Development and Nanoparticle-Mediated Delivery of Novel MDM2/MDM4 Heterodimer Peptide Inhibitors to Enhance
Francesco Merlino1, Annalisa Pecoraro1, Giuseppe Longobardi1
1Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131 Napoli, NA, Italy.
Abstract:
Colorectal cancer (CRC) often involves wild-type p53 inactivation by MDM2 and MDM4 overexpression, promoting tumor progression and resistance to 5-fluoruracil (5-FU). Disrupting the MDM2/4 heterodimer can proficiently reactivate p53, sensitizing cancer cells to 5-FU. Herein, we developed 16 peptides based on Pep3 (1), the only known peptide acting through this mechanism. The new peptides, notably 3 and 9, showed lower IC50 values than 1. When incorporated into tumor-targeted biodegradable nanoparticles, these exhibited cytotoxicity against three different CRC cell lines. Notably, NPs/9 caused a significant increase in p53 levels associated with a strong increment of its main downstream target p21 inducing apoptosis. Also, the combined treatment of 9 with 5-FU caused the activation of nucleolar stress and a synergic apoptotic effect. Hence, the co-delivery of MDM2/4 heterodimer disruptors with 5-FU through nanoparticles might be a promising strategy to overcome drug resistance in CRC.
Insights
New peptides targeting MDM2/4 disrupt cancer cell communication, reactivating p53 and enhancing chemotherapy effectiveness. Nanoparticle delivery of these peptides sensitizes colorectal cancer cells to 5-fluorouracil (5-FU).
Area of Science:
- Oncology
- Molecular Biology
- Drug Delivery
Background:
- Colorectal cancer (CRC) progression is linked to wild-type p53 inactivation by MDM2 and MDM4 overexpression.
- This inactivation promotes tumor growth and resistance to chemotherapy, such as 5-fluorouracil (5-FU).
- Targeting the MDM2/4 interaction offers a strategy to restore p53 function and overcome drug resistance.
Purpose of the Study:
- To develop novel peptides that disrupt the MDM2/4 heterodimer.
- To evaluate the efficacy of these peptides, alone and in nanoparticle formulations, against colorectal cancer cells.
- To investigate the potential of combined peptide and 5-FU therapy for overcoming CRC drug resistance.
Main Methods:
- Design and synthesis of 16 novel peptides based on the Pep3 scaffold.
- In vitro cytotoxicity assays (IC50 determination) of peptides and nanoparticle formulations against CRC cell lines.
- Analysis of p53 and p21 protein levels, nucleolar stress, and apoptosis induction.
- Combination studies with 5-FU to assess synergistic effects.
Main Results:
- Peptides 3 and 9 demonstrated improved efficacy compared to the parent peptide.
- Tumor-targeted nanoparticles loaded with peptide 9 (NPs/9) showed significant cytotoxicity against CRC cells.
- NPs/9 treatment led to increased p53 and p21 levels, inducing apoptosis.
- Combined treatment with peptide 9 and 5-FU resulted in nucleolar stress and synergistic apoptosis.
Conclusions:
- Disrupting the MDM2/4 heterodimer with novel peptides is a viable strategy for p53 reactivation in CRC.
- Tumor-targeted nanoparticles offer an effective delivery system for these therapeutic peptides.
- Co-delivery of MDM2/4 disruptors and 5-FU via nanoparticles presents a promising approach to combat 5-FU resistance in colorectal cancer.
