Changes in glycosylation in Pancreatic Ductal Adenocarcinoma mediated by KRAS mutations

A group from Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Faculty of Medicine, University of Tsukuba, Japan, etc. has reported about changes in glycosylation in Pancreatic Ductal Adenocarcinoma mediated by KRAS gene mutations.

It was shown that Fucosilation and mannosylation were upregurated in pancreatin ductal adenocarcinoma with KRAS gene mutations.
The lectins enriched in KRAS mutants included fucose-binding lectins (AAL, rAAL, AOL, rAOL, rRSIIL, and UEAI) and mannose-binding lectins (rRSL, rBC2LCA, rPAIIL, and NPA).

Detecting Triple-Negative Breast Cancer with using Glycan Profiling of Extracellular Vesicles

A group from Beijing Engineering Research Center for BioNanotechnology, CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing, China, etc. has reported about glycan profiling of extracellular vesicles (EVs) for detecting triple-negative breast cancer (TNBC).

A panel of 3 lectins (ConA, WGA and RCA I) was used to detect the EV surface glycan profiles unique to TNBC.
As a result, they succeeded in getting an area under ROC curve (AUC) of 0.91 with using the weighted sum of 3 lectins (ConA, WGA and RCA I) for discriminatiing TNBC from other BCs and HDs.


They say that prostate cancer can be detected by using its exosomes, but

A group from Institute of Chemistry, Slovak Academy of Sciences, Bratislava, etc. has reported about a measurement using a sandwich scheme with CD63, exosomes and SNA lectin for detecting prostate cancer.

In this experment, exosomes produced by prostate cancer cells are examined as a new biomarker for detecting prostate cancer.

Comparing with exosomes produced by benign (control) cell line RWPE1 and carcinoma cell line 22Rv1, it was showen that
(1) the control exosomes mainly interacted with SNA and MAAII lectins; however, they exhibited a lower affinity than the carcinoma exosomes, and also
(2) PHA-L and PHA-E were only able to bind poorly to control-derived exosomes, while there were no interactions to carcinoma exosomes.
This result is quite reasonable because usually the signal intensity of PHA-L and PHA-E disapper with fully sialylated N-glycans suggesting that sialylation is stronger in carcinoma exsosomes than that of control exosomes.

However, blog author is skeptical about their conclusion that it is possible to perform measurements in a sandwich configuration, i.e., antibody/exosomes/lectin, because exsosmes are generally strongly sialylated and CD63 can not discriminate exsosomes produced by prostate cancer cells from other exosomes.

Sialic Acid is strong on Exosomes, but Why?

Glycans are said to be the face of cells, and the glycosylation on the cell surface changes depending on the tissue and desease state.
As a result, the glycosylation of exosomes released from cells drags the glycosylation of the cell surface, but for some reason, expression of sialic acid tends to be very strong.
For example, there is a paper written by Shimoda and Akiyoshi at. al., Kyoto University (see below).
Why is this?
There is a paper that says it may be aimed at masking the immune system (in Japanese), but is that true?
for example,
In contrast, the authors cited above suggest that it is involved in the uptake of exosomes via Siglecs on the cell surface.

(cited from the above listed paper)

Behind the “Cry for Help” response caused by plant pathogen infection

A group from State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China, etc. has reported about how to induce “cry for help” response to assemble disease suppressing and growth promoting rhizomicrobiome.

The well-studied model pathogen Pseudomonas syringae pv. tomato (Pst) DC3000 and its nonpathogenic derivatives (D36E, D36EFLC and D36EHPM) were used in this experiment using Arabidopsis as a model plant.

Treatment with either DC3000 or the derivatives increased the relative contents of long chain organic acids (LCOAs) and amino acids in root exudates. The bacterial phyla Proteobacteria (32.1%–38.3%) and Actinobacteria (15.4%–20.7%) were the most abundant groups in the rhizosphere, and the genus Devosia (belonging to phylum Proteobacteria) was enriched in the D36E and D36EFLC treatments. Interestingly, the abundance of genus Devosia was negatively correlated with L-malic acid and myristic acid in root exudates but positively correlated with 4-hydroxypyridine.

Finally, it was shown that the metabolites of D36E and D36EFLC alone are sufficient to induce a “cry for help” response. So, this study demonstrates the ability of nonpathogenic strains and their MAMPs to act as elicitors to induce the formation of a disease-suppressive soil legacy, which can potentially support agricultural applications.

International Carbohydrates related Conferences scheduled in 2024 – 2025

  1. 7th canadian Glycomics Symposium & 10th warren Workshop (May 27-29, 2024, Edmonton, Canada)
  2. SialoGlyco 2024 (June 4-7, 2024, Lilli, France)
  3. 31st International Carbohydrate Symposium (July 14-19, 2024, Shanghai, China)
  4. 5th Australasian Glycoscience Symposium (Aug. 27-30 2024, Wellington, New Zealand)
  5. Microbial Glycobiology 2024 (Sept. 8-12, 2024, Southbridge, MA, USA)
  6. 16th Bratislava Symposium on Saccharides (Sept. 23-27, 2024, Smolenice Castle, Slovakia)
  7. HUPO 2024 (Oct. 20-24, 2024, Dresden, Germany)
  8. 2024 Glycobiology Annual Meeting (Nov. 10-13, 2024, Amelia Island, FL, USA)
  9. Glycobiology Gordon Research Conference (Mar. 23-28, 2025, Lucca, Italy)
  10. Glyco27 International Symposium on Glycoconjugates (May 26-30, 2025, Edmonton, Canada)