Lin-Lin Ren

Roles of STAT3 and ZEB1 Proteins in E-cadherin Down-regulation and Human Colorectal Cancer Epithelial-Mesenchymal Transition

Background: Colorectal cancer (CRC) to metastatic disease may involve the epithelial-mesenchymal transition (EMT). Results: STAT3 may regulate N-cadherin, vimentin, and ZEB1 expressions. STAT3-induced cell invasion and down-regulation of E-cadherin may depend on ZEB1. Conclusion: STAT3 may mediate CRC EMT progression and ZEB1 expression. Activation of STAT3 and ZEB1 proteins may contribute to worse prognosis in CRC patients. Significance: Our data may provide potential targets to prevent and/or treat CRC invasion. The progression of colorectal carcinoma (CRC) to invasive and metastatic disease may involve localized occurrences of epithelial-mesenchymal transition (EMT). However, mechanisms of the EMT process in CRC progression are not fully understood. We previously showed that knockdown of signal transducer and activator of transcription 3 (STAT3) up-regulated E-cadherin (a key component in EMT progression) in CRC. In this study, we examined the roles of STAT3 in CRC EMT and ZEB1, an EMT inducer, in STAT3-induced down-regulation of E-cadherin. Knockdown of STAT3 significantly increased E-cadherin and decreased N-cadherin and vimentin expressions in highly invasive LoVo CRC cells. Meanwhile, overexpression of STAT3 significantly reduced E-cadherin and enhanced N-cadherin and vimentin expressions in weakly invasive SW1116 CRC cells. Activation of STAT3 significantly increased CRC cell invasiveness and resistance to apoptosis. Knockdown of STAT3 dramatically enhanced chemosensitivity of CRC cells to fluorouracil. STAT3 regulated ZEB1 expression in CRC cells, and the STAT3-induced decrease in E-cadherin and cell invasion depended on activation of ZEB1 in CRC cells. Additionally, pSTAT3Tyr-705 and ZEB1 expressions were significantly correlated with TNM (tumor, lymph node, and metastasis stages) (p < 0.01). In conclusion, STAT3 may directly mediate EMT progression and regulate ZEB1 expression in CRC. ZEB1 may participate in STAT3-induced cell invasion and E-cadherin down-regulation in CRC cells. The expressions of pSTAT3Tyr-705 and ZEB1 may be positively associated with CRC metastasis. Our data may provide potential targets to prevent and/or treat CRC invasion and metastasis.

Knockdown of ZFX inhibits gastric cancer cell growth in vitro and in vivo via downregulating the ERK-MAPK pathway.

Zinc finger protein X-linked (ZFX) is a zinc finger transcription factor encoded on the X chromosome. Here, we found that ZFX expression was significantly upregulated in gastric cancer (GC) cell lines and tissues. Knockdown of ZFX induced significant apoptosis and cell cycle arrest in SGC7901 and MGC803 cells. Moreover, we demonstrated for the first time that knockdown of ZFX inhibited gastric cancer cell growth in vitro and in vivo via downregulating the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK-MAPK) pathway. Therefore, ZFX play a prominent role in GC tumorigenicity and may have potential applications in the diagnosis or treatment of GC.

Probiotics Clostridium butyricum and Bacillus subtilis ameliorate intestinal tumorigenesis

AIMS To investigate the antitumor effects of probiotics Clostridium butyricum and Bacillus subtilis on colorectal cancer (CRC) progression. MATERIALS & METHODS The effects of C. butyricum and B. subtilis on CRC cells were studied. Male C57BL/6 mice with 1,2-dimethylhydrazine dihydrochloride (DMH)-induced CRC were intervened by these two probiotics and the antitumor effects were examined by comparing the tumor incidence and detecting the inflammatory and immune-related markers. RESULTS & CONCLUSIONS C. butyricum and B. subtilis inhibited the proliferation of CRC cells, caused cell cycle arrest and promoted apoptosis. In vivo, these two probiotics inhibited the development of DMH-induced CRC. The molecular mechanism involved reduced inflammation and improved immune homeostasis. This work establishes a basis for the protective role of probiotics B. subtilis and C. butyricum in intestinal tumorigenesis.

Folic Acid supplementary reduce the incidence of adenocarcinoma in a mouse model of colorectal cancer: microarray gene expression profile

BackgroundWhether Folic acid is a potential drug that may prevent the progression of colorectal carcinoma and when to use are important healthy issues we focus on. Our study is to examine the effect of folic acid on the development of the CRC and the optimal time folic acid should be provided in a mouse-ICR model induced by 1, 2-Dimethylhydrazine. Also, we investigated the gene expression profile of this model related to folic acid.MethodFemale ICR mouse (n = 130) were divided into 7 groups either with the treatment of 1, 2-Dimethylhydrazine (20 mg/kg bodyweight) weekly or folic acid (8 mg/kg bodyweight) twice a week for 12 or 24 weeks. Using a 4 × 44 K Agilent whole genome oligo microarray assay, different gene expression among groups (NS, DMH, FA2, FA3) were identified and selected genes were validated by real-time polymerase chain reaction.ResultsAnimals with a supplementary of folic acid showed a significant decrease in the incidence, the maximum diameter and multiplicity of adenocarcinomas (P < 0.05). Furthermore, there were fewer adenomas or adenocarcinomas developed in the group of folic acid supplementation in pre-adenoma stage compared to group of post-adenoma stage. Meanwhile, about 1070 genes that were changed by 1, 2-Dimethylhydrazine can be reversed by folic acid and 172 differentially genes were identified between the groups of pre- and post- adenoma stage using microarray gene expression analysis.ConclusionOur study demonstrated that folic acid supplementary was significantly associated with the decrease risk of CRC. And the subgroup of providing folic acid without precancerous lesions was more effective than that with precancerous lesions.

TMEFF2 Deregulation Contributes to Gastric Carcinogenesis and Indicates Poor Survival Outcome

Purpose: The role and clinical implication of the transmembrane protein with EGF and two follistatin motifs 2 (TMEFF2) in gastric cancer is poorly understood. Experimental Design: Gene expression profile analyses were performed and Gene Set Enrichment Analysis (GSEA) was used to explore its gene signatures. AGS and MKN45 cells were transfected with TMEFF2 or control plasmids and analyzed for gene expression patterns, proliferation, and apoptosis. TMEFF2 expression was knocked down with shRNAs, and the effects on genome stability were assessed. Interactions between TMEFF2 and SHP-1 were determined by mass spectrometry and immunoprecipitation assays. Results: Integrated analysis revealed that TMEFF2 expression was significantly decreased in gastric cancer cases and its expression was negatively correlated with the poor pathologic stage, large tumor size, and poor prognosis. GSEA in The Cancer Genome Atlas (TCGA) and Jilin datasets revealed that cell proliferation, apoptosis, and DNA damage–related genes were enriched in TMEFF2 lower expression patients. Gain of TMEFF2 function decreased cell proliferation by increasing of apoptosis and blocking of cell cycle in gastric cancer cells. The protein tyrosine phosphatase SHP-1 was identified as a binding partner of TMEEF2 and mediator of TMEFF2 function. TMEFF2 expression positively correlated with SHP-1, and a favorable prognosis was more likely in patients with gastric cancer with higher levels of both TMEFF2 and SHP-1. Conclusion: TMEFF2 acts as a tumor suppressor in gastric cancer through direct interaction with SHP-1 and can be a potential biomarker of carcinogenesis. Clin Cancer Res; 20(17); 4689–704. ©2014 AACR.

miR-194 as a Predictor for Adenoma Recurrence in Patients with Advanced Colorectal Adenoma after Polypectomy

microRNAs (miRNA) are promising predictors in colorectal cancer (CRC). We investigated whether miRNAs could predict adenoma recurrence in patients with advanced colorectal adenoma (ACRA) after polypectomy. miRNA expression profiling was performed by miRNA microarray to identify recurrence-related miRNAs. Candidate miRNAs extracted from formalin-fixed paraffin-embedded blocks of patients with ACRA were measured using real-time PCR. Logistic regression analysis was conducted to investigate whether validated miRNA expression profiles were independent from other known adenoma recurrence risk factors. The prognostic values of six miRNAs and three independent risk factors were assessed by the area under the receiver operating characteristic (ROC) curve analysis. The expressions of six candidate miRNAs were significantly decreased from levels in normal colorectal tissue compared with ARCA with adenoma recurrence (RACRA) in this retrospective cohort. However, only miRNA (miR)-194 emerged as a practical predictor. The sensitivity and specificity of miR-194 as a predictor were 71.0% and 78.0%, respectively, at a cutoff value of 0.1311 in the retrospective cohort. Sensitivity and specificity were 76.1% and 77.2%, respectively, in the prospective cohort using the same cutoff value. Low expression levels of miR-194, adenoma size ≥2 cm, and ≥3 adenomas were independent risk factors for adenoma recurrence. Moreover, low expression of miR-194 was a better predictor of adenoma recurrence than the adenoma size and numbers according to ROC curve analysis. miR-194 may be an independent predictor for adenoma recurrence in patients with ACRA after polypectomy. Cancer Prev Res; 7(6); 607–16. ©2014 AACR.

Downregulation of RPL15 may predict poor survival and associate with tumor progression in pancreatic ductal adenocarcinoma

Early diagnosis and treatment in pancreatic ductal adenocarcinoma (PDAC) is still a challenge worldwide. The poor survival of PDAC patients mainly due to early metastasis when first diagnosed and lack of prognostic biomarker. Ribosomal protein L15 (RPL15), an RNA-binding protein, is a component of ribosomal 60S subunit. It was reported that RPL15 is dysregulated in various type of cancers. However, little is known about the role of RPL15 in PDAC carcinogenesis and progression. Herein, we clarified RPL15 expression status may serve as an independent prognostic biomarker in three independent PDAC patient cohorts. We found that RPL15 was dramatically decreased in PDAC tissues and cell lines. The high expression of RPL15 was inversely correlated with TNM stage, histological differentiation, T classification and vascular invasion. Low expression of RPL15 was significantly associated with poor overall survival of PDAC patients. Furthermore, we demonstrated that the reduction of RPL15 may promote invasion ability of pancreatic cell by inducing EMT process. In conclusion, decreased RPL15 expression is associated with invasiveness of PDAC cells, and RPL15 expression status may serve as a reliable prognostic biomarker in PDAC patients.

Role of C9orf140 in the promotion of colorectal cancer progression and mechanisms of its upregulation via activation of STAT5, β-catenin and EZH2

C9orf140 is a newly identified and characterized gene which is associated with cell proliferation and tumorigenicity. Expression of C9orf140 is upregulated in human gastric cancer and colorectal cancer (CRC); however, little is known about its role in CRC progression. We have investigated the clinical significance, biological effects and mechanisms of C9orf140 signaling. We found that the expression of C9orf140 is dramatically increased in a subset of CRC and correlates significantly with vascular invasion and lymph node metastasis. Our finding showed that knockdown of C9orf140 significantly reduced cell proliferation and invasion in vitro and dramatically increased overall survival and decreased lung metastasis in vivo. Conversely, overexpression of C9orf140 significantly increased lung metastasis and shortened overall survival when compared with control tumors. C9orf140-induced CRC cell invasion may depend on promoting the epithelial-mesenchymal transition progression. STAT5 may directly interact with the enhancer of zeste homolog 2 (EZH2) and β-catenin to enhance C9orf140 gene transactivation. Furthermore, C9orf140 may participate in cell invasion which is induced by STAT5, EZH2 or β-catenin activation. We describe the role of C9orf140 in CRC progression and find that C9orf140 overexpression may be regulated by STAT5, EZH2 and β-catenin interaction.

MicroRNA-508 defines the stem-like/mesenchymal subtype in colorectal cancer

Colorectal cancer includes an invasive stem-like/mesenchymal subtype, but its genetic drivers, functional, and clinical relevance are uncharacterized. Here we report the definition of an altered miRNA signature defining this subtype that includes a major genomic loss of miR-508. Mechanistic investigations showed that this miRNA affected the expression of cadherin CDH1 and the transcription factors ZEB1, SALL4, and BMI1. Loss of miR-508 in colorectal cancer was associated with upregulation of the novel hypoxia-induced long noncoding RNA AK000053. Ectopic expression of miR-508 in colorectal cancer cells blunted epithelial-to-mesenchymal transition (EMT), stemness, migration, and invasive capacity in vitro and in vivo In clinical colorectal cancer specimens, expression of miR-508 negatively correlated with stemness and EMT-associated gene expression and positively correlated with patient survival. Overall, our results showed that miR-508 is a key functional determinant of the stem-like/mesenchymal colorectal cancer subtype and a candidate therapeutic target for its treatment.Significance: These results define a key functional determinant of a stem-like/mesenchymal subtype of colorectal cancers and a candidate therapeutic target for its treatment. Cancer Res; 78(7); 1751-65. ©2018 AACR.

Alcohol consumption and the risk of Barrett's esophagus: a comprehensive meta-analysis.

Several studies have been proposed to investigate the association between alcohol consumption and risk of Barrett’s esophagus (BE), but as of yet, no quantitative summary of the literature to clarify the relationship between them. In our study, twenty eligible cohort studies involving 42925 participants were identified. Combined relative risk (RR) ratios for the highest versus lowest alcohol consumption levels were calculated. The alcohol dose-response analysis was performed to investigate the association between the increment consumption of 10 g/d alcohol and the risk of developing BE. Subgroup analyses were used to examine heterogeneity across the studies. A combined RR of 0.98 (0.62–1.34) was found when comparing highest vs. lowest alcohol consumption levels for BE. An inverse association between alcohol and incidence of BE (RR 0.51; 95% CI: 0.055–0.96) was demonstrated in women. Moreover, Asian drinkers had a relative higher risk of BE (RR 1.34; 95% CI: 1.11–1.56) compared with Western drinkers. In conclusion, our results showed that overall alcohol consumption was not associated with increased BE incidence. The limited data available on alcohol consumption supports a tentative inversion of alcohol consumption with BE risk in women, while Asian drinkers tend to have a higher risk of BE.