As and As/IFN treatments down-regulate the transcription of IκB-α, IL-6, and TNF-α genes in HTLV-1⁺ cells. (A) Relative quantification of IL-6 and TNF-α mRNA in untreated HuT-102 cells (ctrl) or in response to treatment with IFN, As, and combined treatment with As/IFN at 12 hours. Curves represent fluorescence versus RT-PCR cycle number. Amplification plot of the negative control (H₂O) is also included. Inset histograms show the mRNA expression levels as a percentage of the untreated control cells after normalization to G6PD as described in “Materials and methods.” (B) Northern blot analysis of IκB-α mRNA expression in untreated HuT-102 cells (ctrl) or in response to treatment with IFN, As, and combined treatment with As/IFN at 48 hours. Loading was assessed by propidium iodide staining of the 28S and 18S rRNA.