Combined lectin- and immuno-histochemistry (CLIH) for applications in cell biology and cancer diagnosis: Analysis of human urothelial carcinomas.

Lectin histochemistry (LHC) and immunohistochemistry (IHC), which demonstrate the composition and localisation of sugar residues and proteins in cell membranes, respectively, are generally used separately. Using these two methods, we previously demonstrated that malignant transformation of urothelial cells results in the alterations of protein glycosylation and reduced expression of urothelium-specific integral membrane proteins uroplakins (UPs). However, the correlation between these changes was not studied yet. To evaluate this correlation, we developed innovative method, which we named combined lectin- and immuno- histochemistry (CLIH). We used human biopsies of 6 normal urothelia and 9 papillary urothelial carcinomas, i.e. 3 papillary urothelial neoplasms of low malignant potential (PUNLMP), 3 non-invasive papillary urothelial carcinomas of low grade (pTa, l.g.), and 3 invasive papillary urothelial carcinomas of high grade (pT1, h.g.). We tested five different protocols (numbered 1-5) of CLIH on paraffin and cryo-semithin sections and compared them with LHC and IHC performed separately. Additionally, we carried out western and lectin blotting with antibodies against UPs and lectins Amaranthus caudatus agglutinin (ACA), Datura stramonium agglutinin (DSA), and jacalin, respectively. We showed that incubation with primary antibodies first, followed by the mixture of secondary antibodies and lectins is the most efficient CLIH method (protocol number 5). Additionally, 300 nm thick cryo-semithin sections enabled better resolution of co-localisation between sugar residues and proteins than 5 µm thick paraffin sections. In the normal urothelium, CLIH showed co-localisation of lectins ACA and jacalin with UPs in the apical plasma membrane (PM) of superficial umbrella cells. In papillary urothelial carcinomas, all three lectins (ACA, DSA and jacalin) labelled regions of apical PM, where they occasionally co-localised with UPs. Western and lectin blotting confirmed the differences between normal urothelium and papillary urothelial carcinomas. Our results show that CLIH, when used with various sets of lectins and antigens, is a useful, quick, and reliable method that could be applied for basic cell biology research as well as detailed subtyping of human urothelial carcinomas.

Correlation between urothelial differentiation and sensory proteins P2X3, P2X5, TRPV1, and TRPV4 in normal urothelium and papillary carcinoma of human bladder.

Terminal differentiation of urothelium is a prerequisite for blood-urine barrier formation and enables normal sensory function of the urinary bladder. In this study, urothelial differentiation of normal human urothelium and of low and high grade papillary urothelial carcinomas was correlated with the expression and localization of purinergic receptors (P2X3, and P2X5) and transient receptor potential vanilloid channels (TRPV1, and TRPV4). Western blotting and immunofluorescence of uroplakins together with scanning electron microscopy of urothelial apical surface demonstrated terminal differentiation of normal urothelium, partial differentiation of low grade carcinoma, and poor differentiation of high grade carcinoma. P2X3 was expressed in normal urothelium as well as in low grade carcinoma and in both cases immunolabeling was stronger in the superficial cells. P2X3 expression decreased in high grade carcinoma. P2X5 expression was detected in normal urothelium and in high grade carcinoma, while in low grade carcinoma its expression was diminished. The expression of TRPV1 decreased in low grade and even more in high grade carcinoma when compared with normal urothelium, while TRPV4 expression was unchanged in all samples. Our results suggest that sensory proteins P2X3 and TRPV1 are in correlation with urothelial differentiation, while P2X5 and TRPV4 have unique expression patterns.

Performance of nuclear matrix protein 22 urine marker and voided urine cytology in the detection of urinary bladder tumors.

BACKGROUND: Cystoscopy with urinary cytology is the gold standard for the diagnosis and follow-up of patients with tumors of the urinary bladder. The aim of the study was to evaluate the performance of the nuclear matrix protein 22 (NMP22) tumor marker test, BladderChek® point-of-care test and voided urinary cytology for the detection and follow-up of bladder tumors. METHODS: NMP22 was measured using an ELISA assay in stabilized voided urine and using the BladderChek® test. Voided urinary cytology was performed on urine samples. Results were compared to cystoscopic findings and histopathological examination results after transurethral resection of the bladder lesion. RESULTS: For the prediction of malignant histopathological result, sensitivity and specificity were 45.2% and 75.0%, respectively, for NMP22 at a cut-off of 7.5 kU/L, 17.7% and 100% for the BladderChek® test and 37.0% and 100% for voided urine cytology. For the prediction of suspicious or positive cystoscopic finding, sensitivity and specificity were 40.4% and 72.1%, respectively, for NMP22 at a cut-off of 7.5 kU/L, 14.8% and 93.8% for the BladderChek® test and 26.8% and 98.1% for voided urine cytology. CONCLUSIONS: The NMP22 quantitative test showed higher sensitivity and lower specificity compared with voided urine cytology, whereas the sensitivity of the BladderChek® test was low. We could not recommend any of the three non-invasive tests as a replacement for cystoscopy for the diagnosis or follow-up of urinary bladder tumors.