Study On The Function Of Periostin In The Development Of Pancreatic Cancer By UTMD Technique

Objective Periostin expression is 42-fold higher in pancreatic cancer compared with the normal pancreas at the m RNA level.However,the specific mechanism of Periostin in the development of pancreatic cancer is lack of systematic research to date.To further elucidate the role of Periostin in the development and treatment of pancreatic cancer,the purpose of the present study focuses on the following:(1)The function research of Periostin in pancreatic cancer progression.(2)The role of Periostin in the angiogenesis of pancreatic cancer.(3)The study on the relationship between Periostin and chemotherapeutic sensitivity of pancreatic cancer.Methods qRT-PCR and Western blot were used to test Periostin expression in pancreatic cancer cells,pancreatic ductal epithelial cells,pancreatic stromal cells,pancreatic cancer tissues and their adjacent paracancerous tissues.The expression of Periostin in pancreatic cancer was also analyzed by tissue microarray and its relationship with clinicopathological features and prognosis.The Lentiviral vectors(Periostin-sh RNA1,Periostin-sh RNA2,Periostin-Control sh RNA)were separately transfected into pancreatic stellate cells(PSCs)by ultrasound targeted microbubble destruction(UTMD)to silence Periostin gene and human recombinant Periostin protein(r Periostin)was used to improve Periostin expression in pancreatic cancer cells.Pancreatic cancer cells were co-cultured with PSCs supernatant transfected with different lentiviral vectors or r Periostin.The effects of Periostin on proliferation,migration,invasion,clone formation and endothelial cell tube formation ability of pancreatic cancer cells were examined by CCK-8,cell migration assay,invasion assay,wound healing assay,clone formation assay and tube formation assay.The nude mice experiment was used to determine the tumorigenesis,peritoneal metastasis ability of nude mice as well as the sensitivity to gemcitabine when silenced Periostin gene.The effect of Periostin on blood flow signal of nude mice was detected by ultrasound imaging before nude mice were sacrificed.Western blot was used to detect the role of Periostin on EGFR-Akt,EGER-Erk-c-Myc and Erk-VEGF signaling pathways in order to study the potential molecular mechanism of Periostin in pancreatic cancer progression and its resistance to chemotherapy.Results Periostin is exclusively expressed in PSCs and pancreatic stroma tissues,and is not expressed in pancreatic cancer epithelial cells and pancreatic cancer parenchyma.In addition,we used UTMD technology to improve the efficiency of lentiviral transfection of PSCs,which has a wide range of application prospects and may provide some guiding significance for gene therapy of clinical pancreatic cancer.The results of vitro and vivo experiments confirmed that Periostin could promote the proliferation,migration,invasion,clone and tube formation of pancreatic cancer cells,and silencing Periostin could inhibit the tumorigenesis of nude mice and significantly slow down the growth rate and reduced the tumor size as well as blood flow signal.Besides,silencing Periostin could enhance the lethality of gemcitabine on pancreatic cancer cells.In the mechanism study,we clarified that Periostin regulates the survival,metastasis and gene expression of pancreatic cancer cells by activating EGFR-Akt and EGFR-Erk-c-Myc signaling pathway,and promotes the angiogenesis of pancreatic cancer through Erk/VEGF signaling pathway,and regulates the gemcitabine resistance by modulating Akt and Erk signaling pathways.Conclusions Periostin was highly expressed in the stroma of pancreatic cancer and correlated with lymph node metastasis(p <0.01)and p TNM staging(p <0.05).The higher Periostin expression,the later stage.Periostin plays a key role in the angiogenesis of pancreatic cancer and mediates the resistance to gemcitabine,which is an independent prognostic factor for pancreatic cancer.Therefore,Periostin may become a new target for pancreatic cancer treatment.