CONTRIBUTION OF TRANSCRIPTION FACTORS TO ONCOGENESIS

Transcription factors coordinate consitutive and inducible gene expres sion. They recognize and bind specific DNA sequences that are present in the regulatory regions of all genes, and thus allow transcriptional activation or repression of that given gene. Most transcription facto rs do not operate on their own, but form multiunit complexes consistin g of home- or heterodimers. A variety of genetic alterations observed in solid and hematologic malignancies result in gain or loss of functi on mutations of these molecules. As a consequence, a given transcripti on factor modulates its binding specificity and thus regulates the exp ression of a different set of target genes in the tumor cell as compar ed with normal cells. Alternatively, the transcription factor modulate s its ability to interact with partner molecules and thus its binding specificity, its response to incoming signals or its functional activi ty, that Is transcriptional activation or transcriptional repression o f the targeted gene. Based on their functional implication in regulati ng gene expression and thus cellular behavior, Boss or gain of functio n of transcription factor genes play a major role in the development o r progression of tumors.