SRGN Promotes Colorectal Cancer Metastasis as a Critical Downstream Target of HIF-1α

Background/Aims: The chondroitin sulfate proteoglycan serglycin (SRGN), a hematopoietic cell granule proteoglycan, has been implicated in promoting tumor metastasis; however, the underlying mechanisms remain to be elucidated. The present study aimed to investigate the SRGN gene expression and its regulation as downstream signaling of hypoxia-inducible transcription factor 1 alpha (HIF-1α) in colorectal cancer (CRC) cells and tissues. Methods: The expression of SRGN was analyzed in CRC specimens for its correlation with progression and metastasis. Using chromatin-immunoprecipitation (ChIP), quantitative real-time PCR, Western blot, and transwell assay, the functional role and underlying mechanism of SRGN in CRC metastasis were elucidated. Thus, this study provides evidence of a critical role of SRGN in metastatic progression of CRC. Results: Our results indicated that SRGN overexpression was significantly associated with poor prognosis in CRC specimens. SRGN overexpression promoted CRC cell migration and invasion in vitro; however, SRGN depletion exhibited contrasting effects. Mechanistic investigations revealed that HIF-1α regulated SRGN transcription via physically binding to a hypoxia response element in its promoter region. Conclusions: In conclusion, we demonstrated that dysregulated HIF-1α/SRGN signaling promotes CRC progression and metastasis. SRGN may serve as a potential candidate therapeutic target for metastatic CRC.