Objective： Her-2/neu protein overexpression has been demonstrated in lung adenocarcinoma. Its overexpression often indicates a poor prognosis and resistance to chemotherapeutic agents. The objectives of this paper is to explore the effectiveness of double-stranded short inhibitory RNAs （siRNA） targeting Her-2/neu oncogene on the drug sensitivity of Her-2/neu-overexpressing lung adenocarcinoma cells. Methods： Lung adenocarcinoma cell line calu-3 was transfected with siRNAs formulated LipofectAMINE 2000, and Her-2/neu protein and P-gp were determined by flow cytometry （FCM）. The chemosensitivity of transfected cells to cisplatin （CDDP） was measured by MTT. Cell apoptosis detection kit （Annexin V method） was used to examine the drug induced apoptosis rate. Results： siRNA targeting Her-2/neu greatly reduced the cell surface expression of Her-2/neu protein and had no effect on P-gp. Consequently the inhibitory rate of CDDP in combination with siRNA targeting Her-2/neu was （67.1±2.3）%, while the inhibitory rates were （48.1±3.5）%, （46.3±5.9）% and （50.2±2.9）% in untreated control, empty vector and unrelated siRNA groups, respectively. The FCM results showed that the apoptosis rate of cells treated with CDDP combined with siRNAs-Her-2/neu was elevated when compared with unrelated siRNA group and empty vector group. Conclusion： Sequence specific siRNA targeting Her-2/neu was capable of enhancing the chemosensitivity of calu-3 cell to cisplatin.
Objective: Her-2/neu protein overexpression has been demonstrated in Non-small cell lung cancer, especially in lung adenocarcinoma. Its overexpression often indicates a poor prognosis. Therapeutic agents against her-2/neu have been intensively sought over the past decades. The objective of this paper is to investigate the effect of chemically synthesized siRNA targeting her-2/neu on her-2/neu dysregulated human lung adenocarcinoma cells. Methods: Calu-3 cells were transfected with siRNAs formulated LipofectAMINE 2000. The her-2/neu mRNA and protein levels were detected by RT-PCR and flow cytometry (FCM). The biological morphology and growth inhibition of calu-3 cells were observed with light microscopy and MTT assay, respectively. The cell cycle and apoptosis rate were analyzed by FCM. Results: siRNA targeting Her-2/neu down-regulated the transcription of her-2/neu oncogene and protein level. Slowed cell proliferation and cell cycle arrest at G0/1 stage could be also observed, accompanied with enhanced cell apoptosis. Conclusion: Specific siRNA targeting her-2/neu can effectively inhibit her-2/neu expression in her-2/neu overexpressing calu-3 cell lines. siRNA-mediated gene silencing may be a useful therapeutic strategy for cancer.
