Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.
Stem cells yield markers for relapse in colon cancer. Some colon cancer patients do fine after surgery without any chemotherapy, but it has been hard to predict which ones. A CIRM-funded team at the University of California, San Diego, with collaborators at Stanford and Columbia Universities, found a predictor for the need for chemotherapy by looking at the patients’ cancer stem cells.
Previously researchers have looked for markers in the tumors themselves for differences between those who require chemotherapy and those who don’t. Those efforts generally come up empty handed. The current team instead looked for differences in the patient’s cancer stem cells. They found that patients whose stem cells lacked one protein marker called CDX2 did poorer with surgery alone and were candidates for follow-up chemotherapy.
The team published its work in this week’s New England Journal of Medicine and it got wide pickup by online news outlets, but that coverage varied somewhat depending on which group the reporters called. Medical News Today provides the Columbia angle. Newswise distributed a press release with the San Diego voice and BlackDoctor.org used quotes from Stanford as well as the American Cancer Society. The latter lets Stanford’s Michael Clark remind readers that this was a retrospective look back at prior cancer patients and the conclusions need confirmatory studies.
“The data is extremely strong, but you need a prospective analysis to be 100 percent sure. It should be validated in a prospective trial.”
Three studies aim for better heart cells. While researchers have been turning stem cells into heart muscle in lab dishes for several years, getting them to function like normal heart cells either in the dish or when transplanted into animals has been tough. Three research groups published studies this week showing different approaches to making better heart muscle.
Biologists at Japan’s Kyoto University found a sweet spot in the age of new muscle cells when they were most likely to engraft and survive when transplanted in animals. They first created reprogrammed iPS-type stem cells and then matured them toward becoming heart muscle for four, eight, 20 and 30 days. The 20-day cells proved the most able to engraft in the mouse hearts and improve their function as seen by echocardiography.
The Kyoto team published its results in Scientific Reports and BiotechDaily wrote an article on the work.
Give them a jolt.
A group of physician engineers at Columbia University found that exposing lab grown heart muscle cells to electrical stimulation that mimicked the signals the cells would receive in a fetus resulted in stronger, more synchronized heart muscle. They started by engineering the heart muscle cells to grow in three dimensions and then added the electrical signals.
“We applied electrical stimulation to mature these cells, regulate their contractile function, and improve their ability to connect with each other. In fact, we trained the cell to adopt the beating pattern of the heart, improved the organization of important cardiac proteins, and helped the cells to become more adult-like,” said Gordana Vunjak-Novakovic, the lead author on the paper published in Nature Communications.
NewsMedical picked up the university’s press release.
Give them a mattress.
A team at Vanderbilt University in Tennessee found that growing the heart muscle cells on a commonly used lab gel called Matrigel resulted in cells with a shape and contractile function that matched normal heart tissue. The Matrigel formed a cushiony substrate that one team member referred to as a “mattress” for the cells to grow on that is more like the living environment in an animal than the usual lab dish.
ScienceDaily ran the university’s press release about the study published in Circulation Research. In the release, the team speculated that the matrigel worked through a combination of the flexibility of the gel and unknown growth factors released by the gel itself.
With heart disease still a leading cause of death, learning how to make better repair tissue could lead to major improvements in quality and length of lives. Of the 600-plus stem cell clinical trails currently active around the world, at least 70 target heart disease, but very few are striving to provide new tissue to repair damaged heart muscle. Generally, they are using stem cells that secrete various factors that help the heart heal itself. CIRM funds one of those trials being conducted by Capricor.