Kazuhiko Ochiai - Academia.edu (original) (raw)

Papers by Kazuhiko Ochiai

Journal of clinical medicine research, 2015

The Journal of the Japanese Society of Clinical Cytology, 1981

Virus research, 2003

We performed yeast two-hybrid screening of a human kidney cell cDNA library to study the biologic... more We performed yeast two-hybrid screening of a human kidney cell cDNA library to study the biological role of the hantavirus nucleocapsid protein (NP). We found that Seoul virus (SEOV) and Hantaan virus (HTNV) NPs were associated with small ubiquitin-like modifier (SUMO)-1-interacting proteins PIAS1, PIASxbeta, HIPK2, CHD3, and TTRAP, which interacted with the SUMO-1 conjugating enzyme (Ubc-9) and SUMO-1 in the yeast two-hybrid assay. Interactions between the HIPK2, CHD3, and TTRAP proteins and SEOV NP were also shown in a mammalian two-hybrid assay. However, there was no interaction between PIAS proteins and NP, which was probably due to the inhibitory effect of PIAS on transcription in the mammalian two-hybrid assay. Nevertheless, a co-expression experiment suggested the existence of a PIAS-NP interaction in the cytoplasm. The region spanning amino acids 100-125 of SEOV NP, which represents a critical region for NP-NP polymerization, was found to be responsible for the interaction w...

Biomedical research (Tokyo, Japan), 2015

Mutations in the breast cancer susceptibility gene BRCA2 leading to the failure of interactions w... more Mutations in the breast cancer susceptibility gene BRCA2 leading to the failure of interactions with the recombinase RAD51 are associated with an increased risk of cancer in humans. This interaction depends on the eight BRC repeat (BRC1-8) sequences in BRCA2. We previously reported that canine BRC3 has two polymorphisms (T1425P and K1435R) influencing the interaction with RAD51, and 1435R was identified in mammary tumor dog samples. In this study, we investigated the sequence variations of BRC3 and 4 in 236 dogs of five breeds. Allele frequencies of 1425P and 1435R were 0.063 and 0.314, respectively, and there was no other polymorphism in the sequenced region. A mammalian two-hybrid assay using BRC3-4 sequences demonstrated that 1425P allele reduced the binding strength with RAD51 but 1435R had no effect. These results may provide an insight into the functions of not only individual but also multiple BRC repeats of BRCA2 in dogs.

Oncology reports, 2015

Immunotherapy is one of the attractive treatment strategies for advanced prostate cancer. The US ... more Immunotherapy is one of the attractive treatment strategies for advanced prostate cancer. The US Food and Drug Administration (FDA) previously approved the therapeutic vaccine, sipuleucel-T, which is composed of autologous antigen-presenting cells cultured with a fusion protein [prostatic acid phosphatase (PAP) and granulocyte-macrophage colony-stimulating factor (GMCSF)]. Although sipuleucel-T has been shown to prolong the median survival of patients for 4.1 months, more robust therapeutic effects may be expected by modifying the vaccination protocol. In the present study, we aimed to develop and validate a novel vaccination strategy using multiple PAP-fused cytokines for prostate cancer treatment. Using a super gene expression (SGE) system that we previously established to amplify the production of a recombinant protein, significant amounts of PAP-fused cytokines [human GMCSF, interleukin-2 (IL2), IL4, IL7 and mouse GMCSF and IL4] were obtained. We examined the activity of the fus...

Journal of virology, 2014

Equine hepacivirus (EHcV) has been identified as a closely related homologue of hepatitis C virus... more Equine hepacivirus (EHcV) has been identified as a closely related homologue of hepatitis C virus (HCV) in the United States, the United Kingdom, and Germany, but not in Asian countries. In this study, we genetically and serologically screened 31 serum samples obtained from Japanese-born domestic horses for EHcV infection and subsequently identified 11 PCR-positive and 7 seropositive serum samples. We determined the full sequence of the EHcV genome, including the 3' untranslated region (UTR), which had previously not been completely revealed. The polyprotein of a Japanese EHcV strain showed approximately 95% homology to those of the reported strains. HCV-like cis-acting RNA elements, including the stem-loop structures of the 3' UTR and kissing-loop interaction were deduced from regions around both UTRs of the EHcV genome. A comparison of the EHcV and HCV core proteins revealed that Ile(190) and Phe(191) of the EHcV core protein could be important for cleavage of the core pro...

Molecular and cellular endocrinology, Jan 25, 2012

Double-stranded RNA-dependent protein kinase (PKR) is involved in various cellular functions. We ... more Double-stranded RNA-dependent protein kinase (PKR) is involved in various cellular functions. We previously reported that PKR regulates osteoblast differentiation, but the specific mechanisms by which this occurs remain unclear. In this study, we investigated the role of PKR in Glycogen synthase kinase 3β (GSK-3β) regulation of osteoblast differentiation. Lithium chloride (LiCl), a GSK-3β inhibitor, increased GSK-3β phosphorylation in MC3T3-E1 and MG-63 cells. LiCl also inhibited Runx2 and expression of its regulated genes, causing inhibition of Alkaline phosphatase activity and mineralization. LiCl injection to the calvaria in mice suppressed bone formation. Further, GSK-3β phosphorylation was increased in osteoblasts, by Akt-independent mechanisms, in which PKR was constitutively inactivated. A PKR inhibitor, 2-aminopurine, also induced GSK-3β phosphorylation in MC3T3-E1 and MG-63 cells. Further, Runx2 and its regulated genes were inhibited in PKR-inactivated osteoblasts, and diff...

Scientific Reports, 2014

In April 2012 we carried out a 1-year hematological study on a population of wild Japanese monkey... more In April 2012 we carried out a 1-year hematological study on a population of wild Japanese monkeys inhabiting the forest area of Fukushima City. This area is located 70 km from the Fukushima Daiichi Nuclear Power Plant (NPP), which released a large amount of radioactive material into the environment following the Great East Japan Earthquake of 2011. For comparison, we examined monkeys inhabiting the Shimokita Peninsula in Aomori Prefecture, located approximately 400 km from the NPP. Total muscle cesium concentration in Fukushima monkeys was in the range of 78-1778 Bq/kg, whereas the level of cesium was below the detection limit in all Shimokita monkeys. Compared with Shimokita monkeys, Fukushima monkeys had significantly low white and red blood cell counts, hemoglobin, and hematocrit, and the white blood cell count in immature monkeys showed a significant negative correlation with muscle cesium concentration. These results suggest that the exposure to some form of radioactive material contributed to hematological changes in Fukushima monkeys.

Clinical Ovarian Cancer, 2009

Objective: The purpose of this study was to evaluate the results of substituting docetaxel for pa... more Objective: The purpose of this study was to evaluate the results of substituting docetaxel for paclitaxel in women who experienced a paclitaxel-associated hypersensitivity reaction while undergoing chemotherapy for ovarian and endometrial cancer. Patients and Methods: Reviewing a comprehensive data file, we identified all epithelial ovarian cancer and primary endometrial cancer patients who experienced a documented significant hypersensitivity reaction to paclitaxel and were subsequently treated with docetaxel at our university hospital from March 2004 to August 2008. Results: We identified a total of 11 patients who met inclusion criteria of hypersensitivity reaction after paclitaxel injection. Ten cases were noted as mild reactions, and one case presented severe reaction of anaphylaxis; all patients showed cutaneous manifestations, and 3 patients complained of transient palpitation (27.3%). Nine cases (81.8%) were arising in 36 ovarian cancer patients (25%), and 2 were arising in 22 endometrial cancer patients (9.1%). The mean number of cycles hypersensitivity reaction appeared was 1.6 cycles. Two cases discontinued further therapy with taxanes. Nine of 11 cases rechallenged with docetaxel for the replacement of paclitaxel within 3 days after hypersensitivity reaction appeared, and 8 of them well tolerated docetaxel without any reactions. One of them showed cross-reaction to docetaxel and discontinued therapy with taxanes. All residual 8 patients completed due course of taxane-based chemotherapy. Conclusion: The use of docetaxel is a reasonable approach for continuing taxane-based chemotherapy in patients with a paclitaxel hypersensitivity reaction. Mild hypersensitivity reaction to paclitaxel could be the predicting sign for replacement with docetaxel, and early rechallenging with docetaxel is suggested for subsequent successful infusion.

Reproductive biology and endocrinology : RB&E, Jan 24, 2004

After fertilization, embryo development involves differentiation, as well as development of the f... more After fertilization, embryo development involves differentiation, as well as development of the fetal body and extra-embryonic tissues until the moment of implantation. During this period various cellular and molecular changes take place with a genetic origin, e.g. the elongation of embryonic tissues, cell-cell contact between the mother and the embryo and placentation. To identify genetic profiles and search for new candidate molecules involved during this period, embryonic gene expression was analyzed with a custom designed utero-placental complementary DNA (cDNA) microarray. Bovine embryos on days 7, 14 and 21, extra-embryonic membranes on day 28 and fetuses on days 28 were collected to represent early embryo, elongating embryo, pre-implantation embryo, post-implantation extra-embryonic membrane and fetus, respectively. Gene expression at these different time points was analyzed using our cDNA microarray. Two clustering algorithms such as k-means and hierarchical clustering metho...

Veterinary Clinics of North America: Exotic Animal Practice, 2010

Oncology Reports, 2013

Gene expression systems with various promoters, including the cytomegalovirus (CMV) promoter, hav... more Gene expression systems with various promoters, including the cytomegalovirus (CMV) promoter, have been developed to increase the gene expression in a variety of normal and cancer cells. In particular, in the clinical trials of cancer gene therapy, a more efficient and robust gene expression system is required to achieve sufficient therapeutic outcomes. By inserting the triple translational enhancer sequences of human telomerase reverse transcriptase (hTERT), Simian virus 40 (SV40) and CMV downstream of the sequence of the BGH polyA, we were able to develop a novel gene expression system that significantly enhances the expression of the genes of interest. We termed this novel gene expression cassette the super gene expression (SGE) system, and herein verify the utility of the SGE cassette for a replicationdeficient adenoviral vector. We newly developed an adenoviral vector expressing the tumor suppressor, reduced expression in immortalized cells (REIC)/Dickkopf-3 (Dkk-3), based on the CMV promoter-driven SGE system (Ad-SGE-REIC) and compared the therapeutic utility of Ad-SGE-REIC with that of the conventional adenoviral vectors (Ad-CMV-REIC or Ad-CAG-REIC). The results demonstrated that the CMV promoter-SGE system allows for more potent gene expression, and that the Ad-SGE-REIC is superior to conventional adenoviral systems in terms of the REIC protein expression and therapeutic effects. Since the SGE cassette can be applied for the expression of various therapeutic genes using various vector systems, we believe that this novel system will become an innovative tool in the field of gene expression and gene therapy.

Journal of Veterinary Medical Science, 2005

Journal of Veterinary Medical Science, 2001

Mammary tumors are the most common neoplasm in female dogs, Canis canis, and in women. Mutations ... more Mammary tumors are the most common neoplasm in female dogs, Canis canis, and in women. Mutations in human Brca2 confer an increased risk of female breast cancer. Previous studies have shown that the Brca2 tumor suppressor protein interacts with the recombinational repair protein Rad51. We cloned the full-length cDNA of the canine homologues of Brca2 and Rad51 to obtain a basis for studying their relationship with susceptibility to mammary tumors. The canine Brca2 and Rad51 cDNAs are 11 and 1.5 kb long, encoding 3.471 and 339 amino acids, respectively. The amino acid sequence of canine Brca2 showed 68% homology with the human protein, and 58% homology with a murine protein. There were highly conserved regions in the C-terminus of all three proteins, where the Rad51 interacting domain and putative nuclear localization signals are located. Comparing with the partial genomic sequence previously reported, we found possible nuclear polymorphisms in exon 11, some of which result in amino acid substitutions. On the other hand, canine Rad51 protein had extremely high homology (99%) to the human and murine proteins. Expression of both Brca2 and Rad51 was detected in the mammary gland, suggesting that these two genes interact in the canine mammary gland.

Journal of Obstetrics and Gynaecology Research, 2008

Very few cases of postoperative decubitus have been reported. We report two cases of hip decubitu... more Very few cases of postoperative decubitus have been reported. We report two cases of hip decubitus after myomectomy. Case 1 is a 32-year-old Japanese woman who underwent an uncomplicated myomectomy under the combination of general and epidural anesthesia. Twelve hours after surgery, a palpable soft tissue mass developed in the sacral region. On day 3, the soft tissue mass had disappeared and the patient was discharged on day 8. Case 2 is a 33-year-old woman. Under a combination of spinal and epidural anesthesia, a myomectomy was carried out. On day 1 after surgery, a hard mass with redness was detected. On day 8, decubitus improved and she was discharged. We evaluated the temporal changes in anesthetic level in four independent cases. Eighteen hours after surgery, the anesthetic effect still continued below the L2 level. We conclude that the extended effect of epidural anesthesia might be one of the mechanisms causing postoperative decubitus.

Journal of Biological Chemistry, 2009

We previously showed that the tumor suppressor gene REIC/Dkk-3, when overexpressed by an adenovir... more We previously showed that the tumor suppressor gene REIC/Dkk-3, when overexpressed by an adenovirus (Ad-REIC), exhibited a dramatic therapeutic effect on human cancers through a mechanism triggered by endoplasmic reticulum stress. Adenovirus vectors show no target cell specificity and thus may elicit unfavorable side effects through infection of normal cells even upon intra-tumoral injection. In this study, we examined possible effects of Ad-REIC on normal cells. We found that infection of normal human fibroblasts (NHF) did not cause apoptosis but induced production of interleukin (IL)-7. The induction was triggered by endoplasmic reticulum stress and mediated through IRE1alpha, ASK1, p38, and IRF-1. When Ad-REIC-infected NHF were transplanted in a mixture with untreated human prostate cancer cells, the growth of the cancer cells was significantly suppressed. Injection of an IL-7 antibody partially abrogated the suppressive effect of Ad-REIC-infected NHF. These results indicate that Ad-REIC has another arm against human cancer, an indirect host-mediated effect because of overproduction of IL-7 by mis-targeted NHF, in addition to its direct effect on cancer cells.

International Journal of Clinical Oncology, 2009

Apart from typical yolk sac tumors, ovarian tumors with elevated alfa-fetoprotein (AFP) are uncom... more Apart from typical yolk sac tumors, ovarian tumors with elevated alfa-fetoprotein (AFP) are uncommon and the differential diagnosis needs to consider the hepatoid pattern of a yolk sac tumor, hepatocellular carcinoma metastatic to the ovary, hepatoid carcinoma, and other epithelial ovarian tumors. We report here an AFP-producing ovarian tumor with uncertain pathological diagnosis, which was extremely responsive to chemotherapy. A 59-year-old Japanese woman presented with lower abdominal distension and was found to have a left ovarian mass on pelvic examination and magnetic resonance imaging (MRI) scan. Laboratory tests showed serum AFP, 73 687 ng/ml; carbohydrate antigen 125 (CA125), 1599 U/ml; and carcinoembryonic antigen (CEA), 13.9 ng/ml. Total hysterectomy with bilateral salpingo-oophorectomy, partial omentectomy, and low anterior resection of the rectum was performed, without any residual macroscopic tumor. Microscopically, the tumor was characterized by a hepatoid carcinomatous component composed of solid sheets of large eosinophilic cells with pleomorphic nuclei. The pathological stage was pT2N0M0. Tumor cells were diffusely immunoreactive for AFP and cytokeratin (CAM5.2), but monoclonal CEA and CA19-9 were focally positive in the cytoplasm, while CA125 was negative. The patient was treated postoperatively with three cycles of chemotherapy consisting of bleomycin, etoposide, and cisplatin; with this regimen, serum AFP decreased to 16 ng/ml from 12 600 ng/ml just before the initiation of chemotherapy. The patient received secondary cytoreductive surgery of systemic lymphadenectomy, which revealed no evidence of residual tumor.

Gynecologic Oncology, 2004

To evaluate the significance of the expression of HER-2/neu as a prognostic factor, we retrospect... more To evaluate the significance of the expression of HER-2/neu as a prognostic factor, we retrospectively examined its overexpression rates chiefly in ovarian clear cell adenocarcinoma (CCA) and their relationships with FIGO stage, lymph node metastasis, and prognosis. In addition to 90 specimens of CCA (stage I, 52; stage II, 7; stage III, 28; stage IV, 3) obtained between 1987 and 2002, 19 specimens of serous adenocarcinoma (S), 19 specimens of mucinous adenocarcinoma (M), and 19 specimens of endometrioid adenocarcinoma (E) collected at initial surgery were studied. The expression of HER-2/neu was immunohistologically scored on a scale of 0 to 3+ according to the HercepTest scoring system, and 2+ and 3+ were regarded as overexpression. The relationship between HER-2/neu overexpression and outcome was evaluated by the Kaplan-Meier method and the log-rank test. The relationship with advanced-stage cancer was analyzed by Fisher&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s exact test. The relationships with lymph node metastasis and histologic types were compared by the t test. The rate of HER-2/neu overexpression in CCA was 45.6% (0, 1+, 2+, and 3+ in 14, 35, 36, and 5 cases, respectively), and no differences in the overexpression rate were noted among histologic types: 52.7% in S, 42.1% in M, and 26.4% in E. In CCA, no association was observed between HER-2/neu overexpression and cumulative survival rate (P = 0.5708), FIGO stage (P = 0.5147), or lymph node metastasis (P = 0.3624). The absence in CCA of an association between HER-2/neu overexpression and outcome, stage, or lymph node metastasis indicates that HER-2/neu overexpression is not a prognostic risk factor.

Gynecologic Oncology, 2003

Objective. Mature cystic teratoma of the ovary (MCT) is the most common ovarian cystic disease in... more Objective. Mature cystic teratoma of the ovary (MCT) is the most common ovarian cystic disease in young women. Although it is a rare occurrence, some cases develop malignant transformation (MT), which results in serious consequences. However, MT is currently diagnosed only by postoperative pathology in most cases. We have conducted a retrospective study in an attempt to seek the factor to diagnose MT from MCT prior to surgery.