Contribution of cells undergoing epithelial–mesenchymal transition to the tumour microenvironment

Basal Proliferation and Acantholysis May Represent Histological High-Risk Factors for Progression into Invasive Squamous Cell Carcinoma: A Comparison Study in Solid Organ Transplant Recipients and Matched Immunocompetent Patients

Histological risk factors of AKs cannot be directly determined. Recent studies indicate that AKs restricted to the lower third of the epidermis (AK I), with marked basal proliferation (PRO III) and acantholysis, are associated with an increased risk of progression to invasive squamous cell carcinoma (iSCC). To confirm the aforementioned histological risk factors, this study compared AKs from solid organ transplant recipients (sOTRs), known to carry an up to 250-fold higher risk for progression into iSCC, to a matched immunocompetent control group (ICG). In total, 111 AKs from 43 sOTRs showed more AKs (n = 54, 48.7%) graded as AK I compared to 35 AKs (31.5%) in the ICG (p = 0.009). In line with these findings, 89 AKs (80.2%) from sOTRs showed pronounced basal proliferation (PRO III) compared to 37 AKs (33.3%) in the ICG (p < 0.0001). Acantholysis was more frequent in sOTRs than the ICG (59.5% vs. 32.4%, p < 0.0001) and more frequently associated with advanced basal proliferation (p < 0.0001). In conclusion, this study showed that acantholytic AKs graded as AK I and PRO III are predominantly found in a population at high risk of iSCC. Thus, AKs with marked basal proliferation and acantholysis should be assumed to be histological high-risk factors for the progression into iSCC.

Exploration of shared gene signature with development of pre-eclampsia and cervical cancer

Background: The relationship between pre-eclampsia (PE) and cervical cancer (CC) has drawn more attention recently, while little is known about the shared pathogenesis of CC and PE. In the present research, we aimed to generate the shared gene network as well as the prognostic model to reveal the development of CC and PE.

Methods: The transcription data of CC and PE patients were obtained and enrolled into weighted gene co-expression network (WGCNA) analysis. Disease-specific modules in CC and PE were determined to discover the shared genes. The expression patterns of genes at protein level were examined by HPA database. Further, LASSO penalty regression and Cox analysis were applied to create a prognostic signature based on the shared genes, with survival curves and ROC plots employed to confirm the predictive capacity. To uncover the function roles and pathways involved in signature, gene set enrichment analysis (GSEA) was conducted. Finally, the immune infiltration status in CC was depicted using CIBERSORT algorithms.

Results: WGCNA determined three hub modules between CC and PE. A total of 117 shared genes were obtained for CC and PE and mainly enriched in cell proliferation, regulation of cell development and neuron differentiation. Then, we created a robust prognostic model based on the 10 shared genes by performing stepwise Cox analyses. Our proposed model presented a favorable ability in prognosis forecast and was correlated with the infiltration of immunocytes including B cells, macrophages and T cells. GSEA disclosed that high-risk group was involved in cancer-related pathways.

Conclusion: The present project identified the shared genes to uncover the pathogenesis of CC and PE and further proposed and validated a prognostic signature to accurately forecast the clinical outcomes of CC patients.

Circulating Exosome Cargoes Contain Functionally Diverse Cancer Biomarkers: From Biogenesis and Function to Purification and Potential Translational Utility

Although diagnostic and therapeutic treatments of cancer have tremendously improved over the past two decades, the indolent nature of its symptoms has made early detection challenging. Thus, inter-disciplinary (genomic, transcriptomic, proteomic, and lipidomic) research efforts have been focused on the non-invasive identification of unique "silver bullet" cancer biomarkers for the design of ultra-sensitive molecular diagnostic assays. Circulating tumor biomarkers, such as CTCs and ctDNAs, which are released by tumors in the circulation, have already demonstrated their clinical utility for the non-invasive detection of certain solid tumors. Considering that exosomes are actively produced by all cells, including tumor cells, and can be found in the circulation, they have been extensively assessed for their potential as a source of circulating cell-specific biomarkers. Exosomes are particularly appealing because they represent a stable and encapsulated reservoir of active biological compounds that may be useful for the non-invasive detection of cancer. T biogenesis of these extracellular vesicles is profoundly altered during carcinogenesis, but because they harbor unique or uniquely combined surface proteins, cancer biomarker studies have been focused on their purification from biofluids, for the analysis of their RNA, DNA, protein, and lipid cargoes. In this review, we evaluate the biogenesis of normal and cancer exosomes, provide extensive information on the state of the art, the current purification methods, and the technologies employed for genomic, transcriptomic, proteomic, and lipidomic evaluation of their cargoes. Our thorough examination of the literature highlights the current limitations and promising future of exosomes as a liquid biopsy for the identification of circulating tumor biomarkers.

Immunophenotypical alterations with impact on the epithelial-mesenchymal transition (EMT) process in salivary gland adenoid cystic carcinomas

Adenoid cystic carcinoma (ACC) is one of the most common malignant salivary glands neoplasms with an indolent clinical course, slow-growing but locally aggressive and quite often with delayed recurrence and distant metastasis. In order to elucidate this tumoral behavior, we conducted an immunohistochemical study investigating the alterations of epithelial phenotype with anti-cytokeratin (CK) AE1/AE3 and anti-E-cadherin antibodies, and the acquisition of mesenchymal phenotype with vimentin, fibronectin, N-cadherin and P-cadherin in salivary ACCs. Thus, we recorded a reduction of CK AE1/AE3, E-cadherin, P-cadherin and fibronectin reactivity in the solid variant and especially in the cells from the periphery of invasive neoplastic proliferations, regardless histological type. These phenotypical alterations suggest the involvement of the epithelial–mesenchymal transition (EMT) process in the progression of salivary ACCs.

Downregulation of ARMC8 promotes tumorigenesis through activating Wnt/β-catenin pathway and EMT in cutaneous squamous cell carcinomas

BACKGROUND

Aberrant expression of Armadillo repeat containing 8 (ARMC8) plays crucial roles in tumor growth and metastasis of various cancers. The specific role of ARMC8 in cutaneous squamous cell carcinoma (cSCC) is yet to be elucidated.

OBJECTIVE

The present study aimed to investigate the molecular mechanisms of ARMC8 and epithelial-mesenchymal transition (EMT) in cSCC development and provide translational insights for future therapeutics.

METHODS

cSCC tumor specimens were used to determine the ARMC8 by immunohistochemistry. Three cSCC cell lines including HSC-1, HSC-5 and A431 as well as BALB/C mouse tumor model was utilized to study the potential mechanisms in tumorigenesis.

RESULTS

Our data identified ARMC8 as a direct downstream target of miR-664. We found that ARMC8 was remarkably low expression in cSCC patient specimens and cSCC cell lines. Knockdown of ARMC8 promotes tumorigenic behaviors such as increased cell proliferation, migration and invasion capacities in vitro and enhanced tumorigenicity in xenograft mouse model. Whereas ARMC8 over-expression inhibits tumorigenesis in cSCC. Together, it revealed ARMC8 functions as a tumor suppressor via restraining Wnt/β-catenin pathway and epithelial-mesenchymal transition in cSCC.

CONCLUSION

Our data verifies that aberrant expression of ARMC8 plays a vital role in carcinogenesis of cSCC. And overexpression of ARMC8 will facilitate future development of cSCC therapeutic interventions.

Regulatory effect of microRNA-223-3p on breast cancer cell processes via the Hippo/Yap signaling pathway

According to the 2018 global cancer statistics, the incidence and mortality rates of breast cancer are increasing gradually, which seriously threatens the health of women. MicroRNA-223-3p (miR-223-3p) can promote the proliferation and invasion of breast cancer cells. Hippo/Yes-related protein (Yap) signaling pathway activation has been found in a variety of tumors. The present study aimed to investigate the potential mechanism of miR-223-3p in breast cancer. The Cell Counting Kit-8 assay was used to detect cell viability and flow cytometry was used to detect apoptosis. The abilities of cell migration and invasion were detected using scratch and Transwell assays, as well as reverse transcription-quantitative PCR and western blotting to detect gene and protein expression, respectively. The current results demonstrated that miR-223-3p transcription levels were increased in breast cancer cells, and inhibition of miR-223-3p gene expression decreased cell proliferation, migration and invasion. Additionally, inhibition of miR-223-3p expression inhibited epithelial-mesenchymal transition (EMT) in breast cancer cells. miR-223-3p promoted cell proliferation, migration, invasion and EMT, and the western blotting results demonstrated that miR-223-3p inhibition increased the phosphorylation of Yap1 and the protein expression levels of large tumor suppressor kinase 1. In conclusion, results from the present results suggested that miR-223-3p may promote cell proliferation, migration, invasion and EMT through the Hippo/Yap signaling pathway. Therefore, miR-223-3p may be a potential biomarker for breast cancer.

IL-8 promotes cell migration through regulating EMT by activating the Wnt/β-catenin pathway in ovarian cancer

Interleukin‐8 (IL‐8), as an inflammatory chemokine, has been previously shown to contribute to tumorigenesis in several malignancies including the ovarian cancer. However, little is known about how IL‐8 promotes the metastasis and invasion of ovarian cancers cells. In this study, we found that IL‐8 and its receptors CXCR1 and CXCR2 were up‐regulated in advanced ovarian serous cancer tissues. Furthermore, the level of IL‐8 and its receptors CXCR1 and CXCR2 expression were associated with ovarian cancer stage, grade and lymph node metastasis. In vitro, IL‐8 promoted ovarian cancer cell migration, initiated the epithelial‐mesenchymal transition (EMT) program and activated Wnt/β‐catenin signalling. However, when treated with Reparixin (inhibitor of both IL‐8 receptors CXCR1 and CXCR2), effect of both endogenous and exogenous IL‐8 was reversed. Together, our results indicated that IL‐8 triggered ovarian cancer cells migration partly through Wnt/β‐catenin pathway mediated EMT, and IL‐8 may be an important molecule in the invasion and metastasis of ovarian cancer.

Tumor Targeting Strategies of Smart Fluorescent Nanoparticles and Their Applications in Cancer Diagnosis and Treatment

Advantages such as strong signal strength, resistance to photobleaching, tunable fluorescence emissions, high sensitivity, and biocompatibility are the driving forces for the application of fluorescent nanoparticles (FNPs) in cancer diagnosis and therapy. In addition, the large surface area and easy modification of FNPs provide a platform for the design of multifunctional nanoparticles (MFNPs) for tumor targeting, diagnosis, and treatment. In order to obtain better targeting and therapeutic effects, it is necessary to understand the properties and targeting mechanisms of FNPs, which are the foundation and play a key role in the targeting design of nanoparticles (NPs). Widely accepted and applied targeting mechanisms such as enhanced permeability and retention (EPR) effect, active targeting, and tumor microenvironment (TME) targeting are summarized here. Additionally, a freshly discovered targeting mechanism is introduced, termed cell membrane permeability targeting (CMPT), which improves the tumor-targeting rate from less than 5% of the EPR effect to more than 50%. A new design strategy is also summarized, which is promising for future clinical targeting NPs/nanomedicines design. The targeting mechanism and design strategy will inspire new insights and thoughts on targeting design and will speed up precision medicine and contribute to cancer therapy and early diagnosis.

MicroRNA-212-3p inhibits the Proliferation and Invasion of Human Hepatocellular Carcinoma Cells by Suppressing CTGF expression

MicroRNA-212-3p inhibits several human cancers but its effects on hepatocellular carcinoma (HCC) remain unclear. In this study, we show that miR-212-3p is down-regulated in HCC cell lines and tissues, and correlates with vascular invasion (p = 0.001), and the absence of capsule formation (p = 0.009). We found that miR-212-3p influenced the epithelial to mesenchymal transition (EMT) of HCCLM3 and Huh7 cells. Mechanistically, miR-212-3p repressed cell invasion through the suppression of connective tissue growth factor (CTGF). We therefore validate the anti-HCC effects of miR-212-3p through its ability to suppress CTGF and subsequent EMT.

Novel role of Snail 1 in promoting tumor neoangiogenesis

Snail1 plays an important role in epithelial to mesenchymal transition (EMT) during tumor metastasis; however, whether Snai1 potentiates the process of neoangiogenesis is completely unknown. In the present study, tube formation assay was used to evaluate neoangiogenesis in vitro The expression of Snai1 and other pro-neoangiogenic factors was measured by quantitative real time PCR. Tumor derived endothelial cells (TDECs) were stimulated with fibroblast growth factor 1 (FGF1) or VEGF and formed more tubes compared with untreated, whereas cells treated with Sulforaphane had less tube formation. Silencing SNAI1 significantly attenuated tube formation accompanied by decreased CD31, CD34, and VWF expression in TDECs compared with control. In contrast, overexpression of Snai1 led to more CD31, CD34, and VWF expression and tube formation. To determine if the observed effects of SNAI1 on tube formation was a global phenomenon, the same assay was conducted in normal mesenchymal stem cells (MSCs). SNAI1 silencing did not have any effect on tube formation in MSCs. The expression of TIMP2, ENG, and HIF1A was up-regulated 3-fold or higher after silencing SNAI1, and ID1, VEGFA, PLG, LECT1, HPSE were shown down-regulated. Taken together, our study elucidates an important role of EMT inducer Snai1 in regulating tumor neoangiogenesis, suggesting a potential therapeutic target for overcoming tumor EMT.

Nicotine promotes cervical metastasis of oral cancer by regulating peroxiredoxin 1 and epithelial-mesenchymal transition in mice

Background

Tobacco is a major risk factor for oral squamous cell carcinoma (OSCC). However, the role of nicotine in OSCC is not completely understood.

Materials and methods

To analyze the mechanisms of nicotine-induced cervical metastasis, we investigated whether nicotine induced invasion, migration, and epithelial–mesenchymal transition (EMT) via regulating peroxiredoxin 1 (Prx1) in CAL 27 cells. In addition, we established a mouse model to confirm the roles of nicotine in regulating Ets1/Prx1/EMT signaling in OSCC metastasis.

Results

We showed that nicotine induced CAL 27 cell invasion, migration, EMT, and Prx1 and Ets1 expression. Prx1 knockdown inhibited cell invasion, migration, and EMT. Ets1 silencing downregulated Prx1 expression and EMT. Prx1 and Ets1 were shown to interact in CAL 27 cells treated with nicotine, and nicotine could significantly upregulate the binding of the transcription factor Ets1 to the Prx1 gene promoter region. Additionally, an in vivo study showed that nicotine induced tumor metastasis and EMT. Prx1 knockdown inhibited cervical metastasis rates and EMT progression. No significant differences in metastasis rates and EMT-related marker expression levels were observed between vehicle- and nicotine-treated mice.

Conclusion

The results indicate that nicotine promotes cervical lymph node metastasis through regulating Ets1/Prx1/EMT signaling during OSCC pathogenesis; consequently, Prx1 may represent a potential target for the prevention and treatment of OSCC.

Prognostic value of immunoexpression of CCR4, CCR5, CCR7 and CXCR4 in squamous cell carcinoma of tongue and floor of the mouth

Background

Diverse studies have evidenced that chemokines can play a critical role in pathogenesis of oral squamous cell carcinoma (SCC). The main chemokines involved in oral carcinogenesis, tumor invasion and metastasis are CCR4, CCR5, CCR7 and CXCR4, and our aim was to evaluate the prognostic value of the immunoexpression of these chemokines in SCC of tongue and floor of the mouth.

Material and Methods

A retrospective descriptive study of the immunohistochemical expression of CCR4, CCR5, CCR7 and CXCR4 in paraffin-embedded samples of 124 patients with SCC of the tongue and floor of the mouth was performed, considering 98 cases from Brazil and 26 cases from Chile. Associations between variables were analyzed using chi-square test. Survival curves were performed using the Kaplan-Meier method and compared with long-rank test. For multivariate survival analysis, the Cox hazard model was established. The level of significance established was p≤0.05.

Results

The statistical analysis showed that samples with well or moderate WHO model differentiation (p=0.001) and a high expression of CCR5 (p=0.05) were significantly associated with a higher disease specific survival, which were also observed in Cox´s multivariate analysis (p=0.01). A higher expression of CCR7 (p=0.01) interfered significantly in disease-free survival in univariate analysis and in Cox´s multivariate analysis (p=0.05).

Conclusions

These results support additional evidence, showing that chemokine receptors CCR5 and CCR7 are helpful as biomarkers of poor prognosis in patients with SCC of the tongue and floor of the mouth.

Key words:Oral squamous cell carcinoma, prognosis, survival, chemokine receptor.

Tankyrase1 antisense oligodeoxynucleotides suppress the proliferation, migration and invasion through Hippo/YAP pathway in human osteosarcoma cells

Osteosarcoma is the most common malignant tumor of bone with a high potential for metastasis and poor prognosis. This study intends to explore the effect of tankyrase1 (TANK1) in the development of osteosarcoma cells and the underlying mechanism. The osteosarcoma cell line MG-63 cells were cultured and transfected with tankyrase1 antisense oligodeoxynucleotides (TANK1-ASODN). Cell proliferation was detected with CCK-8 and immunofluorescence. Cell migration and invasion were examined by wound healing assay and Transwell assay, respectively. Reverse transcription-quantitative polymerase chain reaction was performed to detect the mRNA level of TANK1 and western blot was conducted to detect relative protein expression during the research. As a result, we demonstrated that TANK1 was upregulated in osteosarcoma. The TANK1-ASODN inhibited MG-63 cell proliferation, migration and invasion. The progress of epithelial-mesenchymal transition (EMT) was also suppressed in TANK1-ASODN transfected MG-63 cells compared to control group. Besides, the TANK1-ASODN activated and modulated the Hippo/YAP signaling which might be the pathway that TANK1 depended on. Overall, our finding supported that TANK1-ASODN slowed down the progress of osteosarcoma by suppressing cell proliferation, migration, invasion and EMT through Hippo/YAP pathway.

miR-103 promotes the metastasis and EMT of hepatocellular carcinoma by directly inhibiting LATS2

Improving the long-term survival of patients with hepatocellular carcinoma (HCC) remains a challenge due to metastasis and recurrence. In this study, we demonstrate that the overexpression of miR-103 in HCC cells promotes epithelial-mesenchymal transition (EMT), and is associated with an enhanced metastasis and poor outcomes, as shown by western blot analysis and immunohistochemistry. Mechanistically, using reporter luciferase assay we reveal that the serine/threonine-protein kinase, large tumor suppressor kinase 2 (LATS2), a key component of the Hippo signaling pathway, is a direct target of miR-103 in HCC cells. Transwell assay, MTT assay and western blot analysis were performed to reveal that LATS2 can counteract the functional effects of miR-103 on HCC metastasis, growth and EMT. The analyses of clinical data indicated that a high expression of miR-103 correlated with a high expression of vimentin, but with a low expression of LATS2 and E-cadherin in HCC tissues. miR-103 also reduced yes-associated protein (YAP) phosphorylation. On the whole, the findings of this study suggest that miR-103 promotes HCC metastasis and EMT by directly inhibiting LATS2. Thus, targeting miR-103/LATS2 may prove to be a promising therapeutic strategy for HCC.

Organotypic three-dimensional assays based on human leiomyoma-derived matrices

Alongside cancer cells, tumours exhibit a complex stroma containing a repertoire of cells, matrix molecules and soluble factors that actively crosstalk between each other. Recognition of this multifaceted concept of the tumour microenvironment (TME) calls for authentic TME mimetics to study cancer in vitro. Traditionally, tumourigenesis has been investigated in non-human, three-dimensional rat type I collagen containing organotypic discs or by means of mouse sarcoma-derived gel, such as Matrigel^®. However, the molecular compositions of these simplified assays do not properly simulate human TME. Here, we review the main properties and benefits of using human leiomyoma discs and their matrix Myogel for in vitro assays. Myoma discs are practical for investigating the invasion of cancer cells, as are cocultures of cancer and stromal cells in a stiff, hypoxic TME mimetic. Myoma discs contain soluble factors and matrix molecules commonly present in neoplastic stroma. In Transwell, IncuCyte, spheroid and sandwich assays, cancer cells move faster and form larger colonies in Myogel than in Matrigel^®. Additionally, Myogel can replace Matrigel^® in hanging-drop and tube-formation assays. Myogel also suits three-dimensional drug testing and extracellular vesicle interactions. To conclude, we describe the application of our myoma-derived matrices in 3D in vitro cancer assays.

This article is part of the discussion meeting issue ‘Extracellular vesicles and the tumour microenvironment’.

MicroRNA-219-5p Promotes Tumor Growth and Metastasis of Hepatocellular Carcinoma by Regulating Cadherin 1

MicroRNAs play significant roles in the development of cancer and may serve as promising therapeutic targets. In our previous work, miR-219-5p was identified as one of the important metastasis-related microRNAs in HCC. Here we demonstrated that miR-219-5p expression was elevated in HCC tissues and was associated with vascular invasion and dismal prognosis. In multivariate analysis, miR-219-5p was identified as an independent prognostic indicator for HCC patients. Functional mechanism analyses showed that miR-219-5p promoted HCC cell proliferation and invasion in in vitro, as well as in vivo, tumor growth and metastasis in nude mice models bearing human HCC tumors. In addition, cadherin 1 (CDH1) was revealed to be a downstream target of miR-219-5p in HCC cells. In conclusion, miR-219-5p promotes tumor growth and metastasis of HCC by regulating CDH1 and can serve as a prognostic marker for HCC patients.

Alterations of microRNAs throughout the malignant evolution of cutaneous squamous cell carcinoma: the role of miR-497 in epithelial to mesenchymal transition of keratinocytes

Skin carcinogenesis is known to be a multi-step process with several stages along its malignant evolution. We hypothesized that transformation of normal epidermis to cutaneous squamous cell carcinoma (cSCC) is causally linked to alterations in microRNAs (miRNA) expression. For this end we decided to evaluate their alterations in the pathologic states ending in cSCC. Total RNA was extracted from formalin fixed paraffin embedded biopsies of five stages along the malignant evolution of keratinocytes towards cSCC: Normal epidermis, solar elastosis, actinic keratosis KIN1-2, advanced actinic keratosis KIN3 and well-differentiated cSCC. Next-generation small RNA sequencing was performed. We found that 18 miRNAs are overexpressed and 28 miRNAs are underexpressed in cSCC compared to normal epidermis. miR-424, miR-320, miR-222 and miR-15a showed the highest fold change among the overexpressed miRNAs. And miR-100, miR-101 and miR-497 showed the highest fold change among the underexpressed miRNAs. Heat map of hierarchical clustering analysis of significantly changed miRNAs and principle component analysis disclosed that the most prominent change in miRNAs expression occurred in the switch from 'early' stages; normal epidermis, solar elastosis and early actinic keratosis to the 'late' stages of epidermal carcinogenesis; late actinic keratosis and cSCC. We found several miRNAs with 'stage specific' alterations while others display a clear 'gradual', either progressive increase or decrease in expression along the malignant evolution of keratinocytes. The observed alterations focused in miRNAs involved in the regulation of AKT/mTOR or in those involved in epithelial to mesenchymal transition. We chose to concentrate on the evaluation of the molecular role of miR-497. We found that it induces reversion of epithelial to mesenchymal transition. We proved that SERPINE-1 is its biochemical target. The present study allows us to further study the pathways that are regulated by miRNAs along the malignant evolution of keratinocytes towards cSCC.

MiR-195 suppresses the metastasis and epithelial-mesenchymal transition of hepatocellular carcinoma by inhibiting YAP

MiR-195, a novel cancer-related microRNA, was previously reported to play an important role in many malignancies. This study aimed to investigate the role of miR-195 mediated epithelial-mesenchymal transition (EMT) and the progression of hepatocellular carcinoma (HCC) as well as the underlying mechanisms. Our result demonstrated that miR-195 were significantly down regulated in HCC and its decreased expression is associated with poor clinical features of HCC patients. Oppositely, expression level of YAP was significantly higher in HCC tissues, and the level of YAP in metastatic tissues was significantly higher. We also found that a strong inversely association between low level expression of miR-195 and high level of YAP in HCC tissues. Notably, this study confirmed that miR-195, YAP and their combination were valuable predictors for the prognosis of HCC patients. We also explored that miR-195 inhibits HCC growth and metastatic capacity. Mechanistically, we confirm that miR-195 inhibits the migration, invasion and EMT of HCC cells by suppressing YAP. Lastly, we revealed YAP was not only the downstream of miR-195 in HCC, but also mediated the promoting effects of miR-195 on the metastasis and EMT of HCC cells. Taken together, miR-195 inhibits the metastasis and EMT in HCC by targeting YAP. MiR-195/YAP pathway may potentially act as novel biomarker and attractive therapeutic target in HCC.

Extracellular vesicles: their role in cancer biology and epithelial-mesenchymal transition

Cell-cell communication is critical across an assortment of physiological and pathological processes. Extracellular vesicles (EVs) represent an integral facet of intercellular communication largely through the transfer of functional cargo such as proteins, messenger RNAs (mRNAs), microRNA (miRNAs), DNAs and lipids. EVs, especially exosomes and shed microvesicles, represent an important delivery medium in the tumour micro-environment through the reciprocal dissemination of signals between cancer and resident stromal cells to facilitate tumorigenesis and metastasis. An important step of the metastatic cascade is the reprogramming of cancer cells from an epithelial to mesenchymal phenotype (epithelial-mesenchymal transition, EMT), which is associated with increased aggressiveness, invasiveness and metastatic potential. There is now increasing evidence demonstrating that EVs released by cells undergoing EMT are reprogrammed (protein and RNA content) during this process. This review summarises current knowledge of EV-mediated functional transfer of proteins and RNA species (mRNA, miRNA, long non-coding RNA) between cells in cancer biology and the EMT process. An in-depth understanding of EVs associated with EMT, with emphasis on molecular composition (proteins and RNA species), will provide fundamental insights into cancer biology.

Epithelial-mesenchymal transition in cancer: Role of the IL-8/IL-8R axis

Epithelial-mesenchymal transition (EMT) is a biological process that is associated with cancer metastasis and invasion. In cancer, EMT promotes cell motility, invasion and distant metastasis. Interleukin (IL)-8 is highly expressed in tumors and may induce EMT. The IL-8/IL-8R axis has a vital role in EMT in carcinoma, which is regulated by several signaling pathways, including the transforming growth factor β-spleen associated tyrosine kinase/Src-AKT/extracellular signal-regulated kinase, p38/Jun N-terminal kinase-activating transcription factor-2, phosphoinositide 3-kinase/AKT, nuclear factor-κB and Wnt signaling pathways. Blocking the IL-8/IL-8R signaling pathway may be a novel strategy to reduce metastasis and improve patient survival rates. This review will cover IL-8-IL-8R signaling pathway in tumor epithelial-mesenchymal transition.

Knockdown of Decoy Receptor 3 Impairs Growth and Invasiveness of Hepatocellular Carcinoma Cell Line of HepG2

Background:

Decoy receptor 3 (DcR3) binds to Fas ligand (FasL) and inhibits FasL-induced apoptosis. The receptor is overexpressed in hepatocellular carcinoma (HCC), and it is associated with the growth and metastatic spread of tumors. DcR3 holds promises as a new target for the treatment of HCC, but little is known regarding the molecular mechanisms underlying the oncogenic properties of DcR3. The present work, therefore, examined the role of DcR3 in regulating the growth and invasive property of liver cancer cell HepG2.

Methods:

HepG2 cells were stably transfected with lentivirus-based short hairpin RNA vector targeting DcR3. After the knockdown of DcR3 was confirmed, cell proliferation, clone formation, ability of migrating across transwell membrane, and wound healing were assessed in vitro. Matrix metalloproteinase-9 (MMP 9) and vascular epithelial growth factor (VEGF)-C and D expressions of the DcR3 knockdown were also studied. Comparisons between multiple groups were done using one-way analysis of variance (ANOVA), while pairwise comparisons were performed using Student's t test. P < 0.05 was regarded statistically significant.

Results:

DcR3 was overexpressed in HepG2 compared to other HCC cell lines and normal hepatocyte Lo-2. Stable knockdown of DcR3 slowed down the growth of HepG2 (P < 0.05) and reduced the number of clones formed by 50% compared to those without DcR3 knockdown (P < 0.05). The knockdown also reduced the migration of HepG2 across transwell matrix membrane by five folds compared to the control (P < 0.05) and suppressed the closure of scratch wound (P < 0.05). In addition, the messenger RNA levels of MMP 9, VEGF-C, and VEGF-D were significantly suppressed by DcR3 knockdown by 90% when compared with the mock control (P < 0.05).

Conclusions:

Loss of DcR3 impaired the growth and invasive property of HCC cell line of HepG2. Targeting DcR3 may be a potential therapeutic approach for the treatment of HCC.

The Significance of Epithelial-to-Mesenchymal Transition for Circulating Tumor Cells

Epithelial to mesenchymal transition (EMT) is a process involved in embryonic development, but it also plays a role in remote metastasis formation in tumor diseases. During this process cells lose their epithelial features and adopt characteristics of mesenchymal cells. Thereby single tumor cells, which dissolve from the primary tumor, are enabled to invade the blood vessels and travel throughout the body as so called "circulating tumor cells" (CTCs). After leaving the blood stream the reverse process of EMT, the mesenchymal to epithelial transition (MET) helps the cells to seed in different tissues, thereby generating the bud of metastasis formation. As metastasis is the main reason for tumor-associated death, CTCs and the EMT process are in the focus of research in recent years. This review summarizes what was already found out about the molecular mechanisms driving EMT, the consequences of EMT for tumor cell detection, and suitable markers for the detection of CTCs which underwent EMT. The research work done in this field could open new roads towards combating cancer.

Singular Value Decomposition Based Features for Automatic Tumor Detection in Wireless Capsule Endoscopy Images

Wireless capsule endoscopy (WCE) is a new noninvasive instrument which allows direct observation of the gastrointestinal tract to diagnose its relative diseases. Because of the large number of images obtained from the capsule endoscopy per patient, doctors need too much time to investigate all of them. So, it would be worthwhile to design a system for detecting diseases automatically. In this paper, a new method is presented for automatic detection of tumors in the WCE images. This method will utilize the advantages of the discrete wavelet transform (DWT) and singular value decomposition (SVD) algorithms to extract features from different color channels of the WCE images. Therefore, the extracted features are invariant to rotation and can describe multiresolution characteristics of the WCE images. In order to classify the WCE images, the support vector machine (SVM) method is applied to a data set which includes 400 normal and 400 tumor WCE images. The experimental results show proper performance of the proposed algorithm for detection and isolation of the tumor images which, in the best way, shows 94%, 93%, and 93.5% of sensitivity, specificity, and accuracy in the RGB color space, respectively.

Transformed MDCK cells secrete elevated MMP1 that generates LAMA5 fragments promoting endothelial cell angiogenesis

Epithelial-mesenchymal transition (EMT) enhances the migration and invasion of cancer cells, and is regulated by various molecular mechanisms including extracellular matrix metalloproteinase (MMP) activity. Previously, we reported transformation of epithelial Madin-Darby canine kidney (MDCK) cells with oncogenic H-Ras (21D1 cells) induces EMT, and significantly elevates MMP1 expression. To explore the biological significance, in this study we characterized 21D1 cells with knocked-down MMP1 expression (21D1^−MMP1). MMP1 silencing diminished 21D1 cell migration, invasion and anchorage-independent growth in vitro. Additionally, 21D1^−MMP1 cells displayed reduced tumour volume when grown as in vivo subcutaneous xenografts in mice. Depletion of MMP1 lowered the ability of the cellular secretome (extracellular culture medium) to influence recipient cell behaviour. For example, supplementation with 21D1 secretome elevated cell migration of recipient fibroblasts, and enhanced endothelial cell angiogenesis (vessel length and branching). By contrast, 21D1^−MMP1 secretome was less potent in both functional assays. We reveal laminin subunit alpha-5 (LAMA5) as a novel biological substrate of MMP1, that generates internal and C-terminal proteolytic fragments in 21D1 secretome. Furthermore, antibody-based inhibition of integrin αvβ3 on endothelial cells nullified the angiogenic capability of 21D1 secretome. Therefore, we report this as a new VEGF-independent mechanism that oncogenic cells may employ to promote tumour angiogenesis.

YBX1/YB-1 induces partial EMT and tumourigenicity through secretion of angiogenic factors into the extracellular microenvironment

Epithelial-mesenchymal transition (EMT) describes a morphogenetic program which confers mesenchymal cell properties, such as reduced cell-cell contact and increased cell migration and invasion, to epithelial cells. Here we investigate the role of the pleiotropic transcription/splicing factor and RNA-binding protein nuclease-sensitive element-binding protein 1 (YBX1/YB-1) in increasing the oncogenic potential of epithelial MDCK cells. Characterization of MDCK cells expressing YBX1 (MDCK^YBX1 cells) revealed a partial EMT phenotype, including cytosolic relocalization of E-cadherin, increased cell scattering, and anchorage-independent growth. Subcutaneous injection of parental MDCK cells into NOD/SCID mice did not form tumours. Critically, MDCK^YBX1 cells established viable tumour xenografts, and immuno-histochemical staining indicated murine vascularization by CD31+ endothelial cells. We analysed the total secretome (containing soluble and extracellular vesicles) of MDCK^YBX1 cells to investigate regulation of the tumour microenvironment. YBX1 expression elevated release of secreted factors known to enhance angiogenesis (TGF-β, CSF-1, NGF, VGF, ADAM9 and ADAM17), compared to MDCK cells. Importantly, treatment with MDCK^YBX1 cell-derived secretome increased recipient 2F-2B endothelial cell motility. This defines YBX1 as an oncogenic enhancer that can regulate tumour angiogenesis via release of secreted modulators into the extracellular microenvironment.

Identification and verification of transgelin-2 as a potential biomarker of tumor-derived lung-cancer endothelial cells by comparative proteomics

To investigate heterogeneity of endothelial cells (ECs) in the tumor microenvironment and biomarkers for antitumor angiogenesis therapy, high-purity (>98%) normal (NECs) and tumor-derived CD105(+) ECs (TECs) were purified from a mouse Lewis lung carcinoma model bearing 0.5 cm tumors by immunomagnetic separation. Proteomics analysis revealed that 48 proteins (28 upregulated and 20 downregulated) were differentially regulated by at least 1.5-fold in TECs, and that these proteins were involved in metabolism, energy pathways, protein folding, cell growth and/or functioned as structural constituents of the cytoskeleton. Upregulation of heat shock protein 60 (Hspd1) and transgelin-2 (Tagln2) was revealed in TECs, and by immunohistochemistry (IHC) in paired tissues from 30 consecutive lung cancer (LC) patients. Higher expression levels of Hspd1, Tagln2 were detected in microvascular ECs of paratumor and tumor tissues than in paired normal counterparts. Stronger Tagln2 staining was associated with clinical stage, tumor size, and histological neural invasion. Higher Hspd1 (area under the curve [AUC], 0.82) and lower Tagln2 (AUC, 0.90) levels were detected in LC patient sera. Pearson correlation analysis revealed a positive correlation between serum Hspd1 and Tagln2 levels. In conclusion, higher Tagln2 levels were associated with tumor development, lymph node metastasis, and neural invasion in LC and may thus serve as a potential biomarker of tumor angiogenesis.

SIGNIFICANCE

High-purity endothelial cells (normal and tumor derived) were prepared to characterize ECs heterogeneity in the tumor microenvironment and to explore biomarkers of early stages of tumor development by proteomics. Candidate proteins Hspd1 and Tagln2, were further verification in the sera and tumor tissues of lung cancer patients. Moreover, higher Tagln2 was significantly associated with clinical tumor development, metastasis, and neural invasion. All these results indicated a crucial role for Tagln2 in TECs for tumor development and metastasis.

The role of Snail1 transcription factor in colorectal cancer progression and metastasis

Snail1 is a zinc-finger transcription factor, which plays a role in colorectal cancer development by silencing E-cadherin expression and inducing epithelialmesenchymal transition (EMT). During EMT tumour cells acquire a mesenchymal phenotype that is responsible for their invasive activities. Consequently, Snail1 expression in colorectal cancer is usually associated with progression and metastasis. Some studies revealed that about 77% of colon cancer samples display Snail1 immunoreactivity both in activated fibroblasts and in carcinoma cells that have undergone EMT. Therefore, expression of this factor in the stroma may indicate how many cells possess the abilities to escape from the primary tumour mass, invade the basal lamina and colonise distant target organs. Blocking snail proteins activity has the potential to avert cancer cell metastasis by interfering with such cellular processes as remodelling of the actin cytoskeleton, migration and invasion, which are clearly associated with the aggressive phenotype of the disease. Moreover, the link between factors from the snail family and cancer stem cells suggests that inhibitory agents may also prove their potency as inhibitors of cancer recurrence.

Heterogeneity analysis of Metastasis Associated in Colon Cancer 1 (MACC1) for survival prognosis of colorectal cancer patients: a retrospective cohort study

Background

Metastasis of colorectal cancer (CRC) is directly linked to patient survival. We previously identified the novel gene Metastasis Associated in Colon Cancer 1 (MACC1) in CRC and demonstrated its importance as metastasis inducer and prognostic biomarker. Here, we investigate the geographic expression pattern of MACC1 in colorectal adenocarcinoma and tumor buds in correlation with clinicopathological and molecular features for improvement of survival prognosis.

Methods

We performed geographic MACC1 expression analysis in tumor center, invasive front and tumor buds on whole tissue sections of 187 well-characterized CRCs by immunohistochemistry. MACC1 expression in each geographic zone was analyzed with Mismatch repair (MMR)-status, BRAF/KRAS-mutations and CpG-island methylation.

Results

MACC1 was significantly overexpressed in tumor tissue as compared to normal mucosa (p < 0.001). Within colorectal adenocarcinomas, a significant increase of MACC1 from tumor center to front (p = 0.0012) was detected. MACC1 was highly overexpressed in 55% tumor budding cells. Independent of geographic location, MACC1 predicted advanced pT and pN-stages, high grade tumor budding, venous and lymphatic invasion (p < 0.05). High MACC1 expression at the invasive front was decisive for prediction of metastasis (p = 0.0223) and poor survival (p = 0.0217). The geographic pattern of MACC1 did not correlate with MMR-status, BRAF/KRAS-mutations or CpG-island methylation.

Conclusion

MACC1 is differentially expressed in CRC. At the invasive front, MACC1 expression predicts best aggressive clinicopathological features, tumor budding, metastasis formation and poor survival outcome.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1150-z) contains supplementary material, which is available to authorized users.

Emerging roles of exosomes during epithelial-mesenchymal transition and cancer progression

Epithelial-mesenchymal transition (EMT) is a highly conserved process defined by the loss of epithelial characteristics, and acquisition of the mesenchymal phenotype. In addition to its central role in development, EMT has been implicated as a cellular process during tumourigenesis which facilitates tumour cell invasion and metastasis. The EMT process has been largely defined by signal transduction networks and transcriptional factors that activate mesenchymal-associated gene expression. Knowledge of secretome components that influence EMT including secreted proteins/peptides and membrane-derived extracellular vesicles (EVs) (i.e., exosomes) has emerged. Here we review EV cargo associated with inducing the hallmarks of EMT and cancer progression, modulators of cell transformation, invasion/migration, angiogenesis, and components involved in establishing the metastatic niche.

BDNF mediated TrkB activation contributes to the EMT progression and the poor prognosis in human salivary adenoid cystic carcinoma

BACKGROUND

The aim of the present study was to investigate whether the expression of Brain-Derived Neurotrophic Factor (BDNF) and its receptor Tropomyosin-related kinase B (TrkB) is correlated with the clinical progression of salivary adenoid cystic carcinoma (SACC) and whether the BDNF/TrkB axis is associated with the induction of epithelial-mesenchymal transition (EMT) in SACC cells.

METHOD

The expression of BDNF, TrkB, and E-cadherin (an EMT biomarker) in 76 primary SACC specimens and 20 normal salivary gland tissues was analyzed by immunohistochemistry. Additionally, the expression of BDNF, TrkB, and E-cadherin in SACC cell lines (SACC-83 and SACC-LM) was analyzed by RT-PCR and Western blotting. The biological role of the BDNF/TrkB axis in the EMT progression of SACC was evaluated after treatment with increased levels of BDNF and by inhibiting TrkB activity in SACC-83 cell line. The progression of SACC cells through EMT was assessed by RT-PCR, Western blotting, photography, migration and invasion assays.

RESULTS

Elevated expression of TrkB (92.1%) and BDNF (89.5%), and downregulated expression of E-cadherin (47.4%) was found in SACC specimens, which was significantly correlated with the invasion and metastasis in SACC (P<0.05). The high expression of TrkB and the low expression of E-cadherin was significantly correlated with the poor prognosis of SACC patients (P<0.05). The expression of TrkB was inversely correlated with the expression of E-cadherin in both SACC cases and cell lines (P<0.05). Increasing BDNF levels after treatment with exogenous recombinant human BDNF (rhBDNF) at 100 ng/ml significantly promoted the activation of TrKB and the progression of EMT in SACC cells. While obstruction of TrkB by its inhibitor, k252a (100 nM), significantly inhibited the EMT progression of SACC cells.

CONCLUSIONS

These results suggest that BDNF-mediated TrkB activation contributes to the EMT progression and the poor prognosis in SACC. The present study demonstrated that the BDNF/TrkB axis promotes the migration and invasion of SACC cells via EMT in vitro. Targeting the inactivation of the BDNF/TrkB axis may be a potential strategy for the treatment of SACC.

Effect of lung squamous cell carcinoma tumor microenvironment on the CD105+ endothelial cell proteome

In lung cancer, antiangiogenic treatment targeting tumor endothelial cells (ECs) provides a survival advantage. To fully elucidate the behavior of ECs in a tumor microenvironment, high-purity (>98%) normal, paratumor-, and tumor-derived CD105(+) ECs were purified from lung squamous cell carcinoma by incubating cells with anti-CD105 antibody-coated magnetic beads. These cells exhibited typical EC characteristics. Totally, 1765 proteins were identified with high confidence by isobaric stable isotope tags and two-dimensional LC/MS/MS (iTRAQ-2DLC/MS/MS). In particular, 178 and 162 proteins were differentially expressed in paratumor- and tumor-derived ECs, respectively, compared to normal ECs. The up- and down-regulation trends showed good interassay correlation. Using gene ontology, they were classified into genes involved in major reprogramming of cellular metabolic processes, oxidative stress response, redox homeostasis, apoptosis, and platelet degranulation/activation. Moreover, tumor angiogenesis-initiating ECs appeared to acquire distinct properties. For example, cell migration and regulation of smooth muscle cell migration of paratumor-derived ECs were significantly faster than that of normal and tumor-derived ECs. Among them, two migration-associated proteins, neuropilin 1 and platelet-derived growth factor receptor β predominantly expressed in ECs of paratumor from 16 patients with lung squamous cell carcinoma, were identified as potential biomarkers for antiangiogenic therapy.

The Roles of Epithelial-to-Mesenchymal Transition (EMT) and Mesenchymal-to-Epithelial Transition (MET) in Breast Cancer Bone Metastasis: Potential Targets for Prevention and Treatment

Many studies have revealed molecular connections between breast and bone. Genes, important in the control of bone remodeling, such as receptor activator of nuclear kappa (RANK), receptor activator of nuclear kappa ligand (RANKL), vitamin D, bone sialoprotein (BSP), osteopontin (OPN), and calcitonin, are expressed in breast cancer and lactating breast. Epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) effectors play critical roles during embryonic development, postnatal growth, and epithelial homeostasis, but also are involved in a number of pathological conditions, including wound repair, fibrosis, inflammation, as well as cancer progression and bone metastasis. Transforming growth factor β (TGFβ), insulin-like growth factor I & II (IGF I & II), platelet-derived growth factor (PDGF), parathyroid hormone-related protein (PTH(rP)), vascular endothelial growth factor (VEGF), epithelial growth factors II/I (ErbB/EGF), interleukin 6 (IL-6), IL-8, IL-11, IL-1, integrin αvβ3, matrix metalloproteinases (MMPs), catepsin K, hypoxia, notch, Wnt, bone morphogenetic proteins (BMP), and hedgehog signaling pathways are important EMT and MET effectors identified in the bone microenviroment facilitating bone metastasis formation. Recently, Runx2, an essential transcription factor in the regulation of mesenchymal cell differentiation into the osteoblast lineage and proper bone development, is also well-recognized for its expression in breast cancer cells promoting osteolytic bone metastasis. Understanding the precise mechanisms of EMT and MET in the pathogenesis of breast cancer bone metastasis can inform the direction of therapeutic intervention and possibly prevention.

Oncogenic H-ras reprograms Madin-Darby canine kidney (MDCK) cell-derived exosomal proteins following epithelial-mesenchymal transition

Epithelial-mesenchymal transition (EMT) is a highly conserved morphogenic process defined by the loss of epithelial characteristics and the acquisition of a mesenchymal phenotype. EMT is associated with increased aggressiveness, invasiveness, and metastatic potential in carcinoma cells. To assess the contribution of extracellular vesicles following EMT, we conducted a proteomic analysis of exosomes released from Madin-Darby canine kidney (MDCK) cells, and MDCK cells transformed with oncogenic H-Ras (21D1 cells). Exosomes are 40-100 nm membranous vesicles originating from the inward budding of late endosomes and multivesicular bodies and are released from cells on fusion of multivesicular bodies with the plasma membrane. Exosomes from MDCK cells (MDCK-Exos) and 21D1 cells (21D1-Exos) were purified from cell culture media using density gradient centrifugation (OptiPrep™), and protein content identified by GeLC-MS/MS proteomic profiling. Both MDCK- and 21D1-Exos populations were morphologically similar by cryo-electron microscopy and contained stereotypical exosome marker proteins such as TSG101, Alix, and CD63. In this study we show that the expression levels of typical EMT hallmark proteins seen in whole cells correlate with those observed in MDCK- and 21D1-Exos, i.e. reduction of characteristic inhibitor of angiogenesis, thrombospondin-1, and epithelial markers E-cadherin, and EpCAM, with a concomitant up-regulation of mesenchymal makers such as vimentin. Further, we reveal that 21D1-Exos are enriched with several proteases (e.g. MMP-1, -14, -19, ADAM-10, and ADAMTS1), and integrins (e.g. ITGB1, ITGA3, and ITGA6) that have been recently implicated in regulating the tumor microenvironment to promote metastatic progression. A salient finding of this study was the unique presence of key transcriptional regulators (e.g. the master transcriptional regulator YBX1) and core splicing complex components (e.g. SF3B1, SF3B3, and SFRS1) in mesenchymal 21D1-Exos. Taken together, our findings reveal that exosomes from Ras-transformed MDCK cells are reprogrammed with factors which may be capable of inducing EMT in recipient cells.