Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada.
J Cell Biochem. 2019 Aug;120(8):14035-14043. doi: 10.1002/jcb.28678. Epub 2019 Apr 16.
We investigated the role of stattic as an adjuvant molecule to increase the cytotoxicity of 5-fluorouracil (5-FU) through specific inhibition of molecular targets, signal transducer and activator of transcription 3 (STAT3) and nuclear factor erythroid 2-related factor 2 (Nrf2) in HT-29 colon cancer cells. Cytotoxicity and apoptotic effects were investigated by methylthiazolyldiphenyl-tetrazolium bromide assay and flow cytometry analysis, respectively. Real-time polymerase chain reaction was applied to assess the messenger RNA (mRNA) level of STAT3, Nrf2, and apoptotic genes including Bax, Bcl-xl, and Bcl-2. The antitumor effect of 5-FU in combination with stattic induced synergistic effect in HT-29 cells with combination indexes (CIs) 0.49. Flow cytometric results related to apoptotic confirmed that there was up to 40% increase in the population of apoptotic cells in HT-29 colon cancer cells incubated with 5-FU and stattic compared with control groups. Our data from gene expression determined a substantial diminish in the mRNA levels of the Nrf2 and antiapoptotic gene Bcl-2 along with a noticeable increase in the level of the proapoptotic Bax in HT-29 colon cells that underwent cotreatment with 5-FU and stattic (P < 0.05). Moreover, the results exhibited that stattic can be used as adjuvant chemotherapy besides the 5-FU. This therapeutic approach in colon cancer could mediate 5-FU chemoresistance via modulating therapeutic targets (ie, STAT3 and Nrf2 pathways) and decreased 5-FU-related adverse effects.
我们研究了 stattic 作为一种佐剂分子的作用，通过特异性抑制分子靶点，即信号转导和转录激活因子 3（STAT3）和核因子红细胞 2 相关因子 2（Nrf2），来增加氟尿嘧啶（5-FU）对 HT-29 结肠癌细胞的细胞毒性。通过甲基噻唑基四唑溴盐测定法和流式细胞术分析分别研究细胞毒性和凋亡作用。应用实时聚合酶链反应评估 STAT3、Nrf2 和包括 Bax、Bcl-xl 和 Bcl-2 在内的凋亡基因的信使 RNA（mRNA）水平。5-FU 与 stattic 联合使用在 HT-29 细胞中产生协同作用，组合指数（CI）为 0.49。与凋亡相关的流式细胞术结果证实，与对照组相比，孵育有 5-FU 和 stattic 的 HT-29 结肠癌细胞中凋亡细胞群体增加了高达 40%。我们从基因表达中获得的数据确定，在用 5-FU 和 stattic 共同处理的 HT-29 结肠细胞中，Nrf2 和抗凋亡基因 Bcl-2 的 mRNA 水平显著降低，而促凋亡 Bax 的水平明显升高（P<0.05）。此外，结果表明，stattic 除了 5-FU 之外还可以用作辅助化疗。这种结肠癌的治疗方法可以通过调节治疗靶点（即 STAT3 和 Nrf2 途径）来介导 5-FU 耐药性，并降低 5-FU 相关的不良反应。
