Role of thyroid hormone-integrin αvβ3-signal and therapeutic strategies in colorectal cancers
Yu-Chen S. H. Yang, Po-Jui Ko, Yi-Shin Pan, Hung‐Yun Lin, Jacqueline Whang‐Peng, Paul J. Davis, Kuan Wang
Abstract
Abstract Thyroid hormone analogues—particularly, l -thyroxine (T 4 ) has been shown to be relevant to the functions of a variety of cancers. Integrin αvβ3 is a plasma membrane structural protein linked to signal transduction pathways that are critical to cancer cell proliferation and metastasis. Thyroid hormones, T 4 and to a less extend T 3 bind cell surface integrin αvβ3, to stimulate the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway to stimulate cancer cell growth. Thyroid hormone analogues also engage in crosstalk with the epidermal growth factor receptor (EGFR)-Ras pathway. EGFR signal generation and, downstream, transduction of Ras/Raf pathway signals contribute importantly to tumor cell progression. Mutated Ras oncogenes contribute to chemoresistance in colorectal carcinoma (CRC); chemoresistance may depend in part on the activity of ERK1/2 pathway. In this review, we evaluate the contribution of thyroxine interacting with integrin αvβ3 and crosstalking with EGFR/Ras signaling pathway non-genomically in CRC proliferation. Tetraiodothyroacetic acid (tetrac), the deaminated analogue of T 4 , and its nano-derivative, NDAT, have anticancer functions, with effectiveness against CRC and other tumors. In Ras -mutant CRC cells, tetrac derivatives may overcome chemoresistance to other drugs via actions initiated at integrin αvβ3 and involving, downstream, the EGFR-Ras signaling pathways.