AIM:To determine the role for the intermediate filament protein nestin in glioma invasion.METHODS:We examined the expression and function of nestin in gliomas(Grades II-IV as defined by the World Health Organization).We determined nestin expression using Immunohistochemical methods.To elucidate nestin’s biological function(s),we reduced mRNA levels by 61%and 87%in two glioblastomaderived neurosphere lines using short hairpin RNAs and determined the effect of reduced nestin expression on glioma cell proliferation and invasion using MTS and matrigel migration assays,respectively.We also utilized quantitative real time polymerase chain reaction assays to determine the effect of reduced nestin expression on the expression of other markers associated with glioma stem cells and their differentiated progenies.RESULTS:We found a significant correlation between nestin immunoreactivity and astrocytoma tumor grade,with 36%of grade II,75%of grade III,and 100%of grade IV tumors expressing significant levels of the protein when assessed using immunohistochemistry.Reduction in nestin expression had no effect on cell growth in culture,but did retard the capacity of one line to migrate in-vitro on matrigel.Interestingly,in the line whose migration was not affected,mRNA levels of a second intermediate filament,synemin(also knowns as desmuslin),were elevated following introduction of shRNA targeting nestin.As synemin was not induced in the line which required nestin for migration,it is a possibility that synemin may compensate for the loss of nestin in this process.CONCLUSION:Nestin expression is prominent in high-grade astrocytomas.Nestin is not required for cell growth but it may,however,be required for cell motility.