What is the effect of hTERT overexpression on telomeres?
In the present study, we showed that stable overexpression of hTERT can increase telomerase activity and telomere length, which significantly promotes the invasive and metastatic potential of telomerase‑positive HepG2 cells but does not affect cell proliferation.
What is the proper relationship between telomeres and telomerase?
Some cells have the ability to reverse telomere shortening by expressing telomerase, an enzyme that extends the telomeres of chromosomes. Telomerase is an RNA-dependent DNA polymerase, meaning an enzyme that can make DNA using RNA as a template.
What is the significance of telomeres and telomerase?
Telomeres, repetitive (TTAGGG) DNA–protein complexes at the ends of chromosomes, are crucial for the survival of cancer cells. They are maintained by an enzyme called telomerase in the vast majority of tumors.
What is the relationship between cancer and telomerase?
It is believed that cancer occurs because a genetic mutation can trigger the production of an enzyme, known as telomerase, which prevents telomeres from shortening. While every cell in the body has the genetic coding to produce telomerase, only certain cells actually need it.
What is ALT pathway?
Alternative lengthening of telomeres (ALT) is a telo- merase-independent but recombination-dependent pathway that maintains telomeres. Here, we describe an assay to visualize ALT-mediated telomeric DNA synthesis in ALT-associated PML bodies (APBs) without DNA-damaging agents or replication inhibi- tors.
What is the function of hTERT?
hTERT is often up-regulated in cells that divide rapidly, including both embryonic stem cells and adult stem cells. It elongates the telomeres of stem cells, which, as a consequence, increases the lifespan of the stem cells by allowing for indefinite division without shortening of telomeres.
What’s the difference between telomerase and telomeres?
A telomere refers to a region of repetitive nucleotide sequences at each end of a chromosome, which protects the end of the chromosome from deterioration or from fusion with neighboring chromosomes, while telomerase refers to the enzyme in a eukaryote that repairs the telomeres of the chromosomes so that they do not …
How chromosomes are protected by telomeres and the enzyme telomerase?
Blackburn and Szostak found that chromosomes without telomeres are protects them from degradation. Greider and Blackburn identified the enzyme that helps telomeres to protect the chromosomes – telomerase. The RNA is complementary to the telomere sequence, which allows the telomeres to be copied efficiently.
Are telomeres in prokaryotes?
Most prokaryotes, relying on circular chromosomes, accordingly do not possess telomeres.
What role do telomeres and telomerase play in cancer progression?
Telomeres maintain genomic integrity in normal cells, and their progressive shortening during successive cell divisions induces chromosomal instability. In the large majority of cancer cells, telomere length is maintained by telomerase.
Does telomerase prevent cancer?
Normal human cells have lower telomerase activity and usually have longer telomeres than cancer cells. The main point of anti-telomerase therapy is the selective destruction of cancer cells while minimizing the effect on normal cells (due to the presence of longer telomeres compared to cancer cells).