RNA polymerase III (pol III)-dependent transcripts are involved in many fundamental activities in a cell， such as splicing and protein synthesis. They also regulate cell growth and influence tumor formation. During recent years vector-based systems for expression of short hairpin (sh) RNA under the control of a pol III promoter have been developed as gene-based medicines. Therefore， there is an increasing interest in means to regulate pol III-dependent transcription. Recently， we have developed a novel anti-gene molecule 'Zorro LNA (Locked Nucleic Acid)'， which simultaneously hybridizes to both strands of super-coiled DNA and potently inhibits RNA polymerase II-derived transcription. We have now applied Zorro LNA in an attempt to also control U6 promoter-driven expression of shRNA.