Expression, phosphorylation, localization, and microtubule binding of tau in colorectal cell lines

Tau is a microtubule-associated protein that causes proper role of neuron by assembling and stabilizing microtubules. The amount and post translational modification of tau can change its function as a stabilizer of microtubules. The aim of the study was to look for the expression of tau in colorectal cancer and normal cells, along with phosphorylation and microtubule binding properties of tau expressed in colorectal cancer cell. Two colorectal cancer cells (SW480 and HCT 116) expressed tau that was also phosphorylated, whereas the others (Caco-2, HT-29 and DLD1) did not. Colorectal normal cell (CCD-18Co) expressed very tiny amount of tau that was not phosphorylated. A big fraction of tau in HCT 116 did not bind to microtubule. The results suggest that some colorectal cancer cells express hyperphosphorylated tau as found in Alzheimer's disease. So, tau in colorectal cancer cells does not look like same as tau in normal adult brain; rather it works nearly same as tau in neurodegenerative disease.