Purification and characterization of lectin from Phyllanthus reticulatus (PRL) plant fruit inducing cytotoxic effect on T47D and SKBR3 breast cancer cell lines

Lectins are a heterogeneous group of carbohydrate-binding proteins that vary in size, structure, molecular organization, and binding patterns. They evoke diverse biological responses by specifically binding to cell surface glycans and function as recognition molecules. In this study, a lectin from the fruit of Phyllanthus reticulatus was purified using mucin-affinity chromatography. The Phyllanthus reticulatus lectin (PRL) is non-specific to blood groups, with its hemagglutination activity strongly inhibited by asialo-mucin and weakly inhibited by mucin, fetuin, asialo-fetuin, and ovalbumin. The purified PRL exists in a monomeric form and has an estimated molecular weight of approximately 36 kDa (as determined by SDS-PAGE) and 35.07 kDa (as determined by ESI-Q-TOF-MS/MALDI-TOF-MS). The hemagglutination activity of PRL remains stable at an acidic pH of 4.2 and at temperatures up to 60 °C. Glycan array analysis revealed a fine sugar specificity towards fucose and fucose-containing complex glycans. Notably, PRL exhibited a dose-dependent cytotoxic effect on T47D and SKBR3 breast cancer cell lines by inducing apoptosis, as assessed through MTT assay and annexin V/PI staining. These results suggest that PRL is a novel plant lectin with strong apoptotic effects on breast cancer cell lines and distinct carbohydrate specificity, highlighting its potential significance in cancer glycobiology.

Cancer snap-shots: Biochemistry and glycopathology of O-glycans: A review

Cancer pathogenesis is strongly linked to the qualitative and quantitative alteration of the cell surface glycans, that are glycosidically linked to proteins and lipids. Glycans that are covalently linked to the polypeptide backbone of a protein through nitrogen or oxygen, are known as N-glycans or O-glycans, respectively. Although the role of glycans in the expression, physiology, and communication of cells is well documented, the function of these glycans in tumor biology is not fully elucidated. In this context, current review summarizes biosynthesis, modifications and pathological implications of O-glycans The review also highlights illustrative examples of cancer types modulated by aberrant O-glycosylation. Related O-glycans like Thomsen-nouveau (Tn), Thomsen-Friedenreich (TF), Lewisa/x, Lewisb/y, sialyl Lewisa/x and some other O-glycans are discussed in detail. Since, the overexpression of O-glycans are attributed to the aggressiveness and metastatic behavior of cancer cells, the current review attempts to understand the relation between metastasis and O-glycans.

Lectin-glycan interactions: a comprehensive cataloguing of cancer-associated glycans for biorecognition and bio-alteration: a review

This comprehensive review meticulously compiles data on an array of lectins and their interactions with different cancer types through specific glycans. Crucially, it establishes the link between aberrant glycosylation and cancer types. This repository of lectin-defined glycan signatures, assumes paramount importance in the realm of cancer and its dynamic nature. Cancer, known for its remarkable heterogeneity and individualized behaviour, can be better understood through these glycan signatures. The current review discusses the important lectins and their carbohydrate specificities, especially recognizing glycans of cancer origin. The review also addresses the key aspects of differentially expressed glycans on normal and cancerous cell surfaces. Specific cancer types highlighted in this review include breast cancer, colon cancer, glioblastoma, cervical cancer, lung cancer, liver cancer, and leukaemia. The glycan profiles unveiled through this review hold the key to tailor-made treatment and precise diagnostics. It opens up avenues to explore the potential of targeting glycosyltransferases and glycosidases linked with cancer advancement and metastasis. Armed with knowledge about specific glycan expressions, researchers can design targeted therapies to modulate glycan profiles, potentially hampering the advance of this relentless disease.

Overexpression of sialyl Lewisa carrying mucin-type glycoprotein in prostate cancer cell line contributes to aggressiveness and metastasis

Metastasis-promoting Lewis and sialyl Lewis antigens expressed on glycoproteins such as mucins are frequently displayed on the surface of prostate cancer cells and could thus be ideal candidates as measures of prostate cancer aggressiveness. The current study describes the altered expression of sialyl Lewisa (sLea) antigen attached to glycoproteins and key glycosyltransferases between normal prostate (RWPE-1) and cancerous cell lines (LNCaP and DU145). Our results suggest that the expression of sLea on different glycoproteins correlates with the aggressiveness of prostate cancer cells, as determined by flow cytometry and fluorescence microscopy. Blotting studies revealed that sLea-bearing glycoproteins, similar to mucins, are predominantly expressed in the more aggressive DU145 cells, followed by LNCaP cells. Immunohistochemistry technique showed a gradient of sLea expression, with low levels in low-grade prostate cancer (stage II/III) and increasing levels in high-grade cancer (stage IV), indicating its potential as a prognostic marker. Additionally, in qRT-PCR analysis significant upregulation of the glycosyltransferases GALNT5 and ST3GAL6 was observed, correlating with the increased sLea expression in LNCaP (3.2- and 14.5-fold) and DU145 (3.3- and 23.75-fold) cells. Our data indicates a correlation between sLea selectin ligand expression and prostate cancer aggressiveness. Furthermore, GALNT5 and ST3GAL6 could serve as benchmarks in PCa malignancy.