CD90/THY1 is overexpressed in prostate cancer-associated fibroblasts and could serve as a cancer biomarker

THY1 is a prognostic-related biomarker via mediating immune infiltration in lung squamous cell carcinoma (LUSC)

Thymus cell antigen 1 (THY1) has been proven to play pivotal roles in many diseases. However, we do not fully understand its functional mechanism, especially in lung squamous cell carcinoma (LUSC). Here, we aimed to perform a comprehensive analysis to explore the expression and prognostic values of THY1 in LUSC using bioinformatic technology. Some online public databases (e.g., ONCOMINE, PrognoScan, TIMER, Kaplan-Meier plotter, STRING, LinkedOmics, and GEPIA) were used to explore the expression, prognostic significance, and potential molecular mechanism of THY1. The analysis indicated that THY1 was significantly up-regulated and closely correlated with poor prognosis in many malignant tumors, including LUSC. Further analysis revealed that over-expression of THY1 was significantly correlated with clinicopathological parameters (e.g., individual cancer stage, age, smoking habits, nodal metastasis status, and TP53 mutation status) in LUSC. The CpG islands methylation of THY1 was negatively correlated with THY1 mRNA expression in The Cancer Genome Atlas Program (TCGA). Further enrichment analysis of THY1 correlated genes revealed that they were mainly correlated with the formation of extracellular matrix (ECM), and got involved in the pathway of epithelial mesenchymal transition (EMT). Furthermore, differentially expressed THY1 was significantly correlated with immune cell infiltrations and poor prognosis in LUSC. In summary, bioinformatic analysis demonstrated that THY1 was significantly over-expressed and closely correlated with unfavorable prognosis in LUSC, which may apply as a promising diagnostic and therapeutic biomarker for LUSC in the future.

Investigating the Role of SNAI1 and ZEB1 Expression in Prostate Cancer Progression and Immune Modulation of the Tumor Microenvironment

Prostate cancer (PCa) is an immunologically cold tumor and the molecular processes that underlie this behavior are poorly understood. In this study, we investigated a primary cohort of intermediate-risk PCa (n = 51) using two NanoString profiling panels designed to study cancer progression and immune response. We identified differentially expressed genes (DEGs) and pathways associated with biochemical recurrence (BCR) and clinical risk. Confirmatory analysis was performed using the TCGA-PRAD cohort. Noteworthy DEGs included collagens such as COL1A1, COL1A2, and COL3A1. Changes in the distribution of collagens may influence the immune activity in the tumor microenvironment (TME). In addition, immune-related DEGs such as THY1, IRF5, and HLA-DRA were also identified. Enrichment analysis highlighted pathways such as those associated with angiogenesis, TGF-beta, UV response, and EMT. Among the 39 significant DEGs, 11 (28%) were identified as EMT target genes for ZEB1 using the Harmonizome database. Elevated ZEB1 expression correlated with reduced BCR risk. Immune landscape analysis revealed that ZEB1 was associated with increased immunosuppressive cell types in the TME, such as naïve B cells and M2 macrophages. Increased expression of both ZEB1 and SNAI1 was associated with elevated immune checkpoint expression. In the future, modulation of EMT could be beneficial for overcoming immunotherapy resistance in a cold tumor, such as PCa.

Prostate cancer research: tools, cell types, and molecular targets

Multiple cancer cell types are found in prostate tumors. They are either luminal-like adenocarcinoma or less luminal-like and more stem-like non-adenocarcinoma and small cell carcinoma. These types are lineage related through differentiation. Loss of cancer differentiation from luminal-like to stem-like is mediated by the activation of stem cell transcription factors (scTF) such as LIN28A, NANOG, POU5F1 and SOX2. scTF expression leads to down-regulation of β2-microglobulin (B2M). Thus, cancer cells can change from the scT F ˜ B 2 M hi phenotype of differentiated to that of scT F ˙ B 2 M lo of dedifferentiated in the disease course. In development, epithelial cell differentiation is induced by stromal signaling and cell contact. One of the stromal factors specific to prostate encodes proenkephalin (PENK). PENK can down-regulate scTF and up-regulate B2M in stem-like small cell carcinoma LuCaP 145.1 cells indicative of exit from the stem state and differentiation. In fact, prostate cancer cells can be made to undergo dedifferentiation or reprogramming by scTF transfection and then to differentiate by PENK transfection. Therapies need to be designed for treating the different cancer cell types. Extracellular anterior gradient 2 (eAGR2) is an adenocarcinoma antigen associated with cancer differentiation that can be targeted by antibodies to lyse tumor cells with immune system components. eAGR2 is specific to cancer as normal cells express only the intracellular form (iAGR2). For AGR2-negative stem-like cancer cells, factors like PENK that can target scTF could be effective in differentiation therapy.

Presence of onco-fetal neighborhoods in hepatocellular carcinoma is associated with relapse and response to immunotherapy

Onco-fetal reprogramming of the tumor ecosystem induces fetal developmental signatures in the tumor microenvironment, leading to immunosuppressive features. Here, we employed single-cell RNA sequencing, spatial transcriptomics and bulk RNA sequencing to delineate specific cell subsets involved in hepatocellular carcinoma (HCC) relapse and response to immunotherapy. We identified POSTN+ extracellular matrix cancer-associated fibroblasts (EM CAFs) as a prominent onco-fetal interacting hub, promoting tumor progression. Cell-cell communication and spatial transcriptomics analysis revealed crosstalk and co-localization of onco-fetal cells, including POSTN+ CAFs, FOLR2+ macrophages and PLVAP+ endothelial cells. Further analyses suggest an association between onco-fetal reprogramming and epithelial-mesenchymal transition (EMT), tumor cell proliferation and recruitment of Treg cells, ultimately influencing early relapse and response to immunotherapy. In summary, our study identifies POSTN+ CAFs as part of the HCC onco-fetal niche and highlights its potential influence in EMT, relapse and immunotherapy response, paving the way for the use of onco-fetal signatures for therapeutic stratification.

Identification of tumor-agnostic biomarkers for predicting prostate cancer progression and biochemical recurrence

The diverse clinical outcomes of prostate cancer have led to the development of gene signature assays predicting disease progression. Improved prostate cancer progression biomarkers are needed as current RNA biomarker tests have varying success for intermediate prostate cancer. Interest grows in universal gene signatures for invasive carcinoma progression. Early breast and prostate cancers share characteristics, including hormone dependence and BRCA1/2 mutations. Given the similarities in the pathobiology of breast and prostate cancer, we utilized the NanoString BC360 panel, comprising the validated PAM50 classifier and pathway-specific signatures associated with general tumor progression as well as breast cancer-specific classifiers. This retrospective cohort of primary prostate cancers (n=53) was stratified according to biochemical recurrence (BCR) status and the CAPRA-S to identify genes related to high-risk disease. Two public cohort (TCGA-PRAD and GSE54460) were used to validate the results. Expression profiling of our cohort uncovered associations between PIP and INHBA with BCR and high CAPRA-S score, as well as associations between VCAN, SFRP2, and THBS4 and BCR. Despite low levels of the ESR1 gene compared to AR, we found strong expression of the ER signaling signature, suggesting that BCR may be driven by ER-mediated pathways. Kaplan-Meier and univariate Cox proportional hazards regression analysis indicated the expression of ESR1, PGR, VCAN, and SFRP2 could predict the occurrence of relapse events. This is in keeping with the pathways represented by these genes which contribute to angiogenesis and the epithelial-mesenchymal transition. It is likely that VCAN works by activating the stroma and remodeling the tumor microenvironment. Additionally, SFRP2 overexpression has been associated with increased tumor size and reduced survival rates in breast cancer and among prostate cancer patients who experienced BCR. ESR1 influences disease progression by activating stroma, stimulating stem/progenitor prostate cancer, and inducing TGF-β. Estrogen signaling may therefore serve as a surrogate to AR signaling during progression and in hormone-refractory disease, particularly in prostate cancer patients with stromal-rich tumors. Collectively, the use of agnostic biomarkers developed for breast cancer stratification has facilitated a precise clinical classification of patients undergoing radical prostatectomy and highlighted the therapeutic potential of targeting estrogen signaling in prostate cancer.

Tumor microenvironment-induced tumor cell plasticity: relationship with hypoxic stress and impact on tumor resistance

The role of tumor interaction with stromal components during carcinogenesis is crucial for the design of efficient cancer treatment approaches. It is widely admitted that tumor hypoxic stress is associated with tumor aggressiveness and thus impacts susceptibility and resistance to different types of treatments. Notable biological processes that hypoxia functions in include its regulation of tumor heterogeneity and plasticity. While hypoxia has been reported as a major player in tumor survival and dissemination regulation, the significance of hypoxia inducible factors in cancer stem cell development remains poorly understood. Several reports indicate that the emergence of cancer stem cells in addition to their phenotype and function within a hypoxic tumor microenvironment impacts cancer progression. In this respect, evidence showed that cancer stem cells are key elements of intratumoral heterogeneity and more importantly are responsible for tumor relapse and escape to treatments. This paper briefly reviews our current knowledge of the interaction between tumor hypoxic stress and its role in stemness acquisition and maintenance. Our review extensively covers the influence of hypoxia on the formation and maintenance of cancer stem cells and discusses the potential of targeting hypoxia-induced alterations in the expression and function of the so far known stem cell markers in cancer therapy approaches. We believe that a better and integrated understanding of the effect of hypoxia on stemness during carcinogenesis might lead to new strategies for exploiting hypoxia-associated pathways and their targeting in the clinical setting in order to overcome resistance mechanisms. More importantly, at the present time, efforts are oriented towards the design of innovative therapeutical approaches that specifically target cancer stem cells.

β-Catenin in the kidney stroma modulates pathways and genes to regulate kidney development

BACKGROUND

Kidney development is regulated by cellular interactions between the ureteric epithelium, mesenchyme, and stroma. Previous studies demonstrate essential roles for stromal β-catenin in kidney development. However, how stromal β-catenin regulates kidney development is not known. We hypothesize that stromal β-catenin modulates pathways and genes that facilitate communications with neighboring cell populations to regulate kidney development.

RESULTS

We isolated purified stromal cells with wild type, deficient, and overexpressed β-catenin by fluorescence-activated cell sorting and conducted RNA Sequencing. A Gene Ontology network analysis demonstrated that stromal β-catenin modulates key kidney developmental processes, including branching morphogenesis, nephrogenesis and vascular formation. Specific stromal β-catenin candidate target genes that may mediate these effects included secreted, cell-surface and transcriptional factors that regulate branching morphogenesis and nephrogenesis (Wnts, Bmp, Fgfr, Tcf/Lef) and secreted vascular guidance cues (Angpt1, VEGF, Sema3a). We validated established β-catenin targets including Lef1 and novel candidate β-catenin targets including Sema3e which have unknown roles in kidney development.

CONCLUSIONS

These studies advance our understanding of gene and biological pathway dysregulation in the context of stromal β-catenin misexpression during kidney development. Our findings suggest that during normal kidney development, stromal β-catenin may regulate secreted and cell-surface proteins to communicate with adjacent cell populations.

What is new in cancer-associated fibroblast biomarkers?

The tumor microenvironment is one of the important drivers of tumor development. Cancer-associated fibroblasts (CAFs) are a major component of the tumor stroma and actively participate in tumor development, invasion, metastasis, drug resistance, and other biological behaviors. CAFs are a highly heterogeneous group of cells, a reflection of the diversity of their origin, biomarkers, and functions. The diversity of CAF origin determines the complexity of CAF biomarkers, and CAF subpopulations expressing different biomarkers may play contrasting roles in tumor progression. In this review, we provide an overview of these emerging CAF biomarkers and the biological functions that they suggest, which may give a better understanding of the relationship between CAFs and tumor cells and be of great significance for breakthroughs in precision targeted therapy for tumors. Video Abstract.

Activated CD90/Thy-1 fibroblasts co-express the Δ133p53β isoform and are associated with highly inflamed rheumatoid arthritis

BACKGROUND

The p53 isoform Δ133p53β is known to be associated with cancers driven by inflammation. Many of the features associated with the development of inflammation in rheumatoid arthritis (RA) parallel those evident in cancer progression. However, the role of this isoform in RA has not yet been explored. The aim of this study was to determine whether Δ133p53β is driving aggressive disease in RA.

METHODS

Using RA patient synovia, we carried out RT-qPCR and RNAScope-ISH to determine both protein and mRNA levels of Δ133p53 and p53. We also used IHC to determine the location and type of cells with elevated levels of Δ133p53β. Plasma cytokines were also measured using a BioPlex cytokine panel and data analysed by the Milliplex Analyst software.

RESULTS

Elevated levels of pro-inflammatory plasma cytokines were associated with synovia from RA patients displaying extensive tissue inflammation, increased immune cell infiltration and the highest levels of Δ133TP53 and TP53β mRNA. Located in perivascular regions of synovial sub-lining and surrounding ectopic lymphoid structures (ELS) were a subset of cells with high levels of CD90, a marker of 'activated fibroblasts' together with elevated levels of Δ133p53β.

CONCLUSIONS

Induction of Δ133p53β in CD90⁺ synovial fibroblasts leads to an increase in cytokine and chemokine expression and the recruitment of proinflammatory cells into the synovial joint, creating a persistently inflamed environment. Our results show that dysregulated expression of Δ133p53β could represent one of the early triggers in the immunopathogenesis of RA and actively perpetuates chronic synovial inflammation. Therefore, Δ133p53β could be used as a biomarker to identify RA patients more likely to develop aggressive disease who might benefit from targeted therapy to cytokines such as IL-6.

SFRP1 induces a stem cell phenotype in prostate cancer cells

Prostate cancer (PCa) ranks second in incidence and sixth in deaths globally. The treatment of patients with castration-resistant prostate cancer (CRPC) continues to be a significant clinical problem. Emerging evidence suggests that prostate cancer progression toward castration resistance is associated with paracrine signals from the stroma. SFRP1 is one of the extracellular proteins that modulate the WNT pathway, and it has been identified as a mediator of stromal epithelium communication. The WNT pathway is involved in processes such as cell proliferation, differentiation, cell anchoring, apoptosis, and cell cycle regulation as well as the regulation of stem cell populations in the prostatic epithelium. In the present study, we explored the role of exogenous SFRP1 on the stem cell phenotype in prostate cancer. The results reveal that cancer stem cell markers are significantly increased by exogenous SFRP1 treatments, as well as the downstream target genes of the Wnt/-catenin pathway. The pluripotent transcription factors SOX2, NANOG, and OCT4 were also up-regulated. Furthermore, SFRP1 promoted prostate cancer stem cell (PCSC) properties in vitro, including tumorsphere formation, migration, bicalutamide resistance, and decreased apoptosis. Taken together, our results indicate that SFRP1 participates in the paracrine signaling of epithelial cells, influencing them and positively regulating the stem cell phenotype through deregulation of the WNT/β-catenin pathway, which could contribute to disease progression and therapeutic failure. This research increases our molecular understanding of how CRPC progresses, which could help us find new ways to diagnose and treat the disease.

Role and mechanism of CD90+ fibroblasts in inflammatory diseases and malignant tumors

Fibroblasts are highly heterogeneous mesenchymal stromal cells, and different fibroblast subpopulations play different roles. A subpopulation of fibroblasts expressing CD90, a 25-37 kDa glycosylphosphatidylinositol anchored protein, plays a dominant role in the fibrotic and pro-inflammatory state. In this review, we focused on CD90⁺ fibroblasts, and their roles and possible mechanisms in disease processes. First, the main biological functions of CD90⁺ fibroblasts in inducing angiogenesis and maintaining tissue homeostasis are described. Second, the role and possible mechanism of CD90⁺ fibroblasts in inducing pulmonary fibrosis, inflammatory arthritis, inflammatory skin diseases, and scar formation are introduced, and we discuss how CD90⁺ cancer-associated fibroblasts might serve as promising cancer biomarkers. Finally, we propose future research directions related to CD90⁺ fibroblasts. This review will provide a theoretical basis for the diagnosis and treatment CD90⁺ fibroblast-related disease.

A cancer-associated fibroblast gene signature predicts prognosis and therapy response in patients with pancreatic cancer

Pancreatic cancer is a lethal malignancy with a 5-year survival rate of about 10% in the United States, and it is becoming an increasingly prominent cause of cancer death. Among pancreatic cancer patients, pancreatic ductal adenocarcinoma (PDAC) accounts for more than 90% of all cases and has a very poor prognosis with an average survival of only 1 year in about 18% of all tumor stages. In the past years, there has been an increasing interest in cancer-associated fibroblasts (CAFs) and their roles in PDAC. Recent data reveals that CAFs in PDAC are heterogeneous and various CAF subtypes have been demonstrated to promote tumor development while others hinder cancer proliferation. Furthermore, CAFs and other stromal populations can be potentially used as novel prognostic markers in cancer. In the present study, in order to evaluate the prognostic value of CAFs in PDAC, CAF infiltration rate was evaluated in 4 PDAC datasets of TCGA, GEO, and ArrayExpress databases and differentially expressed genes (DEGs) between CAF-high and CAF-low patients were identified. Subsequently, a CAF-based gene expression signature was developed and studied for its association with overall survival (OS). Additionally, functional enrichment analysis, somatic alteration analysis, and prognostic risk model construction was conducted on the identified DEGs. Finally, oncoPredict algorithm was implemented to assess drug sensitivity prediction between high- and low-risk cohorts. Our results revealed that CAF risk-high patients have a worse survival rate and increased CAF infiltration is a poor prognostic indicator in pancreatic cancer. Functional enrichment analysis also revealed that "extracellular matrix organization" and "vasculature development" were the top enriched pathways among the identified DEGs. We also developed a panel of 12 genes, which in additional to its prognostic value, could predict higher chemotherapy resistance rate. This CAF-based panel can be potentially utilized alone or in conjunction with other clinical parameters to make early predictions and prognosticate responsiveness to treatment in PDAC patients. Indeed, it is necessary to conduct extensive prospective investigations to confirm the clinical utility of these findings.

Modulation of the antitumor immune response by cancer-associated fibroblasts: mechanisms and targeting strategies to hamper their immunosuppressive functions

Cancer-associated fibroblasts (CAFs) are highly heterogeneous players that shape the tumor microenvironment and influence tumor progression, metastasis formation, and response to conventional therapies. During the past years, some CAFs subsets have also been involved in the modulation of immune cell functions, affecting the efficacy of both innate and adaptive anti-tumor immune responses. Consequently, the implication of these stromal cells in the response to immunotherapeutic strategies raised major concerns. In this review, current knowledge of CAFs origins and heterogeneity in the tumor stroma, as well as their effects on several immune cell populations that explain their immunosuppressive capabilities are summarized. The current development of therapeutic strategies for targeting this population and their implication in the field of cancer immunotherapy is also highlighted.

THY1-mediated mechanisms converge to drive YAP activation in skin homeostasis and repair

Anchored cells of the basal epidermis constantly undergo proliferation in an overcrowded environment. An important regulator of epidermal proliferation is YAP, which can be controlled by both cell-matrix and cell-cell interactions. Here, we report that THY1, a GPI-anchored protein, inhibits epidermal YAP activity through converging molecular mechanisms. THY1 deficiency leads to increased adhesion by activating the integrin-β₁-SRC module. Notably, regardless of high cellular densities, the absence of THY1 leads to the dissociation of an adherens junction complex that enables the release and translocation of YAP. Due to increased YAP-dependent proliferation, Thy1^-/- mice display enhanced wound repair and hair follicle regeneration. Taken together, our work reveals THY1 as a crucial regulator of cell-matrix and cell-cell interactions that controls YAP activity in skin homeostasis and regeneration.

Evaluation of Soluble CD90: Potential for Diagnostic Significance in Endometriosis Patients

Background

Endometriosis is a chronic and debilitating gynecologic disorder, driven by endocrine and immune dysfunctions, which lead to poor endometrial differentiation and attenuated fertility. Escape from immune surveillance and involvement of inflammatory mechanisms appear to be factors in disease progression. Current diagnostic guidelines for endometriosis still lack an efficient biomarker. Here, we report a study on two previously unexplored factors as potential biomarkers for endometriosis.

Methods

A case-control study was performed to evaluate the diagnostic potential of serum CD90 and CD83 levels in endometriosis patients (cases validated by surgical and histological examination) compared to healthy controls. Serum was collected from age-matched females and analyzed by ELISA.

Results

Comparison of endometriosis patients to the control group showed significantly elevated levels of serum CD90 (1160 ± 856 pg/mL vs. 334 ± 228 pg/mL; ^∗∗∗∗p < 0.0001). A threshold value of 479.4 pg/mL was defined based on the control results, and the diagnostic efficiency of the test was estimated. The obtained sensitivity (70.4%), specificity (92.9%), positive predictive value (90.5%), and negative predictive value (76.5%) rated the test as one with promising diagnostic potential. In contrast, the analysis of serum CD83 levels showed comparable values in both groups, suggesting no association with patient status.

Conclusion

Elevated soluble CD90 in human serum is associated with endometriosis, which suggests its putative clinical significance as a biomarker in screening and/or diagnosis of the disease.

Cancer-associated fibroblasts and their role in tumor progression

The stromal elements of a malignant tumor can promote cancer progression and metastasis. The structure of the tumor stroma includes connective tissue elements, blood vessels, nerves, and extracellular matrix (ECM). Some of the cellular elements of the tumor stroma are cancer-associated fibroblasts (CAFs). The origin and function of CAFs have been actively studied over the past thirty years. CAFs produce collagen, the main scaffold protein of the extracellular matrix. Collagen in the tumor stroma stimulates fibrosis, enhances the rigidity of tumor tissue, and disrupts the transmission of proliferation and differentiation signaling pathways. CAFs control tumor angiogenesis, cell motility, tumor immunogenic properties, and the development of resistance to chemo- and immunotherapy. As a result of metabolic adaptation of rapidly growing tumor tissue to the nutrients and oxygen deprivation, the main type of energy production in cells changes from oxidative phosphorylation to anaerobic glycolysis. These changes lead to sequential molecular alterations, including the induction of specified transcriptional factors that result in the CAFs activation. The molecular phenotype of activated CAFs is similar to fibroblasts activated during inflammation. In activated CAFs, alpha-smooth muscle actin (α-SMA) is synthetized de novo and various proteases and fibronectin are produced. Since CAFs are found in all types of carcinomas, these cells are potential targets for the development of new approaches for anticancer therapy. Some CAFs originate from resident fibroblasts of the organs invaded by the tumor, while others originate from epithelial tumor cells, which are undergoing an epithelial-mesenchymal transition (EMT). To date, many molecular and metabolic inducers of the EMT have been discovered including the transforming growth factor-beta (TGF-β), hypoxia, and inflammation. This review classifies modern concepts of molecular markers of CAFs, their functional features, and discusses the stages of epithelial-mesenchymal transition, and the potential of CAFs as a target for antitumor therapy.

CD90 is regulated by notch1 and hallmarks a more aggressive intrahepatic cholangiocarcinoma phenotype

BACKGROUND

Intrahepatic Cholangiocarcinoma (iCCA) is characterized by a strong stromal reaction playing a role in tumor progression. Thymus cell antigen 1 (THY1), also called Cluster of Differentiation 90 (CD90), is a key regulator of cell-cell and cell-matrix interaction. In iCCA, CD90 has been reported to be associated with a poor prognosis. In an iCCA PDX model, we recently found that CD90 was downregulated in mice treated with the Notch γ-secretase inhibitor Crenigacestat. The study aims to investigate the role of CD90 in relation to the NOTCH pathway.

METHODS

THY1/CD90 gene and protein expression was evaluated in human iCCA tissues and xenograft models by qRT-PCR, immunohistochemistry, and immunofluorescence. Notch1 inhibition was achieved by siRNA. THY1/CD90 functions were investigated in xenograft models built with HuCCT1 and KKU-M213 cell lines, engineered to overexpress or knockdown THY1, respectively.

RESULTS

CD90 co-localized with EPCAM, showing its epithelial origin. In vitro, NOTCH1 silencing triggered HES1 and THY1 down-regulation. RBPJ, a critical transcriptional regulator of NOTCH signaling, exhibited putative binding sites on the THY1 promoter and bound to the latter, implying CD90 as a downstream NOTCH pathway effector. In vivo, Crenigacestat suppressed iCCA growth and reduced CD90 expression in the PDX model. In the xenograft model, Crenigacestat inhibited tumor growth of HuCCT1 cells transfected to overexpress CD90 and KKU-M213 cells constitutively expressing high levels of CD90, while not affecting the growth of HuCCT1 control cells and KKU-M213 depleted of CD90. In an iCCA cohort, patients with higher expression levels of NOTCH1/HES1/THY1 displayed a significantly shorter survival.

CONCLUSIONS

iCCA patients with higher NOTCH1/HES1/THY1 expression have the worst prognosis, but they are more likely to benefit from Notch signaling inhibition. These findings represent the scientific rationale for testing NOTCH1 inhibitors in clinical trials, taking the first step toward precision medicine for iCCA.

Cancer-associated fibroblasts and the tumor microenvironment in non-small cell lung cancer

INTRODUCTION

Non-small cell lung cancer (NSCLC) has a markedly poor prognosis as it progresses, and the prognosis is still unsatisfactory even with modern treatments. Cancer is composed of not only cancer cells, but also stroma consisting of various cell types. Cancer-associated fibroblasts (CAFs) are a major component of the stroma and the associated tumor microenvironment (TME). Particularly, CAFs are a critical component in elucidating the biological mechanisms of cancer progression and new therapeutic targets. This article outlines the TME formed by CAFs in NSCLC.

AREAS COVERED

Focusing on the TME in NSCLC, we discuss the mechanisms by which CAFs are involved in cancer progression, drug resistance, and the development of therapies targeting CAFs.

EXPERT OPINION

In the TME, CAFs profoundly contribute to tumor progression by interacting with cancer cells through direct contact or paracrine cytokine signaling. CAFs also interact with various other stromal components to establish a tumor-promoting immunosuppressive microenvironment and remodel the extracellular matrix. Furthermore, these effects are closely associated with drug resistance. Further elucidation of the stromal microenvironment, including CAFs, could prove to be crucial in the treatment of NSCLC.

OUP accepted manuscript

BACKGROUND

Glioblastoma stem cells (GSCs) and their interplay with tumor-associated macrophages (TAMs) are responsible for malignant growth and tumor recurrence of glioblastoma multiforme (GBM), but the underlying mechanisms are largely unknown.

METHODS

Cell viability, stemness, migration, and invasion were measured in GSCs after the knockdown of upstream stimulating factor 1 (USF1). Luciferase assay and chromatin immunoprecipitation qPCR were performed to determine the regulation of CD90 by USF1. Immunohistochemistry and immunofluorescent staining were used to examine the expression of USF1 and GSC markers, as well as the crosstalk between GSCs and TAMs. In addition, the interaction between GSCs and TAMs was confirmed using in vivo GBM models.

RESULTS

We show that USF1 promotes malignant glioblastoma phenotypes and GSCs-TAMs physical interaction by inducing CD90 expression. USF1 predicts a poor prognosis for glioma patients and is upregulated in patient-derived GSCs and glioblastoma cell lines. USF1 overexpression increases the proliferation, invasion, and neurosphere formation of GSCs and glioblastoma cell lines, while USF1 knockdown exerts an opposite effect. Further mechanistic studies reveal that USF1 promotes GSC stemness by directly regulating CD90 expression. Importantly, CD90 of GSCs functions as an anchor for physical interaction with macrophages. Additionally, the USF1/CD90 signaling axis supports the GSCs and TAMs adhesion and immunosuppressive feature of TAMs, which in turn enhance the stemness of GSCs. Moreover, the overexpression of CD90 restores the stemness property in USF1 knockdown GSCs and its immunosuppressive microenvironment.

CONCLUSIONS

Our findings indicate that the USF1/CD90 axis might be a potential therapeutic target for the treatment of glioblastoma.

The opposing action of stromal cell proenkephalin and stem cell transcription factors in prostate cancer differentiation

Background

Loss of prostate cancer differentiation or de-differentiation leads to an untreatable disease. Patient survival would benefit if this can be prevented or reversed. Cancer de-differentiation transforms luminal-like (differentiated) adenocarcinoma into less luminal-like and more stem-like (undifferentiated) small cell carcinoma through a sequential activation of stem cell transcription factors (scTF) POU5F1, LIN28A, SOX2 and NANOG. Like stem cells, prostate small cell carcinoma express this quartet of scTF as well as a 10-fold lower level of β2-microglobulin (B2M) than that of differentiated cell types. In organ development, prostate stromal mesenchyme cells mediate epithelial differentiation in part by secreted factors.

Methods

The identified prostate stromal-specific factor proenkephalin (PENK) was cloned, and transfected into scTF⁺B2M^lo stem-like small cell carcinoma LuCaP 145.1, reprogrammed luminal-like scTF⁻B2M^hi LNCaP, and luminal-like scTF⁻B2M^hi adenocarcinoma LuCaP 70CR. The expression of scTF, B2M and anterior gradient 2 (AGR2) was analyzed in the transfected cells.

Results

PENK caused down-regulation of scTF and up-regulation of B2M to indicate differentiation. When transfected into reprogrammed LNCaP, PENK reversed the reprogramming by down-regulation of scTF with attendant changes in cell appearance and colony morphology. When transfected into LuCaP 70CR, PENK up-regulated the expression of adenocarcinoma antigen AGR2, a marker associated with cancer cell differentiation.

Conclusions

Prostate cancer cells appear to retain their responsiveness to stromal PENK signaling. PENK can induce differentiation to counter de-differentiation caused by scTF activation. The many mutations and aneuploidy characteristic of cancer cells appear not to hinder these two processes. Loss of prostate cancer differentiation is like reprogramming from luminal-like to stem-like.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09090-y.

Expression and purification of a native Thy1-single-chain variable fragment for use in molecular imaging

Molecular imaging using singlechain variable fragments (scFv) of antibodies targeting cancer specific antigens have been considered a non-immunogenic approach for early diagnosis in the clinic. Usually, production of proteins is performed within Escherichia coli. Recombinant proteins are either expressed in E. coli cytoplasm as insoluble inclusion bodies, that often need cumbersome denaturation and refolding processes, or secreted toward the periplasm as soluble proteins that highly reduce the overall yield. However, production of active scFvs in their native form, without any heterologous fusion, is required for clinical applications. In this study, we expressed an anti-thymocyte differentiation antigen-scFv (Thy1-scFv) as a fusion protein with a N-terminal sequence including 3 × hexa-histidines, as purification tags, together with a Trx-tag and a S-tag for enhanced-solubility. Our strategy allowed to recover ~ 35% of Thy1-scFv in the soluble cytoplasmic fraction. An enterokinase cleavage site in between Thy1-scFv and the upstream tags was used to regenerate the protein with 97.7 ± 2.3% purity without any tags. Thy1-scFv showed functionality towards its target on flow cytometry assays. Finally, in vivo molecular imaging using Thy1-scFv conjugated to an ultrasound contrast agent (MBThy1-scFv) demonstrated signal enhancement on a transgenic pancreatic ductal adenocarcinoma (PDAC) mouse model (3.1 ± 1.2 a.u.) compared to non-targeted control (0.4 ± 0.4 a.u.) suggesting potential for PDAC early diagnosis. Overall, our strategy facilitates the expression and purification of Thy1-scFv while introducing its ability for diagnostic molecular imaging of pancreatic cancer. The presented methodology could be expanded to other important eukaryotic proteins for various applications, including but not limited to molecular imaging.

Clinicopathological significance and prognostic value of cancer-associated fibroblasts in prostate cancer patients

INTRODUCTION

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment were considered to play an essential role in tumor growth and development. However, few studies have assessed the prognostic and clinicopathological significance of CAFs in prostate cancer (PCa) patients.

METHODS

One hundred thirty pairs of PCa tissues and normal adjacent tissues (NATs) were immunostained with fibroblast activation protein and α-smooth muscle actin to quantify CAFs. Bioinformatics analysis was used to uncover the possible biological functions of CAFs.

RESULTS

More CAFs were identified in PCa tissues than in NATs. High density of CAFs may be associated with advanced-stage disease, higher Gleason scores, lymphatic metastases, higher PSA, and poor biochemical recurrence-free survival in PCa. Bioinformatics analysis showed that CAFs may regulate tumor progression and recurrence through ECM modification, PI3K-Akt signaling pathway and regulation of cytoskeleton.

CONCLUSION

In summary, our study uncovered the clinicopathological significance and potential mechanism of CAFs and indicated that CAFs may be a useful prognostic biomarker in PCa.

A distinct repertoire of cancer-associated fibroblasts is enriched in cribriform prostate cancer

Outcomes for men with localized prostate cancer vary widely, with some men effectively managed without treatment on active surveillance, while other men rapidly progress to metastatic disease despite curative-intent therapies. One of the strongest prognostic indicators of outcome is grade groups based on the Gleason grading system. Gleason grade 4 prostate cancer with cribriform morphology is associated with adverse outcomes and can be utilized clinically to improve risk stratification. The underpinnings of disease aggressiveness associated with cribriform architecture are not fully understood. Most studies have focused on genetic and molecular alterations in cribriform tumor cells; however, less is known about the tumor microenvironment in cribriform prostate cancer. Cancer-associated fibroblasts (CAFs) are a heterogeneous population of fibroblasts in the tumor microenvironment that impact cancer aggressiveness. The overall goal of this study was to determine if cribriform prostate cancers are associated with a unique repertoire of CAFs. Radical prostatectomy whole-tissue sections were analyzed for the expression of fibroblast markers (ASPN in combination with FAP, THY1, ENG, NT5E, TNC, and PDGFRβ) in stroma adjacent to benign glands and in Gleason grade 3, Gleason grade 4 cribriform, and Gleason grade 4 noncribriform prostate cancer by RNAscope®. Halo® Software was used to quantify percent positive stromal cells and expression per positive cell. The fibroblast subtypes enriched in prostate cancer were highly heterogeneous. Both overlapping and distinct populations of low abundant fibroblast subtypes in benign prostate stroma were enriched in Gleason grade 4 prostate cancer with cribriform morphology compared to Gleason grade 4 prostate cancer with noncribriform morphology and Gleason grade 3 prostate cancer. In addition, gene expression was distinctly altered in CAF subtypes adjacent to cribriform prostate cancer. Overall, these studies suggest that cribriform prostate cancer has a unique tumor microenvironment that may distinguish it from other Gleason grade 4 morphologies and lower Gleason grades.

Identification and validation of a six immune-related gene signature for prediction of biochemical recurrence in localized prostate cancer following radical prostatectomy

Background

Prostate cancer (PCa) is the second lethal heterogeneous cancer among males worldwide, and approximately 20% of PCa patients following radical prostatectomy (RP) will undergo biochemical recurrence (BCR). This study is aimed to identify the immune-related gene signature that can predict BCR in localized PCa following RP.

Methods

Expression profile of genes together with clinical parameters from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus database (GEO) and the immune-related genes from the Molecular Signatures Database v4.0 were applied to construct and validate the gene signature. The Cox regression analyses were conducted to identify the candidate genes and establish the gene signature. To estimate the prognostic power of the risk score, the time-dependent receiver operating characteristic (ROC) analysis and Harrell's index of concordance (C-index) were utilized. We also established a nomogram to forecast the probability of patients' survival.

Results

A total of 268 patients from the TCGA and 77 patients from GSE70770 and six immune-related genes (SCIN, THY1, TBX1, NOTCH4, MAL, BNIP3L) were eventually selected. The Kaplan-Meier analysis demonstrated that patients in the low-risk group had a significantly longer recurrence-free survival (RFS) compared to those in the high-risk group. In the multivariate Cox model, the signature was identified as an independent prognostic factor, which was significantly associated with RFS (TCGA: HR =5.232, 95% CI: 1.762-15.538, P=0.003; GSE70770: HR =2.158, 95% CI: 1.051-4.432, P=0.036). Moreover, the C-index got improved after incorporating the risk score into original clinicopathological parameters. In addition, the novel nomogram was constructed to better predict the 1-, 3- and 5-year RFS.

Conclusions

This signature could serve as an independent prognostic factor for BCR. Incorporation of our signature into traditional risk classification might further stratify patients with different prognosis, which could assist practitioners in developing clinical decision-making.

Targeting cancer stem cells for reversing therapy resistance: mechanism, signaling, and prospective agents

Cancer stem cells (CSCs) show a self-renewal capacity and differentiation potential that contribute to tumor progression and therapy resistance. However, the underlying processes are still unclear. Elucidation of the key hallmarks and resistance mechanisms of CSCs may help improve patient outcomes and reduce relapse by altering therapeutic regimens. Here, we reviewed the identification of CSCs, the intrinsic and extrinsic mechanisms of therapy resistance in CSCs, the signaling pathways of CSCs that mediate treatment failure, and potential CSC-targeting agents in various tumors from the clinical perspective. Targeting the mechanisms and pathways described here might contribute to further drug discovery and therapy.

The mRNA Distribution of Cancer Stem Cell Marker CD90/Thy-1 Is Comparable in Hepatocellular Carcinoma of Eastern and Western Populations

Epidemiology of hepatocellular carcinoma (HCC) showed a correlation between incidence and geographical-relevant risk factors. This study aims to compare the distributions of cancer stem cells (CSC) in two distant populations in Asia and Europe. We analyzed 52 and 43 selected HCC patients undergoing hepatectomy in Ho Chi Minh City (Vietnam) and Trieste (Italy). Each patient sample consisted of HCC, peri-HCC, and non-tumoral (distal) tissue. Demographic data were recorded together with clinical findings. The protocol for the collection of tissue samples and RNA was standardized in both laboratories and gene expression analysis was performed in a single laboratory with identical PCR conditions. Baseline data showed comparable laboratory findings between the two cohorts. mRNA distribution showed a comparable pattern of all CSC markers analyzed with the expression of CD90 progressively increasing from distal and peri-HCC to be highest in HCC (p < 0.001), confirmed by immunofluorescence data. CD90 mRNA distribution was related to HBV-related HCC and a tumor diameter less than 5 cm. Patients with high tumoral CD90 mRNA had a shorter time (p < 0.05) to tumor recurrence compared to patients with lower CD90. This comparative study showed that CD90 mRNA expressions are comparable between Eastern and Western HCC cases.

Toward the Clinical Development and Validation of a Thy1-Targeted Ultrasound Contrast Agent for the Early Detection of Pancreatic Ductal Adenocarcinoma

Early detection of pancreatic ductal adenocarcinoma (PDAC) represents the most significant step toward the treatment of this aggressive lethal disease. Previously, we engineered a preclinical Thy1-targeted microbubble (MBThy1) contrast agent that specifically recognizes Thy1 antigen overexpressed in the vasculature of murine PDAC tissues by ultrasound (US) imaging. In this study, we adopted a single-chain variable fragment (scFv) site-specific bioconjugation approach to construct clinically translatable MBThy1-scFv and test for its efficacy in vivo in murine PDAC imaging, and functionally evaluated the binding specificity of scFv ligand to human Thy1 in patient PDAC tissues ex vivo.

MATERIALS AND METHODS

We recombinantly expressed the Thy1-scFv with a carboxy-terminus cysteine residue to facilitate its thioether conjugation to the PEGylated MBs presenting with maleimide functional groups. After the scFv-MB conjugations, we tested binding activity of the MBThy1-scFv to MS1 cells overexpressing human Thy1 (MS1Thy1) under liquid shear stress conditions in vitro using a flow chamber setup at 0.6 mL/min flow rate, corresponding to a wall shear stress rate of 100 seconds, similar to that in tumor capillaries. For in vivo Thy1 US molecular imaging, MBThy1-scFv was tested in the transgenic mouse model (C57BL/6J - Pdx1-Cre; KRas; Ink4a/Arf) of PDAC and in control mice (C57BL/6J) with L-arginine-induced pancreatitis or normal pancreas. To facilitate its clinical feasibility, we further produced Thy1-scFv without the bacterial fusion tags and confirmed its recognition of human Thy1 in cell lines by flow cytometry and in patient PDAC frozen tissue sections of different clinical grades by immunofluorescence staining.

RESULTS

Under shear stress flow conditions in vitro, MBThy1-scFv bound to MS1Thy1 cells at significantly higher numbers (3.0 ± 0.8 MB/cell; P < 0.01) compared with MBNontargeted (0.5 ± 0.5 MB/cell). In vivo, MBThy1-scFv (5.3 ± 1.9 arbitrary units [a.u.]) but not the MBNontargeted (1.2 ± 1.0 a.u.) produced high US molecular imaging signal (4.4-fold vs MBNontargeted; n = 8; P < 0.01) in the transgenic mice with spontaneous PDAC tumors (2-6 mm). Imaging signal from mice with L-arginine-induced pancreatitis (n = 8) or normal pancreas (n = 3) were not significantly different between the two MB constructs and were significantly lower than PDAC Thy1 molecular signal. Clinical-grade scFv conjugated to Alexa Fluor 647 dye recognized MS1Thy1 cells but not the parental wild-type cells as evaluated by flow cytometry. More importantly, scFv showed highly specific binding to VEGFR2-positive vasculature and fibroblast-like stromal components surrounding the ducts of human PDAC tissues as evaluated by confocal microscopy.

CONCLUSIONS

Our findings summarize the development and validation of a clinically relevant Thy1-targeted US contrast agent for the early detection of human PDAC by US molecular imaging.

The multiple roles of Thy-1 in cell differentiation and regeneration

Thy-1 is a 25-37 kDa glycophosphatidylinositol (GPI)-anchored cell surface protein that was discovered more than 50 years ago. Recent findings have suggested that Thy-1 is expressed on thymocytes, mesenchymal stem cells (MSCs), cancer stem cells, hematopoietic stem cells, fibroblasts, myofibroblasts, endothelial cells, neuronal smooth muscle cells, and pan T cells. Thy-1 plays vital roles in cell migration, adhesion, differentiation, transdifferentiation, apoptosis, mechanotransduction, and cell division, which in turn are involved in tumor development, pulmonary fibrosis, neurite outgrowth, and T cell activation. Studies have increasingly indicated a significant role of Thy-1 in cell differentiation and regeneration. However, despite recent research, many questions remain regarding the roles of Thy-1 in cell differentiation and regeneration. This review aimed to summarize the roles of Thy-1 in cell differentiation and regeneration. Furthermore, since Thy-1 is an outer leaflet membrane protein anchored by GPI, we attempted to address how Thy-1 regulates intracellular pathways through cis and trans signals. Due to the complexity and mystery surrounding the issue, we also summarized the Thy-1-related pathways in different biological processes, and this might provide novel insights in the field of cell differentiation and regeneration.

An EV-Associated Gene Signature Correlates with Hypoxic Microenvironment and Predicts Recurrence in Lung Adenocarcinoma

Extracellular vesicles (EVs) mediate intercellular communications in the tumor microenvironment and contribute to the aggressive phenomenon of cancers. Although EVs in body fluids are supposed to be ideal biomarkers for cancer diagnosis and prognosis, it remains difficult to distinguish the tumor-derived EVs from those released by other tissues. We hypothesized that analyzing the EV-related molecules in tumor tissues would help to estimate the prognostic value of tumor-specific EVs. Here, we investigate the expression of coding genes of proteins carried by small EVs (sEVs) in primary lung adenocarcinoma. Based on the protein-protein interaction network, we identified three network modules (3-PPI-Mod) as a signature that could predict recurrence. This signature was validated in three independent datasets and demonstrated better prognostic value than signature generated from gene expression alone. Meanwhile, the high-risk subgroup assigned by the signature could benefit from adjuvant chemotherapy, although it was not beneficial in unselected patients. Two out of three modules were enriched by proteins identified in sEVs from non-small-cell lung cancer cells. Furthermore, the two modules were remarkably correlated with intratumoral hypoxia score. These results suggest that the 3-PPI-Mod signature was enriched in tumor-derived sEVs and could serve as a prognostic and predictive biomarker for lung adenocarcinoma.

Proteomic Profiling of Human Prostate Cancer-associated Fibroblasts (CAF) Reveals LOXL2-dependent Regulation of the Tumor Microenvironment

In prostate cancer, cancer-associated fibroblasts (CAF) exhibit contrasting biological properties to non-malignant prostate fibroblasts (NPF) and promote tumorigenesis. Resolving intercellular signaling pathways between CAF and prostate tumor epithelium may offer novel opportunities for research translation. To this end, the proteome and phosphoproteome of four pairs of patient-matched CAF and NPF were characterized to identify discriminating proteomic signatures. Samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with a hyper reaction monitoring data-independent acquisition (HRM-DIA) workflow. Proteins that exhibited a significant increase in CAF versus NPF were enriched for the functional categories "cell adhesion" and the "extracellular matrix." The CAF phosphoproteome exhibited enhanced phosphorylation of proteins associated with the "spliceosome" and "actin binding." STRING analysis of the CAF proteome revealed a prominent interaction hub associated with collagen synthesis, modification, and signaling. It contained multiple collagens, including the fibrillar types COL1A1/2 and COL5A1; the receptor tyrosine kinase discoidin domain-containing receptor 2 (DDR2), a receptor for fibrillar collagens; and lysyl oxidase-like 2 (LOXL2), an enzyme that promotes collagen crosslinking. Increased activity and/or expression of LOXL2 and DDR2 in CAF were confirmed by enzymatic assays and Western blotting analyses. Pharmacological inhibition of CAF-derived LOXL2 perturbed extracellular matrix (ECM) organization and decreased CAF migration in a wound healing assay. Further, it significantly impaired the motility of co-cultured RWPE-2 prostate tumor epithelial cells. These results indicate that CAF-derived LOXL2 is an important mediator of intercellular communication within the prostate tumor microenvironment and is a potential therapeutic target.

Up-regulation of THY1 attenuates interstitial pulmonary fibrosis and promotes lung fibroblast apoptosis during acute interstitial pneumonia by blockade of the WNT signaling pathway

Acute interstitial pneumonia (AIP) is an idiopathic pulmonary disease featuring rapid progressive dyspnea and respiratory failure. These symptoms typically develop within several days or weeks in patients without any pre-existing lung disease or external chest disease. Thymocyte differentiation antigen-1 (THY1) has been reported to have an effect on lung fibroblast proliferation and fibrogenic signaling. In this study, the mechanism of THY1 in AIP in influencing pulmonary fibrosis in terms of lung fibroblast proliferation and apoptosis was examined. An AIP mouse model with the pathological changes of lung tissues observed was established to identify the role of THY1 in the pathogenesis of AIP. The expression of THY1, a key regulator of the WNT pathway β-catenin and fibroblasts markers MMP-2, Occludin, α-SMA and Vimentin were determined. Lung fibroblasts of mice were isolated, in which THY1 expression was altered to identify roles THY1 plays in cell viability and apoptosis. A TOP/TOPflash assay was utilized to determine the activation of WNT pathway. Decrement of pulmonary fibrosis was achieved through THY1 up-regulation. The expression of MMP-2, Occludin, α-SMA, Vimentin and β-catenin, and the extent of β-catenin phosphorylation, significantly decreased, thereby indicating that THY1 overexpression inactivated WNT. Cell proliferation was inhibited and apoptosis was accelerated in lung fibroblasts transfected with vector carrying overexpressed THY1. Altogether, this study defines the potential role of THY1 in remission of AIP, via the upregulation of THY1, which renders the WNT pathway inactive. This inactivation of the WNT signaling pathway could alleviate pulmonary fibrosis by reducing lung fibroblast proliferation in AIP. Abbreviations: AIP: Acute interstitial pneumonia; ILDs: interstitial lung diseases; DAD: diffuse alveolar damage; SPF: specific-pathogen-free; NC: negative control; HCMV: human cytomegalovirus; HE: Hematoxylin-eosin; RIPA: radio-immunoprecipitation assay; SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel electrophoresis; BSA: bovine serum albumin; HRP: horseradish peroxidase; ECL: electrochemiluminescence; FBS: fetal bovine serum; DMSO: dimethyl sulfoxide; OD: optical density.

Biological heterogeneity and versatility of cancer-associated fibroblasts in the tumor microenvironment

Increasing lines of evidence show that the malignant behavior of cancer is not exclusively attributable to cancer cells but also radically influenced by cancerous stroma activity and controlled through various mechanisms by the microenvironment. In addition to structural components, such as the extracellular matrix, stromal cells, such as macrophages, endothelial cells, and specifically cancer-associated fibroblasts (CAFs), have attracted substantial attention over recent decades. CAFs provide routes for aggressive carcinomas and contribute to invasion and metastasis through the biochemical alteration and regulation of cancer-related pathways. However, another facet of CAFs that has been neglected by numerous studies is that CAFs might serve as a negative regulator of cancer progression under certain circumstances. The various origins of CAFs, the diverse tissues in which they reside and their interactions with different cancer cells appear to be responsible for this inconsistency. This review summarizes the latest knowledge regarding CAF heterogeneity and offers a novel perspective and a beneficial approach for obtaining an improved understanding of CAFs.

The expressions of HMGA2 and Thy1 in extrahepatic cholangiocarcinoma and their clinicopathological significances

AIMS

Extrahepatic cholangiocarcinoma is a malignant tumor and poor prognosis with intrinsic resistance to cytotoxic agents. The molecular mechanism associated with high malignancy and resistance to chemotherapy and radiotherapy has not been fully elucidated. This study aims to investigate the clinicopathological significances of HMGA2 and Thy1 expression in extrahepatic cholangiocarcinoma.

METHODS

The expressions of HMGA2 and Thy1 in 100 extrahepatic cholangiocarcinoma, 30 peritumoral tissues, 10 adenoma and 15 normal biliary tract tissues were assayed using EnVision immunohistochemistry.

RESULTS

The HMGA2 and Thy1 proteins were overexpression in extrahepatic cholangiocarcinoma compared to peritumoral tissues, adenoma, and normal biliary tract tissues (P < 0.05 or P < 0.01). Adenoma and pericancerous tissues with positive HMGA2 or/and Thy1 protein expression exhibited atypical hyperplasia. The positive correlation was found between the expression of HMGA2 and Thy1 in extrahepatic cholangiocarcinoma (P < 0.01). The positive rates of HMGA2 and Thy1 expression were significantly higher in cases with poor differentiation, lymph node metastasis, invasion, and TNM stage III or IV and no resection (biopsy only) (P < 0.05 or P < 0.01). Kaplan-Meier survival analysis showed that the survival of extrahepatic cholangiocarcinoma patients with positive HMGA2 and/or Thy1 expression is significantly shorter than patients with negative HMGA2 and/or Thy1 expression (P = 0.000). Cox multivariate analysis revealed that positive HMGA2 and/or Thy1 expressions were independently poor prognosis factors in extrahepatic cholangiocarcinoma patients. We calculated the AUC for HMGA2 (AUC = 0.610, 95%CI: 0.519-0.702), or Thy1 (AUC = 0.675, 95%CI: 0.588-0.762), respectively.

CONCLUSIONS

The present study indicated that positive HMGA2 and Thy1 expression are closely associated with the pathogenesis, clinical, pathological and biological behaviors, and poor prognosis in patients with extrahepatic cholangiocarcinoma.

Specific and reliable detection of Myosin 1C isoform A by RTqPCR in prostate cancer cells

Background

Prostate cancer (PC) diagnostics and treatment often present a challenging task due to cancer subtype heterogeneity and differential disease progression in patient subgroups. Hence, the critical issue is finding a reliable and sensitive diagnostic and prognostic PC marker, especially for cases of biopsies with low percentages of cancer cells. Isoform A of myosin 1C was shown to be expressed in PC cells and responsible for their invasive properties, however, its feasibility for diagnostic purposes remains to be elucidated.

Methods

To verify the role of myosin 1C isoform A mRNA expression as a putative prostate cancer marker we performed RT qPCR normalized by three reference genes (GAPDH, YWHAZ, HPRT1) on PC3, RWPE-1, LNCaP and 22Rv1 cell lines. Myosin 1C isoform A detection specificity was confirmed by immunofluorescence staining, cancer and non-cancer prostate cell lines were immunophenotyped by flow cytometry.

Results

Median normalized mRNA expression level of myosin 1C isoform A in PC cells (PC3 and 22Rv1) is two orders of magnitude higher compared to RWPE-1 cells, which functionally correspond to benign prostate cells. Myosin 1C isoform A expression allows PC cell detection even at a dilution ratio of 1:1000 cancer to non-cancer cells. At the protein level, the mean fluorescence intensity of myosin 1C isoform A staining in PC3 nuclei was only twice as high as in RWPE-1, while the immunophenotypes of both cell lines were similar (CD44+/CD90-/CD133-/CD57-/CD24+-).

Conclusions

We report a distinct difference in myosin 1C isoform A mRNA levels in malignant (PC3) and benign (RWPE-1) prostate cell lines and suggest a combination of three reference genes for accurate data normalization. For the first time we provide an immunophenotype comparison of RWPE-1 and PC3 cells and demonstrate that RT qPCR analysis of MYO 1C A using appropriate reference genes is sufficient for PC detection even in low-abundance cancer specimens.

Heterogeneous cancer-associated fibroblast population potentiates neuroendocrine differentiation and castrate resistance in a CD105-dependent manner

Heterogeneous prostatic carcinoma associated fibroblasts (CAF) contribute to tumor progression and resistance to androgen signaling deprivation therapy (ADT). CAF subjected to extended passaging, compared to low passage CAF, were found to lose tumor expansion potential and heterogeneity. Cell surface endoglin (CD105), known to be expressed on proliferative endothelia and mesenchymal stem cells, was diminished in high passage CAF. RNA-sequencing revealed SFRP1 to be distinctly expressed by tumor-inductive CAF, which was further demonstrated to occur in a CD105-dependent manner. Moreover, ADT resulted in further expansion of the CD105⁺ fibroblastic population and downstream SFRP1 in 3-dimensional cultures and patient derived xenograft tissues. In patients, CD105⁺ fibroblasts were found to circumscribe epithelia with neuroendocrine differentiation. CAF-derived SFRP1, driven by CD105 signaling, was necessary and sufficient to induce prostate cancer neuroendocrine differentiation in a paracrine manner. A partially humanized CD105 neutralizing antibody, TRC105, inhibited fibroblastic SFRP1 expression and epithelial neuroendocrine differentiation. In a novel synthetic lethality paradigm, we found that simultaneously targeting the epithelia and its microenvironment with ADT and TRC105, respectively, reduced castrate resistant tumor progression, in a model where either ADT or TRC105 alone had little effect.

Approaches to the discovery of non-invasive urinary biomarkers of prostate cancer

Prostate cancer (PCa) continues to be one of the most common cancers in men worldwide. Prostate specific antigen (PSA) measured in blood has been used for decades as an aid for physicians to detect the presence of prostate cancer. However, the PSA test has limited sensitivity and specificity, leading to unnecessary biopsies, overdiagnosis and overtreatment of patients. For these reasons, there is an urgent need for more accurate PCa biomarkers that can detect PCa with high sensitivity and specificity. Urine is a unique source of potential protein biomarkers that can be measured in a non-invasive way. This review comprehensively summarizes state of the art approaches used in the discovery and validation of urinary biomarkers for PCa. Numerous strategies are currently being used in the discovery of urinary biomarkers for prostate cancer including gel-based separation techniques, mass spectrometry, activity-based proteomic assays and software approaches. Antibody-based approaches remain preferred method for validation of candidate biomarkers with rapidly advancing multiplex immunoassays and MS-based targeted approaches. In the last decade, there has been a dramatic acceleration in the development of new techniques and approaches in the discovery of protein biomarkers for prostate cancer including computational, statistical and data mining methods. Many urinary-based protein biomarkers have been identified and have shown significant promise in initial studies. Examples of these potential biomarkers and the methods utilized in their discovery are also discussed in this review.

Alteration of the Antitumor Immune Response by Cancer-Associated Fibroblasts

Among cells present in the tumor microenvironment, activated fibroblasts termed cancer-associated fibroblasts (CAFs), play a critical role in the complex process of tumor-stroma interaction. CAFs, one of the prominent stromal cell populations in most types of human carcinomas, have been involved in tumor growth, angiogenesis, cancer stemness, extracellular matrix remodeling, tissue invasion, metastasis, and even chemoresistance. During the past decade, these activated tumor-associated fibroblasts have also been involved in the modulation of the anti-tumor immune response on various levels. In this review, we describe our current understanding of how CAFs accomplish this task as well as their potential therapeutic implications.

Bladder cancer cells secrete while normal bladder cells express but do not secrete AGR2

Anterior gradient 2 (AGR2) is a cancer-associated secreted protein found predominantly in adenocarcinomas. Given its ubiquity in solid tumors, cancer-secreted AGR2 could be a useful biomarker in urine or blood for early detection. However, normal organs express and might also secrete AGR2, which would impact its utility as a cancer biomarker. Uniform AGR2 expression is found in the normal bladder urothelium. Little AGR2 is secreted by the urothelial cells as no measurable amounts could be detected in urine. The urinary proteomes of healthy people contain no listing for AGR2. Likewise, the blood proteomes of healthy people also contain no significant peptide counts for AGR2 suggesting little urothelial secretion into capillaries of the lamina propria. Expression of AGR2 is lost in urothelial carcinoma, with only 25% of primary tumors observed to retain AGR2 expression in a cohort of lymph node-positive cases. AGR2 is secreted by the urothelial carcinoma cells as urinary AGR2 was measured in the voided urine of 25% of the cases analyzed in a cohort of cancer vs. non-cancer patients. The fraction of AGR2-positive urine samples was consistent with the fraction of urothelial carcinoma that stained positive for AGR2. Since cancer cells secrete AGR2 while normal cells do not, its measurement in body fluids could be used to indicate tumor presence. Furthermore, AGR2 has also been found on the cell surface of cancer cells. Taken together, secretion and cell surface localization of AGR2 are characteristic of cancer, while expression of AGR2 by itself is not.

Multiplexed targeted mass spectrometry assays for prostate cancer-associated urinary proteins

Biomarkers for effective early diagnosis and prognosis of prostate cancer are still lacking. Multiplexed assays for cancer-associated proteins could be useful for identifying biomarkers for cancer detection and stratification. Herein, we report the development of sensitive targeted mass spectrometry assays for simultaneous quantification of 10 prostate cancer-associated proteins in urine. The diagnostic utility of these markers was evaluated with an initial cohort of 20 clinical urine samples. Individual marker concentration was normalized against the measured urinary prostate-specific antigen level as a reference of prostate-specific secretion. The areas under the receiver-operating characteristic curves for the 10 proteins ranged from 0.75 for CXL14 to 0.87 for CEAM5. Furthermore, MMP9 level was found to be significantly higher in patients with high Gleason scores, suggesting a potential of MMP9 as a marker for risk level assessment. Taken together, our work illustrated the feasibility of accurate multiplexed measurements of low-abundance cancer-associated proteins in urine and provided a viable path forward for preclinical verification of candidate biomarkers for prostate cancer.

Establishment of oral squamous cell carcinoma cell line and magnetic bead-based isolation and characterization of its CD90/CD44 subpopulations

In this study, we describe the establishment of the human papillomavirus 18-positive, stage II, grade 1, T2N0M0 head and neck tumor primary cell line derived from oral squamous cell carcinoma of a non-smoking patient by using two different protocols. Furthermore, a preparation of subpopulations derived from this primary cell line according to the cluster of differentiation molecules CD44/CD90 status using magnetic bead-based separation and their characterization was performed. Impedance-based real-time cell analysis, enzyme-linked immunsorbant assay (ELISA), wound-healing assay, flow-cytometry, gene expression analysis, and MTT assay were used to characterize these four subpopulations (CD44+/CD90-, CD44-/CD90-, CD44+/CD90+, CD44-/CD90-). We optimised methodics for establishement of primary cell lines derived from oral squamous cell carcinoma tissue samples and subsequent separation of mesenchymal (CD90+) and epithelial (CD90-) types of tumorous cells. Primary cell line prepared by using trypsin proteolysis was more viable than the one prepared by using collagenase. According to our results, CD90 separation is a necessary step in preparation of permanent tumor-tissue derived cell lines. Based on the wound-healing assay, CD44+ cells exhibited stronger migratory capacity than CD44- subpopulations. CD44+ subpopulations had also significantly higher expression of BIRC5 and SOX2, lower expression of FLT1 and IL6, and higher levels of basal autophagy compared to CD44- subpopulations. Furthermore, co-cultivation experiments revealed that CD44-/CD90+ cells supported growth of epithelial tumor cells (CD44+/CD90-). On the contrary, factors released by CD44+/CD90+ type of cells seem to have rather inhibiting effect. The most cisplatin-resistant subpopulation with the shortest doubling time was CD44-/CD90+, but this subpopulation had a low migratory capacity.

Thy-1+/- fibroblast subsets in the human peritoneum

Fibrotic thickening of the peritoneum develops in patients receiving peritoneal dialysis (PD) for renal failure. For unknown reasons, however, in some patients it progresses to extensive fibrosis that compromises dialysis capacity of the peritoneum. It is increasingly clear that fibroblasts display large heterogeneity not only between but also within tissues. Differential surface expression of thymocyte differentiation antigen 1 (Thy-1) has been shown to identify functionally distinct fibroblast subsets in several organs. Here, we isolated Thy-1^+/- subsets of human peritoneal fibroblasts (HPFB) and analyzed them in terms of profibrotic myofibroblast features. In healthy individuals, Thy-1⁺ cells constituted ~45% of the HPFB population found in the greater omentum but were not detected in the parietal peritoneum. When propagated in culture and compared with Thy-1^- cells, omentum-derived Thy-1⁺ HPFB consistently displayed an increased expression of α-smooth muscle actin, collagen I, and transforming growth factor-β1. They also showed greater proliferation capacity and enhanced contractile properties. The number of Thy-1⁺ HPFB increased significantly in PD patients and made up more than 70 and 95% of all HPFB found in the omentum and parietal peritoneum, respectively. These data indicate that the expansion of Thy-1⁺ fibroblasts may contribute to fibrotic thickening of the peritoneal membrane during PD.

The fibroblast surface markers FAP, anti-fibroblast, and FSP are expressed by cells of epithelial origin and may be altered during epithelial-to-mesenchymal transition

The identification of fibroblasts and cancer-associated fibroblasts from human cancer tissue using surface markers is difficult, especially because the markers used currently are usually not expressed solely by fibroblasts, and the identification of fibroblast-specific surface molecules is still under investigation. It was aimed to compare three commercially available antibodies in the detection of different surface epitopes of fibroblasts (anti-fibroblast, fibroblast activation protein α, and fibroblast surface protein). The specificity of their expression, employing fibroblast cell lines and tumor-derived fibroblasts from breast and prostate tissues was investigated. Both the established fibroblast cell line HFF-1 and ex vivo primary fibroblasts isolated from breast and prostate cancer tissues expressed the tested surface markers to different degrees. Surprisingly, those markers were expressed also by permanent cell lines of epithelial origin, both benign and cancer-derived (breast-cell lines MCF 10A, HMLE and prostate-cell lines BPH-1, DU 145, and PC-3). The expression of fibroblast activation protein α increased on the surface of previously described models of epithelial cells undergoing epithelial-to-mesenchymal transition in response to treatment with TGF-β1. To prove the co-expression of the fibroblast markers on cells of epithelial origin, we used freshly dissociated human prostate and breast cancer tissues. The results confirmed the co-expression of anti-fibroblast and fibroblast surface protein on CD31/CD45-negative/EpCAM-positive epithelial cells. In summary, our data support the findings that the tested fibroblast markers are not fibroblast specific and may be expressed also by cells of epithelial origin (e.g., cells undergoing EMT). Therefore, the expression of these markers should be interpreted with caution, and the combination of several epitopes for both positive (anti-fibroblast or fibroblast activation protein α) and negative (EpCAM) identification of fibroblasts from breast and prostate tumor tissues is advised. © 2017 International Society for Advancement of Cytometry.

Analysis of Argonaute Complex Bound mRNAs in DU145 Prostate Carcinoma Cells Reveals New miRNA Target Genes

Posttranscriptional gene regulation by microRNAs (miRNAs) contributes to the induction and maintenance of prostate carcinoma (PCa). To identify mRNAs enriched or removed from Ago2-containing RISC complexes, these complexes were immunoprecipitated from normal prostate fibroblasts (PNFs) and the PCa line DU145 and the bound mRNAs were quantified by microarray. The analysis of Ago complexes derived from PNFs or DU145 confirmed the enrichment or depletion of a variety of mRNAs already known from the literature to be deregulated. Novel potential targets were analyzed by luciferase assays with miRNAs known to be deregulated in PCa. We demonstrate that the mRNAs of the death effector domain-containing protein (DEDD), the tumor necrosis factor receptor superfamily, member 10b protein (TNFRSF10B), the tumor protein p53 inducible nuclear protein 1 (TP53INP1), and the secreted protein, acidic, cysteine-rich (SPARC; osteonectin) are regulated by miRNAs miR-148a, miR-20a, miR-24, and miR-29a/b, respectively. Therefore, these miRNAs represent potential targets for therapy. Surprisingly, overexpression of miR-24 induced focus formation and proliferation of DU145 cells, while miR-29b reduced proliferation. The study confirms genes deregulated in PCa by virtue of their presence/absence in the Ago2-complex. In conjunction with the already published miRNA profiles of PCa, the data can be used to identify miRNA-regulated mRNAs.

An efficient method for native protein purification in the selected range from prostate cancer tissue digests

BACKGROUND

Prostate cancer (CP) cells differ from their normal counterpart in gene expression. Genes encoding secreted or extracellular proteins with increased expression in CP may serve as potential biomarkers. For their detection and quantification, assays based on monoclonal antibodies are best suited for development in the clinical setting. One approach to obtain antibodies is to use recombinant proteins as immunogen. However, the synthesis of recombinant protein for each identified candidate is time-consuming and expensive. It is also not practical to generate high quality antibodies to all identified candidates individually. Furthermore, non-native forms (e.g., recombinant) of proteins may not always lead to useful antibodies. Our approach was to purify a subset of proteins from CP tissue specimens for use as immunogen.

METHODS

In the present investigation, ten cancer specimens obtained from cases scored Gleason 3+3, 3+4 and 4+3 were digested by collagenase to single cells in serum-free tissue culture media. Cells were pelleted after collagenase digestion, and the cell-free supernatant from each specimen were pooled and used for isolation of proteins in the 10-30 kDa molecular weight range using a combination of sonication, dialysis and Amicon ultrafiltration. Western blotting and mass spectrometry (MS) proteomics were performed to identify the proteins in the selected size fraction.

RESULTS

The presence of cancer-specific anterior gradient 2 (AGR2) and absence of prostate-specific antigen (PSA)/KLK3 were confirmed by Western blotting. Proteomics also detected AGR2 among many other proteins, some outside the selected molecular weight range, as well.

CONCLUSIONS

Using this approach, the potentially harmful (to the mouse host) exogenously added collagenase was removed as well as other abundant prostatic proteins like ACPP/PAP and AZGP1 to preclude the generation of antibodies against these species. The paper presents an optimized scheme for convenient and rapid isolation of native proteins in any desired size range with minor modifications.

CD90 a potential cancer stem cell marker and a therapeutic target

Cancer Stem Cells (CSCs) have been recently identified and their role in carcinogenesis has been ascertained. CSCs have been correlated with high relapse in certain cancers, multiple drug resistance against chemotherapy and metastasis. Several markers such as CD133, CD24, CD44, EpCAM, and CD26 have been identified to isolate and characterize CSCs. None of these markers or their combinations are universal in nature and can be used to isolate CSCs from all types of cancer. CD90 is one such marker whose expression has been extensively studied in recent years. CD90+ cells have been isolated from several types of tumors and shown to exhibit cardinal properties of CSCs such as proliferation, differentiation, spheroid formation, metastasis and ability to form tumor xenograft in immunodeficient mice. It is also found to be co-expressed with several other CSC markers. CD90 is therefore, suggested as a candidate marker as well as a potential therapeutic target for elimination of CSCs.

Overexpression of Thy1 and ITGA6 is associated with invasion, metastasis and poor prognosis in human gallbladder carcinoma

Gallbladder cancer (GBC) is a rare but highly aggressive cancer for which no well-accepted prognostic biomarkers have been identified. Thymus cell antigen 1 (Thy1), also known as cluster of differentiation (CD)90, and integrin α6 (ITGA6), also known as CD49f, are important molecules in cancer and putative markers of various stem cell types. However, their role in GBC remains to be elucidated. In the present study, Thy1 and ITGA6 expression status in clinical GBC samples, which comprised squamous cell/adenosquamous carcinoma (SC/ASC) and adenocarcinoma (AC) subtypes, was investigated. The associations between Thy1 and ITGA6 expression and clinical parameters and survival rate were analyzed separately. The THY1 and ITGA6 messenger RNA levels were significantly higher in both SC/ASC and AC tissues than in adjacent non-tumor tissues (all P<0.001). These results were subsequently confirmed by immunohistochemical analyses. Overexpression of Thy1 and ITGA6 was correlated with poor differentiation, large tumor size, lymph node metastasis and great invasiveness in SC/ASC (Thy1, P=0.045, P=0.005, P=0.003 and P=0.009, respectively, and ITGA6, P=0.029, P=0.011, P=0.009 and P=0.004, respectively) and AC (Thy1, P=0.027, P<0.001, P=0.003 and P 0.004, respectively, and ITGA6, P=0.002, P=0.003, P=0.006 and P=0.006, respectively). Both Thy1 and ITGA6 were expressed at higher levels in AC with advanced tumor-node-metastasis stage (TNM) than in AC with low TNM stage (P=0.001 and P=0.018, respectively). In addition, patients with elevated Thy1 or ITGA6 expression had shorter overall survival than those with negative Thy1 or ITGA6 expression. Multivariate Cox regression analysis demonstrated that Thy1 (SC/ASC, P=0.001 and AC, P=0.005) and ITGA6 (both P=0.003) were independent predictors of poor prognosis in both SC/ASC and AC patients. In conclusion, Thy1 and ITGA6 could be clinical prognostic markers for GBC.

Cancer-associated fibroblast suppresses killing activity of natural killer cells through downregulation of poliovirus receptor (PVR/CD155), a ligand of activating NK receptor

Cancer-associated fibroblasts (CAFs) play an important role in cancer expansion and progression in tumor microenvironment (TME), via both direct and indirect interactions. Natural killer (NK) cells play a crucial role in anticancer immunity. We investigated the inhibitory effects of CAFs on NK cell activity. CAFs were isolated from endometrial cancer tissue, while normal endometrial fibroblasts (NEFs) were obtained from normal endometrium with no pathological abnormality. NK cells were obtained from allogenic healthy volunteers. CAFs or NEFs were co-cultured at an NK/fibroblast ratio of 1:1 with or without inserted membrane. For NK cell activity, K562 cells were cultured as target cells. NK cell-killing activity was determined by calculating the ratio of PI-positive K562 cells in the presence of NK cells co-cultured with fibroblasts versus NK cells alone. To examine whether NK cell activity was suppressed by IDO pathway, we inhibited IDO activity using the IDO inhibitor 1-MT. We demonstrated that CAFs derived from endometrial cancer induced greater suppression of the killing activity of allogenic NK cells compared with normal endometrial fibroblasts (NEFs). The suppression of NK cell activity by CAFs was inhibited when a membrane was inserted between the CAFs and NK cells, but not by 1-MT, an inhibitor of IDO. We focused on receptor-ligand interactions between CAFs and NK cell and found that cell-surface poliovirus receptor (PVR/CD155), a ligand of activating NK receptor DNAM-1, was downregulated in the CAFs compared with NEFs. To confirm whether PVR downregulation results in the decrease of NK cell-killing activity, PVR expression in NEFs was knocked down using siRNA against PVR (PVRsi). NK cell activity was suppressed by co-culture with PVR-knockdown NEFs, to a similar extent than CAF-induced suppression. CAFs showed increased suppression of NK cell-killing activity compared with NEFs, due to decreased PVR cell surface expression, a ligand of an NK activating receptor. This study demonstrated a novel mechanism of suppression of NK cell activity by CAFs in the TME.