Daisuke Toiyama

Enhancement of the sensitivity of renal cell carcinoma cells to fas-mediated cytotoxicity and apoptosis by the selective cyclooxygenase-2 inhibitor JTE-522.

Background: Cyclooxygenase-2 (COX-2) is a key enzyme involved in the production of prostaglandins and its inhibitors have been shown to induce apoptosis in a variety of cancer cells. We reasoned that combination treatment of renal cell carcinoma (RCC) cells with COX-2 inhibitors and anticancer agents may result in synergistic apoptosis. We examined whether the selective COX-2 inhibitor JTE-522 synergizes with anticancer agents in cytotoxicity and apoptosis against RCC cells. Methods: The cytotoxicity of the selective COX-2 inhibitor JTE-522 and other anticancer agents against the RCC cell lines and the normal renal cell line was determined by the microculture tetrazolium dye assay. Results: JTE-522 was cytotoxic against the Caki-1 RCC cell line. JTE-522 and anti-Fas monoclonal antibody (CH-11) exhibited a synergistic cytotoxic effect against Caki-1 cells. In contrast, JTE-522 in combination with 5-fluorouracil, adriamycin, cis-diamminedichloroplatinum, or interferon-α, all commonly used clinically, resulted in an additive cytotoxic effect. Synergy achieved in cytotoxicity with JTE-522 and CH-11 was shown to be due to apoptosis. Conclusions: The present study demonstrated that the selective COX-2 inhibitor JTE-522 had a cytotoxic effect on RCC and that synergistic cytotoxicity against RCC was obtained with JTE-522 in combination with anti-Fas monoclonal antibody. These results suggest that selective COX-2 inhibitors in combination with immunotherapy may be useful in treating patients with RCC.

The usefulness of serum X-linked inhibitor of apoptosis protein (XIAP) for predicting recurrence of renal cell carcinoma.

396 Background: The X-linked Inhibitor of Apoptosis protein (XIAP) is associated with cell survival by blocking caspase-mediated apoptosis. We have reported the expression and prognostic value of XIAP in human prostate cancer using prostate tissue microarrays (Clin Cancer Res 2007). The expression and prognostic significance of XIAP in renal cell cancer (RCC) has been rarely studied. To our knowledge, no report on the serum XIAP levels from RCC patients has been published. In this study, we examined serum XIAP levels of RCC patients and normal individuals and evaluated its utility as biomarker. METHODS Peripheral blood samples were obtained from 99 patients (68 men and 31 women, median age; 60.7 years [36-85]) with RCC before surgery. All the patients underwent radical or partial nephrectomy. Blood samples were also collected from 52 healthy controls. The histological grade was as follows: Grade1; n= 5, Grade2; n=72, Grade3; n= 22. The serum XIAP levels were measured by a sandwich enzyme-linked immunosorbent assay. Cut off value was calculated by ROC analysis. RESULTS The serum XIAP levels in patients with RCC were higher than those of normal control individuals (328.3 pg/ml vs 156.2 pg/ml, P<0.001). At a median follow up of 33 months (1-105M), tumor with low serum XIAP showed significantly longer progression free survival (PFS) than those with high serum XIAP in Grade 1-2 group (P<0.001). CONCLUSIONS Serum XIAP level is associated with recurrence and prognosis. These results suggest that it may be used as a novel prognosticator and a potential target for renal cell cancer diagnosis and therapy.

Abstract 4644: Significance of serum tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) levels of renal cell carcinoma patients as prognostic and monitoring biomarker

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC TRAIL and its receptors have been reported to play a significant role as cytotoxic and apoptotic mechanisms in cytotoxic T-lymphocytes and natural killer cells. TRAIL has been reported to induce apoptosis preferentially in various types of cancer cells, including renal cell carcinoma (RCC) cells. These findings suggest that TRAIL and its receptors might be useful biomarkers for RCC. In this study, we examined serum TRAIL levels of RCC patients and normal individuals and evaluated its utility as biomarker. Peripheral blood samples were obtained from 85 patients (60 men and 25 women, median age; 63 years [36-85]) with RCC before surgery. All the patients underwent radical or partial nephrectomy. The histological grade and TNM status distribution was as follows: Grade 1, n =1; Grade 2, n = 63 and Grade 3, n = 21; T1, n =56; T2, n = 8; T3, n =18 and T4, n = 3; N1-2, n = 7; and M1, n = 13. Blood samples were also collected from 52 healthy controls. The serum TRAIL levels were measured by a sandwich enzyme-linked immunosorbent assay (ELISA). The serum TRAIL levels in patients with RCC was lower than those of normal control individuals (79±8pg/ml vs 118±16 pg/ml, P =0.038). The serum TRAIL levels in RCC patients with lymph node metastasis (N1-2), distant metastasis (M1), microscopic venous invasion, and stage III-IV were significantly lower compared to those in RCC patients without lymph node metastasis (N0), without distant metastasis (M0), without microscopic venous invasion, and with stage I-II, respectively (P =0.051, P =0.045, P = 0.02, and P = 0.048). The serum TRAIL levels before and after surgery from the same patients (n = 17) was 61±15 pg/ml and 110±29 pg/ml, respectively, with significant difference (P = 0.015). The serum TRAIL levels after the surgery in these patients elevated to be similar to those detected in healthy controls (n = 52). The cause-specific survival rate of the RCC patients with high serum TRAIL was shown to be significantly higher than that of those with low serum TRAIL in the 5-year follow-up (P < 0.0385). The cytotoxicity of recombinant TRAIL and lymphocytes against human RCC cell line ACHN and primary culture RCC cell was measured by Crystal violet assay in the absence and presence of neutralizing anti-TRAIL antibody. TRAIL was estimated to contribute to about 20% of the lymphocyte-mediated cytotoxicity against ACHN and primary culture RCC cell. To our knowledge, the current study is the first to demonstrate the serum TRAIL levels of RCC patients in comparison with those of normal controls, in correlation with clinicopathological factors, and in association with postoperative prognosis. In conclusion, it is suggested that serum TRAIL levels in RCC patients might be utilized not only as diagnostic and prognostic biomarker but also as a possible biomarker for monitoring postoperative progression. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4644.