Study of the suicide gene therapy using HSVtk gene and GCV for oral cancer

基因治疗为肿瘤的治疗提供了新的途径。本研究旨在探讨单纯疱疹病毒胸苷激酶（HSVtk）基因联合更昔洛韦（GCV）自杀基因治疗口腔癌的可行性。使用四种人口腔鳞状细胞癌细胞系。为了评估转导效率，用含有β-半乳糖苷酶基因的腺病毒载体（Ad）或腺相关病毒载体（AAV）体外转导每个细胞系。到转导后24小时，在Ad中，在感染复数（MOI）为10时，几乎100%的细胞被转导，在MOI为1时，10至30%的细胞被转导。AAV的转导效率在MOI为10000时接近100%，在MOI为1000时为40 - 50%。接着，用含有HSVtk基因的Ad或AAV转导每个细胞系，随后施用GCV以评估自杀基因疗法。随后给予GCV导致肿瘤细胞完全死亡。将含HSVtk基因的腺病毒或腺相关病毒（AAV）注射到SCID小鼠体内，然后腹膜内注射GCV，可显著抑制移植口腔鳞癌细胞SAS的裸鼠的肿瘤生长。这些结果表明，自杀基因治疗HSVtk和GCV显示了一个有效的治疗策略，口腔癌。

Gene therapy offers the possibility of new approach to cancer treatment. The purpose of this study was to test the feasibility of suicide gene therapy using herpes simplex virus thymidine kinase (HSVtk) gene and ganciclovir (GCV) for oral cancer. Four human oral squamous cell carcinoma sell lines were used. To evaluate transduction efficiency, each cell line was transduced in vitro with an adenovirus vector (Ad) or adeno-associated virus vector (AAV) containing the β-galactosidase gene. By 24 hours after transduction, nearly 100% of the cells were transduced at a multiplicity of infection (MOI) of 10, and from 10 to 30% at a MOI of 1 in Ad. Transduction efficiency in AAV was nearly 100% at a MOI of 10000, and from 40 to 50% at a MOI of 1000. Next, each cell line was transduced with an Ad or AAV containing the HSVtk gene, and subsequent administration of GCV for the assessment of suicide gene therapy. Subsequent administration of GCV resulted in complete tumor cell death. Ad or AAV containing the HSVtk gene injection followed by intraperiotoneal GCV administration inhibited remarkably tumor growth in the nude mice to which oral squamous cell carcinoma cell SAS was transplanted SCID mouse. These results suggest that suicide gene therapy with HSVtk and GCV has revealed an effective treatment strategy for the oral cancer.