Statin use and survival in resectable pancreatic cancer: confounders and mechanisms.

A first point regards the possible activity of drugs other than statins, such as aspirin or metformin, against pancreatic cancer. As many patients use a combination of these drugs, one might speculate that the association between simvastatin and overall survival in resected pancreatic cancer patients might also be explained by the concomitant use of aspirin or metformin, or that these drugs might result synergistic, as hypothesized for colorectal cancer (3). We wonder whether the authors had access to data on aspirin or metformin use for their population. A second point regards the very high 45% rate of simvastatin or lovastatin users reported by the authors. This figure is different from that of many European countries, thus possibly limiting the attributable fraction of cases for whom the observed findings can be replicated

Antiproliferative effect of somatostatin analogs in advanced gastro-entero-pancreatic neuroendocrine tumors. a systematic review and meta-analysis

A meta-analysis has systematically investigated the antineoplastic efficacy and safety of somatostatin analogs (SSAs) in advanced gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs). Randomized controlled trials (RCTs) reporting the hazard ratio (HR) for disease progression (DP) were evaluated. Response rate and risk ratio (RR) for adverse events were also analyzed. A total of 289 patients (143 receiving SSAs vs. 146 placebo) were evaluated from two RCTs. A significant benefit from SSAs in terms of disease control was observed (HR 0.41, 95% CI: 0.29 to 0.58, P < 0.01; I20%), response rate being 58.0% vs. 32.2%, respectively.The occurrence of adverse events significantly differed from the placebo arm only in terms of biliary stones (RR 3.79, 95% CI: 1.28 to 11.17, P = 0.02; I20%). In conclusion, SSAs showed an antiproliferative effect in advanced GEP-NETs, with a good safety profile

The use of complementary and alternative medicine is frequent in patients with pancreatic disorder

BACKGROUND: Herbal remedies and other complementary and alternative medicine (CAM) are used by 30% of the patients with liver and inflammatory bowel diseases. However, there are no data regarding CAM use in patients with pancreatic disorders, including potential pancreatotoxicity. AIM OF THE STUDY: The aim of the study was to assess the prevalence of CAM use in patients with pancreatic disorders and screen for pancreatotoxicity. MATERIALS AND METHODS: This was a cross-sectional survey of consecutive outpatients seen at a Pancreas Center. Data were collected in a specific questionnaire. Descriptive statistics were used to analyze the prevalence and the patterns of CAM use. Characteristics associated with CAM use were analyzed by appropriate statistics. RESULTS: Of 108 patients (52% male; mean age, 65±13 years), 47 (43.5%) used CAM. The use of CAM was more frequent among patients with previous acute pancreatitis (47%). Reported reasons for the use of CAM were to help standard therapies and for an overall better feeling. About 61% of the patients reported advantages with treatment. As compared with nonusers, CAM users were more often female (55% vs. 42%), with a higher school degree (43% vs. 36%), more frequently performing physical activity (51% vs. 41%), and reporting anxiety (45% vs. 31%). However, none of these differences were statistically significant. Three patients with previous acute pancreatitis reported the use of Serenoa repens that is potentially pancreatotoxic. DISCUSSION: The rate of CAM use in patients with pancreatic disorders is similar to those reported for other digestive diseases. CAM use seems to be more frequent in women with a higher education level and a "healthier lifestyle." Patients might not be aware of the potential pancreatotoxicity of CAM, which should be carefully considered by physician

Modulation of PKM alternative splicing by PTBP1 promotes gemcitabine resistance in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive and incurable disease. Poor prognosis is due to multiple reasons, including acquisition of resistance to gemcitabine, the first-line chemotherapeutic approach. Thus, there is a strong need for novel therapies, targeting more directly the molecular aberrations of this disease. We found that chronic exposure of PDAC cells to gemcitabine selected a subpopulation of cells that are drug-resistant (DR-PDAC cells). Importantly, alternative splicing (AS) of the pyruvate kinase gene (PKM) was differentially modulated in DR-PDAC cells, resulting in promotion of the cancer-related PKM2 isoform, whose high expression also correlated with shorter recurrence-free survival in PDAC patients. Switching PKM splicing by antisense oligonucleotides to favor the alternative PKM1 variant rescued sensitivity of DR-PDAC cells to gemcitabine and cisplatin, suggesting that PKM2 expression is required to withstand drug-induced genotoxic stress. Mechanistically, upregulation of the polypyrimidine-tract binding protein (PTBP1), a key modulator of PKM splicing, correlated with PKM2 expression in DR-PDAC cell lines. PTBP1 was recruited more efficiently to PKM pre-mRNA in DR- than in parental PDAC cells. Accordingly, knockdown of PTBP1 in DR-PDAC cells reduced its recruitment to the PKM pre-mRNA, promoted splicing of the PKM1 variant and abolished drug resistance. Thus, chronic exposure to gemcitabine leads to upregulation of PTBP1 and modulation of PKM AS in PDAC cells, conferring resistance to the drug. These findings point to PKM2 and PTBP1 as new potential therapeutic targets to improve response of PDAC to chemotherapy.Oncogene advance online publication, 3 August 2015; doi:10.1038/onc.2015.270

Mucosal adhesion and anti-inflammatory effects of Lactobacillus rhamnosus GG in the human colonic mucosa. A proof-of-concept study

AIM To investigate the adhesion and anti-inflammatory effects of Lactobacillus rhamnosus GG (LGG) in the colonic mucosa of healthy and ulcerative colitis (UC) patients, both in vivo and ex vivo in an organ culture model. METHODS For the ex vivo experiment, a total of 98 patients (68 UC patients and 30 normal subjects) were included. Endoscopic biopsies were collected and incubated with and without LGG or LGG-conditioned media to evaluate the mucosal adhesion and anti-inflammatory effects [reduction of tumor necrosis factor alpha (TNFa) and interleukin (IL)-17 expression] of the bacteria, and extraction of DNA and RNA for quantification by real-time (RT)-PCR occurred after the incubation. A dose-response study was performed by incubating biopsies at "regular", double and 5 times higher doses of LGG. For the in vivo experiment, a total of 42 patients (20 UC patients and 22 normal controls) were included. Biopsies were taken from the colons of normal subjects who consumed a commercial formulation of LGG for 7 d prior to the colonoscopy, and the adhesion of the bacteria to the colonic mucosa was evaluated by RT-PCR and compared with that of control biopsies from patients who did not consume the formulation. LGG adhesion and TNFa and IL-17 expression were compared between UC patients who consumed a regular or double dose of LGG supplementation prior to colonoscopy. RESULTS In the ex vivo experiment, LGG showed consistent adhesion to the distal and proximal colon in normal subjects and UC patients, with a trend towards higher concentrations in the distal colon, and in UC patients, adhesion was similar in biopsies with active and quiescent inflammation. In addition, bioptic samples from UC patients incubated with LGG conditioned media (CM) showed reduced expression of TNFa and IL-17 compared with the corresponding expression in controls (P < 0.05). Incubation with a double dose of LGG increased mucosal adhesion and the anti-inflammatory effects (P < 0.05). In the in vivo experiment, LGG was detectable only in the colon of patients who consumed the LGG formulation, and bowel cleansing did not affect LGG adhesion. UC patients who consumed the double LGG dose had increased mucosal concentrations of the bacteria and reduced TNFa and IL-17 expression compared with patients who consumed the regular dose (48% and 40% reduction, respectively, P < 0.05). CONCLUSION In an ex vivo organ culture model, LGG showed consistent adhesion and anti-inflammatory effects. Colonization by LGG after consumption for a week was demonstrated in vivo in the human colon. Increasing the administered dose increased the adhesion and effectiveness of the bacteria. For the first time, we demonstrated that LGG effectively adheres to the colonic mucosa and exerts antiinflammatory effects, both ex vivo and in vivo

Alternative polyadenylation of ZEB1 promotes its translation during genotoxic stress in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) is characterized by extremely poor prognosis. The standard chemotherapeutic drug, gemcitabine, does not offer significant improvements for PDAC management due to the rapid acquisition of drug resistance by patients. Recent evidence indicates that epithelial-to-mesenchymal transition (EMT) of PDAC cells is strictly associated to early metastasization and resistance to chemotherapy. However, it is not exactly clear how EMT is related to drug resistance or how chemotherapy influences EMT. Herein, we found that ZEB1 is the only EMT-related transcription factor that clearly segregates mesenchymal and epithelial PDAC cell lines. Gemcitabine treatment caused upregulation of ZEB1 protein through post-transcriptional mechanisms in mesenchymal PDAC cells within a context of global inhibition of protein synthesis. The increase in ZEB1 protein correlates with alternative polyadenylation of the transcript, leading to shortening of the 3' untranslated region (UTR) and deletion of binding sites for repressive microRNAs. Polysome profiling indicated that shorter ZEB1 transcripts are specifically retained on the polysomes of PDAC cells during genotoxic stress, while most mRNAs, including longer ZEB1 transcripts, are depleted. Thus, our findings uncover a novel layer of ZEB1 regulation through 3'-end shortening of its transcript and selective association with polysomes under genotoxic stress, strongly suggesting that PDAC cells rely on upregulation of ZEB1 protein expression to withstand hostile environments