PBK/TOPK Is a Novel Mitotic Kinase Which Is Upregulated in Burkitt's Lymphoma and Other Highly Proliferative Malignant Cells

• Published in: Blood cells, molecules, & diseases molecules, & diseases, 2001-09, Vol.27 (5), p.825-829
• Main Authors: Simons-Evelyn, Michelle, Bailey-Dell, Kim, Toretsky, Jeffrey A., Ross, Douglas D., Fenton, Robert, Kalvakolanu, Dhan, Rapoport, Aaron P.
• Format: Article
• Language: English
• Subjects: Adult; B-Lymphocytes - enzymology; Blood Cells - enzymology; Burkitt Lymphoma - enzymology; Burkitt Lymphoma - pathology; Burkitt's lymphoma; Fetus - cytology; Fetus - enzymology; Humans; Mitogen-Activated Protein Kinase Kinases; mitotic kinase; Palatine Tonsil - cytology; PBK/TOPK; Protein-Serine-Threonine Kinases - genetics; Protein-Serine-Threonine Kinases - metabolism; RNA, Messenger - metabolism; serine–threonine kinases; Tumor Cells, Cultured; Up-Regulation
• ISSN: 1079-9796; 1096-0961
• DOI: 10.1006/bcmd.2001.0452

ABSTRACT PBK/TOPK is a recently cloned serine/threonine kinase which is phosphorylated during mitosis. Earlier work indicated that this kinase is upregulated in a Burkitt's lymphoma cell line (GA-10). To determine whether PBK/TOPK is upregulated in other mitotically active neoplastic cell lines and tissues, Northern analysis was performed on a panel of malignant cell lines and on clinical samples from patients with leukemia or lymphoma. While PBK/TOPK mRNA was not detectable in normal peripheral blood cells and was weakly expressed in hyperplastic tonsillar B-cells, significantly higher levels of mRNA were detected in 8 Burkitt's lymphoma cell lines, 10 other neoplastic cell lines, and 2 clinical samples—one derived from a patient with ALL and a second derived from a patient with relapsed myeloma. In addition, Northern analysis of fetal tissues showed upregulated expression of PBK/TOPK in fetal kidney, lung, spleen, brain, and testis. These data suggest that PBK/TOPK expression is increased in highly proliferative malignant cells and during normal fetal development.