Biomedical subjects

G Dong

Publications and source records attributed to G Dong.

At least 37 records · Page 2Linked to original sources

PubMed2000

Cisplatin and radiation sensitivity in human head and neck squamous carcinomas are independently modulated by glutathione and transcription factor NF-kappaB.

BACKGROUND: Response to neoadjuvant cisplatin-based chemotherapy has been used to predict overall response to chemoradiation therapy and to select patients with head and neck squamous cell carcinoma (HNSCC) for organ preservation therapy in NCI and VA cooperative group trials. However, different molecular determinants have been reported to contribute to sensitivity of cells to cisplatin and radiation, including glutathione (GSH), and activation of nuclear factor-kappaB (NF-kappaB), a transcription factor that regulates cytoprotective genes. We have reported that NF-kappaB is constitutively activated in HNSCC, but the relationship of NF-kappaB to GSH and to cisplatin and radiation sensitivity in HNSCC is unknown. METHODS: We examined human HNSCC lines to define the relationship of cisplatin and radiation sensitivity to intracellular GSH and NF-kappaB and determined whether HNSCC could be sensitized to these modalities by lowering the concentration of glutathione with L-buthionine sulfoximine or inhibiting activation of NF-kappaB by expression of a degradation-resistant mutant inhibitor-kappaBalpha. RESULTS: Cisplatin resistance did not predict radiation resistance in three HNSCC cell lines, UM-SCC-9, 11B, and, 38. Resistance to cisplatin correlated with intracellular GSH, and depletion of GSH by treatment with L-BSO sensitized UM-SCC-9 cells to cisplatin but not radiation. Conversely, radiation resistance was correlated with activation of NF-kappaB. Expression of a mutant Inhibitor-kappaB after gene transfer inhibited NF-kappaB and sensitized UM-SCC-9 cells to radiation but not cisplatin. CONCLUSIONS: GSH and transcription factor NF-alphaB can contribute independently to cisplatin and radiation sensitivity of human HNSCC. These results highlight the need to define molecular determinants of chemotherapy and radiation sensitivity for use in the selection of patients and as novel targets for therapy in future chemoradiation therapy trials for organ preservation in patients with HNSCC.

Base Sequence↗

PubMed2000

Inhibition of transcription factor nuclear factor-kappaB by a mutant inhibitor-kappaBalpha attenuates resistance of human head and neck squamous cell carcinoma to TNF-alpha caspase-mediated cell death.

Tumour necrosis factor-alpha (TNF-alpha) is a cytokine that can induce cell death of different cancers via a cellular cascade of proteases, the caspases. However, TNF-alpha has been detected in tumour and serum of patients with head and neck squamous cell carcinoma (HNSCC), and tumour cell lines derived from this environment often exhibit resistance to TNF-alpha-induced cell death. Cell death mediated by TNF-alpha and caspases may be inhibited by cytoprotective genes regulated by transcription factor nuclear factor-kappaB (NF-kappaB). We recently showed that NF-kappaB is constitutively activated in HNSCC, and that inhibition of NF-kappaB by expression of a nondegradable mutant inhibitor of NF-kappaB, IkappaBalphaM, markedly decreased survival and growth of HNSCC cells in vivo. In the present study, we examined the TNF-alpha sensitivity and response of HNSCC with constitutively active NF-kappaB, and of HNSCC cells in which NF-kappaB is inhibited by stable expression of a dominant negative mutant inhibitor, IkappaBalphaM. Human lines UM-SCC-9, 11B and 38, previously shown to exhibit constitutive activation of NF-kappaB, were found to be highly resistant to growth inhibition by up to 10(4)U/ml of TNF-alpha in 5 day MTT assay. These TNF-alpha resistant HNSCC lines expressed TNF receptor I, and exhibited constitutive and TNF-alpha-inducible activation of NF-kappaB as demonstrated by nuclear localization of NF-kappaB p65 by immunohistochemistry. UM-SCC-9 I11 cells which stably expressed an inhibitor of NF-kappaB, IkappaBalpham, were susceptible to TNF-alpha-induced growth inhibition. DNA cell cycle analysis revealed that TNF-alpha induced growth inhibition was associated with accumulation of cells with sub-G0/G1 DNA content. Cell death was demonstrated by trypan blue staining, and was blocked by caspase inhibitor. We conclude that HNSCC that exhibit constitutive and TNF-alpha-inducible activation of transcription factor NF-kappaB are resistant to TNF-alpha, and that inhibition of NF-kappaB sensitizes HNSCC to TNF-alpha caspase-mediated cytotoxicity. The demonstration of the role of activation of NF-kappaB in resistance of HNSCC to TNF-alpha may be helpful in the identification of potential targets for pharmacological, molecular and immune therapy of HNSCC.

Apoptosis↗

PubMed2000

[Long-term effects of low-dose combined norethisterone and combined 18-metayl-norethisterone on lipid metabolism in healthy women].

OBJECTIVE: To assess the long-term effects of combined oral contraceptive pills use on the mean of serum TG, TC, HDL-C, LDL-C, ApoA1, ApoB and Lp(a). METHODS: The study was carried out in 446 women grouped as combined norethisterone containing ethinylestradiol (EE) 35 micrograms and norethisterone 625 micrograms; combined 18-metayl-norethisterone (norgestrel) containing EE 30 micrograms and 18-metayl-norethisterone 300 micrograms for using 5-25 years, and control subjects wearing IUD for the corresponding period. The three groups were similar in age, body mass index (BMI), continued period of contraceptives use and income. RESULTS: The data showed that changes of varying degree of lipid and lipoprotein parameters were obvious in women of long-term taking low-dose combined norethisterone and norgestrel, compared with the control. The mean of TG, HDL-C, ApoA1 were significantly increased simultaneously (P < 0.05, P < 0.01), indicated multiple effects of two low-dose Chinese COCs on lipid lipoprotein parameters. In addition, A significant increase (P < 0.05) in Lp(a), an independent risk factor for cardiovascular disease, was found in norgestrel group. Further more, the results of stratified analysis to duration of contraceptives use showed that the mean of TC, LDL-C, in the combined norethisterone use less than 15 years, after the adjusting for age, were significantly lower (P < 0.05, P < 0.01) and the ratio of LDL-C/HDL-C was improved (P < 0.05), compared with the Norgestrel; at the same time, the mean of ApoA1 was markedly higher (P < 0.05) in combined norethisterone; the ratio of ApoA1/ApoB (1.87 +/- 0.58) in the combined norethisterone group was superior to the ratio value (1.68 +/- 0.55) in norgestrel group. CONCLUSIONS: These beneficial effects on lipid metabolism have been considered indicators of potential cardiovascular protective effect of the combined norethisterone for taking pill less than 15 years, but these protective effects would be reduced with adverse change in lipid and lipoprotein parameters for taking combined norethisterone more than 15 years. In contrast, the mean of TC, LDL-C, two known risk factors for cardiovascular system, in the norgestrel use less than 15 years, after the adjusting for age, were significantly increased (P < 0.05, P < 0.01), and adverse changes in the TC/HDL-C ratio (P < 0.05) and ASI value, compared with the combined norethisterone; Lp(a) level was markedly higher in the norgestrel group than that in the control group (P < 0.05). These adverse effects on lipid metabolism have been considered indicators of potential cardiovascular harmful effect of low-dose norgestrel.

Adult↗

PubMed2000

[Studies on clinical trials and immune effect of a new purified rabies vaccine prepared from Vero cells].

OBJECTIVE: To observe the safety and neutralizing antibody response of a new purified rabies vaccine prepared from Vero cells. METHODS: The vaccine used was manufactured in Hainan Institute of Biologicals and licensed by the Ministry of Health for clinical trials. The vaccine was administrated in 30 and 318 volunteers during phase I and II clinical trials with preexposure (day 0, 7, and 28) or post exposure (day 0,3,7,14 and 28) vaccination schedules. The "Verorab (PVRV)", a rabies vaccine made in France was used as control. RESULTS: The results showed that the new purified vaccine did not cause any severe and moderate side reactions, the slight side reaction rate was 12% including those complained by vaccines themselves. The immunological effect was determined by detecting neutralizing antibody with mouse neutralization test (NIH). The positive seroconversion rates of neutralizing antibody were 100% (n= 27, GMT 2.89 IU/ml) and 100% (n= 30, GMT 5.29 IU/ml) respectively by pre- exposure and post exposure schedules. No significant difference was found when compared with France "Verorab" vaccine by preexposure schedule (n= 24, GMT 2.13 IU/ml). CONCLUSIONS: The clinical trials indicated that the purified rabies vaccine prepared from Vero cells only showed slight side reaction and had good neutralizing antibody response. Therefore this new vaccine is safe and protective for the prevention of rabies in human.

Animals↗

PubMed2000

[Acute mesenteric vein thrombosis: diagnosis and management].

OBJECTIVE: To evaluate the progress in diagnosis and management of acute mesenteric vein thrombosis (AMVT). METHODS: Fifteen patients with AMVT treated from January 1983 to November 1998 were reviewed retrospectively. They were 7 men and 8 women, aged on average 42 years. The duration from onset of symptoms to admission was 24 - 168 hours (mean 84 hours). RESULTS: Six patients were diagnosed before operation, while 9 during laparotomy. Two patients received conservative treatment and the rest underwent surgery. The average length of bowel resection was 300 cm. All the patients received anticoagulation therapy with heparin immediately after operation. Local thrombolytic therapy was given to 4 patients. Four patients died in hospital and two had sequelae of short bowel syndrome. CONCLUSIONS: AMVT is rare but a potentially lethal emergency disease. Early diagnosis, anticoagulation and appropriate surgical approach are essential to improve the prognosis. It is important to keep vigilance for AMVT in the patients in the hypercoagulation status, especially when the symptoms are inconsistent with abdominal signs. Color-US and CT appear to be sensitive in the diagnosis of this condition. Local thrombolytic therapy will be effective. Second-look is a necessarily procedure for reserving the bowel that may be alive. Laparoscopy technique will play an important role in the diagnosis and treatment for AMVT.

Acute Disease↗

PubMed2000

[Safety and immunogenicity of inactivated bivalent EHF vaccine in humans].

OBJECTIVE: Safety and immunogenicity of inactivated bivalent EHF vaccine in humans were evaluated in the epidemic area of Zhejiang province, China. METHODS: Susceptible persons with negative anti-EHF were selected in Jiande county, Zhejiang province to receive 3 doses of inactivated bivalent EHF vaccine at 0, 7, 28 days. A booster injection was given one year after the primary immunization. Antibody responses were measured in human volunteers by IFA and MCPENT. Local and general reactions were recorded within 72 hours after each vaccination by physicians. RESULTS: Two weeks after the primary vaccination, 99.04% of the subjects developed significant hantavirus antibody titre measured by IFA which had a 37.34% drop one year after the primary vaccination. Seroconversion rate increased to 100% two weeks after the booster dose. Neutralising antibody titres paralleled this trend with 100% of vaccine recipients producing neutralising antibody two weeks after the primary doses. However, it dropped to 80% one year after the primary vaccination. One hundred percent of the vaccine recipients started to respond two weeks after boosting. The geometric mean titre (GMT) of neutralising antibody against 76 - 118 and UR were 18.27 +/- 2.21 and 12.47 +/- 2.16 respectively after the primary injections, but it increased to 37.09 +/- 2.24 and 32.61 +/- 2.05 respectively after the secondary immunization. General and local reaction rates were 0.46% and 1.98%, with no severe side effects observed in the vaccinees. CONCLUSION: The vaccine was well tolerated and could induce good humoral immune response.

Antibodies, Viral↗

PubMed1999

Expression of a dominant-negative mutant inhibitor-kappaBalpha of nuclear factor-kappaB in human head and neck squamous cell carcinoma inhibits survival, proinflammatory cytokine expression, and tumor growth in vivo.

We demonstrated recently that constitutive expression of proinflammatory cytokines interleukin (IL)-1alpha, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor in head and neck squamous cell carcinoma is correlated with activation of transcription factor nuclear factor (NF)-kappaB/Rel A (p50/p65), which binds the promoter region within each of the genes encoding this repertoire of cytokines. NF-kappaB can be activated after signal-dependent phosphorylation and degradation of inhibitor-kappaBalpha and has been reported to promote cell survival and growth. In the present study, we expressed a phosphorylation site mutant of inhibitor-kappaBalpha (IkappaBalphaM) in head and neck squamous cell carcinoma lines UM-SCC-9, -11B, and -38 to determine the effect of inhibition of NF-kappaB on cytokine expression, cell survival in vitro, and growth in vivo. After transfection with IKBalphaM, only a few UM-SCC-9 clones were obtained that stably expressed the mutant IkappaB, suggesting that expression of a mutant IkappaBalpha may affect survival of the transfected UM-SCC cell lines. After cotransfection of IkappaBalphaM with a Lac-Z reporter, we found that the number of surviving beta-galactosidase-positive cells in the three cell lines was reduced by 70-90% when compared with controls transfected with vector lacking the insert. In UM-SCC-9 cells that stably expressed IkappaBalphaM, inhibition of constitutive and tumor necrosis factor-a induced NF-kappaB activation, and production of all four cytokines was observed. Although UM-SCC-9 IkappaBalphaM-transfected cells proliferated at the same rate as vector-transfected cells in vitro, a significant reduction in growth of tumor xenografts was observed in SCID mice in vivo. The decreased growth of UM-SCC-9 IkappaBalphaM-transfected tumor cells accompanied decreased immunohistochemical detection of the activated form of NF-kappaB in situ. These results provide evidence that NF-KB and IkappaBalpha play an important role in survival, constitutive and inducible expression of proinflammatory cytokines, and growth of squamous cell carcinoma. NF-kappaB could serve as a potential target for therapeutic intervention against cytokine and other immediate-early gene responses that contribute to the survival, growth, and pathogenesis of these cancers.

Animals↗

PubMed1999

The host environment promotes the constitutive activation of nuclear factor-kappaB and proinflammatory cytokine expression during metastatic tumor progression of murine squamous cell carcinoma.

We reported previously that tumor cells isolated from metastases of the in vitro transformed squamous cell carcinoma line Pam 212 exhibit an elevation in constitutive production of proinflmmatory cytokines interleukin (IL)-1alpha, IL-6, granulocyte-macrophage colony-stimulating factor, and KC (the murine homologue of chemokine Gro-alpha). The basis for constitutive expression of these cytokines after tumor progression in vivo is unknown. Regulation of the expression of these proinflammatory cytokines involves transcription factor nuclear factor kappaB (NF-kappaB), which can be activated by cytokines such as tumor necrosis factor (TNF)-alpha. In this study, we compared the constitutive and TNF-alpha-induced expression of proinflammatory cytokines in parental Pam 212 and metastatic LY-2 and LY-8 cell lines and determined the relationship of cytokine expression to activation of NF-kappaB. We found that the metastatic cell lines exhibited an increase in constitutive and TNF-alpha-inducible expression of proinflammatory cytokines when compared with parental Pam 212 cells. The increased cytokine expression was associated with an increase in constitutive and TNF-alpha-inducible activation of NF-kappaB as demonstrated by electrophoretic mobility shift assay and luciferase-reporter gene assay. Constitutive nuclear localization of NF-kappaB p65 was observed in LY-2 and LY-8 cells in culture and in tumor specimens but rarely in Pam 212 cells, consistent with the constitutive activation of NF-kappaB in tumor cels after selection in vivo. Induction of NF-kappaB by TNF-alpha was inhibited by the addition of protease inhibitors calpain inhibitor I and N-tosyl-phechloromethyl ketone and antioxidant 1-pyrrolidinecarbodithioic acid, whereas constitutive activation of NF-kappaB and cytokine KC mRNA expression was inhibited by N-tosyl-phechloromethyl ketone alone. Overexpression of a human Ikappa(B)alpha dominant suppresser in Pam 212 cells inhibited TNF-alpha-induced NF-kappaB binding activity and KC expression. These data indicate that activation of NF-kappaB contributes to increased expression of proinflammatory cytokines during metastatic tumor progression of squamous cell carcinoma, and that distinct mechanisms may be involved in the regulation of constitutive and TNF-alpha-induced activation of NF-kappaB in squamous cell carcinoma.

Animals↗

PubMed1999

[Study on a purified and inactivated Japanese encephalitis vaccine prepared on Vero cells using SA14-14-2 attenuated virus strain].

OBJECTIVE: To develop a kind of new Japanese Encephalitis (JE) vaccine prepared on Vero cells. METHODS: A JE attenuated virus strain SA14-14-2 was adapted on Vero cells for preparation of purified inactivated vaccine. Comparison of the growth curves of SA14-14-2 in roller bottle and in spinner flask was made. After the virus inoculation and absorption on Vero cells for 2 hours, cultures were replaced with serum-free MEM, the culture supernatants were harvested on day 2,4,6 after inoculation. The virus fluids were pooled, concentrated by 8% PEG, and purified on 15%-60% sucrose density gradients. The purified virus was inactivated with 0.02% formalin. RESULTS: It showed that virus titer was higher and maintained longer in roller bottle. Mice vaccinated twicely with 0.5 microgram dose of the purified inactivated vaccine induced neutralizing antibody titers equal to that of the mice vaccinated with primary hamster kidney inactivated vaccine. CONCLUSION: This Vero cell prepared purified and inactivated JE vaccine made by SA14-14-2 strain could be used for human as a kind of new JE vaccine.

Animals↗

PubMed1999

Constitutive activation of transcription factors NF-(kappa)B, AP-1, and NF-IL6 in human head and neck squamous cell carcinoma cell lines that express pro-inflammatory and pro-angiogenic cytokines.

We previously reported that human head and neck squamous cell carcinomas (HNSCCs) express the pro-inflammatory and pro-angiogenic cytokines interleukin (IL)-1alpha, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor in vitro and in vivo. The promoter region of the genes encoding these cytokines include binding sites for the transcription factors nuclear factor (NF) kappaB/Rel A, activator protein-1 (AP-1), and CCAAT enhancer-binding protein beta (C/EBPbeta, or NF-IL6), which have been reported to contribute to activation of these cytokine genes. In the study presented here, we examined the activation, composition, and function of these transcription factors in HNSCC cell lines that express pro-inflammatory cytokines, by using electrophoretic mobility shift and reporter-gene assays. Constitutive activation of NF-kappaB, AP-1, and NF-IL6 DNA-binding proteins was detected. Supershift analysis with antibodies specific for NF-kappaB, AP-1, and NF-IL6 binding proteins showed that the NF-kappaB-binding protein included p65/Rel A and p50; AP-1 activity included c-jun, junB, junD, and Fra-1; and NF-IL6 included C/EBPbeta. Mutational analysis of the NF-kappaB, AP-1, and NF-IL6 sites in the IL-8 promoter region showed that NF-kappaB and AP-1 sites contributed to constitutive IL-8 reporter activity in HNSCC. HNSCC lines that exhibited increased IL-8 secretion relative to simian virus 40-immortalized and primary keratinocyte cell lines also demonstrated a concordant increase in NF-kappaB reporter activity relative to nonmalignant keratinocytes. We concluded that the early transcription factors NF-kappaB, AP-1, and NF-IL6 are constitutively activated in human HNSCC cell lines and that NF-kappaB and AP-1 promote expression of the pro-inflammatory and pro-angiogenic cytokine IL-8 in HNSCC. The demonstration of the activation of these transcription factors will be helpful in defining the identity and role of these and other early gene products that contribute to pathogenesis of the malignant phenotype in HNSCC and in defining potential targets for pharmacologic and molecular therapy of HNSCC. Mol. Carcinog. 26:119-129, 1999. Published 1999 Wiley-Liss, Inc.

CCAAT-Enhancer-Binding Proteins↗

PubMed1999

[Plasma thyroid hormones during cardiopulmonary bypass].

OBJECTIVE: To study the changes and clinical significance of plasma thyroid hormones were during cardiopulmonary bypass (CPB). METHODS: Plasma thyroid hormones was studied in 36 patients during open heart surgery under CPB. Blood samples were taken preoperatively, and 1, 2, 3, 4, 5 days postoperatively. Doppler echocardiography was performed in 16 patients before and after surgery for evaluating heart function. RESULTS: Before CPB, the levels of thyroid hormones were within normal range. At early stage after CPB, the levels of FT(3), FT(4), TT(3) and TT(4) were significantly decreased and increased. Both TSH and rT(3) were increased significantly after CPB (P < 0.05) and reached their highest levels at the first postoperative day. TSH and rT(3) were gradually dropped subsequently, but TSH returned to the basic level and the level of rT(3) was still high. A positive relation was seen between plasma thyroid hormones and cardiac function. CONCLUSIONS: The changes of plasma thyroid hormones are closely related to cardiopulmonary bypass and could result in postoperative cardiac disfunction.

Adult↗

PubMed1999

[A study on immunogenicity and safety of bivalent inactivated vaccine against hemorrhagic fever with renal syndrome].

OBJECTIVE: To study side effects and effectiveness of bivalent inactivated vaccine against hemorrhagic fever with renal syndrome in population of a randomized controlled field trial. METHODS: Serum indirect immunofluorescent antibody in 167 persons and neutralization antibody (types I and II) in 69 persons, who received three-dose vaccine, were determined two weeks after immunization, and side effects in 657 vaccinees were observed within 72 houses after immunization. RESULTS: Serum positive conversion rate of indirect immunofluorescent antibody was 99.04% (166/167) with GMT of 24.51 +/- 2.06. Serum positive conversion rate of neutralization antibody was 100% (69/69), 91.30% (63/69) for types I and 88.41% (61/69) for type II, respectively. GMTs for type I and II neutralization antibody were 18.27 +/- 2.21 and 12.47 +/- 2.16, respectively. Side effects at local site vaccinated of the body and temperature rising could be seen in 1.48% and 0.36% of the vaccinees, respectively. No severe side effect and abnormal reaction was found in vaccinees on the field. CONCLUSION: Immune response to bivalent inactivated vaccine against hemorrhagic fever with renal syndrome was satisfactory with slight side effect.

Adolescent↗

PubMed1999

[Effects of BMP on periodontal ligament cell's cell cycling and DNA synthesis: a flow cytometry (FCM) analysis].

OBJECTIVE: To investigate the effects of bone morphogenetic protein (BMP) on the cell cycling and DNA synthesis of periodontal ligament cells (PDLCs). METHODS: The 7th passage PDLCs were cultured in a 5% CO2, humid atmosphere at 37 degrees C in DMEM supplement with 10% fetal bovine serum (FBS) for 24 hours, then BMP was added in medium with 1% FBS. After being cultured another 72 hours, cells were trypsinized, washed and fixed with cold alcohol for 1 hour. To measure DNA content, 1.0 x 10(6) cells were washed with PBS, resuspended in 200 microliters PBS mixed with staining liquid (RNA ase, 0.1% triton-100 and propidium iodide) for 30 minutes at 4 degrees C. DNA specific fluorescence was measured on a Coulter Epics Profile-II (Coulter, USA) using 250 mW 488 nm laser light for excitating and collecting fluorescence at 610-630 nm. Phase fraction analysis was performed on DNA content histograms with multicycle software. RESULTS: When compared with the control, the percentage of PDLC in G1 during exponential growth was decreased by a function of BMP, while the percentage of S and (G2 + M) was increased in the experimental group. CONCLUSION: It suggested that the proliferation of PDLC be most probably regulated in the G1 phase of the cell cycle. BMP can be regarded as a positive regulatory growth factor.

Adolescent↗

PubMed1999

[The comparison between approximate entropy and complexity in the study of sleep EEG].

The Paper introduces two algorithms as a complexity measure. One is the algorithm defined by Kaspar and Schuster, the other is a recently developed statistic quantifying regularity and complexity--Approximate entropy (ApEn). They have been applied for the study of sleep EEG. According to the laboratory application and comparison, the result shows that ApEn is a valued complexity measure.

Algorithms↗

PubMed1998

Effects of interleukin-1alpha, interleukin-1 receptor antagonist, and neutralizing antibody on proinflammatory cytokine expression by human squamous cell carcinoma lines.

Proinflammatory cytokines interleukin (IL)-1alpha, IL-6, IL-8, and granulocyte macrophage colony-stimulating factor (GM-CSF) have been detected in tumor specimens and primary cell cultures from patients with head and neck squamous cell carcinoma. IL-1alpha has been reported to play an important role in inducing the expression of cytokines IL-6, IL-8, and GM-CSF during inflammation. We examined whether these cytokines are expressed together in five primary and seven established UM-SCC cell lines, and we also examined the effects of IL-1alpha, IL-1 receptor antagonist or neutralizing antibody (Ab) upon expression of this repertoire of proinflammatory cytokines in established UM-SCC lines. Secretion of proinflammatory cytokines IL-1alpha, IL-6, IL-8, and GM-CSF was detected by ELISA in both the primary and established UM-SCC lines. Constitutive expression of specific mRNAs for these cytokines was confirmed in the UM-SCC lines by reverse transcriptase-PCR and Northern blot analysis. Addition of recombinant IL (rIL)-1alpha but not rIL-6 induced a dose-dependent increase in IL-8 and GM-CSF production. IL-1 receptor antagonist (IL-RA) or anti-IL-1 neutralizing Ab could completely inhibit the rIL-1alpha-inducible increase in IL-8 and GM-CSF expression, but the inhibitors had a negligible effect on the constitutive level of production of the cytokines. Transfer and expression of the IL-1alpha gene in a low-cytokine-producing cell line, UM-SCC-38, induced IL-8 and GM-CSF expression, but this expression was also not inhibited by IL-1RA or anti-IL-1 neutralizing Ab. We conclude that IL-1alpha can enhance the expression of cytokines IL-8 and GM-CSF in UM-SCC cell lines but that constitutive expression of these cytokines by UM-SCC is not inhibited by exogenous IL-1RA or neutralizing Ab.

Adult↗

PubMed1998

Overexpression of transforming growth factor beta1 in arterial endothelium causes hyperplasia, apoptosis, and cartilaginous metaplasia.

Uninjured rat arteries transduced with an adenoviral vector expressing an active form of transforming growth factor beta1 (TGF-beta1) developed a cellular and matrix-rich neointima, with cartilaginous metaplasia of the vascular media. Explant cultures of transduced arteries showed that secretion of active TGF-beta1 ceased by 4 weeks, the time of maximal intimal thickening. Between 4 and 8 weeks, the cartilaginous metaplasia resolved and the intimal lesions regressed almost completely, in large part because of massive apoptosis. Thus, locally expressed TGF-beta1 promotes intimal growth and appears to cause transdifferentiation of vascular smooth muscle cells into chondrocytes. Moreover, TGF-beta1 withdrawal is associated with regression of vascular lesions. These data suggest an unexpected plasticity of the adult vascular smooth muscle cell phenotype and provide an etiology for cartilaginous metaplasia of the arterial wall. Our observations may help to reconcile divergent views of the role of TGF-beta1 in vascular disease.

Animals↗

PubMed1998

Differential expression of the murine Ly-6A/E antigen homolog of human squamous cell carcinoma antigen E48 during malignant transformation and tumor progression of squamous cell carcinoma line Pam 212.

The mRNA differential display method detected increased expression of the mRNA of an immune recognition antigen known as Ly-6A/E after malignant transformation of the murine squamous cell carcinoma line Pam 212. Subsequent loss of expression of Ly-6A/E occurred with metastatic tumor progression of Pam in vivo. Ly-6 molecules have been implicated in immune cell recognition and signal transduction and are homologous to the human E48 SCC antigen that has been shown to be involved in cell-cell recognition. These observations suggest that loss of Ly-6A/E antigen may contribute to tumor progression and metastasis of squamous cell carcinoma through decreased tumor-lymphocyte or tumor-tumor recognition.

Animals↗

PubMed1998

The host environment promotes the development of primary and metastatic squamous cell carcinomas that constitutively express proinflammatory cytokines IL-1alpha, IL-6, GM-CSF, and KC.

Human and murine squamous cell carcinomas (SCC) have been reported to produce proinflammatory cytokines IL-1alpha, IL-6, GM-CSF, and IL-8 or KC. Production of individual members of the proinflammatory cytokine family has been associated with increased tumor growth or metastasis in a variety of neoplasms. In this study, we determined whether the expression of these cytokines occurs as a result of the events of cellular transformation or culture, or is promoted by interaction of neoplastic cells with factors or cells in the host environment. We compared the expression of proinflammatory cytokines following the spontaneous transformation of murine keratinocytes in vitro, and following the formation of tumors and metastases from these transformed keratinocytes in syngeneic recipients in vivo. Using sensitive ELISA assays, we found that cultures of the in vitro transformed Balb/c SCC line Pam 212 do not produce elevated levels of proinflammatory cytokines IL-1alpha, IL-6, GM-CSF and KC, indicating that transformation or culture alone is insufficient to account for the level of cytokine expression detected in patient and experimental tumors. In contrast, Pam reisolates from primary and metastatic tumors were obtained which constitutively produce markedly elevated levels of cytokines IL-1alpha, IL-6, KC and GM-CSF. The increase in the expression of these cytokines by SCC in vivo occurred independent of T and B lymphocyte-mediated immunity, since increases in expression of the cytokines was observed in lines reisolated from immunodeficient athymic nude and SCID Balb/c congenic mice. The increased expression of cytokines appeared to result from additional events in vivo, rather than due to selection of a pre-existing cytokine-producing subpopulation, since clones of the parental cell line expressed lower cytokine levels than cloned reisolates, and clones of the non-secreting parental cell line that formed tumors in vivo secreted elevated levels of cytokines following reisolation. We conclude that the development of SCC that express proinflammatory cytokines is promoted by tumor-host interaction(s) that are independent of specific T and B cell immunity.

Animals↗