of the Max - MDC

Structure of the Group
Group Leader
PD Dr. Eckart Matthes
Technical Assistant
Inge Krahn*
Scientist
Dr. Harald Bünger
Graduate Student
Lora Dimitrova*
* part of the period reported
Figure 2. Action of L-Hyd4C and 3TC on the different forms of intracellular duck HBV DNA in duck hepatocytes.
RC: relaxed circular DNA, CCC: covalently closed circular DNA, SS: single strand DNA. CCC DNA is the most stable
form and is believed to persist for a long time in liver cells. Consider, that CCC DNA is reduced more by L-Hyd4C
than by 3TC (cooperation with J. Köck, Universität Freiburg).
demonstrates the effects of L-Hyd4C on the different intracellular
forms of duck HBV DNA. These modified nucleosides
analogs are among the most effective inhibitor of hepatitis
B virus (HBV) replication detected so far. The hydroxylation
reduced the cytotoxicity (CD 50 ) of the most effective nucleoside
analogues about 10-100fold in HepG2 cells.
Furthermore, we have compared the effects of L-Hyd4C and
3TC on the erythroid (BFU-E) and granulocyte-macrophage
(CFU-GM) hematopoietic progenitor proliferation of human
bone marrow. L-Hyd4C required a concentration nearly
2fold higher than 3TC to suppress 50% CFU GM colony formation
(cooperation with I. Blau, Charité, Berlin). The
Ames-test has shown that L-Hyd4C has no mutagenic
activity.
We have synthesized the triphosphates of L-Hyd4C and of
further analogs to study their effects on the presumed viral
and cellular targets. For the HBV DNA polymerase we found
an IC 50 value of 0.21 µM and for the duck hepatitis B virus
(DHBV) DNA polymerase 0.049 µM. In contrast, the cellular
DNA polymerases α, β, γ, δ, ε and λ are 350-7500 fold less
sensitive than the HBV DNA polymerase demonstrating that
the cellular DNA replication is not influenced by this compound
(cooperation with U. Hübscher, University of Zürich).
Studies of the metabolism of tritium-labeled L-Hyd4C have
shown that this nucleoside is not a substrate of the human
cytidine deaminase and can be efficiently phosphorylated to
the triphosphate in HepG2 cells.
First in vivo experiments to estimate the systemic toxicity
have revealed that L-Hyd4C has no side effects, a result
stimulating us to initiate investigations of the in vivo efficiency
of this compound in a human-mouse chimera model
of HBV (in cooperation with M. Dandri, University of
Hamburg).
Selected Publications
Matthes, E, Funk, A, Krahn, I, Gaertner, K, von Janta-Lipinski,
M, Lin, L, Will, H, Sirma, S. (2007). Strong and selective inhibitors
of hepatitis B virus replication among novel N 4 -hydroxy- and
5-methyl-β-L-deoxycytidine analogues. Antimicrob. Agents
Chemother. 51, 2523-2530.
Matthes, E, Lehmann, C, Stulich, M, Wu, Y, Dimitrova, L,
Uhlmann, E, von Janta-Lipinski, M. (2005). Potent inhibitory
activity of chimeric oligonucleotides targeting two different sites
of human telomerase. Oligonucleotides 15, 255-268.
Matthes, E, von Janta-Lipinski, M, Will, H, Sirma, H, Li, L Neue
β-L-N4-Hydroxycytosin Nucleoside und ihre Verwendung. PCT
application 21.10.2005.
114 Cancer Research