Identification of TRPV4 as a novel target in invasiveness of colorectal cancer.

BACKGROUND: Emerging evidence has indicated the critical role of TRPV4 in diverse human cancers. However, the underlying molecular mechanism of TRPV4 in colon cancer invasiveness is still unknown. METHODS: Immunohistochemistry staining was used to analyze the expression of TRPV4 and ZEB1 in clinical tissues; Wound healing and transwell assays were applied to determine the cell invasiveness; Western blot was used to explore the relation between TRPV4 and ZEB1. RESULTS: Colon cancer cells were transfected with siRNA against TRPV4 or HC067047 (a selective TRPV4 antagonist), TRPV4 full-length plasmid or siRNA against ZEB1, or both, in order to measure cell migration and invasion. And we found that TRPV4 silencing or inhibition exhibited an inhibitory role in colon cancer cell migration and invasion, coupled with compromised EMT process, and suppressed AKT activity. TRPV4 stimulated expression of ZEB1 and consequently contributed to EMT process and invasiveness. It was also revealed that overexpression of TRPV4 and ZEB1 in clinical patients with local metastasis, and positive correlation between TRPV4 and ZEB1. CONCLUSIONS: Our results uncovered the role of TRPV4 in tumor metastasis and highlighted the potential mechanism of TRPV4-ZEB1 axis in indicating EMT.

Tissue cholesterol metabolism and prostate cancer aggressiveness: Ethno-geographic variations.

BACKGROUND: Prostate cancer (PCa) is more frequent and more aggressive in populations of African descent than in Caucasians. Since the fatty acid composition of peri-prostatic adipose tissue (PPAT) has been shown to differ according to the ethno-geographic origin and is involved in PCa aggressiveness, we aimed to analyze the cholesterol content of PPAT from Caucasian and African-Caribbean patients, in correlation with markers of disease aggressiveness and cholesterol metabolism in cancer tissues. METHODS: The quantification of cholesterol in PPAT was analyzed in 52 Caucasian and 52 African-Caribbean PCa patients, with in each group 26 indolent tumors (ISUP Group1 and pT2) and 26 potentially aggressive tumors (ISUP Group 3-5 and/or pT3). The expression of proteins involved in cholesterol metabolism was analyzed by immunohistochemistry on cancer tissue samples included in tissue microarrays. RESULTS: The amount of cholesterol esters was lower in PPAT from African-Caribbean patients compared with Caucasians, without any correlation with markers of disease aggressiveness. In cancer tissues from African-Caribbean patients, the expression of ABCA1 (involved in cholesterol efflux) was decreased, and that of SREBP-2 (involved in cholesterol uptake) was increased. In both groups of patients, SREBP-2 expression was strongly associated with that of Zeb1, a key player in the epithelial-to-mesenchymal transition (EMT) process. CONCLUSION: These results suggest that cholesterol metabolism differs according to the ethno-geographic origin, in both PPAT and cancer tissues. In African-Caribbeans, the orientation towards accumulation of cholesterol in cancer cells is associated with a more frequent state of EMT, which may promote PCa aggressiveness in this population.

A modified protein marker panel to identify four consensus molecular subtypes in colorectal cancer using immunohistochemistry.

Colorectal cancer (CRC) is a heterogeneous disease with different genetic and molecular backgrounds, leading to a diverse patient prognosis and treatment response. Four consensus molecular subtypes (CMS 1-4) have recently been proposed based on transcriptome profiling. A clinically practical immunohistochemistry (IHC) based CMS classifier consisting of the four markers FRMD6, ZEB1, HTR2B, and CDX2 was then demonstrated. However, the IHC-CMS classifier did not distinguish between CMS2 and CMS3 tumours. In this study, we have applied the proposed transcriptome based and IHC-based CMS classifiers in a CRC cohort of 65 patients and found a concordance of 77.5 %. Further, we modified the IHC-CMS classifier by analysing the differentially expressed genes between CMS2 and CMS3 tumours using RNA-sequencing data from the TCGA dataset. The result showed that WNT signalling was among the most upregulated pathways in CMS2 tumours, and the expression level of CTNNB1 (encoding ß-catenin), a WNT pathway hallmark, was significantly upregulated (P = 1.15 × 10-6). We therefore introduced nuclear ß-catenin staining to the IHC-CMS classifier. Using the modified classifier in our cohort, we found a 71.4 % concordance between the IHC and RNA-sequencing based CMS classifiers. Moreover, ß-catenin staining could classify 16 out of the 19 CMS2/3 tumours into CMS2 or CMS3, thereby showing an 84.2 % concordance with the RNA-sequencing-based classifier. In conclusion, we evaluated CMS classifiers based on transcriptome and IHC analysis. We present a modified IHC panel that categorizes CRC tumours into the four CMS groups. To our knowledge, this is the first study using IHC to identify all four CMS groups.

Expression of Epithelial-Mesenchymal Transition Markers in Treated Pancreatic Ductal Adenocarcinoma.

OBJECTIVES: Epithelial-mesenchymal transition (EMT) plays an important role in the progression, metastasis, and chemoresistance of pancreatic duct adenocarcinoma (PDAC); however, the expression of EMT markers and their clinical significance in PDAC patients who received neoadjuvant therapy (NAT) are unclear. METHODS: We examined the expression of EMT markers, including Zeb-1 (zinc finger E-box-binding homeobox 1), E-cadherin, and vimentin by immunohistochemistry in 120 PDAC patients who received NAT and pancreatectomy from 1999 to 2007. The results were correlated with clinicopathologic parameters and survival. RESULTS: Among 120 cases, 45 (37.5%) and 14 (11.7%) were positive for Zeb-1 and vimentin, respectively, and 25 (20.8%) were E-cadherin-low. The median overall survival and disease-free survival were 35.3 (standard deviation [SD], 2.8) and 15.9 (SD, 3.6) months, respectively, in vimentin-negative group compared with 16.1 (SD, 1.1) (P = 0.03) and 7.0 (SD, 1.1) months (P = 0.02) in the vimentin-positive group. In multivariate analysis, vimentin expression was an independent predictor of shorter disease-free survival (hazard ratio, 2.50; 95% confidence interval, 1.31-4.78; P = 0.016) and overall survival (hazard ratio, 2.55; 95% confidence interval, 1.33-4.89; P = 0.01). CONCLUSIONS: Epithelial-mesenchymal transition markers are frequently expressed in treated PDAC. Vimentin expression is a prognostic biomarker for survival in PDAC patients who received NAT.

The role of Zeb1 in the pathogenesis of morbidly adherent placenta.

Zinc finger E­box­binding homeobox 1 (Zeb1) is a promoter of epithelial­mesenchymal transformation, which may serve an important role in morbidly adherent placenta (MAP). In the present study, the protein expression levels of Zeb1 were examined in the placenta tissues of 60 patients, including 20 patients with placenta accreta (PA) and 20 patients with placenta previa without PA (UPA) and 20 patients in late pregnancy that delivered by cesarean section (normal). The expression levels of Zeb1, N­cadherin, vascular endothelial growth factor (VEGF), Tumor necrosis factor­related apoptosis­inducing ligand­receptor 2 (TRAIL­R2), and tumor necrosis factor­related apoptosis­inducing ligand­receptor 3 (TRAIL­R3) were higher in PA tissues compared with in normal control tissues. The expression levels of E­cadherin and TRAIL­R2 were decreased in PA tissues compared with in normal control tissues. These findings indicated that Zeb1 may serve an important role in placental attachment, thus promoting the development of dangerous PA. Overexpression of Zeb1 may upregulate the expression levels of N­cadherin, VEGF, TRAIL­R3, cyclin D1 and Bcl­2, and downregulate the expression levels of E­cadherin and TRAIL­R2. In addition, Zeb1 regulated the viability, apoptosis and migration of HTR­8/SV neo cells and human umbilical vein endothelial cells by regulating the Akt pathway. In conclusion, these findings indicated that Zeb1 may promote placental implantation by activating the Akt signaling pathway, thus providing a theoretical basis for investigating the causes of MAP.

Role of epithelial-mesenchymal transition factors in the histogenesis of uterine carcinomas.

Several subtypes of high-grade endometrial carcinomas (ECs) contain an undifferentiated component of non-epithelial morphology, including undifferentiated and dedifferentiated carcinomas and carcinosarcomas (CSs). The mechanism by which an EC undergoes dedifferentiation has been the subject of much debate. The epithelial-mesenchymal transition (EMT) is one of the mechanisms implicated in the transdifferentiation of high-grade carcinomas. To improve our understanding of the role of EMT in these tumors, we studied a series of 89 carcinomas including 14 undifferentiated/dedifferentiated endometrial carcinomas (UECs/DECs), 49 CSs (21 endometrial, 29 tubo-ovarian and peritoneal), 17 endometrioid carcinomas (grade 1-3), and 9 high-grade serous carcinomas of the uterus, using a panel of antibodies targeting known epithelial markers (Pan-Keratin AE1/AE3 and E-cadherin), mesenchymal markers (N-cadherin), EMT transcription factors (TFs) (ZEB1, ZEB2, TWIST1), PAX8, estrogen receptors (ER), progesterone receptors (PR), and the p53 protein. At least one of the three EMT markers (more frequently ZEB1) was positive in the sarcomatous component of 98% (n = 48/49) of CSs and 98% (n = 13/14) of the undifferentiated component of UEC/DEC. In addition, 86% of sarcomatous areas of CSs and 79% of the undifferentiated component of UEC/DEC expressed all three EMT-TFs. The expression of these markers was associated with the loss of or reduction in epithelial markers (Pan-keratin, E-cadherin), PAX8, and hormone receptors. In contrast, none of the endometrioid and serous endometrial carcinomas expressed ZEB1, while 6% and 36% of endometrioid and 11% and 25% of serous carcinomas focally expressed ZEB2 and TWIST1, respectively. Although morphologically different, EMT appears to be implicated in the dedifferentiation in both CSs and UEC/DEC. Indeed, we speculate that the occurrence of EMT in a well differentiated endometrioid carcinoma may consecutively lead to a dedifferentiated and undifferentiated carcinoma, while in a type II carcinoma, it may result in a CS.

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.

PIK3R3 Promotes Metastasis of Pancreatic Cancer via ZEB1 Induced Epithelial-Mesenchymal Transition.

BACKGROUND/AIMS: PIK3R3 is a regulatory subunit of phosphatidylinositol 3-kinase (PI3K) which plays an essential role in the metastasis of several types of cancer. However, whether PIK3R3 can promote the metastasis of pancreatic cancer (PC) is still unclear. In this study, we characterized the role of PIK3R3 in metastasis of PC and underlying potential mechanisms. METHODS: RT-PCR, western blot, immunofluorescence (IF) and immunohistochemistry (IHC) were applied to investigate the expression of genes and proteins in different cell lines and tissues. To assess the function of PIK3R3 and related mechanisms, the cells with RNAi-mediated knockdown or overexpression were used to perform a series of in vitro and in vivo assays. RESULTS: PIK3R3 was significantly overexpressed in pancreatic cancer tissues, especially in metastatic cancer tissues, as well as in pancreatic cancer cells. Functional assays suggested that overexpression or knockdown of PIK3R3 could respectively promote or suppress the migration and invasion of PC cells in vitro and in vivo. Further mechanism related studies demonstrated that ERK1/2-ZEB1 pathway-triggered epithelial-mesenchymal transition (EMT) might be responsible for the PIK3R3-induced PC cell migration and invasion. CONCLUSION: PIK3R3 could promote the metastasis of PC by facilitating ZEB1 induced EMT, and could act as a potential therapeutic target to limit PC metastasis.

Classification of Colorectal Cancer in Molecular Subtypes by Immunohistochemistry.

Colorectal cancer (CRC) is a heterogeneous disease, which can be categorized into distinct consensus molecular subtypes (CMSs). These subtypes differ in both clinical as well as biological properties. The gold-standard classification strategy relies on genome-wide expression data, which hampers widespread implementation. Here we describe an immunohistochemical (IHC) Mini Classifier, a practical tool that, in combination with microsatellite instability testing, delivers objective and accurate scoring to classify CRC patients into the main molecular disease subtypes. It is a robust immunohistochemical-based assay containing four specific stainings (FRMD6, ZEB1, HTR2B, and CDX2) in combination with cytokeratin. We also describe an online tool for classification of individual samples based on scoring parameters of these stainings.

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.

The role of epithelial-mesenchymal transition drivers ZEB1 and ZEB2 in mediating docetaxel-resistant prostate cancer.

Docetaxel is the main treatment for advanced castration-resistant prostate cancer; however, resistance eventually occurs. The development of intratumoral drug-resistant subpopulations possessing a cancer stem cell (CSC) morphology is an emerging mechanism of docetaxel resistance, a process driven by epithelial-mesenchymal transition (EMT). This study characterised EMT in docetaxel-resistant sublines through increased invasion, MMP-1 production and ZEB1 and ZEB2 expression. We also present evidence for differential EMT across PC-3 and DU145 in vitro resistance models as characterised by differential migration, cell colony scattering and susceptibility to the CSC inhibitor salinomycin. siRNA manipulation of ZEB1 and ZEB2 in PC-3 and DU145 docetaxel-resistant sublines identified ZEB1, through its transcriptional repression of E-cadherin, to be a driver of both EMT and docetaxel resistance. The clinical relevance of ZEB1 was also determined through immunohistochemical tissue microarray assessment, revealing significantly increased ZEB1 expression in prostate tumours following docetaxel treatment. This study presents evidence for a role of ZEB1, through its transcriptional repression of E-cadherin to be a driver of both EMT and docetaxel resistance in docetaxel-resistant prostate cancer. In addition, this study highlights the heterogeneity of prostate cancer and in turn emphasises the complexity of the clinical management of docetaxel-resistant prostate 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.

Clinical significance of epithelial-mesenchymal transition markers in prostate cancer.

The process of epithelial-to-mesenchymal transition (EMT) contributes to cancer progression, with activation of transcription factors leading to loss of epithelial characteristics and acquirement of mesenchymal properties. We analyzed in human prostate cancer (PCa) the expression of EMT markers at the different stages of PCa natural history, and evaluated its clinical significance. The expression of the key EMT transcription factor Zeb1, together with E-cadherin, vimentin, and N-cadherin, was evaluated by immunohistochemistry on tissue microarrays containing samples of normal prostate (n = 58), clinically localized cancer (CLC) (n = 242), castration-resistant PCa (CRPC) (n = 48), and metastases (n = 43). Zeb 1 expression was not found in normal tissues, and significantly increased with disease progression from pT2 (20% of cases) to pT3 tumors (34%), and then from CLC to metastases and CRPC (62% and 92%). The expression of EMT target genes was more fluctuant according to disease stages, although in CLC N-cadherin was closely associated with Zeb1 staining. In CLC, after adjusting for classical prognostic markers, only vimentin expression was significantly predictive of shorter recurrence-free survival. In CRPC, preserved E-cadherin staining was associated with longer overall survival, and Zeb1 expression in metastases was predictive of decreased survival. Although Zeb1 expression increased according to the different steps of PCa progression, the expression of its target genes does not seem to follow the same kinetics. However, the potential clinical interest of these EMT markers at several stages of the disease is strongly suggested by their predictive value on both recurrence-free and overall survival.

MYC associated zinc finger protein promotes the invasion and metastasis of hepatocellular carcinoma by inducing epithelial mesenchymal transition.

MYC associated zinc finger protein (MAZ) plays a key role in regulation of gene expression and tumor development. Studies have shown that deregulated expression of MAZ is closely related to the progression of tumors such as glioblastoma, breast cancer, prostate cancer and liposarcoma. However, the role of MAZ in hepatocellular carcinoma (HCC) has not been fully elucidated. Here, we found that expression of MAZ was increased in HCC and correlated to the distant metastasis of HCC. Moreover, we found that MAZ had a relationship with zinc finger E-box binding homeobox 1 and 2 (ZEB1 and ZEB2), two important mesenchymal markers in epithelial-mesenchymal transition (EMT) that were over-expressed in HCC. After knocking-down MAZ expression in HCC cell lines using RNA interruption, HCC cell proliferation, tumorigenesis, invasion and migration were significantly inhibited. In addition, we found that expression of other EMT markers was also changed besides ZEB1 and ZEB2 by decreasing MAZ expression, both detected in vivo and in vitro assays. Therefore, we conclude that MAZ can promote the invasion and metastasis of HCC by inducing EMT.

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.

African Americans with pancreatic ductal adenocarcinoma exhibit gender differences in Kaiso expression.

Kaiso, a bi-modal transcription factor, regulates gene expression, and is elevated in breast, prostate, and colon cancers. Depletion of Kaiso in other cancer types leads to a reduction in markers for the epithelial-mesenchymal transition (EMT) (Jones et al., 2014), however its clinical implications in pancreatic ductal adenocarcinoma (PDCA) have not been widely explored. PDCA is rarely detected at an early stage but is characterized by rapid progression and invasiveness. We now report the significance of the subcellular localization of Kaiso in PDCAs from African Americans. Kaiso expression is higher in the cytoplasm of invasive and metastatic pancreatic cancers. In males, cytoplasmic expression of Kaiso correlates with cancer grade and lymph node positivity. In male and female patients, cytoplasmic Kaiso expression correlates with invasiveness. Also, nuclear expression of Kaiso increases with increased invasiveness and lymph node positivity. Further, analysis of the largest PDCA dataset available on ONCOMINE shows that as Kaiso increases, there is an overall increase in Zeb1, which is the inverse for E-cadherin. Hence, these findings suggest a role for Kaiso in the progression of PDCAs, involving the EMT markers, E-cadherin and Zeb1.

MicroRNAs associated with increased AKT gene number in human lung carcinoma.

MicroRNA (miRNA) expression profiles were examined in 3 groups of lung carcinomas that had been stratified by increases in AKT1 or AKT2 gene number. Microarray analysis using 2000 probes revealed 87 miRNAs that were up-regulated and 32 down-regulated miRNAs in carcinomas harboring amplification or high-level polysomy of the AKT1 (AKT1+), as well as 123 up-regulated and 83 down-regulated miRNAs in those of the AKT2 genes (AKT2+), in comparison with carcinomas harboring disomy of both (AKTd/d). In total, 182 miRNAs were up-regulated in AKT1+ or AKT2+, compared with AKTd/d. Among these, 28 miRNAs were up-regulated in both the AKT1+ and AKT2+ groups, with a log2 ratio between 1.02 and 3.71 relative to AKTd/d group, including all miR-200 family members. Quantitative real-time polymerase chain reaction showed that carcinomas exhibiting lymph vessel invasion had significantly lower expression of miR-200a (P=.0230) and miR-200b (P=.0168), regardless of the status of the AKT genes. Moreover, a detailed statistical analysis revealed that, in adenocarcinoma and in the early stage of carcinomas (pathologic stage I/II), expression of miR-200a was higher in the AKT2+ group compared with the AKT1+ group, and these differences were statistically significant (P=.0334 and P=.0239, respectively). However, the expression of miR-200a was not significantly correlated with the expression of its target, the zinc finger E-box-binding homeobox 1 (ZEB1; P=.3801) or E-cadherin (P=.2840), a marker of the epithelial-mesenchymal transition. These results suggest that AKT2 can regulate miR-200a in a histology- or stage-specific manner and that this regulation is independent of subsequent involvement of miR-200a in epithelial-mesenchymal transition.