Adenovirus type 5 EIA gene therapy for ovarian carcinoma

卵巢透明细胞癌(CCC)对铂类药物的耐药与预后不良有关，因此迫切需要对晚期疾病进行有效的治疗。HER2/neu在卵巢上皮性癌中上调的频率高于其他组织学类型的卵巢癌。这项研究的目的是评估用抗HER2抗体Tanstuzumab或人5型腺病毒E1a治疗卵巢CCC的可能性。我们用曲妥珠单抗或E1a处理10个CCC细胞系，评估细胞活力、增殖、克隆形成以及HER2和野生型P53蛋白和这些信号通路下游分子的表达。Western blotting检测到10株细胞中均有不同程度的HER2蛋白表达，免疫组织化学染色检测到5株CCC细胞中均有HER2蛋白表达：仅1株细胞(RMG-I)有HER2基因扩增(荧光原位杂交)。曲妥珠单抗对所测试的四种CCC细胞系(RMG-I、SKOV-2、OVTOKO和OVSAYO)中的任何一种都没有抑制增殖。然而，无论HER2的表达水平如何，E1A(与对照载体相比)都减少了所有10个CCC细胞系的克隆形成。用编码E1a的腺病毒载体感染RMG-I和SMOV-2细胞后，细胞的增殖受到显著抑制(P&lt；0.05)，细胞死亡增加；这种作用需要稳定p53(而不是p73)蛋白，并与Bax上调和caspase9的切割有关。其他机制，如P53非依赖性的细胞凋亡，也可能参与了E1a介导的CCC细胞死亡。最后，在ccc异种移植模型中，E1a的治疗延长了存活时间(P&lt；0.001)。E1a基因治疗由于其稳定野生型p53的能力，作为卵巢CCC的一种治疗方式值得探索，卵巢CCC通常表达野生型p53。

Resistance of ovarian clear cell carcinoma (CCC) to platinum-based chemotherapy is associated with poor prognosis, and an effective treatment for advanced disease is urgently needed. HER2/neu is up-regulated more often in CCC than in other histologic types of epithelial ovarian cancer. The purpose of this study was to assess possible treatment for ovarian CCC with the anti-HER2 antibody tanstuzumab or human adenovirus type 5 E1A. We treated 10 CCC cell lines with transtuzumab or E1A and assessed cell viability, proliferation, and colony formation and the expression of HER2 and wild-type p53 proteins and molecules downstream of those signaling pathways. HER2 protein was detected at various levels in all 10 cell lines by Western blotting and in 5 CCC cell lines by immunohistochemical staining: HER2 gene amplification was detected (by fluorescence in situ hybridization) in only one cell line (RMG-I). Trastuzumab did not inhibit proliferation in any of the four CCC cell lines tested (RMG-I, SKOV-2, OVTOKO, and OVSAYO). However, transfection with E1A (as compared with control vectors) reduced colony formation in all 10 CCC cell lines regardless of HER2 expression level. Infection of RMG-I and SMOV-2 cells with an adenoviral vector encoding E1A led to significant (P<0.05) suppression of proliferation and enhancement of cell death; this effect required stabilization of p53 (but not p73) protein and was associated with the up-regulation of Bax and the cleavage of caspase9. Other mechanisms, such as p53-independent apoptosis, may also be involved in E1A-mediated cell death in CCC. Finally, treatment with E1A prolonged survival in a CCC xenograft model (P<0.001). E1A gene therapy, because of its ability to stabilize wild-type p53, is worth exploring as a treatment modality for women with ovarian CCC, which typically expresses wild-type p53.