Proteins are the building blocks of life. They are produced by molecular machines, called ribosomes. A human ribosome contains some eighty ribosomal proteins. Prof. Mihaela Zavolan’s research group at the Biozentrum of the University of Basel has now discovered that about a quarter of the ribosomal proteins have tissue-specific expression and that different cancer types have their own individual expression pattern of ribosomal proteins. In the future, these patterns may serve as a prognostic marker for cancer and may point towards new therapeutic opportunities.

Cellular machines for protein synthesis

Ribosomes are responsible for protein synthesis and are thus essential for the cell. Therefore, it has long been assumed that the expression of the individual components of the ribosomes is strictly controlled and invariant. A few studies, however, have already suggested that the expression of individual ribosomal proteins is altered in cancers as well as in diseases of the hematopoietic system such as acute lymphoblastic leukemia.

“Cancer signature” revealed by systematic data analysis

Mihaela Zavolan and her co-worker Joao Guimaraes have systematically analyzed ribosomal protein expression in thirty tissue types, three hundred different cell types and sixteen different types of tumors, such as lung and breast cancer. In contrast to previous assumptions, they found a wide variability in ribosomal protein gene expression. In particular, hematopoietic and tumor cells display the most complex expression pattern.