Bradley S. Henson's research while affiliated with Western University of Health Sciences and other places

Background Type 2 diabetes mellitus (T2DM) and periodontitis are two biologically linked diseases that often coexist in complex interaction. While periodontitis may lead to insulin receptor desensitization, diabetes may increase the expression of inflammatory cytokines, such as Tumor Necrosis Factor-α (TNF-α) and Interleukin 6 (IL-6), in the gingival crevicular fluid and activate osteoclasts via Receptor activator of nuclear factor kappa-Β ligand (RANK-L) production, leading to bone resorption. However, the association between the two diseases processes, where one may exacerbate the progression of the other, is unclear. In addition, both diseases have similar mechanistic themes, such as chronic inflammation and oxidative stress. This review aimed to investigate the pathophysiological and molecular mechanisms underlying T2DM and periodontitis. Highlight Uncontrolled diabetes is often associated with severe periodontitis, measured by clinical attachment loss. Alteration in the oral microbiome composition, which may activate the host inflammatory response and lead to irreversible oxidative stress, is a common finding in both diseases. An understanding of the molecular crosstalk between the two disease processes is crucial for developing therapeutic targets that inhibit bone resorption and halt the progression of periodontitis in patients with diabetes. Conclusion The Oral microbiome composition in T2DM and periodontitis shifts toward dysbiosis, favoring bacterial pathogens, such as Fusobacteria and Porphyromonas species. Both conditions are marked by pro-inflammatory immune activity via the activation of Interleukin 17 (IL-17), Interleukin 1 (IL-1), TNF-α, and Nuclear Factor Kappa Beta (NF-κB). Common molecular crosstalk signaling appears to involve advanced glycation end products (AGEs)¹ and oxidative stress. Thus, future drug targets are multifactorial, ranging from modulatory of host inflammatory response to preventing the accumulation of AGEs and oxidative free radicals.

Background/aim: This study investigated a novel combined therapy of rosmarinic acid (RA)/blue light on head and neck squamous cell carcinoma (HNSCC) cell proliferation in vitro. Materials and methods: HNSCC cells were exposed to BL (500 mW/cm2) for 90 s, and incubated with 80 μg/ml RA for 1 hour. Cell viability was determined after 24 h using WST-1 assay. Western blot was used to detect treatment-induced changes in epidermal growth factor receptor (EGFR) activation. Hydrogen peroxide (H2O2) and nitric oxide levels were quantified using CM-H2DCFH-DA assays. Apoptosis was assessed using Annexin V/PI staining and flow cytometry. Results: RA/blue light treatment resulted in a significant reduction in cell viability, EGFR activation and H2O2 levels in all HNSCC cell lines. However, no significant changes in NO production or apoptosis induction were found. Conclusion: RA/blue light effectively decreased HNSCC cell proliferation through reduction in EGFR activation and H2O2 production, and not via induction of apoptosis.

Our labs have observed decreased proliferation of several cultured head and neck squamous cell carcinoma (HNSCC) cell lines when treated with rosmarinic acid or blue light. The purpose of this study was to test the hypothesis that the combination therapy would be more effective than either treatment alone, and to further characterize the cellular mechanisms responsible for these effects. UM-SCC-6 oral squamous carcinoma cells were cultured in 24- or 96-well plates, and cells were exposed to blue light delivered from a Quartz-tungsten-halogen dental curing lamp (500 mW/cm²) for 90 or 120 sec, followed 1 h later by the addition of 80 μg/ml rosmarinic acid. Cell number was assessed at 24h using a WST-1 cell proliferation assay and cell migration was measured with an Oris Universal Migration Assay Kit. Reactive oxygen species (ROS) was quantified with each single treatment and combination using the CM-H2DCFH-DA assay. Western blot analysis was used to monitor changes in levels of cell signaling proteins known to be affected by each single treatment including phosphoAKT (pAKT) and AKT, NF-E2-related factor 2 (NRF2), heme oxygenase-1 (HO-1), and GAPDH (as a loading control). As hypothesized, the combination of rosmarinic acid and blue light was more effective in reducing cell proliferation and migration than either single treatment alone. Both treatments also produced an early increase in ROS. Treatment with blue light significantly increased pAKT while rosmarinic acid decreased AKT activation. However, both treatments increased levels of Nrf2 and its downstream target, HO-1. In order for the transcription factor NRF2 to translocate to the nucleus it needs to be stabilized and activated. AKT is an upstream kinase that is a known activator of NRF2 in response to an increase in ROS. Nuclear NRF2 binds to the antioxidant response element (ARE) within the promoters for phase II detoxifying/antioxidant genes, including that of HO-1. This signaling cascade has been shown to lead to anti-proliferative functions. Our results suggest that blue light induces this pathway by transiently increasing ROS that then significantly activates AKT. Subsequent NRF2 activation leads to increased levels of HO-1. Rosmarinic acid appears to use a different mechanism to upregulate NRF2 due to its downregulation of AKT. Importantly, both treatments activate NRF2, resulting in induction of antioxidant protein expression and ultimately decreasing ROS needed to promote tumor cell growth. This combination therapy may prove to be a useful, non-invasive treatment for HNSCC. Citation Format: Christi N. Waer, Zohra Tumur, Dee Dee Hui, Bonnie Le, Carlos Guerra, Jill Lewis, Bradley Henson. A novel rosmarinic acid/blue light combination treatment inhibits cell proliferation and migration in head and neck squamous cell carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1330.

Objective Assess accuracy of facial morphometric analysis using 3-D CBCT volume rendered images for facial hard/soft tissue treatment planning using multi-clinician analyses across various training backgrounds. Methods The 3-D CBCT and 2-D photographic image records of 25 subjects were evaluated in this study. Standard facial landmarks were identified independently by dental specialists on frontal and lateral images of the face. Facial proportions were calculated on both images and compared. Results 3-D CBCT derived images were more accurate than 2-D photometric analysis when measuring upper and lower lip lengths in frontal view. 3-D CBCT derived images produced proportions comparable to 2-D photometric analysis in lateral view. Conclusions Clinicians of different training backgrounds show higher consistency and accuracy in measurement of the lower facial third from the frontal aspect with 3-D CBCT derived images than with 2-D photographs. No statistical differences were observed from the lateral aspect. 3-D CBCT images eliminated errors caused by obfuscating features in the lower facial third. Keywords Three-dimensional imaging; Photogrammetry; Facial analysis; Facial morphometric analysis; CBCT volumetric rendering

Epidermal growth factor receptor (EGFR) is overexpressed in head and neck squamous cell carcinoma (HNSCC) where it has been shown to promote tumor cell invasion upon phosphorylation. One mechanism by which EGFR promotes tumor progression is by activating signal cascades that lead to loss of E-cadherin, a transmembrane glycoprotein of the cell-cell adherence junctions; however mediators of these signaling cascades are not fully understood. One such mediator, RhoC, is activated upon a number of external stimuli, such as epidermal growth factor (EGF), but its role as a mediator of EGF-stimulated migration and invasion has not been elucidated in HNSCC. In the present study, we investigate the role of RhoC as a mediator of EGF-stimulated migration and invasion in HNSCC. We show that upon EGF stimulation, EGFR and RhoC were strongly activated in HNSCC. This resulted in activation of the phosphatidylinositol 3-Kinase Akt pathway (PI3K-Akt), phosphorylation of GSK-3β at the Ser9 residue, and subsequent down regulation of E-cadherin cell surface expression resulting in increased tumor cell invasion. Knockdown of RhoC restored E-cadherin expression and inhibited EGF-stimulated migration and invasion. This is the first report in HNSCC demonstrating the role RhoC plays in mediating EGF-stimulated migration and invasion by down-regulating the PI3K-Akt pathway and E-cadherin expression. RhoC may serve as a treatment target for HNSCC.

Ethyl carbamate (EC); urethane is a chemical carcinogen (IARC group 2A). It has been commonly found in the fermented food and beverages. EC induced cancerous lesion in different sites due to the formation of active metabolite; vinyl carbamate (VC). The current study aims to investigate the potential risk of cancerous lesions in small and repeated exposure of ethyl carbamate in BALB/C mice. Three groups of BALBL/C mice were treated for 120 days included untreated control; group treated with a single dose of urethane (1.5 g/kg B.w/i.p) at a day one; group treated with repeated doses, the first at a day one and a second at day sixty (1.5g/ kg B.w/i.p). Ethyl carbamate (EC) exposure showed sever changes of serum biochemical markers, apoptosis markers, inflammatory cytokines as well as lipid peroxide formation in lung homogenate, these changes were pronounced in repeated exposure to ethyl carbamate. In addition, histological examinations revealed that epithelial changes in pulmonary tissues were advanced in animals treated with repeated doses of ethyl carbamate. These findings indicate that repeated exposure to ethyl carbamate of fermented foods and beverages is an additional risk for lung cancer due to permanent mitochondrial dysfunction and increase the cellular mitotic activity.

Epidermal growth factor receptor (EGFR) is overexpressed in head and neck squamous cell carcinoma (HNSCC) where it has been shown to promote proliferation and tumor cell invasion upon phosphorylation, however downstream mediators of these signaling cascades are not fully understood. One such mediator, RhoC, is phosphorylated upon a number of external stimuli, such as epidermal growth factor (EFG), but its role as a mediator of EGF-stimulated migration and invasion has not been elucidated in HNSCC. Characterization of signaling cascades that are responsible for tumor progression in HNSCC will help to identify aggressive tumors earlier in the disease process and will aid in the development of new treatment approaches. Objective: In the present study, we investigate the role of RhoC as a mediator of EGF-stimulated migration and invasion in HNSCC. Methods: Dose response curves and time studies were performed to ascertain the optimal EGF treatment conditions for EGFR and RhoC activation. In vitro migration and invasion assays and confocal microscopy were performed following stimulation with 100 ng/ml of EGF, and the specific role of RhoC in invasion-associated signaling cascades was investigated by knockdown with siRhoC. Results: Upon EGF stimulation, EGFR and RhoC were strongly phosphorylated. This resulted in activation of the phosphatidylinositol 3-Kinase AKT pathway, phosphorylation of GSK-3β at the Ser9 residue, and subsequent down regulation of E-cadherin cell surface expression resulting in tumor cell invasion. Knockdown of RhoC restored E-cadherin expression and inhibited EGF-stimulated migration and invasion. Conclusion: RhoC mediates EGF-stimulated migration and invasion by down-regulation of the phosphatidylinositol 3-Kinase AKT pathway and E-cadherin expression. This signaling cascade may serve as a treatment target for HNSCC.

Characterization of signaling cascades that are responsible for tumor development and progression in head and neck squamous cell carcinoma (HNSCC) will help to identify aggressive tumors earlier in the disease process and will aid in the development of new treatment approaches. Phosphorylation of glycogen synthase kinase-3β (GSK-3β) at the Ser9 residue has been shown to promote tumorigenesis in a variety of cancers of epithelial origin, including HNSCC. Studies have shown that GSK-3β can be phosphorylated upon a number of external stimuli, such as epidermal growth factor stimulation, however mediators of this signaling cascade remain elusive. Objective: In the present study, we investigate the role of RhoC as a mediator of EGF-stimulated GSK-3β phosphorylation in HNSCC. Methods: EGF receptor (EGFR), RhoA, and RhoC expression profiles were investigated in a panel of HNSCC cell lines by immunoblot analysis. Dose response curves and time studies were performed to ascertain the optimal EGF treatment conditions for EGFR and RhoC activation. RhoC activation was determined by Rhotekin-binding pull-down assay. The specific role of RhoC in these signaling cascades was investigated by knockdown with siRhoC. Results: EGFR, RhoA and RhoC were variably expressed in a variety of HNSCC cell lines. Cell lines exhibiting strong EGFR and RhoC expression were chosen for EGF stimulation studies. Upon EGF stimulation, EGFR and RhoC were strongly activated, which led to phosphorylation of GSK-3β at the Ser9 residue. Knockdown of RhoC inhibited EGF-stimulated GSK-3β phosphorylation. Conclusion: RhoC mediates EGF-stimulated GSK-3β phosphorylation in malignant keratinocytes and may serve as a treatment target for HNSCC.