BackgroundNeuroblastoma (NB) is the most common cancer in infancy and most frequent cause of death from extracranial solid tumors in children. Ornithine decarboxylase (ODC) expression is an independent indicator of poor prognosis in NB patients. This study investigated safety, response, pharmacokinetics, genetic and metabolic factors associated with ODC in a clinical trial of the ODC inhibitor difluoromethylornithine (DFMO) ± etoposide for patients with relapsed or refractory NB.Methods and FindingsTwenty-one patients participated in a phase I study of daily oral DFMO alone for three weeks, followed by additional three-week cycles of DFMO plus daily oral etoposide. No dose limiting toxicities (DLTs) were identified in patients taking doses of DFMO between 500-1500 mg/m2 orally twice a day. DFMO pharmacokinetics, single nucleotide polymorphisms (SNPs) in the ODC gene and urinary levels of substrates for the tissue polyamine exporter were measured. Urinary polyamine levels varied among patients at baseline. Patients with the minor T-allele at rs2302616 of the ODC gene had higher baseline levels (p=0.02) of, and larger decreases in, total urinary polyamines during the first cycle of DFMO therapy (p=0.003) and had median progression free survival (PFS) that was over three times longer, compared to patients with the major G allele at this locus although this last result was not statistically significant (p=0.07). Six of 18 evaluable patients were progression free during the trial period with three patients continuing progression free at 663, 1559 and 1573 days after initiating treatment. Median progression-free survival was less among patients having increased urinary polyamines, especially diacetylspermine, although this result was not statistically significant (p=0.056).ConclusionsDFMO doses of 500-1500mg/m2/day are safe and well tolerated in children with relapsed NB. Children with the minor T allele at rs2302616 of the ODC gene with relapsed or refractory NB had higher levels of urinary polyamine markers and responded better to therapy containing DFMO, compared to those with the major G allele at this locus. These findings suggest that this patient subset may display dependence on polyamines and be uniquely susceptible to therapies targeting this pathway.Trial RegistrationClinicaltrials.gov NCT#01059071

-diacetylspermine (DiAcSpm) in the urine of colorectal and breast cancer patients was examined to establish its usefulness as a novel diagnostic tool for detecting these cancers at clinically early stages. Experimental Design: Urine samples from 248 colon cancer patients and 83 breast cancer patients as well as 51patients with benign gastrointestinal diseases treated inTokyo Metropolitan Komagome Hospital during the period of August1999 toJanuary 2004 were collected. DiAcSpm was analyzed by ELISA and its sensitivity for malignant conditions was compared with that of serum carcinoembryonic antigen (CEA), CA19-9, and CA15-3. Results: The sensitivity of urinary DiAcSpm for colon cancer patients (n = 248) was 75.8% (mean F 2 SD for 52 healthy controls as a cutoff value), which was markedly higher than the sensitivities of serum CEA (39.5%, P < 0.0001) and CA19-9 (14.1%, P < 0.0001). DiAcSpm was elevated in 60% of tumor-node-metastasis cancer stage 0 + I patients, whereas only 10% (P < 0.0001) and 5% (P < 0.0001) of these patients were CEA-and CA19-9^positive, respectively.The sensitivity of urinary DiAcSpm for 83 cases of breast cancer (60.2%) was higher than the sensitivities of CEA (37.3%, P = 0.0032) and CA15-3 (37.3%, P = 0.0032). DiAcSpm was elevated in 28% of tumor-node-metastasis stage I + II patients, whereas only 3% (P = 0.0064) and 0% (P = 0.001) of these patients were CEA-and CA15-3^positive, respectively. Conclusion:The observations indicate that urinary DiAcSpm is a more sensitive marker than CEA, CA19-9, and CA15-3 and that it can efficiently detect colorectal and breast cancers at early stages.We reported previously that N 1 ,N 12 -diacetylspermine (DiAcSpm) is excreted in the urine of healthy persons, with small individual variations in the amount (1). We devised a high-performance liquid chromatography separation system connected to an in-line enzymatic detection system for DiAcSpm and carried out precise analyses of urinary DiAcSpm in healthy persons as well as patients with malignant diseases.Our analysis revealed that DiAcSpm may be useful as a novel diagnostic and prognostic tumor marker in that its excretion in urine is elevated significantly and frequently in patients with urogenital malignancies and tends to recover to the normal level on remission (2, 3). At the same time, we noted that monoacetylpolyamines that constitute a major part of urinary polyamines, including N-acetylputrescine, N 1 -acetylspermidine, and N 8 -acetylspermidine, were much less sensitive as markers for these urogenital malignancies than DiAcSpm and could not be considered practical tumor markers. The part of our observations concerning conventional monoacetylpolyamines was very well in accord with the popular evaluation of urinary polyamines at that time (4), but our results on DiAcSpm analysis were radically different from those on other polyamine derivatives and looked highly promising (2, 3).Although the biochemistry and clinical chemistry of DiAcSpm remain largely obscure at present because of the lack of intensiv...

N1,N12-diacetylspermine (DiAcSpm) and N1,N8-diacetylspermidine (DiAcSpd) are minor components of human urinary polyamine to which little attention has been paid until recently. HPLC analysis of urinary polyamines has revealed that the excretion of these diacetylpolyamines, in particular, into urine was frequently and markedly increased in association with every type of cancer so far examined. Remission was usually accompanied by recovery of urinary diacetylpolyamines to the normal level. DiAcSpm was more sensitive than CEA for detecting colorectal cancer patients, while DiAcSpd was highly specific for malignant conditions in that the excretion of the latter was scarcely elevated in cases of benign urogenital diseases. An ELISA procedure for rapid determination of DiAcSpm was developed to promote the clinical application of these new tumor markers, and subsequent studies indicated that DiAcSpm was elevated in 60% of colorectal cancer patients at early stages (stage 0 + I), whereas only 10% of these patients were CEA-positive. DiAcSpm may also be useful as a follow-up marker that is efficient for detecting recurrence and sensitive to changes in the clinical condition of patients. The evidence accumulated so far indicates that DiAcSpm and DiAcSpd are promising novel tumor markers. They deserve more intensive studies, including studies of their biochemistry and metabolism.

Background:Early detection of non-small-cell lung cancer (NSCLC) and accurate prognostic risk assessment could improve patient outcome. We examined the significance of urinary N1, N12-diacetylspermine (DiAcSpm) in the detection and prognostic stratification of NSCLC patients.Methods:A DiAcSpm/cutoff ratio (DASr) was established for 260 NSCLC patients, 99 benign lung disease patients, and 140 healthy volunteers, using colloidal gold aggregation methods. The DASr was compared between patients and healthy controls, and the prognostic significance of DASr was examined.Results:The median urinary DASr of NSCLC patients was significantly higher than that of healthy controls (0.810 vs 0.534, P<0.001). The DASr was higher in squamous cell carcinoma (SqCC) patients than in adenocarcinoma patients (1.18 vs 0.756, respectively, P=0.039). An increased urinary DASr value was significantly associated with pathological stage, other histological invasive factors and unfavourable outcomes in patients with completely resected NSCLC. Multivariate Cox regression analysis showed that increased urinary DASr was an independent prognostic factor (hazard ratio=4.652, 95% confidence interval (CI), 2.092–10.35; P<0.001).Conclusions:Urinary DASr was significantly increased in NSCLC, especially in SqCC. Urinary DASr was an independent poor prognostic indicator in patients with completely resected NSCLC. The DASr could be a useful biomarker for detecting malignancies and predicting prognosis.

N1,N12-Diacetylspermine (DiAcSpm)-specific antibodies were raised in rabbits, using N-acetylspermine coupled to mercaptosuccinylated BSA via N-(4-maleimidobutyryloxy)-succinimide as an antigen. Highly DiAcSpm-specific antibodies were enriched from crude sera through a series of affinity-based fractionations. A competitive ELISA system, intended for measuring DiAcSpm in solution, was constructed using this antibody preparation, with N-acetylspermine coupled to a synthetic peptide via N-(8-maleimidocapryloxy)-succinimide as a solid phase antigen. The Ki value for DiAcSpm with this competitive ELISA system was 33 nM, and the cross-reactivity with DiAcSpm, AcSpm, DiAcSpd, N1-AcSpd, and N8-AcSpd was 100, 0.29, 0.20, 0.033, and 0.055%, respectively. This procedure can be applied to the determination of DiAcSpm in human urine samples, giving highly reproducible results. The coefficients of variation obtained were 6.7 and 4.2% for within-run and between-run precision, respectively. The correlation coefficient between DiAcSpm concentrations in urine estimated by ELISA and those by HPLC analysis was calculated to be 0. 99, and the regression equation was expressed as y = 1.04x + 0.026 microM.

Recently, we found N1,N8-diacetylspermidine (Ac2Spd) and N1,N12-diacetylspermine (Ac2Spm) in human urine, and noted that their amount increased significantly in patients with urogenital malignancies. Previous findings that simultaneous reference to these diacetylpolyamines is useful in distinguishing cancer patients from healthy persons were confirmed by more recent analytical data on urine samples from several cancer patients. Further examination revealed that urinary Ac2Spm and Ac2Spd tended to decrease when cancer patients were treated and entered partial remission. In cases where the Ac2Spm and Ac2Spd levels were normal or near-normal after treatments, the prognosis of the patients was generally good. In contrast, when their level remained far above the normal limits after apparently effective treatment, the prognosis of the patients was poor. When a patient is in remission for more than 3 years, urinary levels of both Ac2Spm and Ac2Spd are stabilized and stay below the normal limits, with rare exceptions. The recurrence of a cancer as well as the complication of a second one during the period of follow-up examination was accompanied by elevation of urinary diacetylpolyamines. These observations indicate that urinary Ac2Spm and Ac2Spd are useful as prognostic indicators after treatment and during follow-up examination of cancer patients.

N¹,N¹²-diacetylspermine (DiAcSpm) is a minor component of human urine that constitutes less than 0.5% of total polyamine species in human urine. Structurally related polyamines and acetylpolyamines were separated and analyzed by HPLC and gas chromatography, and refinement of these procedures led to the identification of this minor component. Subsequent analyses of urines from cancer patients as well as healthy persons revealed that DiAcSpm is a promising candidate for a novel tumor marker. It is much more sensitive than established tumor markers in detecting colorectal and other cancers, and most importantly, is able to detect 60% of early colorectal cancers confined to mucous membranes. Serum CEA is able to detect only about 10% of colorectal cancers at this stage. Collection of urine is easy and does not give any pain to patients, which adds another merit to urinary DiAcSpm as a tumor marker. DiAcSpm-specific antibodies were then developed for simpler determination of DiAcSpm in urine, and the antibodies were used to construct an ELISA system. More recently, a reagent kit for DiAcSpm determination based on colloidal gold aggregation that can be used with automatic biochemical analyzers was also developed.

An analytical system developed for fractionating free and monoacetylated polyamines [Hiramatsu, K. et al. (1994) J. Biochem. 115, 584-589] was proved useful also in detecting diacetylpolyamines, namely N1,N8-diacetylspermidine (diAcSpd) and N1,N12-diacetylspermine (diAcSpm). Detection limits were 0.9 and 0.6 pmol (S/N = 5) for diAcSpd and diAcSpm, respectively. Analytical recovery and within-run variation were also satisfactory. Human urine samples were found to contain diAcSpd and diAcSpm. These polyamines were identified on the basis of the following observations: (i) their retention times were coincident with those of authentic samples; (ii) they were deacetylated to N8-acetylspermidine and monoacetyl- and free spermine, respectively, by acetylpolyamine amidohydrolase; and (iii) they were practically inert to direct oxidation by bacterial polyamine oxidase as were authentic samples. The amounts of eleven polyamine species including diAcSpd and diAcSpm in urine samples from 52 healthy persons were determined. Mean values for the major polyamine components were consistent with those reported by others. Although the amounts of diAcSpd and diAcSpm were very small, comprising only 1.4 and 0.46% of total polyamines, respectively, these two compounds were found to be always present in healthy human urine as regular constituents. Moreover, variation in their content among individuals was small, suggesting that excretion of these components in urine is strictly regulated.