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.
For cancer growth timing is everything. A study originating at the University of Southern California suggests tumors are born to be bad. Mutations constantly occur during the life of a tumor but those that occur early on determine if a tumor will grow as a benign mass of a cancerous one that spreads.
Describing the genetic markers the team found, the senior author, Christina Curtis, who recently moved to Stanford, was quoted in a story in ScienceBlog:
“What you see in the final cancer was there from the beginning.”
The CIRM funded team completed detailed genetic analysis of tumor cells surgically removed from colon cancer patients. Doctors treating these patients have long been hampered by an inability to tell which tumors will remain small and benign and which will develop into full-blown cancer. The researchers suggest the genetic fingerprints they have uncovered could lead to improved diagnosis for patients.
Physical forces also key to cell fate. Putting the squeeze on stem cells may be what’s needed to get them to become bone. In this case, a team at the University of California, San Diego, used teeny tiny tweezers called “optical tweezers,” to trigger key internal signals that directed stem cells to go down the path to bone.
“The mechanical environment around a stem cell helps govern a stem cell’s fate. Cells surrounded in stiff tissue such as the jaw, for example, have higher amounts of tension applied to them, and they can promote the production of harder tissues such as bone.”
He said the findings should help researchers trying to replicate the natural stem cell environment in the lab when they try to grow replacement tissues for patients.
Super donors could provide matching tissue. One of the biggest challenges of using stem cells to replace damaged tissue is avoiding immune system rejection of the new cells. CIRM-grantee Cellular Dynamics International (CDI) announced this week that they have made key initial steps to creating a cell bank that could make this much easier.
Our bodies use molecules on the surface of our cells to identify tissue that is ours versus foreign such as bacteria. The huge variation in those molecules, called HLA, makes the matching needed for donor organ, or donor cells, more difficult than the New York Times Sunday crossword. But a few individuals posses an HLA combination that allows them to match to a large percent of the population.
CDI has now created clinical grade stem cell lines using iPS reprogramming of adult tissue from two such “super donors.” Just those two cell lines provide genetic matches for 19 percent of the population. The company plans to develop additional lines from other super donors with the goal of creating a bank that would cover 95 percent of the population.
Reuters picked up the company’s press release. CIRM does not fund this project, but we do fund another cell bank for which CDI is creating cells to better understand the causes of 11 diseases that have complex genetic origins
Narrative tells the tale of developing diabetes therapy. MIT Technology Review has published a well-told feature about the long road to creating a stem cell-based therapy for diabetes. Author Bran Alexander starts with the early days of the “stem cell wars” and carries the tale through treatment of the first patients in the CIRM-funded clinical trial being carried out by ViaCyte and the University of California, San Diego.
The piece quotes Viacyte’s chief scientific officer Kevin D’Amour about the long road:
“When I first came to ViaCyte 12 years ago, cell replacement through stem cells was so obvious. We all said, ‘Oh, that’s the low-hanging fruit.’ But it turned out to be a coconut, not an apple.”
But the article shows that with Viacyte’s product as well as others coming down the pike, that coconut has been cracked and real hope for diabetics lies inside.