Tumor suppressor p53 is mutated in about 50% of cancers. Most malignant melanomas carry wild-type p53, but p53 activity is often inhibited due to overexpression of its negative regulators Mdm2 or MdmX. We performed high throughput screening of 2448 compounds on A375 cells carrying p53 activity luciferase reporter construct to reveal compounds that promote p53 activity in melanoma. Albendazole and fenbendazole, two approved and commonly used benzimidazole anthelmintics, stimulated p53 activity and were selected for further studies. The protein levels of p53 and p21 increased upon the treatment with albendazole and fenbendazole, indicating activation of the p53-p21 pathway, while the levels of Mdm2 and MdmX decreased in melanoma and breast cancer cells overexpressing these proteins. We also observed a reduction of cell viability and changes of cellular morphology corresponding to mitotic catastrophe, i.e., G2/M cell cycle arrest of large multinucleated cells with disrupted microtubules. In summary, we established a new tool for testing the impact of small molecule compounds on the activity of p53 and used it to identify the action of benzimidazoles in melanoma cells. The drugs promoted the stability and transcriptional activity of wild-type p53 via downregulation of its negative regulators Mdm2 and MdmX in cells overexpressing these proteins. The results indicate the potential for repurposing the benzimidazole anthelmintics for the treatment of cancers overexpressing p53 negative regulators.

• Klíčová slova
• Mdm2, MdmX, benzimidazoles, drug repurposing, melanoma, p53,
• MeSH
• albendazol farmakologie   MeSH
• benzimidazoly farmakologie   MeSH
• down regulace MeSH
• fenbendazol farmakologie   MeSH
• jaderné proteiny metabolismus   MeSH
• lidé MeSH
• melanom farmakoterapie   metabolismus   MeSH
• MFC-7 buňky MeSH
• nádorové buněčné linie MeSH
• nádorový supresorový protein p53 metabolismus   MeSH
• přehodnocení terapeutických indikací léčivého přípravku MeSH
• proliferace buněk účinky léků   MeSH
• proteiny buněčného cyklu MeSH
• protoonkogenní proteiny c-mdm2 metabolismus   MeSH
• protoonkogenní proteiny metabolismus   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• rychlé screeningové testy MeSH
• screeningové testy protinádorových léčiv MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• albendazol MeSH
• benzimidazoly MeSH
• fenbendazol MeSH
• jaderné proteiny MeSH
• MDM2 protein, human MeSH Prohlížeč
• MDM4 protein, human MeSH Prohlížeč
• nádorový supresorový protein p53 MeSH
• proteiny buněčného cyklu MeSH
• protoonkogenní proteiny c-mdm2 MeSH
• protoonkogenní proteiny MeSH
• TP53 protein, human MeSH Prohlížeč

Flubendazole (FLU), an anthelmintic drug of benzimidazole type, is now considered a promising anti-cancer agent due to its tubulin binding ability and low system toxicity. The present study was aimed at determining more information about FLU reduction in human liver, because this information has been insufficient until now. Subcellular fractions from the liver of 12 human patients (6 male and 6 female patients) were used to study the stereospecificity, cellular localization, coenzyme preference, enzyme kinetics, and possible inter-individual or sex differences in FLU reduction. In addition, the risk of FLU interaction with other drugs was evaluated. Our study showed that FLU is predominantly reduced in cytosol, and the reduced nicotinamide adenine dinucleotide phosphate (NADPH) coenzyme is preferred. The strict stereospecificity of FLU carbonyl reduction was proven, and carbonyl reductase 1 was identified as the main enzyme of FLU reduction in the human liver. A higher reduction of FLU and a higher level of carbonyl reductase 1 protein were found in male patients than in female patients, but overall inter-individual variability was relatively low. Hepatic intrinsic clearance of FLU is very low, and FLU had no effect on doxorubicin carbonyl reduction in the liver and in cancer cells. All these results fill the gaps in the knowledge of FLU metabolism in human.

• Klíčová slova
• carbonyl reduction, enzyme kinetics, flubendazole, human, sex difference, stereospecificity,
• Publikační typ
• časopisecké články MeSH