Optimization of peptides that target human thymidylate synthase to inhibit ovarian cancer cell growth.
Thymidylate synthase (TS) is a target for pemetrexed and the prodrug 5-fluorouracil (5-FU) that inhibit the protein by binding at its active site. Prolonged administration of these drugs causes TS overexpression, leading to drug resistance. The peptide lead, LR (LSCQLYQR), allosterically stabilizes the inactive form of the protein and inhibits ovarian cancer (OC) cell growth with stable TS and decreased dihydrofolate reductase (DHFR) expression. To improve TS inhibition and the anticancer effect, we have developed 35 peptides by modifying the lead. The d-glutamine-modified peptide displayed the best inhibition of cisplatin-sensitive and -resistant OC cell growth, was more active than LR and 5-FU, and showed a TS/DHFR expression pattern similar to LR. Circular dichroism spectroscopy and molecular dynamics studies provided a molecular-level rationale for the differences in structural preferences and the enzyme inhibitory activities. By combining target inhibition studies and the modulation pattern of associated proteins, this work avenues a concept to develop more specific inhibitors of OC cell growth and drug leads.
Department of Chemical and Pharmaceutical Sciences, University of Ferrara , via Fossato di Mortara 17-19, 44100 Ferrara, Italy.
Michela
M
Pelà
Puneet
P
Saxena
Rosaria
R
Luciani
Matteo
M
Santucci
Stefania
S
Ferrari
Gaetano
G
Marverti
Chiara
C
Marraccini
Andrea
A
Martello
Silvia
S
Pirondi
Filippo
F
Genovese
Severo
S
Salvadori
Domenico
D
D'Arca
Glauco
G
Ponterini
Maria Paola
MP
Costi
Remo
R
Guerrini
D002455:Cell Division / Q000187:drug effects*; D045744:Cell Line, Tumor; D002942:Circular Dichroism; D003461:Crystallography; D005260:Female; D006801:Humans; D056004:Molecular Dynamics Simulation; D010051:Ovarian Neoplasms / Q000473:pathology*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D013940:Thymidylate Synthase / Q000037:antagonists & inhibitors*
D010455:Peptides; D013940:Thymidylate Synthase