Comparison of Efficiency of Infection of Human Cancer Cell Lines Via Retroviral Vector System

Kim, Yeon Soo; Lim, Hee Kyung; Kim, Joo Hang; Min, Jin Sik

Abstract

PURPOSE: There are several reasons why retroviruses are useful as vectors for gene therapy. However, retroviral vectors also have some limitations. Research in retroviral-mediated gene transfer has struggled with low titer and transduction efficiency on certain human target cells even with the addition of polycations to enhance transduction. Efficient in vivo gene transfer with retroviral vectors will require the availability of large amounts of vector at titers higher than generally possible by most current methods. Therefore, transduction efficiency of various human cell types with retroviral vector system is very important in human gene therapy. In an effort to test the transduction efficiency of a retrovial vector in the human cancer cell lines, a retroviral vector was infected into various human cancer cell lines.
MATERIALS AND METHODS
We generated retrovirus producing cell lines through transfection or infection of amphotropic packaging cell line PA317 with ecotropic retroviruses encoding bacterial lacZ gene. The amphotropic retrovirus vector was used to transduce various human cancer cell lines.
RESULTS
Of eight randomly chosen G418-resistant clones generated by transfection, only two clone produced the vector at up to >10 (6) cfu/ml, while one of five clones generated by infection yielded higher-titer virus in the absence of helper virus, up to 1 X 10 (7) cfu/ml, than the transfected clones. Transduction with supernatant derived from a PA317 producer cell line has resulted in transduction levels from 1% to 15%, 5- to 60-fold lower than those analyzed in NIH3T3 cells.
CONCLUSION
These findings suggest that new improved gene transfer method into human cancer cells using retroviruses is required for efficient in vivo cancer gene therapy.