Furthermore, it was demonstrated by an immunoprecipitation-western blotting analysis on 5 cases of CRC with liver metastasis that ZO-1 bound to epidermal growth factor receptor (EGFR) irrespective of the phosphorylation status of EGFR, and that EGFR associated ZO-1 was highly tyrosine-phosphorylated only in the primary CRC, but was dephosphorylated in the liver-metastasized cancers.
Maximal EGFR and HGFR mRNA levels were 4- and 1.2-fold increased and correlated with the presence of liver metastases (P = 0.034) and decreased long-term curability (P = 0.027) but not tumor location, size, or tumor functional characteristics.