Expression profiles of genes associated with viral entry in HCV-infected human liver.

Recent studies have demonstrated that several cellular factors are involved in entry of hepatitis C virus (HCV) into host cells. Detailed gene expression profiles of these factors in HCV-infected livers have not been reported for humans. Transcriptional levels of LDL receptor (LDLR), CD81, scavenger receptor class B type I (SR-BI), claudin-1, and occludin genes in liver samples from patients with chronic hepatitis C were investigated. Serum levels of LDL-cholesterol (LDL-C) and HCV core antigen were also evaluated, and expression of claudin-1 and occludin were immunohistochemically analyzed. Compared with normal liver, transcription of LDLR and claudin-1 genes was significantly suppressed (P < 0.0001) and occludin transcription was significantly up-regulated in HCV-infected livers (P < 0.0001). Significant positive correlations were found for LDLR versus occludin, LDLR versus claudin-1, occludin versus claudin-1, and CD81 versus SR-BI in HCV-infected (P = 0.0012, P < 0.0001, P = 0.0004, and P < 0.0001, respectively) and normal livers (P < 0.0001, P = 0.0051, P < 0.0001, and P < 0.0001, respectively). Positive correlation was observed between serum levels of HCV core antigen and LDL-C (P = 0.0147), with their levels negatively correlated to LDLR (P = 0.0270 and P = 0.0021, respectively). Immunohistochemically, hepatocellular expression of claudin-1 and occludin was increased in HCV-infected livers. Different levels of expression were demonstrated at the mRNA and protein levels for occludin and claudin-1 in HCV-infected and normal livers. Correlation of elements associated with viral entry was comparable in HCV-infected and normal livers.

Therapeutic effect of bezafibrate against biliary damage: a study of phospholipid secretion via the PPARalpha-MDR3 pathway.

OBJECTIVE: Bezafibrate (BF) has been used to treat biliary damage, particularly in patients with primary biliary cirrhosis (PBC), and its clinical efficacy has been demonstrated. The mechanism of action is thought to involve activation of the PPARalpha-MDR3-phospholipid (PL) secretion pathway. We tried to confirm this hypothesis in patients with hepatobiliary disease. METHODS: The levels of serum gamma-glutamyl transpeptidase and alkaline phosphatase, and those of bile components were examined before and after BF administration in patients with obstructive jaundice undergoing percutaneous transhepatic biliary drainage (PTBD). Hepatic expression of PPARalpha and MDR3 was quantified by real-time PCR in patients with PBC or non-alcoholic fatty liver disease (NAFLD). RESULTS: In patients with obstructive jaundice, BF decreased the serum levels of biliary enzymes and increased the bile concentration of PL. In patients with PBC or NAFLD, the expression levels of MDR3 were already up-regulated before starting the BF treatment. Although BF treatment did not further up-regulate MDR3 expression in NAFLD patients, PPARalpha expression was significantly increased. CONCLUSIONS: BF enhanced the secretion of PL into bile in cholestatic patients undergoing PTBD. However, in patients with PBC or NAFLD, diseases that represent cholesterol overload, MDR3 was already expressed at a high level to compensate for bile acids overproduction, and its expression was hardly affected by BF. In patients with chronic liver diseases such as PBC, BF may induce clinical effects via mechanisms independent of PL secretion.

Cyclosporine suppresses cell growth and collagen production in hepatic stellate cells.

BACKGROUND: In HCV-related graft hepatitis, immunosuppression has been implicated in rapid progression to cirrhosis, a serious clinical issue. We investigated the effects of cyclosporine or tacrolimus on cell growth and collagen production by hepatic stellate cells (HSC), which play a role in hepatic fibrosis. MATERIALS AND METHODS: Cultured rat HSCs and human HSC-derived TWNT-4 cells were evaluated for proliferation, type I collagen, phosphorylation states of mitogen-activated protein kinases extracellular signal-regulated kinase 1/2; [MAPKs Erk1/2], c-Jun N-terminal kinase (JNK, p38), as well as the expression of collagen, matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) genes. RESULTS: Cyclosporine suppressed cell growth and collagen production in a concentration-dependent manner. At clinically relevant concentrations of 0.125 micromol (150 ng/mL) cyclosporine significantly reduced collagen production per cell by more than 50%. Similarly, tacrolimus also reduced both collagen concentration and cell number; however, tacrolimus at a clinically relevant concentration of 12.5 nmol (10 ng/mL) did not significantly reduce collagen production. Treatment with cyclosporine reduced type I collagen and TIMP-1 expression and enhanced MMP-1 expression. Cyclosporine also inhibited phosphorylation strongly for JNK and p38, and weakly inhibited for Erk1/2. CONCLUSION: These findings demonstrated that cyclosporine suppresses cell growth and collagen production, suggesting that it may have an antifibrogenic effect.

Hammerhead ribozyme as a therapeutic agent for hyperlipidemia: production of truncated apolipoprotein B and hypolipidemic effects in a dyslipidemia murine model.

In humans, overproduction of apolipoprotein B (apoB) is positively associated with premature coronary artery diseases. To reduce the levels of apoB mRNA, we used adenovirus-mediated vector to target hammerhead ribozyme at GUA(6679) downward arrow of apoB mRNA (designated AvRB15) in the liver of a dyslipidemic mouse model that is deficient in apoB mRNA editing enzyme and overexpresses human apoB100. In this study, we delivered approximately 4 x 10(11) virus particles of AvRB15 (active ribozyme) or AvRB15-mutant (inactive ribozyme) to the animals. Using Southern blot analysis, we readily detected RB15 DNA in the mouse liver as long as day 35 after injection. This result was correlated with the RNA expression of RB15 by RNase protection assay. Using reverse ligation-mediated polymerase chain reaction, the 3' cleavage product of apoB mRNA was detected, and the exact cleavage site was confirmed by sequencing. Importantly, the levels of human and mouse apoB mRNA decreased approximately 80% after AvRB15 transduction. There was a marked decrease in plasma cholesterol, triglyceride, and human apoB of 42, 51, and 62%, respectively, when compared with the inactive ribozyme-treated group. Moreover, ribozyme cleavage of apoB mRNA generated a truncated protein of the expected size (apoB48.1), which was associated with lipoprotein particles in the very low density, low density, and high density lipoprotein fractions. Taken together, these results indicate that apoB mRNA-specific hammerhead ribozyme can be used as a potential therapeutic agent to modulate apoB gene expression and to treat hyperlipidemia.

Recurrent malignant fibrous histiocytoma. A histologic analysis of 50 cases.

This clinicopathologic study deals with 84 patients who had recurrent malignant fibrous histiocytoma (MFH), and is primarily concerned with 50 cases in which specimens of both the initial and recurrent tumors were available for histopathologic examination. Quantitative and qualitative differences in the histologic patterns characterizing MFH, such as storiform and myxoid, between the initial and recurrent tumors, were clear-cut in nearly two-thirds of the cases. Conversion in histologic subtypes of MFH occurred in nine cases, including six cases which converted from myxoid to nonmyxoid pleomorphic. The superficially located tumors recurred somewhat more frequently, but in such cases, there was a significantly better prognosis than was seen with the deeply located tumors. Changes in the degree of mitotic rate, nuclear atypism, and cellularity from the initial to the recurrent tumor correlated better with the biological behavior of the tumor than did the degree in the initial tumor itself. The increased proportion of histiocyte-like tumor cells in the recurrent tumor was another morpholic feature which indicated a much poorer prognosis than did the increased proportion of fibroblast-like tumor cells.

Myofibromatosis in adults (adult counterpart of infantile myofibromatosis).

Five solitary, benign, soft-tissue tumors histologically resembling infantile myofibromatosis but which occurred in adults were found among more than 5,000 benign soft-tissue tumors from a tumor registry. The tumors clinically presented as superficial, painless, and slowly enlarging nodules, usually of more than 10 years' duration, that occurred in the upper (two cases) and lower (two cases) extremities or the buccal mucosa (one case). They developed in the dermis and subcutis as well-circumscribed nodules with an average diameter of 1.2 cm. They were composed of discrete and confluent fibrous tissue with a mixture of bundles of smooth muscle-like cells and a hemangiopericytoma-like area of immature mesenchymal cells. Immunostaining for actin and intermediate filaments revealed the myofibroblastic nature of the tumor cells. The tumors were surgically excised, and there has been no recurrence. Clinicians and pathologists should note that the lesion of infantile myofibromatosis can and does occur in adults.

Elastofibromatous lesion of the stomach in a patient with elastofibroma dorsi.

A 69-year-old woman underwent partial gastrectomy because of peptic ulcer which resisted medical treatment. The resected stomach exhibited a wide thickening of the antral wall around a 1.2 X 0.8 cm ulcer. The cut surface showed a gray-white thickened submucosal layer and had a rubbery elastic consistency. Microscopically, the thickened areas consisted of abundant acellular collagen fibers containing numerous elastinophilic, thick, serrated fibers and globules, identical with the elastofibroma fibers seen in elastofibroma dorsi. Reexamination of the patient revealed bilateral subscapular masses; one of these was biopsied and proved to be an elastofibroma dorsi.

Malignant peripheral nerve-sheath tumors (malignant schwannomas). An immunohistochemical study of 29 cases.

Twenty-nine cases of malignant schwannoma consisted of three groups; 11 tumors associated with von Recklinghausen's disease (group I), nine tumors arising grossly from nerve trunks (group II), and 11 tumors so diagnosed basically on the histologic features (group III). Using the immunoperoxidase methods, the tumors were investigated with regard to S-100 protein, keratin, and epithelial membrane antigen (EMA). Approximately one-third of the cases (10 of 29) were devoid of S-100 positive cells and the remaining two-thirds (19 of 29) contained positive cells, with variable frequencies. The number of S-100 positive cells differed, depending largely on the presence or absence of neurofibroma-like areas in the tumor. The positive cells were rarely found in the group III tumors, which were neither associated with von Recklinghausen's disease nor connected to nerve trunks, even when their histologic features were unequivocal. Certain specific organoid structures in the tumor, such as neuroid or tactoid ones, were positive for S-100 protein. In one of the two malignant epithelioid schwannomas, the tumor cells were strongly positive for S-100 protein, thereby suggesting melanocytic differentiation. This tumor was interpreted as a melanocytic malignant schwannoma rather than a malignant melanoma, based in part on the fact that the overlying epidermis was uninvolved in this patient with von Recklinghausen's disease. True epithelial differentiation in one case of glandular schwannoma was verified by the positive stain of EMA along the inner surface of the glandular element.

Sclerosing adenosis of the prostate. Histopathologic and immunohistochemical analysis.

A prostatic lesion, histologically identical to sclerosing adenosis of the breast, was found in five (1.9%) of 263 patients who underwent transurethral resection, open prostatic adenectomy, radical prostatectomy, or total cystoprostatectomy. This uncommon lesion was a localized proliferation of crowded small glands, small solid nests, and individual cells embedded in a cellular stroma, mimicking a small acinar prostatic adenocarcinoma. The proliferating glands were lined by a single layer of secretory cells surrounded by an eosinophilic membranous structure. Basal cells were disclosed in individual glands or as small nests and even individual cells with immunostainability for basal cell-specific cytokeratin (EAB903), S-100 protein, and muscle-specific actin (HHF35). These findings indicate the benign nature of the lesion with myoepithelial differentiation of the basal cells. In contrast, all 25 small acinar adenocarcinomas examined as controls lacked positive stains for the above three antibodies, verifying the usefulness of these antibodies to distinguish between this benign lesion from adenocarcinoma.

Squamous cell carcinoma arising in mature cystic teratoma of the ovary. Clinicopathologic and topographic analysis.

Clinical and pathologic features of 28 patients with squamous cell carcinoma (SCC) arising in mature cystic teratoma (MCT) of the ovary were analyzed. The overall 5-year survival rate of these patients was 52%. Clinical staging (Stage I versus Stages II or more), histologic differentiation (well versus moderately or poorly differentiated SCC), and the presence of vascular invasion were factors affecting the prognosis of these patients. In 11 tumors, including 2 of the 4 examined in stepwise serial sections, the SCC was considered to have originated from a columnar epithelium (ciliated or nonciliated) or from a metaplastic squamous epithelium. On the other hand, no SCC was a direct transition from the ordinary epidermis of the teratomatous skin tissue. These results strongly support the proposal that SCC arising in MCT derives from the columnar epithelium.

Early gastric carcinoma with multiple endocrine cell micronests.

We report a case of early gastric carcinoma associated with multiple endocrine cell micronests detected in a 64-year-old Japanese man. The micronests were present in the deeper layer of the lamina propria mucosae, an area occupied by early gastric carcinoma involving the mucous membrane of the anterior wall of the gastric body. Histologic and immunohistochemical studies suggested that the micronests were produced by budding of the neoplastic argyrophil cells scattered within the malignant tubules of the carcinoma and may therefore represent another phenotype of this well-differentiated adenocarcinoma.

Epithelioid hemangioma versus Kimura's disease. A comparative clinicopathologic study.

A clinicopathologic and immunohistochemical study of eight cases of epithelioid hemangioma and 11 cases of Kimura's disease was performed. Patients with epithelioid hemangioma (EH) ranged in age from 15 to 56 years (mean, 37 years) and had small papular or nodular lesions occurring most often on the face and scalp. The lesions were less than 2.0 cm in diameter. There were irregularly hypertrophic vascular structures with swollen endothelial cells and of a variable lymphoid infiltrate with eosinophils. The clustering of small vessels around the arteries or veins was another distinctive feature. Arteriovenous shunts were evident in three lesions. Patients with Kimura's disease, however, presented large solitary or multiple nodules occurring most commonly in the periauricular region. Six patients had a history of regional lymphadenopathy; three patients had eosinophilia of the peripheral blood. Microscopically, the distinctive features were of numerous lymphoid follicles and a salient eosinophilic infiltrate. These lymphoid follicles possessed distinct germinal centers and contained an increased number of dendritic cells. Although some small-vessel proliferation was noted, it was not as distinctive as for patients with epithelioid hemangioma. We conclude from this study that the two conditions should be considered different entities.

Ovarian sarcoma with histologic features of telangiectatic osteosarcoma of the bone.

A primary osteosarcoma occurred in the left ovary of a 47-year-old Japanese woman. The preoperative diagnosis, based on computerized tomography, was cystic teratoma. The excised tumor was composed of large multilocular cysts containing blood and associated with an area of solid tissue. Histologically, the tumor was a "pure" osteosarcoma that showed prominent cellular anaplasia and blood-filled spaces lined with tumor cells. The lesion resembled a telangiectatic osteosarcoma of bone. Serum alkaline phosphatase levels reflected progression of the disease. Despite aggressive adjuvant chemotherapy, the patient died 8 months later of a local recurrence and intra-abdominal spread of the tumor.

Malignant neuroepithelioma (peripheral neuroblastoma). A clinicopathologic study of 15 cases.

A clinicopathologic study of 15 cases of malignant neuroepithelioma (peripheral neuroblastoma) of soft tissues is reported. The patients were chiefly young Japanese adults with a median age of 21 years. The tumors arose mainly in the soft tissues of the lower extremity (seven cases) and the trunk (four cases). Microscopically, there were sheets of closely packed, small round or oval cells, and Homer Wright-type rosettes were seen in all cases, one of which also had Flexner-type rosettes. Immunohistochemical cytoplasmic localization of neuron-specific enolase (NSE) was demonstrated in six of the eight cases, using the peroxidase-antiperoxidase (PAP) method. In no case, however, was there any staining reaction for S-100 protein. Of the 14 patients for whom follow-up information could be obtained, nine died within a period of 2 years and two were alive and well for over 5 years after the initial treatment. Differential diagnosis from other soft-tissue round-cell sarcomas, such as embryonal or alveolar rhabdomyosarcoma, extraskeletal Ewing's sarcoma, and others, are briefly discussed, on a clinicopathologic basis.

Malignant fibrous histiocytoma. Proliferative compartment and heterogeneity of "histiocytic" cells.

To elucidate the precise origin and characteristics of the proliferating cells in malignant fibrous histiocytoma (MFH), the authors analyzed 33 MFH tumors, using immunohistochemical techniques with a panel of 12 antibodies. All three types of MFH cells (spindle cells, polygonal cells, and bizarre giant cells) stained positively for mesenchymal antigens (FU3 and vimentin) but did not stain for macrophage/histiocyte markers (HAM 56 and CD68). Therefore, the MFH cells may not represent true histiocytes, although they may be mesenchymal-derived cells behaving as "facultative histiocytes" with superficial resemblance to actual histiocytes. Normal histiocytes in the stroma tested positive for macrophage/histiocyte antigens; the most common cells were HAM 56-positive cells constituting 30-80% of nonneoplastic stromal cells, followed by those positive for CD68 (10-50%), Mac 387 (less than 2%), and S-100 protein (less than 1%). Our results indicate the presence of heterogeneity of "histiocytic" cells in MFH. Proliferating-cell nuclear antigen (PCNA) was expressed not only in the spindle and polygonal MFH cells but also in the bizarre giant cells. These findings suggest that all three types of MFH cells participate in the proliferative compartment of MFH. Uneven PCNA staining of the irregular nuclear segments of the bizarre giant cells may result in abnormal DNA synthesis, possibly contributing to the marked diversity of nuclear morphology in MFH. Touton-type and osteoclast-like giant cells did not stain for PCNA but stained positively for histiocytic markers. Therefore, these giant cells may lack proliferative activity and probably result from normal histiocytes fusing together.

Expression of a tumor-associated antigen RCAS1 in hepatocellular carcinoma.

RCAS1 has been reported as a tumor-associated antigen in uterine and ovarian carcinomas. In vitro studies on RCAS1 indicated that it might function as an apoptosis-inducing factor since binding between RCAS1 and its receptor induced apoptosis in receptor-expressing cells. In this study, 68 surgically resected samples of hepatocellular carcinoma (HCC) were prepared and RCAS1 expression was examined immunohistochemically, because RCAS1 was also positive in all HCC cell lines tested. Clinical and pathological parameters were then compared between RCAS1-positive and -negative HCC cases. As a result, RCAS1 is expressed in 26.5% of HCC cases and vascular invasion is observed at a much higher rate in the RCAS1-positive cases (72.2%) than in RCAS1-negative cases (24.0%). RCAS1 is not an antigen specific for gynecological cancers. In HCC cases, the RCAS1-positive percentage is not high, however, RCAS1-positive HCCs exhibited a trend towards invasive character.

Malignant "triton" tumors: a clinicopathologic and immunohistochemical study of nine cases.

Nine cases of malignant "triton" tumors, based on the coexistence of rhabdomyoblasts and Schwann cell elements, were analyzed clinicopathologically and immunocytochemically. All tumors were stained for myoglobin and S-100 protein by the immunoperoxidase technique. Six of the nine patients were in the third or fourth decade of life. Six cases were associated with von Recklinghausen's disease, and the tumors in two cases grew along nerve trunks. The malignant tumors showed a predilection for the thigh and buttock. Six of the seven deaths occurred within two years of the initial treatments. Strongly positive staining for S-100 protein was observed in three tumors, with transitional zones between the sarcomas and peripheral neurofibroma-like areas, as well as in two tumors composed predominantly of rhabdomyoblastic elements. In four other cases the tumors were only weakly positive for protein S-100. Intracytoplasmic myoglobin was present in all cases. Tumors composed predominantly of rhabdomyosarcomatous elements occurred in four patients, including two children with von Recklinghausen's disease. These results, considered with other findings, suggest that malignant "triton" tumors may not be as rare as previously believed.

Malignant soft tissue neoplasms with the histologic features of renal rhabdoid tumors: an ultrastructural and immunohistochemical study.

Five round cell neoplasms of the soft parts that histologically resembled malignant rhabdoid tumors of the kidney were studied. The tumors were composed mainly of poorly differentiated round or, sometimes, polygonal cells, with a minority of elongated cells; the cytoplasm of many of the cells contained filament-laden acidophilic inclusions. Ultrastructurally, the intracytoplasmic structures were seen to consist of aggregates of 10-nm intermediate filaments, and immunohistochemical staining revealed the presence of cytokeratin and vimentin. All five patients with this tumor had an aggressive clinical course; three of the patients died shortly after the initial diagnosis. As this tumor does not seem to be linked to any known entity, it is referred to as malignant rhabdoid tumor of the soft parts and could be a heterogeneous entity.

Gastric lesions in familial adenomatosis coli: their incidence and histologic analysis.

In order to detect accompanying gastric lesions, we examined 22 patients with familial adenomatosis of the colon belonging to 14 families. Various gastric lesions were confirmed in 15 patients (68.2 per cent) belonging to 13 families. The lesions were found histologically to be adenoma in nine cases, fundic gland polyposis in six, carcinoma in three, and microcarcinoid in two. Fundic gland polyposis consisting of simple hyperplasia of the fundic glands seems to be the gastric lesion specific to familial adenomatosis of the colon and rectum. Familial adenomatosis coli not only affects the colon and rectum, but is also capable of inducing tumorigenicity in other organs. The stomach is one of the organs in which extracolonic lesions occur.

Benign schwannoma of the gastrointestinal tract: a clinicopathologic and immunohistochemical study.

A clinicopathologic and immunohistochemical review was made of 24 cases of distinctive nerve sheath tumors located in the gastrointestinal tract. The tumors were microscopically evident in the presence of peripheral lymphoid cuffing and benign nuclear atypia. The tumors arose in the muscularis propria of the stomach in 23 cases and in the ascending colon in 1 case. The patients included 9 men and 15 women whose ages ranged from 36 to 78 years (average, 58). No recurrence has developed in any patient who underwent resection. Although positive immunostaining for S-100 protein, Leu 7 antigen, and laminin might support the schwannian nature of these tumors, the positive immunoreactivity for glial fibrillary acidic protein (GFAP) indicated the possibility of a myenteric plexus origin. The pattern of S-100 protein immunostaining differed from that seen in cases of gastrointestinal stromal tumors associated with von Recklinghausen's neurofibromatosis or that noted in cases of conventional leiomyomas. We propose that these tumors be designated as benign schwannoma of the gastrointestinal tract.