Exploring intrinsic variability between cultured nasal and bronchial epithelia in cystic fibrosis.

The nasal and bronchial epithelium are unified parts of the respiratory tract that are affected in the monogenic disorder cystic fibrosis (CF). Recent studies have uncovered that nasal and bronchial tissues exhibit intrinsic variability, including differences in mucociliary cell composition and expression of unique transcriptional regulatory proteins which relate to germ layer origin. In the present study, we explored whether intrinsic differences between nasal and bronchial epithelial cells persist in cell cultures and affect epithelial cell functioning in CF.

FDA-approved drug screening in patient-derived organoids demonstrates potential of drug repurposing for rare cystic fibrosis genotypes.

Background: Preclinical cell-based assays that recapitulate human disease play an important role in drug repurposing. We previously developed a functional forskolin induced swelling (FIS) assay using patient-derived intestinal organoids (PDIOs), allowing functional characterization of CFTR, the gene mutated in people with cystic fibrosis (pwCF). CFTR function-increasing pharmacotherapies have revolutionized treatment for approximately 85% of people with CF who carry the most prevalent F508del-CFTR mutation, but a large unmet need remains to identify new treatments for all pwCF.

High-throughput functional assay in cystic fibrosis patient-derived organoids allows drug repurposing.

Background: Cystic fibrosis (CF) is a rare hereditary disease caused by mutations in the cystic fibrosis transmembrane conductance regulator () gene. Recent therapies enable effective restoration of CFTR function of the most common F508del mutation. This shifts the unmet clinical need towards people with rare mutations such as nonsense mutations, of which G542X and W1282X are most prevalent.

Measuring cystic fibrosis drug responses in organoids derived from 2D differentiated nasal epithelia.

Cystic fibrosis is caused by genetic defects that impair the CFTR channel in airway epithelial cells. These defects may be overcome by specific CFTR modulating drugs, for which the efficacy can be predicted in a personalized manner using 3D nasal-brushing-derived airway organoids in a forskolin-induced swelling assay. Despite of this, previously described CFTR function assays in 3D airway organoids were not fully optimal, because of inefficient organoid differentiation and limited scalability.

Forskolin induced swelling (FIS) assay in intestinal organoids to guide eligibility for compassionate use treatment in a CF patient with a rare genotype.

Background: Forskolin-induced swelling of patient-derived organoids has been used to measure patient-specific CFTR function and CFTR modulator response. We present a case where CFTR function assessment in intestinal organoids was decisive for a patients' acceptance to a compassionate use program.

Case Description: A 56 years old female with cystic fibrosis compound heterozygous for F508del and a rare CFTR allele (c.

Forskolin-induced organoid swelling is associated with long-term cystic fibrosis disease progression.

Rationale: Cystic fibrosis (CF) is a monogenic life-shortening disease associated with highly variable individual disease progression which is difficult to predict. Here we assessed the association of forskolin-induced swelling (FIS) of patient-derived organoids with long-term CF disease progression in multiple organs and compared FIS with the golden standard biomarker sweat chloride concentration (SCC).

Methods: We retrieved 9-year longitudinal clinical data from the Dutch CF Registry of 173 people with mutations in the cystic fibrosis transmembrane conductance regulator () gene.

Evaluating CRISPR-based prime editing for cancer modeling and CFTR repair in organoids.

Prime editing is a recently reported genome editing tool using a nickase-cas9 fused to a reverse transcriptase that directly synthesizes the desired edit at the target site. Here, we explore the use of prime editing in human organoids. Common TP53 mutations can be correctly modeled in human adult stem cell-derived colonic organoids with efficiencies up to 25% and up to 97% in hepatocyte organoids.

CRISPR-Based Adenine Editors Correct Nonsense Mutations in a Cystic Fibrosis Organoid Biobank.

Adenine base editing (ABE) enables enzymatic conversion from A-T into G-C base pairs. ABE holds promise for clinical application, as it does not depend on the introduction of double-strand breaks, contrary to conventional CRISPR/Cas9-mediated genome engineering. Here, we describe a cystic fibrosis (CF) intestinal organoid biobank, representing 664 patients, of which ~20% can theoretically be repaired by ABE.