Format

Send to

Choose Destination
Urol Oncol. 2017 Oct;35(10):606.e17-606.e23. doi: 10.1016/j.urolonc.2017.06.004. Epub 2017 Jun 27.

Clinicopathological implications to micropapillary bladder urothelial carcinoma of the presence of sialyl Lewis X-decorated mucin 1 in stroma-facing membranes.

Author information

1
Department of Tumor Pathology, Faculty of Medical Sciences, University of Fukui, Eiheiji, Japan; Department of Urology, Faculty of Medical Sciences, University of Fukui, Eiheiji, Japan.
2
Department of Tumor Pathology, Faculty of Medical Sciences, University of Fukui, Eiheiji, Japan.
3
Division of Surgical Pathology, University of Fukui Hospital, Eiheiji, Japan.
4
Department of Urology, Faculty of Medical Sciences, University of Fukui, Eiheiji, Japan.
5
Department of Tumor Pathology, Faculty of Medical Sciences, University of Fukui, Eiheiji, Japan. Electronic address: motokoba@u-fukui.ac.jp.

Abstract

OBJECTIVES:

Bladder urothelial carcinoma (UC) comprises more than 90% of all bladder cancers. Among several UC variants, micropapillary UC (MPUC) is a rare one with high potential for lymphovascular invasion and subsequent lymph node metastasis. Histologically, MPUC is characterized by the presence of small papillary carcinoma cell clusters surrounded by lacunar spaces. Immunohistochemically, the outer circumference of these clusters, that is, the stroma-facing membrane of carcinoma cells, is reportedly almost invariably positive for mucin 1 (MUC1) protein and to a lesser extent for sialyl Lewis X (sLeX) carbohydrates; however, the clinicopathological implications of these expression patterns have not been fully investigated.

MATERIALS AND METHODS:

We performed immunohistochemical analysis of MPUC (n = 11) and conventional UC (n = 57) for MUC1 and sLeX to determine whether these factors immunolocalized. Dual immunofluorescence staining was also carried out to assess MUC1 and sLeX colocalization. We also performed Western blot analysis of Chinese hamster ovary cells misexpressing both recombinant epitope-tagged MUC1 and glycosyltransferases enabling sLeX biosynthesis.

RESULTS:

MPUC samples preferentially exhibited both MUC1 protein and sLeX carbohydrate expression on the stroma-facing membrane of carcinoma cells. Based on univariate analysis, MUC1 expression in that pattern was positively correlated with tumor extension, lymphovascular invasion, lymph node metastasis, disease stage, and relatively poor patient prognosis. A comparable sLeX expression pattern also correlated positively with tumor extension and nodal metastasis. Based on multivariate analysis, localization of MUC1 and sLeX on the stroma-facing side of the membrane was positively correlated with lymph node metastasis.

CONCLUSIONS:

Overall, our immunofluorescence findings as well as immunoprecipitation analyses of Chinese hamster ovary cell transfectants strongly suggest that MUC1 is a potential scaffold protein for sLeX carbohydrates in MPUC. Both MUC1 and sLeX may cooperatively contribute to MPUC histogenesis and clinicopathological characteristics.

KEYWORDS:

Bladder urothelial carcinoma; Micropapillary urothelial carcinoma; Mucin 1; Sialyl Lewis X

PMID:
28666720
DOI:
10.1016/j.urolonc.2017.06.004
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center