An optimized gene transfection system in WERI-Rb1 cells

The pathogenesis of Rb1 gene inactivation indicates that gene therapy could be a promising treatment for retinoblastoma. An appropriate gene transfer system is the basis for successful gene therapy; however, little attention has been given to an effective gene transfer system for retinoblastoma therapy in previous studies. This study was designed to provide an optimized transgene system for WERI-Rb1 cells (W-RBCs). Green fluorescent protein (GFP) was adopted as a reporter. Four classic viral vectors based on retroviruses, recombinant adeno-associated viruses (rAAV2, rAAV2/1), lentiviruses (LVs) and a novel non-viral vector X-treme HP reagent were adopted for W-RBC gene transfection. The efficacy and cytotoxicity were comprehensively compared among the different vectors through GFP expression and the trypan blue exclusion test. Furthermore, the serum and cell culture status were also optimized for better transfection. Cells transfected by rAAV2/1 expressed more GFP protein and exhibited less staining with trypan blue, compared to the rAAV2 counterpart. However, in comparison to the retroviral group, both the rAAV2/1 and LV groups had considerably less GFP(+) cells. Interestingly, the X-treme HP presented a similar GFP transfection capacity to the retroviral vector, but with a much lower cytotoxicity. Furthermore, there were more GFP(+) cells in a suspended condition than that in an adherent culture. Moreover, cells in a serum-positive system expressed more GFP, while cells in a serum-free system showed lower GFP expression and higher cytotoxicity. In conclusion, the retroviral vector and the X-treme HP are effective for W-RBC gene transfection, while the X-treme HP is more preferable due to its lower cytotoxicity. Moreover, the suspended cell culture system is superior to the adherent system, and the serum protects cell viability and facilitates the gene transfection of W-RBCs. This study presents an effective, convenient, and low toxic transfection system for gene delivery in W-RBCs and provides a promising system for further gene therapy of retinoblastoma.