Keiji Mukai

Publications (8)14.3 Total impact

• Article: UFT and its metabolite gamma-butyrolactone (GBL) inhibit angiogenesis induced by vascular endothelial growth factor in advanced cervical carcinoma.

  Nobutaka Nagai, Keiji Mukai, Eiji Hirata, Hong Hua Jin, Masaaki Komatsu, Mayu Yunokawa
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  ABSTRACT: The aim of this study was to evaluate the potential role of UFT and its metabolite gamma-butyrolactone (GBL) for inhibition of angiogenesis induced by vascular endothelial growth factor (VEGF) in advanced cervical carcinoma by the determination of serum GBL and VEGF, and by immunohistochemical staining to assess VEGF protein expression, before and after UFT therapy. The subjects were 35 patients with an advanced cervical carcinoma and five healthy volunteers between 2002 and 2003 at Hiroshima University Hospital, under informed consent. The patients received two courses of oral fluoropyrimidine (UFT) therapy at a dose of 600 mg/day for 5 and 2 days off treatment. Serum GBL and VEGF was measured before and after UFT therapy by the gas chromatography mass spectrometry and ELISA-kit in 22 patients and five healthy volunteers, respectively. Immunohistochemical detection of VEGF protein was done in 35 cervical cancers. Results The mean serum GBL level before and after UFT therapy was 21.9 +/- 2.3 and 79.3 +/- 6.2 ng/ml, respectively, and it was significantly increased after UFT administration (P < 0.0001). The mean serum VEGF level before and after UFT therapy was 95.3 +/- 28.1 and 67.5 +/- 11.2 pg/ml, respectively, and it was decreased by UFT administration. In 20 out of 33 (66.6%) patients who were detected with VEGF protein, VEGF protein expression was decreased by UFT therapy. The Delta GBL value (GBL after UFT--GBL before UFT therapy) showed a significant inverse correlation with Delta VEGF value (VEGF after therapy--VEGF before therapy) (r2 = 0.940). Our findings suggest that UFT and its metabolite GBL inhibit angiogenesis induced by VEGF to have an antitumor effect on cervical cancer.
  Medical Oncology 01/2008; 25(2):214-21. · 2.14 Impact Factor
• Article: Predicting the chemosensitivity of ovarian and uterine cancers with the collagen gel droplet culture drug-sensitivity test.

  Nobutaka Nagai, Kazuhiko Minamikawa, Keiji Mukai, Eiji Hirata, Masaaki Komatsu, Hisayuki Kobayashi
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  ABSTRACT: We investigated the utility of the collagen gel droplet culture drug-sensitivity test (CD-DST) for predicting the response of gynecological cancers to chemotherapy. Eighty-three cancer patients were enrolled in this study: 26 ovarian, 29 cervical and 31 endometrial cancers. The CD-DST was performed at various concentrations of drugs. We calculated the T/C ratio, where T is the total volume of the treated culture and C is the total volume of the control culture, and a T/C ratio of 50% or less was defined as sensitive in vitro. The efficacy rate (%) was defined as the number of cultures with a T/C ratio of 50% or less, divided by the total number of evaluable cultures. True-positive cases were defined as clinical responders (complete+partial responses) and true-negative cases were defined as clinical non-responders. The overall tumor evaluation rate was found to be 79.1%. The appropriate drug concentrations were selected as 1.0 microg/ml for cisplatin, 20.0 microg/ml for carboplatin, 1.0 microg/ml for paclitaxel and 0.1 microg/ml for docetaxel by the linear regression equations. The in vitro sensitivity for each drug showed a significant correlation with clinical response rates (r=0.592, p=0021). We therefore conclude that the CD-DST can be used to predict the response to anti-cancer drugs, and may also provide important information by contributing to the development of new chemotherapy regimens.
  Anti-Cancer Drugs 07/2005; 16(5):525-31. · 2.41 Impact Factor
• Article: Human papillomavirus DNA status after loop excision for cervical intraepithelial neoplasia grade III - A prospective study.

  Nobutaka Nagai, Keiji Mukai, Takafumi Oshita, Yuko Shiroyama, Koso Ohama
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  ABSTRACT: The aims of the study were to investigate the relationship between human papillomavirus (HPV) DNA status and recurrence of cervical intraepithelial neoplasia (CIN) after loop excision (LEEP/LLETZ). Women (n=161) who underwent loop excision for CIN III and who were followed up prospectively for at least 4 years were the study cohort. Cervical smear cytology and testing for HPV DNA was performed at 3, 6 and 12 months prospectively and thereafter at intervals of 6-12 months, using the PCR method with a consensus primer targeting the L1 region. There has been no recurrence in 141 (81.6%) out of 161 subjects, while squamous intra-epithelial lesions (SIL) of low or high grade on cytology and CIN grade I-III on histology have been detected in 20 subjects. Prior to loop excision, HPV DNA was detected in 17 subjects who developed recurrence (9 had type 16, 2 each had types 18 and 52, and 1 each had types 31, 51, 58, and unknown). Within 3 months postoperatively, 12 (70.7%) subjects became negative for HPV, but 2 remained positive for the same type (1 each had types 16, 18), along with high-grade SIL on cytology, and CIN III on histology within 6 months, so repeat loop excision was performed. On the other hand, cytological findings were normalized in all transiently infected subjects within 18-36 months. Our results suggest that loop excision has improved HPV infection in many cases of CIN III and the persistent infection with a high-risk type of HPV is a predictor of the recurrence of CIN grade III.
  International Journal of Molecular Medicine 05/2004; 13(4):589-93. · 1.98 Impact Factor
• Article: Telomerase activation in endometrial epithelial cells by paracrine effectors from stromal cells in primary cultured human endometrium.

  Takafumi Oshita, Nobutaka Nagai, Keiji Mukai, Kazushi Shigemasa, Masamichi Hiura, Koso Ohama
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  ABSTRACT: Uterine endometrium displays telomerase activity in a menstrual cycle-dependent manner, despite its somatic origin. This study was performed to elucidate the regulation of telomerase in human endometrium. Telomerase activity and human telomerase reverse transcriptase mRNA expression in proliferative endometrium were significantly stronger than those in secretory endometrium. Their expression was only detected in epithelial cells, although stromal cells also showed proliferation. The growth of epithelial cells decreased day by day in accordance with the decline of telomerase activity. Telomerase activity was significantly stronger in co-cultures of epithelial and stromal cells than in cultures of epithelial cells alone. Moreover, the telomerase activity of co-cultured cells was increased by estradiol or basic fibroblast growth factor, whereas that of epithelial cells cultured alone showed no change. Thus, human endometrium shows reversible telomerase activation during the menstrual cycle, unlike cancer tissues. Also, the telomerase activity of uterine endometrial epithelial cells might be modulated by paracrine effectors released from stromal cells, and not only by the direct action of sex steroids such as estradiol and progesterone.
  International Journal of Molecular Medicine 04/2004; 13(3):425-30. · 1.98 Impact Factor
• Article: Overexpression of cyclooxygenase-2 protein and its relationship to apoptosis in cervical carcinoma treated with neoadjuvant chemotherapy.

  Nobutaka Nagai, Xiurong Tian, Keiji Mukai, Eiji Hirata, Tomoyo Kusuda, Yuko Shiroyama, Kazushi Shigemasa, Koso Ohama
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  ABSTRACT: The aims of this study were to examine the overexpression of COX-2 protein and its relationship to apoptosis in cervical carcinoma patients treated with neoadjuvant chemo-therapy (NAC), and to assess the potential role of COX-2 as a predictor of the response to NAC in a series of patients with cervical carcinoma. For immunohistochemical analysis, cervical cancer tissue samples were collected before NAC and 3 weeks after NAC using transcatheter arterial infusion of cisplatin from 40 patients who underwent surgery for advanced cervical carcinoma in stages IB, IIA and IIB and from 5 normal cervical tissues between 1991 and 2000 at the Department of Obstetrics and Gynecology, under informed consent. Patients were randomly assigned to receive one or two arterial infusions of cisplatin. COX-2 protein expression was detected by immunohistochemical staining and was classified as no expression for tumors with negative or <10%, while > or =10% positive staining was defined as overexpression. Detection of apoptosis was done by the TUNEL method. The percentage of cells with DNA fragmentation (apoptotic index, AI) was calculated before NAC and 3 weeks after NAC. The AI ratio (AI after NAC/AI before NAC) was also calculated. COX-2 expression was not detected in the normal cervix. Overexpression of COX-2 protein was detected in 18 out of 40 (45.0%) cervical cancers. A higher incidence of COX-2 protein overexpression was observed in patients with adenocarcinoma than in those with squamous cell carcinoma (p=0.1797, Fisher's exact text). The average AI value before and after NAC was 8.85 versus 11.82 respectively. In COX-2 protein-negative patients with squamous cell carcinoma, the AI ratio was 0.96+/-0.46 following one arterial infusion of cisplatin and 3.19+/-2.72 following two infusions of cisplatin. There was a significant positive correlation between apoptosis and the number of infusions of cisplatin (p=0.0098, Mann-Whitney, U-test). Our findings suggest that COX-2 protein expression could be used as a predictor of chemoresistance and that assessment of the COX-2 status could be useful to identify cervical cancer patients who may benefit from NAC.
  International Journal of Molecular Medicine 11/2003; 12(5):709-14. · 1.98 Impact Factor
• Article: GnRH agonist inhibits human telomerase reverse transcriptase mRNA expression in endometrial cancer cells.

  Nobutaka Nagai, Takafumi Oshita, Keiji Mukai, Yuko Shiroyama, Kazushi Shigemasa, Koso Ohama
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  ABSTRACT: We investigated the relationship between the antiproliferative effect of GnRH agonist and telomerase activity using the endometrial cancer cell line HEC-1A. The subjects were 38 endometrial cancer, and 2 atypical endometrial hyperplasia patients. GnRH-R expression was detected using RT-PCR. HEC-1A cells were incubated with 10(-7)-10(-4) M GnRH agonist (leuprolide acetate), and cell proliferation was determined using MTT assay. The telomerase activity was detected by the TRAP assay and expression of human telomerase reverse transcriptase (hTERT) was assessed by RT-PCR. GnRH-R mRNA was detected at 94.7% (36/38) in endometrial cancer and in both of the atypical endometrial hyperplasia and in HEC-1A cells. Cell proliferation of HEC-1A showed significant inhibition at leuprolide acetate concentrations of 10(-6) M or higher compared with untreated control culture (p<0.05). The telomerase activity showed no marked difference compared with untreated culture. However, hTERT mRNA expression showed a decrease in the leuprolide-treated cells. It is suggested that the mechanism of the antitumor effect of GnRH agonist involved the inhibition of hTERT mRNA expression in the endometrial cancer cells.
  International Journal of Molecular Medicine 11/2002; 10(5):593-7. · 1.98 Impact Factor
• Article: Increased MCL-1 expression is associated with poor prognosis in ovarian carcinomas.

  Kazushi Shigemasa, Osamu Katoh, Yuko Shiroyama, Shoji Mihara, Keiji Mukai, Nobutaka Nagai, Koso Ohama
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  ABSTRACT: To investigate the potential role of the BCL-2 gene family (BAX, BCL-2, MCL-1, and BCL-XL) in ovarian cancer development and progression, mRNA expression levels of these genes were measured using semi-quantitative PCR in epithelial ovarian tumor tissues and normal ovaries. The immunohistochemical expression of MCL-1 in ovarian tumors was also examined. The expression levels of BAX and MCL-1 mRNA were significantly higher in ovarian cancers and in adenomas than in normal ovaries (P < 0.05). In contrast, the BCL-2 mRNA expression level in ovarian cancers was significantly lower than in ovarian adenomas and in normal ovaries (P < 0.05). Expression of BCL-XL mRNA was no different between normal ovaries and ovarian tumors. Log-rank testing showed that low BAX mRNA expression and high MCL-1 mRNA expression significantly correlate with poor survival for patients with stage III ovarian carcinomas (BAX, P = 0.05; MCL-1, P = 0.02). Immunohistochemical analysis showed that diffuse-positive expression of MCL-1 protein in mucinous carcinomas was significantly higher than in mucinous low malignant potential (LMP) tumors (P = 0.03). In ovarian cancer cases, diffuse-positive expression of MCL-1 protein significantly correlates with advanced clinical stage, high histologic grade, and poor survival (stage, P < 0.01; grade, P = 0.01; survival, P = 0.01). These results suggest that increased MCL-1 expression may play an important role in replacing the functions of increased BAX and decreased BCL-2 in ovarian carcinoma cells, thereby promoting cell survival, and resulting in a poor prognosis for patients with ovarian cancer.
  Japanese journal of cancer research: Gann 06/2002; 93(5):542-50.
• Article: Tumor dihydropyrimidine dehydrogenase activity in advanced cervical carcinoma.

  Nobutaka Nagai, Yuko Shiroyama, Takafumi Oshita, Keiji Mukai, Kazushi Shigemasa, Tsuneo Fujii, Yasuhiro Katsube, Shigeru Matsubayashi, Takahiro Murakami, Koso Ohama
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  ABSTRACT: Patients with advanced cervical carcinoma were treated with oral fluoropyrimidine (UFT) as neoadjuvant chemotherapy and its antitumor effect was examined. The relationship between thymidylate synthase (TS) or dihydropyrimidine dehydrogenase (DPD) activity in tumor tissue and apoptosis was also investigated. The subjects were 56 patients with advanced cervical carcinoma. The patients received two courses of therapy consisting of UFT at a dose of 600 mg/day for 5 days and 2 days off treatment. The TS and DPD activity in tumor tissue was measured before and after UFT administration by the FdUMP binding assay and a catalytic assay in 38 patients, respectively. Apoptosis was detected by the TUNEL method, and the apoptotic index (AI) was calculated. Tumor tissue activity of TS or DPD was unrelated to clinicopathologic factors or to the activity of the other enzyme. The mean tumor TS and DPD activity before UFT administration was 5.42+/-3.92 pmol/g tissue and 206.54+/-128.58 pmol/mg/min, respectively, and the levels of these enzymes in two patients showing an antitumor effect were below the mean values. The AI increased from 1.10+/-0.57% before UFT to 1.27+/-0.81% afterwards, and the DPD activity before UFT showed an inverse relationship with the AI after UFT (r=-0.6938). In patients with DPD activity below the median value (186.92 pmol/mg/min), UFT administration significantly caused an increase of the AI (p=0.0002). These results indicate that the DPD activity of advanced cervical carcinoma is a determinant of sensitivity to UFT, suggesting an association between UFT therapy and the induction of apoptosis.
  Oncology Reports 9(5):1033-40. · 1.84 Impact Factor