Ejeskär Katarina, Krona Cecilia, Carén Helena, Zaibak Faten, Li Lingli, Martinsson Tommy, Ioannou Panayiotis A
Dept, Clinical Genetics, University of Gothenburg, Sahlgrenska University Hospital/East, SE-416 85 Gothenburg, Sweden.
BMC Cancer. 2005 Dec 16;5:161. doi: 10.1186/1471-2407-5-161.
Neuroblastoma is a solid tumour of childhood often with an unfavourable outcome. One common genetic feature in aggressive tumours is 1p-deletion. The alpha-enolase (ENO1) gene is located in chromosome region 1p36.2, within the common region of deletion in neuroblastoma. One alternative translated product of the ENO1 gene, known as MBP-1, acts as a negative regulator of the c-myc oncogene, making the ENO1 gene a candidate as a tumour suppressor gene.
Methods used in this study are transfection of cDNA-vectors and in vitro transcribed mRNA, cell growth assay, TUNEL-assay, real-time RT-PCR (TaqMan) for expression studies, genomic sequencing and DHPLC for mutation detection.
Here we demonstrate that transfection of ENO1 cDNA into 1p-deleted neuroblastoma cell lines causes' reduced number of viable cells over time compared to a negative control and that it induces apoptosis. Interestingly, a similar but much stronger dose-dependent reduction of cell growth was observed by transfection of in vitro transcribed ENO1 mRNA into neuroblastoma cells. These effects could also be shown in non-neuroblastoma cells (293-cells), indicating ENO1 to have general tumour suppressor activity. Expression of ENO1 is detectable in primary neuroblastomas of all different stages and no difference in the level of expression can be detected between 1p-deleted and 1p-intact tumour samples. Although small numbers (11 primary neuroblastomas), there is some evidence that Stage 4 tumours has a lower level of ENO1-mRNA than Stage 2 tumours (p = 0.01). However, mutation screening of 44 primary neuroblastomas of all different stages, failed to detect any mutations.
Our studies indicate that ENO1 has tumour suppressor activity and that high level of ENO1 expression has growth inhibitory effects.
神经母细胞瘤是一种儿童实体瘤，其预后通常不佳。侵袭性肿瘤的一个常见基因特征是1p缺失。α-烯醇化酶（ENO1）基因位于染色体区域1p36.2，该区域是神经母细胞瘤常见的缺失区域。ENO1基因的一种可变翻译产物，称为MBP-1，作为c-myc癌基因的负调节因子，使ENO1基因成为肿瘤抑制基因的候选者。
本研究采用的方法包括cDNA载体和体外转录mRNA的转染、细胞生长测定、TUNEL测定、用于表达研究的实时RT-PCR（TaqMan）、基因组测序和用于突变检测的变性高效液相色谱（DHPLC）。
我们在此证明，将ENO1 cDNA转染到1p缺失的神经母细胞瘤细胞系中，与阴性对照相比，随着时间的推移，存活细胞数量减少，并且它诱导细胞凋亡。有趣的是，将体外转录的ENO1 mRNA转染到神经母细胞瘤细胞中，观察到细胞生长有类似但更强的剂量依赖性减少。这些效应在非神经母细胞瘤细胞（293细胞）中也可以显示，表明ENO1具有一般的肿瘤抑制活性。在所有不同阶段的原发性神经母细胞瘤中均可检测到ENO1的表达，并且在1p缺失和1p完整的肿瘤样本之间未检测到表达水平的差异。尽管数量较少（11例原发性神经母细胞瘤），但有一些证据表明，4期肿瘤的ENO1 mRNA水平低于2期肿瘤（p = 0.01）。然而，对所有不同阶段的44例原发性神经母细胞瘤进行突变筛查，未检测到任何突变。
我们的研究表明ENO1具有肿瘤抑制活性，并且高水平的ENO1表达具有生长抑制作用。
