CK2beta is expressed in endometrial carcinoma and has a role in apoptosis resistance and cell proliferation.
Protein kinase CK2 (CK2) is a serine/threonine kinase that participates in important cellular processes. We have recently demonstrated that CK2 plays a role in resistance to TRAIL/Fas-induced apoptosis in endometrial carcinoma (EC) by regulating FLIP. Here, we assessed the immunohistochemical expression of CK2beta in EC and checked its role in cell proliferation and anchorage-independent cell growth. CK2beta immunostaining was assessed in two tissue microarrays, one constructed from paraffin-embedded blocks of 95 ECs and another from 70 samples of normal endometrium. CK2beta expression was correlated with histological type; grade and stage; cell proliferation (Ki-67) and apoptotic index; immunostaining for cyclin D1, PTEN, AKT, beta-catenin, and FLIP. Moreover, the Ishikawa EC cell line was subjected to down-regulation of CK2 by shRNA. CK2beta expression was frequent in EC (nuclear, 100%; cytoplasmic, 87.5%). The staining was more intense in EC than in normal endometrium (P = 0.000), and statistically correlated with AKT, PTEN, beta-catenin, and FLIP. In EC, CK2beta expression correlated with cell proliferation. Knock-down of CK2beta blocked colony formation of EC in soft agar, and also resulted in decreased expression of cyclin D1 and ERK phosphorylation. The results confirm that CK2beta is widely expressed in EC, and suggest a role in cell proliferation and anchorage-independent cell growth.
Pallares
Judit
J
Department of Pathology and Molecular Genetics, Hospital Universitari Arnau de Vilanova, University of Lleida, IRBLLEIDA, Lleida, Spain.
Llobet
David
D
Santacana
Maria
M
Eritja
Nuria
N
Velasco
Ana
A
Cuevas
Dolors
D
Lopez
Susana
S
Palomar-Asenjo
Victor
V
Yeramian
Andree
A
Dolcet
Xavier
X
Matias-Guiu
Xavier
X
D017209:Apoptosis / Q000502:physiology*; D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein / Q000378:metabolism; D047390:Casein Kinase II / Q000096:biosynthesis*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D016889:Endometrial Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D010446:Peptide Fragments / Q000096:biosynthesis*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D046888:Tissue Array Analysis; D051176:beta Catenin / Q000378:metabolism
D014408:Biomarkers, Tumor; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D010446:Peptide Fragments; D051176:beta Catenin; C105173:casein kinase 2 beta (1-16); D047390:Casein Kinase II; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human