Diffuse Pulmonary Meningotheliomatosis with Sarcomatous Transformation in a Shiba Dog.

A 2-year-old neutered female Shiba dog exhibited laboured breathing for 1 month. Computed tomography of the thoracic cavity revealed multiple nodules (2-5 mm diameter) in the lungs. Grossly, the lungs were firm and normal in shape. The nodules were grey-white in colour. Microscopically, the nodules were non-encapsulated and exhibited an irregular shape. They were composed of polygonal or spindle cells with indistinct cell borders arranged in sheets. The cells had large, round, hyperchromatic nuclei and abundant pale eosinophilic cytoplasm with no atypia. Intrapulmonary arterial emboli and infiltration into the bronchioles were observed. Immunohistochemically, the cells were positive for vimentin and negative for cytokeratin, glial fibrillary acidic protein and α-smooth muscle actin. Ultrastructurally, the cells displayed cytoplasmic processes, desmosomes and intermediate filaments. These findings led to a diagnosis of diffuse pulmonary meningotheliomatosis with sarcomatous transformation. To the best of our knowledge, this is the first report of diffuse pulmonary meningotheliomatosis in a dog.

Chronic Basophilic Leukaemia in a Dog.

A 13-year-old neutered female mixed-breed dog with a clinical history of emaciation, inappetence and vomiting for 2 months was presented. Blood tests showed marked leucocytosis with increased neutrophil and basophil count, mild thrombocytosis and anaemia. Seven days after the initial visit, the dog died and was submitted for necropsy examination. Grossly, the bone marrow was red in colour and hepatomegaly and splenomegaly with discolouration were observed. A bone marrow smear showed an increased proportion of basophilic lineage cells. Histologically, the bone marrow showed high cellular density and numerous basophilic lineage cells with a round or segmented nucleus. The cytoplasm contained basophilic granules exhibiting metachromasia on toluidine blue staining. Immunohistochemically, the neoplastic basophils were diffusely positive for vimentin and myeloperoxidase, but negative for CD3, BLA36, CD163, CD204 and c-kit. The immunohistochemical features of neoplastic basophils that had invaded the liver and spleen were similar to those of the basophils in the bone marrow. Based on the clinicopathological and histopathological findings, chronic basophilic leukaemia was diagnosed. The present case study provides insights into the pathological features of chronic basophilic leukaemia in dogs.

Telomere length determined by the fluorescence in situ hybridisation distinguishes malignant and benign cells in cytological specimens.

BACKGROUND: Telomeres are tandem repeats of TTAGGG at the end of eukaryotic chromosomes that play a key role in preventing chromosomal instability. The aim of the present study is to determine telomere length using fluorescence in situ hybridisation (FISH) on cytological specimens. METHODS: Aspiration samples (n = 41) were smeared on glass slides and used for FISH. RESULTS: Telomere signal intensity was significantly lower in positive cases (cases with malignancy, n = 25) as compared to negative cases (cases without malignancy, n = 16), and the same was observed for centromere intensity. The difference in DAPI intensity was not statistically significant. The ratio of telomere to centromere intensity did not show a significant difference between positive and negative cases. There was no statistical difference in the signal intensities of aspiration samples from ascites or pleural effusion (n = 23) and endoscopic ultrasound-guided FNA samples from the pancreas (n = 18). CONCLUSIONS: The present study revealed that telomere length can be used as an indicator to distinguish malignant and benign cells in cytological specimens. This novel approach may help improve diagnosis for cancer patients.

Pancreatic Colloid Carcinoma in an Elderly Cat.

A 21-year-old neutered female domestic shorthaired cat was presented with a history of inappetence, vomiting and haematuria. The cat was humanely destroyed at the owner's request and a necropsy examination was performed. A 0.8 × 0.5 × 0.5 cm mass was located in the left lobe of the pancreas. The mass was gelatinous in nature and the external and cut surfaces were pale yellow in colour. Microscopically, the mass was non-capsulated and comprised an accumulation of extracellular stromal mucin containing suspended neoplastic columnar epithelial cells forming tubular structures. Immunohistochemically, these cells diffusely expressed cytokeratin (CK) AE1/AE3, CK7 and carcinoembryonic antigen and were partially positive for CK19 and trypsin, but negative for vimentin. The tumour was diagnosed as a colloid carcinoma. The clinical presentation in this case was caused by chronic renal failure complicated by secondary renal hyperparathyroidism and associated metastatic calcinosis. To the best of our knowledge, this is the first report of colloid carcinoma arising from the pancreas in a cat.

Cutaneous Angiolymphoid Hyperplasia in a Dog.

A 5-year-old male miniature dachshund was presented with a dermal nodule on the left forelimb that increased to 5 mm in diameter over a 2-month period. Grossly, the nodule was firm, and both the external and cut surfaces were homogeneously pale pink in colour. Microscopically, the nodule was comprised of mainly plump endothelial cells and inflammatory cells; among the latter, lymphocytes were predominant, with few scattered plasma cells, mast cells and macrophages. Lymphoid follicles with germinal centres were often observed. Mitotic figures were not observed amongst the endothelial cells. Immunohistochemically, the endothelial cells were positive for vimentin, factor VIII-related antigen and CD31, and the surrounding cells were positive for smooth muscle actin. Lymphocytes expressed CD3 or BLA36. These findings led to a diagnosis of cutaneous angiolymphoid hyperplasia. To the best of our knowledge, this is the first report of a cutaneous proliferative disorder comprising an admixture of proliferating vascular endothelial cells and lymphocytic infiltration with follicle formation in a dog.

Characterization of Spontaneous Mammary Tumors in Domestic Djungarian Hamsters (Phodopus sungorus).

Mammary tumors that spontaneously occurred in domestic Djungarian hamsters (Phodopus sungorus) were histologically examined. Forty-five mammary tumors included 14 adenomas, 18 adenocarcinomas, 1 lipid-rich carcinoma, 2 adenoacanthomas, 2 malignant adenomyoepitheliomas, 1 benign mixed tumor, and 7 "balloon cell" carcinosarcomas. The latter 4 types were newly recognized neoplasms in Djungarian hamsters. The relatively high incidence of spontaneous mammary carcinosarcomas in domestic Djungarian hamsters is intriguing. Carcinosarcomas exhibited anomalous histological features made up of a mixture of glandular cells, polygonal cells (including "balloon cells"), and sarcomatous spindle cells in varying proportions. Transitional features from glandular cells to polygonal cells and subsequently to sarcomatous spindle cells were observed. Using immunohistochemistry, we observed that glandular cells exhibited an epithelial phenotype (cytokeratin(+)/vimentin(-)), spindle cells exhibited a mesenchymal phenotype (cytokeratin(-)/vimentin(+)), and polygonal cells exhibited an intermediate phenotype (cytokeratin(+)/vimentin(+)). Reduction or loss of ß-catenin expression and gain of S100A4 expression were observed in polygonal and spindle cells. The polygonal cell population included a varying number of characteristic cells that were expanded by large intracytoplasmic vacuoles. Electron microscopy revealed that these "balloon cells" had large cytoplasmic lumens lined by microvilli. These observations suggest that epithelial-mesenchymal transition may account for the pathogenesis of mammary carcinosarcomas in Djungarian hamsters.

Cellular sources of tenascin-C in canine mammary carcinomas.

Tenascin-C (Tn-C) is an extracellular matrix glycoprotein implicated in the progression of several human cancers. In canine mammary carcinomas, accumulation of Tn-C has been recognized in 3 different areas: regions of proliferating myoepithelial cells in complex carcinoma, basement membrane zone in low-grade simple carcinoma, and reactive stroma in high-grade simple carcinoma. To identify the Tn-C synthesizing cells in these areas, we utilized double-labeling immunohistochemistry, branched DNA in situ hybridization, and in situ hybridization-immunohistochemistry double-labeling techniques. In complex carcinomas, Tn-C was generated by proliferating myoepithelial cells. Tn-C in low-grade simple carcinomas was also derived from myoepithelial cells existing as a basal monolayer. However, stromal Tn-C in high-grade carcinomas was mainly synthesized by fibroblasts/myofibroblasts, similar to human breast cancer. Thus, the origin of Tn-C in canine mammary carcinomas differs between low- and high-grade malignancies. The role of myoepithelial cell-generated Tn-C is not yet understood.

Novel method of screening the oxidation and reduction abilities of photocatalytic materials.

Two analytical methods for the evaluation of photocatalytic oxidation and reduction abilities were developed using a photocatalytic microreactor; one is product analysis and the other is reaction rate analysis. Two simple organic conversion reactions were selected for the oxidation and reduction. Since the reactions were one-to-one conversions from the reactant species to the product species, the product analysis was simply performed using gas chromatography, and the reactions were monitored in situ in the photocatalytic microreactor using the UV absorption spectra. The partial oxidation and reduction abilities for each functional group can be judged from the yield and selectivity, and the corresponding reaction rate, while the total oxidation ability can be judged from the conversion. We demonstrated the application of these methods for several kinds of visible light photocatalysts.

Epithelial splicing regulatory protein 1 is a favorable prognostic factor in pancreatic cancer that attenuates pancreatic metastases.

Epithelial splicing regulatory protein 1 (ESRP1) binds the FGFR-2 auxiliary cis-element ISE/ISS-3, located in the intron between exon IIIb and IIIc, and primarily promotes FGFR-2 IIIb expression. Here we assessed the role of ESRP1 in pancreatic ductal adenocarcinoma (PDAC). Immunohistochemical analysis was performed using anti-ESRP1, FGFR-2 IIIb and FGFR-2 IIIc antibodies in 123 PDAC cases. ESRP1 expression vector and small interference RNA (siRNA) targeting ESRP1 were transfected into human PDAC cells, and cell growth, migration and invasion were analyzed. In vivo heterotopic and orthotopic implantations using ESRP1 overexpression clones were performed and effects on pancreatic tumor volumes and hepatic and pulmonary metastases determined. ESRP1 immunoreactivity was strong in the nuclei of cancer cells in well-to-moderately differentiated PDACs but weak in poorly differentiated cancers. Well-to-moderately differentiated cancers also exhibited high FGFR-2 IIIb and low FGFR-2 IIIc expression, whereas this ratio was reversed in the poorly differentiated cancers. Increased ESRP1 expression was associated with longer survival in comparison with low ESRP1 expression, and PANC-1 cells engineered to express ESRP1 exhibited increased FGFR-2 IIIb expression and decreased migration and invasion in vitro, whereas ESRP1 siRNA-transfected KLM-1 cells exhibited increased FGFR-2 IIIc expression and increased cell growth, migration and invasion. In vivo, ESRP1-overexpressing clones formed significantly fewer liver metastases as compared with control clones. ESRP1 regulates the expression pattern of FGFR-2 isoforms, attenuates cell growth, migration, invasion and metastasis, and is a favorable prognostic factor in PDAC. Therefore, devising mechanisms to upregulate ESRP1 may exert a beneficial therapeutic effect in PDAC.

Acinar cell cystadenoma of the pancreas in a cat.

Cystic tumours of the pancreas are heterogeneous lesions with a spectrum of morphology and biological behaviour in people. These are poorly characterized in animals. A multicystic tumour of the pancreas was identified in an 11-year-old, female, mixed breed cat. The tumour was 5.5 cm in diameter and the largest cysts were 1.5 cm in diameter. Microscopically, the cysts were lined by single layered or pseudostratified, flat, cuboidal or columnar epithelial cells that occasionally formed papillary structures with a thin fibrous core. The tumour cells had eosinophilic granules in the apical cytoplasm, similar to zymogen granules, and the nuclei were uniform in size and shape. Mitotic figures were not observed. Immunohistochemically, the tumour cells expressed trypsin, but not cytokeratin 7. A diagnosis of acinar cell cystadenoma of the pancreas was made and this is the first report of this tumour in a cat.

Improvement in skin color achieved by smoking cessation.

It has been well known that habitual smoking accelerates premature skin ageing recognized as 'smoker's face'. However, the effect of smoking cessation on the appearance of skin has not been elucidated. The aim of this study was to evaluate objectively the effect of smoking cessation on the skin's appearance. The stratum corneum carbonyl protein level and skin colour of the cheek and the hand were measured. The change before and during the smoking cessation treatment (0, 2, 4, 8 and 12 weeks), and the success or failure in smoking cessation, was compared and examined. Eighty-four cases who had smoking cessation treatment were examined. The level of the stratum corneum carbonyl protein did not show any difference comparing before and after treatment for the smoking cessation success group and the failure group. The lightness of skin colour showed an upward tendency 4-12 weeks after starting the treatment in the success group and increased significantly compared with the failure group. The redness showed a significant decrease in comparison with before the treatment, and it also showed a significant decrease compared with the failure group. The yellowness did not show any clear tendency. Also, the haemoglobin showed a decreased tendency. Furthermore, multivariate statistical analysis showed a possibility that the lightness and haemoglobin could be changed by smoking cessation treatment. In conclusion, our study showed that an upward tendency of skin lightness was seen to correspond with a haemoglobin decrease accompanied by smoking cessation. If we can easily measure skin improvement as an effect of smoking cessation, it is thought to be a useful aid for smoking cessation support.

Carboplatin plus weekly paclitaxel treatment in non-small cell lung cancer patients with interstitial lung disease.

BACKGROUND: Since advanced non-small cell lung cancer (NSCLC) patients with the interstitial lung disease (ILD) have been excluded from clinical trials, it is uncertain whether chemotherapy really provides a benefit to these patients. PATIENTS AND METHODS: Fifteen advanced NSCLC patients with ILD that was detected on the chest X-rays were enrolled in this study. Carboplatin plus paclitaxel was administered by two methods (method A or method B). Method A: Carboplatin (AUC 6, day 1) and paclitaxel (70 mg/m(2), days 1, 8, 15) were administered every four weeks. Method B: Carboplatin (AUC 2, day 1, 8, 15) and paclitaxel (60 mg/m(2), days 1, 8, 15) were administered every four weeks. RESULTS: The response rate and the disease control rate were 33% and 53%. The median progression-free survival and the median overall survival time were 2.5 months and 7.0 months, respectively. The hematological toxicities were tolerable, but a grade 3 or higher pneumonitis was observed in 4 patients (27%). CONCLUSION: Carboplatin plus weekly paclitaxel must be administered carefully to advanced NSCLC patients with ILD that is detected on chest X-rays after a sufficient evaluation of the risks and the benefits.

Characteristics of paediatric patients with 2009 pandemic influenza A(H1N1) and severe, oxygen-requiring pneumonia in the Tokyo region, 1 September-31 October 2009.

Few reports describe the features of 2009 pandemic influenza A(H1N1) pneumonia in children. We retrospectively reviewed 21 consecutive children admitted to hospital from September to October 2009 in the Tokyo region. The diagnosis of 2009 pandemic influenza A(H1N1) virus infection was based on positive results of real-time RT-PCR or rapid influenza antigen test. All patients were hospitalised for pneumonia with respiratory failure and severe hypoxia. The median interval from onset of influenza symptoms to admission was 14 hours (range: 5-72 hours) and the median interval from the onset of fever (≥38 degrees C) to hospitalisation was 8.5 hours (range: 0-36 hours). All patients required oxygen inhalation. Four patients required mechanical ventilation. Chest radiography revealed patchy infiltration or atelectasis in all patients. Antiviral agents and antibiotics were administrated to all patients. Antiviral agents were administered to 20 patients within 48 hours of influenza symptom onset. No deaths occurred during the study period. Paediatric patients with this pneumonia showed rapid aggravation of dyspnoea and hypoxia after the onset of influenza symptoms.

Choice of attractive conditions by beef cattle in a Y-maze just after release from restraint.

To provide useful information on how to moderate posthandling stress, the attractiveness of different conditions to beef cattle just after release from restraint was determined. Angus heifers were individually allowed to enter a choice area after 2 min of restraint in a squeeze chute and to choose between 2 pens. After the heifer had chosen a pen, it could freely access both test pens and the choice area for a further 5 min. In Exp. 1, each heifer was given 1 of the following choices: a pen with 3 familiar heifers (PEERS) vs. a pen with a pile of hay on a metal rack (FOOD; n = 34); PEERS vs. the bare pen (BARE; n = 34); and FOOD vs. BARE (n = 35). When the choice combination was PEERS vs. BARE, more heifers chose PEERS (P < 0.05). When the choice combination was PEERS vs. FOOD, more heifers than expected tended to choose PEERS (P < 0.10), whereas FOOD and BARE did not differ. The latency to choose either pen was shorter if PEERS was 1 of the 2 choices (P < 0.01). After choosing, more heifers entered the PEERS pen than the FOOD (P < 0.05) or BARE (P < 0.01) pens. In Exp. 2, another 86 heifers were given 1 of the following choices: a pen with a familiar handler standing inside (STI) vs. a pen with a novel object (NO; n = 29); a pen with the handler standing outside the pen (STO) vs. NO (n = 29); a pen in which the handler was sitting inside (SI) vs. NO (n = 28). Fewer heifers chose the pen with the human (STI, STO, and SI; all P < 0.01). Except for the choice of STO vs. NO, the number of heifers that had voluntarily chosen either pen was larger than expected (STI and SI; both P < 0.01). The number of times in which the NO pen was entered was greater than the STI and STO (P < 0.01), although the number of times in which the SI and NO pens were entered was not different. More heifers avoided the human, particularly a standing human. In conclusion, just after handling with restraint, returning cattle to the group of peers and not approaching the cattle needlessly should moderate their stress.

Expression of nestin in rat and human glomerular podocytes.

Nestin is a neuroepithelial precursor cell marker expressed in a variety of human cell types during development. However, no information exists on the expression of nestin in mature glomeruli as well as during the glomerular development. Here, we examined nestin expression in rat and human glomerular tissues in quiescent states using RT-PCR and immunohistochemical methods. Nestin mRNA was detected in the rat glomeruli in parallel with its expression in developing rat brains. In the normal mature rat glomeruli, WT-1 positive cells expressed nestin. Co-expression of nestin and vimentin was observed in mature rat podocytes. Immunoelectron microscopy revealed nestin localization in the cell bodies and primary processes of podocytes. A similar expression pattern was observed for vimentin. In matured glomeruli, nestin was not expressed by mesangial and endothelial cells. In the newborn rat, early developing glomeruli (metanephric cap, metanephric vesicle, comma-shaped vesicle and S-shaped body phases) expressed nestin. In the capillary loop stage, Bowman's capsules also expressed nestin. Immunoelectron microscopy demonstrated that developing podocytes and endothelial cells in S-shaped phase glomeruli expressed nestin. Additionally, in immature glomeruli, the mesangial cells in capillary stage of glomerulus also expressed nexin. As in the rat, WT-1 positive cells in human glomeruli also expressed nestin and immunoelectron microscopy confirmed nestin expression in human glomerular podocytes. These results reveal that in normal condition nestin is expressed in several glomerular cell types at early stage of development and becomes confined to podocytes in mature glomeruli, thus implicating nestin in podocyte functions.

Effect of general anesthesia on the abnormal immune response in patients with rheumatoid arthritis.

OBJECTIVE: To evaluate the influence of mental stress on the neuroendocrine-immune system in patients with rheumatoid arthritis (RA). METHODS: Twenty-four patients with RA and 10 patients with osteoarthritis (OA) who underwent total knee or hip arthroplasty under general anesthesia were enrolled in this study. The blood levels of interleukin-6 (IL-6), IL-1 receptor antagonist (IL-1Ra), tumor necrosis factor-alpha (TNF-alpha), soluble TNF receptors (TNF-Rs) and other substances related to stress were measured just before administering anesthesia on the day of the operation when the patients lay on the operating table and roughly 30 min later when the patients were under general anesthesia without mental stress. These values were compared with those at the same time on the day before the operation, which were considered as controls. RESULTS: In patients with RA under general anesthesia, the levels of IL-6, TNF-alpha, and TNF-R1 and TNF-R2 in the peripheral blood were significantly decreased compared with the levels before anesthesia (p < 0.01). Before anesthesia the levels of IL-1Ra in the peripheral blood were significantly higher, and the level of IL-1Ra was enhanced after the administration of general anesthesia, when compared with the level on the day before the operation (p < 0.01). Such changes were not apparent in patients with OA. CONCLUSION: In patients with RA, excessive mental stress should be eliminated to modify the interaction between the stress-immune system and stress-endocrine system as a method to better control disease activity.

Effects of the extracellular matrix on lumican expression in rat aortic smooth muscle cells in vitro.

Lumican is a small leucine-rich proteoglycan (SLRP), which contributes to cell migration, proliferation, tissue hydration, and collagen fibrillogenesis. Whether lumican is localized in rat aortic smooth muscle cells (SMCs) and what its relationships might be to other extracellular matrix components have not yet been elucidated. In this study, using reverse transcription-polymerase chain reaction (RT-PCR), competitive RT-PCR, and western blot, lumican messenger ribonucleic acid (mRNA) was expressed in cultured rat aortic SMCs. SMCs cultured in serum-free medium showed four bands at 68, 62, 50, and 37 kD. The 68 and 62 kD bands corresponded to proteoglycan, the 50 kD band to glycoprotein, and the 37 kD band to the core protein form of lumican. The relationships of lumican to fibronectin and laminin were also investigated. The lumican mRNA level in SMCs cultured on fibronectin was highest at day 1, but it increased at day 3 in SMCs cultured on laminin. On the fibronectin or laminin-coated plates, SMCs expressed only the 68 and 62 kD bands, corresponding to proteoglycan. Pretreatment with anti-beta1 integrin receptor antibody revealed a decrease in the proteoglycan forms of lumican protein and an additional two bands at 50 and 37 kD, indicating glycoprotein and the core protein of lumican. These results show that lumican was synthesized in cultured rat aortic SMCs as proteoglycan, glycoprotein, and core protein. The extracellular matrix (ECM) affected lumican protein production and restricted the lumican protein form to proteoglycan via the beta1 integrin receptor in SMCs.

[An investigation for (clinico-) toxicological screening of detergents].

In recent years, we sporadically had some cases of accidental ingestion of drinks contaminated with detergent. In such cases it is necessary to identify the detergent for medical care or criminal investigation. Therefore, we made an attempt to establish a simple screening method of detergents, including household detergents, dishwashing detergents and shampoos using color reaction, thin-layer chromatography (TLC) and gel-permeation chromatography (GPC). In color reaction and TLC tests, it was possible to identify the individual sample. In the GPC test, several samples showed characteristic chromatograms, and even the same types of detergents did not give the same chromatogram patterns. From the above-mentioned results, it was suggested that this simple and rapid method may practically be useful to predict the contamination of detergent when controls are available, although not suitable for classification of detergent types.

Expression and localization of basic fibroblast growth factor and its mRNA in solitary fibrous tumor.

Solitary fibrous tumors (SFTs) represent a distinct neoplasm that should be included in the differential diagnosis of spindle-cell neoplasms of the soft tissue. Basic fibroblast growth factor (bFGF or FGF-2) is a mitogenic and angiogenic polypeptide produced by diverse cell types, including the cells derived from normal tissue and neoplastic lesions. In this study, the expression of bFGF, vimentin, CD 34, c-kit (or CD 117), desmin, S-100 protein, and alpha-smooth muscle actin (alpha-SMA) in SFTs, hemangiopericytomas (HPC), gastrointestinal stromal tumors (GIST), and dermatofibrosarcoma protuberans (DFSP) were evaluated to assess their usefulness in the differential diagnosis of these lesions. The expression of bFGF mRNA was also examined in SFTs by in situ hybridization (ISH) using a digoxigenin-labeled bFGF oligonucleotide probe. All the SFTs, GISTs and DFSPs exhibited strong and diffuse immunoreactivity for CD34 and vimentin, and were completely negative for desmin, S-100 protein and alpha-SMA. The HPCs were positive for vimentin, but negative for CD34. In all the SFTs, strong and diffuse nuclear immunostaining was observed with bFGF antibody, contrasting with the negative staining observed in the majority of the HPCs, GISTs, and DFSPs. The bFGF mRNA was also expressed in the SFT cells. The constitutive expression of the bFGF in the SFT widens the spectrum of available markers for these tumors, providing a useful addition to their differential diagnosis in difficult cases, and contributing to the understanding of their histogenesis and molecular pathogenesis.

Expression of fibroblast growth factor (FGF)-10 in human colorectal adenocarcinoma cells.

Fibroblast growth factor (FGF) -10 (keratinocyte growth factor 2, KGF 2) is a new member of the FGF family that is mainly synthesized by mesenchymal cells and acts predominantly on epithelial cells in a paracrine manner. Its actions are dependent on its binding to the iiib isoform of the cell-surface FGF receptor 2 (FGFR2 iiib). FGF-10 is known to play an important role in fetal limb and lung development, skin wound healing and prostatic epithelial cell growth. In the present study, the expression of FGF-10 and FGFR2 iiib in five cultured human colorectal adenocarcinoma cell lines (COLO 205, DLD-1, HCT-15, SW 480 and WiDr) and the localization of FGF-10 messenger RNA (mRNA) and its protein in human colorectal cancer tissues from 10 patients were determined. All five colorectal cancer cell lines expressed FGF-10 mRNA and its protein. FGFR2 iiib mRNAs were expressed in these cells and the recombinant FGF-10 (1 ng/ml) increased the growth rate of COLO 205 cells. To determine the localization of FGF-10 protein and its mRNA in normal and cancerous human colorectal tissues, immunohistochemistry and in situ hybridization were performed. In normal colorectal tissues, FGF-10 and its mRNA were not detected. In contrast, moderate immunoreactivity was present in cancer cells in 5 of 10 colorectal cancer cases and mild immunoreactivity was recognized in adjacent fibroblasts. By using in situ hybridization, FGF-10 mRNA was observed in colorectal cancer cells and fibroblasts adjacent to cancer cells. These findings indicate that FGF-10 and its receptor, FGFR2 iiib expression in colorectal adenocarcinoma cells and FGF-10 may contribute to the growth of cells of this type.