Tzung-Shiahn Sheen

Epstein–Barr virus-encoded small RNA induces insulin-like growth factor 1 and supports growth of nasopharyngeal carcinoma-derived cell lines

To assess the role of insulin-like growth factor 1 (IGF-1) in the growth of nasopharyngeal carcinoma (NPC), three NPC-derived cell lines, C666-1, CNE1 and HONE1, were examined. C666-1 cells maintained NPC phenotype of Epstein–Barr virus (EBV) expression and were positive for IGF-1 secretion, and their growth was strikingly inhibited by treatment with an anti-IGF-1 antibody under low serum condition. On the other hand, CNE1 and HONE1 cells were EBV-negative and did not secrete IGF-1. Although they could not grow under low serum condition, addition of recombinant IGF-1 made them grow. EBV conversion of CNE1 and HONE1 cells reproduced NPC phenotype of EBV expression and accompanied IGF-1 expression. Although they could grow under low serum condition, their growth was strikingly inhibited by treatment with the anti-IGF-1 antibody. These results suggest that EBV infection induces IGF-1 in NPC cell lines, and that the secreted IGF-1 acts as an autocrine growth factor. These findings seem to be operative in vivo, as NPC biopsies consistently express IGF-1. Further studies demonstrated that increased IGF-1 expression reflected transcriptional activation, and EBV-encoded small RNA (EBER) was responsible for IGF-1 induction. EBER is invariably expressed in EBV-associated malignancies, including NPC. The present findings strongly suggest that EBER directly affects the pathogenesis of NPC.

Induction of c-Met Proto-Oncogene by Epstein-Barr Virus Latent Membrane Protein-1 and the Correlation with Cervical Lymph Node Metastasis of Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is distinctive in head and neck carcinomas for its close association with Epstein-Barr virus and its highly metastatic nature. Up-regulation of cell motility is essential for enhancement of metastatic potential. The expression of c-Met proto-oncogene, a high-affinity receptor for hepatocyte growth factor/scatter factor, has been reported to correlate with metastatic ability of the tumor cell. We observed close association of c-Met expression with cervical lymph node metastasis (P = 0.0272) in 39 NPC specimens studied immunohistochemically. Epstein-Barr virus-encoding latent membrane protein-1 (LMP-1) is a primary oncogene and is suggested to enhance the metastatic property of NPC. Previously, we reported that LMP-1 enhanced the motility of Madin-Darby canine kidney (MDCK) epithelial cells that was mediated by activation of Ets-1 transcription factor. Therefore, we examined the interrelationships of LMP-1, Ets-1, and c-Met. In immunohistochemical studies, the expression of LMP-1, Ets-1, and c-Met correlated significantly with each other in NPC (LMP-1 versus Ets-1, P < 0.0001; Ets-1 versus c-Met, P = 0.0012; LMP-1 versus Met, P = 0.0005). Transfection of LMP-1-expressing plasmid in MDCK cells induced c-Met protein expression. The c-Met protein was also induced by Ets-1 expression, and induction of c-Met by LMP-1 was suppressed by introducing a dominant-negative form of Ets-1 in LMP-1-expressing MDCK cells. These results suggest that LMP-1 induces c-Met through the activation of Ets-1, which may contribute in part to the highly metastatic potential of NPC.

Epstein-Barr-Virus-Encoded LMP2A Induces Primary Epithelial Cell Migration and Invasion: Possible Role in Nasopharyngeal Carcinoma Metastasis

ABSTRACT Nonkeratinizing nasopharyngeal carcinomas (NPC) are >95% associated with the expression of the Epstein-Barr virus (EBV) LMP2A latent protein. However, the role of EBV, in particular, LMP2A, in tumor progression is not well understood. Using Affymetrix chips and a pattern-matching computational technique (neighborhood analysis), we show that the level of LMP2A expression in NPC biopsy samples correlates with that of a cellular protein, integrin-alpha-6 (ITGα6), that is associated with cellular migration in vitro and metastasis in vivo. We have recently developed a primary epithelial model from tonsil tissue to study EBV infection in epithelial cells. Here we report that LMP2A expression in primary tonsil epithelial cells causes them to become migratory and invasive, that ITGα6 RNA levels are up-regulated in epithelial cells expressing LMP2, and that ITGα6 protein levels are increased in the migrating cells. Blocking antibodies against ITGα6 abrogated LMP2-induced invasion through Matrigel by primary epithelial cells. Our results provide a link between LMP2A expression, ITGα6 expression, epithelial cell migration, and NPC metastasis and suggest that EBV infection may contribute to the high incidence of metastasis in NPC progression.

Induction Chemotherapy With Mitomycin, Epirubicin, Cisplatin, Fluorouracil, and Leucovorin Followed by Radiotherapy in the Treatment of Locoregionally Advanced Nasopharyngeal Carcinoma

PURPOSE Survival in advanced nasopharyngeal carcinoma (NPC) is compromised by distant metastasis. Because mitomycin is active against hypoxic and G0 cells, which may help to eradicate micrometastasis, we investigated the effect of mitomycin-containing cisplatin-based induction chemotherapy. PATIENTS AND METHODS Recruited for this study were American Joint Committee on Cancer (AJCC) 1992 staging system stage IV NPC patients with the following adverse features: obvious intracranial invasion, supraclavicular or bilateral neck lymph node metastasis, large neck node (> 6 cm), or elevated serum lactate dehydrogenase (LDH) level. Patients were given three cycles of chemotherapy before radiotherapy. The chemotherapy comprised a 3-week cycle of mitomycin, epirubicin, and cisplatin on day 1 and fluorouracil and leucovorin on day 8 (MEPFL). RESULTS From January 1994 to December 1997, 111 patients were recruited. The median follow-up period was 43 months. The actuarial 5-year overall survival rate was 70% (95% confidence interval [CI], 60% to 80%; n = 111). For patients having completed radiotherapy (n = 100), the 5-year locoregional control rate was 70% (95% CI, 55% to 84%) and the distant metastasis-free rate was 81% (95% CI, 73% to 89%). The 5-year distant metastasis-free rate of N3a and N3b disease of AJCC 1997 staging system were 79% (95% CI, 62% to 95%) and 74% (95% CI, 60% to 89%), respectively. By Cox multivariate analysis, high pretreatment serum LDH level (P = .04) and neck nodal enlargement before radiotherapy (P = .001) were adverse prognostic factors of survival. CONCLUSION The good 5-year survival of N3 disease supports the effectiveness of induction MEPFL in the primary treatment of advanced NPC. Further investigation to incorporate concurrent chemoradiotherapy is warranted.

Vascular Leiomyoma of the Head and Neck

Objectives/Hypothesis Vascular leiomyoma, a benign tumor composed of smooth muscle cell and vascular endothelium, is rare in the head and neck region. The authors report their experience with 21 patients.

Clinical Experiences of Removing Foreign Bodies in the Airway and Esophagus with a Rigid Endoscope: A Series of 3217 Cases from 1970 to 1996

This study examined 11,333 rigid endoscopy procedures performed in the Department of Otolaryngology, National Taiwan University Hospital, during a 27-year period from 1970 to 1996. Among these cases, 3217 were performed to remove foreign bodies from the airway (459 cases, 14.3%) and esophagus (2758 cases, 85.7%). Retrospective analysis of these data revealed that peanuts (217 cases) and animal bones (1184 cases) were the most frequent foreign bodies encountered in the airway and esophagus, respectively. The successful rate of removal of these foreign bodies was 99.9% (3213/3217). The complication rate was only 0.2% (8/3217), and the mortality rate was less than 0.1% (2/3217). On the basis of these results, we conclude that foreign bodies in the airway and esophagus can be removed safely under direct visualization through rigid endoscopy with relatively few complications. A significant finding in this study is the declining trend in the number of cases in recent years. Despite the decline in the number of procedures, endoscopic removal of foreign bodies remains as a vital skill of the aerodigestive tract surgeon.

Lymphoepithelial Carcinoma versus Large Cell Undifferentiated Carcinoma of the Major Salivary Glands

Undifferentiated carcinomas of the major salivary glands are rare malignant neoplasms of the head and neck region, and patients with these lesions have a poor prognosis. Patients with lymphoepithelial carcinoma (LEC), a specific subtype of undifferentiated carcinoma, however, have a better prognosis, and LEC seems to differ from large cell undifferentiated carcinoma (LCUC) clinically.

Epstein‐Barr Virus‐encoded Latent Membrane Protein 1 Co‐expresses with Epidermal Growth Factor Receptor in Nasopharyngeal Carcinoma

Latent membrane protein 1 (LMP‐1) is the only Epstein‐Barr virus (EBV)‐encoded oncogenic protein that has been detected in nasopharyngeal carcinoma (NPC), a cancer that is closely associated with EBV. Previous in‐vitro studies have demonstrated that LMP‐1 can upregulate epidermal growth factor receptor (EGFR) in epithelial cells. It was not established whether this cellular effect exists in NPC. To assess the association between LMP‐1 and EGFR in NPC tissues, 60 NPC specimens were examined by immunohistochemistry using anti‐LMP‐1 antibody (CS 1–4) and anti‐EGFR antibodies (EGFR 1, EGFR 1005). The results revealed that 41 (68.3%) specimens were immunopositive for LMP‐1 and 44 (73.3%) specimens over‐expressed EGFR. Morphologically, the expressions of LMP‐1 and EGFR were homogeneously distributed in the tumor nests. In addition, the correlation between LMP‐1 and EGFR was statistically significant (P<0.001, χ2 test, d.f.=1). To elucidate further the correlation between LMP‐1 and EGFR in vivo and in situ, an indirect dual immunofluorescence assay was conducted, using secondary antibodies conjugated with fluorescein isothiocyanate (FITC) or indocarbocyanine (Cy3). The results disclosed an intimate co‐expression of LMP‐1 and EGFR. In summary, the data indicate that over‐expression of EGFR is a common phenomenon in NPC, and that EGFR is co‐expressed with LMP‐1 in NPC. Thus, EBV may play a role in the tumorigenesis of NPC through the effects of LMP‐1 and EGFR.

Nasopharyngeal swab and pcr for the screening of nasopharyngeal carcinoma in the endemic area: A good supplement to the serologic screening

Nasopharyngeal carcinoma (NPC) is a common head and neck cancer in Taiwan. Early detection is the best way to improve survival for this disease.

Induction with mitomycin C, doxorubicin, cisplatin and maintenance with weekly 5-fluorouracil, leucovorin for treatment of metastatic nasopharyngeal carcinoma: a phase II study

SummaryThe combination of cisplatin and 5-fluorouracil (5-FU) (PF) is the most popular regimen for treating metastatic nasopharyngeal carcinoma (NPC) but it is limited by severe stomatitis and chronic cisplatin-related toxicity. A novel approach including induction with mitomycin C, doxorubicin and cisplatin (MAP) and subsequent maintenance with weekly 5-FU and leucovorin (FL) were designed with an aim to reduce acute and chronic toxicity of PF. Thirty-two patients of NPC with measurable metastatic lesions in the liver or lung were entered into this phase II trial. Mitomycin C 8 mg m–2, doxorubicin 40 mg m–2 and cisplatin 60 mg m–2 were given on day 1 every 3 weeks as initial induction. After either four courses or remission was achieved, patients received weekly dose of 5-FU 450 mg m–2 and leucovorin 30 mg m–2 for maintenance until disease progression. With 105 courses of MAP given, 5% were accompanied by grade 3 and 0% were accompanied by grade 4 stomatitis. The dose-limiting toxicity of MAP was myelosuppression. Forty per cent of courses had grade 3 and 13% of courses had grade 4 leukopenia. No grade 3 or 4 cisplatin-related toxicity was observed. The overall response rate was 94% (95% confidence interval (CI) 84.9–100%) with a complete response rate (CR) of 6% (95% CI: 0–15.2%) and a good partial response (PR) rate of 28% (95% CI 11.7–44.6%), which was optionally defined as observance of only equivocal lesion identifiable under imaging study. Twenty-seven cases entered weekly FL maintenance phase. The median duration of maintenance with weekly FL was 38 weeks (8–91 weeks). There was no grade 3 or 4 toxicity noted during weekly FL. The median progression-free survival and overall survival were 11.6 ± 0.4 and 18.1 ± 3.6 months respectively. Six patients with a median follow-up of 19.8 months (9.6–41.0 months) were still alive and five of them had disease under control with FL. Good responders (CR and good PR) had better survival than less satisfactory responders (PR and stable disease) (P = 0.05). From Cox’s multivariate regression analysis, the only significant prognostic factor for survival was good response to MAP (P = 0.042). Liver metastasis was the only significant variable in the best subset regression model that predicted good response to MAP (CR and good PR) (P = 0.027). MAP was an effective combination for metastatic NPC with minimal stomatitis and cisplatin-related toxicity but had significant myelosuppression. Weekly FL was a maintenance therapy with minimal side-effects. The response rate and overall survival of MAP-FL were better than series previously reported even when a subset of patients with poor prognosis was selected. MAP-FL’s role as neoadjuvant or adjuvant therapy is worthy of further study.