Histologically, the tumor was comprised of spindle shaped cells and multinucleated giant cells partially forming storiform pattern. These cell lines were maintained in a culture medium (RPMI 1640) supplemented with 10% FBS, 0.6% Kanamycin Sulfate (GIBCO, Grand Island, NY), and 1% Antibiotic-Antimycotic (GIBCO, Grand Island, NY). The parental tumours of these two cell lines were fixed with formalin and embedded with paraffin. The paraffin embedded-specimens were cut into 4 μm thick sections and then were evaluated immunohistochemically. Tumor implantation in SCID mice NMFH-1 cells (5 × 106) derived from 100-time selleck chemicals llc passages and NMFH-2 cells (5 × 106) derived

from 30-time passages were injected subcutaneously into the backs of 7-week-old female athymic SCID mice Volasertib clinical trial (CB-17/Icr scid; Jcl CLEA Japan, Inc., Osaka, Japan). The transplanted tumors were successfully formed and these xenografted tumors were fixed with formalin and embedded with paraffin. Paraffin embedded-specimens were then cut into

4 μm thick sections and analyzed immunohistochemically. Ki-67 immunohistochemistry Ki-67, bromodeoxy-uridine (BrdU) and proliferating cell nuclear antigen (PCNA) were useful for proliferative markers. BrdU was diffucult to inject into the parental tumors. PCNA showed non-specific reactions in the cytoplasms of the cultured cells in our pilot study. We therefore examined Ki-67 immunohistochemistry for the proliferation of both mononuclear and multinucleated cells. Briefly, both types of cultured cells were incubated on Lab-Tek chamber slides (Nalge Nunc International, Rochester, NY, USA), fixed with 100% methanol for 10 min. The sections of parental tumors and xenografts were deparaffinized selleck in xylene, and then were rehydrated gradually, and heated at 100°C for

20 min with 10 mM citrate buffer (pH6.0) for antigen retrieval. Next, the specimens were treated with 0.3% hydrogen peroxide in methanol for 20 min to inhibit endogenous peroxidase, and incubated with phosphate-buffered saline containing 10% goat serum (Dako, Denmark) for 30 min to CHIR 99021 reduce nonspecific reactions. The specimens were then incubated with the monoclonal mouse antibody (MIB-1, Dako, Denmark) diluted 1:100 for 60 min, and reacted for 60 min with peroxidase-labeled anti-rabbit or anti-mouse antibody (Histofine Simple Stain MAX PO (MULTI); Nichirei Corporation, Tokyo, Japan) for 60 min. All these procedures were performed at room temperature. The peroxidase activity was detected with 3′-diaminobenzidine tetrahydrochloride (Nichirei, Tokyo, Japan). The specimens were counterstained with hematoxylin. The live cell observation Time-lapse video microscopy was used in this experiment. This system has an incubator with a built-in microscope to observe and record the real-time motion of the live cells in the incubator. Both cell types were separately incubated on the non-coated culture dishes, and placed in the incubation imaging system (LCV100, Olympus, Tokyo, Japan) [10, 11].