The RNA-binding Protein SRSF9 Regulates Target Gene DSN1 To Mediate The Development Of Colorectal Cancer

Colorectal cancer is the third most prevalent malignancy and the second most deadly malignancy worldwide.Surgical resection and radiotherapy and chemotherapy are the main methods of colorectal cancer treatment at this stage,but they have limited impact on the cure rate and long-term survival rate.Therefore,it is of great theoretical value to explore the development of colorectal carcinogenesis from multiple perspectives and to find new biological targets to enhance patient survival.RNA binding proteins(RBPs)are a class of proteins widely involved in intracellular RNA stabilization,transport,maturation and degradation and can bind directly to RNA to form RNA-binding protein macromolecular complexes.The serine/arginine-rich proteins(SRPs)are a family of RBPs that regulate variable RNA shear and have been shown to play a pro-oncogenic role in a variety of tumors and are widely involved in post-transcriptional regulation.The role of SRSF9 and m6A modifications in colorectal cancer is not yet clear,and little is known about whether SRSF9 is involved in colorectal carcinogenesis with m6A RBP.Therefore,this project used bioinformatics analysis combined with plate cloning,Transwell Subsequently,we constructed stable overexpression and silencing of SRSF9 colorectal cancer cell line,and demonstrated that SRSF9 promoted the proliferation and invasion of colorectal cancer cells through CCK8,plate cloning,Transwell,scratch healing,three dimensional cell culture and other in vitro functional assays.In vivo tumorigenic assay in nude mice confirmed that SRSF9 enhanced the tumorigenic ability of colorectal cancer cells.Mechanistically,we first confirmed that SRSF9 is a novel m6A RNA binding protein using methylated single-stranded RNA affinity assay and protein silver staining assay;we confirmed that the target gene of SRSF9 protein binding is DSN1(Component Of MIS 12)by m6A-related bioinformatics analysis combined with Western blot.Then,IHC,Western blot and RT-PCR were used to further confirm the correlation between SRSF9 and DSN 1 expression in:colorectal cancer tissues.Finally,RNA stability assay was used to-confirm that SRSF9 significantly enhanced DSN1 m RNA stability;bioconductivity analysis combined with dual luciferase reporter assay further clarified the binding sequence and m6A modification site of SRSF9 protein to DSN1 mRNA,and confirmed that SRSF9 binds target gene DSN1 in an m6A-dependent mannerIn summary,SRSF9 is upregulated in colorectal cancer;SRSF9 promotes proliferation,invasion and migration of colorectal cancer cells and facilitates colorectal cancer cell-cycle progression;SRSF9 is an m6A RNA binding protein and binds the target gene DSN1 in an m6A-dependent manner to ultimately mediate colorectal carcinogenesis.This study demonstrates that SRSF9 as an oncogene and m6A RBP may be a new target for colorectal cancer diagnosis and treatment.