U4 snRNP inhibits premature cleavage and polyadenylation of pre-mRNAs.

The essential role of U4 snRNP in pre-messenger RNA (mRNA) splicing has been well established. In this study, we utilized an antisense morpholino oligonucleotide (AMO) specifically targeting U4 snRNA to achieve functional knockdown of U4 snRNP in HeLa cells. Our results showed that this knockdown resulted in global intronic premature cleavage and polyadenylation (PCPA) events, comparable to the effects observed with U1 AMO treatment, as demonstrated by mRNA 3'-seq analysis. Furthermore, our study suggested that this may be a common phenomenon in both human and mouse cell lines. Additionally, we showed that U4 AMO treatment disrupted transcription elongation, as evidenced by chromatin immunoprecipitation sequencing (ChIP-seq) analysis for RNAPII. Collectively, our results identified a unique role for U4 snRNP in the inhibition of PCPA and indicated a model wherein splicing intrinsically inhibits intronic cleavage and polyadenylation in the context of cotranscriptional mRNA processing.

Application of Mid-Pancreatectomy with End-to-End Anastomosis in Pancreatic Benign Tumors.

Mid-pancreatectomy combined with end-to-end anastomosis is a surgical procedure used to treat benign pancreatic tumors. It involves removing the tumor from the middle section of the pancreas and connecting the proximal and distal ends through an anastomosis. The traditional surgical approach for resecting the middle segment of the pancreas involves closing the proximal pancreas and creating a Roux-en-Y anastomosis with the jejunum. However, this approach carries a double risk of pancreatic stump fistula and pancreatico enteric anastomotic leak postoperatively. In this paper, a new procedure is described where stent tubes were placed into the proximal and distal sides of the pancreatic ducts after ensuring sufficient freedom from the proximal distal pancreas. The pancreatic parenchyma was then sutured continuously under direct vision to achieve pancreatic end-to-end anastomosis. This procedure helps preserve pancreatic function, reducing the risk of postoperative pancreatic insufficiency. However, due to the complexity and risks involved, thorough evaluation and preparation are necessary before surgery. We carefully assess the patient's history, serology, and imaging results to determine the feasibility and effectiveness of the procedure. During surgery, we consider the use of a suitable pancreatic duct stent to ensure the flow of pancreatic juice into the intestine through physiological pathways. Our goal is to remove the tumor while preserving as much normal pancreatic tissue as possible for the anastomosis. After the operation, it is crucial to monitor the patient's pancreatic function, paying close attention to blood glucose levels, drainage fluid volume, and amylase value of the pancreatic anastomosis. During the postoperative follow-up visit, the patient's pancreatic function was assessed, and there was no significant change in quality of life compared to before the surgery. This indicates that mid-pancreatectomy combined with end-to-end anastomosis is a safe and effective procedure for treating pancreatic benign neoplasms.

The U1 antisense morpholino oligonucleotide (AMO) disrupts U1 snRNP structure to promote intronic PCPA modification of pre-mRNAs.

Functional depletion of the U1 small nuclear ribonucleoprotein (snRNP) with a 25 nt U1 AMO (antisense morpholino oligonucleotide) may lead to intronic premature cleavage and polyadenylation of thousands of genes, a phenomenon known as U1 snRNP telescripting; however, the underlying mechanism remains elusive. In this study, we demonstrated that U1 AMO could disrupt U1 snRNP structure both in vitro and in vivo, thereby affecting the U1 snRNP-RNAP polymerase II interaction. By performing chromatin immunoprecipitation sequencing for phosphorylation of Ser2 and Ser5 of the C-terminal domain of RPB1, the largest subunit of RNAP polymerase II, we showed that transcription elongation was disturbed upon U1 AMO treatment, with a particular high phosphorylation of Ser2 signal at intronic cryptic polyadenylation sites (PASs). In addition, we showed that core 3'processing factors CPSF/CstF are involved in the processing of intronic cryptic PAS. Their recruitment accumulated toward cryptic PASs upon U1 AMO treatment, as indicated by chromatin immunoprecipitation sequencing and individual-nucleotide resolution CrossLinking and ImmunoPrecipitation sequencing analysis. Conclusively, our data suggest that disruption of U1 snRNP structure mediated by U1 AMO provides a key for understanding the U1 telescripting mechanism.

Survival benefit of primary tumor resection for gastric cancer with liver metastasis: A propensity score-matched, population-based study.

Objectives: Gastric cancer with liver metastasis (GCLM) is highly aggressive and has a poor prognosis. This study aims to evaluate the survival benefit of primary tumor resection (PTR) for gastric cancer with liver metastasis. Methods: Data on patients with GCLM was extracted from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015. A 1:1 propensity score matching (PSM) analysis was performed to minimize the heterogeneity between the PTR and no-PTR groups. The Kaplan-Meier method and Cox regression analysis were used to assess the impact of primary tumor resection (PTR) on overall survival (OS) and cause-specific survival (CSS). Results: A total of 3,001 patients with GCLM were included, with 328 patients treated with primary tumor resection (PTR), whereas the other 2,673 patients were not. Patients with PTR had a significantly higher OS and CSS rate than those without PTR in unmatched and PSM cohorts. In an unmatched cohort, the median OS was 12.0 months (95% CI, 10 months to 14 months) for those who underwent PTR and 4 months (95% CI, 4 months to 5 months) for those without PTR; the median CSS for those who underwent PTR was 12.0 months (95% CI, 10 months to14 months) and 4 months (95% CI, 4 months to 5 months) for those without PTR, respectively. After PMS, the median OS was 12.0 months (95% CI, 10 months to 17 months) for those who underwent PTR and 7 months (95% CI, 5 months to 10 months) for those without PTR, respectively; the median CSS for those who underwent PTR was 12.0 months (95% CI, 11 months to 17 months) and 7 months (95% CI, 5 months to 8 months) for those without PTR, respectively. In addition, multivariate Cox analysis in the PSM cohort showed that PTR, age, degree of tumor differentiation, and chemotherapy were independent prognostic factors for OS and CSS in GCLM. Specifically, PTR was a significant protective factor for OS (HR: 0.427; 95% CI, 0.325 to 0.561, P <0.001) and CSS (HR: 0.419; 95% CI, 0.313 to 0.561, P <0.001). Conclusion: Primary tumor resection improves the survival of gastric cancer patients with liver metastasis.

Surgical or nonsurgical treatment for nontraumatic rotator cuff tears: Study protocol clinical trial.

BACKGROUND: The optimal treatment for symptomatic, nontraumatic rotator cuff tear is unknown. The primary aim of this randomized controlled trial is to compare functional improvement after surgical and conservative treatment of nontraumatic rotator cuff tears. METHODS: This is a single-centre, randomized clinical trial with a follow-up of 12 months. Patients older than 18 years with magnetic resonance imaging - confirmed nontraumatic rotator cuff tears that are suitable for either surgery or nonsurgery treatment is enrolled. The primary outcome is Constant score. Secondary outcome measures include visual analog scale (VAS) score, patient satisfaction, and American Shoulder and Elbow Surgeons (ASES) score. All scores are assessed by an independent observer who is blinded to the allocation of groups. RESULTS: The study will provide much needed data on surgical vs nonsurgical treatment for nontraumatic rotator cuff tears. Results of this study may help patients, clinicians, and policy makers assess the pivotal question on comparative effectiveness of surgery vs nonsurgical for rotator cuff tears. TRIAL REGISTRATION: This study protocol was registered in Research Registry (researchregistry5442).

Selective inhibition of cyclooxygenase-2 protects porcine aortic endothelial cells from human antibody-mediated complement-dependent cytotoxicity.

BACKGROUND: Cyclooxygenase-2 (COX-2) is an inducible enzyme with catalytic activity for biosynthesis of prostaglandins which are the key mediators of inflammation. COX-2 is also the therapeutic target for widely used non-steroidal anti-inflammatory drugs (NSAIDs). However, the involvement of COX-2 in xenotransplantation (eg, pig-to-non-human primate) remains poorly recognized. METHODS: We investigated the mechanisms that regulate COX-2 expression and the effects of COX-2 on porcine aortic endothelial cell (PAEC) viability using in vitro pig-to-primate xenotransplantation model and in vivo pig-to-mouse cellular transplant model. Regulation of COX-2 expression was assessed by real-time quantitative polymerase chain reaction (qPCR) and Western blotting. The effects of inhibition or downregulation of COX-2 on PAEC viability were assessed by propidium iodide (PI)-Annexin V staining and Cell Counting Kit-8 assay. RESULTS: Human serum triggered robust COX-2 expression in PAECs in a dose- and time-dependent manner. Induction of COX-2 expression by human serum was partially through activation of both canonical and non-canonical nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κb) signaling and increasing intracellular calcium. Cytokines like tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1ß), IL-17, were able to induce COX-2 expression. Selective inhibition of COX-2 by celecoxib dramatically decreased PAEC death in vitro and in vivo as defined by propidium iodide (PI)-Annexin V staining. Consistently, downregulation of COX-2 expression by NF-κb inhibitors or calcium chelator BAPTA decreased human serum-induced PAEC death as well. Silencing of COX-2 expression by small interfering RNA (siRNA) protected PAEC viability when transplanted under kidney capsule of C57BL/6 mice. CONCLUSIONS: Taken together, our data suggest that COX-2 is highly induced in PAECs by xenogenic serum and associated with human antibody-mediated complement-dependent cytotoxicity. COX-2 might be a potential therapeutic target to improve xenotransplantation.