Studies On Mechanism Of Pancreatic Stellate Cells Involved In Pancreatic Intraepithelial Neoplasm(PanINs)Progression

Background:Pancreatic cancer is one of the most lethal malignancies that human being could ever have.Early diagnosis,disease prevention and treatment at its early stage is critical to the prognosis of the patients,thus,studies on precancerous lesions and"inflammation-cancer" transition are regarded as hope for future direction.Desmoplasia,as one of the most important components of the microenvironment in pancreatic cancer,plays a role in inducing immunological evasion and resistance of chemo-and radiotherapy.However,the characteristics and significance in pancreatic precancerous lesions were largely unknown.Methods:We observed the desmoplasia and activation of pancreatic stellate cells(PSCs)in human PanIN lesions with Masson trichrome staining and immunostaining for a-smooth muscle actin(a-SMA),respectively;Based on the semi-quantitative analysis on the pathological slides with different staining techniques with Image J software,correlationship between the desmoplasia and activation of PSCs with grading of PanIN lesions were analyzed;Cells counting,CCK-8 were carried out to evaluate the effect of co-culture with PSCs on the growth of HPNE cells,with or without KRAS gene mutation;EdU assay were carried out to assess the proliferation of HPNE cells with or without co-culture of activated PSCs;Flow cytometry was used to examine the regulation of HPNE cell cycle and apoptosis by PSCs;Expression profiling and analysis on differentially expressed genes with GSEA were carried out to explore the possible molecular mechanism in HPNE under co-culture with PSCs.Resutls:Evident desmoplasia and activation of PSCs could be observed in human PanINs,and were positively correlated with disease gradings;Cell counting and CCK-8 essay showed that both co-culture with PSCs or conditioned media of PSCs could promote the growth of HPNE-e6e7 and HPNE-Kr;EdU and flow cytometry revealed that the growth promotive effect were related to the increased proliferative rate in HPNE cells,as well as regulated cell cycle,but not in relationship with apoptotic status;Results from expression profiling showed that a significant change in gene expression was induced after co-culture with PSCs,and GO analysis on differentially expressed genes resulted in enrichments of various gene sets.Conclusions:Desmoplaisa and activation of PSCs could be observed in PanINs.Activated PSCs could promote the proliferative activity of HPNE cells.