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.

Gossypol induces cell death by activating apoptosis and autophagy in HT-29 cells.

Gossypol is a polyphenolic, yellowish compound derived from cottonseed extract. The present study examined the effects of gossypol on the apoptosis and autophagy of HT­29 cells. A Cell Counting Kit­8 assay, Annexin V­FITC, JC­1 staining and western blotting were used to identify the viability of cells, stages of apoptosis and the expression levels of the signaling proteins. Gossypol promoted apoptosis and induced the loss of mitochondrial membrane potential. Further investigation of the apoptotic mechanism revealed that gossypol increased the ratio of B­cell lymphoma 2 (Bcl-2)-associated X protein/Bcl­2 protein levels and upregulated the expression of caspase­3. Gossypol also enhanced the activity of microtubule­associated protein light chain 3 LC3­II and Beclin­1 and downregulated LC3­I, in a dose­dependent manner. Together, these finding suggested that gossypol may be a novel and potential antitumor agent.

Romidepsin induces G2/M phase arrest via Erk/cdc25C/cdc2/cyclinB pathway and apoptosis induction through JNK/c-Jun/caspase3 pathway in hepatocellular carcinoma cells.

The aim of the study is to demonstrate the effect of Romidepsin in hepatocellular carcinoma (HCC) by inducing G2/M phase arrest via Erk/cdc25C/cdc2/cyclinB pathway and apoptosis through JNK/c-Jun/caspase3 pathway in vitro and in vivo. Human HCC cell lines were cultured with Romidepsin and DMSO (negative control) and 5-fluorouracil (positive control). Then the cells' viability and apoptosis were determined by cell proliferation assay and flow cytometry. Protein concentrations and expression changes were measured by Western blot. Subsequently, Huh7 cells were subcutaneously inoculated into the nude mice, which were employed to further probe the tumor-suppressive effect of Romidepsin in vivo. Romidepsin treatment led to a time- and dose-dependent induction of cell cycle arrest in the G2/M phase and apoptosis. G2/M phase arrest inhibited the proliferation of HCC cells by alterations in p21/cdc25C/cdc2/cyclinB proteins. Increased concentrations of Erk and JNK phosphorylations were observed in a dose-dependent manner in the Romidepsin group, but p38 phosphorylation was not affected. G2/M phase arrest and the apoptosis of HCC cells induced by Romidepsin were mediated by the activation of Erk/MAPK pathways and JNK/MAPK pathways. The tumor size was significantly larger in the negative control group compared to Romidepsin group and no significant loss in body weight was observed in the Romidepsin group. Our findings offer proof-of-concept for use of Romidepsin as a novel class of chemotherapy in the treatment of HCC.

Expression of AQP1 Was Associated with Apoptosis and Survival of Patients in Gastric Adenocarcinoma.

RATIONALE AND OBJECTIVE: Recently, interest in the role of aquaporin 1 (AQP1) in human gastrointestinal carcinogenesis has developed. However, to date no studies have examined relationships between AQP1 expression and specific characteristics of gastric adenocarcinoma. METHODS: We investigated 109 specimens of primary gastric adenocarcinoma and their corresponding normal gastric mucosa using immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) to determine AQP1 expression. We then evaluated disease free survival (DFS) and overall survival (OS) in these patients in association with AQP1 expression. RESULTS: Both immunohistochemical and RT-PCR analyses identified increased AQP1 expression in tumors from patients with gastric adenocarcinoma (p < 0.001). The 3-year DFS and OS rates were higher in the AQP1-negative group than in the positive group (DFS: 77.2 vs. 52.8%, p < 0.001; OS: 85.1 vs. 70.7%, p < 0.001). The 5-year DFS and OS rates exhibited a similar trend (p < 0.001). Subgroup analysis of patients with early gastric adenocarcinoma (stages I and II) revealed a total 5-year OS of 90.0%, with 5-year OS being higher in the AQP1-negative group than in the positive group (95.2 vs. 84.2%). Furthermore, incidence of tumor recurrence following surgical treatment was significantly higher in the AQP1-positive group (4/19, 21.1%) compared with the negative group (0/21, 0%). CONCLUSIONS: Our study demonstrates that AQP1 plays an important role in gastric adenocarcinoma and may therefore represent a novel therapeutic target and prognostic marker in this disease.

Cruciferous vegetable consumption and the risk of pancreatic cancer: a meta-analysis.

BACKGROUND: Previous studies regarding the association between cruciferous vegetable intake and pancreatic cancer risk have reported inconsistent results. We conducted a meta-analysis to demonstrate the potential association between them. METHODS: A systematic literature search of papers was conducted in March 2014 using PubMed, EMBASE, and Web of Science, and the references of the retrieved articles were screened. The summary odds ratios (ORs) with 95% confidence interval (CI) for the highest versus the lowest intake of cruciferous vegetables were calculated. RESULTS: Four cohort and five case-control studies were eligible for inclusion. We found a significantly decreased risk of pancreatic cancer associated with the high intake of cruciferous vegetables (OR 0.78, 95% CI 0.64-0.91). Moderate heterogeneity was detected across studies (P = 0.065). There was no evidence of significant publication bias based on Begg's funnel plot (P = 0.917) or Egger's test (P = 0.669). CONCLUSIONS: Cruciferous vegetable intake might be inversely associated with pancreatic cancer risk. Because of the limited number of studies included in this meta-analysis, further well-designed prospective studies are warranted to confirm the inverse association between cruciferous vegetable intake and risk of pancreatic cancer.

Efficacy of docetaxel combined with oxaliplatin and fluorouracil against stage III/IV gastric cancer.

AIM: To investigate the clinical efficacy and toxic effects of neoadjuvant chemotherapy using docetaxel combined with oxaliplatin and fluorouracil for treating stage III/IV gastric cancer. METHODS: A total of 53 stage III/IV gastric cancer patients were enrolled into the study and treated with neoadjuvant chemotherapy. Two of the cases were excluded. The program was as follows: 75 mg/m(2) docetaxel and 85 mg/m(2) oxaliplatin on day 1 and 1500 mg/m(2) fluorouracil on days 1 to 3 for three weeks. RESULTS: The tumour changes, postoperative remission rate, changes in the symptoms and adverse reactions were observed. The overall clinical efficacy (complete remission + partial remission) of the neoadjuvant chemotherapy was 62.7%. R0 radical resection was performed on 60.8% of the patients, with a remission rate (pathological complete response + pathological subtotal response + pathological partial response) of 74.2%. The Karnofksy score improved in 42 cases. The toxicity reactions mostly included myelosuppression, followed by gastrointestinal mucosal lesions, nausea, vomiting and diarrhoea. CONCLUSION: Neoadjuvant chemotherapy consisting of docetaxel combined with oxaliplatin and fluorouracil is effective for stage III/IV gastric cancer. However, the treatment is associated with a high incidence of bone marrow suppression, which should be managed clinically.

Latexin inhibits the proliferation of CD133+ miapaca-2 pancreatic cancer stem-like cells.

BACKGROUND: An increasing number of evidence suggests that pancreatic cancer contains cancer stem cells (CSCs), which may be relevant to the resistance of chemotherapy. Latexin (Lxn) is a negative regulator of stem cell proliferation and we investigate the effects of Lxn on CD133+ pancreatic cancer stem-like cells. METHODS: CD133+ miapaca-2 cells, a human pancreatic carcinoma cell line, were isolated and sorted by magnetic activated cell sorting and flow cytometry. The capacity for self-renewal, proliferation, and tumorigenicity of CD133+ miapaca-2 cells was determined by the floating spheres test and tumor xenograft assays. Protein and mRNA expression of Lxn in CD133+ and CD133- miapaca-2 cells were detected by Western blotting and qRT-PCR, respectively. After CD133+ miapaca-2 cells were treated with Lxn in serum-free medium (SFM), cell proliferation was assayed with a Cell Counting Kit 8 (CCK-8) and apoptosis was analyzed by flow cytometry. The protein and mRNA expression levels of Bcl-2, bax, and c-myc were also analyzed. RESULTS: We successfully isolated CD133+ miapaca-2 cells that exhibited the capacity for self-renewal in SFM, a proliferation potential in DMEM supplemented with FBS, and high tumorigenicity in nude mice. Lxn protein and mRNA expression levels in CD133+ miapaca-2 cells were significantly lower than those in CD133- cells. Lxn-treated CD133+ miapaca-2 cells exhibited increased apoptosis and low proliferation activity, down-regulation of Bcl-2 and c-myc expression, and up-regulation of Bax expression in a dose-dependent manner. CONCLUSIONS: Lxn induces apoptosis and inhibits the proliferation of CD133+ miapaca-2 cells. These changes are associated with down-regulation of Bcl-2 and c-myc and up-regulation of Bax.

Artesunate inhibits the growth of gastric cancer cells through the mechanism of promoting oncosis both in vitro and in vivo.

This study aims to investigate the significance and mechanism of artesunate involved in suppressing the proliferation of gastric cancer in vitro and in vivo. In the in-vitro experiments, artesunate inhibited the growth of gastric cancer cell lines (SGC-7901, BGC-823, and AGS) with concentration-dependent activity, with no significant effect on GES-1 cells. BGC-823 cells treated with artesunate showed the typical morphologic features of oncosis rather than apoptosis. Meanwhile, we observed calcium overload, downregulation of vascular endothelial growth factor expression, and upregulation of calpain-2 expression in the artesunate-treated BGC-823 cells. In addition, the in-vivo study showed that artesunate produced a dose-dependent tumor regression in nude mice. The antitumor activity of 240 mg/kg artesunate was similar to that of 10 mg/kg docetaxel. Furthermore, compared with the control group, no significant difference was observed in the body weight of artesunate-treated nude mice other than docetaxel-treated nude mice. These observations show that artesunate has concentration-dependent inhibitory activities against gastric cancer in vitro and in vivo by promoting cell oncosis through an impact of calcium, vascular endothelial growth factor, and calpain-2 expression.

Histone acetyltransferases and deacetylases: molecular and clinical implications to gastrointestinal carcinogenesis.

Histone acetyltransferases and deacetylases are two groups of enzymes whose opposing activities govern the dynamic levels of reversible acetylation on specific lysine residues of histones and many other proteins. Gastrointestinal (GI) carcinogenesis is a major cause of morbidity and mortality worldwide. In addition to genetic and environmental factors, the role of epigenetic abnormalities such as aberrant histone acetylation has been recognized to be pivotal in regulating benign tumorigenesis and eventual malignant transformation. Here we provide an overview of histone acetylation, list the major groups of histone acetyltransferases and deacetylases, and cover in relatively more details the recent studies that suggest the links of these enzymes to GI carcinogenesis. As potential novel therapeutics for GI and other cancers, histone deacetylase inhibitors are also discussed.