In cancer, it’s typically not the primary tumour that kills – it’s the metastases. Little wonder, then, that a major topic at the meeting was developing drugs not to shrink the primary tumour, but to stop it from spreading.
Danny Welch from the University of Alabama at Birmingham presented data on an interesting protein called KISS1. (Welch claims the protein is so named because he lived near Hershey, Pennsylvania at the time of its discovery. For you international readers, Hershey, Pennsylvania is the home of Hershey’s, the chocolate company that makes ‘Hershey’s kisses”.)
Anyway, KISS1 inhibits metastasis, but the fascinating thing is that it does so without preventing the spread of tumour cells. Instead, it keeps the metastasized cells from flourishing in their new environment. In other words, if you inject KISS1-expressing tumour cells into mice, they’ll form a primary tumour and cells from the primary tumour will migrate to the lungs. And then they’ll just sit there, lost and lonely.
How does KISS1 do that? The answer isn’t clear, but Welch does have data suggesting that he protein is cleaved into pieces called peptides that are then secreted from the cell. An important question to answer now is: does KISS1 inhibit growth of metastasized tumour cells after they’ve already spread and started forming new tumours? If so, it could address a major concern among those who want to develop drugs to prevent cancer’s spread: what happens if you get there with your new wonder drug too late, after the cells have already begun their invasion?