Welcome to this week’s Sunday Science, featuring a “game-changing” test for leukaemia, curing HIV and type 2 diabetes, how children help women live longer, and why you need sleep to repair your DNA…
A new “game-changing” test to quickly and accurately predict how people will respond to standard treatment for the most common type of leukaemia, chronic lymphocytic leukaemia (CLL) has been developed. This is very important, because different people respond very differently to treatment regimes, depending on their genetic background, and often in cancer on what mutations have caused their cancer. In the case of CLL, it seems that patients with shorter telomeres (which protect the ends of the chromosomes from degrading) tend to get a much faster developing cancer which responds poorly to chemotherapy. This test might also prove useful in other cancers. Original study published here (open access).
On the subject of telomeres, women who have more children tend to have longer telomeres and age more slowly. I must admit I do find this surprising: pregnancy and childbirth are very physiologically demanding on the body (and childbirth is quite dangerous). Assuming giving birth doesn’t kill you, however, it seems that your children might keep you youthful because the high levels of oestrogen during pregnancy has a protective effect on telomeres. It’s a little more nuanced than that, however, as the study was from a population in which mothers receive a high level of social support from the community, which also has beneficial effects on their metabolism and aging. Original study here (open access).
Good news for the many millions suffering from type 2 diabetes: the disease is not, as once thought, inevitably progressive, but can be reversed with weight loss. The Labour MP Tom Watson, for example, made the headlines last year when he claimed to have reversed his type 2 diabetes with a strict diet and exercise regime. Now, a thorough scientific study backs up this example. Study published here (paywalled, and rather technical).
Why we – and all animals – need to sleep has always been something of a biological mystery, the general acceptance being that our minds and bodies need sleep for the efficient functioning of our bodies. A novel study has now found an intriguing new reason: that we need sleep to repair damaged DNA in our neurons. Specifically, the authors used time-lapse imaging of chromosomal markers in single cells in live zebrafish which showed increased chromosome dynamics in individual neurons but not in two other cell types. This increased activity was needed to repair double-strand breaks in the DNA. Original study here (open access).
A second patient has achieved complete remission from HIV. The patient developed Hodgkin’s lymphoma, for which he required a bone marrow stem cell transplant. The donor carried two copies of the mutant CCR5Δ32 allele, which confers HIV resistance (I wrote about the evolution of this mutation and its possible function here). Although these transplants are hardly going to become a standardised cure for HIV, they do offer some insights into targeting that CCR5 receptor for devising other treatments. Original study here (paywalled):
And finally, splashdown for the SpaceX Crew Dragon:
Telomeres at the ends of chromosomes (red dots). Asako J. Nakamura, Christophe E. Redon, William M. Bonner, and Olga A. Sedelnikova [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)%5D. Wikipedia.