Abstract 6054: Weight specific effects of hyaluronic acid on glioblastoma's energy metabolism and bio-molecular content
Authors: Bale Ashwin A. , Harley Brendan , Bhargava Rohit 
Published: April 2023

Abstract
Glioblastoma (GBM) is one of the deadliest forms of brain cancer with inter and intra tumor heterogeneity and altered cell metabolism pathways. Developing multi-dimensional in vitro platforms can help explore different tumor micro-environments and can thus offer therapeutic opportunities. For a molecular-level understanding, non-destructive and label-free imaging techniques combined with in vitro tumor models offer discovery and automation potential for targeted studies. Here, we use the Fourier Transform Infrared (FTIR) spectroscopic imaging technique to profile biomolecular behavior of U87-MG GBM cell lines in a 2D culture in varied metabolic and tumor micro-environment conditions. As a micro-environmental cue, we chose to vary different molecular weights of hyaluronic acid (HA), a key component of brain’s extra-cellular matrix (ECM) and known to significantly influence cell-behavior. U87-MG cell lines were cultured for 72 hours in a DMEM supplemented with combinations of (i) glucose concentration: absent (0 mM), normal (5.5 mM) and elevated (25 mM) and (ii) molecular weights of 2 μg/ml HA: low (10 kDa)-LMW, medium (60 kDa)-MMW and high (500 kDa)-HMW. Fixed cells at different timepoints were imaged with FTIR and stained for HA-specific CD44 and RHAMM markers. Supernatant media was analyzed for metabolite expressions with LC/MS. FTIR study revealed that the Phosphate I/Amide II and Amide I/Amide II IR absorbance ratios were significantly influenced in the presence of 500 kDa HA. Visible differences in the phosphate (~1080 cm−1) and lipid (~2936 cm−1) intensities indicated signs of DNA breakages and changes in oxidative stress levels. Areas under the peaks representing α-helix (decrease) and β-sheet (increase) proteins revealed signs of protein denaturation in HMW HA cultures. These cultures also revealed elevated RHAMM expressions while the CD44 expression remained relatively unchanged. Metabolic profiling with LC/MS revealed an increase in metabolites like choline, histidine, and creatine, for cells cultured in the 0 mM glucose and HMW HA. Ornithine and Methionine remained relatively unaffected by the HA weight but showed some dependence on changing glucose levels. Proline and Tyrosine majorly showed HA weight-specific variations. Overall, this preliminary study has shown the impact of glucose and HA weight-specific effects on the biomolecular content and metabolic profiles of cancer cells. Most of the altered metabolite expressions seen are known to be involved in the Arginine-biosynthesis pathway which suggests a possible alteration in the same in response to environmental glucose and weight-specific HA levels. Further studies would involve the use of multi-dimensional hydrogel-cell models to assess variations in a more bio-mimetic surrounding. Highlighting altered metabolic pathways could help present novel therapeutic targets for future.
Citation Format: Ashwin A. Bale, Brendan Harley, Rohit Bhargava. Weight specific effects of hyaluronic acid on glioblastoma's energy metabolism and bio-molecular content [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6054.