Olfactory Receptor OR2H1 Is an Effective Target for CAR T Cells in Human Epithelial Tumors

Area of Science:

• Oncology
• Immunotherapy
• Molecular Biology

Background:

• Chimeric antigen receptor (CAR)-T cell therapy is effective in hematologic cancers but limited in solid tumors.
• Olfactory receptors (ORs) are found in some solid tumors with restricted normal tissue expression.
• OR2H1 is identified as a potential target in epithelial cancers.

Purpose of the Study:

• To investigate OR2H1 expression in solid tumors and normal tissues.
• To develop and evaluate OR2H1-targeted CAR T-cells for cancer therapy.
• To assess the specificity and efficacy of OR2H1-targeted CAR T-cells.

Main Methods:

• Quantitative real-time PCR (qRT-PCR) and Western blot to assess OR2H1 expression.
• Generation of CAR T-cells targeting the extracellular domain of OR2H1.
• In vitro and in vivo cytotoxic assays using OR2H1-expressing tumor cells.
• CRISPR/Cas9-mediated gene ablation to confirm targeting specificity.
• Immunohistochemistry using recombinant OR2H1 IgG to detect protein expression in patient samples.

Main Results:

• OR2H1 is widely expressed in ovarian, non-small cell lung, and breast cancers, with minimal expression in normal tissues (primarily testis).
• Generated CAR T-cells demonstrated specific cytotoxic activity against OR2H1-expressing tumor cells in vitro and in vivo.
• Recombinant OR2H1 IgG confirmed widespread OR2H1 protein expression in lung, ovarian, and cholangiocarcinoma patient samples, with no significant staining in normal tissues.
• OR2H1 ablation confirmed CAR specificity and highlighted OR2H1's role in tumor glucose metabolism.

Conclusions:

• T-cells redirected against OR2H1 represent a potential therapeutic strategy for various epithelial cancers.
• This approach may offer an acceptable toxicity profile due to the limited expression of OR2H1 in normal tissues.
• OR2H1-targeted immunotherapy holds promise for overcoming challenges in solid tumor treatment.