VEGF expression may explain aggressiveness of renal cell cancers

A new study examining the expression of the vascular endothelial growth factor (VEGF) family of proteins in kidney cancer has yielded several important findings, including the identification of different expression profiles of VEGF proteins in clear cell and papillary type renal cell carcinoma.

UCLA researchers created an array of more than 380 kidney tumors from patients undergoing nephrectomies at UCLA and analyzed a small portion of each for how much protein was present and where the protein was located.

The researchers identified protein expression of the VEGF receptors on clear cell and papillary tumor epithelia.

"Previously, it was thought that these receptors were located only on the blood vessels surrounding the tumor. We were able to locate these receptors to those blood vessels as well as to the cancer cells, themselves," said lead author John Leppert, MD, a UCLA urology resident.

The researchers demonstrated that most of the 380 kidney tumors that they analyzed had high levels of these proteins and receptors. And they identified different expression profiles of the proteins in clear cell and papillary type renal cell carcinoma.

"By analyzing the tumor after it has been removed, we hope to be able to customize a unique treatment for each patient," Dr. Leppert said. "We hope to block the proteins and receptors that signal the creation and recruitment of new blood vessels to the tumor. Our data suggests that both clear cell and papillary type renal cell carcinoma should be included in the clinical trials of these drugs."