Clinical significance of exosomal H19 in therapeutic outcomes. (A) Representative images of plasma exosomes in healthy subjects, patients with pituitary tumors sensitive to drug therapy, and those with pituitary tumors resistant to drug therapy (scale bars, 200 nm). (B) Exosomes were isolated from plasma by ultracentrifugation, from which total RNA was extracted. The H19 RNA level was detected by qRT-PCR, and H19 expression levels in plasma exosomes from the 200 healthy subjects and 206 patients with pituitary tumors were detected. ***P < 0.0001. (C) H19 expression levels in plasma exosomes from 25 patients with prolactinoma before and after DA treatment. Correlation analysis is based on patient sensitivity to BRC or CAB, which indicates that the change of H19 expression may be used as an indicator of the patient’s response to DAs (*P < 0.05).