Expression of CDK11 and CK2 protein complex members in untransformed and malignant breast cells. (A) Immunoblot analysis of cultured breast cell lines, as indicated above the blots. Proteins detected are indicated on the right side of the blots. Actin signal was used as the loading control. (B) Indirect immunofluorescent detection of CDK11, CK2α, and CK2α′ (red color) in breast cell lines. Cell lines are indicated above each set of images and proteins detected are indicated on the left side of the images. Blue, 4′,6-diamidino-2-phenylindole-stained nuclei. Scale bar: 100 μm. (C) Immunohistochemical detection of CDK11 proteins in human normal and malignant breast tissue. Type of breast tissue indicated on the left side of the images. Magnification indicated above the images; dotted ellipse, portion of the 100× image that is shown at 400×. Scale bars: 400 μm for 100× and 100 μm for 400× images. (D) Human microarray tissues stained for CDK11 were scored by two independent observers. The average value was taken and the results plotted for normal (n = 16) versus triple-negative breast cancer (TNBC; n = 44) tissues. Box, first to third (Q1 to Q3) quartiles; diamond, mean; line inside box, median; whiskers, minimum and maximums of data range. CDK, cyclin-dependent kinase; CK2, casein kinase 2.