Pronounced anti-proliferative activity and tumor cell selectivity of 5-alkyl-2-amino-3-methylcarboxylate thiophenes.

Abstract

5-(2-(4-Methoxyphenyl)ethyl)-2-amino-3-methylcarboxylate thiophene (TR560) is the prototype drug of a recently discovered novel class of tumor-selective compounds that preferentially inhibit the proliferation of specific tumor cell types (e.g. leukemia/lymphoma). Here, we further increased tumor selectivity by simplification of the molecule through replacing the 4-methoxyphenyl moiety by an alkyl chain. Several 2-amino-3-methylcarboxylate thiophene derivatives containing at C-5 an alkyl group consisting of at least 6 (hexyl) to 9 (nonyl) carbon units showed pronounced anti-proliferative activity in the mid-nanomolar range with 500- to 1000-fold tumor cell selectivity. The compounds preferentially inhibited the proliferation of T-lymphoma CEM and Molt/4, prostate PC-3, kidney Caki-1 and hepatoma Huh-7 tumor cells, but were virtually inactive against other tumor cell lines including B-lymphoma Raji and cervix carcinoma HeLa cells. The novel prototype drug 3j (containing a 5-heptyl chain) elicited a cytotoxic, rather than cytostatic activity, already after 4 h of exposure. The unusual tumor selectivity could not be explained by a differential uptake (or efflux) of the drug by sensitive versus resistant tumor cells. Exposure of a fluorescent derivative of 3j revealed pronounced uptake of the drug in the cytoplasm, no visible appearance in the nucleus, and a predominant localization in the endoplasmic reticulum. These observations may be helpful to narrow down the intracellular localization and identification of the molecular target of the 5-substituted thiophene derivatives.

• Authors: Joice Thomas, Alenka Jecic, Els Vanstreels, Lizette van Berckelaer, Romeo Romagnoli, Wim Dehaen, Sandra Liekens, Jan Balzarini
• Journal: European journal of medicinal chemistry (Eur J Med Chem) Vol. 132 Pg. 219-235 (May 26 2017) ISSN: 1768-3254 [Electronic] France
• PMID: 28365318 (Publication Type: Journal Article)
• Copyright: Copyright © 2017 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

Chemical References

• Antineoplastic Agents
• Thiophenes

Topics

• Alkylation
• Antineoplastic Agents (chemical synthesis, chemistry, pharmacology)
• Cell Line, Tumor
• Cell Nucleus (metabolism)
• Cell Proliferation (drug effects)
• Endoplasmic Reticulum (metabolism)
• Humans
• Structure-Activity Relationship
• Thiophenes (chemical synthesis, pharmacokinetics, pharmacology)
• Tissue Distribution