Posts Tagged ‘origin’

Origins of Cancer Uncovered.

Wednesday, February 3rd, 2016

logo1267406_mdA new study reported in Science concluded that researchers had visualized the origin of cancer, from the first affected cell and watched its spread in a live animal. This could change the way they understand cancer and lead to new early treatment before the cancer has invaded.

Researchers queried why some cells already have mutations seen in cancer, but do not fully behave like the cancer. They continued “We found that the beginning of cancer occurs after activation of an oncogene or loss of a tumor suppressor, and involves a change that takes a single cell back to a stem cell state.”  That change involving a set of genes could be targeted to stop cancer from ever starting.

Over time researchers imaged live zebrafish to tract development of melanoma and all had the human cancer mutation BRAFV600E–found in most benign moles–and had also lost the cancer suppression gene p53. Researchers engineered the fish so that individual cells would floresce green if a gene called crestin was turned on that indicated activation of a genetic program characteristic of stem cells. This program normally turned off after embronic development, but occasionally for some unknown reason crestin and other genes turned back on in certain cells. The researcher said “Every so often we would see a green spot on a fish.” When we followed them, they became tumors 100 percent of the time.”

They found that these early cancer cells are the crestin and the other activated genes are the same ones turned on during zebrafish embryonic development and these genes also get turned on in human melanoma. They believe these finding will lead to a new genetic test for suspicious moles to see if the cells are behaving like neural crest cells that would indicate the stem cell program has been turned on.

They postulate a new model of cancer formation that goes back to the concept of field-cancerization. In this model the normal cell vecomes primed for cancer when onvogenes are activated and tumor suppressor genes are silenced or lost, but the cancer develops only when a cell in the tissue reverts to a more primitive, embreyonic state and starts dividing and this model may apply to most if not all cancers.