Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA.
PLoS One. 2010 Jun 17;5(6):e11148. doi: 10.1371/journal.pone.0011148.
Oral cancer survival rates increase significantly when it is detected and treated early. Unfortunately, clinicians now lack tests which easily and reliably distinguish pre-malignant oral lesions from those already transitioned to malignancy. A test for proteins, ones found in non-invasively-collected whole saliva and whose abundances distinguish these lesion types, would meet this critical need.
METHODOLOGY/PRINCIPAL FINDINGS: To discover such proteins, in a first-of-its-kind study we used advanced mass spectrometry-based quantitative proteomics analysis of the pooled soluble fraction of whole saliva from four subjects with pre-malignant lesions and four with malignant lesions. We prioritized candidate biomarkers via bioinformatics and validated selected proteins by western blotting. Bioinformatic analysis of differentially abundant proteins and initial western blotting revealed increased abundance of myosin and actin in patients with malignant lesions. We validated those results by additional western blotting of individual whole saliva samples from twelve other subjects with pre-malignant oral lesions and twelve with malignant oral lesions. Sensitivity/specificity values for distinguishing between different lesion types were 100%/75% (p = 0.002) for actin, and 67%/83% (p<0.00001) for myosin in soluble saliva. Exfoliated epithelial cells from subjects' saliva also showed increased myosin and actin abundance in those with malignant lesions, linking our observations in soluble saliva to abundance differences between pre-malignant and malignant cells.
CONCLUSIONS/SIGNIFICANCE: Salivary actin and myosin abundances distinguish oral lesion types with sensitivity and specificity rivaling other non-invasive oral cancer tests. Our findings provide a promising starting point for the development of non-invasive and inexpensive salivary tests to reliably detect oral cancer early.
口腔癌的存活率在早期发现和治疗时显著提高。不幸的是，临床医生目前缺乏能够轻易且可靠地区分癌前口腔病变与已恶变病变的检测手段。如果有一种检测蛋白的方法，这种蛋白存在于非侵入性采集的全唾液中，其丰度可区分这些病变类型，那么这将满足这一关键需求。
方法/主要发现：在一项开创性的研究中，我们使用先进的基于质谱的定量蛋白质组学分析方法，对 4 名癌前病变患者和 4 名恶性病变患者的全唾液可溶性部分进行了分析，以发现此类蛋白。我们通过生物信息学对候选生物标志物进行了优先级排序，并通过 Western 印迹法对选定的蛋白进行了验证。差异表达蛋白的生物信息学分析和初步的 Western 印迹显示，恶性病变患者的肌球蛋白和肌动蛋白丰度增加。我们通过对另外 12 名癌前口腔病变患者和 12 名恶性口腔病变患者的个体全唾液样本进行额外的 Western 印迹验证了这些结果。在区分不同病变类型方面，肌动蛋白的敏感性/特异性值为 100%/75%（p=0.002），可溶性唾液中的肌球蛋白为 67%/83%（p<0.00001）。来自受试者唾液的脱落上皮细胞也显示出恶性病变患者中肌球蛋白和肌动蛋白丰度增加，将我们在可溶性唾液中的观察结果与癌前和恶性细胞之间的丰度差异联系起来。
结论/意义：唾液中的肌动蛋白和肌球蛋白丰度可以区分口腔病变类型，其敏感性和特异性可与其他非侵入性口腔癌检测方法相媲美。我们的研究结果为开发非侵入性和廉价的唾液检测方法以早期可靠地检测口腔癌提供了有希望的起点。
