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Genetic alterations associated with metastatic dissemination and chemoresistance in neuroblastoma
1Laboratory of Clinical & Molecular Pharmacology, Institut Gustave Roussy, Villejuif, France.
Abstract:
Knowledge about genetic alterations specific to the metastatic process and chemoresistance in neuroblastoma is progressing steadily. Low or no CD44 expression, increased NM23 expression and specific mutations of the 5' coding regions of NM23 are distinct features of aggressive, metastatic neuroblastoma. MYCN down-regulates Class I HLA antigen expression in many neuroblastoma cell lines and, in turn, may be regulated by a suppressor gene. The MYCN amplified human neuroblastoma cell line, IGR-N-91, established in vitro, metastasises in the nude mouse and has exhibited co-activation of MYCN and PGY1, resulting from direct activation of the oncoprotein on the PGY1 promoter. In this model, the MYCN product activates angiogenesis, the dissemination process and chemoresistance via specific genes (PGY1 and GST3). MYCN, like the BCL-2 and TP53 products, may also play a key role in apoptosis. The implication of these genes in the potential for metastasis and chemoresistance in neuroblastoma is discussed.
Insights
Genetic factors like CD44, NM23, and MYCN influence neuroblastoma metastasis and chemoresistance. The MYCN gene, a key driver, activates genes involved in angiogenesis, dissemination, and drug resistance.
Area of Science:
- Oncology
- Genetics
- Molecular Biology
Background:
- Neuroblastoma metastasis and chemoresistance are complex processes.
- Specific genetic alterations are increasingly linked to aggressive disease phenotypes.
Purpose of the Study:
- To investigate the role of genetic factors, including CD44, NM23, and MYCN, in neuroblastoma metastasis and chemoresistance.
- To elucidate the molecular mechanisms by which MYCN influences these processes.
Main Methods:
- Analysis of gene expression (CD44, NM23, MYCN, PGY1, GST3, HLA).
- Establishment and characterization of a MYCN-amplified neuroblastoma cell line (IGR-N-91) in a xenograft model.
- Investigation of gene promoter activation and regulation.
Main Results:
- Low CD44 expression and increased NM23 expression/mutation are associated with metastatic neuroblastoma.
- MYCN down-regulates Class I HLA antigen expression.
- In a xenograft model, MYCN co-activated PGY1, promoting angiogenesis, dissemination, and chemoresistance via PGY1 and GST3.
- MYCN may also influence apoptosis, similar to BCL-2 and TP53.
Conclusions:
- Specific genes, notably MYCN, play a critical role in driving neuroblastoma metastasis and chemoresistance.
- Understanding these genetic pathways offers potential therapeutic targets for aggressive neuroblastoma.