OBJECTIVE: The objective of the study was to delineate a process in human ZG, which may regulate both aldosterone production and cell turnover.
DESIGN: This study included a comparison of 20 pairs of ZG and zona fasciculata transcriptomes from adrenals adjacent to an APA (n = 13) or a pheochromocytoma (n = 7).
INTERVENTIONS: Interventions included an overexpression of the top ZG gene (LGR5) or stimulation by its ligand (R-spondin-3).
MAIN OUTCOME MEASURES: A transcriptome profile of ZG and zona fasciculata and aldosterone production, cell kinetic measurements, and Wnt signaling activity of LGR5 transfected or R-spondin-3-stimulated cells were measured.
RESULTS: LGR5 was the top gene up-regulated in ZG (25-fold). The gene for its cognate ligand R-spondin-3, RSPO3, was 5-fold up-regulated. In total, 18 genes associated with the Wnt pathway were greater than 2-fold up-regulated. ZG selectivity of LGR5, and its absence in most APAs, were confirmed by quantitative PCR and immunohistochemistry. Both R-spondin-3 stimulation and LGR5 transfection of human adrenal cells suppressed aldosterone production. There was reduced proliferation and increased apoptosis of transfected cells, and the noncanonical activator protein-1/Jun pathway was stimulated more than the canonical Wnt pathway (3-fold vs 1.3-fold). ZG of adrenal sections stained positive for apoptosis markers.
CONCLUSION: LGR5 is the most selectively expressed gene in human ZG and reduces aldosterone production and cell number. Such conditions may favor cells whose somatic mutation reverses aldosterone inhibition and cell loss.
METHODS: In this open-label phase III study (PROFILE 1029), patients were randomized 1:1 to receive orally administered crizotinib 250 mg twice daily continuously (3-week cycles) or intravenously administered chemotherapy (pemetrexed 500 mg/m2, plus cisplatin 75 mg/m2, or carboplatin [at a dose to produce area under the concentration-time curve of 5-6 mg·min/mL]) every 3 weeks for a maximum of six cycles. PFS confirmed by independent radiology review was the primary end point.
RESULTS: Crizotinib significantly prolonged PFS (hazard ratio, 0.402; 95% confidence interval [CI]: 0.286-0.565; p < 0.001). The median PFS was 11.1 months with crizotinib and 6.8 months with chemotherapy. The objective response rate was 87.5% (95% CI: 79.6-93.2%) with crizotinib versus 45.6% (95% CI: 35.8-55.7%) with chemotherapy (p < 0.001). The most common adverse events were increased transaminase levels, diarrhea, and vision disorders with crizotinib and leukopenia, neutropenia, and anemia with chemotherapy. Significantly greater improvements from baseline in patient-reported outcomes were seen in crizotinib-treated versus chemotherapy-treated patients.
CONCLUSIONS: First-line crizotinib significantly improved PFS, objective response rate, and patient-reported outcomes compared with standard platinum-based chemotherapy in East Asian patients with ALK-positive advanced NSCLC, which is similar to the results from PROFILE 1014. The safety profiles of crizotinib and chemotherapy were consistent with those previously published.