Asymmetric Expression of Protein Kinase CK2 Subunits in Human Kidney Tumors

Renal clear cell carcinomas and the corresponding ipsilateral control tissues were investigated for protein kinase CK2 activity and subunit ratio. The average protein kinase CK2 activity from 21 different kidney samples was 318 U/mg and that from the corresponding tumors 610 U/mg. The subunit ratio of protein kinase CK2α in tumors/normal tissue (T/N) was 1.58 and that of the protein kinase CK2β (T/N) was 2.65. The data suggest that the generally described increase in protein kinase CK2 activity in tumor cells may to some extent result from a deregulation in subunit biosynthesis or degradation. This at least partly owing to the presence of excess enzymatically active protein kinase α-subunit but also to a significantly higher presence of the non-catalytic β-subunit.