外源性p16基因与放疗联合治疗喉鳞癌的实验研究

Combination of Adenovirus p16^(INK4A) Gene Therapy and Ionizing Radiation for Laryngeal Squamons Cell Carcinoma

目的 探讨外源性 p16基因对人喉鳞状细胞癌的抑制作用及与放射治疗联合应用的协同增敏作用。方法 应用携带 p16基因的复制缺陷型腺病毒 (Ad- p16 )转染人喉鳞癌细胞株 ,用 Western Blot方法检测 p16基因在喉鳞癌细胞中的表达 ,体外、体内实验观察 p16基因治疗和放射治疗对喉癌细胞的生长抑制作用。结果 复制缺陷型腺病毒载体可有效地将外源性 p16基因转染入人喉鳞癌细胞株中并使其表达 P16蛋白 ;体外、体内抑瘤实验表明 :Ad- p16基因治疗组、单纯放疗组和 Ad- p16基因与放疗联合治疗组肿瘤生长均明显受抑制 ,疗效显著优于携带 L ac Z基因的重组腺病毒 (Ad- L ac Z)组和 PBS对照组 (P<0 .0 5 ) ,其中联合治疗组肿瘤生长最为缓慢 ,与 Ad- p16基因治疗组和单纯放疗组比较均有显著性差异 (P<0 .0 5 )。结论 p16基因可有效地抑制人喉鳞癌细胞生长 。

Objective To assess the anti-tumor effect of p16 (INK4A) gene transfer and the combined effect of this gene therapy and ionizing radiation in the treatment of laryngeal squamous cell carcinoma. Methods A Complete p16 (INK4A) gene was inserted into a replication-defective recombinant adenovirus, and the tumor cells were infected with Adenovinus-p16 (Ad-p16) and irradiated with X-rays. Confirmation of P16 (INK4A) protein expression after Ad-p16 infection was performed by Western blotting. The therapeutic effects were evaluated both in vitro and in vivo. Results The replication-defective recombinant adenovirus could direct a high level of P16 INK4A protein expression in laryngeal squamous cell carcinoma. Studies both in vitro and in vivo demonstrated that Ad-p16 treatment significantly inhibited the cell growth and the established tumors in mude mice when compared with the control treatments (P<0.05). The combination of Ad-p16 and radiation group resulted in greater inhibition of tumor growth, compared with any other treatment groups and controls (P<0.05). No significant difference was observed between Adenovirus-LacZ(Ad-LacZ) and PBS groups. Conclusion These results demonstrate a significant antitumor effect of Ad-p16 against human laryngeal squamous cell carcinoma and also demonstrate for the first time a combined effect of radiation and Ad-p16 gene transfer in p16 deficient human laryngeal squamous cell carcinoma.