Biology subjects

Miller, Z. A.

Publications and source records attributed to Miller, Z. A..

8 recordsLinked to original sources

bioRxiv2026

TAS2R10 Suppresses ABCG2 Transporter-Associated Chemoresistance and Enhances Cisplatin Sensitivity in Head and Neck Squamous Cell Carcinoma

Cisplatin resistance remains a major barrier in head and neck squamous cell carcinoma (HNSCC) treatment. ATP-binding cassette (ABC) transporters contribute to chemoresistance by limiting intracellular drug accumulation. Bitter taste receptor 10 (T2R10) has been implicated in ABC transporter regulation, but its role in HNSCC remains undefined. HNSCC cell lines were treated with T2R10-agonist caffeine (100 or 200 M), cisplatin, or a combination, and viability was assessed by crystal violet assay. T2R10 promoter activity and expression following caffeine exposure were evaluated using a promoter-driven mCherry reporter and RT-qPCR. ABC transporter expression was measured after caffeine treatment and T2R10 gene (TAS2R10) knockdown or overexpression. Associations between tumor TAS2R10 expression and survival were assessed using TCGA data through GEPIA2. Caffeine enhanced the cisplatin-associated reduction in viability in a cell line- and concentration-dependent manner, with the strongest effect seen in UM-SCC47. A significant effect was observed in FaDu at 200 M of caffeine, and minimal response in RPMI 2650. RPMI 2650 cells and FaDu cells exhibited lower baseline TAS2R10 expression and RPMI 2650 cells did not demonstrate enhanced cisplatin sensitivity following caffeine treatment. Caffeine treatment increased TAS2R10 promoter activity and expression and was associated with decreased ABCG2 expression. TAS2R10 knockdown increased ABCG2 and ABCF1 expression, whereas TAS2R10 overexpression reduced ABCG2 and ABCC1 expression. High tumor TAS2R10 expression was associated with improved disease-free survival (log-rank p=0.0071; HR=0.61) but not overall survival. Caffeine enhances cisplatin sensitivity in selected HNSCC models. Caffeine exposure is associated with increased TAS2R10 expression and reduced expression of chemoresistance-associated transporters, particularly ABCG2.

cancer biology↗

bioRxiv2025

T2R5 agonist phendione decreases cell viability and induces apoptosis in head and neck squamous cell carcinoma

Bitter taste receptors (T2Rs), a family of G-protein coupled receptors, are emerging as potential therapeutic targets in head and neck squamous cell carcinoma (HNSCC). Phendione, a known T2R5 agonist, has not been previously investigated in HNSCC. Here, we show that phendione activates endogenously expressed T2R5 in HNSCC cells and ex vivo tumor samples, inducing sustained calcium responses, reducing cell viability, and promoting apoptosis through a T2R5-dependent mechanism. Analysis of The Cancer Genome Atlas data revealed that high T2R5 expression in HNSCC tumors correlates with improved long-term disease-specific survival, suggesting a potential tumor-suppressive role for T2R5. These findings highlight T2R5 as a promising therapeutic target in HNSCC and support further investigation of phendione or other T2R5 agonists as potential anti-cancer agents.

cancer biology↗

bioRxiv2024

Effects of Pseudomonas aeruginosa pyocyanin and 1-hydroxyphenazine on intracellular calcium, mitochondrial function, and viability in human nasal epithelial cells

Pseudomonas aeruginosa is an opportunistic pathogen that produces phenazine metabolites pyocyanin and 1-hydroxyphenazine that have been suggested to have detrimental effects on mitochondrial function and reactive oxygen species (ROS) production. Prior studies have suggested activation of Ca2+ signaling by pyocyanin in an airway cell line, while others have shown apoptotic effects on cancer cells. Ca2+ is tightly linked to both normal mitochondrial function as well as mitochondrial ROS and apoptosis during mitochondrial Ca2+ overload. We found that pyocyanin but not 1-hydroxyphenazine induced both cytosolic and mitochondrial Ca2+ increases in RPMI 2650 and primary human nasal epithelial cells (HNEC). Similar results were seen in HNEC air-liquid interface (ALI) cells, but these cells did not display a cytosolic Ca2+ response after treatment with pyocyanin. In RPMI 2650, activation of PKC, ER Ca2+ release, and PLC inhibition, indicated potential GPCR activation from pyocyanin. Similarly, ROS production increased after treatment with pyocyanin, but not 1-hydroxyphenazine in all 3 cell types, but with stark differences in CF and non-CF ALIs. In HNEC ALI, pyocyanin reduced ciliary beat frequency (CBF) after 4 hours, while 1-hydroxpyhenazine did not. Despite this, both pyocyanin and 1-hydroxyphenazine decreased in cell viability in RPMI 2650 nasal carcinoma cells but not in HNEC at 24 hours. However, in both RPMI 2650 and HNEC, mitochondrial membrane potential acutely decreased after treatment with either pyocyanin or 1-hydroxyphenazine. Finally, 24-hour pyocyanin treatment decreased expression of ER stress genes in some cancer cells, but not in non-cancerous HNEC. Our data suggest that Ca2+ signaling is not required for acute effects of 1-hydroxyphenazine or pyocyanin on mitochondrial function. The greater sensitivity of RPMI 2650 cells to pyocyanin-induced and 1-hydroxyphenzine-induced cytotoxicity compared with primary cells suggests that these compounds might have some applicability in treating nasal squamous carcinomas or other types of head and neck squamous carcinomas. Although the exact mechanisms of pyocyanin induced apoptosis remains uncertain, the downregulation of the ER stress response may play a role.

physiology↗

bioRxiv2024

Pseudomonas aeruginosa metabolite 3-oxo-C12HSL induces apoptosis through T2R14 and the mitochondrial calcium uniporter

Head and neck squamous cell carcinomas (HNSCCs) arise in the mucosal lining of the upper aerodigestive tract. HNSCCs have high mortality rates and current treatments can be associated with severe morbidities. It is vital to discover effective, minimally invasive therapies that improve survival and quality of life. We previously discovered that bitter taste receptor 14 (T2R14), a GPCR, kills HNSCC cells when activated by bitter agonists. We are now investigating endogenous bitter ligands that exist in HNSCC tumor microenvironment (TME). The TME includes cells, signaling molecules, and microbes that can greatly influence treatment responses and overall prognosis in HNSCC. Pseudomonas aeruginosa is a gram-negative bacterium that colonizes/infects HNSCC patients. 3-oxo-C12SHL is a quorum-sensing N-acyl homoserine lactone (AHL) secreted by P. aeruginosa which is also a bitter compound. 3-oxo-C12HSL induces apoptosis but this has never been linked to T2R activation. We hypothesized that 3-oxo-C12HSL induces apoptosis in HNSCC via T2R14. We show that 3-oxo-C12HSL activates intracellular Ca2+ responses in HNSCC cells. This is inhibited with T2R14 antagonization. 3-oxo-C12HSL may activate additional Ca2+ channels as the Ca2+ dynamics are independent from store-operated calcium entry (SOCE). 3-oxo-C12HSL inhibits cell viability, depolarizes mitochondria, and produces ROS. This induces apoptosis in HNSCC cells. In a comparative screen of quorum-sensing AHLs, 3-oxo-C12HSL was the only AHL that elicited both a Ca2+ response and reduced cell viability. These results suggest that P. aeruginosa may play a significant role in modulating an anti-tumor TME through 3-oxo-C12HSL. Moreover, 3-oxo-C12HSL could be a novel, higher-affinity bitter therapeutic for HNSCC. Further research is warranted to elucidate the mechanisms of other endogenous T2R agonists present in the TME.

physiology↗

bioRxiv2024

Bitter Taste Receptor Agonists Induce Apoptosis in Papillary Thyroid Cancer

BackgroundPapillary thyroid carcinoma (PTC) is the most common thyroid malignancy, with a 20% recurrence rate. Bitter taste receptors (T2Rs) and their genes (TAS2Rs) may regulate survival in solid tumors. This study examined T2R expression and function in PTC cells. MethodsThree PTC cell lines (MDA-T32, MDA-T68, MDA-T85) were analyzed for expression using RT-qPCR and immunofluorescence. Live cell imaging measured calcium responses to six bitter agonists. Viability and apoptosis effects were assessed using crystal violet and caspase 3/7 activation assays. Genome analysis of survival was conducted. ResultsTAS2R14 was consistently highly expressed in all cell lines. Five bitter agonists produced significant calcium responses across all cell lines. All bitter agonists significantly decreased viability and induced apoptosis. Higher TAS2R14 expression correlated with better progression-free survival in patients (p<0.05). ConclusionsT2R activation by bitter agonists induces apoptosis and higher TAS2R expression is associated with survival, suggesting potential therapeutic relevance in thyroid cancer management.

cancer biology↗

bioRxiv2022

Lidocaine Induces Apoptosis in Head and Neck Squamous Cell Carcinoma Cells Through Activation of Bitter Taste Receptor T2R14

Head and neck squamous cell carcinomas (HNSCCs) have high mortality and significant treatment-related morbidity. It is vital to discover effective, minimally invasive therapies that improve survival and quality of life. Bitter taste receptors (T2Rs) are expressed in HNSCCs and their activation can induce apoptosis. Lidocaine is a local anesthetic used in various clinical applications which can also activate bitter taste receptor 14 (T2R14). Lidocaine may have some anti-tumor effects in other cancers, but the mechanism has been mysterious. Here, we found that lidocaine causes intracellular Ca2+ mobilization through activation of T2R14 in HSNCC cells. T2R14 activation with lidocaine depolarizes the mitochondrial membrane, inhibits cell proliferation, and induces apoptosis. Concomitant mitochondrial Ca2+ influx, ROS production causes T2R14-dependent accumulation of poly-ubiquinated proteins, suggesting inhibition of the proteasome as a novel component of T2R14-induced apoptosis. Lidocaine may have therapeutic potential in HNSCC as a topical gel or intratumor injection, warranting future clinical studies. HIGHLIGHTSO_LILidocaine activates bitter taste receptor 14 (T2R14) to increase intracellular Ca2+ and decrease cAMP in head and neck squamous cell carcinoma (HSNCC) cells C_LIO_LILidocaine decreases cell viability and cell proliferation, depolarizes the mitochondrial membrane, and causes production of reactive oxygen species (ROS) C_LIO_LIT2R14 activation with lidocaine induces apoptosis and inhibits the ubiquitin proteasome system (UPS) C_LIO_LILung squamous cell carcinoma (SCC) cells and HNSCC tumor spheroids undergo apoptosis or structural disbandment, respectively, with lidocaine C_LI

cancer biology↗

bioRxiv2022

Cilia stimulatory and antibacterial activities of bitter receptor agonist diphenhydramine: insights into potential complimentary strategies for CF nasal infections

BACKGROUNDBitter compounds increase ciliary beating and nitric oxide (NO) production in nasal epithelial cells through T2Rs in motile cilia. We examined expression of cilia T2Rs and both host and bacterial responses to T2R14 agonist diphenhydramine. METHODUsing cultured human nasal epithelial cells grown at air liquid interface, we measured expression of T2Rs via qPCR. We measured effects of diphenhydramine on ciliary beat frequency via high-speed imaging and nitric oxide production via fluorescent dye DAF-FM. We measured effects of diphenhydramine on growth of lab and clinical strains of Pseudomonas aeruginosa. We measured biofilm formation of P. aeruginosa using crystal violet staining and surface attachment of P. aeruginosa to cystic fibrosis bronchial epithelial (CBFE41o-) cells using CFU counting. RESULTST2R expression increased with mucocilliary differentiation and did not vary between CF and non-CF ALIs. Treatment with P. aeruginosa flagellin decreased expression of diphenhydramine-responsive T2R14 and 40, among other isoforms. Diphenhydramine increased both NO and CBF. Increases in CBF were disrupted after flagellin treatment. Diphenhydramine impaired growth, biofilm production, and surface attachment of P. aeruginosa. CONCLUSIONST2R expression is similar between normal and CF cells but decreases with flagellin treatment. Utilizing T2R agonists as therapeutics within the context of CF, P. aeruginosa infections may require co-treatment with anti-inflammatories to prevent the reduction of T2R expression with TLR activation. T2R agonist diphenhydramine increases NO production and CBF while also decreasing bacterial growth and biofilm production, and thus diphenhydramine or derivate compounds may have potential clinical usefulness in CF infections as a topical therapy. HIGHLIGHTSO_LIT2R14 agonist diphenhydramine increases nitric oxide production and cilia beating C_LIO_LIFlagellin decreases T2R14 expression in primary airway epithelial cells C_LIO_LIT2R14 agonist Diphenhydramine inhibits Pseudomonas growth and biofilm formation C_LI

physiology↗

bioRxiv2017

Immune-related genetic enrichment in frontotemporal dementia

BackgroundConverging evidence suggests that immune-mediated dysfunction plays an important role in the pathogenesis of frontotemporal dementia (FTD). Although genetic studies have shown that immune-associated loci are associated with increased FTD risk, a systematic investigation of genetic overlap between immune-mediated diseases and the spectrum of FTD-related disorders has not been performed.\n\nMethods and findingsUsing large genome-wide association studies (GWAS) (total n = 192,886 cases and controls) and recently developed tools to quantify genetic overlap/pleiotropy, we systematically identified single nucleotide polymorphisms (SNPs) jointly associated with FTD-related disorders namely FTD, corticobasal degeneration (CBD), progressive supranuclear palsy (PSP), and amyotrophic lateral sclerosis (ALS) - and one or more immune-mediated diseases including Crohns disease (CD), ulcerative colitis (UC), rheumatoid arthritis (RA), type 1 diabetes (T1D), celiac disease (CeD), and psoriasis (PSOR). We found up to 270-fold genetic enrichment between FTD and RA and comparable enrichment between FTD and UC, T1D, and CeD. In contrast, we found only modest genetic enrichment between any of the immune-mediated diseases and CBD, PSP or ALS. At a conjunction false discovery rate (FDR) < 0.05, we identified numerous FTD-immune pleiotropic SNPs within the human leukocyte antigen (HLA) region on chromosome 6. By leveraging the immune diseases, we also found novel FTD susceptibility loci within LRRK2 (Leucine Rich Repeat Kinase 2), TBKBP1 (TANK-binding kinase 1 Binding Protein 1), and PGBD5 (PiggyBac Transposable Element Derived 5). Functionally, we found that expression of FTD-immune pleiotropic genes (particularly within the HLA region) is altered in postmortem brain tissue from patients with frontotemporal dementia and is enriched in microglia compared to other central nervous system (CNS) cell types.\n\nConclusionsWe show considerable immune-mediated genetic enrichment specifically in FTD, particularly within the HLA region. Our genetic results suggest that for a subset of patients, immune dysfunction may contribute to risk for FTD. These findings have potential implications for clinical trials targeting immune dysfunction in patients with FTD.

genetics↗