Researchers at Tel Aviv University discover that blocking a certain protein helps prevent the spread of brain cancer cells.
Researchers at Tel Aviv University have discovered a fix to stop certain cells in the brain from helping spread cancerous growths, the university announced on Sunday.
They focused on a problem that had frustrated scientists related to why the brain’s immune system fails to fight the disease and instead encourages division and the spread of deadly glioblastoma cancer cells.
“We’ve been studying glioblastoma for the last decade. We are intrigued by the way that glioblastoma, a very aggressive brain cancer, progresses and advances so quickly in the brain while most treatments are actually useless,” said Prof. Ronit Satchi-Fainaro, Director of the Cancer Biology Research Center and the Head of the Cancer Research and Nanomedicine Laboratory at the university.
Glioblastoma is the deadliest type of cancer in the central nervous system, accounting for most malignant brain tumors. It is aggressive, invasive, and fast-growing, making it resistant to existing treatments, with patients dying within a year of the cancer’s onset.
Moreover, glioblastoma produces “cold tumors,” which do not respond to immunotherapeutic attempts to activate the immune system against it.
“Five years ago, we decided to focus on the interactions between the glioblastoma cells and the resident cells in the microenvironment in the brain. We focused on microglia. These are the immune cells of the brain,” she explained.
“To our surprise, we found that not only do the microglia cells do nothing to stop the cancer cells, they actually play a crucial and negative role by accelerating the division, spread and mobilization of glioblastoma cells,” she said.
Satchi-Fainaro’s team found that the brain secretes a protein called P-Selectin (SELP), which alters the brain’s immune cells so that instead of inhibiting the spread of cancer cells, they do the opposite, enabling them to proliferate and penetrate brain tissues.
They then searched for a way to inhibit the SELP protein so that the microglia do what they’re supposed to do and block the spread of what is normally an incurable cancer.
“SELP is a known protein that normally helps cells travel inside the body – especially white blood cells and endothelial cells that line the interior of blood vessels,” explains Satchi-Fainaro. “The encounter between glioblastoma cells and microglia cells causes them to express SELP in large quantities. In the study, we were able to show that the overexpressed SELP helps the cancer cells travel and penetrate the brain tissue.”
“By inhibiting the secretion of this protein, we actually halted the progression of the glioblastoma in multiple models, in mice and in unique 3D models from brain tissues that has glioblastoma (taken) from patients,” said Satchi-Fainaro.
The results of the study may have lifesaving therapeutic implications and by sheer coincidence, a clinical study is already being conducted to inhibit SELP for a different reason – treating pain associated with sickle cell anemia.
Satchi-Fainaro hopes that since that treatment appears to be showing that inhibiting SELP is proving safe in humans, positive results from that trial could pave the way for relatively rapid approval of a clinical trial repurposing the new treatment for glioblastoma.
“Unfortunately, glioblastoma patients need new treatments immediately. Our treatment may be the needed breakthrough in the battle against the most daunting cancer of all,” she said.
(United with Israel).