Hematology, Oncology and Stem Cell Transplantation Research Center, Shariati Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Life Sci. 2020 Sep 15;257:118060. doi: 10.1016/j.lfs.2020.118060. Epub 2020 Jul 6.
Despite the remarkable anti-proliferative effects of Arsenic trioxide (ATO) in breast cancer cells, the requirement of high, toxic concentrations to induce apoptosis may cause serious side effects in patients. In the present study, we aimed to use BIBR1532, an hTERT inhibitor, in combination with ATO to sensitize MCF7 and MDA-231 cells to lower concentrations of ATO.
Breast cancer cell lines MCF7 and MDA-231 were cultured and treated with different doses of ATO and BIBR1532 for 48 h and its effects on cell survival and proliferation were analyzed by MTT, crystal violet staining, colony formation assay, cell cycle, AnnexinV/PI and Real-time PCR tests.
ATO and BIBR1532 synergistically inhibited proliferation and colony-forming ability of breast cancer cells. Besides, BIBR1532 augmented ATO-induced cytotoxic effects via triggering G1 cell cycle arrest and induction of apoptosis coupled with the down-regulation of NF-κB target genes that were involved in cell cycle progression (e.g. CCND1 and CDK6) and prevention of apoptosis such as Bcl-2, Bcl-xl, c-IAP2, and Survivin Respectively. Moreover, ATO-BIBR1532 significantly reduced the mRNA expression level of RELA, NFKB1, and several validated target genes of the NF-κB signaling pathway including NFKBIA, VEGFC, c-Myc, and hTERT.
The combination of ATO and BIBR1532 synergistically induced its anti-proliferative effect in breast cancer cells by targeting the two key cancer-related pathways, hTERT and NF-κB, and disrupting their feed-forward loop at the same time which result in the reduction of NF-κB transcriptional activity and subsequent down-regulation of its target genes.
尽管三氧化二砷（ATO）在乳腺癌细胞中具有显著的抗增殖作用，但诱导细胞凋亡所需的高浓度、毒性浓度可能会给患者带来严重的副作用。在本研究中，我们旨在使用 hTERT 抑制剂 BIBR1532 与 ATO 联合使用，以降低 ATO 的浓度来敏化 MCF7 和 MDA-231 细胞。
培养乳腺癌细胞系 MCF7 和 MDA-231，并分别用不同剂量的 ATO 和 BIBR1532 处理 48 小时，通过 MTT、结晶紫染色、集落形成试验、细胞周期、AnnexinV/PI 和实时 PCR 试验分析其对细胞存活和增殖的影响。
ATO 和 BIBR1532 协同抑制乳腺癌细胞的增殖和集落形成能力。此外，BIBR1532 通过触发 G1 细胞周期阻滞和诱导凋亡，并下调参与细胞周期进程（如 CCND1 和 CDK6）和阻止凋亡（如 Bcl-2、Bcl-xl、c-IAP2 和 Survivin）的 NF-κB 靶基因，增强了 ATO 诱导的细胞毒性作用。此外，ATO-BIBR1532 显著降低了 RELA、NFKB1 和 NF-κB 信号通路的几个验证靶基因（包括 NFKBIA、VEGFC、c-Myc 和 hTERT）的 mRNA 表达水平。
ATO 和 BIBR1532 的联合使用通过靶向两个关键的癌症相关途径 hTERT 和 NF-κB，并同时破坏它们的正反馈回路，协同诱导乳腺癌细胞的抗增殖作用，导致 NF-κB 转录活性降低，随后下调其靶基因。
