Abstract 319: MALDI-IMS of N-glycan profiles of molecular subclasses of human hepatocellular carcinoma
Authors: DelaCourt Andrew , Mehta Anand , Black Alyson , Drake Richard , Angel Peggi , Hoshida Yujin 
Published: July 2021

Introduction: Hepatocellular Carcinoma (HCC) is the second leading cause of cancer deaths globally, and the incidence rate in the US is increasing. Recent work has identified changes in N-linked glycosylation directly in HCC tissue by MALDI-IMS glycan imaging. However, there was significant inter-tumor heterogeneity, suggesting a potential correlation between the glycan changes and molecular tumor heterogeneity. Therefore, this work will analyze HCC tissues, categorized by subtype, in an effort to fit glycosylation patterns within different classes of HCC.

Methods: To analyze the glycosylation of HCC tissue samples, MALDI-IMS was utilized, which uniquely allows for the analysis of spatially mapped N-glycans to paraffin embedded tissues. The sample set of HCC tissues consisted of Hoshida HCC subtypes 1, 2, and 3 tissues. Tissues were prepared through a previously published protocol that involved antigen retrieval, spraying of PNGase F Prime with a TM-Sprayer, then spraying of MALDI matrix CHCA. Each tissue is then imaged on a Bruker MALDI solariX FT-ICR, and data is analyzed using flexImaging and SCiLS software.

Results: The primary goal of this work was to determine if differences within N-glycan profiles of HCC tissues are related to the differences between Hoshida genetic subtypes. Preliminary data showed that HCC tumors contain increased fucosylation of glycoproteins, yet there was significant heterogeneity within analyzed HCC tissues regarding the expressed glycan structures. With HCC tissues that were categorized into different Hoshida subtypes, glycan MALDI-IMS data showed trends that could approximately separate the subtypes. Subtype 1, which is less differentiated and is associated with poor survival, showed the most extreme tumor-associated glycan expression when compared to the surrounding normal and cirrhotic tissue. Subtype 1 tissues showed a higher number of unique glycan structures that associated with the tumor tissue. Subtype 1 showed an average of 18.00 ± 8.48 tumor-associated glycans, subtype 2 with 4.25 ± 2.21, and subtype 3 with 2.25 ± 1.71. While the identity of these glycan structures varied from tissue to tissue, trends emerged, particularly regarding how branched and fucosylated glycans associate to tumor tissue with each subtype, including decreased fucosylation in subtype 2. Overall, this data shows that some of the heterogeneity in glycan expression of HCC tumors may be attributable to differences between genetic subtypes of HCC.

Conclusion: HCC tissues exhibit glycan expression that is noticeably different from normal or cirrhotic tissue, yet there is significant variation between HCC tissues regarding both the number and identity of glycan structures that are observed on the tissue. Using the Hoshida classification system, some of that variation can be explained, which could have profound impact on the utilization of N-linked glycosylation for biomarker applications.

Citation Format: Andrew DelaCourt, Anand Mehta, Alyson Black, Richard Drake, Peggi Angel, Yujin Hoshida. MALDI-IMS of N-glycan profiles of molecular subclasses of human hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 319.