FGFR1, a novel biomarker for metastatic castration-resistant prostate cancer?

Prediction of Resistance to 177Lu-PSMA Therapy by Assessment of Baseline Circulating Tumor DNA Biomarkers

177Lu-PSMA-617 and 177Lu-PSMA I&T (collectively termed 177Lu-PSMA) are currently being used for the treatment of selected metastatic castration-resistant prostate cancer (mCRPC) patients with PSMA PET-positive disease, but biomarkers for these agents remain incompletely understood. Methods: Pretreatment circulating tumor DNA (ctDNA) samples were collected from 44 mCRPC patients receiving 177Lu-PSMA treatment. Prostate-specific antigen responders and nonresponders were assessed relative to the ctDNA findings at baseline. Results: The ctDNA findings indicated that nonresponders were more likely to have gene amplifications than were responders (75% vs. 39.2%, P = 0.03). In particular, amplifications in FGFR1 (25% vs. 0%, P = 0.01) and CCNE1 (31.2% vs. 0%, P = 0.001) were more likely to be present in nonresponders. CDK12 mutations were more likely to be present in nonresponders (25% vs. 3.6%, P = 0.05). Conclusion: Our analyses indicate that ctDNA assays may contain specific biomarkers predictive of response or resistance for 177Lu-PSMA-treated mCRPC patients. Additional confirmatory studies are required before clinicians can use these findings to make personalized treatment decisions.

Fibroblast growth factor 2: Role in prenatal alcohol-induced stimulation of hypothalamic peptide neurons

Prenatal alcohol exposure (PAE) increases alcohol consumption and risk for alcohol use disorder. This phenomenon in rodents is suggested to involve a stimulatory effect of PAE, in female more than male offspring, on neurogenesis and density of neurons expressing neuropeptides in lateral hypothalamus (LH), including melanin-concentrating hormone (MCH), known to promote alcohol intake. With evidence suggesting a role for fibroblast growth factor 2 (FGF2) and its receptor FGFR1 in stimulating neurogenesis and alcohol drinking, we investigated here whether the FGF2-FGFR1 system is involved in the PAE-induced increase in MCH neurons, in postnatal offspring of pregnant rats given ethanol orally (embryonic day 10-15) at a low-moderate (2 g/kg/day) or high (5 g/kg/day) dose. Our results demonstrate that PAE at the low-moderate but not high dose stimulates FGF2 and FGFR1 gene expression and increases the density of MCH neurons co-expressing FGF2, only in females, but FGFR1 in both sexes. PAE induces this effect in the dorsal but not ventral area of the LH. Further analysis of FGF2 and FGFR1 transcripts within individual MCH neurons reveals an intracellular, sex-dependent effect, with PAE increasing FGF2 transcripts positively related to FGFR1 in the nucleus as well as cytoplasm of females but transcripts only in the cytoplasm of males. Peripheral injection of FGF2 itself (80 μg/kg, s.c.) in pregnant rats mimics these effects of PAE. Together, these results support the involvement of the FGF2-FGFR1 system in mediating the PAE-induced, sex dependent increase in density of MCH neurons, possibly contributing to increased alcohol consumption in the offspring.