Cellular signal-specific peptide substrate is essential for the gene delivery system responding to cellular signals.
Recently, there is a growing interest in the intracellular signal-targeting gene therapy or diagnosis, mainly by using the reaction of targeting enzymes with peptide substrates. In the present study, we proved the importance of target intracellular signal-specificity peptide substrate for intracellular signals-targeting gene therapy or diagnosis. Protein kinase C (PKC) was used as a trigger to activate the transgene expression. Two peptides, a positive peptide showing phosphorylation levels on several PKC isozymes (PKCalpha, betaII, gamma, epsilon, eta, zeta, and iota/lambda) and a negative peptide in which the phosphorylation site was destroyed by changing from serine to alanine, were designed. Moreover, two polymers possessing each peptide as a pendant chain, a PKC-responsive conjugate [PPC(S)] and a negative control conjugate [PPC(A)], were synthesized. After the introduction of complexes into cells or tissues, gene expression for PPC(S)/DNA complexes was higher that for PPC(A)/DNA complexes. However, no difference in gene expression between B16 melanoma tumors and normal skin tissues was identified. These results suggest that a peptide substrate specific to a target intracellular signal is very important for intracellular signals-targeting gene therapy or diagnosis.
Department of Applied Chemistry, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-Ku, Fukuoka 819-0395, Japan. jrjhkang@ri.ncvc.go.jp
Jeong-Hun
JH
Kang
Riki
R
Toita
Tetsuro
T
Tomiyama
Jun
J
Oishi
Daisuke
D
Asai
Takeshi
T
Mori
Takuro
T
Niidome
Yoshiki
Y
Katayama
D000595:Amino Acid Sequence; D045744:Cell Line, Tumor; D015971:Gene Expression Regulation, Enzymologic; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
D007527:Isoenzymes; D010455:Peptides; D011493:Protein Kinase C