Kafka Anja, Tomas Davor, Beroš Vili, Pećina Hrvoje Ivan, Zeljko Martina, Pećina-Šlaus Nives
Laboratory of Neuro-Oncology, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 12, 10000 Zagreb, Croatia.
Ljudevit Jurak Department of Pathology, University Hospital "Sisters of Charity", 10000 Zagreb, Croatia.
Int J Mol Sci. 2014 Jun 13;15(6):10635-51. doi: 10.3390/ijms150610635.
The susceptibility of brain to secondary formation from lung cancer primaries is a well-known phenomenon. In contrast, the molecular basis for invasion and metastasis to the brain is largely unknown. In the present study, 31 brain metastases that originated from primary lung carcinomas were analyzed regarding over expression of Dishevelled-1 (DVL1), Dishevelled-3 (DVL3), E-cadherin (CDH1) and beta-catenin (CTNNB1). Protein expressions and localizations were analyzed by immunohistochemistry. Genetic alterations of E-cadherin were tested by polymerase chain reaction (PCR)/loss of heterozygosity (LOH). Heteroduplex was used to investigate mutations in beta-catenin. DVL1 and DVL3 showed over expression in brain metastasis in 87.1% and 90.3% of samples respectively. Nuclear staining was observed in 54.8% of cases for DVL1 and 53.3% for DVL3. The main effector of the Wnt signaling, beta-catenin, was up-regulated in 56%, and transferred to the nucleus in 36% of metastases. When DVL1 and DVL3 were up-regulated the number of cases with nuclear beta-catenin significantly increased (p=0.0001). Down-regulation of E-cadherin was observed in 80% of samples. Genetic analysis showed 36% of samples with LOH of the CDH1. In comparison to other lung cancer pathologies, the diagnoses adenocarcinoma and small cell lung cancer (SCLC) were significantly associated to CDH1 LOH (p=0.001). Microsatellite instability was detected in one metastasis from adenocarcinoma. Exon 3 of beta-catenin was not targeted. Altered expression of Dishevelled-1, Dishevelled-3, E-cadherin and beta-catenin were present in brain metastases which indicates that Wnt signaling is important and may contribute to better understanding of genetic profile conditioning lung cancer metastasis to the brain.
肺癌原发灶易继发形成脑转移是一种众所周知的现象。相比之下，肺癌侵袭和转移至脑的分子基础在很大程度上尚不清楚。在本研究中，对31例源自原发性肺癌的脑转移瘤进行了分析，检测了Dishevelled-1（DVL1）、Dishevelled-3（DVL3）、E-钙黏蛋白（CDH1）和β-连环蛋白（CTNNB1）的过表达情况。通过免疫组织化学分析蛋白表达和定位。采用聚合酶链反应（PCR）/杂合性缺失（LOH）检测E-钙黏蛋白的基因改变。使用异源双链体研究β-连环蛋白的突变情况。DVL1和DVL3分别在87.1%和90.3%的脑转移瘤样本中呈过表达。DVL1在54.8%的病例中观察到核染色，DVL3为53.3%。Wnt信号通路的主要效应分子β-连环蛋白在56%的转移瘤中上调，36%转移至细胞核。当DVL1和DVL3上调时，核β-连环蛋白阳性病例数显著增加（p=0.0001）。80%的样本中观察到E-钙黏蛋白下调。基因分析显示36%的样本存在CDH1基因杂合性缺失。与其他肺癌病理类型相比，腺癌和小细胞肺癌（SCLC）的诊断与CDH1基因杂合性缺失显著相关（p=0.001）。在1例腺癌脑转移瘤中检测到微卫星不稳定性。β-连环蛋白的第3外显子未发现靶向改变。脑转移瘤中存在Dishevelled-1、Dishevelled-3、E-钙黏蛋白和β-连环蛋白的表达改变，这表明Wnt信号通路很重要，可能有助于更好地理解肺癌转移至脑的基因特征。
