An illustration of the potential for mapping MRI/MRS parameters with genetic over-expression profiles in human prostate cancer.
BACKGROUND
Magnetic resonance imaging (MRI) and MR spectroscopy can probe a variety of physiological (e.g. blood vessel permeability) and metabolic characteristics of prostate cancer. However, little is known about the changes in gene expression that underlie the spectral and imaging features observed in prostate cancer. Tumor induced changes in vascular permeability and angiogenesis are thought to contribute to patterns of dynamic contrast enhanced (DCE) MRI images of prostate cancer even though the genetic basis of tumor vasculogenesis is complex and the specific mechanisms underlying these DCEMRI features have not yet been determined.


METHODS
In order to identify the changes in gene expression that correspond to MRS and DCEMRI patterns in human prostate cancers, we have utilized tissue print micropeel techniques to generate "whole mount" molecular maps of radical prostatectomy specimens that correspond to pre-surgical MRI/MRS studies. These molecular maps include RNA expression profiles from both Affymetrix GeneChip microarrays and quantitative reverse transcriptase PCR (qrt-PCR) analysis, as well as immunohistochemical studies.


RESULTS
Using these methods on patients with prostate cancer, we found robust over-expression of choline kinase a in the majority of primary tumors. We also observed overexpression of neuropeptide Y (NPY), a newly identified angiogenic factor, in a subset of prostate cancers, visualized on DCEMRI.


CONCLUSIONS
These studies set the stage for establishing MRI/MRS parameters as validated biomarkers for human prostate cancer.
Lenkinski
Robert E
RE
Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Ave, Boston, MA 02215, USA.
Bloch
B Nicolas
BN
Liu
Fangbing
F
Frangioni
John V
JV
Perner
Sven
S
Rubin
Mark A
MA
Genega
Elizabeth M
EM
Rofsky
Neil M
NM
Gaston
Sandra M
SM