Erk1/2 activation and modulation of STAT3 signaling in oral cancer.

Oncology reports (2014-09-02)
Ioannis Gkouveris, Nikolaos Nikitakis, Maria Karanikou, George Rassidakis, Alexandra Sklavounou

Constitutive activation of the signal transducer and activator of transcription 3 (STAT3) signaling pathway possesses confirmed oncogenic potential in oral squamous cell carcinoma (OSCC). Crosstalk with other molecular pathways contributes to STAT3 regulation in cancer. The effects of mitogen-activated protein kinases (MAPKs) and particularly extracellular signal-regulated kinase 1/2 (Erk1/2) on STAT3 signaling in OSCC have not been thoroughly investigated. The present study examined the effects of Erk1/2 modulation on STAT3 signaling and cell growth in OSCC cells. Constitutive expression levels of phosphorylated (tyrosine and serine) and total STAT3, Erk1/2 and cyclin D1 were assessed in OSCC cell lines. Erk1/2 modulation was achieved by pharmacological agents; siRNA silencing against Erk1/2 was also performed. Cell proliferation and viability were assessed. Erk1/2 inhibition with either U0126 treatment or specific siRNA silencing resulted in decreases in p-ser STAT3 and cyclin D1 levels and increases in p-tyr STAT3 in OSCC cells. Moreover, Erk1/2 inhibition resulted in a dose-dependent reduction in OSCC cell growth and viability. Erk1/2 induction had the opposite effects. Taken together, these results are supportive of an active crosstalk between the oncogenic Erk1/2 and STAT3 pathways in OSCC, the significance of which requires further investigation.

Product Number
Product Description

Hydrocortisone, BioReagent, suitable for cell culture
Hydrocortisone, ≥98% (HPLC)
Hydrocortisone, γ-irradiated, powder, BioXtra, suitable for cell culture
Hydrocortisone, Pharmaceutical Secondary Standard; Certified Reference Material
Hydrocortisone, United States Pharmacopeia (USP) Reference Standard
Hydrocortisone, meets USP testing specifications
Hydrocortisone for peak identification, European Pharmacopoeia (EP) Reference Standard
Hydrocortisone, European Pharmacopoeia (EP) Reference Standard
Hydrocortisone, VETRANAL®, analytical standard
Hydrocortisone, British Pharmacopoeia (BP) Assay Standard