Oxidative stress and wasting in cancer

The putative role of neuropeptide autoantibodies in anorexia nervosa

PURPOSE OF REVIEW

Anorexia nervosa remains a disease of unknown etiology. This situation explains the failure to develop effective therapy and emphasizes the fact that the neurobiological mechanisms of appetite and emotion are still incompletely understood. The present review is the first summary of recent research assigning to the immune system a new role in energy and emotional regulation by the production of autoantibodies directed against neuropeptides. The results of this research are promising to shed light on the etiology of eating disorders and open new fields for biological diagnosis and follow-up as well as designing new therapeutic strategies.

RECENT FINDINGS

Following the initial identification of autoantibodies against alpha-melanocyte-stimulating hormone, a key neuropeptide involved in the regulation of satiety and mood, in the plasma of patients with anorexia and bulimia nervosa, it has been further found that the serum levels of these autoantibodies correlated with psychopathological traits in individuals with eating disorders. Furthermore, recent findings show that autoantibodies against alpha-melanocyte-stimulating hormone and against some other appetite-regulating peptide hormones are normally present in the blood of humans and rats and their production may be influenced by stress and the gut microflora.

SUMMARY

Novel data provide evidence that autoantibodies against neuropeptides can be involved in the regulation of appetite and emotion and that alteration in autoantibody-mediated signaling pathways may be responsible for the development of eating disorders.

Evaluation of 8-hydroxydeoxyguanosine, thiobarbituric acid-reactive substances and total antioxidant status as possible disease markers in oesophageal malignancies

OBJECTIVES

Evaluation of oxidative stress and diagnostic utility of its markers in oesophageal squamous cell carcinoma (OSCC).

DESIGN

Serum 8-hydroxydeoxyguanosine, thiobarbituric acid-reactive substances (TBARS) and total antioxidant status (TAS) were measured in OSCC (n=75), non-malignant oesophageal diseases (n=30), and healthy subjects (n=79). Three months following oesophagectomy the measurements were repeated.

RESULTS

Exclusively in OSCC, 8-hydroxydeoxyguanosine and TBARS were elevated. TAS was reduced in non-malignancies compared to controls, and in OSCC compared to non-malignancies and controls. Only 8-hydroxydeoxyguanosine was associated with disease progression, lymph node involvement in particular. All indices were good indicators of cancer presence (ROC analysis) and normalized following oesophagectomy. A positive linear relationship between 8-hydroxydeoxyguanosine and TBARS, and negative non-linear between TAS and both 8-hydroxydeoxyguanosine and TBARS was demonstrated.

CONCLUSION

OSCC is associated with oxidative stress, attenuated following oesophagectomy. Consumption of serum antioxidants prevents accumulation of oxidatively modified molecules in non-malignancies. High accuracy of oxidative stress markers in indicating cancer presence warrants further investigation on their possible application as discriminatory markers and in monitoring treatment efficacy.