Long-term outcome after endoscopic resection in patients with hypopharyngeal carcinoma invading the subepithelium: a case series.

Patients with early stage hypopharyngeal carcinoma can be treated with endoscopic resection. However, strict indication for endoscopic resection in cases of hypopharyngeal carcinoma is unclear. In this paper, we evaluated the long-term outcome after endoscopic resection in patients with hypopharyngeal carcinoma invading the subepithelium. Among 16 patients with hypopharyngeal carcinoma who underwent endoscopic resection, eight patients who were histologically confirmed to have tumors with shallow invasion of the subepithelium were studied. Depth of tumor invasion in the subepithelium in those patients ranged from 300 to 720 microm (mean +/- SD, 490 +/- 140 microm). During a median follow-up period of 40 months, none of the eight patients had local recurrence or metastasis. Kaplan-Meier estimates of relapse-free survival rates at 5 years in the eight patients were 100 %. The results of this study suggest that hypopharyngeal carcinoma with slight invasion to the subepithelium can be successfully treated by endoscopic resection.

Increased mitochondrial DNA induces acquired docetaxel resistance in head and neck cancer cells.

Docetaxel is one of the most effective chemotherapeutic agents against cancer; nevertheless, some patients develop resistance. Unfortunately, their causes and mechanisms remain unknown. We created docetaxel-resistant DRHEp2 from human laryngeal cancer HEp2 and investigated the roles of mitochondrial DNA (mtDNA) and reactive oxygen species (ROS) on docetaxel resistance. DRHEp2 had greatly increased mtDNA content. Reduction of mtDNA content in DRHEp2 by ethidium bromide treatment reduced the resistance. These results indicate the possible roles of mtDNA-coded enzymes in mitochondrial respiratory chain (MRC) in resistant mechanisms. Oligomycin A, an Fo-ATPase inhibitor, eliminated docetaxel resistance in DRHEp2; in contrast, inhibitors of other MRC did not. RNA interference targeted to Fo-ATPase d-subunit restored docetaxel-induced cytotoxicity to DRHEp2. These results indicate the roles of Fo-ATPase for resistant mechanisms. Docetaxel induced ROS generation in HEp2 but not in DRHEp2 and antioxidant pyrrolidine dithiocarbamate eliminated docetaxel-induced cytotoxicity, suggesting roles of ROS in docetaxel-induced cell death. Furthermore, inhibition of Fo-ATPase by Oligomycin A induced docetaxel-mediated ROS generation in DRHEp2. Taken together, DRHEp2 acquired docetaxel resistance through increasing Fo-ATPase, which led to diminish docetaxel-induced ROS generation and subsequently inhibited cell death. In conclusion, mtDNA plays an important role in developing docetaxel resistance through the reduction of ROS generation by regulating Fo-ATPase.

N-(4-hydroxyphenyl)retinamide-induced apoptosis triggered by reactive oxygen species is mediated by activation of MAPKs in head and neck squamous carcinoma cells.

N-(4-hydroxyphenyl)retinamide (4HPR), a synthetic retinoid effective in cancer chemoprevention and therapy, is thought to act via apoptosis induction resulting from increased reactive oxygen species (ROS) generation. As ROS can activate MAP kinases and protein kinase C (PKC), we examined the role of such enzymes in 4HPR-induced apoptosis in HNSCC UMSCC22B cells. 4HPR increased ROS level within 1 h and induced activation of caspase 3 and PARP cleavage within 24 h. Activation of MKK3/6 and MKK4, JNK, p38 and ERK was detected between 6 and 12 h, increased up to 24 h and preceded apoptosis. 4HPR-induced activation of these kinases was abrogated by the antioxidants BHA and vitamin C. SP600125, a JNK inhibitor, suppressed 4HPR-induced c-Jun phosphorylation, cytochrome c release from mitochondria and apoptosis. Suppression of JNK1 and JNK2 using siRNA decreased, whereas overexpression of wild type-JNK1 enhanced 4HPR-induced apoptosis. PD169316, a p38, inhibitor suppressed phosphorylation of Hsp27 and apoptosis. PD98059, an MEK1/2 inhibitor, also suppressed ERK1/2 activation and apoptosis induced by 4HPR. Likewise, PKC inhibitor GF109203X suppressed ERK and p38 phosphorylation and PARP cleavage. These data indicate that 4HPR-induced apoptosis is triggered by ROS increase, leading to the activation of the mitogen-activated protein serine/threonine kinases JNK, p38, PKC and ERK, and subsequent apoptosis.

A study of piriform sinus fistula cases.

We have experienced five cases of piriform sinus fistula for the last 10 years. It is a relatively rare disease, and partly because of poor understanding of the disease, in one case infection had repeatedly recurred without being adequately treated for over 20 years, and in most cases there was a long time lapse before the diagnosis. In another case, it was difficult to image the fistula with contrast medium and fistulectomy was performed without identifying it on imaging. We have applied various devices to those cases where imaging of fistula was difficult, and achieved complete resection of fistula and have not observed recurrences of infection after resection.

A clinical study on the cervical lymph node metastasis of maxillary sinus carcinoma.

OBJECTIVE: To improve the management of maxillary sinus carcinoma, we retrospectively investigated the significance of cervical lymph node metastasis in our treated cases and discussed how to deal with the cervical lymph node metastasis as a prognostic factor. METHODS: Medical records of 118 patients with maxillary sinus carcinoma diagnosed and treated in our institute from 1982 to 1997 were retrospectively reviewed. Tumors were staged according to UICC classification 1987. The cumulative survival was analyzed by the Kaplan-Meier method. Generally, the patients had undergone preoperative radiotherapy and surgery. We examined the cervical lymph node metastasis detected at the first examination and the subsequent cervical lymph node metastasis in relation to the prognoses. RESULTS: The incidence of cervical lymph node metastasis at the initial diagnosis was 7.9% (n = 9), and that of secondary cervical lymph node metastasis without recurrence at the primary site after the first treatment was 8.3% (n = 9). In most cases, we observed metastasis to the lymph nodes in the submandibular region and in the jugular chain. The result of treatment of cervical lymph node metastasis was grave. Among the patients with cervical lymph node metastasis detected at the first examination, four patients developed local recurrence and three patients developed distant metastasis. On the other hand, among those with secondary cervical metastasis, three patients developed neck recurrence and three patients developed distant metastasis, but no local recurrence. CONCLUSIONS: In the cervical metastasis of maxillary sinus carcinoma, it is important to treat the primary lesion completely. In addition to it. we should control cervical metastasis and careful neck dissection is required. For the patients with cervical lymph node metastasis, it is necessary to consider the further treatment of distant metastasis.

Correlation of clinicopathological parameters and biological markers related to apoptosis and proliferative activity with a clinical outcome in squamous cell carcinoma of the larynx treated with concurrent chemoradiotherapy.

OBJECTIVE: This study was designed to determine whether biological markers related to apoptosis or proliferative activity are associated with the clinical outcome in patients with squamous cell carcinoma (SCC) of the larynx treated with concurrent chemoradiotherapy. METHODS: Immunostaining with antibodies specific to p53, bcl-2, bax, and MIB-1 was performed to evaluate expression of these proteins in formalin-fixed, paraffin-embedded specimens of 59 patients treated with concurrent chemoradiotherapy (carboplatin, 100 mg/m2, four to six times every week; total radiation dose of 40-65 Gy over 4-6.5 weeks). RESULTS: Multivariate analysis indicated that nodal status was a significant indicator of overall survival (OS: P = 0.001). Patients with bcl-2 positive tumors had better OS than those with bcl-2 negative tumors in both univariate (P = 0.002) and multivariate analyses (P < 0.001 ). In the univariate analysis, a considerable difference in OS was observed among the expressions of bax (P = 0.077), MIB-1 proteins (P = 0.071). and OS. but the difference was not statistically significant. CONCLUSION: This study indicates that nodal status is the major prognostic tactor in patients with SCC of the larynx treated with concurrent chemoradiotherapy. These results provide useful information for predicting prognosis. Further analysis of biological factors is needed to evaluate the value as predictive markers.

Implication of mitochondria-derived reactive oxygen species, cytochrome C and caspase-3 in N-(4-hydroxyphenyl)retinamide-induced apoptosis in cervical carcinoma cells.

N-(4-Hydroxyphenyl)retinamide (4HPR) is currently used in cancer prevention and therapy trials. It is thought that its effects result from induction of apoptosis. 4HPR-induced apoptosis in human cervical carcinoma C33A cells involves enhanced generation of reactive oxygen species (ROS). In this study we explored the mechanism by which 4HPR increases ROS and induces apoptosis in these cells. 4HPR induced cytochrome c release from mitochondria to cytoplasm, activated caspase-3, and caused a membrane permeability transition (MPT). All these 4HPR's effects, as well as the induction of apoptosis, were inhibited by antioxidants, which decrease ROS. Thenoyltrifluoroacetone, a mitochondrial respiratory chain (MRC) complex II inhibitor, and carbonylcyanide m-chlorophenyl hydrazone, which uncouples electron transfer and ATP synthesis and inhibits ROS generation by MRC, inhibited 4HPR-induced ROS generation very effectively. Rotenone, an MRC complex I inhibitor was less effective and azide, an MRC complex IV inhibitor, exhibited a marginal effect. In contrast, antimycin A, an MRC complex III inhibitor, enhanced 4HPR-induced ROS generation. These findings suggest that 4HPR enhances ROS generation by affecting a target between complex II and complex III, presumably coenzyme Q. This effect is followed by release of cytochrome c, increased caspase-3 activity, induction of MPT and eventual DNA fragmentation and cell death.

Antisense epidermal growth factor receptor delivered by adenoviral vector blocks tumor growth in human gastric cancer.

Epidermal growth factor receptor (EGFR) protein overexpression is commonly found in human gastric cancer, and its gene amplification is known to correlate with poor prognosis in gastric cancer patients. With regard to therapy trials targeting EGFR, it has been reported that stable transfection of EGFR antisense or treatment with antibody against EGFR results in growth suppression of human cancer cells that express high levels of EGFR. We have designed an adenovirus-expressing antisense EGFR and have investigated its effect on the growth of gastric cancer in vitro and in vivo. Following infection with EGFR antisense RNA-expressing adenovirus (Ad-EAS), the cell surface EGFR protein levels of infected cancer cells were markedly reduced, and the in vitro growth of Ad-EAS-infected cells was significantly inhibited relative to control-infected cells in all three gastric cancer cell lines (AGS, KKLS, and MKN28) studied here (P < .0002). In a nude mouse subcutaneous tumor system, in vivo tumor growth of MKN28 was significantly inhibited after Ad-EAS treatment, and inhibition on day 48 was 93% by volume compared with that of untreated controls. These results suggest that an adenoviral vector system targeting the down-regulation of EGFR could be a good candidate for the therapy of gastric cancers that overexpress EGFR.

Overexpression of retinoic acid receptor beta in head and neck squamous cell carcinoma cells increases their sensitivity to retinoid-induced suppression of squamous differentiation by retinoids.

Nuclear retinoic acid receptor beta(RARbeta) expression is suppressed in many head and neck squamous cell carcinomas (HNSCCs), and an inverse relationship was found between squamous differentiation and RARbeta expression in such cells. To investigate the role of RARbeta in HNSCC growth and differentiation, we transfected a retroviral RARbeta2 expression vector (LNSbeta) into HNSCC SqCC/Y1 cells, which do not express endogenous RARbeta but do express RARalpha, RARgamma, and retinoid X receptors. Transfected clones expressing RARbeta2 mRNA and protein exhibited enhanced sensitivity to the suppressive effects of all-trans-retinoic acid (ATRA) on squamous differentiation compared with cells transfected with the LNSX vector only; transglutaminase type I level was suppressed after a 3-day treatment with 10(-10) M ATRA in four of five LNSbeta clones, whereas it was not suppressed in LNSX cells even by 10(-6) M ATRA. Similarly, cytokeratin 1 mRNA level was more suppressed in ATRA-treated LNSbeta clones than it was in LNSX cells. This effect was independent of transrepression of activator protein-1. None of the LNSbeta-transfected clones showed an increased growth inhibition by ATRA, 9-cis-retinoic acid, or the synthetic retinoid 6-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-2-naphthale necarboxylic acid. These findings suggest that, in SqCC/Y1 cells, RARbeta mediates suppression of squamous differentiation by ATRA without enhancing its growth-inhibitory effects.

Prognostic significance of clinical parameters and biological markers in patients with squamous cell carcinoma of the head and neck treated with concurrent chemoradiotherapy.

Concurrent chemoradiotherapy is reported to have a fair clinical outcome with organ preservation for patients with squamous cell carcinoma of the head and neck (SCCHN). The aim of this study was to determine whether biological markers are related to proliferative activity or apoptosis of tumor cells and whether clinical factors are associated with a clinical outcome in SCCHN patients treated with concurrent chemoradiotherapy. Immunostaining with antibodies specific for p53, bcl-2, bax, and MIB-1 was performed to evaluate expression of these proteins in formalin-fixed, paraffin-embedded specimens of 111 SCCHN patients treated with concurrent chemoradiotherapy (carboplatin, 100 mg/m2, four to six times every week; total radiation therapy dose of 40-65 Gy over 4-6.5 weeks). Multivariate analysis indicated that nodal status was a significant indicator of overall survival (OS; P = 0.001) and locoregional control (LRC; P = 0.002). In a univariate analysis, patients with a low MIB-1-positive index (< 40%) had better OS than those with a high MIB-1-positive index (> or = 40%; P = 0.013), although the difference was not statistically significant in a multivariate analysis (P = 0.060). Patients with bcl-2-positive tumors had better LRC than those with bcl-2-negative tumors, based on a multivariate analysis (P = 0.017). No statistically significant association was found between p53 or bax expression and clinical outcome. These results indicate that nodal status is the major prognostic factor in SCCHN patients treated with concurrent chemoradiotherapy. In addition, our findings suggest that bcl-2 positivity is associated with better LRC and that the proliferative activity of tumor cells might be prognostic for OS.

Involvement of reactive oxygen species in N-(4-hydroxyphenyl)retinamide-induced apoptosis in cervical carcinoma cells.

BACKGROUND: The inhibitory effects of N-(4-hydroxyphenyl)retinamide (4HPR) on tumorigenesis and tumor growth may result from its ability to induce apoptosis (programmed cell death). Since antioxidants inhibit 4HPR-induced apoptosis, experiments were planned to determine whether the levels of reactive oxygen species increase in cells undergoing apoptosis after exposure to 4HPR. METHODS: Cells of the human cervical carcinoma cell line C33A and normal human cervical epithelial cells were treated with 4HPR and analyzed for survival, induction of apoptosis, generation of reactive oxygen species, and expression of the apoptosis-related proteins Bcl-2 and Bax. RESULTS: Treatment with 4HPR decreased C33A cell number by inducing apoptosis in a time- and dose-dependent fashion. DNA fragmentation typical of apoptosis was observed in cells exposed to 4HPR at concentrations of 3 microM or higher for 6-24 hours. The generation of reactive oxygen species was enhanced by 1.85-fold to 4.5-fold after a 1.5-hour treatment with 0.4-10 microM 4HPR. Pyrrolidine dithiocarbamate, an oxygen radical scavenger, suppressed the rate of generation of reactive oxygen species and inhibited 4HPR-induced apoptosis. 4HPR failed to modulate cellular levels of the Bcl-2 and Bax proteins. N-(4-Methoxyphenyl)retinamide, the major 4HPR metabolite, and several other retinoids that bind to nuclear retinoic acid receptors or retinoid X receptors failed to enhance the generation of reactive oxygen species and to induce apoptosis. 4HPR was much less effective in generating reactive oxygen species and in inducing apoptosis in normal human cervical epithelial cells than in C33A cervical carcinoma cells. CONCLUSIONS: Enhancement of the generation of reactive oxygen species may be involved in apoptotic pathway induction by 4HPR.

Implication of retinoic acid receptor gamma in squamous differentiation and response to retinoic acid in head and neck SqCC/Y1 squamous carcinoma cells.

Nuclear retinoic acid receptors are considered to be the mediators of most of the effects of retinoic acid (RA) on gene expression. To explore the role of RA receptor gamma (RARgamma) in the growth and differentiation of SqCC/Y1 head and neck squamous carcinoma cells, they were transfected with RARgamma sense and antisense expression vectors and stable clones in which RARgamma expression was either increased or blocked were isolated. The growth inhibitory effect of RA in monolayer culture was enhanced in the sense transfectants and decreased in the antisense ones. The ability to form colonies in semisolid medium was abolished by RA in the sense transfectants, while the antisense transfected clones exhibited heterogeneous responses. The expression the squamous differentiation markers cytokeratin K1 transglutaminase type I, and involucrin was increased in the absence of exogenous retinoid in a sense transfected clone and decreased in an antisense transfected clone. RA suppressed squamous differentiation in both types of transfectant. The expression of epidermal growth factor receptor (EGFR) was higher in the antisense and lower in the sense transfectant than in the parental cells and RA decreased EGFR mRNA level in the parental and the sense transfectant but not in the antisense transfectant. In addition activator protein-1 (AP-1) binding activity was decreased by the RA treatment in the sense clones, but not in the antisense ones. These results suggest that RARgamma mediates the effects of RA on the cell growth both in monolayer culture and in semisolid medium possibly through AP-1 suppression.

Differential induction of apoptosis by all-trans-retinoic acid and N-(4-hydroxyphenyl)retinamide in human head and neck squamous cell carcinoma cell lines.

Retinoids have been shown to act as cytostatic agents against a variety of tumor cell types, including squamous carcinoma cells. Recently it was reported that certain retinoids can induce apoptosis as well. Because we are investigating the potential of retinoids in chemoprevention and therapy for head and neck premalignant and malignant lesions, we compared the effects of all-trans-retinoic acid (ATRA) and N-(4-hydroxyphenyl)retinamide (4HPR) on seven human head and neck squamous cell carcinoma cell lines (17A, 17B, 22A, 22B, 38, SqCC/Y1, and 1483). Six of the seven cell lines showed dramatic morphological changes after treatment with 10 micrometer 4HPR, whereas no such changes were induced by 10 micrometer ATRA. To determine whether these retinoids can induce apoptosis, we analyzed both detached and attached cells after 2, 5, and 7 days of treatment for evidence of DNA fragmentation by DNA electrophoresis on agarose gels. In five of the seven cell lines, a DNA ladder was observed after treatment with 10 micrometer 4HPR for 5 or 7 days, whereas treatment with ATRA resulted in a less pronounced effect. In 17B cells, a clear DNA ladder was observed as early as 2 days after treatment with 4HPR; however, neither ATRA nor 9-cis-retinoic acid was as effective. In addition, morphological changes associated with apoptotic cell death, such as chromatin condensation and nuclear segmentation, were observed by propidium iodide staining and by electron microscopic analysis after 4HPR treatment. These results demonstrate that 4HPR causes apoptosis in several head and neck squamous cell carcinoma cell lines and that it is more potent in this effect than ATRA.

Retinoid refractoriness occurs during lung carcinogenesis despite functional retinoid receptors.

Retinoids have demonstrated activity in the prevention of second primary tumors in patients with non-small cell lung cancer (NSCLC). They also contribute to the normal growth and differentiation of human bronchial epithelial (HBE) cells. Because retinoids mediate their actions through retinoid nuclear receptors (RARs and RXRs), aberrant signaling through retinoid receptors could contribute to lung carcinogenesis. Using a lung carcinogenesis model consisting of normal, premalignant, and malignant HBE cells, we examined all-trans retinoic acid (t-RA)-induced changes in cellular growth. These studies revealed that t-RA treatment inhibited the growth of normal HBE cells, but premalignant and malignant HBE cells were relatively resistant to t-RA. Coincident with the development of retinoid refractoriness, basal expression of the retinoic acid nuclear receptor beta (RAR-beta) increased. Analysis of receptor function by gel shift and transient transfection assays of normal, premalignant, and malignant HBE cells demonstrated that receptor-DNA binding and transcriptional activation properties were intact in the t-RA-refractory malignant HBE cells. To compare these findings to NSCLCs in patients, we investigated retinoid receptor expression in NSCLC biopsies. A subset of the tumors expressed RAR-beta, reflecting the RAR-beta expression observed in the malignant HBE cells in culture. These findings demonstrate that retinoid receptor function was intact in the t-RA-refractory malignant HBE cell line, suggesting that the defect in retinoid signaling in this lung carcinogenesis model is not intrinsic to the retinoid receptors.

Inhibition of proliferation and induction of apoptosis in cervical carcinoma cells by retinoids: implications for chemoprevention.

The effects of retinoids including all-trans-retinoic acid (ATRA), 13-CIS-RETINOIC ACID (13CRA), and N-(4-hydroxyphenyl)retinamide (4-HPR) on several cervical carcinoma cell lines in culture were investigated as a prelude to investigating the mechanisms underlying the chemopreventive potential of retinoids in cervical cancer. We found that when used at a concentration of 1 microM, 13CRA and ATRA inhibited the proliferation of three cell lines (ME-180 [HPV 68], SiHa [HPV 18], and HT-3 [HPV-]) by about 80% after a seven-day treatment. Three other cell lines (MS-751 [HPV 18], HeLa [HPV 18], C-33A [HPV-]) were moderately inhibited (30-48%), and two (C-4 II [HPV 18], CaSki [HPV 16]) responded poorly (< 25% inhibition). 4-HPR failed to inhibit the growth of any of these cell lines when used at 1 microM; however, when used at 5 or 10 microM, it induced apoptosis as evidenced by DNA fragmentation in several of the cell lines and was more potent in this effect than 10 microM ATRA. Retinoids that induce apoptosis in malignant cells may be able to exert similar effects on premalignant cells. Such retinoids would be expected to exhibit greater potency as chemopreventive agents than retinoids that exert only cytostatic effects.