Complexity in the tumour microenvironment: Cancer associated fibroblast gene expression patterns identify both common and unique features of tumour-stroma crosstalk across cancer types

Scutellaria barbata D.Don and Scleromitrion diffusum (Willd.) R.J.Wang inhibits the progression of triple negative breast cancer though the activation inhibition of NF-κB triggered by CAFs-derived IL6

ETHNOPHARMACOLOGICAL RELEVANCE

The treatment options for triple-negative breast cancer (TNBC) are limited. Traditional Chinese Medicine (TCM) plays an important role in the treatment of TNBC. The herb pair Scutellaria barbata D.Don and Scleromitrion diffusum (Willd.) R.J.Wang (SH) is commonly used in clinical practice for its anti-tumor properties. It has been proven to have good therapeutic effects on tumor-related diseases, but the underlying molecular mechanisms are not yet fully explained.

AIM OF STUDY

Through bioinformatics, it was validated that IL6, primarily derived from cancer-associated fibroblasts (CAFs), is associated with poor prognosis. Additionally, cell and animal experiments confirmed that SH inhibits tumor proliferation, migration, and growth in an orthotopic tumor model by suppressing the IL6/NF-κB pathway.

MATERIALS AND METHODS

GEO, TCGA and HPA databases were used to analyze the prognostic value of CAFs and IL6, then IL6 resource was detected. After the bioinformatics, the influence of CAFs and CAFs-derived IL6 on TNBC was verified by experiments both in vitro and in vivo. Cell clone formation assay, wound-Healing assay, and Transwell assay were used to detect the promotion of CAFs and CAFs-derived IL6 and the inhibition of SH in vitro. TNBC model in mice was used to prove the promotion of CAFs and CAFs-derived IL6 and the inhibition of SH in vivo. The biological pathway of NF-κB was explored by western blotting through detecting unique molecules.

RESULTS

Bioinformatics analysis revealed that higher proportion of CAFs and elevated level of IL6 were significantly associated with poor prognosis in TNBC. At the same time, IL6 was proved predominantly derived from CAFs. After the indication of bioinformatics, experiments in vitro demonstrated that both CAFs and IL6 could enhance the clone formation and migration ability of MDA-MD-231 cells (231), furthermore, the promotion of CAFs was related with the level of IL6. Based on these data, mechanism was detected that CAFs-derived IL6 enhancement was closely related to the activation of NF-κB signaling pathway, while the activation can be reduced by SH. In the end, the promotion of CAFs/CAFs-derived IL6/NF-κB and the efficacy of SH inhibition were both confirmed by experiments in vivo.

CONCLUSIONS

Bioinformatics data indicates that higher proportion of CAFs and higher level of CAFs-derived IL6 are significantly related to poorer survival of TNBC. CAFs and CAFs-derived IL6 were proved to promote the progression of TNBC both in vitro and in vivo, and the process of which was significantly related to the activation of NF-κB. SH inhibited the progress of TNBC, which was proved to be closely related to CAFs/CAFs-derived IL6/NF-κB.

Revealing a cancer-associated fibroblast-based risk signature for pancreatic adenocarcinoma through single-cell and bulk RNA-seq analysis

PURPOSE

Proliferation of stromal connective tissue is a hallmark of pancreatic adenocarcinoma (PAAD). The engagement of activated cancer-associated fibroblasts (CAFs) contributes to the progression of PAAD through their involvement in tumor fibrogenesis. However, the prognostic significance of CAF-based risk signature in PAAD has not been explored.

METHODS

The single-cell RNA sequencing (scRNA-seq) data sourced from GSE155698 within the Gene Expression Omnibus (GEO) database was supplemented by bulk RNA sequencing data from The Cancer Genome Atlas (TCGA) and microarray data retrieved from the GEO database. The scRNA-seq data underwent processing via the Seurat package to identify distinct CAF clusters utilizing specific CAF markers. Differential gene expression analysis between normal and tumor samples was conducted within the TCGA-PAAD cohort. Univariate Cox regression analysis pinpointed genes associated with CAF clusters, identifying prognostic CAF-related genes. These genes were utilized in LASSO regression to craft a predictive risk signature. Subsequently, integrating clinicopathological traits and the risk signature, a nomogram model was constructed.

RESULTS

Our scRNA-seq analysis unveiled four distinct CAF clusters in PAAD, with two linked to PAAD prognosis. Among 207 identified DEGs, 148 exhibited significant correlation with these CAF clusters, forming the basis of a seven-gene risk signature. This signature emerged as an independent predictor in multivariate analysis for PAAD and demonstrated predictive efficacy in immunotherapeutic outcomes. Additionally, a novel nomogram, integrating age and the CAF-based risk signature, exhibited robust predictability and reliability in prognosticating PAAD. Moreover, the risk signature displayed substantial correlations with stromal and immune scores, as well as specific immune cell types.

CONCLUSIONS

The prognosis of PAAD can be accurately predicted using the CAF-based risk signature, and a thorough analysis of the PAAD CAF signature may aid in deciphering the patient's immunotherapy response and presenting fresh cancer treatment options.

Predicting Survival Signature of Bladder Cancer Related to Cancer-Associated Fibroblast (CAF) Constructed by Intersecting Genes in TCGA and GEO

Bladder cancer was one of the most common carcinomas around the world. However, the mechanism of the disease still remained to be investigated. We expected to establish a prognostic survival model with 9 prognostic genes to predict overall survival (OS) in patients of bladder cancer. The gene expression data of bladder cancer were obtained from TCGA and GEO datasets. TCGA and GEO datasets were used for screening prognostic genes along with developing and validating a 9-gene prognostic survival model by method of weighted gene co-expression network analysis (WGCNA) and LASSO with Cox regression. The relative analysis of evaluate tumor burden mutation (TBM), GO, KEGG, chemotherapy drug and functional pathway were also performed based on CAF-related mRNAs. 151 Overlapping CAF-related genes were distinguished after intersecting differentially expressed genes from 945 genes in TCGA and 491 genes in GEO dataset. 9 Prognostic genes (MSRB2, AGMAT, KLF6, DDAH2, GADD45B, SERPINE2, STMN3, TEAD2, and COMP) were used for construction of prognostic model after LASSO with Cox regression. Receiver operating characteristic (ROC) curves showed a good survival prediction by this model. Functional analysis indicated chemokine, cytokine, ECM interaction, oxidative stress and apoptosis were highly appeared. Potential drugs targeted different CAF-related genes like vemurafenib, irofulven, ghiotepa, and idarubicin were found as well. We constructed a novel 9 CAF-related mRNAs prognostic model and explored the gene expression and potential functional information of related genes, which might be worthy of clinical application. In addition, potential chemotherapy drugs could provide useful insights into the potential clinical treatment of bladder cancer.

The diagnostic and prognostic value of exosomal microRNAs in lung cancer: a systematic review

BACKGROUND

Studies have shown that many exosomal microRNAs (miRNAs) can be used as non-invasive biomarkers of lung cancer, but their diagnostic and prognostic values need to be further clarified.

METHODS

We conducted a systematic literature search in Web of Science, PubMed, and ScienceDirect databases, obtained relevant articles and extracted data, and used statistical methods and statistical software to comprehensively evaluate the diagnostic and prognostic value of exosomal miRNAs in lung cancer.

REGISTRATION NUMBER

PROSPERO CRD42023447398.

RESULTS

In terms of diagnosis, two exosomal miRNAs (miR-486-5p and miR-451a) were reported with the highest frequency in lung cancer patients, both of which had good diagnostic value. Compared with the control group, the pooled sensitivities of miR-486-5p and miR-451a were 0.80 (95% CI: 0.73-0.86) and 0.76 (95% CI: 0.60-0.87), specificities: 0.93 (95% CI: 0.63-0.99) and 0.85 (95% CI: 0.72-0.92), and AUCs: 0.85 (95% CI: 0.81-0.88) and 0.88 (95% CI: 0.84-0.90), for the respective miRNAs. For prognosis, in lung cancer patients with abnormally expressed exosomal miRNAs, miR-1290 was associated with PFS outcome; miR-382, miR-1246, miR-23b-3p, miR-21-5p, and miR-10b-5p were associated with OS outcome; miR-21 and miR-4257 were associated with DFS outcome; miR-125a-3p and miR-625-5p were associated with PFS and OS outcomes; miR-216b and miR-451a were associated with OS and DFS outcomes.

CONCLUSIONS

Exosomal miRNAs are valuable biomarkers in lung cancer patients. Exosomal miR-486-5p and miR-451a can be used as new diagnostic biomarkers for lung cancer. Dysregulated exosomal miRNAs could serve as indicators of survival outcomes in lung cancer patients.

Cancer-associated fibroblasts and prostate cancer stem cells: crosstalk mechanisms and implications for disease progression

The functional heterogeneity and ecological niche of prostate cancer stem cells (PCSCs), which are major drivers of prostate cancer development and treatment resistance, have attracted considerable research attention. Cancer-associated fibroblasts (CAFs), which are crucial components of the tumor microenvironment (TME), substantially affect PCSC stemness. Additionally, CAFs promote PCSC growth and survival by releasing signaling molecules and modifying the surrounding environment. Conversely, PCSCs may affect the characteristics and behavior of CAFs by producing various molecules. This crosstalk mechanism is potentially crucial for prostate cancer progression and the development of treatment resistance. Using organoids to model the TME enables an in-depth study of CAF-PCSC interactions, providing a valuable preclinical tool to accurately evaluate potential target genes and design novel treatment strategies for prostate cancer. The objective of this review is to discuss the current research on the multilevel and multitarget regulatory mechanisms underlying CAF-PCSC interactions and crosstalk, aiming to inform therapeutic approaches that address challenges in prostate cancer treatment.

Drug-Resistance Biomarkers in Patient-Derived Colorectal Cancer Organoid and Fibroblast Co-Culture System

Colorectal cancer, the third most commonly occurring tumor worldwide, poses challenges owing to its high mortality rate and persistent drug resistance in metastatic cases. We investigated the tumor microenvironment, emphasizing the role of cancer-associated fibroblasts in the progression and chemoresistance of colorectal cancer. We used an indirect co-culture system comprising colorectal cancer organoids and cancer-associated fibroblasts to simulate the tumor microenvironment. Immunofluorescence staining validated the characteristics of both organoids and fibroblasts, showing high expression of epithelial cell markers (EPCAM), colon cancer markers (CK20), proliferation markers (KI67), and fibroblast markers (VIM, SMA). Transcriptome profiling was conducted after treatment with anticancer drugs, such as 5-fluorouracil and oxaliplatin, to identify chemoresistance-related genes. Changes in gene expression in the co-cultured colorectal cancer organoids following anticancer drug treatment, compared to monocultured organoids, particularly in pathways related to interferon-alpha/beta signaling and major histocompatibility complex class II protein complex assembly, were identified. These two gene groups potentially mediate drug resistance associated with JAK/STAT signaling. The interaction between colorectal cancer organoids and fibroblasts crucially modulates the expression of genes related to drug resistance. These findings suggest that the interaction between colorectal cancer organoids and fibroblasts significantly influences gene expression related to drug resistance, highlighting potential biomarkers and therapeutic targets for overcoming chemoresistance. Enhanced understanding of the interactions between cancer cells and their microenvironment can lead to advancements in personalized medical research..

Repositioning of antiarrhythmics for prostate cancer treatment: a novel strategy to reprogram cancer-associated fibroblasts towards a tumor-suppressive phenotype

BACKGROUND

Cancer-associated fibroblasts (CAFs) play a significant role in fueling prostate cancer (PCa) progression by interacting with tumor cells. A previous gene expression analysis revealed that CAFs up-regulate genes coding for voltage-gated cation channels, as compared to normal prostate fibroblasts (NPFs). In this study, we explored the impact of antiarrhythmic drugs, known cation channel inhibitors, on the activated state of CAFs and their interaction with PCa cells.

METHODS

The effect of antiarrhythmic treatment on CAF activated phenotype was assessed in terms of cell morphology and fibroblast activation markers. CAF contractility and migration were evaluated by 3D gel collagen contraction and scratch assays, respectively. The ability of antiarrhythmics to impair CAF-PCa cell interplay was investigated in CAF-PCa cell co-cultures by assessing tumor cell growth and expression of epithelial-to-mesenchymal transition (EMT) markers. The effect on in vivo tumor growth was assessed by subcutaneously injecting PCa cells in SCID mice and intratumorally administering the medium of antiarrhythmic-treated CAFs or in co-injection experiments, where antiarrhythmic-treated CAFs were co-injected with PCa cells.

RESULTS

Activated fibroblasts show increased membrane conductance for potassium, sodium and calcium, consistently with the mRNA and protein content analysis. Antiarrhythmics modulate the expression of fibroblast activation markers. Although to a variable extent, these drugs also reduce CAF motility and hinder their ability to remodel the extracellular matrix, for example by reducing MMP-2 release. Furthermore, conditioned medium and co-culture experiments showed that antiarrhythmics can, at least in part, reverse the protumor effects exerted by CAFs on PCa cell growth and plasticity, both in androgen-sensitive and castration-resistant cell lines. Consistently, the transcriptome of antiarrhythmic-treated CAFs resembles that of tumor-suppressive NPFs. In vivo experiments confirmed that the conditioned medium or the direct coinjection of antiarrhythmic-treated CAFs reduced the tumor growth rate of PCa xenografts.

CONCLUSIONS

Collectively, such data suggest a new therapeutic strategy for PCa based on the repositioning of antiarrhythmic drugs with the aim of normalizing CAF phenotype and creating a less permissive tumor microenvironment.

Collagen content and C-X-C motif chemokine ligand 12 expression in neoplastic breast stroma

OBJECTIVE

This study aimed to evaluate the expression of C-X-C motif chemokine ligand 12 and its C-X-C chemokine receptor type 4, and the tumor-stroma ratio using collagen stromal content of breast cancer samples, correlating it with clinicopathological data.

METHODS

Through a retrospective cohort study, samples were obtained from female patients, over 18 years of age, with the disease in stages 1-4, who underwent mastectomy or lumpectomy. The biopsies were provided by the Oncology sector of the Hospital das Clínicas of Universidade Federal de Pernambuco, Recife city, in 2011-2014, including samples of invasive ductal carcinoma, ductal carcinoma in situ, or benign changes (fibroadenoma and hypertrophy), which were analyzed between 2020 and 2022 by immunohistochemistry for the expression of stromal cell characteristics. Collagen content was tested by Gomori staining and digital analysis of images.

RESULTS

Absence of stromal expression of C-X-C motif chemokine ligand 12 was associated with longer disease-free survival (disease-free survival=0.481), and expression of C-X-C chemokine receptor type 4 was associated with lower disease-free survival. An association was observed between clinicopathological variables and stromal expression of chemokines, that is, an association of stromal C-X-C motif chemokine ligand 12 with histological grade, angiolymphatic invasion, and an association between C-X-C chemokine receptor type 4 expression and histological grade. Analyses of digital pixels images of collagen and tumor cells showed a lower percentage of collagen in the invasive ductal carcinoma samples (39%), unlike samples without neoplasms (78%).

CONCLUSION

Low expression of C-X-C motif chemokine ligand 12 may be associated with a worse prognosis for breast cancer. Collagen staining analyzed using digital images represents an opportunity for clinical application and is indicative of the prognosis of the tumor microenvironment in breast carcinoma.

Establishment of a new prognostic risk model of GNG7 pathway-related molecules in clear cell renal cell carcinoma based on immunomodulators

Clear cell renal cell carcinoma (CCRCC) is a common tumor of the urological system for which surgery is the preferred treatment, but there is a lack of therapeutic options after surgery. This study aims to explore the biological role of GNG7 on CCRCC from a genetic perspective. Differences in mRNA expression and patient survival of GNG7 in patients with CCRCC and healthy patients were analyzed using the TCGA database. It was observed that GNG7 gene expression was downregulated in CCRCC tissue compared with healthy tissue, and high GNG7 predicted better prognosis for patients, and GNG7 also showed strong variability in clinical and TMN staging. The immune relevance of GNG7 and related genes was explored using renal cancer data from CCLE and TISIDB database. It was verified that the risk score constructed by 7 GNG7-related regulators might be used as an independent prognostic risk factor for CCRCC. A CCRCC prognostic model that involved 7 immune genes was further established to predict the survival probabilities of patients. At last, the GEO database and immunochemical tissue staining were used to validate GNG7 expression in CCRCC. Our study proposed a novel panel of genes to predict CCRCC OS based on GNG7-related immune genes, which may help to accurately predict the prognosis of CCRCC patients and make better clinical decisions for individual treatment.

Single-cell RNA sequencing reveals the mediatory role of cancer-associated fibroblast PTN in hepatitis B virus cirrhosis-HCC progression

BACKGROUND

Cancer-associated fibroblasts (CAFs) are essential stromal components in the tumor microenvironment of hepatocellular carcinoma (HCC). Hepatitis B virus (HBV) infection induces pathological changes such as liver fibrosis/cirrhosis and HCC. The aim of this research was to explore the novel mediators of CAFs to modulate HBV cirrhosis-HCC progression.

METHODS

The single-cell transcriptome data of HCC were divided into subsets, and the significant subset related to fibrotic cells, along with biological function, and clinical information of HCC was revealed by integrated data analyses. The cell communication, cells communicated weight analysis of signaling pathways, and key genes in signaling pathways analysis of significant CAFs subclasses were conducted to discover the novel gene of CAFs. Bioinformatics, vitro and HBV transfection assays were used to verify the novel gene is an important target for promoting the progression HBV cirrhosis-HCC progression.

RESULTS

Fibroblasts derived from HCC single-cell data could be separated into three cell subclasses (CAF0-2), of which CAF2 was associated with the HCC clinical information. Fibroblasts have opposite developmental trajectories to immune B cells and CD8 + T cells. CAF0-2 had strong interaction with B cells and CD8 + T cells, especially CAF2 had the highest interaction frequency and weight with B cells and CD8 + T cells. Moreover, PTN participated in CAF2-related pathways involved in the regulation of cell communication, and the interactions among CAF2 and PTN contributed the most to B cells and CD8 + T cells. Furthermore, the genes of PTN, SDC1, and NCL from PTN signaling were highest expression in CAF2, B cells, and CD8 + T cells, respectively, and the interaction of PTN- SDC1 and PTN- NCL contributed most to the interaction of CAF2- B cells and CAF2-CD8 + T cells. Bioinformatics and vitro experiments confirm PTN was upregulated in HCC and promoted the proliferation of tumor cells, and HBV infection could initiate PTN to perform cirrhosis-HCC progression.

CONCLUSION

Our findings revealed CAF was associated with hepatocarcinogenesis, and the functional importance of B cells and CD8 + T cells in modulating CAF in HCC. Importantly, PTN maybe a novel mediator of CAF to mediate HBV cirrhosis-HCC progression.

The Tumor Immune Microenvironment in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is a type of kidney cancer that arises from the cells lining the tubes of the kidney. The tumor immune microenvironment (TIME) of ccRCC is a complex interplay of various immune cells, cytokines, and signaling pathways. One of the critical features of the ccRCC TIME is the presence of infiltrating immune cells, including T cells, B cells, natural killer cells, dendritic cells, and myeloid-derived suppressor cells. Among these cells, CD8+ T cells are particularly important in controlling tumor growth by recognizing and killing cancer cells. However, the TIME of ccRCC is also characterized by an immunosuppressive environment that hinders the function of immune cells. Several mechanisms contribute to the immunosuppressive nature of the ccRCC TIME. For instance, ccRCC cells produce cytokines such as interleukin-10 (IL-10) and transforming growth factor-beta (TGF-β), which suppress immune cell activation and promote the differentiation of regulatory T cells (Tregs). Tregs, in turn, dampen the activity of effector T cells and promote tumor growth. In addition, ccRCC cells can express programmed death-ligand 1 (PD-L1), which interacts with the programmed cell death protein 1 (PD-1) receptor on T cells to inhibit their function. In addition, other immune checkpoint proteins, such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and lymphocyte activation gene 3 (LAG-3), also contribute to the immunosuppressive milieu of the ccRCC TIME. Finally, the hypoxic and nutrient-poor microenvironment of ccRCC can stimulate the production of immunosuppressive metabolites, such as adenosine and kynurenine, which further impair the function of immune cells. Understanding the complex interplay between tumor cells and the immune system in the ccRCC TIME is crucial for developing effective immunotherapies to treat this disease.

Stromal nicotinamide N-methyltransferase orchestrates the crosstalk between fibroblasts and tumour cells in oral squamous cell carcinoma: evidence from patient-derived assembled organoids

Nicotinamide N-methyltransferase (NNMT) has been reported to be linked to methylation reprogramming in cancer cells. However, the role of NNMT in the tumour microenvironment (TME) remains elusive. Here, we found that the expression of NNMT was elevated in the stroma of oral squamous cell carcinoma (OSCC). Using a fibroblast-attached organoids (FAOs) model, we confirmed that stromal NNMT expression contributed to the generation of assembled tumour organoids. In a tumour regeneration assay with co-implanted OSCC cells and cancer-associated fibroblasts (CAFs), the tumour-initiating activity was reduced when NNMT was silenced in CAFs. In contrast, overexpression of NNMT in paracancerous fibroblasts (PFs) accelerated tumour growth in co-inoculation experiments. Notably, fibroblast-specific NNMT can regulate type I collagen deposition in both FAOs and xenografts. Further investigations confirmed that the stromal NNMT-aggravated oncogenic activities were attenuated by treatment with inhibitors of either collagen synthesis (e.g. losartan, tranilast, and halofuginone) in fibroblasts, or the focal adhesion kinase (FAK) signal (i.e. defactinib) in cancer cells. Mechanistically, overexpression of NNMT reduced the enrichment of H3K27me3 at the promoter of the gene encoding lysyl oxidase (LOX), a key enzyme that regulates the cross-linking of collagen I. Overall, we propose that the NNMT-LOX-FAK cascade contributes to the crosstalk between cancer cells and fibroblasts during OSCC development, and that NNMT-centric extracellular matrix remodelling is a novel therapeutic target for patients with OSCC.

Cancer organoid co-culture model system: Novel approach to guide precision medicine

Three-dimensional cancer organoids derived from self-organizing cancer stems are ex vivo miniatures of tumors that faithfully recapitulate their structure, distinctive cancer features, and genetic signatures. As novel tools, current cancer organoids have been well established and rapidly applied in drug testing, genome editing, and transplantation, with the ultimate aim of entering clinical practice for guiding personalized therapy. However, given that the lack of a tumor microenvironment, including immune cells and fibrous cells, is a major limitation of this emerging methodology, co-culture models inspire high hope for further application of this technology in cancer research. Co-culture of cancer organoids and immune cells or fibroblasts is available to investigate the tumor microenvironment, molecular interactions, and chimeric antigen receptor-engineered lymphocytes in cancer treatment. In light of the recent progress in cancer organoid co-culture models, it is only possible to recognize the advantages and drawbacks of this novel model to exploit its full potential. In this review, we summarize the recent advances in the application of cancer organoids and co-culture models and how they could be improved in the future to benefit cancer research, especially precision medicine.

Characterization of cancer-related fibroblasts (CAF) in hepatocellular carcinoma and construction of CAF-based risk signature based on single-cell RNA-seq and bulk RNA-seq data

Background

Cancer-associated fibroblasts (CAFs) are involved in tumor growth, angiogenesis, metastasis, and resistance to therapy. We sought to explore the CAFs characteristics in hepatocellular carcinoma (HCC) and establish a CAF-based risk signature for predicting the prognosis of HCC patients.

Methods

The signal-cell RNA sequencing (scRNA-seq) data was obtained from the GEO database. Bulk RNA-seq data and microarray data of HCC were obtained from the TCGA and GEO databases respectively. Seurat R package was applied to process scRNA-seq data and identify CAF clusters according to the CAF markers. Differential expression analysis was performed to screen differentially expressed genes (DEGs) between normal and tumor samples in TCGA dataset. Then Pearson correlation analysis was used to determine the DEGs associated with CAF clusters, followed by the univariate Cox regression analysis to identify CAF-related prognostic genes. Lasso regression was implemented to construct a risk signature based on CAF-related prognostic genes. Finally, a nomogram model based on the risk signature and clinicopathological characteristics was developed.

Results

Based on scRNA-seq data, we identified 4 CAF clusters in HCC, 3 of which were associated with prognosis in HCC. A total of 423 genes were identified from 2811 DEGs to be significantly correlated with CAF clusters, and were narrowed down to generate a risk signature with 6 genes. These six genes were primarily connected with 39 pathways, such as angiogenesis, apoptosis, and hypoxia. Meanwhile, the risk signature was significantly associated with stromal and immune scores, as well as some immune cells. Multivariate analysis revealed that risk signature was an independent prognostic factor for HCC, and its value in predicting immunotherapeutic outcomes was confirmed. A novel nomogram integrating the stage and CAF-based risk signature was constructed, which exhibited favorable predictability and reliability in the prognosis prediction of HCC.

Conclusion

CAF-based risk signatures can effectively predict the prognosis of HCC, and comprehensive characterization of the CAF signature of HCC may help to interpret the response of HCC to immunotherapy and provide new strategies for cancer treatment.

Prostate Cancer Tumor Stroma: Responsibility in Tumor Biology, Diagnosis and Treatment

Simple Summary

The crosstalk between prostate stroma and its epithelium is essential to tissue homeostasis. Likewise, reciprocal signaling between tumor cells and the stromal compartment is required in tumor progression to facilitate or stimulate key processes such as cell proliferation and invasion. The aim of the present work was to review the current state of knowledge on the significance of tumor stroma in the genesis, progression and therapeutic response of prostate carcinoma. Additionally, we addressed the future therapeutic opportunities.

Abstract

Prostate cancer (PCa) is a common cancer among males globally, and its occurrence is growing worldwide. Clinical decisions about the combination of therapies are becoming highly relevant. However, this is a heterogeneous disease, ranging widely in prognosis. Therefore, new approaches are needed based on tumor biology, from which further prognostic assessments can be established and complementary strategies can be identified. The knowledge of both the morphological structure and functional biology of the PCa stroma compartment can provide new diagnostic, prognostic or therapeutic possibilities. In the present review, we analyzed the aspects related to the tumor stromal component (both acellular and cellular) in PCa, their influence on tumor behavior and the therapeutic response and their consideration as a new therapeutic target.

Differential Gene Expression and Weighted Correlation Network Dynamics in High-Throughput Datasets of Prostate Cancer

Precision oncology is an absolute need today due to the emergence of treatment resistance and heterogeneity among cancerous profiles. Target-propelled cancer therapy is one of the treasures of precision oncology which has come together with substantial medical accomplishment. Prostate cancer is one of the most common cancers in males, with tremendous biological heterogeneity in molecular and clinical behavior. The spectrum of molecular abnormalities and varying clinical patterns in prostate cancer suggest substantial heterogeneity among different profiles. To identify novel therapeutic targets and precise biomarkers implicated with prostate cancer, we performed a state-of-the-art bioinformatics study, beginning with analyzing high-throughput genomic datasets from The Cancer Genome Atlas (TCGA). Weighted gene co-expression network analysis (WGCNA) suggests a set of five dysregulated hub genes (MAF, STAT6, SOX2, FOXO1, and WNT3A) that played crucial roles in biological pathways associated with prostate cancer progression. We found overexpressed STAT6 and SOX2 and proposed them as candidate biomarkers and potential targets in prostate cancer. Furthermore, the alteration frequencies in STAT6 and SOX2 and their impact on the patients' survival were explored through the cBioPortal platform. The Kaplan-Meier survival analysis suggested that the alterations in the candidate genes were linked to the decreased overall survival of the patients. Altogether, the results signify that STAT6 and SOX2 and their genomic alterations can be explored in therapeutic interventions of prostate cancer for precision oncology, utilizing early diagnosis and target-propelled therapy.

Identification of CCL4 as an Immune-Related Prognostic Biomarker Associated With Tumor Proliferation and the Tumor Microenvironment in Clear Cell Renal Cell Carcinoma

The last decade has witnessed revolutionary advances taken in immunotherapy for various malignant tumors. However, immune-related molecules and their characteristics in the prediction of clinical outcomes and immunotherapy response in clear cell renal cell carcinoma (ccRCC) remain largely unclear. C-C Motif Chemokine Ligand 4 (CCL4) was extracted from the intersection analysis of common differentially expressed genes (DEGs) of four microarray datasets from the Gene Expression Omnibus database and immune-related gene lists in the ImmPort database using Cytoscape plug-ins and univariate Cox regression analysis. Subsequential analysis revealed that CCL4 was highly expressed in ccRCC patients, and positively correlated with multiple clinicopathological characteristics, such as grade, stage and metastasis, while negatively with overall survival (OS). We performed gene set enrichment analysis (GSEA) and gene set variant analysis (GSVA) with gene sets coexpressed with CCL4, and observed that gene sets positively related to CCL4 were enriched in tumor proliferation and immune-related pathways while metabolic activities in the negatively one. To further explore the correlation between CCL4 and immune-related biological process, the CIBERSORT algorithm, ESTIMATE method, and tumor mutational burden (TMB) score were employed to evaluate the tumor microenvironment (TME) characteristics of each sample and confirmed that high CCL4 expression might give rise to high immune cell infiltration. Moreover, correlation analysis revealed that CCL4 was positively correlated with common immune checkpoint genes, such as programmed cell death protein 1 (PD-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA4), and lymphocyte activating 3 (LAG3). Overall, this study demonstrated that CCL4 might serve as a potential immune-related prognostic biomarker to predict clinical outcomes and immunotherapy response in ccRCC. Moreover, CCL4 might contribute to TME modulation, indicating the mechanism CCL4 involved in tumor proliferation and metastasis, which could provide novel therapeutic perceptions for ccRCC patients.

Biological Models of the Lower Human Airways-Challenges and Special Requirements of Human 3D Barrier Models for Biomedical Research

In our review, we want to summarize the current status of the development of airway models and their application in biomedical research. We start with the very well characterized models composed of cell lines and end with the use of organoids. An important aspect is the function of the mucus as a component of the barrier, especially for infection research. Finally, we will explain the need for a nondestructive characterization of the barrier models using TEER measurements and live cell imaging. Here, organ-on-a-chip technology offers a great opportunity for the culture of complex airway models.

Oral Cancer: Genetics and the Role of Precision Medicine

Oral squamous cell carcinoma (OSCC) is one of the leading cancers in the world. OSCC patients are managed with surgery and/or chemoradiation. Prognoses and survival rates are dismal, however, and have not improved for more than 20 years. Recently, the concept of precision medicine was introduced, and the introduction of targeted therapeutics demonstrated promising outcomes. This article reviews the current understanding of initiation, progression, and metastasis of OSCC from both genetic and epigenetic perspectives. In addition, the applications and integration of omics technologies in biomarker discovery and drug development for treating OSCC are reviewed.

Cancer-Associated Fibroblasts and Tumor-Associated Macrophages in Cancer and Cancer Immunotherapy

Our understanding of the tumor microenvironment (TME), including the interplay between tumor cells, stromal cells, immune cells, and extracellular matrix components, is mandatory for the innovation of new therapeutic approaches in cancer. The cell-cell communication within the TME plays a pivotal role in the evolution and progression of cancer. Cancer-associated fibroblasts (CAF) and tumor-associated macrophages (TAM) are major cell populations in the stroma of all solid tumors and often exert protumorigenic functions; however, the origin and precise functions of CAF and TAM are still incompletely understood. CAF and TAM hold significant potential as therapeutic targets to improve outcomes in oncology when combined with existing therapies. The regulation of CAF/TAM communication and/or their differentiation could be of high impact for improving the future targeted treatment strategies. Nevertheless, there is much scope for research and innovation in this field with regards to the development of novel drugs. In this review, we elaborate on the current knowledge on CAF and TAM in cancer and cancer immunotherapy. Additionally, by focusing on their heterogenous functions in different stages and types of cancer, we explore their role as potential therapeutic targets and highlight certain aspects of their functions that need further research.

Glucocorticoid Receptor: A Multifaceted Actor in Breast Cancer

Breast cancer (BC) is one of the most common cancers in women worldwide. Even though the role of estrogen receptor alpha (ERα) is extensively documented in the development of breast tumors, other members of the nuclear receptor family have emerged as important players. Synthetic glucocorticoids (GCs) such as dexamethasone (dex) are commonly used in BC for their antiemetic, anti-inflammatory, as well as energy and appetite stimulating properties, and to manage the side effects of chemotherapy. However, dex triggers different effects depending on the BC subtype. The glucocorticoid receptor (GR) is also an important marker in BC, as high GR expression is correlated with a poor and good prognosis in ERα-negative and ERα-positive BCs, respectively. Indeed, though it drives the expression of pro-tumorigenic genes in ERα-negative BCs and is involved in resistance to chemotherapy and metastasis formation, dex inhibits estrogen-mediated cell proliferation in ERα-positive BCs. Recently, a new natural ligand for GR called OCDO was identified. OCDO is a cholesterol metabolite with oncogenic properties, triggering mammary cell proliferation in vitro and in vivo. In this review, we summarize recent data on GR signaling and its involvement in tumoral breast tissue, via its different ligands.

Identification of disease-promoting stromal components by comparative proteomic and transcriptomic profiling of canine mammary tumors using laser-capture microdissected FFPE tissue

Cancer-associated stroma (CAS) profoundly influences progression of tumors including mammary carcinoma (mCA). Canine simple mCA represent relevant models of human mCA, notably also with respect to CAS. While transcriptomic changes in CAS of mCA are well described, it remains unclear to what extent these translate to the protein level. Therefore, we sought to gain insight into the proteomic changes in CAS and compare them with transcriptomic changes in the same tissue. To this end, we analyzed CAS and matched normal stroma using laser-capture microdissection (LCM) and LC-MS/MS in a cohort of 14 formalin-fixed paraffin embedded (FFPE) canine mCAs that we had previously characterized using LCM-RNAseq. Our results reveal clear differences in protein abundance between CAS and normal stroma, which are characterized by changes in the extracellular matrix, the cytoskeleton, and cytokines such as TNF. The proteomics- and RNAseq-based analyses of LCM-FFPE show a substantial degree of correlation, especially for the most deregulated targets and a comparable activation of pathways. Finally, we validate transcriptomic upregulation of LTBP2, IGFBP2, COL6A5, POSTN, FN1, COL4A1, COL12A1, PLOD2, COL4A2, and IGFBP7 in CAS on the protein level and demonstrate their adverse prognostic value for human breast cancer. Given the relevance of canine mCA as a model for the human disease, our analysis substantiates these targets as disease-promoting stromal components with implications for breast cancer in both species.

Noncoding RNAs in the Interplay between Tumor Cells and Cancer-Associated Fibroblasts: Signals to Catch and Targets to Hit

Simple Summary

Cancer aggressiveness is the result of a proficient bidirectional interaction between tumor and stromal cells within the tumor microenvironment, among which a major role is played by the so-called cancer-associated fibroblasts. Upon such interplay, both cancer cells and fibroblasts are reprogrammed to sustain malignancy, with changes in the repertoire of noncoding RNAs, mainly microRNAs and long noncoding RNAs. Such molecules are also exchanged between the two cell types through extracellular vesicles. In this review, we summarize the current knowledge of microRNAs and long noncoding RNAs that act intracellularly or extracellularly to sustain tumor-stroma interplay. We also provide our view regarding the possible clinical utility of such noncoding RNAs as therapeutic target/tools or biomarkers to predict patient outcome or response to specific treatments.

Abstract

Cancer development and progression are not solely cell-autonomous and genetically driven processes. Dynamic interaction of cancer cells with the surrounding microenvironment, intended as the chemical/physical conditions as well as the mixture of non-neoplastic cells of the tumor niche, drive epigenetic changes that are pivotal for the acquisition of malignant traits. Cancer-associated fibroblasts (CAF), namely fibroblasts that, corrupted by cancer cells, acquire a myofibroblast-like reactive phenotype, are able to sustain tumor features by the secretion of soluble paracrine signals and the delivery extracellular vesicles. In such diabolic liaison, a major role has been ascribed to noncoding RNAs. Defined as RNAs that are functional though not being translated into proteins, noncoding RNAs predominantly act as regulators of gene expression at both the transcriptional and post-transcriptional levels. In this review, we summarize the current knowledge of microRNAs and long noncoding RNAs that act intracellularly in either CAFs or cancer cells to sustain tumor-stroma interplay. We also report on the major role of extracellular noncoding RNAs that are bidirectionally transferred between either cell type. Upon presenting a comprehensive view of the existing literature, we provide our critical opinion regarding the possible clinical utility of tumor-stroma related noncoding RNAs as therapeutic target/tools or prognostic/predictive biomarkers.

Exosomal miR-500a-5p derived from cancer-associated fibroblasts promotes breast cancer cell proliferation and metastasis through targeting USP28

The tumor microenvironment contributes to tumor progression and metastasis. Cancer-associated fibroblasts (CAFs) form a major cellular component of the tumor microenvironment. In this study, we further explored the mechanisms underlying the tumor-promoting roles of CAFs.

Methods: Patient-derived CAFs and normal fibroblasts (NFs) were isolated from breast carcinomas and adjacent normal breast tissue. Exosomes were isolated by ultracentrifugation and CAF-derived exosomal microRNAs were screened using next-generation sequencing technology. MiR-500a-5p expression was assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and in situ hybridization; Tumor cell proliferation was determined by MTT assays and three-dimensioned (3D) cultures, and tumor metastasis was determined by Transwell assays in vitro. In vivo assays were performed in a nude mouse subcutaneous xenograft model.

Results: We confirmed that CAF-derived exosomes significantly promoted the proliferation and metastasis of breast cancer cells. MiR-500a-5p was highly expressed in MDA-MB-231 and MCF7 cells treated with CAF-derived exosomes. The upregulation of miR-500a-5p was also confirmed in CAFs and CAF-derived exosomes. MiR-500a-5p was transferred from CAFs to the cancer cells, and subsequently promoted proliferation and metastasis by binding to ubiquitin-specific peptidase 28 (USP28).

Conclusions: The present study demonstrates that CAFs promote breast cancer progression and metastasis via exosomal miR-500a-5p and indicate that inhibiting CAF-derived miR-500a-5p is an alternative modality for the treatment of breast cancer.

CCL5-dependent mast cell infiltration into the tumor microenvironment in clear cell renal cell carcinoma patients

We investigated the mechanisms affecting tumor progression and survival outcomes in Polybromo-1-mutated (PBRM1^MUT) clear cell renal cell carcinoma (ccRCC) patients. PBRM1^MUT ccRCC tissues contained higher numbers of mast cells and lower numbers of CD8⁺ and CD4⁺ T cells than tissues from PBRM1^WT ccRCC patients. Hierarchical clustering, pathway enrichment and GSEA analyses demonstrated that PBRM1 mutations promote tumor progression by activating hypoxia inducible factor (HIF)-related signaling pathways and increasing expression of vascular endothelial growth factor family genes. PBRM1^MUT ccRCC tissues also show increased expression of C-C motif chemokine ligand 5 (CCL5). PBRM1-silenced ccRCC cells exhibited greater Matrigel tube formation and cell proliferation than controls. In addition, HMC-1 human mast cells exhibited CCL5-dependent in vitro migration on Transwell plates. High CCL5 expression in PBRM1^MUT ccRCC patients correlated with increased expression of genes encoding IFN-γ, IFN-α, IL-6, JAK-STAT3, TNF-α, and NF-ΚB. Moreover, high CCL5 expression was associated with poorer survival outcomes in ccRCC patients. These findings demonstrate that CCL5-dependent mast cell infiltration promotes immunosuppression within the tumor microenvironment, resulting in tumor progression and adverse survival outcomes in PBRM1^MUT ccRCC patients.

Differential glycosylation of collagen modulates lung cancer stem cell subsets through β1 integrin-mediated interactions

In lung cancer, CD133+ cells represent the subset of cancer stem cells (CSC) able to sustain tumor growth and metastatic dissemination. CSC function is tightly regulated by specialized niches composed of both stromal cells and extracellular matrix (ECM) proteins, mainly represented by collagen. The relevance of collagen glycosylation, a fundamental post-translational modification controlling several biological processes, in regulating tumor cell phenotype remains, however, largely unexplored. To investigate the bioactive effects of differential ECM glycosylation on lung cancer cells, we prepared collagen films functionalized with glucose (Glc-collagen) and galactose (Gal-collagen) exploiting a neoglycosylation approach based on a reductive amination of maltose and lactose with the amino residues of collagen lysines. We demonstrate that culturing of tumor cells on collagen determines a glycosylation-dependent positive selection of CSC and triggers their expansion/generation. The functional relevance of CD133+ CSC increase was validated in vivo, proving an augmented tumorigenic and metastatic potential. High expression of integrin β1 in its active form is associated with an increased proficiency of tumor cells to sense signaling from glycosylated matrices (glyco-collagen) and to acquire stemness features. Accordingly, inhibition of integrin β1 in tumor cells prevents CSC enrichment, suggesting that binding of integrin β1 to Glc-collagen subtends CSC expansion/generation. We provide evidence suggesting that collagen glycosylation could play an essential role in modulating the creation of a niche favorable for the generation and selection/survival of lung CSC. Interfering with this crosstalk may represent an innovative therapeutic strategy for lung cancer treatment.

3D Co-culture of Cancer-Associated Fibroblast with Oral Cancer Organoids

Limits of the available model have, in the long term, challenged the studies of cancer-associated fibroblasts (CAFs) and their interplay with cancer stem cells, one of the key driving forces of patients with oral squamous cell carcinoma (OSCC). In the present study, the 3-dimensional organoid model was employed to investigate whether co-culture with paralleled CAFs promotes stem-like properties of OSCC. Experimentally, tumor organoids and paralleled CAFs were generated from patients with OSCC. Then, the CD44⁺ cells in organoids were sorted out by flow cytometry and co-cultured with CAFs in Matrigel. The results showed that co-culture with CAFs enhances the organoid-forming ability of CD44⁺ cells and that this effect was blocked when production or uptake of lactate in CAFs or CD44⁺ cells was inhibited. Furthermore, the expression levels of CD44 and OCT-4 were detected in organoids incubated with lactate, via immunofluorescence or Western blot assay. The results demonstrated that treatments with lactate promote the organoid-forming ability of CD44⁺ cells, as well as the expression of CD44 and OCT-4 at the protein level in OSCC organoids.

Comparison Between Different 3D Spheroid Tumor Invasion Models

This study aims to make a comparison between different forms of three-dimensional (3D) spheroid U87 tumor cell models that contain fibroblast cells as part of the tumor microenvironment. This purpose is to select the best representative tumor model to be used for further studies to investigate the effects of the anti-invasive pharmacological agents. For this purpose, different options to prepare the 3D spherical invasion model were tested based on the ability of the spheroids to invade in collagen microenvironment. There was a significant positive effect of the fibroblasts on the invasion of the U87 cells in the 3D invasion model compared with the control model that contains U87 cells alone. This result gives proof of the positive effect of the fibroblasts on invasion of tumor cells. Furthermore, these results add more proofs on the importance of adding cells of the tumor microenvironments to the tumor models to make the models more representative to the real in vivo tumor situation.

Pharmacological Modulation of Steroid Activity in Hormone-Dependent Breast and Prostate Cancers: Effect of Some Plant Extract Derivatives

The great majority of breast and prostate tumors are hormone-dependent cancers; hence, estrogens and androgens can, respectively, drive their developments, making it possible to use pharmacological therapies in their hormone-dependent phases by targeting the levels of steroid or modulating their physiological activity through their respective nuclear receptors when the tumors relapse. Unfortunately, at some stage, both breast and prostate cancers become resistant to pharmacological treatments that aim to block their receptors, estrogen (ER) or androgen (AR) receptors, respectively. So far, antiestrogens and antiandrogens used in clinics have been designed based on their structural analogies with natural hormones, 17-β estradiol and dihydrotestosterone. Plants are a potential source of drug discovery and the development of new pharmacological compounds. The aim of this review article is to highlight the recent advances in the pharmacological modulation of androgen or estrogen levels, and their activity through their cognate nuclear receptors in prostate or breast cancer and the effects of some plants extracts.

Single-Cell Transcriptomic Analysis of Tumor-Derived Fibroblasts and Normal Tissue-Resident Fibroblasts Reveals Fibroblast Heterogeneity in Breast Cancer

Cancer-associated fibroblasts (CAFs) are a prominent stromal cell type in solid tumors and molecules secreted by CAFs play an important role in tumor progression and metastasis. CAFs coexist as heterogeneous populations with potentially different biological functions. Although CAFs are a major component of the breast cancer stroma, molecular and phenotypic heterogeneity of CAFs in breast cancer is poorly understood. In this study, we investigated CAF heterogeneity in triple-negative breast cancer (TNBC) using a syngeneic mouse model, BALB/c-derived 4T1 mammary tumors. Using single-cell RNA sequencing (scRNA-seq), we identified six CAF subpopulations in 4T1 tumors including: 1) myofibroblastic CAFs, enriched for α-smooth muscle actin and several other contractile proteins; 2) ‘inflammatory’ CAFs with elevated expression of inflammatory cytokines; and 3) a CAF subpopulation expressing major histocompatibility complex (MHC) class II proteins that are generally expressed in antigen-presenting cells. Comparison of 4T1-derived CAFs to CAFs from pancreatic cancer revealed that these three CAF subpopulations exist in both tumor types. Interestingly, cells with inflammatory and MHC class II-expressing CAF profiles were also detected in normal breast/pancreas tissue, suggesting that these phenotypes are not tumor microenvironment-induced. This work enhances our understanding of CAF heterogeneity, and specifically targeting these CAF subpopulations could be an effective therapeutic approach for treating highly aggressive TNBCs.

Are Synapse-Like Structures a Possible Way for Crosstalk of Cancer with Its Microenvironment?

The failure of therapies directed at targets within cancer cells highlight the necessity for a paradigm change in cancer therapy. The attention of researchers has shifted towards the disruption of cancer cell interactions with the tumor microenvironment. A typical example of such a disruption is the immune checkpoint cancer therapy that disrupts interactions between the immune and the cancer cells. The interaction of cancer antigens with T cells occurs in the immunological synapses. This is characterized by several special features, i.e., the proximity of the immune cells and their target cells, strong intercellular adhesion, and secretion of signaling cytokines into the intercellular cleft. Earlier, we hypothesized that the cancer-associated fibroblasts interacting with cancer cells through a synapse-like adhesion might play an important role in cancer tumors. Studies of the interactions between cancer cells and cancer-associated fibroblasts showed that their clusterization on the membrane surface determined their strength and specificity. The hundreds of interacting pairs are involved in the binding that may indicate the formation of synapse-like structures. These interactions may be responsible for successful metastasis of cancer cells, and their identification and disruption may open new therapeutic possibilities.

Insights into Fibroblast Plasticity: Cellular Communication Network 2 Is Required for Activation of Cancer-Associated Fibroblasts in a Murine Model of Melanoma

Tumor stroma resembles a fibrotic microenvironment, being characterized by the presence of myofibroblast-like cancer-associated fibroblasts (CAFs). In wild-type mice injected with melanoma cells, we show that the stem cell transcription factor Sox2 is expressed by tumor cells and induced in CAFs derived from synthetic fibroblasts. These fibroblasts were labeled postnatally with green fluorescent protein using mice expressing a tamoxifen-dependent Cre recombinase under the control of a fibroblast-specific promoter/enhancer. Conversely, fibroblast activation was impaired in mice with a fibroblast-specific deletion of cellular communication network 2 (Ccn2), associated with reduced expression of α-smooth muscle actin and Sox2. Multipotent Sox2-expressing skin-derived precursor (SKP) spheroids were cultured from murine back skin. Using lineage tracing and flow cytometry, approximately 40% of SKPs were found to be derived from type I collagen-lineage cells and acquired multipotency in culture. Inhibition of mechanotransduction pathways prevented myofibroblast differentiation of SKPs and expression of Ccn2. In SKPs deleted for Ccn2, differentiation into a myofibroblast, but not an adipocyte or neuronal phenotype, was also impaired. In human melanoma, CCN2 expression was associated with a profibrotic integrin alpha (ITGA) 11-expressing subset of CAFs that negatively associated with survival. These results suggest that synthetic dermal fibroblasts are plastic, and that CCN2 is required for the differentiation of dermal progenitor cells into a myofibroblast/CAF phenotype and is, therefore, a therapeutic target in melanoma.

Weighted Gene Co-Expression Network Analysis Identifies Hub Genes Associated with Occurrence and Prognosis of Oral Squamous Cell Carcinoma

Background

The aim of this study was to identify biomarkers closely related to the pathogenesis and prognosis of oral squamous cell carcinoma (OSCC) by using weighted gene co-expression network analysis (WGCNA) based on integrative transcriptome datasets.

Material/Methods

Gene expression profiles of OSCC were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were obtained and we then performed with Gene ontology (GO) and pathway enrichment analysis as well as protein–protein interactions (PPI) network analysis. WGCNA was used to construct the co-expression network. Multipart results were intersected to acquire the candidate genes, and survival analysis was used to identify the hub genes.

Results

A total of 568 DEGs, including 272 upregulated genes and 296 downregulated genes, were identified. GO and pathway analyses revealed that these DEGs were mainly enriched in extracellular matrix (ECM), ECM organization, structural constituent of muscle, and ECM-receptor interaction. The PPI network of DEGs was established, comprising 428 nodes and 1944 edges. In the co-expression network, pink module was the key module, in which 34 genes with high connectivity were identified. After the intersection of multipart results, 24 common genes were chosen as the candidate genes, among which 7 hub genes (PLAU, SERPINE1, LAMC2, ITGA5, TGFBI, FSCN1, and HLF) were identified using survival analysis.

Conclusions

Seven potential biomarkers were identified as being closely related with the initiation and prognosis of OSCC and might serve as potential targets for early diagnosis and personalized therapy of OSCC.

Rictor ablation in BMSCs inhibits bone metastasis of TM40D cells by attenuating osteolytic destruction and CAF formation

The mTOR complex 2 (mTORC2) is recognized as a promising target for breast cancer treatment. As mTORC2-specific inhibitors do not yet exist, studies into the role of mTORC2 in cancer are performed by deleting Rictor or by RNAi-mediated Rictor silencing. The purpose of this study was to explore the effects of Rictor ablation in bone mesenchymal stromal cells (BMSCs) on bone metastasis of breast cancer. First, female mice with the genotype of Prx1-Cre;Rictor^f/f (hereafter RiCKO) or Rictor^f/f (as control) were injected intratibially with cells of the breast cancer cell line (TM40D) at 4 months of age. Three weeks later, osteolytic bone destruction was detected in metastatic legs by X-ray and micro-CT. We found that Rictor ablation in BMSCs inhibited TM40D-induced osteolytic bone destruction and resulted in greater bone volume maintenance in vivo. Lower CTX-I serum level, a decreased number of TRAP+ osteoclasts and lower Cathepsin-K expression observed at the tumor-bone interface indicated that osteoclastogenesis was inhibited in RiCKO mice. Additionally, co-culture experiments confirmed that Rictor deletion in BMSCs diminished osteoclast differentiation partly via down regulation of RANKL expression. Furthermore, Rictor deficiency was found to reduce the transition of BMSCs to CAFs coupled with decreased secretion of cytokines (IL-6, RANKL, TGFβ), which resulted in lower chemotaxis and less proliferation in TM40D cells. These results suggest that Rictor ablation in BMSCs plays dual roles in breast cancer bone metastasis: (1) repression of osteolytic bone destruction; (2) inhibition of tumor growth.

Screening of immunosuppressive factors for biomarkers of breast cancer malignancy phenotypes and subtype-specific targeted therapy

We aimed to screen and validate immunosuppressive factors in luminal- and basal-like breast cancer cell lines and tissue samples associated with malignant phenotypes. The mRNA microarray datasets, GSE40057 and GSE1561, were downloaded and remodeled, and differentially expressed genes were identified. Weighted gene co-expression network analysis (WGCNA) and gene ontology (GO) and KEGG pathway enrichment analysis were performed to explore the immune-related events related to the basal-like breast cancer. The online resources, GOBO, Kaplan–Meier Plotter and UALCAN, were employed to screen for immunosuppressive factors associated with breast cancer malignant phenotypes. Immunohistochemistry was used to evaluate VEGFA and MIF levels in breast tumors and normal breast tissues; qPCRs and western blots were used to validate the expression of clinical immuno-oncology (IO) therapeutic targets CD274 (PD-L1) and IL8 in cell lines. The results showed that various immune-related events contribute to basal-like breast cancer. First, TGFβ1 and IL8 had higher average expression levels in more malignant cell lines; second, MIF and VEGFA had higher average expression levels in more malignant breast cancer tissues, and the high expression levels were associated with poor survival rate. Third, IO targets CD274 and IL8 which were confirmed to be more suitable for the treatment of basal-like breast cancer. In view of the above, during the formation and development of breast cancer, immune-related genes are always activated, and immunosuppressive factors, IL8, TGFβ1, MIF, and VEGFA are up-regulated. Such molecules could be used as biomarkers for breast cancer prognosis. However, because individual immune-related factors can play several biological roles, the mechanistic relationship between immunosuppressive factors and breast cancer malignant phenotypes and the feasibility of their application as drug targets require further investigation.

CDK inhibitors reduce cell proliferation and reverse hypoxia-induced metastasis of neuroblastoma tumours in a chick embryo model

Neuroblastoma is a paediatric cancer with a poor prognosis. This is in part due to widespread metastasis at time of presentation, which is refractory to current treatment modalities. New therapeutic agents that can control not only tumour growth but also metastasis are urgently needed. The differentiation therapy, retinoic acid, is currently used in clinic, leading to terminal differentiation of neuroblastoma cells thus reducing tumour growth in the primary tumour as well as at metastatic sites. However, retinoic acid only works in a subset of patients. We investigated the potential of CDK inhibitors, Palbociclib and RO-3306, on neuroblastoma cell differentiation, tumour progression and metastasis by utilising a 3R compliant cost effective preclinical chick embryo model. In both SK-N-AS and BE(2)C cell lines, when engrafted on the chorioallantoic membrane of chick embryos, we observed a reduction of tumour cell proliferation as well as a reduction in hypoxia preconditioning-driven metastasis by 60%. In addition, the expression of a panel of genes with known roles in metastasis, which increased upon hypoxia-preconditioning, was largely reduced by a CDK1 inhibitor. These results provide a promising alternative to currently existing therapies and might aid the development of new treatment protocols for retinoic acid-resistant patients.

Breast Cancer Tumor Stroma: Cellular Components, Phenotypic Heterogeneity, Intercellular Communication, Prognostic Implications and Therapeutic Opportunities

Although the mechanisms underlying the genesis and progression of breast cancer are better understood than ever, it is still the most frequent malignant tumor in women and one of the leading causes of cancer death. Therefore, we need to establish new approaches that lead us to better understand the prognosis of this heterogeneous systemic disease and to propose new therapeutic strategies. Cancer is not only a malignant transformation of the epithelial cells merely based on their autonomous or acquired proliferative capacity. Today, data support the concept of cancer as an ecosystem based on a cellular sociology, with diverse components and complex interactions between them. Among the different cell types that make up the stroma, which have a relevant role in the dynamics of tumor/stromal cell interactions, the main ones are cancer associated fibroblasts, endothelial cells, immune cells and mesenchymal stromal cells. Several factors expressed by the stroma of breast carcinomas are associated with the development of metastasis, such as matrix metalloproteases, their tissular inhibitors or some of their regulators like integrins, cytokines or toll-like receptors. Based on the expression of these factors, two types of breast cancer stroma can be proposed with significantly different influence on the prognosis of patients. In addition, there is evidence about the existence of bi-directional signals between cancer cells and tumor stroma cells with prognostic implications, suggesting new therapeutic strategies in breast cancer.

Tumor Extracellular Matrix Remodeling: New Perspectives as a Circulating Tool in the Diagnosis and Prognosis of Solid Tumors

In recent years, it has become increasingly evident that cancer cells and the local microenvironment are crucial in the development and progression of tumors. One of the major components of the tumor microenvironment is the extracellular matrix (ECM), which comprises a complex mixture of components, including proteins, glycoproteins, proteoglycans, and polysaccharides. In addition to providing structural and biochemical support to tumor tissue, the ECM undergoes remodeling that alters the biochemical and mechanical properties of the tumor microenvironment and contributes to tumor progression and resistance to therapy. A novel concept has emerged, in which tumor-driven ECM remodeling affects the release of ECM components into peripheral blood, the levels of which are potential diagnostic or prognostic markers for tumors. This review discusses the most recent evidence on ECM remodeling-derived signals that are detectable in the bloodstream, as new early diagnostic and risk prediction tools for the most frequent solid cancers.

Downregulation of miRNA-214 in cancer-associated fibroblasts contributes to migration and invasion of gastric cancer cells through targeting FGF9 and inducing EMT

Background

Cancer-associated fibroblasts (CAFs), one of the principal constituents of the tumor microenvironment, have a pivotal role in tumor progression. Dysregulation of microRNAs (miRNAs) in CAFs contributes to the tumor-promoting ability of CAFs. However, the mechanism underlying the involvement of miRNAs in CAFs of gastric cancer (GC) is not fully understood. This study aimed to explore the effects of miRNA-214 in CAFs on GC migration and invasion.

Methods

The primary CAFs and corresponding normal fibroblasts (NFs) were isolated. Cell counting kit-8, EdU cell proliferation staining and Transwell assays were used to determine the role of miRNA-214 in GC progression. Real-time polymerase chain reaction, Western blot analysis, and dual-luciferase reporter assay were performed to verify the target genes of miRNA-214. Immunofluorescence and Western blot analysis were applied to detect the expression of epithelial–mesenchymal transition (EMT) markers. Immunohistochemistry and in situ hybridization were implemented to analyze the fibroblast growth factor 9 (FGF9) and miRNA-214 expression in human GC tissues, respectively. Finally, to assess its prognostic relevance, Kaplan–Meier survival analysis was conducted.

Results

MiRNA-214 was significantly downregulated in CAFs of GC compared with NFs. The upregulation of miRNA-214 in CAFs inhibited GC cell migration and invasion in vitro but failed to affect proliferation. Moreover, GC cells cultured with conditioned medium from CAFs transfected with miR-214 mimic showed increased expression of E-cadherin and decreased expression of Vimentin, N-cadherin and Snail, indicating the suppression of EMT of GC cells. Furthermore, FGF9 was proved to be a direct target gene of miR-214. The expression of FGF9 was higher in CAFs than that in tumor cells not only in primary tumor but also in lymph node metastatic sites (30.0% vs 11.9%, P < 0.01 and 32.1% vs 12.3%, P < 0.01, respectively). Abnormal expression of FGF9 in CAFs of lymph node metastatic sites was significantly associated with poor prognosis in patients with GC (P < 0.05).

Conclusions

This study showed that miR-214 inhibited the tumor-promoting effect of CAFs on GC through targeting FGF9 in CAFs and regulating the EMT process in GC cells, suggesting miRNA-214/FGF9 in CAFs as a potential target for therapeutic approaches in GC.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0995-9) contains supplementary material, which is available to authorized users.

MiR-141-3p suppresses gastric cancer induced transition of normal fibroblast and BMSC to cancer-associated fibroblasts via targeting STAT4

BACKGROUND

Cancer associated fibroblasts (CAFs) are known to be crucial constituents of cancer microenvironment (CME) and play an important role in initiation, progression and metastasis of various types of cancer, such as oral cancer, pancreatic cancer, and gastric cancer. CAFs are usually derived from normal fibroblasts (NFs), but the mechanism of the transition in gastric cancer has not yet been fully elucidated.

METHODS

qRT-PCR and western blot were employed to investigate differences of miR-141 and STAT4 expression respectively. The CAF-like features and wnt/β-catenin pathway related proteins in NF or BMSC were assessed by qRT-PCR or western blot after treated with the conditioned medium from different indicated groups of gastric cancer cells. The invasion and migration ability of AGS cells after transfection were analyzed by Transwell assay and wound healing assay. Dual-luciferase report assay was employed to determine the direct binding of miR-141 to STAT4 3' UTR.

RESULTS

For the first time, the present study found that STAT4 over-expression in gastric cancer cells induced NFs to obtain CAF-like features via activating wnt/β-catenin pathway. Further gain-of-function and loss-of-function analysis revealed that miR-141 not only limited the migration and invasion of the gastric cancer cells, but also inhibited the transition of NFs and BMSC to CAFs. The luciferase assay indicated that miR-141 directly targeted the 3'-UTR predictive sequence of STAT4.

CONCLUSION

Our data showed that miR-141 inhibited migration and invasion of gastric cancer cells and inhibited transition from NFs to CAFs via targeting STAT4/wnt/β-catenin pathway.

Derivation and Validation of the Potential Core Genes in Pancreatic Cancer for Tumor-Stroma Crosstalk

Background

Pancreatic cancer is a fatal malignancy with a poor prognosis. The interactions between tumor cells and stromal cells contribute to cancer progression. Pancreatic stellate cells (PSCs) play a key role in tumor-stroma crosstalk of pancreatic cancer. The in-depth exploration for tumor-stroma crosstalk is helpful to develop novel therapeutic strategies. Our aim was to identify the potential core genes and pathways in tumor-stroma crosstalk.

Methods

3 microarray datasets were from Gene Expression Omnibus (GEO). Differentially expressed genes (DEGs) were screened through bioinformatics analysis. Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and protein-protein interaction (PPI) network were used to obtain the biological roles of DEGs. The top 15 DEGs were explored by principal component analysis. We validated the top 15 DEGs expression in the tumor-stroma crosstalk model in which PSCs were treated with the mixture of Aspc-1 and Panc-1 supernatant.

Results

A total of 221 genes were filtered as DEGs for tumor-stroma crosstalk. The results of principal component analysis for the top 15 DEGs can distinguish three groups. According to the KEGG enrichment, there were 8, 7, and 7 DEGs enriched in cancer related pathway, PI3K-Akt signaling pathway, and microRNAs, respectively. In the tumor-stroma crosstalk model, significant differences can be validated in the AKAP12, CLDN1, CP, FKBP1A, LAMB3, LSM4, MTMR3, PRKARIA, YWHAZ, and JUND expressions.

Conclusions

These results identified the potential core genes and pathways in pancreatic cancer for tumor-stroma crosstalk, which could provide potential targets for the treatment of pancreatic cancer.

Diagnostic role of circulating extracellular matrix-related proteins in non-small cell lung cancer

Background

Interactions between cancer cells and the surrounding microenvironment are crucial determinants of cancer progression. During this process, bi-directional communication among tumor cells and cancer associated fibroblasts (CAF) regulate extracellular matrix (ECM) deposition and remodeling. As a result of this dynamic process, soluble ECM proteins can be released into the bloodstream and may represent novel circulating biomarkers useful for cancer diagnosis. The aim of the present study was to measure the levels of three circulating ECM related proteins (COL11A1, COL10A1 and SPARC) in plasma samples of lung cancer patients and in healthy heavy-smokers controls and test whether such measurements have diagnostic or prognostic value.

Methods

Gene expression profiling of lung fibroblasts isolated from paired normal and cancer tissue of NSCLC patients was performed by gene expression microarrays. The prioritization of the candidates for the study of circulating proteins in plasma was based on the most differentially expressed genes in cancer associated fibroblasts. Soluble ECM proteins were assessed by western blot in the conditioned medium of lung fibroblasts and by ELISA assays in plasma samples.

Results

Plasma samples from lung cancer patients and healthy heavy-smokers controls were tested for levels of COL11A1 and COL10A1 (n = 57 each) and SPARC (n = 90 each). Higher plasma levels of COL10A1 were detected in patients (p ≤ 0.001), a difference that was driven specifically by females (p < 0.001). No difference in COL11A1 levels between patients and controls was found. SPARC levels were also higher in plasma patients than controls (p < 0.001) with good performance in discriminating the two groups (AUC = 0.744). No significant association was observed between plasma proteins levels and clinicopathological features or survival.

Conclusion

Soluble factors related to proficient tumor-stroma cross-talk are detectable in plasma of primary lung cancer patients and may represent a valuable complementary diagnostic tool to discriminate lung cancer patients from healthy heavy-smokers individuals as shown for the SPARC protein.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4772-0) contains supplementary material, which is available to authorized users.