Hiroshi Ushida

DNMT3L Is a Novel Marker and Is Essential for the Growth of Human Embryonal Carcinoma

Purpose: Testicular germ cell tumors (TGCT) have a unique epigenetic profile distinct from that of other types of cancer. Elucidation of these properties has a potential to identify novel markers for TGCTs. Experimental Design: We conducted comprehensive analysis of DNA methyltransferase (DNMT) gene expression in TGCTs. Based on the expression profiles of DNMT genes in TGCTs, we generated a rabbit polyclonal anti-human DNMT3L antibody. We then studied the role of DNMT3L in TGCTs by the treatment of two embryonal carcinoma (EC) cell lines with a small interfering RNA system. Finally, we evaluated the immunohistochemical detection of DNMT3L in TGCT tissues. We also compared the patterns of DNMT3L immunohistochemistry with those of CD30 and SOX2. Results: Among the DNMT genes, we found that mRNA for DNMT3L was specifically expressed in TGCTs, but neither in normal testicular tissues nor in cancer cells of somatic tissue origin. DNMT3L protein was strongly expressed in two EC cell lines, but not in the cell lines of somatic tissue origin. Transfection of small interfering RNA for DNMT3L significantly reduced DNMT3L expression and resulted in growth suppression and apoptosis in EC cells. Immunohistochemical analysis showed that DNMT3L protein was present only in EC cells, but not in the other types of TGCT components and cancer cells of somatic tissue origin. DNMT3L staining was more prominent and specific than CD30 or SOX2 staining for detecting EC cells. Conclusion: DNMT3L is a novel marker and is essential for the growth of human embryonal carcinoma. Clin Cancer Res; 16(10); 2751–9. ©2010 AACR.

Methylation profile of DNA repetitive elements in human testicular germ cell tumor.

Testicular germ cell tumors (TGCTs) have a unique epigenetic profile distinct from that of other types of cancer. To further evaluate epigenetics of TGCTs, this study examines DNA methylation patterns of DNA repetitive elements in TGCTs. Bisulfite genomic sequencing and combined bisulfite restriction analysis (COBRA) were used to analyze the methylation patterns of DNA repetitive elements (LINE1 and Alu repeats) in embryonal carcinoma (EC) derived cell lines, primary TGCT tissues, noncancerous testicular tissues adjacent to TGCTs and cancer cells derived from somatic tissues (testicular malignant lymphoma tissues and renal cell carcinoma cell lines). Through both bisulfite genomic sequencing and COBRA, LINE1 was extensively hypomethylated in both seminomatous and nonseminomatous TGCT tissues as well as EC cell lines. We studied two Alu repeats locating in the 5′ end of E‐cadherin and XIST by bisulfite genomic sequencing. These two Alu elements were extensively hypomethylated in seminomatous TGCTs, but methylated in nonseminomatous TGCTs, including two EC derived cell lines. This increased unmethylated profile in seminomatous TGCTs was observed also by COBRA for Alu repeats. Although partial demethylation of DNA repetitive elements was observed in cancer cells of somatic tissue origin, the degree of demethylation was more pronounced in TGCTs than in cancer cells of somatic tissue origin. We observed abnormal demethylation of DNA repetitive elements in some of the tissues adjacent to TGCTs. The results indicate that the underlying mechanisms to undergo or maintain demethylation of DNA repetitive sequences differ between TGCTs and cancer cells of somatic tissue origin.

Primary Heterologous Carcinosarcoma of the Ureter with Necrotic Malignant Polyps

Carcinosarcoma is a rare and aggressive disease characterized by biphasic neoplasms with distinct mesenchymal and epithelial components. We report a case of ureteral carcinosarcoma with malignant necrotic polyps. The patient was a 58-year-old woman with painless hematuria, who was later diagnosed as having ureteral carcinosarcoma. Three long pendulous polypoid-shape tumors consisting of high-grade transitional cell carcinoma with chondrosarcomatous and osteosarcomatous elements were found. Two months after nephroureterectomy, the tumor relapsed in the bladder. Despite anterior exenteration, the patient died of local recurrence 6 months after her initial visit. To our knowledge, only 10 cases of this disease have been reported in the literature.

Therapeutic Potential of SOX2 Inhibition for Embryonal Carcinoma

PURPOSE Some nonseminomatous germ cell tumors are resistant to any type of chemotherapy. Control of embryonal carcinoma cells is crucial to manage nonseminomatous germ cell tumors. We established SOX2 targeting therapy in an embryonal carcinoma model. MATERIALS AND METHODS SOX2 expression was evaluated in a series of testicular germ cell tumor tissue samples. The antitumor effect of SOX2 knockdown was analyzed in vitro and in vivo using an embryonal carcinoma model. RESULTS In testicular germ cell tumor tissue SOX2 was expressed in the foci of embryonal carcinoma but negative in seminoma and yolk sac tumors. In an embryonal carcinoma model SOX2-siRNA induced apoptotic cell death in vitro and significant growth suppression in vivo. CONCLUSIONS This study shows the therapeutic potential of SOX2 silencing for embryonal carcinoma. However, further improvements are needed in SOX2-siRNA delivery to the tumor.

Penile verrucous carcinoma arising in HPV-negative condylomatous papules

ejd.2011.1316 Auteur(s) : Noriki FUJIMOTO1 noriki@belle.shiga-med.ac.jp, Gen NAKANISHI1, Hiroshi USHIDA2, Yusaku OKADA2, Ryo TANAKA3, Wataru FUJIMOTO3, Yoshimasa JO4, Ryoei HARA4, Toshihiro TANAKA1 1 Department of Dermatology, 2 Department of Urology, Shiga University of Medical Science, Setatsukinowa, Otsu Shiga 520-2192, Japan 3 Department of Dermatology, 4 Department of Urology, Kawasaki Medical School, Kawasaki Verrucous carcinoma has been considered to be a variant of well-differentiated [...]

Idiopathic retroperitoneal hematoma mimicking cystic tumor associated with hemorrhagic renal cyst

A 54-year-old woman was admitted to the hospital for evaluation of a retroperitoneal cystic mass detected incidentally during a complete followup physical examination for hypertension. CT revealed a 3 3 3 cm. cystic tumor between the inferior vena cava and abdominal aorta, and a 1 3 1 cm. enhanced mass in the left kidney (fig. 1). Magnetic resonance imaging showed that the inferior vena cava and abdominal aorta were deviated laterally by the mass in front of the vertebra, and a high density tumor in the left kidney was found (fig. 2). Angiography demonstrated no feeding arteries to the retroperitoneal mass or ruptured vessels. Preoperative diagnosis was cystic retroperitoneal and left renal tumors. To rule out lymphocele and retroperitoneal hematoma resection of the retroperitoneal mass and left partial nephrectomy were performed. The retroperitoneal mass was adherent to the inferior vena cava, abdominal aorta and vertebra, and had more capsular vessels than expected. Fluid collection of the retroperitoneal mass and left renal mass revealed an old hematoma and hematoma clot, respectively. Histologically, there were features of fibrous scar with fibrin and monocyte infiltration, while the left renal mass had no evidence of malignancy. Final diagnosis was idiopathic retroperitoneal hematoma and benign hemorrhagic renal cyst. No history of gastrointestinal upset, surgery or trauma was noted, and the cause of retroperitoneal hematoma and origin of the bleeding could not be identified. Convalescence was uneventful, although hypertension did not subside. The patient was well without evidence of disease recurrence at 1-year followup.

Recurrent rhabdomyosarcoma after adjuvant chemotherapy for stage I non-seminomatous germ cell tumor with malignant transformation

We report a rare case of stage I non‐seminomatous testicular germ cell tumor with malignant transformation. The patient received two cycles of chemotherapy (cisplatin, bleomycin and etoposide) tailored to testicular germ cell tumors as an adjuvant therapy after orchiectomy. However, 22 months later, the patient developed a metastasis in the occipital region that consisted of solely rhabdomyosarcoma through malignant transformation of a teratoma component. This case highlights an issue related to adjuvant chemotherapy for testicular germ cell tumors with components of malignant transformation.