Han Hui, Yang Sheng, Lin Shun-Guo, Xu Chun-Sen, Han Zhong-Hua
Department of Breast Surgery, The Union Hospital of Fujian Medical University, Fuzhou, Fujian 350001, P.R. China.
Department of Medical Oncology, The Union Hospital of Fujian Medical University, Fuzhou, Fujian 350001, P.R. China.
Mol Med Rep. 2014 Dec;10(6):3092-8. doi: 10.3892/mmr.2014.2659. Epub 2014 Oct 15.
The aim of the present study was to investigate the effects of RNA interference with prostaglandin-endoperoxide synthase 2 (COX‑2) gene on the proliferation and apoptosis of breast cancer MCF‑7 cells, as well as the underlying mechanism. The present study constructed the eukaryotic expression vector of the targeted COX‑2 gene, transfected the MCF‑7 cells and screened the stably expressed clone. Changes in the COX‑2 gene expression in breast cancer MCF‑7 cells prior to and following transfection were examined; the proliferation and apoptosis of MCF‑7 cells were analyzed. Furthermore, changes in the protein levels of survivin, B-cell lymphoma 2 (Bcl‑2) and Bcl-2-associated X (Bax) genes were detected. RNA interference mediated by a lentiviral expression vector significantly decreased the protein expression levels of the COX‑2 gene, and therefore, the proliferation and growth of breast cancer MCF‑7 cells was significantly suppressed and the apoptotic rate increased. Of note, the mRNA and protein expression levels of survivin and Bcl‑2 decreased, while those of Bax increased following COX-2 silencing. RNA interference markedly deactivated the COX‑2 gene, suppressed the proliferation of breast cancer MCF‑7 cells, and, to a certain extent, enhanced the induced spontaneous apoptosis, which is regulated by the Bax gene. These results provided evidence for the potential applications of RNA interference of the targeted COX‑2 gene in gene therapy for the treatment of breast cancer.
本研究旨在探讨RNA干扰前列腺素内过氧化物合酶2（COX‑2）基因对乳腺癌MCF‑7细胞增殖和凋亡的影响及其潜在机制。本研究构建了靶向COX‑2基因的真核表达载体，转染MCF‑7细胞并筛选稳定表达克隆。检测转染前后乳腺癌MCF‑7细胞中COX‑2基因表达的变化；分析MCF‑7细胞的增殖和凋亡情况。此外，检测生存素、B细胞淋巴瘤2（Bcl‑2）和Bcl-2相关X蛋白（Bax）基因蛋白水平的变化。慢病毒表达载体介导的RNA干扰显著降低了COX‑2基因的蛋白表达水平，因此，乳腺癌MCF‑7细胞的增殖和生长受到显著抑制，凋亡率增加。值得注意的是，COX-2沉默后，生存素和Bcl‑2的mRNA和蛋白表达水平降低，而Bax的表达水平升高。RNA干扰显著使COX‑2基因失活，抑制乳腺癌MCF‑7细胞的增殖，并在一定程度上增强由Bax基因调节的诱导性自发凋亡。这些结果为靶向COX‑2基因的RNA干扰在乳腺癌基因治疗中的潜在应用提供了证据。
