Volume 120, Issue 7, Pages 1680-1688 (June 2001) Aberrant expression of G1-phase cell cycle regulators in flat and exophytic adenomas of the human colon  Jirina Bartkova, Minna Thullberg, Premysl Slezak, Edgar Jaramillo, Carlos Rubio, Lars H. Thomassen, Jiri Bartek  Gastroenterology  Volume 120, Issue 7, Pages 1680-1688 (June 2001) DOI: 10.1053/gast.2001.24880 Copyright © 2001 American Gastroenterological Association Terms and Conditions

Fig. 1 Immunoperoxidase staining of normal human colonic mucosa with antibodies to cell-cycle regulatory proteins. (A) Heterogeneous nuclear staining for pRB is mainly restricted to the proliferating lower third of the crypts. (B) Cyclin D2 is undetectable except for some positive lymphoid cells (arrowheads) in the stroma. (C) Heterogeneous nuclear staining of epithelial cells for cyclin D3, with maximum positivity in the upper parts of the crypts. (D) Variable, nuclear, and cytoplasmic staining for CDK4 in the lower parts of crypts. (E) Nuclear and cytoplasmic expression of p16ink4a in the differentiated surface epithelium (arrowheads). (F) Almost homogeneous staining for p18ink4c in epithelial and stromal cells. The large arrows point to the top of the crypts. Gastroenterology 2001 120, 1680-1688DOI: (10.1053/gast.2001.24880) Copyright © 2001 American Gastroenterological Association Terms and Conditions

Fig. 2 Schematic representation of the staining patterns for Ki67 and the indicated cell-cycle regulatory proteins in normal human colonic mucosa compared with the 4 epithelial compartments along the crypt. The width of the bars indicates the relative proportion of positive cells, and the striped and filled modes indicate moderate and strong staining intensity, respectively. The dotted lines indicate lack of staining. Gastroenterology 2001 120, 1680-1688DOI: (10.1053/gast.2001.24880) Copyright © 2001 American Gastroenterological Association Terms and Conditions

Fig. 3 Examples of immunohistochemical detection of cell-cycle regulators in colon adenomas. (A, B) Strong nuclear positivity for pRB in a flat, low-grade adenoma (A) and exophytic, low-grade lesion (B), respectively. (C) Elevated expression of mainly nuclear cyclin D2 in a flat, high-grade adenoma, with a region of both nuclear and cytoplasmic staining marked by an arrowhead. (D) Heterogeneous nuclear staining for cyclin D3 in an exophytic, low-grade lesion. (E, F) Examples of p16 staining patterns: an entirely negative flat adenoma (E) and a heterogeneously positive region of an exophytic lesion (F). (G) The p19ink4d CDK inhibitor is detectable in scattered cells (arrowheads) in a flat adenoma. Gastroenterology 2001 120, 1680-1688DOI: (10.1053/gast.2001.24880) Copyright © 2001 American Gastroenterological Association Terms and Conditions

Fig. 4 Elevated cyclin D1, cyclin D2, and CDK4 correlate with enhanced degree of dysplasia in colonic adenomas. (A, B) Immunostaining for cyclin D1 in flat adenomas of the low-grade (A) versus high-grade (B) dysplasia. (C, D) Analogous examples of cyclin D1 reactivity in low-grade (C) and high-grade (D) adenoma of the exophytic type. Arrowheads in A and C point to positive nuclei. (E, F) Cyclin D2 expression in exophytic lesions of low-grade (E) versus high-grade (F) dysplasia, with the arrowhead in E pointing to a strongly positive nucleus. (G, H) CDK4 is hardly detectable in a flat adenoma with low dysplasia (G), in contrast to strong nuclear positivity in a flat, high-grade lesion (H). Gastroenterology 2001 120, 1680-1688DOI: (10.1053/gast.2001.24880) Copyright © 2001 American Gastroenterological Association Terms and Conditions