Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, 08903, USA.
Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Mol Imaging Biol. 2019 Jun;21(3):410-416. doi: 10.1007/s11307-019-01321-w.
Optical redox imaging (ORI), based on collecting the endogenous fluorescence of reduced nicotinamide adenine dinucleotide (NADH) and oxidized flavoproteins (Fp) containing a redox cofactor flavin adenine dinucleotide (FAD), provides sensitive indicators of cellular metabolism and redox status. ORI indices (such as NADH, FAD, and their ratio) have been under investigation as potential progression/prognosis biomarkers for cancer. Higher FAD redox ratio (i.e., FAD/(FAD + NADH)) has been associated with higher invasive/metastatic potential in tumor xenografts and cultured cells. This study is to examine whether ORI indices can respond to the modulation of oncogene DEK activities that change cancer cell invasive/metastatic potential.
Using lentiviral shRNA, DEK gene expression was efficiently knocked down in MDA-MB-231 breast cancer cells (DEKsh). These DEKsh cells, along with scrambled shRNA-transduced control cells (NTsh), were imaged with a fluorescence microscope. In vitro invasive potential of the DEKsh cells and NTsh cells was also measured in parallel using the transwell assay.
FAD and FAD redox ratios in polyclonal cells with DEKsh were significantly lower than that in NTsh control cells. Consistently, the DEKsh cells demonstrated decreased invasive potential than their non-knockdown counterparts NTsh cells.
This study provides direct evidence that oncogene activities could mediate ORI-detected cellular redox state.
基于收集还原型烟酰胺腺嘌呤二核苷酸（NADH）和含有氧化还原辅因子黄素腺嘌呤二核苷酸（FAD）的氧化黄素蛋白（Fp）的内源性荧光，光学氧化还原成像（ORI）提供了细胞代谢和氧化还原状态的敏感指标。ORI 指数（如 NADH、FAD 及其比值）已被作为癌症进展/预后的潜在生物标志物进行研究。较高的 FAD 氧化还原比（即 FAD/（FAD + NADH））与肿瘤异种移植物和培养细胞中较高的侵袭/转移潜力相关。本研究旨在检验 ORI 指数是否可以响应改变癌细胞侵袭/转移潜力的癌基因 DEK 活性的调节。
使用慢病毒 shRNA，DEK 基因表达在 MDA-MB-231 乳腺癌细胞（DEKsh）中被有效地敲低。这些 DEKsh 细胞与转导 scrambled shRNA 的对照细胞（NTsh）一起用荧光显微镜成像。同时，还使用 Transwell 测定法平行测量 DEKsh 细胞和 NTsh 细胞的体外侵袭潜力。
DEKsh 多克隆细胞中的 FAD 和 FAD 氧化还原比明显低于 NTsh 对照细胞。一致地，DEKsh 细胞表现出比其非敲低对照 NTsh 细胞降低的侵袭潜力。
这项研究提供了直接证据，表明癌基因活性可以介导 ORI 检测到的细胞氧化还原状态。
