CK2 is a messenger-independent protein serine/threonine kinase that has been implicated in cell growth and proliferation. Our recent analysis of squamous cell carcinomas of the head and neck (SCCHN) revealed a significant elevation in CK2 activity in these tumor cells relative to normal mucosa of the upper aerodigestive tract and suggested a correlation with aggressive tumor behavior and poor clinical outcome. In order to further define the distribution of CK2 in these tissues, we have examined the immunohistochemical staining pattern of surgical specimens of both SCCHN tumors and normal upper aerodigestive tract mucosa using a monoclonal antibody directed against the catalytic subunit CK2-α of the kinase, and have compared these data with the subcellular distribution of CK2 activity in these same tissues. These measurements showed that CK2 is predominantly localized to the nuclei of the tumor cells, which agreed closely with the immunohistochemical staining pattern of CK2-α in tumor cells. The chiefly nuclear distribution of CK2-α immunostaining found consistently in SCCHN tumor cells and tumor-infiltrating lymphocytes contrasted with a relatively more predominant cytosolic staining pattern exhibited by various cellular constituents of normal oropharyngeal mucosa. The immunostaining pattern of CK2-α revealed that staining was observed in the cells stained for the proliferation-marker Ki-67; however, strong distinct immunostaining for CK2-α was also observed in large numbers of other cells in these same tumors, suggesting that CK2 elevation in these tumors is not a reflection of proliferative activity alone, but may also relate to the pathobiological behavior of the tumor. Copyright (C) 1999 Elsevier Science Ltd.
|Original language||English (US)|
|Number of pages||9|
|Journal||International Journal of Biochemistry and Cell Biology|
|State||Published - Sep 1999|
Bibliographical noteFunding Information:
This work was supported in part by the American Society for Head and Neck Surgery, the Medical Research Fund of the Department of Veterans Affairs and US Public Health Service Research Grant CA-15062 awarded by the National Cancer Institute, Department of Health and Human Services. The authors gratefully acknowledge Dr. Michael McNutt, Laboratory of Pathology, Swedish Hospital, Seattle, WA, for his critical reading and helpful discussions of the manuscript.