No abstract

No abstract

RNA biology has gained extensive recognition in the last two decades due to the identification of novel transcriptomic elements and molecular functions. Cancer arises, in part, due to the accumulation of mutations that greatly contribute to genomic instability. However, the identification of differential gene expression patterns of wild-type loci has exceeded the boundaries of mutational study and has significantly contributed to the identification of molecular mechanisms that drive carcinogenic transformation. Non-coding RNA molecules have provided a novel avenue of exploration, providing additional routes for evaluating genomic and epigenomic regulation. Of particular focus, long non-coding RNA molecule expression has been demonstrated to govern and direct cellular activity, thus evidencing a correlation between aberrant long non-coding RNA expression and the pathological transformation of cells. lncRNA classification, structure, function, and therapeutic utilization have expanded cancer studies and molecular targeting, and understanding the lncRNA interactome aids in defining the unique transcriptomic signatures of cancer cell phenotypes.

Only 2% of thyroid cancer (TC) cases are anaplastic thyroid cancer (ATC), but this rare, undifferentiated cancer with a highly inflamed tumor microenvironment (TME) presents universally as stage IV with a 5-year survival rate of 3%. Due to its loss of differentiation, ATC is resistant to radioiodine therapy, refractory to external beam radiation, and insufficiently treated by chemotherapy or immunotherapy. Berberine (BBR), a natural plant alkaloid, has vast pharmacological activities, including anti-inflammatory and anti-cancer roles. BBR blocks proliferation, induces cell cycle arrest, promotes apoptosis, and hinders invasion and metastasis. BBR may also inhibit cell proliferation through miRNA interactions and regulate the TME through its anti-inflammatory and antioxidant properties. Research in ATC using BBR is limited, specifically investigation on how BBR reprograms the inflammatory TME via altering miRNA cargo of secretory exosomes and polarization of tumor associated macrophages (TAMs). ATC tissues have extensive infiltration of a mixed TAM population. In ATC, infiltration with classically anti-tumorigenic, inflammatory M1 macrophages has a pro-tumorigenic role. We assessed the secretory profile of ATC cells and found a high expression of pro-inflammatory cytokines, such as TNFα, IL-6, IL-1, MCP-1/2, and MIP-1α/β in ATC conditioned media (CM), supporting the existence of an inflammatory TME. As this chronic inflammation is partially mediated by the presence of M1 TAMs in the TME, we activated monocyte cell line U937 with TPA and polarized with IFNγ and LPS into an M1 phenotype. In the presence of BBR at the activation and polarization stages, inflammatory mediators IL-1β, IL-6, IL-6R, CXCL9, MIP-1α/β, and TNFR1/2 were downregulated in the CM compared to M1 macrophages activated and polarized without BBR. BBR also appeared to prevent some level of activation and polarization of these cells into the M1 phenotype altogether. BBR may have an essential role in lessening the burden of inflammation in ATC through remodeling its tumor immune infiltrates, potentially priming it for greater success in combination therapy. Intervention prior to metastasis warrants secretome analysis to define ATC disease progression. Exosomal cargo, particularly miRNA, secreted by ATC cells was evaluated as exosomes have potential as biomarkers to detect ATC earlier improving prognosis, guide treatment, and avoid unneeded surgeries. Distinct miRNA expression from ATC-secreted exosomes compared to papillary thyroid cancer (PTC)-secreted exosomes revealed six miRNAs specifically downregulated in ATC-secreted exosomes that are known tumor suppressors. We are currently evaluating how BBR alters the miRNA profile of ATC- and PTC-secreted exosomes. The ability of BBR to alleviate inflammation in ATC and remodel its TME releases its chronic hold on ATC progression and may prime the tumor for increased responsiveness to therapy. Citation Format: Tara Jarboe, Kaci Kopec, Nicole R. DeSouza, Sarnath Singh, Augustine Moscatello, Jan Geliebter, Xiu-Min Li, Raj K. Tiwari. Berberine eases inflammation in the anaplastic thyroid cancer microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 243.

Anaplastic thyroid cancer's (ATC) undifferentiated, inflammatory nature makes it one of the most aggressive cancers, with a five-year survival rate of only 4% when metastatic. ATC is a rare cancer that is refractory to conventional therapeutic modalities. Without high expression of targetable genetic lesions, small molecule inhibitors alone have been insufficient in trials. Treatment of ATC could benefit from a holistic approach that reprograms the inflammatory tumor microenvironment (TME). Berberine (BBR), a natural plant-derived alkaloid used extensively in Traditional Chinese Medicine, is a compound shown to exhibit anti-microbial, anti-inflammatory, and anti-cancer properties. Our work aims to exploit the anti-inflammatory activity of BBR in ATC. As the inflammatory status of ATC defines its intractable nature, remodeling its secretome, including its cytokine and chemokine profile and its exosomal cargo, in the TME fundamentally targets ATC's progressive determinant - inflammation. Exosomes, membrane-bound extracellular vesicles, are secreted by cells in the TME, including activated tumor-associated macrophages and ATC cells. Exosomal cargo primarily consists of miRNAs. We observed distinct miRNA expression from ATC-secreted exosomes when compared to papillary thyroid cancer (PTC)-secreted exosomes. Comparative analysis revealed ten miRNAs specifically downregulated in exosomes secreted from anaplastic-like 8505C compared to papillary BCPAP, including: hsa-miR-26b-5p, hsa-miR-125b-5p, hsamiR-138-5p, hsa-miR-148a-5p, hsamiR-152-5p, hsa-miR-191-5p, hsa-miR-9-5p, hsa-miR-21-5p, hsa-miR-134-5p, and hsa-miR-379-5p. The first six miRNAs listed are tumor suppressors, and as such, their downregulation may be contributory to the metastatic propensity and aggressiveness of ATC and its refractory nature towards conventional treatments. In activated macrophage-derived exosomes, miR-21-5p and miR-138-5p were also upregulated. ATC-secreted exosomes activate macrophages, subsequently priming the TME to be pro-tumorigenic and pro-inflammatory. This reciprocal interaction between inflammatory macrophages and ATC cells mediated by exosomal miRNAs defines its metastatic and inflammatory phenotype. We also observed that BBR significantly downregulates phosphorylation of MEK, ERK, and ribosomal protein S6 in proliferating ATC cells with as low as 10 μM BBR treatment. These are important downstream regulators of the pro-proliferative, pro-survival, and metabolic MAPK and PI3K-PTEN-AKT signaling pathways. Overall, the ability for BBR to alleviate the pro-inflammatory phenotype of ATC and remodel its immune environment, while simultaneously depressing overactive signaling in these cell survival pathways, may mark it as an important agent to make ATC amenable to combination therapy with small molecule inhibitors (MEKi) or other immunotherapeutics. Citation Format: Tara Jarboe, Nicole DeSouza, Sarnath Singh, Augustine Moscatello, Jan Geliebter, Raj K. Tiwari, Xiu-Min Li. Berberine-mediated reprogramming of the inflammatory environment in anaplastic thyroid cancer [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 317.