The molecular mechanisms of the carcinogenesis of oral squamous cell carcinomas (OSCCs) are highly variable and result in different features of tumor progression, i.e., local tissue destruction and metastasis to regional lymph nodes. A case of OSCC arising from proliferative verrucous leukoplakia (PVL) was analyzed for its protein expression profile by immunoprecipitation (IP) – high performance liquid chromatography (IP-HPLC) by using 72 antisera and comparing results with those of KB cells. OSCC arising from PVL showedstronger expressions of proteins associated with cell proliferation (MPM2, PCNA, eiF5A, DHS, DOHH), cell survival (pAKT, MDM2, survivin), matrix proteolysis (elaffin), tumor suppression (p16, p21, PTCH1), the WNT/β-catenin pathway (SHH, WNT1, APC, β-catenin, snail), proinflammation (TNFα), angiogenesis (HIF, CMG2, vWF), and cellular protection (HSP-70, FAK, caveolin) and of oncoproteins(STAT3, 14-3-3, K-RAS, PUMA, PIM1) and growth factors (EGFR, bFGF) than KB cells. On the other hand, KB cells showed stronger expressions of proteins associated with apoptosis (caspase-3, caspase-8, caspase-9, PARP, FAS, FASL, TGase-1, BCL2, BAD, BID, BAK, FLIP), matrix proteolysis (MMP-2, MMP-9), transcription signaling (NFkB, p38, E2F-1, HO-1), and tumor suppression (p53, RB1, PTEN) and of oncoproteins (DMBT1, CEA) and growth factor (TGF-β1, c-erbB2, VEGF) than OSCC arising from PVL. These data indicate the cells of OSCC arising from PVL are more resistant and more robust than KB cells. Furthermore, they suggest the oncogenic signalings of OSCC arising from PVL play important roles in the aggressive growth and rapid tumor metastasis to regional lymph nodes.