G protein-coupled receptors (GPCRs) play important roles in a variety of
biological and
pathological processes. They are considered among the most desirable targets for
drug development. Recent studies have demonstrated that many GPCRs, such as
endothelin receptors,
chemokine receptors and
lysophosphatidic acid receptors have been implicated in the
tumorigenesis and
metastasis of multiple human
cancers. In this study, we conducted an in silico analysis of GPCR gene expression in primary human
tumors by analyzing some publicly available gene expression profiling data. Statistical analysis was performed on eight microarray data sets of
non-small cell lung cancer,
breast cancer,
prostate cancer,
melanoma,
gastric cancer and diffused large
B cell lymphoma to identify GPCRs that are up-regulated in primary or metastatic
cancer cells. Our analysis has demonstrated overexpression of several GPCRs in primary
tumor cells, including
chemokine receptors and
protease-activated receptors that were shown to be important for
tumorigenesis by previous studies. In addition, we have uncovered several GPCRs, such as
neuropeptide receptors,
adenosine A2B receptor,
P2Y purinoceptor,
calcium-sensing receptor and
metabotropic glutamate receptors, that are expressed at a significantly higher level in some
cancer tissue and may play a role in
cancer progression. Analysis of
cancer samples in different disease stages also suggests that some GPCRs, such as
endothelin receptor A, may be involved in early
tumor progression and others, such as CXCR4, may play a critical role in
tumor invasion and
metastasis. The present study demonstrates the value of publicly available microarray data as a resource to gain more understanding of
cancer biology, to validate previous findings from in vitro experiments, and to identify potential novel anticancer targets and
biomarkers.