Objective: To evaluate the antitumor immune effects of B7-1 gene expression mediated by adenoviral vectors against squamous cell carcinoma. Transfection of the costimulatory molecule B7-1 gene into certain murine tumors increases antitumor immunity and suppresses tumor growth.
Design: In vitro and in vivo study.
Interventions: A murine squamous cell carcinoma cell line, KLN205, was infected with adenoviral vectors carrying either B7-1 (AdB7) or LacZ (AdCL) genes. Infected cells were injected subcutaneously into the flanks of DBA/2 mice.
Main outcome measures: The growth of tumors infected with adenviral vectors was measured.
Results: AdB7-infected cells grew significantly slower than AdCL-infected cells in vivo, while there was no significant difference in the growth rates between the 2 groups in vitro. Moreover, significant growth suppression of rechallenged noninfected parental cells was observed in the mice immunized with AdB7-infected cells but not in those immunized with AdCL-infected cells.
Conclusion: These results suggest that the B7-1 gene has therapeutic potential for immunotherapy against head and neck squamous cell carcinoma.