STAT3 induction by LPS and TNFα in pancreatic acinar cells

Introduction. Inflammatory mediators have been implicated in the onset and progression of acute pancreatitis (AP). The signaling pathways affected by inflammation in pancreatic cells are still largely unknown. SOCS proteins are cytokine-induced cytokine signaling inhibitors that terminate the inflammatory response. Our previous studies show that SOCS-3 mRNA levels are up regulated in response to bacterial lipopolysaccharide (LPS) or inflammation (TNFα) in acinar cells. With the addition of IL-6 or IL-1β, SOCS-3 expression is down regulated. Since SOCS-3 proteins are known to affect the JAK/STAT pathway, we hypothesized that LPS and TNFα, in combination with the proinflammatory cytokines IL-6 and IL-1β, would mediate STAT3 mRNA expression in pancreatic acinar cells. Methods. Rat pancreatic acinar cells (AR42J) were treated with either LPS (10 μg/ml) or TNF-α (10, 100, or 200 ng/ml) in the presence or absence of IL-6 (20 ng/ml) or IL-1β (10 ng/ml) for 0, 15, 30, 45, 60, 180, or 360 min. Total RNA extracted at each time point was used in multiplex RT-PCR reactions to determine STAT3 mRNA expression. Values were standardized to 18S rRNA. Results. STAT3 mRNA expression was significantly (P < 0.05) increased by 3 h in acinar cells treated with either LPS or TNFα. At the highest concentration of TNFα, the addition of IL-6 and IL-1β significantly (P < 0.05) enhanced STAT3 mRNA expression. When added in combination with the proinflammatory cytokines IL-6 or IL-1β, LPS-induced STAT3 expression remained elevated without further change. Conclusions. STAT3 expression was increased in response to endotoxin and proinflammatory cytokines, suggesting that STAT3 plays a role in initiating the inflammatory response in pancreatic acinar cells. These results indicate that inhibition of pancreatic STAT3 expression is a potential therapeutic strategy during the onset of acute pancreatitis.     

The expression of β-adrenoceptors in human pancreatic cancer cell lines and their roles in cell invasiveness

Objective To investigate the effect and mechanism of β-adrenoceptors on norepi-nephrine-induced invasiveness of pancreatic cancer cell lines. Methods The expression of β-adrenocep-tors mRNA in human pancreatic cancer cell lines MiaPaCa-2 and BxPC3 was detected by using RT-PCR. The cells were randomly divided into control group.10 mol/L NE intervention group, 1 mol/L propranolol intervention group and NE + propranolol intervention group. After 48 h , transwell invasiveness test was used to examine the changes in invasive ability of MiaPaCa-2. The expression of MMP-2, MMP-9 and VEGF mRNA was measured by semi-quantitative RT-PCR. The levels of MMP-2 , MMP-9 and VECF proteins were assayed by immunocytochemistry. Results Both MiaPaCa-2 and BxPC3 expressed β1-and β2-adrenocep-tors. The absorbance ( A) values of invasive cells in NE, NE + propranolol, propranolol and control groups were 0.78±0.02 ,0.32±0.03 ,0.26±0.01 and 0.28±0.02 , respectively, and those in NE intervention group were significantly higher than in control and NE + propranolol groups ( P <0.05) . There was no sig-nificant difference in the number of invasive cells between propranolol and control groups ( P > 0. 05) . In NE group , the expression index of MMP-2 , MMP-9 and VEGF mRNA was 0. 87±0.02 , 1.04±0.02 and 0. 92±0. 01 , and the gray value of the protein expression was 131.20±2.34,105.32±7.21 and 115.60 ±5. 03 , respectively, which were higher than those in control and NE + propranolol groups ( P<0.05). There was no significant difference in the expression levels of MMP-2 , MMP-9 and VEGF mRNA and pro-tein between propranolol and control groups ( P>0.05 ) . Conclusion β-adrenoceptors play an important role in the process of norepinephrine-induced invasiveness of pancreatic cancer cells. NE can promote the invasiveness of MiaPaCa-2 through up-regulating the expression of MMP-2 , MMP-9 and VEGF via β-adre-noceptors.     

The expression of β-adrenoceptors in human pancreatic cancer cell lines and their roles in cell invasiveness

Objective To investigate the effect and mechanism of β-adrenoceptors on norepi-nephrine-induced invasiveness of pancreatic cancer cell lines. Methods The expression of β-adrenocep-tors mRNA in human pancreatic cancer cell lines MiaPaCa-2 and BxPC3 was detected by using RT-PCR. The cells were randomly divided into control group.10 mol/L NE intervention group, 1 mol/L propranolol intervention group and NE + propranolol intervention group. After 48 h , transwell invasiveness test was used to examine the changes in invasive ability of MiaPaCa-2. The expression of MMP-2, MMP-9 and VEGF mRNA was measured by semi-quantitative RT-PCR. The levels of MMP-2 , MMP-9 and VECF proteins were assayed by immunocytochemistry. Results Both MiaPaCa-2 and BxPC3 expressed β1-and β2-adrenocep-tors. The absorbance ( A) values of invasive cells in NE, NE + propranolol, propranolol and control groups were 0.78±0.02 ,0.32±0.03 ,0.26±0.01 and 0.28±0.02 , respectively, and those in NE intervention group were significantly higher than in control and NE + propranolol groups ( P <0.05) . There was no sig-nificant difference in the number of invasive cells between propranolol and control groups ( P > 0. 05) . In NE group , the expression index of MMP-2 , MMP-9 and VEGF mRNA was 0. 87±0.02 , 1.04±0.02 and 0. 92±0. 01 , and the gray value of the protein expression was 131.20±2.34,105.32±7.21 and 115.60 ±5. 03 , respectively, which were higher than those in control and NE + propranolol groups ( P<0.05). There was no significant difference in the expression levels of MMP-2 , MMP-9 and VEGF mRNA and pro-tein between propranolol and control groups ( P>0.05 ) . Conclusion β-adrenoceptors play an important role in the process of norepinephrine-induced invasiveness of pancreatic cancer cells. NE can promote the invasiveness of MiaPaCa-2 through up-regulating the expression of MMP-2 , MMP-9 and VEGF via β-adre-noceptors.     

The expression of β-adrenoceptors in human pancreatic cancer cell lines and their roles in cell invasiveness

Objective To investigate the effect and mechanism of β-adrenoceptors on norepi-nephrine-induced invasiveness of pancreatic cancer cell lines. Methods The expression of β-adrenocep-tors mRNA in human pancreatic cancer cell lines MiaPaCa-2 and BxPC3 was detected by using RT-PCR. The cells were randomly divided into control group.10 mol/L NE intervention group, 1 mol/L propranolol intervention group and NE + propranolol intervention group. After 48 h , transwell invasiveness test was used to examine the changes in invasive ability of MiaPaCa-2. The expression of MMP-2, MMP-9 and VEGF mRNA was measured by semi-quantitative RT-PCR. The levels of MMP-2 , MMP-9 and VECF proteins were assayed by immunocytochemistry. Results Both MiaPaCa-2 and BxPC3 expressed β1-and β2-adrenocep-tors. The absorbance ( A) values of invasive cells in NE, NE + propranolol, propranolol and control groups were 0.78±0.02 ,0.32±0.03 ,0.26±0.01 and 0.28±0.02 , respectively, and those in NE intervention group were significantly higher than in control and NE + propranolol groups ( P <0.05) . There was no sig-nificant difference in the number of invasive cells between propranolol and control groups ( P > 0. 05) . In NE group , the expression index of MMP-2 , MMP-9 and VEGF mRNA was 0. 87±0.02 , 1.04±0.02 and 0. 92±0. 01 , and the gray value of the protein expression was 131.20±2.34,105.32±7.21 and 115.60 ±5. 03 , respectively, which were higher than those in control and NE + propranolol groups ( P<0.05). There was no significant difference in the expression levels of MMP-2 , MMP-9 and VEGF mRNA and pro-tein between propranolol and control groups ( P>0.05 ) . Conclusion β-adrenoceptors play an important role in the process of norepinephrine-induced invasiveness of pancreatic cancer cells. NE can promote the invasiveness of MiaPaCa-2 through up-regulating the expression of MMP-2 , MMP-9 and VEGF via β-adre-noceptors.     

The expression of β-adrenoceptors in human pancreatic cancer cell lines and their roles in cell invasiveness

Objective To investigate the effect and mechanism of β-adrenoceptors on norepi-nephrine-induced invasiveness of pancreatic cancer cell lines. Methods The expression of β-adrenocep-tors mRNA in human pancreatic cancer cell lines MiaPaCa-2 and BxPC3 was detected by using RT-PCR. The cells were randomly divided into control group.10 mol/L NE intervention group, 1 mol/L propranolol intervention group and NE + propranolol intervention group. After 48 h , transwell invasiveness test was used to examine the changes in invasive ability of MiaPaCa-2. The expression of MMP-2, MMP-9 and VEGF mRNA was measured by semi-quantitative RT-PCR. The levels of MMP-2 , MMP-9 and VECF proteins were assayed by immunocytochemistry. Results Both MiaPaCa-2 and BxPC3 expressed β1-and β2-adrenocep-tors. The absorbance ( A) values of invasive cells in NE, NE + propranolol, propranolol and control groups were 0.78±0.02 ,0.32±0.03 ,0.26±0.01 and 0.28±0.02 , respectively, and those in NE intervention group were significantly higher than in control and NE + propranolol groups ( P <0.05) . There was no sig-nificant difference in the number of invasive cells between propranolol and control groups ( P > 0. 05) . In NE group , the expression index of MMP-2 , MMP-9 and VEGF mRNA was 0. 87±0.02 , 1.04±0.02 and 0. 92±0. 01 , and the gray value of the protein expression was 131.20±2.34,105.32±7.21 and 115.60 ±5. 03 , respectively, which were higher than those in control and NE + propranolol groups ( P<0.05). There was no significant difference in the expression levels of MMP-2 , MMP-9 and VEGF mRNA and pro-tein between propranolol and control groups ( P>0.05 ) . Conclusion β-adrenoceptors play an important role in the process of norepinephrine-induced invasiveness of pancreatic cancer cells. NE can promote the invasiveness of MiaPaCa-2 through up-regulating the expression of MMP-2 , MMP-9 and VEGF via β-adre-noceptors.     

The expression of β-adrenoceptors in human pancreatic cancer cell lines and their roles in cell invasiveness

Objective To investigate the effect and mechanism of β-adrenoceptors on norepi-nephrine-induced invasiveness of pancreatic cancer cell lines. Methods The expression of β-adrenocep-tors mRNA in human pancreatic cancer cell lines MiaPaCa-2 and BxPC3 was detected by using RT-PCR. The cells were randomly divided into control group.10 mol/L NE intervention group, 1 mol/L propranolol intervention group and NE + propranolol intervention group. After 48 h , transwell invasiveness test was used to examine the changes in invasive ability of MiaPaCa-2. The expression of MMP-2, MMP-9 and VEGF mRNA was measured by semi-quantitative RT-PCR. The levels of MMP-2 , MMP-9 and VECF proteins were assayed by immunocytochemistry. Results Both MiaPaCa-2 and BxPC3 expressed β1-and β2-adrenocep-tors. The absorbance ( A) values of invasive cells in NE, NE + propranolol, propranolol and control groups were 0.78±0.02 ,0.32±0.03 ,0.26±0.01 and 0.28±0.02 , respectively, and those in NE intervention group were significantly higher than in control and NE + propranolol groups ( P <0.05) . There was no sig-nificant difference in the number of invasive cells between propranolol and control groups ( P > 0. 05) . In NE group , the expression index of MMP-2 , MMP-9 and VEGF mRNA was 0. 87±0.02 , 1.04±0.02 and 0. 92±0. 01 , and the gray value of the protein expression was 131.20±2.34,105.32±7.21 and 115.60 ±5. 03 , respectively, which were higher than those in control and NE + propranolol groups ( P<0.05). There was no significant difference in the expression levels of MMP-2 , MMP-9 and VEGF mRNA and pro-tein between propranolol and control groups ( P>0.05 ) . Conclusion β-adrenoceptors play an important role in the process of norepinephrine-induced invasiveness of pancreatic cancer cells. NE can promote the invasiveness of MiaPaCa-2 through up-regulating the expression of MMP-2 , MMP-9 and VEGF via β-adre-noceptors.     

The expression of β-adrenoceptors in human pancreatic cancer cell lines and their roles in cell invasiveness

Objective To investigate the effect and mechanism of β-adrenoceptors on norepi-nephrine-induced invasiveness of pancreatic cancer cell lines. Methods The expression of β-adrenocep-tors mRNA in human pancreatic cancer cell lines MiaPaCa-2 and BxPC3 was detected by using RT-PCR. The cells were randomly divided into control group.10 mol/L NE intervention group, 1 mol/L propranolol intervention group and NE + propranolol intervention group. After 48 h , transwell invasiveness test was used to examine the changes in invasive ability of MiaPaCa-2. The expression of MMP-2, MMP-9 and VEGF mRNA was measured by semi-quantitative RT-PCR. The levels of MMP-2 , MMP-9 and VECF proteins were assayed by immunocytochemistry. Results Both MiaPaCa-2 and BxPC3 expressed β1-and β2-adrenocep-tors. The absorbance ( A) values of invasive cells in NE, NE + propranolol, propranolol and control groups were 0.78±0.02 ,0.32±0.03 ,0.26±0.01 and 0.28±0.02 , respectively, and those in NE intervention group were significantly higher than in control and NE + propranolol groups ( P <0.05) . There was no sig-nificant difference in the number of invasive cells between propranolol and control groups ( P > 0. 05) . In NE group , the expression index of MMP-2 , MMP-9 and VEGF mRNA was 0. 87±0.02 , 1.04±0.02 and 0. 92±0. 01 , and the gray value of the protein expression was 131.20±2.34,105.32±7.21 and 115.60 ±5. 03 , respectively, which were higher than those in control and NE + propranolol groups ( P<0.05). There was no significant difference in the expression levels of MMP-2 , MMP-9 and VEGF mRNA and pro-tein between propranolol and control groups ( P>0.05 ) . Conclusion β-adrenoceptors play an important role in the process of norepinephrine-induced invasiveness of pancreatic cancer cells. NE can promote the invasiveness of MiaPaCa-2 through up-regulating the expression of MMP-2 , MMP-9 and VEGF via β-adre-noceptors.     

The expression of β-adrenoceptors in human pancreatic cancer cell lines and their roles in cell invasiveness

Objective To investigate the effect and mechanism of β-adrenoceptors on norepi-nephrine-induced invasiveness of pancreatic cancer cell lines. Methods The expression of β-adrenocep-tors mRNA in human pancreatic cancer cell lines MiaPaCa-2 and BxPC3 was detected by using RT-PCR. The cells were randomly divided into control group.10 mol/L NE intervention group, 1 mol/L propranolol intervention group and NE + propranolol intervention group. After 48 h , transwell invasiveness test was used to examine the changes in invasive ability of MiaPaCa-2. The expression of MMP-2, MMP-9 and VEGF mRNA was measured by semi-quantitative RT-PCR. The levels of MMP-2 , MMP-9 and VECF proteins were assayed by immunocytochemistry. Results Both MiaPaCa-2 and BxPC3 expressed β1-and β2-adrenocep-tors. The absorbance ( A) values of invasive cells in NE, NE + propranolol, propranolol and control groups were 0.78±0.02 ,0.32±0.03 ,0.26±0.01 and 0.28±0.02 , respectively, and those in NE intervention group were significantly higher than in control and NE + propranolol groups ( P <0.05) . There was no sig-nificant difference in the number of invasive cells between propranolol and control groups ( P > 0. 05) . In NE group , the expression index of MMP-2 , MMP-9 and VEGF mRNA was 0. 87±0.02 , 1.04±0.02 and 0. 92±0. 01 , and the gray value of the protein expression was 131.20±2.34,105.32±7.21 and 115.60 ±5. 03 , respectively, which were higher than those in control and NE + propranolol groups ( P<0.05). There was no significant difference in the expression levels of MMP-2 , MMP-9 and VEGF mRNA and pro-tein between propranolol and control groups ( P>0.05 ) . Conclusion β-adrenoceptors play an important role in the process of norepinephrine-induced invasiveness of pancreatic cancer cells. NE can promote the invasiveness of MiaPaCa-2 through up-regulating the expression of MMP-2 , MMP-9 and VEGF via β-adre-noceptors.     

The expression of β-adrenoceptors in human pancreatic cancer cell lines and their roles in cell invasiveness

Objective To investigate the effect and mechanism of β-adrenoceptors on norepi-nephrine-induced invasiveness of pancreatic cancer cell lines. Methods The expression of β-adrenocep-tors mRNA in human pancreatic cancer cell lines MiaPaCa-2 and BxPC3 was detected by using RT-PCR. The cells were randomly divided into control group.10 mol/L NE intervention group, 1 mol/L propranolol intervention group and NE + propranolol intervention group. After 48 h , transwell invasiveness test was used to examine the changes in invasive ability of MiaPaCa-2. The expression of MMP-2, MMP-9 and VEGF mRNA was measured by semi-quantitative RT-PCR. The levels of MMP-2 , MMP-9 and VECF proteins were assayed by immunocytochemistry. Results Both MiaPaCa-2 and BxPC3 expressed β1-and β2-adrenocep-tors. The absorbance ( A) values of invasive cells in NE, NE + propranolol, propranolol and control groups were 0.78±0.02 ,0.32±0.03 ,0.26±0.01 and 0.28±0.02 , respectively, and those in NE intervention group were significantly higher than in control and NE + propranolol groups ( P <0.05) . There was no sig-nificant difference in the number of invasive cells between propranolol and control groups ( P > 0. 05) . In NE group , the expression index of MMP-2 , MMP-9 and VEGF mRNA was 0. 87±0.02 , 1.04±0.02 and 0. 92±0. 01 , and the gray value of the protein expression was 131.20±2.34,105.32±7.21 and 115.60 ±5. 03 , respectively, which were higher than those in control and NE + propranolol groups ( P<0.05). There was no significant difference in the expression levels of MMP-2 , MMP-9 and VEGF mRNA and pro-tein between propranolol and control groups ( P>0.05 ) . Conclusion β-adrenoceptors play an important role in the process of norepinephrine-induced invasiveness of pancreatic cancer cells. NE can promote the invasiveness of MiaPaCa-2 through up-regulating the expression of MMP-2 , MMP-9 and VEGF via β-adre-noceptors.     

The expression of β-adrenoceptors in human pancreatic cancer cell lines and their roles in cell invasiveness

Objective To investigate the effect and mechanism of β-adrenoceptors on norepi-nephrine-induced invasiveness of pancreatic cancer cell lines. Methods The expression of β-adrenocep-tors mRNA in human pancreatic cancer cell lines MiaPaCa-2 and BxPC3 was detected by using RT-PCR. The cells were randomly divided into control group.10 mol/L NE intervention group, 1 mol/L propranolol intervention group and NE + propranolol intervention group. After 48 h , transwell invasiveness test was used to examine the changes in invasive ability of MiaPaCa-2. The expression of MMP-2, MMP-9 and VEGF mRNA was measured by semi-quantitative RT-PCR. The levels of MMP-2 , MMP-9 and VECF proteins were assayed by immunocytochemistry. Results Both MiaPaCa-2 and BxPC3 expressed β1-and β2-adrenocep-tors. The absorbance ( A) values of invasive cells in NE, NE + propranolol, propranolol and control groups were 0.78±0.02 ,0.32±0.03 ,0.26±0.01 and 0.28±0.02 , respectively, and those in NE intervention group were significantly higher than in control and NE + propranolol groups ( P <0.05) . There was no sig-nificant difference in the number of invasive cells between propranolol and control groups ( P > 0. 05) . In NE group , the expression index of MMP-2 , MMP-9 and VEGF mRNA was 0. 87±0.02 , 1.04±0.02 and 0. 92±0. 01 , and the gray value of the protein expression was 131.20±2.34,105.32±7.21 and 115.60 ±5. 03 , respectively, which were higher than those in control and NE + propranolol groups ( P<0.05). There was no significant difference in the expression levels of MMP-2 , MMP-9 and VEGF mRNA and pro-tein between propranolol and control groups ( P>0.05 ) . Conclusion β-adrenoceptors play an important role in the process of norepinephrine-induced invasiveness of pancreatic cancer cells. NE can promote the invasiveness of MiaPaCa-2 through up-regulating the expression of MMP-2 , MMP-9 and VEGF via β-adre-noceptors.     

The expression of β-adrenoceptors in human pancreatic cancer cell lines and their roles in cell invasiveness

Objective To investigate the effect and mechanism of β-adrenoceptors on norepi-nephrine-induced invasiveness of pancreatic cancer cell lines. Methods The expression of β-adrenocep-tors mRNA in human pancreatic cancer cell lines MiaPaCa-2 and BxPC3 was detected by using RT-PCR. The cells were randomly divided into control group.10 mol/L NE intervention group, 1 mol/L propranolol intervention group and NE + propranolol intervention group. After 48 h , transwell invasiveness test was used to examine the changes in invasive ability of MiaPaCa-2. The expression of MMP-2, MMP-9 and VEGF mRNA was measured by semi-quantitative RT-PCR. The levels of MMP-2 , MMP-9 and VECF proteins were assayed by immunocytochemistry. Results Both MiaPaCa-2 and BxPC3 expressed β1-and β2-adrenocep-tors. The absorbance ( A) values of invasive cells in NE, NE + propranolol, propranolol and control groups were 0.78±0.02 ,0.32±0.03 ,0.26±0.01 and 0.28±0.02 , respectively, and those in NE intervention group were significantly higher than in control and NE + propranolol groups ( P <0.05) . There was no sig-nificant difference in the number of invasive cells between propranolol and control groups ( P > 0. 05) . In NE group , the expression index of MMP-2 , MMP-9 and VEGF mRNA was 0. 87±0.02 , 1.04±0.02 and 0. 92±0. 01 , and the gray value of the protein expression was 131.20±2.34,105.32±7.21 and 115.60 ±5. 03 , respectively, which were higher than those in control and NE + propranolol groups ( P<0.05). There was no significant difference in the expression levels of MMP-2 , MMP-9 and VEGF mRNA and pro-tein between propranolol and control groups ( P>0.05 ) . Conclusion β-adrenoceptors play an important role in the process of norepinephrine-induced invasiveness of pancreatic cancer cells. NE can promote the invasiveness of MiaPaCa-2 through up-regulating the expression of MMP-2 , MMP-9 and VEGF via β-adre-noceptors.     

Immunotherapy in pancreatic cancer – current status and future

Background: In pancreatic cancer, multimodal protocols, involving chemotherapy, radiation, or regional treatment, are initiated to improve oncological outcome. Since pancreatic adenocarcinoma has been shown to be susceptible to immune stimulation, several immunotherapy approaches have been investigated to define the role of immunotherapy in pancreatic cancer. Method: A review of current and past data concerning experimental and clinical immunotherapy in pancreatic cancer is presented in the context of basic immunotherapeutic principles. Past pitfalls and future developments are analyzed and a synthesis of immune stimulation and immune suppression is deduced on the basis of published data. Results: Preclinical and initial clinical studies with monoclonal antibodies CO17-1A, BW494/32 and anti-epidermal growth factor receptor (EGFR) have been conducted, and various targets suitable for immunotherapy have been identified involving new molecular and gene technology. Targets on pancreatic cancer cells currently under investigation are mucins (MUC-1), glycoproteins (GA733), ras peptides and EGFRs. Side effects are minor and rarely auto-immune reactive. Another approach combines randomized regional with systemic chemoimmunotherapy (mitomycin C, 5-fluorouracil, folinic acid, carboplatin, epirubicin; interferon-gamma, interleukin-2) in nonresectable pancreatic cancer and obtains significant differences in median survival rates (14 months vs 4.5 months in controls) and quality of life. Conclusion: Although single remarkable improvements in the immunological approach to treatment of pancreatic cancer have been made, immunotherapy in pancreatic cancer is still experimental. On the basis of reliable preclinical data, new immunotherapy protocols will have to be evaluated clinically. Careful monitoring of immune responses and side effects, and assessment of quality of life will ensure identification of effective immunotherapy protocols for human pancreatic cancer in the near future.     

Elevated NF-κB activation is conserved in human myocytes cultured from obese type 2 diabetic patients and attenuated by AMP-activated protein kinase

OBJECTIVE

To examine whether the inflammatory phenotype found in obese and diabetic individuals is preserved in isolated, cultured myocytes and to assess the effectiveness of pharmacological AMP-activated protein kinase (AMPK) activation upon the attenuation of inflammation in these myocytes.

RESEARCH DESIGN AND METHODS

Muscle precursor cells were isolated from four age-matched subject groups: 1) nonobese, normal glucose tolerant; 2) obese, normal glucose tolerant; 3) obese, impaired glucose tolerant; and 4) obese, type 2 diabetes (T2D). The level of inflammation (nuclear factor-κB [NF-κB] signaling) and effect of pharmacological AMPK activation was assessed by Western blots, enzyme-linked immunosorbent assay, and radioactive assays (n = 5 for each subject group).

RESULTS

NF-κB-p65 DNA binding activity was significantly elevated in myocytes from obese T2D patients compared with nonobese control subjects. This correlated to a significant increase in tumor necrosis factor-α concentration in cell culture media. In addition, insulin-stimulated glucose uptake was completely suppressed in myocytes from obese impaired glucose tolerant and T2D subjects. It is interesting that activation of AMPK by A769662 attenuated NF-κB-p65 DNA binding activity in obese T2D cells to levels measured in nonobese myocytes; however, this had no effect on insulin sensitivity of the cells.

CONCLUSIONS

This work provides solid evidence that differentiated human muscle precursor cells maintain in vivo phenotypes of inflammation and insulin resistance and that obesity alone may not be sufficient to establish inflammation in these cells. It is important that we demonstrate an anti-inflammatory role for AMPK in these human cells. Despite attenuation of NF-κB activity by AMPK, insulin resistance in obese T2D cells remained, suggesting factors in addition to inflammation may contribute to the insulin resistance phenotype in muscle cells.It is increasingly recognized that chronic activation of inflammatory pathways in skeletal muscle is a major contributing factor in the pathophysiology of insulin resistance, obesity, and type 2 diabetes (T2D) (1–3). Subsequently, inflammation has been attributed to the increased morbidity and mortality associated with obesity. Skeletal muscle is responsible for 75–80% of glucose disposal in humans (4), and impaired insulin action in this tissue is considered the primary site of whole body insulin resistance. Therefore, development of strategies to reverse or prevent inflammation is important to successfully treat chronic diseases such as T2D. However, because the study of potential strategies in humans is difficult, it is essential that an optimal ex vivo model is established. Muscle precursor cell cultures, established from human muscle biopsies, have been shown to display numerous features of mature skeletal muscle (5) and have been used in a number of studies investigating muscle metabolism in T2D patients. It has been shown that myocytes isolated from individuals with T2D retain their donor phenotype, when differentiated into myocytes in vitro, in terms of deficient insulin signaling and phosphatidylinositol 3-kinase activity (6,7). However, the retention of other in vivo phenotypes such as obesity-associated inflammation has not been demonstrated in these cultures. It is important, therefore, to establish whether muscle precursor cells from obese and T2D volunteers retain their inflammatory phenotype in culture to establish this as a model of muscle inflammation and assess how this can be manipulated to treat metabolic diseases.In obesity, accumulation of fatty acids serves to increase circulating levels of proinflammatory cytokines, such as tumor necrosis factor-α (TNF-α), via the activation of nuclear factor-κB (NF-κB), which has been shown to impair numerous other signaling pathways regulating skeletal muscle insulin signaling and fatty acid oxidative capacity (2,3,8). NF-κB is activated by multiple proinflammatory stimuli including TNF-α, lipopolysaccharide, and free fatty acids (9–11). NF-κB signaling, therefore, serves as an indicator of inflammatory tone in skeletal muscle. Given the increasing evidence that there is a causal link between inflammation and metabolic diseases, there is considerable interest in developing anti-inflammatory strategies to counteract the suppression in insulin sensitivity induced by obesity-associated inflammation. Recently, AMP-activated protein kinase (AMPK) has been implicated as a modulator of inflammatory responses based on the fact that treatment with AMPK activators suppresses lipopolysaccharide and palmitate-induced NF-κB activity and expression of proinflammatory cytokines in multiple cell types (12–16). The anti-inflammatory role of AMPK in skeletal muscle, however, is poorly defined. In this article, we examine the level of basal inflammation in muscle cells isolated from lean and obese subjects (representative of the whole glucose tolerance continuum) and assess the role that direct pharmacological activation of AMPK plays in attenuating inflammation in these cells.     

What's new in pancreatic cancer treatment?

Pancreatic cancer represents a major challenge to oncologists because of its high chemoresistant nature and dismal outcomes. Conventional therapy for advanced disease relied for a long time on palliative 5-fluorouracil (5-FU)-based chemotherapy, but with unsatisfactory results. The introduction of the novel antimetabolite gemcitabine provides new optimism for patients with advanced pancreatic cancer, as multiple clinical trials have demonstrated the superiority of gemcitabine over 5-FU and other agents for these patients. The benefits of gemcitabine over conventional therapies include improved response rate and enhanced survival, as well as improvement in disease-related symptoms and quality of life in these patients. With these data, gemcitabine is widely accepted worldwide as the therapy of choice by many oncologists for advanced pancreatic cancer. The current review presents an overview of the clinical studies of gemcitabine over the past decade for the treatment of patients with advanced pancreatic cancer. Other investigational regimens or uses (e.g., fixed dose-rate infusion, intraarterial infusion, adjuvant use, chemo-radiation, etc) are also reviewed. Received: October 27, 2001 / Accepted: November 16, 2001