LncRNA RP11-93B14.5 promotes gastric cancer cell growth through PI3K/AKT signaling pathway.

OBJECTIVE: Emerging evidence indicates that long non-coding RNA (lncRNA) RP11-93B14.5 facilitates tumor progression in variety of malignancies. The present study proposed to study the functional effect of lncRNA RP11-93B14.5 in gastric cancer (GC) as well as the underlying mechanism. METHODS: Bioinformatics analysis was utilized to analyze lncRNA expression in GC tissues. siRNA was used for knockdown of RP11-93B14.5 in GC cells MKN45 and KATO III. The stable knockdown cell lines were constructed by CRISPR-Cas9. Cell counting kit-8 (CCK-8) assay and soft agar colony formation assay were used to analyze GC cell viability. Flow cytometry analysis was performed to analyze the cell cycle distribution of MKN45 and KATO III. RNA sequencing (RNA-seq) was employed to detect differential genes after transfection with siRP11-93B14.5. Quantitative PCR (Q-PCR) was used to examine gene expression in GC cell lines. Western-blot assay was used to measure protein levels. RNA fluorescent in situ hybridization (FISH) was conducted for lncRNA cellular location and expression. RESULTS: Based on the Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) database, RP11-93B14.5 was upregulated in GC tissue, which was also verified in GC cell lines in comparison to the normal gastric epithelial HFE145 cells. Knockdown of RP11-93B14.5 decreased cell viability and the colony number of MKN45 and KATO III cells, and altered cell cycle distribution in vitro. RNA-seq analysis revealed RP11-93B14.5 may modulate genes expression of S100A2 and TIMP2 in MKN45 and KATO III cells. Mechanistically, RP11-93B14.5 may drive the progression of GC via S100A2 related-PI3K/AKT signaling pathway. CONCLUSIONS: LncRNA RP11-93B14.5 knockdown alleviated the malignant phenotypes of GC cells through regulating PI3K/AKT. Our results provide evidence for the role of lncRNAs in regulating tumor progression.

KCNN4-mediated Ca2+/MET/AKT axis is promising for targeted therapy of pancreatic ductal adenocarcinoma.

As a member of the potassium calcium-activated channel subfamily, increasing evidence suggests that KCNN4 was associated with malignancies. However, the roles and regulatory mechanisms of KCNN4 in PDAC have been little explored. In this work, we demonstrated that the level of KCNN4 in PDAC was abnormally elevated, and the overexpression of KCNN4 was induced by transcription factor AP-1. KCNN4 was closely correlated with unfavorable clinicopathologic characteristics and poor survival. Functionally, we found that overexpression of KCNN4 promoted PDAC cell proliferation, migration and invasion. Conversely, the knockdown of KCNN4 attenuated the growth and motility of PDAC cells. In addition to these, knockdown of KCNN4 promoted PDAC cell apoptosis and led to cell cycle arrest in the S phase. In mechanistic investigations, RNA-sequence revealed that the MET-mediated AKT axis was essential for KCNN4, encouraging PDAC cell proliferation and migration. Collectively, these findings reveal a function of KCNN4 in PDAC and suggest it's an attractive therapeutic target and tumor marker. Our studies underscore a better understanding of the biological mechanism of KCNN4 in PDAC and suggest novel strategies for cancer therapy.

Indomethacin down-regulating HMGB1 and TNF-α to prevent pancreatitis after endoscopic retrograde cholangiopancreatography.

Background and aims: Several articles demonstrated that non-steroidal anti-inflammation drugs (NSAIDs) were effective in reducing the incidence of pancreatitis after endoscopic retrograde cholangiopancreatography (PEP). However, studies revealed inconsistent results. The mechanism of NSAIDs in preventing PEP is still little known. Therefore, the aim of our study was to evaluate the efficacy of NSAIDs for PEP prophylaxis and further to explore the mechanism of NSAIDs for prevention of PEP. Methods: Patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) were randomly assigned to receive 100 mg rectal indomethacin or glycerin suppository 15-20 min before ERCP. The primary outcome was the rate of PEP. And the levels of serum HMGB1 and TNF-α were also measured before ERCP and 3 and 24 h after ERCP. Univariate analysis and multivariate analysis were carried out to estimate the independent risk factors for PEP. Results: Totally, 100 patients were enrolled, 50 received indomethacin and 50 with placebo (glycerin suppository). PEP developed in six patients in indomethacin group and 16 in the control group, the difference was significant (p = .016). The levels of HMGB1 and TNF-α were significantly decreased in indomethacin group at 3 (p < .0001) and 24 h (p < .0001) after ERCP, compared to the control group. Multivariate analysis revealed that duration of ERCP (OR, 0.221; 95% CI, 0.072-0.680; p = .008) and usage of NSAIDs (OR, 0.278; 95% CI, 0.090-0.861; p = .026) were independent predictors of PEP. Conclusions: Rectal indomethacin could significantly reduce the risk of PEP by down-regulating the levels of HMGB1 and TNF-α.

Comprehensive profiling of JMJD3 in gastric cancer and its influence on patient survival.

Histone methylation is thought to control the regulation of genetic program and the dysregulation of it has been found to be closely associated with cancer. JMJD3 has been identified as an H3K27 demethylase and its role in cancer development is context specific. The role of JMJD3 in gastric cancer (GC) has not been examined. In this study, JMJD3 expression was determined. The prognostic significance of JMJD3 and its association with clinical parameters were evaluated. JMJD3 dysregulation mechanism and targets were analyzed. The effect of JMJD3 mutation was determined by functional study. Results showed that JMJD3 was overexpressed in different patient cohorts and also by bioinformatics analysis. High JMJD3 expression was correlated with shortened overall survival in patients with GC and was an independent prognosis predictor. Genetic aberration and DNA methylation might be involved in the deregulation of JMJD3 in GC. Downstream network of JMJD3 was analyzed and several novel potential targets were identified. Furthermore, functional study discovered that both demethylase-dependent and demethylase-independent mechanisms were involved in the oncogenic role of JMJD3 in GC. Importantly, histone demethylase inhibitor GSK-J4 could reverse the oncogenic effect of JMJD3 overexpression. In conclusion, our study report the oncogenic role of JMJD3 in GC for the first time. JMJD3 might serve as an important epigenetic therapeutic target and/or prognostic predictor in GC.