Tomohiro Shibasaki

Aggravation of ischemia-reperfusion-triggered acute renal failure in xCT-deficient mice.

This study examined the question of whether deficiency of xCT, a cystine-transporter gene, exacerbates ischemia-reperfusion-induced acute renal failure (ARF). Two weeks after the right nephrectomy of male mice at 16-18weeks of age, the left renal vessels were clamped for 45min to induce renal ischemia. After (24h) induction of ischemia, xCT(-/-) mice had elevated concentrations of blood urea nitrogen and creatinine indicative of ARF, while in xCT(+/-) and xCT(+/+) mice, these parameters did not differ from the sham-operated mice. Immunohistochemical analyses of kidneys using antibodies against the oxidative stress markers revealed stronger staining in xCT(-/-) mice compared with xCT(+/+) mice. Induction of xCT mRNA in the kidneys of xCT(+/+) mice was demonstrated using reverse transcriptase (RT)-PCR analysis and was further confirmed using quantitative RT-PCR. These data provide the first in vivo evidence that xCT is induced by oxidative stress and helps prevent ischemia-reperfusion injury to kidneys.

Sequential molecularly targeted drug therapy including axitinib for a patient with end-stage renal failure and metastatic renal cell carcinoma

A 62‐year‐old male patient with end‐stage renal disease and metastatic renal cell carcinoma (RCC) was referred to our hospital. Sequential targeted therapy consisting of sorafenib, sunitinib, and everolimus was administered, but the patients disease gradually progressed. Axitinib was subsequently administered at a decreased dose of 6 mg/day for 2 weeks, after which the dose was escalated to 10 mg/day. Axitinib therapy was maintained for a total of 6 months without severe adverse effects. Sequential molecularly targeted drug therapy including axitinib, with careful monitoring, is one possible treatment option for patients with metastatic RCC with renal impairment.

Renoprotective Procedures with a Cold Ischemia Time of

Introduction: We evaluated whether nephron sparing surgery (NSS) combined with meticulous suturing of the cut stump under clamping with cooling is beneficial for oncological outcomes and also assessed the relationship between cold ischemia time and deterioration of renal function. Methods: One hundred and six patients with renal cell carcinoma (RCC) were subjected to this procedure. Oncological outcomes and renal function according to the estimated glomerular filtration rate (eGFR) and the tubular excretion rate on renoscintigraphy before and at 12 months after surgery were evaluated. Results: Cancer recurrences were observed in 2 patients with past history of RCC; however, no patient died of cancer. Renal function was evaluated depending on 4 different ischemia times. All groups did not show a remarkable decrease of renal function in terms of eGFR. Renoscintigraphy revealed the deterioration of the affected kidney in patients with >60 min ischemia. Conclusion: The renoprotective procedure of NSS provided maximum preservation of renal function until 60 min of cold ischemia time.

CEREBRAL VENOUS SINUS THROMBOSIS IN PATIENTS WITH METASTATIC TESTICULAR CANCER DURING CHEMOTHERAPY: REPORTS OF TWO CASES

Cerebral venous sinus thrombosis (CVT) is rare but sometimes develops in association with malignant neoplasm. We report two cases of CVT that occurred during cisplatin-based chemotherapy for testicular cancer. A 46-year-old man with stage IIA non-seminomatous germ cell tumour was treated with conventional doses of etoposide and cisplatin (EP). On day 11 of the third treatment course, he developed a systemic seizure. Brain computed tomography (CT) and magnetic resonance (MR) imaging could not detect the cause. Enhanced chest-pelvic CT revealed pelvic thrombosis. Administration of phenytoin for epilepsy of unknown cause and heparin for thrombosis was started. He had completed 4 courses of EP therapy without seizure recurrence. After re-evaluating the brain CT images retrospectively, we found high density of superior sagittal sinus (SSS) and strongly suspected CVT. Another patient was a 47-year-old man with stage IIIB seminomatous germ cell tumour treated with bleomycin, etoposide, and cisplatin (BEP) therapy. On day 11 of the second treatment course, he developed a systemic seizure. Brain CT revealed subarachnoid haemorrhage localised in the right parietal lobe. CT venography revealed a filling defect in the superior sagittal sinus (SSS). MR venography revealed a SSS stenosis. We diagnosed the cause of the seizure as CVT and started administration of anticoagulant therapy. After the thrombus had diminished, chemotherapy was restarted and another 2 courses of BEP therapy was completed.

Abstract 2782: The potential of p4EBP1 expression as predictive biomarker of mRCC

Introduction & objectives Activation of Akt/mTOR pathway induces 4EBP1 phosphorylation, and enhances cell proliferation, anti-apoptotic effect, and angiogenesis in many types of cancers including renal cell carcinoma (RCC). As mTOR and angiogenetic proteins are main targets in metastatic RCC (mRCC) treatment. We assessed the correlation with survivals and phosphorylated 4EBP1 (p4EBP1) expression. Materials & methods We enrolled 254 non-mRCC patients who underwent primary surgery in Yamagata University between 2003 and 2010, and 59 mRCC patients whose resected primary lesion was available. Immunohistochemistry for p4EBP1 was performed on their FFPE samples. We assessed correlations between p4EBP1 expression manners and clinical features (disease-free interval [DFI] for non-mRCC patients, cause-specific survival [CSS] and progression-free survival [PFS] for mRCC patients). The CSS was calculated from mRCC diagnosis to death or last follow-up date. The PFS was calculated based on the durations patients were medicated. Univariate analysis was calculated by log-rank test and multivariate analysis was calculated by Cox-regression analysis. Results Non-mRCC patients with highly p4EBP1 expression were shorter DFI than those without high expression (p = 0.036). Their 5-year disease-free rates were 83.4% and 93.4%, respectively. The independent poor DFI factors were high p4EBP1 expression (HR; 3.4, p = 0.0054), grade (p = 0.0055), and pT stage (p In contrast, mRCC patients with p4EBP1 expression was longer CSS than those without expression (median CSSs; 56.7 and 32.2 months, p = 0.0246). The independent poor CSS factors were no p4EBP1 expression (hazard ratio [HR]; 3.3, p = 0.0409), grade 4 (HR; 8.7, p = 0.0006), and poor prognostic group on MSKCC criteria (HR; 4.2, p = 0.02770). Expression of p4EBP1 showed statistically longer PFS in mRCC patients with axitinib (median PFS; 9.2 and 2.5 months, p = 0.0255). The similar trends were shown in patients with other TKIs and mTOR inhibitors. Conclusion Since non-mRCC patients with the highly p4EBP1 expression had shorter DFI, expression of p4EBP1 should indicate aggressive RCC in nature. Nevertheless, mRCC patients with p4EBP1 expression had longer survival. These results mean that expression of p4EBP1 might be a predictive biomarker for TKIs and mTOR inhibitors. Citation Format: Sei Naito, Osamu Ichiyanagi, Hiromi Ito, Hidenori Kanno, Tomoyuki kato, Yuuta Kurota, Atsushi Yamagishi, Mayu Yagi, Toshihiko Sakurai, Hayato Nishida, Hisashi Kawazoe, Tomohiro Shibasaki, Akira Nagaoka, Norihiko Tsuchiya. The potential of p4EBP1 expression as predictive biomarker of mRCC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2782. doi:10.1158/1538-7445.AM2017-2782

SMAC-N7 PEPTIDE WAS MORE POTENT THAN XIAP GENE TARGETING IN SENSITIZING RENAL CANCER CELLS TO APOPTOTIC STIMULI

253 SMAC-N7 PEPTIDE WAS MORE POTENT THAN XIAP GENE TARGETING IN SENSITIZING RENAL CANCER CELLS TO APOPTOTIC STIMULI Tomoyuki Kato*, Sei Naito, Hisashi Kawazoe, Tomohiro Shibasaki, Yuko Nakano, Takuya Yamanobe, Akira Kajinuma, Akinori Muto, Bilim Vladimir, Akira Nagaoka, Yoshihiko Tomita. Yamagata, Japan. INTRODUCTION AND OBJECTIVE: Renal cell carcinoma (RCC) is known to be resistant to chemoand radiotherapy due to a high apoptotic threshold. Inducing apoptosis in RCC cells leads to tumor regression and a molecule responsible for avoiding apoptosis can be a biomarker of molecular target therapy. In this study we tried to manipulate function of the strong anti-apoptotic molecule, XIAP, using RNAi and a peptide mimicking its inhibitory molecule, the second mitochondriaderived activator of caspase (Smac), releasing from mitochondria when a cell is exposed to apoptotic stimuli. METHODS: The surgical specimens from 34 patients who underwent surgery for RCC from January to December 2005 at the Yamagata University Hospital were subjected to immunohistochemical staining with anti-Smac and XIAP antibodies. Staining score was calculcuated by staining intensity multiplied by percent of positive cells, range 0-300. Caki1 RCC cell line with high levels of XIAP was transfected with XIAP targeting shRNA vector and stable clones were generated. The cell permeable peptide Smac-N7 was applied to in vitro treatment of the Caki1. Detection of apoptosis was performed by Hoechst 33342 and Giemsa staining and cell viability was checked by MTS assay. RESULTS: Smac was found in all tumors with staining scores varying from 200 to 300 and staining intensity was weaker than in normal kidneys. XIAP expression levels increased from pT1 (mean score 164.4±108.2) to pT2(195.0±83.3) and pT3(266.7±57.7), as well as from grade 1 (75.0± 98.7) to grade 2 (201.2 ± 93.6) (p<0.05). XIAP was knocked down by RNAi in clone #14 by 81.6% and in clone #19 by 85.3%. Compared to the parental and mock-transfected cells, neither clone was more sensitive to conventional chemotherapeutic agents, but both clones were more susceptible to Fas-stimulation (p<0.0001) and to pharmacological Bcl-2 inhibition (p<0.0001), as well as to a combination of the two (p<0.0001). Exposure of Caki1 cells to Smac-N7 peptide