Improving gene transfer in human renal carcinoma cells: Utilization of adenovirus vectors containing chimeric type 5 and type 35 fiber proteins

A novel fiber chimeric conditionally replicative adenovirus-Ad5/F35 for tumor therapy

Significant progress has been made in the diagnosis and treatment of cancer; however, significant challenges remain. Conditionally replicating adenoviruses (CRAds), which not only kill cancer cells, but also serve as vectors to express therapeutic genes, are a novel and effective method to treat cancer. However, most adenoviruses are Ad5, which infect cells through the coxsackie and adenovirus receptor (CAR). The transduction efficacy of Ad5 is restricted because of the absent or low expression of CAR on several cancer cells. Ad serotype 35 has a different tropism pattern to Ad5. Ad35 attaches to cells via a non-CAR receptor, CD46, which is expressed widely on most tumor cells. Thus, chimeric adenoviral vectors consisting of the knob and shaft of Ad35 combined with Ad5 have been constructed. The chimeric fiber adenoviral vectors can transduce CAR-positive and CAR-negative cell lines. In this review, we explore the application of the novel fiber chimeric conditionally replicative adenovirus-Ad5/F35 in tumor therapy in terms of safety, mechanism, transduction efficacy, and antitumor effect.

Fiber-substituted conditionally replicating adenovirus Ad5F35 induces oncolysis of human bladder cancer cells in in vitro analysis

OBJECTIVE

To assess the oncolytic effect of fiber-substituted conditionally replicating adenovirus type 5 (Ad5) F35 vector on human bladder cancer cell lines such as 253J, 5637, KK-47, T24, TCCSUP, and UMUC-3 cells.

MATERIALS AND METHODS

Ad5F35 and Ad5 conditionally replicating adenovirus vectors containing the E1 gene controlled by the human midkine promoter (Ad5F35/MKp-E1 and Ad5/MKp-E1, respectively) were constructed. Reverse transcriptase-polymerase chain reaction and cell viability assay were performed in cells transfected with Ad5F35/MKp-E1 or Ad5/MKp-E1.

RESULTS

Of the bladder cancer cells used, considerably lower expression of mRNA for Coxsackie and adenovirus receptor, an Ad5 receptor, was found with T24 and TCCSUP cells. However, the mRNA for CD46, an Ad35 receptor, was abundantly expressed in all the cell types. Ad5F35/MKp-E1 induced oncolysis in a plaque formation unit-dependent manner for all the bladder cancer cells used, with greater efficacy than Ad5/MKp-E1 for T24, TCCSUP, and 253J cells.

CONCLUSION

The results of the present study have shown that Ad5F35/MKp-E1 is more useful for the gene therapy of bladder cancer than Ad5/MKp-E1 is for some cell lines.