ABSTRACT
The objective of this study was to explore the role of the SULF2-mediated ERK/AKT signaling pathway in cervical cancer. SULF2 expression was detected in tumor tissues and tumor-adjacent normal tissues from cervical cancer patients. HeLa cells were divided into six groups: control group, NC group, SULF2 siRNA group, SULF2 group, SULF2 + LY294002 group, and SULF2 + U0125 group. In each group, HeLa cells received the corresponding treatment, followed by measurement of the cellular biological characteristics and expression of the ERK/AKT signaling pathway. We also confirmed the effect of SULF2 in vivo using a xenograft model in nude mice. SULF2 was upregulated in cervical cancer tissues, which was specifically associated with the clinical stage, histological differentiation, and lymphatic metastasis. Compared to the control group, the SULF2 siRNA group displayed decreased expression of SULF2, concomitant with reduced proliferation, migration, and invasion, but there was an increase in the apoptosis rate of HeLa cells, as well as downregulation of the p-Akt/Akt, p-ERK/ERK, and Bax/Bcl-2 ratios and cyclin D1. Additionally, tumor growth was significantly inhibited in the xenograft model of nude mice. The results in the SULF2 group were quite the opposite in which SULF2 facilitated the growth of cervical cancer cells, which was reversed by LY294002 or U0126. SULF2 is highly expressed in cervical cancer, and thus, downregulation of SULF2 can inhibit the ERK1/2 and AKT signaling pathways to suppress the proliferation, invasion, and migration of cervical cancer cells while facilitating apoptosis.
Subject(s)
Humans , Animals , Female , Adult , Middle Aged , Aged , Rabbits , Sulfatases/metabolism , Uterine Cervical Neoplasms/metabolism , Apoptosis , MAP Kinase Signaling System/physiology , Sulfatases/genetics , Immunohistochemistry , HeLa Cells , Signal Transduction , Case-Control Studies , Gene Expression Regulation, Neoplastic , MAP Kinase Signaling System/genetics , Cell Line, Tumor , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , Real-Time Polymerase Chain Reaction , Mice, Nude , Neoplasm StagingABSTRACT
BACKGROUND: CCL2 was up-regulated in neurons and involved in microglia activation and neurological decline in mice suffering from hepatic encephalopathy (HE). However, no data exist concerning the effect of neuron-derived CCL2 on microglia activation in vitro. METHODS: The rats were pretreated with CCL2 receptor inhibitors (INCB or C021, 1 mg/kg/day i.p.) for 3 days prior to thioacetamide (TAA) administration (300 mg/kg/day i.p.) for inducing HE model. At 8 h following the last injection (and every 4 h after), the grade of encephalopathy was assessed. Blood and whole brains were collected at coma for measuring CCL2 and Iba1 expression. In vitro, primary neurons were stimulated with TNF-α, and then the medium were collected for addition to microglia cultures with or without INCB or C021 pretreatment. The effect of the medium on microglia proliferation and activation was evaluated after 24 h. RESULTS: CCL2 expression and microglia activation were elevated in the cerebral cortex of rats received TAA alone. CCL2 receptors inhibition improved neurological score and reduced cortical microglia activation. In vitro, TNF-α treatment induced CCL2 release by neurons. Medium from TNF-α stimulated neurons caused microglia proliferation and M1 markers expression, including iNOS, COX2, IL-6 and IL-1ß, which could be suppressed by INCB or C021 pretreatment. The medium could also facilitate p65 nuclear translocation and IκBα phosphorylation, and NF-κB inhibition reduced the increased IL-6 and IL-1ß expression induced by the medium. CONCLUSION: Neuron-derived CCL2 contributed to microglia activation and neurological decline in HE. Blocking CCL2 or inhibiting microglia excessive activation may be potential strategies for HE.
Subject(s)
Animals , Rats , Hepatic Encephalopathy/metabolism , Microglia/metabolism , Chemokine CCL2/metabolism , Receptors, Chemokine/antagonists & inhibitors , Neurons/metabolism , Thioacetamide , Gene Expression , Hepatic Encephalopathy/chemically induced , Hepatic Encephalopathy/therapy , Interleukin-6/metabolism , Microglia/drug effects , Chemokine CCL2/antagonists & inhibitors , Culture Media/pharmacology , Disease Models, Animal , Nervous System DiseasesABSTRACT
ificantly longer than that in control group (P<0.05). This protocol can be adapted for various postnatal motor neurons studies.