E1A expression is miR-199 dependent.

<p>To assess the expression of E1A in presence or absence of miR-199, 7×10⁴ cells of HepG2 and HepG2/199 cell lines were seeded and infected with 1x10⁶ I.U. of Ad-199T or with 1x10⁶ I.U. of Ad-Control and harvested after 48 hours. E1A levels were evaluated by quantitative PCR analysis (<b>A</b>) and by Western Blot (<b>B</b>). In HepG2, E1A mRNA was expressed following infection by both viruses; conversely, in HepG2/199 the E1A mRNA levels were significantly lower in AD-199T infected cells compared to Ad-Control infected cells. P-values of the comparisons are shown. The same results were obtained at the protein level. This evidence confirms that miR-199, constitutively expressed in HepG2/199 cells, can control E1A expression by targeting the homologous sequences places downstream of the adenoviral E1A gene.