Describe the Mode of Action and Development of Nutlins
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Transcript of Describe the Mode of Action and Development of Nutlins
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8/12/2019 Describe the Mode of Action and Development of Nutlins
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Prevents damaged cells fromproliferating
Promotes senescence
Triggers programmed cell death
Three amino acids, Phe19, trp23and Leu26 fit tightly in theMDM2 binding pocket
P53 Tumoursuppressor
E3 ubiquitin ligase to degrade p53Inactivates trancription by binding to
and blocking the TAD in P53Has a deep p53 binding pocket
MDM2
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Mdm2 acts as an antagonist of p53 p53 transcriptionally activates MDM2 which causes its degradation Creates a negative feedback loop Degrades p53 by adding a ubiquitin to the lysine on the C-terminus
Disruption of the p53-MDM2 interaction by different can lead to theactivation of p53 and tumor growth inhibition
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Cis-imidazoline analogs
Nutlin-1, Nutlin-2 and Nutlin-3
Discovered by screening a chemical library byVassilev et al. 2004 Roche pharmaceuticals,
Nutley N.J
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Binds to p53 binding pocket of mdm2
Inhibit the interaction between mdm2 and p53
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Screening
Screened a diverse library of syntheticchemicals
Several lead structures were identified andoptimized for potency and selectivity
Investigationon binding
Tested all 3 Nutlins enantiomers for percentagebinding of mdm2-p53
Nutlin 3a was the most potent
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Mode ofbinding
Determined the crystal structure of thehuman MDM2Nutlin-2 complex
Binds to the p53 binding site onMDM2
The inhibitor mimics the interactions
of the p53 Replaces the helical structure of the
p53 peptide
Ethoxy Phe19, BromophephenylTrp23, Other Leu26
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1. Nutlins are able to dislodge p53 from binding with MDM2
2. Works in a transcription dependent way
Ideal Resultof Inhibition
Stabilization of the p53 protein
Activation of MDM2 expressionActivation of the p53 pathway
Cell cycle arrest at G1 and G2 or apoptosis
Cell cyclesarrest and
apoptosis
Used human cancer cells, RKO Examine levels of p53 and mdm2
Dose dependent increase
Showed accumulation of p53 and mdm2 consistent withactivation of p53 pathway
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Effect on growth andviablity of cancer cells
Used a MTT assay
Determined that Nutlins workonly for cancer which hadwild type p53
1C 50 value was lesser thatmutants
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Activation of the transcription-independentpathway initiates p53-mediated apoptosis inCLL
Nutlin-3a and fludarabine increased p53levels
Induced apoptosis in wild-type p53 cells butnot in cells with mutant p53
Fludarabine uses both mechanisms to induceapoptosis
Specific mechanisms remain unknown
2006,Transcriptionindependent
anddependent
pathways inCLL cells
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Nutlin causes monoubiquitinatedcytoplasmic p53 accumulation and
translocation to mitochondria MDM2 still retains its E3 ligase activity
Nutlin-induced mitochondrial p53translocation is rapid
Without transcription arm in p53 geneeffect of Nutlins greatly increased
2009,
Mitochondrialp53 Nutlin-induced
apoptosis in
acute(RKO)
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Effects of Velcade increased by Nutlin-3
Investigate the role of mitochondrial function inp53 induced apoptosis
P53 co-localised with a mitochondrial marker
P53 protein elevated in cells with Nutlins
Not sufficient to promote apoptotic response toNutlin
Nutlin could utilize both of p53's pathways topromote apoptosis
2010,Nutlins
and other
chemicals
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8 years have passed since the initial discoveryof Nutlins
Drug design is a very time consuming process
Potential non-genotoxic drug to treat blood andcolon
Still, further studies are still needed to ensureits true therapeutic potential
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Andreeff, M., et al., 2006. Mdm2 inhibitor Nutlin-3a induces p53-mediated apoptosis by transcription dependent and transcription-independent mechanisms and may overcome Atm-mediatedresistance to fludarabine in chronic lymphocytic leukemia. Blood,108, p993-1000.
Chang, H., et al., 2010. MDM2 antagonist nutlin plus proteasomeinhibitor velcade combination displays a synergistic anti-myelomaactivity. Cancer Biology and Therapy, 47, p936-44.
Iwakuma, I. and Lozano, G., 2003. MDM2, An Inroduction.Moelcular Cancer Reserch, 1(14), p993-1000.
Moll, U.M., et al., 2010. The transcription- Independentmitochondrial p53 program is a major contributor to nutlin-induced apoptosis in tumor cells. Cell Cycle, 8, p1711-9.
Moll, U.M. and Petrenko, O., 2003. The MDM2-p53 interaction.
Molecular Cancer Research, 1(14), p1001-1008. Vassilev, L.T., et al., 2004. In vivo activation of the p53 pathway bysmall-molecule antagonists of MDM2. Science, 303, p844-8.
Zhang, C. and Lu, H., 2010. Nutlinstwo roads towards apoptosis.Cancer Biology and Therapy, 10(6), p579-581.