Use ofAmaranthus leucocarpusLectin to Differentiate Cervical Dysplasia (CIN)

O-Glycosylating Enzyme GALNT2 Predicts Worse Prognosis in Cervical Cancer

Identification of novel biomarkers is helpful for the diagnosis and treatment of cervical cancer. Mucin glycosylating enzyme GALNT2 modulates mucin O-glycosylation, and has been revealed as a regulator of tumorigenesis in various cancers. However, the expression pattern of GALNT2 in cervical cancer is still unclear. In this study, we demonstrated that the mRNA expression and protein level of GALNT2 were increased in cervical high-grade intraepithelial neoplasia and tumor tissues compared with normal cervix tissues. Kaplan-Meier plotter showed that overexpression of GALNT2 was associated with worse overall survival in TCGA cohort (p < 0.001, HR = 2.65, 95% CI = 1.62–4.34) and poor disease free survival in GSE44001 cohort (p = 0.0218, HR = 2.15, 95% CI = 1.14–4.06). In addition, GSEA analysis showed that various immune-related pathways were closely related to the expression of GALNT2 in cervical cancer. Moreover, co-expression of GALNT2 and IL1A, IL1B, IL11, CXCL1, CXCL2, CXCL5, CXCL6, CXCR1, or CCR3 predicted poor overall survival, and the expression of GALNT2 also affected the prognostic value of CD47, CD274, CD276, CSF1R, TNFSF9, and TNFSF11 in cervical cancer patients. These findings suggest that GALNT2 might be used as a prognostic biomarker in cervical cancer.

Effects of Germination and Popping on the Anti-Nutritional Compounds and the Digestibility of Amaranthus hypochondriacus Seeds

Amaranth seeds, although a valuable food in Mexico, contain anti-nutritional compounds that can affect food quality. As a part of this work, the proximate composition, fatty acid profile, protein digestibility, and the effect of germination and popping of Amaranthus hypochondriacus seeds was analyzed with the aim of eliminating anti-nutritional compounds. Untreated seeds comprised of 11.35–18.8% protein and 0.27–13.39% lipids, including omega 3, 6, and 9 fatty acids such as oleic, linoleic, linolenic, and arachidonic acid. The main minerals detected were Ca⁺², K⁺¹, and Mg⁺². Nevertheless in vitro studies indicate that germination significantly improved digestibility, whereby treatments aimed at reducing anti-nutritional compounds decreased lectin concentration, while significantly increasing tannins and completely eliminating trypsins and saponins.

130 years of Plant Lectin Research

Lectins are proteins with diverse molecular structures that share the ability to recognize and bind specifically and reversibly to carbohydrate structures without changing the carbohydrate moiety. The history of lectins started with the discovery of ricin about 130 years ago but since then our understanding of lectins has dramatically changed. Over the years the research focus was shifted from 'the characterization of carbohydrate-binding proteins' to 'understanding the biological function of lectins'. Nowadays plant lectins attract a lot of attention especially because of their potential for crop improvement and biomedical research, as well as their application as tools in glycobiology. The present review aims to give an overview of plant lectins and their applications, and how the field evolved in the last decades.

Lectins in Cervical Screening

Cervical screening in low-resource settings remains an unmet need. Lectins are naturally occurring sugar-binding glycoproteins whose binding patterns change as cancer develops. Lectins discriminate between dysplasia and normal tissue in several precancerous conditions. We explored whether lectins could be developed for cervical screening via visual inspection. Discovery work comprised lectin histochemistry using a panel of candidate lectins on fixed-human cervix tissue (high-grade cervical intraepithelial neoplasia (CIN3, n = 20) or normal (n = 20)), followed by validation in a separate cohort (30 normal, 25 CIN1, 25 CIN3). Lectin binding was assessed visually according to staining intensity. To validate findings macroscopically, near-infra red fluorescence imaging was conducted on freshly-resected cervix (1 normal, 7 CIN3), incubated with topically applied fluorescently-labelled lectin. Fluorescence signal was compared for biopsies and whole specimens according to regions of interest, identified by the overlay of histopathology grids. Lectin histochemistry identified two lectins-wheat germ agglutinin (WGA) and Helix pomatia agglutinin (HPA)-with significantly decreased binding to CIN3 versus normal in both discovery and validation cohorts. Findings at the macroscopic level confirmed weaker WGA binding (lower signal intensity) in CIN3 vs. normal for biopsies (p = 0.0308) and within whole specimens (p = 0.0312). Our findings confirm proof-of-principle and indicate that WGA could potentially be developed further as a probe for high-grade cervical disease.

Plant Lectins Targeting O-Glycans at the Cell Surface as Tools for Cancer Diagnosis, Prognosis and Therapy

Aberrant O-glycans expressed at the surface of cancer cells consist of membrane-tethered glycoproteins (T and Tn antigens) and glycolipids (Lewis a, Lewis x and Forssman antigens). All of these O-glycans have been identified as glyco-markers of interest for the diagnosis and the prognosis of cancer diseases. These epitopes are specifically detected using T/Tn-specific lectins isolated from various plants such as jacalin from Artocarpus integrifola, and fungi such as the Agaricus bisporus lectin. These lectins accommodate T/Tn antigens at the monosaccharide-binding site; residues located in the surrounding extended binding-site of the lectins often participate in the binding of more extended epitopes. Depending on the shape and size of the extended carbohydrate-binding site, their fine sugar-binding specificity towards complex O-glycans readily differs from one lectin to another, resulting in a great diversity in their sugar-recognition capacity. T/Tn-specific lectins have been extensively used for the histochemical detection of cancer cells in biopsies and for the follow up of the cancer progression and evolution. T/Tn-specific lectins also induce a caspase-dependent apoptosis in cancer cells, often associated with a more or less severe inhibition of proliferation. Moreover, they provide another potential source of molecules adapted to the building of photosensitizer-conjugates allowing a specific targeting to cancer cells, for the photodynamic treatment of tumors.

Sialyl Lewis x expression in cervical scrapes of premalignant lesions

Sialylated oligosaccharides of glycoproteins and glycolipids have been implicated in tumour progression and metastases. Altered expression of glycosidic antigens has been reported in cervical cancer. In cervix premalignant lesions, an increased expression of sialic acid has been reported. In the present study we determined the expression profiles of the glycosidic antigens Tn, sialyl Tn (sTn), Lewis a (Lea), sialyl Lewis a (sLea), Lewis x (Lex) and sialyl Lewis x (sLex) in cervical scrapes with cytological diagnoses of normal, low-grade squamous intraepithelial lesions (LGSIL) and highgrade squamous intraepithelial lesions (HGSIL). Cervical scrapings were collected to detect tumour antigens expressions by flow cytometry using monoclonal antibodies. Cytometry analysis of Tn, sTn, Lea and Lex did not reveal differences at the expression level among groups. The number of positive cells to sLea antigen increased in the HGSIL group with respect to the normal group (p=0.0495). The number of positive cells to sLex antigen in the samples increased with respect to the grade of squamous intraepithelial lesion (SIL) (p less than 0.001, Mann-Whitney U test). The intensity of expression of this antigen increased in the HGSIL samples with respect to normal samples (p less than 0.0068). sLex antigen could be a candidate to be used as biomarker for the early diagnosis of cervical cancer.

Expression of antigen tf and galectin-3 in fibroadenoma

Background

Fibroadenomas are benign human breast tumors, characterized by proliferation of epithelial and stromal components of the terminal ductal unit. They may grow, regress or remain unchanged, as the hormonal environment of the patient changes. Expression of antigen TF in mucin or mucin-type glycoproteins and of galectin-3 seems to contribute to proliferation and transformations events; their expression has been reported in ductal breast cancer and in aggressive tumors.

Findings

Lectin histochemistry, immunohistochemistry, and immunofluorescence were used to examine the expression and distribution of antigen TF and galectin-3. We used lectins from Arachis hypogaea, Artocarpus integrifolia, and Amaranthus lecuocarpus to evaluate TF expression and a monoclonal antibody to evaluate galectin-3 expression. We used paraffin-embedded blocks from 10 breast tissues diagnosed with fibroadenoma and as control 10 healthy tissue samples. Histochemical and immunofluorescence analysis showed positive expression of galectin-3 in fibroadenoma tissue, mainly in stroma, weak interaction in ducts was observed; whereas, in healthy tissue samples the staining was also weak in ducts. Lectins from A. leucocarpus and A. integrifolia specificaly recognized ducts in healthy breast samples, whereas the lectin from A. hypogaea recognized ducts and stroma. In fibroadenoma tissue, the lectins from A. integrifolia, A. Hypogaea, and A. leucocarpus recognized mainly ducts.

Conclusions

Our results suggest that expression of antigen TF and galectin-3 seems to participate in fibroadenoma development.

Glycosylation pattern in the appendix testis in children with cryptorchidism

In humans, at about week 6, sex cords develop within the forming testes. Testes normally descend to the scrotum; cryptorchidism occurs when one or two testes do not descend to scrotum and in some case are accompanied by the appendix testis. The appendix testis is a small sessile or polypoid structure located at the antero superior pole of the testis, adjacent to the head of the epididymis. Glycans can be involved in development of the appendix testis and cryptorchidism. In this work, lectin histochemistry was used to evaluate glycans expression in appendix testis in children with cryptorchidism. Our results showed that lectin from Lens culinaris, Ulex europaeus I., Canavalia ensiformis, Artocarpus integrifolia, Glycine max, and Griffonia simplicifolia recognizes epithelial and estromal cells. Not interaction was observed with lectin from Amaranthus leucocarpus, while lectin from Dolichus biflorus lectin only recognizes epithelial cells. Our results suggest that O-glycans linked in some glycoproteins represent important elements in appendix testis development.

O-glycosylation expression in fibroadenoma

Fibroadenomas are human benign breast tumors characterized by proliferation of epithelial and stroma cells of the terminal ductal unit. Expression of O-glycans seems to contribute to the proliferation and transformation events. With this in mind, we evaluated the expression of glycans in fibroadenoma tissue through immunohistochemistry with antibodies against mucin epitopes (Anti CA15-3 and MUC1), as well as with lectins specific for glycans linked to proteins or lipids, and we compared findings with healthy breast specimens. Our results show positive expression of CA15-3 and MUC1 in fibroadenoma tissue, mainly in duct and stroma cells, whereas, in normal samples, staining was observed in duct cells. The lectin from Glycine max recognized equally well duct and stroma cells; this was the only lectin showing co-localization with anti-CA15-3 in healthy and tumor tissues. Dolichos biflorus, Artocarpus integrifolia, and Griffonia simplicifolia lectins recognized duct cells in control healthy tissues as well as in fibroadenoma tissue. The lectin from Amaranthus leucocarpus recognized only duct cells in control samples, whereas, in fibroadenoma tissue, it recognized duct and some stromal cells, suggesting that O-glycans-type mucin linked to proteins and mucin participate in the development of fibroadenomas.

Significance of a galactose specific plant lectin for the differential diagnosis of adenocarcinoma cells in effusion

Background:

Distinguishing adenocarcinoma cells from reactively proliferated mesothelial cells and macrophages is one of the greatest challenges in the cytodiagnosis of effusions. Aberrant glycosylation of cell surface glycoconjugates is emblematic to malignancy, and lectins being an important class of probes to demonstrate these aberrations, lectin cytochemistry is of great interest to differentiate adenocarcinoma cells from reactive mesothelial cells.

Aim:

The present study analyzed the potential of a plant lectin to distinguish malignant cells from reactive mesothelial cells and macrophages.

Materials and Methods:

Snake gourd lectin (SGL) was isolated, purified and conjugated to horse radish peroxidase (HRP) and incubated with the cells of benign (46) as well as malignant (39) effusions using the standard immunocytochemical method with diaminobenzidine as the chromogen. The lectin-bound areas were quantitatively assessed as mild, moderate and intense binding.

Statistical Analysis:

The mean score for benign and malignant effusions were statistically analyzed. Student's ‘t’-test was performed to assess the significance.

Results:

The lectin HRP complex bind to the cytoplasm of benign and malignant cells as well as macrophages. A significantly higher score for intense binding (P = 0.001) was found to differentiate malignant cells from reactive mesothelial cells. Macrophages showed intense irregular binding.

Conclusions:

SGL binding assay can play a role in the differential diagnosis of metastatic adenocarcinoma in effusions.