Yun Miyong, Lee Duckgue, Park Moon-Nyeo, Kim Eun-Ok, Sohn Eun Jung, Kwon Byung-Mog, Kim Sung-Hoon
College of Korean Medicine, Kyung Hee University, Seoul, South Korea.
Cell Physiol Biochem. 2015;35(5):1821-30. doi: 10.1159/000373993. Epub 2015 Mar 26.
BACKGROUND/AIMS: Our group reported that cinnamaldehyde derivative, (E)-4-((2-(3-oxopop-1-enyl)phenoxy)methyl)pyridinium malonic acid (CB-PIC) induced apoptosis in hypoxic SW620 colorectal cancer cells via activation of AMP-activated protein kinase (AMPK) and extracellular signal regulated kinase (ERK). Herein, sensitizing effect of CB-PIC was investigated in resistant cancer cells such as paclitaxel (PT) resistant lung cancer cells (H460/PT), and Adriamycin (Adr) resistant breast cancer (MCF7/Adr) and colon cancer (HCT15/cos) cells.
Various drug resistant cell lines were treated with CB-PIC, and the signalling pathway and functional assay were explored by Western blot, Rhodamine assay, FACS, RT-PCR and MTT assay.
We found that CB-PIC effectively exerted cytotoxicity, increased sub G1 population and the cleaved form of poly (ADP-ribose) polymerase (PARP) and caspase 9 in drug resistant cancer cells. Furthermore, CB-PIC sensitized resistant cancer cells to adriamycin via downregulation of survival proteins such as survivin, Bcl-xL and Bcl-2, along with MDR1 suppression leading to accumulation of drug in the intracellular region. Of note, CB-PIC transcriptionally decreased MDR1 expression via suppression of STAT3 and AKT signalling in three resistant cancer cells with highly expressed P-glycoprotein. Nonetheless, CB-PIC did not affect transport activity of P-glycoprotein in a short time efflux assay, while epigallocatechin gallate (EGCG) accumulated Rhodamine 123 into intracellular region of cell by direct inhibition of MDR1 transport activity.
These data demonstrate that CB-PIC suppresses the P-glycoprotein expression through inhibition of STAT3 and AKT signalling to overcome drug resistance in chemo-resistant cancer cells as a potent chemotherapeutic sensitizer.
背景/目的：我们的研究小组报告称，肉桂醛衍生物（E）-4-（（2-（3-氧代-1-烯丙基）苯氧基）甲基）吡啶丙二酸（CB-PIC）通过激活AMP活化蛋白激酶（AMPK）和细胞外信号调节激酶（ERK），诱导缺氧的SW620结肠癌细胞凋亡。在此，研究了CB-PIC对耐药癌细胞的致敏作用，如对紫杉醇（PT）耐药的肺癌细胞（H460/PT）、对阿霉素（Adr）耐药的乳腺癌（MCF7/Adr）和结肠癌细胞（HCT15/cos）。
用CB-PIC处理各种耐药细胞系，通过蛋白质免疫印迹法、罗丹明检测法、流式细胞术、逆转录聚合酶链反应和MTT检测法探索信号通路和功能检测。
我们发现CB-PIC在耐药癌细胞中有效发挥细胞毒性作用，增加亚G1期细胞群以及聚（ADP-核糖）聚合酶（PARP）和半胱天冬酶9的裂解形式。此外，CB-PIC通过下调存活蛋白如survivin、Bcl-xL和Bcl-2，使耐药癌细胞对阿霉素敏感，同时抑制多药耐药蛋白1（MDR1）导致药物在细胞内区域积累。值得注意的是，在三种P-糖蛋白高表达的耐药癌细胞中，CB-PIC通过抑制信号转导和转录激活因子3（STAT3）和蛋白激酶B（AKT）信号通路，转录水平降低MDR1表达。然而，在短时间外排试验中，CB-PIC不影响P-糖蛋白的转运活性，而表没食子儿茶素没食子酸酯（EGCG）通过直接抑制MDR1转运活性，使罗丹明123积累到细胞内区域。
这些数据表明，CB-PIC通过抑制STAT3和AKT信号通路抑制P-糖蛋白表达，作为一种有效的化疗增敏剂克服化疗耐药癌细胞的耐药性。
