Open AccessO rkambi® and amplifier co‐therapy improves function from a rare CFTR mutation in gene‐edited cells and patient tissue
Author(s) -
Molinski Steven V,
Ahmadi Saumel,
Ip Wan,
Ouyang Hong,
Villella Adriana,
Miller John P,
Lee PoShun,
Kulleperuma Kethika,
Du Kai,
Di Paola Michelle,
Eckford Paul DW,
Laselva Onofrio,
Huan Ling Jun,
Wellhauser Leigh,
Li Ellen,
Ray Peter N,
Pomès Régis,
Moraes Theo J,
Gonska Tanja,
Ratjen Felix,
Bear Christine E
Publication year - 2017
Publication title -
embo molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.923
H-Index - 107
eISSN - 1757-4684
pISSN - 1757-4676
DOI - 10.15252/emmm.201607137
Subject(s) - ivacaftor , mutation , cystic fibrosis , cas9 , in silico , cancer research , crispr , biology , medicine , gene , cystic fibrosis transmembrane conductance regulator , genetics
The combination therapy of lumacaftor and ivacaftor (Orkambi ® ) is approved for patients bearing the major cystic fibrosis ( CF ) mutation: ΔF508 . It has been predicted that Orkambi ® could treat patients with rarer mutations of similar “theratype”; however, a standardized approach confirming efficacy in these cohorts has not been reported. Here, we demonstrate that patients bearing the rare mutation: c.3700 A>G, causing protein misprocessing and altered channel function—similar to ΔF508‐ CFTR , are unlikely to yield a robust Orkambi ® response. While in silico and biochemical studies confirmed that this mutation could be corrected and potentiated by lumacaftor and ivacaftor, respectively, this combination led to a minor in vitro response in patient‐derived tissue. A CRISPR /Cas9‐edited bronchial epithelial cell line bearing this mutation enabled studies showing that an “amplifier” compound, effective in increasing the levels of immature CFTR protein, augmented the Orkambi ® response. Importantly, this “amplifier” effect was recapitulated in patient‐derived nasal cultures—providing the first evidence for its efficacy in augmenting Orkambi ® in tissues harboring a rare CF ‐causing mutation. We propose that this multi‐disciplinary approach, including creation of CRISPR /Cas9‐edited cells to profile modulators together with validation using primary tissue, will facilitate therapy development for patients with rare CF mutations.