The purpose of this study is to elucidate the participation of Paneth cells in experimentally induced adenocarcinoma of the intestine. The rats were fed with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) dissolved in drinking water ad libitum at a concentration of 100 micrograms/ml for 28 weeks. They were sacrificed 12 weeks after the last MNNG administration. A number of tumor cells containing large eosinophilic granules in their supranuclear cytoplasm (Paneth cells) were observed in about 20% of the experimentally induced adenocarcinoma of the small intestine. The granules were stained positively with Lendrum, periodic acid-Schiff, Masson's trichrome, and Mallory's phosphotungstic acid hematoxylin. Ultrastructurally, the granules were round, osmiophilic, and relatively even in size. We compared the morphologic features of the Paneth cell-containing small intestinal adenocarcinomas (Group I) with those without Paneth cells (Group II). Group I was distinguished from Group II by its better differentiation, larger tumor size and lower incidence of calcification. Although Paneth cells are extremely rare in human gastrointestinal carcinomas, twenty percent of MNNG-induced intestinal carcinomas harbor Paneth cells. The neoplastic Paneth cells in experimental carcinomas may differentiate from uncommitted cells in the deeper portion of the crypt.
Adenocarcinoma/chemically induced/*ultrastructure ; Animals ; Cell Transformation, Neoplastic/chemically induced/ultrastructure ; Intestinal Neoplasms/chemically induced/*ultrastructure ; *Methylnitronitrosoguanidine ; Rats ; Rats, Inbred Strains

The present study was designed in order to investigate the lectin induced cytoagglutination properties of normal and transformed cells and surface alterations in the early stage of the transformed cells by characterizing the structural changes on the hepatoma surface membrane. Rat and rabbit erythrocytes and Sarcoma 180 ascites tumor cells were used for the lectin-induced cytoagglutination. Plotting % agglutination versus concanavalin A(Con A) concentration, sigmoid curves appeared in all cases. alpha-methyl-D-mannopyranoside(alphaMM) inhibited Con A induced cytoagglutination and the degrees of inhibition depended on the cell types and species. When rats were fed a diet containing 0.06% 3'-methyl-4dimethylaminoazobenzene(3'-Me DAB) for 12 weeks, almost all of the rats had solid liver tumors. Polyacrylamide gel electrophoresis of surface membrane proteins of these rat livers and of transplanted tumor cells showed three distinct protein bands, of which two were absent in normal rat livers. The molecular weights of these proteins were 73,000, 66,000, and 57,000 daltons. Antiserum against primary hepatocarcinoma surface proteins precipitated with three membrane proteins obtained from primary hepatocarcinoma cells as well as transplanted hepatocarcinoma cells, suggesting the presence of specific tumor antigens in these cells.
Animal ; Cell Membrane/pathology* ; Cell Transformation, Neoplastic/ultrastructure* ; Concanavalin A/diagnostic use ; Liver Neoplasms, Experimental/chemically induced ; Liver Neoplasms, Experimental/ultrastructure* ; Methyldimethylaminoazobenzene ; Rabbits ; Rats ; Surface Properties

Hairy cell (HC) transformation of human peripheral blood lymphocytes (PBL) by Coxiella burnetii was studied to clarify the significance of persistency of C. burnetii in a hairy cell line (designated "TOL"). TOL cells which exhibited HC characteristics in hairy cell leukemia (HCL) were persistently infected with C. burnetii. Two strains of C. burnetii, our isolate from TOL cells and the original isolate in 1935, the Nine Mile strain from American Type Culture Collection (ATCC, U.S.A), were inoculated to PBL cultures. HC transformation not only by our isolates (87%) but also by Nine Mile strain (100%) was demonstrated in an average of 20 days. The original observation that Coxiella induced HC transformation in vitro was also confirmed in experiments with PBL exposed to C. burnetii in vivo. Spontaneous development of HC were observed in cultures of PBL only from coxiellemic cases (12/24) but not from C. burnetii negative cases (0/57). All HC cell lines (34) as determined by their morphology and cytochemical markers of HC in HCL remained infected with C. burnetii invariably.
Blood Cells/*microbiology/*ultrastructure ; Cell Line ; *Cell Transformation, Neoplastic ; Coxiella burnetii/isolation & purification/*physiology ; Human ; Leukemia, Hairy Cell/microbiology/*pathology ; Lymphocytes/*microbiology/*ultrastructure ; Microscopy, Electron, Scanning ; Support, Non-U.S. Gov't

The rearrangement of the actin cytoskeleton has been shown to play a critical role in the development of transformation and malignant phenotype of cancer cells. Rho family GTPases regulate the arrangement of the actin cytoskeleton. By wound-healing assay, we have found that NIH 3T3 fibroblast cells move towards the wound- gaps by extending filopodial and lamellipdial structures at the leading edge of the moving cells. We have inactivated the function of Rho GTPases of v-Ras transformed NIH 3T3 cells by overexpressing Rho GTPase-activating (RhoGAP) domain of RhoGAP of p190. We have observed that inactivation of Rho, Rac and Cdc42 GTPases by overexpressing RHG causes inhibition of: (i) polymerization of actin to form filaments, (ii) formation of lamellipodia, filopodia and stress fibres, (iii) cell motility, (iv) cell spreading and (v) cell-to-cell adhesions. These results further strengthen the current knowledge on the role of Rho, Rac and Cdc42 GTPases in the regulation of the rearrangement of actin cytoskeleton. Our results, for the first time, demonstrate that RhoGAP domain of RhoGAP could be used to study the molecular mechanism of Ras-mediated signalling in growth, differentiation and carcinogenesis.
Animals ; Biological Assay ; Cell Line, Transformed ; Cell Movement/*physiology ; Cell Transformation, Neoplastic/*ultrastructure ; Mice ; Microfilaments/metabolism/*ultrastructure ; NIH 3T3 Cells ; Research Support, Non-U.S. Gov't ; Wound Healing ; rho GTP-Binding Proteins/genetics/*physiology

Stem cells are known to maintain stemness at least in part through secreted factors that promote stem-like phenotypes in resident cells. Accumulating evidence has clarified that stem cells release nano-vesicles, known as exosomes, which may serve as mediators of cell-to-cell communication and may potentially transmit stem cell phenotypes to recipient cells, facilitating stem cell maintenance, differentiation, self-renewal, and repair. It has become apparent that stem cell-derived exosomes mediate interactions among stromal elements, promote genetic instability in recipient cells, and induce malignant transformation. This review will therefore discuss the potential of stem cell-derived exosomes in the context of stromal remodeling and their ability to generate cancer-initiating cells in a tumor niche by inducing morphologic and functional differentiation of fibroblasts into tumor-initiating fibroblasts. In addition, the immunosuppressive potential of stem cell-derived exosomes in cancer immunotherapy and their prospective applications in cell-free therapies in future translational medicine is discussed.
Apoptosis ; Cell Communication ; Cell Transformation, Neoplastic ; Disease Progression ; Exosomes ; physiology ; Humans ; Immunotherapy ; methods ; Mesenchymal Stromal Cells ; physiology ; Neoplasms ; blood supply ; pathology ; therapy ; Neoplastic Stem Cells ; ultrastructure ; Neovascularization, Pathologic ; pathology ; Organelle Biogenesis ; Tumor Microenvironment

OBJECTIVETo study the effect of PGC-1alpha in human liver carcinogenesis, and explore the regulatory role of PGC-1alpha in the development of liver cancer.

METHODSThe changes of PGC-1alpha mRNA level in normal human liver tissues and human liver tumors was examined by quantitative RT-PCR. PGC-1alpha mRNA level was interfered by siRNA in human liver cell line L02 in vitro, and their morphological changes were observed by pathology with HE staining. The ultrastructure of cells was observed by electron microscopy. In addition, the gene expression pattern of decreasing PGC-1alpha in L02 cells and liver tumor tissue was compared by human genome 70-mer oligonucleotide microarray analysis.

RESULTSPGC-1alpha expression was weaker in the malignant liver tumors compared with that in normal liver tissues. When PGC-1alpha expression was suppressed in human liver L02 cells, the cells became smaller with enlarged nuclei, and myelin figures were observed in mitochondria by electron microscopy, similar with the ultrastructure of liver cancer cells. Microarray analysis showed that the decrease of PGC-1alpha in L02 cells induced up-regulation of some oncogenes and adhesive genes, and down-regulation of a number of tumor suppressor genes and cell proliferation suppressor genes. The changes of decreasing expression pattern of PGC-1alpha gene in L02 cells were similar to those in human liver cancer tissue.

CONCLUSIONThe results of the present study show that PGC-1alpha is down-regulated in liver cancers and is involved in the malignant transformation in human normal liver cells in vitro, suggesting an important regulatory role of PGC-1alpha in the development of liver cancer.

Adult ; Carcinoma, Hepatocellular ; metabolism ; pathology ; ultrastructure ; Cell Line, Tumor ; Cell Transformation, Neoplastic ; Female ; Gene Expression Profiling ; Gene Expression Regulation, Neoplastic ; Heat-Shock Proteins ; genetics ; metabolism ; Humans ; Liver ; metabolism ; pathology ; Liver Neoplasms ; metabolism ; pathology ; ultrastructure ; Male ; Middle Aged ; Oligonucleotide Array Sequence Analysis ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; RNA Interference ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; Transcription Factors ; genetics ; metabolism

OBJECTIVEImmortal cell line of human embryonic esophageal epithelium (SHEE) was induced by E6E7 genes of human papillomavirus (HPV) type 18 in our laboratory. To identify the fully malignant transformation at its 85th passage (SHEE85), the malignant phenotype, tumorigenesis and invasive potency were studied.

METHODThe cultured SHEE85 cells were observed under the light and the electron microscope (EM) for cell morphology, analyzed by flow cytometry for cell cycle. The tumorigenesis was assayed by plating cells in soft-agar and transplanting cells into the nude mice and SCID mice. To detect invasive potency, cells were cultured on amniotic membrane in vitro and transplanted into peritoneal cavity of mice in vivo.

RESULTSSHEE85 cells were crowded in cultivation with different sizes and shapes under light microscope, and displayed proliferative morphology under EM. Proliferative index was 47% with 12% hyperploidy cells in determination of DNA histogram. Many large colonies grew in soft-agar (4%) and the transplanted tumors were found in all 4 nude and 4 SCID mice, with strong invasive potency demonstrated in vitro and in vivo.

CONCLUSIONThe immortal esophageal epithelial cell line induced by HPV18 E6 E7 is derived from a fully malignant transformation with a strong invasive potency at the 85th passage. It is also a reliable model for studying the cellular and molecular mechanisms of carcinogenesis of the esophageal carcinoma.

Animals ; Cell Division ; genetics ; Cell Transformation, Neoplastic ; Cell Transformation, Viral ; genetics ; Cells, Cultured ; Epithelial Cells ; cytology ; ultrastructure ; virology ; Esophagus ; cytology ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Mice, SCID ; Microscopy, Electron ; Neoplasm Transplantation ; Neoplasms, Experimental ; pathology ; Oncogene Proteins, Viral ; genetics ; Papillomaviridae ; genetics ; Ploidies ; Transplantation, Heterologous

AIMTo study the inhibitory effect and mechanism of nobiletin on Heps tumor bearing mice.

METHODSModels of Heps tumor bearing mice were established. The inhibitory rates of tumor growth were calculated, the apoptosis morphology of tumor tissue was observed. The T lymphocyte transformation capacity was tested by MTT assay, the TNFalpha and IL-2 production were measured by LDH kits.

RESULTSNobiletin could significantly inhibit Heps tumor growth. The inhibitory rates were 42.14% - 65.09% (P < 0.01). The morphology of tumor tissues in nobiletin group had typical characters of necrosis and apoptosis through transmission electron microscope. Nobiletin could stimulate T lymphocyte transformation and the production of TNFalpha and IL-2.

CONCLUSIONNobiletin has obvious antitumor effect on Heps, the main mechanism is to enhance the cellular immune function and induce apoptosis of tumor tissue.

Animals ; Antineoplastic Agents, Phytogenic ; isolation & purification ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Transformation, Neoplastic ; drug effects ; metabolism ; pathology ; Citrus ; chemistry ; Female ; Flavones ; isolation & purification ; pharmacology ; Humans ; Interleukin-2 ; biosynthesis ; Liver Neoplasms, Experimental ; pathology ; prevention & control ; ultrastructure ; Male ; Mice ; Mice, Inbred ICR ; Plants, Medicinal ; chemistry ; T-Lymphocytes ; drug effects ; metabolism ; pathology ; Tumor Necrosis Factor-alpha ; biosynthesis