Interleukin-6 (IL-6) functions as an in vitro autocrine growth factor in renal cell carcinomas

Preoperative serum C- reactive protein: a prognostic marker in patients with upper urinary tract urothelial carcinoma

Background

To analyse the prognostic significance of preoperative C-reactive protein (CRP) serum level in patients with upper urinary tract urothelial carcinoma (UUT-UC).

Methods

We evaluated 158 UUT-UC patients who had undergone surgery in the University Hospital of Hannover (MHH). 143 (89.4%) suffered from cancer in the renal pelvis, 13 (8.1%) patients presented with tumour located in the ureter. A preoperative CRP value was available for 115 patients. The mean (median) follow-up for these patients was 28.3 (15.1) months.

Results

The median (mean) CRP value of all evaluable patients was 10.0 (40.7) mg/l. The CRP-level, stratified into two subgroups (CRP ≤5 vs. >5 mg/l), correlated significantly with muscle invasive tumour stage (36.4 vs. 78.9%; p<0.001), the risk of presenting nodal disease (4.5 vs. 26.8%; p=0.002) and distant metastasis (2.3 vs. 16.9%; p<0.016). The Kaplan-Meier 5-year cancer specific survival (CSS) rates were 54.2 and 26.4% for patients with preoperative CRP levels ≤ and >5 mg/l, respectively (p<0.006). Next to age and the presence of metastasis, multivariate analysis also identified CRP as a continuous variable as an independent prognosticator for CSS.

Conclusions

A high preoperative serum CRP level is associated with locally advanced and metastatic disease in patients with UUT-UC. Its routine use could allow better risk stratification and risk-adjusted follow-up of UUT-UC patients.

Prognostic value of interleukin-6 and interleukin-8 in laryngeal squamous cell cancer

The aim of this study was to evaluate serum levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) as prognostic variables in patients with laryngeal squamous cell cancer. A total of 92 patients with primary diagnosis of laryngeal squamous cell cancer (LSCC), treated between 2003 and 2005, were included in this evaluation. Preoperative serum levels of IL-6 and IL-8 were measured by enzyme-linked immunosorbent assay methods. Results were compared according to clinical and pathological date criteria. Serum IL-6 and IL-8 levels were significantly higher in patients with LSCC compared to healthy controls (P < 0.0001). Serum IL-6 level was associated with lymph node metastasis (P < 0.001), T classification (P < 0.001) and clinical stage (P = 0.001). Multivariate analysis indicated that serum IL-6 was an independent predictor of LSCC-specific progression-free survival (P = 0.049) and overall survival (P = 0.040). Higher serum IL-6 level (IL-6 > 9.7 pg/ml) was associated with a shortened overall survival and progression-free survival (P < 0.05). Our data indicate that serum IL-6 is associated with the development and progression of LSCC. Serum IL-6 may serve as an independent prognostic marker for LSCC patients.

Interleukin-6 induces vascular endothelial growth factor expression and promotes angiogenesis through apoptosis signal-regulating kinase 1 in human osteosarcoma

Osteosarcoma is characterized by a high malignant and metastatic potential. Angiogenesis is essential for the caner metastasis. Interleukin-6 (IL-6) is a multifunctional cytokine that is associated with the disease status and outcomes of cancers. However, the relationship between IL-6 and vascular endothelial growth factor (VEGF) expression in human osteosarcoma is mostly unknown. Here we found that the IL-6 and VEGF expression was correlated with tumor stage and significantly higher than that in normal bone. Incubation of osteosarcoma cells with IL-6 increased VEGF mRNA and protein expression. Pretreatment of cells with IL-6R antibody reduced IL-6-mediated VEGF production. The apoptosis signal-regulating kinase 1 (ASK1)/p38/AP-1 pathway was activated after IL-6 treatment, and IL-6-induced VEGF expression was abolished by the specific inhibitor and siRNA of ASK1, p38, and AP-1 cascades. Importantly, knockdown IL-6 reduced VEGF expression and abolished osteosarcoma conditional medium-mediated angiogenesis. Taken together, these results indicate that IL-6 occurs through ASK1 and p38, which in turn activates AP-1, resulting in the activations of VEGF expression and contributing the angiogenesis of human osteosarcoma cells.

Interleukin-6 and soluble intercellular adhesion molecule-1 in renal cancer patients and cultured renal cancer cells

Serum interleukin-6 (IL-6) and soluble intercellular adhesion molecule-1 (sICAM-1) levels were measured by enzyme-linked immunosorbent assay in 62 renal cancer patients: 30 were tumor-free after radical nephrectomy and 32 presented with metastatic disease. Serum IL-6 was undetectable in all but one of the tumor-free patients, whereas 41% (13 of 32) of the metastatic patients presented serum IL-6 levels. Furthermore, there was a significant correlation between serum IL-6 levels and a shorter overall survival (p = 0.009). Moreover, serum sICAM-1 levels were significantly higher (p = 0.05) in the metastatic patients with detectable serum IL-6 than in those without IL-6, suggesting a possible link between IL-6 and sICAM-1. The probability of a shorter overall survival was greater in the metastatic patients with both serum IL-6 and elevated sICAM-1 levels (>635 ng/ml), than in those with elevated sICAM-1 but without IL-6 (p = 0.01). The production of IL-6 by 16 freshly dissociated renal cancer cells cultured in vitro was also observed. It appeared that IL-6 levels did not correlate with the expression and release of ICAM-1 by cultured cells, although the highest values of ICAM-1 release were found in cultures synthesizing the highest values of IL-6. In conclusion, in vivo presence of serum IL-6 and elevated sICAM-1 levels is related to an unfavorable prognosis; it can be speculated that the cells capable of releasing high levels of sICAM-1 and IL-6 may negatively influence the antitumor response.

Differential activation of the inflammasome in THP-1 cells exposed to chrysotile asbestos and Libby "six-mix" amphiboles and subsequent activation of BEAS-2B cells

Inflammatory responses of THP-1 cells (macrophage cell line) exposed to chrysotile asbestos (Chry) and Libby six-mix (LIB) and the subsequent impact on bronchial epithelial cells were determined. Direct treatment of THP-1 cells with Chry caused cell death, activation of caspase-1 and release of IL-1β, while the addition of caspase-1 inhibitor, Z-YVAD-FMK, reduced IL-1β, suggesting that Chry activated the caspase-1 mediated Nod-like receptor protein 3 (NLRP3) inflammasome; by comparison, LIB had less effects on all of these parameters. Expression of antioxidant enzymes, protein oxidation and nitration, and lipid peroxides in THP-1 cells treated with the two particles suggest that LIB generated more reactive oxygen species (ROS) than the same dose of Chry. Differences in fiber length and surface area suggest a possible role for particulate size in the differential activation of the inflammasome. BEAS-2B cells, representing the bronchial epithelium, treated with supernatants of medium from Chry- or LIB-treated THP-1 cells (conditioned medium) activated the MAPK cascade, increased phosphorylation of ERK and Cot (MAP3K8), increased AP-1 binding activity and induced IL-6 release. To verify that IL-1β from THP-1 cells was responsible for activation of BEAS-2B, conditioned medium with added IL-1Ra, an IL-1β antagonist, was applied to BEAS-2B. Results show that IL-1Ra attenuated effects of conditioned medium, supporting a role of IL-1β, as a secondary mediator, in the transduction of inflammatory signaling from the macrophage to epithelial cells. The effects of LIB-conditioned medium appeared to be less dependent on IL-1β. In conclusion, Chry and LIB induce differential inflammatory responses in THP-1 cells that subsequently lead to differential effects in epithelial cells.

Interactions between rnacrophage cytokines and eicosanoids in expression of antitumour activity

Cytokines and eicosanoid products of macrophages play an essential role in expression of antitumour activity of macrophages either in a cell-to-cell contact system between the effector and the target cell or as cell-free soluble products. In this review the relationship between three main monokines, namely TNF-α, IL-1 and IL-6 and the interrelationship between these monokines and eicosanoids (PGE₂, PGI₂, LTB₄, LTC₄) in their production and in expression of antitumour activity is discussed. Emphasis is given to the effect of tumour burden on production of the monokines and of the eicosanoids and on the production of these compounds by the tumour cells. Finally, the therapeutic implications drawn from animal studies and clinical trials is discussed.

Serum levels of interleukin-6 are not dependent on the kidney function

Interleukin-6, also named B-cell stimulatory factor, is a glycoprotein with a molecular weight of 26 kDa. Increased serum levels of interleukin-6 (IL-6) are found in several disease conditions. We investigated the importance of a deteriorated kidney function upon IL-6 serum concentrations. No relation was found between serum levels of IL-6 and s-creatinine, r = 0.004. On the other hand, the serum concentration of complement protein factor D and soluble IL-2 receptor showed a good correlation to s-creatinine, r = 0.92 and 0.79, respectively. In conclusion, serum levels of IL-6 are not dependent upon a reduced kidney function.

Validation of CRP as prognostic marker for renal cell carcinoma in a large series of patients

BACKGROUND

To evaluate the prognostic significance of the pre-operative C-reactive protein (CRP) serum level in patients with renal cell cancer (RCC).

METHODS

We evaluated 1,161 RCC patients with complete patient and tumour specific characteristics as well as information about their pre-operative CRP-level, who had undergone either radical nephrectomy or nephron-sparing surgery at two German high-volume centres (University Hospitals of Hannover and Ulm). The mean follow-up was 54 months.

RESULTS

The CRP-level, stratified to three subgroups (CRP ≤ 4, 4-10, and >10 mg/l), correlated significantly with tumour stage (p < 0.001), the risk of presenting nodal disease (2.1, 3.1, and 16.4%) and distant metastasis (2.9, 8.6, and 30.0%; p < 0.001). The Kaplan-Meier 5-year cancer specific survival (CSS) rates were 89.4, 77.9, and 49.5%, respectively (p < 0.001). Multivariate analysis identified CRP as an independent prognosticator for CSS as well as overall survival (p < 0.001). Patients with a CRP of 4-10 and >10 mg/l had a 1.67 and 2.48 fold higher risk of dying due to their RCC compared to those with a pre-operative CRP ≤4 mg/l, respectively.

CONCLUSIONS

A high preoperative serum CRP level is an independent predictor of poor survival in patients with RCC. Its routine use could allow better risk stratification and risk-adjusted follow-up of RCC patients.

Role of C-reactive protein in urological cancers: a useful biomarker for predicting outcomes

Based on increasing evidence of the association between cancer-related inflammation and the progression of cancer, the external symptoms of systemic inflammatory response has been shown to be an indicator for the prognosis of many malignancies, including urological cancers. C-reactive protein, a representative acute-phase reactant, is a significant and sensitive inflammatory marker that can be objectively measured using reliable assays in clinical practice worldwide. C-reactive protein has been shown to be significant in the prediction of outcomes of urological cancers. The elevation of C-reactive protein levels, which indicate the presence of cancer-associated systemic inflammatory response, is linked to poorer survival in patients with urological cancers, including renal cell carcinoma, upper urinary tract and bladder cancers, and prostate cancer. With this strong prognostic ability, C-reactive protein can be incorporated into prognostic models and will make them simpler and improve their predictive accuracy. Furthermore, the longitudinal change of C-reactive protein level, C-reactive protein kinetics, provides additional information on patient survival outcomes. As such, C-reactive protein can be used to monitor treatment efficacy and disease course using serial measurements. In testicular cancer, C-reactive protein is associated with a risk of late complications, such as cardiovascular disease, and with the development of second non-germ-cell cancer. Taken together, these findings show that C-reactive protein can act as an important biomarker for urological cancers. This review discusses the importance of C-reactive protein as a prognostic biomarker in urological cancers on the basis of the currently available evidence.

Does interleukin-6 link explain the link between tumour necrosis, local and systemic inflammatory responses and outcome in patients with colorectal cancer?

Cancer-associated inflammation has been identified as a key determinant of disease progression and survival in colorectal cancer. In particular, it has been consistently reported that both the local and systemic inflammatory responses play an important role in determining outcome in colorectal cancer. Given the importance of cancer-associated inflammation, up-regulation or attenuation of these respective inflammatory responses may be important for progression and survival in colorectal cancer. Recent work has focused on the inter-relationships between the tumour and these key inflammatory processes. In particular, tumour necrosis has been reported to be associated with decreased local inflammatory infiltrate and with elevated markers of systemic inflammation in colorectal cancer and has been proposed as a potential link between the systemic and local inflammatory responses. Thus there is increasing interest in the potential biochemical mediators of this link. In this review we examine the evidence for IL-6 in the natural history of colorectal cancer and its relationship with tumour necrosis and the local and systemic inflammatory responses. There is now good evidence that tumour concentrations of IL-6 have been directly associated with increased necrosis, proliferation, differentiation and vascular invasion, while circulating concentrations of IL-6 are directly associated with T-stage, CRP concentrations and poorer survival. Also, interleukin-6 and down-stream pathways, such as the JAK/STAT pathway, have emerged as important factors in the modulation of cancer-associated inflammation. Therefore, IL-6 has emerged as a key mediator of the relationship between tumour necrosis, local and systemic inflammatory responses and outcome in patients with colorectal cancer.

IL-6/IL-6 receptor system and its role in physiological and pathological conditions

IL (interleukin)-6, which was originally identified as a B-cell differentiation factor, is a multifunctional cytokine that regulates the immune response, haemopoiesis, the acute phase response and inflammation. IL-6 is produced by various types of cell and influences various cell types, and has multiple biological activities through its unique receptor system. IL-6 exerts its biological activities through two molecules: IL-6R (IL-6 receptor) and gp130. When IL-6 binds to mIL-6R (membrane-bound form of IL-6R), homodimerization of gp130 is induced and a high-affinity functional receptor complex of IL-6, IL-6R and gp130 is formed. Interestingly, sIL-6R (soluble form of IL-6R) also binds with IL-6, and the IL-6-sIL-6R complex can then form a complex with gp130. The homodimerization of receptor complex activates JAKs (Janus kinases) that then phosphorylate tyrosine residues in the cytoplasmic domain of gp130. The gp130-mediated JAK activation by IL-6 triggers two main signalling pathways: the gp130 Tyr759-derived SHP-2 (Src homology 2 domain-containing protein tyrosine phosphatase-2)/ERK (extracellular-signal-regulated kinase) MAPK (mitogen-activated protein kinase) pathway and the gp130 YXXQ-mediated JAK/STAT (signal transducer and activator of transcription) pathway. Increased IL-6 levels are observed in several human inflammatory diseases, such as rheumatoid arthritis, Castleman's disease and systemic juvenile idiopathic arthritis. IL-6 is also critically involved in experimentally induced autoimmune diseases. All clinical findings and animal models suggest that IL-6 plays a number of critical roles in the pathogenesis of autoimmune diseases. In the present review, we first summarize the IL-6/IL-6R system and IL-6 signal transduction, and then go on to discuss the physiological and pathological roles of IL-6.

BCG response prediction with cytokine gene variants and bladder cancer: where we are?

PURPOSE

Bladder cancer (BC) is one of the most widespread cancers afflicting men and women and also has major philosophical impact on health care worldwide. Despite elaborate characterization of the risk factors and treatment options, BC is still a major epidemiological problem worldwide and its incidence lingers to upswing each year. Over the last three decades, intravesical immunotherapy with the biological response modifier Mycobacterium bovis-Bacillus Calmette Guerin (BCG) has been established as the most effective adjuvant treatment for averting local recurrences and tumor progression following transurethral resection of non-muscle-invasive bladder cancer.

DESIGN AND METHODS

PUBMED database was searched for articles, and manuscripts were selected that provided data regarding the correlation of BCG therapy and its response with different cytokine gene variants.

RESULTS

It is not clear how Bacillus Calmette-Guerin (BCG) works to treat BC. It may stimulate an immune response or cause inflammation of the bladder wall that destroys cancer cells within the bladder. Lot of reports indicated the correlation of various cytokines with respect to BCG therapy in BC, but the exact mechanism is under debate.

CONCLUSION

Research continues to establish the most effectual strain of BCG and the best dosage schedule for the treatment for bladder cancer but, on the other hand, a very critical part of this therapy to find out the correlation of different cytokine with BCG therapy, which will give a better insights not only the mechanism but also a better therapeutic options.

An intermediate-risk multiple myeloma subgroup is defined by sIL-6r: levels synergistically increase with incidence of SNP rs2228145 and 1q21 amplification

IL-6 signaling can be enhanced through transsignaling by the soluble IL-6 receptor (sIL-6r), allowing for the pleiotropic cytokine to affect cells it would not ordinarily have an effect on. Serum levels of sIL-6r can be used as an independent prognostic indicator and further stratify the GEP 70-gene low-risk group to identify an intermediate-risk group in multiple myeloma (MM). By analyzing more than 600 MM patients with ELISA, genotyping, and gene expression profiling tools, we show how the combination of 2 independent molecular genetic events is related to synergistic increases in sIL-6r levels. We also show that the rs2228145 minor allele is related to increased expression levels of an IL-6r splice variant that purportedly codes exclusively for a sIL-6r isoform. Together, the SNP rs2228145 minor allele C and amplification of chromosome 1q21 are significantly correlated to an increase in sIL-6r levels, which are associated with lower overall survival in 70-gene low-risk disease, and aid in identification of the intermediate-risk MM group.

Cytokine profiles in cyst fluids from ovarian tumors reflect immunosuppressive state of the tumor

OBJECTIVE

Ovarian tumors, both benign and malignant, often contain cystic lesions. Analysis of cytokine levels of this enclosed fluid may be a pure way to study cytokine expression to gain more insight in tumor-host interaction.

METHODS

We analyzed the expression of cytokines in 45 cyst fluids from benign and malignant ovarian tumors and mapped the cytokine profiles for the different histological subgroups. The concentration of interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, interferon γ, tumor necrosis factor α, tumor necrosis factor β, transforming growth factor β, and C-C motif chemokine 22 was measured.

RESULTS

The presence of IL-6 in cyst fluid is correlated with malignancy. IL-8 was also expressed in benign samples, but the levels were significantly higher in malignant cyst fluids. Transforming growth factor β was only present in latent form in both benign and malignant cyst fluids. C-C motif chemokine 22 was detectable in higher levels in mucinous samples than in serous samples. IL-10 was not expressed in cyst fluid. T helper 1 subtype (TH1: IL-12 and IFN-γ) and TH2 (IL-4, IL-5) cytokines were similarly expressed in malignant and benign mucinous tumors. However, in the serous group, TH1 and TH2 cytokines were expressed in the benign samples but not in the malignant samples. In the high-grade malignant serous group, we found an inverse relationship between IL-8 levels and overall survival.

CONCLUSIONS

Our results suggest that the immunosuppressive state created by ovarian cancer is reflected in the cystic fluid within the tumor. Furthermore, our findings suggest that type 1 and type 2 tumors have a distinct immunological profile and support the dualistic model for ovarian tumorigenesis.

New insights into the biology of renal cell carcinoma

Ninety percent or more of kidney cancers are believed to be of epithelial cell origin, and are referred to as renal cell carcinoma (RCC), which are further subdivided based on histology into clear-cell RCC (75%), papillary RCC (15%), chromophobe tumor (5%), and oncocytoma (5%). Some genes confer an increased risk of these various histologic RCC subtypes. In practice, there is some overlap among the histologic subtypes, and there are some shared molecular features among these tumor types. This review focuses primarily on the most common form of RCC, clear-cell renal carcinoma, noting some recent advances in the other histologic subtypes.

Expression of the glucocorticoid receptor in renal cell neoplasms: an immunohistochemical and quantitative reverse transcriptase polymerase chain reaction study

Glucocorticoid receptors mediate the action of steroid hormones in a variety of tissues, including the kidney. Our goal was to determine the expression pattern and prognostic significance of glucocorticoid receptor in renal cell neoplasms. Paraffin-embedded microarrays from 200 patients with RCNs including 147 clear cell renal cell carcinomas, 23 papillary, 16 chromophobe renal cell carcinoma, and 14 oncocytomas were analyzed for glucocorticoid receptor expression by immunohistochemistry. Glucocorticoid receptor expression was also quantitated by real-time reverse transcriptase polymerase chain reaction in 45 cases (33 clear cell renal cell carcinomas, 5 chromophobe renal cell carcinomas, and 3 oncocytomas). Strong nuclear glucocorticoid receptor expression was present in normal glomeruli and in the proximal convoluted tubules. Nuclear glucocorticoid receptor expression was found in most clear cell renal cell carcinomas (66%), in 26% of papillary renal cell carcinomas, and in only 6% of chromophobe renal cell carcinomas and 14% of oncocytoma (P < .005). Within the clear cell renal cell carcinoma group, most positive cases (87%) demonstrated strong immunoreactivity (2+ and 3+), whereas only 1 papillary renal cell carcinoma, 1 chromophobe renal cell carcinoma, and none of the oncocytomas showed strong expression. Glucocorticoid receptor α messenger RNA expression was significantly higher in clear cell renal cell carcinoma than in chromophobe renal cell carcinoma, oncocytoma, or in the normal kidney. Significantly more frequent glucocorticoid receptor expression was associated with tumors of low nuclear grade (Fuhrman grade 1 and 2) and low stage (stages 1 and 2; P = .0068 and P = .0002). Survival analysis revealed a significant direct correlation between glucocorticoid receptor expression and overall survival in clear cell renal cell carcinoma (P = .01). In summary, strong glucocorticoid receptor expression was most commonly seen in clear cell renal cell carcinoma and only rarely seen in other subtypes. The glucocorticoid receptor expression pattern in RCNs seems to reflect the histogenetic origin of clear cell renal cell carcinoma from the proximal nephron. Finally, glucocorticoid receptor expression proved to be a marker of less aggressive behavior in clear cell renal cell carcinoma.

Cytokine analysis as a tool to understand tumour-host interaction in ovarian cancer

Epithelial ovarian cancer (EOC) is an immunogenic tumour and exploits many suppressive ways to escape immune eradication. EOC is known to spread primarily by tumour cell implantations in peritoneal cavity. Therefore, ascites may be an ideal fluid compartment to unravel the immune status of the peritoneal cavity. We analysed the expression of IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IFN-γ, TNF-α, TNF-β, TGF-β and CCL22 in ovarian cancer ascites, representing immune activating and suppressing cytokines. We observed high expression of pro-inflammatory cytokines IL-6, IL-8 and immune suppressive cytokines IL-10, CCL22 and TGF-β in most samples whereas Th1 (IL-12p70, IFN-γ) and Th2 (IL-4, IL-5) cytokines were only detectable in 13% of the samples. TGF-β was only detected in latent form, questioning its immune suppressive role. CCL22 was in similar levels present in early stage compared to advanced stage tumours. At advanced stage, we observed a negative correlation with CCL22 levels and Th1/2 cytokine expression. We found a positive correlation between IL-6 concentration in ascites and residual disease after debulking. Additionally, IL-6 levels were remarkably higher at recurrence compared to primary advanced disease, which opens an opportunity for inhibition of IL-6 expression in the prevention of recurrence. Despite the heterogeneity of EOC and the complexity of cytokine functions, our results show that cytokine analysis in ascites may aid in understanding tumour-host interaction in EOC.

Role of C-reactive protein as a biomarker for renal cell carcinoma

The presence of a systemic inflammatory response has been thought to indicate poor prognosis in renal cell carcinoma, based on the assumption that the processes underlying such a response play important roles in the progression of renal cell carcinoma. C-reactive protein (CRP) is a representative acute-phase reactant whose concentration can be objectively measured using a variety of reliable standardized assays. To show that CRP could be an indicator of normal or pathologic processes, recent studies have revealed that CRP is a significant prognostic factor for metastasis and mortality in patients with renal cell carcinoma. Incorporating CRP levels into prognostic algorithms could make those algorithms simpler without reducing their predictive accuracy. Furthermore, CRP kinetics, the analysis of dynamic changes in CRP concentrations, has been shown to generate valuable information relevant to prognosis, specifically information on the likelihood of tumor aggressiveness. Therefore, dynamic changes of CRP concentration could indicate clinical pharmacologic response to therapeutic intervention. Taken together, we could conclude that CRP is a significant biomarker for renal cell carcinoma.

Peptide inhibitors of MK2 show promise for inhibition of abdominal adhesions

BACKGROUND

Abdominal adhesions are a common side effect of surgical procedures with complications including infertility, chronic pain, and bowel obstruction, which may lead to the need for surgical lyses of the adhesions. Mitogen-activated protein kinase-activated protein kinase 2 (MK2) has been implicated in several diseases, involving inflammation and fibrosis. Thus, the development of a cell-penetrating peptide (CPP) that modulates MK2 activity may confer therapeutic benefit after abdominal surgery in general and more specifically after bowel anastomosis.

METHODS

This study evaluated the function of a CPP inhibitor of MK2 in human mesothelial cells and in a rat bowel anastomosis model. To determine IC50 and basic specificity, kinase inhibition was performed using a radiometric assay. Enzyme-linked immunoassay (ELISA) was used to evaluate interleukin-6 (IL-6) expression in response to IL-1β and tumor necrosis factor-α (TNF-α) stimulation in vitro to validate MK2 kinase inhibition. Following bowel anastomosis (10 rats for each control and treatment at 4 and 10 d), the rats were evaluated for weight loss, normal healing (colonic burst strength and hydroxyproline content at the anastomosis), and number and density of adhesions.

RESULTS

The IC50 of the MK2 inhibitor peptide (22 μM) was similar to that of the nonspecific small molecule rottlerin (IC50 = 5 μM). The MK2 inhibitor peptide was effective at suppressing IL-1β and TNF-α stimulated IL-6 expression in mesothelial cells. In vivo, the MK2 inhibitor peptide was effective at suppressing both the density and number of adhesions formed as a result of bowel an anastamosis. Importantly, the peptide had no negative effect on normal healing.

CONCLUSIONS

In conclusion, the peptide inhibitor of MK2, MMI-0100, has the potential to significantly reduce inflammation through suppression of inflammatory cytokine expression and showed promise as a therapeutic for abdominal adhesions.

Prognostic significance of preoperative C-reactive protein elevation and thrombocytosis in patients with non-metastatic renal cell carcinoma

PURPOSE

The aim of this study was to investigate the association of preoperative C-reactive protein (CRP) elevation and thrombocytosis with the prognosis of patients with non-metastatic renal cell carcinoma (RCC).

MATERIALS AND METHODS

This was a retrospective review of the medical records of 177 patients (130 men and 47 women) with non-metastatic RCC who underwent a radical nephrectomy between March 2000 and May 2008 and for whom preoperative CRP and platelet data were available for analysis. Preoperative CRP elevation and thrombocytosis were compared with clinical and pathological variables.

RESULTS

There were 38 patients with CRP elevation and 11 patients with thrombocytosis. The mean follow-up time was 48.3 months (median, 48.0; range, 13-111 months). Twenty-three patients (13.0%) developed metastases and six patients died during the follow-up period. CRP elevation was significantly correlated with anemia (p=0.001), T stage (p=0.004), grade (p=0.025), and metastasis (p<0.001). Thrombocytosis was significantly correlated with anemia (p=0.003), T stage (p=0.002), and metastasis (p=0.001). The univariate analysis identified anemia, CRP elevation, thrombocytosis, tumor histology subtype, tumor size, T stage, and grade as significant prognostic factors associated with recurrence-free survival, whereas the multivariate analyses showed that CRP elevation (p=0.033) and tumor size (p=0.007) were independent prognostic factors.

CONCLUSIONS

Preoperative CRP elevation and thrombocytosis were associated with a poorer prognosis and a higher recurrence rate in patients with non-metastatic RCC. Moreover, preoperative CRP elevation appeared to be an independent predictor of tumor recurrence and prognosis. Preoperative thrombocytosis, however, was not an independent prognostic factor for tumor recurrence and prognosis.

Extracts from Citrus unshiu promote immune-mediated inhibition of tumor growth in a murine renal cell carcinoma model

AIM OF THIS STUDY

Citrus unshiu (Satsuma mandarin, SM) is a citrus fruit the peel of which has been used as a traditional Chinese medicine to treat common cold, relieve exhaustion, and cancer. In this study, we examined how effectively the content and peel extracts of SM can suppress cancer growth. The mechanism underlying cancer-suppressing properties of SM was investigated in tumor-bearing mice with renal carcinoma cell, Renca.

MATERIALS AND METHODS

Effectiveness of SM in tumor suppression was evaluated by measuring size of tumor mass in tumor-bearing mice treated with various doses of SM content and peel extracts. Proliferation of tumor cells and splenocytes was determined by MTT assay and [³H]TdR uptake, respectively. Relevant immunological mechanisms were chased by assaying cytokines including TGF-β, IL-6, IFN-γ, and TNF-α by ELISA.

RESULTS

The content and peel extracts of SM inhibited the growth of tumor cells in tumor-bearing mice. Especially, average tumor volume of two groups treated with 3 and 30 mg peel extracts per mouse weight (kg) were significantly decreased to 52.32% (p<0.05) and 68.72% (p<0.01), respectively. To identify tumor regression mechanism, anti-tumor cytokines measured in Con A-activated splenocytes from tumor-bearing mice. IFN-γ was increased in both of the peel extract-treated groups, while TNF-α, which had been decreased by tumor growth, was rescued to the normal level in SM content and peel extracts-treated groups. However, SM content and peel extracts did not inhibit proliferation and tumor-proliferative cytokines including TGF-β and IL-6 production of tumor cells.

CONCLUSION

These results indicate that SM content and peel extracts have anti-tumor properties in the tumor-bearing murine model. The mechanism underlying the anti-tumor effects of SM extracts is strongly suggested to be via boosting cytokines such as IFN-γ and TNF-α, enhancing immune-mediated anti-tumor properties.

IL-6 increases MMP-13 expression and motility in human chondrosarcoma cells

Chondrosarcoma is a type of highly malignant tumor with a potent capacity to invade locally and cause distant metastasis. Chondrosarcoma shows a predilection for metastasis to the lungs. IL-6 is a multifunctional cytokine that is associated with the disease status and outcomes of cancers. However, the effect of IL-6 on the migration activity of human chondrosarcoma cells is mostly unknown. Here, we found that IL-6 increased the migration and expression of MMP-13 in human chondrosarcoma cells. We also found that human chondrosarcoma tissues had significant expression of IL-6, which was higher than that in normal cartilage. IL-6-mediated migration and MMP-13 up-regulation were attenuated by anti-IL-6 receptor antibody, Ras, Raf-1, and a MEK inhibitor. Activation of the Ras, Raf-1, MEK, ERK, and NF-κB signaling pathways after IL-6 treatment was demonstrated, and IL-6-induced MMP-13 expression and migration activity were inhibited by the specific inhibitor and mutant Ras, Raf-1, MEK, ERK, and NF-κB cascades. In addition, migration-prone sublines demonstrated that cells with increasing migration ability had greater expression of IL-6 and MMP-13. Taken together, these results indicate that IL-6 and IL-6 receptor interaction enhances migration of chondrosarcoma through an increase in MMP-13 production.

Human mesenchymal stem cells promote growth of osteosarcoma: involvement of interleukin-6 in the interaction between human mesenchymal stem cells and Saos-2

Our previous study showed that exogenous human mesenchymal stem cells (hMSCs) targeted established osteosarcoma and promoted its growth and pulmonary metastasis in vivo. As a follow-up, the present study aimed to investigate how hMSCs would interact with Saos-2 through autocrine/paracrine communication. The results showed that co-injection of hMSCs with Saos-2 into the proximal tibia of nude mice could promote tumor growth and progression. In vitro, the proliferation of Saos-2 and hMSCs was promoted by each other's conditioned medium, in which interleukin-6 (IL-6) played an important role. Osteogenic differentiation of hMSCs could be inhibited by conditioned medium of Saos-2, in which IL-6 was also involved. Furthermore, decreased IL-6 secretion by hMSCs during its osteogenesis and increased IL-6 secretion in response to conditioned medium of Saos-2 were observed. Based on these data, we suggest that there was a positive feedback loop of IL-6 in the interaction between hMSCs and Saos-2.

C-reactive protein is a strong predictor for anaemia in renal cell carcinoma: role of IL-6 in overall survival

OBJECTIVE

• To elucidate the association of progression of advanced renal cell carcinoma with anaemia and investigate factors influencing tumor-associated anaemia.

PATIENTS AND METHODS

• We analyzed different clinical variables to study associations with anaemia in 86 metastatic renal cell carcinoma patients. • 45 (52%) of patients had already developed anaemia prior to therapy.

RESULTS

• Anaemic patients had an increase in the serum markers C-reactive protein (CRP), IL-6 and erythropoietin (EPO). In addition we observed substantial correlation between IL-6 and CRP serum levels (R = 0.639, P < 0.0001). • Univariate logistic regression analysis revealed that patients with IL-6 >10 pg/mL had a considerable increase in risk for anaemia (odds ratio 3.86, P= 0.003). • In addition, patients with CRP >0.7 mg/dL had a very strong increase in risk for anaemia (OR = 14.08, P < 0.0001). • Stepwise multivariate logistic regression analysis confirmed CRP >0.7 mg/mL as the only independent predictor for anaemia. Cox-regression modeling selected serum IL-6 as the strongest independent prognostic indicator (hazard ratio 3.58, P < 0.0001).

CONCLUSION

• Anaemia depends on serum IL-6, which is a strong inductor of CRP and regulator of the iron-transport. Serum IL-6 may be considered as a target to treat cancer-related anaemia.

Loss of tumoral expression of soluble IL-6 receptor is associated with disease progression in colorectal cancer

Background:

Interleukin-6 (IL-6) binds both the membrane and soluble forms of the IL-6 receptor (sIL-6R), which induces a complex with gp130, and proliferation of tumour cells. The aim of this study is to clarify the relationship between tumoral sIL-6R expression and disease progression in colorectal cancer patients.

Methods:

We measured tissue concentrations of sIL-6R in tumour and normal mucosa from 161 colorectal cancer patients undergoing surgery, and in supernatants from colon cancer cell lines. The expression of IL-6, IL-6R and gp130 was evaluated by immunohistochemical analysis.

Results:

Loss of tumour expression of sIL-6R as defined by sIL-6R Ca/N ratio <1.0 was significantly associated with factors reflecting disease progression, and was an independent prognostic factor not only in all the patients in this study, but also in the patients with curative intent. Colon cancer cell lines produced sIL-6R in vitro, and the production of sIL-6R in cancer cell lines was stimulated by cytokine stimulation. Immunohistochemistry revealed that loss of tumour expression of sIL-6R was significantly inversely correlated with intense IL-6 expression in the cytoplasm of cancer cells. In addition, tumoral IL-1β expression was significantly correlated with sIL-6R expression.

Conclusion:

Loss of tumour expression of sIL-6R is associated with colorectal cancer disease progression.

Neutralization of interleukin (IL)-10 released by monocytes/macrophages enhances the up-regulatory effect of monocyte/macrophage-derived IL-6 on expressions of IL-6 and MUC1, and migration in HT-29 colon cancer cells

The interactions between monocyte-derived IL-6 and IL-10 in colon cancer are unknown. We continued previous work that showed monocyte/macrophage-derived IL-6 induces IL-6 and MUC1 expression in HT-29 cancer cells, and evaluated if IL-10 present in monocyte/macrophage is involved in this IL-6-mediated effect. We treated HT-29 cells with monocyte/macrophage supernatant following neutralization of monocyte/macrophage-released IL-10. Neutralization markedly enhanced monocyte/macrophage-derived IL-6 effects on HT-29 cells including IL-6 and MUC1 production and cell migration. Double blocking of IL-6 and IL-10 in monocyte/macrophage supernatants abolished this enhancement. Western blot analysis of STAT3 phosphorylation showed that this augmented response in HT-29 cells following IL-10 neutralization is probably mediated through enhanced IL-6-induced phosphorylation (Tyr(705)) of STAT3 proteins. Therefore, monocytes/macrophages have the capacity to release the functionally associated cytokines IL-6 and IL-10 whose interactions can account for the pathogenesis and progression of colon cancer.

Interleukin-6 (IL-6) released by macrophages induces IL-6 secretion in the human colon cancer HT-29 cell line

The level of interleukin-6 (IL-6) is correlated with prognosis and liver metastasis in colon cancer. However, the relationship between macrophage-derived and tumor-derived IL-6 in colon cancer remains unclear. We harvested the macrophage supernatant and studied the IL-6-inducing ability of the macrophage supernatant on the colon cancer cell line HT-29. The macrophage supernatant effectively induced IL-6 secretion of colon cancer cells in vitro. The macrophage supernatant and recombinant IL-6 neutralized with anti-IL-6 or ant-gp130 antibodies dramatically decreased the IL-6-induction ability of cancer cells. IL-6-induction occurred through phosphorylation of STAT3. We analyzed the surgical specimens of 126 patients with colon cancer using an immunohistochemical staining method and demonstrated the colocalization of macrophages and the expression of IL-6 in colon cancer patients. These results indicate that macrophages in tumor infiltrates could release IL-6, which in turn conditions colon cancer cells, causing them to secrete IL-6 themselves via phosphorylation of STAT3.

The -174 G/C polymorphism in interleukin-6 (IL-6) promoter region is associated with serum IL-6 and carcinoembryonic antigen levels in patients with colorectal cancers in Taiwan

INTRODUCTION

We investigated the associations between -174 G/C polymorphism of interleukin-6 (IL-6) gene promoter and serum IL-6 and carcinoembryonic antigen (CEA) levels in Taiwanese patients with colorectal cancer (CRC).

RESULTS AND DISCUSSION

The frequency of the G allele was only 0.043, which is significantly lower compared to Western analogs. On grouping genotypes as G-positive (GG and CG) and G-negative (GG), the average IL-6 level and CEA levels were significantly lower in G-positive patients than in G-negative analogs (IL-6, 3.56 +/- 4.38 vs. 15.38 +/- 9.52 pg/ml, P = 0.021; CEA, 27.7 +/- 25.7 vs. 157.7 +/- 59.6 ng/ml, P = 0.012). The patients without the G allele had higher incidences of synchronous cancers of other origins (P = 0.003).

CONCLUSION

In conclusion, ethnicity affects the status of -174 G/C IL-6 polymorphism. This polymorphism status consequently influences the expressions of serum IL-6 and CEA and incidences of synchronous cancers of other origins.

Bone-derived SDF-1 stimulates IL-6 release via CXCR4, ERK and NF-kappaB pathways and promotes osteoclastogenesis in human oral cancer cells

Oral squamous cell carcinoma (SCC) has a striking tendency to invade to bone. The chemokine stromal cell-derived factor-1 (SDF-1) is constitutively secreted by osteoblasts and plays a key role in homing of hematopoietic cells to the bone marrow. Interleukin (IL)-6 plays an important role in osteoclastogenesis. Herein, we found that SDF-1α increased the secretion of IL-6 in cultured human SCC cells, as shown by reverse transcriptase–polymerase chain reaction and enzyme-linked immunosorbent assay. SDF-1α also increased the surface expression of chemokine receptor 4 (CXCR4) in SCC cells. CXCR4-neutralizing antibody, CXCR4-specific inhibitor (AMD3100) or small interfering RNA against CXCR4 inhibited SDF-1α-induced increase IL-6 production. The transcriptional regulation of IL-6 by SDF-1α was mediated by phosphorylation of extracellular signal-regulated kinases (ERKs) and activation of the nuclear factor-kappa B (NF-κB) components p65 and p50. The binding of p65 and p50 to the NF-κB element on the IL-6 promoter was enhanced by SDF-1α. In addition, IL-6 antibody antagonized the SCC-conditioned medium-increased osteoclastogenesis. These results suggested that SDF-1α from osteoblasts could induce release of IL-6 in human SCC cells via activation of CXCR4, ERK and NF-κB pathway and thereby promote osteoclastogenesis.

C-reactive protein level predicts prognosis in patients with muscle-invasive bladder cancer treated with chemoradiotherapy

OBJECTIVE

To investigate the effect of C-reactive protein (CRP) level on the prognosis of patients with muscle-invasive bladder cancer treated with chemoradiotherapy (ChRT), as it is increasingly recognized that the presence of a systemic inflammatory response is associated with poor survival in various malignancies.

PATIENTS AND METHODS

The clinical records of 88 patients with bladder urothelial carcinoma (cT2-4 N0M0) treated with ChRT were reviewed retrospectively. ChRT comprised external beam radiotherapy to the bladder (40 Gy) with two cycles of cisplatin (50-100 mg) at 3-week intervals. Elevated CRP was defined as > 0.5 mg/dL. The survival rate was calculated using the Kaplan-Meier method, and a multivariate analysis was used to identify significant factors associated with prognosis, using a Cox proportional hazards model.

RESULTS

During the median (range) follow-up of 33 (3-117) months, 19 patients died from bladder cancer; the 5-year cancer-specific survival (CSS) rate was 73%. Ten patients had a high CRP level before ChRT (> or = 0.5 mg/dL) and their CSS rate was significantly worse than that in the remaining patients (P = 0.003). Multivariate analysis showed that CRP and cT stage were independent prognostic indicators for CSS, with a hazard ratio of 1.80 (95% confidence interval 1.01-2.97; P = 0.046). Among 10 patients in those with elevated CRP the CRP levels became normal after ChRT in six, of whom all but one was alive with no evidence of recurrence or metastasis during the follow-up. By contrast, all four with no CRP normalization after ChRT died within 2 years.

CONCLUSIONS

To our knowledge this is the first study to report that elevation of CRP before treatment predicts a poor prognosis in patients with muscle-invasive bladder cancer who are receiving ChRT. Furthermore, failure of CRP levels to normalize after ChRT was associated with extremely poor survival.

Renal cell carcinoma bone metastasis--elucidating the molecular targets

The development of bone metastasis from renal cell carcinoma (RCC) signals a transition to a terminal state for the patient with previously isolated disease. These patients may suffer the morbidity of severe, persistent pain, pathologic fractures, and spinal compression from vertebral metastasis before they succumb to their cancer. Although recent advancements have been made in the understanding of breast and prostate bone metastasis, there has been less knowledge in the area of metastatic RCC to the skeleton. This particular cancer in bone remains relatively resistant to standard forms of treatment such as radiation and chemotherapy. A better understanding of the biology of RCC bone metastasis is critically needed in order to improve treatment. Bone-derived cell lines and an experimental animal model have been developed in order to explore the relevant mechanisms of how RCC cells survive within and destroy the bone. This review will focus on the growth factor signaling pathways most important for the RCC-stimulated osteoclast-mediated bone destruction, namely the epidermal growth factor receptor (EGF-R) and transforming growth factor-beta receptor (TGF-betaR) pathways. By inhibiting these receptors, growth of RCC within the bone is decreased which, directly or indirectly, decreases bone destruction.

Interleukin-6 and its receptor in cancer: implications for translational therapeutics

Interleukin-6 (IL-6) plays a major role in the response to injury or infection and is involved in the immune response, inflammation, and hematopoiesis. Its deregulation impacts numerous disease states, including many types of cancer. Consequently, modulating IL-6 may be an innovative therapeutic strategy in several diseases. A review of relevant published literature regarding IL-6 and its receptor was performed. In addition, a review of the relevance of this cytokine system to human illness, particularly in cancer, was undertaken. IL-6 is a pleiotropic cytokine that is involved in the physiology of virtually every organ system. Aberrant expression of this cytokine has been implicated in diverse human illnesses, most notably inflammatory and autoimmune disorders, coronary artery and neurologic disease, gestational problems, and neoplasms. In cancer, high levels of circulating IL-6 are observed in almost every type of tumor studied and predict a poor outcome. Furthermore, elevated IL-6 levels are associated strongly with several of the striking phenotypic features of cancer. Several molecules have been developed recently that target the biologic function of IL-6. Early results in the clinic suggest that this strategy may have a significant salutary impact on diverse tumors. The field of cytokine research has yielded a deep understanding of the fundamental role of IL-6 and its receptor in health and disease. Therapeutic targeting of IL-6 and its receptor in cancer has strong biologic rationale, and there is preliminary evidence suggesting that targeting of the IL-6 system may be beneficial in the treatment of cancer.

Serum C-reactive protein levels predict survival in hepatocellular carcinoma

BACKGROUND/AIMS

C-reactive protein (CRP) was recently identified as a prognostic factor for patients with hepatocellular carcinoma (HCC) after surgical resection. We investigated the relationship between the serum levels of high sensitivity CRP (H-CRP) and the prognosis of HCC patients.

METHOD

We conducted a cohort study of 90 HCC patients enrolled from 1997 to 1998. All patients were treated and followed for a mean period of 3.2 years. Clinical variables were compared between patients positive for H-CRP (serum H-CRP levels >/=3.0 mg/L, n=47) and those negative for H-CRP (serum H-CRP levels <3.0 mg/L, n=43). We also determined the relationship between serum H-CRP and prognosis in HCC patients.

RESULTS

The survival rate of patients of the H-CRP-positive group was lower than that of H-CRP-negative patients. Tumour stage (stages 3 or 4), total bilirubin >/=1.2 mg/dL, albumin (Alb) <3.5 g/dL, des-gamma-carboxy prothrombin >/=40 mAU/mL, positive H-CRP and initial treatment (transcatheter arterial chemoembolization, hepatic arterial infusion chemotherapy or best supportive care) were identified as significant poor prognostic factors by univariate analysis, while positive H-CRP [hazard ratio (HR), 1.58; P=0.048], Alb<3.5 g/dL (HR, 2.10; P=0.004), tumour stage (stages 3 or 4; HR, 3.05; P=0.001) and initial treatment (HR, 1.88; P=0.029) were considered to be significant determinants of poor prognosis by multivariate Cox proportional hazards analysis.

CONCLUSIONS

The prognosis of H-CRP-positive patients was poorer compared with H-CRP-negative patients. This study confirmed that H-CRP, like CRP, is a marker of poor prognosis in HCC patients.

Interleukin 6 determination in the detection of microbial invasion of the amniotic cavity

A growing body of evidence suggests a role for cytokines in the mechanisms responsible for preterm parturition associated with intrauterine infection. Interleukin 6, a polyfunctional cytokine that is secreted by tissues in the feto-maternal interface in response to microbial products, has been implicated in the host response to intrauterine infection. The purpose of this study was to establish whether measurement of amniotic fluid concentrations of interleukin 6 could be of value in the diagnosis of microbial invasion of the amniotic cavity. Fluid was obtained by transabdominal amniocentesis from patients with preterm labour and intact chorioamniotic membranes and cultured for aerobic and anaerobic bacteria and mycoplasmas. Interleukin 6 concentrations were determined by an ELISA validated for human amniotic fluid. An interleukin 6 concentration above 11.2 ng/ml had a 93.7% sensitivity and a 92.3% specificity in the diagnosis of intra-amniotic infection. Moreover, patients with an amniotic fluid interleukin 6 level above 11.2 ng/ml and a negative amniotic fluid culture failed to respond to tocolysis, delivered a preterm infant and showed histological evidence of chorioamnionitis, and their neonates were at risk for congenital infections.

Hepatocyte growth factor and interleukin-6 in combination with prostate volume are possible prostate cancer tumor markers in patients with gray-zone PSA levels

The aim was to assess whether hepatocyte growth factor (HGF) and interleukin (IL)-6 in combination with prostate volume are able to accurately detect prostate cancer in patients with gray-zone prostate-specific antigen (PSA) levels. A total of 159 patients with PSA levels of <10 ng ml(-1) were enrolled. Forty-two (35.3%) were diagnosed with prostate cancer, whereas 117 (64.7%) had no cancer and were used as benign group. HGF and IL-6 density (HGFD and IL-6D, respectively) values were calculated by dividing serum HGF and IL-6 levels with prostate volume. Median IL-6 (2.3 pg ml(-1)) levels for the prostate cancer group were significantly higher than those for the benign group before adjustment for age (1.7 pg ml(-1)) (P=0.0098). After age adjustments, median IL-6 (2.17 pg ml(-1)), HGFD (0.00972 ng ml(-1) cm(-3)), and IL-6D (0.0848 pg ml(-1) cm(-3)) values for the prostate cancer group were significantly higher than those for the benign group (IL-6, 1.78 pg ml(-1); HGFD, 0.00732 ng/ml/cc; and IL-6D, 0.049 pg/ml/cc; P=0.0416, 0.007 and 0.0005, respectively). In receiver operating characteristic analyses, the areas under the curves for HGFD (0.64) and IL-6D (0.68) were significantly greater than those for HGF (0.52) and IL-6 (0.61) (P=0.0006 and 0.019, respectively). With an HGFD cutoff value of 0.00392 ng ml(-1) cm(-3) (sensitivity=100%, specificity=11%), 11.1% of the benign group were able to avoid unnecessary biopsies without missing prostate cancer. HGF and IL-6 levels in combination with prostate volume were shown to be useful parameters for prostate cancer screening in patients with gray-zone PSA levels.

Interleukin-6 mediates G(0)/G(1) growth arrest in hepatocellular carcinoma through a STAT 3-dependent pathway

Interleukin-6 (IL-6) is a pleiotropic cytokine that regulates diverse cell functions including proliferation and differentiation. Within the liver IL-6 signaling plays a central role during normal hepatic growth and regeneration yet can inhibit the proliferation of hepatocellular carcinoma (HCC) cells. The aim of the current study was to identify underlying mechanisms whereby IL-6 induces cell-cycle arrest in HCC cells. These studies demonstrate that IL-6 inhibits cell-cycle progression at the G(0)/G(1) interface through inhibition of cyclin-dependent kinase (cdk) 2 and cdk4 activity in the absence of changes in total cyclin (A, D1, D3, and E) or cdk (cdk2, 4, and cdc2 p34) expression. Inhibition of signal transduction pathways associated with IL-6 receptor activation demonstrates that IL-6-dependent inhibition of G(0)-G(1) progression occurs via Janus tyrosine kinase-signal transducers and activators of transcription-3 (Jak-STAT3)-dependent induction of p21(waf1/cip1) and is independent of ERK-MAPK signaling. These data demonstrate that, while IL-6 plays a central role in hepatocyte priming and proliferation in vivo, the pronounced inhibition of proliferation observed in HCC cells occurs due to IL-6-STAT3-dependent regulation of cdk2/cdk4 activity and p21(waf1/cip1) expression.

Significance of autologous interleukin-6 production in the HA22T/VGH cell model of hepatocellular carcinoma

Cancer cells may often support their own growth, survival, and drug resistance by autocrine/paracrine loops based on the production of different factors; results from us and others have shown that similar interleukin-6 (IL-6)-related loops are operative in multiple myeloma and prostate or renal cancer. Because this aspect has not been investigated in detail for hepatocellular carcinoma (HCC), we have examined it in HA22T/VGH cells. These differ from other primary liver cancer cell lines (that is, HepG2, HuH-6, and HuH-7) in that enzyme-linked immunosorbent assay (ELISA) showed the HA22T/VGH cells to secrete remarkable amounts of IL-6 (16.8 ng/10(6) cells/24 h); this production, due to constitutive activation of NF-kappaB, is inhibited by agents like curcumin and dehydroxymethylepoxyquinomicin (DHMEQ), which interfere with the transcription factor. Flow cytometry, ELISA, mRNA, and Western blotting analyses were performed to characterize the status of the IL-6 receptor in HA22T/VGH cells. Two transmembrane glycoproteins that form the functional IL-6 receptor have been identified: the ligand-binding gp80 and the signal-transducer gp130. Soluble forms of gp80 also trigger membrane gp130 signaling when complexed with IL-6, while soluble forms of gp130 inhibit the same process. Our results showed that HA22T/VGH cells express gp130 at their surface, but release only traces of its soluble form. For gp80, the cells produced the mRNAs of both its membrane and soluble form. However, in immunoblotting they exhibited a very faint content of the same subunit, which, in addition, was neither expressed at the cell surface nor secreted. In MTT assays, incubation with a neutralizing anti-IL-6 antibody for up to 7 days did not affect the growth of HA22T/VGH cells. Also, other specific anti-IL-6 approaches (siRNA or AODN) failed to produce this result. In conclusion, autostimulatory loops mediated by IL-6 are less likely to occur in HCC than in other kinds of cancer. However, since release of IL-6 is frequent in HCC, especially in its more advanced stages, the use of agents like curcumin or DHMEQ might be beneficial to counteract its adverse systemic effects (e.g., cachexia).

Naturally acquired regulatory mechanism of perioperative cytokine response in neonates

The inflammatory reaction is known to be controlled in neonates. We clarified the characteristics of cytokine profile in neonatal patients and assess its clinical significance. Serum levels of interleukin (IL)-6 and IL-1 receptor antagonist (ra) were determined in 152 pediatric patients and 33 each of maternal and cord bloods. Supernatant IL-1ra levels of cultured monocytes and granulocytes stimulated with IL-1beta or LPS, and IL-1ra mRNA expression of granulocytes were assayed in 15 each of cord and healthy adult bloods. Although surgical stress in neonates was heavier than that in infants, there was no difference in the occurrence of postoperative morbidity and mortality. In neonates, the perioperative serum level of IL-1ra was significantly raised, and the postoperative IL-6 response was well controlled. The serum concentration of IL-1ra in cord blood was not different from that in maternal blood, whereas, the serum concentration of IL-6 in cord blood was significantly reduced than that in maternal blood. In granulocytes, significantly more IL-1ra was produced from cord than from adult blood. An IL-1ra predominant immune status in neonates may be a naturally acquired adaptation system and play a crucial role in attenuating acute inflammatory reaction in a vulnerable host defense.