Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Department of Pediatrics, Pennsylvania State University, Hershey, PA, USA.
Adv Exp Med Biol. 2018;1072:177-181. doi: 10.1007/978-3-319-91287-5_28.
Our previous studies indicate that the mitochondrial redox state and its intratumor heterogeneity are associated with invasiveness and metastatic potential in human breast cancer cell models and mouse xenografts. To further study the molecular basis of redox heterogeneity, we obtained the fluorescence images of Fp (oxidized flavoproteins containing flavin adenine dinucleotide, i.e., FAD), NADH (reduced nicotinamide adenine dinucleotide), and the Fp redox ratio (FpR = Fp/(Fp + NADH)) of MDA-MB-231 xenografts by the Chance redox scanner, then isolated the intratumoral redox subpopulations by dissection according to the redox ratio image. A total of 12 subpopulations were isolated from 4 tumors (2-4 locations from each tumor). The 12 subpopulations were classified into 3 FpR groups: high FpR (HFpR, n = 4, FpR range 0.78-0.92, average 0.85), medium FpR (MFpR, n = 5, FpR range 0.39-0.68, average 0.52), and low FpR (LFpR, n = 3, FpR range 0.15-0.28, average 0.20). The RT-PCR (reverse transcription polymerase chain reaction) analysis on these redox subpopulations showed that PGC-1α is significantly upregulated in the HFpR redox group compared to the MFpR group (fold change 2.1, p = 0.008), but not significantly different between MFpR and LFpR groups, or between HFpR and LFpR groups. These results indicate that optical redox imaging (ORI)-based redox subpopulations exhibit differential expression of PGC1α gene and suggest that PGC1α might play a role in redox mediation of breast cancer progression.
我们之前的研究表明，线粒体氧化还原状态及其肿瘤内异质性与人类乳腺癌细胞模型和小鼠异种移植物的侵袭性和转移潜能有关。为了进一步研究氧化还原异质性的分子基础，我们使用 Chance 氧化还原扫描仪获得了 MDA-MB-231 异种移植瘤的 Fp（含黄素腺嘌呤二核苷酸的氧化黄素蛋白，即 FAD）、NADH（还原型烟酰胺腺嘌呤二核苷酸）和 Fp 氧化还原比（FpR = Fp/（Fp + NADH））的荧光图像，然后根据氧化还原比图像通过解剖分离肿瘤内的氧化还原亚群。从 4 个肿瘤（每个肿瘤 2-4 个部位）中总共分离出 12 个亚群。这 12 个亚群分为 3 个 FpR 组：高 FpR（HFpR，n = 4，FpR 范围 0.78-0.92，平均值 0.85）、中 FpR（MFpR，n = 5，FpR 范围 0.39-0.68，平均值 0.52）和低 FpR（LFpR，n = 3，FpR 范围 0.15-0.28，平均值 0.20）。对这些氧化还原亚群进行 RT-PCR（逆转录聚合酶链反应）分析表明，与 MFpR 组相比，HFpR 氧化还原组中的 PGC-1α 显著上调（倍数变化 2.1，p = 0.008），但在 MFpR 和 LFpR 组之间、HFpR 和 LFpR 组之间无显著差异。这些结果表明，基于光学氧化还原成像（ORI）的氧化还原亚群表现出 PGC1α 基因的差异表达，并提示 PGC1α 可能在乳腺癌进展的氧化还原调节中发挥作用。
