VSL#3 probiotic treatment decreases bacterial translocation in rats with carbon tetrachloride-induced cirrhosis.

BACKGROUND & AIMS: Probiotics can prevent pathological bacterial translocation in cirrhosis by modulating intestinal microbiota and improving gut barrier and immune disturbances. To evaluate the effect of probiotic VSL#3 on bacterial translocation, intestinal microbiota, gut barrier and inflammatory response in rats with experimental cirrhosis. METHODS: Forty-six Sprague-Dawley rats with CCl4 -induced cirrhosis were randomized into two groups: VSL#3 group (n = 22) that received VSL#3 in drinking water, and water group (n = 24) that received water only. Treatment began at week 6 of cirrhosis induction and continued until laparotomy, performed 1 week after development of ascites or at week 20. A control group included 11 healthy rats. At this study end, we evaluated bacterial translocation, intestinal flora, intestinal barrier (ileal claudin-2 and 4, ß-defensin-1, occludin and malondialdehyde as index of oxidative damage) and serum cytokines. RESULTS: Mortality during this study was similar in the VSL#3 group (10/22, 45%) and the water group (10/24, 42%) (P = 1). The incidence of bacterial translocation was 1/12 (8%) in the VSL#3 group, 7/14 (50%) in the water group (P = 0.03 vs. VSL#3 group) and 0/11 in the control group (P = 0.008 vs. water group). The concentration of ileal and caecal enterobacteria and enterococci was similar in the two groups of cirrhotic rats. The ileal occludin concentration was higher and ileal malondialdehyde and serum levels of TNF-α were lower in the VSL#3 group than in the water group (P < 0.05). CONCLUSIONS: VSL#3 decreases bacterial translocation, the pro-inflammatory state and ileal oxidative damage and increases ileal occludin expression in rats with experimental cirrhosis.

Predicting the pathological features of the mesorectum before the laparoscopic approach to rectal cancer.

Pelvic anatomy and tumour features play a role in the difficulty of the laparoscopic approach to total mesorectal excision in rectal cancer. The aim of the study was to analyse whether these characteristics also influence the quality of the surgical specimen. We performed a prospective study in consecutive patients with rectal cancer located less than 12 cm from the anal verge who underwent laparoscopic surgery between January 2010 and July 2013. Exclusion criteria were T1 and T4 tumours, abdominoperineal resections, obstructive and perforated tumours, or any major contraindication for laparoscopic surgery. Dependent variables were the circumferential resection margin (CMR) and the quality of the mesorectum. Sixty-four patients underwent laparoscopic sphincter-preserving total mesorectal excision. Resection was complete in 79.1% of specimens and CMR was positive in 9.7%. Univariate analysis showed tumour depth (T status) (P = 0.04) and promontorium-subsacrum angle (P = 0.02) independently predicted CRM (circumferential resection margin) positivity. Tumour depth (P < 0.05) and promontorium-subsacrum axis (P < 0.05) independently predicted mesorectum quality. Multivariate analysis identified the promontorium-subsacrum angle (P = 0.012) as the only independent predictor of CRM. Bony pelvis dimensions influenced the quality of the specimen obtained by laparoscopy. These measurements may be useful to predict which patients will benefit most from laparoscopic surgery and also to select patients in accordance with the learning curve of trainee surgeons.

Ku70 predicts response and primary tumor recurrence after therapy in locally advanced head and neck cancer.

5-Fluorouracil and cisplatin-based induction chemotherapy (IC) is commonly used to treat locally advanced head and neck squamous cell carcinoma (HNSCC). The role of nonhomologous end joining (NHEJ) genes (Ku70, Ku80 and DNA-PKcs) in double-strand break (DSB) repair, genomic instability and apoptosis suggest a possible impact on tumor response to radiotherapy, 5-fluorouracil or cisplatin, as these agents are direct or indirect inductors of DSBs. We evaluated the relationship between Ku80, Ku70 or DNA PKcs mRNA expression in pretreatment tumor biopsies, and tumor response to IC or local recurrence, in 50 patients with HNSCC. Additionally, in an independent cohort of 75 patients with HNSCC, we evaluated the relationship between tumor Ku70 protein expression and the same clinical outcomes or patient survival. Tumors in the responder group had significantly higher mRNA levels for Ku70, Ku80 and DNA-PKcs than those in the nonresponder group. Ku70 mRNA was the marker most significantly associated with response to IC. Moreover, high tumor Ku70 mRNA expression was associated with significantly longer local recurrence-free survival (LRFS). Ku70 protein expression was also significantly related to response, and patients with higher percentage of tumor cells expressing Ku70 had longer LRFS. In addition, the percentage of Ku70 positive cells, tumor localization and node involvement were significantly associated with overall survival of patient. Therefore, Ku70 expression is a candidate predictive marker that could distinguish patients who are likely to benefit from chemoradiotherapy or radiotherapy after the induction chemotherapy treatment, suggesting a contribution of the NHEJ system in HNSCC clinical outcome.

Fermented milk containing Lactobacillus paracasei subsp. paracasei CNCM I-1518 reduces bacterial translocation in rats treated with carbon tetrachloride.

Probiotics can prevent pathological bacterial translocation by modulating intestinal microbiota and improving the gut barrier. The aim was to evaluate the effect of a fermented milk containing Lactobacillus paracasei subsp. paracasei CNCM I-1518 on bacterial translocation in rats with carbon tetrachloride (CCl4)-induced cirrhosis. Sprague-Dawley rats treated with CCl4 were randomized into a probiotic group that received fermented milk containing Lactobacillus paracasei subsp. paracasei CNCM I-1518 in drinking water or a water group that received water only. Laparotomy was performed one week after ascites development. We evaluated bacterial translocation, intestinal microbiota, the intestinal barrier and cytokines in mesenteric lymph nodes and serum. Bacterial translocation decreased and gut dysbiosis improved in the probiotic group compared to the water group. The ileal ß-defensin-1 concentration was higher and ileal malondialdehyde levels were lower in the probiotic group than in water group. There were no differences between groups in serum cytokines but TNF-α levels in mesenteric lymph nodes were lower in the probiotic group than in the water group. Fermented milk containing Lactobacillus paracasei subsp. paracasei CNCM I-1518 decreases bacterial translocation, gut dysbiosis and ileal oxidative damage and increases ileal ß-defensin-1 expression in rats treated with CCl4, suggesting an improvement in the intestinal barrier integrity.

Modulation of inflammatory response in a cirrhotic rat model with induced bacterial peritonitis.

Bacterial peritonitis is a severe complication in patients with cirrhosis and ascites and despite antibiotic treatment, the inflammatory response to infection may induce renal dysfunction leading to death. This investigation evaluated the effect of TNF-α blockade on the inflammatory response and mortality in cirrhotic rats with induced bacterial peritonitis treated or not with antibiotics. Sprague-Dawley rats with carbon-tetrachloride-induced cirrhosis were treated with an intraperitoneal injection of 10(9) CFU of Escherichia coli diluted in 20 mL of sterile water to induce bacterial peritonitis and randomized to receive subcutaneously-administered placebo, ceftriaxone, anti-TNF-α mAb and ceftriaxone, or anti-TNF-α mAb alone. No differences were observed between groups at baseline in respect to renal function, liver hepatic tests, serum levels of nitrite/nitrate and TNF-α. Treatment with ceftriaxone reduced mortality (73.3%) but differences did not reach statistical significance as compared to placebo. Mortality in rats treated with ceftriaxone and anti-TNF-α mAb was significantly lower than in animals receiving placebo (53% vs. 100%, p<0.01). Serum TNF-α decreased significantly in surviving rats treated with ceftriaxone plus anti-TNF-α mAb but not in treated with antibiotics alone. Additional studies including more animals are required to assess if the association of antibiotic therapy and TNF-α blockade might be a possible approach to reduce mortality in cirrhotic patients with bacterial peritonitis.

Celecoxib induces anoikis in human colon carcinoma cells associated with the deregulation of focal adhesions and nuclear translocation of p130Cas.

Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, is effective as chemopreventive against colon cancer and it is the only nonsteoroidal antiinflammatory drug approved by the FDA for adjuvant therapy in patients with familial adenomatous polyposis. It is also being evaluated, within Phase II and III clinical trials, in combination with standard chemotherapy to treat sporadic colorectal cancer. Nevertheless, its antitumor mechanism of action is still not fully understood. In this study, we have evaluated the in vitro growth inhibitory effect of celecoxib in colon carcinoma cells and analyzed its mechanism of action. We report that the deregulation of the focal adhesion assembly protein Crk-associated substrate 130 kDa (p130Cas) by celecoxib plays a relevant role in the cytotoxic effect of this drug. Thus, celecoxib induces the proteolysis of p130Cas and the nuclear translocation of the 31 kDa generated fragment leading to apoptosis. Furthermore, overexpression of wild-type p130Cas reverts, in part, the growth inhibitory effect of celecoxib. In contrast, FAK and AKT do not appear to be involved in this activity. Our data suggest, for the first time, that the antitumor mechanism of action of celecoxib includes the induction of anoikis, an effect that is not related to COX-2 inhibition. Besides providing new insights into the antitumor effect of celecoxib, this novel mechanism of action holds potential relevance in drug development. Indeed, our results open the possibility to develop new celecoxib derivatives that induce anoikis without COX-2 inhibition so as to avoid the cardiovascular toxicity recently described for the COX-2 inhibitors.