Annexin A1 Interaction with the FPR2/ALX Receptor IDENTIFICATION OF DISTINCT DOMAINS AND DOWNSTREAM ASSOCIATED SIGNALING
JOURNAL OF BIOLOGICAL CHEMISTRY
Authors: Bena, Stefania; Brancaleone, Vincenzo; Wang, Ji Ming; Perretti, Mauro; Flower, Roderick J.
Abstract
Understanding how proresolving agonists selectively activate FPR2/ALX is a crucial step in the clarification of proresolution molecular networks that can be harnessed for the design of novel therapeutics for inflammatory disease. FPR2/ALX, a G protein-coupled receptor belonging to the formyl peptide receptor (FPR) family, conveys the biological functions of a variety of ligands, including the proresolution mediators annexin A1 (AnxA1) and lipoxin A(4), as well as the activating and proinflammatory protein serum amyloid A. FPR2/ALX is the focus of intense screening for novel anti-inflammatory therapeutics, and the small molecule compound 43 was identified as a receptor ligand. Here, we used chimeric FPR1 and FPR2/ALX clones (stably transfected in HEK293 cells) to identify the N-terminal region and extracellular loop II as the FPR2/ALX domain required for AnxA1-mediated signaling. Genomic responses were also assessed with domain-specific effects emerging, so the N-terminal region is required for AnxA1 induction of JAG1 and JAM3, whereas it is dispensable for modulation of SGPP2. By comparison, serum amyloid A non-genomic responses were reliant on extracellular loops I and II, whereas the small molecule compound 43 activated extracellular loop I with downstream signaling dependent on transmembrane region II. In desensitization experiments, the N-terminal region was dispensable for AnxA1-induced FPR2/ALX down-regulation in both the homologous and heterologous desensitization modes.
circKIF4A sponges miR-127 to promote ovarian cancer progression
AGING-US
Authors: Sheng, Shunliang; Hu, Yi; Yu, Furong; Tong, Wenjuan; Wang, Shufen; Cai, Yanlin; Zhu, Jiayu
Abstract
Ovarian cancer is a major gynecologic cancer and common cause of gynecologic cancer death worldwide. However, the molecular mechanisms of ovarian cancer progression are still unclear. circular RNAs (circRNAs) are recently reported to be involved in cancer progression regulation but the potential functions of circRNAs in ovarian cancer remains unknown. In this study, we explored the expression of circKIF4A in ovarian cancer tissues. Then, a series of experiments were conducted to investigate how circKIF4A functioned in ovarian cancer in vitro and in vivo. The results revealed that circKIF4A was highly expressed in ovarian cancer tissues. Knockdown of circKIF4A suppressed cell proliferation and migration in ovarian cancer. Subsequent mechanism study revealed that circKIF4A acted as a competitive endogenous RNA (ceRNA) to promoted ovarian cancer progression by sponging miR-127 and upregulated the expression of Junctional adhesion molecule 3 (JAM3). Therefore, circKIF4A could be a novel biomarker and therapeutic target for ovarian cancer.