While most people are not at risk from Kaposi’s sarcoma herpes virus (KSHV), researchers say those with lowered immune systems, such as AIDS patients or transplant recipients, are more susceptible to developing the sarcoma as a result of infection. Their findings, reported in the August 1 issue of Cancer Research, a journal of the American Association for Cancer Research, offer cautionary evidence that those with weakened immune systems should speak with their doctors before using marijuana medicinally or recreationally.
“These findings raise some serious questions about using marijuana, in any form, if you have a weakened immune system,” said lead study author Jerome E. Groopman, M.D., professor of medicine at Harvard Medical School. “While THC is best known as the main psychotropic part of marijuana, an analog of THC is the active ingredient of marinol, a drug frequently given to AIDS patients, among others, for increasing appetite and limiting chemotherapy-induced nausea and vomiting.”
While previous studies indicated that marijuana smoking was associated with Kaposi’s sarcoma, this is the first to demonstrate that THC itself can assist the virus in entering endothelial cells, which comprise skin and related tissue.
According to Dr. Groopman, the study illustrates the complicated role marijuana and other cannabinoids play in human health. Numerous types of cells display cannabinoid receptors on their outer surfaces, which act as switches that control cellular processes. Dr. Groopman’s laboratory had previously demonstrated that THC could have a protective effect against a certain form of invasive, drug-resistant lung cancer.
To study the combined effect of THC and KSHV, the researchers examined a culture of human skin cells, which are susceptible to infection and could provide a model of Kaposi’s sarcoma. These culture cells display many copies of two prominent cannabinoid receptors. Dr. Groopman and his colleagues found that by bonding to these receptors, low doses of THC activate two proteins responsible for maintaining a cell’s internal framework, or cytoskeleton. By altering the cytoskeleton, THC effectively opens the door for KSHV, allowing the virus to more easily enter and infect the cell. “We can take away that effect by using antagonists that block the two cannabinoid receptors, which adds evidence that THC is the culprit,” Dr. Groopman said.
Once a cell is infected, the presence of THC may also promote the cellular events that turn it cancerous, the researchers say. They found that THC also promotes the production of a viral receptor similar to one that attracts a cell-signaling protein called interleukin-8. Previous studies have noted that this receptor could trigger the cell to reproduce, causing Kaposi’s sarcoma-like lesions in mice. Indeed, the researchers saw that THC induced the infected cells to reproduce and form colonies in culture.
“Here we see both infection and malignancy going on in the presence of THC, offering some serious concerns about the safety of THC among those at risk,” Dr. Groopman said. “Of course, we still do not know the exact molecular events that are occurring here, but these results are just the first part of our ongoing research.”
Greg Lester | EurekAlert!
The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung
A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences