Open AccessIdentification of Pirin as a Molecular Target of the CCG-1423/CCG-203971 Series of Antifibrotic and Antimetastatic Compounds
Author(s) -
Erika M. Lisabeth,
Dylan Kahl,
Indiwari Gopallawa,
Sarah E. Haynes,
Sean A. Misek,
Phillip L. Campbell,
Thomas S. Dexheimer,
Dinesh Khanna,
David A. Fox,
Xiangshu Jin,
Brent R. Martin,
Scott D. Larsen,
Richard R. Neubig
Publication year - 2019
Publication title -
acs pharmacology and translational science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.271
H-Index - 10
ISSN - 2575-9108
DOI - 10.1021/acsptsci.8b00048
Subject(s) - isothermal titration calorimetry , bleomycin , chemistry , luciferase , in vivo , in vitro , biochemistry , cancer research , biology , gene , transfection , genetics , chemotherapy
A series of compounds (including CCG-1423 and CCG-203971) discovered through an MRTF/SRF-dependent luciferase screen has shown remarkable efficacy in a variety of in vitro and in vivo models, including significant reduction of melanoma metastasis and bleomycin- induced fibrosis. Although these compounds are efficacious in these disease models, the molecular target is unknown. Here, we describe affinity isolation-based target identification efforts which yielded pirin, an iron-dependent cotranscription factor, as a target of this series of compounds. Using biophysical techniques including isothermal titration calorimetry and X-ray crystallography, we verify that pirin binds these compounds in vitro. We also show with genetic approaches that pirin modulates MRTF- dependent luciferase reporter activity. Finally, using both siRNA and a previously validated pirin inhibitor, we show a role for pirin in TGF- β - induced gene expression in primary dermal fibroblasts. A recently developed analog, CCG-257081, which co crystallizes with pirin, is also effective in the prevention of bleomycin-induced dermal fibrosis.