Satoru Kanto

Natural killer cells attack tumor cells expressing high levels of sialyl Lewis x oligosaccharides

Epithelial carcinoma and leukemia cells express sialyl Lewis x oligosaccharides as tumor-associated carbohydrate antigens. To determine the role of sialyl Lewis x oligosaccharides in tumor dissemination, human melanoma MeWo cells, which do not express sialyl Lewis x, were transfected with α1,3-fucosyltransferase III (FTIII), and cell lines expressing different amounts of sialyl Lewis x were isolated. When these cells were injected into the tail vein of nude mice, cells expressing moderate amounts of sialyl Lewis x (MeWo-FTIII⋅M) produced a significantly greater number of lung tumor foci than did parental MeWo cells. In contrast, cells expressing large amounts of sialyl Lewis x (MeWo-FTIII⋅H) produced few lung tumor foci in nude mice but were highly tumorigenic in beige mice, which have defective natural killer (NK) cells. In vitro assays demonstrated that MeWo-FTIII⋅H cells are much more sensitive to NK cell-mediated cytotoxicity than are MeWo-FTIII⋅M cells or parental MeWo cells and the susceptibility of MeWo-FTIII⋅H cells to NK cell-mediated cytolysis can be inhibited by preincubating MeWo-FTIII⋅H cells with anti-sialyl Lewis x antibody. Moreover, we discovered that NK cell-mediated cytolysis of MeWo-FTIII⋅H cells can be inhibited by the addition of an antibody against the NK cell receptor CD94 or sialyl Lewis x oligosaccharides. These results, combined with structural analysis of MeWo-FTIII⋅H cell carbohydrates, indicate that moderate amounts of sialyl Lewis x lead to tumor metastasis, whereas expression of high levels of sialyl Lewis x leads to an NK cell attack on tumor cells, demonstrating that expression of different amounts of sialyl Lewis x results in entirely different biological consequences.

Seven pregnancies and deliveries from non-mosaic Klinefelter syndrome patients using fresh and frozen testicular sperm.

AbstractPurpose: The aim of this study was to investigate the feasibility of using frozen-thawed testicular sperm as well as the timing of testicular sperm extraction (TESE) in patients with non-mosaic Klinefelter syndrome. Methods: Intracytoplasmic sperm injection (ICSI) was performed in six of 17 (35%) patients whose sperm was recovered by TESE. Multiple biopsies of both testes were performed on the day of oocyte retrieval in all but one of the six patients. Results: Seven pregnancies and deliveries were achieved in five couples, and one couple was unsuccessful. Five pregnancies were achieved using fresh motile sperm, and two were achieved using frozen-thawed sperm. Sperm cryopreservation was not possible in one of the five couples because of the small number of recovered sperm, and possible in four other couples for subsequent ICSI. One woman whose husband had TESE performed prior to ovarian stimulation did not become pregnant. This may be due to the attainment of only a few immotile sperm following the frozen-thawed procedure. Conclusion: The outcome of ICSI using fresh or frozen-thawed testicular sperm in patients with non-mosaic Klinefelter syndrome was identical; however, TESE should be performed on the day of oocyte retrieval until such time as a procedure with a higher sperm yield from TESE is available. Moreover, an improved recovery procedure after cryopreservation-thawing of a single spermatozoon must be developed.

Fresh motile testicular sperm retrieved from nonobstructive azoospermic patients has the same potential to achieve fertilization and pregnancy via ICSI as sperm retrieved from obstructive azoospermic patients

OBJECTIVE To compare the fertilization and pregnancy rates using fresh testicular sperm between nonobstructive azoospermic (NOA) patients and obstructive azoospermic (OA) patients. DESIGN We evaluated sperm quality of testicular sperm retrieved by microdissection testicular sperm extraction (MD-TESE) in NOA patients and compared the fertilization rate and pregnancy rate via intracytoplasmic sperm injection (ICSI) between NOA and OA patients. SETTING Private hospital-based infertility research laboratory. PATIENT(S) A total of 58 couples in which the husband was diagnosed with azoospermia. INTERVENTION(S) Analytic examination of the outcomes and description of the NOA cases achieving pregnancies; oocyte retrieval and testicular sperm retrieval were performed simultaneously. MAIN OUTCOME MEASURE(S) Comparison of fertilization rate and pregnancy rate at the first ICSI attempt. RESULT(S) Testicular sperm were retrieved from 17 of 40 NOA patients and 18 of 18 OA patients. Motile sperm were successfully retrieved from 16 of the 17 NOA patients. There was no significant difference in fertilization rate and pregnancy rate between OA and NOA cases. Of the 17 NOA patients, nine pregnancies were achieved using fresh motile testicular sperm. CONCLUSION(S) Fresh motile testicular sperm retrieved from NOA patients may have the same potential to achieve fertilization and pregnancy as sperm retrieved from OA patients. The MD-TESE technique might contribute to the high retrieval rate of fresh motile testicular sperm even in NOA patients.

Risk factors in past histories and familial episodes related to development of testicular germ cell tumor.

Abstract  Background:  A retrospective study was conducted to examine the host factors of 240 testicular germ cell tumor patients. This study was performed to address a new theory proposed by Skakkebaek called testicular dysgenesis syndrome which claims that cryptorchism, hypospadias, poor semen quality and testicular germ cell tumors are symptoms of an underlying testicular dysgenesis in uterus.

Fresh testicular sperm retrieved from men with spinal cord injury retains equal fecundity to that from men with obstructive azoospermia via intracytoplasmic sperm injection

OBJECTIVE To examine the outcomes of intracytoplasmic sperm injection (ICSI) with testicular sperm retrieved from men with spinal cord injury. DESIGN Retrospective study. SETTING Private hospital-based infertility research laboratory. PATIENT(S) Twenty-two couples of whom one partner was a man with spinal cord injury (SCI). INTERVENTION(S) Reviewing the outcomes of testicular sperm extraction (TESE)-ICSI. MAIN OUTCOME MEASURE(S) Testicular sperm retrieval rate, fertilization rate, pregnancy rate, comparison with patients with obstructive azoospermia. RESULT(S) Testicular sperm were retrieved from 19 of 22 (86%) patients with SCI. Intracytoplasmic sperm injection resulted in a fertilization rate of 236 of 364 (65%). Of 19 couples, 14 couples achieved 18 pregnancies, and 22 infants (14 singleton and 4 twin) were born. (Pregnancy per couple was 74% and that per ICSI was 54%). There was no significant difference in pregnancy rate at the first ICSI between SCI couples and obstructive azoospermia couples (68% SCI, 68% obstructive azoospermia). However, pregnancy rate per fresh testicular sperm-ICSI was significantly higher than that per frozen-thawed sperm-ICSI in SCI couples (64% SCI fresh, 25% SCI frozen-thawed) although no significant difference was seen in obstructive azoospermia couples (76% obstructive azoospermia fresh, 63% obstructive azoospermia frozen-thawed). There was no significant difference in pregnancy rate between fresh ET cycle and frozen-thawed ET cycle in SCI couples. CONCLUSION(S) Testicular sperm in men with SCI may possess disadvantages in freezing and thawing compared with that in men with obstructive azoospermia. Fresh testicular sperm-ICSI may offer optimum outcome for SCI couples desirous of pregnancy.

Clinical features of testicular tumors in children

Aim:  Testicular tumors are not common pediatric solid tumors, especially in Asian children. There have been few reviews of cases in Japan to date. We present the clinical features of 14 pediatric testicular tumor patients.

Clinical features of prostate cancer patients younger than 50 years: report of seven cases.

Abstract Background : The incidence of prostate cancer increases with age and latent cancer is common in older men. But clinical prostate cancer is rare in men aged < 50 years.

A birth of twins—one boy and one girl—from a single embryo transfer and a possible natural pregnancy

PurposeTo describe a rare case of a birth of dizygotic twins with different-sex infants from a single embryo transfer.Methods and resultsA patient, who had her right ovary and tube removed, and her husband were treated with ICSI and a single embryo transfer. When a single fresh embryo was transferred on day 4, following oocyte retrieval using GnRH agonist-long protocol, two gestational sacs were recognized at 8 weeks of gestation. Healthy twins with a boy and a girl were delivered at 37 weeks 0 days of gestation by a cesarean section. The boy’s weight was 2096g, and his height was 45.0cm, while the girl’s weight was 1988g, and her height was 41.5cm. Peripheral lymphocyte chromosome analysis of the two infants showed normal karyotype, 46, XY (boy) and 46, XX (girl).ConclusionsA single embryo transfer could produce different-sex twins.

A variant of Runx2 that differs from the bone isoform in its splicing is expressed in spermatogenic cells

Background. Members of the Runx gene family encode transcription factors that bind to DNA in a sequence-specific manner. Among the three Runx proteins, Runx2 comprises 607 amino acid (aa) residues, is expressed in bone, and plays crucial roles in osteoblast differentiation and bone development. We examined whether the Runx2 gene is also expressed in testes. Methods. Murine testes from 1-, 2-, 3-, 4-, and 10-week-old male mice of the C57BL/6J strain and W∕Wv strain were used throughout the study. Northern Blot Analyses were performed using extracts form the murine testes. Sequencing of cDNA clones and 5′-rapid amplification of cDNA ends were performed to determine the full length of the transcripts, which revealed that the testicular Runx2 comprises 106 aa residues coding novel protein. Generating an antiserum using the amino-terminal 15 aa of Runx2 (Met1 to Gly15) as an antigen, immunoblot analyses were performed to detect the predicted polypeptide of 106 aa residues with the initiating Met1. With the affinity-purified anti-Runx2 antibody, immunohistochemical analyses were performed to elucidate the localization of the protein. Furthermore, bioinformatic analyses were performed to predict the function of the protein. Results. A Runx2 transcript was detected in testes and was specifically expressed in germ cells. Determination of the transcript structure indicated that the testicular Runx2 is a splice isoform. The predicted testicular Runx2 polypeptide is composed of only 106 aa residues, lacks a Runt domain, and appears to be a basic protein with a predominantly alpha-helical conformation. Immunoblot analyses with an anti-Runx2 antibody revealed that Met1 in the deduced open reading frame of Runx2 is used as the initiation codon to express an 11 kDa protein. Furthermore, immunohistochemical analyses revealed that the Runx2 polypeptide was located in the nuclei, and was detected in spermatocytes at the stages of late pachytene, diplotene and second meiotic cells as well as in round spermatids. Bioinformatic analyses suggested that the testicular Runx2 is a histone-like protein. Discussion. A variant of Runx2 that differs from the bone isoform in its splicing is expressed in pachytene spermatocytes and round spermatids in testes, and encodes a histone-like, nuclear protein of 106 aa residues. Considering its nuclear localization and differentiation stage-dependent expression, Runx2 may function as a chromatin-remodeling factor during spermatogenesis. We thus conclude that a single Runx2 gene can encode two different types of nuclear proteins, a previously defined transcription factor in bone and cartilage and a short testicular variant that lacks a Runt domain.

Gene Expression Profiling Identifies a Set of Transcripts That Are Up-Regulated in Human Testicular Seminoma

Seminoma constitutes one subtype of human testicular germ cell tumors and is uniformly composed of cells that are morphologically similar to the primordial germ cells and/or the cells in the carcinoma in situ. We performed a genome-wide exploration of the genes that are specifically up-regulated in seminoma by oligonucleotide-based microarray analysis. This revealed 106 genes that are significantly and consistently up-regulated in the seminomas compared to the adjacent normal tissues of the testes. The microarray data were validated by semi-quantitative RT-PCR analysis. Of the 106 genes, 42 mapped to a small number of specific chromosomal regions, namely, 1q21, 2p23, 6p21-22, 7p14-15, 12p11, 12p13, 12q13-14 and 22q12-13. This list of up-regulated genes may be useful in identifying the causative oncogene(s) and/or the origin of seminoma. Furthermore, immunohistochemical analysis revealed that the seminoma cells specifically expressed the six gene products that were selected randomly from the list. These proteins include CCND2 and DNMT3A and may be useful as molecular pathological markers of seminoma.