Simple quantitative PCR analysis for allelic Pten loss in tumor progression.

We describe a simple method to accurately detect and quantify both Pten mutation and allele-specific loss using allele-specific PCR analysis. Our approach used a heterozygous genomic DNA with one wild-type and one mutant Pten allele as a reference at a single concentration to calculate the percent ratio of the wild-type Pten gene for the detection of allele-specific gene loss. With a standard curve, ratios from PCR data were used to quantitate the wild-type Pten allele copy number loss in tumor specimens. We demonstrate the utility of our approach to calculate allele-specific Pten loss during tumor progression and show that our approach generates quantitative data that are comparable to those obtained from digital droplet PCR. As a method to detect both mutation and allele-specific gene loss, our approach is less subject to the variability of sample amount that are often very limited in clinical analysis. Since conventional PCR is easy to be carried out, our method simplifies the workflow in any laboratory and would provide significant advantages for simplicity to quantify allele-specific gene loss.

Probe-free allele-specific copy number detection and analysis of tumors.

Cancer development and progression frequently involve nucleotide mutations as well as amplifications and deletions of genomic segments. Quantification of allele-specific copy number is an important step in characterizing tumor genomes for precision medicine. Despite advances in approaches to high-throughput genomic DNA analysis, inexpensive and simple methods for analyzing complex nucleotide and copy number variants are still needed. Real-time polymerase chain reaction (PCR) methods for discovering and genotyping single nucleotide polymorphisms are becoming increasingly important in genetic analysis. In this study, we describe a simple, single-tube, probe-free method that combines SYBR Green I-based quantitative real-time PCR and quantitative melting curve analysis both to detect specific nucleotide variants and to quantify allele-specific copy number variants of tumors. The approach is based on the quantification of the targets of interest and the relative abundance of two alleles in a single tube. The specificity, sensitivity, and utility of the assay were demonstrated in detecting allele-specific copy number changes critical for carcinogenesis and therapeutic intervention. Our approach would be useful for allele-specific copy number analysis or precise genotyping.

Pediatric Oral Health Service Access in Racial/Ethnic Minority Neighborhoods: A Geospatial Analysis in Washington, D.C., USA.

Oral health plays a crucial role in overall well-being. One of the goals set by the US Department of Health and Human Service, Healthy People 2030 is to reducing dental caries in children and adolescents. The study aims to investigate the accessibility of pediatric dental care in neighborhoods with mixed-race and predominantly African American populations in the Washington District of Columbia (DC) area. Our objective is to uncover and highlight the disparities that exist in pediatric dental care within these communities. We have specifically examined the geographic and socio-demographic aspects of pediatric dental care facilities, utilizing geospatial tools such as modeling and mapping, as well as data from the clinical database at Howard University College of Dentistry. The detailed analysis of dental care access revealed significant disparities among various Wards in the region. Specifically, Wards 5, 7, and 8 stood out as having both the highest concentrations of African American residents and the lowest availability of pediatric dentistry providers when compared to the more affluent Wards 1, 2, and 3. Howard University College of Dentistry's pediatric dentistry department played a crucial role in providing dental care services to the community. Over the course of the year 2022, they recorded a total of 3,855 visits from residents of the DC area. Notably, a substantial portion of these visits, specifically 1,566 visits, were from individuals residing in Wards 5, 7 and 8. This data underscores the significant demand for pediatric dental services in these underserved communities and highlights the importance of addressing the disparities in access to care.

A Computational Approach: The Functional Effects of Thyroid Peroxidase Variants in Thyroid Cancer and Genetic Disorders.

PURPOSE: Thyroid peroxidase (TPO) is essential for the synthesis of thyroid hormones. However, specific mutations render TPO antigenic and prone to autoimmune attacks leading to thyroid cancer, TPO deficiency, and congenital hypothyroidism (CH). Despite technological advancement, most experimental procedures cannot quickly identify the genetic causes of CH nor detect thyroid cancer in the early stages. METHODS: We performed saturated computational mutagenesis to calculate the folding energy changes (∆∆G) caused by missense mutations and analyzed the mutations involved in post-translational modifications (PTMs). RESULTS: Our results showed that the functional important missense mutations occurred in the heme peroxidase domain. Through computational saturation mutagenesis, we identified the TPO mutations in G393 and G348 affecting protein stability and PTMs. Our folding energy calculations revealed that seven of nine somatic thyroid cancer mutations destabilized TPO. CONCLUSION: These findings highlight the impact of these specific mutations on TPO stability, linking them to thyroid cancer and other genetic thyroid-related disorders. Our results show that computational mutagenesis of proteins provides a quick insight into rare mutations causing Mendelian disorders and cancers in humans.

Recombinant immunotoxin induces tumor intrinsic STING signaling against head and neck squamous cell carcinoma.

The innate immune stimulator of interferon genes (STING) pathway is known to activate type I interferons (IFN-I) and participate in generating antitumor immunity. We previously produced hDT806, a recombinant diphtheria immunotoxin, and demonstrated its efficacy against head and neck squamous cell carcinoma (HNSCC). However, it's unknown whether the tumor-intrinsic STING plays a role in the anti-HNSCC effects of hDT806. In this study, we investigated the innate immune modulation of hDT806 on HNSCC. hDT806 significantly upregulated the level of STING and the ratio of p-TBK1/TBK1 in the HNSCC cells. Moreover, intratumoral hDT806 treatment increased the expression of STING-IFN-I signaling proteins including IFNA1, IFNB, CXCL10 and MX1, a marker of IFN-I receptor activity, in the HNSCC xenografts. Overexpression of STING mimicked the hDT806-induced upregulation of the STING-IFN-I signaling and induced apoptosis in the HNSCC cells. In the mouse xenograft models of HNSCC with STING overexpression, we observed a significant suppression of tumor growth and reduced tumor weight with increased apoptosis compared to their control xenograft counterparts without STING overexpression. Collectively, our data revealed that hDT806 may act as a stimulator of tumor-intrinsic STING-IFN-I signaling to inhibit tumor growth in HNSCC.

Sickle cell disease: Contributing factors and radiological assessments.

Sickle Cell Disease (SCD) is genetically described as an autosomal blood disorder resulting from the presence of a mutated form of hemoglobin. Morbidity, frequency of crisis, degree of anemia, and organ systems involved vary considerably per patient. Dental health professionals and other specialists commonly request comprehensive medical consultations prior to performing complex periodontal, endodontic, and surgical procedures. In order to have successful dental outcomes and minimize posttreatment dental complications, relevant disease indicators are noted. This review is to raise awareness of the impact of oral diseases in patients with sickle cell disease and to emphasize the importance of full medical disclosure, radiographic interpretation, and a well-documented medical history, and a well-written consultation which can guide treatment planning and greatly improve the course of dental treatment.

Loperamide, an FDA-approved antidiarrhea drug, effectively reverses the resistance of multidrug resistant MCF-7/MDR1 human breast cancer cells to doxorubicin-induced cytotoxicity.

Loperamide is an FDA-approved antidiarrhea drug which acts on the µ-opioid receptors in the mesenteric plexus of large intestine and exhibits limited side effects. We hypothesized that loperamide might reverse the multidrug resistance (MDR) of human cancer cells to chemotherapeutic agents. MCF-7/MDR1 cells express high level of MDR1 and are resistant to doxorubicin. We found that loperamide significantly enhanced the cytotoxicity of doxorubicin to MCF-7/MDR1 cells in a dose-dependent manner. In conclusion, loperamide reversed the resistance of MCF-7/MDR1 cells to doxorubicin, suggesting that chemotherapy in combination with loperamide may benefit patients with MDR tumors once applied in clinic.

Changes in cell ultrastructure and inhibition of JAK1/STAT3 signaling pathway in CBRH-7919 cells with astaxanthin.

Astaxanthin (AST), a xanthophylls carotenoid, possesses significant anticancer effects. However, to date, the molecular mechanism of anticancer remains unclear. In the present research, we studied the anticancer mechanism of AST, including the changes in cell ultrastructure, such as the mitochondrion, rough endoplasmic reticulum (RER), Golgi complex, and cytoskeleton, the inhibition of Janus kinase 1(JAK1)/transduction and the activators of the transcription-3 (STAT3) signaling pathway using rat hepatocellular carcinoma CBRH-7919 cells. Cell apoptosis was evaluated and the expressions of JAK1, STAT3, non-metastasis23-1 (nm23-1), and apoptotic gene like B-cell lymphoma/leukemia-2 (bcl-2), B-cell lymphoma-extra large (bcl-xl), proto-oncogene proteins c myc (c-myc) and bcl-2- associated X (bax) were also examined. The results showed that AST could induce cancer cell apoptosis. Under transmission electron microscope, the ultrastructure of treated cells were not clearly distinguishable, the membranes of the mitochondrion, RER, Golgi complex were broken or loosened, and the endoplasmic reticulum (ER) was degranulated. Cytoskeleton depolymerization of the microtubule system led to the collapse of extended vimentin intermediate filament bundles into short agglomerations with disordered distributions. AST inhibited the expression of STAT3, its upstream activator JAK1, and the STAT3 target antiapoptotic genes bcl-2, bcl-xl, and c-myc. Conversely, AST enhanced the expressions of nm23-1 and bax. Overall, our findings demonstrate that AST could induce the apoptosis of CBRH-7919 cells, which are involved in cell ultrastructure and the JAK1/STAT3 signaling pathway.

Converged DNA Damage Response Renders Human Hepatocellular Carcinoma Sensitive to CDK7 Inhibition.

Hepatocellular carcinoma (HCC) is a lethal malignancy with high mortality. The inhibition of cyclin-dependent kinase 7 (CDK7) activity has shown therapeutic efficacy in HCC. However, the underlying molecular mechanisms remain elusive. Here, we show that three HCC lines, HepG2, Hep3B, and SK-Hep-1, were highly susceptible to the CDK7 inhibitor THZ1. In mouse models, THZ1 effectively reduced HepG2 tumor growth and tumor weight. THZ1 arrested cell cycle and triggered MYC-related apoptosis in HepG2. To evaluate how MYC protein levels affected THZ1-induced apoptotic cell death, we overexpressed MYC in HepG2 and found that exogenously overexpressed MYC promoted cell cycle progression and increased cells in the S phase. THZ1 drastically engendered the apoptosis of MYC-overexpressing HepG2 cells in the S and G2/M phases. Importantly, transcription-inhibition-induced apoptosis is associated with DNA damage, and exogenous MYC expression further enhanced the THZ1-induced DNA damage response in MYC-overexpressing HepG2 cells. Consistently, in the HepG2 xenografts, THZ1 treatment was associated with DNA-damage-induced cell death. Together, our data indicate that the converged effect of MYC-promoted cell cycle progression and CDK7 inhibition by THZ1 confers the hypersensitivity of HCC to DNA-damage-induced cell death. Our findings may suggest a new therapeutic strategy of THZ1 against HCC.

Oral Health Service Access in Racial/Ethnic Minority Neighborhoods: A Geospatial Analysis in Washington, DC, USA.

Previous studies on individual-level variables have improved our knowledge base of oral health service use. However, environmental or contextual variables are also important in understanding oral health disparities in racial and ethnic neighborhoods. Based on Bronfenbrenner's ecological framework, this study examines the geographic availability of oral health providers in Washing-ton DC, U.S.A. Census tract-level data were drawn from the American Community Survey, joined with tract-level shapefiles, and overlaid with the geographic location of dental services throughout the city. Visual maps, descriptive statistics, and spatial lag regression models showed that census tracts with higher concentrations of African Americans were significantly farther from their nearest oral health providers (r = 0.19, p < 0.001), after controlling for neighborhood poverty rate, median age, and gender. Such findings confirm that in urban areas with highly di-verse populations such as Washington DC, racial disparities in oral health care access are signifi-cant. The study highlights that identifying neighborhoods with limited oral health care providers should be a priority in diminishing racial disparities in oral health service access. Improving access to racial/ethnic minority communities, especially African American neighborhoods, will require changes in health policies and programs, workforce development, resource allocation, community outreach, and educational programs.

Antitumor Efficacy of EGFR-Targeted Recombinant Immunotoxin in Human Head and Neck Squamous Cell Carcinoma.

Over 90% of head and neck squamous cell carcinoma (HNSCC) overexpresses the epidermal growth factor receptor (EGFR). However, the EGFR-targeted monotherapy response rate only achieves 10-30% in HNSCC. Recombinant immunotoxin (RIT) often consists of an antibody targeting a tumor antigen and a toxin (e.g., diphtheria toxin [DT]) that kills cancer cells. We produced a humanized RIT, designated as hDT806, targeting overexpressed EGFR and investigated its effects in HNSCC. Distinct from the EGFR-targeted tyrosine kinase inhibitor erlotinib or antibody cetuximab, hDT806 effectively suppressed cell proliferation in the four HNSCC lines tested (JHU-011, -013, -022, and -029). In JHU-029 mouse xenograft models, hDT806 substantially reduced tumor growth. hDT806 decreased EGFR protein levels and disrupted the EGFR signaling downstream effectors, including MAPK/ERK1/2 and AKT, while increased proapoptotic proteins, such as p53, caspase-9, caspase-3, and the cleaved PAPR. The hDT806-induced apoptosis of HNSCC cells was corroborated by flow cytometric analysis. Furthermore, hDT806 resulted in a drastic inhibition in RNA polymerase II carboxy-terminal domain phosphorylation critical for transcription and a significant increase in the γH2A.X level, a DNA damage marker. Thus, the direct disruption of EGFR signaling, transcription inhibition, DNA damage, as well as apoptosis induced by hDT806 may contribute to its antitumor efficacy in HNSCC.

Using GIS to Analyze Inequality in Access to Dental Care in the District of Columbia.

BACKGROUND: Access to dental care in mixed-race and predominantly African American wards in the District of Columbia (DC) was investigated in relation to community development. METHODS: This study used high-resolution geographic information system (GIS) tools to map all general dentistry and periodontal practice locations in DC wards. The spatial analysis contextualized each ward's land use and demographic data obtained from DC government reports. FINDINGS: The analysis revealed inter-ward inequity in dental care access, which was measured by proximity to and number of dental clinics in each DC ward. Residents in affluent wards had access to many dental practices and superior amenities. Residents in wards poorly served by public transportation and with few resources had few, if any, dental clinics. CONCLUSIONS: Dental practices are inequitably distributed across DC wards. DC policy should prioritize community development-specifically, resource allocation and community outreach-to promote health equity and improve access to and quality of dental care among residents of color.

Discourse about human papillomavirus (HPV)-associated oropharyngeal cancer (OPC) on Twitter: Lessons for public health education about OPC and dental care.

Objectives: Public understanding of human papillomavirus (HPV)-associated oropharyngeal cancer (OPC) is minimally understood. Therefore uncovering communication gaps between the public and healthcare professionals regarding this disease is vital. Social media provide an unobtrusive way to understand public perception about health issues. Study design: Computer-assisted quantitative content analysis. Methods: Tweets about HPV-associated OPC (N = 3,112) were collected for 40 weeks using the standard real-time streaming Application Programming Interface (API). The collection of tweets was not limited to one specific geographic location but worldwide. All tweets were entered into nVivo 12.0 to conduct computer-assisted quantitative content analysis. We used an inductive method to develop a coding scheme and examined the frequency of specific keywords, terms, and phrases in texts. Results: Findings show that (a) the majority of discourse on Twitter focused on risk factors and prevention with little information on diagnosis, treatment, and prognoses; (b) many tweets promoted HPV vaccination among boys and emphasized the risk of HPV-associated OPC among males; (c) the role of dental care professionals in the prevention and detection of OPC minimally appeared; (d) the public referred to OPC as oral cancer, head and neck cancer, or throat cancer; and (e) health organizations in New Zealand, Australia, and the United Kingdom led the discussion on HPV-associated OPC on Twitter. Conclusions: The current study unravels the utility of social media data and data mining techniques in understanding public perception and understanding of HPC-associated OPC. The outcomes from the current study provide baseline knowledge of where communication gaps exist in terms of HPV-associated OPC, without which the planning of potential interventions and much-needed social media-based campaigns cannot be effectively undertaken.

Improvement of prostate cancer detection by integrating the PSA test with miRNA expression profiling.

Prostate-specific antigen (PSA) test is limited in prostate cancer diagnosis due to its inaccuracy. A new approach which integrates the PSA test with miRNA profiling was investigated to improve prostate cancer diagnosis. Six prostate cancer-related miRNAs (miR-16, -21, -34c, -101, -125b, -141) were tested in five cultured prostate cell lines and 20 human prostate specimens. We found that the miRNA expression profiles were significantly different between nontumorigenic and tumorigenic cell lines and specimens. Positive predictive value analysis of prostate cancer was increased from 40% to 87.5% by integrating patient PSA blood levels with miR-21 and miR-141 profiles.

Astaxanthin induces mitochondria-mediated apoptosis in rat hepatocellular carcinoma CBRH-7919 cells.

We designed to study the role of mitochondria in astaxanthin-induced apoptosis in hepatocellular carcinoma cells. Effect of astaxanthin on cell proliferation was studied by using methyl thiazolyl tetrazolium (MTT) in three tumor cell lines (CBRH-7919, SHZ-88 and Lewis) and normal human hepatocyte HL-7702 cell. Cell apoptosis rate, changes of mitochondrial morphology, mitochondrial transmembrane potential and electron transport chain were evaluated respectively. Expressions of B cell lymphoma/leukemia-2 (Bcl-2) and Bcl-2 associated X protein (Bax) were detected by Western blot. Results as following, astaxanthin had little effect on HL-7702 cell, however its inhibition was most pronounced in CBRH-7919 cell line with an IC50 of 39 µM. This dose of astaxanthin and CBRH-7919 cell line were chosen for further studies. Astaxanthin could induce cell apoptosis and mitochondrial membrane damage. The mitochondrial transmembrane potential and function of electron transport chain were decreased. The expression of Bcl-2 protein was down-regulated but that of Bax protein was up-regulated. In conclusion, astaxanthin showed anticancer effect by inducing cell apoptosis through the regulation of mitochondrial-dependent manner.

Mitogen-activated protein kinase inhibition-induced modulation of epidermal growth factor receptor signaling in human head and neck squamous cell carcinoma.

BACKGROUND: Epidermal growth factor receptor (EGFR) overexpression is one of the most notable characteristics in head and neck squamous cell carcinoma (HNSCC). The MAPK kinase (MEK) inhibitor trametinib has shown efficacy to treat HNSCC; however, the molecular mechanism remains unclear. METHODS: HNSCC lines, mouse models, Western blot, and flow cytometry were employed to analyze the anticancer effects of trametinib. RESULTS: The JHU-011, JHU-022, and JHU-029 HNSCC cells with different genetic alterations were highly susceptible to trametinib. Trametinib effectively reduced EGFR expression, which was accompanied by the reduction of pro-survival protein MYC, and the increased expression of a MYC-targeted cyclin-dependent kinase inhibitor p27kip1 and pro-apoptotic protein BIM. Trametinib resulted in G1 arrest of the cells, markedly reduced cell numbers in S phase, and significantly increased apoptosis. In mouse models, trametinib strongly inhibited tumors growth. CONCLUSIONS: The MAPK-ERK signaling inhibition by trametinib may target EGFR and the downstream proteins against HNSCC.

Evaluation of Vertebrate-Specific Replication-Defective Zika Virus, a Novel Single-Cycle Arbovirus Vaccine, in a Mouse Model.

The flavivirus Zika (ZIKV) has emerged as a global threat, making the development of a ZIKV vaccine a priority. While live-attenuated vaccines are known to induce long-term immunity but reduced safety, inactivated vaccines exhibit a weaker immune response as a trade-off for increased safety margins. To overcome the trade-off between immunogenicity and safety, the concept of a third-generation flavivirus vaccine based on single-cycle flaviviruses has been developed. These third-generation flavivirus vaccines have demonstrated extreme potency with a high level of safety in animal models. However, the production of these single-cycle, encapsidation-defective flaviviruses requires a complicated virion packaging system. Here, we investigated a new single-cycle flavivirus vaccine, a vertebrate-specific replication-defective ZIKV (VSRD-ZIKV), in a mouse model. VSRD-ZIKV replicates to high titers in insect cells but can only initiate a single-round infection in vertebrate cells. During a single round of infection, VSRD-ZIKV can express all the authentic viral antigens in vertebrate hosts. VSRD-ZIKV immunization elicited a robust cellular and humoral immune response that protected against a lethal ZIKV challenge in AG129 mice. Additionally, VSRD-ZIKV-immunized pregnant mice were protected against vertically transferring a lethal ZIKV infection to their offspring. Immunized male mice were protected and prevented viral accumulation in the testes after being challenged with lethal ZIKV. Overall, our results indicate that VSRD-ZIKV induces a potent protective immunity against ZIKV in a mouse model and represents a promising approach to develop novel single-cycle arbovirus vaccines.

Generation and preliminary characterization of vertebrate-specific replication-defective Zika virus.

Zika virus (ZIKV) is a mosquito-borne flavivirus that replicates in both vertebrate and insect cells, whereas insect-specific flaviviruses (ISF) replicate only in insect cells. We sought to convert ZIKV, from a dual-tropic flavivirus, into an insect-specific virus for the eventual development of a safe ZIKV vaccine. Reverse genetics was used to introduce specific mutations into the furin cleavage motif within the ZIKV pre-membrane protein (prM). Mutant clones were selected, which replicated well in C6/36 insect cells but exhibited reduced replication in non-human primate (Vero) cells. Further characterization of the furin cleavage site mutants indicated they replicated poorly in both human (HeLa, U251), and baby hamster kidney (BHK-21) cells. One clone with the induced mutation in the prM protein and at positions 291and 452 within the NS3 protein was totally and stably replication-defective in vertebrate cells (VSRD-ZIKV). Preliminary studies in ZIKV sensitive, immunodeficient mice demonstrated that VSRD-ZIKV-infected mice survived and were virus-negative. Our study indicates that a reverse genetic approach targeting the furin cleavage site in prM can be used to select an insect-specific ZIKV with the potential utility as a vaccine strain.

Structural Optimization of 2,3-Dihydro-1H-cyclopenta[b]quinolines Targeting the Noncatalytic RVxF Site of Protein Phosphatase 1 for HIV-1 Inhibition.

Combination antiretroviral therapy (cART) suppresses human immunodeficiency virus-1 (HIV-1) replication but is unable to permanently eradicate HIV-1. Importantly, cART does not target HIV-1 transcription, which is reactivated in latently infected reservoirs, leading to HIV-1 pathogenesis including non-infectious lung, cardiovascular, kidney, and neurodegenerative diseases. To address the limitations of cART and to prevent HIV-1-related pathogenesis, we developed small molecules to target the noncatalytic RVxF-accommodating site of protein phosphatase-1 (PP1) to prevent HIV-1 transcription activation. The PP1 RVxF-accommodating site is critical for the recruitment of regulatory and substrate proteins to PP1. Here, we confirm that our previously developed 1E7-03 compound binds to the PP1 RVxF-accommodating site. Iterative chemical alterations to 1E7-03 furnished a new analogue, HU-1a, with enhanced HIV-1 inhibitory activity and improved metabolic stability compared to 1E7-03. In a Split NanoBit competition assay, HU-1a primarily bound to the PP1 RVxF-accommodating site. In conclusion, our study identified HU-1a as a promising HIV-1 transcription inhibitor and showed that the PP1 RVxF-accommodating site is a potential drug target for the development of novel HIV-1 transcription inhibitors.

Salvianolic acid B inhibits growth of head and neck squamous cell carcinoma in vitro and in vivo via cyclooxygenase-2 and apoptotic pathways.

Overexpression of cyclooxygenase-2 (COX-2) in oral mucosa has been associated with increased risk of head and neck squamous cell carcinoma (HNSCC). Celecoxib is a nonsteroidal anti-inflammatory drug, which inhibits COX-2 but not COX-1. This selective COX-2 inhibitor holds promise as a cancer preventive agent. Concerns about cardiotoxicity of celecoxib, limits its use in long-term chemoprevention and therapy. Salvianolic acid B (Sal-B) is a leading bioactive component of Salvia miltiorrhiza Bge, which is used for treating neoplastic and chronic inflammatory diseases in China. The purpose of this study was to investigate the mechanisms by which Sal-B inhibits HNSCC growth. Sal-B was isolated from S. miltiorrhiza Bge by solvent extraction followed by 2 chromatographic steps. Pharmacological activity of Sal-B was assessed in HNSCC and other cell lines by estimating COX-2 expression, cell viability and caspase-dependent apoptosis. Sal-B inhibited growth of HNSCC JHU-022 and JHU-013 cells with IC(50) of 18 and 50 microM, respectively. Nude mice with HNSCC solid tumor xenografts were treated with Sal-B (80 mg/kg/day) or celecoxib (5 mg/kg/day) for 25 days to investigate in vivo effects of the COX-2 inhibitors. Tumor volumes in Sal-B treated group were significantly lower than those in celecoxib treated or untreated control groups (p < 0.05). Sal-B inhibited COX-2 expression in cultured HNSCC cells and in HNSCC cells isolated from tumor xenografts. Sal-B also caused dose-dependent inhibition of prostaglandin E(2) synthesis, either with or without lipopolysaccharide stimulation. Taken together, Sal-B shows promise as a COX-2 targeted anticancer agent for HNSCC prevention and treatment.