Nucleolin: a prognostic marker in cancer?

Nucleolin, a major protein of the nucleolus which is required for cell proliferation is the subject of numerous studies in the field of oncology. Many studies suggest that the level of expression of nucleolin and its cellular localization could be an indication of the clinical outcome in several cancers. Quite logically for a protein required for the cancer cells to increased protein synthesis, a correlation between the high level of nucleolin expression and the poor prognosis of the patients is often reported. Unexpectedly, in several studies it was also found that a low nucleolin expression could be also associated with an unfavorable prognosis. In these commentary I discuss these studies and the possible implications for using nucleolin as a prognostic marker in oncology.