Oncogene amplification in neoplastic development and progression of human cancers.

Increased dosage of cellular oncogenes resulting from amplification of DNA is a frequent genetic abnormality of tumor cells. Certain types of human tumors carry a specific amplified cellular oncogene at frequencies of up to 50 to 60%. Human neuroblastoma has been prototypic for a contribution of amplification to tumorigenesis, and evidence is emerging that amplification may be an early event involved in a malignant form of this cancer. It is unclear at which stage amplification plays a role in other cancers. Amplification of cellular oncogenes is a good predictor for clinical outcome in some human malignancies and is a paradigm for the application of oncogene research in a clinical context.