Significance and prognostic value of Gli-1 and Snail/E-cadherin expression in progressive gastric cancer

Retracted article: Knockdown of long non-coding RNA AGAP2-AS1 suppresses the proliferation and metastasis of glioma by targeting microRNA-497-5p

Yi Sun, Yulong Shen and Xing Li. Knockdown of long non-coding RNA AGAP2-AS1 suppresses the proliferation and metastasis of glioma by targeting microRNA-497-5p. Bioengineered. 2021 Oct. doi: 10.1080/21655979.2021.1995573.Since publication, significant concerns have been raised about the compliance with ethical policies for human research and the integrity of the data reported in the article.When approached for an explanation, the authors provided some original data but were not able to provide all the necessary supporting information. As verifying the validity of published work is core to the scholarly record's integrity, we are retracting the article. All authors listed in this publication have been informed.We have been informed in our decision-making by our editorial policies and the COPE guidelines. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as 'Retracted.'

Identifying the optimal treatment strategy in patients with resectable non-cardia gastric cancer

BACKGROUND

Multimodal treatment strategy including perioperative chemotherapy (PEC), postoperative chemoradiation therapy (POCR), and postoperative chemotherapy (POC) has been accepted as the standard of care in gastric cancer (GC). The ideal sequence and type of therapy remain undetermined.

METHOD

The National Cancer Database was examined from 2006 to 2016 to identify patients with resectable non-cardia gastric cancer. Patient outcomes were compared based on the receipt of PEC, POCR, and POC. This comparison was repeated in a sub-group of patients who received optimal treatment. Optimal treatment was defined as initial chemotherapy within 45 days of diagnosis, resection within 45 days of diagnosis, negative margins, adjuvant chemotherapy within 90 days of resection and standard radiation dose (45 Gy). Kaplan-Meier test, log-rank test, and multivariable analysis (MVA) were performed.

RESULTS

We identified 9589 patients. Median survival was greater in the PEC group followed by POCR and POC (60.6, 42.3, and 31.2 months, respectively). On MVA, factors associated with worse overall survival included age above median (≥ 63 years), Charlson-Deyo score of ≥ 1, non-academic/research program, poorly differentiated/undifferentiated grade, positive margins, and positive lymph nodes. Both PEC and POCR were associated with improved survival when compared to POC (HR 0.78 and 0.79; p < 0.001). When compared with PEC, no significant difference was noted with POCR (HR 1.01; p = 0.987). These results were maintained in optimally treated cohort (n = 3418).

CONCLUSION

In patients with resectable non-cardia gastric cancer, both perioperative chemotherapy and postoperative chemoradiation therapy were associated with improved survival when compared to postoperative chemotherapy. No difference was noted between perioperative chemotherapy and postoperative chemoradiation therapy. These results were maintained in the optimally treated cohort.

Insight into the transcription factors regulating Ischemic Stroke and Glioma in Response to Shared Stimuli

Cerebral ischemic stroke and glioma are the two leading causes of patient mortality globally. Despite physiological variations, 1 in 10 people who have an ischemic stroke go on to develop brain cancer, most notably gliomas. In addition, glioma treatments have also been shown to increase the risk of ischemic strokes. Stroke occurs more frequently in cancer patients than in the general population, according to traditional literature. Unbelievably, these events share multiple pathways, but the precise mechanism underlying their co-occurrence remains unknown. Transcription factors (TFs), the main components of gene expression programmes, finally determine the fate of cells and homeostasis. Both ischemic stroke and glioma exhibit aberrant expression of a large number of TFs, which are strongly linked to the pathophysiology and progression of both diseases. The precise genomic binding locations of TFs and how TF binding ultimately relates to transcriptional regulation remain elusive despite a strong interest in understanding how TFs regulate gene expression in both stroke and glioma. As a result, the importance of continuing efforts to understand TF-mediated gene regulation is highlighted in this review, along with some of the primary shared events in stroke and glioma.

Overview on the Role of E-Cadherin in Gastric Cancer: Dysregulation and Clinical Implications

Gastric cancer is the fifth most common cancer and the third most common cause of cancer death all over the world. E-cadherin encoded by human CDH1 gene plays important roles in tumorigenesis as well as in tumor progression, invasion and metastasis. Full-length E-cadhrin tethered on the cell membrane mainly mediates adherens junctions between cells and is involved in maintaining the normal structure of epithelial tissues. After proteolysis, the extracellular fragment of the full-length E-cadhein is released into the extracellular environment and the blood, which is called soluble E-cadherin (sE-cadherin). sE-cadherin promots invasion and metastasis as a paracrine/autocrine signaling molecule in the progression of various types of cancer including gastric cancer. This review mainly summarizes the dysregulation of E-cadherin and the regulatory roles in the progression, invasion, metastasis, and drug-resistance, as well as its clinical applications in diagnosis, prognosis, and therapeutics of gastric cancer.

Clinical and prognostic significances of cancer stem cell markers in gastric cancer patients: a systematic review and meta-analysis

Background

Gastric cancer (GC) is considered one of the most lethal malignancies worldwide, which is accompanied by a poor prognosis. Although reports regarding the importance of cancer stem cell (CSC) markers in gastric cancer progression have rapidly developed over the last few decades, their clinicopathological and prognostic values in gastric cancer still remain inconclusive. Therefore, the current meta-analysis aimed to quantitatively re-evaluate the association of CSC markers expression, overall and individually, with GC patients’ clinical and survival outcomes.

Methods

Literature databases including PubMed, Scopus, ISI Web of Science, and Embase were searched to identify the eligible articles. Hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were recorded or calculated to determine the relationships between CSC markers expression positivity and overall survival (OS), disease-free survival (DFS)/relapse-free survival (RFS), disease-specific survival (DSS)/ cancer-specific survival (CSS), and clinicopathological features.

Results

We initially retrieved 4,425 articles, of which a total of 66 articles with 89 studies were considered as eligible for this meta-analysis, comprising of 11,274 GC patients. Overall data analyses indicated that the overexpression of CSC markers is associated with TNM stage (OR = 2.19, 95% CI 1.84–2.61, P = 0.013), lymph node metastasis (OR = 1.76, 95% CI 1.54–2.02, P < 0.001), worse OS (HR = 1.65, 95% CI 1.54–1.77, P < 0.001), poor CSS/DSS (HR = 1.69, 95% CI 1.33–2.15, P < 0.001), and unfavorable DFS/RFS (HR = 2.35, 95% CI 1.90–2.89, P < 0.001) in GC patients. However, CSC markers expression was found to be slightly linked to tumor differentiation (OR = 1.25, 95% CI 1.01–1.55, P = 0.035). Sub-analysis demonstrated a significant positive relationship between most of the individual markers, specially Gli-1, Oct-4, CD44, CD44V6, and CD133, and clinical outcomes as well as the reduced survival, whereas overexpression of Lgr-5, Nanog, and sonic hedgehog (Shh) was not found to be related to the majority of clinical outcomes in GC patients.

Conclusion

The expression of CSC markers is mostly associated with worse outcomes in patients with GC, both overall and individual. The detection of a combined panel of CSC markers might be appropriate as a prognostic stratification marker to predict tumor aggressiveness and poor prognosis in patients with GC, which probably results in identifying novel potential targets for therapeutic approaches.

Protein expression-based classification of gastric cancer by immunohistochemistry of tissue microarray

Recently, the Cancer Genome Atlas and Asian Cancer Research Group propose two new classifications system of gastric cancer by using multi-platforms of molecular analyses. However, these highly complicated and cost technologies have not yet been translated into full clinical utility. In addition, the clinicians are expected to gain more guidance of treatment for different molecular subtypes. In this study, we developed a panel of gastric cancer patients in population from Southern China using commercially accessible TMA and immunohistochemical technology. A cohort of 259 GC patients was classified into 4 subtypes on the basis of expression of mismatch repair proteins (PMS2, MLH1, MSH2, and MSH6), E-cadherin and p21 protein. We observed that the subtypes presented distinct prognosis. dMMR-like subtype was associated with the best prognosis, and E-cadherin-a subtype was associated with the worst prognosis. Patients with p21-High and p21-Ligh subtypes had intermediate overall survival. In multivariate analysis, the dMMR-like subtype remained an independent prediction power for overall survival in the model. We described a molecular classification of gastric cancers using clinically applicable assay. The biological relevance of the four subtypes was illustrated by significant differences in prognosis. Our molecular classification provided an effective and inexpensive screening tool for improving prognostic models. Nevertheless, our study should be considered preliminary and carries a limited predictive value as a single-center retrospective study.

Immunodetection of Epithelial-Mesenchymal Transition and Tumor Proliferation Markers in GLi-1-positive Oral Squamous Cell Carcinoma

In oral squamous cell carcinoma (OSCC), involvement and activation of the Hedgehog pathway (HH) may be related to epithelial-mesenchymal transition and cell proliferation. The present study aimed to evaluate epithelial-mesenchymal transition and proliferative potential in OSCC cases demonstrating activation of the HH pathway. Twenty-three GLi-1-positive OSCC cases were submitted to immunohistochemical detection of Snail, Slug, N-cadherin, E-cadherin, β-catenin, and MCM3 proteins. Clinical-pathologic immunoexpression data were obtained from the invasion front and tumor islets, and then compared. At the invasion front, OSCC cases presented positive Snail, Slug, and MCM3 expression in the nuclei of tumor cells. Loss of membrane and cytoplasmic expression of E-cadherin and β-catenin was also observed. Positive N-cadherin expression was observed in 31.78% of the cases. GLi-1 immunoexpression was associated with loss of membrane E-cadherin (P<0.001), membrane β-catenin (P<0.001), and cytoplasmic β-catenin (P=0.02) expression. In the tumor islets, we observed nuclear expression of GLi-1, Snail, Slug, and MCM3. E-cadherin and β-catenin showed positivity in tumor cell membranes. Statistically significant positive correlations between GLi-1 and Snail (P=0.05), E-cadherin (P=0.01), and cytoplasmic β-catenin (P=0.04) were found. GLi-1 was associated with clinical staging, while membrane β-catenin expression was related to the presence of metastasis in lymph nodes and to clinical staging. The HH pathway may be involved in regulating the expression of the mesenchymal phenotype. The loss of membrane E-cadherin and β-catenin expression was observed at the tumor front region, whereas cell adhesion protein expression was detected in tumor islets regardless of MCM3.

Propofol Reduces Epithelial to Mesenchymal Transition, Invasion and Migration of Gastric Cancer Cells through the MicroRNA-195-5p/Snail Axis

BACKGROUND Gastric cancer (GC) is a life-threating malignancy worldwide. Accumulating studies suggest propofol has anti-tumor functions in addition to the anesthetic effect. This study aimed to figure out the effects of propofol treatment in GC development. MATERIAL AND METHODS Human GC SGC-7901 and NCI-N87 cells were treated with different doses of propofol. Then the invasion and migration of GC cells was measured. SGC-7901 cells following 10 μM propofol treatment were applied in the following experiments. MicroRNAs (miRNAs) with differential expression in cells with or without propofol treatment were analyzed. Expression of miR-195-5p, Snail, vimentin and E-cadherin in SGC-7901 cells was measured, and then loss-of-function of miR-195-5p and gain-of-function of Snail were performed. Target relation between miR-195-5p and Snail was confirmed using luciferase assay. Xenograft tumor was induced in nude mice to identify the effect of propofol on GC in vivo. RESULTS Propofol reduced epithelial to mesenchymal transition (EMT), invasion and migration of GC cells in a dose-dependent manner. Propofol elevated miR-195-5p expression but reduced Snail expression, and it reduced vimentin but increased E-cadherin expression in SGC-7901 cells. miR-195-5p directly bound to Snail. miR-195-5p inhibition or Snail promotion reversed propofol-inhibited malignant behaviors of SGC-7901 cells. In vitro results were reproduced in in vivo experiments. CONCLUSIONS Our study found that propofol could inhibit EMT, invasion, and migration of GC cells by promoting miR-195-5p expression and suppressing Snail expression. This study may provide novel insights in GC treatment.

The inhibitory effect and safety of GANT61 on HeLa cells in nude mice

The Hedgehog (Hh) pathway effector Gli1 plays an important role in cervical cancer, and GANT61 is an Hh signaling inhibitor. In this study, we aimed to investigate the inhibitory effect of GANT61 on cervical cancer and to study its safety in nude mice. We used in vivo experiments to assess the effect of GANT61 on the growth of cervical cancer HeLa cells, and we measured the WBC, HGB, PLT, ALT, AST and Cre levels in nude mice. Next, we examined the organ and tumor morphology and distant metastasis by HE staining. We used immunohistochemistry to monitor the expression levels of Gli1, FoxM1, Ki-67, cyclinD1, E-cadherin, vimentin, survivin, caspase-3 and CD34+. Western blotting and RT-RCR were used to measure Gli1 expression. GANT61 inhibited the growth and metastasis of HeLa cervical cancer cells upon their transplantation into nude mice, and we preliminarily propose that GANT61 is safe for nude mice. These findings suggest that GANT61 could be used as a Hedgehog inhibitor to inhibit EMT and proliferation and to promote apoptosis via Gli1 downregulation.

microRNA-33a prevents epithelial-mesenchymal transition, invasion, and metastasis of gastric cancer cells through the Snail/Slug pathway

Invasion and metastasis are responsible for the majority of deaths in gastric cancer (GC). microRNA-33a (miR-33a) might function as a tumor suppressor in multiple cancers. Here, we describe the regulation and function of miR-33a in GC and mechanisms involved in epithelial-mesenchymal transition (EMT) and metastasis. First, GC tissues and adjacent normal tissues were collected. miR-33a upregulation or SNAI2 depletion on GC cells were introduced to assess the detailed regulatory mechanism of them. We assessed the expression of miR-33a, SNAI2, Snail/Slug signaling pathway-related genes, and EMT-related markers in GC tissues and cells. miR-33a distribution in GC tissues and adjacent normal tissues was measured. Cell proliferation, migration and invasion, and cell cycle distribution were assessed. In nude mice, GC tumor growth and lymph node metastasis were observed. Furthermore, the predicative value of miR-33a in the prognosis of GC patients was evaluated. The obtained results indicated that lowly expressed miR-33a, highly expressed SNAI2, activated Snail/Slug, and increased EMT were identified in GC tissues. miR-33a was located mainly in the cytoplasm. miR-33a targeted and negatively regulated SNAI2. MKN-45 and MKN-28 cell lines were selected for in vitro experiments. Upregulated miR-33a expression or siRNA-mediated silencing of SNAI2 suppressed the activation of Snail/Slug, whereby GC cell proliferation, invasion and migration, EMT, tumor growth, and lymph node metastasis were inhibited. High expression of miR-33a was a protective factor influencing the prognosis of GC. This study suggests that miR-33a inhibited EMT, invasion, and metastasis of GC through the Snail/Slug signaling pathway by modulating SNAI2 expression.NEW & NOTEWORTHY miR-33a targets and inhibits the expression of SNAI2, overexpression of SNAI2 activates the Snail/Slug signaling pathway, the Snail/Slug signaling pathway promotes GC cell proliferation, invasion, and metastasis, and overexpression of miR-33a inhibits cell proliferation, invasion, and metastasis. This study provides a new therapeutic target for the treatment of GC.

FOXS1 is regulated by GLI1 and miR-125a-5p and promotes cell proliferation and EMT in gastric cancer

Gastric cancer (GC) is the fourth most common malignant neoplasm and the second leading cause of cancer death. Identification of key molecular signaling pathways involved in gastric carcinogenesis and progression facilitates early GC diagnosis and the development of targeted therapies for advanced GC patients. Emerging evidence has revealed a close correlation between forkhead box (FOX) proteins and cancer development. However, the prognostic significance of forkhead box S1 (FOXS1) in patients with GC and the function of FOXS1 in GC progression remain undefined. In this study, we found that upregulation of FOXS1 was frequently detected in GC tissues and strongly correlated with an aggressive phenotype and poor prognosis. Functional assays confirmed that FOXS1 knockdown suppressed cell proliferation and colony numbers, with induction of cell arrest in the G0/G1 phase of the cell cycle, whereas forced expression of FOXS1 had the opposite effect. Additionally, forced expression of FOXS1 accelerated tumor growth in vivo and increased cell migration and invasion through promoting epithelial–mesenchymal transition (EMT) both in vitro and in vivo. Mechanistically, the core promoter region of FOXS1 was identified at nucleotides −660~ +1, and NFKB1 indirectly bind the motif on FOXS1 promoters and inhibit FOXS1 expression. Gene set enrichment analysis revealed that the FOXS1 gene was most abundantly enriched in the hedgehog signaling pathway and that GLI1 expression was significantly correlated with FOXS1 expression in GC. GLI1 directly bound to the promoter motif of FOXS1 and significantly decreased FOXS1 expression. Finally, we found that miR-125a-5p repressed FOXS1 expression at the translational level by binding to the 3′ untranslated region (UTR) of FOXS1. Together, these results suggest that FOXS1 can promote GC development and could be exploited as a diagnostic and prognostic biomarker for GC.

The role and molecular mechanism of Trop2 induced epithelial-mesenchymal transition through mediated β-catenin in gastric cancer

The present study elucidates the potential role of Trop2 in tumor invasion and the promotion of epithelial-mesenchymal transition (EMT) when binding β-catenin in GC. The role of Trop2 in promoting EMT in GC cells was examined by a variety of experimental assays. Moreover, the underlying molecular mechanism of Trop2 in promoting EMT was studied by in vivo and in vitro assays. The Trop2 expression in relation to tumor metastasis status was detected by IHC in 248 cases of GC tissues and 86 cases of matched adjacent tissues. Trop2 promoted the metastasis and induces EMT in GC. Meanwhile, the elevated protein levels of Trop2 and mesenchymal markers were also found in the TGF-β1-induced EMT model in GC cells. Importantly, Trop2 physically bound and activated β-catenin to promote EMT; moreover, Trop2 increased the accumulation of β-catenin in the nucleus to accelerate metastasis in GC cells. Inhibition of Trop2 expression in GC cells prevented the migration and invasion of GC cells in vivo. Trop2+/vimentin+ expression was higher in GC tissues than that in matched adjacent tissues, and Trop2+/vimentin+ expression in GC was associated with the differentiation, TNM stage, and distant metastases. These sets of data reveal a novel regulatory network of Trop2 in EMT and GC metastasis, suggesting Trop2 as a useful marker for inducing EMT and metastasis of GC, which may help to lead a better understanding of the pathogenesis of the GC.

Clinical significance of Stathmin1 expression and epithelial-mesenchymal transition in curatively resected gastric cancer

In our previous study, it was demonstrated that the Stathmin1 (STMN1) is overexpressed in gastric cancer (GC) and that its high expression level is associated with tumor invasion and metastasis. Epithelial-mesenchymal transition (EMT) has also been shown to be critically involved in GC invasion and metastasis. Certain studies have indicated that STMN1 may serve an important role in the EMT process. However, the association between STMN1 expression and EMT-associated markers, as well as clinicopathological characteristics of patients with GC, remains unclear. The aim of the present study was to investigate the clinicopathological significance and prognostic value of STMN1 and EMT-associated markers in GC. The expression of STMN1 and the EMT-associated proteins E-cadherin (E-Cad) and vimentin (VIM) were analyzed by immunohistochemistry in GC and adjacent non-tumorous tissues. Associations between the expression of these markers and clinicopathological parameters were analyzed. The association between STMN1 expression and EMT-associated markers was investigated in the GC cell lines BGC-803 and SGC-7901. The results revealed that STMN1 was expressed in 63.5% of the 167 GC tissues, which was significantly higher than the percentage observed in the adjacent non-tumorous tissues (P=0.003). The STMN1 expression was demonstrated to be positively associated with the VIM levels (P=0.001) and negatively associated with the E-Cad levels (P=0.022) in GC tissues. The STMN1 expression was associated with Lauren's Classification, invasion depth, lymph node metastasis and pathological Tumor-Node-Metastasis (pTNM) stage (P<0.05). In the univariate analyses, the high E-Cad expression was a positive prognostic indicator for overall survival, whereas the high STMN1 and VIM expression was a negative indicator. COX multiple regression analysis demonstrated that the pTNM stage [hazard ratio (HR) 1.912, 95% confidence interval (CI): 1.282–2.851, P=0.001] and E-Cad expression (HR 0.403, 95% CI: 0.249–0.650, P=0.000) were independent prognostic factors. It was also revealed that the expression level of E-Cad decreased, while the expression level of VIM increased by depleting STMN1 levels in GC cells. The present results suggest that the aberrant expression of STMN1 may promote tumor progression through EMT in GC.

The targeted regulation of Gli1 by miR-361 to inhibit epithelia-mesenchymal transition and invasion of esophageal carcinoma cells

Epithelia-mesenchymal transition (EMT) is critical for invasion and metastasis of esophageal carcinoma. Gli1, a transcriptional factor in Hedgehog pathway, is correlated with EMT, invasion and metastasis of tumors. However, its role in esophageal cancer is still unknown. Bioinformatics analysis revealed relationship between microRNA (miR)-361 and 3'-UTR of Gli1 gene. This study thus investigated the role of miR-361 and Gli1 in invasion and metastasis of esophageal cancer. Both tumor and adjacent tissues were collected from 58 esophageal cancer patients to test the expressions of miR-361 and Gli1, the relationship of which was confirmed by dual-luciferase reporter gene assay. Cultured esophageal cancer cells EC9706 were transfected with mimic NC, miR-361 mimic, si-NC, si-Gli1, miR-361 mimics+si-Glil, pQC or pQC-FU-Gli1. Transwell and colony formation assays were performed for cell invasion and attachment-independent growth. Expressions of Gli1, Snail, E-cadherin and N-cadherin proteins were revealed by Western blotting. The expression of Gli1 was significantly elevated in esophageal cancer tissues, along with lower miR-361 expression which was correlated with TNM stage. MiR-361 inhibited the expression of Gli1 via targeting on 3'-UTR of Gli1 gene. The transfection of miR-361 mimics and/or si-Gli1 significantly suppressed the growth of malignant cells. The over-expression of miR-361 and/or silencing of Gli1 decreased intracellular expression of Gli1, Snail and N-cadherin, and increased E-cadherin expression to suppress EMT and invasion of tumor cells while the opposite effects were obtained by over-expression of Gli1. Abnormal elevation of Gli1 and decrease of miR-361 were found in esophageal cancer tissues. MiR-361 weakened invasion of cancer cells and impeded EMT process via the inhibition of Gli1.

Identification and validation of a Hedgehog pathway-based 3-gene prognostic signature for gastric cancers

Developing prognostic factors for patients with gastric cancer (GC) is crucial for the accurate identification of subgroups with distinct clinical outcomes and the development of effective treatment strategies. The aim of this study was to determine novel gene expression signatures from the hedgehog (Hh) signaling pathway as predictors of risk with biological significance. The Cancer Genome Atlas (TCGA) GC (STAD) cohort was used as the training dataset to select for significant prognostic Hh genes. Three Hh genes, indian hedgehog (IHH), patched 1 (PTCH1) and smoothened frizzled class receptor (SMO), were identified to be significant prognostic factors. On this basis, a 3-Hh-gene set was constructed and the high-risk patients of the training cohort were distinguished against low-risk cases [hazard ratio (HR)=1.73, 95% confidence interval (CI)=1.26-2.39, P=0.00069]. Then the gene signature was externally validated in a combined dataset from Gene Expression Omnibus (n=631), and experimentally confirmed in an independent cohort of 126 clinical GC samples by immunohistochemistry (IHC). Validation in the combined GEO dataset yielded consistent results (HR=1.45, 95% CI=1.17-1.81, P=0.00068), and remained significant for stages I-III, HER2-positive and surgery alone subgroups. Subsequently, we further demonstrated that this mRNA-based gene set could be successfully transferred to an IHC-based signature in our local cohort (HR=2.04, 95% CI=1.09-3.82, P=0.02). In addition, this signature served as an independent prognostic indicator for overall survival in the multivariate Cox analysis (HR=2.133, 95% CI=1.110-4.099, P=0.02). In conclusion, we successfully generated a stable III-Hh-gene model with the ability to separate patients into prognostic subgroups, which may have notable biological importance and be easily utilized clinically.

Small interfering RNA-mediated knockdown of fatty acid synthase attenuates the proliferation and metastasis of human gastric cancer cells via the mTOR/Gli1 signaling pathway

Fatty acid synthase (FASN), the main enzyme involved in de novo lipogenesis, is overexpressed in several types of tumor tissues. In addition, it is associated with tumor cell proliferation, metastasis, epithelial-mesenchymal transition (EMT) and a poor prognosis. However, the precise functions and internal mechanisms of FASN with regard to the proliferation, metastasis and EMT in gastric cancer (GC) cells remain elusive. The present study investigated FASN protein expression in 18 randomly selected pairs of GC tumors and matched normal tissues by western blot analysis. FASN-specific small interfering RNA (siRNA) was then transfected into SGC-7901 cells to examine the effect of FASN on proliferation and migration in vitro. Western blotting was used to detect the protein expression of FASN, EMT-related markers and key signaling molecules of the mechanistic target of rapamycin/zinc finger protein GLI1 (mTOR/Gli1) pathway. Reverse transcription-quantitative polymerase chain reaction was conducted to detect the mRNA expression of FASN and EMT-related markers. The FASN level was higher in the GC tissues compared with that in the surrounding normal tissues. Knockdown of FASN suppressed GC cell proliferation and metastasis in vitro. The silencing of FASN expression using siRNA reversed EMT at the protein and mRNA levels and decreased the expression of Gli1 via regulation of AMP-activated protein kinase/mTOR and protein kinase B/mTOR signaling in GC cells. Inhibition of FASN suppresses GC proliferation and metastasis through targeting of the mTOR/Gli1 signaling pathway, indicating that it may serve as a potential target for the treatment of GC.

Targeting GLI Transcription Factors in Cancer

Aberrant activation of hedgehog (Hh) signaling has been observed in a wide variety of tumors and accounts for more than 25% of human cancer deaths. Inhibitors targeting the Hh signal transducer Smoothened (SMO) are widely used and display a good initial efficacy in patients suffering from basal cell carcinoma (BCC); however, a large number of patients relapse. Though SMO mutations may explain acquired therapy resistance, a growing body of evidence suggests that the non-canonical, SMO-independent activation of the Hh pathway in BCC patients can also account for this adverse effect. In this review, we highlight the importance of glioma-associated oncogene (GLI) transcription factors (the main downstream effectors of the canonical and the non-canonical Hh cascade) and their putative role in the regulation of multiple oncogenic signaling pathways. Moreover, we discuss the contribution of the Hh signaling to malignant transformation and propose GLIs as central hubs in tumor signaling networks and thus attractive molecular targets in anti-cancer therapies.

Prognostic and clinicopathological value of Gli-1 expression in gastric cancer: A meta-analysis

Glioma associated oncogene-1 (Gli-1) is considered as a strong positive activator of downstream target genes of hedgehog signal pathway in mammalians. However, its diagnostic and prognostic value in gastric cancer remains unclear and controversial. Therefore, a quantitative meta-analysis was conducted to determine the clinical value of Gli-1 in gastric cancer patients. Twelve eligible articles with 886 gastric cancer patients were included in this meta-analysis. The relationship between Gli-1 expression in gastric cancer patients and clinicopathological features and 5-year overall survival (OS) was evaluated using pooled odds ratios (ORs) and hazard ratio (HR) with 95% confidence intervals (CIs). The meta-analysis showed that the upregulated Gli-1 was associated with sample type (gastric cancer tissues) (OR 10.31, 95%CI 7.14-14.88; P = 0.000), differentiation type (OR 3.76, 95%CI 2.55-5.53; P = 0.000), depth of invasion (OR 8.17, 95%CI 3.60-18.55; P = 0.000), lymph node metastasis (OR 3.97, 95%CI 2.73-5.78; P = 0.000) and high TNM stage (OR 3.65, 95%CI 1.89-7.04; P = 0.000). Three studies including 316 patients were assessed for the correlation between Gli-1 and 5-year OS, which indicated that positive Gli-1 expression was associated with poor prognosis in gastric cancer patients (HR 2.14, 95%CI 1.35-3.40; P = 0.001). Little publication bias was identified by funnel plots and Egger's tests. The sensitivity analysis indicated that no study substantially influenced pooled OR/HR. Taken together, Gli-1 is a credible indicator for highly aggressive tumor with poor prognosis in gastric cancer patients.

Clinical Significance of Gli-1 And Caveolin-1 Expression in the Human Small Cell Lung Cancer

Background: Lung cancer is the leading causes of cancer-related deaths around the world. Abnormal activation of the hedgehog (Hh) signaling pathway has been found to be involved in the occurrence, invasion, and metastasis of cancers. Autophagy also plays a significant role in the growth and metastasis of cancers. However, the correlation between the Hh signaling pathway and autophagy in small cell lung cancer (SCLC) is still poorly understood. This study aimed to investigate the significance of Hh signaling pathway and autophagy in SCLC. Materials and Methods: The expression of the Hh-induced transcriptional factor, glioma associated oncogene-1 (Gli-1) and the autophagy-related molecule caveolin-1 (Cav-1) and their clinical significance was performed to detect and assay by immunohistochemistry in tissue microarray including 70 patients with SCLC. Results: In our study, 47 (67.1%) patients had positive Gli-1 expression, 49 (70.0%) patients had positive Cav-1 expression, and 44 (62.9%) patients had negative fibroblastic Cav-1 expression. In SCLC, Gli-1 expression increased markedly, and was closely associated with decreased fibroblastic Cav-1 expression. Furthermore, we also found that Gli-1 expression was closely associated with increased Cav-1 expression. Conclusions: Our findings suggested that abnormal activation of the Hh signaling pathway is closely related to autophagy in SCLC. We envision that novel targets may come with the further investigation of Gli-1 and Cav-1 in carcinogenesis of SCLC.

Gastric adenocarcinoma

Gastric cancers, with gastric adenocarcinoma (GAC) as the most common histological type, impose a considerable global health burden. Although the screening strategies for early detection have been shown to be successful in Japan and South Korea, they are either not implemented or not feasible in most of the world, leading to late diagnosis in most patients. Helicobacter pylori infection contributes to the development of many endemic GACs, and pre-emptive eradication or early treatment of this bacterial infection might provide effective primary prevention. GACs are phenotypically and genotypically heterogeneous. Localized (clinical stage I) GAC is best treated either endoscopically or with limited surgical resection, but clinical stage II or stage III tumours require multidisciplinary adjunctive approaches in addition to surgery. Although GAC is highly treatable in its early stages, advanced (clinical stage IV) GAC has a median survival of just ∼9-10 months. However, detailed molecular and immune profiling of GAC is yielding promise; early studies with immune checkpoint inhibitors suggest that GAC is amenable to immune modulation. Molecular studies have yielded a vast quantity of new information for potential exploitation. Nevertheless, advances against GACs have lagged compared with other tumours of similar incidence, and more research is necessary to overcome the obstacles to prolong survival.

Aberrant activation of hedgehog signaling promotes cell proliferation via the transcriptional activation of forkhead Box M1 in colorectal cancer cells

BACKGROUND

Recent evidence suggests that the aberrant activation of Hedgehog (Hh) signaling by Gli transcription factors is characteristic of a variety of aggressive human carcinomas, including colorectal cancer (CRC). Forkhead box M1 (FoxM1) controls the expression of a number of cell cycle regulatory proteins, and FoxM1 expression is elevated in a broad range of human malignancies, which suggests that it plays a crucial role in tumorigenesis. However, the mechanisms underlying FoxM1 expression are not fully understood. Here, we aim to further investigate the molecular mechanism by which Gli1 regulates FoxM1 in CRC.

METHODS

Western blotting and immunohistochemistry (IHC) were used to evaluate FoxM1 and Gli1 protein expression, respectively, in CRC tissues and matched adjacent normal mucosa. BrdU (5-bromo-2'-deoxyuridine) and clone formation assays were used to clarify the influence of FoxM1 on CRC cell growth and proliferation. Chromatin immunoprecipitation (ChIP) and luciferase experiments were performed to explore the potential mechanisms by which Gli1 regulates FoxM1. Additionally, the protein and mRNA expression levels of Gli1 and FoxM1 in six CRC cell lines were measured using Western blotting and real-time PCR. Finally, the effect of Hh signaling on the expression of FoxM1 was studied in cell biology experiments, and the effects of Hh signaling activation and FoxM1 inhibition on the distribution of CRC cells among cell cycle phases was assessed by flow cytometry.

RESULTS

Gli1 and FoxM1 were abnormally elevated in human CRC tissues compared with matched adjacent normal mucosa samples, and FoxM1 is a downstream target gene of the transcription factor Gli1 in CRC and promoted CRC cell growth and proliferation. Moreover, the aberrant activation of Hh signaling promoted CRC cell proliferation by directly binding to the promoter of FoxM1 and transactivating the activity of FoxM1 in CRC cells.

CONCLUSION

The dysregulation of the Hh-Gli1-FoxM1 axis is essential for the proliferation and growth of human CRC cells and offers a potent target for therapeutic intervention in CRC.

Galectin-1 induces invasion and the epithelial-mesenchymal transition in human gastric cancer cells via non-canonical activation of the hedgehog signaling pathway

Galectin-1 (Gal-1) has been reported to be an independent prognostic indicator of poor survival in gastric cancer and overexpression of Gal-1 enhances the invasiveness of gastric cancer cells. However, the downstream mechanisms by which Gal-1 promotes invasion remains unclear. Moreover, the function of Gal-1 in the epithelial-mesenchymal transition (EMT) in gastric cancer has not yet been elucidated. In this study, we observed Gal-1 expression was upregulated and positively associated with metastasis and EMT markers in 162 human gastric cancer tissue specimens. In vitro studies showed Gal-1 induced invasion, the EMT phenotype and activated the non-canonical hedgehog (Hh) pathway in gastric cancer cell lines. Furthermore, our data revealed that Gal-1 modulated the non-canonical Hh pathway by increasing the transcription of glioma-associated oncogene-1 (Gli-1) via a Smoothened (SMO)-independent manner, and that upregulation of Gal-1 was strongly associated with gastric cancer metastasis. We conclude that Gal-1 promotes invasion and the EMT in gastric cancer cells via activation of the non-canonical Hh pathway, suggesting Gal-1 could represent a promising therapeutic target for the prevention and treatment of gastric cancer metastasis.

CD44v6: A metastasis-associated biomarker in patients with gastric cancer?: A comprehensive meta-analysis with heterogeneity analysis

BACKGROUND

The diagnostic and prognostic value of CD44v6 in patients with gastric cancer remains unclear. Therefore, a quantitative meta-analysis was conducted to determine the clinical value of CD44v6 in patients with gastric cancer.

METHODS

Sixteen studies with 2177 patients were included. Pooled odds ratios (ORs) and hazard ratio (HR) with 95% confidence intervals (CIs) were calculated to estimate the impact of CD44v6 in patients with gastric cancer on clinicopathological features and 5-year overall survival (OS). Sensitivity analysis, subgroup analysis, and regression analysis were introduced to evaluate the heterogeneity across the studies. Publication bias was also explored among the studies.

RESULTS

The meta-analysis showed that the upregulated CD44v6 was associated with lymph node metastasis (OR 1.91, 95% CI 1.19-3.08; P = 0.007), distant metastasis (OR 3.41, 95% CI 2.01-5.78; P = 0.000), high TNM stage (OR 2.29, 95% CI 1.10-4.75; P = 0.026), lymphatic vessel invasion (OR 1.59, 95% CI 1.21-2.09; P = 0.001), and vascular invasion (OR 1.57, 95% CI 1.19-2.07; P = 0.001). When excluded 1 study based on sensitivity analysis, pooled HR indicated that CD44v6 positive expression was correlated poor 5-year OS (OR 1.76, 95% CI 1.30-2.39; P = 0.000), meanwhile, heterogeneity was eliminated. The heterogeneity of Lauren type mainly existed in the big sample size subgroup. Different region and publication year might contribute to the heterogeneity of differentiation type. While the heterogeneity of lymph node mainly existed in Asian and big sample size group. Publication bias was observed among 12 studies on lymph node metastasis (Ppublication bias = 0.041), and 5 studies on TNM stage (Ppublication bias = 0.026).

CONCLUSION

Taken together, CD44v6 overexpression might be correlated to the characteristics of tumor metastasis in gastric cancer, consisting with many mechanism studies. Therefore, CD44v6 might present a metastasis-associated biomarker in patients with gastric cancer.

Galectin-1 from cancer-associated fibroblasts induces epithelial-mesenchymal transition through β1 integrin-mediated upregulation of Gli1 in gastric cancer

BACKGROUND

Gastric cancer (GC) is characterized by the excessive deposition of extracellular matrix, which is thought to contribute to this tumor's malignant behavior. Epithelial-mesenchymal transition (EMT) is regarded as a crucial contributing factor to cancer progression. Galectin-1 (Gal-1), a β-galactoside-binding protein abundantly expressed in activated cancer-associated fibroblasts (CAFs), has been reported to be involved in GC progression and metastasis by binding to β1 integrin, which, in turn, can bind to matrix proteins and activate intracellular cascades that mediate EMT. Increasing evidence suggests that abnormal activation of the hedgehog (Hh) signaling pathway enhances GC cell migration and invasion. The purpose of our study is to explore the role of Gal-1 in the GC progression and metastasis as well as the regulatory mechanism.

METHODS

We hypothesized that Gal-1 binding to β1 integrin would lead to paracrine signaling between CAFs and GC cells, mediating EMT by upregulating Gli1. Invasion and metastasis effects of the Gal-1 and Gli1 were evaluated using wound healing and invasion assay following transfection with mimics. Additionally, to facilitate the delineation of the role of the Hh signaling in GC, we monitored the expression level of associated proteins. We also evaluated the effects of β1 integrin on these processes. Furthermore, Gal-1 and Gli1 expression in GC patient samples were examined by immunohistochemistry and western blot to determine the correlation between their expression and clinicopathologic characteristics. The Kaplan-Meier method and Cox proportional hazards model were used to analyze the relationship of expression with clinical outcomes.

RESULTS

Gal-1 was found to induce EMT, GC cell migration and invasion. Further data showed that Gal-1 up-regulated Gli1 expression. β1 integrin was responsible for Gal-1-induced Gli1 expression and EMT. In clinical GC tissue, it confirmed a positive relationship between Gal-1 and Gli1 expression. Importantly, their high expression is correlated to poor prognosis.

CONCLUSION

Gal-1 from CAFs binds to a carbohydrate structure in β1 integrin and plays an important role in the development of GC by inducing GC metastasis and EMT through targeting Gli1. This study highlights the potential therapeutic value of Gal-1 for suppression of GC metastasis.

Significance of the hedgehog pathway-associated proteins Gli-1 and Gli-2 and the epithelial-mesenchymal transition-associated proteins Twist and E-cadherin in hepatocellular carcinoma

It has been found that abnormal activation of the hedgehog (Hh) signaling pathway is involved in the occurrence, invasion and metastasis of malignant tumors. In addition, epithelial-mesenchymal transition (EMT) also performs an important function in the invasion and metastasis of malignant tumors. However, the significance of the Hh signaling pathway and EMT in hepatocellular carcinoma (HCC) remains unknown. In the present study, the expression of Gli family zinc finger 1 (Gli-1) and Gli family zinc finger 2 (Gli-2), which are key transcriptional factors in the Hh signaling pathway, and Twist and E-cadherin, which are two factors involved in EMT, was examined in 42 patients with HCC and 20 cases of non-tumorous liver (NTL) tissue by immunohistochemistry. Clinicopathological information was collected in order to analyze the correlation of the Hh signaling pathway with EMT. The present study aimed to examine the difference in the expression of Gli-1, Gli-2, E-cadherin and Twist in HCC and NTL to assess the diagnostic value of these factors in HCC. Additionally, the present study aimed to elucidate the correlation between those proteins and other clinicopathological parameters. Whether abnormal activation of the Hh signaling pathway is closely associated with EMT was also evaluated. Gli-1 and Twist expression was found to be significantly increased and E-cadherin expression was found to be decreased in HCC in contrast to NTL (Gli-1, P=0.019; Twist, P=0.003; E-cadherin, P<0.001). Increased Twist expression was associated with the tumor size (P=0.043), and loss of or decreased E-cadherin expression was associated with the histological type of HCC (P=0.021). There was an inverse association between the expression of Twist and E-cadherin (P=0.006). These results showed that Twist overexpression by induction of EMT changes is involved in the occurrence and progression of HCC. However, the role of Hh signaling pathway-associated proteins in HCC may require elucidation by additional studies using additional materials in the future.

Roles of Signaling Pathways in the Epithelial-Mesenchymal Transition in Cancer

The epithelial-mesenchymal transition (EMT) is a cellular process though which an epithelial phenotype can be converted into a phenotype of mesenchymal cells. Under physiological conditions EMT is important for embryogenesis, organ development, wound repair and tissue remodeling. However, EMT may also be activated under pathologic conditions, especially in carcinogenesis and metastatic progression. Major signaling pathways involved in EMT include transforming growth factor β(TGF-β), Wnt, Notch, Hedgehog and other signaling pathways. These pathways are related to several transcription factors, including Twist, Smads and zinc finger proteins snail and slug. These interact with each other to provide crosstalk between the relevant signaling pathways. This review lays emphasis on studying the relationship between EMT and signaling pathways in carcinogenesis and metastatic progression.

Prognostic role of Gli1 expression in solid malignancies: a meta-analysis

Gli1 is a downstream transcriptional factor of Sonic hedgehog pathway in mammalians, and has been recognized as a proliferative indicator of carcinogenesis. However, its actual role in prognosis among solid malignancies remains unclear. Therefore we performed this meta-analysis aiming to discover the correlation between Gli1 positivity and clinical prognosis in patients suffering from diverse carcinomas. A total of 39 studies containing 4496 cases were selected into our quantitative analysis via electronic database search. Original data of 3-year, 5-year, 10-year overall survival and disease-free survival were extracted and calculated using odds ratio and Mantel-Haenszel model. Subgroup analysis was also conducted to clarify the possible confounding factors. P < 0.05 was considered significant in statistics. Gli1 redundancy was associated with worse 3-year, 5-year, 10-year overall survival and disease-free survival in solid malignancies. Different source regions, sample-size, mean-age and detection approaches had no impact on the negative prognostic effect of Gli1 over-expression. Nevertheless, stratified by cancer type and subcellular localization, cytoplasmic Gli1 expression and Gli1 positivity in intracranial tumors was not correlated to poorer 3-year and 5-year prognosis. The over-expression of Gli1 is a credible indicator of poorer prognosis in most of solid malignancies, irrespective of intracranial tumors.

SET7/9 inhibits oncogenic activities through regulation of Gli-1 expression in breast cancer

SET7/9 is a protein lysine methyltransferase that had been initially identified as a histone lysine methyltransferase which generates monomethylation at histone 3 lysine 4. Different functions were attributed to the protein methylation mediated by SET7/9. In this study, we found that the expression of SET7/9 declined in a majority of the human breast cancer tissues examined compared with normal tissues. Knockdown of SET7/9 promoted the proliferation, migration, and invasion of breast cancer cells. Knockdown of SET7/9 also increased the tumorigenicity of breast cancer cells in vivo. On the contrary, overexpression of SET7/9 in breast cancer cells inhibited these processes. Microarray analysis indicated that Gli-1 may play function as a downstream factor of SET7/9. Overexpression of SET7/9SET7/9 inhibits Gli-1 expression. While knockdown of SET7/9 promotes the expression of Gli-1. Gli-1 inhibited by cyclopamine blocked knockdown SET7/9-driven proliferation, migration, and invasion in breast cancer cell. Furthermore, Gli-1 expression in human breast cancer tissues is negatively correlated with SET7/9 expression. Together, these results helped to realize the antioncogene functions of SET7/9 in breast cancer cells and provided a novel direction to treat breast cancer.

Correlation of overexpression of nestin with expression of epithelial-mesenchymal transition-related proteins in gastric adenocarcinoma

BACKGROUND

Nestin is associated with neoplastic transformation. However, the mechanisms by which nestin contributes regarding invasion and malignancy of gastric adenocarcinoma (GAC) remain unknown. Recent studies have shown that the epithelial-mesenchymal transition (EMT) is important in invasion and migration of cancer cells. In the present study, we aimed to investigate the expression of nestin and its correlation with EMT-related proteins in GAC.

MATERIALS AND METHODS

The expression of nestin and EMT-related proteins was examined in GAC specimens and cell lines by immunohistochemistry and Western blotting. Clinicopathological features and survival outcomes were retrospectively analyzed.

RESULTS

Positive nestin immunostaining was most obviously detected in the cytoplasm, nucleus or both cytoplasm and nucleus of tumor cells in 19.2% (24/125) of GAC tissues, which was significantly higher than that in normal gastric mucosa tissues (1.7%, 1/60) (p=0.001). Nestin expression was closely related to several clinicopathological factors and EMT-related proteins (E-cadherin, vimentin and Snail) and displayed a poor prognosis. Interestingly, simultaneous cytoplasmic and nuclear nestin expression correlated with EMT-related proteins (E-cadherin, vimentin and Snail) (p<0.05) and lymph node metastasis (p=0.041) and a shorter survival time (p<0.05), but this was not the case with cytoplasmic or nuclear nestin expression.

CONCLUSIONS

Nestin, particularly expression in both cytoplasm and nucleus, might be involved in regulating EMT and malignant progression in GAC, with potential as an unfavorable indicator in tumor diagnosis and a target for clinical therapy.

CD44, Sonic Hedgehog, and Gli1 Expression Are Prognostic Biomarkers in Gastric Cancer Patients after Radical Resection

Aim. CD44 and Sonic Hedgehog (Shh) signaling are important for gastric cancer (GC). However, the clinical impact, survival, and recurrence outcome of CD44, Shh, and Gli1 expressions in GC patients following radical resection have not been elucidated. Patients and Methods. CD44, Shh, and Gli1 protein levels were quantified by immunohistochemistry (IHC). The association between CD44, Shh, and Gli1 expression and clinicopathological features or prognosis of GC patients was determined. The biomarker risk score was calculated by the IHC staining score of CD44, Shh, and Gli1 protein. Results. The IHC positive staining of CD44, Shh, and Gli1 proteins was correlated with larger tumour size, worse gross type and histological type, and advanced TNM stage, which also predicted shorter overall survival (OS) and disease-free survival (DFS) after radical resection. Multivariate analysis indicated the Gli1 protein and Gli1, CD44 proteins were predictive biomarkers for OS and DFS, respectively. If biomarker risk score was taken into analysis, it was the independent prognostic factor for OS and DFS. Conclusions. CD44 and Shh signaling are important biomarkers for tumour aggressiveness, survival, and recurrence in GC.

Cooperative integration between HEDGEHOG-GLI signalling and other oncogenic pathways: implications for cancer therapy

The HEDGEHOG-GLI (HH-GLI) signalling is a key pathway critical in embryonic development, stem cell biology and tissue homeostasis. In recent years, aberrant activation of HH-GLI signalling has been linked to several types of cancer, including those of the skin, brain, lungs, prostate, gastrointestinal tract and blood. HH-GLI signalling is initiated by binding of HH ligands to the transmembrane receptor PATCHED and is mediated by transcriptional effectors that belong to the GLI family, whose activity is finely tuned by a number of molecular interactions and post-translation modifications. Several reports suggest that the activity of the GLI proteins is regulated by several proliferative and oncogenic inputs, in addition or independent of upstream HH signalling. The identification of this complex crosstalk and the understanding of how the major oncogenic signalling pathways interact in cancer is a crucial step towards the establishment of efficient targeted combinatorial treatments. Here we review recent findings on the cooperative integration of HH-GLI signalling with the major oncogenic inputs and we discuss how these cues modulate the activity of the GLI proteins in cancer. We then summarise the latest advances on SMO and GLI inhibitors and alternative approaches to attenuate HH signalling through rational combinatorial therapies.

Racial and ethnic disparities in gastric cancer outcomes: More important than surgical technique?

Racial and ethnic disparities in cancer care are major public health concerns and their identification is necessary to develop interventions to eliminate these disparities. We and others have previously observed marked disparities in gastric cancer outcomes between Eastern and Western patients. These disparities have long been attributed to surgical technique and extent of lymphadenectomy. However, more recent evidence suggests that other factors such as tumor biology, environmental factors such as Helicobacter pylori infection and stage migration may also significantly contribute to these observed disparities. We review the literature surrounding disparities in gastric cancer and provide data pertaining to potential contributing factors.

Snail1 correlates with patient outcomes in E-cadherin-preserved gastroesophageal junction adenocarcinoma

PURPOSE

The poor prognosis of gastroesophageal junction (GEJ) adenocarcinoma is largely associated with metastasis. We here report the first study to investigate the expression of epithelial-mesenchymal transition (EMT) markers Snail1 and E-cadherin in GEJ adenocarcinoma.

METHODS

Snail1 and E-cadherin were detected by immunohistochemistry in a cohort of 128 patients with surgically resected GEJ adenocarcinoma. We assessed the pathologic and prognostic relevance in all patients and within clinically different preserved E-cadherin and reduced E-cadherin-expressing sub-groups.

RESULTS

Immunoreactivity for Snail1 and E-cadherin was positive in 68 and 43 % of tumors, respectively. Snail1-positive tumors had more frequent lymph node metastasis and advanced tumor stage. E-cadherin expression was highly associated with histological differentiation, tumor size, advanced stage, presence of lymph node metastasis and distant metastasis. Patients with positive E-cadherin expression or negative Snail1 expression had significantly favorable overall survival rate. In E-cadherin-preserved tumors, the expression of Snail1 was related to lymph node metastasis, advanced stage and poor patient outcome. However, Snail1 expression had no statistically significant relationship with clinicopathologic parameters or prognosis in the reduced E-cadherin-expressing sub-group. Multivariate survival analysis identified that tumor stage [hazard ratio (HR) 2.440; 95 % confidence interval (CI) 1.216-4.896; P = 0.012], lymph node metastasis (HR 2.404; 95 % CI 1.188-4.867; P = 0.015) and gender (HR 3.244; 95 % CI 1.568-6.714; P = 0.002) were independent prognostic markers for overall survival.

CONCLUSIONS

Snail1 may act more critically in E-cadherin-positive tumors. Evaluation of Snail1 and E-cadherin in GEJ adenocarcinoma may help in assessing malignant properties and stratifying patients.

The therapeutic potential of targeting the epithelial-mesenchymal transition in cancer

INTRODUCTION

The process of epithelial-to-mesenchymal transition (EMT) has long been advocated as a process during tumor progression and the acquisition of metastatic potential of human cancers. EMT has also been linked with resistance to cancer therapies.

AREAS COVERED

Basic research has provided evidence connecting EMT to increased invasion, angiogenesis and metastasis of cancer cells. A number of signaling pathways such as notch, wnt, hedgehog and PI3K-AKT, and various other individual factors therein, have been intricately connected to the onset of EMT. Here, we provide latest updates on the evidences that further highlight an association between various signaling pathways and EMT, with a focus on therapeutic targets that may have the potential to reverse EMT.

EXPERT OPINION

Our understanding of EMT and its underlying causes is rapidly evolving and a number of putative targets have been identified. It is crucial, now than ever before, to design novel translational and clinical studies for the benefit of advanced stage cancer patients with metastatic disease.