COMPARISON OF TUMOR-GROWTH BETWEEN HSP25-TRANSFECTED AND HSP27-TRANSFECTED MURINE L929 CELLS IN NUDE-MICE

We have developed a novel system for examining the possible contributi on of small heat shock proteins (hsp) to tumor growth. L929 fibrosarco ma cells, which do not express significant levels of endogenous hsp25, were stably transfected with either murine hsp25 or human hsp27. Both transfected genes were over-expressed and the respective proteins wer e phosphorylated in L929 cells. L929 cells transfected with hsp25 exhi bited enhanced tumor growth compared to control transfected L929 cells upon s.c. injection into nude mice. In contrast, cells transfected wi th hsp27 exhibited delayed tumor progression in comparison to controls . Although these 2 heat shock genes and respective proteins are struct urally very similar, they apparently exhibit distinct effects on tumor growth in this system. (C) 1997 Wiley-Liss, Inc.