The lncRNA SNHG9, an oncogenic regulator, stabilizes PRMT7 by binding to PTBP1 in the progression of colorectal cancer

Long noncoding RNAs (lncRNAs), widely regarded as nonprotein-coding transcripts longer than 200 nucleotides in length, play active roles in tumorigenesis, including in colorectal cancer (CRC). The abnormally elevated lncRNA small nucleolar RNA host gene 9 (SNHG9) in CRC samples was observed in The Cancer Genome Atlas (TCGA) database. However, the biological role and potential mechanism of SNHG9 in CRC development remain elusive. Herein, 49 paired CRC tissues and matched adjacent normal tissues were obtained to examine SNHG9 levels. Biological functions related to cell proliferation, migration and invasion were evaluated using CCK-8, colony formation, and Transwell assays and western blot analysis. RNA pull-down and RNA immunoprecipitation (RIP) assays were used to verify the SNHG9/PTBP1/PRMT7 regulatory axis. Interestingly, our data revealed that increasing levels of SNHG9 in CRC tissues and cells were positively correlated with poor prognosis and tumour metastasis, while depletion of SNHG9 caused the suppression of cell proliferation, migration, and invasion. Moreover, cytoplasmic SNHG9 enhanced the mRNA stability of PRMT7 by directly binding to PTBP1 through the “lncRNA‒RNA binding protein (RBP)” complex. The regulatory function of SNHG9 on PRMT7 was also validated via rescue functional assays. In summary, our data demonstrated that SNHG9 may play an oncogenic role in CRC tumorigenesis by stabilizing PRMT7 by recruiting PTBP1. This could be a prognostic biomarker and therapeutic target for CRC.