Date of Award
3-18-2024
Document Type
Doctoral Dissertation - Open Access
Degree Name
Doctor of Philosophy
Department
Basic Medical Sciences
First Advisor
Raj K. Tiwari
Second Advisor
Xiu-Min Li
Third Advisor
Jan Geliebter
Abstract
Anaplastic thyroid cancer is a rare, fatal cancer with a five-year survival of 4%. Universally diagnosed at stage IV, anaplastic thyroid cancer is characterized by its lack of differentiation, rapid proliferative rate, highly inflammatory tumor microenvironment, and metabolic dysregulation. Refractory to all established therapies, anaplastic thyroid cancer requires a novel therapeutic approach that targets all of these drivers of anaplastic thyroid cancer carcinogenesis. We propose natural alkaloid berberine as a therapeutic with multitarget efficacy to alter mitochondrial metabolism and reprogram anaplastic thyroid cancer’s aggressive phenotype. Our in vitro model uses monocyte cell line U937, anaplastic thyroid cancer cell lines T238 and SW1736, and immortalized normal thyroid cell line Nthy-ori-3-1. Validation of in vitro findings via RNA Sequencing was conducted by Genewiz from Azenta and Qiagen’s Ingenuity Pathway Analysis was used for in silico modeling.
In targeting the aggressiveness of anaplastic thyroid disease, berberine selectively slowed proliferation by 80% in anaplastic thyroid cancer cells from 48 to 72 hours while sparing normal cells. Berberine reduced migratory capacity by 33% in T238 cells and 51% in SW1736 cells after 24 hours. Berberine reduced both migration and invasion by 30% in T238. These observations were substantiated by Western blot analysis – berberine selectively decreased phosphorylation of MEK, ERK, and ribosomal protein S6, crucial downstream regulators of the pro-proliferative and pro-survival pathways in anaplastic thyroid cancer cells. Further, berberine specifically modulated cancer-associated metabolism as observed through an increase in AMPKα phosphorylation, a major rate-limiting protein in cancer-induced dysregulation with an anti-tumor effect.
Modeling the anaplastic thyroid cancer tumor microenvironment, U937 cells were activated and polarized into a proinflammatory macrophage phenotype. Following berberine treatment at the activation/polarization stages, 19 soluble inflammatory mediators were significantly downregulated in the conditioned media compared to controls. U937 cells polarized using anaplastic thyroid cancer-conditioned media pre-treated with berberine also showed decreased IFN-γ and TNF-α secretion.
Validation of in vitro findings via RNA Sequencing revealed more than 400 significantly differentially expressed genes involved in mitochondrial metabolism, glycometabolism, sirtuin signaling, apoptosis, and proliferation. Following a comprehensive analysis, we identified significant downregulation of 22 of 37 total mitochondrially encoded genes and 13 of 13 mitochondrially encoded protein-coding genes comprising the oxidative phosphorylation complexes, illuminating a clear link between berberine treatment and altered mitochondrial metabolism in anaplastic thyroid cancer. Additionally, protein expression of significantly downregulated mitochondrial genes identified via RNA Sequencing was validated via Western blot, demonstrating decreased mitochondrially-encoded protein expression related to oxidative phosphorylation.
This work reveals a novel role for berberine as an inhibitor of mitochondrial metabolism that can be used to reprogram the aggressive nature of anaplastic thyroid cancer and open the door for promising combination therapy in treating fatal anaplastic thyroid cancer.
Recommended Citation
Jarboe, Tara, "Remodeling Anaplastic Thyroid Cancer’s Aggressive Profile and Metabolic Signature by Natural Alkaloid Berberine" (2024). NYMC Student Theses and Dissertations. 66.
https://touroscholar.touro.edu/nymc_students_theses/66
