Takao Satou

Kinki University, Ōsaka, Ōsaka, Japan

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Publications (98)217.17 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Oxaliplatin is a key drug commonly used in colorectal cancer treatment. Despite high clinical efficacy, its therapeutic application is limited by common, dose-limiting occurrence of neuropathy. Since usual symptomatic neuropathy treatments fail to improve the patients' condition, there is an urgent need to advance our understanding of the pathogenesis of neuropathy to propose effective therapy and ensure adequate pain management. Oxaliplatin-induced neuropathy was recently reported to be associated with protein kinase C (PKC) activation. It is unclear, however, whether PKC inhibition can prevent neuropathy. In our current studies, we found that a PKC inhibitor, tamoxifen, inhibited oxaliplatin-induced neuropathy via the PKC/extracellular signal-regulated kinase (ERK)/c-Fos pathway in lumbar spinal cords (lumbar segments 4–6). Additionally, tamoxifen was shown to act in synergy with oxaliplatin to inhibit growth in tumor cells-implanted mice. Moreover, mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor, PD0325901, suppressed oxaliplatin-induced neuropathy and enhanced oxaliplatin efficacy. Our results indicate that oxaliplatin-induced neuropathy is associated with PKC/ERK/c-Fos pathway in lumbar spinal cord. Additionally, we demonstrate that disruption of this pathway by PKC and MEK inhibitors suppresses oxaliplatin-induced neuropathy, thereby suggesting that PKC and MEK inhibitors may be therapeutically useful in preventing oxaliplatin-induced neuropathy and could aid in combination antitumor pharmacotherapy. This article is protected by copyright. All rights reserved.
    International Journal of Cancer 11/2014; · 6.20 Impact Factor
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    ABSTRACT: Dimethyl fumarate (DMF) is a fumaric acid ester that is used to treat psoriasis and multiple sclerosis. Recently, DMF was found to exhibit anti-tumor effects. However, the molecular mechanisms underlying these effects have not been elucidated. In this study, we investigated the mechanism of DMF-induced apoptosis in different human hematopoietic tumor cell lines. We found that DMF induced apoptosis in different human hematopoietic tumor cell lines but it did not affect the normal human B lymphocyte cell line RPMI 1788. We also observed a concurrent increase in caspase-3 activity and in the number of Annexin-V-positive cells. Furthermore, an examination of the survival signals, which are activated by apoptotic stimuli, revealed that DMF significantly inhibited nuclear factor-κB (NF-κB) p65 nuclear translocation. In addition, DMF suppressed B-cell lymphoma extra-large (Bcl-xL) and X-linked inhibitor of apoptosis (XIAP) expression whereas Bcl-2, survivin, Bcl-2-associated X protein (Bax), and Bim levels did not change. These results indicated that DMF induced apoptosis by suppressing NF-κB activation, and Bcl-xL and XIAP expression. These findings suggested that DMF might have potential as an anticancer agent that could be used in combination therapy with other anticancer drugs for the treatment of human hematopoietic tumors.
    Biomedecine [?] Pharmacotherapy 09/2014; · 2.11 Impact Factor
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    ABSTRACT: Pulmonary emphysema and type 2 diabetes mellitus (T2DM), both caused by lifestyle factors, frequently concur. Respectively, the diseases affect lung alveolar and pancreatic islet cells, which express cell adhesion molecule 1 (CADM1), an immunoglobulin superfamily member. Protease-mediated ectodomain shedding of full-length CADM1 produces C-terminal fragments (CTFs) with proapoptotic activity. In emphysematous lungs, the CADM1 shedding rate and thus the level of CTFs in alveolar cells increase. In this study, CADM1 expression in islet cells was examined by western blotting. Protein was extracted from formalin-fixed, paraffin-embedded sections of pancreata isolated from patients with T2DM (n = 12) or from patients without pancreatic disease (n = 8) at autopsy. After adjusting for the number of islet cells present in the adjacent section, we found that full-length CADM1 decreased in T2DM islets, while ectodomain shedding increased. Hemoglobin A1c levels, measured when patients were alive, correlated inversely with full-length CADM1 levels (P = 0.041) and positively with ectodomain shedding rates (P = 0.001). In immunofluorescence images of T2DM islet cells, CADM1 was detected in the cytoplasm, but not on the cell membrane. Consistently, when MIN6-m9 mouse beta cells were treated with phorbol ester and trypsin to induce shedding, CADM1 immunostaining was diffuse in the cytoplasm. When a form of CTFs was exogenously expressed in MIN6-m9 cells, it localized diffusely in the cytoplasm and increased the number of apoptotic cells. These results suggest that increased CADM1 ectodomain shedding contributes to blood glucose dysregulation in T2DM by decreasing full-length CADM1 and producing CTFs that accumulate in the cytoplasm and promote apoptosis of beta cells. Thus, this study has identified a molecular alteration shared by pulmonary emphysema and T2DM.
    PLoS ONE 06/2014; 9(6):e100988. · 3.53 Impact Factor
  • The Journal of Dermatology 05/2014; 41(5):459-61. · 2.35 Impact Factor
  • European journal of dermatology : EJD. 02/2014;
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    ABSTRACT: Bisphosphonates are an important class of antiresorptive drugs used in the treatment of metabolic bone diseases. Recent studies have shown that nitrogen-containing bisphosphonates induced apoptosis in rabbit osteoclasts and prevented prenylated small GTPase. However, whether bisphosphonates inhibit osteoclast formation has not been determined. In the present study, we investigated the inhibitory effect of minodronate and alendronate on the osteoclast formation and clarified the mechanism involved in a mouse macrophage-like cell lines C7 and RAW264.7. It was found that minodronate and alendronate inhibited the osteoclast formation of C7 cells induced by receptor activator of NF-kappaB ligand and macrophage colony stimulating factor, which are inhibited by the suppression of geranylgeranyl pyrophosphate (GGPP) biosynthesis. It was also found that minodronate and alendronate inhibited the osteoclast formation of RAW264.7 cells induced by receptor activator of NF-kappaB ligand. Furthermore, minodronate and alendornate decreased phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt; similarly, U0126, a mitogen protein kinase kinase 1/2 (MEK1/2) inhibitor, and LY294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor, inhibited osteoclast formation. This indicates that minodronate and alendronate inhibit GGPP biosynthesis in the mevalonate pathway and then signal transduction in the MEK/ERK and PI3K/Akt pathways, thereby inhibiting osteoclast formation. These results suggest a novel effect of bisphosphonates that could be effective in the treatment of bone metabolic diseases, such as osteoporosis.
    Journal of Biomedical Science 02/2014; 21(1):10. · 2.74 Impact Factor
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    ABSTRACT: The calcium channel blocker verapamil inhibits the transport function of multidrug resistance protein 1 (MDR1). Although verapamil acts to reverse MDR in cancer cells, the underlying mechanism remains unclear. In the present study, we investigated the mechanism of reversing MDR by verapamil in anti-cancer drug-resistant multiple myeloma (MM) cell lines. We found that verapamil suppresses MDR1 and survivin expressions and increases Bim expression via suppression of Src activation. Furthermore, dasatinib reversed the drug-resistance of the drug-resistant cell lines. These findings suggest that Src inhibitors are potentially useful as an anti-MDR agent for the treatment of malignant tumor cells.
    Leukemia research 10/2013; · 2.36 Impact Factor
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    ABSTRACT: Increased motility and invasiveness of cancer cells are reminiscent of the epithelial-mesenchymal transition (EMT), which occurs during cancer progression and metastasis. Recent studies have indicated the expression of receptor activator of nuclear factor-¿B (RANK) in various solid tumors, including breast cancer. Although activation of the RANK ligand (RANKL)/RANK system promotes cell migration, metastasis, and anchorage-independent growth of tumor-initiating cells, it remains to be investigated if RANKL induces EMT in breast cancer cells. In this study, we investigated whether RANKL induces EMT in normal breast mammary epithelial cells and breast cancer cells, and the mechanism underlying such induction. Expression levels of vimentin, N-cadherin, E-cadherin, Snail, Slug, and Twist were examined by real-time polymerase chain reaction. Cell migration and invasion were assessed using Boyden chamber and invasion assays, respectively. The effects of RANKL on signal transduction molecules were determined by western blot analyses. We found that stimulation by RANKL altered the cell morphology to the mesenchymal phenotype in normal breast epithelial and breast cancer cells. In addition, RANKL increased the expression levels of vimentin, N-cadherin, Snail, and Twist and decreased the expression of E-cadherin. We also found that RANKL activated nuclear factor-¿B (NF-¿B), but not extracellular signal-regulated kinase 1/2, Akt, mammalian target of rapamycin, c-Jun N-terminal kinase, and signal transducer and activator of transcription 3. Moreover, dimethyl fumarate, a NF-¿B inhibitor, inhibited RANKL-induced EMT, cell migration, and invasion, and upregulated the expressions of Snail, Twist, vimentin, and N-cadherin. The results indicate that RANKL induces EMT by activating the NF-¿B pathway and enhancing Snail and Twist expression. These findings suggest that the RANKL/RANK system promotes tumor cell migration, invasion, and metastasis via the induction of EMT.
    Journal of Experimental & Clinical Cancer Research 09/2013; 32(1):62. · 3.27 Impact Factor
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    ABSTRACT: Several autocrine soluble factors, including macrophage inflammatory protein-1α and tumour necrosis factor-alpha (TNF-α), promote the survival and growth of multiple myeloma (MM) cells. We hypothesised that inhibition of the TNF-α autocrine loop may enhance the cytotoxic effect of anticancer drugs in MM cell lines. In the present study, a TNF-α-neutralizing antibody suppressed cell proliferation and enhanced the cytotoxic effect of anticancer drugs on MM cells. In addition, combination treatment with the TNF-α-neutralizing antibody and the chemotherapy agent melphalan inhibited nuclear factor κB (NF-κB) p65 nuclear translocation and mammalian target of rapamycin (mTOR) activation and upregulated the expression of Bax and Bim. Treatment of ARH-77 cells with the NF-κB inhibitor dimethyl fumarate or the mTOR inhibitor rapamycin suppressed NF-κB p65 nuclear translocation and enhanced the cytotoxic effect of melphalan. Furthermore, infliximab, a monoclonal antibody against TNF-α, also enhanced the cytotoxic effect of anticancer drugs in ARH-77 cells. These results indicated that TNF-α-neutralizing antibodies or infliximab enhanced the cytotoxic effect of anticancer drugs by suppressing the TNF receptor/mTOR/NF-κB pathways. The inhibition of TNF-α may thus provide a new therapeutic approach to control tumour progression and bone destruction in MM patients.
    European journal of cancer (Oxford, England: 1990) 08/2013; · 4.12 Impact Factor
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    ABSTRACT: Aim: Patients with scirrhous carcinoma of the gastrointestinal tract frequently develop peritoneal carcinomatosis-particularly of the peritoneal extension type (PET), which has a bad prognosis. We developed a novel animal model, suitable for testing treatments for PET. In order to develop the model, we scraped the entire peritoneum of Fischer 344 rats with sterile cotton swabs and injected 1×10(6) cells of the RCN-9 cell type into the peritoneal cavity. In the novel experimental model, RCN-9 cells adhered only to the exposed basement membrane. The submesothelial layer and fibroblasts in the submesothelial layer grew and increased to a maximum at day 7, then decreased during late-phase peritoneal carcinomatosis. At day 14, RCN-9 cells coated the peritoneum in a manner similar to PET. We successfully established a novel animal model of peritoneal carcinomatosis that mimics clinicopathological features of PET. Fibroblasts in the submesothelial layer potentially play an important role in peritoneal carcinomatosis.
    Anticancer research 04/2013; 33(4):1439-46. · 1.87 Impact Factor
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    ABSTRACT: Our previous study indicated that consuming (-)-epigallocatechin gallate (EGCG) before or after traumatic brain injury (TBI) eliminated free radical generation in rats, resulting in inhibition of neuronal degeneration and apoptotic death, and improvement of cognitive impairment. Here we investigated the effects of administering EGCG at various times pre- and post-TBI on cerebral function and morphology. Wistar rats were divided into five groups and were allowed access to (1) normal drinking water, (2) EGCG pre-TBI, (3) EGCG pre- and post-TBI, (4) EGCG post-TBI, and (5) sham-operated group with access to normal drinking water. TBI was induced with a pneumatic controlled injury device at 10 weeks of age. Immunohistochemistry and lipid peroxidation studies revealed that at 1, 3, and 7 days post-TBI, the number of 8-Hydroxy-2'-deoxyguanosine-, 4-Hydroxy-2-nonenal- and single-stranded DNA (ssDNA)-positive cells, and levels of malondialdehyde around the damaged area were significantly decreased in all EGCG treatment groups compared with the water group (P < 0.05). Although there was a significant increase in the number of surviving neurons after TBI in each EGCG treatment group compared with the water group (P < 0.05), significant improvement of cognitive impairment after TBI was only observed in the groups with continuous and post-TBI access to EGCG (P < 0.05). These results indicate that EGCG inhibits free radical-induced neuronal degeneration and apoptotic death around the area damaged by TBI. Importantly, continuous and post-TBI access to EGCG improved cerebral function following TBI. In summary, consumption of green tea may be an effective therapy for TBI patients.
    Journal of Neural Transmission 11/2012; 120(5). · 2.87 Impact Factor
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    ABSTRACT: Intraperitoneally administrated epithelial cellular adhesion molecule (EpCAM) monoclonal antibody is a therapeutic agent in patients with malignant effusion in several types of carcinoma. However, the role of EpCAM in peritoneal metastasis (PM) lesions and primary lesions of gastric cancer (GC) is still unclear. Therefore, in this study, we investigated EpCAM expression in GC patients with PM. We investigated the expression of EpCAM in 35PM lesions and 104 biopsy samples as primary lesions. Immunohistochemical staining was performed using the Ventana Benchmark XT (Roche Diagnostics) system. EpCAM expression was evaluated by calculating the total immunostaining score, which is the product of the proportion score and the intensity score. Overexpression was defined as a total score greater than 4. All PM specimens showed overexpression of EpCAM, and GC cells in both the surface layer and the deep layer of the PM showed a high expression of EpCAM. Meanwhile, in the biopsy sample, the expression of EpCAM ranged from none to strong. The EpCAM score results for PM specimens and biopsy samples were 11.0 ± 2.0 and 6.9 ± 3.9, respectively. The difference between the scores was statistically significant (P < 0.05). The intraperitoneally administrated EpCAM antibody might have a anti-cancer effect in PM lesions of GC. Additionally, it can be assumed that only GC cells which express a high level of EpCAM might metastasize to the peritoneum.
    Targeted Oncology 11/2012; 8(4). · 3.46 Impact Factor
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    ABSTRACT: BACKGROUND: We conducted a phase II study involving a single administration of intraperitoneal chemotherapy with paclitaxel followed by sequential systemic chemotherapy with S-1+ paclitaxel for advanced gastric cancer patients with peritoneal metastasis. METHODS: Gastric cancer patients with peritoneal metastasis were enrolled. Paclitaxel (80 mg/m(2)) was administered intraperitoneally at staging laparoscopy. Within 7 days, patients received systemic chemotherapy with S-1 (80 mg/m(2)/day on days 1-14) plus paclitaxel (50 mg/m(2) on days 1 and 8), followed by 7-days rest. The responders to this chemotherapy underwent second-look laparoscopy, and gastrectomy with D2 lymph node dissection was performed in patients when the disappearance of peritoneal metastasis had been confirmed. The primary endpoint of the study was overall survival rate. RESULTS: Thirty-five patients were enrolled. All patients were confirmed as having localized peritoneal metastasis by staging laparoscopy. Eventually, gastrectomy was performed in 22 patients. The median survival time of the total patient population and those patients in which gastrectomy was performed was 21.3 and 29.8 months, respectively. The overall response rate was 65.7 % for all patients. The frequent grade 3/4 toxic effects included neutropenia and leukopenia. CONCLUSIONS: Sequential intraperitoneal and intravenous paclitaxel plus S-1 was well tolerated in gastric cancer patients with peritoneal metastasis.
    Journal of Gastrointestinal Surgery 10/2012; · 2.36 Impact Factor
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    ABSTRACT: Nitrogen-containing bisphosphonates (N-BPs) induce apoptosis in tumor cells by inhibiting the prenylation of small G-proteins. However, the details of the apoptosis-inducing mechanism remain obscure. The present study showed that the induction of apoptosis by N-BPs in hematopoietic tumor cells is mediated by mitochondrial apoptotic signaling pathways, which are activated by the suppression of geranylgeranyl pyrophosphate (GGPP) biosynthesis. Furthermore, N-BPs decreased the levels of phosphorylated extracellular signal-regulated kinase (ERK) and mTOR via suppression of Ras prenylation and enhanced Bim expression. The present results indicated that N-BPs induce apoptosis by decreasing the mitochondrial transmembrane potential, increasing the activation of caspase-9 and caspase-3, and enhancing Bim expression through inhibition of the Ras/MEK/ERK and Ras/mTOR pathways. The accumulation of N-BPs in bones suggests that they may act more effectively on tumors that have spread to bones or on Ras-variable tumors. This is the first study to show that the specific molecular pathways of N-BP-induced apoptosis.
    Biochemical pharmacology 10/2012; · 4.25 Impact Factor
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    ABSTRACT: We have previously reported free radical production after traumatic brain injury (TBI), which induces neural stem cell (NSC) degeneration and death. However, the effects of aging on NSC proliferation around the damaged area following TBI have not been investigated. Therefore, in this study, we used 10-week (young group) and 24-month-old (aged group) rat TBI models to investigate the effects of aging on NSC proliferation around damaged tissue using immunohistochemical and ex vivo techniques. Young and aged rats received TBI. At 1, 3 and 7 days after TBI, immunohistochemical and lipid peroxidation studies were performed. Immunohistochemistry revealed that the number of nestin-positive cells around the damaged area after TBI in the aged group decreased significantly when compared with those in the young group (P < 0.01). However, the number of 8-hydroxy-2'-deoxyguanosine-, 4-hydroxy-2-nonenal- and single-stranded DNA (ssDNA)-positive cells and the level of peroxidation around the damaged area after TBI significantly increased in the aged group, compared with those in the young group (P < 0.01). Furthermore, almost all ssDNA-positive cells in young and aged groups co-localized with NeuN and nestin staining. Ex vivo studies revealed that neurospheres, which differentiated into neurons and glia in culture, could only be isolated from injured brain tissue in young and aged groups at 3 days after TBI. These results indicate that, although there were fewer NSCs that have the potential to differentiate into neurons and glia, these NSCs escaped free radical-induced degeneration around the damaged area after TBI in the aged rat brain.
    Journal of Neural Transmission 09/2012; · 2.87 Impact Factor
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    ABSTRACT: Aim: A preliminary study with the aim of evaluating the safety and efficacy of a single intraperitoneal administration of paclitaxel, combined with intravenous administration of paclitaxel plus S-1, was carried out in gastric cancer patients with peritoneal metastasis. Paclitaxel was administered intraperitoneally at 80 mg/m(2). After one to two weeks, S-1 was administered at 80 mg/m(2)/day for 14 consecutive days, followed by seven days' rest. Paclitaxel was administered intravenously at 50 mg/m(2) on days 1 and 8. The safety, pharmacokinetic analysis and efficacy of this therapy were investigated. Fifteen patients were enrolled in this study. The toxic effects of the intraperitoneal chemotherapy were mild. The toxic effects with the systemic chemotherapy were acceptable. The ratio of (AUC peri)/(AUC pla) was 1065:1 in the pharmacokinetic analysis. The one-year overall survival rate was 10/15 (66.7%). A single intraperitoneal administration of paclitaxel combined with intravenous administration of paclitaxel plus S-1 is a well-tolerated and feasible treatment for patients with gastric cancer with peritoneal metastasis.
    Anticancer research 09/2012; 32(9):4071-5. · 1.87 Impact Factor
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    ABSTRACT: Multidrug resistance represents a major obstacle for the chemotherapy of a wide variety of human tumors. To investigate the underlying mechanisms associated with resistance to anti-cancer drugs, we established anti-cancer drug-resistant multiple myeloma (MM) cell lines RPMI8226/ADM, RPMI8226/VCR, RPMI8226/DEX, and RPMI8226/L-PAM, the 50% inhibitory concentration values of which were 77-, 58-, 79-, and 30-fold higher than their parental cell lines, respectively. The resistant cell lines overexpressed MDR1 and survivin, or showed decreased Bim expression. These results indicated that regulating these factors with inhibitors might be a viable approach to increasing the susceptibility of quiescent MM cells to chemotherapy.
    Leukemia research 07/2012; 36(10):1315-22. · 2.36 Impact Factor
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    ABSTRACT: The prognosis of gastric cancer patients with peritoneal metastasis is very poor. Recent findings suggest that use of trastuzumab, a monoclonal antibody-based agent that targets human epidermal growth factor receptor 2 (HER2), may improve the prognosis of gastric cancer patients with HER2 overexpression and/or gene amplification. However, whether these mechanisms of HER2 upregulation are present in gastric cancer patients with peritoneal metastasis is unclear. The status of HER2 expression in a cohort of samples obtained from 35 gastric cancer patients with peritoneal metastasis was investigated using immunohistochemistry and fluorescence in situ hybridization. In 18 cases, we also investigated the influence of induction chemotherapy on HER2 overexpression. The frequency of HER2 overexpression and gene amplification was 2.9 % (1/35) in peritoneal metastatic lesions. There was concurrence in HER2 status in the samples examined prior to and following induction of chemotherapy. Most samples from the gastric cancer patients with peritoneal metastasis did not show HER2 amplification and/or overexpression. Although our study size was small, these results suggest that trastuzumab, which is critically dependent on HER2 expression, might not be an effective agent for these patients. Consequently, other therapeutic approaches for these patients must be developed.
    Targeted Oncology 07/2012; 7(4). · 3.46 Impact Factor
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    ABSTRACT: Osteoclast differentiation is influenced by receptor activator of the NF-κB ligand (RANKL), macrophage colony-stimulating factor (M-CSF), and CD9, which are expressed on bone marrow stromal cells and osteoblasts. In addition, osteoprotegerin (OPG) is known as an osteoclastogenesis inhibitory factor. In this study, we investigated whether bisphosphonates and statins increase OPG expression and inhibit the expression of CD9, M-CSF, and RANKL in the bone marrow-derived stromal cell line ST2. We found that bisphosphonates and statins enhanced OPG mRNA expression and inhibited the expression of CD9, M-CSF, and RANKL mRNA. Futhermore, bisphosphonates and statins decreased the membrane localization of Ras and phosphorylated ERK1/2, and activated the p38MAPK. This indicates that bisphosphonates and statins enhanced OPG expression, and inhibited the expression of CD9, M-CSF, and RANKL through blocking the Ras/ERK pathway and activating p38MAPK. Accordingly, we believe that its clinical applications will be investigated in the future for the development of osteoporosis therapy.
    Molecular and Cellular Endocrinology 05/2012; 361(1-2):219-31. · 4.24 Impact Factor
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    ABSTRACT: Ameloblastoma with bone formation is rare. We report a case of a 55-year-old woman with ameloblastoma accompanied by prominent osteoplasia. Histopathological examination exhibited an abundant stromal component between tumor nests. Therefore, she was diagnosed as the desmoplastic variant, except for the numerous bone trabeculae. The distinction between new bone formation and invasion of the bone marrow poses a problem. A thin rim of fibrous bone that can be accentuated by Masson-trichrome staining suggests the former.
    Oral surgery, oral medicine, oral pathology and oral radiology. 05/2012; 113(5):e23-8.

Publication Stats

739 Citations
217.17 Total Impact Points


  • 1986–2014
    • Kinki University
      • • Department of Pathology
      • • Department of Surgery
      • • Department of Internal Medicine
      Ōsaka, Ōsaka, Japan