Endogenous tumour necrosis factor in cancer patients

Acute moderate elevation of TNF-alpha does not affect systemic and skeletal muscle protein turnover in healthy humans

CONTEXT

Skeletal muscle wasting has been associated with elevations in circulating inflammatory cytokines, in particular TNF-alpha.

OBJECTIVE

In this study, we investigated whether TNF-alpha affects human systemic and skeletal muscle protein turnover via a 4-h recombinant human (rh) TNF-alpha infusion. We hypothesize that TNF-alpha increases human muscle protein breakdown and/or inhibits synthesis.

SUBJECTS AND METHODS

Using a randomized, controlled, crossover design, postabsorptive healthy young males (n = 8) were studied 2 h under basal conditions followed by a 4-h infusion of either rhTNF-alpha (700 ng . m(-2) . h(-1)) or 20% human albumin (control), which was the vehicle of rhTNF-alpha. Systemic and skeletal muscle protein turnover was estimated by a combination of tracer dilution methodology (primed continuous infusion of l-[ring-(2)H(5)]phenylalanine and l-[(15)N-leucine], with prime of l-[ring-(2)H(4)]tyrosine) and femoral arterial-venous differences over the leg and muscle biopsies.

RESULTS

Plasma TNF-alpha concentration rapidly increased from basal levels of approximately 0.7 to 17 pg . ml(-1) with rhTNF-alpha infusion. Whole body protein synthesis, breakdown, and net degradation were similar after the basal and infusion period of the control and rhTNF-alpha trials. Skeletal muscle, musculus vastus lateralis, protein fractional synthetic rate was not different over 4 h of control or rhTNF-alpha (rate of incorporation of (15)N-leucine). Muscle protein turnover determined with the phenylalanine three-compartment model showed similar muscle synthesis, breakdown, and net muscle degradation after 2-h basal and after 4-h control or rhTNF-alpha infusion.

CONCLUSION

This study is the first to show in humans that TNF-alpha does not affect systemic and skeletal muscle protein turnover, when acutely elevated for 4 h to moderate levels not causing adverse effects.

Tumor necrosis factor-alpha and transforming growth factor-beta reflect severity of liver damage in primary biliary cirrhosis

BACKGROUND AND AIMS

The pathogenesis of primary biliary cirrhosis (PBC) is unknown. The role of cytokines such as tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta), and the effect of ursodeoxycholic acid (UDCA) in modifying the cytokine environment in patients with PBC has remained largely unstudied. Our aims were to determine: (i) the relationship between serum levels of TNF-alpha and TGF-beta and the severity of PBC; and (ii) the effects of UDCA therapy on TNF-alpha and TGF-beta levels in patients with PBC.

METHODS

We studied 90 patients who had been treated with UDCA (53 patients) or placebo (37 patients) for 2 years as part of a randomized, double-blind, controlled trial. Patients were divided into histological stage I/II or stage III/IV disease. Serum TNF-alpha and TGF-beta levels were quantified by enzyme-linked immunoabsorbent assay.

RESULTS

Baseline levels of TNF-alpha were significantly greater in patients with stage III/IV compared to stage I/II disease. After 2 years of treatment with UDCA, patients showed a significantly greater decrease in TNF-alpha levels and progression risk score compared to placebo-treated patients. TNF-alpha and TGF-beta levels were significantly reduced compared to baseline levels in the UDCA-treated group after 2 years, while there was no significant change in the levels of placebo-treated patients.

CONCLUSIONS

Serum TNF-alpha and TGF-beta levels may reflect severity of disease in patients with PBC. The beneficial effects of UDCA therapy may be explained by lowering serum levels of these two cytokines.

The role of cytokines in cancer cachexia

A large number of observations point towards cytokines, polypeptides released mainly by immune cells, as the molecules responsible for the metabolic derangements associated with cancer-bearing states. Indeed, these alterations lead to a pathological state known as cancer cachexia which is, unfortunately, one of the worst effects of malignancy, accounting for nearly a third of cancer deaths. It is characterized by weight loss together with anorexia, weakness, anemia, and asthenia. The complications associated with the appearance of the cachectic syndrome affect both the physiological and biochemical balance of the patient and have effects on the efficiency of the anticancer treatment, resulting in a considerably decreased survival time. At the metabolic level, cachexia is associated with loss of skeletal muscle protein together with a depletion of body lipid stores. The cachectic patient, in addition to having practically no adipose tissue, is basically subject to an important muscle wastage manifested as an excessive nitrogen loss. The metabolic changes are partially mediated by alterations in circulating hormone concentrations (insulin, glucagon, and glucocorticoids in particular) or in their effectiveness. The present study reviews the involvement of different cytokines in the metabolic and physiological alterations associated with tumor burden and cachexia. Among these cytokines, some can be considered as procachectic (such as tumor necrosis factor-alpha), while others having opposite effects can be named as anticachectic cytokines. It is the balance between these two cytokine types that finally seems to have a key role in cancer cachexia.

Is TNF really involved in cachexia?

A review on the possible involvement of tumor necrosis factor-alpha (TNF) in cachexia is presented. While this cytokine is definitely linked to sepsis and tumor-associated weight loss in some experimental models, other cytokines, such as interleukin-6 (IL-6) or interferon-gamma (IFN-gamma), alone or in combination with TNF, may also play an important role in the development of cachexia.

Serum levels of tumor necrosis factor in squamous cell carcinoma of the head and neck

PURPOSE

Tumor necrosis factor (TNF)-alpha is a multifunctional cytokine that influences the clinical outcome in a number of diseases. This study was undertaken to evaluate its role in the differential diagnosis of malignant and benign tumors and in the follow-up of patients. We also studied the correlation of TNF-alpha levels with the stage and differentiation of the diseases.

METHODS

In this study, serum levels of TNF-alpha are determined by the immunoradiometric assay method in 26 patients with head and neck cancer, and results are compared with 8 control patients with benign diseases. In both groups, serum samples were taken before and after the therapy. After centrifugation, the sera was stored at -70 degrees C until analyzed. TNF-alpha levels were measured by TNF-alpha immunoradiometric assay (IRMA) kit (Medgenix, Diagnostics SA, Belgium).

RESULTS

The pretreatment mean value of TNF-alpha in the study group (814.1 pg/mL) was almost 100 times higher than in the control group (8.6 pg/mL) (P = .001). It was also noted that posttreatment mean value (94 pg/mL) was significantly lower than pretreatment mean value in the study group (P = .001). No statistically significant difference was found between serum TNF-alpha levels and the stage and differentiation of the tumor.

CONCLUSION

The serum levels of TNF-alpha may be an efficient tumor marker in the diagnosis of patients with head and neck cancer.

Tumour necrosis factor-alpha, interleukin-1 beta and interleukin-6 in patients with renal cell carcinoma

Patients with renal cell carcinoma (RCC) can exhibit fever, weight loss and increases in acute phase proteins. Interleukin (IL)-1, tumour necrosis factor (TNF) and IL-6 are considered major mediators of local and systemic inflammation. We measured plasma IL-1 beta, TNF-alpha (immunoradiometric assay) and IL-6 (ELISA) in 78 consecutive patients with untreated RCC and in 56 normal subjects. IL-6 plasma levels were higher in patients with RCC (mean 24.2 pg/ml, 11.1-37.3, 95% confidence interval) than in normal subjects (11.6 pg/ml, 10.1-13.1, n = 39, P < 0.01). The patients with fever or weight loss had higher blood levels of IL-6. IL-6 blood levels were also higher in patients with lymph node invasion and/or distant metastases (94.7 pg/ml, 39.0-150.4, n = 15) than in patients with undisseminated RCC (7.4, 4.1-10.7, n = 63, P < 0.0001). An abnormal IL-6 plasma value (> 40 pg/ml) had a positive predictive value of 91.0% for lymph node and/or metastatic spread of RCC. IL-6 was statistically correlated with C-reactive protein (nephelometric assay) blood values r' = 0.67, n = 78, P < 0.001). The TNF-alpha and IL-1 beta levels were not significantly different in patients with or without fever or weight loss. The plasma levels of the three cytokines were not correlated with the size of the primary tumour. An increased plasma value of IL-6 is a good marker for tumour dissemination in patients with untreated RCC.

Prognostic relevance of transforming growth factor alpha (TGF-alpha) and tumor necrosis factor alpha (TNF-alpha) detected in breast cancer tissues by immunohistochemistry

The function of different growth factors in the development and progression of malignant tumors and the role of cytotoxic cytokines in the host response generated against neoplasms have been recently studied. Anti-TGF-alpha and anti-TNF-alpha monoclonal antibody families have been developed and characterized previously by our laboratory. Libraries of anti-TGF-alpha and anti-TNF-alpha monoclonal antibodies were selected for equal immunoreactivity both in native (frozen) and in formaldehyde fixed, paraffin embedded histological sections. No differences were found between native and fixed samples demonstrated in 10 cases in the present prospective study. Retrospective investigation was performed in 35 histopathological specimens of breast cancer patients detailed clinically and observed during 5 years after the surgical treatment. Correlation between TGF-alpha and/or TNF-alpha expression and clinical staging--TNM score, lymph node metastasis, tumor recurrence and survival time--was analyzed. According to our present study, the TGF-alpha positive patients had worse clinical prognosis than the TNF-alpha positive and double positive cases during long term observation.

Effects of clofazimine analogues and tumor necrosis factor-alpha individually and in combination on human polymorphonuclear leukocyte functions in vitro

In the present study the individual and interactive effects of clofazimine, or three analogues of this agent (selected on the basis of similar or superior pro-oxidative properties: B669, B746 and B4021) and human recombinant TNF-alpha on the generation of antimicrobial oxidants by human polymorphonuclear leukocytes (PMNL), as well as release of granule enzymes from these cells, were investigated in vitro. All four riminophenazines at the concentrations tested (0.5 and 1.0 micrograms/ml) significantly increased myeloperoxidase (MPO)-mediated iodination, superoxide (0(2).-) generation, oxygen (0(2)) consumption and chemiluminescence (CL), as well as the release of both primary and secondary granule contents (measured as the release of MPO, lysozyme and vitamin B12-binding protein) by stimulated PMNL. Similar, but less impressive effects were observed with TNF-alpha (0.4-50.0 ng/ml). When PMNL were preincubated with both TNF-alpha and clofazimine or its analogues, the observed stimulation of cellular oxidative metabolism and granule enzyme release was at least additive in many assays. These data demonstrate that the spectrum of effects of clofazimine and its analogues on PMNL closely resemble those of TNF-alpha. Furthermore, TNF-alpha potentiates the pro-oxidative effects of clofazimine and its analogues on PMNL. Among the riminophenazines tested, clofazimine and B669 appear to be the most potent pro-oxidative agents for PMNL.

Hormonal factors associated with weight loss in patients with advanced breast cancer

Fasting blood samples were collected from 83 patients with histologically proven breast cancer and analysed for plasma glucagon, serum immunoreactive tumour necrosis factor (TNF alpha), insulin, glucose, growth hormone, cortisol and TSH. Samples from patients with known diabetes mellitus or thyroid disease, and those on parenteral nutrition or with evidence of infection were excluded as were patients who had a history of weight loss through dieting or who were anorexic. Fasting plasma glucagon, serum cortisol and immunoreactive TNF alpha concentrations in patients with stage IV breast cancer who had developed weight loss were significantly higher than those in patients with stage IV disease who had not developed weight loss. There were no significant differences in the fasting serum concentrations of insulin, glucose, growth hormone and TSH between the two patient groups. The association between weight loss in stage IV breast cancer and increased concentrations of plasma glucagon, serum cortisol and TNF alpha suggests a possible role for these hormonal factors in the development of cancer cachexia.

Tumour necrosis factor-alpha immunodetection in blood monocytes and serum: preliminary findings in weight-losing cancer patients

The peptide tumour necrosis factor-alpha (TNF-alpha) is a central mediator of the host response. Identifying where and when TNF-alpha is produced may give insights into its potential role in various pathophysiological states. This paper describes a quantitative analysis of TNF-alpha expression in peripheral blood monocytes (PBM) at the single cell level. A pilot study has been undertaken, using this method to assess TNF-alpha expression in PBM from healthy volunteers and cancer patients. We also report mildly elevated serum TNF-alpha levels in the cancer patients, using an immunoradiometric assay (IRMA) sensitive to 1 pg/mL of recombinant TNF-alpha. The results of this preliminary investigation suggest that TNF-alpha production may be altered in cancer patients.