The present invention relates to non-activated Wnt inhibition polypeptides (WIPs) containing: (a) a
protein transduction domain (PTD) which enables said WIPs to permeate a
cell membrane without the aid of a
cell membrane
receptor; and (b) a Wnt
antagonist domain which is inactive by itself, but is activated in mammalian cells and then secreted out of the cells to function to inhibit Wnt
signal transduction. Also, the invention relates to a method for preparing said non-activated WIPs, and a pharmaceutical composition containing said WIPs as active ingredients. Said non-activated WIPs can be produced in large quantities through the culture of
bacteria such as E coli., and are biochemically inactive before being administered into the
human body, and thus the production cost thereof is only one several tenths of that of previously known active proteins (sFRPs, DKKs, etc.) having uses similar thereto, and the isolation / purification and handling / administration processes thereof are significantly simple and convenient. When said non-activated WIPs are administered
in vivo, they will have the effects of inhibiting the invasive growth and
metastasis of
cancer cells and treating immune diseases, such as
rheumatoid arthritis by pharmacological mechanisms different from those of the previously known sFRPs or DKKs.