Expression of HPV-16 E5 oncogene does not affect tyrosinase mRNA transcription and protein expression levels. Tyrosinase mRNA levels were evaluated by RT-PCR in FRM and M14 melanoma control cells (CTR), in cells treated with 20 nM Con-A (+ ConA) and in cell expressing the HPV-16 E5 (+ E5). Panel a) – Total mRNA (1 μg) was reverse transcribed and amplified with HuTyr-1/HuTyr-2. Four independent experiments gave similar results. All the samples showed similar levels of tyrosinase mRNA. Western blot analysis (panel b) and densitometric quantisation (panel c) of the chemo-luminescent signals of tyrosinase protein levels. No protein modulation was observed under any experimental condition. Results represent the mean ± standard deviation (SD) of four independent experiments. (A.U. = Arbitrary Unit).