Lectin-Based Protein Microarray for the Glycan Analysis of Colorectal Cancer Biomarkers: The Insulin-Like Growth Factor System

Unlocking the future of colorectal cancer detection: Advances in screening glycosylation-based biomarkers on biological mass spectrometry technology

The incidence of colorectal cancer (CRC) is increasingly affecting younger populations, with its mortality rate rising annually. However, current clinical diagnostic techniques, such as colonoscopy and CEA antigen testing, remain invasive and prone to false-positive results, complicating early diagnosis and intervention. Glycosylation, a key post-translational modification, plays an essential role in cellular function, physiological regulation, and disease processes. In recent years, mass spectrometry technology has emerged as a powerful tool for screening glycan biomarkers, owing to its exceptional separation capabilities and sensitivity. This review encompasses the advancements in CRC glycan biomarkers from 2016 to 2024, with particular emphasis placed on N/O-glycan biomarkers identified through mass spectrometry. Nonetheless, the intrinsic low abundance and polyhydroxy nature of glycans hinder the specificity and sensitivity of current glycan biomarkers. To overcome these limitations, this article outlines pretreatment strategies for N/O-glycans, including glycan release, enrichment, purification, and derivatization, in conjunction with relative quantification techniques and high-throughput bioinformatics tools for biomarker screening. These strategies are anticipated to enhance the efficiency and precision of glycan biomarker identification through mass spectrometry. These advancements hold significant promise for enhancing CRC prevention, diagnosis, and treatment, thereby potentially improving patient outcomes and quality of life.

Glycomic profiling of parathyroid neoplasms via lectin microarray analysis

PURPOSE

Parathyroid carcinoma (PC) is a rare malignancy with a poor prognosis. Diagnosis of PC is often difficult in clinical practice and efficient diagnostic markers are still needed for differential diagnosis. Aberrant glycosylations of glycoproteins were identified with lectin microarray in various cancers, while relevant information is lacking in PC.

METHODS

In this study, 8 PC and 6 parathyroid adenoma (PA) tissues were assessed using a microarray consisting of 70 lectins. Overall lectin-specific glycosylation patterns were compared between PA and PC tissues. Lectins with significant differential response between PC and PA were further validated by lectin histochemistry.

RESULTS

The difference in signal intensities was found in 71.4% (50/70) of the lectins between the two groups (P < 0.05). The vast majority of PCs had higher intensity signals than PAs (PCs vs. PAs, ratio >1) and amaranthus caudatus (ACL) showed the most significantly different response between them (ratio = 2.45). Lectin histochemistry further confirmed higher ACL intensity in PCs than in PAs. The differentially expressed glycans in PC tissues were primarily glucose, mannose, and galactose-based.

CONCLUSION

PC presented unique glycomic features and ACL may serve as a candidate diagnostic marker for PC.

Prediction of Mortality in Patients on Peritoneal Dialysis Based on the Fibrinogen Mannosylation

As we already reported, fibrinogen fucosylation emerged as a prognostic marker of peritoneal membrane function in end-stage renal disease (ESRD) patients on peritoneal dialysis. After a follow-up period of 18 months, we estimated the ability of employed lectins, as well as other biochemical parameters, to serve as mortality predictors in these patients. Following a univariate Cox regression analysis, ferritin, urea clearance, residual diuresis, hyperglycemia, and an increase in the signal intensity obtained with Galanthus nivalis lectin (GNL) emerged as potential mortality predictors, but additional multivariate Cox regression analysis pointed only to glucose concentration and GNL as mortality predictors. Higher signal intensity obtained with GNL in patients that died suggested the importance of paucimannosidic/highly mannosidic N-glycan structures on fibrinogen as factors that are related to unwanted cardiovascular events and all-cause mortality and can possibly be seen as a prediction tool. Altered glycan structures composed of mannose residues are expected to affect the reactivity of mannosylated glycoproteins with mannose-binding lectin and possibly the entire cascade of events linked to this lectin. Since patients with ESRD are prone to cardiovascular complications and the formation of atherosclerotic plaques, one can hypothesize that fibrinogen with increasingly exposed mannose residues may contribute to the unwanted events.

A novel ALG10/TGF-β positive regulatory loop contributes to the stemness of colorectal cancer

The roles of asparagine-linked glycosylation (ALG) members in tumorigenic process have been widely explored. However, their effects in colorectal cancer progression are still confusing. Here, we screened 12 ALGs' expression through online datasets and found that ALG10 was mostly upregulated in colorectal cancer tissues. We found that ALG10 knockdown significantly suppressed the expression of stemness markers, ALDH activity, and sphere-formation ability. In vivo tumorigenic analysis indicated that ALG10 knockdown attenuated the tumor-initiating ability and chemoresistance of colorectal cancer cells. Further mechanistic studies showed that ALG10 knockdown suppressed the activity of TGF-β signaling by reducing TGFBR2 glycosylation, which was necessary for ALG10-mediated effects on colorectal cancer stemness; Conversely, TGF-β signaling activated ALG10 gene promoter activity through Smad2's binding to ALG10 gene promoter and TGF-β signaling promoted the stemness of colorectal cancer cells in an ALG10-dependent manner. This work identified a novel ALG10/TGF-β positive regulatory loop responsible for colorectal cancer stemness.