Recombinant prostate-specific antigen proaerolysin shows selective protease sensitivity and cell cytotoxicity.
Native proaerolysin is a channel-forming bacterial protoxin that binds to cell-surface receptors and then is activated by furin or furin-like proteases. We genetically engineered proaerolysin by replacing the furin-cleavage sequence with a prostate-specific antigen-selective sequence. The recombinant modified proaerolysin was expressed and purified from Aeromonas salmonicida in good yields and purity. Recombinant modified proaerolysin had no furin sensitivity and markedly increased prostate-specific antigen sensitivity relative to wild-type proaerolysin. Human prostate cancer cells were significantly more sensitive to recombinant modified proaerolysin in the presence of active prostate-specific antigen when compared with the absence of prostate-specific antigen or the presence of potent prostate-specific antigen inhibitors. Most normal human cells with the exception of prostate and renal epithelial cells showed very low sensitivity to recombinant modified proaerolysin. Our results suggest that recombinant modified proaerolysin is a potent prostate-specific antigen-sensitive protoxin that deserves further development for regional therapy of benign and malignant prostate growths.
Singh
Ravibhushan
R
Cancer Research Institute, Scott & White Memorial Hospital, 5701 South Airport Road, Temple, TX 76502, USA.
Browning
Jeff L
JL
Abi-Habib
Ralph
R
Wong
Kevin
K
Williams
Simon A
SA
Merchant
Rosemina
R
Denmeade
Samuel R
SR
Buckley
Thomas J
TJ
Frankel
Arthur E
AE
D048409:Aeromonas salmonicida / Q000737:chemistry; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D016503:Drug Delivery Systems; D004354:Drug Screening Assays, Antitumor; D004591:Electrophoresis, Polyacrylamide Gel; D005818:Genetic Engineering; D006801:Humans; D008297:Male; D010447:Peptide Hydrolases / Q000378:metabolism; D052899:Pore Forming Cytotoxic Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D011355:Prodrugs; D017430:Prostate-Specific Antigen / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000188:drug therapy*
D000970:Antineoplastic Agents; D001427:Bacterial Toxins; C518473:PRX302; D052899:Pore Forming Cytotoxic Proteins; D011355:Prodrugs; D010447:Peptide Hydrolases; D017430:Prostate-Specific Antigen