HSulf-1 modulates HGF-mediated tumor cell invasion and signaling in head and neck squamous carcinoma

Recently, we cloned a novel sulfatase domain-containing downregulated gene, HSulf-1, which modulates heparin-binding growth factor signaling in ovarian cancer. Based on the pilot data showing the loss of HSulf-1 in head and neck squamous cell carcinoma cell lines (SCCHN), we sought to employ SCCHN as a model to define the role of HSulf-1 in the molecular regulation of tumorigenicity. Three SCCHN lines (012SCC, WMMSCC, and 015SCC) had no detectable HSulf-1 mRNA. Clonal lines of HSulf-1-expressing 012SCC attenuated the activation of ERK/mitogen-activated protein kinase (MAPK) signaling mediated by fibroblast growth factor (FGF-2) and both ERK/MAPK and Akt signaling mediated by hepatocyte growth factor (HGF). Consistent with this downregulation, phosphorylation of HGF receptor, c-Met, which is frequently overexpressed in SCCHN, was also attenuated in HSulf-1 clonal 012SCC cell lines. HGF markedly enhanced the motility and migration of vector-transfected cells in a transwell invasion chamber. However, HGF-mediated motility and invasion was attenuated in HSulf-1 clonal 012SCC cell lines. In addition, transfected cells displayed significant growth inhibition concomitant with a decrease in mitogenicity, as measured by thymidine incorporation and increased sensitivity to staurosporine- and cisplatin-induced apoptosis. These data suggest that HSulf-1 normally functions as a negative regulator in cell growth and loss of HSulf-1 in SCCHN potentiates growth factor signaling, enhances motility, invasiveness and inhibits stress-induced apoptosis, with a resulting increase in tumorigenicity.     

miR-1 as a tumor suppressive microRNA targeting TAGLN2 in head and neck squamous cell carcinoma

Based on the microRNA (miRNA) expression signatures of hypopharyngeal and esophageal squamous cell carcinoma, we found that miR-1 was significantly down-regulated in cancer cells. In this study, we investigated the functional significance of miR-1 in head and neck squamous cell carcinoma (HNSCC) cells and identified miR-1-regulated novel cancer pathways. Gain-of-function studies using miR-1 revealed significant decreases in HNSCC cell proliferation, invasion, and migration. In addition, the promotion of cell apoptosis and cell cycle arrest was demonstrated following miR-1e transfection of cancer cells. A search for the targets of miR-1 revealed that transgelin 2 (TAGLN2) was directly regulated by miR-1. Silencing of TAGLN2 significantly inhibited cell proliferation and invasion in HNSCC cells. Down-regulation of miR-1 and up-regulation of TAGLN2 were confirmed in HNSCC clinical specimens. Our data indicate that TAGLN2 may have an oncogenic function and may be regulated by miR-1, a tumor suppressive miRNA in HNSCC. The identification of novel miR-1-regulated cancer pathways could provide new insights into potential molecular mechanisms of HNSCC carcinogenesis.     

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

BackgroundDiscoidin 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.MethodsReal-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.ResultsDDR2 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.ConclusionDDR2 plays an important role in HNSCC metastasis, and might be a promising target for future therapies in this type of cancer.     

Identification of novel molecular targets regulated by tumor suppressive miR-1/miR-133a in maxillary sinus squamous cell carcinoma

Based on our microRNA (miRNA) expression signature analysis of maxillary sinus squamous cell carcinoma (MSSCC), we found that miR-1 and miR-133a were significantly reduced in tumor tissues. Quantitative real-time RT-PCR revealed that the expression levels of miR-1 and miR-133a were significantly downregulated in clinical MSSCC tumor tissues compared with normal tissues. We focused on the functional significance of miR-1 and miR-133a in cancer cells and identification of the novel cancer networks regulated by these miRNAs in MSSCC. Restoration of downregulated miRNAs (miR-1 or miR-133a) in cancer cells revealed that both miRNAs significantly inhibited cancer cell proliferation and induced cell apoptosis. Molecular target identification of these miRNAs showed that transgelin 2 (TAGLN2) and purine nucleoside phosphorylase (PNP) were regulated by miR-1 and miR-133a. Both TAGLN2 and PNP mRNA expression levels were significantly upregulated in clinical MSSCC tumor tissues. Silencing studies of target genes demonstrated that both genes inhibited cancer cell proliferation. The identification of novel miR-1/miR-133a-regulated cancer pathways could provide new insights into potential molecular mechanisms of MSSCC oncogenesis.     

KiSS1 mediates platinum sensitivity and metastasis suppression in head and neck squamous cell carcinoma

Although surgery and radiotherapy have been the standard treatment modalities for head and neck squamous cell carcinoma (HNSCC), the integration of cisplatin (CDDP)-based therapy has led to improvements in local and regional control of disease for patients. However, many trials show that only 10-20% of patients benefit from this treatment intensification, which can result in profound treatment-associated morbidity and mortality. Moreover, the marginal survival improvement suggests that CDDP resistance is an innate characteristic of HNSCC. To elucidate the biological mechanisms underpinning CDDP resistance in HNSCC, we utilized an experimental model of CDDP resistance in this disease. We first observed significant enhancements in local tumor growth and metastasis, as well as adverse survival, in CDDP-resistant (CR) tumors compared with sensitive tumors. To elucidate the molecular mechanisms of this phenotype, we undertook a systems biology-based approach utilizing high-throughput PCR arrays, and we identified a significant suppression of KiSS1 mRNA and protein expression in the CR cells, but no significant regions of genomic loss with array comparative genomic hybridization. Genetic suppression of KiSS1 in CDDP-sensitive cell lines rendered them CR, an observation that was mechanistically linked to alterations in glutathione S-transferase-π expression and function. We next confirmed that, in human HNSCC tumors, loss of KiSS1 expression was associated with metastatic human HNSCC tumors compared with non-metastatic tumors. Genetic reconstitution of KiSS1 in CR cells abrogated cellular migration and induced CDDP sensitivity. To confirm these findings in a murine model, either CR or KiSS1-transfected CR cells were studied in an orthotopic model of HNSCC, or survival studies revealed significant improvement in survival of the mice bearing CR-KiSS1 tumors. Mechanistically, alterations in apoptotic pathways and CDDP metabolism contributed to KiSS1-associated chemotherapy sensitization. These studies provided further direct evidence for the role of KiSS1 loss in biologically aggressive HNSCC and suggest potential targets for therapy in CR cancers.     

Cyclophilin A-EMMPRIN interaction induces invasion of head and neck squamous cell carcinoma

Extracellular matrix remodeling crucial to tumorigenesis involves proteolytic enzymes, primarily matrix metalloproteinases (MMPs). MMP production is stimulated by multiple factors, including the extracellular matrix metallo-proteinase inducer EMMPRIN/CD147. Overexpression of EMMPRIN, a member of the immunoglobulin superfamily, promotes invasion, metastasis, growth and survival of malignant cells. Cyclophilin A (CypA) is a multifunctional protein that promotes cancer progression in various cancer types. CypA can interact with and activate EMMPRIN; however, the role of CypA-EMMPRIN interaction in oncogenicity is not completely understood. To investigate tumorigenicity induced by the CypA-EMMPRIN interaction, we stimulated EMMPRIN-expressing head and neck squamous cell carcinoma (HNSCC) cells with CypA. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide dye assay revealed that HNSCC cell proliferation increased upon stimulation of the cells with CypA, whereas cisplatin-induced cell death decreased after stimulation. Gelatin zymography showed that CypA also induced MMP-9 up-regulation. Moreover, HNSCC cell invasion through Matrigel?-coated membranes was increased upon stimulation of cells with CypA. This elevated invasive potential was abrogated by an EMMPRIN function-blocking antibody. These findings suggest that CypA, through its interaction with EMMPRIN, contributes to HNSCC tumorigenesis.     

Frequently methylated tumor suppressor genes in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a very aggressive cancer. In advanced stages, the patient has poor chances of receiving effective treatment, and survival rates are low. To facilitate timely diagnosis and improve treatment, elucidation of early detection markers is crucial. DNA methylation markers are particularly advantageous because DNA methylation is an early event in tumorigenesis, and the epigenetic modification, 5-methylcytosine, is a stable mark. A genome-wide screen using Restriction Landmark Genomic Scanning found a set of genes that are most commonly methylated in head and neck cancers. Five candidate genes: septin 9 (SEPT9), sodium-coupled monocarboxylate transporter 1 (SLC5A8), functional smad-suppressing element on chromosome 18 (FUSSEL18), early B-cell factor 3 (EBF3), and iroquois homeobox 1 (IRX1) were methylated in 27% to 67% of the HNSCC patient samples tested. Furthermore, approximately 50% of the methylated tumor samples shared methylation between two of the five genes (most commonly between EBF3 and IRX1), and 15% shared methylation between three of the five genes. Expression analysis revealed candidate gene down-regulation in 25% to 93% of the HNSCC samples, and 5-aza-2'-deoxycytidine treatment was able to restore expression in at least 2 of 5 HNSCC cell lines for all of the genes tested. Overexpression of the three most frequently down-regulated candidates, SLC5A8, IRX1, and EBF3, validated their tumor suppressor potential by growth curve analysis and colony formation assay. Interestingly, all of the candidates identified may be involved in the transforming growth factor beta signaling pathway, which is often disrupted in HNSCC.     

Tumor suppressive microRNA-218 inhibits cancer cell migration and invasion through targeting laminin-332 in head and neck squamous cell carcinoma

Recent our microRNA (miRNA) expression signature revealed that expression of microRNA-218 (miR-218) was reduced in cancer tissues, suggesting a candidate of tumor suppressor in head and neck squamous cell carcinoma (HNSCC). The aim of this study was to investigate the functional significance of miR-218 and its mediated moleculer pathways in HNSCC. Restoration of miR-218 in cancer cells led to significant inhibition of cell migration and invasion activities in HNSCC cell lines (FaDu and SAS). Genome-wide gene expression analysis of miR-218 transfectants and in silico database analysis showed that focal adhesion pathway was a promising candidate of miR-218 target pathways. The laminins are an important and biologically active part of the basal lamina, the function of that are various such as influencing cell differentiation, migration and adhesion as well as proliferation and cell survival. Interestingly, all components of laminin-332 (LAMA3, LAMB3 and LAMC2) are listed on the candidate genes in focal adhesion pathway. Furthermore, we focused on LAMB3 which has a miR-218 target site and gene expression studies and luciferase reporter assays showed that LAMB3 was directly regulated by miR-218. Silencing study of LAMB3 demonstrated significant inhibition of cell migration and invasion. In clinical specimens with HNSCC, the expression levels of laminin-332 were significantly upregulated in cancer tissues compared to adjacent non-cancerous tissues. Our analysis data showed that tumor suppressive miR-218 contributes to cancer cell migration and invasion through regulating focal adhesion pathway, especially laminin-332. Tumor suppressive miRNA-mediated novel cancer pathways provide new insights into the potential mechanisms of HNSCC oncogenesis.     

Actin-related protein 2/3 complex subunit 5 (ARPC5) contributes to cell migration and invasion and is directly regulated by tumor-suppressive microRNA-133a in head and neck squamous cell carcinoma

Our expression signatures of human cancers including head and neck squamous cell carcinoma (HNSCC) demonstrated that downregulation of microRNA-133a (miR-133a) were frequently observed in cancer cells. The restoration of miR-133a in cancer cells revealed that it functions as a tumor suppressor. In this study, we investigated the novel molecular targets of miR-133a in HNSCC cancer cells and its oncogenic function, especially as it contributes to cancer cell migration and invasion. The genome-wide gene expression analysis and bioinformatics study showed that actin-related protein 2/3 complex subunit 5 (ARPC5) is a candidate target of miR-133a. Furthermore, luciferase reporter assay demonstrated that ARPC5 is directly regulated by miR-133a. Silencing of ARPC5 revealed significant inhibition of cell migration and invasion in HNSCC cell lines, SAS, HSC3 and IMC-3. In HSC3 cells, restoration of miR-133a or silencing ARPC5 led to a reorganization of the actin cytoskeleton and a subsequent change in cell morphology to a round, bleb-like shape. The expression levels of ARPC5 were significantly higher in HNSCC tissues than in non-cancer tissues. Immunohistochemistry showed that the levels of ARPC5 expression were significantly higher in invasive cancer cells. ARPC5 contributed to cancer cell migration and invasion in HNSCC and this gene was directly regulated by miR-133a. Our analysis of novel tumor-suppressive miR?133a-mediated cancer pathways provides new insights into the potential mechanisms of HNSCC oncogenesis.     

MicroRNA-138 suppresses invasion and promotes apoptosis in head and neck squamous cell carcinoma cell lines

Metastasis is a critical event in the progression of head and neck squamous cell carcinoma (HNSCC). To identify microRNAs associated with HNSCC metastasis, six paired HNSCC cell lines with different metastatic potential were examined. Using microarrays, a panel of differentially expressed microRNAs was identified, including reduction of miR-138 in highly metastatic cells. Ectopic transfection of miR-138 suppressed cell invasion and led to cell cycle arrest and apoptosis. Knockdown of miR-138 enhanced cell invasion and suppressed apoptosis. Thus, our results suggested miR-138 acts as a tumor suppresser and may serve as a therapeutic target for HNSCC patients at risk of metastasis.     

PD-L1在头颈部鳞癌中的表达及其临床意义

目的探讨程序性死亡受体配体1(PD-L1)在头颈部鳞癌(HNSCC)组织中的表达及其临床意义。方法收集69例HNSCC患者的肿瘤组织和外周血标本,应用免疫组织化学法检测肿瘤组织中PD-L1的表达情况,应用免疫透射比浊法检测外周血C反应蛋白(CRP)水平,分析PD-L1表达情况与患者临床特征及外周血CRP水平的关系。结果 HNSCC患者的PD-L1阳性表达率为14.5%(10/69),PD-L1阴性表达和PD-L1阳性表达HNSCC患者的1年内远处转移情况和血管内皮生长因子(VEGF)表达状态比较,差异均有统计学意义(P﹤0.05)。PD-L1阴性表达患者的远处无转移生存情况明显优于PD-L1阳性表达患者(P﹤0.01)。PD-L1阳性表达患者的外周血CRP水平低于PD-L1阴性表达患者(P﹤0.05)。结论 PD-L1可能是HNSCC患者的潜在预后生物标志物,并且与机体的免疫状态密切相关。     

头颈部鳞癌手术切缘分子标记物

手术是头颈部鳞癌治疗的主要方法之一,阴性切缘对于手术治疗的效果十分关键.研究显示,分子生物学检测较常规病理检查可更早期、更准确地对手术切缘进行评估,为术后治疗策略的制定和预后预测提供更佳的依据.     

Caveolin-1-negative head and neck squamous cell carcinoma primary tumors display increased epithelial to mesenchymal transition and prometastatic properties

Distant metastases arise in 20-30% of patients with squamous cell carcinoma of the head and neck (HNSCC) in the 2 years following treatment. Therapeutic options are limited and the outcome of the patients is poor. The identification of predictive biomarkers of patient at risk for distant metastasis and therapies are urgently needed. We previously identified a clinical subgroup, called “R1” characterized by high propensity for rapid distant metastasis. Here, we showed that “R1” patients do not or at very low level express caveolin-1 (Cav1). Low or no expression of Cav1 is of bad prognosis. Disappearance of Cav1 enables cells to undergo epithelial-mesenchymal transition (EMT). EMT is associated with enhanced migration and invasion. Our study uncovered a new target, α₅β₁ integrin. Targeting α₅β₁ integrins might not only prevent metastasis of HNSCC but also delay the development of the primary tumor by reducing tumor cell viability. Cav1 detection might be taken into consideration in the future in the clinic not only to identify patients at high risk of metastasis but also to select patient who might benefit from an anti-integrin therapy.     

miR-375靶向SHOX2调控人食管鳞癌细胞侵袭迁移的初步研究

目的 探讨miR-375/SHOX2轴对食管鳞癌细胞侵袭迁移能力的影响,为食管鳞癌的靶向治疗寻找潜在新靶点。方法 选取对数生长期的人食管鳞癌细胞（kyse-70、kyse-30）,分别过表达以及干扰miR-375和SHOX2基因,采用克隆形成、MTT、划痕、Transwell等体外细胞功能学实验检测miR-375、SHOX2对食管鳞癌细胞增殖、迁移和侵袭能力的影响,通过拯救实验验证miR-375对SHOX2的靶向调控作用。结果 与对照组的kyse-70、kyse-30细胞相比,过表达miR-375或干扰SHOX2基因后的细胞增殖率、克隆形成率和Transwell细胞穿透数均降低,差异均有统计学意义（P＜0.01）;与对照组的kyse-70、kyse-30细胞相比,干扰miR-375或过表达SHOX2后的细胞增殖率、克隆形成率和Transwell细胞穿透数均升高,差异均有统计学意义（P＜0.01）;miR-375过表达后的食管鳞癌细胞SHOX2基因表达减少,而抑制miR-375后SHOX2基因表达增强。拯救实验结果显示,共转染miR-375和SHOX2后细胞增殖和侵袭能力较对照组又有所增强。结论 miR-375抑制食管鳞癌细胞增殖和侵袭;SHOX2促进食管鳞癌细胞增殖和侵袭。miR-375靶向负调控SHOX2表达,对食管鳞癌细胞的增殖和侵袭起调控作用。