Fumiya Hongo

Nitric oxide sensitizes prostate carcinoma cell lines to TRAIL-mediated apoptosis via inactivation of NF-kappa B and inhibition of Bcl-xl expression.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been shown to be selective in the induction of apoptosis in cancer cells with minimal toxicity to normal tissues and this prompted its potential therapeutic application in cancer. However, not all cancers are sensitive to TRAIL-mediated apoptosis and, therefore, TRAIL-resistant cancer cells must be sensitized first to become sensitive to TRAIL. Treatment of prostate cancer (CaP) cell lines (DU145, PC-3, CL-1, and LNCaP) with nitric oxide donors (e.g. (Z)-1-[2-(2-aminoethyl)-N-(2-ammonio-ethyl)amino]diazen-1-ium-1, 2-diolate (DETANONOate)) sensitized CaP cells to TRAIL-induced apoptosis and synergy was achieved. The mechanism by which DETANONOate mediated the sensitization was examined. DETANONOate inhibited the constitutive NF-κB activity as assessed by EMSA. Also, p50 was S-nitrosylated by DETANONOate resulting in inhibition of NF-κB. Inhibition of NF-κB activity by the chemical inhibitor Bay 11-7085, like DETANONOate, sensitized CaP to TRAIL apoptosis. In addition, DETANONOate downregulated the expression of Bcl-2 related gene (Bcl-xL) which is under the transcriptional regulation of NF-κB. The regulation of NF-κB and Bcl-xL by DETANONOate was corroborated by the use of Bcl-xL and Bcl-x κB reporter systems. DETANONOate inhibited luciferase activity in the wild type and had no effect on the mutant cells. Inhibition of NF-κB resulted in downregulation of Bcl-xL expression and sensitized CaP to TRAIL-induced apoptosis. The role of Bcl-xL in the regulation of TRAIL apoptosis was corroborated by inhibiting Bcl-xL function by the chemical inhibitor 2-methoxyantimycin A3 and this resulted in sensitization of the cells to TRAIL apoptosis. Signaling by DETANONOate and TRAIL for apoptosis was examined. DETANONOate altered the mitochondria by inducing membrane depolarization and releasing modest amounts of cytochrome c and Smac/DIABLO in the absence of downstream activation of caspases 9 and 3. However, the combination of DETANONOate and TRAIL resulted in activation of the mitochondrial pathway and activation of caspases 9 and 3, and induction of apoptosis. These findings demonstrate that DETANONOate-mediated sensitization of CaP to TRAIL-induced apoptosis is via inhibition of constitutive NF-κB activity and Bcl-xL expression.

Expression of X-Linked Inhibitor of Apoptosis Protein Is a Strong Predictor of Human Prostate Cancer Recurrence

Purpose: The X-linked inhibitor of apoptosis protein (XIAP) is associated with cell survival by blocking caspase-mediated apoptosis. We examined the expression patterns of XIAP with regard to human prostate cancer, predicting that XIAP status may predict cancer recurrence and/or clinical outcome. Experimental Design: Immunohistochemistry was done on tissue microarrays constructed from 226 primary prostate cancer specimen. The protein expression distribution was examined across the spectrum of epithelial tissues and its association with standard clinicopathologic covariates and tumor recurrence was examined in 192 outcome-informative patients. Results: The mean XIAP expression was significantly higher in prostate cancer compared with prostatic intraepithelial neoplasia (PIN), normal, and benign prostatic hyperplasia. We observed that XIAP is an independent predictor of tumor recurrence in multivariate Cox proportional hazards analysis in all patients as well as after substratifying by Gleason score. Interestingly, patients with high XIAP levels had a much lower probability of tumor recurrence than those with lower XIAP expression. Even patients with high-grade tumors who had higher XIAP levels had a lower risk of recurrence compared with any patient whose tumors express lower XIAP. Conclusions: XIAP is expressed at higher levels in prostate cancers compared with matched normal tissues. High XIAP expression is strongly associated with a reduced risk of tumor recurrence and is not directly associated with Gleason score, tumor stage, capsular involvement, or preoperative prostate-specific antigen status, suggesting that it is a novel prognosticator and a potential target for prostate cancer diagnosis and therapy. Significantly, these findings provide important and extensive validation of previous results.

Gene therapy with TRAIL against renal cell carcinoma

Tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) induces apoptosis in cancer cells. However, TRAIL is not toxic against most normal cells. We have accordingly examined by in vivo electroporation whether TRAIL induces apoptosis in renal cell carcinoma. In addition, combination treatment with TRAIL and 5-fluorouracil (5-FU) against renal cell carcinoma was also investigated. The NC65 renal cell carcinoma line was used as a target. pCAGGS TRAIL was injected into the NC65 tumors in the right flanks of severe combined immunodeficient mice. Tumors were pulsed with the CUY21 electroporator. Electroporation was done once on day 0 or thrice on days 0, 2, and 4. Apoptosis was determined by terminal deoxyribonucleotide transferase–mediated nick-end labeling assay. When TRAIL gene therapy using in vivo i.t. electroporation was done once only, the growth of NC65 tumors was not inhibited. However, when TRAIL gene therapy was done thrice, growth suppression of the NC65 tumors was observed. Transfection of the TRAIL gene by in vivo electroporation induced apoptosis in NC65 tumors. When NC65 cells were treated with TRAIL gene therapy in combination with 5-FU, stronger growth suppression was obtained. TRAIL gene therapy did not induce liver dysfunction in severe combined immunodeficient mice. This study shows that TRAIL gene therapy induced growth suppression and apoptosis in NC65 tumors without severe side effects, and that combination treatment of NC65 cells with TRAIL gene therapy and 5-FU resulted in higher antitumor activity. These findings suggest that TRAIL gene therapy and/or 5-FU may be effective against renal cell carcinoma without harmful toxic effects. [Mol Cancer Ther 2006;5(9):2165–71]

Feasibility of Tri-Weekly Docetaxel-Based Chemotherapy for Elderly Patients (Age 75 and Older) with Castration-Resistant Prostate Cancer

Objectives: To evaluate the efficacy and safety of docetaxel-based chemotherapy for elderly metastatic castration-resistant prostate cancer (CRPC) patients aged 75 or higher. Methods: Twenty CRPC patients aged 75 or higher (older group) and 31 CRPC patients younger than 75 years (younger group) were treated by a regimen of docetaxel (70 mg/m2) once every 3 weeks. Adjustment for docetaxel dosage and period per cycle was subject to investigator’s judgment. Results: The median relative dose intensity of both groups was 0.84, while the median dose intensity and the number of treatment cycles of the younger and older groups were 14.6 versus 12.3 mg/m2/week (p = 0.021), and 9 versus 8 cycles (p = 0.15), respectively. In the older group, PSA response rate was 50%, median time to biochemical progression was 7.5 months, and median survival time was 15.5 months, without any significant difference compared to those of the younger group. No significant difference in the incidence of grade 3–4 adverse events was noted between both groups. All these parameters for efficacy are comparable to those reported for tri-weekly docetaxel regimen. Conclusions: Tri-weekly treatment by docetaxel (70 mg/m2) with proper adjustment might contribute to maintaining efficacy and safety of the treatment for elderly CRPC patients.

Therapy‐related acute myeloid leukemia and myelodysplastic syndrome among refractory germ cell tumor patients

To analyze cases of therapy‐related acute myeloid leukemia and myelodysplastic syndrome diagnosed after chemotherapy for refractory testicular and extragonadal germ cell tumor in our experience.

Mevalonate pathway blockage enhances the efficacy of mTOR inhibitors with the activation of retinoblastoma protein in renal cell carcinoma

Renal cell carcinoma (RCC) is the most common malignancy of kidney and remains largely intractable once it recurs after resection. mTOR inhibitors have been one of the mainstays used against recurrent RCC; however, there has been a major problem of the resistance to mTOR inhibitors, and thus new combination treatments with mTOR inhibitors are required. We here retrospectively showed that regular use of antilipidemic drug statins could provide a longer progression free survival (PFS) in RCC patients prescribed with an mTOR inhibitor everolimus than without statins (median PFS, 7.5 months vs. 3.2 months, respectively; hazard ratio, 0.52; 95% CI, 0.22-1.11). In order to give a rationale for this finding, we used RCC cell lines and showed the combinatorial effects of an mTOR inhibitor with statins induced a robust activation of retinoblastoma protein, whose mechanisms were involved in statins-mediated hindrance of KRAS or Rac1 protein prenylation. Finally, statins treatment also enhanced the efficacy of an mTOR inhibitor in RCC xenograft models. Thus, we provide molecular and (pre)clinical data showing that statins use could be a drug repositioning for RCC patients to enhance the efficacy of mTOR inhibitors.

Incidence and outcome of interstitial lung disease (ILD) with everolimus treatment for metastatic renal cell carcinoma.

427 Background: Interstitial lung disease (ILD) is known as one of the adverse events during treatment with everolimus for metastatic renal cell carcinoma (mRCC). METHODS We retrospectively assessed the incidence and outcome of ILD in mRCC patients treated with everolimus. From April 2010 to August 2012, 25 cases were treated with everolimus after failure of one or two TKIs in our institute. All adverse events were graded in accordance with NCI CTCAE, version 3.0. RESULTS A total of 25 patients received treatment with everolimus. They included 18 male and 7 female patients ranging in age from 21 to 84 years (median 62). According to MSKCC risk criteria, 6 cases were at favorable risk, 16 cases were at intermediate risk, and 3 cases were at poor risk. Median treatment term was 4 months (range 2-17 months). SD was in 19 cases and PD was in 6 cases. Progression free survival was 3.5 months and overall survival was 12 months. ILD was found in 7 cases (28%). 1 was G1, 5 were G2 and 1 was G3. Corticosteroid therapy was initiated in 3 cases. In 5 of 7 ILD cases, everolimus was re-challenged. In our series, patients with ILD showed significantly better progression free survival than those without ILD (PFS was 8 months vs. 3 months. Log-rank, p < 0.001). There were no significant different between the 2 groups in over all survival (12 months in patients with ILD vs. 10 months in patients without ILD. Log-rank, NS). CONCLUSIONS Everolimus appears to be effective and well-tolerated in our institute. Re-challenge of everolimus was feasible after improving of everolimus-induced ILD in cases of grade 1-2.

CNPY2 inhibits MYLIP-mediated AR protein degradation in prostate cancer cells

The androgen receptor (AR) is a ligand-dependent transcription factor that promotes prostate cancer (PC) cell growth through control of target gene expression. This report suggests that Canopy FGF signaling regulator 2 (CNPY2) controls AR protein levels in PC cells. We found that AR was ubiquitinated by an E3 ubiquitin ligase, myosin regulatory light chain interacting protein (MYLIP) and then degraded through the ubiquitin-proteasome pathway. CNPY2 decreased the ubiquitination activity of MYLIP by inhibition of interaction between MYLIP and UBE2D1, an E2 ubiquitin ligase. CNPY2 up-regulated gene expression of AR target genes such as KLK3 gene which encodes the prostate specific antigen (PSA) and promoted cell growth of PC cells. The cell growth inhibition by CNPY2 knockdown was rescued by AR overexpression. Furthermore, positive correlation of expression levels between CNPY2 and AR/AR target genes was observed in tissue samples from human prostate cancer patients. Together, these results suggested that CNPY2 promoted cell growth of PC cells by inhibition of AR protein degradation through MYLIP-mediated AR ubiquitination.

Individualized Dosing of Axitinib Based on First-Dose Area Under the Concentration–Time Curve for Metastatic Renal-Cell Carcinoma

Background Previous studies have revealed that higher exposure of axitinib leads to better prognosis in metastatic renal‐cell carcinoma. We thus assessed individualized dosing of axitinib on the basis of the first‐dose area under the concentration–time curve from 0 to 12 hours (AUC0‐12) for sunitinib‐pretreated metastatic renal‐cell carcinoma patients. Patients and Methods In this prospective single‐arm trial, the starting dose of axitinib was 5 mg twice daily. A series of blood samples were taken at predetermined times after the first dose to calculate AUC0‐12. On day 15 of axitinib administration, the dose was adjusted to ensure ≥ 150 ng·h/mL AUC0‐12 at steady state according to first‐dose AUC0‐12. The primary end point was the 6‐month progression‐free survival rate. Results Twenty‐six Japanese patients were enrolled. The median recommended dose based on the first‐dose AUC0‐12 was 2.5 mg (range, 1‐16 mg) twice daily. The 6‐month progression‐free survival rate for all enrolled patients and per‐protocol set, from which 3 patients were excluded for not adjusting to the recommended dose on day 15, was 84.6% (95% confidence interval, 65.5‐94.1) and 82.6% (95% confidence interval, 61.8‐93.3), respectively. The most common nonhematologic adverse events were hypertension, hand–foot syndrome, fatigue, and decreased appetite. Eighteen patients (75%) developed grade 3 hypertension; however, actual blood pressure could be controlled using antihypertensive agents. Other adverse events were manageable during the protocol treatment. Conclusion Individualized dosing of axitinib based on the first‐dose AUC0‐12 might have promising efficacy and manageable toxicity. Micro‐Abstract Individualized dosing of axitinib based on drug exposure remains unknown. In this study we evaluated the efficacy and safety of the recommended axitinib dose on the basis of the first‐dose area under the concentration–time curve from 0 to 12 hours in metastatic renal‐cell carcinoma. Adjusting to the recommended dose lead to promising efficacy and manageable toxicity. The current study provides novel information to develop individualized axitinib treatment.

MP20-12 PREDICTIVE VALUE OF TUMOR CONTACT LENGTH ON MAGNETIC RESONANCE IMAGING FOR EXTRACAPSULAR EXTENSION OF PROSTATE CANCER

for overall detection rate of PCa and histological analysis of each Likert group (5,4,3), TB, SB and RARP samples according to Gleason score. Results determined diagnostic accuracy of biopsy samples in comparison to definitive histological diagnosis. RESULTS: 67/79 (84.1%) patients had TB positive for PCa, with a second lesion positive in 17/79 cases. Gleason score of TB and SB was equivalent in 29 (36.7%). Gleason score was higher in TB and SB in 15 (19%) and 35 (44%) cases, respectively. TB was benign in 14 patients. Gleason score at biopsy and RARP were equivalent in 49 (52.7%) cases but higher in RARP and biopsy in 10 and 34 cases, respectively. TB was PCa positive in 38/41 (92.7%) Likert 5 lesions. 2/3 remaining patients had PCa positive SB in an identical region to TB. 21/ 27 (77.8%) Likert 4 lesions had TB positive PCa, 3/6 remaining cases had PCa positive SB in an identical region to TB. TB was positive in 9/ 11 (81.8%) of Likert 3 lesions with SB negative in the remaining 2 patients. The correlation between mpMRI-TPFB-RARP was positive for 97.6% Likert 5, 88.9% Likert 4 and 85.7% Likert 3 lesions. mpMRI identified a suspicious lesion confirmed on RARP in 74 patients (93.7%). 2/5 patients with a negative correlation had a second MRI lesion that corresponded to RARP. CONCLUSIONS: The results of our analysis demonstrate the accuracy of mpMRI and the reliability of TB taken during TPFB in confirming PCa when compared to SB and definitive histological diagnosis.