N-Linked Glycosylation and Near-Infrared Spectroscopy in the Diagnosis of Prostate Cancer

The Association between Urine N-Glycome and Prognosis after Initial Therapy for Primary Prostate Cancer

Next to prostate-specific antigen, no biochemical biomarkers have been implemented to guide patient follow-up after primary therapy for localized prostate cancer (PCa). We evaluated the prognostic potential of urine N-glycome in terms of event-free survival (EFS) in patients undergoing primary therapy for PCa. The prognostic features of the urine N-glycosylation profile at diagnosis, assessed in 77 PCa patients, were determined in terms of EFS next to standard clinical parameters. The majority of patients were diagnosed with International Society of Urological Pathology grade ≤ 3 (82%) T1-2 tumors (79%) and without pelvic lymph node invasion (96%). The patients underwent active surveillance (14%), robot-assisted laparoscopic prostatectomy (48%), or external beam radiotherapy (37%). Decreased ratios of biantennary core-fucosylation were noted in patients who developed an event, which was linked to a shorter EFS in both the intention-to-treat cohort and all subcohort analyses. Combining the urine N-glycan biomarker with the D'Amico Risk Classification for PCa resulted in an improved nomogram for patient classification after primary therapy. The rate of urine N-glycan biantennary core-fucosylation, typically linked to more aggressive disease status, is lower in patients who eventually developed an event following primary therapy and subsequently in patients with a worse EFS. The combination of urine N-glycan biomarkers together with clinical parameters could, therefore, improve the post-therapy follow-up of patients with PCa.

Prognostic Features of Near-Infrared Spectroscopy Following Primary Radical Prostatectomy

BACKGROUND

Only a few biomarkers have been evaluated for their prognostic value with regard to biochemical recurrence (BCR) following primary radical prostatectomy. We explored the possibilities of using near-infrared (NIR) spectroscopy as a prognostic biomarker for BCR-free survival (BCR-FS).

METHODS

Tissue specimens from 82 prostate cancer patients were obtained. Formalin-fixed paraffin-embedded slides (hematoxylin-eosin-stained) were analyzed using NIR spectroscopy. Prognostic features for BCR-FS were determined following normalization of the spectra.

RESULTS

Several differences were found throughout the NIR spectrum for the patients with or without BCR, for both the first derivative and second derivative of the NIR spectrum. Following categorization and Cox regression analysis, spectral regions at 5236 cm^-1 (first derivative; median BCR-FS not reached versus 3.2 years; HR_high = 0.18 [0.08-0.39]; and p < 0.0001) and at 5956 cm^-1 (second derivative; median BCR-FS not reached versus 3.8 years; HR_low = 0.22 [0.10-0.48]; and p = 0.0002) showed prognostic properties for BCR-FS. The combination of both parameters further increased the prognostic value of NIR (p < 0.0001).

CONCLUSIONS

We demonstrated NIR spectral variations between patients with or without BCR, which have been shown to have prognostic value. This easy-to-use technique could possibly further improve post-primary radical prostatectomy monitoring and swift referral to adjuvant local therapies. Further elaboration is highly recommended to fully elucidate these variations and to gain a deeper insight into the changing chemical and physical compositions of the prostate tumor architecture.

A Tissue Section-Based Near-Infrared Spectroscopical Analysis of Salivary Gland Tumors

Simple Summary

Salivary gland tumors (SGTs) are a group of rare tumors that vary in clinical and histological behavior. Histological classification is difficult and requires an experienced pathologist. Based on recent research in other medical fields, this study investigated the value of near-infrared (NIR) spectroscopy in the diagnosis of SGTs supplementary to the histological investigation. The acquired spectra were analyzed with chemometric techniques. Enzymatic treatment (neuraminidase) resulted in spectral peak differences between healthy controls and different SGT types. Some malignant SGTs had higher spectral changes, suggesting bigger alterations in glycosylation of salivary mucins. Future biochemical research based on the further enzymatic dissection of SGTs and infrared spectroscopy could help pathologists to better understand the nature of these types of tumors.

Abstract

SGTs vary in histological behavior. Mucins, a major component in salivary glands, consist of a glycosylated and sialylated protein core. Rapid evolutions in glycobiology have demonstrated the important role of glycoproteins in cancer development. NIR spectroscopy is a method for the biochemical analysis of substrates. NIR spectra can be analyzed using specific chemometrics. Our aim was to explore the diagnostic possibilities of NIR spectroscopy in SGTs. 238 Hematoxylin and Eosine stained (H&E) SGT tissue sections were examined using NIR spectroscopy. 45 deparaffinized tissue sections were treated with neuraminidase to identify wavelengths in the NIR spectrum related to sialylation. NIR spectra were analyzed with chemometrics. NIR spectra could distinguish malignant SGTs from controls and benign SGTs. Prediction models based on the entire spectral range resulted in a 73.1% accurate classification of malignant SGTs and controls, while, based on neuraminidase experimental spectral peak differences (1436 nm; 1713 nm; 1783 nm; 1924 nm; 2032 nm; 2064 nm; 2178 nm; 2216 nm), an improved overall correct classification rate of 91.9% was obtained between healthy subjects and malignant tumors. H&E tissue section-based NIR spectroscopy can identify malignant SGTs from controls, promising an alternative method in the diagnosis of SGTs.

N-glycan structures of Wisteria floribunda agglutinin-positive Mac2 binding protein in the serum of patients with liver fibrosis†

The extent of liver fibrosis predicts prognosis and is important for determining treatment strategies for chronic hepatitis. During the fibrosis progression, serum levels of Mac2 binding protein (M2BP) increase and the N-glycan structure changes to enable binding to Wisteria floribunda agglutinin (WFA) lectin. As a novel diagnostic marker, glycosylation isomer of M2BP (M2BPGi) has been developed. However, its glycan structures recognized by WFA are unclear. In this study, we analyzed site-specific N-glycan structures of serum M2BP using Glyco-RIDGE (Glycan heterogeneity-based Relational IDentification of Glycopeptide signals on Elution profile) method. We evaluated five sample types: 1) M2BP immunoprecipitated from normal healthy sera (NHS-IP(+)), 2) M2BP immunoprecipitated from sera of patients with liver cirrhosis (stage 4; F4-IP(+)), 3) M2BP captured with WFA from serum of patients with liver cirrhosis (stage 4; F4-WFA(+)), 4) recombinant M2BP produced by HEK293 cells (rM2BP), and 5) WFA-captured rM2BP (rM2BP-WFA(+)). In NHS-IP(+) M2BP, bi-antennary N-glycan was the main structure, and LacNAc extended to its branches. In F4-IP(+) M2BP, many branched structures, including tri-antennary and tetra-antennary N-glycans, were found. F4-WFA(+) showed a remarkable increase in branched structures relative to the quantity before enrichment. In recombinant M2BP, both no sialylated-LacdiNAc and -branched LacNAc structures were emerged. The LacdiNAc structure was not found in serum M2BP. Glycosidase-assisted HISCL assays suggest that, reactivity with WFA of both serum and recombinant M2BP depends on unsialylated and branched LacNAc, and in part of recombinant, depends on LacdiNAc. On M2BPGi, the highly branched LacNAc, probably dense cluster of LacNAc, would be recognized by WFA.

Identification of crucial genes and pathways associated with prostate cancer in multiple databases

OBJECTIVE

Prostate cancer (PCa) is a malignant neoplasm of the urinary system. This study aimed to use bioinformatics to screen for core genes and biological pathways related to PCa.

METHODS

The GSE5957 gene expression profiles were obtained from the Gene Expression Omnibus (GEO) database to identify differentially expressed genes (DEGs). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the DEGs were constructed by R language. Furthermore, protein-protein interaction (PPI) networks were generated to predict core genes. The expression levels of core genes were examined in the Tumor Immune Estimation Resource (TIMER) and Oncomine databases. The cBioPortal tool was used to study the co-expression and prognostic factors of the core genes. Finally, the core genes of signaling pathways were determined using gene set enrichment analysis (GSEA).

RESULTS

Overall, 874 DEGs were identified. Hierarchical clustering analysis revealed that these 24 core genes have significant association with carcinogenesis and development. LONRF1, CDK1, RPS18, GNB2L1 (RACK1), RPL30, and SEC61A1 directly related to the recurrence and prognosis of PCa.

CONCLUSIONS

This study identified the core genes and pathways in PCa and provides candidate targets for diagnosis, prognosis, and treatment.

Tissue N-linked glycosylation as potential prognostic biomarker for biochemical recurrence-free survival

PURPOSE

Only few biomarkers have been evaluated for their prognostic value following radical prostatectomy. We explored if tissue N-glycosylation shows prognostic properties for biochemical recurrence (BCR)-free survival.

MATERIALS AND METHODS

Tissue N-glycosylation profile was determined from 82 prostate cancer (PCa) patients and prognostic features were compared to clinical and biochemical parameters for BCR-free survival.

RESULTS

Majority presented with Gleason score 3 + 4 (41%), extensive local disease (62%) and without pelvic lymph nodes invasion (83%). Several parameters (low T stage, low Gleason score, low EAU risk groups for BCR, absence of positive surgical margins, high ratio of fucosylated triantennary structures on total of multiantennary structures [3AFc/MA], low ratio of fucosylated biantennary with core-branched N-acetylglucosamine on total of biantennary structures, and high ratio of triantennary structures on total of multiantennary structures) proved to have a univariate beneficial effect on BCR-free survival. Multivariate analysis proved positive surgical margins and 3AFc/MA to be independent prognosticators.

CONCLUSIONS

Tissue N-glycans are a powerful prognostic tool and can be an asset in PCa as the ratio of 3AFc/MA is independently associated with BCR-free survival. This could be of clinical use in guiding patients following radical prostatectomy, e.g. referral to adjuvant radiotherapy. Further elaboration of this biomarker is warranted.