The expression
level of DKK-1, an inhibitor of canonical WNT signaling, was decreased in Cal27cis, a sub-cell line of Cal27, and was obtained by treating Cal27 with increasing concentrations of cisplatin. Overexpression of DKK-1 in both Cal27 and Cal27cis resulted in increased sensitivity to cisplatin, suggesting DKK-1 and the WNT signaling pathway as a marker and target for cisplatin chemosensitivity. In human glioma cells, a previous study showed that transfection of DKK-1into human glioma cell line U87MG causes the cells more sensitive to cisplatin and alkylating agent [15]. Our current study revealed that the expression of bax and caspase-3 increased, whereas the expression of bcl-2 decreased in the SHG44 -DDK-1 SCH772984 purchase cells, further confirming the pro-apoptosis function of DKK-1. We speculate that the function of DKK-1 may be tissue or cell type specific. Another possibility is that mutations of DKK-1 could be ABT-263 mw the causes of different functions of DKK-1. A screening of 73 brain tumors, however, revealed that no obvious mutations of DKK-1 were found in these brain tumors [21]. More studies, especially direct comparison of DKK-1 in different cell types at the same condition, are needed in order to better understand
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