Chimeras offer a new way to study childhood neuroblastoma in mice

Good news! Amazing stuff! Chimeras may open up a new way to study and treat cancer! Cancer is history!

"Human-mouse chimeras have been used in the past to study Alzheimer's disease and brain development. Jaenisch, who is also a professor of biology at MIT, and his lab had been working for years to create chimeric mice with human cells in the neural crest -- the group of developing cells that go on to form parts of the sympathetic nervous system -- and published their findings in 2016. ...
To create these chimeric mice, ... first engineered human pluripotent stem cells to express two genes known to be abnormal in neuroblastoma, MYCN and mutated ALK, and modified them so they became neural crest cells, from which human neuroblastomas are derived. The genes could be turned on and off with the addition of doxycycline, an antibiotic. They also inserted the gene for eGFP, a brightly glowing fluorescent protein originally isolated from jellyfish. This would allow the team to tell whether the cells were spreading correctly through the bodies of the mice, and would cause any tumors originating from these human cells to be luminous under fluorescent light.
The researchers injected mouse embryos with these cells, and watched over the course of embryonic development as the cells proliferated and human tissues crept into the developing peripheral nervous systems of the tiny mice. To activate the two cancer-causing genes, researchers spiked the pregnant mice’ water with doxycycline, and over the next few days in utero -- and in the weeks and months after the pups were born -- the researchers inspected the chimeras to see whether tumors would appear. 
Over the course of the next 15 months, 14% of the mice developed tumors -- 29 mice out of 198 total. The tumors mostly appeared in the space behind the abdominal cavity close to the nerves along the spinal cord, although one mouse developed a tumor in its adrenal gland. Both locations are common places for human children to develop neuroblastoma."


Whitehead Institute - News - 2020 - Chimeras offer a new way to study childhood cancers in mice