• Seen: How a cell becomes cancerous
  
  
  

  Seen: How a cell becomes cancerous

  Gina Kolata | NYT News Service | Jan 30, 2016, 04.05 AM IST
  It was just a tiny speck, a single cell that researchers had marked with a fluorescent green dye. But it was the very first cell of what would grow to be a melanoma, the deadliest form of skin cancer. Never before had researchers captured a cancer so early.
  
  The cell was not a cancer yet. But its state was surprising: It was a cell that had reverted to an embryonic form, when it could have developed into any cell type. As it began to divide, cancer genes took over and the single primitive cell barreled forward into a massive tumour.
  
  Those were the findings of Dr Leonard Zon of Boston Children's Hospital, Dr Charles K Kaufman, and their colleagues, in a study published on Thursday in the journal Science that offers new insight into how cancers may develop.
  
  The researchers stumbled on that first cell of a melanoma when they set out to solve a puzzle that has baffled cancer investigators: Why do many cells that have cancer genes never turn cancerous?
  
  Much more study is needed, but researchers say the result can help understand why melanomas and possibly other cancers form, and potentially prevent them.
  
  It may provide a way to stop melanomas from growing back after they have been cut down by drugs.
  
  The prevailing idea about the development of a cancer is that genes randomly mutate in a healthy cell, perhaps from sun exposure, perhaps from simple bad luck.