International Journal of Cancer Research1811-97271811-9735Academic Journals Inc.10.3923/ijcr.2006.188.198PitcockA. M. Hasanuzzaman D. Lejeune A. Guggilam J. Francis SehgalI. 2200622Increased ROS in prostate cancer cells has been associated with cellular proliferation; however, the roles of ROS during invasion or metastasis are less well defined. While proliferation leads to higher density, invasive cells leave the cell mass and exist in a lower density state. Our aim was to determine if ROS levels vary with cell density and determine if ROS play a role in motility, adhesion or invasion. We found that ROS are increased in prostate cancer cells grown at low density and that this increase was particularly apparent in migrating cells. Inhibition of ROS reduced cell motility, adhesion to matrix substrates and invasion through Matrigel. Catalase activity was found to be down-regulated at low density but SOD activity and glutathione ratio were unaltered. Reduced catalase activity may contribute mechanistically to increased ROS at low density and this ROS appears to promote motility, adhesion and in vitro invasion.]]>Aebi, H.,1984in vitro.]]>1984pp: 121-126pp: 121-126Beers, Jr. R.F. and I.W. Sizer,1952195133140Chiarugi, P.,2003522832Chowdhury, S.K., A. Gemin and G. Singh,200533311391145Felty, Q., W.C. Xiong, D. Sun, S. Sarkar, K.P. Singh, J. Parkash and D. Roy,20054469006909Gao, N., L. Shen, Z. Zhang, S.S. Leonard and H. He et al.,2004253345Griffith, O.W.,1980106207212Kawaguchi, T.,200553964Kim, C.S., V.V. Vasko, Y. Kato, M. Kruhlak, M. Saji, S.Y. Cheng and M.D. Ringel,200514644564463Kim, M.H., H.S. Cho, M. Jung, M.H. Hong and S.K. Lee et al.,20052616691674Kleinman, H.K., M.L. McGarvey, L.A. Liotta, P.G. Robey, K. Tryggvason and G.R. Martin,19822161886193Lim, S.D., C. Sun, J.D. Lambeth, F. Marshall and M. Amin et al.,200562200207Mooney, D., L. Hansen, J. Vacanti, R. Langer, S. Farmer and D. Ingber,1992151497505Poser, I. and A.K. Bosserhoff,200419173188Shariftabrizi, A., M.R. Khorramizadeh, F. Saadat, K. Alimoghadam, F. Safavifar and M.R. Ebrahimkhani,2005273109116Anderson, M.E.,19851985pp: 317-323pp: 317-323