Programmed cell death, or apoptosis, helps keep us healthy by ensuring that excess or potentially dangerous cells self-destruct. One way cells know it’s time to die is through signals received by so-called death receptors that stud cells’ surfaces. When these signals go awry, the result can be cancer (uncontrolled cell growth) or autoimmune disease (cells self-destructing too readily).
Researchers at Harvard Medical School (HMS) and the Program in Cellular and Molecular Medicine at Boston Children’s Hospital deconstructed a death receptor called Fas to learn more about its workings, using nuclear magnetic resonance (NMR) spectroscopy to reveal its structure.
They found that for immune cells to hear the “time to die” signal, a portion of Fas called the transmembrane region must coil into an intricate three-part formation, allowing the signal to pass into the cell. The NMR imaging also revealed that the amino acid proline is critical for the formation’s stability. Cancer-causing mutations in the transmembrane region (one of them affecting proline itself) deformed this delicate structure and prevented signals from passing through.
This better understanding of the Fas death receptor, published last week in Molecular Cell, could lead to new approaches that bypass Fas to encourage apoptosis in cancer or, conversely, inhibit Fas in autoimmune disease.
To help public health investigators, policy makers, epidemiologists and others keep up with the virus, the team at HealthMap has released a dedicated Zika virus tracking resource at http://www.healthmap.org/zika/. The new map brings in Zika-related information and news from a variety of sources in near real-time, and includes a constantly updated interactive timeline of the virus’s explosive spread across South and Central America.
Oral squamous cell carcinoma (OSCC), a kind of oral cancer, affects some 30,000 Americans annually. It spreads through the lymphatic system and often has already metastasized by the time it’s diagnosed. The top image here is a healthy mouse tongue; the bottom is the swollen tongue of a mouse with OSCC. The cancerous tongue is overloaded with lymphatic vessels, appearing in blue and white, which help the tumor spread to the regional lymph nodes. The Bielenberg lab in Boston Children’s Hospital’s Vascular Biology Program is studying ways of blocking the progression of this and other cancers by inhibiting their spread through the lymphatic system. (Image: Bielenberg laboratory/Kristin Johnson)
Jason Ayres, a family doctor in Alabama, was speechless as he held his adopted son Patrick’s heart in his hands. Well, a replica of his son’s heart — an exact replica, 3-D printed before the 3-year-old boy had lifesaving open-heart surgery.
A family walks into their oncologist’s office and sits down. Their son’s care team is there, ready to discuss the sequencing report they received about the tumor in his leg.
“We think we have something,” the oncologist says. “We found a known cancer-associated mutation in one gene in the tumor. There’s a drug that targets that exact mutation, and other children and adults whose tumors have this mutation have responded well. We’ll have to monitor your son closely, but we think this is a good option.”
This hypothetical conversation, while common in adult oncology, happens rarely (if at all) on the pediatric side. This kind of personalized, genomics-driven medicine (where the genetic alterations in a patient’s tumor drive therapy, not the tumor’s location) isn’t a standard approach for childhood cancers yet.
Note that I said yet. The door to personalized pediatric genomic cancer medicine is cracking open, in part because three recent papers — including one out of Dana-Farber/Boston Children’s Cancer and Blood Disorders Center — are starting to convince the field that clinical genomics can indeed be done in pediatric oncology. …
It’s long been a mystery why some of our cells can have mutations associated with cancer, yet are not truly cancerous. Now researchers have, for the first time, watched a cancer spread from a single cell in a live animal, and found a critical step that turns a merely cancer-prone cell into a malignant one.
Their work, published today in Science, offers up a new set of therapeutic targets and could even help revive a theory first floated in the 1950s known as “field cancerization.”
“We found that the beginning of cancer occurs after activation of an oncogene or loss of a tumor suppressor, and involves a change that takes a single cell back to a stem cell state,” says Charles Kaufman, MD, PhD, a postdoctoral fellow in the Zon Laboratory at Boston Children’s Hospital and the paper’s first author. …
A deep genetic analysis, involving nearly 65,000 people, finds a surprising risk factor for schizophrenia: variation in an immune molecule best known for its role in containing infection, known as complement component 4 or C4.
The findings, published this week in Nature, also support the emerging idea that schizophrenia is a disease of synaptic pruning, and could lead to much-needed new approaches to this elusive, devastating illness. …
Of the various ways for a cell to die — necrosis, autophagy, etc. — apoptosis is probably the most orderly and contained. Also called programmed cell death (or, colloquially, “cellular suicide”), apoptosis is an effective way for diseased or damaged cells to remove themselves from a population before they can cause problems such as tumor formation.
Conventional wisdom holds that apoptosis is exclusive to multicellular organisms. Lieberman disagrees. She thinks that microbial cells — such as those of bacteria and parasites — can die in apoptotic fashion as well. In a recent Nature Medicine paper, she and her team make the case for the existence of what they’ve dubbed “microptosis.” And they think it could be harnessed to treat parasitic and other infections. …
More than 75 percent of children diagnosed with cancer are surviving into adulthood, leaving more and more parents to wonder: Will my child be able to have children down the road?
They’re right to be concerned. The cancer treatments that are so effective at saving children’s lives can themselves cause a host of problems that don’t manifest until years later. These late effects include particularly harsh impacts on fertility.
On our sister blog Notes, urologist Richard Yu, MD, PhD, of Boston Children’s Hospital and fertility specialist Elizabeth Ginsberg, MD, of Brigham and Women’s Hospital outline where the science of fertility preservation is going.
“It may take 15 or 20 years to develop the techniques to help a child who is 8 years old now,” notes Yu. “But if you don’t preserve something now, you run the risk of not being able to do anything for them later, which is where we are now with a large number of adults who survived childhood cancer.”
“Negative.” “Normal.” “Fails to confirm the diagnosis of . . .” “Etiology of the patient’s disease phenotype remains unknown.”
These are words I heard repeatedly in the first 11 years of my son’s life. Even as new genes for my son’s rare muscle disorder were discovered around the world, negative or “normal” genetic test results were reported back to us 13 times. …