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1.
Background: Local, sustained delivery of cytokines at a tumor can enhance induction of antitumor immunity and may be a feasible neoadjuvant immunotherapy for breast cancer. We evaluated the ability of intratumoral poly-lactic-acid-encapsulated microspheres (PLAM) containing interleukin 12 (IL-12), tumor necrosis factor (TNF-), and granulocyte-macrophage colony stimulating factor (GM-CSF) in a murine model of breast cancer to generate a specific antitumor response.Methods: BALB/c mice with established MT-901 tumors underwent resection or treatment with a single intratumoral injection of PLAM containing IL-12, TNF-, or GM-CSF, alone or in combination. Two weeks later, lymph nodes and spleens were harvested, activated with anti-CD3 monoclonal antibodies (mAb) and rhIL-2, and assessed for antitumor reactivity by an interferon (IFN) release assay. Tumor-infiltrating lymphocyte (TIL) analysis was performed on days 2 and 5 after treatment by mechanically processing the tumors to create a single cell suspension, followed by three-color fluorescence-activated cell sorter (FACS) analysis.Results: Intratumoral injection of cytokine-loaded PLAM significantly suppressed tumor growth, with the combination of IL-12 and TNF- leading to increased infiltration by polymorphonuclear cells and CD8+ T-cells in comparison with controls. The induction of tumor-specific reactive T-cells in the nodes and spleens, as measured by IFN- production, was highest with IL-12 and TNF-. This treatment resulted in resistance to tumor rechallenge.Conclusions: A single intratumoral injection of IL-12 and TNF-–loaded PLAM into a breast tumor leads to infiltration by polymorphonuclear cells and CD8+ T-cells with subsequent tumor regression. In addition, this local therapy induces specific antitumor T-cells in the lymph nodes and spleens, resulting in memory immune response.  相似文献   

2.
We investigated the activity of alpha-interferon (-IFN), gamma-interferon (-IFN) and tumor necrosis factor-alpha (TNF-) in a panel of ten human bladder tumor cell lines. All cytokines were tested at concentrations of 100–10000 U/ml in a clonogenic assay system. We found that -IFN was active against five of the ten lines while -IFN was only active against one line. TNF was active against five of the ten lines. Maximum synergisms were obtained between the -IFN and TNF, occurring in nine of the ten cell lines. We conclude that -IFN and TNF are active as single agents and synergistic when used together in vitro in human bladder tumor cell lines.  相似文献   

3.
Human recombinant tumor necrosis factor- (rTNF-, 10-12–10-8 M) inhibited the proliferation of androgen-dependent LNCaP cells by 32–56%. In contrast, proliferation of androgen-independent PC-3 and JCA-1 cells was only slightly inhibited, or not inhibited at all, respectively. Human recombinant interferon- (rIFN-, 500 U/ml) decreased proliferation of PC-3 and JCA-1 cells by 35% and 53%, respectively, but had no effect on LNCaP cells. Interestingly, the combination of rIFN- and TNF- had greater antiproliferative effects on JCA-1 cells than treatment with either cytokine alone. However, the antiproliferative effects of this combination were similar to those observed for PC-3 or LNCaP cells treated with rIFN- or TNF- alone, respectively. These data suggest that some forms of androgen-independent prostate cancer may benefit from a combination therapy of IFN- and TNF-, while the use of IFN- alone may be more efficacious in others.  相似文献   

4.
Background: Severe systemic toxicity and hemodynamic changes after isolated limb perfusion (ILP) with tumor necrosis factor- (TNF-) and melphalan, with or without interferon-, have been reported in several series. We studied whether these side effects could be precluded by preventing leakage from the isolated circuit into the systemic circulation.Methods: Clinical and pharmacokinetic data for 20 consecutive patients with recurrent melanoma of the limbs who were treated by ILP with TNF- (3–4 mg) and melphalan, with or without interferon-, were studied. Leakage rates and TNF- levels were determined during and after ILP and were correlated with systemic toxicity and hemodynamic changes.Results: Only two patients experienced leaks (2% and 13%) during ILP. For 18 patients without leakage, the mean peak systemic TNF- level was 2.8 ng/ml at 10 minutes after ILP. After leakage, the peak systemic TNF- levels were 31.9 and 88.3 ng/ml at 5 minutes. Toxicity was mild and consisted mainly of fever (n = 17) and nausea/vomiting (n = 19) during the first day after ILP. Some patients developed tachycardia (n = 6), hypotension (n = 3; responding immediately to fluid challenge), a decrease in the WBC count (n = 3; grade I) or thrombocyte count (n = 11; grade I/II, no hemorrhage or therapeutic intervention), or hepatotoxicity [cytolysis (n = 15; 14 grade I/II and 1 grade IV) or hyperbilirubinemia (n = 7; grade I/II, all resolving spontaneously)]. Patients with tachycardia or hepatotoxicity exhibited significantly higher TNF- levels after ILP, compared with other patients.Conclusions: Systemic toxicity after ILP with TNF- is minimal and does not differ from that after ILP with melphalan alone when leakage is adequately controlled.  相似文献   

5.
Background: The anticancer role of tumor necrosis factor-alpha (TNF-) has been limited by toxicity. These experiments evaluate blocking endogenous interferon-gamma (IFN-) activity to abrogate TNF- toxicity. Methods: C57Bl/6 mice bearing MCA 105 tumor were treated with TNF- and anti-IFN- antibody (Ab) to evaluate the effect on the acute lethality of TNF- and their efficacy as evaluated by tumor growth rate, tumor histology, and survival. Results: Anti-IFN- Ab decreased TNF- lethality. Anti-IFN- Ab alone increased tumor growth significantly more than did nonimmune IgG (p2<0.0001). Tumor-bearing mice that received nonimmune IgG and TNF- had slower tumor growth (p2<0.02) and a trend toward improved survival (p=0.07) compared with saline-treated controls. Anti-IFN- Ab abrogated the antitumor effect of TNF-, prevented acute tumor necrosis histologically, and resulted in tumor growth rate and host survival similar to that of controls. The findings in mice that received anti-IFN- Ab and high-dose TNF- were comparable with those in mice that received a lower, equitoxic dose of TNF- alone. Conclusions: Blocking endogenous IFN- accelerates tumor growth in this model and partially abrogates the toxic and antitumor activity of exogenous TNF- equally. This suggests that blocking endogenous IFN- activity is not a useful strategy for limiting TNF- treatment toxicity.Presented in part at the 45th Annual Cancer Symposium of The Society of Surgical Oncology, New York, New York, March 15–18, 1992.  相似文献   

6.
Extracellular matrix and integrin composition of the normal bladder wall   总被引:2,自引:0,他引:2  
Summary We performed an immunohistochemistry study of the normal human bladder so as to understand the interactions of extracellular matrix (ECM) components and the integrins of cell adhesion that accommodate the volume changes and maintain an impermeable barrier to reabsorption of urine in the bladder. The normal human urothelial cell and/or its plasma membrane contained integrins 3, V, 1, and 4 but did not contain integrin 3. The urothelial basement membrane (UBM) contained collagen type IV and laminin. Fibronectin and integrins 3 and 4 were found in or near the UBM area, with types I and III collagen and tenascin abutting the area. The patterns of collagen, laminin, tenascin, vitronectin, fobronectin, and the 3, V, 1, and 3 integrins in the lamina propria, vessels, nerves, and smooth-muscle layers are described. These findings detail the normal anatomical ECM/integrin relationship that provides the cellular basis for bladder-wall relationships responsible for its impermeable state and other functions.  相似文献   

7.
We investigated the relationships between tumor necrosis factor (TNF) gene polymorphism, circulating TNF-alpha (TNF-) concentrations, and bone mineral density (BMD) in the lumbar spine. TNF gene polymorphisms studied were the Nco I polymorphism within the first intron of TNF-beta (TNF-) and three single nucleotide polymorphisms in the promoter region of the TNF- gene, at positions –857, –863, and –1031. Allelic variants of the TNF gene were identified using restriction fragment length polymorphism (RFLP) analysis in 177 postmenopausal Japanese women within 10 years after menopause, aged 56.4 ± 4.5 years (mean ± SD). A significantly higher prevalence of the alleles TNF--863A (20.3% versus 9.9%) and TNF--1031C (21.3% versus 12.4%) was seen in the low BMD group (Z-score < 0, n = 91) than in the high BMD group (0 Z-score, n = 86). In genotype analysis, although difference did not reach a significant level, women with the rarest allelic variants, i.e., homozygous TNFb1, TNF--863A, and TNF--1031C, showed the lowest BMD Z-scores. Women with another rarest allelic variant, TNF--857T/T had significantly lower BMD Z-scores than did women with TNF--857C/T or –857C/C. The BMD Z-score decreased significantly with an increase in the total number of such rare alleles. Serum concentrations of TNF- did not differ significantly among groups divided by genotypes. Multiple linear regression analysis revealed that the total number of rare alleles, in addition to the body mass index and the number of years since menopause, was an independent predictor of the BMD. These presumptive functional polymorphisms of the TNF gene may be associated with the lumbar spine BMD in early postmenopausal Japanese women.  相似文献   

8.
The overproduction of cytokines such as the tumor necrosis factor- (TNF-) and interleukin-1 (IL-1) may cause further deterioration in the already critical condition of patients with shock, sepsis, and acute inflammation. The effectiveness of infusion therapy of natural human IgG to such patients is suggested to depend partly upon the inhibition of the productivity of these cytokines. In this study, we investigated the modulation effects of IgG and its fragments on the production of TNF- and IL-1, on human peripheral blood mononuclear cells (PBMC). The production of TNF- and IL-1 was found to be dose-dependently inhibited by IgG when stimulated by lipopolysaccharide (LPS), phytohemagglutinin (PHA), concanavalin A (Con A), and interleukin-2 (IL-2). However, no inhibition was seen when stimulated by phorbormyristate acetate (PMA). The F(ab)2 fragment showed enhancing effects on cytokine production by LPS, while the Fc fragment showed not as much inhibitory effect as whole intact IgG. IgG showed no direct cytotoxic effect on PBMC. These data suggest that natural human IgG inhibits TNF- and IL-1 production by PBMC through the Fc portion. The results of this study led us to conclude that whole intact IgG may be the best form of therapeutic delivery.  相似文献   

9.
Background Tumor necrosis factor (TNF)-–based hyperthermic isolated limb perfusion (HILP) is one of the most active available approaches for locally advanced soft tissue sarcomas (STS) of the limbs. The aim of this study was to investigate the anticancer activity of a novel drug regimen including doxorubicin (DXR) and low-dose TNF-.Methods HILP with low-dose TNF- (1 mg) and DXR (8.5 mg/L of limb volume) was given to 21 patients with limb-threatening STS: 14 had primary and 7 had recurrent STS, most of which were high grade (grade 1, n = 3; grade 2, n = 6; grade 3, n = 12). Resection of the tumor remnant was performed 6 to 8 weeks after HILP. TNF- concentrations in plasma and perfusate were measured throughout perfusion.Results A major tumor response was observed at histology and clinical evaluation in 90% and 62% of patients, respectively. After a median follow-up of 30 months, limb salvage and local disease control were achieved in 71% and 81% of cases, respectively. Fourteen patients had moderate regional toxicity, which was resolved in all cases. One patient had severe limb toxicity, which did not require amputation. Systemic side effects were minimal, and there were no postoperative deaths. The perfusate/plasma area under the curve ratio for TNF- was 56.Conclusions HILP with low-dose TNF- and DXR seems to be an active neoadjuvant drug regimen against limb-threatening STS. This therapeutic approach can achieve high limb-sparing surgery rates with acceptable local and negligible systemic toxicity.  相似文献   

10.
Tumor necrosis factor- (TNF-) is a mediator of inflammation in human and animal renal disease. Pentoxiphylline (PTX) is an inhibitor of TNF-. In this study we examined the effects of PTX on TNF-, proteinuria, nitrite production, and apoptosis in an experimental model of Adriamycin (ADR) nephropathy in rats. Rats were divided into four groups: untreated Wistar rats (controls), PTX treatment alone, ADR treatment alone to induce nephropathy, and ADR treatment followed by PTX. ADR treatment followed by PTX treatment prevented the increase in serum TNF- levels and proteinuria in rats with ADR-nephropathy (P<0.05). Urine nitrite levels were significantly increased in the ADR-induced nephropathy group and the increase was prevented in the ADR-induced nephropathy group when they also received PTX. The urine nitrite levels were not different between the PTX-treated group and the untreated control rats. PTX prevented the rise of serum TNF- in ADR nephropathy rats and a decrease in proteinuria, urine nitrite, and apoptosis in the renal tissue. These findings suggest a beneficial anti-inflammatory effect of PTX.  相似文献   

11.
We measured systemic serum levels of interleukin-1 receptor antagonist (IL-1ra), interleukin-1 (IL-1), tumor necrosis factor (TNF-), and interleukin-6 (IL-6) during the preoperative, anhepatic, and postreperfusional phases up to the 7th postoperative day in 60 patients undergoing orthotopic liver transplantation (LTx). In contrast to IL-1, IL-1ra, TNF-, and IL-6 showed a significant elevation in relation to the early phase after reperfusion, while TNF- displayed a high grade of scatter. In addition, IL-1ra levels were significantly elevated during the anhepatic phase. Maximum serum levels were found at 15 min after reperfusion, 120 min after reperfusion, and on the 1st postoperative day, respectively. Serum levels decreased considerably at 24 h and 7 days after reperfusion. The comparative monitoring of systemic cytokine and cytokine antagonist levels, in particular the liberation of IL-1ra and IL-6 may provide useful parameters for the development of new liver preservation theories for LTx.  相似文献   

12.
Low bone mineral density (BMD) is a frequent, often persistent complication in patients with major depressive disorder (MDD) and anorexia nervosa (AN) that increases the risk of pathologic fractures. The pathogenetic process underlying osteopenia in MDD and AN is still unclear, although several factors, including a dysbalance of cytokines, are associated with loss of bone mass. Alterations in the serum levels of cytokines have been observed in patients with MDD, AN, and other psychiatric disorders. Therefore, we examined serum levels of cytokines, markers of bone turnover, and BMD in 13 patients with MDD and a lifetime history of AN. Bone turnover markers (osteocalcin and C-terminal degradation products of type I collagen) and tumor necrosis factor (TNF-) in patients were significantly increased compared with those of the control group. Osteoprotegerin (OPG) in patients was significantly decreased. Eight of 13 patients (62%) displayed osteopenia at the lumbar spine. TNF- correlated significantly with C-terminal degradation products of type I collagen, an osteoclastic marker, but significantly negatively with OPG. Our data suggest that TNF- and OPG may play a role in the pathogenetic process underlying osteopenia in these patients.  相似文献   

13.
The role of proinflammatory cytokines in a rat model of toxin-induced hemolytic uremic syndrome (HUS) was studied. Male Sprague-Dawley rats underwent continuous saline infusion (6 ml/h) via a tail vein and received a bolus injection of saline (control), lipopolysaccharide (LPS, 10 g/100 g body weight), ricin (6.7 g/100 g body weight), or ricin with LPS (ricin+LPS). They were then observed for 8 h. Blood samples and kidney tissues were obtained at the end of the experiment. The effects of FR 167653, a potent inhibitor of interleukin-1 (IL-1) and tumor necrosis factor- (TNF-) production, were also examined in ricin+LPS-treated rats. Only ricin+LPS-treated rats developed significant thrombocytopenia, hemolysis, and oliguric acute renal failure with extensive glomerular thrombotic microangiopathy, which was characterized by glomerular microthrombi and apoptosis of glomerular endothelial cells. Thrombotic microangiopathy was not detected in other organs, including the brain, liver, spleen, pancreas, lung, colon, and intestine. Significantly elevated levels of serum IL-1 and TNF- were detected only in ricin+LPS-treated rats. Treatment of ricin+LPS-treated rats with FR 167653 significantly reduced the serum levels of IL-1 and TNF-, accompanied by improvement of the oliguric renal failure and glomerular thrombotic microangiopathy. These findings indicate that the increased serum levels of IL-1 and TNF-, which probably result in the apoptosis of glomerular endothelial cells, play a pivotal role in the development of this rat model of toxin-induced HUS. The findings also suggest that inhibition of these proinflammatory cytokines may prevent the development of HUS.  相似文献   

14.
Henoch-Schönlein purpura (HSP) is one of the most common types of vasculitis disorders in childhood and is characterized by a rash, arthritis, abdominal pain, and renal involvement. The factors that determine and mediate the severity of HSP and its renal involvement remain poorly understood, although it is likely that pro-inflammatory cytokines, including tumor necrosis factor- (TNF-), are involved in the pathogenesis. Serum and urine levels of TNF- were measured in children with HSP in the acute and convalescent phases by ELISA. Serum TNF- levels were significantly higher in proteinuric HSP in the acute phase (36.6±8.5 pg/ml) compared with those with HSP without renal involvement and those with hematuric HSP (25.4±4.5 and 27.1±3.9 pg/ml) (P<0.005). However, these significantly higher levels disappeared in the convalescent phase. Using matched serum samples from the same patients, serum TNF- levels of proteinuric HSP patients were significantly lower in the convalescent phase (29.9±4.6 pg/ml, P <0.05) than in the acute phase (39.1±8.2 pg/ml). Although urine TNF- levels were higher in proteinuric HSP in the acute phase and reduced in the convalescent phase, there were no significantly high or low levels. These results suggest that increased TNF- levels in the serum induce a series of functional and morphological changes in the glomerular cells in the acute phase and may be used as markers for monitoring the disease activity of HSP with severe renal involvement.  相似文献   

15.
The present study was conducted to clarify whether endotoxin-induced liver injury could be improved by modulating the function of hepatic macrophages using OK432, an immunostimulant derived from Streptococcus. OK432 elevated the capacity of hepatic macrophages to produce superoxide and tumor necrosis factor (TNF), and enhanced the mRNA expression of interleukin-1-, -, and TNF- in liver nonparenchymal cells (NPC). However, intravenous (iv) preadministration of OK432 reduced the mRNA expression of TNF- in liver NPC enhanced by the endotoxin injection, decreased the serum level of GOT and lactic dehydrogenase (LDH), and improved the survival rate of endotoxin-injected rats. Histological examination revealed a significant reduction in cell vacuolization and focal necrosis in the livers of the endotoxin-injected rats pretreated with OK432. These results indicate that hepatic macrophages play a crucial role in endotoxin-induced liver injury, and that TNF- is one of the factors most likely to be implicated in the development of endotoxin-induced liver injury. Thus, it is suggested that the administration of OK432 provides liver protection by modulating the responsiveness of hepatic macrophages against endotoxin.  相似文献   

16.
We have quantified and characterized 1-, 2-and -adrenoceptor subtypes in porcine bladder detrusor and bladder neck, human bladder detrusor, and porcine and human prostate. 1-, 2- and -adrenoceptor were identified in radioligand binding studies using [3H]prazosin, [3H]RX 821002 and [125I]iodocyanopindolol, respectively, as the radioligands. In porcine male and female detrusor and bladder neck and male prostate, adrenoceptors were detected in the order of abundance > 2 1 (not detectable), with no major differences between the sexes or between detrusor and bladder neck. In human detrusor and prostate the order of abundance was > 2 1 (not detectable) and 1 > 2. respectively. The 2-adrenoceptors in all tissues were homogeneously of the 2A-subtype as evidenced by competition binding studies with yohimbine, prazosin, ARC 239 and oxymetazoline. The -adrenoceptors represented a mixed population with a dominance of the 2-subtype in all tissues as demonstrated by competition binding with ICI 118,551 and CGP 20,712A. We conclude that pigs may be a suitable model for studies of detrusor function with respect to adrenoceptor expression. They may be less suitable for studies of bladder neck or prostate function.  相似文献   

17.
The purposes of this study were to measure the serum levels of vascular permeability growth factor (VPGF) and tumor necrosis factor (TNF) in minimal lesion nephrotic syndrome (MLNS) patients and to assess their effect on albuminuria in rats. Serum for VPGF and TNF was obtained during relapse and remission from 18 MLNS patients. Tumor necrosis factor was infused at the rate of 10 and 20 ng/h and VPGF at the rate of 20 and 40 ng/h for 5 days into the left renal artery of rats. Urinary albumin (24-h collection) was measured prior to infusion and on days 2, 4 and 5. Rats infused with 1% bovine serum albumin served as controls. Serum VPGF and TNF levels in MLNS patients in relapse were not different from those seen during remission. A significant increase in albuminuria was observed on day 4 and 5 only when rats were infused with TNF at the rate of 20 ng/h as compared to the excretion seen in same animals prior to the infusion of cytokine and on days 4 and 5 of normal controls. Neither VPGF nor TNF seems to be the circulating pathogenic cytokine for proteinuria in MLNS. However, TNF may contribute to the increased albuminuria via a paracrine effect at the glomerulus.  相似文献   

18.
Abstract Background: The role of tumor necrosis factor alpha (TNF-) in wound healing is unclear and the results are contradictory. In vivo, TNF- induces vessel growth, an important step in promoting wound healing. However, a reduced amount of collagen, hydroxyproline, and granulation tissue was found after TNF- treatment. It is also unknown if this is a direct effect, by influencing cells involved in wound healing, or an indirect effect due to a negative or positive effect on cells such as macrophages. Material and Methods: The current study was undertaken to test the effect of TNF- on wound epithelialization and neovascularization in vivo. In the first experiment, standardized full-thickness dermal wounds (2.25 mm diameter, 0.125 mm depth) were created on the dorsum of the ears of male hairless mice. The wounds were treated either with TNF- (100 ng/ml, 1 µg/ml, 5 µg/ml; n = 10 per group), monoclonal TNF- antibody (10 µg/ml; n = 10), or vehicle (n = 10). Wound epithelialization and neovascularization were analyzed every 3rd day by intravital microscopy until complete healing.In a second experiment, the same wound model was used, but in order to impair the healing process, macrophages were depleted. To reduce macrophages, two out of four groups (n = 10 per group) were pretreated with iota-carrageenan (MR groups), and the other two groups received only saline (N groups). One N group and one MR group were treated with TNF- (1 µg/ml). The other N group and MR group received vehicle only (carboxymethylcellulose). Using intravital microscopy and computerized planimetry, wound epithelialization and neovascularization were measured every 3rd day until complete healing. Immunohistochemistry was performed to detect TNF-, macrophages, fibronectin, and vitronectin receptors. Results: In the first experiment the wounds treated with 1 µg/ml healed significantly earlier than controls (13.9 ± 2 vs. 17.3 ± 2.8 days, respectively; p < 0.05). Epithelialization in the antibody group was significantly slower compared to controls (20.1 ± 2 days; p < 0.05). Neovascularization was significantly enhanced in the group treated with 1 µg/ml TNF- (p < 0.05). In the second experiment the wounds treated with TNF- were significantly earlier epithelialized (13.1 ± 0.6) and vascularized (16.0 ± 0.5) compared to controls (16.8 ± 0.4 vs. 17.6 ± 0.5; p < 0.05). Wound closure was significantly delayed in the MR group treated with vehicle only (20.4 ± 1) and equal to controls in the MR group treated with TNF- (16.8 ± 0.6). Conclusion: The results demonstrate the TNF- accelerates wound epithelialization and neovascularization in this in vivo model. TNF- is able to compensate for the negative effect of macrophage reduction and seems to have a direct effect on the wound-healing process.  相似文献   

19.
Many cytokines, including transforming growth factor- (TGF-) and tumor necrosis factor- (TNF-), are involved in the inflammatory process of Henoch-Schönlein purpura (HSP). The objective of this study was to investigate whether TGF- C-509T and TNF- G-308A polymorphisms are associated with childhood HSP. The loci of interest were amplified from genomic DNA using specific primers and polymerase chain reaction, and these two polymorphisms were compared between Chinese children with HSP and healthy controls. The disease severities evaluated and expressed as symptom score of patients with different genotypes were also compared. The TGF- -509 TT genotype was more common in children with HSP than controls (31% vs. 8%, P =0.03, odds ratio=4.95). The allelic frequencies of TGF- -509, genotypic and allelic frequencies of TNF- -308 were not significantly different. Patients with the TT genotype had more severe clinical presentations than non-TT (TC+CC) patients (4.1±0.42 vs. 2.7±0.31, P =0.018). These results suggest that the TT genotype of the C-509T polymorphism of the TGF- gene might be related to the susceptibility of Chinese children to HSP and to the severity of this disease.  相似文献   

20.
Background: The signal transduction pathways important in regulating the growth and differentiation of malignant cells are poorly understood. Recent evidence has implicated activation of the protein kinase C (PKC) family of signaling proteins in pancreatic carcinoma during cytokine-induced cytostasis and differentiation. Methods: A human pancreatic adenocarcinoma (HPAC) cell line was exposed to tumor necrosis factor- (TNF-; 40 ng/ml) for 6 days. Cytostasis and viability were confirmed by daily MTT [(3(4,5)-dimethyl-thiazol-2-yl) 2,5-diphenyl-tetrazolium bromide] and trypan exclusion assay. Protein fractions were isolated daily and subjected to immunoblot analysis for the normal (terminally differentiated) pancreatic ductal cell marker carbonic anhydrase II (CA II) as well as specific PKC isoforms (, , , , and). Results: Growth arrest occurred in HPAC cells after exposure to TNF- for 48 h, with viability maintained above 90% throughout the 6-day time course. CA II immunoreactivity was not detected in untreated controls but appeared after 2 days of TNF- exposure, peaking on day 6. Concurrently, TNF- induced the selective downregulation of PKC-, whereas PKC- levels increased. PKC- and PKC- immunoreactivity did not change. The atypical PKC- isoform developed a doublet banding pattern in response to TNF-, although overall PKC- levels did not change. Conclusions: TNF--induced growth arrest and differentiation in HPAC cells is associated with the selective downregulation of PKC- and upregulation of PKC-.Presented at the 48th Annual Cancer Symposium of The Society of Surgical Oncology, Boston, Massachusetts, March 23–26, 1995.  相似文献   

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