The Lineage Determining Factor GRHL2 Collaborates with FOXA1 to Establish a Targetable Pathway in Endocrine Therapy-Resistant Breast Cancer.

Notwithstanding the positive clinical impact of endocrine therapies in estrogen receptor-alpha (ERα)-positive breast cancer, de novo and acquired resistance limits the therapeutic lifespan of existing drugs. Taking the position that resistance is nearly inevitable, we undertook a study to identify and exploit targetable vulnerabilities that were manifest in endocrine therapy-resistant disease. Using cellular and mouse models of endocrine therapy-sensitive and endocrine therapy-resistant breast cancer, together with contemporary discovery platforms, we identified a targetable pathway that is composed of the transcription factors FOXA1 and GRHL2, a coregulated target gene, the membrane receptor LYPD3, and the LYPD3 ligand, AGR2. Inhibition of the activity of this pathway using blocking antibodies directed against LYPD3 or AGR2 inhibits the growth of endocrine therapy-resistant tumors in mice, providing the rationale for near-term clinical development of humanized antibodies directed against these proteins.

Correlation of Echocardiogram and Exercise Test Data in Children with Aortic Stenosis.

Previous pediatric exercise test criteria for aortic stenosis severity were based on cardiac catheterization assessment, whereas current criteria are based on echocardiographic valve gradients. We sought to correlate exercise test criteria with echocardiographic assessment of severity. We report 65 studies, 51 patients (mean age of 13 ± 4 years; 75% males), with aortic stenosis (AS) who had a maximal exercise test between 2005 and 2016. We defined three groups based on resting mean Doppler gradient across their aortic valve: severe AS (n = 10; gradient of ≥ 40 mmHg), moderate AS (n = 20; gradient 25-39 mmHg), and mild AS (n = 35; gradient ≤ 24 mmHg). We studied symptoms (chest pain) during exercise, resting electrocardiogram changes (left ventricular hypertrophy [LVH]), complex arrhythmias during exercise, change in exercise systolic blood pressure (SBP; delta SBP = peak SBP-resting SBP), exercise duration, work, echocardiogram parameters (LVH), and ST-T wave changes with exercise. Additionally, we compared work and delta SBP during exercise with 117 control males and females without heart disease. Severe AS patients have statistically significant differences when compared with mild AS in ST-T wave depression during exercise, LVH on resting electrocardiogram, and echocardiogram. There was a significant difference in delta SBP between severe AS and normal controls (delta SBP 21.6 vs. 46.2 mmHg), and between moderate AS and normal controls (delta SBP 32 vs. 46.2 mmHg). There were no significant complications during maximal exercise testing. Children with echocardiographic severe and moderate AS have exercise testing abnormalities. Exercise test criteria for severity of AS were validated for echocardiographic criteria for AS severity.