Abrogation of VEGF expression in human head and neck squamous cell carcinoma decreases angiogenic activity in vitro and in vivo

Synthesis of ribozyme against vascular endothelial growth factor165 and its biological activity in vitro

AIM: To investigate the designation, synthesis and biological activity of against vascular endothelial growth factor₁₆₅ (VEGF₁₆₅) ribozyme.

METHODS: The ribozyme against VEGF₁₆₅ was designed with computer. The transcriptional vector was constructed which included the anti-VEGF₁₆₅ ribozyme and 5’, 3’ self-splicing ribozymes. The hammerhead ribozyme and substrate VEGF₁₆₅ mRNA were synthesized through transcription in vitro. The cleavage activity of the ribozyme on target RNA was observed in a cell-free system.

RESULTS: The anti-VEGF₁₆₅ ribozyme was released properly from the transcription of pGEMRz212 cleaved by 5’ and 3’ self-splicing ribozymes which retained its catalytic activity, and the cleavage efficiency of ribozyme reached 90.7%.

CONCLUSION: The anti-VEGF₁₆₅ ribozyme designed with computer can cleave VEGF₁₆₅ mRNA effectively.

Feasibility of VEGF ASODN mixed with lipiodol transfecting liver cancer via hepatic artery infusion in rats

AIM: To study the distribution and stability of VEGF ASODN in Walker-256 cells and to explore the distribution of VEGF ASODN in rat's liver, lung and kidney after mixed with lipiodol for hepatic artery infusion.

METHODS: The 5-FITC labeled VEGF ASODN was given into Walker-256 cell culture media. The cellular distribution was observed by fluorescent microscope. Walker-256 carcinosarcoma was transplanted into Wistar rat liver to establish the liver cancer model. 5'-FITC labeled VEGF ASODN mixed with (mixed group, n = 6) or without (TAI group, n = 6) ultra-fluide lipiodol was administrated via hepatic artery. The frozen samples of rats' liver, lung and kidney tissues were collected at 1, 3, and 6d after ASODN administration. The distribution of ASODN was determined under fluorescent microscope.

RESULTS: ASODN could enter the cytoplasm within 2 h and enter the nuclei within 4 h. Accumulation of the ASODN reached the high point in the nuclei at 6h. After that, they began to disappear. No fluorescence could be seen in cells at 48 h. At 1d and 3d, the fluorescence stained stronger in the liver in the mixed group than that in TAI group. More fluorescence could be detected in lung and kidney in TAI group than that in the mixed group. At 6 d, no fluorescence could be detected in TAI group tissues, but a little florescence could be seen in the mixed group tissues. ASODN could be seen in cancer cells and normal hepatic cells.

CONCLUSION: VEGF ASODN can transfect Walker-256 cells. VEGF ASODN stays longer in the liver, is transfected more into hepatic and cancerous cells and distributes less in other tissue when mixed with lipiodol. VEGF ASODN mixed with lipiodol via hepatic artery is an ideal way treating liver carcinoma.