Expression of 14-3-3 sigma, cyclin-dependent kinases 2 and 4, p16, and Epstein-Barr nuclear antigen 1 in nasopharyngeal carcinoma.

OBJECTIVE: The protein 14-3-3 sigma plays a role in cell cycle arrest by sequestering cyclin-dependent kinase 1 cyclin B1 complexes, as well as cyclin-dependent kinases 2 and 4, hence its definition as a cyclin-dependent kinase inhibitor. However, the nature of the interaction between these biological markers in nasopharyngeal carcinoma is unknown. This study aimed to investigate whether altered expression of these markers contributes to nasopharyngeal carcinogenesis. METHODS: The study population consisted of 30 nasopharyngeal carcinoma patients and 10 patients without nasopharyngeal carcinoma. The nasopharyngeal carcinoma cell lines TW02, TW04 and Hone-1 were also assessed. We analysed levels of messenger RNA and protein for the p16 gene and the 14-3-3 sigma, Epstein-Barr nuclear antigen 1, and cyclin-dependent kinase 2 and 4 proteins, in nasopharyngeal carcinoma tissue specimens and cell lines and in normal nasopharyngeal tissue. RESULTS: Protein and messenger RNA levels for cyclin-dependent kinase 2 and Epstein-Barr nuclear antigen 1 were significantly higher in nasopharyngeal carcinoma compared with normal tissue, while levels of cyclin-dependent kinase 4 generally were not; results for 14-3-3 sigma varied. Nasopharyngeal carcinoma patients had diminished p16 gene expression, compared with normal tissue. CONCLUSION: Levels of cyclin-dependent kinase 2 and Epstein-Barr nuclear antigen 1 were significantly higher in nasopharyngeal carcinoma than in normal tissue, while p16 gene expression was diminished. These three proteins may contribute to nasopharyngeal carcinogenesis.

Expression of FLJ10540 is correlated with aggressiveness of oral cavity squamous cell carcinoma by stimulating cell migration and invasion through increased FOXM1 and MMP-2 activity.

Matrix metalloproteinase (MMP)-2 plays critical roles in tumor development and in the metastasis of multiple cancers, including human oral cavity squamous cell carcinoma (OCSCC). One of the upstream regulators of MMP-2 is FOXM1, which is overexpressed in a microarray dataset of OCSCC. It is interesting that FLJ10540 exhibits similar gene expression profiles with MMP-2 and FOXM1, raising the possibility that these molecules might participate in MMP-2-elicited cancer progression and metastasis of OCSCC. To examine this connection, we first showed that FLJ10540 was significantly overexpressed in OCSCC. A strong FLJ10540 expression was significantly correlated with an advanced tumor node metastasis stage and the cumulative 5-year survival rate. Thus, an elevated FLJ10540 expression is an indicator of poor survival. Functionally, FLJ10540 had the abilities to stimulate cell migration and invasion in oral cancer cells through increased FOXM1 and MMP-2 expressions. Conversely, the depletion of the FLJ10540 expression by small interfering RNAs suppressed the FOXM1 and MMP-2 protein expressions. The suppression of either FLJ10540 or FOXM1 could cause significant inhibition on cell migratory and invasive ability in oral cancer cells. Finally, the immunohistochemical and western blotting analyses of human aggressive OCSCC specimens showed a significant positive correlation among FLJ10540, FOXM1 and MMP-2 expressions. These findings suggest that FLJ10540 is not only an important prognostic factor but also a new therapeutic target in the FLJ10540/FOXM1/MMP-2 pathway for OCSCC treatment.

Overexpression of cyclin E messenger ribonucleic acid in nasopharyngeal carcinoma correlates with poor prognosis.

AIMS: S-phase kinase-associated protein 2 is required for the degradation of p27 protein, which is a negative regulator of cyclin E/cyclin-dependent kinase 2 complex. The present study examined the expression of cyclin E, S-phase kinase-associated protein 2 and p27 protein in nasopharyngeal carcinoma. METHODS: Tissue from 35 cases of nasopharyngeal carcinoma and 10 normal nasopharyngeal tissue samples underwent reverse polymerase chain reaction to detect messenger ribonucleic acid. Immunohistochemical analysis was performed on 29 nasopharyngeal tissue samples in order to detect protein expression. RESULTS: Messenger ribonucleic acid expression in the nasopharyngeal carcinoma tissue samples analysed indicated a 1.75-fold change in the amount of S-phase kinase-associated protein 2, a 0.34-fold change in the amount of cyclin E and a 0.31-fold change in the amount of p27 protein, compared with positive controls. High levels of cyclin E significantly correlated with late-stage nasopharyngeal carcinoma (p = 0.009) and a poor overall survival (p = 0.010). Immunohistochemical analysis indicated positive expression of S-phase kinase-associated protein 2 in 16/29 nasopharyngeal tissue samples (55 per cent), of cyclin E in 13/29 samples (45 per cent) and of p27 protein in 17/29 (59 per cent) samples. CONCLUSIONS: Overexpression of cyclin E messenger ribonucleic acid showed an adverse prognostic significance, correlating with an advanced stage of nasopharyngeal carcinoma and a low overall survival rate.

Ablation of advanced tongue or base of tongue cancer and reconstruction with free flap: functional outcomes.

AIM: To evaluate the functional outcomes of patients who underwent total or nearly total glossectomy for advanced tongue or base of tongue cancer. MATERIAL AND METHODS: We used the radial forearm free flap (RFFF), anterior lateral thigh flap (ALTF) or fibular osteocutaneous flap (FOCF) to reconstruct the oral defect after radical resection in 39 patients undergoing total or nearly total glossectomy with laryngeal preservation. RESULTS: Good functional outcomes, measured by independent feeding, speech and swallowing were achieved in 35, 36 and 35 patients, respectively. The cumulative 4-year survival rates were 63.8% for tongue cancer and 42.9% for base of tongue cancer. CONCLUSION: Reconstruction with free flaps is a feasible method to restore the functional outcomes in speech and deglutition among patients who undergo total or nearly total glossectomy with laryngeal preservation.

Loss of cyclin D1 and p16 expression correlates with local recurrence in nasopharyngeal carcinoma following radiotherapy.

BACKGROUND: The cyclin D1/p16/Rb pathway plays a critical role in tumorigenesis and each component of this pathway may be affected in various malignancies. The purpose of this study was to investigate the expression and prognostic significance of these proteins in nasopharyngeal carcinoma (NPC). PATIENTS AND METHODS: Sixty-five patients undergoing radiotherapy for NPC were analyzed. The expression of cyclin D1, p16 and pRb was evaluated with immunohistochemical analysis of archived pretreatment tumor materials and expression of these proteins was correlated with clinicopathological parameters. RESULTS: Positive expression of cyclin D1 was observed in 43 of 65 NPCs (66%). p16 and pRb inactivation was identified in 42 of 65 (65%) and four of 65 (6%) tumors, respectively. All but seven tumors (58 of 65, 89%) contained at least one alternation in the cyclin D1/p16/Rb pathway. Loss of cyclin D1 as well as p16 was closely related to local recurrence after radiotherapy for NPC (P = 0.015 and 0.047). No association between pRb expression and clinicopathological outcome was apparent. CONCLUSIONS: The study's results suggest that the cyclin D1/p16/Rb pathway plays an important role in NPC tumorigenesis. We also find that cyclin D1 and p16 protein levels in NPC may be of use clinically as a predictor of local tumor control.

Diagnostic usefulness of telomerase activity in nasopharyngeal carcinoma.

Telomeres are specialized structures at the ends of eukaryotic chromosomes which are composed of simple repetitive G-rich hexameric sequences. Activation of telomerase, a ribonucleoprotein that synthesizes telomeric DNA, is found in most malignant tumors. However, little data is available concerning the correlation between telomerase activity and NPC (nasopharyngeal carcinoma). In this study, telomerase activation was determined using the TRAP (telomerase repeat amplification protocol) assay in 62 nasopharyngeal biopsies (25 NPC, 25 non-malignant nasopharyngeal lymphoid tissues, 12 post-irradiated nasopharyngeal tissues). The results showed that strong telomerase activity was present in both NPC and non-malignant nasopharyngeal biopsies. Post-irradiated nasopharyngeal samples had a significantly lower telomerase activity than NPC and non-malignant nasopharyngeal lymphoid tissues. It is well known that nasopharyngeal tissue is infiltrated by numerous lymphocytes, which might retain telomerase activity. Therefore, the finding that the telomerase activation was lowest in post-irradiated nasopharyngeal tissues is reasonable because of the destruction of activated lymphocytes and NPC by radiation. NPC biopsies with positive lymph node involvement exhibited higher levels of telomerase compared to those without lymph node involvement. Our data indicate a positive association between telomerase activity and tumor potential for lymphatic spreading in limited local tumors. In addition, telomerase activity may be useful as a diagnostic marker in the detection of tumor cells in recurrent NPC, but not in primary NPC.

Evidence for a role of the N terminus and leucine-rich repeat region of the Mi gene product in regulation of localized cell death.

The tomato Mi gene confers resistance against root-knot nematodes and potato aphids. Chimeric constructs of the functional gene, Mi-1. 2, with a homolog, Mi-1.1, were produced, and their phenotypes were examined in Agrobacterium rhizogenes-transformed roots. Exchange of the leucine-rich repeat (LRR) region of Mi-1.1 into Mi-1.2 resulted in the loss of ability to confer nematode resistance, as did substitution of a 6-amino acid sequence from the Mi-1.1 LRR into Mi-1.2. Introduction of the Mi-1.2 LRR-encoding region into Mi-1.1 resulted in a lethal phenotype, as did substitution of the fragment encoding the N-terminal 161 amino acids of Mi-1.1 into Mi-1.2. Transient expression of the latter two chimeric constructs in Nicotiana benthamiana leaves produced localized cell death. The cell death caused by the N-terminal exchange was suppressed by coinfiltration with a construct expressing the N-terminal 161 amino acids of Mi-1.2. The phenotypes of these and other constructs indicate that the LRR region of Mi-1.2 has a role in signaling localized cell death and that the N-terminal 161 amino acids have a role in regulating this death.

A new transnasal approach to endoscopic marsupialization of the nasolabial cyst.

OBJECTIVE: Nasolabial cyst is a mucus-secreting, nonodontogenic cyst in the nasofacial area. It is usually situated behind the ala nasi, extending backward beneath the nasal floor into the inferior meatus and forward into the labio-gingival sulcus behind the upper lip. Patients with nasolabial cysts generally undergo surgical removal of the cyst via a transoral sublabial approach. This article reports a simple, less invasive surgical procedure for the treatment of nasolabial cysts. STUDY DESIGN: A transnasal endoscopic marsupialization method was designed to treat patients with nasolabial cysts. From 1996 through 1998, 16 consecutive patients underwent this new surgical procedure. METHODS: With patients under local anesthesia, the roof of the cyst, which was firmly attached to the mucous membrane of the anterior nasal floor, was removed transnasally with a sickle knife and scissors. Under the guidance of a nasoendoscope, the opening of the cyst was widened with bite forceps. Meanwhile, the cut edges of the nasal mucosa and the epithelium lining of the cyst were adequately matched. The nose was then loosely packed. RESULTS: All but 1 of the 15 patients were successfully treated with this technique, and the whole surgical procedure was usually completed within 15 to 20 minutes. Postoperative endoscopic and radiological findings revealed that the cyst was replaced by an air-containing sinus with a persistent opening at the anterior or anterolateral nasal floor. There has been no evidence of mucus accumulation in the newly created sinus or recurrence of the cyst during a mean follow-up of 16 months. CONCLUSIONS: Transnasal endoscopic marsupialization is a simple and effective surgical procedure for treatment of nasolabial cysts.

5' proximal regions of Arabidopsis nitrate reductase genes direct nitrate-induced transcription in transgenic tobacco.

Nitrate reductase (NR) is the first enzyme in nitrate assimilation, a critical process for plant survival. The regulation of NR gene expression is complex, involving both internal and external factors. Of these, nitrate induction of NR gene expression has been studied most extensively and is well conserved among bacteria, fungi, and higher plants. We are interested in understanding the mechanism of nitrate induction of higher plant NR genes. Here we describe promoter analyses of the 5' flanking regions of the Arabidopsis NR genes, NR1 and NR2, with respect to nitrate induction of gene expression. To facilitate these analyses, a nitrate induction procedure using T1 transgenic tobacco plants was established. Approximately 1.5-kb 5' flanking regions of the two Arabidopsis NR genes (NR1 and NR2) were fused to a reporter gene and its expression in transgenic plants was analyzed. Deletion analyses of these regions show that 238- and 188-bp 5' flanking regions of the NR1 and NR2, respectively, contain sequences responsive to nitrate induction.

Near-total laryngopharyngectomy with pectoralis major myocutaneous flap in advanced pyriform carcinoma.

Successful restoration of phonation, as well as swallowing in laryngopharyngeal surgery for patients with advanced pyriform carcinoma still remains a major challenge. In a five-year period, near-total laryngectomy operations were performed on 21 patients with laryngopharyngeal carcinoma. This report particularly emphasizes the value of near-total laryngopharyngectomy with a pectoralis major myocutaneous flap for four extensive hypopharyngeal carcinoma cases (three of which were of pyriform origin). All four patients regained intelligible shunt speech and smooth swallowing. The follow-up period ranged from 19 to 44 months. They have had no recurrence of disease since surgery. The authors suggest that an advanced pyriform carcinoma case, with a normal contralateral hemilarynx and pyriform sinus, is a candidate for a near-total excision of the laryngopharynx.

External ear canal schwannoma: an unusual case report.

To the best of our knowledge, this is the first report of external ear canal schwannoma in the English literature. Several detailed clinical and pathological features were demonstrated. We suggest that if a tender, encapsulated mass is found in the external ear canal, the diagnosis of schwannoma should be taken into consideration.

A long-standing cystic lymph node metastasis from occult thyroid carcinoma--report of a case.

The authors describe a patient with a cervical cystic mass present for 14 years which proved to be a cystic metastasis from a papillary carcinoma of the thyroid gland. This is probably the first case report of a long-term lateral cervical cyst caused by an occult thyroid carcinoma.

Intracerebral arteriovenous fistula: report of one case.

Intracranial arteriovenous fistula (AVF) is rare. Of the 320 arteriovenous malformations (AVMs) treated by Halbach over the past ten years, only five (1.6%) had a single arteriovenous connection. In the present study, a male infant developed focal seizure and intracranial hemorrhage without cardiac decompensation at the age of 42 days. When he was 3 years and 4 months old, status epileptics occurred, and AVF was discovered via CT scan and cerebral angiographic examination. The AVF was fed by a middle cerebral artery and drained into a huge cortical vein over the left parietooccipital area. Endovascular therapy and/or surgery were suggested, but the family refused. Though seizures occurred occasionally, the patient's consciousness level had become more clear, and he was discharged after three weeks' hospitalization. The patient was noted to be lethargic and only could roll over partially at the age of 3 year and 8 months, in the latest follow-up.

Cavernous sinus thrombosis following odontogenic and cervicofacial infection.

Cavernous sinus thrombosis (CST) is rarely seen clinically as a complication of infectious processes since the discovery of penicillin. At the present time, dental abscess is an uncommon cause of CST. We now report our experiences with a 60-year-old diabetic male, who developed CST 38 days after extraction of an infected upper third molar tooth. The importance of eradicating regional cervicofacial foci of infection is stressed.