SummaryXenograft transplantation of human tumor cells into immunodeficient mice is an important method to clarify the roles of specific molecules or chemicals in vivo. Recently, this method has been reported as a definitive examination to identify tumor stem cells. In this study, the authors compared the morphology and the quality and quantity of ribonucleic acid (RNA) and protein in paraffin-embedded tissues of nude mice implanted with human uterine cervical cancer cells, followed by fixation with commonly used fixatives, including 4% paraformaldehyde (PFA), 10% neutral buffered formalin (NBF), 20% NBF, and 99% ethanol (EtOH). The quality of the isolated RNA from PFA-and NBF-fixed paraffin-embedded tissues was high, while EtOH-fixed tissues showed degradation of RNA. NBF-fixed tissues showed excellent quality of morphology, but EtOH-fixed tissues showed contraction of cells. Immunohistochemical results showed differences depending on fixations. The 99% EtOH-fixed samples showed decreases of Ki-67 and VEGF-A immunoreactivities, but improved cytokeratin immunoreactivity. This study indicated that formalin fixation is better than alcohol fixation for RNA preservation in paraffinembedded cancer cell implantation models. Immunohistochemical results differed markedly depending on fixation materials and antibodies; therefore, suitable fixations are needed to quantify and compare the results of immunohistochemical staining on cancer cell implanted nude mice tissues. (J Histochem Cytochem 59:68-75, 2011)

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Colorectal cancer (CRC) is one of the most common cancers worldwide, and many patients are already at an advanced stage when they are diagnosed. Therefore, novel biomarkers for early detection of colorectal cancer are required. In this study, we performed a global shotgun proteomic analysis using formalin-fixed and paraffin-embedded (FFPE) CRC tissue. We identified 84 candidate proteins whose expression levels were differentially expressed in cancer and non-cancer regions. A label-free semiquantitative method based on spectral counting and gene ontology (GO) analysis led to a total of 21 candidate proteins that could potentially be detected in blood. Validation studies revealed cyclophilin A, annexin A2, and aldolase A mRNA and protein expression levels were significantly higher in cancer regions than in non-cancer regions. Moreover, an in vitro study showed that secretion of aldolase A into the culture medium was clearly suppressed in CRC cells compared to normal colon epithelium. These findings suggest that decreased aldolase A in blood may be a novel biomarker for the early detection of CRC.

Abstract. Nestin, a class VI intermediate filament protein, was originally described as a neuronal stem cell marker during central nervous system development. Nestin is expressed in gliomas, and its expression levels are higher in gliomas with high WHO histopathological classification grades than in those with low grades. In the present study, we examined whether nestin regulates the biological activities of human glioma cells. Immunohistochemically, the nestin expression patterns in 10 human glioblastoma patients were examined. The expression levels of nestin in A172, a human high-grade glioma cell line, and KG-1-C, a human low-grade glioma cell line, were examined using real-time PCR, Western blot and immunofluorescence analyses. An expression vector carrying a short hairpin RNA targeting nestin was stably transfected into A172 (Sh) cells. The effects of decreased expression levels of nestin in Sh cells on cell growth, migration, invasion, adhesion to extracellular matrices and fibrillar actin expression on three-dimensional culture plates were examined. The nestin expression vector was transiently transfected into KG-1-C (Nes) cells, and the effects of the nestin overexpression on cell growth and migration were examined. Nestin was expressed in the cytoplasm of the glioblastoma cells in all cases examined. Sh cells showed marked decreases in the expression levels of nestin mRNA and protein, and the growth rate of Sh cells was lower than that of sham (Sc) cells. In contrast, the adhesion activity of Sh cells to types I and IV collagens, fibronectin and laminin was higher than that of Sc cells. Fibrillar actin was clearly detected at the periphery of colonies of Sh cells at the attachment sites on three-dimensional culture plates. The migration and invasion of Sh cells were markedly inhibited compared with those of Sc cells. In contrast, the levels of nestin expression markedly increased in the Nes cells, which were transiently transfected with the nestin expression vector. The growth rate and motility of Nes cells were higher than those of the mock cells. In conclusion, nestin plays important roles in cell growth, migration, invasion and adhesion to extra-cellular matrices in glioma cells. Nestin may serve as a novel candidate for molecular-targeted therapy for gliomas, including glioblastomas.

Fibroblast growth factor receptors (FGFR) FGFR1 through FGFR3 possess IIIb and IIIc isoforms as the result of alternative splicing of the immunoglobulin-like domain. The IIIb isoforms are mainly expressed in normal epithelial cells, and IIIc isoforms are expressed in mesenchymal cells. Single nucleotide polymorphisms (SNPs) of the FGFR2 gene are associated with endometrial cancer, and missense mutations or copy number gains of the FGFR2 gene occur in breast cancer. In uterine cervical cancer, FGFR2 IIIb, also known as keratinocyte growth factor receptor (KGFR), was reported to be highly expressed in squamous cell carcinoma (SCC), which accounts for 90% of all cervical cancer patients. However, there has been no report on the expression and roles of FGFR2 IIIc in cervical cancer. In the present study, we determined the expression and roles of FGFR2 IIIc in CIN and cervical SCC. In noncancerous cervical tissues, FGFR2 IIIc immunoreactivity was either not present or very faintly localized in squamous epithelial cells. In CINs 1 and 2, FGFR2 IIIc was localized at the basal to lower two-thirds of squamous epithelium, whereas FGFR2 IIIc was strongly expressed in most of the squamous epithelium, except for the superficial layer in CIN 3. FGFR2 IIIc protein was detected in keratinizing and non-keratinizing types of SCC in all cervical cancer patients examined (8 and 21 cases, respectively). In situ hybridization (ISH) analysis using an FGFR2 IIIc-specific antisense RNA probe showed that the expression patterns of FGFR2 IIIc mRNA are similar to those of FGFR2 IIIc protein in noncancerous and CIN tissues. In addition, FGFR2 IIIc mRNA was strongly expressed in the invasive fronts of cancer cell nests in cancer tissues. Moreover, full-length FGFR2 IIIc cDNA, subcloned to pIRES2-EGFP vector, was stably transfected into CaSki cells, which are derived from a well-differentiated type of SCC. The growth rates of the FGFR2 IIIc-transfected CaSki cells were higher than those of mock cells in vitro. Cell migration assays did not show any differences between FGFR2 IIIc-transfected CaSki cells and mock cells. To assess the effect of FGFR2 IIIc expression on tumorigenicity, the CaSki cells were injected into nude mice. The FGFR2 IIIc-transfected CaSki cells tended to form larger subcutaneous tumors than mock cells in nude mice. These findings suggest that FGFR2 IIIc plays important roles in the carcinogenesis and proliferation of cervical cancer cells. FGFR2 IIIc is considered to be a novel therapeutic target for inhibiting the growth of CIN and cervical cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 286.