Pal Rahul, Edward Kert, Ma Liang, Qiu Suimin, Vargas Gracie
Center for Biomedical Engineering, The University of Texas Medical Branch, Galveston, Texas, 77555.
Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Texas, 77555.
Lasers Surg Med. 2017 Nov;49(9):866-873. doi: 10.1002/lsm.22697. Epub 2017 Jul 5.
Multiphoton autofluorescence microscopy (MPAM) has shown potential in identifying features that are directly related to tissue microstructural and biochemical changes throughout epithelial neoplasia. In this study, we evaluate the autofluorescence spectral characteristics of neoplastic epithelium in dysplasia and oral squamous cell carcinoma (OSCC) using multiphoton autofluorescence spectroscopy (MPAS) in an in vivo hamster model of oral neoplasia in order to identify unique signatures that could be used to delineate normal oral mucosa from neoplasia.
MATERIALS/METHODS: A 9,10-dimethyl-1,2-benzanthracene (DMBA) hamster model of oral precancer and OSCC was used for in vivo MPAM and MPAS. Multiphoton Imaging and spectroscopy were performed with 780 nm excitation while a bandpass emission 450-650 nm was used for MPAM. Autofluorescence spectra was collected in the spectral window of 400-650 nm.
MPAS with fluorescence excitation at 780 nm revealed an overall red shift of a primary blue-green peak (480-520 nm) that is attributed to NADH and FAD. In the case of oral squamous cell carcinoma (OSCC) and some high-grade dysplasia an additional prominent peak at 635 nm, attributed to PpIX was observed. The fluorescence intensity at 635 nm and an intensity ratio of the primary blue-green peak versus 635 nm peak, showed statistically significant difference between control and neoplastic tissue.
Neoplastic transformation in the epithelium is known to alter the intracellular homeostasis of important tissue metabolites such as NADH, FAD, and PpIX, which was observed by MPAS in their native environment. A combination of deep tissue microscopy owing to higher penetration depth of multiphoton excitation and depth resolved spectroscopy could prove to be invaluable in identification of cytologic as well as biomolecular spectral characteristic of oral epithelial neoplasia. Lasers Surg. Med. 49:866-873, 2017. © 2017 Wiley Periodicals, Inc.
多光子自发荧光显微镜（MPAM）已显示出在识别与整个上皮瘤变过程中组织微观结构和生化变化直接相关的特征方面的潜力。在本研究中，我们使用多光子自发荧光光谱（MPAS）在口腔瘤变的体内仓鼠模型中评估发育异常和口腔鳞状细胞癌（OSCC）中肿瘤上皮的自发荧光光谱特征，以识别可用于区分正常口腔黏膜和肿瘤的独特特征。
材料/方法：使用9,10 - 二甲基 - 1,2 - 苯并蒽（DMBA）仓鼠口腔癌前病变和OSCC模型进行体内MPAM和MPAS研究。多光子成像和光谱分析在780 nm激发下进行，而带通发射450 - 650 nm用于MPAM。在400 - 650 nm光谱窗口收集自发荧光光谱。
780 nm荧光激发的MPAS显示，归因于NADH和FAD的主要蓝绿色峰（480 - 520 nm）整体红移。在口腔鳞状细胞癌（OSCC）和一些高级别发育异常的情况下，观察到一个归因于原卟啉IX（PpIX）的额外突出峰，位于635 nm。635 nm处的荧光强度以及主要蓝绿色峰与635 nm峰的强度比在对照组织和肿瘤组织之间显示出统计学上的显著差异。
已知上皮中的肿瘤转化会改变重要组织代谢物如NADH、FAD和PpIX的细胞内稳态，MPAS在其原生环境中观察到了这一点。由于多光子激发具有更高的穿透深度，深度组织显微镜检查与深度分辨光谱学相结合在识别口腔上皮瘤变的细胞学和生物分子光谱特征方面可能被证明具有极高的价值。《激光外科学与医学》49:866 - 873，2017年。©2017威利期刊公司
