Head And Neck Squamous Cell Carcinoma Metastasis Research Articles

Overexpression of DDR2 contributes to cell invasion and migration in head and neck squamous cell carcinoma

Background Discoidin domain receptor 2 (DDR2) is a unique receptor tyrosine kinase (RTK) that is activated by fibrillar collagens. Although DDR2 contributes to the metastasis of some tumors, its role in head and neck squamous cell carcinoma (HNSCC) remains unknown. The aim of this study was to investigate the expression level, clinical and pathological significance, and biologic function of DDR2 in HNSCC.Methods Real-time quantitative PCR, western blot, and immunohistochemical staining were employed to assess the expression levels of DDR2 in HNSCC specimens. Adenovirus-mediated overexpression of DDR2 was used to evaluate its consequences on cell proliferation, invasion, migration, and the process of hypoxia-induced epithelial-mesenchymal transition (EMT). Then nude mouse xenograft and tail vein metastasis models were utilized to validate the in vitro results.Results DDR2 was highly expressed in high grade HNSCC tissues and lowly expressed in low grade HNSCC tissues, but absent or rarely expressed in cancer-associated normal tissues. Both the frequency and expression intensity of DDR2 were significantly associated with tumor pathologic stage and lymph node metastasis. In vitro, DDR2 overexpression in HNSCC cells failed to alter cell proliferation but markedly accelerates cell invasion and migration as well as hypoxia-induced EMT. In vivo, elevated expression of DDR2 speeds up the metastasis of HNSCC cells to the lung.Conclusion DDR2 plays an important role in HNSCC metastasis, and might be a promising target for future therapies in this type of cancer.

Immunohistochemical markers of distant metastasis in laryngeal and hypopharyngeal squamous cell carcinomas

Metastasis remains a major cause of mortality in head and neck squamous cell carcinoma (HNSCC). Current clinicopathological features have shown limited predictability for the risk of distant metastasis in individual patients, and therefore more accurate and reliable markers are needed. The aim of this study was to investigate the ability of various molecular markers present in primary tumors to predict the risk of developing distant metastasis. Restrictive clinical criteria were applied for patient selection in order to carry out a case-control study with comparable clinical features on a group-wide basis and a similar risk of metastasis. All patients were surgically treated (with postoperative radiotherapy when appropriate) and classified as stage IV disease. Immunohistochemical analysis was performed for a panel of proteins known to participate in cellular processes relevant to metastatic dissemination (E-cadherin, annexin A2, cortactin, FAK, EGFR, p53, and p-AKT). Results showed that the loss of E-cadherin expression was significantly correlated with the risk of distant metastasis (P = 0.002; log-rank test), while the loss of annexin A2 expression was nearly statistically significant (P = 0.06). None of the other protein markers assessed were associated with the development of distant metastasis. Therefore, according to our data the loss of epithelial adhesion seems to play a central role in the development of metastasis in HNSCC, and more importantly, immunohistochemical assessment of key proteins involved in cell adhesion regulation, such as E-cadherin could represent a useful tool to evaluate easily and routinely the metastatic potential of these carcinomas.

Utility of abdominal imaging to assess for liver metastasis in patients with head and neck cancer and abnormal liver function tests

PurposeTo determine the utility of abdominal imaging to further evaluate abnormal pre-operative liver function tests (LFTs) in patients with head and neck squamous cell carcinoma (HNSCC). MethodsRecords of patients evaluated by the head and neck surgery service from January 2004 through December 2009 were reviewed. For patients with abnormal alkaline phosphatase, alanine transaminase, or aspartate transaminase, subsequent abdominal imaging was assessed. ResultsOf the 862 patients with HNSCC who had documented LFTs, 109 (12.6%) had one or more abnormal values. In the same time period, LFTs were also obtained on 361 patients with benign head and neck tumors; of these, 40 (11.1%) had abnormalities. Of the 109 patients with HNSCC and abnormal LFTs, 78 (71.6%) underwent abdominal imaging (ultrasound, CT, MRI, or PET/CT). Overall, liver metastasis was demonstrated in only 1 of 109 patients with abnormal LFTs (0.92%) and in only 1 of 862 patients with HNSCC (0.12%). ConclusionsWhile HNSCC patients rarely present with liver metastasis, they often have abnormal LFTs. Although the presence of liver metastasis can dramatically change patient management, the yield of follow-up liver imaging for all patients with elevated LFTs is exceedingly low. Thus, the use of risk-stratified abdominal imaging may be prudent and cost effective in a select group of patients in whom distant metastasis is more likely. However, characteristics of this group are difficult to define given the rarity of liver metastasis in HNSCC.

TGF-β2 dictates disseminated tumour cell fate in target organs through TGF-β-RIII and p38α/β signalling

In patients non-proliferative disseminated tumour cells (DTCs) can persist in the bone marrow (BM) while other organs (i.e. lung) present growing metastasis. This suggested that the BM might be a metastasis “restrictive soil” by encoding dormancy-inducing cues in DTCs. Here we show in a HNSCC model that strong and specific TGFβ2 signalling in the BM activates p38α/β, inducing a [ERK/p38]low signalling ratio. This results in induction of DEC2/SHARP1 and p27, downregulation of CDK4 and dormancy of malignant DTCs. TGFβ2-induced dormancy required TGFβ-receptor-I, TGFβ-receptor-III and SMAD1/5 activation to induce p27. In lungs, a metastasis “permissive soil” with low TGFβ2 levels, DTC dormancy was short lived and followed by metastatic growth. Importantly, systemic inhibition of TGFβ-receptor-I or p38α/β activities awakened dormant DTCs fueling multi-organ metastasis. Our work reveals a “seed and soil” mechanism where TGFβ2 and TGFβRIII signalling through p38α/β regulates DTC dormancy and defines restrictive (BM) and -permissive (lung) microenvironments for HNSCC metastasis.

Tumour-suppressive microRNA-29s inhibit cancer cell migration and invasion by targeting laminin–integrin signalling in head and neck squamous cell carcinoma

Background:Our recent studies of microRNA (miRNA) expression signatures demonstrated that microRNA-29s (miR-29s; miR-29a/b/c) were significantly downregulated in head and neck squamous cell carcinoma (HNSCC) and were putative tumour-suppressive miRNAs in human cancers. Our aim in this study was to investigate the functional significance of miR-29s in cancer cells and to identify novel miR-29s-mediated cancer pathways and responsible genes in HNSCC oncogenesis and metastasis.Methods:Gain-of-function studies using mature miR-29s were performed to investigate cell proliferation, migration and invasion in two HNSCC cell lines (SAS and FaDu). To identify miR-29s-mediated molecular pathways and targets, we utilised gene expression analysis and in silico database analysis. Loss-of-function assays were performed to investigate the functional significance of miR-29s target genes.Results:Restoration of miR-29s in SAS and FaDu cell lines revealed significant inhibition of cancer cell migration and invasion. Gene expression data and in silico analysis demonstrated that miR-29s modulated the focal adhesion pathway. Moreover, laminin γ2 (LAMC2) and α6 integrin (ITGA6) genes were candidate targets of the regulation of miR-29s. Luciferase reporter assays showed that miR-29s directly regulated LAMC2 and ITGA6. Silencing of LAMC2 and ITGA6 genes significantly inhibited cell migration and invasion in cancer cells.Conclusion:Downregulation of miR-29s was a frequent event in HNSCC. The miR-29s acted as tumour suppressors and directly targeted laminin–integrin signalling. Recognition of tumour-suppressive miRNA-mediated cancer pathways provides new insights into the potential mechanisms of HNSCC oncogenesis and metastasis and suggests novel therapeutic strategies for the disease.

The impact of sphingosine kinase-1 in head and neck cancer.

Head and neck squamous cell carcinoma (HNSCC) has a high reoccurrence rate and an extremely low survival rate. There is limited availability of effective therapies to reduce the rate of recurrence, resulting in high morbidity and mortality of advanced cases. Late presentation, delay in detection of lesions, and a high rate of metastasis make HNSCC a devastating disease. This review offers insight into the role of sphingosine kinase-1 (SphK1), a key enzyme in sphingolipid metabolism, in HNSCC. Sphingolipids not only play a structural role in cellular membranes, but also modulate cell signal transduction pathways to influence biological outcomes such as senescence, differentiation, apoptosis, migration, proliferation, and angiogenesis. SphK1 is a critical regulator of the delicate balance between proliferation and apoptosis. The highest expression of SphK1 is found in the advanced stage of disease, and there is a positive correlation between SphK1 expression and recurrent tumors. On the other hand, silencing SphK1 reduces HNSCC tumor growth and sensitizes tumors to radiation-induced death. Thus, SphK1 plays an important and influential role in determining HNSCC proliferation and metastasis. We discuss roles of SphK1 and other sphingolipids in HNSCC development and therapeutic strategies against HNSCC.

Enhancement of head and neck squamous cell carcinoma proliferation, invasion, and metastasis by tumor‐associated fibroblasts in preclinical models

Head and neck squamous cell carcinoma (HNSCC) has had little improvement in mortality rates in decades. A clearer understanding of the HNSCC tumor microenvironment will aid in finding more effective targeted therapies for this disease. Tumor-associated fibroblasts (TAFs) are the largest stromal cellular components of the tumor microenvironment in HNSCC. We isolated TAFs from clinical HNSCC cases and propagated in vitro. The effects of TAF-secreted paracrine factors on in vitro HNSCC migration, invasion, and proliferation was assessed. The effect of TAFs on HNSCC growth and metastases was determined in an orthotopic floor-of-the-mouth tumor model. TAF-conditioned media increased HNSCC cell migration, invasion, and proliferation. TAFs increased HNSCC tumor growth and metastases in vivo. TAFs play a major role in increasing tumor growth and metastasis in HNSCC. Targeting the tumor stroma may be important to reduce the rate of HNSCC metastasis.

Abstract 4182: microRNA-29 family as tumor suppressive microRNAs in head and neck squamous cell carcinoma: microRNA-29a/b/c inhibits cell migration and invasion targeting focal adhesion and ECM pathways.

Abstract BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide. In spite of considerable advances in multimodality therapy such as surgery, radiation therapy and chemotherapy, the overall five-year survival rate for patients with HNSCC is around 40%. Understanding of the molecular cancer pathway underlying HNSCC could significantly improve diagnosis, therapy, and disease prevention. Our microRNA (miRNA) expression signatures of hypopharyngeal squamous cell carcinoma (SCC), and maxillary sinus SCC revealed that the expression of microRNA-29 family (miR-29a/b/c) was significantly reduced in cancer tissues. The aim of the study was to investigate the functional significance of miR-29a/b/c and to explore the novel molecular pathways and responsibility genes regulated by miR-29a/b/c in HNSCC. METHODS: Gain-of-function studies were performed to investigate cancer cell proliferation, migration and invasion by mature miRNAs transfection into HNSCC cell lines (SAS and FaDu). To identify the biological processes or pathways potentially regulated by the miR-29 family, we applied genome-wide gene expression analysis and in silico study; TargetScan database [http://www.targetscan.org/] and GENECODIS software, which assigned a number of the putative miRNA targets to known pathways in KEGG [http://www.genome.jp/kegg/pathway.html]. The expression levels of miR-29-family target genes were verified using public database of Gene Expression Omnibus (GEO) in HNSCC clinical specimens. RESULTS: Expression levels of miR-29 family were significantly reduced in HNSCC clinical specimens compared to adjacent non-cancerous tissues (P<0.05). Restoration of each miR-29 family significantly inhibited cancer cell proliferation, migration, and invasion in the HNSCC cell lines. Our expression and in silico analysis showed that miR-29 family appeared to be an important modulator of tumor cell processes through suppression of many targets, particularly those involved in “focal adhesion” and “ECM (extra-cellular matrix)-receptor interaction” signaling pathways (P<0.05). Among two pathways, seven genes were putative targets regulated by miR-29 family (CAV2, CDC42, ITGA6, LAMC1, COL4A1, LAMC2, and COL6A1). Gene expression data showed that three genes (ITGA6, COL4A1 and LAMC2), were significantly up-regulated in clinical HNSCC tumor specimens compared with normal epithelium. CONCLUSIONS: miR-29 family functioned as pivotal suppressor of cell migration and invasion in HNSCC through targeting “focal adhesion” and “ECM” signaling pathways. Elucidation of tumor suppressive miR-29 family-mediated cancer pathways and putative targets might be provided the novel molecular mechanisms to understand local tumor recurrence or distant metastasis of HNSCC. Citation Format: Nijiro Nohata, Toyoyuki Hanazawa, Takashi Kinoshita, Naoko Kikkawa, Noriko Yamamoto, Hirofumi Yoshino, Toshihiko Itesako, Hideki Enokida, Masayuki Nakagawa, Yoshitaka Okamoto, Naohiko Seki. microRNA-29 family as tumor suppressive microRNAs in head and neck squamous cell carcinoma: microRNA-29a/b/c inhibits cell migration and invasion targeting focal adhesion and ECM pathways. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4182. doi:10.1158/1538-7445.AM2013-4182

Abstract 1490: p38 MAPK mediates epithelial-mesenchymal transition by regulating p38IP and snail in head and neck squamous cell carcinoma (HNSCC).

Abstract Objectives: Understanding the molecular mechanisms that mediate HNSCC metastasis may enable identification of novel therapeutic targets. We have reported the role of the E-cadherin transcriptional repressor, Snail, in the inflammation-induced promotion of EMT in HNSCC. Herein we demonstrate that inflammatory mediators also upregulate p38 and p38 interacting protein (p38IP), thus further defining the cycle by which inflammation promotes tumor progression. Methods: A molecular biology study. Real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot analysis, and 3-D spheroid culture were used to determine how inflammation affects p38, p38IP and EMT. Results: p38 kinase inhibitor treated, and p38 shRNA HNSCC cell lines demonstrated a significant upregulation in E-cadherin mRNA and a decrease in the mRNA expression of the transcriptional repressor Snail. p38 shRNA HNSCC cell lines show a less invasive phenotype in a spheroid model, and demonstrate decreased tumor growth in a SCID mouse model. An inverse relationship between p-p38 and E-cadherin was demonstrated in situ by immunohistochemical staining of human HNSCC tissue sections. Activation of p38 is required for the robust IL-1β induced E-cadherin downregulation and Snail upregulation. IL-1β increases p-p38 and has a more rapid and robust effect on p38. Snail overexpression also enhanced p-p38 in vitro. Inhibition of p38 blocked HNSCC tumor growth in vivo. p38 activates p38IP, a p38 downstream component in STAGA transcriptional activator complex, in HNSCC cell lines. p38 bound to and stabilized p38IP, a subunit of histone acetyltransferase STAGA, resulting in enhanced transcription of Snail. Inhibition of p38IP blocked HNSCC migration and invasion both in vitro and in vivo. In HNSCC patient samples, p38IP expression was increased compared to adjacent normal tissue. Conclusions: In gastrulation, a Snail-independent P38/P38IP pathway is required in the primitive streak to downregulate E-cadherin expression at the posttranscriptional level. Herein we provide the first report that in HNSCC a snail-dependent p38/p38IP pathway is essential for E-cadherin down-regulation and cell invasion. Our work herein demonstrates for the first time that a snail-p38/p38IP feedback loop jointly down regulates E-cadherin and drives a potent EMT in HNSCC. This newly defined pathway has important implications for targeted chemoprevention and therapy. Citation Format: Yuan Lin, Guangyu Wang, Jie Luo, Chi Lai, Elliot Abemayor, David Elashoff, Steve Dubinett, Maie A. St. John. p38 MAPK mediates epithelial-mesenchymal transition by regulating p38IP and snail in head and neck squamous cell carcinoma (HNSCC). [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1490. doi:10.1158/1538-7445.AM2013-1490

In vitro evaluation of sialyl Lewis X relationship with head and neck cancer stem cells.

To evaluate in vitro the potential links between sialyl Lewis X (sLeX) and cancer stem cells (CSC) in head and neck squamous cell carcinoma (HNSCC). HNSCC is an aggressive malignancy with high mortality mainly due to metastasis. CSC have emerged as important players in HNSCC metastasis. sLeX is a tetrasaccharide carbohydrate known to play a key role in metastatic dissemination by promoting binding of the tumor cells to the endothelium. Experimental, in vitro. Laboratory of Head and Neck Cancer Metastasis, University of Michigan. A panel of stage- and anatomic-site specific primary and metastatic HNSCC cell lines was assessed by flow cytometry to quantify sLeX relative expression levels. Serum-free conditioned media from the same HNSCC lines was collected over a time course of 72 hours and assessed by Western blot for secreted sLeX expression. Representative HNSCC cell lines were cultured as floating orospheres (condition that enhance CSC growth) or under normal adherent conditions and characterized by flow cytometry for CSC markers (CD44, aldehyde dehydrogenase [ALDH]) comparatively with sLeX expression. sLeX is predominantly expressed in carcinomas originating from the oral cavity. Secreted sLeX is also found to be high in oral carcinomas and increased over the analyzed time course. Floating orospheres were strongly positive for CD44 and ALDH, confirming CSC enrichment of the orospheres. Tumor cells grown as orospheres are 95% to 100% positive for sLeX compared to 10% to 40% of adherent counterpart. These studies provide the first evidence of sLeX relationship with CSC in HNSCC.

Rab25 regulates invasion and metastasis in head and neck cancer.

Head and neck squamous cell carcinoma (HNSCC) is one of the 10 most common cancers with a 50% five-year survival rate, which has remained unchanged for the past three decades. One of the major reasons for the aggressiveness of this cancer is that HNSCCs readily metastasize to cervical lymph nodes that are abundant in the head and neck region. Hence, discovering new molecules controlling the metastatic process as well as understanding their regulation at the molecular level are essential for effective therapeutic strategies. Rab25 expression level was analyzed in HNSCC tissue microarray. We used a combination of intravital microscopy in live animals and immunofluorescence in an in vitro invasion assay to study the role of Rab25 in tumor cell migration and invasion. In this study, we identified the small GTPase Rab25 as a key regulator of HNSCC metastasis. We observed that Rab25 is downregulated in HNSCC patients. Next, we determined that reexpression of Rab25 in a metastatic cell line is sufficient to block invasion in a three-dimensional collagen matrix and metastasis to cervical lymph nodes in a mouse model for oral cancer. Specifically, Rab25 affects the organization of F-actin at the cell surface, rather than cell proliferation, apoptosis, or tumor angiogenesis. These findings suggest that Rab25 plays an important role in tumor migration and metastasis, and that understanding its function may lead to the development of new strategies to prevent metastasis in oral cancer patients.

The Tumor Microenvironment Contribution to Development, Growth, Invasion and Metastasis of Head and Neck Squamous Cell Carcinomas

Head and neck squamous cell carcinoma (HNSCC) is a complex tissue that contains tumor cells and the surrounding stroma, which is populated by different types of mesenchymal cells and the extracellular matrix (ECM). Collectively, they are referred to as the tumor microenvironment (TME). Recent studies have shown that TME has a more profound influence on the growth and metastasis of HNSCC than was previously appreciated. Because carcinoma-associated fibroblasts (CAFs) are frequently observed in the stroma of the tumor, this review focuses on the potential role of tumor-CAFs interactions in progression of HNSCC. Tumor-CAFs crosstalk enhances the production of growth factors, cytokines, chemokines, matrix metalloproteinases (MMPs), and inflammatory mediators, which eventually facilitates tumor growth. In fact, factors and cells that do not support tumor growth are usually down regulated or mitigated in TME. Therefore TME may determine the fate of the tumors at the site of invasion and metastasis. For tumor cells that survive at these sites, stromal activation may serve to establish a supportive tumor stroma, fostering the outgrowth of the metastatic cells. The concept of tumor-stromal interactions and microenvironmental niche has profound consequences in tumor growth and metastasis and therefore, it's understanding will open up new strategies for the diagnosis, prognosis and therapy of HNSCC.

Autocrine and paracrine loops between cancer cells and macrophages promote lymph node metastasis via CCR4/CCL22 in head and neck squamous cell carcinoma

Lymph node metastasis is a poor prognostic factor for patients with head and neck squamous cell carcinoma (HNSCC). However, its molecular mechanism has not yet been fully understood. In our study, we investigated the expression of CCR4 and its ligand CCL22 in the HNSCC tumor microenvironment and found that the CCR4/CCL22 axis was involved in lymph node metastasis of HNSCC. CCR4 was expressed in 20 of 31 (64.5%) human tongue cancer tissues, and its expression was significantly correlated with lymph node metastasis (p < 0.01) and lymphatic invasion (p < 0.05). CCR4 was expressed in three of five human HNSCC cell lines tested. CCR4(+) HNSCC cells, but not CCR4(-) cells, showed enhanced migration toward CCL22, indicating that functional CCR4 was expressed in HNSCC cell lines. CCL22 was also expressed in cancer cells (48.4% of tongue cancer tissues) or CD206(+) M2-like macrophages infiltrated in tumors and draining lymph nodes. CCL22 produced by cancer cells or CD206(high) M2-like macrophages increased the cell motility of CCR4(+) HNSCC cells in vitro in an autocrine or paracrine manner. In the mouse SCCVII in vivo model, CCR4(+) cancer cells, but not CCR4(-) cells, metastasized to lymph nodes which contained CCL22 producing M2-like macrophages. These results demonstrate that lymph node metastasis of CCR4(+) HNSCC is promoted by CCL22 in an autocrine or M2-like macrophage-dependent paracrine manner. Therefore, the CCR4/CCL22 axis may be an attractive target for the development of diagnostic and therapeutic strategies for patients with HNSCC.

Dysregulated miR-363 affects head and neck cancer invasion and metastasis by targeting podoplanin

Head and neck squamous cell carcinoma (HNSCC) is characterised by an elevated capacity for tumour invasion and lymph node metastasis and the cause remains to be determined. Recent studies suggest that microRNAs can regulate the evolution of malignant behaviours by regulating multiple target genes. In this study, we have first confirmed that miR-363 is down-regulated in HNSCC tissues with lymph node metastasis and cell lines with highly invasive capacity. We used bioinformatics, cellular and molecular methods to predict and prove that miR-363 directly targeted to podoplanin (PDPN) and caused up-regulation of PDPN in HNSCC. MSP assay showed that DNA promoter methylation was involved in silencing the miR-363 in HNSCC. Furthermore, we provided evidence to demonstrate that PDPN dysregulation caused by down-regulation of miR-363 contributes to HNSCC invasion and metastasis. These data reveal a key role of miR-363-PDPN in HNSCC metastasis and support biological and clinical links between miR-363-PDPN and HNSCC.

Receptor-type Protein Tyrosine Phosphatase β Regulates Met Phosphorylation and Function in Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer and has a high rate of mortality. Emerging evidence indicates that hepatocyte growth factor receptor (or Met) pathway plays a pivotal role in HNSCC metastasis and resistance to chemotherapy. Met function is dependent on tyrosine phosphorylation that is under direct control by receptor-type protein tyrosine phosphatase β (RPTP-β). We report here that RPTP-β expression is significantly downregulated in HNSCC cells derived from metastatic tumors compared to subject-matched cells from primary tumors. Knockdown of endogenous RPTP-β in HNSCC cells from primary tumor potentiated Met tyrosine phosphorylation, downstream mitogen-activated protein (MAP) kinase pathway activation, cell migration, and invasion. Conversely, restoration of RPTP-β expression in cells from matched metastatic tumor decreased Met tyrosine phosphorylation and downstream functions. Furthermore, we observed that six of eight HNSCC tumors had reduced levels of RPTP-β protein in comparison with normal oral tissues. Collectively, the results demonstrate the importance of RPTP-β in tumor biology of HNSCC through direct dephosphorylation of Met and regulation of downstream signal transduction pathways. Reduced RPTP-β levels, with or without Met overexpression, could promote Met activation in HNSCC tumors.

Apricoxib upregulates 15-PGDH and PGT in tobacco-related epithelial malignancies

Background:Despite focused research in conventional therapies and considerable advances in the understanding of the molecular carcinogenesis of head and neck squamous cell carcinoma (HNSCC), the 5-year survival rate for patients with advanced disease remains ∼15–20%. The major causes of HNSCC-related deaths are cervical node and distant metastasis. E-cadherin has a key role in epithelial intercellular adhesion and its downregulation is a hallmark of epithelial–mesenchymal transition (EMT), which is associated with invasion, metastasis, and poor prognosis. Epithelial–mesenchymal transition is the major mechanism responsible for mediating invasiveness and metastasis of epithelial cancers. Recently, we reported the role of E-cadherin transcriptional repressors in the inflammation-induced promotion of EMT in HNSCC, which is mediated by COX-2. These findings suggest that therapies targeting the cyclooxygenase pathway may diminish the propensity for tumour metastasis in HNSCC by blocking the PGE2-mediated induction of E-cadherin transcriptional repressors.Methods:Herein, we evaluate the efficacy of the COX-2 inhibitor, apricoxib, in HNSCC cell lines. Apricoxib is effective in preventing tumour cell growth in three-dimensional, and anchorage-independent growth assays, as well as decreasing the capacity for tumour cell migration.Results:Herein, we evaluate the efficacy of the COX-2 inhibitor, apricoxib, in HNSCC cell lines. Apricoxib is effective in preventing tumour cell growth in three-dimensional, and anchorage-independent growth assays, as well as decreasing the capacity for tumour cell migration. Treatment of HNSCC cells with apricoxib also causes greater upregulation of E-cadherin and Muc1 expression and downregulation of vimentin, as compared with celecoxib treatment. This has significant implications for targeted chemoprevention and anti-cancer therapy because E-cadherin expression has been implicated as a marker of sensitivity to epidermal growth factor receptor tyrosine kinase inhibitor and other therapies. We show for the first time the molecular mechanisms underlying the efficacy of apricoxib in HNSCC cells.Conclusion:In addition to reversing EMT via inhibition of COX-2, apricoxib upregulates 15-prostaglandin dehydrogenase and the prostaglandin transporter, thereby reducing the levels of active PGE2 by both suppressing its synthesis and increasing its catabolism. These findings have significant implications for metastasis and tumour progression in HNSCC.

Epithelial-to-mesenchymal transition and cancer stem(-like) cells in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the 6th commonest cancer worldwide. Relapse, thought to involve cancer stem(-like) cells (CSCs), and the development of metastases are common and survival rates remain low. Epithelial-to-mesenchymal transition (EMT) is a key event in metastasis and increasing evidence suggests a link between EMT and CSCs. MicroRNAs regulate multiple cellular processes including EMT and have been implicated in a CSC phenotype. This review aims to highlight key events that are involved in EMT, discusses their relevance in HNSCC progression and metastasis and explores the possibility of targeting EMT as a novel therapy in HNSCC.

One-step nucleic acid amplification for detecting lymph node metastasis of head and neck squamous cell carcinoma

Lymph node stage is an important prognostic factor in head and neck squamous cell carcinoma (HNSCC). We previously reported the clinical usefulness of sentinel lymph node biopsy diagnosed by genetic analysis using quantitative RT-PCR. However, this method takes about 3h. In this study, we attempted to develop a more efficient method for the intraoperative genetic detection of lymph node metastasis in HNSCC. A total of 312 lymph nodes (65 patients) were diagnosed by the one-step nucleic acid amplification (OSNA) method using GD-100. OSNA consists of a short homogenization step followed by amplification of cytokeratin 19 (CK19) mRNA directly from the lysate. Each lymph node was divided into two to diagnose metastasis. One half was used for the OSNA assay, and the other was subjected to semi-serial sectioning, sliced at 200-μm intervals and examined by H&E and cytokeratin AE1/AE3 immunohistochemical staining. The accuracy of OSNA assay was evaluated based on histopathological diagnosis. Sixty-one of 312 lymph nodes were pathologically metastasis-positive. The overall concordance rate between the OSNA assay using breast cancer criteria and histopathology was 94.2%. The optimal cut-off for the copy number of CK19 mRNA in assessing lymph node metastasis of HNSCC was 300 copies/μl, which had the highest diagnostic accuracy (95.2%). The OSNA assay can be completed within 30 min. The OSNA assay, which shows high sensitivity and specificity, suggests the possibility to be used as a novel tool for the genetic detection of lymph node metastasis in HNSCC patients.

Low-Level Expression of miR-375 Correlates with Poor Outcome and Metastasis While Altering the Invasive Properties of Head and Neck Squamous Cell Carcinomas

Small, noncoding microRNAs (miRNAs) have been shown to be abnormally expressed in every tumor type examined. We used comparisons of global miRNA expression profiles of head and neck squamous cell carcinoma (HNSCC) samples and adjacent normal tissue to rank those miRNAs that were most significantly altered in our patient population. Rank Consistency Score analysis revealed miR-375 to have the most significantly lowered miRNA levels in tumors relative to matched adjacent nonmalignant tissue from the same patient among 736 miRNAs that were evaluated. This result has been previously observed by other groups; however, we extend this finding with the unique observation that low miR-375 expression levels correlate significantly with cancer survival and distant metastasis. In a study of 123 primary HNSCC patients using multivariable Cox proportional hazard ratios (HR) and 95% confidence intervals (CI), both death from disease (HR: 12.8, 95% CI: 3 to 49) and incidence of distant metastasis (HR: 8.7, 95% CI: 2 to 31) correlated with lower expression levels of miR-375 regardless of the site or stage of the tumor. In addition, we found that oral cavity tumor cell lines (eg, UMSCC1 and UMSCC47) overexpressing miR-375 were significantly less invasive in vitro than their matched empty vector controls. We conclude that miR-375 represents a potential prognostic marker of poor outcome and metastasis in HNSCC and that it may function by suppressing the tumor's invasive properties.

Value of18F-Fluorodeoxyglucose Position Emission Tomography/Computed Tomography in Diagnosis of Cervical Lymph Node Metastasis of Head and Neck Squamous Cell Carcinoma: Comparison with Computed Tomography and Magnetic Resonance Imaging

Received January 31, 2012 Revised April 17, 2012 Accepted May 9, 2012 Address for correspondence Kyung Tae, MD Departments of OtolaryngologyHead and Neck Surgery, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-792, Korea Tel +82-2-2290-8585 Fax +82-2-2293-3335 E-mail kytae@hanyang.ac.kr Background and ObjectivesZZCervical lymph node metastasis is a very important prognostic factor of head and neck squamous cell carcinoma (HNSCC). Therefore, strict evaluation of cervical lymph node metastasis is necessary for accurate staging and proper treatment planning. This study compares computed tomography (CT) and magnetic resonance imaging (MRI) to position emission tomography-computed tomography (PET-CT), and evaluates the clinical role of PET-CT in the diagnosis of cervical metastasis of HNSCC. Subjects and MethodZZFrom October 2004 to September 2010, we studied 74 patients with HNSCC who underwent PET-CT, CT and MRI before undergoing neck dissection for the treatment of cervical lymph node metastasis. We compared pathologic results of 374 cervical lymph node levels in 74 patients with results of PET-CT, CT and MRI. We analyzed and compared sensitivity, specificity, predictability and accuracy of the three imaging methods. ResultsZZAmong the 74 patients, 49 (66.2%) patients had positive cervical lymph node metastasis. Of the 374 cervical lymph node levels, 86 levels were confirmed to be positive lymph node metastasis. Sensitivity and specificity of PET-CT was 87.4% and 94.8% when the cut-off value of SUVmax was 1.855. Sensitivity, specificity, positive and negative predictive value and accuracy of PET-CT were higher than those of CT or MRI. ConclusionZZPET-CT is more effective than CT or MRI in the diagnosis of cervical lymph node metastasis of HNSCC. Korean J Otorhinolaryngol-Head Neck Surg 2012;55:364-8