ABSTRACT
Wnt/ß-catenin signaling plays important role in cancers. Compound 759 is one of the compounds previously screened to identify inhibitors of the Wnt/ß-catenin pathway in A549 cells [Lee et al. in Bioorg Med Chem Lett 20:5900-5904, 2010]. However, the mechanism by which Compound 759 induces the inhibition of the Wnt/ß-catenin pathway remains unknown. In our study, we employed various assays to comprehensively evaluate the effects of Compound 759 on lung cancer cells. Our results demonstrated that Compound 759 significantly suppressed cell proliferation and Wnt3a-induced Topflash activity and arrested the cell cycle at the G1 stage. Changes in Wnt/ß-catenin signaling-related protein expression, gene activity, and protein stability including Axin, and p21, were achieved through western blot and qRT-PCR analysis. Compound 759 treatment upregulated the mRNA level of p21 and increased Axin protein levels without altering the mRNA expression in A549 cells. Co-treatment of Wnt3a and varying doses of Compound 759 dose-dependently increased the amounts of Axin1 in the cytosol and inhibited ß-catenin translocation into the nucleus. Moreover, Compound 759 reduced tumor size and weight in the A549 cell-induced tumor growth in the in vivo tumor xenograft mouse model. Our findings indicate that Compound 759 exhibits potential anti-cancer activity by inhibiting the Wnt/ß-catenin signaling pathway through the increase of Axin1 protein stability.
Subject(s)
Axin Protein , Cell Proliferation , Lung Neoplasms , Mice, Nude , Wnt Signaling Pathway , Humans , Axin Protein/metabolism , Wnt Signaling Pathway/drug effects , Animals , Cell Proliferation/drug effects , Lung Neoplasms/drug therapy , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Mice , Protein Stability/drug effects , Xenograft Model Antitumor Assays , A549 Cells , beta Catenin/metabolism , beta Catenin/antagonists & inhibitors , Wnt3A Protein/metabolism , Cell Line, Tumor , Antineoplastic Agents/pharmacology , Mice, Inbred BALB CABSTRACT
Leukotriene B4 (LTB4) is a potent chemoattractant that can recruit and activate immune cells such as neutrophils, eosinophils, and monocytes to sites of inflammation. Excessive production of LTB4 has been linked to acute and chronic inflammatory diseases, including asthma, rheumatoid arthritis, and psoriasis. Inhibiting the binding of LTB4 to its receptors, BLT1 and BLT2, is a potential strategy for treating these conditions. While several BLT1 antagonists have been developed for clinical trials, most have failed due to efficacy and safety issues. Therefore, discovering selective BLT2 antagonists could improve our understanding of the distinct functions of BLT1 and BLT2 receptors and their pharmacological implications. In this study, we aimed to discover novel BLT2 antagonists by synthesizing a series of biphenyl analogues based on a BLT2 selective agonist, CAY10583. Among the synthesized compounds, 15b was found to selectively inhibit the chemotaxis of CHO-BLT2 cells with an IC50 value of 224 nM without inhibiting the chemotaxis of CHO-BLT1 cells. 15b also inhibited the binding of LTB4 and BLT2 with a Ki value of 132 nM. Furthermore, 15b had good metabolic stability in liver microsomes and moderate bioavailability (F = 34%) in in vivo PK studies. 15b also showed in vivo efficacy in a mouse model of asthma, reducing airway hyperresponsiveness by 59% and decreasing Th2 cytokines by up to 46%. Our study provides a promising lead for the development of selective BLT2 antagonists as potential therapeutics for inflammatory airway diseases such as asthma and chronic obstructive pulmonary disease.
Subject(s)
Arthritis, Rheumatoid , Asthma , Mice , Cricetinae , Animals , Leukotriene B4 , Asthma/drug therapy , Inflammation , CHO Cells , Receptors, Leukotriene B4/metabolismABSTRACT
The endocrine-disrupting effects of androgenic signaling play crucial roles in several androgen-related diseases. In attempting to develop an in vitro cell line to be used in androgen receptor (AR)-mediated reporter gene assays, we developed a stable 22Rv1/MMTV cell line, which is a human prostate cancer cell line that endogenously expresses functional AR, to evaluate AR-mediated transcriptional activation (TA). Using 22Rv1/MMTV cells, we established and optimized a test protocol for the AR-TA assay and validated the proposed assay using 20 compounds recommended by the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM). All the performance parameters for agonist and antagonist assays were 91-100% comparable between the 22Rv1/MMTV assay and the ICCVAM report. In conclusion, the AR-TA assay using 22Rv1/MMTV cells might be a quick and relatively inexpensive method for screening large numbers of chemicals for their potential to activate or inhibit AR-mediated gene transcription.
