New Cancer Cell Therapy Wipes Out Solid Tumors in Mice

Scientists just solved one of cancer treatment's toughest puzzles, and it could change everything for the 85% of cancer patients battling solid tumors.

Researchers at Columbia University engineered immune cells so sensitive they can find and destroy cancer cells that hide from current treatments. In lab tests with human cancer cells and mouse models, these "HIT cells" completely wiped out kidney, ovarian, and pancreatic tumors without a trace.

The breakthrough targets a protein called CD70 that appears on many solid tumor cells. Previous cancer-fighting cells could only detect high levels of this protein, missing cancer cells with faint amounts. Those leftover cells regrow into new tumors, which is why so many treatments eventually fail.

"You can't cure somebody if you just eliminate a small fraction or even 90% of their tumor," said study author Michel Sadelain. The team discovered that cancer cells scientists thought lacked CD70 actually had low levels that were simply invisible to conventional detection methods.

HIT cells work like upgraded versions of CAR T therapy, which already fights blood cancers successfully but struggles against solid tumors. The new design mimics the most sensitive natural immune cells in our bodies, creating protein hooks that grab onto even the faintest cancer markers.

The technology is plug-and-play, meaning scientists can redesign it to hunt different cancer proteins. This opens doors to treating multiple cancer types with similar approaches instead of starting from scratch each time.

Normal cells don't use the CD70 pathway, so HIT cells mostly ignore healthy tissue. That reduces the risk of attacking the wrong cells, a major concern with other cancer treatments that target proteins found in both tumors and normal organs.

The Ripple Effect

This advance matters beyond the lab. Over 85% of cancers are solid tumors, affecting millions of people whose treatment options remain limited compared to blood cancer patients. Pancreatic and ovarian cancers are notoriously aggressive with low survival rates.

The same sensitivity principle could apply to other hard-to-detect cancer markers. By engineering immune cells that see what current methods miss, researchers might finally corner cancers that have always had escape routes.

Clinical trials in humans are the essential next step to see if these results translate from mice to people. The team hopes their approach will lead to treatments that eliminate every last cancer cell, not just most of them.

"We hope our CD70-directed HIT cells help us find a way to eradicate the entire tumor," said study author Sophie Hanina.