Figure 3.

The regulatory circuit during oncogenic transformation. NF-κB, IL6, let-7 microRNA, and Lin28B are key components of the positive feedback loop underlying the epigenetic switch from normal to transformed cells. The switch is induced by an initial inflammatory signal (Src activation) that activates NF-κB, which turns on IL6 transcription and inhibits let-7 microRNA via Lin28B. The resulting high levels of IL6 activate NF-κB, thereby completing the positive feedback loop that maintains the transformed phenotype.