Aims: Differential display reverse transcription polymerase chain reaction (RT-PCR) was performed to identify genes associated with the invasive potential of human epithelioid sarcoma.
Methods: Two different clonal subpopulations, GRU-1A and GRU-1B, derived from the same human epithelioid sarcoma cell line GRU-1 and known to differ greatly in their invasive potential were compared by means of mRNA fingerprinting.
Results: Using a set of 10 arbitrary upstream primers and nine anchored oligo-dT primers, 22 candidate gene fragments were identified; differential expression was confirmed in four of these fragments by northern blot analysis. At the mRNA level, apoferritin light chain was predominantly expressed by the highly invasive cell line GRU-1A. In contrast, the mitochondrial gene M1, encoding cytochrome c oxidase I, and the TI-227H gene were expressed more strongly by the low invasive cell line GRU-1B. Furthermore, a novel gene fragment was identified and cloned that was preferentially expressed in the low invasive cell line GRU-1B, and therefore might have an inhibitory role in invasion. Consequently, this gene fragment was designated as expressed in low invasive sarcoma cells (ELISC-1).
Conclusions: A novel gene fragment (ELISC-1) and three known genes were identified as potential regulators of tumour invasiveness. Cloning of the entire sequence of ELISC-1 and subsequent investigations are required to establish its biological role.