Department of Oncology, Immunology, and Surgery, Nagoya City University Graduate School of Medical Sciences Nagoya, Japan.
Cancer Med. 2012 Aug;1(1):68-75. doi: 10.1002/cam4.13. Epub 2012 Jul 12.
RET encodes the tyrosine kinase receptor of growth factors belonging to the glial-derived neurotrophic factor family. Recently, RET gene rearrangements with N-terminal of KIF5B gene were identified in lung adenocarcinomas from large-scale sequencing. We investigated RET mRNA expression by real-time reverse-transcriptase polymerase chain reaction (RT-PCR) assay using LightCycler, and KIF5B/RET gene rearrangements using newly established fluorescence in situ hybridization (FISH) analysis in surgically treated nonsmall cell lung cancer (NSCLC) cases. RET protein expression was also investigated by immunohistochemistry (IHC). This study included 157 surgically removed NSCLC cases for mRNA level analyses. The RET/β actin mRNA levels were not significantly different between lung cancer (6.359 ± 15.268) and adjacent normal lung tissues (8.205 ± 28.931, P = 0.6332). Tumor/normal (T/N) ratio of RET/β actin mRNA levels was not different within gender, stage, smoking status, and pathological subtypes. T/N ratio of RET/β actin mRNA levels was significantly higher in KIF5B/RET rearrangement samples (161.763 ± 123.488) than in wild-type samples (5.9013 ± 17.148, P = 0.044). Although RET IHC positivity was not perfectly correlated with KIF5B/RET arrangement, we have detected the KIF5B/RET rearrangements using FISH analysis. Thus, we have successfully introduced FISH for diagnosing KIF5B/RET positive lung adenocarcinoma. This method facilitates the molecular evaluation for RET fusions and could be applicable in clinical practice to detect lung cancer that may be responsive to RET inhibitors.
RET 编码属于神经胶质衍生神经营养因子家族的生长因子的酪氨酸激酶受体。最近，在大规模测序的肺腺癌中发现了 RET 基因与 KIF5B 基因 N 端的重排。我们使用 LightCycler 通过实时逆转录聚合酶链反应 (RT-PCR) 检测来研究 RET mRNA 表达，并使用新建立的荧光原位杂交 (FISH) 分析在手术治疗的非小细胞肺癌 (NSCLC) 病例中研究 KIF5B/RET 基因重排。还通过免疫组织化学 (IHC) 研究了 RET 蛋白表达。这项研究包括 157 例手术切除的 NSCLC 病例进行 mRNA 水平分析。肺癌 (6.359 ± 15.268) 和相邻正常肺组织中的 RET/β肌动蛋白 mRNA 水平没有显着差异 (P = 0.6332)。性别、分期、吸烟状况和病理亚型内的 RET/β肌动蛋白 mRNA 水平的 T/N 比值没有差异。KIF5B/RET 重排样本的 RET/β肌动蛋白 mRNA 水平的 T/N 比值（161.763 ± 123.488）明显高于野生型样本（5.9013 ± 17.148，P = 0.044）。尽管 RET IHC 阳性与 KIF5B/RET 排列不完全相关，但我们已经使用 FISH 分析检测到 KIF5B/RET 重排。因此，我们成功地引入了 FISH 来诊断 KIF5B/RET 阳性肺腺癌。该方法有利于 RET 融合的分子评估，并且可以在临床实践中应用于检测可能对 RET 抑制剂有反应的肺癌。
