It’s one of the deadliest cancers. Now, scientists at Northwestern University say they’ve identified a molecule that one day might help fight glioblastoma multiforme, an incurable brain cancer that typically kills in 14 to 16 months.
Working with mice with glioblastoma, they found that an RNA molecule called miR-182 can suppress cancer-causing genes.
“Our study identified miR-182 as a glioblastoma tumor suppressor that reduces the expression of several oncogenes that promote cancer development,” says Alexander Stegh, an assistant professor of neurology and medicine who was senior author of the research reported in the journal Genes and Development.
Analyzing large-scale genomic data, Stegh and his colleagues found more patients with higher levels of miR-182 survived longer with the deadly cancer. It suppressed a cancer gene that protects cancer cells against chemotherapy and radiation and also slowed two other cancer genes.
To reach tumor cells in the brain, though, requires getting past a fierce biological guardian — the blood-brain barrier. To do that, the researchers gave the RNA a ride on spherical nucleic acids — a nanostructure invented by a Northwestern colleague, Chad Mirkin, that has unusual properties allowing it to safely reach its target without damaging healthy cells or triggering an immune response that would impede them.
“Small gold nanoparticles are conjugated with miR-182 sequences,” Stegh says. “They cross the blood-brain/blood-tumor barrier and accumulate within brain-tumor sites, where they target oncogenes . . . and prolong survival in our mouse models.
“These particles . . . could also potentially be used for gene-silencing in other cancers and diseases of genetic origin.”
Unlike standard chemotherapy, which keeps cancer cells from reproducing by attacking its DNA and also harms healthy tissue, Stegh says this method stopped cancer cells in mice by targeting the genes that are their source.
There have been other promising-sounding findings in the past on glioblastoma, but its survival rate has remained largely unchanged for decades. Even if the latest finding proves to translate to humans, the jump from mouse studies to human results takes years.
Glioblastoma’s better-known victims have included U.S. Sen. Edward M. Kennedy, TV sportscaster Tim Weigel, actor Sam Bottoms, best-selling investment author Gordon Murray and former Chicago Sun-Times restaurant critic Pat Bruno.
Good version of intestinal bug might help fight bad one
Giving patients a good version of an intestinal bug that’s one of the most common infections people pick up in hospitals appears to help prevent recurring problems with a dangerous form of the bacteria.
It’s a major step toward preventing repeated bouts of Clostridium difficile, known as Cdiff., a stubborn, potentially deadly infection, according to a study led by Dr. Dale Gerding of the Hines VA Hospital and Loyola University Medical Center, who reported on the research in the Journal of the American Medical Association.
The researchers gave patients previously treated with antibiotics after suffering diarrhea or colitis resulting from Cdiff. a liquid medicine containing spores of a harmless form of the bacteria for a week and found they were far less likely to have repeated bouts of the stubborn, potentially deadly bug.
More research needed on sexual side-effects of hair-loss drug, study says
Not enough has been done to establish that the drug finasteride — a popular treatment or male-pattern baldness — is safe, Northwestern University researchers say in an analysis published in the journal JAMA Dermatology.
They say none of the 34 published clinical trials looking at finasteride looked in-depth at the risk of erectile dysfunction and lowered sex drive associated with the drug: how likely is it to occur, how severe is it, and will it go away if a man stops taking it?
“People who take or prescribe the drug assume it’s safe, but there is insufficient information to make that judgment,” said lead study author Dr. Steven Belknap, adding that the findings reflect a broader problem with how clinical trials are done and reported. “Typically, there is more focus on the desirable effects of the drug being studied compared to the toxic effects.”