Galectin-1-induced Up-regulation Of CCL7 In PSCs Promotes Pancreatic Carcinoma Progression Via CCL7/CCR5 Axis

Background:As a highly lethal malignancy,pancreatic ductal adenocarcinoma(PDAC)is distinguished by a poor prognosis because of metastasis and resistance to chemoradiotherapy.Recent researches have found that,in the tumor microenvironment(TME),there are huge amount of stromal cells among which mainly are pancreatic stellate cells(PSCs).Tons of evidences have indicated that,PSCs may act a key role in the progression of PDAC.Our previous studies have found that Galectin-1,highly expressed by PSCs,could induce secretion of some chemokines by NF-κB pathway.However,how Galectin-1 modulates PSCs and subsequently-secreted chemokines impacts PDAC remain unknown.Objectives:Explore how Galectin-1 modulates secretion of CCL7 in PSCs and subsequently impacts PDAC progression by CCL7.Methods:Three primary isolated,identified PSCs were successfully cultured in our lab for Galectin-1 stimulation.We utilized chemokine antibody array assay to test chemokine secretion and screened out the chemokine with the most significant difference.To verify the above results,we implied lentivirus to knock down Galectin-1 and ELISA,qRT-PCR,Western Blot assay.Flow cytometry assay was conducted to determine the receptor of CCL7 in PDAC.CCK8,EdU,Transwell assays were utilized to investigate the CCL7-driven proliferation,migration and invasion of PDAC cells.CCL7 neutralizing antibody,Maraviroc(blockade of CCR5)and BAY 11-7082(blockade of NF-κB pathway)were employed to further certify the outcomes.Furthermore,recombinant CCL7 protein was used to explore its influence on Epithelial-Mesenchymal Transition cascade of PD AC cells and Maraviroc as well as U0126 were employed to further demonstrate the results.Lastly,we conducted in vivo experiment by nude mice subcutaneous implanted tumor model to prove our conclusion.Results:Galectin-1 induces the secretion of CCL7 in PSCs via NF-Kb pathway.Knockdown of Galectin-1 or CCR5 blockade could significantly reduce the invasion and migration of PD AC cells.CCL7 promotes EMT cascade in PDAC via ERK-JNK pathway.In vivo experiment indicated the ability of CCL7 in promoting tumor growth.Conclusion:Generally speaking,our studies confirmed that(1)Galectin-1-induced secretion of CCL7 in PSCs via NF-κB.(2)CCL7 could promotes proliferation and EMT cascade of PDAC cells,among which ERK-JNK may play a vital role.In future research of comprehensive therapy of PDAC,we should take the aspect of tumor microenvironment into accout.