Blocking telomerase proved to be ineffective.
Scientists at the University of Case Western reserve in the US have developed a new method of inhibiting the growth of cancerous tumors through delivery to cancer cells synthetic nucleotides. Recently incorporated into telomeres, damage them, and thus kill the cell. Article researchers published in the journal Cell Reports.
Called telomeres the ends of chromosomes, consisting of TTAGGG repeats (in humans). They prevent the loss of genes during mitosis because DNA polymerase cannot synthesize a copy of DNA from the end, but every time replication is the shortening of the telomeres. When the telomeres become too short, cells age and die. Telomerase rebuilds telomeres, but its excessive activity promotes cancer, in which malignant cells become virtually immortal.
Blocking telomerase proved to be an inefficient way of dealing with tumors, because of the time required for depletion of telomeres, cancer cells employ alternative mechanisms for lengthening the ends of chromosomes. Therefore, researchers have come up with a way to make ourselves unstable telomeres. He is to deliver into the cell nucleotide 5-FdUTP, which is a fluorinated pyrimidine, having a toxic effect.
Telomerase builds 5-FdUTP in telomeres, creating areas that hinder the formation at chromosome ends, T-loops, which close the DNA strand. The result activates mechanisms that normally responds to damage in chromosomes and stopping the cell cycle. It is shown that 5-FdUTP kills human cancer cells with elevated telomerase activity.