Inhibition of Radiation-Induced Salivary Gland Fibrosis by Targeting Copper Metabolism

NIH RePORTER · DE · R01 · $597,722 · view on reporter.nih.gov ↗

Abstract

ABSTRACT A first-line treatment for head and neck cancer is radiation therapy, but ionizing radiation can lead to chronic oral complications such as fibrosis of the salivary glands (SG) and xerostomia. Therapeutic strategies to restore SG function include gene therapy, stem cell transplantation and various bioengineering approaches; however, they are dependent on the presence of residual functional SG tissue, a condition not met with full radiation treatment due to extensive fibrotic coverage of the SG. Although a role for Lysyl Oxidase (LOX) in radiation-induced fibrosis has not been investigated in SG, it is notable that each LOX family member has been implicated in various fibrotic disorders affecting a wide range of organs. This has prompted efforts to develop monoclonal antibodies targeting specific LOX enzymes; however, recent Phase II clinical trials of a monoclonal antibody against Lysyl Oxidase-Like (LOXL2) failed to show efficacy against primary sclerosing cholangitis. These findings underscore the importance of considering functional redundancy when targeting individual LOX and since the catalytic site of all LOX family members possesses a conserved binding site for copper (Cu), focusing on inhibition of Cu delivery to these enzymes is a novel antifibrotic strategy. Preliminary studies have identified a novel compound, MKV3, as a potent inhibitor of the ATP7A copper transporter. Furthermore, ATP7A trafficking to the plasma membrane enhances LOX activity in cancer cells which is blocked by MKV3. Ionizing radiation was found to stimulate Cu-dependent ATP7A trafficking in rat parotid Par-C10 cells and that copper modulators, such as tetrathiomolybdate (TTM) and MKV3, block this process. To extend these findings to in vivo studies, preliminary results indicate that radiation treatment not only triggers Cu-dependent ATP7A trafficking in mouse submandibular glands (SMG) from the perinuclear region to the plasma membrane but also causes collagen deposition of ex

Key facts

NIH application ID
11310016
Project number
5R01DE034293-03
Recipient
UNIVERSITY OF MISSOURI-COLUMBIA
Principal Investigator
Olga Juliana Baker; MICHAEL J. PETRIS
Activity code
R01
Funding institute
DE
Fiscal year
2026
Award amount
$597,722
Award type
5
Project period
2024-08-01T00:00:00 → 2029-04-30T00:00:00