Turning back cancer

Work is now gathering pace on identifying how to use the natural plasticity of cancer cells to return them to a benign state, instead of just going full-out on destroying them.

The idea isn’t new. It was more than 80 years ago when developmental biologists started looking at the idea that cancer was basically a disrupted development disease, with the breakdown of the social interaction of cells that repair organs, tissues and bodies. So could such malignant development be reversed? Reports of cancers spontaneously regressing in patients suggested it could. Experiments have shown that liver cancer cells can lose their malignant behaviour, while human breast cancer cells have been reprogrammed into harmless fat cells.

It appeared that the tissue environment around the cancer cells influenced their behaviour, so the search was on for the mechanisms responsible. The cancer could be retrained by exposure to embryonic environments in which closely related cell types were generated.

Lab research as far back as the 1970s discovered that a vitamin A derivative called retinoic acid could force immature APL (acute promyelocytic leukaemia) cells to differentiate into mature white blood cells. Retinoic acid beneficially alters the shape of a protein involved in causing APL. This procedure in conjunction with chemotherapy and an arsenic compound is still used to this very day.

Cancer research has been largely focused on selectively killing cancer cells, with little attention devoted to how our bodies naturally suppress cancer. Not a few biologists and cancer researchers say this approach isn’t working, not least because cancer cells quickly evolve resistance to any treatment aimed at destroying them. Key to retraining cancer is to understand how cells differentiate and obtain their particular functions. Embryonic cells have the ability to form any type of cell. Signals from their environment and neighbours progressively restrict the type of cell they can form. A set of four genes called the Yamanaka factors can sometimes reprogramme mature somatic cells (and cancer cells) to become pluripotent stem cells that can then be persuaded to form any type of cell in the body.

The work continues. As one scientist put it – after decades of fighting, maybe it’s time to take a step back and devote a little more attention to negotiation.