Strong antiviral activity of the new l-hydroxycytidine derivative, l-Hyd4FC, in HBV-infected human chimeric uPA/SCID mice.

Background: Suppression of viral replication with nucleoside/nucleotide inhibitors has been shown to greatly improve the outcome of chronic HBV infection. β-l-nucleoside analogues, especially β-l-deoxycytidine derivatives represent one of the most efficient groups of antiretroviral compounds. We recently described that hydroxylation of the amino group of these β-l-deoxycytidine derivatives preserved their strong HBV inhibitory activity in vitro, but strongly reduced their cytotoxicity.

Potent inhibitory activity of chimeric oligonucleotides targeting two different sites of human telomerase.

Suppression of telomerase activity in tumor cells has been considered as a new anticancer strategy. Here, we present chimeric oligonucleotides (chimeric ODNs) as a new type of telomerase inhibitor that contains differently modified oligomers to address two different sites of telomerase: the RNA template and a suggested protein motif. We have shown previously that phosphorothioate-modified oligonucleotides (PS ODNs) interact in a length-dependent rather than in a sequence-dependent manner, presumably with the protein part of the primer-binding site of telomerase, causing strong inhibition of telomerase.

Real-time determination of telomerase activity in cell extracts using an optical biosensor.

A biosensoric approach has been developed to determine the activity of telomerase in tumor cell lysates. An optical sensor, the grating coupler, was used to monitor the association and dissociation of unlabeled compounds on the sensor surface in real time, by virtue of an evanescent field. An oligonucleotide was immobilized on the surface of the optical biosensor and linked with two other oligonucleotides by complementary sequences in an overlapping manner.

Detection of activity of telomerase in tumor cells using fiber optical biosensors.

Human telomerase plays an important role in the cancerogenesis as it is up-regulated in 80-90% of malignant tumors. Thus, it is considered as a potential cancer marker and relevant target in oncology. Its task is the extension of guanine-rich strands of the telomere using an intrinsic RNA as the template.