Browsing by Author "Tomás, Ana R."

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    The curcumin analog HO-3867 selectively kills cancer cells by converting mutant p53 protein to transcriptionally active wildtype p53
    (American Society for Biochemistry and Molecular Biology, 2018-03-23) Madan, Esha; Parker, Taylor M.; Bauer, Matthias R.; Dhiman, Alisha; Pelham, Christopher J.; Nagane, Masaki; Kuppusamy, M. Lakshmi; Holmes, Matti; Holmes, Thomas R.; Shaik, Kranti; Shee, Kevin; Kiparoidze, Salome; Smith, Sean D.; Park, Yu-Soon A.; Gomm, Jennifer J.; Jones, Louise J.; Tomás, Ana R.; Cunha, Ana C.; Selvendiran, Karuppaiyah; Hansen, Laura A.; Fersht, Alan R.; Hideg, Kálmán; Gogna, Rajan; Kuppusamy, Periannan; Surgery, School of Medicine
    p53 is an important tumor-suppressor protein that is mutated in more than 50% of cancers. Strategies for restoring normal p53 function are complicated by the oncogenic properties of mutant p53 and have not met with clinical success. To counteract mutant p53 activity, a variety of drugs with the potential to reconvert mutant p53 to an active wildtype form have been developed. However, these drugs are associated with various negative effects such as cellular toxicity, nonspecific binding to other proteins, and inability to induce a wildtype p53 response in cancer tissue. Here, we report on the effects of a curcumin analog, HO-3867, on p53 activity in cancer cells from different origins. We found that HO-3867 covalently binds to mutant p53, initiates a wildtype p53-like anticancer genetic response, is exclusively cytotoxic toward cancer cells, and exhibits high anticancer efficacy in tumor models. In conclusion, HO-3867 is a p53 mutant-reactivating drug with high clinical anticancer potential.
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    HIF-transcribed p53 chaperones HIF-1α
    (Oxford University Press, 2019-11-04) Madan, Esha; Parker, Taylor M.; Pelham, Christopher J.; Palma, Antonio M.; Peixoto, Maria L.; Nagane, Masaki; Chandaria, Aliya; Tomás, Ana R.; Canas-Marques, Rita; Henriques, Vanessa; Galzerano, Antonio; Cabral-Teixeira, Joaquim; Selvendiran, Karuppaiyah; Kuppusamy, Periannan; Carvalho, Carlos; Beltran, Antonio; Moreno, Eduardo; Pati, Uttam K.; Gogna, Rajan; Surgery, School of Medicine
    Chronic hypoxia is associated with a variety of physiological conditions such as rheumatoid arthritis, ischemia/reperfusion injury, stroke, diabetic vasculopathy, epilepsy and cancer. At the molecular level, hypoxia manifests its effects via activation of HIF-dependent transcription. On the other hand, an important transcription factor p53, which controls a myriad of biological functions, is rendered transcriptionally inactive under hypoxic conditions. p53 and HIF-1α are known to share a mysterious relationship and play an ambiguous role in the regulation of hypoxia-induced cellular changes. Here we demonstrate a novel pathway where HIF-1α transcriptionally upregulates both WT and MT p53 by binding to five response elements in p53 promoter. In hypoxic cells, this HIF-1α-induced p53 is transcriptionally inefficient but is abundantly available for protein-protein interactions. Further, both WT and MT p53 proteins bind and chaperone HIF-1α to stabilize its binding at its downstream DNA response elements. This p53-induced chaperoning of HIF-1α increases synthesis of HIF-regulated genes and thus the efficiency of hypoxia-induced molecular changes. This basic biology finding has important implications not only in the design of anti-cancer strategies but also for other physiological conditions where hypoxia results in disease manifestation.