Compound of Formula (I): wherein R1, R2 and R3, which are identical or different, are hydrogen atom or C1-4 alkyl, and R4 is a saturated C6-9 linear, branched or cyclic hydrocarbon radical or a radical of Formula (II) wherein X is S or O, Y is a hydrogen atom or up to 2 halogen atoms, Z is a single bond or a divalent radical being O, S, - CR2-, in which R is hydrogen or C1-4 alkyl, or other divalent radical with 2-10 carbon atoms and, optionally, O and/or S atoms linked in the form of a chain, wherein - if the radicals contain 2 or more O and/or S atoms - the latter are separated from one another by at least 2 carbon atoms, and it also being possible for 2 adjacent carbon atoms to be linked together by a double bond, and the free valencies of the carbon atoms being saturated by a hydrogen atom and/or C1-4 alkyl groups, Ar is an aromatic ring system which has up to two rings and which may be substituted by up to three radicals from the group of fluorine, chlorine, bromine, methoxy, C1-4 alkyl, trifluoromethyl and trifluoromethoxy, salts and/or solvates thereof, for use in the treatment of a tumor bearing deregulated MYC oncoproteins, wherein said compound is capable of increasing UTR-dependent expression of at least one MYC gene.Composé de Formule (I), ainsi que ses sels et solvates, destinés à être utilisés pour traiter une tumeur portant des oncoprotéines MYC dérégulées, ledit composé étant capable daugmenter lexpression dépendante dUTR dau moins un gène MYC. Dans la Formule (I), R1, R2 et R3, qui peuvent être identiques ou différents, sont un atome dhydrogène ou un alkyle C1-4, et R4 est un radical hydrocarbure C6-9 saturé, linéaire, ramifié ou cyclique ou un radical de Formule (II) où X est S ou O, Y est un atome dhydrogène ou jusquà 2 atomes dhalogène, Z est une liaison simple ou un radical divalent de type O, S, - CR2-, R étant un atome dhydrogène ou un alkyle C1-4, ou un autre radical divalent ayant de 2 à 10 atomes de carbone et, éventuellement, des atomes O
