Amplification of cellular oncogenes in cancer cells.
Regulatory or structural alterations of cellular oncogenes have been implicated in the causation of various cancers. Oncogene alteration by point mutations can result in a protein product with strongly enhanced oncogenic potential. Aberrant expression of cellular oncogenes may be due to tumor-specific chromosomal translocations that dysregulate the normal functions of a proto-oncogene. Amplification of cellular oncogenes can also augment their expression by increasing the amount of DNA template available for the production of mRNA. It appears that amplification of certain oncogenes is a common correlate of the progression of some tumours and also occurs as a rare sporadic event affecting various oncogenes in different types of cancer. Amplified copies of oncogenes may or may not be associated with chromosomal abnormalities signifying DNA amplification: double minute chromosomes and homogeneously staining chromosomal regions. Amplified oncogenes, whether sporadic or tumour type-specific, are expressed at elevated levels, in some cases in cells where their diploid forms are normally silent. Increased dosage of an amplified oncogene may contribute to the multistep progression of at least some cancers.
D000818:Animals; D001483:Base Sequence; D002273:Carcinogens / Q000494:pharmacology; D002460:Cell Line; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D025063:Chromosome Disorders; D002874:Chromosome Mapping; D002999:Clone Cells; D003110:Colonic Neoplasms / Q000235:genetics; D004247:DNA; D004261:DNA Replication; D005784:Gene Amplification; D005786:Gene Expression Regulation; D006801:Humans; D007621:Karyotyping; D007951:Leukemia, Myeloid / Q000235:genetics; D008938:Mitosis; D009369:Neoplasms / Q000235:genetics*; D009447:Neuroblastoma / Q000235:genetics; D009857:Oncogenes; D000090063:Proto-Oncogene Mas; D011995:Recombination, Genetic; D014178:Translocation, Genetic
D002273:Carcinogens; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D004247:DNA