Eps8 (Epidermal growth factor receptor substrate no.8)有兩個isoforms，分別為p97Eps8及p68Eps8。我們實驗室先前已發現p97Eps8 參與在v-Src所調控的腫瘤生成。為了進一步了解p97Eps8所調控的訊息傳遞，我們利用yeast two-hybrid的方法來搜尋能與p97Eps8有交互作用的蛋白質，並發現TLE2 (transducin-like enhancer of split 2)會和Eps8有交互作用，更進一步的研究顯示主要能與p68Eps8有交互作用。此外，TLE2與p97Eps8及p68Eps8皆在IV5 (v-Src-transformed cells)細胞中有大量表達的情形。我們也發現，當我們抑制IV5細胞中的Eps8也能抑制tle2的轉錄，降低TLE2表現量，然而在IV5細胞中有表達的另一TLE family member，TLE3卻不會隨Eps8的表現量增減而改變，顯示TLE2在Eps8的訊息傳遞途徑中具有一定重要性。在此同時，我們也發現TLE2具有至少兩種isoforms (約76kDa及118kDa)，表現量會隨Eps8表現增減而有所改變。顯示在Eps8參與在v-Src所調控的腫瘤生成中，TLE2 isoforms或許也具有相當的重要性。當進一步研究TLE2在細胞轉型的作用，實驗結果發現TLE2具有抑制正常細胞NIH3T3及表達p97Eps8的人類腎臟293T細胞在軟洋菜膠中形成colony的能力。我們的研究結果顯示，Eps8可能透過調控TLE2表現及與TLE2交互作用來調控TLE2在細胞轉型上的功能。

Two isoforms, i.e. p97Eps8 and p68Eps8, were detected in many cultured cell lines by Eps8 antibody. Our previous studies indicated that p97Eps8 participates in v-Src-mediated tumorigenesis. To characterize Eps8-mediated signal transduction, we previously identified TLE2 (transducin-like enhancer of split 2) as one of its associated proteins by yeast-two hybrid screening. Further studies indicated that TLE2, as well as both Eps8 isoforms, was overexpressed in v-Src transformed IV5 cells. Interestingly, decreased expression of TLE2 was detected in Eps8-attenuated IV5 cells suggested its involvement in Eps8-mediated signal transduction. To study the role of TLE2 in cell proliferation and transformation, we transiently expressed tle2 into NIH3T3 cells or Eps8 overexpressing human kidney 293T cells. We found TLE2 overexpression could inhibit their anchorage-independent growth in soft agar. These findings suggested that TLE2 might be able to interact with Eps8 and inhibit the transforming ability of Eps8.

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