To better understand the signaling pathways active in sarcomas, researchers at Moffitt Cancer Center used state-of-the-art mass spectrometry-based proteomics to characterize a family of protein enzymes that act as "on" or "off" switches important in the biology of cancer. The tyrosine kinases they identified, the researchers said, could act as "drivers" for the growth and survival of sarcomas.
Sarcomas are relatively rare forms of cancer. In contrast to carcinomas, which arise from epithelial cells (in breast, colon and lung cancers, for example), sarcomas are tumors derived from bone, fat, muscle or vascular tissues.
"Sarcomas are rare, diverse malignancies that arise from connective tissues," said study lead author Eric B. Haura, M.D., program leader for Experimental Therapeutics. "We hypothesized that we could identify important proteins that drive the growth and survival of these poorly understood sarcomas using an approach to characterize signaling proteins using mass spectrometry."
According to Haura, whose lab focuses on signaling pathways in cancer and understanding the role of kinases, protein phosphorylation plays a significant role in a wide range of cellular processes and is commonly disrupted in diseases such as cancer. The study approach is novel by engaging proteomics, an emerging and increasingly powerful approach to study proteins in disease in a more global and unbiased manner.
In this study, the Moffitt researchers identified 1,936 unique tyrosine phosphorylated peptides corresponding to 844 unique phospho-tyrosine proteins and found 39 tyrosine kinases in sarcoma cells. Of the 99 tyrosine kinases present in the human genome, the research team identified peptides corresponding to nearly 40 percent of the tyrosine kinome.