Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Kagawa, Japan.
Immunotherapy Division, Shizuoka Cancer Center Research Institute, Shizuoka, Japan.
Cancer Genomics Proteomics. 2023 Jul-Aug;20(4):375-382. doi: 10.21873/cgp.20389.
BACKGROUND/AIM: Epidermal growth factor receptor (EGFR) signaling inhibitors are potent therapeutic agents for EGFR-mutant non-small-cell lung cancer, but the effects of such inhibitors on the localization of EGFR mutations in tumor tissues remain to be elucidated. Thus, a simple and efficient technology for the detection of mutations in tumor tissue specimens needs to be developed.
Using an EGFR mutation-specific peptide nucleic acid (PNA)-DNA probe, the EGFR mutation-positive part of whole NSCLC tissues was visualized by immunofluorescence. Formalin-fixed paraffin-embedded sections obtained from A549, NCI-H1975, HCC827 and PC-9 tumors transplanted into nude mice were subjected to staining using PNA-DNA probes specific for the mRNA sequences producing the L858R, del E746-A750 and T790M mutations.
The probes for the L858R mutation showed intense positive staining in H1975 cells, and the probe for the del E746-A750 mutation exhibited positive staining specifically in HCC827 and PC-9 tumors. On the other hand, A549 tumors without EGFR mutation did not show any significant staining for any PNA-DNA probe. In combination staining, the addition of cytokeratin stain increased the positive staining rate of each PNA-DNA probe. In addition, the positive staining rate of the probes for the L858R mutation was comparable to that of the antibody to EGFR L858R mutated protein.
PNA-DNA probes specific for EGFR mutations might be useful tools to detect heterogeneous mutant EGFR expression in cancer tissues and efficiently evaluate the effect of EGFR signaling inhibitors on tissues of EGFR-mutant cancer.
背景/目的：表皮生长因子受体（EGFR）信号抑制剂是治疗 EGFR 突变型非小细胞肺癌的有效药物，但这些抑制剂对肿瘤组织中 EGFR 突变定位的影响仍需阐明。因此，需要开发一种简单有效的肿瘤组织标本突变检测技术。
使用 EGFR 突变特异性肽核酸（PNA）-DNA 探针，通过免疫荧光法可视化整个 NSCLC 组织中 EGFR 突变阳性部分。对移植入裸鼠的 A549、NCI-H1975、HCC827 和 PC-9 肿瘤的福尔马林固定石蜡包埋切片进行 PNA-DNA 探针特异性染色，该探针针对产生 L858R、del E746-A750 和 T790M 突变的 mRNA 序列。
针对 L858R 突变的探针在 H1975 细胞中显示出强烈的阳性染色，而针对 del E746-A750 突变的探针特异性地在 HCC827 和 PC-9 肿瘤中显示阳性染色。另一方面，没有 EGFR 突变的 A549 肿瘤对任何 PNA-DNA 探针均未显示出任何显著染色。在联合染色中，添加细胞角蛋白染色增加了每种 PNA-DNA 探针的阳性染色率。此外，针对 L858R 突变的探针的阳性染色率与针对 EGFR L858R 突变蛋白的抗体相当。
针对 EGFR 突变的 PNA-DNA 探针可能是一种有用的工具，可用于检测癌症组织中异质性突变 EGFR 表达，并有效地评估 EGFR 信号抑制剂对 EGFR 突变型癌症组织的作用。
