6885 Glucose Utilization Differs Between RAS-like and BRAF-like Thyroid Cancer
Authors: Kumari S , Chuki E , Klubo-Gwiezdzinska J 
Published: October 2024

Abstract
Disclosure: S. Kumari: None. E. Chuki: None. J. Klubo-Gwiezdzinska: None.
Background: RAS-like thyroid cancer (TC) tends to be more differentiated and less [1][8]Fluorodeoxyglucose Positron Emission Tomography-avid as compared with BRAF-like TC. Therefore, we hypothesized that glucose metabolism may differ between RAS-like and BRAF-like tumors and performed a study aimed at metabolomic profiling of TC. Methods: Based on Institutional Review Board approved protocol, we obtained fresh frozen human TC samples with corresponding normal tissue and performed targeted metabolomics including oxidative phosphorylation (OXPHOS), glycolysis and tricarboxylic acid (TCA) markers using mass spectrometry (MS). The Trusight 500 gene panel was used to determine molecular signature of tumors. Similarly, we performed targeted metabolomics of 4 BRAF-like and 2 RAS-like human TC cell lines. The data were analyzed using Ingenuity Pathway Analysis (Qiagen). We also analyzed mRNA expression of OXPHOS and glycolytic enzymes in 496 human TC tissue samples of The Cancer Genome Atlas (TCGA). The division into BRAF-like and RAS-like TC was based on well-established BRAF-RAS score (BRS) ranging from -1 to +1 for BRAF-like and RAS-like TC, respectively. Results: The study cohort consisted of 20 patients, 13 with BRAF-like and 7 with RAS-like tumors, aged 43±12 years old, 90% (18/20) females, with an average tumor size of 3±1.9 cm, multifocal growth in 55% (11/20) patients, central neck lymph node (LN) metastases in 55% (11/20), lateral neck LN metastases in 15% (3/20) patients and no distant metastases. The tumor size tended to be larger in RAS-like cohort (BRAF-like 2.27±1.28 vs RAS-like 4.34±2.52, p=0.08), and LN metastases more prevalent in BRAF-like cohort (BRAF-like 45% vs RAS-like 10%, p=0.08). Metabolomics data revealed that compared with normal thyroid, human TC tissue samples were characterized by an increased glucose metabolism (p&lt;0.001), TCA (p&lt;0.001) and gluconeogenesis (p&lt;0.001). RAS-like tumors were characterized by a significantly higher TCA (p&lt;0.001) and lower gluconeogenesis (p&lt;0.001) as compared with BRAF-like tumors. Consistently, we found that TCA (p&lt;0.001) and glucose metabolism (p&lt;0.001) was higher in RAS-like vs BRAF-like cell lines. Transcriptomic profiling revealed that RAS-like TC was characterized by an increased expression of majority of tested OXPHOS enzymes compared to BRAF-like tumors, as evidenced by positive correlation with BRS, ranging from r = 0.28 to 0.54, p&lt;0.001. Consistently, BRAF-like TC was associated with an upregulated mRNA expression of anaerobic glycolysis markers, with lactate dehydrogenase A, characterized by the highest negative correlation (r = -0.6, p&lt;0.001) with BRS. Conclusion:RAS-like TC is more likely to utilize glucose through Krebs cycle, while BRAF-like tumors are more prone towards anaerobic glycolysis. Therapeutic strategies based on diverse metabolic profiles may provide a personalized approach to TC therapy.
Presentation: 6/3/2024