By: Josh Baxt
Computer giant IBM has a side business in the life sciences, and it’s doing interesting work on cancer. In a recent paper published in the Journal of the American Chemical Society (JACS), researchers at IBM Healthcare and Life Sciences outlined how new polymers can selectively destroy cancer cells by slicing them open.
“They poke a bunch of holes in the membrane,” said IBM researcher and first author on the paper Nathaniel Park in a phone interview. “It’s hard for the cancer cells to stop this or develop resistance.”
The technology arose from IBM’s computer expertise. Around ten years ago, the company realized the polymers they had developed to make chips could be reapplied to the life sciences. The team, led by James Hedrick, has used these macromolecules against antibiotic-resistant bacteria, many of which have a negative charge.
“Antimicrobial polymers get their efficacy from their cationic charge,” said Park. “So, they’re positively charged, and this allows them to selectively associate with the microbes over healthy human cells.”
The JACS study showed the same strategy can be effective against cancer cells, which can also be negatively charged. The macromolecules they’ve created take their cue from peptides and antibodies, which can also home in on cancer cells.
“These are more like biologics,” said Park. “They are not proteins or peptides per se, but they do mimic their functions and are in a similar weight class.”
The IBM macromolecules contain a positively-charged block, which binds to cancer cells, while a second piece burrows into cell membranes. The self-assembling components resist the body’s efforts to eliminate them – a problem with peptides – though they decompose on their own after a couple of days.
The molecules proved effective against both cancer cells and “cancer stem cells.” They also kept cells from migrating, the deadliest aspect of cancer. In practice, these molecules would likely be infused like standard chemotherapy.
Unlike chemotherapy, however, this approach does not trigger apoptosis, the programmed cell death cancers sometimes learn to resist. Rather, it causes necrosis – the cells just die. Though the researchers tried, they were unable to force the cancer cells to build up resistance against these macromolecules.
“If you treat the cells through multiple passages, where you stress and back off, stress and back off, the polymer will retain its potency,” said Parks. “With a typical small molecule cancer drug, like doxorubicin, you quickly get to lethal amounts. You can’t dose the cancer without killing the patient.”
The study was conducted by IBM Research – Almaden in San Jose, in collaboration with Singapore’s Institute of Bioengineering and Nanotechnology, Institute of Molecular and Cell Biology and the Genome Institute of Singapore.
While the results are promising, this research is quite early stage, working in cell lines and animal models. The team is now looking for collaborators.
“We would like to find a partner in industry to help take these systems forward,” said Park, “to see if some of them can make their way to the clinic in an eight to ten-year timeframe.”