TelomeraseAn enzyme that functions to replace the ends of chromosomes. Normally, during DNA replication, chromosome ends are shortened by a small amount. Telomerase is turned off in most adult tissues, a process that limits the number of cell divisions that can be completed by those cells. In cancer cells, telomerase is often reactivated, allowing the cells to divide indefinitely. is critical for the development of most human cancers. Without this enzymeA protein that speeds up the process of chemical reactions in the body without becoming altered in the process. Almost every biological process is driven by the activity of enzymes. Without enzyme catalysts, the complex reactions that build and break down cell parts would not happen at a rate compatible with life. Enzyme names usually describe the reaction that is being catalyzed and all of them end in -ase., chromosomes become progressively shorter each time the cell divides, and after a certain point, the chromosomes are too short to be reproduced successfully. At this point, the cell enters into a state of non-growth, called senescenceIn the context of cell division, the term refers to the aging and death of a culture of cells. All normal cells (aside from stem cells) have a limited ability to divide. Cancer cells do not undergo senescence, instead, they are capable of dividing indefinitely. Cells which can divide indefinitely are termed immortal. Outside of cell biology, senescence refers to the aging process.. Researchers at Harvard University have been working to uncover the mechanism linking telomerase activity to cancer, and in a recent publication, they identified the important role of the PinX1 geneA stretch of DNA that leads to the production of an RNA. The RNA is produced during the process of transcription. This RNA can be used to guide the formation of a protein via translation or can be used directly in the cell..
PinX1 is a natural telomerase inhibitor, and in most human breast cancers, it's expression is inhibited. Because PinX1 suppresses telomerase activity, decreased PinX1 expression leads to increased telomerase activity. This prevents cells from reaching senescence, and allows them to keep reproducing. These findings suggest that altering PinX1 activity may be an effective approach to treating cancers over expressing telomerase.
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