Polyamine reduced diet (PRD) nutrition therapy in hormone refractory prostate cancer patients.

BACKGROUND: Reducing polyamine uptake by selecting low polyamine-containing foodstuffs and reducing bacterial gut production can improve performance status and pain control in hormone refractory prostate cancer (HRPC) patients. Long term PRD observance and tolerance were assessed. Cancer specific survival was studied in function of PRD and time of PRD initiation. METHODS: Twenty-six volunteers, age: 68+/-10 years with metastatic HRPC accepted a polyamine reduced diet and partial gut decontamination with oral neomycin or nifuroxazide (750 mg daily, one week out of two). Time from HRPC to PRD initiation was 10+/-8 months. WHO performance status, EORTC pain scale, body weight, blood counts and serum proteins were regularly assessed. Sixteen other HRPC patients eating a normal diet served as "controls". RESULTS: Mean diet observance is 25+/-24 months. Tolerance is good. WHO performance status and EORTC pain scales were significantly improved respectively at 3 months (0.5+/-0.7 vs 0.7+/-0.9: p=0.03) and 6 months (0.5+/-0.8 vs 1+/-1.3, p=0.02) compared to initial values. Median cancer specific survival times after HRPC and PRD initiation are respectively 36 and 21 months. Eleven PRD patients started the diet before a 9 months cut-off period (after HRPC) and 15 patients after. Median cancer specific survival times for these two groups of patients are respectively 44 and 34 months, p=0.014. Median cancer specific survival times (after HRPC) for PRD patients compared to controls are 36 vs 17 months (p=0.004). CONCLUSIONS: Polyamine-reduced diet is well observed and tolerated. It seems to improve and/or maintain quality of life for HRPC patients. Early PRD initiation in HRPC is promising and may impact favorably cancer specific survival. These results open a rationale for PRD in HRPC management and warrant further investigation.

Polyamine deficient diet to relieve pain hypersensitivity.

There is a compelling body of evidence that N-methyl-d-aspartate receptors (NMDA-R) play a critical role in the development and maintenance of pain hypersensitivity. However, long-term treatments with NMDA-R antagonists are limited by unacceptable side effects. Since polyamines modulate the functioning of NMDA-R and mainly originate from normal dietary intake and bacterial metabolism in the gut, we developed a nutritional therapy based on dietary polyamine deficiency. Here, we reported that a polyamine deficient diet (PD diet) for 7 days prevented the enhancement of tyrosine phosphorylation of the spinal NR2B subunit-containing NMDA-R associated with inflammation in rats. Based on these data, we studied the ability of PD diet to prevent long-lasting pain hypersensitivity associated with tissue injury on one hind paw by evaluating long-lasting changes in both mechanical nociceptive threshold and weight bearing. A PD diet strongly reduced long-lasting hyperalgesia induced by inflammation or incision, especially in fentanyl-treated rats. Moreover a PD diet also prevented the exaggerated hyperalgesia induced by a second inflammation performed 7 days after the first one. A PD diet also opposed paradoxical hyperalgesia induced by non-nociceptive environmental stress in rats with pain and opioid experiences. A PD diet reversed pain hypersensitivity associated with monoarthritis or neuropathy and restored the analgesic effect of morphine. Since PD diet was devoid of any noticeable side effects, this nutritional therapy could be part of an effective and safe strategy for pre-emptive analgesia and for reducing the transition from acute to chronic pain and its outcomes in various pain syndromes.

The new orally active iron chelator ICL670A exhibits a higher antiproliferative effect in human hepatocyte cultures than O-trensox.

By comparing the antiproliferative effect of the iron chelators ICL670A and O-trensox in the human hepatoma cell line HUH7 and human hepatocyte cultures, we have shown that ICL670A decreased cell viability, inhibited DNA replication and induced DNA fragmentation more efficiently than O-trensox. O-trensox and ICL670A induced a cell cycle blockade in G0-G1 and S phases respectively. In parallel, ICL670A inhibited polyamine biosynthesis by decreasing ornithine decarboxylase and spermidine/spermine N(1)-acetyltransferase activities. O-trensox increased polyamine biosynthesis and particularly putrescine level by stimulating spermidine-spermine N(1)-acetyltransferase activity which could activate the polyamine retro-conversion pathway. Moreover, the two chelators exhibit some cytotoxic effect in the two culture models; ICL670A was more cytotoxic than O-trensox and higher concentrations of the two chelators were necessary to induce a cytotoxicity in primary cultures versus hepatoma cells. These results suggested that ICL670A has the most efficient antitumoral effect, blocks cell proliferation by a pathway different of O-trensox and may constitute a potential drug for anticancer therapy.

Atmospheric pressure chemical ionization-mass spectrometry method to improve the determination of dansylated polyamines.

Determination of polyamine pools is still a step impossible to circumvent in studies aimed at determining the pathophysiological role of natural polyamines. In addition, polyamine measurement in biological fluids and tissues may have clinical relevance, especially in cancer patients. Among the wide panel of analytical methods developed for the quantification of polyamines, high-performance liquid chromatographic (HPLC) separation of polyamines after derivatization with dansyl chloride remains the most commonly used method. In this work, we show that atmospheric pressure chemical ionization-mass spectrometry (MS) can be used to detect and quantify biologically relevant polyamines after dansylation, without chromatographic separation. Positive-ion mass spectra for each dansylated polyamine were generated after optimization by flow injection analysis (FIA). FIA coupled with MS detection by selected ion monitoring greatly increased the sensitivity of the polyamine detection. The method is linear over a wide range of polyamine concentrations and allows detection of quantities as low as 5 fmol. The FIA/MS method is about 50-fold more sensitive than the conventional HPLC/fluorimetry procedure. A good correlation (r>0.98) between these two methods was observed. The FIA/MS method notably reduces the time of analysis per sample to 1.5 min and turns out to be rapid, efficient, cost saving, reproducible, and sufficiently simple to allow its routine application.