Biomedical subjects

Z Y Tang

Publications and source records attributed to Z Y Tang.

At least 19 recordsLinked to original sources

PubMed2006

Six cases of ectopic ACTH syndrome caused by thymic carcinoid.

The ectopic ACTH syndrome (EAS) caused by thymic carcinoid is rare and its diagnosis remains a challenge to the endocrinologist. Here are six cases of EAS with a typical Cushing habitus accompanied by hyperpigmentation and hypokalemia. For all six patients, the high dose (8 mg) dexamethasone suppression test (HDDST) showed lack of suppression, computed tomography (CT) scanning documented anterior mediastinal masses, and the mediastenal tumors removed were confirmed as ACTH secreting thymic carcinoids by positive ACTH and NSE staining. Our data indicate that HDDST chest radiologic imaging and other laboratory examinations will greatly assist in diagnosing the thymic carcinoid-induced EAS at an earlier stage, which will significantly improve the long-term survival of the patient.

ACTH Syndrome, Ectopic↗

PubMed2002

The biological behaviour of human adenoid cystic carcinoma cells transduced with interleukin-2-gene.

Adenoid cystic carcinoma (ACC) of the salivary glands is a highly infiltrative malignant tumour with a tendency for lung metastasis. Gene therapy could be a potentially effective therapy for ACC and its metastasis. The aims of the study were: To transduce interleukin-2 (IL-2) gene into an ACC cell line with predisposition for lung metastasis (ACC-M); to compare the bioactivity of the gene-transduced cells and the parent cell line in vitro and in vivo. The IL-2 gene was transduced via a bicistronic retroviral vector into the ACC-M cells. The growth rate and DNA cell cycles of the parent ACC-M, the control viral vector AmGCEN, and the gene transduced AmIL-2 cell cultures were compared quantitatively and by flow cytometry, respectively. The tumourigenic ability of the three cell lines was verified by inoculation in athymic nude mice. The tumours developed were extracted and compared quantitatively and histologically. There was no difference in the growth rate and the DNA count between the ACC-M, AmGCEN, and AmIL-2 cell cultures. In the animal experiment, both the ACC-M and AmGCEN cells stimulated lung metastasis in all the mice, whereas there was no tumour found in the 1 x 10(6) AmIL-2 cells inoculation. On 3 x 10(6) AmIL-2 cells stimulation, three out of six mice developed tumours but the mass and volume of the tumours were smaller than the other two groups. Under light microscopy, the ACC-M tumours were mainly poorly differentiated with minimal cellular matrix, whereas the AmIL-2 tumours were well differentiated with ample matrix. The transduction of IL-2 gene can reduce the tumourigenicity of ACC-M cells and induces tumour cell differentiation in mice. The IL-2 gene can be a potential effective gene for the treatment of adenoid cystic carcinoma of salivary glands and its lung metastasis.

Animals↗

PubMed2001

[Telomerase activity in bladder cancer tissues].

OBJECTIVE: To study the correlation between telomerase and bladder cancer. METHODS: The telomerase activity was detected by telomerase PCR ELISA in 41 cases of bladder cancer tissues and 23 cases of non-cancerous bladder tissues. RESULTS: The telomerase activity was positive in 34 cases of bladder cancer tissues (82.9%) and 1 case of non-cancerous tissues (4.3%); the difference of positive rate was significant (P < 0.01). CONCLUSIONS: Telomerase activity is related with bladder cancer closely; telomerase activation may be an important molecular step in the initiation and development of bladder cancer; telomerase may be an excellent molecular biomarker in finding bladder cancer at an early stage and in postoperative following-up.

Adult↗

PubMed2001

Experience of 1000 patients who underwent hepatectomy for small hepatocellular carcinoma.

BACKGROUND: Recently, the implementation of screening programs using alpha-fetoprotein (AFP) and ultrasonography in high risk populations has identified increasing numbers of patients with small hepatocellular carcinoma (small HCC). The aim of this study was to summarize the authors' experience in patients who underwent hepatectomy for small HCC and the factors that influence or improve long term survival. METHODS: The study included 1000 patients who underwent hepatectomy for small HCC (< or = 5 cm) and compared them with 1366 patients who underwent hepatectomy for large HCC (> 5 cm) during the same period. A Cox proportional-hazards model was used for multivariate analysis of prognostic factors. RESULTS: Comparison between patients with small HCC (n = 1000 patients) and patients with large HCC (n = 1366 patients) revealed that those with small HCC had a higher resection rate (93.6% [1000 of 1068 patients] vs. 55.7% [1366 of 2451 patients]; P < 0.01), a higher curative resection rate (80.5% [805 of 1000 patients] vs. 60.7% [829 of 1366 patients]; P < 0.01), a lower operative mortality rate (1.5% [15 of 1000 patients] vs. 3.7% [50 of 1366 patients]; P < 0.01), better differentiation of tumor cells (Edmondson Grade 3-4; 14.9% vs. 20.1%; P < 0.01), a higher incidence of single nodule tumors (82.6% vs. 64.4%; P < 0.01), a higher proportion of well encapsulated tumors (73.3% vs. 46.3%; P < 0.01), a lower incidence of tumor emboli in the portal vein (4.9% vs. 20.8%; P < 0.01), and higher survival rates after undergoing resection (5 years: 62.7% vs. 37.1%; P < 0.01; 10 years: 46.3% vs. 29.2%; P < 0.01). No significant difference was found between survival after undergoing minor resection (n = 949 patients) or lobectomy (n = 51 patients) in patients with small HCC (P > 0.05). Reresection for subclinical recurrence or solitary pulmonary metastasis after small HCC resection was undertaken in 84 patients. CONCLUSIONS: Resection is still the modality of first choice for the treatment of patients with small HCC. Minor resection instead of lobectomy was the key to increasing resectability and decreasing operative mortality, and reresection for subclinical recurrence or solitary pulmonary metastasis was important approach to prolonging survival further.

Adolescent↗

PubMed2001

Efficacy of intra-hepatectomy 5-FU on recurrence and metastasis of human hepatocellular carcinoma in nude mice.

A novel intra-operative chemotherapy nude mouse model for human hepatocellular carcinoma (HCC) has been developed. Intra-peritoneal (i.p.) administration of 5-fluorouracil (5-FU) was begun 2 hr before hepatic resection of HCC and then continued post-operatively for 4 consecutive days. This regime, termed intra-hepatectomy chemotherapy (IHC), significantly prolonged animal survival compared with pre-operative 5-FU, neoadjuvant therapy, 5-FU post-operative adjuvant therapy, surgery alone, 5-FU without surgery, and the untreated control. The median survival of the intra-operative 5-FU-treated group was 127 days compared with 78 days for the neoadjuvantly-treated animals and 53 days for the control group (p<0.006). When all animals with neoadjuvant 5-FU treatment had died, 60% of the animals in the IHC group were still alive (p<0.011). Survival of all other treatment groups, including 5-FU without surgery, surgery alone, and adjuvant post-operative chemotherapy, was not significantly different from the untreated control group. Five animals in the IHC group were free of tumor when sacrificed at day 150 post-surgically. While 100% of animals in the control group had lymph nodes draining the liver involved with metastases, only 20% of animals in the IHC group had lymph node metastases. These data suggested that IHC therapy increased survival by preventing metastases of cancer cells not removed in the liver resection procedure. The results of this study indicate that IHC therapy for resection of HCC should be investigated clinically.

Animals↗

PubMed2001

Chromosome 8p deletion is associated with metastasis of human hepatocellular carcinoma when high and low metastatic models are compared.

Recently, we found that chromosome 8p deletion might be associated with hepatocellular carcinoma (HCC) metastasis by analyzing the differences in chromosomal alterations between primary tumors and their matched metastatic lesions of HCC with comparative genomic hybridization (CGH) (Qin et al. 1999). To further confirm this interesting finding, the genomic changes of two models bearing human HCC with different metastatic potentials (LCI-D20 and LCI-D35), and the new human HCC cell line with high metastatic potential (MHCC97) were analyzed by CGH. Gains on 1q, 6q, 7p, and 8q, and losses on 13p, 14p, 19p, 21, and 22 were detected in both LCI-D20 and LCI-D35 models. However, high copy number amplification of a minimum region at 1q12-q22 and 12q, and deletions on 1p32-pter, 3p21-pter, 8p, 9p, 10q, 14q, and 15p were detected only in the LCI-D20 model. Gains on 1p21-p32, 2p13-p21, 6p12-pter, 9p, 15q, and 16q11-q21, and losses on 2p23-pter, 4q24-qter, 7q31-qter, 12q, 17p, and 18 were detected only in the LCI-D35 model. The chromosomal aberration patterns in the MHCC97 cell line were similar to its parent LCI-D20 model, except that gains on 19q and losses on 4, 5, 10q, and 13q were found only in the cell line. These results provide some indirect clues to the metastasis-related chromosomal aberrations of HCC and further support the finding that 8p deletion is associated with HCC metastasis. 1q12-22 and 12q might harbor a novel oncogene(s) that contributes to the development and progression of HCC. Amplification on 8q and deletions on 4q and 17p may be not necessary for HCC metastasis.

Animals↗

PubMed2001

The potential of plasma thrombomodulin as a biomarker of portal vein tumor thrombus in hepatocellular carcinoma.

PURPOSE: To study the relationship between thrombomodulin (TM) plasma levels and the formation of portal vein tumor thrombus (PVTT) in patients with hepatocellular carcinoma (HCC). METHODS: Pre- and-postoperative plasma TM levels of 45 patients with HCC and six patients with benign liver-occupying lesion were measured by enzyme-linked immunosorbent assay (ELISA), and the expression of TM in human HCC tissues was determined by immunohistochemistry assay. RESULTS: The preoperative plasma TM level of patients with HCC (10.2+/-5.7 ng/ml) was significantly higher than that of those patients with benign liver-occupying lesion (6.1+/-2.2 ng/ml) and that of normal controls (5.7+/-1.0 ng/ml), respectively (P<0.05). The postoperative TM level of 40 patients with HCC whose tumors had been removed decreased significantly than the preoperative TM level (10.8+/-5.3 ng/ml versus 7.6+/-4.2 ng/ ml, P < 0.05), whereas there was no significant difference between the preoperative and postoperative TM level of six patients with benign liver-occupying lesion (6.1+/-2.2 ng/ml versus 5.9+/-1.8 ng/ml, P>0.05). The preoperative plasma TM level of patients with single HCC (11.5+/-5.9 ng/ml) or no PVTT (11.4+/-5.6 ng/ml) was significantly higher than that of those patients with multiple HCC (8.1+/-4.6 ng/ml) or PVTT (6.9+/-4.5 ng/ ml), respectively (P<0.05). The preoperative plasma TM level of the patients with HCC tissue that stained positive for TM was significantly higher than those with tissue that stained negative for TM (12.2+/-6.5 ng/ ml versus 8.7+/-4.6 ng/ml, P<0.05). The postoperative plasma TM level showed no difference between the patients with HCC tissue stained positive and negative for TM (8.3+/-4.1 ng/ml versus 7.6+/-4.4 ng/ml, P>0.05). There was also no significant difference between the plasma TM level and other clinicopathological futures. CONCLUSIONS: Plasma TM increases in patients with HCC and can be a biomarker of the formation of PVTT.

Adult↗

PubMed2001

Combined IL-12 and GM-CSF gene therapy for murine hepatocellular carcinoma.

Among various immunotherapeutic approaches, interleukin-12 (IL-12) is particularly appealing because of its superior antitumor effects, which have been demonstrated in preclinical as well as clinical studies. However, IL-12 therapy was often accompanied by severe side effects due mainly to the supranormal induction of interferon-gamma. To optimize the therapeutic efficacy and lower the side effects of IL-12, we have investigated the antitumor activity of combined IL-12 and granulocyte-macrophage colony-stimulating factor (GM-CSF) gene therapy in a highly malignant and poorly immunogenic murine hepatocellular carcinoma model. Using a versatile hydrodynamics-based DNA delivery method, we showed that the combined gene delivery of IL-12 and GM-CSF induced very strong antitumor cellular immunity and achieved significant therapeutic efficacy, whereas each cytokine gene alone yielded appreciable but less effects. We also observed that the combined therapy induced lower levels of interferon-gamma than did IL-12 alone. These results suggest that combined IL-12 and GM-CSF therapy can render a stronger antitumor effect as well as lowering potential side effects.

Animals↗

PubMed2001

Multimodality treatment in hepatocellular carcinoma patients with tumor thrombi in portal vein.

AIM: To compare the therapeutic effect and significances of multimodality treatment for hepatocellular carcinoma (HCC) with tumor thrombi in portal vein (PVTT). METHODS: HCC patients (n=147) with tumor thrombi in the main portal vein or the first branch of portal vein were divided into four groups by the several therapeutic methods. There were conservative treatment group in 18 out of patients (group A); and hepatic artery ligation(HAL) and/or hepatic artery infusion (HAI) group in 18 patients (group B), in whom postoperative chemoembolization was done periodically; group of removal of HCC with PVTT in 79 (group C) and group of transcatheter hepatic arterial chemoembolization (TACE) or HAI and/or portal vein infusion (PVI) after operation in 32 (group D). RESULTS: The median survival period was 12 months in our series and the 1-,3-, and 5-year survival rates were 44.3%, 24.5% and 15.2%, respectively. The median survival times were 2, 5, 12 and 16 months in group A, B, C and D, respectively. The 1-, 3- and 5-year survival rates were 5.6%, 0% and 0% in group A; 22.2%, 5.6% and 0% in group B; 53.9%, 26.9% and 16.6% in group C; 79.3%, 38.9% and 26.8% in group D, respectively. Significant difference appeared in the survival rates among the groups (P < 0.05). CONCLUSION: Hepatic resection with removal of tumor thrombi and HCC should increase the curative effects and be encouraged for the prolongation of life span and quality of life for HCC patients with PVTT, whereas the best therapeutic method for HCC with PVTT is with regional hepatic chemotherapy or chemoembolization after hepatic resection with removal of tumor thrombi.

Adult↗

PubMed2001

Hepatocellular carcinoma--cause, treatment and metastasis.

In the recent decades, the incidence of hepatocellular carcinoma (HCC) has been found to be increasing in males in some countries. In China, HCC ranked second of cancer mortality since 1990s. Hepatitis B and C viruses (HBV and HCV) and dietary aflatoxin intake remain the major causative factors of HCC. Surgery plays a major role in the treatment of HCC, particularly for small HCC. Down-staging unresectable huge HCC to smaller HCC and followed by resection will probably be a new approach for further study. Liver transplantation is indicated for small HCC, however, some issues remain to be solved. Different modes of regional cancer therapy for HCC have been tried. Systemic chemotherapy has been disappointing in the past but the future can be promising. Biotherapy, such as cytokines, differentiation inducers, anti-angiogenic agents, gene therapy and tumor vaccine will probably play a role, particularly in the prevention of tumor recurrence. HCC invasiveness is currently the major target of study. Tremendous works have been done at the molecular level, which will provide clues for biomarker of HCC progression as well as targets for intervention.

Animals↗

PubMed2001

Abnormal beta-catenin gene expression with invasiveness of primary hepatocellular carcinoma in China.

AIM: To study the abnormal expression of beta-catenin gene and its relationship ith invasiveness of primary hepatocellular carcinoma among Chinese people. METHODS: Thirty-four hepatocellular carcinoma (HCC) specimens and adjacent para-cancerous tissues, 4 normal liver tissues were immunohistochemically stained to study subcellular distribution of beta-catenin. Semiquantitive analysis of expression of beta-catenin gene exon 3 mRNA was examined by RT-PCR and in situ hybridization. The relationship between expressions of both beta-catenin protein, mRNA and clinicopathological characteristics of HCC was also analyzed. RESULTS: Immuno-histochemistry showed that all normal liver tissues and para-cancerous tissues examined displayed membranous type staining for beta-catenin protein, occasionally with weak expression in the cytoplasm. While 21 cases (61.8%) of HCC examined showed accumulated type in cytoplasms or nuclei. The accumulated type Labling Index (LI) of cancer tissue and para-cancerous tissue was (59.9 +/- 26.3) and (18.3 +/- 9.7) respectively (P<0.01). Higher accumulated type LI was closely related with invasiveness of HCC. Results of RT-PCR showed the beta-catenin gene exon 3 mRNA Expression Index (EI) of 34 HCCs was higher than that of para-cancerous tissue and normal liver tissue. Using in situ hybridization, the signal corresponding to beta-catenin gene exon 3 mRNA was particularly strong in cytoplasm of HCC when compared with those of para-cancerous and normal liver tissues. Over expression of beta-catenin exon 3 was also found to be correlated with high metastatic potential of HCC. CONCLUSION: Abnormal expression of beta-catenin gene may contribute importantly to the invasiveness of HCC among Chinese people.

Cadherins↗

PubMed2001

Metastatic human hepatocellular carcinoma models in nude mice and cell line with metastatic potential.

Metastatic human HCC model is needed for the studies on mechanism and intervention of metastatic recurrence. By using orthotopic implantation of histologically intact tissues of 30 surgical specimens, a patient-like metastatic model of human HCC in nude mice (LCI-D20) and a low metastatic model of human HCC in nude mice (LCI-D35) have been established. All mice with transplanted LCI-D20 tumors exhibited extremely high metastatic ability including spontaneous metastasis to liver, lungs, lymph nodes and peritoneal seeding. Remarkable difference was also found in expression of some of the invasiveness related genes and growth factors between the LCI-D20 and LCI-D35 tumors. PAI-1 increased gradually following tumor progression in LCI-D20 model, and correlated with tumor size and AFP level. Phasic expression of tissue intercellular adhesion molecule-1 in this model was also observed. Using corneal micropocket model, it was demonstrated that the vascular response induced by LCI-D20 tumor was stronger than that induced by LCI-D35 tumor. Similar report on metastatic human HCC model in nude mice and human HCC cell line with metastatic potential was rarely found in the literature. This LCI-D20 model has been widely used for the studies on intervention of metastasis, including anti-angiogenesis,antisense approach, metalloproteinase inhibitor, differentiation inducer, etc. It is concluded that the establishment of metastatic human HCC model in nude mice and human HCC cell line with metastatic potential will provide important models for the in vitro and in vitro study of HCC invasiveness, angiogenesis as well as intervention of HCC recurrence.

Animals↗

PubMed2001

Establishment of cell clones with different metastatic potential from the metastatic hepatocellular carcinoma cell line MHCC97.

AIM: To establish clone cells with different metastatic potential for the study of metastasis-related mechanisms. METHODS: Cloning procedure was performed on parental hepatocellular carcinoma (HCC) cell line MHCC97, and biological characteristics of the target clones selected by in vivo screening were studied. RESULTS: Two clones with high (MHCC97-H) and low (MHCC97-L) metastatic potential were isolated from the parent cell line. Compared with MHCC97-L, MHCC97-H had smaller cell size (average cell diameter 43 microm vs 50 microm) and faster in vitro and in vivo growth rate (tumor cell doubling time was 34.2h vs 60.0h). The main ranges of chromosomes were 55-58 in MHCC97-H and 57-62 in MHCC97-L. Boyden chamber in vitro invasion assay demonstrated that the number of penetrating cells through the artificial basement membrane was (37.5 +/- 11.0) cells/field for MHCC97-H vs (17.7 +/- 6.3)/field for MHCC97-L. The proportions of cells in G0-G1 phase, S phase, and G2-M phase for MHCC97-H/MHCC97-L were 0.56/0.65, 0.28/0.25 and 0.16/0.10, respectively, as measured by flow cytometry. The serum AFP levels in nude mice 5wk after orthotopic implantation of tumor tissue were (246 +/- 66) microg.L(-1) for MHCC97-H and (91 +/- 66) microg.L(-1) for MHCC97-L. The pulmonary metastatic rate was 100% (10/10) vs 40% (4/10). CONCLUSION: Two clones of the same genetic background but with different biological behaviors were established, which could be valuable models for investigation on HCC metastasis.

Albumins↗

PubMed2001

Inhibition of hematopoietic progenitor cell proliferation by ethanol in human immunodeficiency virus type 1 tat-expressing transgenic mice.

BACKGROUND: A number of hematological abnormalities are associated with both human immunodeficiency virus type 1 (HIV-1) infection and alcohol abuse. There is little information on how alcohol abuse might further influence the survival and growth of hematopoietic progenitors in HIV-infected individuals in the presence of immune system abnormalities and anti-HIV drugs. Because there is evidence that viral transactivator Tat itself can induce hematopoietic suppression, in this study we examined the role of ethanol as a cofactor in transgenic mice that expressed HIV-1 Tat protein. METHODS: Tat transgenic mice and nontransgenic littermates were given ethanol (20% v/v) and the anti-HIV drug 3'-azido-3'-deoxythymidine (AZT; 1 mg/ml) in drinking water. Immunosuppression in mice was induced by weekly intraperitoneal injections of anti-CD4 antibody. Hematopoiesis was examined by erythroid colony forming unit (CFU-E) and granulocyte/macrophage colony-forming unit (CFU-GM) assays of the bone marrow progenitor cells. RESULTS: Administration of ethanol for 7 weeks resulted in a 50% decrease in the proliferative capacity of CFU-E- and CFU-GM-derived progenitors from transgenic mice compared with that of ethanol-treated nontransgenic controls. Similar decreases also were observed in transgenic mice treated with AZT or a combination of AZT and ethanol. Furthermore, ethanol and AZT were significantly more toxic to the granulopoietic progenitors (40-50% inhibition) than to the erythropoietic progenitors (10-20% inhibition) in Tat transgenic mice. Although a 10 day exposure of Tat transgenic and nontransgenic mice to a combination of ethanol and AZT had no suppressive effect on the erythropoietic and granulopoietic progenitor cells, there was a marked decrease (40-60%) in CFU-GM in mice made immunodeficient by CD4+ T-lymphocyte depletion. The ethanol-treated Tat transgenic mice but not the nontransgenic litter-mates also showed a significant decrease (25%) in CFU-GM. CONCLUSION: Our in vivo study strongly suggests that ethanol ingestion in HIV-1-infected individuals, particularly those on antiretroviral drugs, might increase bone marrow toxicity and contribute to HIV-1-associated hematopoietic impairment.

Animals↗

PubMed2001

[On-line determination of niobium and tantalum in soil and geochemical exploration samples by inductively coupled plasma atomic emission spectrometry with solvent extraction flow injection].

A new method for the determination of trace niobium and tantalum in soil and geochemical exploration samples by inductively coupled plasma atomic emission spectrometry with solvent extraction flow injection was proposed. The niobium and tantalum were extracted with the mixed solvent of MIBK and TBP at 1 mol.L-1 HF and 4 mol.L-1 H2SO4. Experiment conditions and manifold parameters were investigated in detail. The detection limits were 0.5 x 10(-12) g.L-1 and 0.8 x 10(-12) g.L-1. The proposed method was rapid, simple and accurate, it has been applied to the determination of trace niobium and tantalum in national standard samples. The results were in good agreement with certified values with precisions of 4.5% and 5.1% RSD (n = 10). The sample throughput for niobium and tantalum is 20.h-1.

Flow Injection Analysis↗

PubMed2001

[Determination of trace Sn in geosamples by flow injection on-line co-precipitation hydride generation atomic fluorescence spectrometry].

It is reported that a FI on-line co-precipitation technique for the pre-concentration of trace amount of Sn with the precipitate of Mg(OH)2 as carrier is hyphenated with AFS determination. The co-precipitation is carried out in NaOH medium and the precipitate is collected in a precipitation collector. The precipitate is then dissolved by HCl and reacted with NaBH4, the hydride is transferred directly into the atomizer. The relative standard deviation is 5.15% for 10 determinations of 30 ng.mL-1 Sn and the detection limit of 0.21 ng.g-1 is obtained. The developed method has been applied to the determination of trace Sn in geosamples with satisfactory results.

Chemical Precipitation↗

PubMed2000

Human Kaposi's sarcoma cell-mediated tumorigenesis in human immunodeficiency type 1 tat-expressing transgenic mice.

BACKGROUND: The human immunodeficiency virus type 1 (HIV-1) transactivator (Tat) protein has been linked to the development and course of Kaposi's sarcoma (KS) associated with acquired immunodeficiency disease syndrome (AIDS-KS). Tat is an 86-101 amino-acid protein encoded by two exons. To evaluate the growth-promoting effects of Tat in AIDS-KS in vivo, we developed transgenic mice expressing the one-exon-encoded 72 amino-acid protein (Tat(72)) and the two-exon-encoded 86 amino-acid protein (Tat(86)). METHODS: Human KS SLK cells were injected subcutaneously into CD4(+) T-cell-depleted male mice, and the tumors that formed after 3-4 weeks were recovered and analyzed for the expression of Tat protein(s), different cytokine messenger RNAs (mRNAs), and matrix metalloproteinases (MMPs). All statistical tests were two-sided. RESULTS: The average tumor weight was maximum in Tat(86) mice ( approximately 600 mg) compared with Tat(72) ( approximately 200 mg) and nontransgenic ( approximately 100 mg) mice (P<.005). Histologic examination of tumors showed spindle-shaped SLK cells with prominent infiltrates of inflammatory cells. All of the tumors from Tat mice expressed abundant Tat mRNA, suggesting that the infiltrating mouse cells actively expressed Tat. A comparison of the growth-promoting cytokines in the tumors from Tat(86)-transgenic and nontransgenic mice showed that the expression of the following cytokines was substantially increased in the tumors of the Tat(86) mice: tumor necrosis factor-alpha, interleukin 6, interleukin 8, granulocyte-macrophage colony-stimulating factor, and basic fibroblast growth factor. Furthermore, these tumors showed abundant expression of a 105-kd MMP activity associated with infiltrates of host leukocytes in the lesions. CONCLUSION: Our in vivo data clearly suggest that extracellular Tat can contribute to the growth and tumorigenesis of human KS cells.

Animals↗

PubMed2000

Inhibitory effects of synthetic beta peptide on invasion and metastasis of liver cancer.

PURPOSE: To study the inhibitory effects of synthetic beta peptide on invasion and metastasis of liver cancer. METHODS: Membrane-type intercellular adhesion molecule-1 (ICAM-1) expression of SMMC-7721 cultured hepatoma cells (7721 cells) was detected by immunofluorescence cell flowmeter. The adhesion of 7721 cells to fibronectin (FN) was assayed by the MTT method. The adhesion of 7721 cells to 7721 cells, 7721 cells to endothelial cells, and 7721 cells to lymphocyte cells was detected by adhesion assay. LCI-D20 human liver cancer metastasis model in nude mice was used in this experiment. One hundred micrograms of beta peptide per mouse were injected subcutaneously after tumor was resected premetastatically or postmetastatically to observe its effect on liver cancer metastasis after hepatectomy. RESULTS: Membrane-type ICAM-1 expression of SMMC-7721 cells treated by beta peptide was lower than that of the untreated cells. The adhesion of 7721 cells to FN, 7721 cells to 7721 cells, 7721 cells to endothelial cells, and 7721 cells to lymphocyte cells was also lower in the beta peptide group than in the untreated group. CONCLUSIONS: beta Peptide can block the adhesion of 7721 cells to FN, 7721 cells to some host cells in vitro, and inhibit HCC metastasis of LCI-D20 model posthepatectomy in vivo, so it could potentially act as an antimetastasis drug.

Animals↗