Low Expression of the Snail Gene is a Good Prognostic Factor in Node-Negative Invasive Ductal Carcinomas

Abstract

While Snail is a zinc-finger transcription factor that triggers the epithelial-mesenchymal transition, it has also been reported to be indirectly regulated by estrogen receptor alpha (ERalpha) and to be involved in the transcriptional repression of the aromatase gene. The aim of the present study was to examine the role of Snail expression in node-negative invasive ductal carcinomas. We analyzed Snail mRNA expression levels in 86 node-negative invasive ductal carcinomas by real-time quantitative RT-PCR and studied whether Snail mRNA expression correlates with clinicopathological factors. No correlation was found between Snail mRNA expression and ERalpha protein expression levels. However, we observed that none of the 34 patients showing low Snail mRNA expression developed distant metastasis while 6 of 52 (12%) showing high expression of Snail mRNA did. The level of Snail mRNA expression was not found to be significantly correlated with clinicopathological factors. No inverse correlation was found between the Snail and aromatase mRNA expression levels in our series. Our data show that low expression of Snail mRNA is a good prognostic factor in node-negative invasive ductal carcinomas. Snail expression is suggested to be involved in distant metastasis in node-negative invasive ductal carcinomas.