Introduction of in vitro transcribed ENO1 mRNA into neuroblastoma cells induces cell death.

• BACKGROUND: 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: 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. RESULTS: 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. CONCLUSION: Our studies indicate that ENO1 has tumour suppressor activity and that high level of ENO1 expression has growth inhibitory effects.

Keyword

Apoptosis

Apoptosis Regulatory Proteins

physiology

Cell Line

Cell Line

Tumor

Cell Proliferation

DNA Mutational Analysis

DNA

Complementary

metabolism

DNA-Binding Proteins

metabolism

Gene Deletion

Genes

Tumor Suppressor

Genetic Vectors

Genome

Humans

In Situ Nick-End Labeling

Models

Genetic

Mutation

Neuroblastoma

genetics

metabolism

Phosphopyruvate Hydratase

metabolism

RNA

Messenger

metabolism

RNA

Small Interfering

metabolism

Reverse Transcriptase Polymerase Chain Reaction

Transcription

Genetic

Transfection

Tumor Cells

Cultured

Tumor Markers

Biological

metabolism

Tumor Suppressor Proteins

metabolism

Publication and Content Type

ref (subject category)

art (subject category)