Murine Models of Acute Myeloid Leukaemia

Acute myeloid leukaemia (AML) is a rare but severe form of human cancer that results from a limited number of functionally cooperating genetic abnormalities leading to uncontrolled proliferation and impaired differentiation of hematopoietic stem and progenitor cells. Before the identification of genetic driver lesions, chemically, irradiation or viral infection-induced mouse leukaemia models provided platforms to test novel chemotherapeutics. Later, transgenic mouse models were established to test the in vivo transforming potential of newly cloned fusion genes and genetic aberrations detected in patients’ genomes. Hereby researchers constitutively or conditionally expressed the respective gene in the germline of the mouse or reconstituted the hematopoietic system of lethally irradiated mice with bone marrow virally expressing the mutation of interest. More recently, immune deficient mice have been explored to study patient-derived human AML cells in vivo. Unfortunately, although complementary to each other, none of the currently available strategies faithfully model the initiation and progression of the human disease. Nevertheless, fast advances in the fields of next generation sequencing, molecular technology and bioengineering are continuously contributing to the generation of better mouse models. Here we review the most important AML mouse models of each category, briefly describe their advantages and limitations and show how they have contributed to our understanding of the biology and to the development of novel therapies.

Effect of charge and surface area on the cytotoxicity of cationic metallointercalation reagents

Reaction of a series of nitrogen donor ligands (1-phenylpyrazoles, 2-phenylpyridine, benzo[h]quinoline, 1-(2′-pyridyl)indole, 1-phenylindazole, and 2-phenylindazole) with palladium(II) and platinum(II) salts gave complexes where ortho-metallation had occurred resulting in bidentate binding to the metal centres through N and C atoms. These cyclometallated products were isolated as µ-chloro dimers. Subsequent treatment of these µ-chloro dimers with chelating diamines such as 1,2-ethanediamine converted them into 14 cationic (1+) complexes. Analogous coordination mixed ligand complexes (charge 2+) were prepared by reaction of dichloro(1,2-ethanediamine-N,N′)palladium(II) with aromatic diamines such as 2-(1′-pyrazolyl)pyridine, 2,2′-bipyridine, and 1,10-phenanthroline. The complexes exhibited growth inhibitory activity against L1210 mouse leukæmia cells in vitro over a wide concentration range; in general, the cyclometallated complexes were more active than the mixed ligand complexes, although one cyclometallated organoplatinum complex was less active than the mixed ligand analogue. Substitution around the periphery of the aromatic ligands also resulted in increased activity. One complex, derived from 1-(2'-pyridyl)indole, was tested in vivo and showed no significant antitumour inhibition against P388 leukæmia at doses below toxic levels. Key words: anticancer, metallointercalator, cyclometallation, palladium, platinum, cytotoxicity.