Expression And Effect Of CXCL13 Chemokine In Hepatocellular Carcinoma

Hepatocellular carcinoma(HCC)is the most primary malignant tumor of the liver cells and the third most deadly tumor globally.There are more than 750,000 new cases diagnosed every year worldwide and the incidence increase with year.The study of the pathogenesis and the improvement of its diagnosis and treatment is one of the most important problems of global public health.The main risk factors for HCC development have been clearly identified,such as hepatitis B and C virus infection,alcohol abuse,and some chronic liver diseases,no matter what the starting factors,chronic inflammation is the key process of HCC.While from inflammation to cancer,which involves the interaction and regulation of various components of immune system,changes of the tumor microenvironment and the abnormal activation of important signaling pathways are most important factor in the development of HCC.The key factor of this regulatory network is always a hotspot in cancer research,which is expected to provide a new target for the diagnosis and treatment of HCC.Chemokines are a group of small,soluble proteins which have similar structure and functions,that can chemotactic targeting cell movement.Because of the regulation of angiogenesis,immunoregulation and inflammatory processes,chemokines play an important role in development of tumor.CXCL13 is a member of the CXC chemokine family,mainly in the liver,serum,lymph nodes and stomach,of which the liver accounted for nearly 50%.CXCL13 mainly has chemotaxis to B cells,and also have some regulatory role some T cells,which is involved in immune regulation.In recent years,some research have found CXCL13 and its receptor CXCR5 participate in many malignant tumors,including lung cancer,breast cancer,colon cancer,prostate cancer and so on.Abnormal activation of JNK,ERK and other signaling pathways and induction of lymph node metastasis are involved in pathogenesis.At the same time,many studies have found that CXCL13 is closely associated with liver disease,for example,high expression of CXCL13 have been found in patients with hepatitis C infection,liver fibrosis and primary biliary cirrhosis,suggesting that it may be involved in chronic liver injury,inflammation and fibrosis.However,whether,and how does CXCL13 participate in the process of HCC has not been reported yet.This study will evaluate the expression of CXCL13 in human HCC tissues and peripheral blood and clarify the potential mechanisms.Objects.(1)To investigate the expression of CXCL13 in human HCC tissues and peripheral blood,also the relationship between CXCL13,clinical TNM stage and some laboratory indexs;(2)To study the effect of CXCL13 on the secretion of cytokines from T cells and IgG subclasses from B cells,and to explore the role of CXCL13 in HCC tumor microenvironment;(3)To study the interaction between CXCL13/CXCR5 and Wnt/?-catenin signaling pathway.Methods(1)32 patients with hepatocellular carcinoma and 12 healthy controls were recruited,to analyze the expression of CXCL13 in HCC tissues by RT-PCR and Western blot;ELISA was used to test the concentration of serum CXCL13 in HCC patients and healthy controls;(2)In vitro PBMCs cultured with Hep G2 supernatant,stimulateded T,B lymphocytes,than used CXCL13 and its inhibitor dexamethasone to treat cells,the levels of IL-12,IL4,IL-6,and IL-17,and four IgG subclasses were detected by ELISA;(3)Hep G2 cells were cultured in vitro,respectively using Wnt/?-catenin pathway activator Li CL and inhibitor DKK-1,also CXCL13 and dexamethasone to treat cells,Western blot was used to detect the interaction between CXCL13/CRCR5 and key molecules in Wnt/?-catenin pathway,such as ?-catenin,GSK-3?,p-GSK-3?.Results(1)The m RNA and protein expression of CXCL13 level were increased with the HCC clinical stage.The serum CXCL13 concentration of HCC patients were higher than that of healthy controls,and increased with clinical stage.Meanwhile CXCL13 level was positively correlated with serum ALT and AST.;(2)In vitro PBMCs cultured with Hep G2 supernatant,CXCL13 could obviously promote the expressions of IL-12 and IL-17,and induce IgG4 secreted by B cells;(3)Western blot was used to detect the interaction between CXCL13/CRCR5 and key molecules of Wnt/?-catenin signaling,the pathway activator Li CL can significantly increase the expression of CXCL13 and CXCR5,while the blocking agent DKK-1 can down regulated the expression of CXCL13 and CXCR5;Conversely,CXCL13 can significantly increase the expression of ?-catenin and down regulate the expression of p-GSK-3?,while dexamethasone is just the opposite.The CXCL13 and Wnt/?-catenin signaling shared a positive feedback loop.ConclusionsCXCL13 level was increased in both tissue and serum of advanced HCC patients,and positively correlated with serum ALT and AST.The effect of CXCL13 on promoting liver cancer is related to the facilitation of IL-12,IL-17 and IgG4,and the activation of Wnt/?-catenin pathway.CXCL13 may act as a potential target for the diagnosis and treatment of HCC.