FaDu Cancer Cells Research Articles

Organoselenium-based Azomethines as Apoptosis Inducers in Colorectal Carcinoma via P53, BAX, Caspase-3, Caspase-6, and Caspase-9 Modulations.

Organoselenium (OSe) agents and Schiff bases have demonstrated immense potential in the pharmaceutical field due to their broad spectrum of medicinal activities. We herein report the antitumor activities of bis diselenide-based Schiff bases (3a-3c) derived from bis(4-aminophenyl)diselenide 2 and organoselenide-based Schiff bases (5a-c) derived from p-(methylselanyl)phenyl amine (4). The antitumor activity was estimated against fifteen cancer cell lines. Also, the growth inhibition percentage (GI%) of the Schiff bases tethered OSe compounds was evaluated against two normal cell lines, namely, human skin fibroblasts (HSF) and olfactory ensheathing cell line (OEC), to estimate the potential safety and selectivity. Furthermore, the cytotoxic inhibitory concentration 50 (IC50) was assessed against the cancer cell lines with the most outstanding GI% using the SRB assay. Compounds 3a, 3b, 3c, and 5a showed the lowest IC50 values compared to those of doxorubicin (DOX) against HCT116, HEPG2, A549, MDA-MB-468, and FaDu cancer cell lines, respectively, especially against the HCT116 subtype, assuring their potential anticancer activity. On the other side, the apoptotic potentials of the most active compounds (3a, 3b, 3c, and 5a) were also evaluated for apoptosis-related genes (P53, BAX, caspases 3, 6, 8, and 9, MMP2, MMP9, and BCL-2). Interestingly, compounds 3a, 3b, 3c, and 5a upregulated P53, BAX, and caspases 3, 6, 8, and 9 by (2.66, 2.26, 2.44, and 2.57)-, (1.62, 1.52, 1.37, and 1.47)-, (1.87, 1.75, 2.02, and 1.75)-, (1.96, 1.74, 2.06, and 2.30)-, (4.25, 3.78, 3.53, and 3.96)-, and (2.04, 1.72, 1.90, and 1.63)-fold change, respectively. Furthermore, MMP2, MMP9, and BCL-2 were downregulated by (0.39, 0.51, 0.33, and 0.28)-, (0.29, 0.32, 0.37, and 0.41)-, and (0.42, 0.35, 0.29, and 0.38)-fold-change, upon treatment with compounds 3a, 3b, 3c, and 5a, respectively, assuring the apoptotic potentials. Finally, molecular docking also greatly recommends the potential activity of the examined candidates (especially 3a and 3c) against the GSTP1 receptor as a recommended mechanism for their antitumor activity. Our findings point to significant anticancer activities of Schiff bases tethered OSe agents, suggesting their promising potential for development as effective anticancer drugs.

Increasing the Dye Payload of Cetuximab-IRDye800CW Enables Photodynamic Therapy.

Cetuximab (Cet)-IRDye800CW, among other antibody-IRDye800CW conjugates, is a potentially effective tool for delineating tumor margins during fluorescence image-guided surgery (IGS). However, residual disease often leads to recurrence. Photodynamic therapy (PDT) following IGS is proposed as an approach to eliminate residual disease but suffers from a lack of molecular specificity for cancer cells. Antibody-targeted PDT offers a potential solution for this specificity problem. In this study, we show, for the first time, that Cet-IRDye800CW is capable of antibody-targeted PDT in vitro when the payload of dye molecules is increased from 2 (clinical version) to 11 per antibody. Cet-IRDye800CW (1:11) produces singlet oxygen, hydroxyl radicals, and peroxynitrite upon activation with 810 nm light. In vitro assays on FaDu head and neck cancer cells confirm that Cet-IRDye800CW (1:11) maintains cancer cell binding specificity and is capable of inducing up to ∼90% phototoxicity in FaDu cancer cells. The phototoxicity of Cet-IRDye800CW conjugates using 810 nm light follows a dye payload-dependent trend. Cet-IRDye800CW (1:11) is also found to be more phototoxic to FaDu cancer cells and less toxic in the dark than the approved chromophore indocyanine green, which can also act as a PDT agent. We propose that antibody-targeted PDT using high-payload Cet-IRDye800CW (1:11) could hold potential for eliminating residual disease postoperatively when using sustained illumination devices, such as fiber optic patches and implantable surgical bed balloon applicators. This approach could also potentially be applicable to a wide variety of resectable cancers that are amenable to IGS-PDT, using their respective approved full-length antibodies as a template for high-payload IRDye800CW conjugation.

Design and synthesis of novel tetrabromophthalimide derivatives as potential tubulin inhibitors endowed with apoptotic induction for cancer treatment.

Although various approaches exist for treating cancer, chemotherapy continues to hold a prominent role in the management of this disease. Besides, microtubules serve as a vital component of the cellular skeleton, playing a pivotal role in the process of cell division making it an attractive target for cancer treatment. Hence, the scope of this work was adapted to design and synthesize new anti-tubulin tetrabromophthalimide hybrids (3-17) with colchicine binding site (CBS) inhibitory potential. The conducted in vitro studies showed that compound 16 displayed the lowest IC50 values (11.46 µM) at the FaDu cancer cell lines, whereas compound 17 exhibited the lowest IC50 value (13.62 µM) at the PC3 cancer cell line. However, compound 7b exhibited the lowest IC50 value (11.45 µM) at the MDA-MB-468 cancer cell line. Moreover, compound 17 was observed to be the superior antitumor candidate against all three tested cancer cell lines (MDA-MB-468, PC3, and FaDu) with IC50 values of 17.22, 13.15, and 13.62 µM, respectively. In addition, compound 17 showed a well-established upregulation of apoptotic markers (Caspases 3, 7, 8, and 9, Bax, and P53). Moreover, compound 17 induced downregulation of the antiapoptotic markers (MMP2, MMP9, and BCL-2). Furthermore, the colchicine binding site inhibition assay showed that compounds 15a and 17 exhibited particularly significant inhibitory potentials, with IC50 values of 23.07 and 4.25 µM, respectively, compared to colchicine, which had an IC50 value of 3.89 µM. Additionally, cell cycle analysis was conducted, showing that compound 17 could prompt cell cycle arrest at both the G0-G1 and G2-M phases. On the other hand, a molecular docking approach was applied to investigate the binding interactions of the examined candidates compared to colchicine towards CBS of the β-tubulin subunit. Thus, the synthesized tetrabromophthalimide hybrids can be regarded as outstanding anticancer candidates with significant apoptotic activity.

A novel approach to pH-Responsive targeted cancer Therapy: Inhibition of FaDu cancer cell proliferation with a pH low insertion Peptide-Conjugated DGAT1 inhibitor

Targeting enzymes involved in lipid metabolism is increasingly recognized as a promising anticancer strategy. Efficient inhibition of diacylglycerol O-transferase 1 (DGAT1) can block fatty acid (FA) storage. This, in turn, triggers an increase in free polyunsaturated FA concentration, leading to peroxidation and ferroptosis. In this study, we report the development of a pH-sensitive peptide (pHLIP)-drug conjugate designed to selectively deliver DGAT1 inhibitors to cancer cells nested within the acidic microenvironment of tumors. We utilized two previously established pHLIP sequences for coupling with drugs. The study of DGAT1 conjugates in large unilamellar vesicles (LUVs) of different compositions did not reveal enhanced pH-dependent insertion compared to POPC LUVs. However, using in vitro 3D tumor spheroids, significant antiproliferative effects were observed upon exposure to pHLIP-T863 (DGAT1 inhibitor) conjugates, surpassing the inhibitory activity of T863 alone. In conclusion, our study provides the first evidence that pHLIP-based conjugates with DGAT1 inhibitors have the potential to specifically target the acidic compartment of tumors. Moreover, it sheds light on the limitations of LUV models in capturing the pH-dependency of such conjugates.

Abstract 3481: Comparative spatial transcriptomic analysis of monoclonal antibodies targeting the same molecule: A comparison between cetuximab and panitumumab

Abstract Background: In recent years, multiple therapeutic monoclonal antibodies have been developed that target the same molecules. Examples include trastuzumab and pertuzumab for HER2, cetuximab (CTX) and panitumumab (PNT) for EGFR, as well as pembrolizumab and nivolumab for PD-1. Currently, comparative studies between different monoclonal antibodies with same target primarily focus on comparing their efficacy, which makes it challenging to discern the factors contributing to their varied effectiveness. In this study, we conducted a comparative analysis of CTX and PNT using integrated data of fluorescence imaging and spatial transcriptomics (ST) to explore their distribution, as well as the associated cell types and genes in tumor tissues. Method: A FaDu cancer cell line, which has high EGFR expression, was used to establish tumor model in BALB/C nude mice. In the tumor model, fluorescence dye-conjugated CTX or PNT was intravenously administered. In vivo fluorescence imaging was conducted at 0, 2, and 40 hours. Tumor tissues at 2 and 40 hours were dissected for drug distribution images and 10X Visium ST. SPADE algorithm [1], CellDART [2], and Stopover analysis [3] were employed for integrative analysis, cell type deconvolution, and topological association of interesting genes. Results: In vivo imaging demonstrated that both antibodies exhibited high tumor uptake at 2 hrs, with further increase observed at 40 hrs post-injection. Initially, CellDART analysis confirmed that in the 2 hrs sample, both CTX and PNT exhibited a distribution similar to cancer cells among the various cell types. However, in the 40 hrs sample, the distribution pattern resembled that of cancer cells and inflammatory macrophages for both antibodies. A stopover analysis revealed a higher concordance between CTX distribution and EGFR expression in both the 2 and 40 hrs samples compared to that of PNT. Lastly, the top 100 up-regulated differentially expressed genes which are highly associated with drug distribution were identified through SPADE analysis. Notably, when we checked the intersection between CTX and PNT administered samples for these genes, there was 83% discordance in the associated genes in the 2 hrs sample and 93% in the 40 hrs sample. Conclusion: In the examination of the distribution patterns of two distinct therapeutic antibodies targeting EGFR within cancer tissues, a notable observation was made: while the cell types exhibited similarity, the associated genes demonstrated divergence, with different degrees of alignment with the intended target. This analytical approach, scrutinizing the distribution of different antibodies within tissue sharing a common target, holds promise as a widely applicable method for elucidating divergent therapeutic effects.

Anticancer Properties of Plectranthus ornatus-Derived Phytochemicals Inducing Apoptosis via Mitochondrial Pathway.

Since cancer treatment by radio- and chemotherapy has been linked to safety concerns, there is a need for new and alternative anticancer drugs; as such, compounds isolated from plants represent promising candidates. The current study investigates the anticancer features of halimane (11R*,13E)-11-acetoxyhalima-5,13-dien-15-oic acid (HAL) and the labdane diterpenes 1α,6β-diacetoxy-8α,13R*-epoxy-14-labden-11-one (PLEC) and forskolin-like 1:1 mixture of 1,6-di-O-acetylforskolin and 1,6-di-O-acetyl-9-deoxyforskolin (MRC) isolated from Plectranthus ornatus in MCF7 and FaDu cancer cell lines. Cytotoxicity was assessed by MTT assay, ROS production by Di-chloro-dihydro-fluorescein diacetate assay (DCFH) or Red Mitochondrial Superoxide Indicator (MitoSOX) and Mitochondrial Membrane Potential (MMP) by fluorescent probe JC-1 (5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine iodide). In addition, the relative amounts of mitochondrial DNA (mtDNA) were determined using quantitative Real-Time-PCR (qRT-PCR) and damage to mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) by semi-long run quantitative Real-Time-PCR (SLR-qRT-PCR). Gene expression was determined using Reverse-Transcription-qPCR. Caspase-3/7 activity by fluorescence was assessed. Assessment of General In Vivo Toxicity has been determined by Brine Shrimp Lethality Bioassay. The studied HAL and PLEC were found to have a cytotoxic effect in MCF7 with IC50 = 13.61 µg/mL and IC50 = 17.49 µg/mL and in FaDu with IC50 = 15.12 µg/mL and IC50 = 32.66 µg/mL cancer cell lines. In the two tested cancer cell lines, the phytochemicals increased ROS production and mitochondrial damage in the ND1 and ND5 gene regions and reduced MMP (ΔΨm) and mitochondrial copy numbers. They also changed the expression of pro- and anti-apoptotic genes (Bax, Bcl-2, TP53, Cas-3, Cas-8, Cas-9, Apaf-1 and MCL-1). Studies demonstrated increase in caspase 3/7 activity in tested cancer cell lines. In addition, we showed no toxic effect in in vivo test for the compounds tested. The potential mechanism of action may have been associated with the induction of apoptosis in MCF7 and FaDu cancer cells via the mitochondrial pathway; however, further in vivo research is needed to understand the mechanisms of action and potential of these compounds.

Membrane composition is a functional determinant of NIR-activable liposomes in orthotopic head and neck cancer.

Near-infrared (NIR)-activable liposomes containing photosensitizer (PS)-lipid conjugates are emerging as tunable, high-payload, and tumor-selective platforms for photodynamic therapy (PDT)-based theranostics. To date, the impact that the membrane composition of a NIR-activable liposome (the chemical nature and subsequent conformation of PS-lipid conjugates) has on their in vitro and in vivo functionality has not been fully investigated. While their chemical nature is critical, the resultant physical conformation dictates their interactions with the immediate biological environments. Here, we evaluate NIR-activable liposomes containing lipid conjugates of the clinically-used PSs benzoporphyrin derivative (BPD; hydrophobic, membrane-inserting conformation) or IRDye 700DX (hydrophilic, membrane-protruding conformation) and demonstrate that membrane composition is critical for their function as tumor-selective PDT-based platforms. The PS-lipid conformations were primarily dictated by the varying solubilities of the two PSs and assisted by their lipid conjugation sites. Conformation was further validated by photophysical analysis and computational predictions of PS membrane partitioning (topological polar surface area [tPSA], calculated octanol/water partition [cLogP], and apparent biomembrane permeability coefficient [Papp]). Results show that the membrane-protruding lipo-IRDye700DX exhibits 5-fold more efficient photodynamic generation of reactive molecular species (RMS), 12-fold expedited phototriggered burst release of entrap-ped agents, and 15-fold brighter fluorescence intensity as compared to the membrane-inserting lipo-BPD-PC (phosphatidylcholine conjugate). Although the membrane-inserting lipo-BPD-PC exhibits less efficient photo-dynamic generation of RMS, it allows for more sustained phototriggered release, 10-fold greater FaDu cancer cell phototoxicity, and 7.16-fold higher tumor-selective delivery in orthotopic mouse FaDu head and neck tumors. These critical insights pave the path for the rational design of emerging NIR-activable liposomes, whereby functional consequences of membrane composition can be tailored toward a specific therapeutic purpose.

Abstract LB026: Nanoscale, antigen-dependent, reversible IL-12 secretion by CAR T cells for cancer treatment

Abstract BACKGROUND - Interleukin(IL)-12 activates T cells pivots the switch that turns lingering inflammation into acute inflammation and cancer rejection. However, its clinical utilization is limited by severe systemic toxicity. Here, we present a conditional, antigen-dependent, non-editing CRISPR-activation (CRISPRa) circuit (RB-2-12) that induces minimally effective doses of IL-12 for autocrine activation of CAR-T cells. METHODS - RB-2-12 is a CAR T cell engineered to express the IL-12 heterodimer via conditional transcription of its two endogenous subunits p35 and p40. The circuit includes a lentiviral constructs encoding an anti-HER2 (4D5) single chain variable fragment, with CD28 and CD3ζ co-stimulatory domains linked to a tobacco etch virus (TEV) protease and two single guide RNAs (sgRNA) targeting the promoter region for IL-12A orL-12B. A second constructs encodes linker for activation of T cells, complexed to nuclease-deactivated/dead Cas9 (dCas9)-VP64-p65-Rta transcriptional activator (VPR) via a TEV-cleavable linker (LdCV). Activation of CAR brings CAR-TEV in proximity to LdCV releasing dCas9 for nuclear localization to the regulatory regions and conditionally and reversibly induce nanoscale expression of the p70 heterodimer. RB-2-12 was compared in vitro to control (cRB-2-12, lacking the IL-12 sgRNAs). Results - RB-2-12 induced low concentrations of IL-12 upon exposure to HER2+ FaDu cancer cells resulting in significantly enhanced production of interferon (IFN)-γ, cytotoxic activity and proliferation (Figure 1a). These effects were comparable to co-culturing conventional HER2-specific CAR-T cells with a modified FaDu cell line expressing high doses of IL-12. In vivo administration of RB-2-12 significantly enhanced survival of mice carrying FaDu xenografts compared to mice treated with the respective conventional CAR-t cells or RB-2-12 lacking the guide RNAs targeting the IL-12 gene subunits CONCLUSIONS - We have previously shown that tandem suppression of PD-1 expression upon HER-2 CAR activation using CRISPR interference enhances anti-cancer properties of CAR-T cells in vivo against HER2-FaDu xenografts by promoting their persistence and long-term tumor colonization (companion abstract submitted to SITC annual meeting). We hypothesize that addition of a Th1 polarizing component such as IL-12 will exponentially increase the efficacy of reprogrammed CAR-T cells by combining enhancement of effector functions to cellular fitness. At the same time, the autocrine effects of nanoscale IL-12 production limit the risk of off-tumor leakage and systemic toxicity. Such cumulative synthetic biology approaches are currently investigated in vitro and in vivo model systems. Current work is testing the effectiveness of RB-2-12 in vivo against FaDu xenografts. Citation Format: Zhifen Yang, Maggie Bobbin, Hana Choi, Ofir Stefanson, Khristina Magallanes, Jin Yang, Bing Wang, Alessandra Cesano, Lei Stanley Qi, Francesco M. Marincola. Nanoscale, antigen-dependent, reversible IL-12 secretion by CAR T cells for cancer treatment [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 LB026.

Cellular Effects of Ultraviolet-Radiated Reduced-Titanium Dioxide Nanoparticles on Human Hypopharyngeal Adenocarcinoma Cells.

The cellular effects of ultraviolet (UV)-radiated reduced-titanium dioxide (TiO₂) nanoparticles were investigated on human hypopharyngeal adenocarcinoma cells (FaDu). In 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the viability of FaDu cells exposed to UV (254 nm) for 10 minutes, in the presence of reduced-TiO₂ nanoparticles in rutile, was dose- and time-dependently decreased. The UV-radiated reduced-TiO₂ suppressed the cell proliferation by inhibiting the expression of cell cycle kinase, cyclin dependent kinase 2 (Cdk2), and its functional regulators Cyclin E and Cyclin B1 as well as proliferation-regulating proteins of p85 regulatory sub-unit of phosphoinositide3-kinases (PI3K p85), phosphorylated protein kinase B (p-AKT/p-PKB) and phosphorylated mammalian target of rapamycin (p-mTOR). In addition, the mitochondria disintegration and deoxyribonucleic acid (DNA) damage were confirmed by detecting the accumulated Bax in cytoplasm, phosphorylated-H2A histone family member X (γ-H2AX) in chromosomes and phosphorylated checkpoint 2 (p-Chk2). Our results support that UV-activated reduced-TiO₂ in rutile sensitized UV-induced proliferation suppression of FaDu cancer cells by the enhanced photocat-alytic activity.

Pepsin promotes laryngopharyngeal neoplasia by modulating signaling pathways to induce cell proliferation.

Pepsin plays an important role in laryngopharyngeal reflux (LPR), a risk factor for the development of hypopharyngeal squamous cell carcinomas (HPSCC). However, the role of pepsin in HPSCC is not clear. We show by immunohistochemistry that pepsin positivity occurs in a significant proportion of human primary HPSCC specimens, and in many cases matched adjacent uninvolved epithelia are negative for pepsin. Pepsin positivity is associated with nodal involvement, suggesting that pepsin may have a role in metastasis. Treatment of FaDu cancer cells with pepsin increased cell proliferation, possibly by inducing G1/S transition. We also observed significant changes in expression of genes involved in NF-kappaB, TRAIL and Notch signaling. Our data suggest that pepsin plays an important role in HPSCC and that targeting pepsin could have potential therapeutic benefits.

Antarvedisides A-B from Manglicolous Lichen Dirinaria consimilis (Stirton) and their Pharmacological Profile

The chemical examination of acetone extract of Dirinaria consimilis resulted in isolation of six depsides of which two novel metabolites namely antarvediside A (1) and antarvediside B (2) and four known metabolites i.e. sekikaic acid (3), atranorin (4), divaricatic acid (5) and 2’-O-methyl divaricatic acid (6). From the pharmacological screening of the isolates (1-6), it was found that 1 and 2 exhibited better inhibition of ABTS and superoxide free radicals than that of the standard and compound 4 showed significant inhibition of protein denaturation with IC50 value of 390 mg/mL with respect to indomethacin with 110 mg/mL. From the SRB assay results, the better IC50 values was determined by compound 2 of 10.5, 11.50 and 12.50 μg/mL on HeLa, MCF-7 and FADU cancer cell lines, respectively. Thus, the outcomes revealed that the D. consimilis is a new source to treat free radicals, inflammation and cancer.

Therapeutic Efficacy Of Plasma Activated Medium In 2d And 3d In Vitro Head And Neck Fadu Cancer Cell

Plasma Activated Media (PAM) has shown an increasing anticancer effect in the past few [1-3]. In in vitro, decrease in cell proliferation [2.4], DNA damage [2;5] and apoptosis [6] were observed. The main advantage of PAM is its possibility to be prepared in advance and it can be used several weeks after activation by plasma jet when it is stored at the right temperature [2;7]. The aim of this work is to investigate the inhibitory effect of PAM and hydrogen peroxide H2O2 on Head and Neck cancerous cells (FaDu). The response of FaDu cells in monolayer cultures and Multi Cellular Tumor Spheroids (MCTS) after treatment with different PAMs was compared. A homemade helium plasma jet was used to produce PAM. Helium plasma jet was generated using dielectric barrier discharge configuration. Helium was injected with flowmeter and the gas flow is fixed at 3L/min. One treatment with PAM induces cell detachment from MTCs since the first day in a PAM exposure dependent manner. This is due to the presence of H2O2 in PAM. However, a rapid spheroids regrowth is observed attributed to a resistance of FaDu cells to H2O2. After multiple treatments of MCTS with PAM we obtained an inhibition of cell growth. MCTS is brought out with a comparison of PAM effect on 2D versus MCTS. Inversely, PAM induces cell death in the case of 2D cell culture. This result underlines the importance of working with MCTS instead of 2D cells.

Redox-responsive micelles for triggered drug delivery and effective laryngopharyngeal cancer therapy

In this study, we reported a redox-responsive drug delivery system (DDS) based on heparosan and deoxycholic acid conjugates (HSDs) for effective treatment of laryngopharyngeal carcinoma. The amphiphilic HSDs can self-assemble into stable nanoscale micelles in aqueous medium with favorable drug loading capacity for doxorubicin (DOX). The HSD micelles can exhibit glutathione (GSH)-triggered drug release behavior and reach a nearly 100% release rate in a high GSH level (10 mM) environment. Moreover, FaDu cancer cells can internalize HSD micelles by clathrin-mediated endocytosis, which is energy dependent, fast, and effective. The DOX@HSD induced inhibition of FaDu cancer cells can achieve a minimum of 10-fold selectivity relative to that of COS-7 normal cells. Overall, the redox-responsive DDSs show good biocompatibility and are promising in the clinical treatment of laryngopharyngeal carcinoma.

NET-producing CD16high CD62Ldim neutrophils migrate to tumor sites and predict improved survival in patients with HNSCC.

The concept of functional neutrophil subsets is new and their clinical significance in malignancies is unknown. Our study investigated the role of CD16dim CD62Lhigh , CD16high CD62Lhigh and CD16high CD62Ldim neutrophil subsets in head and neck squamous cell carcinoma (HNSCC) patients. These neutrophil subsets may play different roles in immune-related activity in cancer, based on their profile, activation state and migration ability within a tumor site, which may be important in predicting cancer prognoses. Tumor biopsies and blood were obtained from newly diagnosed untreated HNSCC patients and healthy controls. Neutrophil subsets and their phenotype were characterized using flow cytometry. Isolated granulocytes were assessed for anti-tumor immune functions. Compared to controls HNSCC patients exhibited increased CD16high CD62Ldim neutrophils in blood; this subset displayed a distinct phenotypes with high expression of CD11b and CD18. This subset was prone to migrate into the tumor facilitated by tumor-derived IL-8. Furthermore, IL-8 was also found to activate neutrophils and thereby promoting subset transition. Various assays demonstrated that activated CD16high CD62Ldim neutrophils inhibited migration, proliferation and induced apoptosis of FaDu cancer cells. Neutrophil elastase detected in activated CD16high CD62Ldim neutrophils and tumor biopsies suggested that CD16high CD62Ldim neutrophils impart anti-tumoral activity via neutrophil extracellular traps. Furthermore, increased fraction of CD16high CD62Ldim neutrophils was shown to correlate with an increased survival rate. Our study demonstrates the clinical relevance of the CD16high CD62Ldim neutrophil subset, providing evidence for its increased migration capacity, its anti-tumor activity including increased NET formation and finally its correlation with increased survival in HNSCC patients.

MicroRNA-203 inhibits tumour growth and metastasis through PDPN.

MicroRNAs play an important role in regulating hypopharyngeal cancer development. miR-203 has been previously shown to possess antitumour capabilities in many cancers, but not in hypopharyngeal cancer. Using human normal and hypopharyngeal cancer specimens, we explored the expression levels of miR-203 in the two groups and further correlated them with different stages of cancer and lymph node metastasis. Applying human pharynx FaDu cancer cells and lentiviral transduction technique, we investigated the effects of miR-203 on cancer cell viability, migration and invasion. Moreover, we studied the novel relationship between miR-203 and podoplanin (PDPN) in hypopharyngeal cancer. The downregulated levels of miR-203 in human hypopharyngeal cancer tissues were associated with advanced cancer stages and lymph node metastasis. High levels of miR-203 inhibited cell viability, migration and invasion of hypopharyngeal cancer cells. Further studies suggested miR-203 directly targeted and inhibited PDPN expression. PDPN silencing suppresses hypopharyngeal cancer cell abilities. In addition, PDPN overexpression was able to reverse miR-203 inhibitory effects on cell viability, migration and invasion. PDPN acts as an oncogene to promote hypopharyngeal cancer cell viability, migration and invasion. miR-203 directly targets PDPN to suppress its expression, thus exerting inhibitory effects on cancer metastasis.

Abstract 5593: Cigarette smoke and therapeutic response to chemotherapy and radiotherapy in cancer cells

Abstract Background: The 2014 Surgeon General's Report concludes that cigarette smoke (CS) causes increased cancer specific mortality. Clinical data support that the effects of CS are reversible, but there are no extant biologic models that have shown therapeutic response profiles for cancer cells exposed to CS. Methods: An acute, subacute, and chronic dose escalated CS exposure model was developed to test the hypothesis that CS decreases therapeutic response to chemotherapy (CT, cisplatin) and radiotherapy (RT, 0, 2, 4, and 6 Gy) in a reversible manner in cancer cells. Results: H460, A549, and FaDu cancer cells were treated with single and multiple exposure CS for up to 12 weeks. Subacute and prolonged exposure to CS significantly decreased response to CT and RT. CS increased survival fraction following CT or RT between 30-157% across all cell lines. Exposure of cancer cells to CS for 6 or 9 weeks followed by removal of CS for 3 and 6 weeks resulted in a partial to complete restoration of baseline therapeutic response in a cell specific manner; however, all cell lines required several weeks to achieve a partial or full restoration of therapeutic response. Dose response curves for CS exposure demonstrate that H460 and A549 cells had a decreased therapeutic response profile at higher CS concentrations while FaDu cells were more sensitive to lower concentrations to CS. Dose response curves further demonstrated that high dose CS exposure was cytotoxic in all cell lines. Results were verified in all cell lines using 2 additional repeated experiments with freshly thawed cancer cells purchased from ATCC over 10 months. Conclusions: CS exposure reproducibly decreases therapeutic response to CT and RT in a dose dependent and reversible manner, reflective of clinical observations. Dose specific effects may vary between cancer cells. Data suggest that the biologic effects of CS removal, such as with acute smoking cessation in cancer patients, may not manifest in an immediate restoration of cancer cell response to CT or RT. Citation Format: Graham W. Warren, Michelle Romano, Samantha Sobus, Sundaravadivel Balasubramanian. Cigarette smoke and therapeutic response to chemotherapy and radiotherapy in cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5593. doi:10.1158/1538-7445.AM2015-5593

Midazolam inhibits the proliferation of human head and neck squamous carcinoma cells by downregulating p300 expression.

The objective of this study was to investigate the mechanism of midazolam in inhibiting the proliferation of hypopharyngeal squamous carcinoma cells. Cultured FaDu cancer cells were treated with different concentrations of midazolam. MTT and BrdU incorporation assays were then used to evaluate cancer cell proliferation. The mRNA and protein levels of p300, a key factor involved in the tumorigenesis of numerous cancers, were measured with RT-PCR and Western blotting, respectively. Midazolam inhibited the expression of p300 and the proliferation of FaDu cells. Additionally, knockdown of p300 resulted in increased expression of p21 and p27 and decreased expression of p-Rb while inhibiting the proliferation of FaDu cells. Midazolam inhibits the proliferation of human head and neck squamous carcinoma cells by downregulating p300. Midazolam may be useful for the treatment of hypopharyngeal squamous cancers.

MicroRNA-193b enhances tumor progression via down regulation of neurofibromin 1.

Despite improvements in therapeutic approaches for head and neck squamous cell carcinomas (HNSCC), clinical outcome has remained disappointing, with 5-year overall survival rates hovering around 40–50%, underscoring an urgent need to better understand the biological bases of this disease. We chose to address this challenge by studying the role of micro-RNAs (miRNAs) in HNSCC. MiR-193b was identified as an over-expressed miRNA from global miRNA profiling studies previously conducted in our lab, and confirmed in HNSCC cell lines. In vitro knockdown of miR-193b in FaDu cancer cells substantially reduced cell proliferation, migration and invasion, along with suppressed tumour formation in vivo. By integrating in silico prediction algorithms with in vitro experimental mRNA profilings, plus mRNA expression data of clinical specimens, neurofibromin 1 (NF1) was identified to be a target of miR-193b. Concordantly, miR-193b knockdown decreased NF1 transcript and protein levels significantly. Luciferase reporter assays confirmed the direct interaction of miR-193b with NF1. Moreover, p-ERK, a downstream target of NF1 was also suppressed after miR-193b knockdown. FaDu cells treated with a p-ERK inhibitor (U0126) phenocopied the reduced cell proliferation, migration and invasion observed with miR-193b knockdown. Finally, HNSCC patients whose tumours expressed high levels of miR-193b experienced a lower disease-free survival compared to patients with low miR-193b expression. Our findings identified miR-193b as a potentially novel prognostic marker in HNSCC that drives tumour progression via down-regulating NF1, in turn leading to activation of ERK, resulting in proliferation, migration, invasion, and tumour formation.

Protection of p53 Wild Type Cells From Taxol by Genistein in the Combined Treatment of Lung Cancer

This study specifies the basic principles to selectively kill p53-deficient cells (H1299, FaDu) by taxol and to protect p53 wild type cells (A549) by the prior administration of structurally related flavonoids (apigenin, genistein, and quercetin). Cytotoxic and cytostatic properties of flavonoids were investigated in vitro by flow cytometry and were compared to known anticancer drugs (cisplatin, doxorubicin, etoposide). It was confirmed that doxorubicin induced growth arrest and protected A549 cells from taxol while simultaneously killing or blocking H1299 and FaDu cancer cells. It was found that doxorubicin could be successfully substituted in this way by the isoflavone genistein used at physiologically relevant concentrations. The other compounds analyzed revealed less selectivity (apigenin, cisplatin) or demonstrated higher toxicity (cisplatin, etoposide, and quercetin). We concluded that genistein-based therapy may have antagonistic effects when combined with mitotic poisons. The proposed therapeutic strategy allows protection of p53 wild type cells from taxol and selectively increases apoptosis in p53-deficient cells. This strategy exploits the naturally occurring compound that can be used without significant toxicity in rather high concentrations as present in common diets.