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bioRxiv · 10.1101/357293

Reactivation of TAp73 tumor suppressor by protoporphyrin IX, a metabolite of aminolevulinic acid, compensates for p53 loss and induces apoptosis in TP53-deficient cancer cells.

Sznarkowska, A.·Kostecka, A.·Koczergo, K.·Kawiak, A.·Acedo, P.·Lion, M.·Inga, A.·Zawacka-Pankau, J.
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Abstract

BackgroundThe p73 protein is a tumor suppressor that shares structural and functional similarity with p53. p73 is expressed in two major isoforms; the TA isoform that interacts with p53 pathway, thus acting as tumor suppressor and the N-terminal truncated {Delta}N isoform that inhibits TAp73 and p53 and thus, acts as an oncogene.\n\nResultsBy employing a drug repurposing approach, we found that protoporphyrin IX (PpIX), a metabolite of aminolevulinic acid (ALA) applied in photodynamic therapy of cancer, stabilizes TAp73 and activates TAp73-dependent apoptosis in cancer cells lacking p53. The mechanism of TAp73 activation is via disruption of TAp73/MDM2 and TAp73/MDMX interactions and inhibition of TAp73 degradation by ubiquitin ligase Itch.\n\nConclusionOur findings may in future contribute to the successful repurposing of PpIX into clinical practice.

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Sznarkowska, A., Kostecka, A., Koczergo, K., Kawiak, A., Acedo, P., Lion, M., Inga, A., Zawacka-Pankau, J.. 2018-06-28. Reactivation of TAp73 tumor suppressor by protoporphyrin IX, a metabolite of aminolevulinic acid, compensates for p53 loss and induces apoptosis in TP53-deficient cancer cells.. https://doi.org/10.1101/357293

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