Ichidai Tanaka, Delphine Dayde, Mei Chee Tai, Haruki Mori, Luisa M Solis, Satyendra C Tripathi, Johannes F Fahrmann, Nese Unver, Gargy Parhy, Rekha Jain, Edwin R Parra, Yoshiko Murakami, Clemente Aguilar-Bonavides, Barbara Mino, Muge Celiktas, Dilsher Dhillon, Julian Phillip Casabar, Masahiro Nakatochi, Francesco Stingo, Veera Baladandayuthapani, Hong Wang, Hiroyuki Katayama, Jennifer B Dennison, Philip L Lorenzi, Kim-Anh Do, Junya Fujimoto, Carmen Behrens, Edwin J Ostrin, Jaime Rodriguez-Canales, Tetsunari Hase, Takayuki Fukui, Taisuke Kajino, Seiichi Kato, Yasushi Yatabe, Waki Hosoda, Koji Kawaguchi, Kohei Yokoi, Toyofumi F Chen-Yoshikawa, Yoshinori Hasegawa, Adi F Gazdar, Ignacio I Wistuba, Samir Hanash, Ayumu Taguchi
Journal of the National Cancer Institute 114(2) 290-301 2021年9月15日
BACKGROUND: About 20% of lung adenocarcinoma (LUAD) is negative for the lineage-specific oncogene Thyroid transcription factor 1 (TTF-1) and exhibits worse clinical outcome with a low frequency of actionable genomic alterations. To identify molecular features associated with TTF-1-negative LUAD, we compared the transcriptomic and proteomic profiles of LUAD cell lines. SRGN, a chondroitin sulfate proteoglycan Serglycin, was identified as a markedly overexpressed gene in TTF-1-negative LUAD. We therefore investigated the roles and regulation of SRGN in TTF-1-negative LUAD. METHODS: Proteomic and metabolomic analyses of 41 LUAD cell lines were done using mass spectrometry. The function of SRGN was investigated in 3 TTF-1-negative and 4 TTF-1-positive LUAD cell lines and in a syngeneic mouse model (n = 5 to 8 mice per group). Expression of SRGN in was evaluated in 94 and 105 surgically resected LUAD tumor specimens using immunohistochemistry. All statistical tests were two-sided. RESULTS: SRGN was markedly overexpressed at mRNA and protein levels in TTF-1-negative LUAD cell lines (P < .001 for both mRNA and protein levels). Expression of SRGN in LUAD tumor tissue was associated with poor outcome (hazard ratio = 4.22, 95% confidential interval = 1.12 to 15.86; likelihood ratio test, P = .03), and with higher expression of Programmed cell death 1 ligand 1 (PD-L1) in tumor cells and higher infiltration of Programmed cell death protein 1 (PD-1)-positive lymphocytes. SRGN regulated expression of PD-L1, as well as proinflammatory cytokines including Interleukin-6 (IL-6), Interleukin-8 (IL-8), and C-X-C motif chemokine 1 (CXCL1) in LUAD cell lines, and increased migratory and invasive properties of LUAD cells and fibroblasts, and enhanced angiogenesis. SRGN was induced by DNA de-methylation resulting from Nicotinamide N-methyltransferase (NNMT)-mediated impairment of methionine metabolism. CONCLUSION: Our findings suggest that SRGN plays a pivotal role in tumor-stromal interaction and reprogramming into an aggressive and immunosuppressive tumor microenvironment in TTF-1-negative LUAD.