Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
Department of Pathology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Biopreserv Biobank. 2023 Oct;21(5):493-503. doi: 10.1089/bio.2022.0090. Epub 2022 Oct 19.
Although the immunogenicity of formalin-fixed paraffin-embedded tissue sections can decrease during storage and transport, the exact mechanism of antigenic loss and how to prevent it are not clear. Herein, we investigated changes in the expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), E-cadherin, and Ki-67 in human breast tissue microarray (TMA) tissue sections stored for up to 3 months in dry and wet conditions. The positive rates of ER and PR expression were minimally changed after 3 months of storage, but the Allred scores of ER and PR stored in humid conditions decreased remarkably in comparison to fresh-cut tissue. The HER-2 antigenicity and RNA integrity of breast TMA sections stored in dry conditions diminished gradually with storage time, whereas the immunoreactivity and RNA quality of HER-2 in humid conditions decreased sharply as storage length increased. The area and intensity of E-cadherin staining in tissue sections stored in dry conditions did not change significantly and were minimally changed after 3 months, respectively. In contrast, the area and intensity of E-cadherin staining in tissue sections stored in humid conditions decreased significantly as storage length increased. Finally, the Ki-67 labeling index of tissue sections stored for 3 months in dry (9% decrease) and wet (31.9% decrease) conditions was decreased in comparison to fresh sections. In conclusion, these results indicate that water is a crucial factor for protein and RNA degradation in stored tissue sections, and detailed guidelines are required in the clinic.
尽管福尔马林固定石蜡包埋组织切片的免疫原性在储存和运输过程中会降低，但抗原丢失的确切机制以及如何防止抗原丢失尚不清楚。在此，我们研究了储存长达 3 个月的干燥和湿润条件下的人乳腺组织微阵列（TMA）组织切片中雌激素受体（ER）、孕激素受体（PR）、人表皮生长因子受体 2（HER-2）、E-钙黏蛋白和 Ki-67 的表达变化。储存 3 个月后，ER 和 PR 的阳性率变化极小，但在潮湿条件下储存的 ER 和 PR 的 Allred 评分与新鲜组织相比显著降低。干燥条件下储存的 TMA 组织切片中 HER-2 抗原性和 RNA 完整性随储存时间逐渐减弱，而在潮湿条件下储存的 HER-2 免疫反应性和 RNA 质量随储存时间的延长而急剧下降。储存于干燥条件下的组织切片中 E-钙黏蛋白染色的面积和强度无明显变化，分别在储存 3 个月后有轻微变化。相比之下，在潮湿条件下储存的组织切片中 E-钙黏蛋白染色的面积和强度随储存时间的延长而显著降低。最后，干燥（降低 9%）和湿润（降低 31.9%）条件下储存 3 个月的组织切片的 Ki-67 标记指数与新鲜切片相比降低。总之，这些结果表明水是储存组织切片中蛋白质和 RNA 降解的关键因素，临床需要详细的指南。
