A Novel Cell-Penetrating Antibody Fragment Inhibits the DNA Repair Protein RAD51.
Sci Rep
; 9(1): 11227, 2019 08 02.
Article
em En
| MEDLINE
| ID: mdl-31375703
ABSTRACT
DNA damaging chemotherapies are successful in cancer therapy, however, the damage can be reversed by DNA repair mechanisms that may be up-regulated in cancer cells. We hypothesized that inhibiting RAD51, a protein involved in homologous recombination DNA repair, would block DNA repair and restore the effectiveness of DNA damaging chemotherapy. We used phage-display to generate a novel synthetic antibody fragment that bound human RAD51 with high affinity (KD = 8.1 nM) and inhibited RAD51 ssDNA binding in vitro. As RAD51 is an intracellular target, we created a corresponding intrabody fragment that caused a strong growth inhibitory phenotype on human cells in culture. We then used a novel cell-penetrating peptide "iPTD" fusion to generate a therapeutically relevant antibody fragment that effectively entered living cells and enhanced the cell-killing effect of a DNA alkylating agent. The iPTD may be similarly useful as a cell-penetrating peptide for other antibody fragments and open the door to numerous intracellular targets previously off-limits in living cells.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fragmentos de Imunoglobulinas
/
Antineoplásicos Alquilantes
/
Reparo do DNA
/
Rad51 Recombinase
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article