Multiple Molecular and Cellular Mechanisms of Action of Lycopene in Cancer Inhibition

Figure 2

PDGFR-, IGF-IR-, and VEGFR-mediated signal transduction pathways are possible targets for lycopene. PDGFR, IGF-IR, and VEGFR are activated at the cell surface during tumourigenesis. Activation of these receptors induces several downstream signalling pathways. Among these pathways, the Ras-MAPK (including ERK, JNK, and p38) and PI3K-AKT pathways transduce signals into the nucleus to activate transcription factors that regulate the expression of genes that are important for proliferation, cell-cycle progression, apoptosis, inflammation, angiogenesis, invasion, and metastasis. Lycopene has been shown to inhibit the IGF-induced activation of IGFR by increasing the expression of IGFBPs. Similarly, lycopene directly binds to PDGF to reduce the autophosphorylation of PDGFR and VEGFR.