Kiyoshi Misawa

Cyclin D1 overexpression correlates with poor prognosis in patients with tongue squamous cell carcinoma.

Tongue squamous cell carcinoma makes up a large percentage of head and neck cancers, and the incidence among young patients is increasing. The aim of this study was to reveal the correlation between cyclin D1 (CCND1) expression and clinical and histologic features. We performed an immunohistochemical study on the level of CCND1 expression in tumor specimens obtained from 94 patients with tongue squamous cell carcinoma. The relationship between the expression and the following features such as age, sex, smoking and alcohol intake history, T, N, histologic grade, and multiple primary cancer was analyzed. Eighteen patients (19%) showed CCND1 overexpression (tumor cell nuclei positivity >/=50%). The 5-year survival rate of high CCND1 expressors was 39%, which was significantly poor (p=0.04). N classification correlated with CCND1 expression. CCND1 overexpression is associated with poor survival associated with progression of lymph node spread in patients with tongue squamous cell carcinomas. CCND1 expression may be a useful biologic marker for prognosis.

Immunohistochemical Analysis of Small Cell Carcinoma of the Head and Neck: A Report of Four Patients and a Review of Sixteen Patients in the Literature with Ectopic Hormone Production

Small cell carcinoma (SCC) occurs mostly in the lung, and in some patients is accompanied by production of ectopic hormones. Small cell carcinoma of the head and neck is very rare. We report 4 patients with SCC of the head and neck (larynx, tonsil, maxillary sinus, and parotid gland). The patient with SCC of the maxillary sinus demonstrated a high level of plasma serotonin and overexpression of parathyroid hormone; however, he did not show any related symptoms. The patient with SCC of the tonsil showed the syndrome of inappropriate secretion of antidiuretic hormone associated with antidiuretic hormone hyperproduction at the terminal stage. In the literature, 16 patients with SCC of the head and neck with ectopic hormone production have been reported. Antidiuretic hormone and adrenocorticotropic hormone were the hormones that caused clinical symptoms (paraneoplastic syndromes). We believe that the evaluation of hormonal syndromes is valuable for diagnosis and treatment.

Galanin and galanin receptor type 1 suppress proliferation in squamous carcinoma cells: activation of the extracellular signal regulated kinase pathway and induction of cyclin-dependent kinase inhibitors

Galanin receptor 1 (GALR1) maps to a common region of 18q loss in head and neck squamous cell carcinomas and is frequently inactivated by methylation. To investigate effects of GALR1 and its signaling pathways, we stably expressed hemaglutinin-tagged GALR1 in a human oral carcinoma cell line (UM-SCC-1-GALR1) that expresses no endogenous GALR1. In transfected cells, galanin induced activation of the extracellular-regulated protein kinase-1/2 (ERK1/2) and suppressed proliferation. Galanin stimulation mediated decreased expression of cyclin D1 and increased expression of the cyclin-dependent kinase inhibitors (CKI), p27Kip1 and p57Kip2. Pretreatment with the ERK1/2-specific inhibitor U0126 prevented these galanin-induced effects. Phosphatidylinositol 3-kinase (PI3K) pathway activation did not differ in UM-SCC-1-GALR1 and UM-SCC-1-mock cells after galanin treatment. Pertussis toxin and LY294002 inhibition demonstrated that galanin and GALR1 induce ERK1/2 activation via Gαi, not the PI3K pathway-linked to the Gβγ subunit. Galanin and GALR1 also inhibit colony formation and tumor growth in vivo. Our results implicate GALR1, a Gi protein-coupled receptor, as a tumor suppressor gene that inhibits cell proliferation via ERK1/2 activation.

Audiological Outcome of Infants with Congenital Cytomegalovirus Infection in a Prospective Study

The aim of this study was to evaluate the audiological outcome of long-term follow-up of infants with asymptomatic congenital cytomegalovirus (CMV) infection as defined by the presence of CMV DNA in neonatal urine. 12599 pregnant women underwent screening for CMV IgG and IgM antibodies between 1996 and 2003. Eighteen infants with congenital CMV infection were identified. These infants underwent the newborn hearing screening test or auditory brainstem response test. Follow-up hearing assessments were performed with the auditory brainstem response and behavioral audiometry. The seropositive rate of CMV IgG antibody among the pregnant women was 75.3%, and the yearly seropositive rate decreased over the study period. One hundred and forty-six pregnant women were positive for IgM antibody, and 18 neonates (12.3%) had congenital CMV infection. Sensorineural hearing loss (SNHL) was detected in 4 (25%) of the 16 infants with asymptomatic infection and 1 (50%) of the 2 infants with symptomatic infection during the first 6 months of life. Two infants who passed the newborn hearing screening had a delayed-onset SNHL in follow-up examinations up to 4 years of age. Two had progressive hearing loss and 2 had improvement of hearing loss. Screening of pregnant women for CMV infection and repeated audiological examinations of infants are necessary because there are infants with delayed-onset SNHL or improved SNHL caused by asymptomatic congenital CMV infection.

Epigenetic Inactivation of Galanin Receptor 1 in Head and Neck Cancer

Purpose: One copy of the galanin receptor 1 (GALR1) locus on 18q is often deleted and expression is absent in some head and neck squamous cell carcinoma (HNSCC) cell lines. To determine if loss of heterozygosity and hypermethylation might silence the GALR1 gene, promoter methylation status and gene expression were assessed in a large panel of HNSCC cell lines and tumors. Experimental Design: Promoter methylation of GALR1 in 72 cell lines and 100 primary tumor samples was analyzed using methylation-specific PCR. GALR1 expression and methylation status were analyzed further by real-time PCR and bisulfite sequencing analysis. Results: The GALR1 promoter was fully or partially methylated in 38 of 72 (52.7%) HNSCC cell lines but not in the majority 18 of 20 (90.0%) of nonmalignant lines. GALR1 methylation was also found in 38 of 100 (38%) primary tumor specimens. Methylation correlated with decreased GALR1 expression. In tumors, methylation was significantly correlated with increased tumor size (P = 0.0036), lymph node status (P = 0.0414), tumor stage (P = 0.0037), cyclin D1 expression (P = 0.0420), and p16 methylation (P = 0.0494) and survival (P = 0.045). Bisulfite sequencing of 36 CpG sites upstream of the transcription start site revealed that CpG methylation within transcription factor binding sites correlated with complete suppression of GALR1 mRNA. Treatment with trichostatin A and 5-azacytidine restored GALR1 expression. In UM-SCC-23 cells that have total silencing of GALR1, exogenous GALR1 expression and stimulation with galanin suppressed cell proliferation. Conclusions: Frequent promoter hypermethylation, gene silencing, association with prognosis, and growth suppression after reexpression support the hypothesis that GALR1 is a tumor suppressor gene in HNSCC.

Galanin receptor subtype 2 suppresses cell proliferation and induces apoptosis in p53 mutant head and neck cancer cells.

Purpose: Galanin and its three receptors (GALR1-3) are expressed in many normal tissues, but silenced in some tumors. Contradictory roles for galanin and its receptors in various tumors have been reported. To understand their function, investigations of individual galanin receptors are necessary. In head and neck squamous carcinoma cells (HNSCC) with silenced GALR1 and GALR2, we showed that reexpressed GALR1 suppresses tumor cell proliferation via Erk1/2-mediated effects on cdk inhibitors and cyclin D1. Others showed that GALR2 could induce apoptosis in neuroblastoma cells with wild-type p53, whereas GALR2 stimulated proliferation in small cell lung cancer. In this study, we investigated the role of GALR2 in HNSCC cells that have mutant p53 and do not express GALR1. Experimental Design: UM-SCC-1, a human oral carcinoma cell line with a splice site mutation causing a 46-bp p53 off-frame deletion, was stably transfected to express GALR2 (UM-SCC-1-GALR2). Results: Galanin treatment of UM-SCC-1-GALR2 caused morphologic changes and a marked decrease in cell number that were not observed in UM-SCC-1-mock cells. Galanin and GALR2 resulted in decreased bromodeoxyuridine incorporation, p27Kip1 and p57Kip2 up-regulation, and decreased cyclin D1 expression. These effects were similar to GALR1 signaling in HNSCC, but GALR2 also induced caspase-3–dependent apoptosis, which was confirmed by Annexin-V staining and DNA fragmentation analysis. These were not observed with GALR1. Conclusion: This study shows that GALR2 reexpression can inhibit cell proliferation and induce apoptosis in HNSCC cells with mutant p53. GALR2 may be a feasible target for HNSCC therapy.

Tumor suppressor activity and inactivation of galanin receptor type 2 by aberrant promoter methylation in head and neck cancer.

There is accumulating evidence that galanin receptors (GALRs) may be tumor suppressors in head and neck squamous cell carcinoma (HNSCC). Promoter methylation status and gene expression were assessed in a large panel of head and neck primary tumors, based on the hypothesis that cytosine‐guanine dinucleotide (CpG) hypermethylation might silence the galanin receptor 2 (GALR2) gene.

Cochlear implant in children with asymptomatic congenital cytomegalovirus infection.

Objective: To evaluate the development of speech perception and auditory skills after cochlear implantation in deaf children with asymptomatic congenital cytomegalovirus (CMV) infection diagnosed based on the presence of CMV DNA in the neonatal urine. Study Design: A prospective study of congenital CMV infection was done between 1996 and 2003. Of 18 children diagnosed with congenital CMV infection, 2 deaf children with asymptomatic CMV infections received cochlear implantation. Results: The 2 deaf children who received cochlear implantation had delayed-onset, progressive sensorineural hearing loss on follow-up audiometric examinations administered at 29 and 39 months of age. After cochlear implantation, their Infant-Toddler Meaningful Auditory Integration Scale scores increased consistently during 36 months of follow-up; these results were similar to those of 5 congenitally deaf children without CMV infection who had cochlear implantation. Conclusions: Cochlear implantation was effective for improving the development of speech perception and auditory skills in deaf children with asymptomatic congenital CMV infection. There was no significant difference in the development of useful auditory integration between our general pediatric cochlear implant population without CMV infection and those with asymptomatic CMV infection.

Aberrant Methylation Inactivates Somatostatin and Somatostatin Receptor Type 1 in Head and Neck Squamous Cell Carcinoma

Purpose The aim of this study was to define somatostatin (SST) and somatostatin receptor type 1 (SSTR1) methylation profiles for head and neck squamous cell carcinoma (HNSCC) tumors at diagnosis and follow up and to evaluate their prognostic significance and value as a biomarker. Methods Gene expression was measured by quantitative RT-PCR. Promoter methylation status was determined by quantitative methylation-specific PCR (Q-MSP) in HNSCC. Results Methylation was associated with transcription inhibition. SST methylation in 81% of HNSCC tumor specimens significantly correlated with tumor size (P = 0.043), stage (P = 0.008), galanin receptor type 2 (GALR2) methylation (P = 0.041), and tachykinin-1 (TAC1) (P = 0.040). SSTR1 hypermethylation in 64% of cases was correlated with tumor size (P = 0.037), stage (P = 0.037), SST methylation (P < 0.001), and expression of galanin (P = 0.03), GALR2 (P = 0.014), TAC1 (P = 0.023), and tachykinin receptor type 1 (TACR1) (P = 0.003). SST and SSTR1 promoter hypermethylation showed highly discriminating receiver operator characteristic curve profiles, which clearly distinguished HNSCC from adjacent normal mucosal tissues. Concurrent hypermethylation of galanin and SSTR1 promoters correlated with reduced disease-free survival (log-rank test, P = 0.0001). Among patients with oral cavity and oropharynx cancer, methylation of both SST and SSTR1 promoters correlated with reduced disease-free survival (log-rank test, P = 0.028). In multivariate logistic-regression analysis, concomitant methylation of galanin and SSTR1 was associated with an odds ratio for recurrence of 12.53 (95% CI, 2.62 to 59.8; P = 0.002). Conclusions CpG hypermethylation is a likely mechanism of SST and SSTR1 gene inactivation, supporting the hypothesis that SST and SSTR1 play a role in the tumorigenesis of HNSCC and that this hypermethylation may serve as an important biomarker.

Galanin receptor subtypes 1 and 2 as therapeutic targets in head and neck squamous cell carcinoma

Importance of the field: Despite advances in the therapeutic approaches for head and neck squamous cell carcinoma (HNSCC) at some sites, no substantial improvement in treatment efficacy and survival has occurred over the past several decades. Recent application of molecular biology has focused on the importance of galanin and its receptors as potential therapeutic targets for HNSCC. Areas covered in this review: Our aim is to examine galanin receptor 1 (GALR1) and galanin receptor 2 (GALR2) as HNSCC therapeutic targets and explore opportunities and strategies for making use of GALR1 and GALR2 signaling. What the reader will gain: This review provides recent data about galanin receptor signaling and function in various cell types, especially HNSCC. Signaling through GALR1 induces cell cycle arrest and suppresses proliferation in HNSCC. Similar to GALR1, GALR2 not only induces cell cycle arrest but also apoptosis, which was not observed with GALR1. Take home messages: GALR1 and GALR2 act as tumor suppressors in HNSCC, in a p53-independent manner. The current data suggest that GALR1 and GALR2 are potentially significant therapeutic targets and prognostic factors in HNSCC.