Only by viewing a Seurat painting at close range can you appreciate the hidden
complexities1 of
pointillism(点描绘法) -- small, distinct dots of pure color
applied2 in patterns to form an image from a distance. Similarly, biologists and geneticists have long sought to
analyze4 profiles of
genes5 at the single cell level but technology limitations have only allowed a view from afar until now. Research published in the July 22 issue of Nature Biotechnology, shows for the first time that a novel genomic sequencing method called Smart-Seq can help scientists conduct in-depth analyses of clinically relevant single cells. Smart-Seq has many possible applications, including
helping6 scientists to better understand the complexities of
tumor7 development. This is vitally important as many clinically important cells exist only in small numbers and require single cell analysis. The study was conducted by a team of researchers from the Ludwig Institute for Cancer Research, the Karolinska Institutet in Sweden, the University of California, San Diego and Illumina Inc.
"While our results are preliminary, we showed that it is possible to do studies of individual, clinically relevant cells," says biomedical scientist Rickard Sandberg, researcher at the Ludwig Institute for Cancer Research and principal
investigator8 at the Department of Cell and
Molecular9 Biology, Karolinska Institutet. "Cancer researchers around the world will now be able to analyze these cells more
systematically10 to enable them to produce better methods of
diagnosis11 and therapy in the future."
Previous research showed that it is common for one
gene3 to give rise to several forms of the same protein through different cut-and-paste
configurations12 of its raw copy. The phenomenon, known as
splicing13(拼接) , means that cells from the same tissue are not so
homogenous14(同质的) as
previously15 thought.
The research team has now taken its study a step further and developed a method for the complete mapping of the gene expression of individual cells. In showing which genes are active, it is now possible to
accurately16 describe and study differences in gene expression between individual cells from the same tissue.
"Scientists have been waiting for a long time for such a method to come along, but technical limitations have made it difficult to produce a
sufficiently17 sensitive and
robust18 method," says Dr. Sandberg. "The method has several areas of applications including cancer research where it can be used to study which cell types form cancer tumors in individual patients."
In the study, scientists studied tumor cells in the blood system of a patient with
recurring19 malignant20 melanoma. Once they had identified the tumor cells in a regular blood test, the team used Smart-Seq to analyze their gene expression. By using this method, researchers could show that the tumor cells had
activated21 many important
membrane22(细胞膜) proteins that are understood to be responsible for their ability to
evade23 the body's monitoring system and spread in the blood or
lymph(淋巴) .
The study was conducted with the support of several funding bodies, including the European Research Council, the Swedish Research Council, the Foundation for Strategic Research, the Åke Wiberg Foundation and the National Institutes of Health (NIH).