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Nucleophosmin (NPM) and human epidermal growth factor receptor-2 (Her-2) are abnormally expressed in various types of human malignant tumors, including gastric cancer, and have been closely associated with cancer chemoresistance. However, their interaction and roles in oxaliplatin resistance are not fully understood. Therefore, the present study aimed to elucidate the relationship between NPM and Her-2 in gastric cancer cell lines and clinical samples, and further investigated their role in the resistance of gastric cancer to oxaliplatin. Western blotting and reverse transcription-quantitative polymerase chain reaction confirmed that NPM and Her-2 expression were significantly upregulated in gastric cancer cells and clinical samples, and that their expression levels were strongly correlated. However, Her-2 expression was not affected by upregulation or downregulation of NPM expression in gastric cancer cells. Cell counting kit-8 assays demonstrated that the cell sensitivity to oxaliplatin decreased simultaneously with an increase in NPM expression. Furthermore, inhibition of Her-2 expression using trastuzumab significantly increased the sensitivity of the cells to oxaliplatin, which occurred simultaneously with the downregulation of NPM. These results indicated that inhibition of NPM, as a Her-2 downstream signal, may be a novel strategy to overcome oxaliplatin-resistant gastric cancer, and that trastuzumab and oxaliplatin may exhibit a synergistic antitumor effect in Her-2-positive gastric cancer cells. [ABSTRACT FROM AUTHOR]

Human LIGHT (lymphotoxin-related inducible ligand that competes for glycoprotein D binding to herpesvirus entry mediator on T cells) is the 14th member of the tumor necrosis factor (TNF) superfamily and is therefore also known as TNFSF14. LIGHT has been proven to be a multifunctional molecule affecting cell proliferation, differentiation and a number of other biological processes, in particular, cell growth inhibition. However, the expression and molecular mechanisms of the LIGHT gene in human colorectal carcinoma cells remain largely unclear. In the present study, the LIGHT gene was overexpressed using a lentiviral expression vector in HCT116 human colorectal carcinoma cells in vitro and in vivo, in order to explore the mechanism by which the LIGHT gene inhibits cell growth and suppresses tumor formation. The results showed that the recombinant lentivirus with LIGHT overexpression inhibited the proliferative capacity of the HCT116 cells and significantly decreased the xenografted tumor volumes in nude mice. Furthermore, LIGHT treatment effectively initiated increased caspase-3 and decreased Bcl-2 activities in the HCT116 cells. This study provides a basis for the improved understanding of the role and molecular mechanisms of the LIGHT gene in human colorectal carcinoma cells and may facilitate further functional studies of LIGHT. [ABSTRACT FROM AUTHOR]