TLE2全名為Transducin-like enhancer of split，隸屬於Gro/TLE family中的一員，他們作為一種transcriptional corepressor 並且藉由和許多可以和DNA結合的轉錄因子進行交互作用進而調控下游蛋白。此家族在哺乳動物中從發現至今已經有六位成員(TLE1~6)，有愈來愈多的證據顯示他們在調控脊椎或非脊椎動物細胞分化上扮演著重要的角色，其中包括神經、肌肉骨骼、造血細胞的發育。他們參與在許多分化和生存的訊息傳遞路徑上， 顯示著這個蛋白質在生物體內的重要性。根據我們實驗室的研究指出，p97Eps8參與在大腸直腸癌細胞的生長與惡化中，而Gro/TLE2 protein為之前利用yeast-two hybrid 篩選出一系列會和p97Eps8有交互作用的蛋白質之ㄧ，因此我們建立了一個假設：Eps8和TLE2的交互作用在大腸直腸癌的形成和生長也許扮演了一個重要的角色。首先我們利用RT-PCR分析在不同的大腸直腸癌細胞株中TLE2基因的表現，發現在這些細胞株中除了存在有wild type TLE2，還同時存在數種isoform，我們從中找到了四種比wild type TLE2還要短isoforms ( TLE2 i-1、i-2、i-3、i-4 )。為了要了解TLE2在細胞轉型上所扮演的角色，我們在NIH3T3 cell以及293T cell中大量表達TLE2以及isoforms進行soft agar assay，發現他們並不會促進NIH3T3 形成colony，反而還有些微的抑制現象；而在293T中他們會抑制Eps8所促進的colony formation，以上的結果顯示TLE2也許在細胞中所扮演的是抑制細胞轉型的蛋白質。

TLE2 ( Transducin-like Enhancer of split 2) is a member of Gro/TLE family and might function as a corepressor together with a variety of DNA-binding proteins. There are six members (TLE1~6) in this family. Increasing evidence has indicated that Gro/TLE proteins play important roles during the regulation of numberous cell-differentiation events (including neuronal development, skelectogenesis, myogenesis and hematopoiesis ) in both invertebrates and vertebrates. Moreover, Gro/TLE is involved in several signal–transducin cascades, implying that this family members play important role in cellular development and survival. Our previous studies indicated that p97Eps8 participates in colon cancer progression. Since TLE2 was identified as one of its interacting proteins by yeast-two hybrid screening, we hypothesized that the interaction between Eps8 and TLE2 may play an important role in cancer formation. To address this issue, we utilized RT-PCR to analyze TLE2 gene expression in various colon cancer cell lines. We found that there are several TLE2 isoforms existing in these cells (TLE2 i-1、i-2、i-3、i-4). Furthermore, these isoforms were expressed variously in colon tumor specimens. To study the role of TLE2 in cell transformation, we transiently expressed TLE2 isoforms in NIH3T3, 293T and Ha-Ras inducible 7-4 cells. We found TLE2 as well as its isoforms could inhibit colony formatin of 293T cells, and 7-4 cells in soft agar. These findings suggested that TLE2 might play an inhibitory role in cell transformation.

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