Cancer-specific sialylation of insulin-like growth factor 1 receptor impairs therapeutic antibody binding and efficacy

Hassan, A. A.; Chen, Q.; Fung, K. S. W.; To, S. K. Y.; Cheung, L. W. T.; Zhang, C.; Liu, N.; Lok, C. N.; Che, C.-M.; Ip, P. P. C.; Li, X.; Wong, A. S.-T.

doi:10.1101/2025.10.17.682592

bioRxiv · 10.1101/2025.10.17.682592

Cancer-specific sialylation of insulin-like growth factor 1 receptor impairs therapeutic antibody binding and efficacy

Hassan, A. A.·Chen, Q.·Fung, K. S. W.·To, S. K. Y.·Cheung, L. W. T.·Zhang, C.·Liu, N.·Lok, C. N.·Che, C.-M.·Ip, P. P. C.·Li, X.·Wong, A. S.-T.

View original source ↗Export metadata ↓

Abstract

Despite extensive efforts to develop insulin-like growth factor (IGF1R)-targeted therapies for various malignancies, none has received clinical approval in the past two decades. Here, we reveal that N-glycan sialylation significantly decreases recognition by the humanized monoclonal anti-IGF1R antibody ganitumab across various cancer types, reducing its efficacy both in vitro and in vivo. Sialoforms of IGF1R are virtually absent in normal cells, indicating that the modification is tumor-specific. Pharmacological inhibition of sialyltransferases significantly sensitizes metastatic tumors to ganitumab in a ganitumab-resistant ovarian cancer model. Enzymatic removal of sialic acids from tissue sections resulted in marked enhancement in antibody binding to ovarian cancer patient tumors, but not normal tissues. Upregulation of 2-6 sialyltransferase ST6GAL1 in tumor tissues was found to be responsible for sialylation of IGF1R. Consequently, ST6GAL1-high tumors were more likely to benefit from desialylation-mediated enhancement of ganitumab binding. Furthermore, through comprehensive glycoproteomics analysis, structural prediction, and molecular dynamics simulation, we identify Asn-607 (N607) as a crucial site harboring sialylated glycans. Mechanistically, N607 glycosylation destabilizes the IGF1R-ganitumab complex. Overexpression of IGF1R Asn-607-Gln (N607Q) mutant in IGF1R-knockout cancer cells increases ganitumab efficacy compared to wild-type IGF1R in vivo. Taken together, these findings highlight sialylation as a common barrier in IGF1R-targeted therapies and provide crucial insights for therapy enhancement in cancer and patient stratification for future clinical trials. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=99 SRC="FIGDIR/small/682592v1_ufig1.gif" ALT="Figure 1"> View larger version (14K): org.highwire.dtl.DTLVardef@17c6d5corg.highwire.dtl.DTLVardef@1efe2f7org.highwire.dtl.DTLVardef@1dd05aorg.highwire.dtl.DTLVardef@159fb23_HPS_FORMAT_FIGEXP M_FIG C_FIG Synopsis2-6 sialylation of IGF1R Asn-607 by ST6GAL1 is prevalent in cancer. This modification disrupts the interaction of IGF1R with therapeutic mAb ganitumab. Removal of sialylation augments ganitumab efficacy.

Explore related subjects

cancer biology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Hassan, A. A., Chen, Q., Fung, K. S. W., To, S. K. Y., Cheung, L. W. T., Zhang, C., Liu, N., Lok, C. N., Che, C.-M., Ip, P. P. C., Li, X., Wong, A. S.-T.. 2025-10-19. Cancer-specific sialylation of insulin-like growth factor 1 receptor impairs therapeutic antibody binding and efficacy. https://doi.org/10.1101/2025.10.17.682592

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Epigenetic progression of pancreatic cancer to aggressive subtypes involves alternate routes of lineage reprogramming in subtype-intermediate progenitor cells

Pancreatic ductal adenocarcinoma (PDAC) progression involves malignant cell state plasticity. Epigenetic changes underlie this plasticity, yet the PDAC cis-regulatory landscape remains understudied. To address this, we profiled 33 primary tumors and 7 metastases from 39 patients with single-cell ATAC-seq, paired with 10 single-cell RNA-seq profiles. We found that epigenetic GATA6+/KRT17+ co-accessibility identifies a classical-basal subtype-intermediate progenitor state (SIP) associated with better clinical outcomes. SIP cells display limited epigenetic reprogramming from premalignant epithelium and retain gastric-intestinal differentiation reminiscent of neoplastic precursors. Lineages without GATA6+/KRT17+ co-accessibility exhibit greater lineage and epithelial-mesenchymal plasticity. Classical PDACs that repress basal gene accessibility activate neural-like progenitor (NRP) and tuft lineage enhancers, whereas basal committed tumors display esophageal transdifferentiation. Compared to SIP, classical-NRP and basal committed tumors have poorer outcomes, and show distinct PD-1/PD-L1 immune proteomic phenotypes and prognostic myofibroblast epigenetic states, respectively. Our work reveals links between lineage reprogramming, EMT, and epigenetic progression in human PDAC.

cancer biology↗

bioRxiv2026

Tissue resident CD4+ memory T-cells mark response to immune checkpoint inhibition in high-grade glioma

Background: Immune checkpoint inhibitors (ICI) are efficacious in many solid tumors, but response in glioma is restricted to a small subgroup. The determinants of response and resistance to ICI remain poorly understood. Methods: Here we exploit a syngeneic hypermutated high-grade glioma model with dichotomous response to combined PD-1 and CTLA-4 inhibition to unravel determinants of tumor-infiltrating T-cells driving response. Tumor-infiltrating T-cells from ICI-responsive and non-responsive tumors were analyzed by single-cell RNA and T-cell receptor sequencing and tumor-reactive T-cell receptor clonotypes were functionally validated to characterize their transcriptional phenotypes. We verify our findings in IDH1 wildtype glioblastoma patients treated with neoadjuvant pembrolizumab. Results: ICI response was associated with intratumoral clonal expansion of tumor-reactive cytotoxic T-cells and increased infiltration of CXCR6+ CD4+ tissue resident memory T-cells (Trm). CD4 stem-like memory T-cells in responding tumors demonstrated elevated interferon responses, following trajectories toward clonally expanded Trm, versus trajectories toward exhaustion in non-responsive tumors. In responsive tumors, CD4+ Trm interacted with infiltrating CXCR3+ tumor-reactive and clonally expanded, yet transcriptionally versatile cytotoxic T-cells. Probing the post neoadjuvant ICI high-grade glioma patient tissue dataset, we confirmed increased CXCR6 expression in CD4+ T cells and the association of CD4+ Trm with prolonged overall survival. Conclusion: These findings identify CD4 tissue-resident memory T-cells as determinants of ICI response in IDH1 wildtype high-grade glioma and warrant their further investigation to improve immunotherapy outcomes.

cancer biology↗

bioRxiv2026

Low-dose doxorubicin drives caveolin-1 depended re-epithelialization of breast cancer cells as a mechanism of cancer plasticity

Breast cancer progression is driven by dynamic changes in epithelial plasticity, membrane organization, and intracellular signaling, yet the effects of sustained low-dose chemotherapy on these processes remain poorly understood. Here, we investigated the impact of prolonged low-dose doxorubicin on membrane remodeling, epithelial phenotype, membrane-associated Ras lipid-anchor localization, and autophagy in mesenchymal-like MDA-MB-231 breast cancer cells. Low-dose doxorubicin significantly increased Caveolin-1 expression and enhanced E-cadherin protein levels, accompanied by a transition toward a more compact epithelial-like morphology with increased cell-cell contacts. Live-cell imaging demonstrated a significant reduction in the membrane-to-cytoplasm fluorescence ratio of the lipid-anchored GFP-tH probe, indicating redistribution from the plasma membrane to the cytoplasm following treatment. Analysis of autophagy-related proteins revealed decreased LC3-I together with increased LC3-II, ATG5, and p62 expression, consistent with autophagosome accumulation and impaired autophagic flux. Collectively, our findings demonstrate that low-dose doxorubicin promotes extensive remodeling of plasma membrane organization, epithelial plasticity, membrane-associated lipid-anchor localization, and autophagy. This integrated response reveals previously unrecognized links between membrane architecture, Ras membrane association, and autophagy during phenotypic reprogramming of breast cancer cells, providing mechanistic insight into cellular adaptations elicited by sub-cytotoxic doxorubicin exposure.

cancer biology↗