Nasopharyngeal carcinoma (NPC) is one of the most common cancers of the head and neck, particularly in Southern China and Southeast Asia with high treatment failure due to the development of local recurrence and distant metastasis. The molecular mechanisms related to the progression of NPC have not been fully understood. In this study, we showed that antidiabetes drugs rosiglitazone and metformin inhibit NPC cell growth through reducing the expression of integrin-linked kinase (ILK). Blockade of PPAR gamma and AMPK alpha overcame the effects of rosiglitazone and metformin on ILK protein. Importantly, overexpression of ILK abrogated the effect of rosiglitazone and metformin on NPC cell growth. Furthermore, these agents reduced ILK promoter activity, which was not observed in AP-2 alpha, but not Sp1 site mutation in ILK gene promoter. In addition, silencing of AP-2 alpha or overexpression of Sp1 reversed the effect of these agents on ILK protein expression and cell growth. Chromatin immunoprecipitation (ChIP) assay showed that rosiglitazone induced AP-2 alpha, while metformin reduced Sp1 protein binding to the DNA sequences in the ILK gene promoter. Intriguingly, overexpression of Sp1 abolished the effect of rosiglitazone on AP-2 alpha protein expression. Collectively, we show that rosiglitazone and metformin inhibit ILK gene expression through PPAR gamma- and AMPK alpha-dependent signaling pathways that are involved in the regulation of AP-2 alpha and Sp1 protein expressions. The effect of combination of rosiglitazone and metformin demonstrates greater extent than single agent alone. The cross-talk of PPAR gamma and AMPK alpha signaling enhances the synergistic effects of rosiglitazone and metformin. This study unveils novel mechanisms by which oral antidiabetes drugs inhibit the growth of human NPC cells. (C) 2013 Elsevier Inc. All rights reserved.