YD-8 Cells Research Articles

Aspirin induces apoptosis in YD-8 human oral squamous carcinoma cells through activation of caspases, down-regulation of Mcl-1, and inactivation of ERK-1/2 and AKT

NSAIDs and COX-2 inhibitors show anti-cancer activities in many cancer cells. In this study, we investigated the effects of NSAIDs (aspirin or indomethacin) and COX-2 inhibitor (NS-398) on growth of YD-8 human oral squamous carcinoma cells. Interestingly, among drugs tested, aspirin showed strongest inhibitory effects on viability and survival of YD-8 cells. Profoundly, aspirin treatment resulted in severe cell shrinkage and nuclear DNA fragmentation in YD-8 cells, suggesting the aspirin-induced apoptosis in YD-8 cells. Data of Western blot further demonstrated that aspirin treatment caused activation of caspases, down-regulation of Mcl-1 protein, dephosphorylation of ERK-1/2 and AKT, and also IκB-α proteolysis-dependent NF-κB activation in YD-8 cells. Aspirin, however, had no effect on expressions of Bcl-2, XIAP, and HIAP-1 in YD-8 cells. Importantly, pretreatment with z-VAD-fmk, a pan-caspase inhibitor blocked the aspirin-induced apoptosis and Mcl-1 down-regulation in YD-8 cells. These findings collectively suggest that aspirin induces apoptosis in YD-8 cells and the induction may be correlated to activation of caspases, caspase-dependent Mcl-1 proteolysis, inactivation of ERK-1/2 and AKT, and activation of NF-κB. It is suggested that aspirin may be applied a potential anti-cancer drug against human oral squamous carcinoma.

Cloning and sequencing of beta-1,4-endoglucanase gene (celA) from Pseudomonas sp. YD-15.

A beta-1,4-endoglucanase gene (celA) from Pseudomonas sp. YD-15 was cloned in Escherichia coli DH5 alpha and its nucleotide sequence determined. The open reading frame of celA was 1830 base pairs and the enzyme was composed of 609 amino acids with a molecular weight of 63,617 Da. The deduced amino acid sequence and putative active site of CelA had high amino acid homology with family E cellulases. By dot blot analysis, the induction of celA according to carbon sources was determined. The transcripts hybridizing to the internal fragment of celA were detected in total RNA isolated from Pseudomonas sp. YD-15 cells grown on avicel and glycerol, but not from cells grown on glucose and cellobiose.