From Normal Skin to Squamous Cell Carcinoma: A Quest for Novel Biomarkers

Figure 2

Dysregulation of cellular signalling in SCC. Aberrant activation of EGFR induces phosphorylation of β-catenin and GSK-3β, leading to uncoupling of β-catenin from both destruction complex (β-catenin/GSK-3β/APC/CK1/Axin) and E-cadherin/p120/α-catenin complex and translocation to the nucleus. Once translocated to the nucleus it influences gene transcription, including Cyclin D1, c-Myc, MMP-1, and MMP-7 (viable biomarkers for SCC) which have important roles in proliferation, cell cycle, migration, and invasion. The figure also shows one of the first events in SCC carcinogenesis, namely, the induction of tumor suppressor p53 mutations. EGFR: epidermal growth factor receptor; GSK-3β: glycogen synthase kinase 3 beta; APC: adenomatous polyposis coli; CK1: casein kinase 1; MMP-1: matrix metalloproteinase 1; MMP-7: matrix metalloproteinase 7.