Takeharu Kanazawa

Prof. Takeharu Kanazawa


Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 May 2015 in The Laryngoscope
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TKTakeharu Kanazawa
Takeharu Kanazawa
DKDaigo Komazawa
Daigo Komazawa
KIKanako Indo
Kanako Indo
YAYusuke Akagi
Yusuke Akagi
YLYogaku Lee
Yogaku Lee
YWYusuke Watanabe
Yusuke Watanabe
Objectives/Hypothesis: Severe vocal fold lesions such as vocal fold sulcus, scars, and atrophy induce a communication disorder due to severe hoarseness, but a treatment has not been established. Basic fibroblast growth factor (bFGF) therapies by either four‐time repeated local injections or regenerative surgery for vocal fold scar and sulcus have previously been reported, and favorable outcomes have been observed. In this study, we modified bFGF therapy using a single of bFGF injection, which may potentially be used in office procedures.Study Design: Retrospective chart review.Methods: Five cases of vocal fold sulcus, six cases of scars, seven cases of paralysis, and 17 cases of atrophy were treated by a local injection of bFGF. The injection regimen involved injecting 50 µg of bFGF dissolved in 0.5 mL saline only once into the superficial lamina propria using a 23‐gauge injection needle. Two months to 3 months after the injection, phonological outcomes were evaluated.Results: The maximum phonation time (MPT), mean airflow rate, pitch range, speech fundamental frequency, jitter, and voice handicap index improved significantly after the bFGF injection. Furthermore, improvement in the MPT was significantly greater in patients with (in increasing order) vocal fold atrophy, scar, and paralysis. The improvement in the MPT among all patients was significantly correlated with age; the MPT improved more greatly in younger patients.Conclusions: Regenerative treatments by bFGF injection—even a single injection—effectively improve vocal function in vocal fold lesions.Level of Evidence: 4 Laryngoscope, 125:E338–E344, 2015

20 February 2007 in European Archives of Oto-Rhino-Laryngology
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Journal Article
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TKTakeharu Kanazawa
Takeharu Kanazawa
HNHiroshi Nishino
Hiroshi Nishino
MHMasahiro Hasegawa
Masahiro Hasegawa
YOYasushi Ohta
Yasushi Ohta
YIYukiko Iino
Yukiko Iino
YNYutaka Noda
Yutaka Noda

1 April 2009 in Clinical Cancer Research
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TKTakeharu Kanazawa
Takeharu Kanazawa
PKPavan K. Kommareddi
Pavan K. Kommareddi
TIToshihide Iwashita
Toshihide Iwashita
BKBhavna Kumar
Bhavna Kumar
KMKiyoshi Misawa
Kiyoshi Misawa
TCThomas Carey
Thomas Carey
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.

5 August 2015 in Toxins
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TKTakeharu Kanazawa
Takeharu Kanazawa
KMKiyoshi Misawa
Kiyoshi Misawa
YMYuki Misawa
Yuki Misawa
TUTakayuki Uehara
Takayuki Uehara
HFHirofumi Fukushima
Hirofumi Fukushima
TCThomas Carey
Thomas Carey
Therapeutic outcome in head and neck squamous cell carcinoma (HNSCC) is poor in most advanced cases. To improve therapeutic efficiency, novel therapeutic targets and prognostic factors must be discovered. Our studies have identified several G protein-coupled receptors (GPCRs) as promising candidates. Significant epigenetic silencing of GPCR expression occurs in HNSCC compared with normal tissue, and is significantly correlated with clinical behavior. Together with the finding that GPCR activity can suppress tumor cell growth, this indicates that GPCR expression has potential utility as a prognostic factor. In this review, we discuss the roles that galanin receptor type 1 (GALR1) and type 2 (GALR2), tachykinin receptor type 1 (TACR1), and somatostatin receptor type 1 (SST1) play in HNSCC. GALR1 inhibits proliferation of HNSCC cells though ERK1/2-mediated effects on cell cycle control proteins such as p27, p57, and cyclin D1, whereas GALR2 inhibits cell proliferation and induces apoptosis in HNSCC cells. Hypermethylation of GALR1, GALR2, TACR1, and SST1 is associated with significantly reduced disease-free survival and a higher recurrence rate. Although their overall activities varies, each of these GPCRs has value as both a prognostic factor and a therapeutic target. These data indicate that further study of GPCRs is a promising strategy that will enrich pharmacogenomics and prognostic research in HNSCC.

22 April 2017 in Acta Oto-Laryngologica
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TKTakeharu Kanazawa
Takeharu Kanazawa
KKKazuya Kurakami
Kazuya Kurakami
KKKazutaka Kashima
Kazutaka Kashima
UKUjimoto Konomi
Ujimoto Konomi
DKDaigo Komazawa
Daigo Komazawa
YWYusuke Watanabe
Yusuke Watanabe
Objective: Unilateral vocal cord paralysis (UVCP) not only induces severe dysphonia, but aspiration as well. Although laryngeal framework surgery is usually performed to treat this condition, the procedure is not tolerated by some patients. In the previous study, basic fibroblast growth factor (bFGF) injections for vocal cord scarring and sulcus have been reported to provide favorable outcomes while being minimally invasive. In this study, the authors retrospectively investigated phonological outcomes after bFGF injection in patients with UVCP. Methods: This study was registered in University hospital Medical Information Network – Clinical Trials Registry (UMIN000019347). Nineteen patients with unilateral cord paralysis were treated with bFGF injection. The treatment regimen involved a single injection of 50 μg of bFGF into the muscle layer. More than six months after the injection, aerodynamic and acoustic outcomes were examined. Results: The voice handicap index, maximum phonation time, mean airflow rate, and pitch range improved significantly after injection of bFGF. No sex-related differences were observed in any phonological parameter. Conclusion: bFGF injection, an easy method and suitable as an office procedure, significantly improved the hoarseness caused by UVCP. It is expected to be widely adopted and effective adjunctive drugs, and procedures are anticipated to be developed.

10 April 2013 in SpringerPlus
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TKTakeharu Kanazawa
Takeharu Kanazawa
NFNoriyoshi Fukushima
Noriyoshi Fukushima
SIShoichiro Imayoshi
Shoichiro Imayoshi
TNTakafumi Nagatomo
Takafumi Nagatomo
KKKazumi Kawada
Kazumi Kawada
KIKeiichi Ichimura
Keiichi Ichimura
Recurrent respiratory papillomatosis (RRP), a chronic upper respiratory condition characterized by diffuse multiple recurring papillomas, is thought to result from human papillomavirus (HPV) type 6 or 11 infection. Although RRP is an intractable disease, malignant transformation of RRP is rare. The underlying mechanism, however, has not been elucidated. We describe the clinical course of a patient who underwent more than 130 operations for RRP associated with HPV type 6 infection and subsequently suffered spontaneous malignant transformation to squamous cell carcinoma. Immunohistochemical analysis revealed that malignant transformation might result from a genomic defect, such as p53 inactivation, leading to stimulation of uncontrolled cell proliferation by HPV type 6 for an extended period, but not directly because of HPV itself. Our results could help in the development of novel therapeutic strategies for severe RRP, although further studies are required before clinical application of molecular targeted therapies.