Effect of epigenetic treatment on SST<sub>2</sub> expression in neuroendocrine tumour patients
Julie Refardt, Maria J. Klomp, Peter M. van Koetsveld, Fadime Dogan, Mark Konijnenberg, Tessa Brabander, Richard A. Feelders, Wouter W. de Herder, Leo J. Hofland, Johannes Hofland
Abstract
Dear Editor, Several preclinical studies have uncovered that epigenetic drugs can upregulate somatostatin receptor subtype 2 (SST 2 ) expression in neuroendocrine tumour (NET) models, 1,2 which could be of eminent importance for NET patients with low tumoural SST expression. In a prospective clinical proof-of-concept trial involving nine advanced NET patients with low SST expression, we were able to show that epigenetic treatment with the histone deacetylase (HDAC) inhibitor valproic acid and the DNA methyltransferase (DNMT) inhibitor hydralazine did not lead to an increase in tumour-uptake of 68 Ga-DOTATATE, contradicting the in vitro data.