CPNE3 Positive Feedback YAP1 Pathway Promotes Chemotherapy Resistance In Gastric Cancer

Objective:Chemotherapy resistance is an important factor contributing to the poor prognosis of gastric cancer patients,and YAP1 plays an important role in the development of gastric cancer by regulating the expression of its downstream genes,which are widely involved in regulating various cancer-promoting processes including chemotherapy resistance,however,its mechanism has not been fully elucidated.It has been shown that CPNE3 is closely related in the development of various cancers,and its function and mechanism in gastric cancer have not been reported in the literature so far.The aim of this study was to screen potential new target genes downstream of YAP1 and to investigate the biological functions of CPNE3 in gastric cancer through in vivo and in vitro experiments.Methods:1.Screening of potential downstream target genes of YAP1 by m RNA sequencing.2.The regulatory effect of YAP1 on the transcriptional activity of CPNE3 was examined by RT-q PCR,Western Blotting and luciferase reporter gene assay.3.Investigation of the effect of CPNE3 on malignant biological behavior and chemoresistance of gastric cancer cells by CCK-8,transwell and colony formation assay.4.To construct BGC-823 cell line with stable knockdown of CPNE3 by GRISPCas9,and further investigate the effect of knockdown of CPNE3 on gastric cancer tumor growth in vivo by cell line xenograft model(CDX).Results:1.Dual luciferase reporter assay showed that YAP1 and TEAD1-4 can synergistically activate CPNE3 promoter activity.2.Real-time quantitative PCR and immunoblotting assays showed that down-regulation of YAP1 inhibited CPNE3 m RNA and protein expression,while overexpression of YAP1 did the opposite.3.Immunoblotting assays showed that knockdown of CPNE3 inhibited the YAP1 pathway,while overexpression of CPNE3 did the opposite.4.The results of cell function assay showed that CPNE3 could promote invasive migration and chemoresistance of gastric cancer cells.5.Knockdown of CPNE3 significantly inhibited tumor growth in vivo.Conclusion:CPNE3 is a downstream target gene of YAP1,which can further positively regulate the YAP1 pathway after YAP1 induction and activation,and then participate in regulating gastric cancer cell proliferation,invasion migration and chemotherapy resistance.CPNE3 could be a new target for gastric cancer treatment.