Bio · Science · Vital-Edible-Health

Damage Control: Recovering From Radiation and Chemotherapy

Protein discovery could boost efficacy of bone marrow replacement treatments

Researchers at the University of California, San Diego School of Medicine report that a protein called beta-catenin plays a critical, and previously unappreciated, role in promoting recovery of stricken hematopoietic stem cells after radiation exposure.

The findings, published in the May 1 issue of Genes and Development, provide a new understanding of how radiation impacts cellular and molecular processes, but perhaps more importantly, they suggest new possibilities for improving hematopoietic stem cell regeneration in the bone marrow following cancer radiation treatment.

Ionizing radiation exposure – accidental or deliberate – can be fatal due to widespread destruction of hematopoietic stem cells, the cells in the bone marrow that give rise to all blood cells. A number of cancer treatments involve irradiating malignancies, essentially destroying all exposed blood cells, followed by transplantation of replacement stem cells to rebuild blood stores. The effectiveness of these treatments depends upon how well the replacement hematopoietic stem cells do their job.

Via UCSD Health Sciences. Read full text HERE

Bio · Science

New type of extra-chromosomal DNA discovered

A team of scientists from the University of Virginia and University of North Carolina in the US have discovered a previously unidentified type of small circular DNA molecule occurring outside the chromosomes in mouse and human cells. The circular DNA is 200-400 base pairs in length and consists of non-repeating sequences. The new type of extra-chromosomal circular DNA (eccDNA) has been dubbed microDNA. Unlike other forms of eccDNA, in microDNA the sequences of base pairs are non-repetitive and are usually found associated with particular genes. This suggests they may be produced by micro-deletions of small sections of the chromosomal DNA.

This result suggests that the DNA found in tissue cells may exhibit more variation than previously thought, and the implication of this is that sequencing of the DNA in blood cells (which are the cells usually used for sequencing) may give misleading results if micro-deletions have occurred in the DNA of other tissues but not in blood cells. Examples in which this might be important are in genetic sequencing for autism or schizophrenia, which could be caused by incorrect functioning of certain genes in brain tissue. Many cancers are also caused by incorrect functioning of genes; in this case tumor suppressor genes, and sequencing of blood cell DNA could also give misleading results.

Excerpts from an article via PhysOrg