Toshiki Etani

GPX2 overexpression is involved in cell proliferation and prognosis of castration-resistant prostate cancer

There is a need for exploration of new therapeutic strategies that target distinct molecular mechanisms of castration-resistant prostate cancer (CRPC) because its emergence following androgen deprivation therapy is a major clinical problem. In this report, we investigated the role of glutathione peroxidase 2 (GPX2) in CRPC. GPX2 expression was analyzed in rat and human CRPC cells. Next, we determined the proliferation rate and level of reactive oxygen species (ROS) in GPX2-small interfering RNA (siRNA)-transfected CRPC cells. For in vivo analysis, siRNA-transfected cells were subcutaneously implanted into normal and castrated nude mice. Further, immunohistochemical and prognostic analyses of GPX2 were performed using human specimens. Silencing of GPX2 caused significant growth inhibition and increased intracellular ROS in both rat (PCai1) and human (PC3) CRPC cells. Flow cytometry and western blot analyses revealed that the decrease in proliferation rate of the GPX2-silenced cells was due to cyclin B1-dependent G2/M arrest. Furthermore, knockdown of Gpx2 inhibited tumor growth of PCai1 cells in castrated mice. Immunohistochemical analyses indicated that expression of GPX2 was significantly higher in residual cancer foci after neoadjuvant hormonal therapy than in hormone naive cancer foci. Moreover, patients with high GPX2 expression in biopsy specimen had significantly lower prostate-specific antigen recurrence-free survival and overall survival than those with no GPX2 expression. These findings suggest that GPX2 is a prognostic marker in CRPC and affects proliferation of prostate cancer under androgen depletion partially through protection against ROS signaling.

A Case of Renal Primitive Neuroectodermal Tumor Confirmed by Fluorescence in situ Hybridization

Primitive neuroectodermal tumor (PNET) is a member of the Ewings sarcoma family of tumors (ESFT). We report a case of PNET in a 66-year-old male who presented with a large solid tumor within the parenchyma of the middle pole of the left kidney with metastases to the left adrenal gland and right ischium. A fine-needle biopsy was performed and showed a small round cell tumor. Results of immunohistochemical staining suggested this tumor belonged to ESFT. Preoperative VDC-IE (combined vincristine, doxorubicin and cyclophosphamide followed by another combination of ifosfamide and etoposide) chemotherapy and left radical nephrectomy and adrenalectomy were performed. The histopathological findings of the resected tumor were similar to those in the biopsy specimen, but the results of AE1/AE3 were different. For the diagnosis, fluorescence in situ hybridization was performed. Split signals of the EWSR1 gene were detected, and transmission electron microscopy showed neuroendocrine granules and microtubules. The final diagnosis of this tumor was PNET of the kidney.

Novel Closing Method Using Subcutaneous Continuous Drain for Preventing Surgical Site Infections in Radical Cystectomy

To reduce the incidence of surgical site infection (SSI) after radical cystectomy, a new closing method using subcutaneous continuous aspiration drain was developed and compared to the conventional closing method. The new method involved (a) closed aspiration with an indwelling aspiration drain without suture of the subcutaneous fat and (b) covering with hydrocolloid wound dressing after suture of the dermis with 4-0 absorbable thread and reinforcement using strips. The incidence of SSI was significantly improved by using the new method. Furthermore, univariate and multivariate analysis associated with SSI revealed that the new closing method was statistically correlated with 85% reduction of SSI (odds ratio: 0.15, 95% confidence interval: 0.03–0.69).Our new method using continuous aspiration with subcutaneous drain is useful for preventing SSI through removal of effusions and reduction of dead space by apposition of the subcutaneous fat.

Pure Lymphoepithelioma-Like Carcinoma Originating from the Urinary Bladder.

Lymphoepithelioma-like carcinoma of the urinary bladder (LELCB) is a rare variant of infiltrating urothelial carcinoma. We report a case of LELCB in a 43-year-old man. Ultrasonography and cystoscopy revealed two bladder tumors, one on the left side of the trigone and the other on the right side of the trigone. Transurethral resection of the bladder tumors was performed and pathological analysis revealed undifferentiated carcinoma. We therefore performed radical cystectomy and urinary diversion. Immunohistochemically the tumor cells were positive for cytokeratin, but negative for Epstein-Barr virus-encoded small RNA in situ hybridization as found for previous cases of LELCB. The final pathological diagnosis was a lymphoepithelioma-like variant of urothelial carcinoma with perivesical soft tissue invasion. For adjuvant systemic chemotherapy, three courses of cisplatin were administered. The patient subsequently became free of cancer 72 months postoperatively. Based on the literature, pure or predominant LELCB types show favorable prognoses due to their sensitivity to chemotherapy or radiotherapy. An analysis of the apparent diffusion coefficient (ADC) values of bladder tumors examined in our institution revealed that the ADC value measured for this LELCB was relatively low compared to conventional urothelial carcinomas. This suggests that measuring the ADC value of a lymphoepithelioma-like carcinoma prior to operation may be helpful in predicting LELCB.

A pilot study of gemcitabine and paclitaxel as third-line chemotherapy in metastatic urothelial carcinoma

Background: We evaluated the effectiveness of gemcitabine and paclitaxel therapy in patients with metastatic urothelial carcinoma for whom two lines of sequential chemotherapy had been unsuccessful. Methods: A total number of 105 patients who had previously received first-line chemotherapy consisting of gemcitabine and cisplatin or carboplatin, were treated with second-line gemcitabine and docetaxel therapy between June 2006 and May 2015. Of these patients, 15 with an Eastern Cooperative Oncology Group Performance Status of 0 or 1 were administered gemcitabine and paclitaxel as third-line treatment from 2013 after failure of the second-line therapy. For each 21-day cycle, gemcitabine (1000 mg/m2) was administered on days 1, 8, and 15, and paclitaxel (200 mg/m2) on day 1. Patients were assessed for each cycle and any adverse events were noted. Furthermore, a Short Form Health Survey questionnaire was used to assess each patient’s quality of life. Results: Third-line gemcitabine and paclitaxel treatment cycles were undertaken for a median of four times (range 2–9). The disease control rate was 80.0%. After second-line gemcitabine and docetaxel therapy was completed, median progression-free survival and median overall survival were determined as 9.8 and 13.0 months, respectively. The only prognostic factor for overall survival, as determined by univariate and multivariate analyses, was third-line gemcitabine and paclitaxel therapy. Neutropenia (66.7%) and thrombocytopenia (53.3%) were noted as the grade 3 treatment-related toxicities. After two cycles of third-line gemcitabine and paclitaxel therapy, the pre- and post-treatment quality of life scores did not differ significantly. Conclusions: Results demonstrate that third-line combination therapy using gemcitabine and paclitaxel is a feasible option for metastatic urothelial carcinoma patients.

Nonpalpable testicular pure seminoma with elevated serum alpha-fetoprotein presenting with retroperitoneal metastasis: a case report

BackgroundPatients with a primary pure seminoma in the testis who have elevated serum alpha-fetoprotein are rare and should be treated as patients with nonseminomatous germ cell tumors. However, nonpalpable testicular tumors in this condition have never been reported. We describe a case of nonpalpable pure testicular seminoma with elevated serum alpha-fetoprotein presenting retroperitoneal metastasis.Case presentationA 29-year-old Asian man was referred to our hospital with right flank pain. Computed tomography showed a mass located between his aorta and inferior vena cava, but a testicular tumor was not detected. His serum levels of lactate dehydrogenase, alpha-fetoprotein, and DUPAN-2 were high. Although no tumor or nodule was palpable in his testis, ultrasonography revealed multiple low echoic lesions in his right testicular parenchyma. He was diagnosed with right testicular cancer with retroperitoneal lymph node metastasis and underwent right high orchiectomy. A pathological examination revealed pure seminoma and no nonseminomatous components were found in the specimen. Three courses of induction systemic chemotherapy (cisplatin, etoposide, and bleomycin) normalized his serum alpha-fetoprotein and DUPAN-2 levels. Three additional courses of chemotherapy (etoposide and bleomycin) were performed, and treatment was completed with laparoscopic retroperitoneal lymph node dissection. Pathology of the dissected specimen showed fibrous and necrotic tissue with no viable cells. He is alive without recurrence 54 months after orchiectomy.ConclusionsWe report a case of pure testicular seminoma with elevated serum alpha-fetoprotein and DUPAN-2 presenting retroperitoneal metastasis. We recommend an ultrasound examination of bilateral testes when large retroperitoneal tumors are detected in young men, even if a mass is not palpable in the scrotum.

A Case of Metastatic Urothelial Carcinoma Treated with Pemetrexed as Third-Line Chemotherapy with Discussion and Literature Review.

Pemetrexed is an antifolate agent that is regarded as an alternative second-line chemotherapy against advanced or metastatic urothelial carcinoma (UC). However, there is limited information on pemetrexed in a third-line setting. We report a case of metastatic UC treated with pemetrexed as third-line chemotherapy following gemcitabine and cisplatin (GC) and gemcitabine and docetaxel (GD) therapies. A 73-year-old man with a history of transurethral resection of bladder carcinoma presented with pollakiuria. CT revealed a mass in the left renal pelvis that had invaded into the parenchyma of the left kidney, as well as para-aortic and mediastinum lymph node enlargement. Urinary cytology of the lesion in the left renal pelvis revealed UC. Thus, the patient was diagnosed with left renal pelvic carcinoma (cT3N2M0). After having received 4 courses of GC therapy, another mediastinum lymph node was enlarged. He subsequently received 3 courses of GD therapy as second-line chemotherapy, which showed little efficacy against the metastatic lesions. The patient was administered 3 courses of pemetrexed as third-line chemotherapy; however, its effect on tumor reduction was not sufficient. Finally, metastasis to the liver was observed, and he died 21 months after initiation of chemotherapy. For pathological confirmation, needle biopsy of a metastatic lymph node performed after death revealed high-grade UC and a high positivity of programmed death ligand 1 (PD-L1) in the tumor, which suggested that he could have benefited from anti-PD-L1 antibody immunotherapy. This report describes the outcome of pemetrexed treatment and proposes another possible candidate as third-line chemotherapy against metastatic UC.

Long-term survival of a patient with pulmonary metastatic urothelial carcinoma following metastasectomy

Cisplatin-based systemic chemotherapy is the gold standard for the treatment of patients with metastatic urothelial carcinoma (UC), which is a chemosensitive cancer. However, long-term survival has been deemed disappointing. We describe here a case of UC with solitary pulmonary metastasis who had successfully achieved long-term disease-free survival by combination of cisplatin-based chemotherapy and pulmonary metastasectomy. From the finding of this article, we propose that adjuvant chemotherapy may be considered as a viable option after metastasectomy in low volume pulmonary metastatic UC patients.

MP64-11 CHEMOPREVENTIVE AND CHEMOTHERAPEUTIC POTENTIALS OF LUTEOLIN VIA REGULATION OF OXIDATIVE STRESS IN CASTRATION-RESISTANT PROSTATE CANCER

prostate tumor micro-environment contribute to prostate cancer(PCa) progression, however, their effects on PCa chemo-sensitivity remained unclear. METHODS: CD4þT cell infiltration from post-chemotherapy paraffin embedded specimens was performed by IHC. CRPC cell lines–C4-2, CWR22RV1 and CD4(þ) T cell lines–HH and Molt-3 were used in vitro co-culture system. After 48 hours co-culture, the PCa cell chemo-sensitivity were detected by CCK8, Tunel and Western-blot. Various cell cytokine was determined by Cytokine arrays and QPCR. RESULTS: We found more CD4þT cell infiltration in tumor area (Figure 1A) than in adjacent normal prostate (Figure 1B) in clinical samples. After co-culture with the CD4þT cells, C4-2 and 22Rv1 cells become more resistant to Doc treatment in a dose-dependent manner ranging from 1 nM to 8 nM (Figure 2A). Tunel results indicated that CD4þT cells protect PCa cells from Doc-induced apoptosis (Figure 2C). Meanwhile, the level of cleaved PARP, another indicator for the apoptotic process were also decreased (Figure 2B). QPCR and Cytokine arrays indicates that after co-culture with PCa CD4þT cells could secrete a significantly higher CCL5 (Figure 3A). Moreover, CCL5 stimulation enhanced PCa resistance to docetaxel(Figure 3B). Anti-ccl5 neutralization antibody could reverse co-culture PCa resistance to docetaxel. CONCLUSIONS: CD4þT cells significantly attenuated prostate cancer chemo-sensitivity in vitro. Additionally, CCL5 secreted by CD4þT cells plays a key factor in chemo-therapy resistance.

GPX2 promotes development of bladder cancer with squamous cell differentiation through the control of apoptosis

Herein, we elucidated the molecular mechanisms and therapeutic potential of glutathione peroxidase 2 (GPX2) in bladder cancer. GPX2 expression gradually increased during progression from normal to papillary or nodular hyperplasia (PNHP) and urothelial carcinoma (UC) in a rat N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN)-induced bladder carcinogenesis model. GPX2 overexpression was more marked in UC with squamous differentiation (SqD) than in pure UC. Clinical intraepithelial lesions of papillary UC and invasive UC with SqD also had strong GPX2 expression in human radical cystectomy specimens. In addition, prognostic analysis using transurethral specimens revealed that low expression level of GPX2 predicted poor prognosis in patients with pure UC. Further, UC cell lines, BC31 and RT4, cultured in vitro also overexpressed GPX2. Knock-down of GPX2 induced significant inhibition of intracellular reactive oxygen species (ROS) production, in addition to significant growth inhibition and increased apoptosis with activation of caspase 3 or 7 in both BC31 and RT4 cells. Interestingly, tumor growth of BC31 cells subcutaneously transplanted in nude mice was significantly caused the induction of apoptosis, as well as inhibition of angiogenesis and SqD by GPX2 down-regulation. Our findings demonstrated that GPX2 plays an important role in bladder carcinogenesis through the regulation of apoptosis against intracellular ROS, and may be considered as a novel biomarker or therapeutic target in bladder cancer.