Abstract
Human breast tumours are diverse in their natural history and in their
responsiveness to treatments. Variation in transcriptional programs
accounts for much of the biological diversity of human cells and
tumours. In each cell, signal transduction and regulatory systems
transduce information from the cell's identity to its environmental
status, thereby controlling the level of expression of every gene
in the genome. Here we have characterized variation in gene expression
patterns in a set of 65 surgical specimens of human breast tumours
from 42 different individuals, using complementary DNA microarrays
representing 8,102 human genes. These patterns provided a distinctive
molecular portrait of each tumour. Twenty of the tumours were sampled
twice, before and after a 16-week course of doxorubicin chemotherapy,
and two tumours were paired with a lymph node metastasis from the
same patient. Gene expression patterns in two tumour samples from
the same individual were almost always more similar to each other
than either was to any other sample. Sets of co-expressed genes were
identified for which variation in messenger RNA levels could be related
to specific features of physiological variation. The tumours could
be classified into subtypes distinguished by pervasive differences
in their gene expression patterns.
Users
Please
log in to take part in the discussion (add own reviews or comments).