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Dive into the research topics where Tamio Okimoto is active.

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Featured researches published by Tamio Okimoto.


Geriatrics & Gerontology International | 2012

A retrospective analysis comparing the safety and efficacy of chemotherapy in elderly and non-elderly non-small-cell lung cancer patients.

Yukari Tsubata; Takeshi Honda; Tamio Okimoto; Kiyotaka Miura; Fumi Karino; Shinichi Iwamoto; Taeko Suzuki; Shunichi Hamaguchi; Hibiki Kanda; Akihisa Sutani; Takashige Kuraki; Takeshi Isobe

Aim:  The number of elderly patients with non‐small‐cell lung cancer (NSCLC) is increasing in Japan. We retrospectively analyzed and compared the safety and efficacy of chemotherapy in elderly and non‐elderly NSCLC patients who received chemotherapy at Shimane University Hospital.


PLOS ONE | 2018

Chloroquine augments TRAIL-induced apoptosis and induces G2/M phase arrest in human pancreatic cancer cells

Hiroyuki Monma; Yuichi Iida; Tamami Moritani; Tamio Okimoto; Ryosuke Tanino; Yoshitsugu Tajima; Mamoru Harada

Autophagy contributes to the treatment-resistance of many types of cancers, and chloroquine (CQ) inhibits autophagy. The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) kills cancer cells but is minimally cytotoxic to normal cells. However, because the therapeutic efficacy of TRAIL is limited, it is necessary to augment TRAIL-induced anti-tumor effects. In this study, we explored the anti-tumor effects of a combination of CQ and TRAIL on two human pancreatic cancer cell lines: TRAIL-sensitive MiaPaCa-2 cells and Panc-1 cells that are less sensitive to TRAIL. Although both CQ and TRAIL reduced cancer cell viability in a dose-dependent manner, the combination acted synergistically. CQ increased the expression level of type-II LC3B without decreasing the expression of p62, an autophagic substrate, thus indicating inhibition of autophagy. CQ did not increase the levels of death receptors on cancer cells but reduced the expression of anti-apoptotic proteins. A combination of CQ and TRAIL significantly increased cancer cell apoptosis. CQ induced cell-cycle arrest in the G2/M phase. Also, CQ increased the p21 level but reduced that of cyclin B1. A combination of CQ and TRAIL reduced the colony-forming abilities of cancer cells to extents greater than either material alone. In xenograft models, combination CQ and TRAIL therapy significantly suppressed the growth of subcutaneously established MiaPaCa-2 and Panc-1 cells, compared with the untreated or monotherapy groups. Together, the results indicate that CQ in combination with TRAIL may be useful to treat human pancreatic cancer.


Internal Medicine | 2019

A Low Crizotinib Concentration in the Cerebrospinal Fluid Causes Ineffective Treatment of Anaplastic Lymphoma Kinase-positive Non-small Cell Lung Cancer with Carcinomatous Meningitis

Tamio Okimoto; Yukari Tsubata; Takamasa Hotta; Megumi Hamaguchi; Mika Nakao; Shunichi Hamaguchi; Akinobu Hamada; Takeshi Isobe

The central nervous system is a common site of relapse in patients receiving crizotinib, which is presumed to be associated with the low concentration of crizotinib in the cerebrospinal fluid (CSF). Our patient received surgical treatment for anaplastic lymphoma kinase-positive stage IIA lung adenocarcinoma. His cancer recurred with brain metastases and carcinomatous meningitis. We started whole-brain radiation therapy (WBRT) and subsequently administered crizotinib. The concentration of crizotinib on day 15 in the plasma was 158 ng/mL, and that in the spinal fluid was 4.32 ng/mL. WBRT may elevate the CSF/plasma crizotinib concentration ratio; clinicians may therefore consider performing WBRT prior to crizotinib initiation.


Respirology case reports | 2018

Pleuroparenchymal fibroelastosis after haematopoietic stem cell transplantation without graft-versus-host disease findings: PPFE after HSCT without GVHD findings

Tamio Okimoto; Yukari Tsubata; Megumi Hamaguchi; Akihisa Sutani; Shunichi Hamaguchi; Takeshi Isobe

Although rare, pleuroparenchymal fibroelastosis (PPFE) is a serious late‐onset complication of haematopoietic stem cell transplantation (HSCT). It remains unclear whether graft‐versus‐host disease (GVHD) is involved in the development of PPFE. We report the case of a patient with PPFE after HSCT. The patient experienced pneumothorax repeatedly despite surgical treatment. A surgical specimen demonstrated PPFE findings, without evidence of GVHD. In this case, development of PPFE was not associated with GVHD, and immunosuppressive therapy did not improve pulmonary function. Surgical biopsy is recommended for precise treatment and elucidation of pathogenesis in each suspected PPFE patient.


Oncotarget | 2018

Bcl-2 inhibition sensitizes triple-negative human breast cancer cells to doxorubicin

Touko Inao; Yuichi Iida; Tamami Moritani; Tamio Okimoto; Ryosuke Tanino; Hitoshi Kotani; Mamoru Harada

Breast cancers can be divided into several types. Because triple-negative breast cancer (TNBC) is the most refractory to current anti-cancer therapies, efficient treatment has been urgently required. Members of the Bcl-2 family play pro- and anti-apoptotic roles in mitochondria-mediated apoptosis. Some Bcl-2 family members are expressed in breast cancer and influence the response to anti-cancer therapies. In this study, we investigated whether Bcl-2 inhibition could sensitize TNBC cells to the genotoxic drug doxorubicin (DR). Treatment with a combination of the Bcl-2 inhibitor ABT-199 and DR synergistically decreased the viability of the TNBC cell lines MDA-MB-231 and BT-549. In an apoptosis assay, the combination treatment resulted in only a marginal effect in BT-549 cells, whereas drastic apoptosis was induced in MDA-MB-231 cells treated with both ABT-199 and DR. Both caspase-8 and -9 were involved in the combination treatment-induced apoptosis. Short interfering RNA-mediated knockdown of Bcl-2 increased the sensitivity of both cell lines to DR. The combination treatment also significantly decreased the colony-forming ability of the TNBC cell lines. In a xenograft mouse model, oral administration of ABT-199 augmented the DR-induced antitumor effect on subcutaneously established MDA-MB-231 cells. These results indicate that the combination of DR with Bcl-2 inhibitors, including ABT-199, may be a promising treatment modality for TNBC patients.


Oncotarget | 2018

Successful rechallenge with ceritinib after leukocytoclastic vasculitis during ceritinib treatment for non-small cell lung cancer harboring the EML4-ALK fusion protein

Tamio Okimoto; Yukari Tsubata; Takamasa Hotta; Megumi Hamaguchi; Takae Okuno; Yohei Shiratsuki; Akari Kodama; Mika Nakao; Yoshihiro Amano; Shunichi Hamaguchi; Noriaki Kurimoto; Reiko Tobita; Takeshi Isobe

Anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitors (TKIs) dramatically improve progression-free survival compared to cytotoxic agents. It is therefore important to manage patients with ALK-TKIs until drug resistance occurs. Leukocytoclastic vasculitis (LCV) is a rare complication during cancer treatment and is associated with a variety of factors. Currently, it is unclear whether we should withdraw a treatment when drug-induced LCV develops. We report a 40-year-old man with advanced pulmonary adenocarcinoma harboring the EML4-ALK fusion protein who developed LCV during ceritinib treatment. Four weeks after withdrawing ceritinib, we could successfully perform rechallenge with ceritinib at the normal dose. Rapid and massive tumor apoptosis due to ceritinib treatment may lead to neoantigen release and immune complexes deposition. To the best of our knowledge, we report the first case of LCV in a patient during ALK-TKI treatment. Following this occurrence, we were able to successfully perform rechallenge with ceritinib. Therefore, key drugs used in a patients treatment regimen should not be discontinued without careful evaluation, and we should also consider the possibility of rechallenge.


Respirology case reports | 2016

Exogenous lipoid pneumonia caused by herbicide inhalation.

Takamasa Hotta; Yukari Tsubata; Tamio Okimoto; Teppei Hoshino; Shunichi Hamaguchi; Takeshi Isobe

Exogenous lipoid pneumonia is caused by aspiration or inhalation of oily substances. Generally, lipoid pneumonia has non‐specific clinical and radiological presentations and may be misdiagnosed as bacterial pneumonia. Our patient, a 68‐year‐old man who had been diagnosed with pneumonia on three previous occasions, was admitted to our hospital with a fourth similar episode. Computed tomography of the chest revealed extensive consolidations with air bronchograms in lung fields on the right side. The bronchoalveolar lavage fluid (BALF) increased ghost‐like macrophages that stained positive for lipid. Our patient reported that he had sprayed herbicide in large quantities without wearing a mask. We analysed the BALF and herbicide by gas chromatography and diagnosed exogenous lipoid pneumonia caused by inhalation of herbicide. Clinicians should be aware of lipoid pneumonia, which may present as infectious pneumonia.


Cancer Research | 2013

Abstract 3353: Effect of erlotinib on the pharmacokinetics of irinotecan and its metabolites: A drug-drug interaction study.

Emiko Sanematsu; Issei Toyooka; Yuki Takashima; Tamio Okimoto; Yukari Tsubata; Hideyuki Saito; Takeshi Isobe; Akinobu Hamada

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Purpose: Since irinotecan and erlotinib are used in treatment for non-small cell lung cancer (NSCLC), co-administration of these drugs might be an effective treatment for NSCLC. However, drug-drug interaction should be concerned because these drugs are metabolized by CYP3A4 and excreted into bile by ABC transporters. To clarify the drug-drug interaction when these drugs are co-administered, we examined the effect of this co-administration on the pharmacokinetics of irinotecan, its active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38), SN-38 glucuronide (SN-38G) in animal model. Methods: Cytotoxicity of irinotecan and SN-38 with erlotinib against NSCLC cell line (A549) was assessed. To elucidate the effect of drug-drug interaction between irinotecan and erlotinib, male Sprague-Dawley rats were treated with 10 mg/kg irinotecan and 25 mg/kg erlotinib. The concentrations of irinotecan, SN-38, SN-38G and erlotinib in plasma, bile, and tissues were analyzed by high-performance liquid chromatography. Pharmacokinetic parameters were calculated by non-compartmental model methods. Results: Co-exposured erlotinib enhanced the cytotoxicity of SN-38 in a dose-dependent manner, however it did not significantly affect the cytotoxicity of irinotecan against A549 that is resistant to erlotinib. Additionally, co-administration of erlotinib resulted in a significant increase of plasma concentration of irinotecan, SN-38 and SN-38G compared to irinotecan alone, but decrease in the biliary excretion. Erlotinib significantly increased the concentration of irinotecan and SN-38G in kidney and that of SN-38 in lung and jejunum. On the other hand, co-administration of irinotecan intended to decrease the plasma concentration of erlotinib but significant differences of pharmacokinetic parameters were not observed. Also, levels of erlotinib in tissues were not affected by co-administration of irinotecan. Conclusions: We proposed the possibility of combination therapy of irinotecan with erlotinib because the plasma concentration of irinotecan and its active metabolite SN-38 significantly increased in vivo and the cytotoxicity of SN-38 against NSCLC cell line enhanced. New effective salvage chemotherapy regimens are needed in patients with NSCLC. We conducted a phase I/II clinical study of combination chemotherapy with irinotecan and erlotinib for recurrent NSCLC because our data have shown synergistic/additive effects between irinotecan and epidermal growth factor receptor-tyrosine kinase inhibitor. Citation Format: Emiko Sanematsu, Issei Toyooka, Yuki Takashima, Tamio Okimoto, Yukari Tsubata, Hideyuki Saito, Takeshi Isobe, Akinobu Hamada. Effect of erlotinib on the pharmacokinetics of irinotecan and its metabolites: A drug-drug interaction study. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3353. doi:10.1158/1538-7445.AM2013-3353


Journal of Infection and Chemotherapy | 2013

Efficacy and safety of piperacillin/tazobactam versus biapenem in late elderly patients with nursing- and healthcare-associated pneumonia

Fumi Karino; Kiyotaka Miura; Hiroshi Fuchita; Naoya Koba; Emiko Nishikawa; Takamasa Hotta; Tamio Okimoto; Shinichi Iwamoto; Yukari Tsubata; Mitsuhiro Tada; Shunichi Hamaguchi; Takeshi Honda; Miki Ohe; Akihisa Sutani; Takashige Kuraki; Hiroyasu Takeyama; Takeshi Isobe


Anticancer Research | 2012

Tumor Angiogenesis in 75 Cases of Pleomorphic Carcinoma of the Lung

Yukari Tsubata; Akihisa Sutani; Tamio Okimoto; Motoki Matsuura; Isao Murakami; Ryousuke Usuda; Tsuneo Okumichi; Sei-Ichi Kakegawa; Kenichi Togashi; Shinji Kosaka; Yoshinori Yamashita; Koji Kishimoto; Takashige Kuraki; Takeshi Isobe

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Akihisa Sutani

Saitama Medical University

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