PYGO2 increases proliferation and migration capacities through critical signaling pathways in esophageal squamous cell carcinoma.

Esophageal cancer, an increasingly prevalent malignancy, is a major concern for global health. The development of esophageal squamous cell carcinoma (ESCC) involves various genetic abnormalities that affect key cell signaling pathways, including Wnt, Hh, Apoptosis, MAPK, EGFR, AKT, Notch, and EMT. Additionally, this malignancy involves some changes in the expression of long noncoding RNAs (LncRNAs). The present study examines the relationship between PYGO2 gene expression and the activity of cell signaling pathways in KYSE-30 and YM-1ESCC cell lines. To this end, several cellular and molecular tests were performed, including cell migration, cell cycle, and apoptosis. Also, expression levels of CD133 and CD44 markers, real-time PCR, and western blot were analyzed after inducing PYGO2 protein expression in the cells. Overexpression of the PYGO2 protein resulted in the upregulation of Wnt pathway-related genes, leading to enhanced cell migration and proliferation and reduced apoptosis in both cell lines. Furthermore, PYGO2 gene expression induction analysis showed the correlation of several involved genes in Wnt, Hh, Apoptosis, MAPK, EGFR, AKT, and EMT pathways with various LncRNAs.

Elucidated tumorigenic role of MAML1 and TWIST1 in gastric cancer is associated with Helicobacter pylori infection.

BACKGROUND: Epithelial-mesenchymal transition (EMT) has a fundamental role in tumor initiation, progression, and metastasis. Helicobacter pylori (HP) induces EMT and thus causes gastric cancer (GC) by deregulating multiple signaling pathways involved in EMT. TWIST1 and MAML1 have been confirmed to be critical inducers of EMT via diverse signaling pathways such as Notch signaling. This study aimed to investigate for the first time possible associations between TWIST1/MAML1 mRNA expression levels, HP infection, and clinicopathological characteristics in GC patients. METHOD: TWIST1 and MAML1 mRNA expression levels were evaluated in tumoral and adjacent normal tissues in 73 GC patients using the quantitative reverse transcription PCR (RT-qPCR) method. PCR technique was also applied to examine the infection with HP in GC samples. RESULTS: Upregulation of TWIST1 and MAML1 expression was observed in 35 (48%) and 34 (46.6%) of 73 tumor samples, respectively. Co-overexpression of these genes was found in 26 of 73 (35.6%) tumor samples; meanwhile, there was a significant positive correlation between MAML1 and TWIST1 mRNA expression levels (P < 0.001). MAML1 overexpression exhibited meaningful associations with advanced tumor stages (P = 0.006) and nodal metastases (P ˂ 0.001). 34 of 73 (46.6%) tumors tested positive for HP, and meanwhile, MAML1 expression was positively related with T (P = 0.05) and grade (P = 0.0001) in these HP-positive samples. Increased TWIST1 expression was correlated with patient sex (P = 0.035) and advanced tumor grade (P = 0.017) in HP-infected tumors. Furthermore, TWIST1 and MAML1 expression levels were inversely linked with histologic grade in HP-negative tumor samples (P = 0.021 and P = 0.048, respectively). CONCLUSION: We propose TWIST1 and MAML1 as potential biomarkers of advanced-stage GC that determine the characteristics and aggressiveness of the disease. Based on accumulating evidence and our findings, they can be introduced as promising therapeutic targets to modify functional abnormalities in cells that promote GC progression. Moreover, HP may enhance GC growth and metastasis by disrupting TWIS1/MAML1 expression patterns and related pathways.

SOX2/SALL4 stemness axis modulates Notch signaling genes to maintain self-renewal capacity of esophageal squamous cell carcinoma.

Stemness phenotype is considered as the centerpiece of cancer biology due to its potential in conventional chemo-radiotherapy resistance and tumor recurrence after clinical intervention. This feature in tumor mass belongs to activation of core regulatory stemness factors and different cell signaling pathways in cancer stem cells. We aimed in this study to elucidate contribution of Notch signaling pathway in stemness state of esophageal squamous cell carcinoma (ESCC) through their relevance with stem cell markers SOX2 and SALL4. 50 ESCC tumor and related margin normal tissues were considered and categorized based on SOX2/SALL4 expression pattern, and mRNA levels of Notch signaling genes including ligands, receptors, target genes, and transcriptional coactivator were analyzed in the selected groups using qRT-PCR. Concomitant overexpression of stem cell markers SOX2 and SALL4 in ESCCs upregulated the involved genes in Notch signaling pathway. Upregulation of Notch pathway genes associated with depth of tumor invasion and lymph node metastasis of ESCC. Based on biological function of SOX2 and SALL4 axis in stemness state potential, our results may suggest contribution of Notch signaling pathway in self-renewal capacity of ESCCs, as well as invasion and metastasis of the disease. To the best of our knowledge, this is the first report elucidating the crosstalk between SOX2/SALL4 stemness factors and Notch signaling pathway in cancer research.

Crosstalk between MMP-13, CD44, and TWIST1 and its role in regulation of EMT in patients with esophageal squamous cell carcinoma.

Matrix metalloproteinases (MMPs) play key roles in epithelial-mesenchymal transition (EMT) for the development of cancer cell invasion and metastasis. MMP-13 is an extracellular matrix (ECM)-degrading enzyme that plays crucial roles in angiogenesis, cell cycle regulation, niche maintenance, and transforming squamous epithelial cells in various tissues. CD44, a transmembrane glycoprotein expressed on esophageal tumor cells, is required for EMT induction and invasion in esophageal squamous cell carcinoma (ESCC). The transcription factor TWIST1, as EMT and stemness marker, regulates MMPs expression and is identified as the downstream target of CD44. In this study, we aimed to investigate the probable interplay between the expression of key genes contributing to ESCC development, including MMP-13, TWIST1, and CD44 with clinical features for introducing novel diagnostic and therapeutic targets in the disease. The gene expression profiling of MMP-13, TWIST1, and CD44 was performed using quantitative real-time PCR in tumor tissues from 50 ESCC patients compared to corresponding margin non-tumoral tissues. Significant overexpression of MMP-13, CD44S, CD44V3, CD44V6, and TWIST1 were observed in 74%, 36%, 44%, 44%, and 52% of ESCC tumor samples, respectively. Overexpression of MMP-13 was associated with stage of tumor progression, metastasis, and tumor location (P < 0.05). There was a significant correlation between TWIST1 overexpression and grade (P < 0.05). Furthermore, overexpression of CD44 variants was associated with stage of tumor progression, grade, tumor invasion, and location (P < 0.05). The results indicated the significant correlation between concomitant expression of MMP-13/TWIST1, TWIST1/CD44, and CD44/MMP-13 with each other in a variety of clinicopathological traits, including depth of tumor invasion, tumor location, stage of tumor, and lymph node involvement in ESCC tissue samples (P < 0.05). Collectively, our results indicate that the TWIST1-CD44-MMP-13 axis is involved in tumor aggressiveness, proposing these genes as regulators of EMT, diagnostic markers, and therapeutic targets in ESCC.

MEIS1 promotes expression of stem cell markers in esophageal squamous cell carcinoma.

BACKGROUND: MEIS1 (Myeloid ecotropic viral integration site 1) as a homeobox (HOX) transcription factor plays regulatory roles in a variety of cellular processes including development, differentiation, survival, apoptosis and hematopoiesis, as well as stem cell regulation. Few studies have established pluripotency and self-renewal regulatory roles for MEIS1 in human esophageal squamous cell carcinoma (ESCC), and our aim in this study was to evaluate the functional correlation between MEIS1 and the stemness markers in ESCC patients and cell line KYSE-30. METHODS: Expression pattern of MEIS1 and SALL4 gene expression was analyzed in different pathological features of ESCC patients. shRNA in retroviral vector was used for constantly silencing of MEIS1 mRNA in ESCC line (KYSE-30). Knockdown of MEIS1 gene and the expression pattern of selected stemness markers including SALL4, OCT4, BMI-1, HIWI, NANOG, PLK1, and KLF4 were evaluated using real-time PCR. RESULTS: Significant correlations were observed between MEIS1 and stemness marker SALL4 in different early pathological features of ESCC including non-invaded tumors, and the tumors with primary stages of progression. Retroviral knockdown of MEIS1 in KYSE-30 cells caused a noteworthy underexpression of both MEIS1 and major involved markers in stemness state of the cells including SALL4, OCT4, BMI-1, HIWI and KLF4. CONCLUSIONS: The results highlight the important potential role of MEIS1 in modulating stemness properties of ESCCs and cells KYSE-30. These findings may confirm the linkage between MEIS1 and self-renewal capacity in ESCC and support probable oncogenic role for MEIS1 in the disease.

TWIST1 correlates with Notch signaling pathway to develop esophageal squamous cell carcinoma.

Notch signaling pathway mediates different biological processes including stem cell self-renewal, progenitor cell fate decision, and terminal differentiation. TWIST1 plays a key role in tumor development and metastasis through inducing epithelial-mesenchymal transition (EMT). Expression of the core transcriptional complex of Notch pathway and its target genes, as well as TWIST1 overexpression, are closely related to the aggressive clinicopathological variables of esophageal squamous cell carcinoma (ESCC). Here we aimed to functionally elucidate probable crosstalk between TWIST1 and Notch pathway in ESCCs. Correlation between TWIST1 and Notch target genes was analyzed in 50 ESCCs and corresponding normal tissues. Using retroviral system, enforced expression of TWIST1 was established in ESCC line KYSE-30 cells and expression of Notch signaling genes was assessed. Significant correlation between TWIST1 and HEY1/HEY2 expression was found in different pathological variable of ESCC poor prognosis. Induced expression of TWIST1 in KYSE-30 cells caused a noteworthy increase of Notch pathway genes expression revealing regulatory role of TWIST1 on Notch signaling genes in the cells. Based on existed correlations between expression of TWIST1 and Notch pathway genes in different pathological features of ESCC patients, as well as KYSE-30 cell line, we may extrapolate that TWIST1 is involved in aggressiveness of the disease through regulation of Notch signaling genes. To the best of knowledge, this is the first report describing the impact of TWIST1 on Notch cascade genes in ESCC.

Crosstalk between MEIS1 and markers of different cell signaling pathways in esophageal squamous cell carcinoma.

The homeobox transcription factor MEIS1 is involved in cell fate decision, stem cells properties, gastrointestinal (GI) tract development, and progression of several malignancies such as esophageal squamous cell carcinoma (ESCC). Increasing evidences suggest the crosstalk between MEIS1 and cell signaling pathways. Therefore, our aim in present study was to investigate the probable linkage of MEIS1 expression with key genes of different cell signaling pathways in ESCC tumorigenesis, and their correlation with clinicopathological feature of the patients. The gene expression profiling of MEIS1 and different cell signaling genes including SALL4, SIZN1, and HEY1 (stemness state, BMP, and NOTCH signaling pathways, respectively) was performed using quantitative real-time reverse transcription polymerase chain reaction (PCR) in fresh tumoral compared to margin normal tissues of 50 treatment-naive ESCC samples. The mRNA expression of MEIS1/SIZN1, SIZN1/HEY1, and SIZN1/SALL4 were significantly associated to each other (P < 0.05). There were remarkable correlations between concomitant mRNA expression of MEIS1 and SIZN1 in tumors with invasion to adventitia, early stages of tumor progression and poorly differentiated tumors. Moreover, expression of MEIS1 and HEY1 was correlated to each other in primary stages of tumor progression and non-invaded tumors. Expression of MEIS1 was significantly associated with SALL4 in poorly differentiated tumors. Our results indicated that correlation between different cell signaling pathway-related genes may lead to esophageal tumorigenesis. It is illustrated that MEIS1 as a HOX gene has a significant correlation with stemness state, BMP, and NOTCH signaling pathways via the SIZN1.

MAML1 promotes ESCC aggressiveness through upregulation of EMT marker TWIST1.

BACKGROUND: Mastermind-like 1 (MAML1) is the main transcriptional co-activator of Notch signaling pathway. It plays essential roles in several pathways including MEF2C, p53, Nf-кB and Wnt/ß-catenin. TWIST1 is known as a regulator of epithelial mesenchymal transition (EMT), which is considered as a primary step in promotion of tumor cell metastasis. Since concomitant expression of these genes was observed in tumors, our aim in this study was to elucidate the linkage between MAML1 and TWIST1 co-overexpression in esophageal squamous cell carcinoma (ESCC). RESULTS: While MAML1 silencing significantly down-regulated TWIST1, its ectopic expression up-regulated TWIST1 expression in both mRNA and protein levels in KYSE-30 cells. Expression of mesenchymal markers was increased significantly after MAML1 and TWIST1 ectopic expression, while epithelial markers expression was significantly decreased after silencing of both genes. Concomitant protein expression of MAML1 and TWIST1 was significantly observed in ESCC patients. Enforced expression of TWIST1 had no impact on MAML1 gene expression in KYSE-30 cells. CONCLUSION: The results clearly suggest transcriptional regulation of TWIST1 by MAML1 transcription factor in ESCC cells KYSE-30. Since TWIST1 is known as an EMT inducing marker, our results may revealed the mastermind behind TWIST1 function and introduced MAML1 as an upstream master regulator of TWIST1 and EMT in KYSE-30 cells.

TWIST1, MMP-21, and HLAG-1 co-overexpression is associated with ESCC aggressiveness.

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive types of cancer, requiring reliable biomarkers for prognosis and therapeutic responsiveness. TWIST1, as an important factor responsible for metastasis of several cancers, is involved in tumor invasion and metastasis through indirectly regulation of MMP-21 expression. On the other hand, NF-Ä¸ß which is a regulator of HLAG-1 has direct interaction with TWIST1 protein. In this retrospective study we investigated the clinical significance of TWIST1, MMP-21, and HLAG-1 expression in ESCC, and the possible correlation between these genes and progression of the disease. The gene expression analyses of TWIST1, MMP-21, and HLA-G1 were performed by relative comparative real-time polymerase chain reaction in 58 ESCCs compared with corresponding margin-normal esophageal tissues. Significant overexpression of HLAG-1, TWIST1, and MMP-21 messenger RNA was observed in 22.4%, 41.4%, and 60.3% of tumor samples, respectively. Concomitant overexpression of TWIST1/MMP-21 and TWIST1/HLAG-1 were significantly correlated to each other in various clinicopathological features, including depth of tumor invasion, stage of tumor progression, lymphatic invasion, and grade of tumor cell differentiation ( P < 0.05). The current study is the first report of coexpression of TWIST1, MMP-21, and HLAG-1 in ESCC. Such findings suggest an oncogenic role for concomitant expression of these genes in ESCC invasion and metastasis.

MAML1 regulates EMT markers expression through NOTCH-independent pathway in breast cancer cell line MCF7.

Tumor relapse is the main cause of breast cancer related deaths and metastasis due to epithelial-mesenchymal transition (EMT) having a critical role in this process. MAML1 is the main co activator of NOTCH signaling pathway and its role in EMT remains unknown. In this study, this role was evaluated through overexpression and knockdown study of MAML1 in MCF7 and MDA-MB-231 cells. MAML1 overexpression up regulated the epithelial and down regulated the mesenchymal markers. In addition, MAML1 silencing decreased epithelial and increased mesenchymal markers. Notch inhibition using γ-secretase inhibitor resulted in increased E-cadherin expression. MAML1 ectopic expression, further increased E-cadherin expression with inhibition of NOTCH signaling. Wound healing assay showed that MAML1 overexpression decreases the rate of migration, while MAML1 silencing increases this rate significantly. In conclusion, our data indicated that MAML1 negatively regulates EMT markers expression in breast cancer cells.

Role of MAML1 in targeted therapy against the esophageal cancer stem cells.

BACKGROUND: Esophageal cancer is the sixth-leading cause of cancer-related deaths worldwide. Cancer stem cells (CSCs) are the main reason for tumor relapse in esophageal squamous cell carcinoma (ESCC). The NOTCH pathway is important in preservation of CSCs, therefore it is possible to target such cells by targeting MAML1 as the main component of the NOTCH transcription machinery. METHODS: In present study we isolated the CD44+ ESCC CSCs and designed a MAML1-targeted therapy to inhibit the NOTCH signaling pathway. CSCs were isolated using magnetic cell sorting utilizing the CD44 cell surface marker. Several stem cell markers were analyzed in the levels of protein and mRNA expression. The isolated CSCs were characterized in vivo in NUDE mice. Biological role of MAML1 was assessed in isolated CD44+ CSCs. A drug resistance assay was also performed to assess the role of MAML1 in CD44+ CSCs with 5FU resistance. RESULTS: The CD44+ CSCs had ability to form tumors in NUDE mice. MAML1 silencing caused a significant decrease (p = 0.019) and ectopic expression caused a significant increase in migration of CD44+ CSCs (p = 0.012). Moreover, MAML1 silencing and ectopic expression significantly increased and decreased 5FU resistance, respectively (p < 0.05). MAML1 silencing significantly increased the number of cells in G1 phase (p = 0.008), and its ectopic expression significantly increased the number of CD44+ CSCS in S phase (p = 0.037). CONCLUSIONS: MAML1 may be utilized for targeted therapy with a low side effect to eliminate the CD44+ CSCs through inhibition of canonical NOTCH pathway in ESCC patients.

Correlation between SALL4 stemness marker and bone morphogenetic protein signaling genes in esophageal squamous cell carcinoma.

SALL4, as a stemness marker, plays a key role in the maintenance of pluripotency and self-renewal of cancer stem cells. To elucidate probable linkage between SALL4 stemness marker and bone morphogenetic protein (BMP) cell signaling pathway, we aimed to analyze the expression levels of the related genes in esophageal squamous cell carcinoma (ESCC) patients. Tumoral and corresponding margin normal tissues from 50 treatment-naive ESCC patients were subjected for expression analysis using relative comparative real-time reverse transcription polymerase chain reaction. There were significant correlations between SALL4 mRNA and BMP signaling target genes expression including SIZN1, VENTX, and DIDO1 (P < 0.01). Tight associations of gene expression were observed in primary stages of tumor progression (stages I/II), and the invaded tumors to the adventitia (T3/T4). Furthermore, significant correlations between the expression of BMP signaling target genes were observed (P < 0.01). SALL4 may play role in tumorigenesis and tumor cell invasiveness of ESCC through correlation with BMP signaling genes.

WNT and NOTCH signaling pathways as activators for epidermal growth factor receptor in esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is the most common histological type of esophageal cancer, with a poor prognosis. Deregulation of WNT and NOTCH signaling pathways is important in ESCC progression, which can be due to either malfunction of their components or crosstalk with other pathways. Therefore, identification of new crosstalk between such pathways may be effective to introduce new strategies for targeted therapy of cancer. A correlation study was performed to assess the probable interaction between growth factor receptors and WNT/NOTCH pathways via the epidermal growth factor receptor (EGFR) and Musashi1 (MSI1), respectively. METHODS: Levels of MSI1/EGFR mRNA expression in tumor tissues from 48 ESCC patients were compared to their corresponding normal tissues using real-time polymerase chain reaction. RESULTS: There was a significant correlation between EGFR and MSI1 expression (p = 0.05). Moreover, there was a significant correlation between EGFR/MSI1 expression and grade of tumor differentiation (p = 0.02). CONCLUSION: This study confirms a direct correlation between MSI1 and EGFR and may support the important role of MSI1 in activation of EGFR through NOTCH/WNT pathways in ESCC.

The cross-regulation between SOX15 and Wnt signaling pathway.

WNT/B-CATENIN signaling pathway is one of the key dysregulated pathways in different tumor types, which regulate the expression of several genes involved in cell proliferation, differentiation, and survival. This pathway is being modulated by sex-determining region Y-box (SOX) family genes. The functions of these genes are suggested as tumor suppressor or oncogene. SOX genes transcribe a group of transcription factors that play important roles in embryonic development and carcinogenesis. Among them, SOX15 is recently been identified as a novel tumor suppressor in pancreatic and esophagus cancers with a potential role in modulating Wnt/b-catenin signaling. This report summarizes the current knowledge about Wnt/b-catenin signaling pathway and its cross talk with SOX15 with particular emphasis on the value of SOX gene expression as prognostic or predictive biomarker in cancer.

TWIST1 upregulates the MAGEA4 oncogene.

Overexpression of MAGEA4 oncogene has been demonstrated in different malignancies; however, little is known about its exact mechanism for overexpression. TWIST1, as a bHLH transcription factor, activates a cell migration-invasion program involved in both embryonic and tumor development. Since MAGEA4 overexpression was statistically correlated to TWIST1, we aimed to elucidate the probable regulatory role of TWIST1 on MAGEA4 expression in KYSE30 cells. METHODS: Expression pattern of MAGEA4 and TWIST1 was analyzed in 55 ESCC patients using relative comparative real-time PCR. In silico analysis of the MAGEA4 gene was performed. Methylation status of MAGEA4 promoter was determined by quantitative methylation specific PCR (qMSP). Using a retroviral system, KYSE30 cells were transduced to ectopically express TWIST1, followed by qRT-PCR, Western blot analysis, chromatin immunoprecipitation (ChIP), and luciferase assays to elucidate the regulatory role of TWIST1 on MAGEA4 gene expression. RESULTS: Concomitant overexpression of MAGEA4 and TWIST1 was detected in ESCC in significant correlation with each other in different clinicopathological indices of poor prognosis (P < 0.05). The TWIST1-expressing cells showed significantly higher MAGEA4 expression compared to control cells. ChIP and luciferase assays results confirmed indirect binding of TWIST1 to the E-boxes of MAGEA4 promoter sequence and revealed a novel regulatory role of TWIST1 in MAGEA4 upregulation. CONCLUSION: Since MAGEA4 is a highly expressed oncogene in a variety of malignancies in significant correlation with tumor cell invasiveness and aggressiveness, our finding may help understand one regulatory mechanism of increased expression in tumor cells. © 2016 Wiley Periodicals, Inc.

Ectopic expression of TWIST1 upregulates the stemness marker OCT4 in the esophageal squamous cell carcinoma cell line KYSE30.

BACKGROUND: The transcription factor TWIST1 plays an important role in the epithelial-mesenchymal transition (EMT) process and in the migration, invasion and metastasis of cancer cells. OCT4, which is a homeobox transcription factor, has an important role in the self-renewal potential of cancer cells. Our aim here is to elucidate impact of ectopic expression of TWIST1 on OCT4 gene expression in esophageal squamous cell carcinoma (ESCC). METHODS: The ESCC line was KYSE30. GP293T cells were transfected with purf-IRES-GFP and pGP plasmids to produce recombinant viral particles. A semi-confluent KYSE30 culture was transduced with the prepared retroviral particles. mRNA extraction and cDNA synthesis were performed from normal KYSE30 cells and those ectopically expressing TWIST1. Expressional analysis of TWIST1 and OCT4 were performed with relative comparative real-time PCR. RESULTS: Ectopic expression of TWIST1 in KYSE30 cells was related to its significant overexpression: nearly nine-fold higher in GFP-hTWIST1 KYSE-30 cells than in control GFP cells. This induced expression of TWIST1 caused significant upregulation of OCT4 in GFP-hTWIST1 KYSE-30 cells: nearly eight-fold higher. In silico analysis predicted the correlation of TWIST1 and OCT4 through ETS2. CONCLUSIONS: Overexpressed TWIST1 can be correlated with upregulation of the cancer stem cell marker OCT4 and the protein may play critical regulatory role in OCT4 gene expression. Since OCT4 is involved in the self-renewal process, the results may suggest a new linkage between TWIST1 and OCT4 in the cell biology of ESCC, highlighting the probable role of TWIST1 in inducing self-renewal.

Contribution of MAML1 in esophageal squamous cell carcinoma tumorigenesis.

BACKGROUND: Notch signaling pathway is involved in different cellular and developmental processes including cell proliferation, differentiation and apoptosis. Mastermind like1 (MAML1) is a critical key transcription coactivator of this pathway. In this study, we aimed to examine MAML1 protein expression in esophageal squamous cell carcinoma (ESCC) and reveal its association with clinicopathological variables of the patients. METHODS: Tumoral and their margin normal tissues from 56 ESCC patients were recruited for protein expression analysis using immunohistochemistry (IHC). Furthermore, MAML1 expression was analyzed in ESCC cell line KYSE-30 using immunocytochemistry. RESULTS: Overexpression of MAML1 was detected in 59% of tumor samples. It was significantly associated with different indices of poor prognosis including depth of tumor invasion (P=0.026), grade of tumor differentiation (P=0.002), stage of tumor progression (P=0.004) and sex (P=0.027). CONCLUSION: Beside the appearing evidences explaining MAML1 role in different cellular processes and its deviations in different malignancies and also based on its correlation with different clinicopathological variables of ESCC, MAML1 can be proposed as potentially novel molecular marker for ESCC progression and tumorigenesis as well as therapeutic target to inhibit and reverse progression and development of the disease.

Predicting the molecular role of MEIS1 in esophageal squamous cell carcinoma.

The three amino acid loop extension (TALE) class myeloid ecotropic viral integration site 1 (MEIS1) homeobox gene is known to play a crucial role in normal and tumor development. In contrast with its well-described cancer stemness properties in hematopoietic cancers, little is known about its role in solid tumors like esophageal squamous cell carcinoma (ESCC). Here, we analyzed MEIS1 expression and its clinical relevance in ESCC patients and also investigated its correlation with the SOX2 self-renewal master transcription factor in the ESCC samples and in the KYSE-30 ESCC cell line. MEIS1 mRNA and protein expression were significantly decreased in ESCC disease (P < 0.05). The inverse correlation between MEIS1 mRNA expression and tumor cell metastasis to the lymph nodes (P = 0.004) was significant. Also, MEIS1 protein levels inversely correlated to lymph node involvement (P = 0.048) and high tumor stage (stages III/IV, P = 0.030). The low levels of DNA methylation in the MEIS1 promoter showed that this suppression does not depend on methylation. We showed that downregulation of EZH2 restored MEIS1 expression significantly. Also, we investigated that MEIS1 downregulation is concomitant with increased SOX2 expression. To the best of our knowledge, this is the first report on the MEIS1 gene in ESCC. The inverse correlation of MEIS1 with metastasis, tumor staging, and the role of EZH2 in methylation, together with its correlation with stemness factor SOX2 expression, led us to predict cancer stemness properties for MEIS1 in ESCC.

Expression analysis of BRUCE protein in esophageal squamous cell carcinoma.

Apoptosis is a form of cell death in response to diverse stressful physiological or pathological stimuli. One of the most important gene families involved in apoptosis is inhibitors of apoptosis. As a member of inhibitors of apoptosis, BRUCE can suppress apoptosis and promote cell division. Because esophageal squamous cell carcinoma (ESCC) cells, as well as other cancer cells, are immortal, our aim in this study was to analyze BRUCE protein expression in ESCC and evaluate its correlation with tumoral clinicopathologic features. Fifty ESCC specimens were examined for BRUCE protein expression using immunohistochemistry. A defined scoring method was applied. BRUCE protein was detected in 82% of tumors. Tumor progression stage and invasion depth correlated significantly with BRUCE protein expression (P=.019 and .005, respectively). Furthermore, association of BRUCE expression with tumor location was near significant (P=.058). The correlation of BRUCE overexpression in ESCC and disease aggressiveness may confirm the importance of BRUCE in ESCC progression and invasiveness. Therefore, BRUCE protein may be a molecular marker for aggressive ESCC and, thus, a potential therapeutic target to inhibit tumor cell progression and invasion.

Aberrant expression of DPPA2 and HIWI genes in colorectal cancer and their impacts on poor prognosis.

Cancer cells have countless behaviors of pluripotent embryonic stem cells and germ line cells, such as unlimited proliferation, self-renewal, and migration. Expression of specific germ line and embryonic genes in tumor cells may be associated with indefinite growth and invasiveness of such cells. Developmental pluripotency factor 2 (DPPA2) and HIWI are two important developmental genes which are involved in embryonic and germ line stem cell properties. Deciphering the role of these genes seems to be necessary for understanding cancer initiation and progression. Tumoral and normal tissues from 46 colorectal cancer (CRC) patients were subjected to gene expression analysis using quantitative real-time reverse transcription-polymerase chain reaction, prior to any therapeutic intervention. Overexpression of DPPA2 and HIWI was detected in 26.1 and 34.8 % of specimens, respectively. Significant correlation between DPPA2 overexpression and lymph node metastasis of the tumor cells (P=0.049) was seen in the samples with advanced stages (III/IV) of the tumor development. HIWI mRNA expression was significantly associated to the depth of tumor invasion (P=0.020) and the stage of tumorigenesis progression (P=0.030). In samples with overexpression of at least one gene, DPPA2 mRNA expression was significantly correlated to the stage of tumor (P=0.017). In the same samples, a significant correlation was observed between mRNA expression of HIWI and the stage of tumor cells (P=0.034). These results documented the important role of HIWI and DPPA2 in tumorigenesis and also in lymph node metastasis of tumor cells. Further evaluation is required to uncover the detailed role of HIWI and DPPA2 and their interactions in tumorigenesis of CRC.