Landscape of Alternative Splicing Events Related to Prognosis and Immune Infiltration in Glioma: A Data Analysis and Basic Verification.

Background: Glioma is a prevalent primary brain cancer with high invasiveness and typical local diffuse infiltration. Alternative splicing (AS), as a pervasive transcriptional regulatory mechanism, amplifies the coding capacity of the genome and promotes the progression of malignancies. This study was aimed at identifying AS events and novel biomarkers associated with survival for glioma. Methods: RNA splicing patterns were collected from The Cancer Genome Atlas SpliceSeq database, followed by calculating the percentage of splicing index. Expression profiles and related clinical information of glioma were integrated based on the UCSC Xena database. The AS events in glioma were further analyzed, and glioma prognosis-related splicing factors were identified with the use of bioinformatics analysis and laboratory techniques. Further immune infiltration analysis was performed. Results: Altogether, 9028 AS events were discovered. Upon univariate Cox analysis, 425 AS events were found to be related to the survival of patients with glioma, and 42 AS events were further screened to construct the final prognostic model (area under the curve = 0.974). Additionally, decreased expression of the splicing factors including Neuro-Oncological Ventral Antigen 1 (NOVA1), heterogeneous nuclear ribonucleoprotein C (HNRNPC), heterogeneous nuclear ribonucleoprotein L-like protein (HNRNPLL), and RNA-Binding Motif Protein 4 (RBM4) contributed to the poor survival in glioma. The immune infiltration analysis demonstrated that AS events were related to the proportion of immune cells infiltrating in glioma. Conclusions: It is of great value for comprehensive consideration of AS events, splicing networks, and related molecular subtype clusters in revealing the underlying mechanism and immune microenvironment remodeling for glioma, which provides clues for the further verification of related therapeutic targets.

Construction of a novel ceRNA network and identification of lncRNA ADAMTS9-AS2 and PVT1 as hub regulators of miRNA and coding gene expression in gastric cancer.

BACKGROUND: Studies on the interactions of single long non-coding RNA, microRNA, and mRNA have many limitations; therefore, it is necessary to study the complex regulatory network of gastric cancer (GC) pathogenesis systematically. METHODS: In this study, gene and miRNA expression data for GC were downloaded from The Cancer Genome Atlas and used for transcriptome profiling, differential gene analysis, and construction of an lncRNA-miRNA-mRNA regulatory network in conjunction with an online database to identify the key genes and subnetworks in GC pathogenesis. Real-time quantitative polymerase chain reaction was used to detect the expression of hub lncRNAs in 54 paired GC and matched normal mucosal tissues. RESULTS: We constructed an lncRNA-miRNA-mRNA competitive endogenous RNA regulatory network containing 1,626 network nodes and 2,704 interactions. LncRNA ADAMTS9-AS2 and PVT1 were identified as key node genes in this competitive endogenous RNA network. Quantitative reverse transcription-polymerase chain reaction revealed ADAMTS9-AS2 downregulation and PVT1 upregulation in 54 pairs of GC and normal tissues adjacent to the cancer tissues. CONCLUSIONS: This study systematically analysed the lncRNA-miRNA-mRNA regulatory network in GC and identified ADAMTS9-AS2 and PVT1 as key regulatory genes in this network, providing new understanding of GC pathogenesis and insights for its early diagnosis and treatment.

[Short-term preoperative treatment of celecoxib, a selective cyclooxygenase-2 inhibitor, on E-cadherin expression in gastric carcinoma tissues].

BACKGROUND AND OBJECTIVE: Cyclooxygenase-2 (COX-2) inhibitors have been shown to exert chemopreventive effects against gastrointestinal carcinomas. This study was to investigate the effect of celecoxib, a selective COX-2 inhibitor, on the expression of E-cadherin and serum levels of soluble E-cadherin in gastric carcinomas. METHODS: Fifty-nine gastric carcinoma patients were randomly divided into two groups: surgery group (n=22) and celecoxib plus surgery group (n=37). Patients in the surgery group underwent surgical resection after diagnosis, while patients in the celecoxib plus surgery group received oral celecoxib, 200 mg twice daily for six days before curative resection. Twenty healthy subjects were recruited as normal controls. COX-2 and E-cadherin expressions were detected by immunohistochemistry. Serum levels of soluble E-cadherin were quantitatively measured using a commercially available enzyme-linked immunosorbent assay (ELISA) kit. RESULTS: Compared to the surgery group, the expression of COX-2 was significantly lower while that of E-cadherin was significantly higher in celecoxib plus surgery group. The concentrations of serum soluble E-cadherin before treatment were significantly higher in the surgery [(53.47+/-9.62) ng/mL] and the celecoxib plus surgery [(51.57+/-9.79) ng/mL] groups than in the control group [(37.17+/-5.38) ng/ml] (P<0.01). The soluble E-cadherin levels after surgery in both groups [(39.29+/-7.72) ng/mL and (29.29+/-8.28) ng/mL] were significantly lower than those before surgery (P<0.01). The soluble E-cadherin level on the sixth day [(44.11+/-8.36) ng/mL] was significantly lower than that before treatment in the celecoxib plus surgery group (P<0.01). CONCLUSION: Short-term preoperative treatment of celecoxib up-regulates the expression of E-cadherin in gastric carcinomas.

[Celecoxib induces apoptosis and inhibits angiogenesis in gastric cancer].

OBJECTIVE: The aim of this study was to explore the effect of celecoxib, a cyclooxygenase-2 inhibitor, on induction of apoptosis and inhibition of angiogenesis in gastric cancer. METHODS: Fifty nine gastric cancer patients were randomly divided into 2 groups: celecoxib group (n = 37) and control group (n = 22). The patients in the celecoxib group were treated orally with celecoxib 200 mg twice daily for 7 days before resection. The patients in the control group received surgical resection alone. Another group of 20 healthy subjects were recruited as normal control. The number of apoptotic tumor cells was measured by terminal deoxynucleotidyl transferse-mediated dUTP nick end labeling (TUNEL). The expression of COX-2, VEGF and the microvessel density (MVD) were evaluated by immunohistochemistry. RESULTS: The TUNEL results showed an increase of apoptosis in the tumor cells after celecoxib treatment in comparison with that in the control group (7.1% +/- 1.0% vs. 6.2% +/- 0.9%, P < 0.05). The expression level of COX-2 and VEGF in the gastric cancer tissues was significantly decreased in the celecoxib group compared with those in the control group (P < 0.05). Furthermore, MVD was also significantly lower in the celecoxib group when compared with that in the control group (30.48 +/- 5.02 vs. 38.98 +/- 4.58, P < 0.05). CONCLUSION: Oral intake of celecoxib can induce apoptosis and suppress angiogenesis in gastric cancer. It may become an effective agent in the treatment of gastric cancer.

Effects of nociceptin/orphanin FQ on rats with cathartic colon.

AIM: To demonstrate the change and effect of nociceptin/orphanin FQ in the colon of rats with cathartic colon. METHODS: The cathartic colon model was established by feeding rats rhubarb for 3 mo, the changes of colonic electromyography were investigated by both suspension muscle strips test and serosal recordings of colonic myoelectrical activity. Immunohistochemical staining (S-P methods) and image analysis were used to determine the changes of nociceptin/orphanin FQ in the proximal colon and distal colon of rats with cathartic colon. RESULTS: Suspension muscle strips test in vitro showed OFQ (10(-9)-10(-6) mol/L) concentration dependently caused an immediate tonic contraction in the isolated colon. But the increase of tension in cathartic colon was less than control groups (P < 0.01). Intravenous administration of OFQ (1 microg/kg) caused phasic contractions in the proximal colon, while the amplitude of phasic contractions caused by OFQ in cathartic colon was much lower than that in the control groups (2.58 +/- 0.41 vs 4.16 +/- 0.53, t = -2.6, P = 0.012). OFQ was highly expressed in the myenteric plexus of the rat colon but not in the muscle cells. The immunoreactivity of OFQ in the proximal colon in cathartic colon rats decreased significantly compared with the control group (P = 0.001). CONCLUSION: Colonic smooth muscle of cathartic colon showed low sensitivity to the stimulation of OFQ, suggesting that it might be caused by the abnormal distribution of OFQ or the abnormalities of receptors, leading to the disorganization of dynamic and incoordinated contractions.