The epithelial-mesenchymal transition regulators Twist, Slug, and Snail are associated with aggressive tumour features and poor outcome in prostate cancer patients.

The prognostic importance of transcription factors promoting epithelial-mesenchymal transition (EMT) and angiogenesis has not been well explored in prostate cancer patients with long follow-up, nor the interplay between these factors. The objective of this study was to assess the individual protein expression and co-expression of Twist, Slug (Snai2), Snail (Snai1), and hypoxia-inducible factor-1 alpha (Hif-1α) in prostate cancer in relation to EMT, angiogenesis, hypoxia, tumour features, disease recurrence, and patient survival. Immunohistochemical staining was performed on tissue microarray sections from 338 radical prostatectomies with long follow-up. In addition, 41 cases of prostatic hyperplasia, 33 non-skeletal metastases, 13 skeletal metastases, and 33 castration-resistant prostate carcinomas were included. Our findings were validated in external gene expression data sets. Twist was overexpressed in primary prostate cancer and markedly reduced in distant metastases (p < 0.0005). Strong expression of Twist and Slug was associated with Hif-1α in localised prostate cancer (p ≤ 0.001), and strong Twist was associated with Hif-1α in castration-resistant carcinomas (p = 0.044). Twist, Slug, and increased Snail at the tumour stromal border were associated with vascular factors (p ≤ 0.045). Each of the three EMT-regulating transcription factors were associated with aggressive tumour features and shorter time to recurrence and cancer-specific death. Notably, the co-expression of factors demonstrated an enhanced influence on outcome. In the subgroup of E-cadherinlow carcinomas, strong Slug was associated with shorter time to all end points and was an independent predictor of time to multiple end points, including cancer-specific death (hazard ratio 3.0, p = 0.041). To conclude, we demonstrate an important relation between EMT, hypoxia, and angiogenesis and a strong link between the investigated EMT regulators and aggressive tumour features and poor patient outcome in prostate cancer. Despite the retrospective nature of this long-term study, our findings could have a significant impact on the future treatment of prostate cancer, where tailored therapies might be directed simultaneously against epithelial-mesenchymal phenotypes, angiogenesis, and tumour hypoxia.

Epithelial-mesenchymal transition in undifferentiated carcinoma of the pancreas with and without osteoclast-like giant cells.

Undifferentiated carcinoma (UC) and undifferentiated carcinoma with osteoclast-like giant cells (UCOGC) are peculiar variants of pancreatic ductal adenocarcinoma (PDAC), characterized by hypercellularity and absence of glandular patterns. The inflammatory microenvironment is peculiar in UCOGC, since it is dominated by macrophages and osteoclast-like giant cells. However, from a molecular point of view, both UC and UCOGC are very similar to conventional PDAC, sharing alterations of the most common genetic drivers. Clinically, UC usually show a worse prognosis, whereas UCOGC may show a better prognosis if it is not associated with a PDAC component. To highlight potential biological differences between these entities, we investigated the role of the epithelial to mesenchymal transition (EMT) in UC and UCOGC. Specifically, we analyzed the immunohistochemical expression of three well-known EMT markers, namely Twist1, Snai2, and E-cadherin, in 16 cases of UCOGC and 10 cases of UC. We found that EMT is more frequently activated in UC (10/10 cases) than in UCOGC (8/16 cases; p = 0.05). Furthermore, in UCOGC, EMT was activated with a higher frequency in cases with an associated PDAC component. Snai2 was the most frequently and strongly expressed marker in both tumor types (10/10 UC, 8/16 UCOGC), and its expression was higher in UC than in UCOGC (mean immunohistochemical score: 4.8 in UC vs. 2.1 in UCOGC, p < 0.01). Our results shed new light on the biology of UC and UCOGC: EMT appeared as a more important process in UC, and Snai2 emerged as a central EMT effector in this setting.

Systematic analysis reveals a functional role for STAMBPL1 in the epithelial-mesenchymal transition process across multiple carcinomas.

BACKGROUND: Deubiquitinating enzymes (DUBs) are linked to cancer progression and dissemination, yet less is known about their regulation and impact on epithelial-mesenchymal transition (EMT). METHODS: An integrative translational approach combining systematic computational analyses of The Cancer Genome Atlas cancer cohorts with CRISPR genetics, biochemistry and immunohistochemistry methodologies to identify and assess the role of human DUBs in EMT. RESULTS: We identify a previously undiscovered biological function of STAM-binding protein like 1 (STAMBPL1) deubiquitinase in the EMT process in lung and breast carcinomas. We show that STAMBPL1 expression can be regulated by mutant p53 and that its catalytic activity is required to affect the transcription factor SNAI1. Accordingly, genetic depletion and CRISPR-mediated gene knockout of STAMBPL1 leads to marked recovery of epithelial markers, SNAI1 destabilisation and impaired migratory capacity of cancer cells. Reversely, STAMBPL1 expression reprogrammes cells towards a mesenchymal phenotype. A significant STAMBPL1-SNAI1 co-signature was observed across multiple tumour types. Importantly, STAMBPL1 is highly expressed in metastatic tissues compared to matched primary tumour of the same lung cancer patient and its expression predicts poor prognosis. CONCLUSIONS: Our study provides a novel concept of oncogenic regulation of a DUB and presents a new role and predictive value of STAMBPL1 in the EMT process across multiple carcinomas.

Cancer cells grown in 3D under fluid flow exhibit an aggressive phenotype and reduced responsiveness to the anti-cancer treatment doxorubicin.

3D laboratory models of cancer are designed to recapitulate the biochemical and biophysical characteristics of the tumour microenvironment and aim to enable studies of cancer, and new therapeutic modalities, in a physiologically-relevant manner. We have developed an in vitro 3D model comprising a central high-density mass of breast cancer cells surrounded by collagen type-1 and we incorporated fluid flow and pressure. We noted significant changes in cancer cell behaviour using this system. MDA-MB231 and SKBR3 breast cancer cells grown in 3D downregulated the proliferative marker Ki67 (P < 0.05) and exhibited decreased response to the chemotherapeutic agent doxorubicin (DOX) (P < 0.01). Mesenchymal markers snail and MMP14 were upregulated in cancer cells maintained in 3D (P < 0.001), cadherin-11 was downregulated (P < 0.001) and HER2 increased (P < 0.05). Cells maintained in 3D under fluid flow exhibited a further reduction in response to DOX (P < 0.05); HER2 and Ki67 levels were also attenuated. Fluid flow and pressure was associated with reduced cell viability and decreased expression levels of vimentin. In summary, aggressive cancer cell behaviour and reduced drug responsiveness was observed when breast cancer cells were maintained in 3D under fluid flow and pressure. These observations are relevant for future developments of 3D in vitro cancer models and organ-on-a-chip initiatives.

PITX2 Expression in Non-functional Pituitary Neuroendocrine Tumor with Cavernous Sinus Invasion.

Although most pituitary neuroendocrine tumors (PitNETs) show benign behavior, a significant number of PitNETs exhibit an aggressive course including cavernous sinus (CS) invasion. To date, the cause of CS invasion has not been fully elucidated. In this study, we analyzed the relationship between CS invasion in PitNETs and the expression of PITX2 and SNAIL1, which are the transcription factors associated with the morphogenesis of pituitary gland. Sixty cases with non-functional PitNETs were classified into four types: type 1a, none of CS invasion and suprasellar expansion; type 1b, suprasellar expansion without CS invasion; type 2a, CS invasion without suprasellar expansion; and type 2b, CS invasion with suprasellar expansion. We analyzed the expression of PITX2 and SNAIL1 employing quantitative real-time polymerase chain reaction (qPCR) and immunohistochemistry. Other parameters such as mitotic count, Ki-67 index, and p53 expression were also analyzed, which were previously reported as potential tumor proliferative markers in PitNETs. PITX2 expression was significantly higher in PitNETs with CS invasion than PitNETs without CS invasion (P = 0.019). Expression of SNAIL1 was significantly elevated in PitNETs with suprasellar expansion compared with PitNETs without suprasellar expansion (P = 0.02). There was no apparent relationship between CS invasion and mitotic count, Ki-67 index, and p53 expression (mitotic count, P = 0.11; Ki-67 index, P = 0.61; p53, P = 0.66). High PITX2 expression was observed in non-functional PitNETs with CS invasion, suggesting that PITX2 may be involved in CS invasion of PitNETs.

Expression of selected epithelial-mesenchymal transition transcription factors in serous borderline ovarian tumors and type I ovarian cancers.

Epithelial ovarian neoplasms are a heterogeneous group including tumor subsets with distinct clinicopathologic and molecular features. Recent evidence from molecular and genomic studies suggests that whereas low-grade serous carcinomas and high-grade serous carcinomas likely develop on two separate pathways, the low-grade serous carcinomas and serous borderline ovarian tumors may represent various stages of the same developmental continuum. The transformation of borderline ovarian tumors into an invasive neoplasm is associated with an array of molecular changes, inter alia controlled by p53 and PI3K/Akt pathway, as well as with a decrease in E-cadherin expression. The latter implies that epithelial-mesenchymal transition is a critical determinant of borderline ovarian tumor invasiveness. The aim of this study was to analyze the expression of transcription factors involved in epithelial-mesenchymal transition: SNAIL, SLUG, TWIST 1, TWIST 2, ZEB 1, and ZEB 2 in borderline tumors and type I ovarian cancers. The study included tissue specimens from 42 patients with histopathologically verified ovarian masses. The expressions for SLUG, TWIST 1, ZEB1, and ZEB 2 were scored based on the nuclear staining, and the expressions of SNAIL and TWIST 2 based on the cytoplasmic and/or nuclear staining. The proportions of ovarian tumors with the immunoexpression of the epithelial-mesenchymal transition transcription factors were 85.7% for SNAIL, 100% for SLUG, 9.5% for TWIST 1, 95.2% for TWIST 2, 23.8% for ZEB 1, and 0% for ZEB 2. The expression patterns of SNAIL, SLUG, TWIST, and ZEB identified in this study suggest that both serous borderline ovarian tumors and type I ovarian cancers undergo dynamic epithelial-mesenchymal interconversions. Our findings obtained in the two groups of tumors which shared some etiopathogenic pathways imply that the expression of the epithelial-mesenchymal transition transcription factors may be activated at early stages of the epithelial-mesenchymal transition, and thus these molecules may play a pivotal role in the development of both serous borderline ovarian tumors and type I ovarian cancer.

Snail immunohistochemical overexpression correlates to recurrence risk in non-muscle invasive bladder cancer: results from a longitudinal cohort study.

The current WHO/ISUP classification and grading system subdivides urothelial tumours into prognostically distinct categories. Understanding the molecular pathways involved in bladder cancer development can improve patient stratification and management. This study aims to investigate the relationship between Snail, Slug and E-cadherin expressions and clinico-pathological features of non-muscle invasive bladder carcinoma (NMIBC). All patients attending the same urological centre from January to May 2002, who were pathologically diagnosed with NMIBC, were enrolled in this longitudinal cohort study. E-cadherin, Snail and Slug protein expressions were assessed by immunohistochemical analysis and compared with follow-up data. The main outcome measures were recurrence and progression rates. The cohort under investigation included 43 patients (38 men and 5 women, mean age 67.7 ± 10.6 years). High-grade (HG) carcinomas were 20/43, with 10 invasive cases (pT1). Low-grade (LG) carcinomas were 23/43, with no invasive cases (pTa). Among the eight HGpTa cases with recurrence, strong Snail expression was detected in six (75%). Out of the 17 LGpTa patients who experienced recurrence, 12 (70.6%) showed strong positivity for Snail. Among the 10 HGpT1 cases, recurrence was observed in 4, of which, 3 (75%) stained intensely for Snail. The Kaplan-Meier curves showed significantly different recurrence rates for patients with strong or weak Snail reactivity (p = 0.027). E-cadherin and Slug expression did not correlate with any of the parameters considered. On multivariate analysis, Snail expression was recognised as an independent prognostic factor for tumour recurrence (p = 0.003). In our study population, Snail immunohistochemical overexpression proved to be related to tumour recurrence in patients affected by NMIBC.

Prognostic value of Twist, Snail and E-cadherin expression in pathological N0 non-small-cell lung cancer: a retrospective cohort study.

OBJECTIVES: Lung cancer is the leading cause of cancer-related death worldwide. The 5-year survival rate for patients after curative surgery with pathological N0 non-small-cell lung cancer (NSCLC) is as low as 56%, which is due to recurrence and metastasis. Emerging evidence suggests that epithelial-mesenchymal transition is important for cancer metastasis. Twist and Snail are epithelial-mesenchymal transition regulators that induce metastasis by down-regulating E-cadherin. The aim of this study was to evaluate the prognostic value of Twist, Snail and E-cadherin expression in patients with resectable pathological N0 NSCLC. METHODS: The expression levels of Twist, Snail and E-cadherin in 78 patients with resected pathological N0 NSCLC were assessed using immunohistochemistry. The association between the expression of Twist/Snail/E-cadherin and overall survival (OS) and recurrence-free survival (RFS) was investigated. RESULTS: High expression of Twist, Snail and E-cadherin was detected in 18%, 21% and 53% of NSCLC samples, respectively. High expression of Twist and Snail and low expression of E-cadherin were associated with worse RFS [hazard ratio (HR) 2.29, 95% confidence interval (CI) 1.07-4.87, P = 0.026; HR 2.54, 95% CI 1.24-5.20, P = 0.008 and HR 2.41, 95% CI 1.23-4.73, P = 0.007, respectively] and worse OS (HR 2.26, 95% CI 1.01-5.04, P = 0.040; HR 2.56, 95% CI 1.20-5.43, P = 0.011 and HR 2.42, 95% CI 1.18-4.95, P = 0.012, respectively). Co-expression of at least 2 markers from the combination of high Twist/high Snail/low E-cadherin expression predicted poor RFS and OS (HR 4.12, 95% CI 2.08-8.16, P < 0.001 and HR 4.28, 95% CI 2.08-8.77, P < 0.001, respectively), and it was an independent predictor of RFS and OS (HR 3.99, 95% CI 1.89-8.44, P < 0.001 and HR 4.16, 95% CI 1.88-9.18, P < 0.001, respectively). CONCLUSIONS: Co-expression of at least 2 markers from the combination of high Twist/high Snail/low E-cadherin expression was a significant prognostic predictor in patients with pathological N0 NSCLC.

Expression of E-cadherin, Slug and NCAM and its relationship to tumor invasiveness in patients with acromegaly

Pituitary adenomas account for 10-15% of primary intracranial tumors. Growth hormone (GH)-secreting adenomas account for 13% of all pituitary adenomas and cause acromegaly. These tumors can be aggressive, invade surrounding structures and are highly recurrent. The objective of this study was to evaluate E-cadherin, Slug and neural cell adhesion molecule (NCAM) expression in GH-secreting pituitary adenomas and its relationship to tumor invasiveness. A cross-sectional study of patients who underwent hypophysectomy due to GH-secreting pituitary adenoma from April 2007 to December 2014 was carried out. The medical records were reviewed to collect clinical data. Immediately after surgery, tumor samples were frozen in liquid nitrogen and stored in a biofreezer at -80°C for assessment of E-cadherin 1 (CDH1), SLUG (SNAI2), and NCAM (NCAM1) by real-time PCR. The samples were fixed in formalin and embedded in paraffin for immunohistochemical analysis of E-cadherin and NCAM. Thirty-five patients with acromegaly were included in the study. Of these, 65.7% had invasive tumors. Immunohistochemically, E-cadherin was expressed in 96.7% of patients, and NCAM in 80% of patients. There was no statistically significant relationship between tumor grade or invasiveness and immunohistochemical expression of these markers. Regarding gene expression, 50% of cases expressed CDH1, none expressed SNAI2, and 53.3% expressed NCAM1. There was no statistically significant relationship between tumor grade or invasiveness and gene expression of CDH1, SNAI2, and NCAM1. The absence of Slug overexpression and of E-cadherin and NCAM suppression suggests that expression of these markers is not associated with tumor invasiveness in GH-secreting pituitary adenomas.

Expression of E-cadherin, Slug and NCAM and its relationship to tumor invasiveness in patients with acromegaly.

Pituitary adenomas account for 10-15% of primary intracranial tumors. Growth hormone (GH)-secreting adenomas account for 13% of all pituitary adenomas and cause acromegaly. These tumors can be aggressive, invade surrounding structures and are highly recurrent. The objective of this study was to evaluate E-cadherin, Slug and neural cell adhesion molecule (NCAM) expression in GH-secreting pituitary adenomas and its relationship to tumor invasiveness. A cross-sectional study of patients who underwent hypophysectomy due to GH-secreting pituitary adenoma from April 2007 to December 2014 was carried out. The medical records were reviewed to collect clinical data. Immediately after surgery, tumor samples were frozen in liquid nitrogen and stored in a biofreezer at -80°C for assessment of E-cadherin 1 (CDH1), SLUG (SNAI2), and NCAM (NCAM1) by real-time PCR. The samples were fixed in formalin and embedded in paraffin for immunohistochemical analysis of E-cadherin and NCAM. Thirty-five patients with acromegaly were included in the study. Of these, 65.7% had invasive tumors. Immunohistochemically, E-cadherin was expressed in 96.7% of patients, and NCAM in 80% of patients. There was no statistically significant relationship between tumor grade or invasiveness and immunohistochemical expression of these markers. Regarding gene expression, 50% of cases expressed CDH1, none expressed SNAI2, and 53.3% expressed NCAM1. There was no statistically significant relationship between tumor grade or invasiveness and gene expression of CDH1, SNAI2, and NCAM1. The absence of Slug overexpression and of E-cadherin and NCAM suppression suggests that expression of these markers is not associated with tumor invasiveness in GH-secreting pituitary adenomas.

Selective cyclooxygenase-2 inhibitor NS-398 attenuates myocardial fibrosis in mice after myocardial infarction via Snail signaling pathway.

OBJECTIVE: The role of NS-398 in Snail pathway of myocardial cells in mice after myocardial infarction and its effect on myocardial fibrosis were investigated in this study. MATERIALS AND METHODS: C57BL/6 mice were selected to establish mouse models of myocardial infarction with permanent ligation of anterior descending branch and sham-operation models without ligation. After successful establishment of models, 30 mice were randomly divided into sham-operation group, myocardial infarction group and drug intervention group. The drug intervention group was treated with intraperitoneal injection of NS-398 (5 mg/kg) at 1 week after modeling for 3 weeks. The survival status of mice after operation was monitored, the cardiac function was detected via echocardiography, the collagen levels in heart tissue pathological sections were detected via Masson staining and Sirius red staining. Moreover, the expressions of Snail and type I collagen levels were detected via immunohistochemistry, and the Snail protein expression level and the activity and expression level of E-cadherin protein were detected via Western blotting. RESULTS: At 4 weeks after establishment of myocardial infarction model, the fibrosis reaction was obvious, and the cardiac function was decreased, accompanied with Snail activation. The administration of NS-398 for 3 weeks inhibited the Snail activity expression and significantly improved the fibrosis degree after infarction. However, it did not improve the cardiac function. Inhibiting Snail improved the fibrosis reaction after infarction, in which Snail/E-cadherin signaling pathway was involved. CONCLUSIONS: NS-398 improves the myocardial fibrosis in mice after myocardial infarction through inhibiting the Snail signaling pathway.

Expression of Epithelial-Mesenchymal Transition Regulating Transcription Factors in Head and Neck Squamous Cell Carcinomas.

BACKGROUND/AIM: The transcription factors Twist, Snail, Slug, ZEB1 and ZEB2 regulate epithelial-mesenchymal transition (EMT) and their expression has been associated with a poor prognosis in several cancer entities. The aim of this analysis was to investigate in parallel the expression of all of these transcription factors in head and neck squamous cell carcinomas (HNSCCs) in order to gain insight into their possible co-expression. MATERIALS AND METHODS: Tumor tissue samples were immunohistochemically stained using antibodies against these transcription factors. The staining intensity and cellular distribution of the immunoreactivity was recorded. RESULTS: In general, transcription factor immunoreactivity was noted in the nucleus of both cancer and stromal cells. The highest immunoreactivity was observed for Twist. Snail, Slug, ZEB1 and ZEB2 showed a much lesser immunoreactivity in cancer cells and they were expressed independently from each other. CONCLUSION: Twist is the major transcription factor active in HNSCC; the other transcription factors of EMT seem to be of less importance in this tumor entity.

Tumoral and stromal expression of Slug, ZEB1, and ZEB2 in brain metastasis.

Epithelial-to-mesenchymal transition (EMT) has an active role in the malignant progression of epithelial tumor cells. The aim of the study was to identify the existence of the EMT mechanism in brain metastasis. Tumors from 29 patients with brain metastases were assessed in terms of the immunoexpression of EMT-related factors including Slug, ZEB1, ZEB2, and E-cadherin in tumor cells and the surrounding mesenchymal stromal cells. The results were compared between primary tumors and their matched metastatic brain tumors. Analysis of tumor cell expression showed that Slug, ZEB1, or ZEB2 expression was found in more than 10% of the neoplastic cells in the metastatic lesions of 17 cases (59%) and in the primary lesions of 7 cases (24%, P=0.02). The expression level of ZEB2 was negatively correlated with that of E-cadherin (P=0.05). There were no differences in the tumoral expression levels of Slug, ZEB1, or ZEB2 among the primary organs. Analysis of stromal cell expression revealed a global increase in ZEB1 and ZEB2 expression levels with metastases (P<0.0001). Quantitative analysis confirmed that messenger RNA expression of ZEB1 and ZEB2 was elevated in metastatic lesions. The increased expression of EMT-related factors in brain metastasis was found not only in tumor cells, but also in tumor-associated stromal cells. Our results suggest that EMT-related factors play a role as a facilitator of brain metastasis.

Increased risk of poor survival in ovarian cancer patients with high expression of SNAI2 and lymphovascular space invasion.

This study is aimed to conduct a meta-analysis to evaluate the prognostic value of lymphovascular space invasion(LVSI) and to explore the potential association of SNAI1 and SNAI2 with LVSI in ovarian cancer. A systematic literature search in PubMed, ISI Web of Science, and Medline was conducted to identify relevant studies assessing the prognostic value of LVSI in ovarian cancer. The main outcomes analyzed were progression free survival/disease free survival and overall survival. TCGA database was used to explore the potential link of SNAI1 and SNAI2 with LVSI status. A total of 11 eligible studies enrolling 1817 patients were included for the meta-analysis. The overall analysis indicated that LVSI presence was associated with shorter duration of survival in ovarian cancer patients. Multivariate analysis indicated that both advanced stage and SNAI2 expression were associated with increased risk of LVSI presence. Survival analysis indicated that tumors with LVSI presence and high SNAI2 expression were significantly correlated with poorer survival when compared to tumors with both LVSI absence and low SNAI2 expression. In conclusion, LVSI presence was associated with worse clinical outcomes in ovarian cancer. Increased expression of SNAI2 and advanced stage were independent risk factors for LVSI presence. Our findings also emphasizes the potential of SNAI2 in promoting lymphovascular spread of ovarian cancer.

Tumor budding at the invasive front of colorectal cancer may not be associated with the epithelial-mesenchymal transition.

Tumor budding is thought to reflect the epithelial-mesenchymal transition (EMT). However, the molecular mechanism linking tumor buds and the EMT remains unclear. Here, we examined the induction of tumor budding and EMT and their association with EMT-related proteins (ZEB1, TWIST, SNAIL, and SLUG) in colorectal cancer (CRC). Immunohistochemical expression of pan-cytokeratin was examined for identification of tumor budding in 101 CRCs. Grading of tumor budding was classified into low- and high-grade groups. Tissue microarray was conducted to identify tumor budding sites. The expression of E-cadherin, ZEB1, TWIST, SNAIL, and SLUG was examined in areas of tumor budding and the surrounding tumor stroma using a double-immunostaining method. Specifically, pan-cytokeratin and EMT-related proteins were assessed by double immunostaining. Low or no expression of E-cadherin was found in areas of tumor budding. Moreover, ZEB1, TWIST, SNAIL, and SLUG were not expressed in regions of tumor budding. However, the expression level of ZEB1 in the stromal cells surrounding tumor budding was significantly more frequent than that of TWIST, SNAI, and SLUG. In addition, the expression of EMT-related proteins in surrounding stromal cells was significantly greater in areas of high-grade tumor budding than in low-grade areas. Our present results suggest that EMT-related proteins play a minor role in forming tumor buds. In addition, our findings suggest the existence of subtypes of stromal cells in CRC with phenotypical and functional heterogeneity.

The role of miRNA-21 and epithelial mesenchymal transition (EMT) process in colorectal cancer.

AIMS: The study was conducted to assess the expression levels of epithelial mesenchymal transition (EMT) proteins (E-cadherin, N-cadherin, snail-1 and vimentin) and miRNA-21. In addition, we correlated these data with clinicopathological features in Colorectal cancer. METHODS: H&E slides from a total of 59 formalin fixed paraffin embedded tissue blocks were examined by a pathologist to demarcate normal and tumour regions. Immunohistochemical analysis of mismatch repair proteins (MLH1, MSH2 and MSH6) and EMT markers (E-cadherin, N-cadherin, snail-1 and vimentin) was performed. The miRNA-21 expression levels were determined using qRT-PCR and the data was analysed using the relative quantification method. The Fisher's exact and Pearson's χ2 tests were used to correlate snail-1, E-cadherin, miRNA-21 and clinicopathological data. RESULTS: Our results showed a statistically significant correlation between high miRNA-21 expression levels and E-cadherin positive cases. There was also an association between high miRNA-21 expression levels and negative snail-1 expression. No significant correlation was seen between miRNA-21 expression levels and clinicopathological features. Moreover, high expression levels of miRNA-21 were significantly associated with the sporadic cases. CONCLUSIONS: Our data suggest that miRNA-21 in association with E-cadherin and snail-1 does not play a significant role in the development and progression of this disease.

Immunopathological characterization of cryptoglandular anal fistula: a pilot study investigating its pathogenesis.

AIM: The pathogenesis of cryptoglandular anal fistula (AF) is still under debate. Tissue inflammation could play a primary role. The pathological process of epithelial mesenchymal transition (EMT) might be involved but has never been investigated. METHOD: In a prospective pilot study, 12 patients with an AF had a fistulectomy. The excised track was divided into proximal (intrasphincteric) and distal (extrasphincteric) parts which were subjected to standard histopathological examination. The cytokines IL-8 and IL-1beta were analysed as markers of inflammation, while EMT was evaluated by expression of TGF-beta, Vimentin, Zeb-1, Snail and E-cadherin. The mRNA and protein expression of these molecules was investigated by real-time PCR (RT-PCR), Western blot analysis and immunohistochemistry and was compared with that of the normal adjacent tissue. RESULTS: Chronic inflammation and granulation tissue and a stratified epithelium were evident on standard histopathological examination. The cytokine IL-8 was more expressed in the proximal than the distal part of the track (fold increase 4.34 vs 3.60), while the reverse was found for IL-1beta (fold increase 1.33 vs 2.01); both were more intensely expressed compared with the normal anal mucosa. EMT was demonstrated, in both proximal and distal parts of the track, with an increase of TGF-beta, Vimentin, Zeb-1 and Snail and a mean decrease of E-cadherin. Western blot analysis and immunohistochemistry confirmed the protein expression. CONCLUSION: The study suggests that chronic inflammation is present in cryptoglandular fistulas. The inflammatory pattern might be different in the proximal than in the distal part of the fistula track. The cytokines IL-1beta and IL-8 could play a possible role in fistula formation. The study demonstrates for the first time the potential importance of EMT in the pathogenesis of cryptoglandular AF.

PD-L1 expression is associated with epithelial-to-mesenchymal transition in adenocarcinoma of the lung.

PD-1/PD-L1-targeted immunotherapy has emerged as a promising therapeutic strategy for pulmonary adenocarcinoma (pADC). Epithelial-to-mesenchymal transition (EMT) is involved in the progression and immune evasion of cancers. Therefore, we investigated the association between PD-L1 expression and EMT phenotype in pADC. Immunohistochemistry for E-cadherin (epithelial marker), ZEB1, SNAIL, SLUG, vimentin (mesenchymal markers), PD-L1, CD8, and PD-1 was performed on 477 cases of pADC. Cases were classified into epithelial, mesenchymal, epithelial-mesenchymal, and unspecified types based on immunohistochemical results. PD-L1 expression was scored as 0 in 14.0% (n=67), 1 in 26.4% (n=126), 2 in 51.2% (n=244), and 3 in 8.4% (n=40). PD-L1 score was positively correlated with SNAIL and vimentin H scores (P<.001, both). After dichotomizing patients into PD-L1-negative and PD-L1-positive groups, PD-L1 positivity was significantly higher in patients with mesenchymal (71.2%; 84/118) and epithelial-mesenchymal (62.7%; 84/134) phenotypes compared with those with epithelial (50.6%; 44/87) and unspecified (50.0%; 35/70) phenotypes (P=.005). The significant association between PD-L1 expression and EMT phenotype was maintained in EGFR-mutated pADCs. Moreover, cases with EMT phenotype (ie, mesenchymal and epithelial-mesenchymal) were infiltrated by higher numbers of CD8+ and PD-1+ cells than those with epithelial and unspecified phenotypes in EGFR-mutated pADCs (P=.043 for CD8+ cells and P<.001 for PD-l+ cells). Particularly, cases with EMT phenotype and PD-L1 expression showed the greatest amount of CD8+ and PD-1+ cells in EGFR-mutated cases (P=.043 for CD8+ cells and P=.005 for PD-1+ cells). This study demonstrates that EMT phenotype is related to PD-L1 overexpression in pADC cells and patients with EMT-phenotype pADC may benefit from PD-1/PD-L1-blocking immunotherapy.

BRAF and epithelial-mesenchymal transition in primary cutaneous melanoma: a role for Snail and E-cadherin?

In vitro studies in melanoma indicate that up-regulation of the transcriptional repressor Snail occurs with a concomitant decrease of its target E-cadherin, both hallmarks of epithelial-mesenchymal transition-an association not established in vivo. We sought to elucidate the relationship between BRAF, Snail, E-cadherin, and established histopathologic prognosticators in primary cutaneous melanoma. Archived annotated samples with a diagnosis of primary cutaneous melanoma were retrieved (n = 68 cases; 34 BRAF mutant and 34 BRAF wild type) and immunohistochemically stained for Snail and E-cadherin protein expression. A semiquantitative scoring system was used. Multivariate logistic analysis was used to control confounders of BRAF. Snail expression was significantly associated only with ulceration (42% versus 13%; P = .02). E-cadherin expression was present in 26% of BRAF mutant and 71% of BRAF wild-type cases (P = .0003). Loss of E-cadherin expression was associated with female sex (60% versus 34%; P = .05), BRAF mutation (74% versus 29%; P = .0003), thickness greater than or equal to 1 mm (68% versus 32%; P = .004), mitosis (63% versus 25%; P = .007), and ulceration (75% versus 44%; P = .05). BRAF mutation was associated with male sex (60% versus 30%; P = .02), Breslow thickness (P = .007), thickness greater than or equal to 1 mm (68% versus 29%; P = .002), and ulceration (75% versus 42%; P = .02). Snail expression did not correlate with loss of E-cadherin expression (47% versus 53%; P = .79). After controlling for potential confounding, BRAF mutation was associated with loss of E-cadherin (adjusted odds ratio, 8.332; 95% confidence interval, 2.257-30.757; P = .0015) and Breslow thickness greater than 1 mm (adjusted odds ratio, 7.360; 95% confidence interval, 1.534-35.318; P = .0126). Our findings, indicating that mutant BRAF represses E-cadherin expression, implicating a catalytic role for BRAF in epithelial-mesenchymal transition.

Evaluation of aldehyde dehydrogenase 1 and transcription factors in both primary breast cancer and axillary lymph node metastases as a prognostic factor.

BACKGROUND: Aldehyde dehydrogenase 1 (ALDH1) is a marker of breast cancer stem cells, and the expression of ALDH1 may be a prognostic factor of poor clinical outcome. The epithelial-mesenchymal transition may produce cells with stem-cell-like properties promoted by transcription factors. We investigated the expression of ALDH1 and transcription factors in both primary and metastatic lesions, and prognostic value of them in breast cancer patients with axillary lymph node metastasis (ALNM). METHOD: Forty-seven breast cancer patients with ALNM who underwent surgery at Okayama University Hospital from 2002 to 2008 were enrolled. We retrospectively evaluated the levels of ALDH1 and transcription factors, such as Snail, Slug and Twist, in both primary and metastatic lesions by immunohistochemistry. RESULTS: In primary lesions, the positive rate of ALDH1, Snail, Slug and Twist was 19, 49, 40 and 26%, respectively. In lymph nodes, that of ALDH1, Snail, Slug and Twist was 21, 32, 13 and 23%, respectively. The expression of ALDH1 or transcription factors alone was not significantly associated with a poor prognosis. However, co-expression of ALDH1 and Slug in primary lesions was associated with a shorter DFS (P = 0.009). CONCLUSIONS: The evaluation of the co-expression of ALDH1 and transcription factors in primary lesions may be useful in prognosis of node-positive breast cancers.