Expression of hepatocyte growth factor activator and hepatocyte growth factor activator inhibitor type 1 in human hepatocellular carcinoma.

Hepatocyte growth factor activator inhibitor type 1 (HAI-1), a Kunitz-type serine protease inhibitor for hepatocyte growth factor activator (HGFA), is responsible for proteolytic activation of hepatocyte growth factor. We examined the expression of HGFA and HAI-1 in liver tissues of chronic liver diseases including hepatocellular carcinoma (HCC). HGFA expression was detected not only in the liver tissues of chronic hepatitis and cirrhosis and in the nontumorous liver tissues surrounding HCC, but also in HCC tissues. On the other hand, none of the liver tissues of hepatitis and cirrhosis and none of the nontumorous tissues surrounding HCC were stained with anti-HAI-1. However, 35% of HCC tissues were stained with anti-HAI-1, and HAI-1 positivity increased as the histological grade decreased and as serum alpha-fetoprotein increased. Transduction of antisense HAI-1 inhibited the growth of human hepatoma cells. These results suggest the possibility that HAI-1 plays an important role in the progression of HCC.

Identification of hepatocyte growth factor activator inhibitor type 2 (HAI-2)-related small peptide (H2RSP): its nuclear localization and generation of chimeric mRNA transcribed from both HAI-2 and H2RSP genes.

A novel small gene, designated hepatocyte growth factor activator inhibitor type 2 (HAI-2)-related small peptide (H2RSP) was cloned and characterized in the process of the search for splicing variant forms of HAI-2 by 3'-rapid amplification of cDNA ends (RACE). The gene consisted of 4 exons spanning approximately 1 kb and was located in 11 kb downstream of HAI-2 gene (19q.13.11). The novel transcript identified by 3'-RACE was thought to be chimerically transcribed from both HAI-2 (exons 1-7) and H2RSP (exons 2-4) genes. Wild-type H2RSP mRNA (0.5 kb) was detected abundantly in various tissues including the gastrointestinal tract, whereas chimeric mRNA (1.5 kb) was found mainly in the kidney, prostate, and placenta by Northern blot analysis. The predicted amino acid sequence of H2RSP contained two unique domains, namely the serine-rich region (exon 3) and the lysine-rich region (exon 4). Transfection of deleted series of H2RSP cDNAs fused to enhanced green fluorescent protein (EGFP) into HeLa cells revealed that H2RSP has nuclear localization signal in the lysine-rich region. Immunohistochemical study using anti-H2RSP polyclonal antibody indeed revealed the nuclear localization of this peptide in vivo. These results suggest that H2RSP and H2RSP/HAI-2 chimeric peptides might function as a transcriptional regulatory peptide at the nucleus.

Solitary fibroleiomyomatous hamartoma of the lung in a patient without a pre-existing smooth-muscle tumor.

A solitary well-demarcated tumor was found in the left lung of a 53-year-old man. It was located in the posterior region of the lower lobe just adjacent to, but apart from, the pleura. It was resected by video-associated thoracic surgery. Macroscopically, the tumor was a whitish solid nodule without hemorrhage or necrosis, and it was 1.5 cm in diameter. Histologically, the tumor consisted of a proliferation of fibromuscular tissue in interlacing fascicles in which many tubular or cleft-like epithelial inclusions were involved. The epithelial inclusions showed cystic changes with goblet cell metaplasia in part, but no atypical changes. Other mesenchymal components such as cartilaginous, myxomatous or adipose tissues were not seen. The patient had no history of neoplasm, including smooth-muscle tumor. Thus, we diagnosed this tumor as a "true" fibroleiomyomatous hamartoma, as distinct from so-called fibroleiomyomatous hamartoma or benign metastasizing leiomyoma, which are usually found in the lungs of women who have had hysterectomies, as multiple fibromuscular nodules. We report here this rare case and we review and discuss published reports of fibromuscular tumors of the lung.

Reduced expression of hepatocyte growth factor activator inhibitor type-2/placental bikunin (HAI-2/PB) in human glioblastomas: implication for anti-invasive role of HAI-2/PB in glioblastoma cells.

Hepatocyte growth factor activator inhibitor type-2/placental bikunin (HAI-2/PB) is a serine proteinase inhibitor that contains 2 Kunitz-domains and a presumed transmembrane domain. It has broad inhibitory spectra against various serine proteinases showing potent inhibitory activities not only to hepatocyte growth factor activator but also to plasmin, trypsin and kallikreins. In this study, we investigated the expression of HAI-2/PB in human gliomas in vivo and the effects of HAI-2/PB on the fibrinolytic and invasive capabilities of human glioblastoma cells in vitro. With RNA blot analysis, HAI-2/PB mRNA was expressed in normal brain and in low-grade astrocytomas, but was hardly detectable in anaplastic astrocytomas and glioblastomas, indicating that its expression levels were inversely correlated with the histological grade of human gliomas. To further explore the possible role of HAI-2/PB in glioma progression, cultured human glioblastoma cell lines (U251 and YKG-1) were transiently transfected with an expression vector harboring human HAI-2/PB cDNA. Subsequent analysis indicated that the expression of HAI-2/PB suppressed the fibrinolytic activities of both glioblastoma cell lines. Moreover, HAI-2/PB inhibited Matrigel invasion of U251 and YKG-1 cells by 30% and 64%, respectively. This anti-invasive effect appeared to be mediated primarily by the inhibitory activity of HAI-2/PB against the serine proteinase-dependent matrix degradation. These findings suggest that the reduced expression of HAI-2/PB is possibly involved in the progression of human gliomas.

Pericellular activation of hepatocyte growth factor/scatter factor (HGF/SF) in colorectal carcinomas: roles of HGF activator (HGFA) and HGFA inhibitor type 1 (HAI-1).

Activation of hepatocyte growth factor/scatter factor (HGF/SF) is a critical limiting step in the HGF/SF-induced signaling pathway mediated by MET receptor tyrosine kinase. Although HGF/SF-MET signaling could have potentially important roles in the invasive growth of tumors and tumor angiogenesis, little is known about the regulation of HGF/SF activation in the tumor tissues. This activation occurs in the extracellular milieu caused by proteolytic cleavage at the bond between Arg194-Val195 in the single-chain HGF precursor to generate the active two-chain heterodimeric form. Here we show that activation of HGF/SF is significantly enhanced in colorectal carcinoma tissues compared with normal colorectal mucosa, and HGF activator (HGFA), a recently identified factor XII-like serine proteinase, is critically involved in this process. Furthermore, we also show that HGF activator inhibitor type 1 (HAI-1) should have an important regulatory role in the pericellular activation of HGF/SF having diverse roles acting as a cell surface specific inhibitor of active HGFA and a reservoir of this enzyme on the cell surface. The latter property might paradoxically ensure the concentrated pericellular HGFA activity in certain cellular conditions in which shedding of HAI-1/HGFA complex from the plasma membrane is upregulated.

Primary cutaneous Langerhans cell histiocytosis showing malignant phenotype in an elderly woman: report of a fatal case.

BACKGROUND: Langerhans cell histiocytosis (LCH) is a proliferating disorder of Langerhans cells (LC) that are characterized by the presence of Birbeck granules. LCH has been considered to be a disease of childhood and there have been limited cases of adult LCH. We report here a fatal case of histiocytic tumor showing Langerhans cell phenotype, arising in the skin of a 74-year-old woman. METHOD: In addition to routine histological and immunohistological sections, electron microscopic examination and human androgen receptor gene (HUMARA) assays were performed. RESULTS: Histological examination revealed a dense dermal infiltrative proliferation of fairly large tumor cells with abundant ill-defined cytoplasms and oval or indented nuclei, in which numerous eosinophils were associated with the tumor nests. Tumor cells were positive with anti-S-100 and CD1a antibodies but negative with HMB-45 antibody or other epithelial or lymphocytic markers. Ultrastructural analysis showed typical Birbeck granules in the cytoplasm of the tumor cells. HUMARA assay of the tumor tissue revealed the nonrandom X inactivation pattern, indicating the clonal proliferation. CONCLUSIONS: We diagnosed this tumor as Langerhans cell histiocytosis with a clonal neoplastic phenotype originated in the skin. Although she demonstrated no recurrence nor metastases for 6 months after surgical resection of primary skin lesion and subsequent radiation therapy, the tumor recurred and extended multisystemically, and she died of multiple organ failure 14 months after initial diagnosis. Therefore, we would like to emphasize this case as LC "sarcoma" or "malignant" LCH.

Mouse hepatocyte growth factor activator inhibitor type 1 (HAI-1) and type 2 (HAI-2)/placental bikunin genes and their promoters.

Hepatocyte growth factor (HGF) activator inhibitor type 1 (HAI-1) and type 2 (HAI-2) were recently discovered as specific inhibitors of HGF activator. Each of them contains two Kunitz-type serine protease inhibitor domains and a transmembrane domain, so that their overall structures are similar to each other. In this study, mouse genes encoding HAI-1 and HAI-2 were cloned by screening of a mouse genomic bacterial artificial chromosome library and by polymerase chain reaction of mouse genomic DNA, respectively. The genes (mHAI-1 and mHAI-2) were defined to consist of 11 and eight exons spanning 11 kbp and 9.5 kbp, respectively. Neither a TATA nor CAAT box was found in 5'-flanking regions of both genes and no apparent homologous portion was observed between mHAI-1 and mHAI-2 promoter regions. Promoter assay of mHAI-1 and human HAI-1 revealed that the potential binding sites of a complex of Egr-1-3 and Sp1, which was well-conserved between human (-42 to -58) and mouse (-44 to -57), might be a key portion of its transcriptional regulation to function as not only house-keeping but also early responsive genes.

Tubal ectopic pregnancy associated with an adenomatoid tumor.

We present a case of coexistence of an ectopic pregnancy and an adenomatoid tumor in the same fallopian tube. The adenomatoid tumor is the most common benign neoplasm of the fallopian tube, and the vast majority of ectopic pregnancies occur in the fallopian tube. However, coexistence of these two conditions is extremely rare, and there has been only one previously reported case in the English literature. In the present case, the placental tissue, consisting of chorionic villi and decidua, was present in the ampulla, and the adenomatoid tumor was found in the myosalpinx, just proximal to the implantation site, replacing a large part of the myosalpinx. The close spatial relationship of these two lesions suggests that an adenomatoid tumor could have interfered with transportation of the fertilized ovum through the tube, possibly via impaired contractile activity of the myosalpinx, and consequently caused the ectopic tubal pregnancy.

Amyloid beta protein precursor is involved in the growth of human colon carcinoma cell in vitro and in vivo.

Amyloid beta protein precursor (APP) is a membrane-bound protein ubiquitously expressed in a variety of types of cells. However, its biological functions remain largely uncertain, particularly in non-neural cells and tumors. Our previous studies revealed that a secreted form of APP having a Kunitz-type inhibitor domain is a major serine proteinase inhibitor secreted by human colon carcinoma cells. In our study, we used an antisense RNA strategy to selectively inhibit the expression of APP in the human colon carcinoma cell line SW837. A vector capable of expressing an antisense mRNA complementary to 911 bases of the 5' end of APP mRNA was transfected into SW837 cells. After selection, 2 stably transfected antisense clones were obtained in which both the APP protein and mRNA were significantly suppressed. The proliferative potential and colony-forming efficiency of the antisense clones in vitro were markedly suppressed compared with the parent and mock-transfected clones. The addition of the conditioned medium of parent cells or purified secretory APP enabled these antisense effects to be overcome in vitro. The suppressed growth was also observed in vivo when the cells were injected subcutaneously into nude mice. Histologically, formation of tubular structures appeared to be suppressed in the antisense clones in vivo. These observations suggest potentially important roles of APP in cellular proliferation and differentiation of colon carcinoma cells.

Regulation of fibronectin expression and splicing in migrating epithelial cells: migrating MDCK cells produce a lesser amount of, but more active, fibronectin.

Previously we have demonstrated that in MDCK epithelial cells not only transforming growth factor-beta (TGF-beta) but also hepatocyte growth factor/scatter factor (HGF/SF) regulates fibronectin (FN) splicing by increasing the ratio of EDA-containing FN (EDA+ FN) mRNA to EDA-minus FN (EDA- FN) mRNA (EDA+/EDA- ratio). EDA+ FN is known to be upregulated in tissues where cells actively migrate, such as those during morphogenesis, wound healing, and tumorigenesis. However, a direct association between cell migration and FN splicing at the EDA region has never been investigated. In this work, we have shown by using an in vitro wound migration assay that migrating epithelial cells regulate FN production and splicing differently compared to nonmigrating cells. Wounds were introduced as migration stimuli into the 10-day-old confluent cell sheet, where the EDA+/EDA- ratio and FN mRNA expression levels were stable. In migrating cells at the wound edge, the FN mRNA level decreased by 0.73-fold and the EDA+/EDA- ratio increased by 1.32-fold when compared with nonmigrating cells apart from the wound edge. HGF/SF significantly stimulated cell migration at the wound edge and concomitantly decreased the FN mRNA level by 0.60-fold and increased the EDA+/EDA- ratio by 1.84-fold in migrating cells. In nonmigrating cells apart from the wound edge, FN mRNA expression and splicing were not influenced by either wound stimulation or HGF/SF. EDA+ FN stimulates cell migration more effectively than EDA- FN and thus is considered to be a more active variant of FN. Taken together, migrating MDCK cells appear to regulate FN mRNA expression and splicing to produce a lesser amount of, but more active, FN.

Pena-shokeir type I syndrome with thymic and systemic lymphoid hyperplasia: report of an autopsy case.

We report a case of Pena-Shokeir type I syndrome in a female neonate who died of respiratory failure shortly after the birth at 32 weeks of gestation. In general appearance, she had apparent ocural hypertelorism, a depressed tip of the nose, low-set malformed ears, and microglossia in the head. There were severe contractures at the ankle, hand, fingers, and toes, and moderate contractures at the hip, shoulder, knee, and elbow. An autopsy analysis showed severe pulmonary hypoplasia and group atrophy of the skeletal muscle tissues. In addition to these findings which are well known characteristics of the infant with this syndrome, the thymus was markedly hyperplastic and lymph nodes were systemically swollen, especially the mesenteric ones which were visible and measured 2-5 mm in diameter. Histologically, the lymph nodes showed massive paracortical hyperplasia without apparent follicular structures, although no atypical lymphocytes were observed in both the thymus and lymph nodes. Immunohistochemically, proliferating lymphocytes seemed to be immature CD4+/CD8+ T cells, suggesting the insufficiency of T-cell negative selection in the thymus. This report is the first case of Pena-Shokeir type I syndrome with T-lymphocytic disorder.

Activation of hepatocyte growth factor/scatter factor in colorectal carcinoma.

Activation of hepatocyte growth factor/scatter factor (HGF/SF) in the extracellular milieu is a critical limiting step in the HGF/SF-induced signaling pathway mediated by Met receptor tyrosine kinase, which has potentially important roles in tumor biology and progression. However, little is known concerning the regulation of HGF/SF activation in tumors. Immunoblot analysis revealed that the activation of HGF/SF was enhanced significantly in colorectal carcinoma tissues compared with the corresponding normal mucosa. Serum-free conditioned media of cultured human colorectal carcinoma cell lines contained HGF/SF-activating activity, and the addition of a single-chain precursor form of HGF/SF to the serum-free culture of these cells resulted in HGF/SF-dependent modulation of cellular phenotypes, such as increased scattering and enhanced secretion of vascular endothelial growth factor. This processing activity was enhanced by thrombin treatment but was inhibited significantly by a neutralizing antibody against HGF activator (HGFA), a factor XIIa-like serine proteinase believed to be expressed mainly in the liver. The activity was also inhibited by recombinant HGFA inhibitor type 1 (HAI-1). The presence of HGFA mRNA and secretion of HGFA protein were confirmed in the cell lines. Therefore, extrahepatic expression of HGFA in the colorectal carcinoma cells could be responsible for the single-chain HGF/SF-processing activity of the cells. We examined the expression of HGFA and HAI-1 in human colorectal mucosa and adenoma-carcinoma sequence. Immunohistochemically, HGFA was stained weakly in the normal enterocytes, and immunoreactivity was increased modestly in the neoplastic differentiation. The subcellular localization of HGFA immunoreactivity was altered in carcinoma cells showing basal or cell-stroma interface staining patterns, compared with normal and adenoma cells with a supranuclear or apical staining pattern. In contrast to HGFA, the expression of HAI-1 decreased significantly in carcinoma cells relative to the adjacent normal or adenoma cells, indicating that the net balance between HGFA and HAI-1 shifts in favor of HGFA in carcinomas. In fact, pro-HGFA and the active form of HGFA proteins increased in carcinoma tissue compared with the corresponding normal mucosa. It was concluded that HGFA is expressed in colorectal mucosa and tumors and could be involved in the activation of HGF/SF in colorectal carcinomas. Therefore, the balance between HGFA and HAI-1 could play an important role in the regulation of HGF/SF activity in colorectal carcinomas.

Hepatocyte growth factor activator inhibitor type 1 is a specific cell surface binding protein of hepatocyte growth factor activator (HGFA) and regulates HGFA activity in the pericellular microenvironment.

Hepatocyte growth factor activator (HGFA) is responsible for proteolytic activation of the precursor form of hepatocyte growth factor in injured tissues. To date, two specific inhibitors of HGFA have been identified, namely HGFA inhibitor type 1 (HAI-1) and type 2 (HAI-2)/placental bikunin (PB). Both inhibitors are first synthesized as integral membrane proteins having two Kunitz domains and a transmembrane domain, and are subsequently released from cell surface by shedding. Here we show that an active form of HGFA is specifically complexed with membrane-form HAI-1, but not with HAI-2/PB, on the surface of epithelial cells expressing both inhibitors. This binding required the enzyme activity of HGFA. The selective binding of HGFA to the cell surface HAI-1 was further confirmed in an engineered system using Chinese hamster ovary cells, in which only the cells expressing HAI-1 retained exogenous HGFA. The binding of HGFA to HAI-1 was reversible, and no irreversible modifications affecting the enzyme activity occurred during the binding. Importantly, HAI-1 and the HGFA.HAI-1 complex were quickly released from the cell surface by treatment with phorbol 12-myristate 13-acetate or interleukin 1beta accompanying the generation of 58-kDa fragments of HAI-1, which are less potent against HGFA, as well as significant recovery of HGFA activity in the culture supernatant. This regulated shedding was completely inhibited by BB3103, a synthetic zinc-metalloproteinase inhibitor. We conclude that HAI-1 is not only an inhibitor but also a specific acceptor of active HGFA, acting as a reservoir of this enzyme on the cell surface. The latter property appears to ensure the concentrated pericellular HGFA activity in certain cellular conditions, such as tissue injury and inflammation, via the up-regulated shedding of HGFA.HAI-1 complex. These findings shed light on a novel function of the integral membrane Kunitz-type inhibitor in the regulation of pericellular proteinase activity.

Expression of emmprin (CD147), a cell surface inducer of matrix metalloproteinases, in normal human brain and gliomas.

EMMPRIN (extracellular matrix metalloproteinase inducer), also called CD147, basigin or M6 in the human, is a member of the immunoglobulin superfamily that is present on the surface of tumor cells and stimulates adjacent fibroblasts to produce matrix metalloproteinases (MMPs). In our study, we investigated expression of EMMPRIN in human normal brain and gliomas, since mouse basigin and chicken HT7, the species homologues of human EMMPRIN, are associated with neuronal interactions and normal blood-brain barrier function, respectively. EMMPRIN expression was detected in all samples of non-neoplastic brain and glioma tissues examined. However, expression levels of EMMPRIN mRNA and protein were significantly higher in gliomas than in non-neoplastic brain. Moreover, levels of mRNA expression and immunohistochemical staining correlated with tumor progression in gliomas: They were highest in the most malignant form of glioma, glioblastoma multiforme, followed by anaplastic astrocytoma and then low-grade astrocytoma. Also, immunolocalization revealed quite different distributions in non-neoplastic brain and glioma: EMMPRIN was demonstrated only in vascular endothelium in non-neoplastic regions of the brain, whereas it was present in tumor cells but not in proliferating blood vessels in malignant gliomas. These data indicate that an MMP inducer molecule EMMPRIN is differently expressed in human normal brain and gliomas and could be associated with astrocytoma progression. Possible mechanisms whereby glioma cell EMMPRIN could influence tumor progression will be discussed.

Primary vaginal adenocarcinoma arising from the metanephric duct remnant.

Primary vaginal adenocarcinoma unrelated to in utero exposure to diethylstilbestrol (DES) is very uncommon. We report a case of 65-year-old Japanese woman who presented with primary adenocarcinoma in the anterior wall of the vagina, where the left ureter-like metanephric duct remnant abnormally terminated. Histological examination in serial sections revealed the direct connection between the carcinoma and the metanephric duct remnant. Moreover, the remnant epithelium showed varying degrees of dysplastic changes, including carcinoma in situ in close proximity to the carcinoma. This patient also had a bicornate uterus and left renal aplasia. To our knowledge, this is the first reported case of a primary vaginal adenocarcinoma arising from the metanephric duct remnant. Although the precise mechanism involved in carcinogenesis in this clinicopathological setting remains unknown, adenocarcinoma should be included in the differential diagnosis of vaginal tumors in patients with renal aplasia and/or an ectopic termination of the ureter or metanephric duct remnant, especially when the tumor is in the anterior wall.

Glioma cell extracellular matrix metalloproteinase inducer (EMMPRIN) (CD147) stimulates production of membrane-type matrix metalloproteinases and activated gelatinase A in co-cultures with brain-derived fibroblasts.

Extracellular matrix metalloproteinase inducer (EMMPRIN) also called CD147, basigin or M6 in the human is a member of the immunoglobulin superfamily that is enriched on the surface of tumor cells and stimulates adjacent stromal cells to produce several matrix metalloproteinases (MMPs). In this study, we have demonstrated that coculturing of EMMPRIN-expressing human glioblastoma multiforme cells (U251) with brain-derived human fibroblasts not only stimulates production, but also activation of pro-gelatinase A (proMMP-2), an enzyme that is enriched in malignant gliomas and most likely crucial to tumor progression. Production of membrane types 1 and 2-MMPs (MT1-MMP and MT2-MMP), which are activators of proMMP-2, was also stimulated in these cocultures. Stimulation of MMP-2, MT1-MMP and MT2-MMP production was inhibited by anti-EMMPRIN monoclonal antibody in a dose-dependent manner. Thus, we have shown, for the first time, that EMMPRIN causes increased expression of MT1-MMP and MT2-MMP, as well as increased production and activation of MMP-2.

Front-cell-specific expression of membrane-type 1 matrix metalloproteinase and gelatinase A during cohort migration of colon carcinoma cells induced by hepatocyte growth factor/scatter factor.

Migration of tumor cells is usually assessed as single cell locomotion in vitro using Boyden chamber type assays. In vivo, however, carcinoma cells frequently invade the surrounding tissue as coherent clusters or nests of cells. We have called this type of movement "cohort migration" and developed a two-dimensional in vitro cohort migration model, in which human rectal well-differentiated adenocarcinoma cells (L-10) migrate from piled-up cell islands as coherent sheets of cells when stimulated with hepatocyte growth factor/scatter factor. In this study, we examined whether there is a cohort migration-specific way of expression of matrix metalloproteinases (MMP) and whether degradation of extracellular matrix is necessary for this type of migration. Production of membrane-type 1-MMP (MT1-MMP) and gelatinase A (MMP-2) by L-10 cells was demonstrated by gelatin zymography, immunoblotting, and reverse transcription-PCR. When cohort migration was induced with hepatocyte growth factor/scatter factor, MT1-MMP and MMP-2 were immunolocalized predominantly in the leading edges of the front cells of migrating cell sheets, with the following cells being negative. In addition, during the cohort migration on gelatin-coated substratum, the gelatin matrix was degraded by the cells, in a very organized manner, causing radially arrayed lysis of gelatin matrix at the sites of leading edges. BB94, a synthetic inhibitor specific to MMPs, tissue inhibitor of metalloproteinases-1 and -2, and the COOH-terminal hemopexin-like domain of MMP-2 inhibited the migration on gelatin matrix. Thus, these data demonstrate that gelatin matrix is reorganized to suit cell migration via leading-edge-of-front-cell-specific localization of MT1-MMP and MMP-2 during cohort migration and suggest that the reorganization is essential for this type of migration.

Solitary fibrous tumor of the vagina.

The solitary fibrous tumor (SFT) is a rare tumor that most commonly arises in the pleura. Recent evidence has indicated that this tumor originates from mesenchymal, probably fibroblastic, cells and is not restricted to the pleura. However, its occurrence in the female genital tract is extremely rare. We report a case of primary SFT that originated from the vagina in a 34-year-old female. It was a pedunculated polypoid tumor and occurred at the site of scar tissue, caused by laceration during her last labor 7 years previously. Histologically, the tumor was predominantly composed of a random proliferation of spindle cells, intimately admixed with collagen. Immunohistochemically, the cells were strongly positive for CD34, vimentin and bcl-2, but were negative for S-100 protein, neuron-specific enolase, smooth muscle actin, desmin, CD68, cytokeratins and epithelial membrane antigen. To the best of our knowledge, this is the first reported case of a primary vaginal SFT in the English literature. Our report suggests to include SFT in the differential diagnosis of a spindle cell neoplasm originating from the vagina.

Genomic structure and chromosomal localization of the human hepatocyte growth factor activator inhibitor type 1 and 2 genes.

Hepatocyte growth factor activator inhibitor type 1 (HAI-1) and type 2 (HAI-2) are recently discovered Kunitz-type serine protease inhibitors which can be purified and cloned from human stomach cancer cell line MKN45 as specific inhibitors against hepatocyte growth factor activator (HGFA). HAI-2 was identical with the protein originally reported as placental bikunin. Both proteins contain two Kunitz inhibitor domains (KDs), of which the first domain (KD1) is mainly responsible for the inhibitory activity against HGFA, and are expressed ubiquitously in various tissues. In this study, we cloned the genes coding for these two structurally similar proteins by screening of human genomic bacterial artificial chromosome (BAC) library and their genomic structures were compared. HAI-1 and -2 genes consist of 11 and 8 exons spanning 12 kbp and 12.5 kbp, respectively. Three exons were inserted between KD1 and KD2 of each gene, of which the middle one was the low-density lipoprotein (LDL) receptor-like domain (HAI-1) and the testis specific exon (HAI-2). Apparently homologous regions between HAI-1 and -2 were not found in 5'-flanking region and neither TATA nor CAAT box was present. The genes were mapped to chromosome 15q15 (HAI-1) and 19q13.11 (HAI-2). These results suggested that although HAI-1 and -2 genes might be derived from same ancestor gene, they acquired distinctive in vivo roles during their evolution.

Mouse hepatocyte growth factor activator gene: its expression not only in the liver but also in the gastrointestinal tract.

A cDNA encoding mouse hepatocyte growth factor activator (HGFA) has been cloned by RT-PCR, based on the screening result from the database of expressed sequence tags. Subsequently, its gene was cloned from a mouse genomic bacterial artificial chromosome library using the cDNA as a probe. Sequencing analysis revealed that mouse HGFA protein deduced from the cDNA, similar to its human and rat counterparts, has two epidermal growth factor-like domains, type 1 and 2 fibronectin homology domains, a single kringle domain and a catalytic domain of serine proteinase, and the gene consists of 14 exon spanning approximately 7.5 kb. Interestingly, mouse HGFA mRNA was detected not only in the liver but also in the gastrointestinal tract by RNA blot analysis. Since hepatocyte growth factor (HGF) is up-regulated in the damaged gastrointestinal mucosa, our present data suggest that HGFA might activate proHGF directly in the gastrointestinal mucosa and play an important role in wound repair throughout the gastrointestinal tract.