Upper tract urothelial carcinoma (UTUC) is a rare tumor with an extraordinary variation between Eastern and Western countries. A disintegrin and metalloprotease-9 (ADAM9) is a metzincin cell surface protease involved in various tumorigenic processes. OIP5-AS1 has been identified as an oncogenic long non-coding RNA (lncRNA), while miR-30c-5p is known to regulate tumor suppressor functions in various cancers. This study aims to elucidate the molecular mechanisms by which OIP5-AS1 and miR-30c-5p regulate ADAM9 in UTUC.

ADAM9 expression was evaluated by immunohistochemistry in human UTUC tissues. In vitro study, we demonstrated the regulatory relationship between ADAM9, miR-30c-5p and OIP5-AS1 by real-time PCR, Western blot and dual luciferase reporter assay using UTUC cell lines. The role of OIP5-AS1/miR-30c-5p/ADAM9 signaling pathway in proliferation, motility and invasion was analyzed by functional assays. Proteomics and RNA sequencing have identified several genes that may be regulated by ADAM9. These genes were analyzed using Interpretive Phenomenological Analysis (IPA) to identify potential molecular pathways that may be regulated by ADAM9.

ADAM9 was significantly upregulated in UTUC compared to normal urothelial tissues. Elevated ADAM9 expression correlated significantly with advanced tumor stage. High expression level of ADAM9 in UTUC tissues confers poor survival. Silencing of ADAM9 and OIP5-AS1 or overexpression of miR-30c-5p inhibited proliferation, migration and invasion of UTUC cells. In addition, OIP5-AS1 functioned as a competitive endogenous RNA for miR-30c-5p, leading to the upregulation of ADAM9 expression in UTUC cells. Functional assays revealed that ADAM9 overexpression counteracted the effects of OIP5-AS1 and miR-30c-5p on tumor cell proliferation, migration and invasion.

These findings implicate the OIP5-AS1/miR-30c-5p/ADAM9 regulatory axis, which may be future therapeutic targets for UTUC.