Identification of Prognosis-Related Molecular Subgroups and Construction of a Prognostic Prediction Model Using Immune-Related Genes in Pancreatic Cancer.

Background: Pancreatic cancer patients with similar clinicopathological status exhibit substantially different therapeutic responses, which might be caused by the vast molecular heterogeneity of tumors. In this study, we attempted to identify specific molecular subgroups and construct a prognostic prediction model based on the expression level of immune-related genes in pancreatic cancer. The transcriptome profiling, single nucleotide variation, copy number variation, clinicopathological information, and follow-up data of pancreatic cancer patients were obtained from The Cancer Genome Atlas database. Thereafter, the immune-related genes with prognostic significance were identified for further consensus cluster analysis. The molecular characteristics and clinicopathological information were compared between the identified subgroups, and a weighted correlation network analysis was performed to identify the hub genes associated with the subgroups. Finally, the prognostic prediction model based on immune-related genes was established using the least absolute shrinkage and selection operator (LASSO) analysis. Results: A total of 67 immune-relevant genes with prognostic significance were selected and used for the consensus cluster analysis. The total samples were divided into two groups, C1 and C2. The subgroup C1 had a significantly worse prognosis than C2, as well as lower levels of immune cell infiltration, which indicate an immunosuppressed state. The mutational rate of the cancer-related genes including KRAS, TP53, and RNF43 was higher in the C1 subgroup. The C1 subgroup was associated with more advanced tumor grade and T stage and with higher mortality. Using LASSO regression, we developed a prognostic prediction model based on the expression levels of 19 immune-related genes, which we validated in three external data sets. In addition, we identified four potential therapeutic and prognostic biomarkers (TNNT1, KCNN4, SH2D3A, and PHLDA2). Conclusion: We identified two novel molecular subgroups of pancreatic cancer and developed a prognostic prediction model based on the expression levels of immune-related genes, which could be used in a clinical setting and could aid in unraveling the molecular processes leading to the development of pancreatic cancer.

Downregulation of long noncoding RNA SNHG14 suppresses cell proliferation and invasion by regulating EZH2 in pancreatic ductal adenocarcinoma (PDAC).

BACKGROUNDS: Previous studies have showed that long non-coding RNAs (lncRNAs) are critical regulators in many cancers. The aim of this study is to investigate the clinical role and functional effects of long non-coding RNA SNHG14 in pancreatic ductal adenocarcinoma (PDAC). METHODS: The expression of SNHG14 in 58 pairs of pancreatic cancer tissues and adjacent normal tissues was detected by quantitative real-time PCR (qRT-PCR) analysis. The correlations between SNHG14 expression and PDAC patients' clinicopathological characteristics and prognosis were statistically assessed. Cell counting kit-8 (CCK8) and transwell cell invasion assays were employed to detect the capacities of cell proliferation and cell invasion. The western blot analysis was used to detected the expression of E-cadherin and Vimentin. RESULTS: In the study, we found that SNHG14 expression was higher in PDAC tissue compared to adjacent normal tissues by qRT-PCR analysis. Higher SNHG14 expression was significantly associated with advanced TNM stage and positive lymph node metastasis in PDAC patients. Furthermore, we demonstrated that higher SNHG14 expression acted as a poor predictor in PDAC patients compared with lower SNHG14 expression. Moreover, we showed that higher SNHG14 expression promoted cell proliferation, cell colony formation and cell invasion ability in PDAC. Upregulation of SNHG14 expression promoted cell invasion by affecting E-cadherin expression via interacting with EZH2. CONCLUSIONS: Thus, these results indicated that SNHG14 expression acts as a prognostic maker for PDAC and potential target of PDAC treatment.

Circular RNA ciRS-7 promotes the proliferation and metastasis of pancreatic cancer by regulating miR-7-mediated EGFR/STAT3 signaling pathway.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is the most deadly type of tumor, and its pathogenesis remains unknown. Circular RNAs (circRNAs) may be functional and bind to microRNAs and consequently, influence the activity of targeted mRNAs. Recent researches indicate that one circRNA, ciRS-7, acts as a sponge of miR-7 and thus, inhibits its activity. It is well known that miR-7 is a cancer suppressor in many cancers. However, the relationship between ciRS-7 and miR-7, and the role of ciRS-7 in PDAC, remains to be elucidated. METHODS: miR-7 and ciRS-7 expression in 41 pairs of PDAC tumors and their paracancerous tissues were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The relationships between their expression levels and clinicopathological features in PDAC tissues were assessed. The relationship between miR-7 and ciRS-7 was also assessed by Spearman's correlation. We also used cell lines to evaluate the role of ciRS-7 in cell line behavior. The ciRS-7 interfere RNA (siRNA) and its empty vector were transfected into PDAC cells. PDAC cells proliferation and invasion abilities were detected by MTT assay and invasion analysis. The expression of proteins was assessed by Western blotting. RESULTS: ciRS-7 expression was significantly higher in PDAC tissues than paracancerous tissues (P = 0.002). However, miR-7 expression showed the opposite trend (P = 0.048). Moreover, ciRS-7 expression was inversely correlated with miR-7 in PDAC (rs = -0.353, P = 0.023). ciRS-7 expression was also significantly elevated in venous invasion (3.72 ± 2.93 vs. 2.14 ± 1.26; P = 0.028) and lymph node metastasis (4.19 ± 2.75 vs. 2.32 ± 1.90; P = 0.016) in PDAC patients. Furthermore, ciRS-7 knockdown suppressed cell proliferation and invasion of PDAC cells (P < 0.05), and the downregulation of ciRS-7 resulted in miR-7 overexpression and subsequent inhibition of epidermal growth factor receptor (EGFR) and signal transducer and activator of transcription 3 (STAT3). CONCLUSIONS: Circular RNA ciRS-7 plays an oncogene role in PDAC, partly by targeting miR-7 and regulating the EGFR/STAT3 signaling pathway.

Aurora A Inhibition Eliminates Myeloid Cell-Mediated Immunosuppression and Enhances the Efficacy of Anti-PD-L1 Therapy in Breast Cancer.

The Aurora A inhibitor alisertib shows encouraging activities in clinical trials against advanced breast cancer. However, it remains unclear whether and how the inflammatory microenvironment is involved in its efficacy. Here, we demonstrated that inhibition of Aurora A directly reshaped the immune microenvironment through removal of tumor-promoting myeloid cells and enrichment of anticancer T lymphocytes, which established a tumor-suppressive microenvironment and significantly contributed to the regression of murine mammary tumors. Mechanistically, alisertib treatment triggered apoptosis in myeloid-derived suppressor cells (MDSC) and macrophages, resulting in their elimination from tumors. Furthermore, alisertib treatment disrupted the immunosuppressive functions of MDSC by inhibiting Stat3-mediated ROS production. These alterations led to significant increases of active CD8+ and CD4+ T lymphocytes, which efficiently inhibited the proliferation of tumor cells. Intriguingly, alisertib combined with PD-L1 blockade showed synergistic efficacy in the treatment of mammary tumors. These results detail the effects of Aurora A inhibition on the immune microenvironment and provide a novel chemo-immunotherapy strategy for advanced breast cancers. SIGNIFICANCE: These findings show that inhibition of Aurora A facilitates an anticancer immune microenvironment, which can suppress tumor progression and enhance anti-PD-L1 therapy in breast cancer.See related commentary by Rivoltini et al., p. 3169.

The effect of adjuvant chemotherapy in resectable cholangiocarcinoma: A meta-analysis and systematic review.

BACKGROUND: The benefit of adjuvant chemotherapy for resectable cholangiocarcinoma remains unclear due to the lack of randomized control studies. This study aimed to investigate the possible benefit of postoperative adjuvant chemotherapy for resectable cholangiocarcinoma. DATA SOURCES: Relevant research articles published before 1st March 2018 in PubMed, Embase and the Cochrane library databases were retrieved. Published data were extracted and analyzed by RevMan 5.3, and the results were presented as hazard ratios (HRs) [95% confidence intervals (CI)] and forest plots. RESULTS: One prospective and eighteen retrospective studies were included, with a total number of 11,458 patients, 4696 of whom received postoperative chemotherapy. There was a significant improvement of the overall survival (OS) for patients who underwent operation + adjuvant chemotherapy compared to those who underwent operation alone (HR = 0.61; P < 0.001). Subgroup analyses show that the postoperative chemotherapy group compared with operation alone group are indicated as follows: hilar cholangiocarcinoma group (HR = 0.60; P < 0.001), intrahepatic cholangiocarcinoma group (HR = 0.60; P < 0.001), R1 resection group (HR = 0.71; P = 0.04), LN-positive diagnosis group (HR = 0.58; P < 0.001), gemcitabine-based chemotherapy group (HR = 0.42; P < 0.001), distal cholangiocarcinoma group (HR = 0.48; P = 0.17), R0 resection group (HR = 0.69; P = 0.43), and 5-flurouracil-based chemotherapy group (HR = 0.90; P = 0.66), respectively. CONCLUSIONS: Postoperative adjuvant chemotherapy can improve the OS in intrahepatic and hilar cholangiocarcinoma patients. However, distal cholangiocarcinoma patients gain no benefit from postoperative adjuvant chemotherapy. Prospective randomized trials are warranted in order to define the standard chemotherapy regimen.

MSI2 knockdown represses extrahepatic cholangiocarcinoma growth and invasion by inhibiting epithelial-mesenchymal transition.

PURPOSE: To investigate the expression and functional role of Musashi2 (MSI2), an RNA-binding protein, in extrahepatic cholangiocarcinoma (eCCA). PATIENTS AND METHODS: We measured MSI2 expression in human specimens and cell lines using Western blot and quantitative real-time polymerase chain reaction, and we analyzed its association with clinicopathologic features in eCCA patients. Univariate and multivariate analyses were performed to identify risk factors correlated with overall survival and disease-free survival. Functional experiments were used to study the mechanisms of MSI2 in regulating eCCA cell growth, migration, and invasion. RESULTS: MSI2 expression was upregulated significantly in both human specimens and cell lines, and high MSI2 expression was associated with lymph node metastasis, advanced TNM stage, and poor prognosis in eCCA patients. Additionally, MSI2 overexpression promoted eCCA cell growth, migration, and invasion, while MSI2 knockdown repressed eCCA cell migration and invasion by inhibiting epithelial-mesenchymal transition. CONCLUSION: MSI2 is an independent prognostic factor for eCCA patients, and MSI2 downregulation inhibits eCCA cell growth and metastasis. MSI2 may be a potential therapeutic target for eCCA patients.

The BET inhibitor I-BET762 inhibits pancreatic ductal adenocarcinoma cell proliferation and enhances the therapeutic effect of gemcitabine.

As one of the most fatal malignancies, pancreatic ductal adenocarcinoma (PDAC) has significant resistance to the currently available treatment approaches. Gemcitabine, the standard chemotherapeutic agent for locally advanced and metastatic PDAC, has limited efficacy, which is attributed to innate/acquired resistance and the activation of prosurvival pathways. Here, we investigated the in vitro efficacy of I-BET762, an inhibitor of the bromodomain and extraterminal (BET) family of proteins, in treating PDAC cell lines alone and in combination with gemcitabine (GEM). The effect of these two agents was also examined in xenograft PDAC tumors in mice. We found that I-BET762 induced cell cycle arrest in the G0/G1 phase and cell death and suppressed cell proliferation and metastatic stem cell factors in PDAC cells. In addition, the BH3-only protein Bim, which is related to chemotherapy resistance, was upregulated by I-BET762, which increased the cell death triggered by GEM in PDAC cells. Moreover, GEM and I-BET762 exerted a synergistic effect on cytotoxicity both in vitro and in vivo. Furthermore, Bim is necessary for I-BET762 activity and modulates the synergistic effect of GEM and I-BET762 in PDAC. In conclusion, we investigated the effect of I-BET762 on PDAC and suggest an innovative strategy for PDAC treatment.

Circulating microRNA-21 as a prognostic, biological marker in cholangiocarcinoma.

AIMS: The prognosis of cholangiocarcinoma (CCA) is generally poor because there is a lack of effective diagnostic tools including laboratory assessments and imageological examination. Therefore, a novel biological marker (biomarker) to effectively diagnose cancer is highly desirable in clinical. Previously, serum microRNAs as biomarkers of cancers have been reported. However, it was still unclear about the clinical significance of serum microRNA-21 (miR-21) expression levels for CCA. MATERIALS AND METHODS: The serum samples were separately collected from fifty patients of CCA, 15 patients of hepatolithiasis, and 15 healthy volunteers; quantitative real-time polymerase chain reaction was used for measuring miR-21 expression level in serum. The clinicopathological data were recorded before patients discharged. RESULTS: In the CCA serum, the expression level of miR-21 significantly upregulated (P < 0.05). With the tumor, node, and metastasis stage developed (Stage I vs. III and IV, P < 0.05), the serum miR-21 expression level increased, but there was no statistical difference between Stage I patients and hepatolithiasis patients or healthy control (P > 0.05 for both). Furthermore, the miR-21 level was significant difference between pre- and post-operative serum (P < 0.05) for the high miR-21 expression group. The serum miR-21 expression levels were defective in discriminating patients with CCA from healthy control subjects by receiver-operator curve analysis because the area under the curve (AUC) value was 0.871 which was not better than the conventional CCA markers-carbohydrate antigen 19-9 (AUC value = 0.96). However, in serum, high expression level miR-21 was significantly related to clinical stage, invasion depth, lymph vessel infiltration, metastasis status, differentiation status, whether to resection, and poor survival of CCA patients (P < 0.05 for all). CONCLUSIONS: This study suggested that serum miR-21 was a promising biomarker for diagnosing the late stage CCA and would have potential to be a useful prognostic biomarker of CCA.

Benchtop and animal validation of a portable fluorescence microscopic imaging system for potential use in cholecystectomy.

We propose a portable fluorescence microscopic imaging system (PFMS) for intraoperative display of biliary structure and prevention of iatrogenic injuries during cholecystectomy. The system consists of a light source module, a camera module, and a Raspberry Pi computer with an LCD. Indocyanine green (ICG) is used as a fluorescent contrast agent for experimental validation of the system. Fluorescence intensities of the ICG aqueous solution at different concentration levels are acquired by our PFMS and compared with those of a commercial Xenogen IVIS system. We study the fluorescence detection depth by superposing different thicknesses of chicken breast on an ICG-loaded agar phantom. We verify the technical feasibility for identifying potential iatrogenic injury in cholecystectomy using a rat model in vivo. The proposed PFMS system is portable, inexpensive, and suitable for deployment in resource-limited settings.

miR-21 and KLF4 jointly augment epithelial­mesenchymal transition via the Akt/ERK1/2 pathway.

miR-21 induces epithelial-mesenchymal transition (EMT) of human cholangiocarcinoma (CCA) cells. However, the mechanism by which this occurs remains unclear. In the present study, high throughput platform was employed to detect the genes that are differential expressed in QBC939 cells transfected with a hsa-miR-21 antagomir or control vectors. The EMT-related Krüppel-like factor 4 (KLF4) gene was downregulated after miR-21 was knocked down. Overexpression of miR-21 upregulated KLF4, Akt, ERK and mesenchymal cell markers (N-cadherin and vimentin), downregulated the expression of epithelial cell marker E-cadherin and reduced cell migration and invasion. Immunohistochemistry showed that KLF4, pAkt and pERK were upregulated in tumor xenografts transfected with miR-21 mimics. Inhibitors of the PI3K-Akt and ERK1/2 pathways, LY294002 and U0126, significantly suppressed the EMT phenotype. The present data demonstrated that overexpression of miR-21, accompanied with KLF4, augmented the EMT via inactivation of Akt and ERK1/2 pathways. In conclusion, we have identified a novel mechanism that may be targeted in an attempt to relieve the malignant biological behavior of CCA cells.

[The clinical value of pancreatic fistula risk predicting system after pancreaticoduodenectomy].

OBJECTIVE: To evaluate the clinical value of a preoperative predictive scoring system which was established by the National Cancer Center Hospital (NCCH) for the postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy. METHODS: The clinical data of 269 patients who underwent pancreaticoduodenectomy at the Affiliated Provincial Hospital of Anhui Medical University from February 2008 to February 2014 were studied retroprospectively. The five indexes which including gender, portal invasion, pancreatic cancer, main pancreatic duct index and intra abdominal fat thickness were calculated in the NCCH predictive score system. Patients with a score over 4 were defined as high risk of POPF, and those with score less than 4 were defined as low risk of POPF. Then the factors associated with POPF were analyzed by Logistic regression test. The enumeration data and measurement data were compared with χ2 test and t test. Risk factors for postoperative pancreatic fistula were analyzed through single factor and multiple factors Logistic regression analysis. The sensitivity and specificity of the predictive scoring system were determined by receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 33 patients were diagnosed as POPF, including 15 in grade A, 11 in grade B and 7 in grade C. The univariate analysis showed that the factors associated with POPF are gender, total serum bilirubin level, pancreatic cancer, portal invasion, the pancreatic texture, main pancreatic duct diameter and the pancreaticojejunostomy. The multivariate analysis showed that gender, pancreatic texture, portal invasion and main pancreatic duct diameter were the independent risk factor of POPF. The rate of pancreatic fistula of high risk group was 53.8% (14/26), and the rate of pancreatic fistula of the low risk group was 7.8% (19/243). There were significant differences in the pancreatic fistula rate between the high risk and low risk of POPF (χ2=46.231, P<0.01). The results of ROC curve analysis showed that the sensitivity and specificity of the predictive scoring system were 87.9% and 94.1%, respectively. The area under the curve was 0.946 (95% CI: 0.895-0.997). CONCLUSIONS: The NCCH preoperative predictive scoring system could accurately predict the occurrence of POPF. While large, multicenter prospective randomized controlled trials is still needed to further confirm it.

MicroRNA-21 regulates biological behavior by inducing EMT in human cholangiocarcinoma.

MicroRNAs (miRNAs) have recently been demonstrated to play a crucial role in malignant progression including differentiation, proliferation, metastasis and invasion, MicroRNA-21 (mir-21) also has been reported to have association with tumor invasion and metastasis in some tumors including cholangiocarcinoma (CCA). In this study, we further investigated the association of mir-21 with CCA biological behavior by transfecting miR-21 mimics or mir-21 inhibitor into QBC939 and RBE cells accompanied with the tumor xenografts experiment. Results indicated that over-expression of miR-21 significantly promoted cell migration, invasion and xenografts growth, whereas contrary phenomenon was observed in mir-21 inhibitor group. Furthermore, we explored the expression of EMT related proteins in CCA cells and tumor xenografts. Results showed that E-cadherin was decreased and N-cadherin, Vimentin were up-regulated significantly when miR-21 was over-expressed. In conclusion, microRNA-21 is crucial for CCA carcinogenesis and metastasis, which could induce EMT process, thereby promote the invasion and migration of CCA cells. These findings may provide new strategy for prevention and treatment of CCA in the future.

Postoperative anastomotic bile duct stricture is affected by the experience of surgeons and the choice of surgical procedures but not the timing of repair after obstructive bile duct injury.

Bile duct injury (BDI) is one of the most severe complications of biliary operation. This study is to investigate the correlation between the timing of bile duct repair and anastomotic bile duct stricture. Transverse BDI models were constructed in 60 dogs that were divided randomly into BDI5, BDI10, BDI15, BDI20, and BDI30 groups according to days of injury (5, 10, 15, 20, and 30 days). The morphological and histological changes of anastomotic stoma of hepaticojejunostomy (HJ) were observed after bile duct reconstruction. TGF-ß1, α-SMA, and collagen of anastomotic stoma were detected. After HJ, the concentration of direct bilirubin decreased significantly, dropping to 50% after one week, and returning to normal levels after three weeks. The anastomotic diameter shrunk from 1.5 cm to 0.6 cm without significant difference. At 3 months and 6 months after HJ, the expression of TGF-ß in the anastomotic tissue in BDI5 group was higher than that in BDI10, BDI15, BDI20, and BDI30 groups. However, no significant differences were observed (F = 1.282, P > 0.05 at 3 months; F = 1.308, P > 0.05 at 6 months). Similarly, the expression of α-SMA and collagen did not vary significantly. For obstructive BDI, repairing time is not a relevant factor for postoperative anastomotic stenosis, but surgeons and operation methods are the key factors. For patients with BDI, hospitals should focus on the experience of surgeons and the choice of operation methods in order to achieve a good long-term effect.

Fragile histidine triad (FHIT) suppresses proliferation and promotes apoptosis in cholangiocarcinoma cells by blocking PI3K-Akt pathway.

Fragile histidine triad (FHIT) is a tumor suppressor protein that regulates cancer cell proliferation and apoptosis. However, its exact mechanism of action is poorly understood. Phosphatidylinositol 3-OH kinase (PI3K)-Akt-survivin is an important signaling pathway that was regulated by FHIT in lung cancer cells. To determine whether FHIT can regulate this pathway in cholangiocarcinoma QBC939 cells, we constructed an FHIT expression plasmid and used it to transfect QBC939 cells. Protein and mRNA expression were measured by western blotting and qRT-PCR, respectively. The viability and apoptosis of QBC939 cells were then assessed using MTT assays and flow cytometry. Our results revealed that the expression of survivin and Bcl-2 was downregulated, and caspase 3 was upregulated, in cells overexpressing FHIT. In addition, FHIT suppressed the phosphorylation of Akt. The changes in cell proliferation and apoptosis were obvious in cells overexpressing FHIT which parallels that of treatment with LY294002, a potent inhibitor of phosphoinositide 3-kinases. Treatment with LY294002 further decreased the expression of survivin and Bcl-2 and increased caspase-3 levels. These results suggest that FHIT can block the PI3K-Akt-survivin pathway by suppressing the phosphorylation of Akt and the expression of survivin and Bcl-2 and upregulating caspase 3.

Analysis of diagnosis and treatment for pancreatic neuroendocrine neoplasms: results of 47 cases in a single institution.

BACKGROUND/AIMS: There are few large sample, single-center series that focus on the methods of diagnosis, treatment and long-term survival of patients with Pancreatic neuroendocrine neoplasms (pNENs). METHODOLOGY: Forty-seven patients with pNENs treated at Anhui province hospital affliated of Anhui Medical University during January 2002 to December 2013 were analyzed retrospectively. Clinical data were collected and statistically analyzed. RESULTS: The sensitivity of abdominal ultrasound, CT and MRI was 71.2% (28/39), 92.3% (38/41), and 75% (6/8), respectively. All patients received operation. 46 underwent radical surgery, pancreatic fistula in 9 patients, seroperitoneum in 4 patients, incisional infection in 4 patients. The cases of grade G1, G2, and G3 were 22, 19, and 6, respectively. The cases of stage I, II, III and IV were 32, 11, 4, and 0, respectively. The overall 1-, 3, and 5-year survival rates were 94.9%, 88.4%, and 84.4%. Univariate analysis showed that TNM, WHO classification, lymph nodes metastasis, vascular and neural invasion were risk factors of pNENs. CONCLUSION: Sprial CT was an optimal diagnostic method, while surgery was the first choice for treatment. Surgical resection in pNENs results in long-term survival. TNM, WHO classification, lymphatic metastasis, vascular and neural invasion were closely related to the prognosis of pNENs.

Risk factors of postoperative complications of pancreatoduodenectomy.

BACKGROUND/AIMS: To investigate the risk factors of postoperative complications of pancreaticoduodenectomy. METHODOLOGY: 207 cases suffered from pancreatic carcinoma or periampullary carcinoma received pancreatoduodenectomy in the Anhui Provincial Hospital from Dec. 2007 to Dec. 2012 were analyzed. 17 clinicopathologic factors that could possibly influence postoperative mortality and morbidity were selected for univariate analysis and multivariate analysis using Logistic Regression. RESULTS: Univariate analysis showed that major risk factors of postoperative mortality and morbidity of the patients were operation history, pre-operative drainage, total serum bilirubin level, alanine aminotransferase, serum albumin, serum pre-albumin, pancreatic texture and pancreatic duct diameter (P<0.05). Multivariate analysis showed that alanine aminotransferase, pancreatic texture and pancreatic duct diameter were the independent risk factors of complications after pancreatoduodenectomy. Pancreatic duct diameter was the independent risk factor of pancreatic fistula. Pancreatic fistula was the independent risk factor of hemorrhage. CONCLUSION: Postoperative complications of pancreatoduodenectomy are closed related to alanine aminotransferase, parenchyma texture and pancreatic duct diameter.

Prognostic value of HIF-1α expression in patients with gastric cancer.

The role of hypoxia-inducible factors-1 alpha (HIF-1α) expression in gastric cancer remains controversial. We performed a systematic review of the literature with meta-analysis. Electronic databases were used to identify published studies before December 1, 2012. Pooled hazard ratio (HR) or odds ratio (OR) with 95 % confidence interval (95 % CI) was used to estimate the strength of the association between HIF-1α expression and survival of gastric cancer patients. Heterogeneity and publication bias were also assessed. Final analysis of 1,268 patients from 9 eligible studies was performed. High HIF-1α expression was significantly correlated with poor overall survival (OS) of gastric cancer patients (HR = 2.14, 95 % CI = 1.32-3.48). Subgroup analysis indicated that HIF-1α over-expression had an unfavorable impact on OS in Asian patients (HR = 2.35, 95 % CI = 1.41-3.92). Moreover, up-regulation of HIF-1α was significantly associated with the depth of invasion (OR = 2.49, 95 % CI = 1.28-4.83), lymph node metastasis (OR = 2.15, 95 % CI = 1.27-3.66), and vascular invasion (OR = 2.23, 95 % CI = 1.20-4.14). HIF-1α expression might be a predicative factor of poor prognosis for gastric cancer particularly in Asia.

[Molecular mechanism of γ-aminobutyric acid inhibitory on the growth of cholangiocarcinoma QBC939 cell line].

OBJECTIVE: To explore the molecular mechanism of γ-aminobutyric acid (GABA) inhibitory on the growth of cholangiocarcinoma cell line (QBC939). METHODS: QBC939 cells were cultured in different groups and treated with GABA, GABA + bicuculine (A receptor antagonist), GABA + phaclofen (B receptor antagonist) for 48 hours. MTT assay was used to determine the proliferation of QBC939 cells. Annexin V-FITC/PI binding assay was used to detect apoptosis in the QBC939 cells. Western blot was applied to check the expression of signal transducer and activator of transcription 3 (STAT3) and phosphorylation-STAT3 (p-STAT3) proteins in different groups of QBC939 cells. Animal models of cholangiocarcinoma bearing nude mice were established by subcutaneous injection of QBC939 cells and randomized into 2 groups: control and GABA-treated groups. The effect of GABA was evaluated after 5 weeks, including the body weight and tumor volume. The expression of p-STAT3 was detected by immunohistochemistry and Western blot in xenograft tumors. RESULTS: MTT and FCM assays both showed that the effect of GABA inhibitory on the proliferation (15.30% ± 0.80% vs. 2.66% ± 0.74%, t = 23.15, P = 0.00) and induced apoptosis (23.15% ± 0.21% vs. 4.30% ± 0.69%, t = 52.40, P = 0.00) of QBC939 cells could be antagonized by phaclofen, but not bicuculine. The expression of STAT3 and p-STAT3 proteins were all observed in the QBC939 cells and GABA significantly down-regulated p-STAT3 protein expression (0.77 ± 0.00 vs. 0.45 ± 0.01, t = 63.14, P = 0.00), this action was also antagonized by phaclofen (0.45 ± 0.01 vs. 0.76 ± 0.01, t = 56.25, P = 0.00). Xenograft tumor volume ((0.62 ± 0.03) cm³ vs. (0.34 ± 0.03) cm³, t = 13.45, P = 0.00) and the expression of p-STAT3 protein were significantly decreased in GABA-treated group as compared with control group. CONCLUSIONS: GABA may inhibit the growth of cholangiocarcinoma cells QBC939 through GABA(B) receptor, and down-regulation of the p-STAT3 expression perhaps is one of its anti-tumor mechanisms.

NAD(P)H: quinone oxidoreductase 1 (NQO1) C609T gene polymorphism association with digestive tract cancer: a meta-analysis.

NAD(P)H: quinone oxidoreductase 1 (NQO1) C609T gene polymorphisms have been reported to influence the risk for digestive tract cancer (DTC) in many studies; however, the results remain controversial and ambiguous. We therefore carried out a meta-analysis of published case-control studies to derive a more precise estimation of any associations. Electronic searches were conducted on links between this variant and DTC in several databases through April 2012. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of associations in fixed or random effect models. Heterogeneity and publication bias were also assessed. A total of 21 case-control studies were identified, including 6,198 cases and 7,583 controls. Overall, there was a statistically significant association between the NQO1 C609T polymorphism and DTC risk (TT vs. CC: OR=1.224, 95%CI=1.055-1.421; TT/CT vs. CC: OR=1.195, 95%CI=1.073-1.330; TT vs. CT/CC: OR=1.183, 95%CI=1.029-1.359; T vs. C: OR=1.180, 95%CI=1.080-1.290). When stratified for tumor location, the results based on all studies showed the variant allele 609T might have a significantly increased risk of upper digest tract cancer (UGIC), but not colorectal cancer. In the subgroup analysis by ethnicity, we observed a significantly risk for DTC in Caucasians. For esophageal and gastric cancer, a significantly risk was found in both populations, and for colorectal, a weak risk was observed in Caucasians, but not Asians. This meta-analysis suggested that the NQO1 C609T polymorphism may increase the risk of DTC, especially in the upper gastric tract.