o up-regulation of cyclin D1. The CDKIs, p21Kip1 and p27Kip1, are frequently down-regulated in human cancers. The mechanism of ERK regulation of p21Kip1 and p27Kip1 remains unclear. ERK may directly phosphorylate p21Kip1 and p27Kip1. These data suggested that ANXA10 activates the MAPK signaling pathway by phosphorylating ERK and promotes the G1 cell cycle by down-regulating CDKIs in OSCC progression. To date, the expression of ANXA10 in OSCC tissues and its correlation to clinicopathological features have not been elucidated. In our study, though the positive rates of ANXA10 in earlystage tumors were significantly low, the positive rates in advancedtumors were significantly increased; this strongly implies that ANXA10 may play an important role in cancer progression. Given that ANXA10 overexpression may predict malignancy, patient stratification by ANXA10 status may provide a more personalized approach to human oral cancer therapy. In conclusion, our results indicated that ANXA10 is overexpressed frequently in OSCCs and that this overexpression may be associated with tumoral progression by promoting cell-cycle progression in the G1 phase through activation of the ERK/ MAPK signaling pathway, leading to decreased expression of CDKIs. While further studies are needed to study the interaction of ANXA10 and the ERK/MAPK signaling pathway, these data suggested that ANXA10 plays an important role in cellular proliferation and expression is likely to be a biomarker of progression and a potential therapeutic target for development of anticancer drugs in primary OSCCs. Materials and Methods Ethics Statement The study protocol was approved by the Ethical Committee of Graduate School of Medicine, Chiba University and was performed in accordance with the ethical Rutin web standards laid down in the Declaration of Helsinki. Written informed consent was received from all patients. OSCC cellular lines and tissue samples The human OSCC cellular lines were purchased from the Human Science Research Resources Bank, Osaka, Japan. Sa3 was kindly provided by Dr. S. Fujita at Wakayama Medical University, Wakayama, Japan. Primary cultured HNOKs served as normal controls. All cells were maintained in Dulbecco’s modified Eagle’s medium/F-12 HAM supplemented with 10% fetal bovine serum and 50 units/ml penicillin and streptomycin in a humidified 5% CO2/air atmosphere at 37uC. 
One hundred pairs of primary OSCC samples and corresponding normal oral epithelial tissues were obtained during surgeries at Chiba University Hospital, Chiba, Japan. All patients provided informed consent for use of the protocol, which the institutional review board of Chiba University reviewed and approved. The resected tissues were divided into two parts; one was frozen immediately and stored at 280uC until RNA isolation, and the second was fixed in 20% buffered formaldehyde solution for pathologic diagnosis and IHC. Histopathological diagnosis of each tissue was performed according to the World Health Organization criteria by the Department of Pathology, Chiba University Hospital. Clinicopathological staging was determined according to the tumor-node-metastases classification of the International Union against Cancer. All OSCC samples were confirmed ANXA10 in Oral Cancer 5 ANXA10 in Oral Cancer histologically and checked to ensure the presence of tumoral in more than 80% of specimens. Quantitative real-time reverse transcription-PCR Total RNA was isolated using Trizol Reagent according to the manufa
