Expression of monoacylglycerol lipase as a marker of tumour invasion and progression in malignant melanoma.

BACKGROUND: Accumulating evidence suggests that the lipid lytic enzyme monoacylglycerol lipase (MAGL) promotes tumour invasion and metastasis through up-regulation of pro-tumorigenic signalling lipids in several tumour cell lines. However, the expression status of MAGL in clinical melanoma tissues and its clinicopathological significance remain unclear. OBJECTIVE: To correlate the tumour expression status of MAGL with the clinicopathological information of patients with malignant melanoma. METHODS: Polymerase chain reaction (PCR) array screening was performed, and the results were validated using immunocytochemical analysis of tumour and non-tumour melanocytic cell lines. Immunohistochemical staining for MAGL was performed for 74 melanoma samples, including 48 primary and 26 metastatic tumours, in which the expression of MAGL was determined by evaluating the percentage of MAGL-positive tumour cells and the MAGL staining intensity. Finally, we analysed the association of MAGL expression status with tumour progression, tumour thickness and vascular invasion of the primary lesion. RESULTS: Immunocytochemical analysis revealed that MAGL was expressed in all 12 melanoma cell lines, but not in normal human epidermal melanocytes. In the immunohistochemical analysis, positive staining for MAGL was noted in 32 of 48 (64.5%) primary lesions, 14 of 17 (82.4%) lymph node metastatic lesions and 7 of 9 (77.8%) skin metastatic lesions. Metastatic tumours had a significantly higher staining intensity (P = 0.033 for lymph node, P = 0.010 for skin). In the analysis of primary lesions, higher MAGL expression correlated with greater tumour thickness (P = 0.015) and the presence of vascular invasion (P = 0.017). On further evaluation of MAGL-positive primary lesions, staining intensity of MAGL tended to be higher in deeper areas of the tumour mass. CONCLUSIONS: The expression of MAGL in tumour cells reflects the aggressiveness of melanoma cells and may serve as a marker of tumour progression.

Organ Perfusion for Uterus Transplantation in Non-Human Primates With Assumed Procurement of a Uterus From a Brain-Dead Donor.

BACKGROUND: Clinical studies of uterus transplantation have been performed to treat uterine factor infertility. Because the uterus is a pelvic visceral organ, the method of perfusion for the procurement of vital organs from a brain-dead donor should be modified for removal of the uterus. Herein, we report the results of a preliminary study in cynomolgus monkeys of a new perfusion method for uterus transplantation with assumed procurement of a uterus from a brain-dead donor. METHODS: Cynomolgus monkeys were used; thoracolaparotomy was performed on the donor. A perfusion catheter was then placed into the unilateral femoral artery and/or external iliac artery. Cross-clamping was performed for the aorta under the diaphragm and the inferior vena cava was divided in the pleural space. The perfusion solution was then administered via the catheter to perfuse all organs in the abdominal cavity, including those in the pelvic cavity. After the perfusion, gross observation and histopathological examination of abdominal organs were conducted. RESULTS: Gross findings showed that all abdominal organs turned white in all specimens, indicating favorable perfusion of the uterus and all other organs in the abdomen. Pathological findings showed that almost no hemocytes were observed in the vessels of each organ. CONCLUSIONS: With perfusion via the femoral artery and/or external iliac artery, all organs in the abdominal cavity, including the uterus, could be perfused. It was suggested that this technique could be useful for uterus transplantation assuming the procurement of a uterus from a brain-dead donor.

Upregulation of integrin ß4 promotes epithelial-mesenchymal transition and is a novel prognostic marker in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDA) is a highly aggressive and often lethal malignant tumor. Several studies have shown that epithelial-mesenchymal transition (EMT) is frequently observed in clinical samples of PDA and is related to high metastatic rates and poor outcomes. To identify candidate molecules regulating EMT in PDA, we previously used cDNA microarray analysis and identified integrin ß4 (ITGB4) as one of the genes upregulated in high-EMT xenografts derived from PDA patients. The aim of the current study was to clarify the clinicopathological and functional significance of ITGB4 overexpression in PDA. ITGB4 upregulation in high-EMT xenografts was confirmed by immunohistochemistry. Immunohistochemical analyses of 134 surgically resected PDA cases revealed intratumoral heterogeneity with respect to ITGB4 expression and showed that cancer cells undergoing EMT often display strong diffuse ITGB4 expression. High levels of ITGB4 expression were significantly correlated with the hallmarks of EMT (solitary cell infiltration, reduced E-cadherin expression, and increased vimentin expression), with high tumor grade, and with the presence of lymph node metastasis, and showed an independent prognostic effect. Immunocytochemical analyses of PDA cell lines revealed that localization of ITGB4 changed from regions of cell-cell contact to diffuse cytoplasm and cell edges with occasional localization in filopodia during EMT. Knockdown of ITGB4 reduced the migratory and invasive ability of PDA cells. Overexpression of ITGB4 promoted cell scattering and cell motility in combination with downregulation of E-cadherin and upregulation of vimentin expression. In conclusion, we elucidated the prognostic and clinicopathological significance of ITGB4 overexpression in PDA and also the potential role for ITGB4 in the regulation of cancer invasion and EMT.

Earthquake dynamics. Mapping pressurized volcanic fluids from induced crustal seismic velocity drops.

Volcanic eruptions are caused by the release of pressure that has accumulated due to hot volcanic fluids at depth. Here, we show that the extent of the regions affected by pressurized fluids can be imaged through the measurement of their response to transient stress perturbations. We used records of seismic noise from the Japanese Hi-net seismic network to measure the crustal seismic velocity changes below volcanic regions caused by the 2011 moment magnitude (M(w)) 9.0 Tohoku-Oki earthquake. We interpret coseismic crustal seismic velocity reductions as related to the mechanical weakening of the pressurized crust by the dynamic stress associated with the seismic waves. We suggest, therefore, that mapping seismic velocity susceptibility to dynamic stress perturbations can be used for the imaging and characterization of volcanic systems.

Functionalized gold nanorods for thermal ablation treatment of bladder cancer.

Nanomaterial-directed, photothermal ablation is a practical future approach for the treatment of early-stage bladder cancer. Using a new PEGylation technique with bi-functional nitrophenyl carbonate PEG (bi-NPC-PEG) that promotes uniform suspension of the nanomaterial in solution, we have shown that gold nanorods conjugated to an anti-EGFR antibody (nano-alphaEGFR) bind effectively to EGFR-expressing bladder cancer cells. The subsequent application of infrared light, specifically tuned to the plasmon resonance of the nanorods used in this work, allows for the specific heating of nano-alphaEGFR to the point of localized cellular death. Such an approach, administering nano-alphaEGFR intravesically via a urinary catheter and infrared light via a modified cystoscope, represents a novel, future clinical application of this technology, which avoids the problem of systemic exposure and clearance of nanoparticles from body.

Comparisons among isolates of Sweet potato feathery mottle virus using complete genomic RNA sequences.

We determined the complete or partial nucleotide sequences of eight Sweet potato feathery mottle virus (SPFMV) isolates and compared them with 12 other partial SPFMV sequences. The genome organization of the isolate Bungo (strain group C) was very different from those of isolates in the russet crack, ordinary (O), and east Africa groups. 10-O appeared to be a recombinant of isolates S and O, with a recombination site within the P1 gene. This study will help to provide a better understanding of the taxonomy and biology of SPFMV and how these features relate to virulence.

Annexin II overexpression correlates with stromal tenascin-C overexpression: a prognostic marker in colorectal carcinoma.

BACKGROUND: Overexpression of annexin II, a calcium-dependent phospholipid-binding protein, has been reported in various carcinomas. One of its ligands is tenascin-C, an extracellular matrix glycoprotein with predominantly antiadhesive qualities that also has been reported to be a prognostic marker for several carcinomas. In the current study, the authors investigated the correlation between the overexpression of annexin II and tenascin-C in colorectal carcinoma. METHODS: Western blot analysis of annexin II expression was examined in four human colorectal carcinoma cell lines. Using immunohistochemical methods, the authors also examined expression of annexin II and tenascin-C in 105 primary colorectal carcinoma cases. RESULTS: Although annexin II was expressed in human colon carcinoma cell lines, there was no apparent correlation between its expression level and the metastatic potential of these cell lines. The authors observed overexpression of annexin II and tenascin-C proteins in 29.5% and 49.5%, respectively, of colorectal carcinoma cases. Overexpression of annexin II was found to be correlated significantly with histologic type, tumor size, depth of invasion, and pTNM stage, whereas tenascin-C overexpression was noted to be correlated significantly with histologic type, depth of invasion, lymphatic invasion, venous invasion, lymph node metastasis, and pTNM stage. Expression of annexin II was shown to be correlated significantly with that of tenascin-C. Multivariate analysis demonstrated that annexin II and tenascin-C cooverexpression was an independent factor of poor prognosis in patients with colorectal carcinoma. CONCLUSIONS: The data from the current study suggest that both annexin II and tenascin-C are overexpressed in advanced colorectal carcinoma and that they may be related to the progression and metastatic spread of colorectal carcinoma.

DNA cytofluorometric analysis of chondrocytes in human articular cartilages under normal aging or arthritic conditions.

OBJECTIVE: Since most chondrocytes in articular cartilage are in the resting phase (G0) of the cell cycle, it has been difficult to investigate their cell kinetics using 3H-thymidine autoradiography, or immunohistochemistry. In the present study, DNA cytofluorometry, which is useful to analyse the cell kinetics even for such inactive cell populations as in the G0 phase, was applied to human chondrocytes of the articular cartilages under normal aging and pathologic conditions such as osteoarthritis (OA), rheumatoid arthritis (RA), and aseptic necrosis (AN). DESIGN: The human articular cartilages for the study were obtained from autopsy and surgical materials. Fifty joints were used for the study of aging, 54 for the study of OA, 20 for studying RA, and 10 for AN study. The isolated chondrocytes were quickly prepared from fresh articular cartilages, using a combination method of enzymatic digestion with papain and collagenase, followed by mechanical cell separation by churning and homogenization. RESULTS: The DNA histograms obtained by cytofluorometry with propidium-iodide staining showed that most chondrocytes had diploid DNA content (2c) in all cartilages studied, suggesting that they were in the G0 phase. However, there were a few chondrocytes having tetraploid DNA content (4c) in the normally aged articular cartilages, and there were some cells having DNA content between 2c and 4c in the diseased cartilages. The former cells were considered to be G0-phase cells of the 4c chondrocytes, while the latter cells were considered to be in the DNA synthetic (S) phase or G2-phase of the 2c chondrocytes. The frequency of 4c chondrocytes in aged cartilage was significantly increased, compared to that in the young cartilage. In contrast to the normal cartilage, the frequency of S- and G2-phase cells, which was expressed as the S- G2 index, in diseased cartilages (OA, RA and AN) was significantly high (P< 0.0001). In OA cartilage, the S-G2 index was much higher in the severe or moderate stage than in the mild stage, suggesting that the chondrocytes in clusters may actively proliferate. CONCLUSION: These results showed that in normal articular cartilages most chondrocytes are in the G0 phase, while some became 4c polyploid cells, and that these G0-phase chondrocytes had a potential to proliferate under diseased conditions.

Bcl-X expression in esophageal squamous cell carcinoma: association with tumor progression and prognosis.

BACKGROUND AND OBJECTIVES: Bcl-2 family proteins are regulators of programmed cell death and important in the development and progression of human various tumors. The role of these proteins in the development, progression and differentiation of esophageal squamous cell carcinoma (ESCC) is unclear. METHODS: We investigated the expression of Bcl-2, Bcl-X, and Bax using immunohistochemistry in 86 ESCCs, and scored the expression by the weighted score. RESULTS: Bcl-2 expression related to pT category (P=0.043) and histological grade (P = 0.001). Bcl-X expression related to pT category (P = 0.003), pN category (P = 0.041) and the number of positive nodes (P = 0.036), and had a tendency to relate to histological grade (P = 0.086). Bax expression had a tendency to relate to pN category (P = 0.081). The inverse relationship between Bcl-2 and Bcl-X expression was detected (P = 0.001), while the positive one between Bcl-X and Bax expression was detected (P = 0.014). Patients with low Bcl-X weighted score had a significantly longer survival compared with those with high Bcl-X weighted score. Multivariate analysis revealed Bcl-X expression as the independent prognostic factors (P = 0.022). CONCLUSION: These results imply that Bcl-2 family proteins, especially Bcl-X, may contribute to the progression in ESCC.

Annexin II overexpression is correlated with poor prognosis in human gastric carcinoma.

Annexins belong to a family of the calcium-dependent phospholipid binding proteins. They are also substrates of receptor tyrosine kinases. Overexpression of Annexin II, which has been reported in various carcinomas, is thought to be associated with cell proliferation, differentiation and cell-cell adhesion in the pathogenesis of carcinoma, but the functions of Annexins have not been fully elucidated. In this study, we investigated the role of Annexin II (p36) and its relationship with c-erbB-2 overexpression in gastric carcinoma. We studied Annexin II expression using Western blot analysis in 8 human gastric carcinoma cell lines and expression of Annexin II and c-erbB-2 using, immunohistochemistry in 153 primary gastric carcinomas. Western blot revealed that Annexin II was expressed in 8 human gastric carcinoma cell lines. It was more strongly expressed in the cell membrane than in the cytoplasm of tumor cells in primary gastric carcinoma tissues. Thirty-three percent of all cases were immunopositive for Annexin II, overexpression of which was more frequent in differentiated type (p = 0.0009), lymph node, metastasis (p = 0.0147) and venous invasion (p = 0.0092). Annexin II and c-erbB-2 overexpression were significantly correlated p = 0.0002) and patients with Annexin II had poorer prognoses (p = 0.0066). Multivariate analysis showed that immunopositivity of both Annexin II and c-erbB-2 was an independent and poor prognostic factor (p = 0.0037). In conclusion, Annexin II was overexpressed in advanced gastric carcinomas and it could contribute to the progression of gastric carcinoma.

Indication of splenectomy for gastric carcinoma involving the proximal part of the stomach.

BACKGROUND/AIMS: The role of splenectomy in the surgical management of gastric carcinoma is controversial and there is no consensus of opinion regarding the therapeutic value of splenectomy. The aim of this study was to search for possible metastasis to lymph nodes in the splenic hilum or along the splenic artery to avoid unnecessary splenectomy and to determine its indication. METHODOLOGY: The clinical records of 204 patients who underwent total gastrectomy combined with splenectomy for gastric carcinomas involving the proximal part of the stomach were analyzed. RESULTS: The incidence of nodal involvement to the splenic hilum and/or along the splenic artery was 49 (24.0%) of 204 gastric carcinomas involving the proximal part of the stomach that underwent combined gastrectomy and splenectomy. The characteristics of gastric carcinoma with metastasis to these nodes included a larger tumor, deeper penetration (T3, 4 tumors), a number of lymph node metastasis, and infiltrative type. In T2 cases, all the tumors with cancerous involvement to these nodes showed intraoperative gross serosal change). When the tumor size was less than 40 mm, nodal metastatic rate to the splenic hilum and/or along the splenic artery was very low. CONCLUSIONS: In conclusion, splenectomy should be conducted in T2 cases with gross serosal change and T3, 4 cases. With regard to tumor size, in the cases with a tumor whose size was less than 40 mm, it is possible to preserve the spleen in most cases. In the near future, splenectomy should be clarified precisely by randomized trials in advanced gastric carcinoma.

Acridine orange induces binucleation in chondrocytes.

OBJECTIVE: Although it is well known that binuclear cells commonly appear among the chondrocytes of normal cartilages as well as among neoplastic chondrocytes of chondrosarcomas, the mechanism of binucleation is still unclear. Therefore, this study was undertaken to clarify the mechanism of binucleation in chondrocytes, using primary culture cells of growth plate cartilage. DESIGN: These chondrocytes were exposed to acridine orange (AO) which is a fluorescent dye for differentiating certain DNAs and RNAs in nuclei and cytoplasm, and which inhibits mitosis. After exposure to 0.5 microg/ml AO, for 0, 6, 24, 48, and 96 h, the following parameters were investigated: (1) cell growth rate (GR); (2) frequency of hyperdiploid cells (%HDC) by DNA cytofluorometry; (3) mitotic index (MI); (4) BrdU labeling index (LI); (5) frequency of binuclear cells (%BNC). RESULTS: Compared with the control cells, which were cultured in AO-free medium, the GR was remarkably inhibited at 24 h. MI was also decreased from 6 to 24 h, and LI decreased at 48 h. However, these parameters were recovered at 96 h. The %HDC was increased from 6 to 96 h, and the %BNC was also increased to a maximum of six times that of the control cells at 96 h. DISCUSSION: These results suggested that the binuclear cells observed among the cultured chondrocytes may be formed from G2 arrested cells by amitotic nuclear division, but not by mitosis without cytoplasmic division or cell fusion.

[Effectiveness of high-dose, intermittent 5'-DFUR therapy for advanced gastric cancer].

We report a case of advanced gastric cancer with multiple liver metastases and peritoneal dissemination. The patient was effectively treated with high-dose 5'-DFUR. A 52-year-old patient with advanced gastric cancer and multiple liver metastases, who showed a high serum level of CEA and CA19-9 underwent simple D1 gastrectomy. Thereafter, he received per os 1,200 mg/day of 5'-DFUR intermittently (5 days a week) and TAI every four months postoperatively. The serum levels of both CEA and CA19-9 fell dramatically to within the normal range and were maintained thereafter until the present. The size and number of the liver metastases dramatically decreased, judging from CT and angiography findings.

Failure of the expression of phospholipid hydroperoxide glutathione peroxidase in the spermatozoa of human infertile males.

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) was intensely expressed in mitochondria in the midpiece of human spermatozoa by immunostaining with anti-PHGPx monoclonal antibodies. The PHGPx not only reduced phospholipid hydroperoxide but also scavenged hydrogen peroxide in human spermatozoa. We found a dramatic decrease in the level of expression of PHGPx in the spermatozoa of some infertile males by immunoblotting with anti-PHGPx monoclonal antibodies. These individuals accounted for about 10% of the group of 73 infertile males that we examined. All seven patients with PHGPx-defective spermatozoa were classified as suffering from oligoasthenozoospermia, a defect in which both the number and the motility of spermatozoa are significantly below normal. Males with PHGPx-defective spermatozoa accounted for 26% of the 27 infertile males with oligoasthenozoospermia. No defects in expression of PHGPx in spermatozoa were observed in 31 fertile volunteers. After a 3-h incubation, the relative number of motile spermatozoa with low-level expression of PHGPx was significantly lower than that of spermatozoa with normal expression of PHGPx. The PHGPx-defective spermatozoa failed to incorporate rhodamine 123, revealing a loss of mitochondrial membrane potential. Ultrastructual analysis of mitochondria by electron microscopy demonstrated that the morphology of mitochondria in PHGPx-defective spermatozoa was abnormal. The results suggest that failure of the expression of mitochondrial PHGPx in spermatozoa might be one of the causes of oligoasthenozoospermia in infertile men.

Membrane lipid control of cytokinesis.

In the final stage of cell division, cytokinesis constricts and then seals the plasma membrane between the two daughter cells. The constriction is powered by a contractile ring of actin filaments, and scission involves rearrangement of the lipid bilayer of the cell membrane. We have shown that the lipid phosphatidylethanolamine (PE), which normally resides in the internal leaflet of the bilayer, is exposed on the external leaflet of the cleavage furrow as a result of enhanced transbilayer movement of the phospholipids during cytokinesis. To investigate the role of PE in cytokinesis, we employed two different approaches: manipulation of cell surface PE by a PE-binding peptide and establishment of a mutant cell line specifically defective in PE biosynthesis. Both approaches provide evidence that surface exposure of PE is essential for disassembly of the contractile ring at the final stage of cytokinesis. Based on these findings, we proposed that the transbilayer redistribution of PE plays a critical role in mediating coordinated movements between the contractile ring and the plasma membrane that are required for the proper progression of cytokinesis.

Binuclear cells induced by acridine orange in giant cell tumor of bone.

We have recently found the presence of many binuclear cells among isolated and smeared cells in giant cell tumor of the bone (GCT). These binuclear cells are possibly associated with the formation of multinuclear cells. Therefore, this study was undertaken to clarify the mechanism of binucleation in GCT, using primary culture cells exposed to acridine orange (AO) which is a fluorescent vital staining dye for the cytoplasm and nucleus and which inhibits mitosis. The cells were isolated from explants of fresh tumor materials obtained from two GCT patients (GCT1 and GCT2). These cells were cultured in Dulbecco's modified Eagle medium (DMEM) with 10% Fetal calf serum (FCS). After exposure to 0.5 microgram/ml AO, for 0, 6, 24, 48, 96 and 144 hours the following parameters were investigated: 1) cell growth rate (GR); 2) frequency of hyperdiploid cells (%HDC) by DNA cytofluorometry; 3) mitotic index (MI); 4) BrdU labeling index (LI); 5) frequency of binuclear cells (%BNC). Compared to the control cells which were cultured in AO-free medium, the GR of both GCT cells exposed to AO was remarkably inhibited. The MI was 0 from 24 to 144 hours. The %HDC was increased at 24 hours and was maintained high until 144 hours. The LI was temporarily increased at 6 hours, but was decreased at 48 hours. The %BNC was gradually increased. AO inhibited DNA synthesis and cell mitotic activity in cultured GCT cells and it finally caused inhibition of cell growth. However, the frequencies of G2 arrest cells and binuclear cells were increased. These results suggested that the binuclear cells in GCT may be formed from G2 arrest cells by amitotic nuclear division, but not by mitosis without cytoplasmic division, or by cell fusion.

Preparation of non-fouling surface through the coating with core-polymerized block copolymer micelles having aldehyde-ended PEG shell.

A new type of surface modification with reactive polymeric micelle was carried out for the creation of non-fouling surface. Amphiphilic poly(ethylene glycol)-b-poly(D,L lactide) (PEG/PLA) copolymers possessing acetal group at PEG-end and methacryloyl group at PLA-end were quantitatively synthesized via an anionic polymerization technique. A micelle of narrow distribution was prepared from the block copolymer. Acetal groups on the micelle surface were quantitatively converted into aldehyde group by an acid treatment. The methacryloyl group located in the core of the micelle was polymerized via radical polymerization to form core-polymerized micelle having reactive aldehyde groups on the surface. The core-polymerized reactive micelle was coated to a primary amino-containing polypropylene (PP) plate that was prepared by a plasma treatment. A reductive amination reaction was employed for a conjugation of the reactive core-polymerized micelle on the surface via a covalent linkage. The coating was evaluated by X-ray photoelectron spectroscopy, zeta-potential measurement, and the adsorption of bovine serum albumin, and compared with the PEG-coating under the same condition. The ratio of peak from &Cmacr;&z.sbnd;O bond to C&z.sbnd;&Cmacr;&z.sbnd;C bond indicated that the density of PEG on the surface was higher for the micelle coating than the linear PEG-coating. This is also confirmed by the zeta-potential measurement. By coating the amino-PP surface with micelle, the zeta-potential was remarkably decreased while the PEG-coating under the same condition decreased only appreciably, indicating that micelle coating efficiently masked the surface charge. Further, micelle-covered surface exhibited reduction of protein adsorption. The reduction of protein adsorption along with remarkably masked surface charge implies the high applicability of the micelle coatings to biomedical and bioanalytical applications.

Relationship between binuclear and multinuclear cells in giant cell tumor of bone.

Giant cell tumor of bone (GCT) consists of stromal and multinuclear type tumor cells. Although most people believe that the stromal cells are mononuclear, we recently found the existence of many binuclear cells among stromal cells using DNA cytofluorometric examination. This study, using 18 tumors of GCT was conducted to elucidate the cell biological significance of the binuclear cell, especially its relationship to multinuclear cell formation or tumor cell proliferation. The investigation was carried out by means of DNA-RNA cytofluorometry with acridine orange (AO) and histological method. Using fluorescence microscopic observation, we counted the numbers of both mononuclear and binuclear cells and calculated the index of % BNC, which expresses the frequency (percentage) of binuclear cells in a population of mononuclear and binuclear cells. The index of % S-G2 obtained by DNA-RNA cytofluorometry showed the frequency (percentage) of mononuclear cells in the S and G2 phases of the cell cycle. In the histological study, we counted the numbers of multinuclear giant cells with more than 3 nuclei in the cytoplasm and stromal cells including mononuclear and binuclear cells and calculated MNS/SC, which showed the percentage of multinuclear cells in the stromal cells in the microscopic field. Eight tumors showed a value of % BNC greater than 10% and 2 had a value of 40%. The index of % BNC significantly correlated with the average value of MNC/SC in all tumors. There was no significant correlation between % BNC and the average value of % S-G2, in 18 tumors although 4 tumors having a % BNC value greater than 20% showed a % S-G2 value greater than 12% in 18 tumors. These results revealed the presence of many binuclear cells among stromal cells of GCT and suggested that these binuclear cells might be formed in association with the active proliferation of mononuclear cells and closely relate to the formation of multinuclear giant cells.