Abstract

CRYL1 is a novel tumor suppressor in clear cell renal cell carcinoma (ccRCC), with low expression predicting poor patient prognosis. • CRYL1 inhibits ccRCC progression by suppressing proliferation, colony formation, and migration, while inducing apoptosis. • CASR is identified as a key downstream mediator of CRYL1′s tumor-suppressive function. • CRYL1 exerts its anti-migratory effects at least in part by transcriptionally upregulating CASR. • The CRYL1/CASR axis represents a promising novel therapeutic target for advanced ccRCC. Background Identifying novel biomarkers and elucidating the underlying molecular mechanisms are crucial for improving the diagnosis and treatment of advanced clear cell renal cell carcinoma (ccRCC). In our previous investigations, crystallin lambda 1 (CRYL1) was preliminarily identified as an emerging tumor suppressor. The present study expands upon this observation by further exploring its tumor-suppressive role and the underlying molecular mechanisms. Methods Seventy patients with ccRCC were selected to validate CRYL1 expression and its clinical significance. In vitro proliferation, migration, and apoptosis assays were performed to assess the effects of CRYL1 overexpression. Transcriptome sequencing combined with bioinformatics analysis identified the calcium-sensing receptor (CASR) as a key downstream target of CRYL1 . In vitro functional assays of CASR and further bioinformatics analyses were subsequently conducted. Rescue experiments in vitro and immunohistochemistry (IHC) of tissues validated their regulatory relationship. Subcutaneous xenograft mouse models were used for in vivo validation. Results Low CRYL1 expression was significantly associated with advanced clinical stage (p = 0.012), poorer disease-free survival (DFS, p = 0.031), and poorer overall survival (OS, p = 0.049). CRYL1 overexpression potently suppressed proliferation, colony formation, and migration and induced apoptosis in Caki-1 and OSRC-2 cell lines. In