Even if you’re sitting very still, some of your cells might be on the move, especially if your body is fighting an infection or healing a wound. Cells do this by rearranging their cytoskeletons, the framework that gives cells their shape. The problem is when cancer cells move – damaging an entire organ or metastasizing to distant sites in the body.Two protein networks make up the cytoskeleton and allow for cellular movement – actin and microtubules. Actin is the major driver, while microtubules play a secondary role as navigator. However, a recent study led by Dr. Robert Margolis challenges that accepted dogma. He and his team found that glioblastoma cells, a type of brain cancer, are the exception to the rule. To Dr. Margolis’ surprise, glioblastoma cell movement persists even when the actin scaffolding is completely disassembled.
“This still needs to be confirmed, but something unusual is definitely happening,” explains Dr. Margolis, professor in Sanford-Burnham’s Tumor Development Program. “This is very atypical behavior for cells.”
More information about glioblastoma development and behavior is desperately needed. As Dr. Margolis knows all too well, glioblastoma is the most common and most aggressive type of primary brain tumor. Like many others, he’s lost a friend to the disease.
“That’s what we’re here for,” he says of his lab.
When Dr. Margolis and his team, including Sanford-Burnham colleagues Dr. Rati Fotedar and Dr. Andreas Panopoulos, blocked actin in glioblastoma cells using chemical inhibitors or genetic manipulation, cells continued to put out protrusions that were full of microtubule polymers. They were amazed to find that glioblastoma cells display this unprecedented mode of transportation.
“Basically, to move, a cell has to make a protrusion, then adhere to the surrounding tissue or surface, move forward, then pull up what’s behind,” Dr. Margolis says. “And it turns out that microtubules can do these things alone.”
Panopoulos A, Howell M, Fotedar R, & Margolis RL (2011). Glioblastoma motility occurs in the absence of actin polymer. Molecular biology of the cell PMID: 21551075