Kim Jeong-Oh, Shin Jung-Young, Kim Min Young, Son Kyoung Hwa, Jung Chan Kwon, Kim Tae-Jung, Kim Su Young, Park Jae Kil, Sung Sook Whan, Bae Sang Ju, Min Hyun Jung, Kang Jin-Hyoung
Laboratory of Medical Oncology, Cancer Research Institute, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Surg Oncol. 2018 Mar;27(1):106-113. doi: 10.1016/j.suronc.2018.01.006. Epub 2018 Feb 8.
We screened resected tumor tissues from patients with lung cancer for EGFR mutations, ALK rearrangements, and rearranged during transfection (RET) gene variants (including RET rearrangements and the Kinesin Family Member 5B (KIF5B)-RET fusion gene) using various methods including reverse transcription polymerase chain reaction (RT-PCR), transcript assays, fluorescence in situ hybridization (FISH), and immunohistochemistry (IHC). We also examined the protein expression of associated downstream signaling molecules to assess the effect of these variants on patient outcome.
We constructed a tissue microarray (TMA) comprising 581 resected tumor tissues from patients with lung adenocarcinoma and analyzed the microarray by both FISH (using RET break-apart and KIF5B-RET SY translocation probes) and a commercial RET transcript assay. We evaluated the expression of RET and RET-related signaling molecules, including p-AKT and p-ERK, by TMA -based IHC staining.
Among the 581 specimens, 51 (8.8%) specimens harbored RET rearrangements, including 12 cases (2.1%) carrying a KIF5B-RET fusion gene. Surprisingly, RET expression was lower in KIF5B-RET fusion gene-positive than in RET wild-type specimens. We detected activating EGFR mutations in 11 (21.6%) of the 51 RET variant-positive specimens. Among the KIF5B-RET fusion gene-positive specimens, p-ERK expression was significantly lower in the EGFR mutation subgroup showing RET expression than in the EGFR mutation subgroup that did not express RET. Similarly, the RET rearrangement group showed significant variation in the expression level of p-AKT (P = 0.028) and p-ERK, whose expression remarkably increased in specimens not expressing RET. The expression of p-ERK markedly increased in the RET rearrangement group regardless of RET expression.
This result suggests that a combination of RET and ERK inhibitors may be an effective treatment strategy for lung adenocarcinoma patients harboring RET variants.
我们使用包括逆转录聚合酶链反应（RT-PCR）、转录分析、荧光原位杂交（FISH）和免疫组织化学（IHC）在内的多种方法，对肺癌患者切除的肿瘤组织进行了表皮生长因子受体（EGFR）突变、间变性淋巴瘤激酶（ALK）重排以及转染期间重排（RET）基因变异（包括RET重排和驱动蛋白家族成员5B（KIF5B）-RET融合基因）的筛查。我们还检测了相关下游信号分子的蛋白表达，以评估这些变异对患者预后的影响。
我们构建了一个组织芯片（TMA），包含581例肺腺癌患者切除的肿瘤组织，并通过FISH（使用RET断裂分离探针和KIF5B-RET SY易位探针）和商业RET转录分析对该芯片进行分析。我们通过基于TMA的IHC染色评估RET及RET相关信号分子（包括磷酸化蛋白激酶B（p-AKT）和磷酸化细胞外信号调节激酶（p-ERK））的表达。
在581个样本中，51个（8.8%）样本存在RET重排，其中12例（2.1%）携带KIF5B-RET融合基因。令人惊讶的是，KIF5B-RET融合基因阳性样本中的RET表达低于RET野生型样本。在51个RET变异阳性样本中，我们检测到11个（21.6%）样本存在激活的EGFR突变。在KIF5B-RET融合基因阳性样本中，显示RET表达的EGFR突变亚组中的p-ERK表达显著低于不表达RET的EGFR突变亚组。同样，RET重排组中p-AKT（P = 0.028）和p-ERK的表达水平存在显著差异，其表达在不表达RET的样本中显著增加。无论RET表达情况如何，RET重排组中p-ERK的表达均显著增加。
该结果表明，RET和ERK抑制剂联合使用可能是治疗携带RET变异的肺腺癌患者的有效治疗策略。
