Pivalyloxymethyl butyrate (AN9) is an anticancer derivative of butyric acid. In this study, doxorubicin (DXR) and AN9 synergistically inhibited the growth of lymphoma and lung carcinoma cells, whereas there was no synergy between AN9 and antimetabolites. AN9 did not affect the intracellular uptake of DXR. Among anthracyclines and their derivatives, the synergistic effect was prominent in compounds with a daunosamine moiety, suggesting that AN9 may affect the catabolism of these compounds. The degradation of DXR in the extract from AN9-treated cells was much less than that in extract from untreated cells. AN9 did not directly inhibit the enzyme activity but rather suppressed expression of the enzyme. With respect to the expression of drug resistance-related genes, there was no significant difference between untreated and AN9-treated cells. However, AN9 significantly down-regulated the levels NADPH-cytochrome P450 reductase and DT-diaphorase mRNA in the presence of DXR but not the level of xanthine oxidase mRNA. The enhancement of the sensitivity to anthracyclines was closely associated with the suppression of the mRNA expression.

The outcome of patients with non-Hodgkin’s lymphoma has been improved by current approaches to treatment. Nevertheless, many patients either do not have a complete remission or ultimately relapse. To identify such patients, it is important to be able to predict the outcome. We previously found that the differentiation inhibitory factor/nm23 was correlated with the prognosis of acute myeloid leukemia. To examine the prognostic effect of nm23 on non-Hodgkin’s lymphoma, we established an enzyme-linked immunosorbent assay procedure to determine nm23-H1 protein levels in plasma and assessed the association of this protein level with the response to chemotherapy, overall survival, and progression-free survival in patients with aggressive non-Hodgkin’s lymphoma. The plasma concentration of nm23-H1 was significantly higher in patients with malignant lymphoma than in normal controls, especially in aggressive non-Hodgkin’s lymphoma. The complete remission rate in patients with higher nm23-H1 levels was significantly worse than that in patients with lower nm23-H1 levels. Overall survival and progression-free survival were also lower in patients with higher nm23-H1 levels than in those with lower levels. The 3-year survival rates in patients with low and high nm23-H1levels were 79.5% and 6.7% (P = .0001). A multivariate analysis of prognostic factors showed that the plasma nm23-H1level was independently associated with the survival and progression-free survival. An elevated plasma nm23-H1concentration predicts a poor outcome of advanced non-Hodgkin’s lymphoma. Therefore, nm23-H1 in plasma may be useful for identifying a distinct group of patients at very high risk.

Soluble Fas (sFas) in the serum is believed to be able to inhibit apoptosis of lymphocytes. It has been reported that the serum sFas level is increased in various diseases, including malignant lymphoma and systemic lupus erythematosus. We studied the association between sFas and the prognosis of patients with aggressive non-Hodgkin's lymphoma (NHL). Compared with normal controls, the serum sFas level was increased significantly in patients with aggressive NHL and adult T cell leukemia/lymphoma. Among patients with aggressive NHL, the complete remission rate was significantly decreased in the subgroup having high serum sFas levels. Both the overall survival rate and the disease-free survival (DFS) rate were significantly lower for this subgroup than for patients with low serum sFas levels. The 5-year survival rates estimated by the KaplanMeier method for patients with high and low serum sFas levels were 27.6% and 68.3%, respectively (P ‫؍‬ 0.0001). The 5-year DFS rates estimated for patients with high and low serum sFas levels were 44.7% and 71.9%, respectively (log-rank test: P ‫؍‬ 0.0023, and generalized Wilcoxon test: P ‫؍‬ 0.0014). Among patients with a low and low-intermediate risk group according to the International Prognostic Index (IPI), the 5-year survival rates for low and high serum sFas subgroups were 72.8% and 42.0%, respectively, showing a significant difference (Wilcoxon test: P ‫؍‬ 0.0163, log-rank test: P ‫؍‬ 0.0115). Among patients with a high-intermediate and high risk group, the 5-year survival rates for low and high serum sFas subgroups were 51.6% and 17.4%, respectively, again showing a significant difference (Wilcoxon test: P ‫؍‬ 0.0001, log-rank test: P ‫؍‬ 0.0002). Multivariate analysis of a series of prognostic factors, including the five used to calculate the IPI, showed that the serum sFas level was an independent prognostic factor for the overall survival. Based on these results, a serum sFas level of 10 ng/ml or more can be considered to indicate a poor prognosis in patients with advanced NHL, and this finding may be useful for developing strategies for further treatment.