Final answer:
The alteration in DNA structure, leading to the abnormal production of telomerase at a time when it is usually not expressed, is referred to as an epigenetic change. This concept is significant in the study of cancer, where the regulation of telomerase plays a role in the uncontrolled division of abnormal cells.
Step-by-step explanation:
When telomerase appears in a cell, it is not because the coding sequences of the gene have been mutated. Instead, the protein produced is essentially normal, but it is being produced at an abnormal time. A gene that is normally repressed has been activated for some reason. Such an alteration in DNA structure is referred to as epigenetic change.
Cancer can often be understood as a series of genetic and epigenetic changes. Telomerase, which is typically found in stem cells and cancer cells, helps to maintain telomeres, ensuring that cells can divide without losing vital DNA. In normal cells, telomerase is not usually active, but in cancer cells, the enzyme becomes active after the telomeres have significantly shortened. Inhibiting telomerase is a therapeutic strategy under consideration to stop the division of cancerous cells.
Epigenetic regulation refers to modifications in gene expression that do not change the DNA sequence but affect how cells read genes. This regulation is a key player in cancer pathogenesis and can result in genes being inappropriately activated, such as the gene for telomerase in many cancers.