Mesenchymal Tumor Cells Research Articles

Two Approaches for Assessing Human Safety of Disperse Blue 1

Disperse Blue 1 is an anthraquinone dye used at low levels in semipermanent hair color formulations. Dietary administration of Disperse Blue 1 in a National Toxicology Program (NTP) carcinogenesis bioassay produced transitional- and squamous-cell tumors, leiomyomas, and leiomyosarcomas of the urinary bladders of male and female F344/N rats. The occurrence of tumors in the urinary bladder of rats was associated with urothelial hyperplasia and the presence of urinary calculi. Despite the occurrence of urinary bladder calculi and other nonneoplastic changes, there was no evidence of urinary bladder carcinogenesis in B6C3F 1 mice fed Disperse Blue in the diet for up to 2 years. A study conducted in rats of the same strain by Burnett and Squire confirmed the occurrence of calculi and transitional-cell neoplasms in the rat bladder. However, no mesenchymal-cell tumors were detected at a comparable dietary level. Further, Burnett and Squire found evidence of reversibility of the proliferative changes in the rat urinary bladder following cessation of treatment at 6 months. Disperse Blue 1 has been tested in a variety of in vivo and in vitro genotoxicity assays and was negative in vivo but produced a weak and mixed pattern of genotoxic responses in vitro which may be attributable to a constituent of the commercial preparations. Evaluation of the available data for Disperse Blue 1 and comparison with the responses observed in the urinary bladders of rats administered other rodent bladder carcinogens considered to act through a secondary mechanism indicate that a threshold approach is appropriate for assessing risk. With this approach, an uncertainty factor of 1000 applied to the no-observed-adverse-effect level in the NTP bioassay yielded a safe exposure level of 45-56 μg/kg/day. In contrast, with a conventional quantitative risk assessment approach, the exposure level corresponding to an upper limit on lifetime risk of 10 −6 to 10 −5 was 0.39 to 3.9 μg/kg/day, respectively. The safe level of Disperse Blue 1 derived using the threshold approach is approximately 20 times greater than the maximum average daily applied dose of 2.7 μg/kg/day associated with its use in semipermanent hair color formulations, while the exposure associated with the 10 −5 risk level using the linearized multistage model in the conventional approach was determined to be 1.5 times greater. Because oral absorption is substantially more than dermal absorption, the actual margin of safety is most likely much greater than either of these comparisons suggests. The difference in the estimates derived using the two approaches demonstrates the importance of incorporating information on the mechanism of action into the risk assessment process.

Malignant Fibrous Histiocytoma and Macrophage Differentiation.

Malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma of adult life. Its clinicopathological entity, however, is not completely established because of its uncertain histogenesis. In this review, the histogenesis of MFH is discussed through an overview of the concept of macrophage ontogeny. Our recent multiparametric studies indicate that MFH is a tumor of mesenchymal cells with fibroblastic differentiation. Histiocyte-like cells in the tumor are considered to be not neoplastic component but infiltrated macrophages. Because this tumor is not one of the histocytes or macrophages, the term “malignant fibrous histiocytoma” is inappropriate. Instead, this tumor should be renamed as a special type of mesenchymal cell tumor differentiating toward fibroblasts and producing monocyte chemoattractants and macrophage differentiation factors.

Fine-needle aspiration biopsy: dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans (DFSP) represents a spectrum of mesenchymal spindle cell tumors that typically involve both dermis and subcutis. Presented herein are six cases of DFSP, four of which were initially diagnosed by FNAB. The cytologic features useful in the identification of this lesion on Papanicolaou- and Diff-Quik-stained smears are discussed. Chief among these are the storiform stromal fragments, presence of entrapped adipose tissue and the recognition of fibrohistiocytic spindle cells. The potential pitfalls and the differential diagnostic possibilities of spindle-cell lesions, particularly those of fibrohistiocytic origin are discussed.

Histomorphologic Features of Spontaneous and Chemically-Induced Pulmonary Neoplasms in B6C3F1 Mice and Fischer 344 Rats

The histomorphologic features of spontaneous and chemically-induced lung neoplasms in male and female B6C3F1 mice and Fischer 344 rats are described. Primary pulmonary neoplasms in mice and rats were classified as alveolar/bronchiolar (A/B) adenoma or carcinoma (including variants with squamous and mucinous cell differentiation), bronchial adenoma or carcinoma, squamous cell carcinoma or mesenchymal tumors. A/B adenomas and carcinomas were the most common spontaneous pulmonary neoplasms observed in both mice and rats, but were observed less frequently in rats. In the National Toxicology Program (NTP) historical control database the incidence of spontaneous A/B adenomas in male (n = 2,084) and female (n = 2,079) mice is 13.8% and 4.9%, respectively; for A/B carcinomas, it is 5.3% and 2.4%, respectively. In male (n = 3,877) and female (n = 3,919) rats, spontaneous pulmonary neoplasms are rare with historical control rates less than 3% for A/B adenomas or carcinomas in either sex. The spontaneous A/B adenomas and carcinomas observed in mice and rats typically had papillary, solid or mixed (papillary and solid) histologic growth patterns. Pulmonary neoplasms from mice and rats treated with chemical carcinogens reviewed from 2-year studies consisted primarily of A/B adenomas and carcinomas. These tumors had papillary, glandular/tubular, solid or mixed (combination of 2 or more) histologic growth patterns. A few of the A/B neoplasms had areas of squamous or mucinous cell differentiation. Other less frequently occurring spontaneous and chemically-induced neoplasms included squamous cell carcinomas, bronchial adenomas and carcinomas, and sarcomas.

Histomorphologic Features of Spontaneous and Chemically-Induced Pulmonary Neoplasms in B6C3F1 Mice and Fischer 344 Rats*1

The histomorphologic features of spontaneous and chemically-induced lung neoplasms in male and female B6C3F1 mice and Fischer 344 rats are described. Primary pulmonary neoplasms in mice and rats were classified as alveolar/bronchiolar (A/B) adenoma or carcinoma (including variants with squamous and mucinous cell differentiation), bronchial adenoma or carcinoma, squamous cell carcinoma or mesenchymal tumors. A/B adenomas and carcinomas were the most common spontaneous pulmonary neoplasms observed in both mice and rats, but were observed less frequently in rats. In the National Toxicology Program (NTP) historical control database the incidence of spontaneous A/B adenomas in male (n = 2,084) and female (n = 2,079) mice is 13.8% and 4.9%, respectively; for A/B carcinomas, it is 5.3% and 2.4%, respectively. In male (n = 3,877) and female (n = 3,919) rats, spontaneous pulmonary neoplasms are rare with historical control rates less than 3% for A/B adenomas or carcinomas in either sex. The spontaneous A/B adenomas and carcinomas observed in mice and rats typically had papillary, solid or mixed (papillary and solid) histologic growth patterns. Pulmonary neoplasms from mice and rats treated with chemical carcinogens reviewed from 2-year studies consisted primarily of A/B adenomas and carcinomas. These tumors had papillary, glandular/tubular, solid or mixed (combination of 2 or more) histologic growth patterns. A few of the A/B neoplasms had areas of squamous or mucinous cell differentiation. Other less frequently occurring spontaneous and chemically-induced neoplasms included squamous cell carcinomas, bronchial adenomas and carcinomas, and sarcomas.

Expression of the MyoD1 muscle determination gene defines differentiation capability but not tumorigenicity of human rhabdomyosarcomas.

Several human rhabdomyosarcoma cell lines, cultured primary tumor explants, and biopsies of tumor and normal skeletal muscle tissue expressed a 2.0-kilobase transcript that hybridized to the mouse muscle determination gene MyoD1. This transcript was found in tumor cell lines and primary explants that developed multinucleated myotubes but was absent in Wilms' tumors or cell lines and primary explants that developed multinucleated myotubes but was absent in Wilms' tumors or cell lines derived from other mesenchymal tumor cell types. Expression of the human homolog of MyoD1 therefore can define a tumor as a rhabdomyosarcoma. Transfection of the mouse MyoD1 gene into the human rhabdomyosarcoma cell line RD increased the ability of the tumor cells to differentiate into multinucleated myotubes and enhanced myosin heavy-chain gene expression but did not decrease tumorigenicity in nude mice.

Expression of the MyoD1 muscle determination gene defines differentiation capability but not tumorigenicity of human rhabdomyosarcomas.

Several human rhabdomyosarcoma cell lines, cultured primary tumor explants, and biopsies of tumor and normal skeletal muscle tissue expressed a 2.0-kilobase transcript that hybridized to the mouse muscle determination gene MyoD1. This transcript was found in tumor cell lines and primary explants that developed multinucleated myotubes but was absent in Wilms' tumors or cell lines and primary explants that developed multinucleated myotubes but was absent in Wilms' tumors or cell lines derived from other mesenchymal tumor cell types. Expression of the human homolog of MyoD1 therefore can define a tumor as a rhabdomyosarcoma. Transfection of the mouse MyoD1 gene into the human rhabdomyosarcoma cell line RD increased the ability of the tumor cells to differentiate into multinucleated myotubes and enhanced myosin heavy-chain gene expression but did not decrease tumorigenicity in nude mice.

Radiobiological Characterization of 53 Human Tumor Cell Lines

We investigated the in vitro radiobiological survival parameters of 53 human tumor cell lines studied in exponential growth. Epithelial cell lines derived from 24 patients with head and neck carcinoma, 15 patients with ovarian carcinoma, and mesenchymal tumor cell lines derived from 14 patients with bone and soft tissue sarcomas were studied. Survival data are analyzed using the multi-target and linear quadratic models. The head and neck and ovarian carcinoma tumor cell lines were more radioresistant as measured by D0, D, and alpha parameters, compared with the bone and soft-tissue sarcoma lines. The radiobiological parameters of tumor cell lines reported herein are similar to parameters of tumor cell lines derived from head and neck and soft tissue sarcoma patients presently being followed for clinical outcome following radiotherapy in our clinic.

Mouse Hepatoblastomas: A Histologic, Ultrastructural, and Immunohistochemical Study

Hepatoblastomas from B6C3F1 and BALB/c mice were examined by light and electron microscopy and by immunohistochemical reactions for alpha-fetoprotein, keratin, and vimentin. Tumors occurred in one group of a chronic bioassay for the interaction of diet, genetic strain, and the carcinogen, 2-acetylaminofluorene. Tumors had several populations (including epithelial and mesenchymal cells) in various stages of differentiation. Neoplastic epithelial cells had features of embryonal hepatocytes, such as sparse cytoplasmic organelles, absence of glycogen, abundant free ribosomes, occasional bile canaliculi, and peroxisome-like dense bodies. Embryonal fibroblast-like cells had pleomorphic and folded nuclei with prominent perinuclear chromatin and dispersed cytoplasmic organelles. Fibroblast-like cells were surrounded by bundles of collagen fibrils. Intermediate or transitional types of cells were seen. No tumor cells were immunoreactive for mouse alpha-fetoprotein (AFP) antibody, unlike those in hepatocellular adenomas or carcinomas. Epithelial and mesenchymal tumor cells contained intermediate filaments throughout the cytoplasm; some of these cells stained for keratin but not for vimentin. These findings suggest that mouse hepatoblastomas are derived from bipotential liver blastema cells and are composed of a mixture of several cell populations.

植物性配糖体ｇｉｎｓｅｎｏｓｉｄｅの唾液腺腫ようの増殖抑制に関する実験的研究

Recently, a number of antitumor agents have been found that inhibit growth and induce phenotypic reversion in certain malignant tumors.Plant glycoside-ginsenoside is an antitumor chemical compound discovered by Dr. Odashima in 1979. This ginsenoside is producted Rh1 and Rh1, but despite their chemical similarities, their effects on tumor cells are remarkably different. In fundamental studies, insenoside Rh2 is already refered to as having strong antitumor activities in certain malignant tumors.In this study, antitumor effects of ginsenoside Rh2 on a chemically induced salivary gland tumor in animals were investigated. Experimental method: Male dd-strain mice (2 month old) were used as the experimental subjects. To induce the formation of salivary gland tumors, 10% 20-methylcholanthrene in olive oil, which roughly amounts to 1.0mg/100g, was injected into the surgically exposed submaxillary gland of the mice. Those subject with induced, submaxillary gland tumors were divided into two groups, i.e., the control group and the ginsensoide administered group. In the latter group, two methods were used for administration of ginsenoside Rh2. Ginsenoside Rh2 in 40% ethanol, which roughly amounts to 1.0mg/100g, was injected subcutaneously and/or into the induced tumor. This administration was performed 2 to 3 times a week for a total of 10 times. At the conclusion of treatment, all mice in each group were scarified and the submaxillary gland tumors were histopathologically examined.Experimental results: The ginsenoside administered group showed a considerably slow tumor growth compared with the control group. In general condition, the mice of the ginsenoside administered group showed a remarkable loss of body weight despite no observed decrease in food intake. According to histopathological findings, ginsenoside Rh2 was effective in the epithelial and/or mesenchymal malignant tumor cells. Some nuclear swelling, pyknosis, cell degeneration and destructive cells in the cell nest of the tumors were observed.In summary the authors were impressed with ginsenoside Rh2's antitumor effects.

Human pleomorphic adenomas transplanted to nude mice.

Tissue from 13 human pleomorphic adenomas was transplanted to a total of 64 nude mice. Eight of the tumors were transplanted into a second passage of mice, 17 in all. In 39 mice of first passage, there was a definite increase in graft size. Microscopic examination showed no change in the histologic pattern from the donor tumor to the transplanted tissue. The heterochromatin pattern after staining with the DNA-specific fluorochrome D287/170 allowed distinction between human and murine cells and showed that both epithelial and mesenchymal cells were of human derivation. Autoradiographic studies with tritiated thymidine showed that both epithelial and mesenchymal tumor cells were labeled. Our results thus show that cell proliferation in the human pleomorphic adenoma takes place in epithelial areas as well as in mesenchymal areas.

Prostaglandin and hydroxyeicosatetraenoic acid synthesis by human mesenchymal tumors.

The metabolism of arachidonic acid was investigated by radioimmunoassay and chromatographic techniques in 5 sarcomas and one embryonal carcinoma of human origin maintained as transplantable tumors in nude mice. The results obtained indicate that: the absolute quantities of arachidonic acid metabolites produced by a given tumor varied between experiments but the overall distribution pattern of these products, in general, remained constant from passage to passage; each tumor showed a different arachidonic acid metabolite profile in quality and quantity; 2 sarcomas of the same histological type could be clearly distinguished by their arachidonic acid metabolites; the predominant product in all tumors was 12-HETE or 15-HETE, whereas thromboxane A2 was synthesized in low quantities by all tumors; PGF2 alpha was synthesized at the highest rate by an alveolar rhabdomyosarcoma; PGE2 synthesis was highest in a malignant fibrous histiocytoma; and total prostaglandin synthesis was low in the chondrosarcoma and synovial-cell sarcomas. All results reported in this study are for the complete tumor which includes both neoplastic and stromal cells. The role that these products play in the biological behavior of mesenchymal tumor cells and normal tissues of the host remains to be determined.

The distribution of epithelial membrane antigen in the kidney and its tumours.

The distribution of epithelial membrane antigen (EMA) in the kidney and its tumours has been studied using a polyclonal anti-EMA antiserum and the immunoperoxidase-antiperoxidase technique (PAP). Twelve fetal and 10 adult kidneys examined showed EMA to be confined to the distal tubular or collecting duct epithelium or their embryological precursors. The examination of 55 primary renal tumours showed EMA to be present on the epithelial tumours, on tubular epithelium in nephroblastoma, but not on mesenchymal tumour cells nor on undifferentiated areas of nephroblastoma.

Gliosarcomas: histological, immunohistochemical, ultrastructural, and tissue culture studies.

Thirty-nine cases of gliosarcomas, two initiating as fibrosarcomas, 25 as mixed gliomas and sarcomas, and 12 as anaplastic gliomas with secondary sarcomas, were studied by light microscopy, immunohistochemistry, using GFAP, factor VIII/RAg, and Ulex europaeus I agglutinin (UEA I), electron microscopy and tissue culture. GFAP was found variably positive in the glial areas; F VIII/RAg and UEA I, markers of both normal and neoplastic endothelial cells and their derivatives, were found in vessels of both gliomatous and sarcomatous parts of GS, less intensive in hyperplastic glomeruloid structures and, with decreasing intensity, in adjacent fibrosarcomatous areas, while UEA I, giving stronger reaction than F VIII/RAg, was occasionally demonstrated in sarcomatous cells. In vitro studies confirmed previous data of a separate growth of glial and mesenchymal cells with a divergent migratory speed. Electron microscopy demonstrated the frequent close admixture of glial and mesenchymal tumor cells, which showed the feature of either fibrosarcoma or angiosarcoma. The frequent resemblance of the latter with endothelial cells was supported by the occasional demonstration of Weibel-Palade-like bodies in both vascular endothelial and adjacent sarcomatous cells. These observations confirm the hypothesis that at least part of the sarcomatous components in many GS originate from vascular endothelial proliferation and obviously represent the final stage of a process starting with the endothelial hyperplasia in anaplastic gliomas.

Ultrastructural observations on the histogenesis of localized fibrous tumours of the pleura (benign mesothelioma).

Five localized fibrous tumours of the pleura (benign mesothelioma) were studied ultrastructurally in order to elucidate their histogenesis. The histological subtypes of this benign fibrous lesion of the visceral pleura, i.e. the cellular, the collagenous, and the hyaline, were separately analysed. The tumours are composed of undifferentiated mesenchymal cells, intermediate and differentiated fibroblasts as well as collagenous interstitial tissue. The varying distribution of these cell elements account for the various histological subtypes. Morphological similarities between the mesenchymal tumour cells and the superficial mesothelial cells, which are always separated from the true tumour tissue by an intact basement membrane, were not observed. The different cellular elements can be regarded as parts of a continuous spectrum of cytodifferentiation, in which the mature fibroblasts are derived via intermediate forms from the undifferentiated cells. It is concluded that the localized fibrous tumours of the pleura arise from immature mesenchymal stem cells, which seems to be normally found in the submesothelial layer of the visceral pleura.

Modulation of N-Nitrosodimethylamine Kidney Tumorigenesis by Unilateral Hydronephrosis and Multiple Putrescine Administrations

The effects of unilateral hydronephrosis by ligation of the right ureter and/or multiple injections of putrescine on kidney tumorigenesis by a single intrarenal injection of N-nitrosodimethylamine (DMN) were studied. Inbred female W rats in the unilateral hydronephrotic groups given or not given putrescine developed kidney tumors and/or neoplastic or preneoplastic lesions of the liver at an incidence of 55.6%. Almost all kidney tumors developed in the contralateral kidneys, which showed hypertrophy due to unilateral hydronephrosis. Rats having unilateral hydronephrosis and subjected to long-term putrescine administration after DMN injection frequently contracted large mesenchymal cell tumors (83%), whereas the group not given putrescine developed no mesenchymal cell tumors. Histologically, epithelial cell tumors showed a marked decrease in both gamma-glutamyltransferase activity and trypan blue uptake, but mesenchymal cell tumors did not.

Collagen fibrillogenic activity in mouse mesenchymal tumor tissues and cells

Collagen fibrillogenic activity of mouse mesenchymal tumor cell lines m, Ht, and F was investigated. When nu/nu mice were subcutaneously inoculated with the cells, the production of argyllophilic fibers, hydroxyproline content, and lysyl oxidase activity were most prominent in the tumors produced by the m, and least in the tumors produced by the F. Prolyl hydroxylase activity was lowest in the m-cell tumors and highest in the F-cell tumors. Hydroxyprolien content and lysyl oxidase activity in the culture media correlated with the findings in the tumor tissues. However, prolyl hydroxylase activity in these cells did not correlate with hydroxyproline content or lysyl oxidase activity produced in the culture media. Thus, production of fibrous connective tissues is specific to each cell line, and the amount of collagen in the tumor tissues is significantly related to the amount of collagen secreted ( r = 0.966) and lysyl oxidase activity synthesized by the tumor tissues ( r = 1.000, P < 0.05). Lysyl oxidase activity is closely related to the amount of collagen in vitro ( r = 0.970). These findings suggest that lysyl oxidase and not prolyl hydroxylase activity is an index of collagen fibrillogenesis and plays an important role in collagen deposition.

Liver tumors distinguished by immunofluorescence microscopy with antibodies to proteins of intermediate-sized filaments.

Antibodies against constitutive proteins of different types of intermediate-sized filaments were used in immunofluorescence microscopy on frozen sections of normal rat liver and various rat liver tumors induced by treatment with nitrosamines. Antibodies to tonofilament prekeratin stained bile duct epithelia and hepatocytes of normal liver and hepatocellular carcinoma cells and ductal cells of cholangiofibromas. These cells were not significantly stained by antibodies to vimentin. By contrast, antibodies to vimentin stained mesenchymal cells of normal liver and cells of early and advanced angiosarcomas and of undifferentiated spindle cell sarcoma. These mesenchymal tumor cells were not stained with antibodies to prekeratin. The presence of intermediate-sized filaments in these tumors, often in large whorl-like aggregates, was also demonstrated by electron microscopy. The results show that immunofluorescence microscopy with antibodies to cytoskeletal proteins is a powerful tool for the classification and differential diagnosis of mesenchymal and epithelial liver tumors. We propose that staining with antibodies to proteins of different types of intermediate filaments can be used to improve the identification of tumors of other organs, including metastases, as well as non-neoplastic proliferative lesions.

Morphologic character of transforming renal cell cultures derived from Wistar rats given dimethylnitrosamine.

The morphologic character of kidney cells during serial subculture following isolation from Wistar rats treated several hours to 1 week previously with a carcinogenic dose of dimethylnitrosamine (DMN; 60 mg/kg body weight following protein deprivation) was compared with the appearance of cultures derived from normal control rats. Apart from early signs of cell toxicity, cultures from DMN-treated rats appeared similar to those from untreated rats for the first four passages. Control cells underwent senescence usually by subculture 4, whereas the test cultures survived to express morphologic transformation (usually at subculture 5) as dense macroscopic colonies of piled up cells. In 18 of the 20 test cultures, the cell populations that persisted in continuous culture following expression of morphologic transformation were exclusively mesenchymal, closely resembling DMN-induced renal mesenchymal tumor cells in continuous culture. In the remaining 2 test cultures from DMN-treated rats, a persisting population of abnormal epithelium was present in addition to morphologically transformed mesenchymal cells. The occurrence of populations of altered mesenchymal and epithelial cells characterized by prolonged survival in vitro following isolation from rats shortly after treatment with a carcinogenic dose of DMN was believed to be related to the long-term induction in the rat kidney of a high incidence of mesenchymal tumors and a lower incidence of cortical epithelial tumors by the same dose schedule.

Smooth-muscle-associated contractile protein in renal mesenchymal tumour cells and in transformed cells from DMN-injected rats.

Cryostat sections and established in vitro cultures of dimethylnitrosamine(DMN)-induced renal mesenchymal tumours and monolayer cultures of transformed kidney cells derived from rats treated with a carcinogenic dose of DMN were examined by indirect immunofluorescence with human serum containing smooth muscle antibody. Eight mesenchymal tumours examined showed filamentous cytoplasmic staining of spindle cells infiltrating between renal tubules, whilst in normal kidneys interstitial cells were only weakly positive. In established in vitro cultures from 6 mesenchymal tumours, different patterns of staining were observed in morphologically different cell forms, ranging from fine filamentous staining in giant cells to diffuse cytoplasmic fluorescence in small bipolar cells, and cell outline staining in polygonal cells. In addition filamentous staining of microvillous projections and nucleolar staining were observed in some tumour cells. Monolayer cultures of transformed kidney cells showed strong staining of coarse, randomly-orientated cytoplasmic filaments, whilst fibroblasts cultured from normal rat kidney demonstrated an ordered array of fine, parallel filaments. Specificity of the immunofluorescent staining reaction was established by failure to obtain staining with normal serum, with smooth muscle antibody serum neutralized by homogenates of smooth muscle or extracts containing actin derived from smooth muscle. These results indicate that there is an apparent increase of actin-like contractile microfilaments in transformed cells and in renal mesenchymal tumours. The cytoplasmic contracile microfilaments in these cells may play a role in tumour cell mobility and invasion.