Induction of matrix metalloproteinases by Epstein-Barr virus latent membrane protein 1 isolated from nasopharyngeal carcinoma.

Epstein--Barr virus latent infection is associated with human malignancies including Burkitt's lymphoma, gastric carcinoma and the highly invasive nasopharyngeal carcinoma (NPC). Increased expression of EBV latent membrane protein 1, LMP1, is correlated with tumor progression and metastasis in NPC. LMP1 induces cellular proteins including cytokines and matrix metalloproteinases (e.g., MMP1, MMP2 and MMP9). MMPs are endopeptidases involved in the degradation of extracellular matrix proteins; and their upregulation in cancer implicates their potential role in tumor metastasis. In light of the role of LMP1 in cytokine dysregulation and the fact that MMPs are regulated by cytokines, we examined whether LMP1 promotes NPC metastasis via the induction of MMPs. To delineate the oncogenic role of LMP1 in NPC, we first investigated the induction of MMP1, MMP2, MMP3 and MMP9 in LMP1-positive NPC tumor samples (n=15) by quantitative RT-PCR. We showed a significant induction of MMP1 and MMP3 transcripts in the EBV LMP1-positive NPC tissues, compared with biopsies obtained from the adjacent non-tumor tissues. To investigate the role of LMP1 in MMP expression in NPC, we cloned the LMP1 gene from NPC samples and transiently expressed it in MRC5 cells (human lung fibroblasts). Following transfection, a time-dependent elevation of endogenous MMP3 expression was found in the LMP1-transfectants by quantitative RT-PCR and Western analysis. Taken together, we observed that MMP3 is upregulated in LMP1-positive NPC tumors and LMP1-expression in fibroblasts is associated with MMP3 and cytokine expression. Our results suggest that LMP1 may contribute to invasiveness of NPC cells via the expression of MMP3 in fibroblasts.

Sustained elevation of Epstein-Barr virus antibody levels preceding clinical onset of nasopharyngeal carcinoma.

We have monitored Epstein-Barr virus (EBV) IgA antibody levels of 39 nasopharyngeal carcinoma (NPC) cases for up to 15 years before clinical onset of NPC, and assessed preclinical serologic status of another 68 cases. Our results identify a serologic window preceding diagnosis when antibody levels are raised and sustained. This window can persist for as long as 10 years, with a mean duration estimated to as 37+/-28 months. Ninety-seven of these 107 NPC cases exhibited such a window. Cases that did not may reflect individual antibody response to EBV. Serologic screening at enrollment identified those cases who had already entered the window and became clinically manifested earlier (median=28 months) than those who entered the window after enrollment (median=90 months). The former account for 19 of 21 cases diagnosed within 2 years of screening. Nasopharyngeal carcinoma risk levels among seropositive subjects were also highest during this period. Both prediction rates and risk levels declined thereafter; cases detected at later times were composed of increasing proportions of individuals who entered the serological window after screening. Our findings establish EBV antibody as an early marker of NPC and suggest that repeated screening to monitor cases as they enter this window has considerable predictive value, with practical consequences for cancer treatment.

Expression of cytoplasmic and nuclear Survivin in primary and secondary human glioblastoma.

Clinically, human glioblastoma (GBM) may develop de novo or from a low-grade glioma (secondary GBM), and molecular alterations in the two pathways may differ. This study examined the status of Survivin expression and apoptosis in 30 primary and 26 secondary GBMs. Our results show that cytoplasmic Survivin positivity was significantly (P<0.001) more frequent in primary GBMs (83%) than that in secondary GBMs (46%). In addition, an inverse correlation of cytoplasmc Survivin positivity with GBM apoptotic index, and a positive association between cytoplasmic Survivin and size of the tumours were observed. These results suggest that cytoplasmic Survivin, via its antiapoptotic function, may be involved in the tumorigenesis of many primary GBMs, but only in a small fraction of secondary GBMs. Furthermore, the overall progression times from low-grade precursor lesions to secondary GBMs were significantly shorter (P<0.05) in cytoplasmic Survivin-positive cases (mean, 15.6 months) than those in Survivin-negative cases (mean, 23.8 moths), and the positive expression level of Survivin in cytoplasm was upregulated in most secondary GBMs when compared to matched pre-existing low-graded lesions. These results suggest that the increased accumulation of Survivin in the cytoplasm of more malignant glioma cells may prove to be a selective advantage, thus accelerating progression to a more aggressive phenotype.

Clusterin plays an important role in hepatocellular carcinoma metastasis.

To identify genes associated with tumor metastasis in hepatocellular carcinoma (HCC), gene expression profiles between a pair of primary HCC (H2-P) and their matched metastatic HCC (H2-M) were compared. Overexpression of clusterin (CLU) was found in H2-M cells. To determine the roles CLU played in HCC metastasis, CLU was transfected into H2-P cells. Overexpression of CLU in H2-P cells increased cell migration by twofold in vitro and formation of metastatic tumor nodules in liver by eightfold in vivo. To evaluate the correlation of CLU expression with HCC metastasis, the expression levels of CLU in HCCs were investigated using a tissue microarray (TMA) containing 104 pairs of primary HCCs and their matched metastases. The frequency of CLU overexpression increased significantly in metastatic HCCs (59.1%) compared with that in primary tumors (32.6%, P<0.001). To gain additional insight into the function of CLU, the expression profile of H2P-CLU was compared with vector-transfected H2-P cells by cDNA microarray. A total of 35 upregulated and 14 downregulated genes were detected in H2P-CLU. One of the upregulated genes known as YKL-40, which is implicated in matrix-remodeling and metastasis, was further studied using TMA. A significant correlation (P<0.001) between the expression levels of YKL-40 and CLU was observed, implying that the CLU-YKL-40 pathway may play an important role in HCC metastasis.

Inverse planning in three-dimensional conformal and intensity-modulated radiotherapy of mid-thoracic oesophageal cancer.

The aim of this study is to demonstrate the use of inverse planning in three-dimensional conformal radiation therapy (3DCRT) of oesophageal cancer patients and to evaluate its dosimetric results by comparing them with forward planning of 3DCRT and inverse planning of intensity-modulated radiotherapy (IMRT). For each of the 15 oesophageal cancer patients in this study, the forward 3DCRT, inverse 3DCRT and inverse IMRT plans were produced using the FOCUS treatment planning system. The dosimetric results and the planner's time associated with each of the treatment plans were recorded for comparison. The inverse 3DCRT plans showed similar dosimetric results to the forward plans in the planning target volume (PTV) and organs at risk (OARs). However, they were inferior to that of the IMRT plans in terms of tumour control probability and target dose conformity. Furthermore, the inverse 3DCRT plans were less effective in reducing the percentage lung volume receiving a dose below 25 Gy when compared with the IMRT plans. The inverse 3DCRT plans delivered a similar heart dose as in the forward plans, but higher dose than the IMRT plans. The inverse 3DCRT plans significantly reduced the operator's time by 2.5 fold relative to the forward plans. In conclusion, inverse planning for 3DCRT is a reasonable alternative to the forward planning for oesophageal cancer patients with reduction of the operator's time. However, IMRT has the better potential to allow further dose escalation and improvement of tumour control.

Clinicopathologic significance of plasma matrix metalloproteinase-2 and -9 levels in patients with undifferentiated nasopharyngeal carcinoma.

UNLABELLED: Increased in plasma pro-MMP2 and pro-MMP9 levels in patients with advanced stage NPC were observed. Plasma pro-MMP2 is a significant independent prognostic marker for undifferentiated NPC. AIM: Upregulation of matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) expression is observed in many cancers and high level of these proteins are found in peripheral blood of many cancer patients. In this study, we aimed at evaluating the plasma pro-MMP2 and pro-MMP9 pro-enzymes (pro-MMP2 and pro-MMP9) levels and their clinical significances in patients with undifferentiated nasopharyngeal carcinoma (NPC). METHODS: The plasma pro-MMP2 and pro-MMP9 levels were measured in 40 NPC patients and 40 normal individuals by enzyme linked immunosorbant assay. RESULTS: By using the Cox-regression model, a high pro-MMP2 level was found to be significantly correlated with poorer survival. Patients with plasma pro-MMP2 below 650 ng/ml had higher 5-year survival rate of 89%, compared with 50% for patients with plasma pro-MMP2 above 650 ng/ml. CONCLUSIONS: A high level of plasma pro-MMP2 was associated with poor survival of NPC patients independent of sex, age and stage.

Coriolus versicolor polysaccharide peptide slows progression of advanced non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a leading cause of cancer deaths, and over 60% of patients present with advanced stages. Although polysaccharide peptides (PSP), isolated from the fungus Coriolus versicolor, have been reported to have anti-tumor effects, its clinical efficacy has not been properly evaluated. METHODS: Double-blind placebo-controlled randomized study to evaluate the effects of 28-day administration of PSP (Windsor Pharmaceutical, Hong Kong) on patients, who had completed conventional treatment for advanced NSCLC. RESULTS: Thirty-four patients, with no significant difference in their baseline demographic, clinical or tumor characteristics, or previous treatment regimes (P>0.05) were recruited into each of the PSP and control arms. After 28-day treatment, there was a significant improvement in blood leukocyte and neutrophil counts, serum IgG and IgM, and percent of body fat among the PSP, but not the control, patients (P<0.05). Although the evaluable PSP patients did not improve in NSCLC-related symptoms, there were significantly less PSP patients withdrawn due to disease progression, than their control counterparts (5.9 and 23.5%, respectively; P=0.04; OR 4.00). There was no reported adverse reaction attributable to the trial medications. CONCLUSION: PSP treatment appears to be associated with slower deterioration in patients with advanced NSCLC.

Hypoxic constriction and reactive oxygen species in porcine distal pulmonary arteries.

To determine whether reactive oxygen species (ROS) play an essential role in hypoxic pulmonary vasoconstriction (HPV) and the cellular locus of ROS production and action during HPV, we measured internal diameter (ID) at constant transmural pressure, lucigenin-derived chemiluminescence (LDCL), and electron paramagnetic resonance (EPR) spin adduct spectra in small distal porcine pulmonary arteries, and dichlorofluorescein (DCF) fluorescence in myocytes isolated from these arteries. Hypoxia (4% O2) decreased ID, increased DCF fluorescence, tended to increase LDCL, and in some preparations produced EPR spectra consistent with hydroxyl and alkyl radicals. Superoxide dismutase (SOD, 150 U/ml) or SOD + catalase (CAT, 200 U/ml) did not alter ID during normoxia but reduced or abolished the constriction induced by hypoxia. SOD also blocked HPV in endothelium-denuded arteries after restoration of the response by exposure to 10-10 M endothelin-1. Confocal fluorescence microscopy demonstrated that labeled SOD and CAT entered pulmonary arterial myocytes. SOD, SOD + CAT, and CAT blocked the increase in DCF fluorescence induced by hypoxia, but SOD + CAT and CAT also caused a stable increase in fluorescence during normoxia, suggesting that CAT diminished efflux of DCF from cells or oxidized the dye directly. We conclude that HPV required increased concentrations of ROS produced by and acting on pulmonary arterial smooth muscle rather than endothelium.

Effects of pharmacological preconditioning with U50488H on calcium homeostasis in rat ventricular myocytes subjected to metabolic inhibition and anoxia.

1. The effects of pharmacological preconditioning with U50488H (U(50)), a selective kappa-opioid receptor agonist, on Ca(2+) homeostasis in rat ventricular myocytes subjected for 9 min to metabolic inhibition (MI) and anoxia (A), consequences of ischaemia, were studied and compared with those of preconditioning with brief periods of MI/A. 2. Precondition with 30 micro M of U(50) for three cycles of 1 min each cycle separated by 3 min of recovery (UP) significantly increased the percentage of non-blue cells following MI/A. The effect of UP is the same as that of preconditioning with an inhibitor of glycolysis and an oxygen scavenger for three 1-min cycles separated by three-minute recovery (MI/AP). The results indicate that like MI/AP, UP also confers cardioprotection. 3. MI/A increased intracellular Ca(2+) ([Ca(2+)](i)) and reduced the amplitude of caffeine-induced [Ca(2+)](i) transients, an indication of Ca(2+) content in the sarcoplasmic reticulum (SR). MI/A also reduced the electrically-induced [Ca(2+)](i) transient, that indicates Ca(2+)-release during excitation-contraction coupling, and Ca(2+) sparks in unstimulated myocytes, that indicates spontaneous Ca(2+)-release from SR. It also prolonged the decline of the electrically-induced [Ca(2+)](i) transient and slowed down the recovery of the electrically-induced [Ca(2+)](i) transient after administration of caffeine. In addition, MI/A prolonged the decline of caffeine induced [Ca(2+)](i) transient, an indication of Na(+)-Ca(2+) exchange activity, and UP prevented it. So UP, that confers cardioprotection, prevented the changes induced by MI/A. With the exception of Ca(2+)-spark, which was not studied, the effects of MI/AP are the same as those of UP. 4. It is concluded that pharmacological preconditioning with U(50), that confers immediate cardioprotection, prevents changes of Ca(2+) homeostasis altered by MI/A in the rat heart. This may be responsible, at least partly, for the cardioprotective action. 5. The study also provided evidence that MI/A causes mobilization of Ca(2+) from SR to cytoplasm causing Ca(2+)-overload which may be due to reduced Ca(2+)-uptake by SR. MI/A also reduces spontaneous and electrically induced Ca(2+) release from SR.

Management of extensive cervical nodal metastasis in nasopharyngeal carcinoma after radiotherapy: a clinicopathological study.

OBJECTIVES: To evaluate the efficacy of afterloading brachytherapy following radical neck dissection (RND) in the management of extensive cervical lymph node disease in nasopharyngeal carcinoma after radiotherapy; and to examine prospectively prognostic factors and the pathologic behavior of neck disease. PATIENTS: Twenty-seven patients with nasopharyngeal carcinoma who had extensive cervical lymph node metastasis following external radiotherapy were treated with RND. Thirteen of them also underwent afterloading brachytherapy with iridium wire (Ir 192). The RND specimens of the 27 patients were also examined with step serial whole-specimen sectioning. RESULTS: All patients survived and their wounds healed primarily. Pathologic examination revealed 183 tumor-bearing lymph nodes that contained tumors in the neck: level I, 4% (8/183); level II, 53% (96/183); level III, 34% (62/183); level IV, 5% (9/183); and level V, 4% (8/183). Extracapsular tumor extension was seen in 84% of patients. Multivariate analysis identified the number of tumor-bearing lymph nodes detected in the specimens to be the only significant factor that affected control of disease. Although the neck disease in the group of patients who had afterloading brachytherapy was more extensive, the 3-year actuarial tumor control for the groups with and without brachytherapy were 60% and 61%, respectively. CONCLUSIONS: Recurrent cervical lymph nodes after radiotherapy in nasopharyngeal carcinoma are extensive and RND is mandatory for a successful salvage. When the nodal metastasis infiltrate or adhere to surrounding tissue, afterloading brachytherapy with iridium wire can provide satisfactory local tumor control.

The predictive value of the 1997 American Joint Committee on Cancer stage classification in determining failure patterns in nasopharyngeal carcinoma.

BACKGROUND: A retrospective analysis of treatment outcomes in patients with nasopharyngeal carcinoma (NPC) was performed in which the newly revised 1997 American Joint Committee on Cancer (AJCC) stage classification was applied and compared with the 1988 AJCC and Ho stage classifications, with emphasis on the predictive value of different staging systems in determining failure patterns in NPC. METHODS: Three hundred and twenty-four patients with newly diagnosed NPC treated between September 1989 and August 1991 and originally staged according to Ho stage classification were re-staged according to the 1988 and 1997 AJCC stage classifications. In addition to stage grouping, patients were also classified into the following prognostic categories to study the failure patterns: early disease group (T1-2N0-1), advanced local disease group (T3-4N0-1), advanced nodal disease group (T1-2N2-3), and advanced locoregional disease group (T3-4N2-3). The overall survival (OAS), relapse-free survival (RFS), local relapse-free survival, nodal relapse-free survival, and distant metastases-free survival were compared among different stage groups and prognostic categories in the three staging systems. RESULTS: In the new AJCC system, the percentages of patients with Stage I, II, III, and IV disease were 15.1%, 31.5%, 28.1%, and 25.3%, respectively, whereas most patients were classified as having Stage IV disease (65.7%) in the old AJCC system and Stage II or III disease (74.1%) in the Ho system. The 5 year OAS rates in the 1997 AJCC Stage I, II, III, and IV disease were 97.7%, 78.7%, 79.5%, and 61.4%, respectively. The corresponding 5 year RFS rates were 95.7%, 64.7%, 54.5%, and 41.1%. Using the 1997 AJCC system to define the four prognostic categories, the early disease group had the lowest incidence of relapse (27.6%) and death (18.4%), whereas the advanced locoregional disease group had the highest incidence of relapse (61.4%) and death (43.2%). Both the advanced local disease group and the advanced nodal disease group had similar rates of relapse (46.7% vs. 47.2%), but local relapse was the major cause of failure in the former group (61.8%), whereas distant metastases was the major cause in the latter group (44%). CONCLUSIONS: Using the 1997 AJCC staging system, the authors observed a better distribution of patient numbers as well as segregation of survival curves among different stage groups. Moreover, prognostic categories with distinct prognosis and failure patterns were definable by the new system, which has important implications in selecting appropriate patient treatment strategies.

Inhibition of voltage-gated K(+) currents by endothelin-1 in human pulmonary arterial myocytes.

Recent studies demonstrate that endothelin-1 (ET-1) constricts human pulmonary arteries (PA). In this study, we examined possible mechanisms by which ET-1 might constrict human PA. In smooth muscle cells freshly isolated from these arteries, whole cell patch-clamp techniques were used to examine voltage-gated K(+) (K(V)) currents. K(V) currents were isolated by addition of 100 nM charybdotoxin and were identified by current characteristics and inhibition by 4-aminopyridine (10 mM). ET-1 (10(-8) M) caused significant inhibition of K(V) current. Staurosporine (1 nM), a protein kinase C (PKC) inhibitor, abolished the effect of ET-1. Rings of human intrapulmonary arteries (0.8-2 mm OD) were suspended in tissue baths for isometric tension recording. ET-1-induced contraction was maximal at 10(-8) M, equal to that induced by K(V) channel inhibition with 4-aminopyridine, and attenuated by PKC inhibitors. These data suggest that ET-1 constricts human PA, possibly because of myocyte depolarization via PKC-dependent inhibition of K(V). Our results are consistent with data we reported previously in the rat, suggesting similar mechanisms may be operative in both species.

Adoptive transfer of autologous Epstein-Barr virus-specific cytotoxic T cells for nasopharyngeal carcinoma.

Tumor cells from NPC patients are regularly and latently infected with EBV. To examine whether the virus serves as target for immune intervention of the cancer, we determined levels of EBV-specific CTLp in peripheral blood from NPC patients, long-term survivors of the cancer and healthy subjects. CTLp levels of test subjects varied between 3- 3,000/10(6) PBMCs. The plasma EBV burden increased when the CTLp level fell below 150, whereas the EBV burden of PBMCs was not correlated with CTLp level. Compared with healthy carriers, CTLp levels of patients were lower and varied over a wider range, between 3-1,500/10(6) PBMCs. The quantitative immune deficit was probably attributed to the tumor because, first, CTLp in survivors was restored to levels similar to those in healthy carriers after the tumor had been successfully treated. Second, the CTLp level changed as disease progressed, being lower in local disease, increased in locoregional disease and decreased again when the tumor metastasized. Based on these findings, 4 patients with advanced disease were infused with 5 x 10(7)-3 x 10(8) autologous EBV CTLs. The treatment was safe and unaccompanied by inflammatory or other complications, but whether it improved tumor control could not be discerned from the large tumor bulk. Nevertheless, the treatment regularly increased CTLp levels of patients, maintained it at higher levels for protracted periods and, in 3 patients, restored host surveillance of EBV replication, reducing the plasma EBV burden. Taken together, these results provided a rationale to further explore EBV as a target of immune intervention of NPC.

Chinese nasopharyngeal carcinoma patients treated with radiotherapy: association between satisfaction with information provided and quality of life.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is highly prevalent in southern China. Prominent acute side effects of radiotherapy create problems in daily living and working that can generate considerable financial difficulties. A better adjustment to a diagnosis of NPC appears to be associated with an improved rate of recovery, a better quality of life (QoL), a quicker return to work, and normal functioning. Patient satisfaction with physician consultation and the way information is provided in particular may have significant bearing on QoL. The current study reports on short-term QoL after radiotherapy in NPC patients as a function of satisfaction with the information provided. METHODS: Newly referred Hong Kong Chinese NPC patients (n = 211) completed interview measures at baseline before the initiation of radiotherapy, at 4 months after baseline (immediate posttreatment consultation) (FU 1), and again at 8 months (short-term postradiation period) after baseline (FU 2). Satisfaction with the information provided was measured by five items selected from the cognitive subscale of the Medical Interview Satisfaction Scale (MISS). QoL was measured by the Chinese version of the Functional Assessment of Cancer Therapy-General Scale (FACT-G (Ch)). RESULTS: After adjustment for overall patient satisfaction (the PSQ-9), optimism, worry about family, anger, eating ability, subjective health, family income, and occupation at FU 1, treatment between baseline and FU 1, and disease recurrence after baseline, the 5-item MISS at FU 1 (beta = 0.21, P < 0.01) was found to significantly predict patient QoL at FU 2. Adjustment for baseline QoL and disease stage did not appear to alter this relation (beta = 0.20, P < 0.01). CONCLUSIONS: To the authors' knowledge, there is very little research concerning NPC. The results of the current study reinforced the need to improve physicians' information provision during consultations with Chinese NPC patients shortly after the end of treatment.

Salvage treatment for persistent and recurrent T1-2 nasopharyngeal carcinoma by stereotactic radiosurgery.

OBJECTIVE: To study the efficacy of stereotactic radiosurgery in salvaging early-stage persistent and recurrent nasopharyngeal carcinoma (NPC) after primary radiotherapy. METHODS: A prospective single-arm study evaluating the response and outcome of patients with rT1-2 NPC treated by stereotactic radiosurgery. Eleven patients with rT1-2 were treated by radiosurgery between March 1998 and March 2000. Four patients were treated for persistent disease occurring within 4 months after primary radiotherapy, six were treated for first recurrence, and one for third recurrence. Six patients had rT1 disease and five had rT2 disease. Most patients had disease not amenable to brachytherapy, surgery, or external re-irradiation. The median target volume was 5.8 cc (range, 3.3-16.9). Radiosurgery was performed with multiple noncoplanar arcs of photon, with a median dose of 12.5 Gy delivered to the 80% isodose line (range, 12-14 Gy). Median follow-up time after radiosurgery was 18 months (range, 9-30). RESULTS: Nine patients had complete regression of tumor as assessed by imaging, nasopharyngoscopy, and biopsy; one patient had partial regression of tumor; whereas one patient had static disease. The overall response rate was 91% (10 of 11) and the complete response rate was 82% (9 of 11). Two patients with complete response subsequently had local relapse develop, with one recurrence outside the treated volume 8 months after radiosurgery, and the other within the treated volume 6 months after radiosurgery. One patient with a partial response had neck node recurrence develop. Temporal lobe necrosis occurred in one patient but probably represents sequelae of primary radiation after reviewing the dosimetry. Ten patients are still alive, whereas one patient with local relapse had distant metastases develop and died. The estimated 1-year local control rate after radiosurgery was 82%. CONCLUSIONS: Our preliminary results indicate that stereotactic radiosurgery is an effective treatment modality for persistent and recurrent T1-T2 NPC, and early control rate seems to be comparable to other salvage treatments. More clinical experiences and longer follow-up are still needed to validate our results and to address fully the role of radiosurgery in salvaging local failures of NPC.

Partial HIF-1alpha deficiency impairs pulmonary arterial myocyte electrophysiological responses to hypoxia.

Chronic hypoxia depolarizes and reduces K+ current in pulmonary arterial smooth muscle cells (PASMCs). Our laboratory previously demonstrated that hypoxia-inducible factor-1 (HIF-1) contributed to the development of hypoxic pulmonary hypertension. In this study, electrophysiological parameters were measured in PASMCs isolated from intrapulmonary arteries of mice with one null allele at the Hif1a locus encoding HIF-1alpha [Hif1a(+/-)] and from their wild-type [Hif1a(+/+)] littermates after 3 wk in air or 10% O2. Hematocrit and right ventricular wall and left ventricle plus septum weights were measured. Capacitance, K+ current, and membrane potential were measured with whole cell patch clamp. Similar to our laboratory's previous results, hypoxia-induced right ventricular hypertrophy and polycythemia were blunted in Hif1a(+/-) mice. Hypoxia increased PASMC capacitance in Hif1a(+/+) mice but not in Hif1a(+/-) mice. Chronic hypoxia depolarized and reduced K+ current density in PASMCs from Hif1a(+/+) mice. In PASMCs from hypoxic Hif1a(+/-) mice, no reduction in K+ current density was observed, and depolarization was significantly blunted. Thus partial deficiency of HIF-1alpha is sufficient to impair hypoxia-induced depolarization, reduction of K+ current density, and PASMC hypertrophy.

Anti-tumor effects of human peripheral gammadelta T cells in a mouse tumor model.

Peripheral gammadelta T cells derived from healthy donors were found to exhibit cytotoxicity against a variety of tumor cell lines in vitro, including CNE2, which was established from nasopharyngeal carcinoma (NPC). The anti-tumor effects were further studied in a mouse model. Control nude mice inoculated s.c. with 5 x 10(6) CNE2 cells regularly developed hypodermal tumors, which progressively increased in size, and animals had a mean survival of 35 +/- 3.4 days. Tumor growth was arrested and tumor size was reduced after animals were infused with 5 x 10(7) gammadelta T cells derived from a healthy donor. The anti-tumor effects were temporary, however, and tumor growth was resumed after about 1 week in a group of the animals that had been given a single dose of gammadelta T cells. In another group of animals given 2 doses of gammadelta cells 1 week apart, resumption of tumor growth was delayed for a further week. Mean survival of the 2 groups was increased to 61 +/- 15.7 and 74 +/- 12.9 days, respectively. Immunohistology revealed an accumulation of infused cells in tumors attended by focal tumor necrosis in specimens taken 2 days after infusion. Infiltrative cells virtually disappeared from tumor tissues 6 days after infusion, accompanied by increased mitotic indices of tumor cells. These temporal relationships suggested that the accumulation of infused gammadelta T cells in hypodermal tumors was responsible for the observed anti-tumor effects.

Hypoxic constriction of porcine distal pulmonary arteries: endothelium and endothelin dependence.

To determine the role of endothelium in hypoxic pulmonary vasoconstriction (HPV), we measured vasomotor responses to hypoxia in isolated seventh-generation porcine pulmonary arteries < 300 microm in diameter with (E+) and without endothelium. In E+ pulmonary arteries, hypoxia decreased the vascular intraluminal diameter measured at a constant transmural pressure. These constrictions were complete in 30-40 min; maximum at PO(2) of 2 mm Hg; half-maximal at PO(2) of 40 mm Hg; blocked by exposure to Ca(2+)-free conditions, nifedipine, or ryanodine; and absent in E+ bronchial arteries of similar size. Hypoxic constrictions were unaltered by indomethacin, enhanced by indomethacin plus N(G)-nitro-L-arginine methyl ester, abolished by BQ-123 or endothelial denudation, and restored in endothelium-denuded pulmonary arteries pretreated with 10(-10) M endothelin-1 (ET-1). Given previous demonstrations that hypoxia caused contractions in isolated pulmonary arterial myocytes and that ET-1 receptor antagonists inhibited HPV in intact animals, our results suggest that full in vivo expression of HPV requires basal release of ET-1 from the endothelium to facilitate mechanisms of hypoxic reactivity in pulmonary arterial smooth muscle.

Patterns of failure after induction chemotherapy and radiotherapy for locoregionally advanced nasopharyngeal carcinoma: the Queen Mary Hospital experience.

PURPOSE: Our center contributed 183 patients to the Asian-Oceanian Clinical Oncology Association (AOCOA) multicenter randomized trial comparing induction chemotherapy (CT) followed by radiotherapy (RT) vs. RT alone in patients with locoregionally advanced undifferentiated nasopharyngeal carcinoma (NPC). In a preliminary report no difference in terms of overall survival or relapse-free survival was found between the 2 treatment arms. To study the long-term outcome and patterns of failure after CT for NPC, we analyzed our own center data for which a uniform radiation treatment protocol was adopted and a longer follow-up time was available. METHODS AND MATERIALS: Between September 1989 and August 1993, a total of 183 patients were recruited into the AOCOA randomized study from our center. Patients with newly diagnosed NPC of Ho's T3 disease, N2-N3 disease, or with neck node size of at least 3 cm were eligible. Stratification was made according to the nodal size (< or = 3 cm, >3- 6 cm, > 6 cm). Patients were randomized to receive 2-3 cycles of CT with cisplatin 60 mg/m(2) and epirubicin 110 mg/m(2) D1 followed by RT or RT alone. Four patients were excluded from the current analysis (2 died before treatment, 2 received treatment elsewhere). The remaining 179 patients were randomized to the two treatment arms, with 92 to the CT arm and 87 to the RT arm. Two patients in the CT arm had RT only, and all patients completed radiation treatment. Overall survival (OAS), relapse-free survival (RFS), local relapse-free survival (LRFS), nodal relapse-free survival (NRFS), and distant metastases-free survival (DMFS) were analyzed using Kaplan--Meier method and significance of survival curve differences calculated using log--rank test. Analysis was performed based on the intent-to-treat. RESULTS: The median follow-up was 70 months. At the time of analysis, 50% of patients in the CT arm and 61% in the RT arm had relapse, while 32% in the CT arm and 36% in the RT arm had died of the disease. The median RFS was 83 months in the CT arm and 37 months in the RT arm. The median OAS has not yet been reached for both arms. No significant differences were found for the various endpoints, although there was a trend suggesting better nodal control in the CT arm. The 5-year rates for the various endpoints in the CT arm vs. the RT arm were: 53% vs. 42% for RFS (p = 0.13), 70% vs. 67% for OAS (p = 0.68), 80% vs. 77% for LRFS (p = 0.73), 89% vs. 80% for NRFS (p = 0.079), and 70% vs. 68% for DMFS (p = 0.59). There was also no significant difference in the patterns of failure between both arms: in the CT arm, 28% of failures were local only, 13% regional only, 4% locoregional, 44% distant, and 11% mixed locoregional and distant. In the RT arm, 23% of failures were local only, 13% regional only, 11% locoregional, 43% distant, and 9% mixed locoregional and distant. CONCLUSION: Induction chemotherapy with the regimen used in the current study did not improve the treatment outcome or alter the failure patterns in patients with locoregionally advanced NPC, although there was a trend suggesting better nodal control in the combined modality arm. Alternative strategies of combining chemotherapy and radiotherapy should be tested and employed instead.

Isolation of a novel candidate oncogene within a frequently amplified region at 3q26 in ovarian cancer.

Amplification of 3q25-q26 was one of the most frequent chromosomal alterations in human ovarian carcinoma. A chromosome microdissection-hybrid selection method was applied to isolate transcribed sequences from a primary ovarian cancer containing high-copy-number amplification of 3q26 using 3q26 band-specific DNAs generated by chromosome microdissection. Using this method, we have isolated a novel candidate oncogene eIF-5A2 (eukaryotic initiation factor 5A2). eIF-5A2 shares 82% identity of amino acid sequence with eIF-5A including the minimum domain needed for eIF-5A maturation by hypusine modification at lysine-50 residue. Amplification and overexpression of eIF-5A2 was frequently detected in primary ovarian cancers and ovarian cancer cell lines. The proliferation-related function of eIF-5A supports that eIF-5A2 is a candidate oncogene related to the development of ovarian cancer.