TWIST1 transcriptionally regulates glycolytic genes to promote the Warburg metabolism in pancreatic cancer.

Reprogrammed glucose metabolism is essential for tumor initiation and development, especially for pancreatic ductal adenocarcinoma (PDAC). Most cancer cells rely on aerobic glycolysis, a phenomenon termed "the Warburg effect", to support uncontrolled proliferation and evade apoptosis. However, the direct regulators of the Warburg effect remain areas of active investigation. In this study, we found that the highly conserved transcription factor, TWIST1, is a crucial regulator of aerobic glycolysis in PDAC. Genetic silencing of TWIST1 significantly inhibited the glycolytic phenotypes of PDAC cells as revealed by reduced glucose uptake, lactate production, and extracellular acidification rate, which can be restored by re-expression of siRNA-resistant TWIST1. Moreover, tamoxifen-inducible expression of TWIST1 promoted the Warburg metabolism of PDAC cells. Mechanistically, by luciferase reporter assay and chromatin immunoprecipitation experiment, we showed that TWIST1 can directly increase the expression of several glycolytic genes, including SLC2A1, HK2, ENO1, and PKM2. Of note, the transcriptional regulation by TWIST1 was not dependent on HIF1α or c-Myc. In The Cancer Genome Atlas and Gene Expression Omnibus accession GSE15471, we confirmed that TWIST1 was closely associated with the glycolysis pathway. Collectively, our findings indicate that TWIST1 is likely to act as important regulator of the Warburg effect in PDAC.

Diagnostic and prognostic value of circulating miR-18a in the plasma of patients with gastric cancer.

The aim of this manuscript is to analyze the diagnostic and prognostic value of circulating miR-18a in the plasma of patients with gastric cancer. In this study, 82 patients with gastric cancer and 65 healthy controls were enrolled in the study, and 10 ml of peripheral venous blood was collected for RNA extraction. miR-18a expression was determined using TaqMan quantitative real-time polymerase chain reaction assay and was further correlated with patients' clinicopathological parameters and the follow-up data. The results indicated that plasma miR-18a was upregulated in gastric cancer patients compared with healthy controls (P < 0.001). miR-18a yielded an area under the receiver-operating characteristic curve of 0.907 with 80.5 % sensitivity and 84.6 % specificity in discriminating gastric cancer from healthy controls. Plasma miR-18a expression was significantly associated with pathological grade (P = 0.036) and lymph node status (P = 0.025), but not with tumor stage (P = 0.075). Both log-rank test and univariate Cox regression analysis showed that the higher miR-18a expression in plasma was associated with shorter disease-free survival and disease-specific survival of the patients with gastric cancer (P = 0.023 and P = 0.027; P = 0.036 and P = 0.043, respectively), which was also not proven by multivariate Cox regression analysis (P = 0.238 and P = 0.160, respectively). In conclusion, this study showed that miR-18a may be a promising biomarker for the detection of gastric cancer and its upregulation may be potentially associated with unfavorable prognosis of bladder cancer, suggesting that miR-18a might serve as a potential biological marker for further risk stratification in the management of gastric cancer.

Effects of sphincter of Oddi motility on the formation of cholesterol gallstones.

AIM: To investigate the mechanisms and effects of sphincter of Oddi (SO) motility on cholesterol gallbladder stone formation in guinea pigs. METHODS: Thirty-four adult male Hartley guinea pigs were divided randomly into two groups, the control group (n = 10) and the cholesterol gallstone group (n = 24), which was sequentially divided into four subgroups with six guinea pigs each according to time of sacrifice. The guinea pigs in the cholesterol gallstone group were fed a cholesterol lithogenic diet and sacrificed after 3, 6, 9, and 12 wk. SO manometry and recording of myoelectric activity were obtained by a multifunctional physiograph at each stage. Cholecystokinin-A receptor (CCKAR) expression levels in SO smooth muscle were detected by quantitative real-time PCR (qRT-PCR) and serum vasoactive intestinal peptide (VIP), gastrin, and cholecystokinin octapeptide (CCK-8) were detected by enzyme-linked immunosorbent assay at each stage in the process of cholesterol gallstone formation. RESULTS: The gallstone formation rate was 0%, 0%, 16.7%, and 83.3% in the 3, 6, 9, and 12 wk groups, respectively. The frequency of myoelectric activity in the 9 wk group, the amplitude of myoelectric activity in the 9 and 12 wk groups, and the amplitude and the frequency of SO in the 9 wk group were all significantly decreased compared to the control group. The SO basal pressure and common bile duct pressure increased markedly in the 12 wk group, and the CCKAR expression levels increased in the 6 and 12 wk groups compared to the control group. Serum VIP was elevated significantly in the 9 and 12 wk groups and gastrin decreased significantly in the 3 and 9 wk groups. There was no difference in serum CCK-8 between the groups. CONCLUSION: A cholesterol gallstone-causing diet can induce SO dysfunction. The increasing tension of the SO along with its decreasing activity may play an important role in cholesterol gallstone formation. Expression changes of CCKAR in SO smooth muscle and serum VIP and CCK-8 may be important causes of SO dysfunction.

Stanniocalcin 2 expression predicts poor prognosis of hepatocellular carcinoma.

Previous studies have shown that the expression level of stanniocalcin 2 (STC2) is associated with tumor progression. However, to date, the association between STC2 and clinicopathological factors in hepatocellular carcinoma (HCC) has not been investigated. The clinical significance of STC2 was investigated in 30 fresh HCC samples using western blot analysis and in 240 HCC tissues using immunohistochemical analysis. The level of STC2 in cancerous tissue was higher than in the matched non-cancerous tissues. Using immunohistochemistry, the STC2-positive group exhibited a higher incidence of lymph node metastasis and venous invasion compared with the STC2-negative group. Kaplan-Meier survival analysis revealed that the positive expression of STC2 correlated with poor overall survival (OS) and disease-free survival of HCC patients (P<0.01). STC2 expression was observed to be an independent prognostic factor for OS in HCC patients by multivariate analysis (hazard ratio, 2.39; 95% confidence interval, 1.04-5.89; P=0.013). These data suggest that STC2 expression may be a useful indicator of poor prognosis in HCC patients.

Upregulation of microRNA-25 associates with prognosis in hepatocellular carcinoma.

BACKGROUND: Accumulating evidence has shown that up-regulation of microRNA-25(miR-25) is associated with the prognosis of several types of human malignant solid tumors. However, whether miR-25 expression has influence on the prognosis of hepatocellular carcinoma (HCC) is still unknown. METHODS: The differentially expressed amount of the miR-25 was validated in triplicate by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Survival rate was analyzed by log-rank test, and survival curves were plotted according to Kaplan-Meier. Multivariate analysis of the prognostic factors was performed with Cox regression model. RESULTS: The expression of miR-25 was significantly upregulated in HCC tissues when compared with adjacent normal tissues (p<0.0001). Patients who had high miR-25 expression had a shorter overall survival than patients who had low miR-25 expression (median overall survival, 31.0 months versus 42.9 months, p=0.0192). The multivariate Cox regression analysis indicated that miR-25 expression (HR=2.179; p=0.001), TNM stage (HR=1.782; p=0.014), and vein invasion (HR=1.624; p=0.020) were independent prognostic factors for overall survival. CONCLUSION: Our data suggests that the overexpression of miR-25 in HCC tissues is of predictive value on poor prognosis. VIRTUAL SLIDE: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1989618421114309.