SUMMARY Despite the importance of programmed cell death-1 (PD-1) in inhibiting T cell effector activity, the mechanisms regulating its expression remain poorly defined. We found that the chromatin organizer special AT-rich sequence-binding protein-1 (Satb1) restrains PD-1 expression induced upon T cell activation by recruiting a nucleosome remodeling deacetylase (NuRD) complex to Pdcd1 regulatory regions. Satb1 deficienct T cells exhibited a 40-fold increase in PD-1 expression. Tumor-derived Transforming Growth Factor β (Tgf-β) decreased Satb1 expression through binding of Smad proteins to the Satb1 promoter. Smad proteins also competed with the Satb1-NuRD complex for binding to Pdcd1 enhancers, releasing Pdcd1 expression from Satb1-mediated repression, Satb1-deficient tumor-reactive T cells lost effector activity more rapidly than wild-type lymphocytes at tumor beds expressing PD-1 ligand (CD274), and these differences were abrogated by sustained CD274 blockade. Our findings suggest that Satb1 functions to prevent premature T cell exhaustion by regulating Pdcd1 expression upon T cell activation. Dysregulation of this pathway in tumor-infiltrating T cells results in diminished anti-tumor immunity.
Due to their cytotoxic activities, many anticancer drugs cause extensive damage to the intestinal mucosa and have antibiotic activities. Here, we show that cisplatin induces significant changes in the repertoire of intestinal commensal bacteria that exacerbate mucosal damage. Restoration of the microbiota through fecal-pellet gavage drives healing of cisplatin-induced intestinal damage. Bacterial translocation to the blood stream is correspondingly abrogated, resulting in a significant reduction in systemic inflammation, as evidenced by decreased serum IL-6 and reduced mobilization of granulocytes. Mechanistically, reversal of dysbiosis in response to fecal gavage results in the production of protective mucins and mobilization of CD11b myeloid cells to the intestinal mucosa, which promotes angiogenesis. Administration of Ruminococcus gnavus, a bacterial strain selectively depleted by cisplatin treatment, could only partially restore the integrity of the intestinal mucosa and reduce systemic inflammation, without measurable increases in the accumulation of mucin proteins. Together, our results indicate that reconstitution of the full repertoire of intestinal bacteria altered by cisplatin treatment accelerates healing of the intestinal epithelium and ameliorates systemic inflammation. Therefore, fecal microbiota transplant could paradoxically prevent life-threatening bacteremia in cancer patients treated with chemotherapy.
This study has been funded by the Basque Government, Dept. of Health grant 2007111063 and Dept. of Industry (Saiotek) grant S-PC11UN008. Jairo Perez-Sanz was the recipient of a grant from Fundación Jesús de Gangoiti Barrera. The authors have no conflicts of interest to declare.
Objective: To evaluate the influence on sperm parameters and in vitro fertilization (IVF) outcomes of the administration of 400 mg/day of vitamin E for 3 months to men from infertile couples who are undergoing IVF. Design: Double-blind, placebo-controlled, randomized study. Setting: Human reproduction unit of a university hospital. Patient(s): A total of 101 couples, 50 in the vitamin E group and 51 in the placebo group, undergoing IVF, among whom 64.4% of cases had an abnormal spermiogram according to World Health Organization (WHO) criteria. Intervention(s): Vitamin E (a-tocopherol), 400 mg daily by mouth for 3 months, with sperm analysis performed immediately before starting the treatment and 3 months later on the day of IVF. Main Outcome Measure(s): WHO sperm parameters and IVF outcomes. Result(s): Although there was a statistically significant increase in progressive motility in the vitamin E group compared with beforetreatment values, a similar increase occurred in the placebo group. Normal morphology was even better in the placebo group. Regarding IVF outcomes, better fertilization rates were observed in the placebo group, but the live-birth rate per transfer was statistically significantly higher in the vitamin E group: 17 (41.46%) of 41 versus 9 (20.46%) of 44 in the placebo group. Although the clinical pregnancy rates (both per transfer and per cycle started) and the implantation rate were somewhat higher in the vitamin E group (43.9% and 25%; 36.0% and 22.0%; and 24.7% and 14.1%, respectively), the increase was not statistically significant. Conclusion(s):The effect of vitamin E on classic sperm parameters was not an improvement over placebo. Nonetheless, vitamin E administration was associated with a statistically significantly higher live-birth rate, and there was a trend toward better results in other IVF parameters.
Pancreatic ductal adenocarcinoma, which represents 80% of pancreatic cancers, is mainly diagnosed when treatment with curative intent is not possible. Consequently, the overall five-year survival rate is extremely dismal—around 5% to 7%. In addition, pancreatic cancer is expected to become the second leading cause of cancer-related death by 2030. Therefore, advances in screening, prevention and treatment are urgently needed. Fortunately, a wide range of approaches could help shed light in this area. Beyond the use of cytological or histological samples focusing in diagnosis, a plethora of new approaches are currently being used for a deeper characterization of pancreatic ductal adenocarcinoma, including genetic, epigenetic, and/or proteo-transcriptomic techniques. Accordingly, the development of new analytical technologies using body fluids (blood, bile, urine, etc.) to analyze tumor derived molecules has become a priority in pancreatic ductal adenocarcinoma due to the hard accessibility to tumor samples. These types of technologies will lead us to improve the outcome of pancreatic ductal adenocarcinoma patients.
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