Identification of oxidized protein hydrolase as a potential prodrug target in prostate cancer.

Abstract

BACKGROUND:

Esterases are often overexpressed in cancer cells and can have chiral specificities different from that of the corresponding normal tissues. For this reason, ester prodrugs could be a promising approach in chemotherapy. In this study, we focused on the identification and characterization of differentially expressed esterases between non-tumorigenic and tumorigenic prostate epithelial cells.

METHODS:

Cellular lysates from LNCaP, DU 145, and PC3 prostate cancer cell lines, tumorigenic RWPE-2 prostate epithelial cells, and non-tumorigenic RWPE-1 prostate epithelial cells were separated by native polyacrylamide gel electrophoresis (n-PAGE) and the esterase activity bands visualized using α-naphthyl acetate or α-naphthyl-N-acetylalaninate (ANAA) chiral esters and Fast Blue RR salt. The esterases were identified using nanospray LC/MS-MS tandem mass spectrometry and confirmed by Western blotting, native electroblotting, inhibition assays, and activity towards a known specific substrate. The serine protease/esterase oxidized protein hydrolase (OPH) was overexpressed in COS-7 cells to verify our results.

RESULTS:

The major esterase observed with the ANAA substrates within the n-PAGE activity bands was identified as OPH. OPH (EC 3.4.19.1) is a serine protease/esterase and a member of the prolyl oligopeptidase family. We found that LNCaP lysates contained approximately 40% more OPH compared to RWPE-1 lysates. RWPE-2, DU145 and PC3 cell lysates had similar levels of OPH activity. OPH within all of the cell lysates tested had a chiral preference for the S-isomer of ANAA. LNCaP cells were stained more intensely with ANAA substrates than RWPE-1 cells and COS-7 cells overexpressing OPH were found to have a higher activity towards the ANAA and AcApNA than parent COS-7 cells.

CONCLUSIONS:

These data suggest that prodrug derivatives of ANAA and AcApNA could have potential as chemotherapeutic agents for the treatment of prostate cancer tumors that overexpress OPH.

• Authors: Christopher A McGoldrick, Yu-Lin Jiang, Victor Paromov, Marianne Brannon, Koyamangalath Krishnan, William L Stone
• Journal: BMC cancer (BMC Cancer) Vol. 14 Pg. 77 (Feb 10 2014) ISSN: 1471-2407 [Electronic] England
• PMID: 24512522 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents
• Enzyme Inhibitors
• Prodrugs
• Hydrolases
• Esterases

Topics

• Animals
• Antineoplastic Agents (administration & dosage)
• COS Cells
• Cell Line, Tumor
• Chlorocebus aethiops
• Enzyme Inhibitors (administration & dosage)
• Esterases (antagonists & inhibitors, metabolism)
• Humans
• Hydrolases (antagonists & inhibitors, metabolism)
• Male
• Oxidation-Reduction (drug effects)
• Prodrugs (administration & dosage)
• Prostatic Neoplasms (drug therapy, enzymology)
• Rats
• Swine