Although, accumulation of nuclear and cytoplasmic beta-catenin has been observed in ESCCs, mutation of APC and beta-catenin are not found in ESCCs. Therefore, another mechanism for cytoplasmic beta- catenin accumulation might exist in ESCCs. Materials and Methods: Human ESCCs cell lines and the 293 stable transfectants expressing
Wnt-1, Wnt-5A, and Wnt-7A were cultured under standard conditions. The TOPFlash or FOPFlash reporter plasmids were transfected. Results: Transfected mutant beta-catenin as well as an axin fragment harbing the GSK3 beta interaction domain, the latter a potent GSK3 beta inhibitor. both robustly activated pTOPFlash in ESCCs cells. When pTOPFlash/pFOPFlash reporters were transfected in ESCCs cell lines followed by cocultivation with 293 cells that stably express Wnt -1, all cell lines except one demonstrated TCF mediated transcriptional. But, cells were co- cultured, Wnt - 7A or Wnt - 5A did not activate TCF mediated transcription in a cell number dependent fashion. Discussion; We report the activation of TCF promoter gene by extemal Wnt stimuli in ESCCs cells.