Categoria: 2014

Signal transduction by receptor tyrosine kinases (RTKs) and nuclear receptors for steroid hormones is essential for body homeostasis, but the cross-talk between these receptor families is poorly understood. We observed that glucocorticoids inhibit signalling downstream of ​EGFR, an RTK. The underlying mechanism entails suppression of ​EGFR’s positive feedback loops and simultaneous triggering of negative feedback loops that normally restrain ​EGFR. Our studies in mice reveal that the regulation of ​EGFR’s feedback loops by glucocorticoids translates to circadian control of ​EGFR signalling: ​EGFR signals are suppressed by high glucocorticoids during the active phase (night-time in rodents), while ​EGFR signals are enhanced during the resting phase. Consistent with this pattern, treatment of animals bearing ​EGFR-driven tumours with a specific kinase inhibitor was more effective if administered during the resting phase of the day, when glucocorticoids are low. These findings support a circadian clock-based paradigm in cancer therapy.

Vai all’articolo originale (in inglese): Mattia Lauriola, Yehoshua Enuka, Amit Zeisel, Gabriele D’Uva, Lee Roth, Michal Sharon-Sevilla, Moshit Lindzen, Kirti Sharma, Nava Nevo, Morris Feldman, Silvia Carvalho, Hadas Cohen-Dvashi, Merav Kedmi, Nir Ben-Chetrit, Alon Chen, Rossella Solmi, Stefan Wiemann, Fernando Schmitt, Eytan Domany & Yosef Yarden. Diurnal suppression of ​EGFR signalling by glucocorticoids and implications for tumour progression and treatment. Nature Communications, 2015