Molecular signatures of X chromosome inactivation and associations with clinical outcomes in epithelial ovarian cancer.

X chromosome inactivation (XCI) is a key epigenetic gene expression regulatory process, which may play a role in women's cancer. In particular tissues, some genes are known to escape XCI, yet patterns of XCI in ovarian cancer (OC) and their clinical associations are largely unknown. To examine XCI in OC, we integrated germline genotype with tumor copy number, gene expression and DNA methylation information from 99 OC patients. Approximately 10% of genes showed different XCI status (either escaping or being subject to XCI) compared with the studies of other tissues. Many of these genes are known oncogenes or tumor suppressors (e.g. DDX3X, TRAPPC2 and TCEANC). We also observed strong association between cis promoter DNA methylation and allele-specific expression imbalance (P = 2.0 × 10-10). Cluster analyses of the integrated data identified two molecular subgroups of OC patients representing those with regulated (N = 47) and dysregulated (N = 52) XCI. This XCI cluster membership was associated with expression of X inactive specific transcript (P = 0.002), a known driver of XCI, as well as age, grade, stage, tumor histology and extent of residual disease following surgical debulking. Patients with dysregulated XCI (N = 52) had shorter time to recurrence (HR = 2.34, P = 0.001) and overall survival time (HR = 1.87, P = 0.02) than those with regulated XCI, although results were attenuated after covariate adjustment. Similar findings were observed when restricted to high-grade serous tumors. We found evidence of a unique OC XCI profile, suggesting that XCI may play an important role in OC biology. Additional studies to examine somatic changes with paired tumor-normal tissue are needed.

Kaolin-based hemostatic dressing improves hemorrhage control from a penetrating inferior vena cava injury in coagulopathic swine.

BACKGROUND: Retrohepatic inferior vena cava (RIVC) injuries are often lethal due to challenges in obtaining hemorrhage control. We hypothesized that packing with a new kaolin-based hemostatic dressing (Control+; Z-Medica, Wallingford, CT) would improve hemorrhage control from a penetrating RIVC injury compared with packing with standard laparotomy sponges alone. METHODS: Twelve male Yorkshire pigs received a 25% exchange transfusion of blood for refrigerated normal saline to induce a hypothermic coagulopathy. A laparotomy was performed and a standardized 1.5 cm injury to the RIVC was created which was followed by temporary abdominal closure and a period of uncontrolled hemorrhage. When the mean arterial pressure reached 70% of baseline, demonstrating hemorrhagic shock, the abdomen was re-entered, and the injury was treated with perihepatic packing using standard laparotomy sponges (L; n = 6) or a new kaolin-based hemostatic dressing (K; n = 6). Animals were then resuscitated for 6 hours with crystalloid solution. The two groups were compared using the Wilcoxon rank sum test and Fisher exact test. A p value of 0.05 or less was considered statistically significant. RESULTS: There was no difference in the animal's temperature, heart rate, mean arterial pressure, cardiac output, and blood loss at baseline or before packing was performed (all p > 0.05). In the laparotomy sponge group, five of six pigs survived the entire study period, whereas all six pigs treated with kaolin-based D2 hemostatic dressings survived. Importantly, there was significantly less blood loss after packing with the new hemostatic kaolin-based dressing compared with packing with laparotomy sponge (651 ± 180 mL vs. 1073 ± 342 mL; p ≤ 0.05). CONCLUSION: These results demonstrate that the use of this new hemostatic kaolin-based dressing improved hemorrhage control and significantly decreased blood loss in this penetrating RIVC model. LEVEL OF EVIDENCE: This is basic science research based on a large animal model, level V.