Critical role of Aquaporin-1 and telocytes in infantile hemangioma response to propranolol beta-blockade

ABSTRACT: Propranolol, a non-selective β-adrenergic receptor (ADRB) antagonist, is the first-line therapy for severe infantile hemangiomas (IH). Since the incidental discovery of propranolol efficacy in IH, preclinical and clinical investigations have shown evidence of adjuvant propranolol response in some malignant tumors. However, the mechanism for propranolol antitumor effect is still largely unknown, owing to the absence of a tumor model responsive to propranolol at non-toxic concentrations. Immunodeficient mice engrafted with different human tumor cell lines were treated with anti-VEGF bevacizumab, to create a model sensitive to propranolol. Proteomics analysis was used to reveal propranolol-mediated protein alteration correlating with tumor growth inhibition and Aquaporin-1 (AQP1), a water channel modulated in tumor cell migration and invasion, was identified. IH tissues and cells were then functionally investigated. Our functional protein association networks analysis and knockdown of ADRB2 and AQP1 indicated that propranolol treatment and AQP1 downregulation trigger the same pathway, suggesting that AQP1 is a major driver of betablockers antitumor response. Examining AQP1 in human hemangioma samples, we found it exclusively in a perivascular layer, so far unrecognized in IH, made of telocytes (TC). Functional in vitro studies showed that AQP1-positive telocytes play a critical role in IH response to propranolol and that modulation of AQP1 in IH-TC by propranolol or shAQP1 decreases capillary-like tube formation in a Matrigel based angiogenesis assay. We conclude that IH sensitivity to propranolol may rely at least in part to a cross talk between lesional vascular cells and stromal telocytes.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human)

SUBMITTER: Stephane Claverol  

LAB HEAD: Bonneu M.

PROVIDER: PXD021457 | Pride | 2021-01-25

REPOSITORIES: Pride