Abstract 542: A disintergrin and metalloprotease (ADAM) 15 promotes non-small cell lung cancer (NSCLC) proliferation through cytosolic domain, not extra-cytosolic metalloprotease activity

Abstract

Abstract Emerging evidence indicates that proteins of a disintergrin and metalloprotease (ADAM) family contribute to cancer progression and metastasis. ADAM15 is up-regulated in multiple cancers and the enzymatic activities of its extracellular metalloprotrease domain promote cancer proliferation and migration by mediating the ErbB signaling pathway. In lung cancer, the enzymatic activity of ADAM15 extracellular domain is reported to be independent of ErbB signaling, indicating an alternative mechanism in promoting lung cancer progression. However, the role of ADAM15 in non-small cell lung cancer (NSCLC) and its correlation to patient prognosis is not well understood. This study demonstrated the longest ADAM15 isoforms, isoform 6 (i6), which contained the most cytoplasmic Src homology 3 (SH3) binding motifs, was significantly up-regulated in progressive NSCLC cell. Comparison of i6 and isoform 1 (i1) revealed that the cytoplasmic domain was essential for NSCLC cell proliferation and aggressiveness. ADAM15 i6, but not i1, mediated the activation the activation of the Src homolog 2 domain containing (Shc) through physical interaction with growth factor receptor-bound protein 2 (Grb2). ADAM15 i6 overexpression promoted NSCLC cell growth in a xenograft mouse model, while ADAM15 or Grb2 knockdown resulted in tumor shrinkage. ADAM15 was overexpressed in primary NSCLC tissues compared to adjacent normal tissues. Patients with ADAM15 i6 high-expressing lung tumors had shorter survival times. Thus, a novel mechanism of the ADAM15 cytoplasmic domain is identified in NSCLC tumor progression. This may help shed light on the molecular mechanisms of ADAM proteins and facilitate development of novel therapy for NSCLC. Citation Format: Hsin-Han Hou. A disintergrin and metalloprotease (ADAM) 15 promotes non-small cell lung cancer (NSCLC) proliferation through cytosolic domain, not extra-cytosolic metalloprotease activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 542.