ObjectiveTo establish an animal model of anaplastic thyroid cancer with high metastatic activity as in human body. MethodsHuman anaplastic thyroid cancer cell line TAK was injected into one of the lateral lobes of the thyroid gland, as well as in the subcuitis in a series of nude mice. Mice were sacrificed when found moribund, and autopsy and histology were performed subsequently.ResultsThe implantation of human anaplastic thyroid cancer cells in an ectopic enviroment did not permit expression of metastasis potential. In contrast, intrathyroid implantation did. Lymph node (5/10), lung (3/10) and one metastasis (1/10) were noted upon histological examination. ConclusionAn animal model with high metastatic activity is established when human anaplastic thyroid cancer cell line TAK is implanted orthotopically into nude mice.
【Abstract】 Objective To investigate the impact of dermal papillary cells on vascularization of tissue engineered skinsubstitutes consisting of epidermal stem cells and allogeneic acellular dermal matrix. Methods Human foreskins from routinecircumcisions were collected to separate epidermal cells by using dispase with trypsogen. Collagen type IV was used to isolateepidermal stem cells from the 2nd and 3rd passage keratinocytes. Dermal papilla was isolated by the digestion method of collagenaseI from fetus scalp and cultured in routine fibroblast medium. Tissue engineered skin substitutes were reconstructed by seedingepidermal stem cells on the papillary side of allogeneic acellular dermis with (the experimental group) or without (the controlgroup) seeding dermal papillary cells on the reticular side. The two kinds of composite skin substitutes were employed to cover skindefects (1 cm × 1 cm in size) on the back of the BALB/C-nu nude mice (n=30). The grafting survival rate was recorded 2 weeks aftergrafting. HE staining and immunohistochemistry method were employed to determine the expression of CD31 and calculate themicrovessel density at 2 and 4 weeks after grafting. Results Those adhesion cells by collagen type IV coexpressed Keratin 19 andβ1 integrin, indicating that the cells were epidermal stem cells. The cultivated dermal papillary cells were identified by expressinghigh levels of α-smooth muscle actin. The grafting survival rate was significantly higher in experimental group (28/30, 93.3%), thanthat in control group (24/30, 80.0%). HE staining showed that the epithelial layer in experimental group was 12-layered with largeepithelial cells in the grafted composite skin, and that the epithelial layer in control group was 4-6-layered with small epithelial cells.At 2 and 4 weeks after grafting, the microvessel density was (38.56 ± 2.49)/mm2 and (49.12 ± 2.39)/mm2 in experimental group andwas (25.16 ± 3.73)/mm2 and (36.26 ± 3.24)/mm2 in control group respectively, showing significant differences between 2 groups(P lt; 0.01). Conclusion Addition of dermal papillary cells to the tissue engineered skin substitutes can enhance vascularization,which promotes epidermis formation and improves the grafting survival rate.
Objective The human amniotic epithel ial cells (hAECs) are a recently identified new type of stem cells.It has previously been shown that hAECs express hepatocyte-related gene and possess intracellular features and functional properties of hepatocytes. The hAECs may be a candidate seed cell for l iver regeneration. To research the survival and migrationin vivo of hAECs via adeno-associated virus-mediated the green fluorescent protein gene (AAV-GFP) transfection, and toexplore the expression of hepatocyte-l ike function. Methods Thirty nude mice (aging 6-8 weeks, half males and females, and weighing 20-22 g) were randomly divided into 3 groups (groups A, B, and C, n=10). The mice of groups A and C were made the 2/3 partial hepatectomy model, and the mice of group B underwent open abdominal operation without hepatectomy. The hAECs transfected by AAV-GFP were transplanted into the inferior end of the spleen in groups A and B with a cell density of 5 × 106/mL and a volume of 0.2 mL; the same volume of normal sal ine was injected in group C. At 4 hours, the nude mice were sacrificed and the samples of l iver, spleen, heart, lung, brain, and kidney were harvested and the general observation, histological observation, and immunofluorescence detection were performed for the hAECs survival, migration, and the functional properties of hepatocytes. Results No tumor tissue was found in l iver and spleen of 3 groups, and HE staining showed no tumor cells. There were a lot of roundl ike and deeply-stained cells with less cytoplasm and large nucleus in the spleen and the l iver of group A; no abnormal cells were found in l iver and spleen of groups B and C and in kidney, heart, bung, and brain of groups A, B, and C. The GFP+ cells were detected in the spleen and l iver of group A with expressing human albumin, but no GFP+ cells was found in l iver and spleen of groups B and C and in heart, kidney, lung, and brain of groups A, B, and C. Conclusion AAV-GFP infected hAECs transplanted into SCID nude mice with hepatectomy can keep the hepatocyte-l ike function. It will be beneficial to further identify their biological characteristics.
Objective To provide the seed cells for bone tissue engineering, to establ ish immortal ized human bone marrow mesenchymal stem cells (MSCxj) and to investigate the ectopic osteogenesis of MSCxj. Methods MSCxjs of the 35thand 128th generations were maintained and harvested when the cell density reached 2 109. Then, these cells were co-cultured with heterogeneous bone scaffold in groups A (the 35th generation, n=12) and group B (the 128th generation, n=12); heterogeneous bone alone was used in group C (n=12). The cell prol iferation was observed by scanning electron microscopy (SEM) after 48 hours and 18 days of osteogenic induction culture. The complex was implanted subcutaneouly through a 3-mm-incision at both sides of the back in 18 nude mice. Tetracycl ine label ing was performed before the animals were sacrificed. Tetracycl ine fluorescence staining, HE staining, ponceau staining, and immunohistochemistry staining for osteocalcin were performed at 4, 8, and 12 weeks after transplantation; the morphologic quantitative analysis was made. Results After 48 hours, SEM showed that MSCxjs adhered to heterogeneous bone and grew well; after 18 days, a large number of new filamentous extracellular matrix and small granules were found to cover the cells. The results of tetracycl ine fluorescence staining, HE staining, and ponceau staining in groups A and B showed that the osteogenesis was not obvious at 4 weeks after transplantation; osteoid matrix deposition was noted around and in theheterogeneous bone at 8 weeks; and osteogenesis was increased at 12 weeks. There was no significant difference in bone formation between groups A and B. Osteogenesis was not observed in group C. The osteocalcin expressions were positive in groups A and B. The bone ingrow percentages of groups A and B were 5.64% ± 2.68% and 4.92% ± 2.95% at 8 weeks, and 13.94% ± 2.21% and 14.34% ± 3.46% at 12 weeks, showing significant differences between 8 weeks and 12 weeks at the same group (P lt; 0.05) and no significant difference between groups A and B at the same time (P gt; 0.05). Conclusion MSCxj has favorable abil ities of ectopic osteogenesis and can be appl ied as seeded cells in bone tissue engineering.
Objective To investigate the feasibility and characteristic of tissue engineered testicular prosthesis with highdensity polyethylene(HDPE，trade name: Medpor) and polyglycolic acid(PGA). Methods The chondrocytes were isolated from the swine articular.The PGA scaffold was incorporated with medpor which semidiameters were 6mmand 4mm respectively.Then, the chondrocytes (5×10 7/ml) were seeded onto Medpor-PGA scaffold and cultured for 2 weeks. The ten BALB／C mice were divided into two groups randomly(n=5). In the experimental group, the cell-scaffold construct was implanted into subcutaneous pockets on the back of nude mice. In the control group, the Medpor-PGA scaffold was implanted. The mice of two groups were sacrificed to harvest the newly formed cartilage prosthesis after 8 weeks. Macroscopy, histology and immunohistochemistry observations were made. Results The gross observation showed that on changes were in shape and at size, the color and elasticity were similar to that of normal cartilage and that the cartilage integrated with Medpor in the experimental group; no cartilage formed and fiberlike tissue was found in the control group. HE staining showed that many mature cartilage lacuna formed without blood vessel and some PGA did not degradated completely. Toluidine blue staining showed extracellular matrix had metachromia. Safranin O-fast green staining showed that many proteoglycan deposited and collagen type Ⅱ expression was bly positive. In the control group, Medpor was encapsulated by fiber tissue with rich blood vessel. Conclusion The newly formed complex of Medpor-PGA and cells was very similar to testicle in gross view and to normal cartilage in histology. This pilot technique of creating testicular prosthesis by incorporating tissue-engineered cartilage with Medpor demonstrated success.
ObjectiveTo evaluate therapeutic effect of the targeting recombinant adenovirus Ad-EAFP-PALB/r-Caspase-3 on primary hepatocellular carcinoma cells (HepG2) and subcutaneous implanted tumors of nude mice. MethodsHepG 2 cells, breast cancer MDA-MB-231 cells， and normal hepatic L-02 cells were infected with the previously constructed targeting recombinant adenovirus Ad-EAFP-PALB/r-Caspase-3, then morphological change was observed and apoptosis index was detected by cell morphologic assay. Tumor growth and pathological changes were observed after the implanted tumors model of nude mice were injected with the recombinant adenovirus. Results Both apoptosis and obvious apoptotic peak of cells were observed by flow cytometry (FCM) in HepG 2 cell group. The apoptosis index of MDA-MB-231 and L-02 cells was 0 and 7.3%, respectively, which were significantly lower than that of HepG2 cells (48.2%), Plt;0.01. The volume of subcutaneous tumor of nude mice was (0.26±0.31) cm 3 in HepG2 cell group, (0.25±0.15) cm 3 in MDA-MB-231 cell group， and (0.26±0.28) cm 3 in control group on two weeks after implantation of cancer cells, and no statistical difference was found among them (Pgt;0.05). The volume of subcutaneous tumor of nude mice was (0.53±0.12) cm 3 in HepG 2 cell group, (0.49±0.22) cm 3 in MDA-MB-231 cell group， and (0.54±0.13) cm 3 in control group on four weeks after implantation of cancer cells, and the difference was not significant among them (Pgt;0.05). But on eight weeks after implantation of cancer cells, the volume of tumor was (0.65±0.13) cm 3 in HepG 2 cell group, (1.27±0.32) cm 3 in MDA-MB-231 cell group， and (1.43±1.09) cm 3 in control group, which suggested that the growth of tumor in HepG 2 cell group slowed down significantly when compared with MDA-MB-231 cell group and control group (Plt;0.01), although the difference in the latter two groups was not significant (Pgt;0.05). The necrosis regions were found with lymphocytic infiltration and apoptosis cells in HepG2 cell group after injection of recombinant adenovirus Ad-EAFP-PALB/r-Caspase-3, but no pathological change of cells was found in control group after injection. It was found that the cells in MDA-MB-231 cell group were solidly arranged with small glandular lumenlike structure, marked cellular atypia, multinucleated tumor cells and megakaryocytic tumor cells, which was not different from that before injection. ConclusionThe targeting recombinant adenovirus Ad-EAFP-PALB/r-Caspase-3 induces the apoptosis of primary hepatocellular carcinoma in vivo and in vitro, which may provide new ways of targeted gene therapy.
Objective To establish a xenograft model of hydroxycamptothecine (HCPT)-resistant human gastric cancer cell line (SGC-7901/HCPT) in nude mice and study its biological characteristics. Methods The SGC-7901 and SGC-7901/ HCPT cells were cultured in vitro. The cell suspension was injected subcutaneously into the nude mice. When the subcutaneous carcinoma was 1.0 cm in diameter, it was cut off and divided into pieces of 0.1-0.2 cm in diameter． Then the small pieces of tumor were re-transplanted subcutaneously into the second generation nude mice until the fourth generation. The morphological feature, ultramicro-structure, and growth characteristics of the fourth generation transplanted tumor were examined. The drug resistance was measured by methyl thiazolyl tetrazolium (MTT) assay. Results The transplanted tumor in nude mice was round or oval, and many blood vessels were on its surface. Under the light microscope, the sizes of SGC-7901 transplanted tumor cells were similar, and sizes of cell nuclei were also similar; Meanwhile, the morphous of SGC-7901/HCPT transplanted tumor cells were irregular and in disorder, and the size of the cell nuclei was different from each other. Under the electron microscope, the mitochondria and endoplasmic reticulum of SGC-7901 transplanted tumor cells were nearly normal and no swelling in cell nuclei; Meanwhile the cell nuclei of SGC-7901/HCPT transplanted tumor cells were lightly swelled, a the mitochondria and endoplasmic reticulum were obviously swelled. By MTT assay, compared with SGC-7901 transplanted tumor cells, the resistance index of SGC-7901/HCPT transplanted tumor cells was 9.02±0.78 in HCPT, and resistance index to Adriamycin， Mitomycin C, 5-fluorouracil, and Etoposide was 1.24±0.09, 1.31±0.17, 0.96±0.12, and 1.07±0.16, respectively. Conclusions A transplanted tumor model of SGC-7901/HCPT in nude mice is established successfully， and showing stable drug resistance to HCPT and no cross-resistance to other chemotherapeutics, which can be used for further experiments.
ObjectiveTo explore the endothelial cells from human peripheral blood and islet of rat co-transplantation under the renal capsule of diabetic nude mice to improve the survival and function of transplanted islet. MethodsThe endothelial cells from human peripheral blood(5×105)and freshly isolated rat islet cells were co-transplanted under the renal capsule of diabetic nude mice model, then the fasting blood glucose, body weight, peripheral blood C-peptide level, and intraperitoneal glucose tolerance test(IPGTT) were measured to evaluated the islet graft survival and function. ResultsCompared with the control group, the fasting blood glucose level significantly decreased(P < 0.01), peripheral blood C-peptide level rised(P < 0.01), and body weight increased(P < 0.01) of receptor nude mice in experience group, the IPGTT also improved. ConclusionThe endothelial cells from human peripheral blood and islet of rat co-transplan-tation can obviously improve the survival and function of transplanted islet of nude mice.
ObjectiveTo study the expression of lipid associated with neutrophil gelatinase associated lipocalin (NGAL) in nude mice orthotopic pancreatic cancer tissues and the relationship between the occurred and development of pancreatic cancer. MethodsThe expressions of NGAL mRNA and protein of pancreatic cancer tissues and their adjacent tissues, and normal pancreatic tissues in nude mice were detected by using RT-PCR and immunohistochemical methods. ResultsThe expressions of NGAL mRNA in pancreatic cancer tissues and adjacent tissues were significantly higher than that in normal pancreatic tissues (P < 0.05), and the expression of NGAL mRNA in pancreatic carcinoma tissues was significantly higher than that in para carcinoma tissues (P < 0.05). The strong positive expression rate of NGAL protein in pancreatic carcinoma tissues was significantly higher than thoes in para carcinoma tissues and normal pancreatic tissues (P < 0.05). ConclusionsNGAL is highly expressed in pancreatic cancer tissues, and NGAL may be an important regulatory factor in the development of pancreatic cancer.
ObjectiveTo study the feasibility of human adipose-derived stem cells (hADSCs) combined with small intestinal submucosa powder (SISP)/chitosan chloride (CSCl)-β-glycerol phosphate disodium (GP)-hydroxyethyl cellulose (HEC) for adipose tissue engineering. MethodshADSCs were isolated from human breast fat with collagenase type I digestion, and the third passage hADSCs were mixed with SISP/CSCl-GP-HEC at a density of 1×106 cells/mL. Twenty-four healthy female nude mice of 5 weeks old were randomly divided into experimental group (n=12) and control group (n=12), and the mice were subcutaneously injected with 1 mL hADSCs+SISP/CSCl-GP-HEC or SISP/CSCl-GP-HEC respectively at the neck. The degradation rate was evaluated by implant volume measurement at 0, 1, 2, 4, and 8 weeks. Three mice were euthanized at 1, 2, 4, and 8 weeks respectively for general, histological, and immunohistochemical observations. The ability of adipogenesis (Oil O staining), angiopoiesis (CD31), and localized the hADSCs (immunostaining for human Vimentin) were identified. ResultsThe volume of implants of both groups decreased with time, but it was greater in experimental group than the control group, showing significant difference at 8 weeks (t=3.348, P=0.029). The general observation showed that the border of implants was clear with no adhesion at each time point;fat-liked new tissues were observed with capillaries on the surface at 8 weeks in 2 groups. The histological examinations showed that the structure of implants got compact gradually after injection, and SISP gradually degraded with slower degradation speed in experimental group;adipose tissue began to form, and some mature adipose tissue was observed at 8 weeks in the experimental group. The Oil O staining positive area of experimental group was greater than that of the control group at each time point, showing significant difference at 8 weeks (t=3.411, P=0.027). Immunohistochemical staining for Vemintin showed that hADSCs could survive at each time point in the experimental group;angiogenesis was most remarkable at 2 weeks, showing no significant differences in CD31 possitive area between 2 groups (P>0.05), but angiogenesis was more homogeneous in experimental group. ConclusionSISP/CSCl-GP-HEC can use as scaffolds for hADSCs to reconstruct tissue engineered adipose.