Increased GS-II lectin binding and SATB2 downregulation are biological features for sessile serrated lesions and microvesicular hyperplastic polyps

Abstract

Sessile serrated lesions (SSLs) and microvesicular hyperplastic polyps (MVHPs) are colorectal lesions displaying gastric differentiation. Griffonia simplicifolia-II (GS-II) is a lectin specific to terminal α/βGlcNAc residues. Here, we assessed GS-II binding and performed immunostaining for HIK1083 (specific to terminal αGlcNAc residues), MUC5AC, MUC6, and special AT-rich sequence binding protein 2 (SATB2) in SSLs, MVHPs, and tubular adenomas (TAs). We observed MUC5AC positivity in 28 of 30 SSLs, but in only three of 23 TAs. Moreover, 24 of 30 SSLs were MUC6-positive, while none of the 23 TAs were MUC6-positive. None of the 30 SSLs or 23 TAs showed HIK1083 positivity. All 30 SSLs and 26 MVHPs were GS-II-positive, while only seven of 23 were in TAs. GS-II staining was mainly distributed in the Golgi region, but SSLs and MVHPs showed goblet cell distribution, in 20 of 30 and 19 of 26 cases, respectively. All SSLs, MVHPs, and TAs were SATB2-positive, but 21 of 30 SSLs and 12 of 26 MVHPs showed decreased staining intensity relative to adjacent mucosa, a decrease seen in only two of 23 in TAs. These results indicate overall that increased terminal βGlcNAc and decreased SATB2 expression are characteristics of SSLs and MVHPs.

Keywords: GS-II; SATB2; microvesicular hyperplastic polyps; sessile serrated lesions; βGlcNAc.

Figure 1

Gastric‐type mucin expression in tubular adenomas (TAs) and sessile serrated lesions (SSLs). (a, b) Hematoxylin and eosin staining in TAs (a) and SSLs (b). (c, d) Immunostaining for MUC5AC in TAs (c) and SSLs (d). (e, f) Immunostaining for MUC6 in TAs (e) and SSLs (f). (g, h) Immunostaining for HIK1083 in TAs (g) and SSLs (h). Scale bars, 100 μm (a–h).

Figure 2

Terminal βGlcNAc residues and SATB2 expression in tubular adenomas (TAs), microvesicular hyperplastic polyps (MVHPs), and sessile serrated lesions (SSLs). (a–c) Hematoxylin and eosin staining in TAs (a), MVHPs (b), and SSLs (c). (d–f), Griffonia simplicifolia‐II horseradish peroxidase (GS‐II‐HRP) staining in TAs (d), MVHPs (e), and SSLs (f). (g–i) Immunostaining for SATB2 in TAs (g), MVHPs (h), and SSLs (i). Black and orange arrowheads in (b), (c), (e), (f), (h), and (i) indicate lesion sites and adjacent colonic mucosa, respectively. Scale bars, 100 μm (a–i).

Figure 3

Griffonia simplicifolia‐II horseradish peroxidase (GS‐II‐HRP) staining of sessile serrated lesions (SSLs), microvesicular hyperplastic polyps (MVHPs), and tubular adenomas (TAs) in the presence of N‐glycosidase digestion. (a), (b) GS‐II‐HRP staining in SSLs without (a) and with (b) N‐glycosidase digestion. (c), (d) GS‐II‐HRP staining in MVHPs without (c) and with (d) N‐glycosidase digestion. (e), (f) GS‐II‐HRP staining in TAs without (e) and with (f) N‐glycosidase digestion. (g), (h) GS‐II‐HRP staining of colorectal carcinoma without (g) and with (h) N‐glycosidase digestion. Black arrowheads in (g) and orange arrowheads in (h) indicate respective positive sites. (i), (j) GS‐II‐HRP staining in gastric pyloric glands without (i) and with (j) N‐glycosidase digestion. Scale bars, 100 μm (a–j).