September 28, 2021, NEW YORK –Researchers led by Ludwig MIT investigator Scott Manalis reported on September 28th in Nature Communications a technique that, for the first time, allows them to measure the half-life time and generation rate of cells released by tumors in mice.
Circulating tumor cells (CTCs), which can seed metastases, are exceedingly rare, but researchers have devised strategies to capture them. Their analysis can yield information about a patient’s tumor and could even help physicians track tumor responses to treatment.
“Circulating tumor cells are attractive because you can get them from blood, and they provide a window into the tumor. It’s a lot easier than biopsying the tumor,” said Manalis, who is also the David H. Koch Professor of Engineering at MIT and a member of the Koch Institute for Integrative Cancer Research.
In mice, CTCs are even more difficult to find because mice only have a little more than 1 milliliter of blood. Being able to study CTCs in mice could help researchers answer many outstanding questions about CTCs.
The Manalis group designed a system that removes blood from a mouse with a tumor and flows it into a healthy mouse. Through a separate tube, blood from the healthy mouse flows back to the tumor-bearing mouse. Two cell-counters (one for each mouse) detect and remove circulating tumor cells from the blood.
Working with the laboratory of Ludwig MIT’s Tyler Jacks, the researchers used the system to study mice with three different types of tumors: pancreatic cancer, small cell lung cancer and non-small cell lung cancer. They found that the half-life of CTCs from these tumors ranged from 40 seconds to about 250 seconds. However, the generation rates showed much more variability. Small cell lung tumors, which are aggressively metastatic, could shed more than 100,000 CTCs per hour, while non-small cell lung tumors and pancreatic tumors shed as few as 60 in that much time.
Manalis and his team plan to use their system to examine CTCs in mouse models of other types of cancer and study how various therapies affect their generation rate and half-live times.
The MIT release from which this summary is derived can be found here.