methods:Two cell lines, Tca8113 and Tca8113/nm23-H1( an nm23-H1-transfected tongue squamous cell carcinoma cell line). Detecting the intracellular levels of nm23-H1 protein in two cell lines. The two cell lines were exposed to cisplatin with or without ouabain pretreatment, then cell mortality rate, apoptosis and mitochondrial membrane potential were analyzed using MTT and flow cytometer. Detecting the intracellular platinum levels in the same time.The data were analyzed by a one-way analysis of variance (ANOVA), and where appropriate, SNK-q test for multiple comparisons was used. Statistical significance was set at P-value＜0.05.
Results: Tca8113/nm23-H1 showed significant overexpression of intracellular nm23-H1 protein compared with non-transfected Tca8113 cells. Tca8113/nm23-H1 showed a significantly increased cell mortality rate and apoptosis compared with Tca8113 when exposed to cisplatin. In contrast, Tca8113/nm23-H1 was more sensitive to cisplatin than Tca8113 and Tca8113/nm23-H1 pretreated with ouabain, a selective inhibitor of Na+, K+-ATPase. Pretreatment with ouabain resulted in no differences in cisplatin sensitivity between the two cell lines examined. Intracellular platinum level in Tca8113 was significantly lower than that in Tca8113/nm23-H1, whereas ouabain pretreatment resulted in no differences in intracellular platinum accumulations in the two cell lines.
Conclusions:Our data support the conclusion that nm23-H1 may be related to Na+, K+-ATPase activity and that elevation of nm23-H1 expression in tongue cancer cell, in combination with cisplatin treatment，may be considered as a potential therapy for tongue squamous cell carcinoma.