Gen p53jako hamulec molekularny przeciwdziałający powstawaniu nowotworów

*Paweł Kowalczyk

Summary
Neoplastic transformation in cancer depends on accumulation of alterations in many families of genes that control signal transduction, cell proliferation and genomic stability. These changes observed in nature generally involve two groups of genes with opposite functions: oncogenes and tumor supressor genes. There are many tumor suppressor genes that are inactivated in almost every type of human cancer, most important being TP53.
The p53protein is involved in the regulation of cell cycle, apoptosis and cell differentiation. p53plays a central role in a complex DNA damage-sensing network which, in response to genotoxic stress such as ionizing radiation, either shunts the cell into a prolonged G1 arrest, presumably to allow for DNA repair and/or directs the cell along the apoptotic pathway. The p53tumour suppressor gene has proven to be one of the genes most often mutated in human cancers (about 50%) what demonstrate their role in the development of cancers.
It involves mainly point mutations leading to amino acid substitutions in the central region of the protein which impair its normal functions. Analysis of the mutational events that target the p53gene has revealed evidence for both exogenous and endogenous mutational mechanisms. More than 90% of the mutations reported so far are clustered between exons 4 and 9. This region is highly conserved throughout evolution and contains the DNA binding domain of the protein which is essential to p53functional activity.

To jest tylko fragment artykułu. Aby przeczytać całość, przejdź do Czytelni medycznej.