RESUMO
Background: This study aims to explore the role of RCAN1 in esophageal squamous cell carcinoma (ESCC) cells, determine the mRNA level of three RCAN1 isoforms in ESCC tissue, and evaluate the prognostic value of three RCAN1 isoforms. Methods: Colony-forming assay, Wound-healing assay and Transwell assay were used to evaluate the effect of RCAN1 on cell proliferation, migration and invasion. The mRNA expression of three RCAN1 isoforms was detected in paired tumor and normal tissues from 100 ESCC patients by real-time PCR. Kaplan-Meier survival curves and Cox proportional hazards model were used to evaluate the prognostic value of three RCAN1 isoforms. A nomogram was used to predict the probability of 2-year and 5-year overall survival (OS). Results: In vitro, knockdown of RCAN1 could promote ESCC cell proliferation, migration and invasion abilities. Compared to the paired normal tissues, RCAN1 isoform 1 (RCAN1.1, P=0.0027) and RCAN1 isoform 2 (RCAN1.2, P=0.0006) were significantly decreased in tumor tissues. The low expression of RCAN1.2 mRNA was associated with advanced stage (P=0.0176) and lymph node metastasis (LNM, P=0.0219). ESCC patients with low RCAN1.2 mRNA levels had shorter survival time compared to those with high RCAN1.2 levels (P=0.007). Multivariate COX analysis indicated that RCAN1.2 mRNA level was an independent prognostic indicator of OS of patients with ESCC (hazard ratio=0.5266, P=0.03554). The concordance index of nomogram to predict OS was 0.693 based on LNM, RCAN1.2, tumor stage and patients' age. Conclusion: These findings show that RCAN1 gene play a role in preventing proliferation, migration, and invasive activity of ESCC cells. RCAN1.2 mRNA level is a novel prognostic marker in ESCC, targeting RCAN1.2 may provide a potential therapeutic approach in ESCC.
RESUMO
Our prior studies have confirmed that long-term colonization of Porphyromonas gingivalis (Pg) and overexpression of the inflammatory factor glycogen synthase kinase 3ß (GSK3ß) promote the malignant evolution of esophageal squamous cell carcinoma (ESCC). We aimed to investigate the functional mechanism by which Pg could promote ESCC malignancy and chemo-resistance through GSK3ß-mediated mitochondrial oxidative phosphorylation (mtOXPHOS), and the clinical implications. The effects of Pg and GSK3ß on mtOXPHOS, malignant behaviors and response to paclitaxel and cisplatin treatment of ESCC cells were evaluated by in vitro and in vivo studies. The results showed that Pg induced high expression of the GSK3ß protein in ESCC cells and promoted the progression and chemo-resistance via GSK3ß-mediated mtOXPHOS in human ESCC. Then, Pg infection and the expression of GSK3ß, SIRT1 and MRPS5 in ESCC tissues were detected, and the correlations between each index and postoperative survival of ESCC patients were analysed. The results showed that Pg-positive ESCC patients with high-expression of GSK3ß, SIRT1 and MRPS5 have significant short postoperative survival. In conclusion, we demonstrated that the effective removal of Pg and inhibition of its promotion of GSK3ß-mediated mtOXPHOS may provide a new strategy for ESCC treatment and new insights into the aetiology of ESCC.
RESUMO
Two new chlorinated metabolites 4-chloro-1-hydroxy-3-methoxy-6-methyl-8-methoxycarbonyl-xanthen-9-one (1) and 2'-acetoxy-7-chlorocitreorosein (2), together with three known compounds (3-5), were obtained from the EtOAc extract of the endophytic fungus Penicillium citrinum HL-5126 isolated from the mangrove Bruguiera sexangula var. rhynchopetala collected in the South China Sea. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. All compounds were evaluated for their antibacterial and topoisomerase I inhibitory activities. Compound 2 exhibited antibacterial activity against Vibrio parahaemolyticus with an MIC value of 10 µm.