SHCBP1 Promotes The Proliferation And Migration Of Gastric Cancer Cells By Regulating Cell Mitosis

Background: Gastric cancer is the second deadliest cancer in China,it is urgent to develop new therapies for gastric cancer to solve this major national health problems.SHCBP1(SHC SH2-bingding protein 1),plays an important role in the process of cell growth and differentiation.However,its specific role and mechanism in gastric tumorigenesis have not been reported.Objective: To explore the expression of SHCBP1 in human gastric cancer tissues,and reveal the biological function and mechanism of SHCBP1 in the proliferation,migration and invasion of gastric cancer cells,providing proves for the treatment of gastric cancer targeting SHCBP1.Methods: Oncogene SHCBP1 was screened out according to gene chip of cancer tissues from 16 gastric cancer patients and the clinical data of gastric cancer patients in TCGA database.Immunohistochemical staining was used to verify the expression of SHCBP1 in gastric cancer tissues.After the knocking out of SHCBP1 using CRISPR/Cas9,the proliferation,migration and invasion of gastric cancer cells were detected by MTT assays,clone formation assays,cell scratch assays,Transwell assays,and cells xenograft mice.In addition,cell immunofluorescence staining,immunoprecipitation and protein mass spectrometry were used to reveal the molecular mechanism of SHCBP1 regulating the growth of gastric cancer cells.Results: SHCBP1 was found to be highly expressed in gastric cancer tissue by analyzing the gene chip data of 16 sets of gastric cancer tissue and TCGA database.The immunohistochemical staining results of 180 cases of gastric cancer showed that SHCBP1 was not only highly expressed in the cancer tissues,but also negatively correlated with the prognosis of gastric cancer patients.Knockout of SHCBP1 using CRISPR/Cas9 significantly inhibited the proliferation,migration and invasion of gastric cancer cell lines in vitro,and also suppressed the cell tumorigenesis in vivo.Immunofluorescence staining revealed that SHCBP1 was localized at the cytoplasm in G0 phase,nucleus in G1/S phase,spindle in M phase,and the midbody in cytokinesis phase respectively.The results of immunoprecipitation and protein mass spectrometry identification showed that SHCBP1 interacts with MISP(mitotic spindle positioning).Protein truncation and co-immunoprecipitation assays showed that the 355-562 AA domain of SHCBP1 can interact with MISP to promote the phosphorylation of MISP for the cell division regulation.Conclusion: SHCBP1 is closely related to the occurrence and development of gastric cancer,and it regulates the mitosis by interacting with the mitotic regulator MISP to promote the phosphorylation of MISP for the cell division regulation.