[Adenovirus mediated gene transfer of tyrosinase gene on HepG2 cell by magnetic resonance imaging].
OBJECTIVE
To evaluate the transfect results of recombinant adenovirus vector carrying tyrosinase gene (Ad-tyr) in vitro by magnetic resonance imaging (MRI) after the Ad-tyr was transfected into HepG2 cell.


METHODS
The Ad-tyr which carried the full-length cDNA of tyrosinase gene was transfected into HepG2 cell. The transfected cells were scan by MRI sequences of T1 weighted image (T1WI) , T2 weighted image (T2WI) , and short time inversion recovery (STIR) to observe the MRI signals of expressed melanin. Masson-Fontana staining was performed to search for melanin granules in transfected cells. Real-time PCR method was used to search for cDNA of tyrosinase gene.


RESULTS
Ad-tyr was transfected into HepG2 cells and synthesized a large amount of melanin inside. The synthesized melanin of 1 x 10(6) cells which had been transfected by Ad-tyr with the 50, 150, and 300 multiplicity of infection separately were all sufficient to be detected by MRI and showed high signals in MRI T1WI, T2WI, and STIR sequences. The signal intensities of MRI were positively correlated to the amounts of transfected Ad-tyr. The melanin granules were found in HepG2 cells in Masson-Fontana staining. The cDNA amount of tyrosinase gene in transfected HepG2 cells, which was detected by real-time PCR, was remarkably higher than that in nontransfected cells.


CONCLUSIONS
The synthesized melanin of HepG2 cells, which controlled by expression of exogenous gene, can be detected by MRI, indicating that the adenovirus vector can efficiently carry the tyrosinase gene into HepG2 cells.
Yuan
Jian-Peng
JP
Department of Radiology, Second Affiliated Hospital, Sun Yat-sen University, Guangzhou 510120, China.
Liang
Bi-Ling
BL
Deng
He-Ran
HR
Liu
Zhuang-Sheng
ZS
Bai
Shou-Min
SM
Zhong
Jing-Lian
JL
D000256:Adenoviridae / Q000235:genetics* / Q000378:metabolism; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000235:genetics; D056945:Hep G2 Cells; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008543:Melanins / Q000032:analysis / Q000235:genetics; D014442:Monophenol Monooxygenase / Q000096:biosynthesis / Q000235:genetics*; D014162:Transfection
D008543:Melanins; D014442:Monophenol Monooxygenase