Fucoxanthin Inhibits the Proliferation and Metastasis of Human Pharyngeal Squamous Cell Carcinoma by Regulating the PI3K/Akt/mTOR Signaling Pathway.

Human pharyngeal squamous cell carcinoma (HPSCC) is the most common malignancy in the head and neck region, characterized by high mortality and a propensity for metastasis. Fucoxanthin, a carotenoid isolated from brown algae, exhibits pharmacological properties associated with the suppression of tumor proliferation and metastasis. Nevertheless, its potential to inhibit HPSCC proliferation and metastasis has not been fully elucidated. This study represents the first exploration of the inhibitory effects of fucoxanthin on two human pharyngeal squamous carcinoma cell lines (FaDu and Detroit 562), as well as the mechanisms underlying those effects. The results showed dose-dependent decreases in the proliferation, migration, and invasion of HPSCC cells after fucoxanthin treatment. Further studies indicated that fucoxanthin caused a significant reduction in the expression levels of proteins in the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) pathway, as well as the downstream proteins matrix metalloproteinase (MMP)-2 and MMP-9. Specific activators of PI3K/AKT reversed the effects of fucoxanthin on these proteins, as well as on cell proliferation and metastasis, in FaDu and Detroit 562 cells. Molecular docking assays confirmed that fucoxanthin strongly interacted with PI3K, AKT, mTOR, MMP-2, and MMP-9. Overall, fucoxanthin, a functional food component, is a potential therapeutic agent for HPSCC.

Discovery of a potent cytotoxic agent that promotes G2/M phase cell cycle arrest and apoptosis in a malignant human pharyngeal squamous carcinoma cell line.

Squamous cell carcinoma is the major form of malignancy that arises in head and neck cancer. The modest improvement in the 5­year survival rate underpins its complex etiology and provides the impetus for the discovery of new therapeutics. The present study describes the discovery of an indole­based small molecule (24a) that was a potent cytotoxic agent with antiproliferative and pro­apoptotic properties against a pharyngeal carcinoma cell line, Detroit 562, effectively killing the cells at a half­maximal inhibitory concentration of 0.03 µM, as demonstrated using cell proliferation studies. The antiproliferative property of 24a was demonstrated by its ability to promote G2/M blockade, as assessed by cell cycle analysis using flow cytometry and the monitoring of real­time cell cycle progression by the fluorescence ubiquitination­based cell cycle indicator. This pro­apoptotic property is supported by the promotion of TUNEL­staining and increase in the activities of caspases­3/7 and ­6, in addition to the expression of death receptors and the cleavage of poly (ADP­ribose) polymerase 1 protein as demonstrated by western blotting. Given that Detroit 562 lacks functional p53, it is suggested that 24a acts independently of the tumor suppressor.

Prognostic significance of hypoxia-inducible factor-1α expression in advanced pharyngeal cancer without human papillomavirus infection.

OBJECTIVE: This study aimed to clarify the association between both hypoxia-inducible factor-1α and glucose transporter type-1 expression and survival outcome in advanced pharyngeal cancer without human papillomavirus infection. METHOD: Twenty-five oropharyngeal and 55 hypopharyngeal cancer patients without human papillomavirus infection were enrolled. All patients had stage III-IV lesions and underwent concurrent chemoradiotherapy or surgery. Hypoxia-inducible factor-1α and glucose transporter type-1 expression were investigated in primary lesions by immunohistochemistry. RESULTS: There were 41 and 39 cases with low and high hypoxia-inducible factor-1α expression, and 28 and 52 cases with low and high glucose transporter type-1 expression, respectively. There was no significant correlation between hypoxia-inducible factor-1α and glucose transporter type-1 expression. In univariate analysis, nodal metastasis, clinical stage and high hypoxia-inducible factor-1α expression, but not glucose transporter type-1 expression, predicted significantly worse prognosis. In multivariate analysis, hypoxia-inducible factor-1α overexpression was significantly correlated with poor overall survival, disease-specific survival and recurrence-free survival. CONCLUSION: High hypoxia-inducible factor-1α expression was an independent risk factor for poor prognosis for advanced human papillomavirus-unrelated pharyngeal cancer.

Association of mRNA Expression Levels of LRP1 and Actin-Binding Proteins with the Development of Laryngeal and Laryngopharyngeal Squamous Cell Carcinoma.

We analyzed the association of the level of mRNA expression of the main endocytosis receptor LRP1 and actin-binding proteins (ezrin, profilin-1, cofilin-1, and adenylyl cyclase-associated protein 1) with the development and metastasis of laryngeal and laryngopharyngeal squamous cell carcinoma. The mRNA expression was evaluated in paired tissue samples using quantitative reverse transcription real-time PCR (RT-qPCR) and SYBR Green reagents. The study included 38 patients with stage T1-4N0-1M0 laryngeal and laryngopharyngeal squamous cell carcinoma and 10 patients with chronic hyperplastic laryngitis or grade II-III epithelial dysplasia. The expression of LRP1 in patients with laryngeal and laryngopharyngeal squamous cell carcinoma depended on the stage of the tumor process. Against the background of low expression of LRP1 mRNA, the relationship between cofilin 1 and profilin 1 expression became stronger (r=0.08; p=0.05) and a correlation between cofilin 1 and esrin expression (r=0.7; p=0.05) appeared. Studies on a larger patient cohort are required to make a definite conclusion on the role of LRP1 in the development of laryngeal and laryngopharyngeal squamous cell carcinoma.

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.

Correlation Between Semiquantitative Metabolic Parameters After PET/CT and Histologic Prognostic Factors in Laryngeal and Pharyngeal Carcinoma.

Positron emission tomography/computed tomography (PET/CT) has shown prognostic significance in head and neck cancer patients. The underlying pathologic features that could explain the mechanisms associated with this observation are not clear. To analyze the correlation between 18-F-fluoro-2-deoxy-D-glucose (18F-FDG) uptake assessed by PET/CT in head and neck cancer and histopathologic prognostic factors. Ninety-nine patients with laryngeal and pharyngeal squamous cell carcinoma were retrospectively reviewed for pretreatment PET/CT measurements, namely standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). The corresponding histologic material was evaluated for tumor stroma-related prognostic factors such as the amount and type of stroma, lymphocytic response, tumor budding activity, and size of tumor cell nests in the tumor core area and tumor front. TLG and MTV were associated with tumor localization, as they were higher in oropharyngeal tumors. These values were also associated with tumor cell nest size in the tumor core with higher values corresponding to tumors with smaller nests. MTV40% was marginally associated with fibroblastic stroma type and higher budding activity. SUVmax was not associated with the histological factors in the whole sample, but higher values trended with higher tumor budding activity and stroma-rich tumors of the oropharynx. 18F-FDG PET measurements in head and neck squamous cell carcinomas are associated with prognostic histopathologic factors and suggest a possible correlation of glucose metabolism to epithelial-to-mesenchymal transition.

Mechanisms of different response to ionizing irradiation in isogenic head and neck cancer cell lines.

BACKGROUND: Treatment options for recurrent head and neck tumours in the previously irradiated area are limited, including re-irradiation due to radioresistance of the recurrent tumour and previous dose received by surrounding normal tissues. As an in vitro model to study radioresistance mechanisms, isogenic cells with different radiosensitivity can be used. However, they are not readily available. Therefore, our objective was to establish and characterize radioresistant isogenic human pharyngeal squamous carcinoma cells and to evaluate early radiation response in isogenic parental, radioresistant and radiosensitive cells. METHODS: Radioresistant cells were derived from parental FaDu cells by repeated exposure to ionizing radiation. Radiosensitivity of the established isogenic radioresistant FaDu-RR cells was evaluated by clonogenic assay and compared to isogenic parental FaDu and radiosensitive 2A3 cells. Additional phenotypic characterization of these isogenic cells with different radiosensitivity included evaluation of chemosensitivity, cell proliferation, cell cycle, radiation-induced apoptosis, resolution of DNA double-strand breaks, and DNA damage and repair signalling gene expression before and after irradiation. RESULTS: In the newly established radioresistant cells in response to 5 Gy irradiation, we observed no alteration in cell cycle regulation, but delayed induction and enhanced resolution of DNA double-strand breaks, lower induction of apoptosis, and pronounced over-expression of DNA damage signalling genes in comparison to parental cells. On the other hand, radiosensitive 2A3 cells were arrested in G2/M-phase in response to 5 Gy irradiation, had a prominent accumulation of and slower resolution of DNA double-strand breaks, and no change in DNA damage signalling genes expression. CONCLUSIONS: We concluded that the emergence of the radioresistance in the established radioresistant isogenic cells can be at least partially attributed to the enhanced DNA double-strand break repair, altered expression of DNA damage signalling and repair genes. On the other hand, in radiosensitive isogenic cells the reduced ability to repair a high number of induced DNA double-strand breaks and no transcriptional response in DNA damage signalling genes indicate on a lack of adaptive response to irradiation. Altogether, our results confirmed that these isogenic cells with different radiosensitivity are an appropriate model to study the mechanisms of radioresistance.

Omethoate induces pharyngeal cancer cell proliferation and G1/S cell cycle progression by activation of Akt/GSK-3ß/cyclin D1 signaling pathway.

Omethoate is a broad category of organophosphorous pesticides (OPs) and has toxic effects on human health under long-term, low-dose exposure. However, the role of omethoate in cancer development remains elusive. The incidence of global head and neck squamous cell carcinomas (HNSCC) has markedly increased in recent years. Thus, we examined whether omethoate induced the proliferation of FaDu cells (a cell line of HNSCC) and if so, what the underlying mechanism was. The study revealed that omethoate induced FaDu cell growth in a dose- and time-dependent manner. Omethoate stimulated FaDu cell proliferation was mainly due to enhancing the G1 to S phase transition by flow cytometry analysis. We also found that omethoate up-regulated cyclin D1, a key gene controlling the G1-S transition. Furthermore, we showed that omethoate was capable of activating the Akt/GSK-3ß signaling pathway. Blockage of Akt by siRNA or small molecule inhibitor significantly suppressed omethoate-induced cyclin D1 expression and cell proliferation. Collectively, these findings demonstrated for the first time that omethoate could induce the pharyngeal cancer cell proliferation by activation of the Akt/GSK-3ß/cyclin D1 signaling pathway.

miR­490­5p regulates the proliferation, migration, invasion and epithelial­mesenchymal transition of pharyngolaryngeal cancer cells by targeting mitogen­activated protein kinase kinasekinase 9.

MicroRNA (miRNA/miR) has been identified to be a promising tool in treating pharyngolaryngeal cancer. The present study aimed to investigate the role of miR­490­5p in the regulation of proliferation, migration, invasion and epithelial­mesenchymal transition (EMT) of pharyngolaryngeal cancer cells. The data of miR­490­5p expression levels of 45 cases were obtained from the People's Hospital of Xinjiang Uygur Autonomous Region, and the prediction of the target of miR­490­5p was conducted by bioinformatics and verified using a luciferase assay. Cell viability was determined by cell counting kit­8. Migration and invasion rates were measured by wound healing test and Transwell apparatus, respectively. Colony formation rate was measured by plate colony formation assay. mRNA and protein levels were determined by quantitative polymerase chain reaction and western blotting, respectively. miR­490­5p expression was significantly depressed in primary pharyngolaryngeal cancer tissues and cell lines, leading to an unfavorable prognosis. Evidently, miR­490­5p overexpression decreased the cell viabilities of BICR 18 and FaDu cells. Mechanically, miR­490­5p could target mitogen­activated protein kinase kinasekinase 9 (MAP3K9). The overexpression of MAP3K9 could promote cell viability, migration and invasion rates, EMT process and ability of cloning, miR­490­5p could target MAP3K9 and further modulate the proliferation, migration, invasion and EMT of pharyngolaryngeal cancer cells. The results of the present study provide a novel entry point to the treatment of pharyngolaryngeal cancer.

Citrate-Induced p85α⁻PTEN Complex Formation Causes G2/M Phase Arrest in Human Pharyngeal Squamous Carcinoma Cell Lines.

Citrate is a key intermediate of the tricarboxylic acid cycle and acts as an allosteric signal to regulate the production of cellular ATP. An elevated cytosolic citrate concentration inhibits growth in several types of human cancer cells; however, the underlying mechanism by which citrate induces the growth arrest of cancer cells remains unclear. The results of this study showed that treatment of human pharyngeal squamous carcinoma (PSC) cells with a growth-suppressive concentration of citrate caused cell cycle arrest at the G2/M phase. A coimmunoprecipitation study demonstrated that citrate-induced cell cycle arrest in the G2/M phase was associated with stabilizing the formation of cyclin B1-phospho (p)-cyclin-dependent kinase 1 (CDK1) (Thr 161) complexes. The citrate-induced increased levels of cyclin B1 and G2/M phase arrest were suppressed by the caspase-3 inhibitor Ac-DEVD-CMK and caspase-3 cleavage of mutant p21 (D112N). Ectopic expression of the constitutively active form of protein kinase B (Akt1) could overcome the induction of p21 cleavage, cyclin B1-p-CDK1 (Thr 161) complexes, and G2/M phase arrest by citrate. p85α-phosphatase and tensin homolog deleted from chromosome 10 (PTEN) complex-mediated inactivation of Akt was required for citrate-induced G2/M phase cell cycle arrest because PTEN short hairpin RNA or a PTEN inhibitor (SF1670) blocked the suppression of Akt Ser 473 phosphorylation and the induction of cyclin B1-p-CDK1 (Thr 161) complexes and G2/M phase arrest by citrate. In conclusion, citrate induces G2/M phase arrest in PSC cells by inducing the formation of p85α-PTEN complexes to attenuate Akt-mediated signaling, thereby causing the formation of cyclin B1-p-CDK1 (Thr 161) complexes.

Evaluation of pemetrexed and etoposide as therapeutic regimens for human papillomavirus-positive oral and oropharyngeal cancer.

Although human papillomavirus (HPV) positive oral and oropharyngeal cancers have distinct epidemiologic and molecular characteristics compared to HPV-negative cancers, all patients with oral and oropharyngeal cancers received same standard regimen regardless of HPV status. For these reasons, specific regimens for patients with HPV-positive oral and oropharyngeal cancer are needed. Differentially expressed genes (DEG) between HPV-positive and HPV-negative oropharyngeal cancers were re-analyzed and categorized from public database. Then, druggable targets to HPV-positive oral and oropharyngeal cancer were identified and were validated with E6/E7, which is oncogene of HPV, transfected oral and oropharyngeal cancer cell lines and HPV infected cell lines. In DEG analysis, HPV-positive oral and oropharyngeal cancer showed distinct disease entity from HPV-negative cancers. Unlike HPV-negative oral and oropharyngeal cancer, thymidylate synthase (TS) and topoisomerase II (Topo II) were overexpressed in HPV-positive cancers. Transfection of Lenti-virus containing E6/ E7 to HPV-negative oral and oropharyngeal cancer cells induced upregulation of TS and Topo II in those cells. Although cisplatin, which is standard regimen in head and neck cancers, showed more effectiveness in HPV-negative cells, 5-FU and pemetrexed, which are TS inhibitors, or etoposide, which is Topo II inhibitors, worked more effectively in HPV-positive cells. In addition, cisplatin/etoposide and cisplatin/pemetrexed combination regimens showed synergic effects in HPV-positive cells. Pemetrexed or etoposide alone, or in combination with other chemotherapeutic agents such as cisplatin, can be used as novel substitutes in a regimen of concurrent chemoradiotherapy or a palliative regimen for HPV-positive oral and oropharyngeal cancer patients. However, a well-designed clinical trial is needed.

Epithelial-Mesenchymal Transition during Metastasis of HPV-Negative Pharyngeal Squamous Cell Carcinoma.

In epithelial tumors, a shift towards a mesenchymal phenotype has been associated with increased invasiveness and metastasis. It is assumed that this phenomenon plays a major role in disease progression and ultimately prognosis. This study investigated epithelial-mesenchymal transition (EMT) in human papillomavirus- (HPV-) negative pharyngeal squamous cell carcinoma. Tissue was obtained from one hypopharyngeal primary tumor and a regional lymph node metastasis during surgery with curative intention. A cell culture was established from the primary tumor and mesenchymal growth conditions were emulated. Gene expression profiling was performed (Human 8 × 60 K design array, Agilent Technologies) and EMT was assessed by a gene set (MSigDB: M5930, Hallmark_epithelial_mesenchymal_transition), applying gene set expression analysis (GSEA). Immunohistochemical staining and flow cytometry of CD44 and E-cadherin were compared in primary tumor, metastasis, and cell cultures. Primary tumor and metastasis were highly positive for CD44. A loss of E-cadherin occurred in the metastasis. Flow cytometry showed the appearance of a population without E-cadherin in spheroid colonies. In GSEA, the EMT phenotype was enriched in the primary tumor compared to metastasis and cell cultures (FDR < 25%, p < 5%). EMT showed variable expression during metastasis. It may thereby be a dynamic state in HPV-negative pharyngeal squamous cell carcinoma that is active only during the process of metastasis itself. Thereby, the primary tumor as well as the metastasis may exhibit fewer EMT properties.

Differential Prognostic Value of Metabolic Heterogeneity of Primary Tumor and Metastatic Lymph Nodes in Patients with Pharyngeal Cancer.

BACKGROUND/AIM: We aimed to explore the prognostic value of metabolic heterogeneity of 18F-FDG uptake in chemoradiotherapy-treated pharyngeal cancer patients. PATIENTS AND METHODS: This study included 52 consecutive patients with pharyngeal cancer who underwent 18F-FDG PET/CT before definitive chemoradiotherapy. The heterogeneity factor (HF) was defined as the derivative (dV/dT) of a volume-threshold function for primary tumors and metastatic lymph nodes. The relationships between clinical parameters and HFs of primary tumors (pHF) and metastatic lymph nodes (nHF) were analyzed. RESULTS: The pHF (range=∓1.367 - -0.027; median=-0.152) was significantly correlated with the maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis. Induction chemotherapy response was not correlated with HF, whereas response to radiotherapy was significantly better in patients with high pHF (low heterogeneity). Consistently, the 2-year locoregional recurrence-free survival was significantly better in patients with high pHF (82.9% for pHF>-0.152 vs. 30.5% for pHF<-0.152, log-rank p=0.009). The nHF (range=-1.067 - -0.039; median=-0.160) was not correlated with response to radiotherapy and locoregional recurrences. CONCLUSION: pHF, but not nHF, was a significant predictor of response to radiotherapy and locoregional recurrence in pharyngeal cancer. Thus, HF use can prevent unnecessary treatment and surgical delays.

Biochanin-A induces apoptosis and suppresses migration in FaDu human pharynx squamous carcinoma cells.

The aim of the present study was to investigate biochanin-A-induced anticancer effects and their cellular signaling pathway in FaDu pharyngeal squamous carcinoma cells. Biochanin-A induced cell death through increased cytotoxicity of FaDu cells in a dose- and time-dependent manner. The number of cells with nucleus condensation and the apoptotic population were increased in the FaDu cells stimulated with biochanin-A for 24 h. Furthermore, extrinsic apoptotic factors such as FasL and their downstream target caspase-8 were increased and activated in the FaDu cells treated with biochanin-A in a dose-dependent manner. Moreover, biochanin-A decreased the expression of intrinsic anti-apoptotic factors such as Bcl-2 and Bcl-xL, and increased the level and activation of intrinsic apoptotic factors such as Bad and caspase-9. Finally, biochanin-A induced the activation of caspase-3 and Poly(ADP ribose) polymerase (PARP) in FaDu cells. Our results suggest that biochanin-A-induced apoptosis was mediated by death receptor mediated-extrinsic and mitochondria-dependent intrinsic apoptotic signaling pathways. Biochanin-A also inhibited wound healing migration and proliferation of FaDu cells via the downregulation and inactivation of matrix metalloproteinase-2 and -9 that are mediated by the suppression of p38, mitogen activated protein kinase (MAPK), NF-κB and Akt cellular signaling pathways. Therefore, these data suggest that the biochanin-A may act as a potential chemotherapeutic compound to treat head and neck cancer.

The Distribution of Phosphatidylcholine Species in Superficial-Type Pharyngeal Carcinoma.

Objectives. Superficial-type pharyngeal squamous cell carcinoma (STPSCC) is defined as carcinoma in situ or microinvasive squamous cell carcinoma without invasion to the muscular layer. An exploration of the biological characteristics of STPSCC could uncover the invasion mechanism of this carcinoma. Phosphatidylcholine (PC) in combination with fatty acids is considered to play an important role in cell motility. Imaging mass spectrometry (IMS) is especially suitable for phospholipid analysis because this technique can distinguish even fatty acid compositions. Study Design. IMS analysis of frozen human specimens. Methods. IMS analysis was conducted to elucidate the distribution of PC species in STPSCC tissues. STPSCC tissue sections from five patients were analyzed, and we identified the signals that showed significant increases in the subepithelial invasive region relative to the superficial region. Results. Three kinds of PC species containing arachidonic acid, that is, PC (16:0/20:4), PC (18:1/20:4), and PC (18:0/20:4), were increased in the subepithelial invasive region. Conclusion. These results may be associated with the invasion mechanism of hypopharyngeal carcinoma.

Correlation of pretreatment 18F-FDG PET tumor textural features with gene expression in pharyngeal cancer and implications for radiotherapy-based treatment outcomes.

PURPOSE: This study investigated the correlation of the matrix heterogeneity of tumors on 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) with gene-expression profiling in patients with pharyngeal cancer and determined the prognostic factors for radiotherapy-based treatment outcomes. METHODS: We retrospectively reviewed the records of 57 patients with stage III-IV oropharyngeal or hypopharyngeal cancer who had completed definitive therapy. Four groups of the textural features as well as 31 indices were studied in addition to maximum standard uptake value, metastatic tumor volume, and total lesion glycolysis. Immunohistochemical data from pretreatment biopsy specimens (Glut1, CAIX, VEGF, HIF-1α, EGFR, Ki-67, Bcl-2, CLAUDIN-4, YAP-1, c-Met, and p16) were analyzed. The relationships between the indices and genomic expression were studied, and the robustness of various textural features relative to cause-specific survival and primary relapse-free survival was analyzed. RESULTS: The overexpression of VEGF was positively associated with the increased values of the matrix heterogeneity obtained using gray-level nonuniformity for zone (GLNUz) and run-length nonuniformity (RLNU). Advanced T stage (p = 0.01, hazard ratio [HR] = 3.38), a VEGF immunoreactive score of >2 (p = 0.03, HR = 2.79), and a higher GLNUz value (p = 0.04, HR = 2.51) were prognostic factors for low cause-specific survival, whereas advanced T stage, a HIF-1α staining percentage of ≥80%, and a higher GLNUz value were prognostic factors for low primary-relapse free survival. CONCLUSIONS: The overexpression of VEGF was associated with the increased matrix index of GLNUz and RLNU. For patients with pharyngeal cancer requiring radiotherapy, the treatment outcome can be stratified according to the textural features, T stage, and biomarkers.

Toll-like receptor 3 stimulation triggers metabolic reprogramming in pharyngeal cancer cell line through Myc, MAPK, and HIF.

Toll-like receptor 3 (TLR3) has a dual role in cancer; its activation can trigger apoptosis as well as stimulate cancer cell survival, proliferation, and progression. We have shown here that TLR3 activation can induce metabolic reprogramming in a pharyngeal cancer cell line, leading to increased aerobic glycolysis, cell migration, elevated levels of reactive oxidative species (ROS), and decreased anti-oxidative response. Key proteins in these signaling pathways are heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1), pyruvate kinase M2 (PKM2), and CD44 variants, which were over-expressed after TLR3 stimulation. TLR3 activation also induced upregulation of different genes involved in cancer progression (VEGF, MMP9, uPAR) and enzymes involved in glycolytic pathway. Most of the observed effects were Myc-dependent; however, some of them were also connected with MAPK and HIF signaling pathways. Since TLR3 agonists are being investigated as potential novel cancer therapy adjuvants and apoptosis inducers, alone or in combination with other therapeutic options, data presented here suggest extreme caution before their introduction into clinical practice. The fact that TLR3 ligands [poly(I:C) and poly(A:U)] can also aid cancer survival and progression, through induction of metabolic reprogramming, emphasizes the need to investigate this particular topic. Our data suggest that the combination of TLR3 ligands with Myc or MAPK inhibitors may be a way to neutralize their undesirable effects while enhancing their anti-tumor effect. © 2016 Wiley Periodicals, Inc.

Immunohistochemical studies and fluorodeoxyglucose uptake on positron emission tomography in pharyngeal cancer for predicting radiotherapy-based treatment outcomes.

OBJECTIVES: This study correlated immunohistochemical studies with fluorodeoxyglucose (FDG) uptake on positron emission tomography-computed tomography (PET-CT) and identified prognostic factors for radiotherapy (RT)-based treatment outcomes in patients with squamous cell carcinoma of the oropharynx and hypopharynx. METHODS: Genomic data from pre-treatment biopsy specimens (Glut1, CAIX, VEGF, HIF-1α, EGFR, Ki-67, Bcl-2, CLAUDIN-4, YAP-1, c-Met and p16) of 76 patients were analysed using tissue microarrays. FDG uptake was evaluated using the maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV) and total lesion glycolysis (TLG). RESULTS: The overexpression of Glut1 positively associated with increased values of the SUVmax, MTV and TLG, whereas VEGF and HIF-1α expression with the MTV and TLG, respectively. A VEGF immunoreactive score (IRS) >2 (P = 0.001, hazard ratio [HR] = 3.94) and an MTV defined by an SUV of 2.5 (MTV2.5) >14.5 mL (P = 0.004, HR = 3.31) were prognostic factors for low cause-specific survival, whereas a VEGF IRS >2 (P = 0.02, HR = 2.83) for low primary relapse-free survival. CONCLUSION: The overexpression of Glut1, VEGF and HIF-1α associated with increased FDG uptake. For patients with pharyngeal cancer requiring RT, the treatment outcome can be stratified by VEGF and MTV2.5.

The Characteristic of S100A7 Induction by the Hippo-YAP Pathway in Cervical and Glossopharyngeal Squamous Cell Carcinoma.

S100A7 is expressed in many squamous cell carcinomas (SCCs). Our previous study revealed that S100A7 was dramatically induced in several SCC cells and activation of the Hippo pathway significantly promoted S100A7 in epidermoid carcinoma cells. However, whether the Hippo pathway regulates S100A7 expression in SCCs remains largely unknown. Here, we uncover that S100A7 induction by the Hippo-YAP pathway displays different characteristic in cervical and glossopharyngeal SCC. In well differentiated HCC94 cervical cells and FaDu pharyngeal cells, S100A7 is easily induced by both suspension and dense culture, which is accompanied by an increase in YAP phosphorylation and a decrease in nuclear YAP. Strikingly, these correlations of S100A7 and YAP reverse after recovery of cell attachment or relief from dense culture. Further examination finds that S100A7 induction is significantly repressed by nuclear YAP, which is validated by activation or inhibition of the Hippo pathway via loss- and/or gain-of- LATS1 and MST1 function. Subsequently, we prove that TEAD1 is required for YAP transcriptional repression of S100A7. However, S100A7 is hardly induced in poorly differentiated SiHa cervical cells and NCI-H226 pulmonary cells even in suspension or activation of the Hippo pathway. More importantly, cervical and lingual SCC tissues array analyses show that S100A7 expression displays the positive correlation with pYAP-S127 and the negative correlation with nuclear YAP in the majority of well differentiated but not in poorly differentiated tissues. Collectively, our findings demonstrate that the different induction of S100A7 toward activation of the Hippo pathway mainly depends on the degree of cell differentiation in cervical and glossopharyngeal SCC.

Immunohistochemical overexpression of hypoxia-induced factor 1α associated with slow reduction in 18fluoro-2-deoxy-D-glucose uptake for chemoradiotherapy in patients with pharyngeal cancer.

BACKGROUND: This study examined genomic factors associated with a reduction in 18fluoro-2-deoxy-D-glucose (FDG) uptake during positron emission tomography-computed tomography (PET-CT) for definitive chemoradiotherapy (CRT) in patients with pharyngeal cancer. METHODS: The pretreatment and interim PET-CT images of 25 patients with advanced pharyngeal cancers receiving definitive CRT were prospectively evaluated. The maximum standardized uptake value (SUVmax) of the interim PET-CT and the reduction ratio of the SUVmax (SRR) between the two images were measured. Genomic data from pretreatment incisional biopsy specimens (SLC2A1, CAIX, VEGF, HIF1A, BCL2, Claudin-4, YAP1, MET, MKI67, and EGFR) were analyzed using tissue microarrays. Differences in FDG uptake and SRRs between tumors with low and high gene expression were examined using the Mann-Whitney test. Cox regression analysis was performed to examine the effects of variables on local control. RESULTS: The SRR of the primary tumors (SRR-P) was 0.59 ± 0.31, whereas the SRR of metastatic lymph nodes (SRR-N) was 0.54 ± 0.32. Overexpression of HIF1A was associated with a high iSUVmax of the primary tumor (P < 0.001) and neck lymph node (P = 0.04) and a low SRR-P (P = 0.02). Multivariate analysis revealed that patients who had tumors with low SRR-P or high HIF1A expression levels showed inferior local control. CONCLUSION: In patients with pharyngeal cancer requiring CRT, HIF1A overexpression was positively associated with high interim SUVmax or a slow reduction in FDG uptake. Prospective trials are needed to determine whether the local control rate can be stratified using the HIF1A level as a biomarker and SRR-P.