Highly immunogenic cancer cells require activation of the WNT pathway for immunological escape.

Abstract

PD-1 blockade exerts antitumor effects by reinvigorating tumor antigen–specific CD8+ T cells. Whereas neoantigens arising from gene alterations in cancer cells comprise critical tumor antigens in antitumor immunity, a subset of non–small cell lung cancers (NSCLCs) harboring substantial tumor mutation burden (TMB) lack CD8+ T cells in the tumor microenvironment (TME), which results in resistance to PD-1 blockade therapy. To overcome this resistance, clarifying the mechanism(s) impairing antitumor immunity in highly mutated NSCLCs is an urgent issue. Here, we showed that activation of the WNT/β-catenin signaling pathway contributed to the development of a noninflamed TME in tumors with high TMB. NSCLCs that lacked immune cell infiltration into the TME despite high TMB preferentially up-regulated the WNT/β-catenin pathway. Immunologic assays revealed that those patients harbored neoantigen-specific CD8+ T cells in the peripheral blood but not in the TME, suggesting impaired T cell infiltration into the TME due to the activation of WNT/β-catenin signaling. In our animal models, the accumulation of gene mutations in cancer cells increased CD8+ T cell infiltration into the TME, thus slowing tumor growth. However, further accumulation of gene mutations blunted antitumor immunity by excluding CD8+ T cells from tumors in a WNT/β-catenin signaling-dependent manner. Combined treatment with PD-1 blockade and WNT/β-catenin signaling inhibitors induced better antitumor immunity than either treatment alone. Thus, we propose a mechanism-oriented combination therapy whereby immune checkpoint inhibitors can be combined with drugs that target cell-intrinsic oncogenic signaling pathways involved in tumor immune escape.

• Authors: Yoshiko Takeuchi, Tokiyoshi Tanegashima, Eiichi Sato, Takuma Irie, Atsuo Sai, Kota Itahashi, Shogo Kumagai, Yasuko Tada, Yosuke Togashi, Shohei Koyama, Esra A Akbay, Takahiro Karasaki, Keisuke Kataoka, Soichiro Funaki, Yasushi Shintani, Izumi Nagatomo, Hiroshi Kida, Genichiro Ishii, Tomohiro Miyoshi, Keiju Aokage, Kazuhiro Kakimi, Seishi Ogawa, Meinoshin Okumura, Masatoshi Eto, Atsushi Kumanogoh, Masahiro Tsuboi, Hiroyoshi Nishikawa
• Journal: Science immunology (Sci Immunol) Vol. 6 Issue 65 Pg. eabc6424 (Nov 12 2021) ISSN: 2470-9468 [Electronic] United States
• PMID: 34767457 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Animals
• CD8-Positive T-Lymphocytes (immunology)
• Carcinoma, Non-Small-Cell Lung (genetics, immunology, pathology)
• Female
• Humans
• Lung Neoplasms (genetics, immunology, pathology)
• Mice
• Mice, Inbred BALB C
• Mice, Nude
• Tumor Escape (immunology)
• Tumor Microenvironment (immunology)
• Wnt Signaling Pathway (immunology)