Expression of the E-cadherin repressors Snail, Slug and Zeb1 in urothelial carcinoma of the urinary bladder: relation to stromal fibroblast activation and invasive behaviour of carcinoma cells

Bladder cancer immune-related markers: diagnosis, surveillance, and prognosis

As an immune-related tumor type, bladder cancer has been attracting much attention in the study of its markers. In recent years, researchers have made rapid progress in the study of immune-related markers for bladder cancer. Studies have shown that immune-related markers play an important role in the diagnosis, prognosis assessment and treatment of bladder cancer. In addition, the detection of immune-related markers can also be used to evaluate the efficacy of immunotherapy and predict the treatment response of patients. Therefore, in depth study of the expression of immune-related markers in bladder cancer and their application in the clinic is of great significance and is expected to provide new breakthroughs for individualized treatment of bladder cancer. Future studies will focus more on how to detect immune-related markers with low cost and high accuracy, as well as develop new immunotherapeutic strategies to bring better therapeutic outcomes to bladder cancer patients.

LncRNA MEG3 Inhibits the Epithelial-mesenchymal Transition of Bladder Cancer Cells through the Snail/E-cadherin Axis

OBJECTIVE

This study aimed to investigate the role of the long noncoding RNA (lncRNA) maternally expressed gene 3 (MEG3) in the epithelial-mesenchymal transition (EMT) of bladder cancer cells and the potential mechanisms.

METHODS

Cell invasion, migration, and wound healing assays were conducted to assess the effects of MEG3 on the invasive and migratory capabilities of bladder cancer cells. The expression levels of E-cadherin were measured using Western blotting, RT-qPCR, and dual luciferase reporter assays. RNA immunoprecipitation and pull-down assays were performed to investigate the interactions between MEG3 and its downstream targets.

RESULTS

MEG3 suppressed the invasion and migration of bladder cancer cells and modulated the transcription of E-cadherin. The binding of MEG3 to the zinc finger region of the transcription factor Snail prevented its ability to transcriptionally repress E-cadherin. Additionally, MEG3 suppressed the phosphorylation of extracellular regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK), and P38, thereby decreasing the expression of Snail and stimulating the expression of E-cadherin.

CONCLUSION

MEG3 plays a vital role in suppressing the EMT in bladder cancer cells, indicating its potential as a promising therapeutic target for the treatment of bladder cancer.

Immunomodulatory Precision: A Narrative Review Exploring the Critical Role of Immune Checkpoint Inhibitors in Cancer Treatment

An immune checkpoint is a signaling pathway that regulates the recognition of antigens by T-cell receptors (TCRs) during an immune response. These checkpoints play a pivotal role in suppressing excessive immune responses and maintaining immune homeostasis against viral or microbial infections. There are several FDA-approved immune checkpoint inhibitors (ICIs), including ipilimumab, pembrolizumab, and avelumab. These ICIs target cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed death ligand 1 (PD-L1). Furthermore, ongoing efforts are focused on developing new ICIs with emerging potential. In comparison to conventional treatments, ICIs offer the advantages of reduced side effects and durable responses. There is growing interest in the potential of combining different ICIs with chemotherapy, radiation therapy, or targeted therapies. This article comprehensively reviews the classification, mechanism of action, application, and combination strategies of ICIs in various cancers and discusses their current limitations. Our objective is to contribute to the future development of more effective anticancer drugs targeting immune checkpoints.

Characterization and verification of CAF-relevant prognostic gene signature to aid therapy in bladder cancer

Cancer-associated fibroblasts (CAFs) are significantly involved in determining the patient's prognosis and response to bladder cancer (BLCA) therapy. CAFs can induce epithelial-mesenchymal transformation (EMT) as well as complex interaction with immune cells. Hence, it is imperative to identify potential markers for enhancing our understanding of CAFs in BLCA progression and immune regulation. A variety of algorithms and analyses were employed in the study, leading to the development of a novel prognostic feature for CAFs-Stromal-EMT (CSE)-prognostic feature. This feature was constructed based on the genes MFAP5, PCOLCE2, and JUN. Furthermore, we revealed that patients with higher CSE risk scores responded to immunotherapy better compared to those with lower. Finally, we verified two CSE-related genes using in vitro experiments. Our results suggested that the CSE-prognostic feature could predict the prognosis and evaluate the response of patients to immune and chemotherapies. This would aid clinicians in designing treatment strategies for patients with BLCA.

Tumorigenic effects of human mesenchymal stromal cells and fibroblasts on bladder cancer cells

Background

Patients with muscle-invasive bladder cancer face a poor prognosis due to rapid disease progression and chemoresistance. Thus, there is an urgent need for a new therapeutic treatment. The tumor microenvironment (TME) has crucial roles in tumor development, growth, progression, and therapy resistance. TME cells may also survive standard treatment of care and fire up disease recurrence. However, whether specific TME components have tumor-promoting or tumor-inhibitory properties depends on cell type and cancer entity. Thus, a deeper understanding of the interaction mechanisms between the TME and cancer cells is needed to develop new cancer treatment approaches that overcome therapy resistance. Little is known about the function and interaction between mesenchymal stromal cells (MSC) or fibroblasts (FB) as TME components and bladder cancer cells.

Methods

We investigated the functional impact of conditioned media (CM) from primary cultures of different donors of MSC or FB on urothelial carcinoma cell lines (UCC) representing advanced disease stages, namely, BFTC-905, VMCUB-1, and UMUC-3. Underlying mechanisms were identified by RNA sequencing and protein analyses of cancer cells and of conditioned media by oncoarrays.

Results

Both FB- and MSC-CM had tumor-promoting effects on UCC. In some experiments, the impact of MSC-CM was more pronounced. CM augmented the aggressive phenotype of UCC, particularly of those with epithelial phenotype. Proliferation and migratory and invasive capacity were significantly increased; cisplatin sensitivity was reduced. RNA sequencing identified underlying mechanisms and molecules contributing to the observed phenotype changes. NRF2 and NF-κB signaling was affected, contributing to improved cisplatin detoxification. Likewise, interferon type I signaling was downregulated and regulators of epithelial mesenchymal transition (EMT) were increased. Altered protein abundance of CXCR4, hyaluronan receptor CD44, or TGFβ-signaling was induced by CM in cancer cells and may contribute to phenotypical changes. CM contained high levels of CCL2/MCP-1, MMPs, and interleukins which are well known for their impact on other cancer entities.

Conclusions

The CM of two different TME components had overlapping tumor-promoting effects and increased chemoresistance. We identified underlying mechanisms and molecules contributing to the aggressiveness of bladder cancer cells. These need to be further investigated for targeting the TME to improve cancer therapy.

The role of cancer-associated fibroblasts in bladder cancer progression

Cancer-associated fibroblasts (CAFs) are key stromal cells in the tumor microenvironment (TME) that critically contribute to cancer initiation and progression. In bladder cancer (BCa), there is emerging evidence that BCa CAFs are actively involved in cancer cell proliferation, invasion, metastasis, and chemotherapy resistance. This review outlines the present knowledge of BCa CAFs, with a particular emphasis on their origin and function in BCa progression, and provides further insights into their clinical application.

HIV-1 Proteins gp120 and Tat Promote Epithelial-Mesenchymal Transition and Invasiveness of HPV-Positive and HPV-Negative Neoplastic Genital and Oral Epithelial Cells

The incidence of human papillomavirus (HPV)-associated anogenital and oropharyngeal cancer in human immunodeficiency virus (HIV)-infected individuals is substantially higher than in HIV-uninfected individuals. HIV may also be a risk factor for the development of HPV-negative head and neck, liver, lung, and kidney cancer. However, the molecular mechanisms underlying HIV-1-associated increase of epithelial malignancies are not fully understood. Here, we showed that HPV-16-immortalized anal AKC-2 and cervical CaSki epithelial cells that undergo prolonged exposure to cell-free HIV-1 virions or HIV-1 viral proteins gp120 and tat respond with the epithelial-mesenchymal transition (EMT) and increased invasiveness. Similar responses were observed in HPV-16-infected SCC-47 and HPV-16-negative HSC-3 oral epithelial cancer cells that were cultured with these viral proteins. EMT induced by gp120 and tat led to detachment of poorly adherent cells from the culture substratum; these cells remained capable of reattachment, upon which they coexpressed both E-cadherin and vimentin, indicative of an intermediate stage of EMT. The reattached cells also expressed stem cell markers CD133 and CD44, which may play a critical role in cancer cell invasion and metastasis. Inhibition of transforming growth factor (TGF)-β1 and MAPK signaling and vimentin expression, and restoration of E-cadherin expression reduced HIV-induced EMT and the invasive activity of HPV-16-immortalized anal and cervical epithelial cells. Collectively, our results suggest that these approaches along with HIV viral suppression with antiretroviral therapy (ART) might be useful to limit the role of HIV-1 infection in the acceleration of HPV-associated or HPV-independent epithelial neoplasia. IMPORTANCE HPV-16-immortalized genital and oral epithelial cells and HPV-negative oral cancer cells that undergo prolonged contact with cell-free HIV-1 virions or with viral proteins gp120 and tat respond by becoming more invasive. EMT cells induced by HIV-1 in cultures of HPV-16-immortalized anal and cervical epithelial cells express the stem cell markers CD133 and CD44. These results suggest that the interaction of HIV-1 with neoplastic epithelial cells may lead to their de-differentiation into cancer stem cells that are resistant to apoptosis and anti-cancer drugs. Thus, this pathway may play a critical role in the development of invasive cancer. Inhibition of TGF-β1 and MAPK signaling and vimentin expression, and restoration of E-cadherin expression reduced HIV-induced EMT and the invasiveness of HPV-16-immortalized anal and cervical epithelial cells. Taken together, these results suggest that these approaches might be exploited to limit the role of HIV-1 infection in the acceleration of HPV-associated or HPV-independent epithelial neoplasia.

Chronic Arsenic Exposure Upregulates the Expression of Basal Transcriptional Factors and Increases Invasiveness of the Non-Muscle Invasive Papillary Bladder Cancer Line RT4

The bladder is a target organ for inorganic arsenic, a carcinogen and common environmental contaminant found in soil and water. Urothelial carcinoma (UC) is the most common type of bladder cancer (BC) that develops into papillary or non-papillary tumors. Papillary tumors are mostly non-muscle invasive (NMIUC), easier treated, and have a better prognosis. Urothelial carcinoma can be molecularly sub-typed as luminal or basal, with papillary tumors generally falling into the luminal category and basal tumors exclusively forming muscle invasive urothelial carcinomas (MIUC). It is unclear why some UCs develop more aggressive basal phenotypes. We hypothesized that chronic arsenic exposure of a papillary luminal bladder cancer would lead to the development of basal characteristics and increase in invasiveness. We treated the human papillary bladder cancer cell line RT4 with 1 µM arsenite (As³⁺) for twenty passages. Throughout the study, key luminal and basal gene/protein markers in the exposed cells were evaluated and at passage twenty, the cells were injected into athymic mice to evaluate tumor histology and measure protein markers using immunohistochemistry. Our data indicates that chronic As³⁺- treatment altered cellular morphology and decreased several luminal markers in cell culture. The histology of the tumors generated from the As³⁺-exposed cells was similar to the parent (non-treated) however, they appeared to be more invasive in the liver and displayed elevated levels of some basal markers. Our study demonstrates that chronic As³⁺ exposure is able to convert a non-invasive papillary bladder cancer to an invasive form that acquires some basal characteristics.

A review of the biology and therapeutic implications of cancer-associated fibroblasts (CAFs) in muscle-invasive bladder cancer

Cancer-associated fibroblasts (CAFs) play a fundamental role in the development of cancers and their response to therapy. In recent years, CAFs have returned to the spotlight as researchers work to unpick the mechanisms by which they impact tumour evolution and therapy responses. However, study of CAFs has largely been restricted to a select number of common cancers, whereas research into CAF biology in bladder cancer has been relatively neglected. In this review, we explore the basics of CAF biology including the numerous potential cellular origins of CAFs, alongside mechanisms of CAF activation and their diverse functionality. We find CAFs play an important role in the progression of bladder cancer with significant implications on tumour cell signaling, epithelial to mesenchymal transition and the capacity to modify components of the immune system. In addition, we highlight some of the landmark papers describing CAF heterogeneity and find trends in the literature to suggest that the iCAF and myCAF subtypes defined in bladder cancer share common characteristics with CAF subtypes described in other settings such as breast and pancreatic cancer. Moreover, based on findings in other common cancers we identify key therapeutic challenges associated with CAFs, such as the lack of specific CAF markers, the paucity of research into bladder-specific CAFs and their relationship with therapies such as radiotherapy. Of relevance, we describe a variety of strategies used to target CAFs in several common cancers, paying particular attention to TGFβ signaling as a prominent regulator of CAF activation. In doing so, we find parallels with bladder cancer that suggest CAF targeting may advance therapeutic options in this setting and improve the current poor survival outcomes in bladder cancer which sadly remain largely unchanged over recent decades.

Cancer-associated fibroblasts in breast cancer: Challenges and opportunities

The tumor microenvironment is proposed to contribute substantially to the progression of cancers, including breast cancer. Cancer-associated fibroblasts (CAFs) are the most abundant components of the tumor microenvironment. Studies have revealed that CAFs in breast cancer originate from several types of cells and promote breast cancer malignancy by secreting factors, generating exosomes, releasing nutrients, reshaping the extracellular matrix, and suppressing the function of immune cells. CAFs are also becoming therapeutic targets for breast cancer due to their specific distribution in tumors and their unique biomarkers. Agents interrupting the effect of CAFs on surrounding cells have been developed and applied in clinical trials. Here, we reviewed studies examining the heterogeneity of CAFs in breast cancer and expression patterns of CAF markers in different subtypes of breast cancer. We hope that summarizing CAF-related studies from a historical perspective will help to accelerate the development of CAF-targeted therapeutic strategies for breast cancer.

MicroRNA-370-3p shuttled by breast cancer cell-derived extracellular vesicles induces fibroblast activation through the CYLD/Nf-κB axis to promote breast cancer progression

Breast cancer is a malignancy arising in the mammary epithelial tissues. Recent studies have indicated the abundance of microRNAs (miRNAs) in extracellular vesicles (EVs), and their interactions have been illustrated to exert crucial roles in the cell-to-cell communication. The present study focused on investigating whether EV-delivered miR-370-3p affects breast cancer. Initially, the miR-370-3p expression pattern was examined in the cancer-associated fibroblasts (CAFs), normal fibroblasts (NFs), and cancerous cells-derived EVs. The relation of miR-370-3p to CYLD was assessed using luciferase activity assay. Afterwards, based on ectopic expression and depletion experiments in the MCF-7 breast cancer cells, we evaluated stemness, migration, invasion, and sphere formation ability, and EMT, accompanied with measurement on the expression patterns of pro-inflammatory factors and nuclear factor-kappa B (NF-κB) signaling-related genes. Finally, tumorigenesis and proliferation were analyzed in vivo using a nude mouse xenograft model. The in vitro experiments revealed that breast cancer cell-derived EVs promoted NF activation, while activated fibroblasts contributed to enhanced stemness, migration, invasion, as well as EMT of cancerous cells. In addition, EVs could transfer miR-370-3p from breast cancer cells to NFs, and EV-encapsulated miR-370-3p was also found to facilitate fibroblast activation. Mechanistically, EV-encapsulated miR-370-3p downregulated the expression of CYLD through binding to its 3'UTR and activated the NF-κB signaling pathway, thereby promoting the cellular functions in vitro and in vivo in breast cancer. Taken together, EVs secreted by breast cancer cells could carry miR-370-3p to aggravate breast cancer through downregulating CYLD expression and activating the NF-κB signaling pathway.

Identification of the Functions and Prognostic Values of RNA Binding Proteins in Bladder Cancer

Post-transcriptional regulation plays a leading role in gene regulation and RNA binding proteins (RBPs) are the most important posttranscriptional regulatory protein. RBPs had been found to be abnormally expressed in a variety of tumors and is closely related to its occurrence and progression. However, the exact mechanism of RBPs in bladder cancer (BC) is unknown. We downloaded transcriptomic data of BC from the Cancer Genome Atlas (TCGA) database and used bioinformatics techniques for subsequent analysis. A total of 116 differentially expressed RBPs were selected, among which 61 were up-regulated and 55 were down-regulated. We then identified 12 prognostic RBPs including CTIF, CTU1, DARS2, ENOX1, IGF2BP2, LIN28A, MTG1, NOVA1, PPARGC1B, RBMS3, TDRD1, and ZNF106, and constructed a prognostic risk score model. Based on this model we found that patients in the high-risk group had poorer overall survival (P < 0.001), and the area under the receiver operator characteristic curve for this model was 0.677 for 1 year, 0.697 for 3 years, and 0.709 for 5 years. Next, we drew a nomogram based on the risk score and other clinical variables, which showed better predictive performance. Our findings contribute to a better understanding of the pathogenesis, progression and metastasis of BC. The model of these 12 genes has good predictive value and may have good prospects for improving clinical treatment regimens and patient prognosis.

MDM2 induces EMT via the B‑Raf signaling pathway through 14‑3‑3

MDM2 proto-oncogene, E3 ubiquitin protein ligase (MDM2) is a well-known oncogene and has been reported to be closely associated with epithelial-to-mesenchymal transition (EMT). The present study first demonstrated that the expression levels of MDM2 were markedly increased in TGF-β-induced EMT using quantitative PCR and western blotting. In addition, MDM2 was demonstrated to be associated with pathological grade in clinical glioma samples by immunohistochemical staining. Furthermore, overexpression of MDM2 promoted EMT in glioma, lung cancer and breast cancer cell lines using a scratch wound migration assay. Subsequently, the present study explored the mechanism by which MDM2 promoted EMT and revealed that MDM2 induced EMT by upregulating EMT-related transcription factors via activation of the B-Raf signaling pathway through tyrosine 3-monooxygenase activation protein ε using RNA sequencing and western blotting. This mechanism depended on the p53 gene. Furthermore, in vivo experiments and the colony formation experiment demonstrated that MDM2 could promote tumor progression and induce EMT via the B-Raf signaling pathway. Since EMT contributes to increased drug resistance in tumor cells, the present study also explored the relationship between MDM2 and drug sensitivity using an MTT assay, and identified that MDM2 promoted cell insensitivity to silibinin treatment in an EMT-dependent manner. This finding is crucial for the development of cancer therapies and can also provide novel research avenues for future biological and clinical studies.

Advances in bladder cancer biology and therapy

The field of research in bladder cancer has seen significant advances in recent years. Next-generation sequencing has identified the genes most mutated in bladder cancer. This wealth of information allowed the definition of driver mutations, and identification of actionable therapeutic targets, as well as a clearer picture of patient prognosis and therapeutic direction. In a similar vein, our understanding of the cellular aspects of bladder cancer has grown. The identification of the cellular geography and the populations of different cell types and quantifications of normal and abnormal cell types in tumours provide a better prediction of therapeutic response. Non-invasive methods of diagnosis, including liquid biopsies, have seen major advances as well. These methods will likely find considerable utility in assessing minimal residual disease following treatment and for early-stage diagnosis. A significant therapeutic impact on patients with bladder cancer is found in the use of immune checkpoint inhibitor therapeutics. These therapeutics have been shown to cure some patients with bladder cancer and significantly decrease adverse events. These developments provide patients with better monitoring opportunities, unique therapeutic options and greater hope for prolonged survival.

miR-30b-5p modulate renal epithelial-mesenchymal transition in diabetic nephropathy by directly targeting SNAI1

OBJECT

Renal tubulointerstitial fibrosis plays a significant role in the development of diabetic nephropathy (DN). SNAI1 is a main activator of epithelial-to-mesenchymal transition (EMT) in the process of fibrosis. This study aimed to investigate the effect of miR-30b-5p targeting SNAI1 on the EMT in DN.

METHODS

Bioinformatics and miRNAs microarray analyses were used to predict the candidate miRNA targeting SNAI1, that is miR-30b-5p. The db/db mice was as DN animal model and renal tissues of mice were stained with PAS. The miR-30b-5p expression in mouse and human renal tissue were examined by quantitative RT-PCR (qRT-PCR) and fluorescence in situ hybridization (FISH), while SNAI1 expression was determined by qRT-PCR and immunohistochemistry. Luciferase reporter gene assay was used to confirm miR-30b-5p directly target 3'-UTR of the SNAI1 mRNA. In vitro, HK-2 cells were treated with high glucose to establish hyperglycemia cell model and transfected with miR-30b-5p mimics to overexpress miR-30b-5p. Expression of miR-30b-5p, SNAI1 and EMT related indicators (E-cadherin, a-SMA and Vimentin) in HK-2 cells under different treatments were determined by qRT-PCR and/or western-blot. In addition, immunofluorescence was performed to evaluate a-SMA expression in HK-2 cells under different treatments.

RESULTS

Bioinformatics analyses revealed miR-30b-5p had complementary sequences with SNAI1 mRNA and the seed region of miR-30b-5p was conserved in human and a variety of animals, including mice. Microarray analysis showed miR-30b expression decreased in DN mice, which was further verified in db/db mice by qRT-PCR and in human DN by FISH. Contrary to miR-30b-5p, SNAI1 expression level was upregulated in db/db mice. Correlation analysis suggested SNAI1 mRNA level was negatively with miR-30b-5p level in renal tissue of db/db mice. Luciferase reporter gene assay confirmed miR-30b-5p directly targeted SNAI1 mRNA. In high glucose induced HK-2 cells, expression levels of miR-30b-5p and E-cadherin were decreased, while SNAI1, a-SMA and Vimentin were increased. Overexpression miR-30b-5p in high glucose induced HK-2 cells could reverse that phenomenon to some extent.

CONCLUSION

These findings suggest that miR-30b-5p play a protective role by targeting SNAI1 in renal EMT in DN.

PIK3CA Is Regulated by CUX1, Promotes Cell Growth and Metastasis in Bladder Cancer via Activating Epithelial-Mesenchymal Transition

PIK3CA is a key component of phosphatidylinositol 3-kinase (PI3K) pathway that its involvement in tumorigenesis has been revealed by previous research. However, its functions and potential mechanisms in bladder cancer are still largely undiscovered. Tissue microarray (TMA) with 66 bladder cancer patients was surveyed via immunohistochemistry to evaluate the level of PIK3CA and CUX1 and we found upregulation of PIK3CA in bladder cancer tissue and patients with higher level of PIK3CA presented with poorer prognosis. Overly expressed PIK3CA promoted growth, migration, invasion, and metastasis of bladder cancer cells and knockdown of PIK3CA had the opposite effect. Gain-of-function and loss-of-function studies showed that PIK3CA expression was facilitated by CUX1, leading to activation of epithelial-mesenchymal transition (EMT), accompanied by upregulated expression of Snail, β-catenin, Vimentin and downregulated expression of E-cadherin in the bladder cancer cell lines. Besides, over-expressed CUX1 could restore the expression of downregulated Snail, β-catenin, Vimentin and E-cadherin which was induced by PIK3CA knockdown. These results revealed that PIK3CA overexpression in bladder cancer was regulated by the transcription factor CUX1, and PIK3CA exerted its biological effects by activating EMT.

15-Deoxy-Δ12,14-prostaglandin J2 Induces Epithelial-to-mesenchymal Transition in Human Breast Cancer Cells and Promotes Fibroblast Activation

In inflammation-associated carcinogenesis, COX-2 is markedly overexpressed, resulting in accumulation of various prostaglandins. 15-deoxy-Δ^12,14-prostaglandin J₂ (15d-PGJ₂) is one of the terminal products of COX-2-catalyzed arachidonic acid catabolism with oncogenic potential. Epithelial-to-mesenchymal transition (EMT) is a process by which epithelial cells lose their polarity and adhesiveness, and thereby gain migratory and invasive properties. Treatment of human breast cancer MCF-7 cells with 15d-PGJ₂ induced EMT as evidenced by increased expression of Snail and ZEB1, with concurrent down-regulation of E-cadherin. Nuclear extract from 15d-PGJ₂-treated MCF-7 cells showed the binding of Snail and ZEB1 to E-box sequences present in the E-cadherin promoter, which accounts for repression of E-catherin expression. Unlike 15d-PGJ₂, its non-electrophilic analogue 9,10-dihydro-15d-PGJ₂ failed to induce EMT, suggesting that the α,β-unsaturated carbonyl group located in the cyclopentenone ring of 15d-PGJ₂ is essential for its oncogenic function. Notably, the mRNA level of interleukin-8 (IL-8)/CXCL8 was highly elevated in 15d-PGJ₂-stimulated MCF-7 cells. 15d-PGJ₂-induced up-regulation of IL-8/CXCL8 expression was abrogated by silencing of Snail short interfering RNA. Treatment of normal fibroblast with conditioned medium obtained from cultures of MCF-7 cells undergoing EMT induced the expression of activated fibroblast marker proteins, α-smooth muscle actin and fibroblasts activation protein-α. Co-culture of normal fibroblasts with 15d-PGJ₂-stimulated MCF-7 cells also activated normal fibroblast cells to cancer associated fibroblasts. Taken together, above findings suggest that 15d-PGJ₂ induces EMT through up-regulation of Snail expression and subsequent production of CXCL8 as a putative activator of fibroblasts, which may contribute to tumor-stroma interaction in inflammatory breast cancer microenvironment.

Plantamajoside inhibits hypoxia-induced migration and invasion of human cervical cancer cells through the NF-κB and PI3K/akt pathways

Plantamajoside (PMS) is a major compound of Plantago asiatica and possesses anti-tumor property in several types of cancers. However, the effect of PMS on cervical cancer has not been investigated. This study aimed to investigate the effect of PMS on the migration and invasion of cervical cancer cell lines under hypoxic condition. Our results demonstrated that PMS significantly inhibited hypoxia-caused increases in cell migration and invasion of cervical cancer cells. The hypoxia-induced epithelial-mesenchymal transition (EMT) process was prevented by PMS with increased E-cadherin expression, and decreased expression levels of N-cadherin and vimentin in cervical cancer cells. Besides, the expression levels of transcription factors slug and snail were suppressed by PMS in hypoxia-induced cervical cancer cells. The increased mRNA and protein levels of hypoxia-inducible factor 1alpha (HIF-1α) in hypoxia-induced cervical cancer cells were prevented by PMS. Furthermore, PMS blocked the hypoxia-induced activation of NF-κB and PI3K/Akt pathway in cervical cancer cells. Taken together, these findings suggest that PMS exerted an anti-tumor activity in cervical cancer through preventing the hypoxia-induced EMT. Thus, PMS might serve as a therapeutic agent for the treatment of cervical cancer.

A Complex and Evolutive Character: Two Face Aspects of ECM in Tumor Progression

Tumor microenvironment, including extracellular matrix (ECM) and stromal cells, is a key player during tumor development, from initiation, growth and progression to metastasis. During all of these steps, remodeling of matrix components occurs, changing its biochemical and physical properties. The global and basic cancer ECM model is that tumors are surrounded by activated stromal cells, that remodel physiological ECM to evolve into a stiffer and more crosslinked ECM than in normal conditions, thereby increasing invasive capacities of cancer cells. In this review, we show that this too simple model does not consider the complexity, specificity and heterogeneity of each organ and tumor. First, we describe the general ECM in context of cancer. Then, we go through five invasive and most frequent cancers from different origins (breast, liver, pancreas, colon, and skin), and show that each cancer has its own specific matrix, with different stromal cells, ECM components, biochemical properties and activated signaling pathways. Furthermore, in these five cancers, we describe the dual role of tumor ECM: as a protective barrier against tumor cell proliferation and invasion, and as a major player in tumor progression. Indeed, crosstalk between tumor and stromal cells induce changes in matrix organization by remodeling ECM through invadosome formation in order to degrade it, promoting tumor progression and cell invasion. To sum up, in this review, we highlight the specificities of matrix composition in five cancers and the necessity not to consider the ECM as one general and simple entity, but one complex, dynamic and specific entity for each cancer type and subtype.

During mitosis ZEB1 "switches" from being a chromatin-bound epithelial gene repressor, to become a microtubule-associated protein

Microtubules are polymers of α/β-tubulin, with microtubule organization being regulated by microtubule-associated proteins (MAPs). Herein, we describe a novel role for the epithelial gene repressor, zinc finger E-box-binding homeobox 1 (ZEB1), that "switches" from a chromatin-associated protein during interphase, to a MAP that associates with α-, β- and γ-tubulin during mitosis. Additionally, ZEB1 was also demonstrated to associate with γ-tubulin at the microtubule organizing center (MTOC). Using confocal microscopy, ZEB1 localization was predominantly nuclear during interphase, with α/β-tubulin being primarily cytoplasmic and the association between these proteins being minimal. However, during the stages of mitosis, ZEB1 co-localization with α-, β-, and γ-tubulin was significantly increased, with the association commonly peaking during metaphase in multiple tumor cell-types. ZEB1 was also observed to accumulate in the cleavage furrow during cytokinesis. The increased interaction between ZEB1 and α-tubulin during mitosis was also confirmed using the proximity ligation assay. In contrast to ZEB1, its paralog ZEB2, was mainly perinuclear and cytoplasmic during interphase, showing some co-localization with α-tubulin during mitosis. Considering the association between ZEB1 with α/β/γ-tubulin during mitosis, studies investigated ZEB1's role in the cell cycle. Silencing ZEB1 resulted in a G₂-M arrest, which could be mediated by the up-regulation of p21^Waf1/Cip1 and p27^Kip1 that are known downstream targets repressed by ZEB1. However, it cannot be excluded the G₂/M arrest observed after ZEB1 silencing is not due to its roles as a MAP. Collectively, ZEB1 plays a role as a MAP during mitosis and could be functionally involved in this process.

Fibroblasts in urothelial bladder cancer define stroma phenotypes that are associated with clinical outcome

Little attention was given to the interaction between tumor and stromal cells in urothelial bladder carcinoma (UBC). While recent studies point towards the existence of different fibroblast subsets, no comprehensive analyses linking different fibroblast markers to UBC patient survival have been performed so far. Through immunohistochemical analysis of five selected fibroblast markers, namely alpha smooth muscle actin (ASMA), CD90/Thy-1, fibroblast activation protein (FAP), platelet derived growth factor receptor-alpha and -beta (PDGFRa,-b), this study investigates their association with survival and histopathological characteristics in a cohort of 344 UBC patients, involving both, muscle-invasive and non-muscle-invasive cases. The data indicates that combinations of stromal markers are more suited to identify prognostic patient subgroups than single marker analysis. Refined stroma-marker-based patient stratification was achieved through cluster analysis and identified a FAP-dominant patient cluster as independent marker for shorter 5-year-survival (HR(95% CI)2.25(1.08–4.67), p = 0.030). Analyses of interactions between fibroblast and CD8a-status identified a potential minority of cases with CD90-defined stroma and high CD8a infiltration showing a good prognosis of more than 80% 5-year-survival. Presented analyses point towards the existence of different stroma-cell subgroups with distinct tumor-modulatory properties and motivate further studies aiming to better understand the molecular tumor–stroma crosstalk in UBC.

The Interaction of CDH20 With β-Catenin Inhibits Cervical Cancer Cell Migration and Invasion via TGF-β/Smad/SNAIL Mediated EMT

Cancer-associated cadherin 20 (CDH20) is a novel identified cadherin that is genetically altered in several types of human cancer, including cervical cancer. However, its involvement in the progression of cervical cancer remains unknown. In this study, we show that CDH20 was downregulated in clinical cervical cancer samples and its expression correlated with cervical cancer clinical features. CDH20 negatively regulated the migration and invasion of cervical cancer cells. CDH20 increased the expression and promoted the cytoplasm and membrane translocation of β-catenin, and interacted with β-catenin. Mechanistically, CDH20/β-catenin suppressed transforming growth factor-β (TGF-β)-induced epithelial-to-mesenchymal transition (EMT) by downregulating Snail through reducing the phosphorylation and nuclear translocation of Smad2/3. Taken together, our data suggest that CDH20 may act as a tumor suppressor that interacts with β-catenin to inhibit cervical cancer cell migration and invasion via TGF-β/Smad/Snail mediated EMT.

Epigenetics of Bladder Cancer: Where Biomarkers and Therapeutic Targets Meet

Bladder cancer (BC) is the most common neoplasia of the urothelial tract. Due to its high incidence, prevalence, recurrence and mortality, it remains an unsolved clinical and social problem. The treatment of BC is challenging and, although immunotherapies have revealed potential benefit in a percentage of patients, it remains mostly an incurable disease at its advanced state. Epigenetic alterations, including aberrant DNA methylation, altered chromatin remodeling and deregulated expression of non-coding RNAs are common events in BC and can be driver events in BC pathogenesis. Accordingly, these epigenetic alterations are now being used as potential biomarkers for these disorders and are being envisioned as potential therapeutic targets for the future management of BC. In this review, we summarize the recent findings in these emerging and exciting new aspects paving the way for future clinical treatment of this disease.

Oct4 mediates Müller glia reprogramming and cell cycle exit during retina regeneration in zebrafish

The rapid induction of pluripotency-inducing factor Oct4 in the injured retina necessitates the de novo induction of stem cells and their subsequent cell cycle exit.

Octamer-binding transcription factor 4 (Oct4, also known as Pou5F3) is an essential pluripotency-inducing factor, governing a plethora of biological functions during cellular reprogramming. Retina regeneration in zebrafish involves reprogramming of Müller glia (MG) into a proliferating population of progenitors (MGPCs) with stem cell–like characteristics, along with up-regulation of pluripotency-inducing factors. However, the significance of Oct4 during retina regeneration remains elusive. In this study, we show an early panretinal induction of Oct4, which is essential for MG reprogramming through the regulation of several regeneration-associated factors such as Ascl1a, Lin28a, Sox2, Zeb, E-cadherin, and various miRNAs, namely, let-7a, miR-200a/miR-200b, and miR-143/miR-145. We also show the crucial roles played by Oct4 during cell cycle exit of MGPCs in collaboration with members of nucleosome remodeling and deacetylase complex such as Hdac1. Notably, Oct4 regulates Tgf-β signaling negatively during MG reprogramming, and positively to cause cycle exit of MGPCs. Our study reveals unique mechanistic involvement of Oct4, during MG reprogramming and cell cycle exit in zebrafish, which may also account for the inefficient retina regeneration in mammals.

The coexpression of fibroblast activation protein (FAP) and basal-type markers (CK 5/6 and CD44) predicts prognosis in high-grade invasive urothelial carcinoma of the bladder

High-grade urothelial carcinoma (UC) of the bladder is a heterogeneous disease with dismal prognosis. Bladder tumors with basal phenotype are intrinsically aggressive, and morphological parameters that define disease staging remain main prognosticators. We intend to evaluate the role of cancer-associated fibroblasts (CAFs) in the prognosis of bladder cancer and its association with basal and luminal phenotypes. Clinical and pathological parameters, including the immunohistochemical expression of fibroblast activation protein (FAP) and markers of basal (CK5/6, CD44) and luminal (CK20, GATA3) phenotypes, have been investigated in a series of 121 patients with UC of the bladder treated by radical cystectomy with lymph node dissection, and their implication in long-term cancer-specific survival has been evaluated. A cytoplasmic immunostaining of FAP in CAFs implies worse disease-specific survival (hazard ratio [HR] = 1.68; P = .048). FAP expression is associated with tumor staging (P < .0001), with best discrimination at T2a/T2b level, and with negative expression of markers of luminal phenotype, such as CK20 (P < .0001) and GATA3 (P = .005). In the multivariate analysis, simultaneous expression of FAP, CK5/6, and CD44 is a strong prognosticator of disease-specific survival (HR = 2.3; P = .001), together with nodal invasion (HR = 3.47; P < .0001) and bladder infiltration up to deep muscle or beyond (HR = 2.47; P = .02). There is no association between positive FAP expression in primary tumor and nodal disease (P = .22). FAP expression in CAFs favors tumor invasion in high-grade invasive UC of the bladder with basal phenotype. This new immunohistochemical marker could be added to the routine immunohistochemical protocol to predict clinical behavior in these patients.

Targeting Oncogenic Nuclear Factor Kappa B Signaling with Redox-Active Agents for Cancer Treatment

SIGNIFICANCE

Nuclear factor kappa B (NF-κB) signaling is essential under physiologically relevant conditions. However, aberrant activation of this pathway plays a pertinent role in tumorigenesis and contributes to resistance. Recent Advances: The importance of the NF-κB pathway means that its targeting must be specific to avoid side effects. For many currently used therapeutics and those under development, the ability to generate reactive oxygen species (ROS) is a promising strategy.

CRITICAL ISSUES

As cancer cells exhibit greater ROS levels than their normal counterparts, they are more sensitive to additional ROS, which may be a potential therapeutic niche. It is known that ROS are involved in (i) the activation of NF-κB signaling, when in sublethal amounts; and (ii) high levels induce cytotoxicity resulting in apoptosis. Indeed, ROS-induced cytotoxicity is valuable for its capabilities in killing cancer cells, but establishing the potency of ROS for effective inhibition of NF-κB signaling is necessary. Indeed, some cancer treatments, currently used, activate NF-κB and may stimulate oncogenesis and confer resistance.

FUTURE DIRECTIONS

Thus, combinatorial approaches using ROS-generating agents alongside conventional therapeutics may prove an effective tactic to reduce NF-κB activity to kill cancer cells. One strategy is the use of thiosemicarbazones, which form redox-active metal complexes that generate high ROS levels to deliver potent antitumor activity. These agents also upregulate the metastasis suppressor, N-myc downstream regulated gene 1 (NDRG1), which functions as an NF-κB signaling inhibitor. It is proposed that targeting NF-κB signaling may proffer a new therapeutic niche to improve the efficacy of anticancer regimens.

The microRNA-15a-PAI-2 axis in cholangiocarcinoma-associated fibroblasts promotes migration of cancer cells

BACKGROUND

Cholangiocarcinoma (CCA) has an abundance of tumor stroma which plays an important role in cancer progression via tumor-promoting signals. This study aims to explore the microRNA (miRNA) profile of CCA-associated fibroblasts (CCFs) and the roles of any identified miRNAs in CCA progression.

METHODS

miRNA expression profiles of CCFs and normal skin fibroblasts were compared by microarray. Identified downregulated miRNAs and their target genes were confirmed by real-time PCR. Their binding was confirmed by a luciferase reporter assay. The effects of conditioned-media (CM) of miRNA mimic- and antagonist-transfected CCFs were tested in CCA migration in wound healing assays. Finally, the levels of miRNA and their target genes were examined by real-time PCR and immunohistochemistry in clinical CCA samples.

RESULTS

miR-15a was identified as a downregulated miRNA in CCFs. Moreover, PAI-2 was identified as a novel target gene of miR-15a. Recombinant PAI-2 promoted migration of CCA cells. Moreover, CM from miR-15a mimic-transfected CCFs suppressed migration of CCA cells. Lower expression of miR-15a and higher expression of PAI-2 were observed in human CCA samples compared with normal liver tissues. Importantly, PAI-2 expression correlated with poor prognosis in CCA patients.

CONCLUSIONS

These findings highlight the miR-15a/PAI-2 axis as a potential therapeutic target in CCA patients.

Stromal Clues in Endometrial Carcinoma: Loss of Expression of β-Catenin, Epithelial-Mesenchymal Transition Regulators, and Estrogen-Progesterone Receptor

Supplemental Digital Content is available in the text.

Epithelial-stroma interactions in the endometrium are known to be responsible for physiological functions and emergence of several pathologic lesions. Periglandular stromal cells act on endometrial cells in a paracrine manner through sex hormones. In this study, we immunohistochemically evaluated the expression of epithelial-mesenchymal transition regulators (SNAIL/SLUG, TWIST, ZEB1), adhesion molecules (β-catenin and E-cadhenin), estrogen (ER)-progesterone (PR) receptor and their correlation with each other in 30 benign, 148 hyperplastic (EH), and 101 endometrioid-type endometrial carcinoma (EC) endometria. In the epithelial component, loss of expression in E-cadherin, ER and PR, and overexpression of TWIST and ZEB1 were significantly higher in EC than in EH (P<0.01). In the periglandular stromal component, β-catenin and SNAIL/SLUG expression were significantly higher in normal endometrium and simple without atypical EH compared with complex atypical EH and EC (P<0.01). In addition, periglandular stromal TWIST expression was significantly higher in EH group compared with EC (P<0.05). There was significantly negative correlation between β-catenin and ER, TWIST and ER, and TWIST and PR in hyperplastic and carcinomatous glandular epithelium, whereas there was a significantly positive correlation between β-catenin and SNAIL-SLUG, β-catenin and TWIST, β-catenin and ER, β-catenin and PR, SNAIL-SLUG and ER, SNAIL-SLUG and PR, TWIST and ER, TWIST and PR, in periglandular/cancer-associated stromal cells (P<0.01). In conclusion, the pattern of positive and negative correlations in the expression of epithelial-mesenchymal transition regulators (SNAIL-SLUG and TWIST), sex hormone receptors (ER and PR), and β-catenin between ECs and hyperplasia, as well as between epithelium and stroma herein, is suggestive of a significant role for these proteins and their underlying molecular processes in the development of endometrial carcinomas.

Prognostic significance of E-cadherin and ZEB1 expression in intraductal papillary mucinous neoplasm

There is an urgent need to investigate the genetic changes that occur in intraductal papillary mucinous neoplasm (IPMN), which is a well-known precursor of pancreatic cancer. In this study, gene expression profiling was performed by removing unwanted variation to determine the differentially expressed genes (DEGs) associated with malignant progression of IPMN. Among the identified DEGs, zinc finger E-box binding homeobox 1 (ZEB1) and E-cadherin, a crucial regulator of epithelial-to-mesenchymal transition (EMT), was validated among identified DEGs.

A total of 76 fresh-frozen tissues were used for gene expression profiling and formalin-fixed, paraffin-embedded blocks from 87 patients were obtained for immunohistochemical analysis. Loss of E-cadherin expression (p = 0.023, odd ratio [OR] = 4.923) and expression of ZEB1 in stromal cells (stromal ZEB1, p < 0.001, OR = 26.800) were significantly correlated with degree of dysplasia. The hazard of death was significantly increased in patients with loss of E-cadherin expression (hazard ratio [HR] = 13.718, p = 0.004), expression of epithelial ZEB1 (HR = 19.117, p = 0.001), and stromal ZEB1 (HR = 6.373, p = 0.043).

Based on the results of this study, loss of E-cadherin and expression of stromal ZEB1 are associated with increased risk of malignant progression. Epithelial and stromal ZEB1, as well as E-cadherin may be strong predictors of survival in patients with IPMN. Our finding suggests that these EMT markers may be utilized as potential prognosticators and may be used to improve and personalize treatment of IPMN.

Effects of silencing Rab27a gene on biological characteristics and chemosensitivity of non-small cell lung cancer

Rab27a, a member of the Rab protein family, can regulate the tumor microenvironment and promote the development of the tumor. Elevated expression of Rab27a is closely connected with many human cancers containing non-small cell lung cancer (NSCLC). But the role of Rab27a in non-small cell lung cancer and its possible mechanism is particularly unclear. In this research, we explored the effect of silencing Rab27a in vitro and in vivo, furnishing evidence that Rab27a could be a potential therapeutic target in NSCLC. Compared with corresponding control cells, silencing Rab27a had decreased ability of cell proliferation, migration and invasion in vitro and slower growth of xenograft tumors in mice. The expressions of apoptosis-associated proteins were induced with a reduction of anti-apoptotic protein in the NSCLC cells down-regulated Rab27a. Furthermore, Rab27a was associated with resistance to conventional chemotherapeutic agents. Our findings suggested that Rab27a might play a critical role in increasing chemosensitivity in NSCLC.

An FGFR inhibitor converts the tumor promoting effect of TGF-β by the induction of fibroblast-associated genes of hepatoma cells

Tumors consistently mimic wound-generating chronic inflammation; however, why they do not heal like wounds with fibrotic scars remains unknown. The components of the tumor microenvironment, such as transforming growth factor β (TGF-β) and fibroblast growth factors (FGFs), may account for this phenomenon. Tumor formation involves continuous activation of the FGF pathway, whereas the repair of tissue injury is a self-limiting process accompanied with controlled activation of the FGF pathway. In the tumor microenvironment TGF-β increases the secretion of FGFs, further promoting the malignant biological properties of tumors. However, during wound healing, sufficient TGF-β together with moderate FGFs lead to matrix deposition and the formation of fibrotic scars. In the present study, TGF-β1 combined with AZD4547, an FGF receptor (FGFR) inhibitor, transformed hepatoma cells into less malignant fibroblast-like cells with respect to morphology, physiological properties, and gene expression profiles. In vivo experiments showed that TGF-β1 combined with AZD4547 not only inhibited tumor growth but also promoted tumor parenchyma fibrosis. Our results indicate that FGFR inhibitor treatment converts the effect of TGF-β on the hepatocellular carcinoma cells from tumor promotion into tumor inhibition by enhancing the induction effect of TGF-β on some fibroblast-associated genes. Converting human liver cancer cells into less malignant fibroblast-like cells and inducing tumor parenchyma cell fibrosis provides an alternative strategy for limiting tumor progression.

Stroma-regulated HMGA2 is an independent prognostic marker in PDAC and AAC

Background:

The HMGA2 protein has experimentally been linked to EMT and cancer stemness. Recent studies imply that tumour–stroma interactions regulate these features and thereby contribute to tumour aggressiveness.

Methods:

We analysed 253 cases of pancreatic ductal adenocarcinoma (PDAC) and 155 cases of ampullary adenocarcinoma (AAC) for HMGA2 expression by IHC. The data were correlated with stroma abundance and supplemented by experimental studies.

Results:

HMGA2 acts as an independent prognostic marker associated with a significantly shorter overall survival in both tumour types. Overall, HMGA2-positivity was more frequent in patients with PDAC than with AAC. The HMGA2 status in tumour cells significantly correlated with the abundance of PDGFRβ-defined stroma cells. In vivo co-injection of Panc-1 cancer cells with pancreatic stellate cells increased tumour growth in a manner associated with increased HMGA2 expression. Furthermore, in vitro treatment of Panc-1 with conditioned media from PDGF-BB-activated stellate cells increased their ability to form tumour spheroids.

Conclusions:

This study identifies HMGA2 expression in tumour cells as an independent prognostic marker in PDAC and AAC. Correlative data analysis gives novel tissue-based evidence for a heterotypic cross-talk with stroma cells as a possible mechanism for HMGA2 induction, which is further supported by experimental models.

Specificity protein 1: Its role in colorectal cancer progression and metastasis

Specificity protein 1 (Sp1) is a widely expressed transcription factor that plays an important role in the promotion of oncogenes required for tumor survival, progression and metastasis. Sp1 is highly expressed in several cancers including colorectal cancer (CRC) and is related to poor prognosis. Therefore, targeting Sp1 is a rational for CRC therapy. In this review, we will recapitulate the current understanding of Sp1 signaling, its molecular mechanisms, and its potential involvement in CRC growth, progression and metastasis. We will also discuss the current therapeutic drugs for CRC and their mechanism of action via Sp1.

Effects of increased Kindlin-2 expression in bladder cancer stromal fibroblasts

Kindlin-2 is a focal adhesion protein highly expressed in bladder cancer stromal fibroblasts. We investigated the prognostic significance of Kindlin-2 in bladder cancer stromal fibroblasts and evaluated the effects of Kindlin-2 on the malignant behaviors of tumor cells. Immunohistochemical staining of 203 paraffin-embedded bladder cancer tissues showed that Kindlin-2 expression correlated with advanced stage, high grade, and relapse of bladder cancer. Kaplan-Meier survival analysis demonstrated that patients exhibiting high Kindlin-2 expression had shorter survival times than those with low Kindlin-2 expression (p < 0.01). Multivariate analysis revealed that high Kindlin-2 expression leads to poor prognosis in bladder cancer. Using cancer-associated fibroblasts (CAFs) isolated from human bladder cancer tissue, we observed that Kindlin-2 knockdown decreased CAFs activation, resulting in decreased expression of α-smooth muscle actin (α-SMA) and the extracellular matrix protein fibronectin. Kindlin-2 suppression also reduced CAF-induced bladder cancer cell migration and invasion. Moreover, we found that Kindlin-2 activates CAFs and promotes the invasiveness of bladder cancer cells by stimulating TGF-β-induced epithelial-mesenchymal transition. These results support targeting Kindlin-2 and the corresponding activated CAFs in bladder cancer therapy.

Cardamonin, a chalcone, inhibits human triple negative breast cancer cell invasiveness by downregulation of Wnt/β-catenin signaling cascades and reversal of epithelial-mesenchymal transition

Cardamonin (CD), an active chalconoid, has shown potent anticancer effects in preclinical studies; however, the effect and underlying mechanism of CD for the treatment of triple negative breast cancer (TNBC) is unclear. This study aims to examine the cytotoxic effects of CD and investigate the underlying mechanism in human TNBC cells. The results show that CD exhibits cytotoxicity by inducing apoptosis and cell cycle arrest in TNBC cells via modulation of Bcl-2, Bax, cyt-C, cleaved caspase-3, and PARP. We find that CD significantly increases expression of the epithelial marker E-cadherin, while reciprocally decreasing expression of mesenchymal markers such as snail, slug, and vimentin in BT-549 cells. In parallel with epithelial-mesenchymal transition (EMT) reversal, CD down regulates invasion and migration of BT-549 cells. CD markedly reduces stability and nuclear translocation of β-catenin, accompanied with downregulation of β-catenin target genes. Using the TopFlash luciferase reporter assay, we reveal CD as a specific inhibitor of the Wnt3a-induced signaling. These results suggest the involvement of the Wnt/β-catenin signaling in the CD-induced EMT reversion of BT-549 cells. Notably, CD restores the glycogen synthase kinase-3β (GSK3β) activity, required for β-catenin destruction via the proteasome-mediated system, by inhibiting the phosphorylation of GSK3β by Akt. These occurrences ultimately lead to the blockage of EMT and the invasion of TNBC cells. Further antitumor activity of CD was tested in 4T1 (TNBC cells) induced tumor and it was found that CD significantly inhibited the tumor volume at dose of 5 mg/kg-treated mice. © 2016 BioFactors, 43(2):152-169, 2017.

A common framework for EMT and collective cell migration

During development, cells often switch between static and migratory behaviours. Such transitions are fundamental events in development and are linked to harmful consequences in pathology. It has long been considered that epithelial cells either migrate collectively as epithelial cells, or undergo an epithelial-to-mesenchymal transition and migrate as individual mesenchymal cells. Here, we assess what is currently known about in vivo cell migratory phenomena and hypothesise that such migratory behaviours do not fit into alternative and mutually exclusive categories. Rather, we propose that these categories can be viewed as the most extreme cases of a general continuum of morphological variety, with cells harbouring different degrees or combinations of epithelial and mesenchymal features and displaying an array of migratory behaviours.

A Polycomb-mir200 loop regulates clinical outcome in bladder cancer

Bladder cancer (BC) is a highly prevalent disease, ranking fifth in the most common cancers worldwide. Various miRNAs have recently emerged as potential prognostic biomarkers in cancer. The miR-200 family, which repressed the epithelial-to-mesenchymal transition (EMT), is repressed in multiple advanced cancers. However, its expression and function in BC is still poorly understood. Here we show that miR-200 family displays increased expression, probably due to the activation of specific oncogenic signaling pathways, and reduced promoter methylation, in BC compared to normal bladder samples. Furthermore, we show that the expression of these miRNAs is decreased in high grade and stage tumors, and the down-regulation is associated with patient's poor clinical outcome. Our data indicate that the miR-200 family plays distinct roles in Non-Muscle (NMIBC) and Muscle-Invasive BC (MIBC). In MIBC, miR-200 expression post transcriptionally regulates EMT-promoting transcription factors ZEB1 and ZEB2, whereas suppresses BMI1 expression in NMIBC. Interestingly, we show that increased EZH2 and/or BMI1 expression repress the expression of miR-200 family members. Collectively, these findings support a model of BC progression through a coordinated action between the Polycomb Repression Complex (PRC) members repressing the miR-200 expression, which ultimately favors invasive BC development. Since pharmacological inhibition of EZH2 in BC cell lines lead to increased miR-200 expression, our findings may support new therapeutic strategies for BC clinical management.

The hallmarks of CAFs in cancer invasion

The ability of cancer cells to move out of the primary tumor and disseminate through the circulation to form metastases is one of the main contributors to poor patient outcome. The tumor microenvironment provides a niche that supports cancer cell invasion and proliferation. Carcinoma-associated fibroblasts (CAFs) are a highly enriched cell population in the tumor microenvironment that plays an important role in cancer invasion. However, it remains unclear whether CAFs directly stimulate cancer cell invasion or they remodel the extracellular matrix to make it more permissive for invasion. Here we discuss paracrine communication between cancer cells and CAFs that promotes tumor invasion but also stimulates CAFs to remodel the matrix increasing cancer dissemination.

Detection of Soluble ED-A(+) Fibronectin and Evaluation as Novel Serum Biomarker for Cardiac Tissue Remodeling

Background and Aims. Fibronectin containing the extra domain A (ED-A⁺ Fn) was proven to serve as a valuable biomarker for cardiac remodeling. The study was aimed at establishing an ELISA to determine ED-A⁺ Fn in serum of heart failure patients. Methods. ED-A⁺ Fn was quantified in serum samples from 114 heart failure patients due to ischemic (ICM, n = 44) and dilated (DCM, n = 39) cardiomyopathy as well as hypertensive heart disease (HHD, n = 31) compared to healthy controls (n = 12). Results. In comparison to healthy volunteers, heart failure patients showed significantly increased levels of ED-A⁺ Fn (p < 0.001). In particular in ICM patients there were significant associations between ED-A⁺ Fn serum levels and clinical parameters, for example, increased levels with rising NYHA class (p = 0.013), a negative correlation with left ventricular ejection fraction (p = 0.026, r: −0.353), a positive correlation with left atrial diameter (p = 0.008, r: 0.431), and a strong positive correlation with systolic pulmonary artery pressure (p = 0.002, r: 0.485). In multivariate analysis, ED-A⁺ Fn was identified as an independent predictor of an ischemic heart failure etiology. Conclusions. The current study could clearly show that ED-A⁺ Fn is a promising biomarker in cardiovascular diseases, especially in heart failure patients due to an ICM. We presented a valid ELISA method, which could be applied for further studies investigating the value of ED-A⁺ Fn.

[Tumour-stroma interactions in urothelial cancer]

BACKGROUND

The histopathological structure of malignant tumours involves two essential compartments - the tumour parenchyma with the actual transformed cells, and the supportive tumour stroma. The latter consists of specialized mesenchymal cells, such as fibroblasts, macrophages, lymphocytes and vascular cells, as well as of their secreted products, including components of the extracellular matrix, matrix modifying enzymes and numerous regulatory growth factors and cytokines. In consequence, the tumour stroma has the ability to influence virtually all aspects of tumour development and progression, including therapeutic response.

AIM

In this article we review the current knowledge of tumor stroma interactions in urothelial carcinoma and present various experimental systems that are currently in use to unravel the biological basis of these heterotypic cell interactions.

RESULTS

For urothelial carcinoma, an extensive tumour stroma is quite typical and markers of activated fibroblasts correlate significantly with clinical parameters of advanced disease. Another clinically important variable is provided by the stromal expression of syndecan-1.

CONCLUSION

Integration of markers of activated stroma into clinical risk evaluation could aid to better stratification of urothelial bladder carcinoma patients. Elucidation of biological mechanisms underlying tumour-stroma interactions could provide new therapeutical targets.

The emerging role of Snail1 in the tumor stroma

The transcription factor Snail1 leads to the epithelial-mesenchymal transition by repressing the adherent and tight junctions in epithelial cells. This process is related to an increase of cell migratory and mesenchymal properties during both embryonic development and tumor progression. Although Snail1 expression is very limited in adult animals, emerging evidence has placed Snail at the forefront of medical science. As a transcriptional repressor, Snail1 confers cancer stem cell-like traits on tumor cells and promotes drug resistance, tumor recurrence and metastasis. In this review, we summarize recent reports that suggest the pro-tumorigenic roles of Snail1 expression in tumor stroma. The crosstalk between tumor and stromal cells mediated by Snail1 regulates paracrine communication, pro-tumorigenic abilities of cancer cells, extracellular matrix characteristics and mesenchymal differentiation in cancer stem cells and cancer-associated fibroblasts. Therefore, understanding the regulation and functional roles of Snail1 in the tumor microenvironment will provide us with new therapies for treating metastatic disease.

CXCR4 pharmacogical inhibition reduces bone and soft tissue metastatic burden by affecting tumor growth and tumorigenic potential in prostate cancer preclinical models

BACKGROUND

The majority of prostate cancer (Pca) patient morbidity can be attributed to bone metastatic events, which poses a significant clinical obstacle. Therefore, a better understanding of this phenomenon is imperative and might help to develop novel therapeutic strategies. Stromal cell-derived factor 1α (SDF-1α) and its receptor CXCR4 have been implicated as regulators of bone resorption and bone metastatic development, suggesting that agents able to suppress this signaling pathway may be used as pharmacological treatments. In this study we studied if two CXCR4 receptor antagonists, Plerixafor and CTE9908, may affect bone metastatic disease induced by Pca in preclinical experimental models

METHODS

To verify the hypothesis that CXCR4 inhibition affects Pca metastatic disease, selective CXCR4 compounds, Plerixafor, and CTE9908, were tested in preclinical models known to generate bone lesions. Additionally, the expression levels of CXCR4 and SDF-1α were analyzed in a number of human tissues derived from primary tumors, lymph-nodes and osseous metastases of Pca as well as in a wide panel of human Pca cell lines to non-tumorigenic and tumorigenic phenotype.

RESULTS

Bone-derived Pca cells express higher CXCR4 levels than other Pca cell lines. This differential expression was also observed in human Pca samples. In vitro evidence supports the hypothesis that factors produced by bone microenvironment differentially sustain CXCR4 and SDF1-α expression with respect to prostate microenvironment determining increased efficacy toward Plerixafor. The use of SDF1-α neutralizing antibodies greatly reduced the increase of CXCR4 expression in cells co-cultured with bone stromal cells (BMSc) and to a lesser extent in cells co-cultured with prostate stromal cells (HPSc) and partially reduced SDF1-α Plerixafor efficacy. SDF-1α induced tumor cell migration and invasion, as well as MMP-9, MMP-2, and uPA expression, which were reduced by Plerixafor. The incidence of X-ray detectable bone lesions was significantly reduced following Plerixafor and CTE9908 treatment Kaplan-Meier probability plots showed a significant improvement in the overall survival of mice treated with Plerixafor and CTE9908. The reduced intra-osseous growth of PC3 and PCb2 tumor cells after intratibial injection, as a result of Plerixafor and CTE9908 treatment, correlated with decreased osteolysis and serum levels of both mTRAP and type I collagen fragments (CTX), which were significantly lower with respect to controls.

CONCLUSIONS

Our report provides novel information on the potential activity of CXCR4 inhibitors on the formation and progression of Pca bone and soft tissue metastases and supports a biological rationale for the use of these inhibitors in men at high risk to develop clinically evident bone lesions.

TGFβ1 secreted by cancer-associated fibroblasts induces epithelial-mesenchymal transition of bladder cancer cells through lncRNA-ZEB2NAT

Urinary bladder cancer (UBC) patients at muscle invasive stage have poor clinical outcome, due to high propensity for metastasis. Cancer-associated fibroblasts (CAFs), one of the principal constituents of the tumor stroma, play an important role in tumor development. However, it is unclear whether CAFs from UBC induce cell invasion and which signaling pathway is involved. Herein, we found that conditional medium from UBC CAFs (CAF-CM) enhanced the invasion of UBC cells. CAF-CM induced the epithelial-mesenchymal transition (EMT) by regulating expression levels of EMT-associated markers in UBC cells. Higher concentration of TGFβ1 in CAF-CM, comparing with the CM from adjacent normal fibroblast, led to phosphorylation of Smad2 in UBC cells. Additionally, inhibition of TGFβ1 signaling decreased the EMT-associated gene expression, and cancer cell invasion. Interestingly, a long non-coding RNA, ZEB2NAT, was demonstrated to be essential for this TGFβ1-dependent process. ZEB2NAT depletion reversed CAF-CM-induced EMT and invasion of cancer cells, as well as reduced the ZEB2 protein level. Consistently, TGFβ1 mRNA expression is positively correlated with ZEB2NAT transcript and ZEB2 protein levels in human bladder cancer specimens. Our data revealed a novel mechanism that CAFs induces EMT and invasion of human UBC cells through the TGFβ1-ZEB2NAT-ZEB2 axis.

Expression of E-cadherin repressors SNAIL, ZEB1 and ZEB2 by tumour and stromal cells influences tumour-budding phenotype and suggests heterogeneity of stromal cells in pancreatic cancer

Background:

There is evidence that tumour–stroma interactions have a major role in the neoplastic progression of pancreatic ductal adenocarcinoma (PDAC). Tumour budding is thought to reflect the process of epithelial–mesenchymal transition (EMT); however, the relationship between tumour buds and EMT remains unclear. Here we characterize the tumour-budding- and stromal cells in PDAC at protein and mRNA levels concerning factors involved in EMT.

Methods:

mRNA in situ hybridisation and immunostaining for E-cadherin, β-catenin, SNAIL1, ZEB1, ZEB2, N-cadherin and TWIST1 were assessed in the main tumour, tumour buds and tumour stroma on multipunch tissue microarrays from 120 well-characterised PDACs and associated with the clinicopathological features, including peritumoural (PTB) and intratumoural (ITB) budding.

Results:

Tumour-budding cells showed increased levels of ZEB1 (P<0.0001) and ZEB2 (P=0.0119) and reduced E-cadherin and β-catenin (P<0.0001, each) compared with the main tumour. Loss of membranous β-catenin in the main tumour (P=0.0009) and tumour buds (P=0.0053), without nuclear translocation, as well as increased SNAIL1 in tumour and stromal cells (P=0.0002, each) correlated with high PTB. ZEB1 overexpression in the main tumour-budding and stromal cells was associated with high ITB (P=0.0084; 0.0250 and 0.0029, respectively) and high PTB (P=0.0005; 0.0392 and 0.0007, respectively). ZEB2 overexpression in stromal cells correlated with higher pT stage (P=0.03), lymphatic invasion (P=0.0172) and lymph node metastasis (P=0.0152).

Conclusions:

In the tumour microenvironment of phenotypically aggressive PDAC, tumour-budding cells express EMT hallmarks at protein and mRNA levels underlining their EMT-type character and are surrounded by stromal cells expressing high levels of the E-cadherin repressors ZEB1, ZEB2 and SNAIL1, this being strongly associated with the tumour-budding phenotype. Moreover, our findings suggest the existence of subtypes of stromal cells in PDAC with phenotypical and functional heterogeneity.

Malignancy of bladder cancer cells is enhanced by tumor-associated fibroblasts through a multifaceted cytokine-chemokine loop

The microenvironment of tumor cells is critically involved in tumor development and progression. Tumor-associated fibroblasts (TAFs) represent a major constituent of the tumor stroma. Tumor cells are operative in the activation of TAFs, whereas TAFs in turn contribute to tumor cell malignancy. This report describes mechanisms of communication between fibroblasts and urinary bladder cancer (UBC) cells. Migration of bladder cancer cell lines RT112 and Cal-29, representing two different grades of dedifferentiation, was enhanced by cocultivation with TAFs. Conditioned medium from tumor cells induced the release of interleukin (IL)-8, hepatocyte growth factor (HGF), matrix metalloproteinase-2, granulocyte macrophage colony-stimulating factor, and monocyte chemotactic protein (MCP)-1 by TAFs. Tumor cell-derived IL-1α was identified as a major mediator of these stimulatory effects. Fibroblasts, on the other hand, exerted a migration and invasion stimulating influence on UBC cells. MCP-1 and HGF were shown to promote cell migration of both bladder cancer cell lines.

Urokinase-type plasminogen activator receptor (uPAR) expression is associated with T-stage and survival in urothelial carcinoma of the bladder

OBJECTIVES

To evaluate the expression-and localization pattern of the urokinase-type plasminogen activator receptor (uPAR), focusing on its clinical implications in patients with urothelial neoplasia of the bladder treated with radical cystectomy. uPAR is a central molecule in tissue remodeling during cancer invasion and metastasis and is an established prognostic marker in cancer. The expression and localization of uPAR and its prognostic significance is only limitedly investigated in urothelial bladder neoplasia.

MATERIALS AND METHODS

The expression-and localization pattern of uPAR was investigated in formalin-fixed paraffin-embedded tumor tissue from 149 patients treated with radical cystectomy between 1988 and 2005. uPAR expression was determined by immunohistochemistry and scored as either negative or positive. Separate values were obtained for cancer cells, macrophages, and myofibroblasts at the invasive front and tumor core, respectively. Statistical analyses were performed to evaluate the association of uPAR localization and score with clinicopathologic covariates and survival.

RESULTS

uPAR positivity was seen in 122/137 (89%) and 118/149 (74%) of the neoplasias at the invasive front and tumor core, respectively. uPAR was primarily expressed by myofibroblasts and macrophages in the surrounding stroma as well as some cancer cells. A significant association between uPAR positivity and T-stage as well as grade was found for all 3 cell types in tumor core (P ≤ 0.04 for all comparisons). In univariate analysis, the uPAR positive group had a shorter survival than the uPAR negative group (hazard ratio = 2.39; 95% CI: 1.15-5.01; P = 0.020).

CONCLUSIONS

The expression of uPAR is a possible prognostic marker that could be useful in identification of patients with aggressive, highly invasive tumors that could benefit from additional chemotherapy or more intensive follow-up after cystectomy.

ZEB2 and ZEB1 expression in a spontaneous canine model of invasive micropapillary carcinoma of the mammary gland

ZEB1 and ZEB2 have been recently related to cancer prognosis. We investigated their expression and its association with clinicopathological parameters and overall survival in invasive micropapillary carcinoma (IMPC), which is a metastasising neoplasm of the canine mammary gland. Immunohistochemical evaluation showed nuclear and cytoplasmic staining for ZEB2 and nuclear staining for ZEB1. 'In situ' areas presented higher positivity for cytoplasmic ZEB2 than invasive areas of IMPC did (p = 0.03). ZEB1 positivity was associated with a low histological grade (p = 0.01). A shorter overall survival rate was observed in IMPCs that were positive for cytoplasmic ZEB2 (p = 0.04). Antibodies specificity in canine species was confirmed by western blot. Our results indicated that cytoplasmic ZEB2 appears to be an important factor in the early stages of malignancy and predicts a poor overall survival rate for IMPC in this canine mammary cancer model. ZEB1 downregulation appears to be associated with the dedifferentiation process of IMPC.