Yukio Yamano

Identification of cisplatin-resistance related genes in head and neck squamous cell carcinoma.

Resistance to cisplatin is a major obstacle to successful treatment of head and neck squamous cell carcinoma (HNSCC). To investigate the molecular mechanism of this resistance, we compared the gene expression profiles between the cisplatin‐sensitive SCC cell lines (Sa‐3, H‐1 and KB) and the cisplatin‐resistant cell lines established from them (Sa‐3R, H‐1R and KB‐R) using Affymetrix U133 Plus 2.0 microarray. We identified 199 genes differentially expressed in each group. To identify important functional networks and ontologies to cisplatin resistance, the 199 genes were analyzed using the Ingenuity Pathway Analysis Tool. Fifty‐one of these genes were mapped to genetic networks, and we validated the top‐10 upregulated genes by real‐time reverse transcriptase‐polymerase chain reaction. Five novel genes, LUM, PDE3B, PDGF‐C, NRG1 and PKD2, showed excellent concordance with the microarray data. In 48 patients with oral SCC (OSCC), positive immunohistochemical staining for the five genes correlated with chemoresistance to cisplatin‐based combination chemotherapy. In addition, the expression of the five genes predicted the patient outcomes with chemotherapy. Furthermore, siRNA‐directed suppressed expression of the five genes resulted in enhanced susceptibility to cisplatin‐mediated apoptosis. These results suggested that these five novel genes have great potential for predicting the efficacy of cisplatin‐based chemotherapy against OSCC. Global gene analysis of cisplatin‐resistant cell lines may provide new insights into the mechanisms underlying clinical cisplatin resistance and improve the efficacy of chemotherapy for human HNSCC.

State of heat shock factor 1 expression as a putative diagnostic marker for oral squamous cell carcinoma

Heat shock factor 1 (HSF1) is responsible for expres-- sion of a large class of heat shock proteins that have been implicated in the malignant phenotype of human cancers. Little is known about the effect of a high level of HSF1 on the behavior of oral squamous cell carcinoma (OSCC). In this study, we assessed the value of HSF1 for predicting clinical outcomes in OSCC. Quantitative reverse transcriptase-polymerase chain reaction and Western blotting showed that the expressions of HSF1 mRNA and protein in OSCC-derived cell lines (HSC-2, HSC-3, HSC-4, Sa3, Ca9-22, KON and Ho-1-u-1) were elevated compared with those in human normal oral keratinocytes (P<0.05). Similar to in vitro data, HSF1 mRNA expression in primary OSCCs (n=50) was significantly greater than in normal counterparts (P<0.05). Since HSF1 was observed in the nucleus and cytoplasm by immu-- nohistochemistry, we investigated the correlation between the HSF1 expression status at each subcellular location and the clinical behavior of OSCCs. Among the clinical classifications, higher nuclear HSF1 expression was closely related to tumor size and histopathologic types (P<0.05). These results showed for the first time that nuclear HSF1 expression may contribute to cancer progression and that HSF1 might be a potential diagnostic biomarker and a therapeutic target for OSCCs.

Upregulation of thioredoxin reductase 1 in human oral squamous cell carcinoma

Thioredoxin reductase 1 (TrxR1) catalyzes the nicotinamide adenine dinucleotide phosphate-dependent reduction of oxidized thioredoxin (Trx). Trx, which is over-expressed in many human tumors, is a selenocysteine-containing protein associated with cell proliferation and apoptosis inhibition. This selenium-containing redox system regulates the activity of various enzymes and counteracts oxidative stress in cells such as hypoxia and cytotoxic agents. Consequently, TrxR1 could play an important role in tumor progression and resistance to chemotherapy due to its anti-apoptotic functions. To characterize cancer-related gene expression changes in oral squamous cell carcinomas (OSCC), we compared the gene expression profiles in OSCC primary tumors with patient-matched normal oral epithelium. Microarray analysis showed TrxR1 upregulation in primary tumors. Gene ontology analysis showed highly significant cancer-related function. The TrxR1 expression examined by immunohistochemistry was correlated with regional lymph node metastasis (P<0.05) and the clinical stages of 50 patients (P<0.01). Overexpression of TrxR1 could contribute to cancer progression and might be a potential molecular marker for therapy.

Overexpression and altered subcellular localization of autophagy-related 16-like 1 in human oral squamous-cell carcinoma: correlation with lymphovascular invasion and lymph-node metastasis

Autophagy is a dynamic process of subcellular degradation, which has recently sparked great interest because it is involved in various developmental processes and various diseases including cancer. Autophagy-related 16-like 1 is a component of a large protein complex essential for autophagosome formation. We previously applied proteomic methods to characterize differentially expressed proteins in oral squamous cell carcinoma cells and detected significantly high expression levels of autophagy-related 16-like 1 in oral squamous cell carcinoma-derived cell lines compared to human normal oral keratinocytes. In the current study, to further determine the potential involvement of autophagy-related 16-like 1 in oral squamous cell carcinoma, we evaluated the state of autophagy-related 16-like 1 protein expression in human oral premalignant lesions and primary oral squamous cell carcinomas, and correlated the results with clinicopathologic variables. Autophagy-related 16-like 1 immunoreaction was predominant in a variety of subcellular components of oral squamous cell carcinoma tissues, including the cytoplasm and plasma membrane of malignant cells (45% and 39%, respectively) and peritumoral and intratumoral stroma (52%), whereas all of the components in normal tissues had no or faint autophagy-related 16-like 1 expression. In addition, high stromal expression of autophagy-related 16-like 1 was associated significantly with lymphovascular invasion of tumor cells (P = .037) and positive lymph node status (P = .015). Furthermore, cytoplasmic and plasma membranous autophagy-related 16-like 1 were also expressed in abundance in the oral premalignant lesion cells (74% and 32%, respectively). Our finding suggests that dysregulation of autophagy-related 16-like 1 protein expression is a frequent and early event during oral carcinogenesis and could affect the malignant behavior of oral squamous cell carcinoma cells.

Downregulation of Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1 in Oral Squamous Cell Carcinoma: Correlation with Tumor Progression and Poor Prognosis

Objective: To identify genes associated with therapeutic targets of oral squamous cell carcinoma (OSCC), we compared gene expression profiles in OSCC-derived cell lines with human normal oral keratinocytes. Methods: We analyzed the gene expression profiles of OSCCs using Affymetrix GeneChip analysis. The identified genes were analyzed by an Ingenuity Pathway Analysis tool to identify networks of interacting genes. A candidate gene was further evaluated for the expression status of the mRNA and protein in OSCC-derived cell lines and primary OSCCs. Results: The microarray data identified 188 genes downregulated in OSCC-derived cell lines, and the genetic pathways associated with expression changes were generated. Among the genes mapped to the network with the highest significance, carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) was analyzed further. CEACAM1 mRNA and protein were frequently downregulated in OSCC-derived cell lines compared with human normal oral keratinocytes. Immunohistochemical analysis showed that primary OSCCs were significantly decreased in CEACAM1. Moreover, CEACAM1 expression was correlated with the TNM staging. We also found that CEACAM1-negative expression was significant both for disease-free (p = 0.036) and overall survival (p = 0.032). Conclusion: Repression of CEACAM1 could contribute to cancer progression and may indicate a poor prognosis for patients with OSCC.

Endoscopically assisted removal of a fish bone penetrating the parotid duct: an unusual case.

PURPOSE The aim was to evaluate the efficacy of endoscopy-assisted surgery for treating a foreign body (fish bone) deeply embedded in the parotid duct. PATIENTS AND METHODS We report the case of a 67-year-old man with diffuse swelling of the cheek and the discharge of pus from the parotid duct orifice caused by a fish bone that had penetrated into the parotid duct. The preoperative examination using ultrasonography and computed tomography showed a linear foreign body. RESULTS The fish bone was thought to be embedded deeply in the parotid duct; therefore, we used a combined approach (endoscopy with open surgery), because we anticipated difficulties with endoscopic removal of the fish bone. The endoscopic view showed that the fish bone had partially penetrated the soft tissue in the parotid duct wall, but the fish bone could not be removed endoscopically. With endoscopic assistance, the impacted fish bone was removed using an intraoral surgical approach. The clinical outcome was satisfactory during a 10-month follow-up period, with no evidence of complications. CONCLUSIONS The combined surgical and endoscopic approach resulted in the safe and effective removal of a foreign body from the salivary duct that could not be removed using sialendoscopy alone.

Antitumor activity of satraplatin in cisplatin-resistant oral squamous cell carcinoma cells

The aim of the current study was to identify the antitumor activity of satraplatin in paired cisplatin (CDDP)‐resistant oral squamous cell carcinoma (OSCC) cell line and its parental cell line.

FBLIM1 enhances oral cancer malignancy via modulation of the epidermal growth factor receptor pathway

Filamin‐binding LIM protein 1 (FBLIM1) is related to regulation of inflammatory responses, such as chronic recurrent multifocal osteomyelitis; however, the relevance of FBLIM1 in oral squamous cell carcinoma (OSCC) is unknown. The aim of the current study was to elucidate the possible role of FBLIM1 in the carcinogenesis of OSCC. We analyzed FBLIM1 expression using quantitative reverse transcriptase‐polymerase chain reaction (qRT‐PCR), immunoblot analysis, and immunohistochemistry. The expression levels of FBLIM1 were up‐regulated significantly (P < 0.05) in OSCC‐derived cell lines and primary OSCCs specimens compared with normal counterparts. FBLIM1 expression also was correlated with the primary tumoral size (P < 0.05) and vascular invasion (P < 0.05). We then assessed tumoral progression after treatment with FBLIM1 siRNA and clopidogrel, an antiplatelet agent. Similar to the FBLIM1 knockdown effect, clopidogrel‐treated cells had attenuated functions of proliferation, migration, and invasiveness. Interestingly, clopidogrel treatment led to down‐regulation of epidermal growth factor receptor (EGFR) and FBLIM1. These findings identify FBLIM1 as a putative therapeutic target by using clopidogrel for inhibiting over activation of EGFR signaling to prevent OSCC malignancy.

Contents Vol. 76, 2009

A.B. Benson, Chicago, Ill. A.Y. Chang, Singapore A.-L. Cheng, Taipei J.F. Cleary, Madison, Wisc. M.S. Ernstoff , Lebanon, N.H. J.J. Grau, Barcelona D.F. Hayes, Ann Arbor, Mich. C.S. Johnson, Buff alo, N.Y. M.J. Kelley, Durham, N.C. P.J. Loehrer, Indianapolis, Ind. J.R. Marshall, Buff alo, N.Y. S. Monfardini, Milan R. Nagler, Haifa R. Ohno, Nagoya B. Pestalozzi, Zurich H.M. Pinedo, Curacao D. Raghavan, Cleveland, Ohio E.A. Repasky, Buff alo, N.Y. C.N. Sternberg, Rome R. Stupp, Lausanne M.S. Tallman, Chicago, Ill. S. Tanaka, Hiroshima M. Tian, Houston, Tex. D.L. Trump, Buff alo, N.Y. T. Wiegel, Ulm W. Yasui, Hiroshima H. Zhang, Hangzhou City Editor-in-Chief