Objective To investigate the changes of A20 expression stimulated by free fatty acids (FFA) and its pathway.Methods HepG2 cells and U937 cells were stimulated by 0.5 mmol/L mixed FFA.The expression of A20,phosphor-p65 and phosphor-IκBα of neclear factor (NF)-κB pathway and phosphor-c-Jun N-terminal kinase (JNK),JNK,phosphor-extracellular signal-regulated kinase (ERK),ERK,phosphor-p38 and p38 of mitogen-activated protein kinase (MAPK) pathway were detected by Western blotting.The level of interleukin (IL)-12p,IL-1β,tumor necrosis factor (TNF)-α,IL-6,IL-10 and IL-8 cytokines in the supernatant of cell culture were detected by flow cytometry.T-test was performed for statistical analysis.Results The level of A20 changed along with the stimulated time of FFA.NF-κB and MAPK pathways were activated after FFA stimulation.The secretion of IL-6 and IL-8 increased after HepG2 cells stimulated by FFA and both reached peak at 24 hour.Compared with control group,the difference in IL-8 was statistically significant ((423.8 ± 8.9) pg/mL vs (12.4 ± 4.5) pg/mL,t=41.28,P＜0.01).The difference in IL-6 was also statistically significant ((4 082±423.6) pg/mL vs (52.9±29.5) pg/mL,t=9.49,P＜0.01).After U937 cells were stimulated by FFA,the secretion of IL-8 increased compared with control group.And in a certain period of time the secretion was time dependence.The maximum secretion of 24 hours was (200.6±5.7) pg/mL vs (5.0±3.9) pg/mL,and the difference was statistically significant (t=28.16,P＜0.01).IL-10,IL-12p,IL-1β and TNF-α were detected.Both NF-κB pathway and MAPK pathway were detected.Conclusions The in vitro FFA mediated steatotic cell model could induce the expression change of A20 and secretion of inflammatory cytokines.NF-κB and MAPK pathways involved in the response to FFA in HepG2 cells and U937 cells.

Background:CBX3 is a member of heterochromatin protein family. Recent studies indicated that CBX3 was closely related to lung cancer,osteosarcoma,gastric cancer. Aims:To investigate the expression and clinical significance of CBX3 in colorectal cancer,and explore the potential mechanism. Methods:Thirty colorectal cancer patients from June 2011 to June 2012 at Shanghai Renji Hospital were enrolled. Real-time quantitative PCR and immunohistochemistry were used to determine mRNA and protein expressions of CBX3 in colorectal cancer tissues and corresponding paracancerous tissues, respectively. Human colorectal cancer cell line RKO was transfected with overexpressed plasmid or siRNA of CBX3. Cell proliferation was measured by CCK-8 assay,Western blotting was implemented to determine the protein expressions of CBX3 and p53. Results:The mRNA and protein expressions of CBX3 were significantly increased in colorectal cancer tissues than in corresponding paracancerous tissues. Increased protein expression of CBX3 was closely correlated with tumor size (P ＝ 0. 025 ),lymph node metastasis (P ＝ 0. 013 )and TNM staging (P ＝ 0. 020 ). After intervention with overexpressed plasmid of CBX3,the mRNA and protein expressions of CBX3 were efficiently upregulated in RKO cells, cell proliferation and protein expression of p53 were significantly increased. Meanwhile,the mRNA and protein expressions of CBX3 were efficiently downregulated in RKO cells after knockdown of CBX3,resulting in significantly decreased cell proliferation and protein expression of p53. Conclusions:CBX3 may promote the proliferation of colorectal cancer cells via influencing the expression of p53,thus promoting the progression of colorectal cancer. This indicates that CBX3 has the potential to be a new target for diagnosis and therapy of colorectal cancer.