N‑glycosylation and receptor tyrosine kinase signaling affect claudin‑3 levels in colorectal cancer cells

Abstract

Changes in protein levels in different components of the apical junctional complex occur in colorectal cancer (CRC). Claudin-3 is one of the main constituents of tight junctions, and its overexpression can increase the paracellular flux of macromolecules, as well as the malignant potential of CRC cells. The aim of this study was to investigate the molecular mechanisms involved in the regulation of claudin-3 and its prognostic value in CRC. In silico evaluation in each of the CRC consensus molecular subtypes (CMSs) revealed that high expression levels of CLDN3 (gene encoding claudin-3) in CMS2 and CMS3 worsened the patients' long-term survival, whereas a decrease in claudin-3 levels concomitant with a reduction in phosphorylation levels of epidermal growth factor receptor (EGFR) and insulin-like growth factor 1 receptor (IGF1R) could be achieved by inhibiting N-glycan biosynthesis in CRC cells. We also observed that specific inactivation of these receptor tyrosine kinases (RTKs) led to a decrease in claudin-3 levels, and this regulation seems to be mediated by phospholipase C (PLC) and signal transducer and activator of transcription 3 (STAT3) in CRC cells. RTKs are modulated by their N-linked glycans, and inhibition of N-glycan biosynthesis decreased the claudin-3 levels; therefore, we evaluated the correlation between N-glycogenes and CLDN3 expression levels in each of the CRC molecular subtypes. The CMS1 (MSI immune) subtype concomitantly exhibited low expression levels of CLDN3 and N-glycogenes (MGAT5, ST6GAL1, and B3GNT8), whereas CMS2 (canonical) exhibited high gene expression levels of CLDN3 and N-glycogenes (ST6GAL1 and B3GNT8). A robust positive correlation was also observed between CLDN3 and B3GNT8 expression levels in all CMSs. These results support the hypothesis of a mechanism integrating RTK signaling and N-glycosylation for the regulation of claudin-3 levels in CRC, and they suggest that CLDN3 expression can be used to predict the prognosis of patients identified as CMS2 or CMS3.

Landscape of N1‐methyladenosin (m1A) modification pattern in colorectal cancer

“…Studies demonstrated that overexpression of claudin‐3 can increase the paracellular flux of macromolecules and the malignant potential of CRC cells. They concluded that the expression of CLDN3 can be used to predict the prognosis of CRC 26–28 . Von Willebrand factor (VWF) and MUC2 are believed to have shared a common ancestor 29 .…”

Evaluation of the Prognostic Relevance of Differential Claudin Gene Expression Highlights Claudin-4 as Being Suppressed by TGFβ1 Inhibitor in Colorectal Cancer

“…Many claudins are dysregulated in a range of cancers, as in the case of the CLDN1 and CLDN2 genes, which are overexpressed in colorectal cancer ( Dhawan et al, 2011 ; Mori et al, 2011 ; Pope et al, 2014 ; Wang et al, 2019 ). CLDN3 is similarly overexpressed at the mRNA level in CRC tumors that belong to the consensus molecular subgroup (CMS)-CMS2 and CMS3, which correspond to a poor prognosis ( Tang et al, 2011 ; Perez et al, 2020 ). Colorectal cancers have significant levels of CLDN4 expression ( Georges et al, 2012 ).…”

Effects of 1,2-Dimethylhydrazine on Barrier Properties of Rat Large Intestine and IPEC-J2 Cells

“…An enhanced expression indicates an increase in the malignant potential. However, the authors note that this effect depends on the molecular subtype of colorectal cancer [ 40 ].…”