The Sahara flowed with rivers in 6,000 B.C.. Science just proved that ancient Africans kept cattle on its grasslands. Wisps of evidence surrendered to powerful molecular analyses. Breast cancer research is more interesting, and its proofs, just announced, are (like the Sahara dairymen’s) gleaned by techniques devised only in the last few years. Amazing insights flow from technologies on which the paint is scarcely dry.
First, those Sahara cows. The evidence was in pottery shards, reliably dated to 6,000 B.C. Molecules impregnated the shards. New analytic techniques identified them. They were fats. They matched milk fats from African animals published recently in a database. So the Africans had kept herds. This enabled anthropologists to date ancient Saharan cave paintings of people herding and milking cattle and goats. Before the molecular techniques, dating the paintings had been impossible.
Second, breast cancer: Whole genome sequencing is the new technique. (Machines read the molecular pattern of all 25,000 human genes.) It has become fast and cheap. It used to be too slow and costly to analyze hundreds of tumors. But no longer. A tumor’s genetic machinery is no longer hidden. From this beginning, therapy tailored to a cancer’s unique genes may ensue (eventually).
Just published are patterns of gene abnormalities distinguishing each known breast cancer type. In some cancers, single “steps” in DNA’s long, ladder-like helix are changed. In others, whole sections of the helix switch their locations, or are missing entirely. Some cancers infest their DNA with extra copies of genes. In others, genes are normal but are regulated (i.e. make their proteins) abnormally. The differences are in the thousands, and tumors’ genes mutate as tumors grow.
Two years ago, it was impossible to know this. New techniques, painstakingly refined by researchers, are swiftly bringing science to life’s most fundamental level: genes and how they function (and malfunction). Research now can not only find all the abnormalities. It can tackle: What causes them? What chemical cascades do they trigger? How does that turn cells cancerous? And, once we know those things, how to cancel the harm?
Cancer’s details were hidden, like the evidence of Sahara dairymen, lying in the desert’s potsherds since 6,000 B.C. No longer.
What phenomenon in nature?
What was discovered?
Thousands of genetic abnormalities that distinguish tumor cells in all known types of breast cancer.
What was known before?
Some breast cancers had genetic abnormalities, but not a comprehensive list of all of them.
What remains unknown?
The causes and consequences of most breast cancer abnormalities, and how to cure them.
J. Gray and B. Druker, The breast cancer landscape, 486 Nature 328-329, 21 June 2012.
M. Ellis et al. Whole-genome analysis informs breast cancer response to aromatase inhibition, 486 Nature 353-360, 21 June 2012.
S. Shah, et al., The clonal and mutational evolution spectrum of primary triple-negative breast cancers, 486 Nature 395-399, 21 June, 2012.
P. Stephens, The landscape of cancer genes and mutational processes in breast cancer, 486 Nature 400-404, 21 June 2012;
S. Banerji, et al., Sequence analysis of mutations and translocations across breast cancer subtypes, 486 Nature 405-409, 21 June 2012
And on the cows: J. Dunne, First dairying in green Saharan Africa in the fifth millennium BC, 486 Nature 390-394, 21 June 2012.