Reversal of drug resistance of trastuzumab-resistant human breast cancer cells by recombinant adenovirus carrying PTEN gene / 中国肿瘤生物治疗杂志

ABSTRACT

Objective:To study the role of adenoviral-mediated PTEN gene transfection in reversing drug resistance of trastuzumab-resistant human breast cancer.Methods:Recombinant adenoviruses carrying PTEN gene(AdPTEN) were constructed and transfected into trastuzumab-resistant human breast cancer cell line BT474.Proliferation and apoptosis of BT474 cells treated with AdPTEN and trastuzumab were measured by MTT assay and FCM.Time course of BT474 cells apoptosis induced by AdPTEN was analyzed by detection of DNA fragmentation.Western blotting was employed to measure phosphorylated-Akt expression levels in AdPTEN treated BT474 cells.The nude mice model of BT474 cells was employed to observe the effects of AdPTEN and trastuzumab on trastuzumab-resistant human breast cancer in vivo.The expression of PTEN gene,cancer cells apoptosis and ultrastructural changes were evaluated after the mice were sacrificed.Results:We successfully constructed recombinant AdPTEN;and the titer of the recombinant adenovirus was about 4.2?1011TCID50/ml.PTEN gene expression was identified by PCR,RT-PCR and Western blotting assay.Combinatorial AdPTEN and trastuzumab significantly suppressed the proliferation of BT474 cells and induced the apoptosis.The percentage of apopotosis cells treated with AdPTEN was(20.7?5.82)%,companied by cells cycle arrest in G1 phrase(P