oxypurinol and Cachexia

Cachexia is a common complication of cancer and may be responsible for 22% of all cancer-related deaths. The exact cause of death in cancer cachexia patients is unknown. Recently, atrophy of the heart has been described in cancer cachexia animal models, which resulted in impaired cardiac function and is likely to contribute to mortality. In cancer patients hyperuricaemia independent of tumour lysis syndrome is often associated with a worse prognosis. Xanthine oxidase (XO) metabolizes purines to uric acid and its inhibition has been shown to improve clinical outcome in patients with chronic heart failure.. The rat Yoshida AH-130 hepatoma cancer cachexia model was used in this study. Rats were treated with 4 or 40 mg/kg/d oxypurinol or placebo starting one day after tumour-inoculation for maximal 15 days. Cardiac function was analyzed by echocardiography on day 11.. Here we show that inhibition of XO by oxypurinol significantly reduces wasting of the heart and preserves cardiac function. LVEF was higher in tumour-bearing rats treated with 4 mg/kg/d (61±4%) or 40 mg/kg/d (64±5%) oxypurinol vs placebo (51±3%, both p<0.05). Fractional shortening was improved by 4 mg/kg/d (43±3%) oxypurinol vs placebo (30±2, p<0.05), while 40 mg/kg/d oxypurinol (41±5%) did not reach statistical significance. Cardiac output was increased in the 4 mg/kg/d dose only (71±11 mL/min vs placebo 38±4 mL/min, p<0.01).. Inhibition of XO with oxypurinol has beneficial effects on cardiac mass and function in a rat model of severe cancer cachexia, suggesting that XO might be a viable drug target in cancer cachexia.

Topics: Animals; Cachexia; Cardiomyopathies; Liver Neoplasms; Liver Neoplasms, Experimental; Male; Oxypurinol; Rats; Rats, Wistar; Xanthine Oxidase

Cachexia is a common co-morbidity in cancer occurring in up to 80% of patients depending on the type of cancer. Uric acid (UA), the end-product of the purine metabolism, is elevated in cachexia due to tissue wasting and upregulated xanthine oxidase (XO) activity. High serum UA levels indicate increased XO-dependent production of oxygen free radicals (reactive oxygen species; ROS) and correlate with metabolic illness and poor survival. We hypothesized that XO-inhibition might reduce inflammatory signals accounting for tissue wasting and improve survival in experimental cancer cachexia. Animals were inoculated intraperitoneally with AH-130 hepatoma cells and treated with two XO-inhibitors: allopurinol [Allo, low (LD) and high dose (HD) 4 and 40 mg/kg/d] and its more effective active metabolite oxypurinol (Oxy, 4 and 40 mg/kg/d) or placebo for 15 days. Weight loss and tissue wasting of both fat and lean tissue (assessed by NMR-scanning) was reduced by both LD and HD Allo and LD-Oxy, but not by HD-Oxy. A robust induction of XO-activity for generation of reactive oxygen species was seen in the placebo group (assessed by electron paramagnetic spectroscopy), which was reduced by XO-inhibition. Increased ROS induced cytokine signaling, proteolytic activity and tissue degradation were all attenuated by XO inhibition. Survival was significantly and dose dependently improved. Food intake and spontaneous locomotor activity were higher, indicating a higher quality of life. Inhibition of XO can reduce tissue wasting and improve survival in cancer cachexia and clearly clinical studies are needed.

Topics: Allopurinol; Animals; Body Composition; Body Weight; Cachexia; Caspase 3; Enzyme Inhibitors; Male; Neoplasms; Oxidative Stress; Oxypurinol; Random Allocation; Rats; Rats, Wistar; Reactive Oxygen Species; Treatment Outcome; Uric Acid; Xanthine Oxidase

Cancer cachexia is a wasting condition, driven by systemic inflammation and oxidative stress. This study investigated eicosapentaenoic acid (EPA) in combination with oxypurinol as a treatment in a mouse model of cancer cachexia. Mice with cancer cachexia were randomized into 4 treatment groups (EPA (0.4 g/kg/day), oxypurinol (1 mmol/L ad-lib), combination, or control), and euthanized after 29 days. Analysis of oxidative damage to DNA, mRNA analysis of pro-oxidant, antioxidant and proteolytic pathway components, along with enzyme activity of pro- and antioxidants were completed on gastrocnemius muscle. The control group displayed earlier onset of tumor compared to EPA and oxypurinol groups (P<0.001). The EPA group maintained body weight for an extended duration (20 days) compared to the oxypurinol (5 days) and combination (8 days) groups (P<0.05). EPA (18.2±3.2 pg/ml) and combination (18.4±3.7 pg/ml) groups had significantly higher 8-OH-dG levels than the control group (12.9±1.4 pg/ml, P≤0.05) indicating increased oxidative damage to DNA. mRNA levels of GPx1, MURF1 and MAFbx were higher following EPA treatment compared to control (P≤0.05). Whereas oxypurinol was associated with higher GPx1, MnSOD, CAT, XDH, MURF1, MAFbx and UbB mRNA compared to control (P≤0.05). Activity of total SOD was higher in the oxypurinol group (32.2±1.5 U/ml) compared to control (27.0±1.3 U/ml, P<0.01), GPx activity was lower in the EPA group (8.76±2.0 U/ml) compared to control (14.0±1.9 U/ml, P<0.05), and catalase activity was lower in the combination group (14.4±2.8 U/ml) compared to control (20.9±2.0 U/ml, P<0.01). There was no change in XO activity. The increased rate of weight decline in mice treated with oxypurinol indicates that XO may play a protective role during the progression of cancer cachexia, and its inhibition is detrimental to outcomes. In combination with EPA, there was little significant improvement from control, indicating oxypurinol is unlikely to be a viable treatment compound in cancer cachexia.

Topics: Adenocarcinoma; Animals; Cachexia; Catalase; Cell Line, Tumor; Drug Evaluation, Preclinical; Drug Therapy, Combination; Eicosapentaenoic Acid; Enzyme Inhibitors; Female; Gene Expression; Mice; Mice, Inbred BALB C; Mice, Nude; Muscle, Skeletal; Muscular Atrophy; Neoplasm Transplantation; Neoplasms, Experimental; Organ Size; Oxidative Stress; Oxypurinol; Superoxide Dismutase; Tumor Burden; Weight Loss; Xanthine Oxidase