P15 hairpin constructs and use

A genetically modified TGB-3 viral sequence comprising a sequence selected from the group consisting of

• (a) a nucleotide sequence comprising SEQ ID NO:
• 3 and an antisense sequence of SEQ ID NO:
• 3;
• (b) a nucleotide sequence comprising a fragment of SEQ ID NO:
• 3 and an antisense sequence of said fragment of SEQ ID NO:
• 3;
• (c) a nucleotide sequence comprising a modified SEQ ID NO:
• 3 and an antisense sequence of said modified SEQ ID NO:
• 3;
• and
• (d) a nucleotide sequence comprising modified SEQ ID NO:3 fragment and an antisense sequence of said modified SEQ ID NO:
• 3 fragment;
• wherein said genetically modified TGB-3 viral sequence when transcribed in a cell is capable of forming a double-stranded self-complementing RNA molecule.