A novel WT1 gene mutation associated with wilms' tumor and congenital male genitourinary malformation

WT1 is located on the short arm of human chromosome 11 and consists of 10 coding exons. Mutations of this gene have been reported to be the cause of Wilms' tumor, congenital male genitourinary malformations, and/or renal disorders. We describe here a novel WT1 gene mutation, i.e. a point mutation at intron 7 (+2) in both the tumor and the germline cells of a patient with Wilms' tumor and congenital male genitourinary malformation, but without renal disorder. The position of the mutation is at a splice donor site of intron 7, which causes the splicing out of exon 7 and generates a truncated protein. This type of mutation in the WT1 zinc finger domain has not been reported before. The mutation is of paternal origin and is heterozygous in the germline cells. In the tumor cells, however, the maternal allele is largely lost, from 11p12 to 11p15, which results in maternal loss of heterozygosity. These results, together with the data from previous reports, suggest that WT1 may function in gonadogenesis, nephrogenesis, and Wilms' tumor tumorigenesis.

Granulocyte colony-stimulating factor receptor expression on human transitional cell carcinoma of the bladder

Receptors for granulocyte colony-stimulating factor (G-CSFRs) have been confirmed on the cell surfaces of several non-haematopoietic cell types, including bladder cancer cells. This observation has naturally led to the hypothesis that the expression of G-CSFR on these cells may enhance their growth by G-CSF. In this study, the expression of G-CSFR was determined in both established human bladder cancer cell lines and primary bladder cancers. We studied five different human bladder cancer cell lines (KU-1, KU-7, T-24, NBT-2 and KK) and 26 newly diagnosed bladder tumours. G-CSFR mRNA expressions on cultured cell lines were determined using the reverse transcriptase polymerase chain reaction (RT-PCR) method. Furthermore, the G-CSFR binding experiments on the cultured cell lines were conducted using the Na(125)I-labelled G-CSF ligand-binding assay method. Moreover, the G-CSFR mRNA expressions on primary bladder tumour specimens were assessed using the in situ RT-PCR method. Three out of the five cultured cell lines (KU-1, NBT-2 and KK) exhibited G-CSFR mRNA signals when the RT-PCR method was used. The G-CSFR binding experiments showed an equilibrium dissociation constant (K[d]) of 490 pM for KU-1, 340 pM for NBT-2 and 103 pM for KK cells. With in situ RT-PCR, the tumour cells of 6 out of 26 primary bladder tumour specimens (23.1%) presented positive G-CSFR mRNA signals. Thus, in this study, G-CSFR expression was frequently observed on bladder cancer cells. Therefore, the clinical use of G-CSF for patients with bladder cancer should be selected with great care.

Constitutive production of multiple cytokines and a human chorionic gonadotrophin beta-subunit by a human bladder cancer cell line (KU-19-19): possible demonstration of totipotential differentiation

Bladder cancer cells have been shown to secrete a variety of factors that are not related to cells of urothelial origin. The histogenesis of these tumour developments is uncertain, and a variety of theories have been previously reported. In the present manuscript, we identify the factors constitutively produced by a human bladder cancer cell line (KU-19-19) that was found to produce beta human chorionic gonadotrophin (beta-hCG), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin 1alpha (IL-1alpha), interleukin 6 (IL-6) and interleukin 8 (IL-8). The cells were obtained from a case of metastatic carcinoma that was originally diagnosed to be a grade 3 (WHO classification), invasive transitional cell carcinoma of the bladder. On microscopic observation, the cultured cells exhibited an epithelial appearance with vacuole formation in their cytoplasm. Ultrastructural observations revealed relatively marked microvilli and a tight junction. Significant amounts of beta-hCG, G-CSF, GM-CSF, IL-1alpha, IL-6 and IL-8 concentrations in the supernatant from cultured cells were demonstrated by enzyme-linked immunosorbent assays, while the expression of mRNA of these marker proteins in cancer cells was also significantly exhibited by reverse transcription polymerase chain reaction (RT-PCR). In addition, the expression of G-CSF receptor and IL-6 receptor mRNA was also shown by RT-PCR. Xenograft transplantability using nude mice was observed in association with the presence of severe neutrophilia in the peripheral blood. These results indicate that this cell line appears to be an effective model for the study of transitional cell carcinoma of the bladder with multipotent differentiation potentials.

Characterization of the common acute lymphoblastic leukaemia antigen (CD10) as an activation molecule on mature human B cells

Distinct expression pattern of CD10 molecules during B cell activation was analysed using in vivo and in vitro systems. By two-colour flowcytometrical analysis, CD10 was found to be expressed at a specific stage of in vivo activating B cells. The expression of CD10 during B cell activation appeared to be unique from that of other activation-related B cell antigens including L29, MA6, OKT9 and OKT10. Although the expression of CD10 was associated with that of the activation-related B cell antigens, CD10+ B cells could be separated in the distinct fractions to those expressing other activation-related B cell antigens when fractionated by cell gravity. In particular, certain CD10+ B cells were detected positive for the resting B cell antigen, L30. In vitro studies revealed that CD10+ B cells arose from CD10- B cells at an early step of B cell activation, and disappeared lately when activated by Staphylococcus aureus Cowan I. Collectively, CD10 was an antigen transiently expressed at an early phase of B cell activation process. Expression of CD10 and other antigens on Burkitt's lymphomas (15 cases) was studied next. All cases were CD10+, and 87% (13 cases) were also L30+. In addition, six of CD10+ L30+ cases were L29+. This observation suggested that Burkitt's lymphomas were phenotypically similar to the B cells at an early phase of activation, those expressing CD10 and L30, simultaneously. The present study has dissected a precise expression pattern of CD10 on mature B cell activation in vitro and in vivo, and could be implicated for the histogenesis of one of the poorly characterized B cell lymphoma, namely Burkitt's lymphoma.

Morphology and function of human neuroblastoma xenotransplanted in nude mice

Nine human neuroblastomas were serially transplanted in nude mice. All transplanted tumors were taken from patients older than the age of 1 year 10 months. In contrast, the authors were unable to transplant tumors from patients younger than 1 year 7 months of age, in spite of many attempts. All transplanted tumors produced varying amounts of cathecolamines as revealed by the liquid chromatography and formalin-induced fluorescence techniques. The content of the cathecolamines was closely correlated with the number and size of secretory granules. In high cathecolamine-producing tumors, cell clusters showing strong yellow-orange fluorescence plus a positive argyrophil reaction suggesting pheochromoblastic differentiation were demonstrated by our combined cathecolamine fluorescence and argyrophil reaction method. One of the transplantable tumor lines was demonstrated by unique host responses and biochemical data, to produce adrenocorticotropic hormone and increased cathecolamines. Our observations indicate that neuroblastoma derived from neural crest cells seem to have a nearly complete hormone production function as compared with their normal counterparts.

Human yolk sac tumor serially transplanted in nude mice: its morphologic and functional properties

Three human yolk sac tumors (TE, OE, and TT-1) were serially transplanted into nude mice. The histology of the transplanted tumors is moderately different from that of the original tumor; the transplants had mainly a tubular structure with an inconspicuous endodermal sinus structure due to a decreased mesenchymal element surrounding the vascular core. Ultrastructural features of the transplanted tumor cells, however, were identical to those of the original tumor. Immunochemical survey of the blood plasma of nude mice bearing these tumors demonstrated the production of adult type human plasma proteins including prealbumin, albumin (Alb), alpha 1-antitrypsin (alpha AT), transferrin (Tf), hemopexin, and alpha 1-fetoprotein (AFP). The types of adult plasma proteins that were produced varied, depending on the tumor line but were the same between serial passages within the same tumor line. The intracellular localization of AFP, alpha AT, Tf, and Alb was also investigated by immunoelectron microscopy. Plasma proteins of the adult type and AFP were localized mainly within the membrane systems of the endoplasmic reticulum and Golgi complex and occasionally on the microvilli. These results suggest that transplanted human yolk sac tumors have almost all of the protein-producing function possessed by their normal counterparts.

Human neuroblastoma serially transplanted in nude mice and metastases

A human neuroblastoma from a female patient was directly transplanted into nude mice and serial transplantation was established. Histology of the transplanted tumor was almost the same as that of the patient. During serial transplantation, a high frequency of metastasis to distant organs such as ovaries, lymph node and cerebrum was observed, especially in the ovaries where the metastatic rate reached to 66%. Regarding the distribution of organs involved, there is close similarity between that in the patient with neuroblastoma and tumor-bearing mice. This transplantable human neuroblastoma provided a unique research tool for studies on its morphological and biological nature, including metastasis.