflammation, and ecological niche remodeling. Specifically, immunosuppressive TME formation is promoted and mediators released via CAFs and multiple immune cells that collectively support chronic inflammation, thereby inducing pre-metastatic ecological niche formation, and ultimately driving a vicious cycle of tumor proliferation and metastasis. This review comprehensively explores the process of CAFs and metabolic regulation of the dynamic evolution of tumor-adapted TME, with particular focus on the mechanisms by which CAFs promote the formation of an immunosuppressive microenvironment and support metastasis. Existing findings confirm that multiple components of the TME act cooperatively to accelerate the progression of tumor events. The potential applications and challenges of targeted therapies based on CAFs in the clinical setting are further discussed in the context of advancing research related to CAFs.

Sono-blasting Triggered Cascading-Amplification of Oxidative Stress for Enhanced Interventional Therapy of Hepatocellular Carcinoma

Interventional therapy is widely regarded as a highly promising treatment approach for nonsurgical liver cancer. However, the development of drug resistance and tolerance to hypoxic environments after embolization can lead to increased angiogenesis, enhanced tumor cell stemness, and greater invasiveness, resulting in metastasis and recurrence. To address these challenges, a novel approach involving the use of lecithin and DSPE-PEG comodified Ca2+ loaded (NH4)2S2O8 (LDCNSO) drug in combination with transcatheter arterial embolization (TAE) has been proposed. The sono-blasting effect of LDCNSO under ultrasound triggers a cascading amplification of oxidative stress, by releasing sulfate radical (·SO4-), hydroxyl radical (·OH), and superoxide (·O2-), inducing Ca2+ overload, and reducing glutathione (GSH) levels, which eventually leads to apoptosis. LDCNSO alongside TAE has demonstrated remarkable therapeutic efficacy in the rabbit orthotopic cancer model, resulting in significant inhibition of tumor growth. This research provides valuable insights for the effective treatment of orthotopic tumors.

What's new about the tumor microenvironment of urothelial carcinoma?

Urothelial carcinoma is a significant global health concern that accounts for a substantial part of cancer diagnoses and deaths worldwide. The tumor microenvironment is a complex ecosystem composed of stromal cells, soluble factors, and altered extracellular matrix, that mutually interact in a highly immunomodulated environment, with a prominent role in tumor development, progression, and treatment resistance. This article reviews the current state of knowledge of the different cell populations that compose the tumor microenvironment of urothelial carcinoma, its main functions, and distinct interactions with other cellular and non-cellular components, molecular alterations and aberrant signaling pathways already identified. It also focuses on the clinical implications of these findings, and its potential to translate into improved quality of life and overall survival. Determining new targets or defining prognostic signatures for urothelial carcinoma is an ongoing challenge that could be accelerated through a deeper understanding of the tumor microenvironment.

Connective Tissue Growth Factor: Regulation, Diseases, and Drug Discovery

In drug discovery, selecting targeted molecules is crucial as the target could directly affect drug efficacy and the treatment outcomes. As a member of the CCN family, CTGF (also known as CCN2) is an essential regulator in the progression of various diseases, including fibrosis, cancer, neurological disorders, and eye diseases. Understanding the regulatory mechanisms of CTGF in different diseases may contribute to the discovery of novel drug candidates. Summarizing the CTGF-targeting and -inhibitory drugs is also beneficial for the analysis of the efficacy, applications, and limitations of these drugs in different disease models. Therefore, we reviewed the CTGF structure, the regulatory mechanisms in various diseases, and drug development in order to provide more references for future drug discovery.

Myeloid-derived suppressor cells in cancer: therapeutic targets to overcome tumor immune evasion

Paradoxically, tumor development and progression can be inhibited and promoted by the immune system. After three stages of immune editing, namely, elimination, homeostasis and escape, tumor cells are no longer restricted by immune surveillance and thus develop into clinical tumors. The mechanisms of immune escape include abnormalities in antitumor-associated immune cells, selection for immune resistance to tumor cells, impaired transport of T cells, and the formation of an immunosuppressive tumor microenvironment. A population of distinct immature myeloid cells, myeloid-derived suppressor cells (MDSCs), mediate immune escape primarily by exerting immunosuppressive effects and participating in the constitution of an immunosuppressive microtumor environment. Clinical trials have found that the levels of MDSCs in the peripheral blood of cancer patients are strongly correlated with tumor stage, metastasis and prognosis. Moreover, animal experiments have confirmed that elimination of MDSCs inhibits tumor growth and metastasis to some extent. Therefore, MDSCs may become the target of immunotherapy for many cancers, and eliminating MDSCs can help improve the response rate to cancer treatment and patient survival. However, a clear definition of MDSCs and the specific mechanism involved in immune escape are lacking. In this paper, we review the role of the MDSCs population in tumor development and the mechanisms involved in immune escape in different tumor contexts. In addition, we discuss the use of these cells as targets for tumor immunotherapy. This review not only contributes to a systematic and comprehensive understanding of the essential role of MDSCs in immune system reactions against tumors but also provides information to guide the development of cancer therapies targeting MDSCs.