TY - JOUR
T1 - Potent antiviral activity of north-methanocarbathymidine against Kaposi's sarcoma-associated herpesvirus
AU - Zhu, Weimin
AU - Burnette, Angela
AU - Dorjsuren, Dorjbal
AU - Roberts, Paula E.
AU - Huleihel, Mahmoud
AU - Shoemaker, Robert H.
AU - Marquez, Victor E.
AU - Agbaria, Riad
AU - Sei, Shizuko
PY - 2005/12/1
Y1 - 2005/12/1
N2 - Kaposi's sarcoma-associated herpesvirus (KSHV) infection is a prerequisite for the development of Kaposi's sarcoma (KS). Blocking lytic KSHV replication may hinder KS tumorigenesis. Here, we report potent in vitro anti-KSHV activity of 2′-evo-methanocarba thymidine [North-methanocarbathymidine (N-MCT)], a thymidine analog with a pseudosugar ring locked in the northern conformation, which has previously been shown to block the replication of herpes simplex virus types 1 and 2. N-MCT inhibited KSHV virion production in lytically induced KSHV-infected BCBL-1 cells with a substantially lower 50% inhibitory concentration (IC50) than those of cidofovir (CDV) and ganciclovir (GCV) (IC50, mean ± standard deviation: 0.08 ± 0.03, 0.42 ± 0.07, and 0.96 ± 0.49 μM for N-MCT, CDV, and GCV, respectively). The reduction in KSHV virion production was accompanied by a corresponding decrease in KSHV DNA levels in the N-MCT-treated BCBL-1 cells, indicating that the compound blocked lytic KSHV DNA replication. A time- and dose-dependent accumulation of N-MCT-triphosphate (TP) was demonstrated in lytically induced BCBL-1 cells, while uninfected cells showed virtually no accumulation. The levels of N-MCT-TP were significantly decreased in the presence of 5′-ethynylthymidine, a potent inhibitor of herpesvirus thymidine kinase, resulting in the abrogation of anti-KSHV activity of N-MCT. N-MCT-TP more effectively blocked in vitro DNA synthesis by KSHV DNA polymerase with an IC50 of 6.24 ± 0.08 μM (mean ± standard deviation) compared to CDV-diphosphate (14.70 ± 2.47 μM) or GCV-TP (24.59 ± 5.60 μM). Taken together, N-MCT is a highly potent and target-specific anti-KSHV agent which inhibits lytic KSHV DNA synthesis through its triphosphate metabolite produced in KSHV-infected cells expressing a virally encoded thymidine kinase.
AB - Kaposi's sarcoma-associated herpesvirus (KSHV) infection is a prerequisite for the development of Kaposi's sarcoma (KS). Blocking lytic KSHV replication may hinder KS tumorigenesis. Here, we report potent in vitro anti-KSHV activity of 2′-evo-methanocarba thymidine [North-methanocarbathymidine (N-MCT)], a thymidine analog with a pseudosugar ring locked in the northern conformation, which has previously been shown to block the replication of herpes simplex virus types 1 and 2. N-MCT inhibited KSHV virion production in lytically induced KSHV-infected BCBL-1 cells with a substantially lower 50% inhibitory concentration (IC50) than those of cidofovir (CDV) and ganciclovir (GCV) (IC50, mean ± standard deviation: 0.08 ± 0.03, 0.42 ± 0.07, and 0.96 ± 0.49 μM for N-MCT, CDV, and GCV, respectively). The reduction in KSHV virion production was accompanied by a corresponding decrease in KSHV DNA levels in the N-MCT-treated BCBL-1 cells, indicating that the compound blocked lytic KSHV DNA replication. A time- and dose-dependent accumulation of N-MCT-triphosphate (TP) was demonstrated in lytically induced BCBL-1 cells, while uninfected cells showed virtually no accumulation. The levels of N-MCT-TP were significantly decreased in the presence of 5′-ethynylthymidine, a potent inhibitor of herpesvirus thymidine kinase, resulting in the abrogation of anti-KSHV activity of N-MCT. N-MCT-TP more effectively blocked in vitro DNA synthesis by KSHV DNA polymerase with an IC50 of 6.24 ± 0.08 μM (mean ± standard deviation) compared to CDV-diphosphate (14.70 ± 2.47 μM) or GCV-TP (24.59 ± 5.60 μM). Taken together, N-MCT is a highly potent and target-specific anti-KSHV agent which inhibits lytic KSHV DNA synthesis through its triphosphate metabolite produced in KSHV-infected cells expressing a virally encoded thymidine kinase.
UR - http://www.scopus.com/inward/record.url?scp=28844434895&partnerID=8YFLogxK
U2 - 10.1128/AAC.49.12.4965-4973.2005
DO - 10.1128/AAC.49.12.4965-4973.2005
M3 - Article
AN - SCOPUS:28844434895
SN - 0066-4804
VL - 49
SP - 4965
EP - 4973
JO - Antimicrobial Agents and Chemotherapy
JF - Antimicrobial Agents and Chemotherapy
IS - 12
ER -