Ets-1: A plausible marker of invasive potential and lymph node metastasis tn human oral squamous cell carcinomas

The proto-oncogene Ets-1 is a transcription factor known to regulate the ex pression of a number of genes involved in extracellular matrix remodelling. It has been postulated to play a role in angiogenesis, cell migration, and regulation of tumour invasion. In betel- and tobacco-related oral tumourig enesis, oral squamous cell carcinomas (SCCs) having a poor prognosis often exhibit extensive local disease with spread into regional lymph nodes. At p resent, no tumour marker is available to predict the metastatic potential o f oral carcinomas. To elucidate the involvement of Ets-1 in human oral tumo urigenesis, 60 cases of oral SCC, 30 potentially malignant lesions, and 30 samples of normal oral mucosa were examined by immunohistochemistry and the findings corroborated with immunoblotting, The relationship of Ets-1 expre ssion with the degree of differentiation, lymph node metastasis, and tumour stage was determined in oral SCCs. Ets-1 was not detected in the normal or al epithelium. Among the 60 cases of oral SCC, 35 cases (58 per cent) showe d positive staining for the Ets-1 protein in tumour cells. In potentially m alignant lesions, 14 of 30 cases (47 per cent) showed Ets-1 immunopositivit y, Ets-1 expression correlated significantly with tumour stage (p=0.01) and lymph node metastasis (p=0.005). The presence of Ets-1 mRNA in oral SCCs w as confirmed by reverse transcription-polymerase chain reaction (RT-PCR). T hese findings suggest that overexpression of Ets-1 in potentially malignant lesions may he related to angiogenesis and its expression in oral SCCs may be one of the factors involved in tumour progression and lymph node metast asis. Copyright (C) 1999 John Wiley & Sons, Ltd.