Abstract
Merlin ((Moesin-ezrin-radixin-like protein, also known as schwannomin) is a tumor suppressor protein which is encoded by the neurofibromatosis type 2 gene, NF2. Loss of function mutations or deletions in NF2 which normally restrains tumor growth, leads to the formation of multiple tumors including schwannoma, meningioma and ependymoma. We tested whether NF2/Merlin is expressed and exerts similar control on proliferation of colorectal cancer cells and modulates the rate of their apoptosis. Expression of NF2/Merlin was reduced in colorectal cancer cells as compared with adjacent non-cancerous cells. Overexpression of NF2 inhibited colony formation by tumor cells and inhibited proliferation of cancer cells both in vitro and in vivo. The rate of apoptosis was also increased in colorectal cancer cells by overexpression of NF2. These findings show that NF2/Merlin is also reduced in tumors that do not arise in the context of neurofibromatosis and that induction of its expression might be used to control tumor growth.