ABSTRACT
BACKGROUND: Circular RNA (circRNA) plays a significant role in cisplatin (DDP) resistance. The purpose of this study was to explore the role of circ_0005667 in DDP resistance of endometrial carcinoma (EC) cells. METHODS: The expression of circular RNA circ_0005667, microRNA-145-5p (miR-145-5p) and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) in DDP-sensitive and DDP-resistant EC tissues and EC cells was determined by quantitative real-time PCR (qRT-PCR). The expression of apoptosis-related proteins, drug resistance-related proteins and IGF2BP1 proteins were detected by western blot. The half-maximal inhibitory concentration (IC 50 ) of DDP was determined using a cell counting kit-8 (CCK-8) assay. For functional assays, cell proliferation, migration, invasion and cell apoptosis were determined using 5-ethynyl-2'-deoxyuridine (EdU) assay, wound healing assay, transwell assay and flow cytometry assay, respectively. The binding relationship between miR-145-5p and circ_0005667 or IGF2BP1 was verified by dual-luciferase reporter assay. A xenograft experiment was applied to clarify the functional role of circ_0005667 in vivo . RESULTS: Levels of circ_0005667 and IGF2BP1 were markedly increased, whereas miR-145-5p was downregulated in DDP-resistant EC tissues and cells. The circ_0005667 deficiency could enhance DDP sensitivity, inhibit cell proliferation, migration and invasion and promote cell apoptosis in DDP-resistant EC cells in vitro . Mechanistically, circ_0005667 modulated IGF2BP1 expression through sponging miR-145-5p. In addition, miR-145-5p depletion attenuated circ_0005667 silencing-induced effects in EC cells. The regulation of miR-145-5p in DDP resistance involved low IGF2BP1 expression. In vivo experiments revealed that circ_0005667 silencing could improve the sensitivity of the tumor to DDP. CONCLUSION: Circ_0005667 enhanced DDP resistance in EC by elevating IGF2BP1 through sponging miR-145-5p.
Subject(s)
Endometrial Neoplasms , MicroRNAs , Humans , Female , RNA, Circular/genetics , Cisplatin/pharmacology , Endometrial Neoplasms/drug therapy , Endometrial Neoplasms/genetics , Apoptosis , Cell Proliferation , MicroRNAs/genetics , Drug Resistance, Neoplasm/geneticsABSTRACT
BACKGROUND AND OBJECTIVES: miRNAs play a crucial role in regulating immune responses. However, the effect of miR-124-3p on type 2 inflammation in allergic rhinitis (AR) is unclear. We aimed to study the immune regulation of miR-124-3p in AR and the mechanisms involved. METHODS: The direct interaction between miR-124-3p and IL-4Rα was confirmed through a dual-luciferase reporter assay. In vitro splenic lymphocytes from mice and peripheral blood mononuclear cells (PBMCs) from healthy individuals were cultured and treated with miR-124-3p mimic/inhibitor. Twenty-four female C57BL/C mice were divided into four groups: control, AR model, miR-124-3p agomir, and miR-124-3p antagomir groups (n = 6 per group). The allergic responses were evaluated based on the number of sneezing and nasal scratching, the serum HDM-specific IgE (sIgE) levels, and the degree of nasal mucosa eosinophil infiltration. The expression of IL-4Rα, p-STAT6, and type 2 inflammatory cytokines (IL-4, IL-5 and IL-13) in lymphocytes or nasal mucosa was determined by qPCR, western blotting, flow cytometry, immunohistochemistry and immunofluorescence. RESULTS: miR-124-3p directly targets the 3'UTR of IL-4Rα. The miR-124-3p mimic lowered the IL-4Rα, p-STAT6, IL-4, IL-5, and IL-13 expression levels in both mouse splenic lymphocytes and human PBMCs in vitro, and the miR-124-3p inhibitor rescued these changes. Furthermore, the miR-124-3p agomir decreased the levels of IL-4Rα and IL-4 in nasal mucosa, Th2 differentiation in spleen, and allergic response in AR mice. Moreover, the miR-124-3p antagonist increased the IL-4Rα and IL-4 levels and further aggravated the allergic responses. CONCLUSIONS: miR-124-3p might attenuate type 2 inflammation in AR by regulating IL-4Rα signaling, and miR-124-3p may be a promising new target in AR treatment.
Subject(s)
MicroRNAs , Rhinitis, Allergic , Mice , Humans , Female , Animals , Interleukin-13/pharmacology , Th2 Cells , Mice, Inbred BALB C , Interleukin-4/metabolism , Leukocytes, Mononuclear/metabolism , Interleukin-5 , Disease Models, Animal , Mice, Inbred C57BL , Nasal Mucosa , MicroRNAs/genetics , MicroRNAs/metabolism , Inflammation/metabolismABSTRACT
BACKGROUND: Inhibitors of arachidonate lipoxygenase 5 (ALOX5) exhibit anticancer activity. Zileuton is an FDA-approved drug for treating asthma and an ALOX5 inhibitor. This study evaluated the efficacy of zileuton in cervical cancer, determined the molecular mechanism of action, and assessed ALOX5 expression in cervical cancer patients. METHODS: The effects of zileuton were evaluated using cervical cancer cell lines and xenograft mouse models. Loss-of-function analysis of ALOX5 was performed using siRNA. The levels of ALOX5 and 5-HETE were determined using immunohistochemistry and ELISA. RESULTS: Zileuton resulted in cell proliferation inhibition and apoptosis induction in a dose-dependent manner, regardless of cellular origin or HPV infection. In two independent cervical cancer xenograft mouse models, zileuton at nontoxic doses significantly prevented tumor formation and decreased tumor growth. Zileuton acts on cervical cancer cells by inhibiting the ALOX5-5-HETE axis. Of note, ALOX5-5-HETE was significantly upregulated in cervical cancer compared with normal tissue. Inhibition of ALOX5 via the siRNA approach mimics the inhibitory effects of zileuton and confirms the roles of ALOX5 in cervical cancer. CONCLUSIONS: Our work demonstrates that the ALOX5-5-HETE axis is activated in cervical cancer, with important roles in growth and survival, and this can be therapeutically targeted by zileuton. Our findings also provide preclinical evidence to assess the efficacy of zileuton in cervical cancer in clinical settings.
